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Sample records for chinese bellflower root

  1. Chinese bellflower root anaphylaxis: IgE-binding components and cross-reactivity with mugwort and birch.

    PubMed

    Kim, Sae-Hoon; Lee, Sang-Min; Park, Heung-Woo; Cho, Sang-Heon; Min, Kyung-Up; Kim, You-Young; Chang, Yoon-Seok

    2009-09-01

    A 56-year-old man who had suffered from seasonal rhinitis in spring and autumn experienced recurrent generalized urticaria and an oral burning sensation after eating several cooked herbs for 3 months. A skin-prick test showed positive responses to various pollens, celery, Chinese bellflower, and arrowroot. The Chinese bellflower-specific IgE ELISA OD value was 1.547. Oral challenge with unprocessed raw Chinese bellflower root provoked oral burning sensation, eyelid swelling, generalized urticaria, and hypotension. In an ELISA inhibition test, IgE binding to Chinese bellflower was significantly inhibited by Chinese bellflower, mugwort, and birch pollen extract. SDS-PAGE and immunoblot assay revealed nine IgE-binding components, and common protein bands were detected in the range of 40~55 kDa (Chinese bellflower-mugwort-birch) and 14 kDa (Chinese bellflower-birch). Chinese bellflower root can cause anaphylaxis and may have cross-reactivity with mugwort and birch. PMID:19721867

  2. Complex root networks of Chinese characters

    NASA Astrophysics Data System (ADS)

    Lee, Po-Han; Chen, Jia-Ling; Wang, Po-Cheng; Chi, Ting-Ting; Xiao, Zhi-Ren; Jhang, Zih-Jian; Yeh, Yeong-Nan; Chen, Yih-Yuh; Hu, Chin-Kun

    There are several sets of Chinese characters still available today, including Oracle Bone Inscriptions (OBI) in Shang Dynasty, Chu characters (CC) used in Chu of Warring State Period, Small Seal Script in dictionary Shuowen Jiezi (SJ) in Eastern Han Dynasty, and Kangxi Dictionary (KD) in Qing Dynasty. Such as Chinese characters were all constructed via combinations of meaningful patterns, called roots. Our studies for the complex networks of all roots indicate that the roots of the characters in OBI, CC, SJ and KD have characteristics of small world networks and scale-free networks.

  3. Dynamics of fine roots in five Chinese temperate forests.

    PubMed

    Quan, Xiankuai; Wang, Chuankuan; Zhang, Quanzhi; Wang, Xingchang; Luo, Yiqi; Bond-Lamberty, Ben

    2010-07-01

    We used a minirhizotron method to investigate spatial and temporal dynamics of fine roots (diameter < or =2 mm) in five Chinese temperate forests: Mongolian oak forest, aspen-birch forest, hardwood forest, Korean pine plantation and Dahurian larch plantation. Fine root dynamics were significantly influenced by forest type, soil layer, and sampling time. The grand mean values varied from 1.99 to 3.21 mm cm(-2) (root length per minirhizotron viewing area) for the fine root standing crop; from 6.7 to 11.6 microm cm(-2) day(-1) for the production; and from 3.2 to 6.1 microm cm(-2) day(-1) for the mortality. All forests had a similar seasonal "sinusoidal" pattern of standing crop, and a "unimodal" pattern of production. However, the seasonal dynamics of the mortality were largely unsynchronized with those of the production. The minimum values of standing crop, production and mortality occurred in March for all forests, whereas the maximum values and occurrence time differed among forest types. The standing crop, production and mortality tended to decrease with soil depth. The different spatiotemporal patterns of fine roots among the forests highlight the need for forest-specific measurements and modeling of fine root dynamics and forest carbon allocation. PMID:20217175

  4. Dynamics of fine roots in five Chinese temperate forests

    SciTech Connect

    Quan, Xiankuai; Wang, Chuankuan; Zhang, Q.; Wang, X.; Luo, Y.; Bond-Lamberty, Benjamin

    2010-07-01

    Quantifying fine root production and mortality is crucially needed for modeling forest ecosystem carbon cycling, but the fine root dynamics are poorly understood in Chinese temperate forests. We used a minirhizotron method to investigate spatial and temporal dynamics of fine roots (diameter ≤ 2 mm) in five representative temperate forests in northeastern China. Our specific objectives were to: (1) compare standing crop, production and mortality of fine roots among the five stands; (2) examine fine root phenology for the stands; and (3) examine vertical distribution patterns of fine roots for the stands. Fine root dynamics were significantly affected by forest type, soil layer, sampling time and their interactions. The mean values of fine root standing crop varied from 8.0 to 12.8 mm cm-2; those of production varied from 0.027 to 0.046 mm cm-2 d-1; and those of mortality varied from 0.013 to 0.024 mm cm-2 d-1. All stands had a similar seasonal “sinusoidal” pattern of fine root standing crop, and a “unimodal” pattern of production. However, the seasonal dynamics of the mortality was unsynchronized with that of the production. The minimum values of standing crop, production and mortality occurred in March for all stands, while the maximum values and occurring time differed among forest types. The occurrence of the maximum standing crop varied from DOY (day of year) 222 for the oak stand to DOY 271 for the aspen-birch stand; that of the maximum production varied from DOY 188 for the pine and hardwood stands to DOY 239 for the larch stand; and that of the maximum mortality varied from DOY 222 for the oak and aspen-birch stands to DOY 287 for the larch stand. The standing crop, production and mortality of fine roots tended to decrease with soil depths, of which the relative contribution at 0 -10 cm depth averaged 38%, 46%, and 58% of total, respectively. The fact that the production was approximate twice as great as the mortality suggested a net carbon input to

  5. Phenol removal by peroxidases extracted from Chinese cabbage root

    SciTech Connect

    Rhee, H.I.; Jeong, Y.H.

    1995-12-31

    More than four million tons of Chinese cabbages are produced in Korea. Most of them are used as raw materials for Kimchi, but root parts of them are discarded as agricultural wastes. A trial for the application of agricultural waste to industrial waste water treatment was made as an effort to the efficient use of natural resources and to reduce water pollution problem simultaneously. Peroxidases of both solid and liquid phases were obtained from Chinese cabbage roots by using commercial juicer. The differences in peroxidase activity among the various cultivars of Chinese cabbages in Korea were little and electrophoretic patterns of various peroxidases will be discussed. The optimum pH and temperature for enzyme activity will be discussed also. Since peroxidases are distributed into 66% in liquid (juice) and 34% in solid phase (pulp), enzymes from both phases were applied to investigate the enzymatic removal of phenol from waste water. After phenol solution at 150 ppm being reacted with liquid phase enzyme (1,800 unit/1) for 3 hours in a batch stirred reactor, 96% of phenol could be removed through polymerization and precipitation. Also, phenol could be removed from initial 120 ppm to final 5 ppm by applying solid phase enzyme in an air lift reactor (600 unit/1). Almost equivalent efficiencies of phenol removal were observed between two systems, even though only one third of the enzymes in batch stirred reactor was applied in air lift reactor. The possible reason for this phenomenon is because peroxidases exist as immobilized forms in solid phase.

  6. The root and development of otorhinolaryngology in traditional Chinese medicine.

    PubMed

    Yap, L; Pothula, V B; Warner, J; Akhtar, S; Yates, E

    2009-09-01

    There is an increasing trend in society to look beyond conventional medicine to find answers to problems in health. Traditional Chinese medicine (TCM) is one of the most popular alternative, complementary therapies worldwide. It is becoming a popular alternative in otorhinolaryngology where its use in the treatment of sinusitis, tinnitus, deafness and Meniere's disease is growing. Despite the general awareness of TCM, the literature relating specifically to otorhinolaryngology is relatively scarce. In this review, we have traced the origin and development of otorhinolaryngology with respect to TCM and have provided a few interesting insights into otorhinolaryngology, as it used to be practised. Archaeological sources have shown that diseases affecting the ear, nose and throat were of medical concern as early as the 18th century BC. The first practising otorhinolaryngologist can be traced back to the 5th century BC. Acupuncture, moxibustion, herbal therapy and massage were amongst his treatments. Otorhinolaryngology was recognised as a major specialty when formal medical education began in the 7th century AD. Therapeutic measures since then expanded to include exercise, food therapy and surgery. References to using oesophageal speech as a substitute voice generator, the use of copper wire to excise nasal polyps, procedures for removal of sharp foreign bodies in the oropharynx, repair of lacerated trachea and treatment of cancer of lips can be found in historical notes. In conclusion, from its primitive roots, TCM has developed into a distinct branch of health care system in China today that works alongside Western medicine. PMID:19597834

  7. Temporal-spatially transformed synthesis and formation mechanism of gold bellflowers

    NASA Astrophysics Data System (ADS)

    Lin, Jing; Zhang, Molly G.; Tang, Yuxia; Wen, Bronte; Hu, Hao; Song, Jibing; Liu, Yijing; Huang, Peng; Chen, Xiaoyuan

    2016-03-01

    Anisotropic gold nanostructures with unique plasmonic properties, specifically the strong absorption of light in the near-infrared region (650-900 nm) due to the excitation of plasmon oscillations, have been widely employed as photothermal conversion agents (PTCAs) for cancer photothermal therapy (PTT). However, the reported PTCAs show suboptimal photothermal conversion efficiency (η), even gold nanocages (η = 63%), which limits their biomedical applications. Herein, we fabricated gold bellflowers (GBFs) with an ultrahigh photothermal conversion efficiency (η = 74%) via a novel liquid/liquid/gas triphasic interface system, using chloroauric acid as a gold source, and o-phenetidine as a reducing agent. The well-defined GBFs with multiple-branched petals show adjustable localized surface plasmon resonance (LSPR) from 760 to 1100 nm by tuning the petal length and circular bottom diameter. Originating from the monophasic and biphasic systems used in the creation of gold nanourchins (GNUs) and gold microspheres (GMPs) respectively, the triphasic interface system successfully produced GBFs. The possible formation mechanisms of GNUs, GMPs, and GBFs in the different systems were also investigated and discussed. We found that the formation mechanism of GNUs and GBFs followed classical crystallization, while the formation of GMPs followed non-classical crystallization.Anisotropic gold nanostructures with unique plasmonic properties, specifically the strong absorption of light in the near-infrared region (650-900 nm) due to the excitation of plasmon oscillations, have been widely employed as photothermal conversion agents (PTCAs) for cancer photothermal therapy (PTT). However, the reported PTCAs show suboptimal photothermal conversion efficiency (η), even gold nanocages (η = 63%), which limits their biomedical applications. Herein, we fabricated gold bellflowers (GBFs) with an ultrahigh photothermal conversion efficiency (η = 74%) via a novel liquid/liquid/gas triphasic

  8. The abiotic and biotic drivers of rapid diversification in Andean bellflowers (Campanulaceae).

    PubMed

    Lagomarsino, Laura P; Condamine, Fabien L; Antonelli, Alexandre; Mulch, Andreas; Davis, Charles C

    2016-06-01

    The tropical Andes of South America, the world's richest biodiversity hotspot, are home to many rapid radiations. While geological, climatic, and ecological processes collectively explain such radiations, their relative contributions are seldom examined within a single clade. We explore the contribution of these factors by applying a series of diversification models that incorporate mountain building, climate change, and trait evolution to the first dated phylogeny of Andean bellflowers (Campanulaceae: Lobelioideae). Our framework is novel for its direct incorporation of geological data on Andean uplift into a macroevolutionary model. We show that speciation and extinction are differentially influenced by abiotic factors: speciation rates rose concurrently with Andean elevation, while extinction rates decreased during global cooling. Pollination syndrome and fruit type, both biotic traits known to facilitate mutualisms, played an additional role in driving diversification. These abiotic and biotic factors resulted in one of the fastest radiations reported to date: the centropogonids, whose 550 species arose in the last 5 million yr. Our study represents a significant advance in our understanding of plant evolution in Andean cloud forests. It further highlights the power of combining phylogenetic and Earth science models to explore the interplay of geology, climate, and ecology in generating the world's biodiversity. PMID:26990796

  9. Temporal-spatially transformed synthesis and formation mechanism of gold bellflowers

    PubMed Central

    Lin, Jing; Zhang, Molly G.; Tang, Yuxia; Wen, Bronte; Hu, Hao; Song, Jibing; Liu, Yijing; Huang, Peng; Chen, Xiaoyuan

    2015-01-01

    Anisotropic gold nanostructures with unique plasmonic properties, specifically the strong absorption of light in near-infrared region (650∼900 nm) due to the excitation of plasmon oscillations, have been widely employed as photothermal conversion agents (PTCAs) for cancer photothermal therapy (PTT). However, the reported PTCAs bear suboptimal photothermal conversion efficiency (η), even gold nanocage (η = 63%), which limits their biomedical applications. Herein, we fabricated gold bellflowers (GBFs) with ultrahigh photothermal conversion efficiency (η = 74%) via a novel liquid/liquid/gas triphasic interface system, using chloroauric acid as a gold source, and o-phenetidine as a reducing agent. The well-defined GBFs with multiple-branched petals show adjustable localized surface plasmon resonance (LSPR) from 760 to 1100 nm by tuning the petal length and circular bottom diameter. Originating from the monophasic and biphasic systems used in the creation of gold nanourchins (GNUs) and gold microspheres (GMPs) respectively, the triphasic interface system successfully produced GBFs. The possible formation mechanisms of GNUs, GMPs, and GBFs in the different systems were also investigated and discussed. We found the formation mechanism of GNUs and GBFs followed classical crystallization, while the formation of GMPs followed non-classical crystallization. PMID:26525291

  10. Temporal-spatially transformed synthesis and formation mechanism of gold bellflowers.

    PubMed

    Lin, Jing; Zhang, Molly G; Tang, Yuxia; Wen, Bronte; Hu, Hao; Song, Jibing; Liu, Yijing; Huang, Peng; Chen, Xiaoyuan

    2016-04-14

    Anisotropic gold nanostructures with unique plasmonic properties, specifically the strong absorption of light in the near-infrared region (650-900 nm) due to the excitation of plasmon oscillations, have been widely employed as photothermal conversion agents (PTCAs) for cancer photothermal therapy (PTT). However, the reported PTCAs show suboptimal photothermal conversion efficiency (η), even gold nanocages (η = 63%), which limits their biomedical applications. Herein, we fabricated gold bellflowers (GBFs) with an ultrahigh photothermal conversion efficiency (η = 74%) via a novel liquid/liquid/gas triphasic interface system, using chloroauric acid as a gold source, and o-phenetidine as a reducing agent. The well-defined GBFs with multiple-branched petals show adjustable localized surface plasmon resonance (LSPR) from 760 to 1100 nm by tuning the petal length and circular bottom diameter. Originating from the monophasic and biphasic systems used in the creation of gold nanourchins (GNUs) and gold microspheres (GMPs) respectively, the triphasic interface system successfully produced GBFs. The possible formation mechanisms of GNUs, GMPs, and GBFs in the different systems were also investigated and discussed. We found that the formation mechanism of GNUs and GBFs followed classical crystallization, while the formation of GMPs followed non-classical crystallization. PMID:26525291

  11. Locating QTLs controlling several adult root traits in an elite Chinese hybrid rice.

    PubMed

    Liang, Yong Shu; Zhan, Xiao Deng; Wang, Hui Mming; Gao, Zhi Qiang; Lin, Ze chuan; Chen, Dai Bo; Shen, Xi Hong; Cao, Li Yong; Cheng, Shi Hua

    2013-09-10

    This study aimed to elucidate the genetics of the adult root system in elite Chinese hybrid rice. Several adult root traits in a recombinant inbred line (RIL) population of Xieyou 9308 and two backcross F1 (BCF1) populations derived from the RILs were phenotyped under hydroponic culture at heading stage for quantitative trait locus (QTL) mapping and other statistical analysis. There a total of eight QTLs detected for the root traits. Among of them, a pleiotropic QTL was repeatedly flanked by RM180 and RM5436 on the short arm of chromosome 7 for multiple traits across RILs and its BCF1 populations, accounting for 6.88% to 25.26% of the phenotypic variances. Only additive/dominant QTLs were detected for the root traits. These results can serve as a foundation for facilitating future cloning and molecular breeding. PMID:23624393

  12. Ion Flux in Roots of Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook) under Aluminum Stress

    PubMed Central

    Ma, Zhihui; Huang, Binlong; Xu, Shanshan; Chen, Yu; Cao, Guangqiu; Ding, Guochang; Lin, Sizu

    2016-01-01

    Chinese fir is a tall, fast-growing species that is unique to southern China. In Chinese fir plantations, successive plantings have led to a decline in soil fertility, and aluminum toxicity is thought to be one of the main reasons for this decline. In this study, Non-invasive Micro-test Technology was used to study the effect of aluminum stress on the absorption of 4 different ions in the roots of the Chinese fir clone FS01. The results are as follows: with increased aluminum concentration and longer periods of aluminum stress, the H+ ion flow gradually changed from influx into efflux; there was a large variation in the K+ efflux, which gradually decreased with increasing duration of aluminum stress; and 1 h of aluminum stress uniformly resulted in Ca2+ influx, but it changed from influx to efflux after a longer period of aluminum stress. Changes in the different concentrations of aluminum had the largest influence on Mg2+. PMID:27270726

  13. Ion Flux in Roots of Chinese Fir (Cunninghamia lanceolata (Lamb.) Hook) under Aluminum Stress.

    PubMed

    Ma, Zhihui; Huang, Binlong; Xu, Shanshan; Chen, Yu; Cao, Guangqiu; Ding, Guochang; Lin, Sizu

    2016-01-01

    Chinese fir is a tall, fast-growing species that is unique to southern China. In Chinese fir plantations, successive plantings have led to a decline in soil fertility, and aluminum toxicity is thought to be one of the main reasons for this decline. In this study, Non-invasive Micro-test Technology was used to study the effect of aluminum stress on the absorption of 4 different ions in the roots of the Chinese fir clone FS01. The results are as follows: with increased aluminum concentration and longer periods of aluminum stress, the H+ ion flow gradually changed from influx into efflux; there was a large variation in the K+ efflux, which gradually decreased with increasing duration of aluminum stress; and 1 h of aluminum stress uniformly resulted in Ca2+ influx, but it changed from influx to efflux after a longer period of aluminum stress. Changes in the different concentrations of aluminum had the largest influence on Mg2+. PMID:27270726

  14. Triphase Interface Synthesis of Plasmonic Gold Bellflowers as Near-Infrared Light Mediated Acoustic and Thermal Theranostics

    PubMed Central

    2015-01-01

    We present a novel gold bellflower (GBF) platform with multiple-branched petals, prepared by a liquid–liquid–gas triphase interface system, for photoacoustic imaging (PAI)-guided photothermal therapy (PTT). Upon near-infrared (NIR) laser irradiation, the GBFs, with strong NIR absorption, showed very strong PA response and an ultrahigh photothermal conversion efficiency (η, ∼74%) among the reported photothermal conversion agents. The excellent performance in PAI and PTT is mainly attributed to the unique features of the GBFs: (i) multiple-branched petals with an enhanced local electromagnetic field, (ii) long narrow gaps between adjacent petals that induce a strong plasmonic coupling effect, and (iii) a bell-shaped nanostructure that can effectively amplify the acoustic signals during the acoustic propagation. Besides the notable PTT and an excellent PAI effect, the NIR-absorbing GBFs may also find applications in NIR light-triggered drug delivery, catalysis, surface enhanced Raman scattering, stealth, antireflection, IR sensors, telecommunications, and the like. PMID:24842342

  15. Chemical constituents of Chinese natural medicine, morindae radix, the dried roots of morinda officinalis how.: structures of morindolide and morofficinaloside.

    PubMed

    Yoshikawa, M; Yamaguchi, S; Nishisaka, H; Yamahara, J; Murakami, N

    1995-09-01

    A new iridoid lactone, morindolide, and a new iridoid glucoside, morofficinaloside, have been isolated from a Chinese natural medicine, Morindae Radix, the dried root of Morinda officinalis How. together with a number of known compounds: five anthraquinones, four iridoid glucosides, a monoterpene glycoside, two sterols, an ursane-type triterpene, and a lactone compound. The chemical structures of the new compounds were determined on the basis of chemical and physicochemical evidence. PMID:7586069

  16. A study of the distobuccal root canal orifice of the maxillary second molars in Chinese individuals evaluated by cone-beam computed tomography

    PubMed Central

    HAN, Xuan; YANG, Haibing; LI, Guoju; YANG, Lin; TIAN, Cheng; WANG, Yan

    2012-01-01

    As is commonly understood, the root canal morphology of the maxillary molars is usually complex and variable. It is sometimes difficult to detect the distobuccal root canal orifice of a maxillary second molar with root canal treatment. No literature related to the distobuccal root canals of the maxillary second molars has been published. Objective To investigate the position of the distobuccal root canal orifice of the maxillary second molars in a Chinese population using cone-beam computed tomography (CBCT). Material and methods In total, 816 maxillary second molars from 408 patients were selected from a Chinese population and scanned using CBCT. The following information was recorded: (1) the number of root canals per tooth, (2) the distance between the mesiobuccal and distobuccal root canal orifice (DM), (3) the distance between the palatal and distobuccal root canal orifice (DP), (4) the angle formed by the mesiobuccal, distobuccal and palatal root canal orifices (∠ PDM). DM, DP and ∠ PDM of the teeth with three or four root canals were analyzed and evaluated. Results In total, 763 (93.51%) of 816 maxillary second molars had three or four root canals. The distance between the mesiobuccal and distobuccal orifice was 0.7 to 4.8 mm. 621 (81.39%) of 763 teeth were distributed within 1.5-3.0 mm. The distance between the palatal and distobuccal orifice ranged from 0.8 mm to 6.7 mm; 585 (76.67%) and were distributed within 3.0-5.0 mm. The angle (∠ PDM) ranged from 69. 4º to 174.7º in 708 samples (92.80%), the angle ranged from 90º to 140º. Conclusions The position of the distobuccal root canal orifice of the maxillary second molars with 3 or 4 root canals in a Chinese population was complex and variable. Clinicians should have a thorough knowledge of the anatomy of the maxillary second molars. PMID:23138744

  17. [Eco-toxicological effects of heavy metals on the inhibition of seed germination and root elongation of Chinese cabbages in soils].

    PubMed

    Song, Yufang; Xu, Huaxia; Ren, Liping; Gong, Ping; Zhou, Qixing

    2002-01-30

    The Eco-toxicity effects of individual Cu, Zn, Pb and Cd on the inhibition of seed germination and root elongation of Chinese cabbages (Brassica pekimensis) were tested in four types of soils (red loam soils, meadow brown soils, chestnut soils and dark brown soils) and water solution. The combined effects of heavy metals pollution were determined with meadow brown soils. Results indicated that with same concentration, the inhibition rates of heavy metals on root elongation of Chinese cabbages are stronger than that on the seed germination. The inhibition effects of heavy metals on the root elongation of Chinese cabbages in soils are much lower than that in water, indicating that soils play an important role of buffering on heavy metals pollution. Inhibition rates of heavy metals on the root elongation (IRHMRE) of Chinese cabbages are significantly negative related with the contents of organic matter (OR) and Kjedahl-nitrogen (K-N) in soils, however, there is no significant related between IRHMRE and soil pH, so does the content of T-K. In the concentrations that result in the irritated effect in the single form of Cu, Zn, Pb and Cd pollution, synergic effects are produced significantly when four heavy metals are combined. As the results, the threshold values that result in the inhibition effects on root elongation in Chinese cabbages decrease markedly. PMID:11987391

  18. Why Chinese People Play Western Classical Music: Transcultural Roots of Music Philosophy

    ERIC Educational Resources Information Center

    Huang, Hao

    2012-01-01

    This paper addresses the complex relationship between Confucian values and music education in East Asia, particularly its history in China. How does one account for the present "cultural fever" of Western classical music that has infected more than 100 million Chinese practitioners? It is proposed that Western classical music finds transcultural…

  19. Short-term microbiological effects of scaling and root planing and essential-oils mouthwash in Chinese adults*

    PubMed Central

    He, Jia-yan; Qi, Gang-gang; Huang, Wu-jing; Sun, Xu-dong; Tong, Yu; Peng, Chun-mei; Zhou, Xue-ping; Chen, Hui

    2013-01-01

    Objective: To assess the short-term effect of scaling and root planing (SRP) and essential-oils mouthwash on the levels of specific bacteria in Chinese adults. Methods: Fifty Chinese adults with chronic periodontitis were randomly assigned to full-mouth SRP or a 7-d essential-oils mouthwash regimen. In addition, 22 periodontally healthy adults used essential-oils mouthwash for 7 d. Clinical examination and plaque/saliva sampling were performed at baseline and on Day 7. Quantitative real-time polymerase chain reaction (PCR) was used to measure Aggregatibacter actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), Porphyromonas gingivalis (Pg), Prevotella intermedia (Pi), and total bacterial loads in saliva, supra- and sub-gingival plaque samples. Results: The detection frequencies of four tested species remained unchanged after either treatment. However, the bacterial loads of Fn, Pg, and Pi were significantly reduced by SRP; the mean reduction of bacterial counts in saliva ranged from 52.2% to 62.5% (p<0.01), in supragingival plaque from 68.2% to 81.0% (p<0.05), and in subgingival plaque from 67.9% to 93.0% (p<0.01). Total bacterial loads were reduced after SRP in supra- and sub-gingival plaque (p<0.05). Essential-oils mouthwash reduced Fn levels in supragingival plaque by a mean of 53.2%, and reduced total bacterial loads in supra- and sub-gingival plaque (p<0.01). In subgingival plaque from periodontal patients, Pg and Pi reductions were high after SRP compared to essential-oils mouthwash (93.0% vs. 37.7% and 87.0% vs. 21.0%, p<0.05). No significant bacterial reduction was observed in periodontally healthy subjects using essential-oils mouthwash. Conclusions: SRP and essential-oils mouthwash both have an impact on saliva and gingival plaque flora in Chinese periodontitis patients in 7 d, with greater microbiological improvement by SRP. PMID:23645178

  20. Metal (Pb, Cd, and Cu)-induced reactive oxygen species accumulations in aerial root cells of the Chinese banyan (Ficus microcarpa).

    PubMed

    Liu, Nan; Lin, Zhifang; Mo, Hui

    2012-10-01

    The current study evaluated the toxicity of three heavy metals to aerial roots of the Chinese banyan (Ficus microcarpa), which is a tree species native to China. In a laboratory experiment, segments of aerial roots cut from trees were treated with 0, 25, 50, 100, and 200 μM of lead, cadmium, or copper (Cu). The contents of these heavy metals in cells increased and root cell viability decreased with increases in treatment concentration. High levels of reactive oxygen species accumulated in the aerial root sections after heavy metal treatment. Both biochemical assay and histochemical localization showed that O(2) (•-), which is a precursor of H(2)O(2) accumulated in root sections and that the amount accumulated was positively related to heavy metal concentration, especially for Cu-treated samples. Histochemical staining with diaminobenzidine (DAB) and a fluorometric scopoletin oxidation assay indicated that the amount of H(2)O(2) accumulated was positively related to heavy metal concentration in the treatments; the scopoletin fluorescence assay was more sensitive and efficient than DAB staining for detection and quantification of H(2)O(2). The results indicate that aerial roots are sensitive to heavy metal-induced oxidative damage and that aerial roots have the potential to be used as indicators of heavy metal pollution in urban areas. PMID:22678550

  1. Leaf and root glucosinolate profiles of Chinese cabbage (Brassica rapa ssp. pekinensis) as a systemic response to methyl jasmonate and salicylic acid elicitation.

    PubMed

    Zang, Yun-xiang; Ge, Jia-li; Huang, Ling-hui; Gao, Fei; Lv, Xi-shan; Zheng, Wei-wei; Hong, Seung-beom; Zhu, Zhu-jun

    2015-08-01

    Glucosinolates (GSs) are an important group of defensive phytochemicals mainly found in Brassicaceae. Plant hormones jasmonic acid (JA) and salicylic acid (SA) are major regulators of plant response to pathogen attack. However, there is little information about the interactive effect of both elicitors on inducing GS biosynthesis in Chinese cabbage (Brassica rapa ssp. pekinensis). In this study, we applied different concentrations of methyl jasmonate (MeJA) and/or SA onto the leaf and root of Chinese cabbage to investigate the time-course interactive profiles of GSs. Regardless of the site of the elicitation and the concentrations of the elicitors, the roots accumulated much more GSs and were more sensitive and more rapidly responsive to the elicitors than leaves. Irrespective of the elicitation site, MeJA had a greater inducing and longer lasting effect on GS accumulation than SA. All three components of indole GS (IGS) were detected along with aliphatic and aromatic GSs. However, IGS was a major component of total GSs that accumulated rapidly in both root and leaf tissues in response to MeJA and SA elicitation. Neoglucobrassicin (neoGBC) did not respond to SA but to MeJA in leaf tissue, while it responded to both SA and MeJA in root tissue. Conversion of glucobrassicin (GBC) to neoGBC occurred at a steady rate over 3 d of elicitation. Increased accumulation of 4-methoxy glucobrassicin (4-MGBC) occurred only in the root irrespective of the type of elicitors and the site of elicitation. Thus, accumulation of IGS is a major metabolic hallmark of SA- and MeJA-mediated systemic response systems. SA exerted an antagonistic effect on the MeJA-induced root GSs irrespective of the site of elicitation. However, SA showed synergistic and antagonistic effects on the MeJA-induced leaf GSs when roots and leaves are elicitated for 3 d, respectively. PMID:26238545

  2. Leaf and root glucosinolate profiles of Chinese cabbage (Brassica rapa ssp. pekinensis) as a systemic response to methyl jasmonate and salicylic acid elicitation*

    PubMed Central

    Zang, Yun-xiang; Ge, Jia-li; Huang, Ling-hui; Gao, Fei; Lv, Xi-shan; Zheng, Wei-wei; Hong, Seung-beom; Zhu, Zhu-jun

    2015-01-01

    Glucosinolates (GSs) are an important group of defensive phytochemicals mainly found in Brassicaceae. Plant hormones jasmonic acid (JA) and salicylic acid (SA) are major regulators of plant response to pathogen attack. However, there is little information about the interactive effect of both elicitors on inducing GS biosynthesis in Chinese cabbage (Brassica rapa ssp. pekinensis). In this study, we applied different concentrations of methyl jasmonate (MeJA) and/or SA onto the leaf and root of Chinese cabbage to investigate the time-course interactive profiles of GSs. Regardless of the site of the elicitation and the concentrations of the elicitors, the roots accumulated much more GSs and were more sensitive and more rapidly responsive to the elicitors than leaves. Irrespective of the elicitation site, MeJA had a greater inducing and longer lasting effect on GS accumulation than SA. All three components of indole GS (IGS) were detected along with aliphatic and aromatic GSs. However, IGS was a major component of total GSs that accumulated rapidly in both root and leaf tissues in response to MeJA and SA elicitation. Neoglucobrassicin (neoGBC) did not respond to SA but to MeJA in leaf tissue, while it responded to both SA and MeJA in root tissue. Conversion of glucobrassicin (GBC) to neoGBC occurred at a steady rate over 3 d of elicitation. Increased accumulation of 4-methoxy glucobrassicin (4-MGBC) occurred only in the root irrespective of the type of elicitors and the site of elicitation. Thus, accumulation of IGS is a major metabolic hallmark of SA- and MeJA-mediated systemic response systems. SA exerted an antagonistic effect on the MeJA-induced root GSs irrespective of the site of elicitation. However, SA showed synergistic and antagonistic effects on the MeJA-induced leaf GSs when roots and leaves are elicitated for 3 d, respectively. PMID:26238545

  3. Diversity of indigenous endophytic bacteria associated with the roots of Chinese cabbage (Brassica campestris L.) cultivars and their antagonism towards pathogens.

    PubMed

    Haque, Md Azizul; Yun, Han Dae; Cho, Kye Man

    2016-05-01

    The study aimed to reveal the diversity of endophytic bacteria in the roots of Chinese cabbage (CC) cultivated in two areas in Korea, namely, Seosang-gun (SS) and Haenam-gun (HN), and also in a transgenic plant (TP) from the laboratory. A total of 653 colonies were isolated from the interior of CC roots, comprising 118, 302, and 233 isolates from SS, HN, and TP samples, respectively. Based on 16S rRNA gene sequence analysis, the isolates belonged to four major phylogenetic groups: high-G+C Gram-positive bacteria (HGC-GPB), low-G+C Gram-positive bacteria (LGC-GPB), Proteobacteria, and Bacteriodetes. The most dominant groups in the roots of the SS, HN, and TP cultivars were LGC-GPB (48.3%), Proteobacteria (50.2%), and HGC-GPB (38.2%), respectively. Importantly, most of the isolates that produced cell-walldegrading enzymes belonged to the genus Bacillus. Bacillus sp. (HNR03, TPR06), Bacillus pumilus (SSR07, HNR11, TPR07), and Bacillus subtilis (TPR03) showed high antagonism against the tested food-borne pathogenic bacteria. In addition, Bacillus sp. (HNR03, TPR06), Bacillus pumilus (SSR07, HNR11, HNR17, TPR11), Microbacterium oxidans (SSR09, TPR04), Bacillus cereus HNR10, Pseudomonas sp. HNR13, and Bacillus subtilis (TPR02, TPR03) showed strong antagonistic activity against the fungi Phythium ultimum, Phytophthora capsici, Fusarium oxysporum, and Rhizoctonia solani. The endophytes isolated from the TP cultivar showed the strongest antagonistic reactions against pathogens. This study is the first report on endophytic bacteria from Chinese cabbage roots. PMID:27095454

  4. Corrupt practices in chinese medical care: the root in public policies and a call for Confucian-market approach.

    PubMed

    Fan, Ruiping

    2007-06-01

    This paper argues that three salient corrupt practices that mark contemporary Chinese health care, namely the over-prescription of indicated drugs, the prescription of more expensive forms of medication and more expensive diagnostic work-ups than needed, and illegal cash payments to physicians-i.e., red packages-result not from the introduction of the market to China, but from two clusters of circumstances. First, there has been a loss of the Confucian appreciation of the proper role of financial reward for good health care. Second, misguided governmental policies have distorted the behavior of physicians and hospitals. The distorting policies include (1) setting very low salaries for physicians, (2) providing bonuses to physicians and profits to hospitals from the excessive prescription of drugs and the use of more expensive drugs and unnecessary expensive diagnostic procedures, and (3) prohibiting payments by patients to physicians for higher quality care. The latter problem is complicated by policies that do not allow the use of governmental insurance and funds from medical savings accounts in private hospitals as well as other policies that fail to create a level playing field for both private and government hospitals. The corrupt practices currently characterizing Chinese health care will require not only abolishing the distorting governmental policies but also drawing on Confucian moral resources to establish a rightly directed appreciation of the proper place of financial reward in the practice of medicine. PMID:18018995

  5. Roots Revisited.

    ERIC Educational Resources Information Center

    Hughes, Barnabas

    1998-01-01

    Offers historical information about square roots. Presents three different methods--Hero's method, visual method, and remainder method--which can be used to teach the finding of square roots and one method for determining cube roots. (ASK)

  6. Infection of Plasmodiophora brassicae in Chinese cabbage.

    PubMed

    Ji, R; Zhao, L; Xing, M; Shen, X; Bi, Q; Peng, S; Feng, H

    2014-01-01

    Brassica crops infected by Plasmodiophora brassicae can produce root galls (clubroots) and be prevented from growing normally. To understand the series of changes that occur in the host root during root gall production, the resistance character of 21 Chinese cabbage lines were identified and then resistant and susceptible lines were used for infection observation. Hydroponic technology system was used for plants growing, and the infection process of P. brassicae in the roots of resistant and susceptible Chinese cabbage was examined based on morphology and microscopic characteristics using micoscope. In susceptible Chinese cabbage, the root hair infection stage occurred over approximately 7 days after inoculation, the cortical infection happened over approximatly 14 days after inoculation, and clubroots formed in approximately 30 days after inoculation. However, in resistant Chinese cabbage, the pathogen could be prevented and maintained in the root hair infection stage. This research provides a foundation for the subsequent studies of cabbage resistance of P. brassicae. PMID:25526218

  7. Square Root +

    ERIC Educational Resources Information Center

    Frederiksen, John G.

    1969-01-01

    A rational presentation of the so-called long division method for extracting the square root of a number. Diagrams are used to show relationship of this technique to the binomial theorem. Presentation exposes student to many facets of mathematics in addition to the mechanics of funding square root and cube root. Geometry, algebraic statements,…

  8. Root Hairs

    PubMed Central

    Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

    2014-01-01

    Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

  9. The Chinese negotiation.

    PubMed

    Graham, John L; Lam, N Mark

    2003-10-01

    Most Westerners preparing for a business trip to China like to arm themselves with a list of etiquette how-tos. "Carry a boatload of business cards," tipsters say. "Bring your own interpreter." "Speak in short sentences." "Wear a conservative suit." Such advice can help get companies in the door and even through the first series of business transactions. But it won't sustain the prolonged, year-in, year-out associations Chinese and Western businesses can now achieve. The authors' work with dozens of companies and thousands of American and Chinese executives over the past 20 years has demonstrated that a superficial adherence to etiquette rules gets executives only so far. They have witnessed communication breakdowns between American and Chinese businesspeople time and time again. The root cause: the American side's failure to understand the much broader context of Chinese culture and values, a problem that too often leaves Western negotiators flummoxed and flailing. American and Chinese approaches often appear incompatible. Americans see Chinese negotiators as inefficient, indirect, and even dishonest, while the Chinese see American negotiators as aggressive, impersonal, and excitable. Such perceptions have deep cultural origins. Yet those who know how to navigate these differences can develop thriving, mutually profitable, and satisfying business relationships. Four cultural threads have bound the Chinese people together for some 5,000 years, and these show through in Chinese business negotiations. They are agrarianism, morality, the Chinese pictographic language, and wariness of strangers. Most Western businesspeople often find those elements mysterious and confusing. But ignore them at any time during the negotiation process, and the deal can easily fall apart. PMID:14521100

  10. [The effect of berberine in sterilizing infective root canal of deciduous teeth].

    PubMed

    Su, R Y

    1992-09-01

    This investigation introduces the effect of sterilizing infective deciduous root canal with Chinese traditional herb berberine. Through the bacterial test, animal test, clinical practice, and comparing with the dental root disinfectant for mocresol (FC) and comphorphenol (CP) it indicates that berberine Chinese traditional herb is a excellent disinfectant for infective deciduous root canal. PMID:1306446

  11. Chinese Americans.

    ERIC Educational Resources Information Center

    Lyman, Stanford M.

    This book on the Chinese Americans focuses on such aspects of intergroup relations, community characteristics, social problems, acculturation, racial and social discrimination, and economic opportunities for the ethnic group as: the Chinese diaspora; forerunners of overseas Chinese community organization; Chinese community organization in the…

  12. Roots and Root Function: Introduction

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A number of current issues related to water management, ecohydrology, and climate change are giving impetus to new research aimed at understanding roots and their functioning. Current areas of research include: use of advanced imaging technologies such as Magnetic Resonance Imaging to observe roots...

  13. Why fine tree roots are stronger than thicker roots: The role of cellulose and lignin in relation to slope stability

    NASA Astrophysics Data System (ADS)

    Zhang, Chao-Bo; Chen, Li-Hua; Jiang, Jing

    2014-02-01

    Plant roots help to reinforce the soil, increase slope stability and decrease water erosion. Root tensile strength plays an important role in soil reinforcement and slope stabilization. The relationship between tensile strength and internal chemical composition of roots is unknown due to limited studies. Thus, it is difficult to determine why root tensile strength tends to decrease with increasing root diameter. In this study, biomechanical and biochemical tests were performed on the roots of Chinese pine (Pinus tabulaeformis) to determine the relationships among tensile strength and the contents of the main chemical composition: cellulose, alpha-cellulose and lignin in the roots with different diameters. Our results confirmed that the tensile strength of Chinese pine roots decreased with increasing root diameter, and this relationship might be a power function. The chemical contents of the roots and root diameter were also related to each other with significant power regression. With increasing root diameter, the cellulose content and alpha-cellulose content increased, but the lignin content decreased. In addition, the lignin content exhibited a significantly positive relationship with tensile strength. Furthermore, the ratios of lignin/cellulose and lignin/alpha-cellulose decreased with increasing root diameter following significant power regressions, and they also demonstrated a positive relationship with tensile strength. Taken together, these results may be useful for studies on root tensile strength, soil reinforcement and slope stability.

  14. Chinese Literature

    ERIC Educational Resources Information Center

    Hsu, Kai-yu

    The earliest recorded Chinese literature that has survived consists of folk songs mixed with verses and rhymes. Two factors determined the general pattern of subsequent development in Chinese literature: the nature of the written Chinese language and the establishment of the Confucian school as the orthodoxy in literary criticism. By 1800 there…

  15. Things Chinese.

    ERIC Educational Resources Information Center

    Law, Yip Wang

    Presented in this booklet are brief descriptions of items and activities that are symbolic of Chinese culture. Some of the items and activities described include a traditional Chinese child's outfit, dolls, sandalwood fans, writing and printing materials and techniques, toys and crafts, a Chinese abacus, and eating utensils. Several recipes for…

  16. Automated Root Tracking with "Root System Analyzer"

    NASA Astrophysics Data System (ADS)

    Schnepf, Andrea; Jin, Meina; Ockert, Charlotte; Bol, Roland; Leitner, Daniel

    2015-04-01

    Crucial factors for plant development are water and nutrient availability in soils. Thus, root architecture is a main aspect of plant productivity and needs to be accurately considered when describing root processes. Images of root architecture contain a huge amount of information, and image analysis helps to recover parameters describing certain root architectural and morphological traits. The majority of imaging systems for root systems are designed for two-dimensional images, such as RootReader2, GiA Roots, SmartRoot, EZ-Rhizo, and Growscreen, but most of them are semi-automated and involve mouse-clicks in each root by the user. "Root System Analyzer" is a new, fully automated approach for recovering root architectural parameters from two-dimensional images of root systems. Individual roots can still be corrected manually in a user interface if required. The algorithm starts with a sequence of segmented two-dimensional images showing the dynamic development of a root system. For each image, morphological operators are used for skeletonization. Based on this, a graph representation of the root system is created. A dynamic root architecture model helps to determine which edges of the graph belong to an individual root. The algorithm elongates each root at the root tip and simulates growth confined within the already existing graph representation. The increment of root elongation is calculated assuming constant growth. For each root, the algorithm finds all possible paths and elongates the root in the direction of the optimal path. In this way, each edge of the graph is assigned to one or more coherent roots. Image sequences of root systems are handled in such a way that the previous image is used as a starting point for the current image. The algorithm is implemented in a set of Matlab m-files. Output of Root System Analyzer is a data structure that includes for each root an identification number, the branching order, the time of emergence, the parent

  17. Root gravitropism

    NASA Technical Reports Server (NTRS)

    Masson, P. H.

    1995-01-01

    When a plant root is reoriented within the gravity field, it responds by initiating a curvature which eventually results in vertical growth. Gravity sensing occurs primarily in the root tip. It may involve amyloplast sedimentation in the columella cells of the root cap, or the detection of forces exerted by the mass of the protoplast on opposite sides of its cell wall. Gravisensing activates a signal transduction cascade which results in the asymmetric redistribution of auxin and apoplastic Ca2+ across the root tip, with accumulation at the bottom side. The resulting lateral asymmetry in Ca2+ and auxin concentration is probably transmitted to the elongation zone where differential cellular elongation occurs until the tip resumes vertical growth. The Cholodny-Went theory proposes that gravity-induced auxin redistribution across a gravistimulated plant organ is responsible for the gravitropic response. However, recent data indicate that the gravity-induced reorientation is more complex, involving both auxin gradient-dependent and auxin gradient-independent events.

  18. Root canal

    MedlinePlus

    Endodontic therapy ... the root of a tooth. Generally, there is pain and swelling in the area. The infection can ... You may have some pain or soreness after the procedure. An over-the-counter anti-inflammatory drug, such as ibuprofen or naproxen, can help relieve ...

  19. Protoanemonin content variation between Clematis spp.: leaf, stem and root.

    PubMed

    Jin, Fangming; Narkowicz, Christian; Jacobson, Glenn A

    2013-02-01

    The content of protoanemonin, a known biologically active constituent of Clematis spp., was determined by GC-MS in the leaf, stem and root extracts of one Chinese species and four Australian Clematis taxa. The results showed that protoanemonin concentrations varied between different plants and that leaves contained higher concentrations than stems and roots. To our knowledge this is the first study to determine protoanemonin content variation in leaf, stem and root of Clematis spp. PMID:23513731

  20. Fine root mercury heterogeneity: metabolism of lower-order roots as an effective route for mercury removal.

    PubMed

    Wang, Jun-Jian; Guo, Ying-Ying; Guo, Da-Li; Yin, Sen-Lu; Kong, De-Liang; Liu, Yang-Sheng; Zeng, Hui

    2012-01-17

    Fine roots are critical components for plant mercury (Hg) uptake and removal, but the patterns of Hg distribution and turnover within the heterogeneous fine root components and their potential limiting factors are poorly understood. Based on root branching structure, we studied the total Hg (THg) and its cellular partitioning in fine roots in 6 Chinese subtropical trees species and the impacts of root morphological and stoichiometric traits on Hg partitioning. The THg concentration generally decreased with increasing root order, and was higher in cortex than in stele. This concentration significantly correlated with root length, diameter, specific root length, specific root area, and nitrogen concentration, whereas its cytosolic fraction (accounting for <10% of THg) correlated with root carbon and sulfur concentrations. The estimated Hg return flux from dead fine roots outweighed that from leaf litter, and ephemeral first-order roots that constituted 7.2-22.3% of total fine root biomass may have contributed most to this flux (39-71%, depending on tree species and environmental substrate). Our results highlight the high capacity of Hg stabilization and Hg return by lower-order roots and demonstrate that turnover of lower-order roots may be an effective strategy of detoxification in perennial tree species. PMID:22126585

  1. Chinese Calligraphy.

    ERIC Educational Resources Information Center

    Stanford Univ., CA. Stanford Program on International and Cross Cultural Education.

    This unit is designed to introduce secondary or post-secondary students to the ancient art of Chinese calligraphy through step-by-step instructions on writing Chinese characters. Because each character is made up of a series of single brush strokes, it is believed that if students learn to recognize these as components of completed characters, the…

  2. Chinese Cooking.

    ERIC Educational Resources Information Center

    Kane, Tony

    This unit, intended for secondary level students, is a general introduction to Chinese cooking. It is meant to inform students about the origins of Chinese cooking styles in their various regional manifestations, and it can be used to discuss how and why different cultures develop different styles of cooking. The first part of the unit, adapted…

  3. Pythium Root Rot (and Feeder Root Necrosis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pythium species cause a number of diseases on corn. Among the Pythium diseases, root rot presents the least conspicuous aboveground symptoms. Broadly defined, root rot also includes feeder root necrosis. At least 16 species of Pythium are known to cause root rot of corn. These include P. acanthicu...

  4. Chinese Connections

    ERIC Educational Resources Information Center

    Skilling, William C.

    2012-01-01

    When L. Brooks Patterson, the executive of Oakland County, Michigan, publicly called for the county to become the first in America to teach Mandarin Chinese in every public school district, the Oxford Community Schools responded immediately. Over the past four years, the school district of 5,030 students in southeastern Michigan has elevated the…

  5. Chinese Geography through Chinese Cuisine

    ERIC Educational Resources Information Center

    Lipman, Jonathan

    2010-01-01

    China has the world's largest population, now over 1.3 billion, but its land area (much of it high mountains or desert) is about the same as that of the United States, which has less than one-fourth as many people. So Chinese farmers have learned to use every inch of their fertile land intensively. Pressure on the land has required extremely…

  6. Patterns of reproductive isolation in Nolana (Chilean bellflower).

    PubMed

    Jewell, Cathleen; Papineau, Amy Douglas; Freyre, Rosanna; Moyle, Leonie C

    2012-08-01

    We examined reproductive isolating barriers at four postmating stages among 11 species from the morphologically diverse genus Nolana (Solanaceae). At least one stage was positively correlated with both genetic and geographic distance between species. Postzygotic isolation was generally stronger and faster evolving than postmating prezygotic isolation. In addition, there was no evidence for mechanical isolation, or for reproductive character displacement in floral traits that can influence pollinator isolation. In general, among the potential isolating stages examined here, postzygotic barriers appear to be more effective contributors to reducing gene flow, including between sympatric species. PMID:22834759

  7. Using Square Roots

    ERIC Educational Resources Information Center

    Wilson, William Wynne

    1976-01-01

    This article describes techniques which enable the user of a comparatively simple calculator to perform calculations of cube roots, nth roots, trigonometric, and inverse trigonometric functions, logarithms, and exponentials. (DT)

  8. The Root Pressure Phenomenon

    ERIC Educational Resources Information Center

    Marsh, A. R.

    1972-01-01

    Describes experiments demonstrating that root pressure in plants is probably controlled by a circadian rhythm (biological clock). Root pressure phenomenon plays significant part in water transport in contradiction with prevalent belief. (PS)

  9. Chinese Culture and Leadership.

    ERIC Educational Resources Information Center

    Wong, Kam-Cheung

    2001-01-01

    Describes essential characteristics of Chinese philosophical tradition; Discusses Western perspectives on value leadership in education, particularly moral leadership. Discuses moral leadership from a Chinese philosophical perspective, especially Confucianism. Draws implications for using Chinese cultural and philosophical traditions to develop…

  10. Parasiticidal effects of Morus alba root bark extracts against Ichthyophthirius multifiliis infecting grass carp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Ichthyophthirius multifiliis (Ich) is an important fish parasite that can result in significant losses in aquaculture. In order to find efficacious drugs to control Ich, the root bark of Morus alba, a traditional Chinese medicine, was evaluated for its antiprotozoal activity. The M. alba root bark w...

  11. Corky root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Corky root rot (corchosis) was first reported in Argentina in 1985, but the disease was presumably present long before that. The disease occurs in most alfalfa-growing areas of Argentina but is more common in older stands. In space-planted alfalfa trials scored for root problems, corky root rot was ...

  12. WHY ROOTING FAILS.

    SciTech Connect

    CREUTZ,M.

    2007-07-30

    I explore the origins of the unphysical predictions from rooted staggered fermion algorithms. Before rooting, the exact chiral symmetry of staggered fermions is a flavored symmetry among the four 'tastes.' The rooting procedure averages over tastes of different chiralities. This averaging forbids the appearance of the correct 't Hooft vertex for the target theory.

  13. Armillaria root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    First described on grapevines in California in the 1880s, Armillaria root rot occurs in all major grape-growing regions of the state. The causal fungus, Armillaria mellea, infects woody grapevine roots and the base of the trunk (the root collar), resulting in a slow decline and eventual death of the...

  14. BLACK ROOT ROT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black Root Rot Prepared by G. S. Abawi, Revised by L.E. Hanson Black root rot is caused by Thielaviopsis basicola (syn. Chalara elegans). The pathogen is widely distributed, can infect more than 130 plant species in 15 families, and causes severe black root rot diseases in ornamentals and crops suc...

  15. Chinese Calendar and Chinese Telegraphic Code.

    ERIC Educational Resources Information Center

    Defense Language Inst., Monterey, CA.

    This manual contains: (1) Chinese calendars for the hundred years from 1881 to 1980; and (2) the Chinese telegraphic code. Each page in Part One presents the calendar for each year in both Chinese and English. There are 97 charts in Part Two representing the telegraphic code. (AMH)

  16. A Cone-Beam Computed Tomographic Study on Mandibular First Molars in a Chinese Subpopulation

    PubMed Central

    Ma, Yue; Han, Ting; Chen, Xinyu; Wan, Fang; Lu, Yating; Yan, Songhe; Wang, Yan

    2015-01-01

    The purpose of this study was to conduct a cone-beam computed tomographic (CBCT) investigation on the root and canal configuration of the mandibular first molars, especially the morphology of the disto-lingual (DL) root, in a Chinese subpopulation. A total of 910 CBCT images of the mandibular first molars were collected from 455 patients who underwent CBCT examinations as a preoperative assessment for implants or orthodontic treatment. The following information was analyzed and evaluated: tooth position, gender, root and root canal number per tooth, root canal type of the mesial root(s) and distal root(s), angle of the DL root canal curvature, distance between two distal canal orifices in the teeth with DL root, and angle of disto-buccal canal orifice–disto-lingual canal orifice–mesio-lingual canal orifice (DB-DL-ML). Most of the mandibular first molars (64.9%, n = 591) had two roots with three root canals, and most of the mesial root canals (87.7%, n = 798) were type VI. The prevalence of the DL root was 22.1% (n = 201). The right side had a higher prevalence of DL root than the left side (p<0.05). Additionally, the curvature of the DL root canal were greater in the bucco-lingual (BL) orientation (30.10°±14.02°) than in the mesio-distal (MD) orientation (14.03°± 8.56°) (p<0.05). Overall there was a high prevalence of DL root in the mandibular first molars, and most of the DL roots were curved in different degrees. This study provided detailed information about the root canal morphology of the mandibular first molars in a Chinese subpopulation. PMID:26241480

  17. Relations of fine-root morphology on (137)Cs uptake by fourteen Brassica species.

    PubMed

    Aung, Han Phyo; Aye, Yi Swe; Mensah, Akwasi Dwira; Omari, Richard Ansong; Djedidi, Salem; Oikawa, Yosei; Ohkama-Ohtsu, Naoko; Yokoyama, Tadashi; Bellingrath-Kimura, Sonoko Dorothea

    2015-12-01

    Fourteen Brassica species consisting of seven leafy vegetables and seven root vegetables were examined for (137)Cs uptake differences in relation to their fine-root morphological characters. A pot experiment was conducted from November 2014 to February 2015 in a Phytroton using a contaminated soil of Fukushima prefecture. Leafy vegetables showed bigger root diameters, larger root surface area and larger root volume. Consequently, leafy vegetables had higher (137)Cs uptake compared to root vegetables. Among the three fine-root parameters, only root surface area was observed as a significant contributing factor to higher (137)Cs uptake in terms of transfer factor (TF, dry weight basis). Kakina exhibited higher (137)Cs TF value (0.20) followed by Chinese cabbage (0.18) and mizuna (0.17). Lower TF values were observed in turnip (0.059), rutabaga (Kitanoshou) (0.062) and radish (Ha daikon) (0.064). PMID:26355648

  18. Root canal irrigants

    PubMed Central

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-01-01

    Successful root canal therapy relies on the combination of proper instrumentation, irrigation, and obturation of the root canal. Of these three essential steps of root canal therapy, irrigation of the root canal is the most important determinant in the healing of the periapical tissues. The primary endodontic treatment goal must thus be to optimize root canal disinfection and to prevent reinfection. In this review of the literature, various irrigants and the interactions between irrigants are discussed. We performed a Medline search for English-language papers published untill July 2010. The keywords used were ‘root canal irrigants’ and ‘endodontic irrigants.’ The reference lists of each article were manually checked for additional articles of relevance. PMID:21217955

  19. The Roots of Literacy.

    ERIC Educational Resources Information Center

    Goodman, Yetta M.

    This review of research with children aged two to six on their reading, writing, and oral language development speaks of five roots of a tree of literate life that require nourishment in the soil of a written language environment. The roots discussed are the development of print awareness in situational contexts, the development of print awareness…

  20. Cylindrocarpon root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cylindrocarpon root rot of alfalfa has been found sporadically in Canada and the northern United States. The etiology of this disease is not fully understood, but the priority for research has not been high because of its infrequent occurrence. The infected area of the root initially has a water-soa...

  1. Irrational Square Roots

    ERIC Educational Resources Information Center

    Misiurewicz, Michal

    2013-01-01

    If students are presented the standard proof of irrationality of [square root]2, can they generalize it to a proof of the irrationality of "[square root]p", "p" a prime if, instead of considering divisibility by "p", they cling to the notions of even and odd used in the standard proof?

  2. Pythium Root Rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Pythium root rot is a disease that is found in agricultural and nursery soils throughout the United States and Canada. It is caused by several Pythium species, and the symptoms are typified by leaf or needle chlorosis, stunting, root rot, and plant death. The disease is favored by wet soils, overc...

  3. Root-knot nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Although root-knot nematodes (Meloidogyne species) can reduce crop yields worldwide, methods for their identification are often difficult to implement. This review summarizes the diagnostic morphological and molecular features for distinguishing the ten major previously described root-knot nematode ...

  4. Trees and Roots.

    ERIC Educational Resources Information Center

    Jones, Lethonee A.

    Constructing a family history can be significant in helping persons understand and appreciate the root system that supports and sustains them. Oral history can be a valuable resource in family research as Alex Haley demonstrated in writing "Roots." The major difficulty of using oral tradition in tracing a family history is that family members with…

  5. Sugarbeet root aphid on postharvest root storage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sugarbeet root aphid (SBRA), Pemphigus betae Doane, is a serious insect pest of sugarbeet in several North American sugarbeet production areas; however, it is rarely an economic pest in the Red River Valley (RRV). In 2012 and 2013, all RRV factory districts were impacted by SBRA outbreaks, and ...

  6. Root Nutrient Foraging1

    PubMed Central

    Giehl, Ricardo F.H.; von Wirén, Nicolaus

    2014-01-01

    During a plant's lifecycle, the availability of nutrients in the soil is mostly heterogeneous in space and time. Plants are able to adapt to nutrient shortage or localized nutrient availability by altering their root system architecture to efficiently explore soil zones containing the limited nutrient. It has been shown that the deficiency of different nutrients induces root architectural and morphological changes that are, at least to some extent, nutrient specific. Here, we highlight what is known about the importance of individual root system components for nutrient acquisition and how developmental and physiological responses can be coupled to increase nutrient foraging by roots. In addition, we review prominent molecular mechanisms involved in altering the root system in response to local nutrient availability or to the plant's nutritional status. PMID:25082891

  7. Images of Chinese and Chinese Americans Mirrored in Picture Books.

    ERIC Educational Resources Information Center

    Cai, Mingshui

    1994-01-01

    Examines how 73 picture storybooks portrayed Chinese and Chinese Americans and how the books reflect the Chinese culture. Finds that most present positive images of Chinese and Chinese Americans, that cultural inauthenticity is the main flaw of many books, and that more picture books are needed that feature flesh and blood contemporary Chinese and…

  8. American Counseling in the Mind of a Chinese Counselor.

    ERIC Educational Resources Information Center

    Zhang, Weijun

    1994-01-01

    Illustrating three instances he encountered here in the United States, the Chinese counselor argues that American counseling is deeply rooted in rugged individualism, and often at the expense of the family and community. The suitability of American counseling for other cultures is thus questioned. (Author/NB)

  9. Developmental Dyscalculia and Low Numeracy in Chinese Children

    ERIC Educational Resources Information Center

    Chan, Winnie Wai Lan; Au, Terry K.; Tang, Joey

    2013-01-01

    Children struggle with mathematics for different reasons. Developmental dyscalculia and low numeracy--two kinds of mathematical difficulties--may have their roots, respectively, in poor understanding of exact non-symbolic numerosities and of symbolic numerals. This study was the first to explore whether Chinese children, despite cultural and…

  10. Leveraging Chinese Culture for Effective Organizational Leadership: The China Case

    ERIC Educational Resources Information Center

    Wang, Jia

    2008-01-01

    This article examined organizational leadership in the context of China. Taking a cultural perspective, this literature review traced the cultural roots of Chinese leadership and analyzed the cultural impact on leadership practice in organizations. It further provided general guidelines for leadership development in China, followed by…

  11. Chinese restaurant syndrome

    MedlinePlus

    ... of symptoms that some people have after eating Chinese food. A food additive called monosodium glutamate (MSG) has ... Reports of serious reactions to Chinese food first appeared in ... thought to be the cause of these symptoms. There have been many ...

  12. Happy (Chinese) New Year!

    ERIC Educational Resources Information Center

    Johnson, Georgia G.

    1979-01-01

    Suggestions are made for a classroom celebration of Chinese New Year, including discussion of the Chinese calendar and customs, a short list of appropriate children's stories, and food ideas, including a recipe for fortune cookies. (SJL)

  13. Economic strategies of plant absorptive roots vary with root diameter

    NASA Astrophysics Data System (ADS)

    Kong, D. L.; Wang, J. J.; Kardol, P.; Wu, H. F.; Zeng, H.; Deng, X. B.; Deng, Y.

    2016-01-01

    Plant roots typically vary along a dominant ecological axis, the root economics spectrum, depicting a tradeoff between resource acquisition and conservation. For absorptive roots, which are mainly responsible for resource acquisition, we hypothesized that root economic strategies differ with increasing root diameter. To test this hypothesis, we used seven plant species (a fern, a conifer, and five angiosperms from south China) for which we separated absorptive roots into two categories: thin roots (thickness of root cortex plus epidermis < 247 µm) and thick roots. For each category, we analyzed a range of root traits related to resource acquisition and conservation, including root tissue density, different carbon (C), and nitrogen (N) fractions (i.e., extractive, acid-soluble, and acid-insoluble fractions) as well as root anatomical traits. The results showed significant relationships among root traits indicating an acquisition-conservation tradeoff for thin absorptive roots while no such trait relationships were found for thick absorptive roots. Similar results were found when reanalyzing data of a previous study including 96 plant species. The contrasting economic strategies between thin and thick absorptive roots, as revealed here, may provide a new perspective on our understanding of the root economics spectrum.

  14. Chinese-Mandarin; Chinese Character Exercise Book.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This writing exercise book, designed to accompany the Defense Language Institute's Chinese-Mandarin Basic Course, consists of step-by-step illustrations for copying 825 characters in the Chinese writing system. [Not available in hard copy due to marginal legibility of original document.] (AMM)

  15. Quantitative measurements of root water uptake and root hydraulic conductivities

    NASA Astrophysics Data System (ADS)

    Zarebanadkouki, Mohsen; Javaux, Mathieu; Meunier, Felicien; Couvreur, Valentin; Carminati, Andrea

    2016-04-01

    How is root water uptake distributed along the root system and what root properties control this distribution? Here we present a method to: 1) measure root water uptake and 2) inversely estimate the root hydraulic conductivities. The experimental method consists in using neutron radiography to trace deuterated water (D2O) in soil and roots. The method was applied to lupines grown aluminium containers filled with a sandy soil. When the lupines were 4 weeks old, D2O was locally injected in a selected soil regions and its transport was monitored in soil and roots using time-series neutron radiography. By image processing, we quantified the concentration of D2O in soil and roots. We simulated the transport of D2O into roots using a diffusion-convection numerical model. The diffusivity of the roots tissue was inversely estimated by simulating the transport of D2O into the roots during night. The convective fluxes (i.e. root water uptake) were inversely estimating by fitting the experiments during day, when plants were transpiring, and assuming that root diffusivity did not change. The results showed that root water uptake was not uniform along the roots. Water uptake was higher at the proximal parts of the lateral roots and it decreased by a factor of 10 towards the distal parts. We used the data of water fluxes to inversely estimate the profile of hydraulic conductivities along the roots of transpiring plants growing in soil. The water fluxes in the lupine roots were simulated using the Hydraulic Tree Model by Doussan et al. (1998). The fitting parameters to be adjusted were the radial and axial hydraulic conductivities of the roots. The results showed that by using the root architectural model of Doussan et al. (1998) and detailed information of water fluxes into different root segments we could estimate the profile of hydraulic conductivities along the roots. We also found that: 1) in a tap-rooted plant like lupine water is mostly taken up by lateral roots; (2) water

  16. Computers and Chinese Linguistics.

    ERIC Educational Resources Information Center

    Kierman, Frank A.; Barber, Elizabeth

    This survey of the field of Chinese language computational linguistics was prepared as a background study for the Chinese Linguistics Project at Princeton. Since the authors' main purpose was "critical reconnaissance," quantitative emphasis is on systems with which they are most familiar. The complexity of the Chinese writing system has presented…

  17. Chinese Folktales for Children.

    ERIC Educational Resources Information Center

    Kwok, Irene

    This bilingual text contains ten traditional Chinese folktales which have been rewritten for children. Each story deals with interpersonal relationships and/or stresses the Chinese way of life. Each page of text is given first in English and then in Chinese and is illustrated with a full-page drawing. The titles of the folktales are: (1) "One…

  18. MANDARIN CHINESE DICTIONARY.

    ERIC Educational Resources Information Center

    WANG, FRED FANGYU

    IN RESPONSE TO THE NEEDS OF THE GROWING NUMBER OF AMERICAN HIGH SCHOOL AND COLLEGE STUDENTS LEARNING CHINESE, SETON HALL UNIVERSITY UNDERTOOK A CONTRACT WITH THE U.S. OFFICE OF EDUCATION TO COMPILE A BILINGUAL POCKET-SIZE DICTIONARY FOR BEGINNING STUDENTS OF SPOKEN MANDARIN CHINESE. THE PRESENT WORK IS THE CHINESE TO ENGLISH SECTION IN PRELIMINARY…

  19. Roots in plant ecology.

    PubMed

    Cody, M L

    1986-09-01

    In 1727 the pioneer vegetation scientist Stephen Hales realized that I much that was of importance to his subject material took place below on ground. A good deal of descriptive work on plant roots and root systems was done in the subsequent two centuries; in crop plants especially, the gross morphology of root systems was well known by the early 20th century. These descriptive studies were extended to natural grasslands by Weaver and his associates and to deserts by Cannon by the second decade of this century, but since that time the study of subterranean growth form appears to have lapsed, as a recent review by Kummerow indicates. Nevertheless, growth form is an important aspect of plant ecology, and subterranean growth form is especially relevant to the study of vegetation in and areas (which is the main subject of this commentary). Moreover, there is a real need for more research to be directed towards understanding plant root systems in general. PMID:21227785

  20. Grass Rooting the System

    ERIC Educational Resources Information Center

    Perlman, Janice E.

    1976-01-01

    Suggests a taxonomy of the grass roots movement and gives a general descriptive over view of the 60 groups studied with respect to origin, constituency, size, funding, issues, and ideology. (Author/AM)

  1. Reading with Roots

    ERIC Educational Resources Information Center

    Gibson, Margaret I.

    1986-01-01

    Recommends a method of teaching Russian vocabulary that focuses on new words in context and on their structure: root, prefix, suffix, sound changes, and borrowings. Sources for teachers are given in the bibliography. (LMO)

  2. The phenomenology of rooting.

    PubMed

    Kerievsky, Bruce Stephen

    2010-09-01

    This paper examines the attractions of passionate involvement in wanting particular outcomes, which is popularly known as rooting. The author's lifelong personal experience is the source of his analysis, along with the insights provided by spiritual literature and especially the work of Dr. Thomas Hora, with whom the author studied for 30 years. The phrase "choiceless awareness," utilized by J. Krishnamurti, and attained via meditation, is seen as the means of transcending a rooting mode of being in the world. PMID:20165983

  3. [Antidepressant active constituents in the roots of Morinda officinalis How].

    PubMed

    Cui, C; Yang, M; Yao, Z; Cao, B; Luo, Z; Xu, Y; Chen, Y

    1995-01-01

    Five compounds having antidepressant activities have been isolated from the roots of Morinda officinalis, a Chinese traditional Yang-tonic drug. These compounds were identified as succinic acid (1), nystose (2), 1F-fructofuranosylnystose (3), inulin-type hexasaccharide (4) and heptasaccharide (5) by chemical and spectroscopic methods. All of the compounds are isolated from the species of genus Morinda for the first time. PMID:7626209

  4. Modeling root reinforcement using root-failure Weibull survival function

    NASA Astrophysics Data System (ADS)

    Schwarz, M.; Giadrossich, F.; Cohen, D.

    2013-03-01

    Root networks contribute to slope stability through complicated interactions that include mechanical compression and tension. Due to the spatial heterogeneity of root distribution and the dynamic of root turnover, the quantification of root reinforcement on steep slope is challenging and consequently the calculation of slope stability as well. Although the considerable advances in root reinforcement modeling, some important aspect remain neglected. In this study we address in particular to the role of root strength variability on the mechanical behaviors of a root bundle. Many factors may contribute to the variability of root mechanical properties even considering a single class of diameter. This work presents a new approach for quantifying root reinforcement that considers the variability of mechanical properties of each root diameter class. Using the data of laboratory tensile tests and field pullout tests, we calibrate the parameters of the Weibull survival function to implement the variability of root strength in a numerical model for the calculation of root reinforcement (RBMw). The results show that, for both laboratory and field datasets, the parameters of the Weibull distribution may be considered constant with the exponent equal to 2 and the normalized failure displacement equal to 1. Moreover, the results show that the variability of root strength in each root diameter class has a major influence on the behavior of a root bundle with important implications when considering different approaches in slope stability calculation. Sensitivity analysis shows that the calibration of the tensile force and the elasticity of the roots are the most important equations, as well as the root distribution. The new model allows the characterization of root reinforcement in terms of maximum pullout force, stiffness, and energy. Moreover, it simplifies the implementation of root reinforcement in slope stability models. The realistic quantification of root reinforcement for

  5. The "Green" Root Beer Laboratory

    ERIC Educational Resources Information Center

    Clary, Renee; Wandersee, James

    2010-01-01

    No, your students will not be drinking green root beer for St. Patrick's Day--this "green" root beer laboratory promotes environmental awareness in the science classroom, and provides a venue for some very sound science content! While many science classrooms incorporate root beer-brewing activities, the root beer lab presented in this article has…

  6. Quantitative Comparison and Metabolite Profiling of Saponins in Different Parts of the Root of Panax notoginseng

    PubMed Central

    2015-01-01

    Although both rhizome and root of Panax notoginseng are officially utilized as notoginseng in “Chinese Pharmacopoeia”, individual parts of the root were differently used in practice. To provide chemical evidence for the differentiated usage, quantitative comparison and metabolite profiling of different portions derived from the whole root, as well as commercial samples, were carried out, showing an overall higher content of saponins in rhizome, followed by main root, branch root, and fibrous root. Ginsenoside Rb2 was proposed as a potential marker with a content of 0.5 mg/g as a threshold value for differentiating rhizome from other parts. Multivariate analysis of the metabolite profile further suggested 32 saponins as potential markers for the discrimination of different parts of notoginseng. Collectively, the study provided comprehensive chemical evidence for the distinct usage of different parts of notoginseng and, hence, is of great importance for the rational application and exploitation of individual parts of notoginseng. PMID:25118819

  7. The root economics spectrum: divergence of absorptive root strategies with root diameter

    NASA Astrophysics Data System (ADS)

    Kong, D.; Wang, J.; Kardol, P.; Wu, H.; Zeng, H.; Deng, X.; Deng, Y.

    2015-08-01

    Plant roots usually vary along a dominant ecological axis, the root economics spectrum (RES), depicting a tradeoff between resource acquisition and conservation. For absorptive roots, which are mainly responsible for resource acquisition, we hypothesized that root strategies as predicted from the RES shift with increasing root diameter. To test this hypothesis, we used seven contrasting plant species for which we separated absorptive roots into two categories: thin roots (< 247 μm diameter) and thick roots. For each category, we analyzed a~range of root traits closely related to resource acquisition and conservation, including root tissue density, carbon (C) and nitrogen (N) fractions as well as root anatomical traits. The results showed that trait relationships for thin absorptive roots followed the expectations from the RES while no clear trait relationships were found in support of the RES for thick absorptive roots. Our results suggest divergence of absorptive root strategies in relation to root diameter, which runs against a single economics spectrum for absorptive roots.

  8. Root architecture and root and tuber crop productivity.

    PubMed

    Villordon, Arthur Q; Ginzberg, Idit; Firon, Nurit

    2014-07-01

    It is becoming increasingly evident that optimization of root architecture for resource capture is vital for enabling the next green revolution. Although cereals provide half of the calories consumed by humans, root and tuber crops are the second major source of carbohydrates globally. Yet, knowledge of root architecture in root and tuber species is limited. In this opinion article, we highlight what is known about the root system in root and tuber crops, and mark new research directions towards a better understanding of the relation between root architecture and yield. We believe that unraveling the role of root architecture in root and tuber crop productivity will improve global food security, especially in regions with marginal soil fertility and low-input agricultural systems. PMID:24630073

  9. Stachbotrys Root Rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stachybotrys root rot is caused by Stachybotrys chartarum, a cellulytic saprophytic hyphomycete fungus. The pathogen produces mycotoxins including a host of immunosupressant compounds for human and is one of the causes of the "sick building syndrome." Although S. chartarum is rarely known as a plan...

  10. Violet root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The fungus causing violet root rot, Helicobasidium brebissonii (anamorph Rhizoctonia crocorum), is widely distributed in Europe and North America but is rarely of much economic importance on alfalfa. The disease has also been reported in Australia, Argentina, and Iran. The disease is characterized b...

  11. "Roots": Medium and Message.

    ERIC Educational Resources Information Center

    Kinnamon, Keneth

    A national telephone survey indicated that audiences rated the television production of "Roots" positively in terms of the following: realistic portrayal of the people and the times; relevance for contemporary race relations; perceived emotional effect; and increased understanding of the psychology of black people. However, a comparison of the…

  12. Great Plains Roots.

    ERIC Educational Resources Information Center

    Frey, Jennifer

    2001-01-01

    Sandy White Hawk, Sicangu Lakota, was adopted by white missionaries as an infant and suffered child abuse. After 33 years, she found her birth family and formed First Nations Orphans Association, which uses songs and ceremonies to help adoptees return to their roots. Until the 1970s, federal agencies and welfare organizations facilitated removal…

  13. The Roots of Reading.

    ERIC Educational Resources Information Center

    Montoya, Colleen, Ed.

    2002-01-01

    This newsletter covers educational issues affecting schools in the Western Regional Educational Laboratory's 4-state region (Arizona, California, Nevada, and Utah) and nationwide. The following articles appear in the Volume 4, Number 1 issue: (1) "The Roots of Reading"; (2) "Breaking the Code: Reading Literacy in K-3"; (3) "Improving Secondary…

  14. Fine root turnover: a story of root production and root phenology

    NASA Astrophysics Data System (ADS)

    McCormack, M. L.; Adams, T. S.; Smithwick, E. A.; Eissenstat, D. M.

    2012-12-01

    Fine root turnover in terrestrial ecosystems partially controls carbon flow from plants into soils as well the amount of roots available for nutrient and water uptake. However, we have poor understanding of basic patterns and variability in fine root turnover. We address this shortfall through the use of a heuristic model and analysis of a multi-year minirhizotron dataset exploring the impacts of fine root phenology and production on fine root turnover rates across 12 temperate tree species in a common garden experiment. The heuristic model allowed us to calculate fine root turnover given different patterns of root production and different fine root lifespans. Using the model we found that patterns of phenology characterized by a single, concentrated peak resulted in slower calculated root turnover rates while broader and bi-modal production patterns resulted in faster turnover rates. For example, for roots with median lifespans of 91 days, estimates of root turnover increased from 1.5 yr-1 to 4.0 yr-1 between the pattern of concentrated root production and the pattern with root production spread equally throughout the year. Turnover rates observed in the common garden ranged from 0.75 yr-1 to 1.33 yr-1 and 0.93 yr-1 to 2.14 yr-1 when calculated as annual production divided by maximum standing root crop or average standing root crop, respectively. Turnover varied significantly across species and interannual variability in root production and turnover was high. Patterns of root phenology observed at the common garden included concentrated root production in late spring as well as several examples of bi-modal and broader patterns of root production with roots produced across spring, summer and fall. Overall, both phenology and total root production impacted estimates of root turnover, particularly for short-lived fine roots with median lifespans of less than one year. Our results suggest that better understanding fine root phenology and production will improve our

  15. The Physiology of Adventitious Roots.

    PubMed

    Steffens, Bianka; Rasmussen, Amanda

    2016-02-01

    Adventitious roots are plant roots that form from any nonroot tissue and are produced both during normal development (crown roots on cereals and nodal roots on strawberry [Fragaria spp.]) and in response to stress conditions, such as flooding, nutrient deprivation, and wounding. They are important economically (for cuttings and food production), ecologically (environmental stress response), and for human existence (food production). To improve sustainable food production under environmentally extreme conditions, it is important to understand the adventitious root development of crops both in normal and stressed conditions. Therefore, understanding the regulation and physiology of adventitious root formation is critical for breeding programs. Recent work shows that different adventitious root types are regulated differently, and here, we propose clear definitions of these classes. We use three case studies to summarize the physiology of adventitious root development in response to flooding (case study 1), nutrient deficiency (case study 2), and wounding (case study 3). PMID:26697895

  16. Control of Panama disease of banana by rotating and intercropping with Chinese chive (Allium tuberosum Rottler): role of plant volatiles.

    PubMed

    Zhang, Hui; Mallik, Azim; Zeng, Ren Sen

    2013-02-01

    Intercropping and rotating banana (Musa spp.) with Chinese chive (Allium tuberosum Rottler) has been used as an effective method to control Panama disease (Fusarium wilt) of banana in South China. However, the underlying mechanism is unknown. In this study, we used aqueous leachates and volatiles from Chinese chive to evaluate their antimicrobial activity on Fusarium oxysporum f. sp. cubense race 4 (FOC), the causal agent of Panama disease in banana, and identified the antifungal compounds. Both leaf and root leachates of Chinese chive displayed strong inhibition against FOC, but the concentrated leachates showed lower inhibition than the original leachates. In a sealed system volatiles emitted from the leaves and roots of Chinese chive inhibited mycelial growth of FOC. Volatile compounds emitted from the intact growing roots mimicking natural environment inhibited spore germination of FOC. We identified five volatiles including 2-methyl-2-pentenal and four organosulfur compounds (dimethyl trisulfide, dimethyl disulfide, dipropyl disulfide, and dipropyl trisulfide) from the leaves and roots of Chinese chive. All these compounds exhibited inhibitory effects on FOC, but 2-methyl-2-pentenal and dimethyl trisulfide showed stronger inhibition than the other three compounds. 2-Methyl-2-pentenal at 50-100 μl/l completely inhibited the mycelial growth of FOC. Our results demonstrate that antifungal volatiles released from Chinese chive help control Panama disease in banana. We conclude that intercropping and rotating banana with Chinese chive can control Panama disease and increase cropland biodiversity. PMID:23355016

  17. Chinese by Choice

    ERIC Educational Resources Information Center

    Beem, Kate

    2008-01-01

    A 2004 College Board survey revealed that school districts around America wanted to offer Chinese, but finding qualified teachers was a problem, says Selena Cantor, director of Chinese Language and Culture Initiatives for the College Board. So last year, a new College Board program brought guest teachers from China to school districts in 31…

  18. Chinese Foods; Teacher's Handbook.

    ERIC Educational Resources Information Center

    Huang, Joe, Ed.

    Different styles of Chinese cooking, traditional food items, cooking utensils, serving techniques, and the nutritional value of Chinese cooking are described in this teaching guide. Lesson plans for the preparation of simple dishes are presented. Recipes, a shopping guide to San Francisco's Chinatown, a guide to sources of supplies, and a…

  19. Hairy roots are more sensitive to auxin than normal roots

    PubMed Central

    Shen, Wen Hui; Petit, Annik; Guern, Jean; Tempé, Jacques

    1988-01-01

    Responses to auxin of Lotus corniculatus root tips or protoplasts transformed by Agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. Three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. Root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exogenous auxin concentration. The sensitivity of hairy root tips or protoplasts to exogenous auxin was found to be 100-1000 times higher than that of untransformed material. PMID:16593928

  20. Hairy roots are more sensitive to auxin than normal roots.

    PubMed

    Shen, W H; Petit, A; Guern, J; Tempé, J

    1988-05-01

    Responses to auxin of Lotus corniculatus root tips or protoplasts transformed by Agrobacterium rhizogenes strains 15834 and 8196 were compared to those of their normal counterparts. Three different types of experiments were performed, involving long-term, medium-term, or short-term responses to a synthetic auxin, 1-naphthaleneacetic acid. Root tip elongation, proton excretion by root tips, and transmembrane electrical potential difference of root protoplasts were measured as a function of exogenous auxin concentration. The sensitivity of hairy root tips or protoplasts to exogenous auxin was found to be 100-1000 times higher than that of untransformed material. PMID:16593928

  1. Root canal retained restorations: 3. Root-face attachments.

    PubMed

    Dummer, P M; Edmunds, D H; Gidden, J R

    1990-10-01

    It has been common practice for many years to use retained roots to provide support and stability for partial or full dentures. The retention of such overdentures is greatly enhanced if the remaining roots are modified and restored with posts and root-face attachments. The final article in this series on root canal retained restorations classifies and describes some of the root-face attachments currently available, and also describes a number of prefabricated post systems with integral overdenture attachments. Guidelines for clinical and laboratory procedures are given. PMID:2097234

  2. Strigolactones Effects on Root Growth

    NASA Astrophysics Data System (ADS)

    Koltai, Hinanit

    2012-07-01

    Strigolactones (SLs) were defined as a new group of plant hormones that suppress lateral shoot branching. Our previous studies suggested SLs to be regulators of root development. SLs were shown to alter root architecture by regulating lateral root formation and to affect root hair elongation in Arabidopsis. Another important effect of SLs on root growth was shown to be associated with root directional growth. Supplementation of SLs to roots led to alterations in root directional growth, whereas associated mutants showed asymmetrical root growth, which was influenced by environmental factors. The regulation by SLs of root development was shown to be conducted via a cross talk of SLs with other plant hormones, including auxin. SLs were shown to regulate auxin transport, and to interfere with the activity of auxin-efflux carriers. Therefore, it might be that SLs are regulators of root directional growth as a result of their ability to regulated auxin transport. However, other evidences suggest a localized effect of SLs on cell division, which may not necessarily be associated with auxin efflux. These and other, recent hypothesis as to the SLs mode of action and the associated root perception and response to environmental factors will be discussed.

  3. Aquaporins and root water relations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Water is one of the most critical resources limiting plant growth and crop productivity, and root water uptake is an important aspect of plant physiology governing plant water use and stress tolerance. Pathways of root water uptake are complex and are affected by root structure and physiological res...

  4. Springback in root gravitropism

    NASA Technical Reports Server (NTRS)

    Leopold, A. C.; Wettlaufer, S. H.

    1989-01-01

    Conditions under which a gravistimulus of Merit corn roots (Zea mays L.) is withdrawn result in a subsequent loss of gravitropic curvature, an effect which we refer to as springback.' This loss of curvature begins within 1 to 10 minutes after removal of the gravistimulus. It occurs regardless of the presence or absence of the root cap. It is insensitive to inhibitors of auxin transport (2,3,5-triiodobenzoic acid, naphthylphthalamic [correction of naphthylphthalmaic] acid) or to added auxin (2,4-dichlorophenoxyacetic acid). Springback is prevented if a clinostat treatment is interjected to neutralize gravistimulation during germination, which suggests that the change in curvature is a response to a memory' effect carried over from a prior gravistimulation.

  5. Springback in root gravitropism.

    PubMed

    Leopold, A C; Wettlaufer, S H

    1989-01-01

    Conditions under which a gravistimulus of Merit corn roots (Zea mays L.) is withdrawn result in a subsequent loss of gravitropic curvature, an effect which we refer to as springback.' This loss of curvature begins within 1 to 10 minutes after removal of the gravistimulus. It occurs regardless of the presence or absence of the root cap. It is insensitive to inhibitors of auxin transport (2,3,5-triiodobenzoic acid, naphthylphthalamic [correction of naphthylphthalmaic] acid) or to added auxin (2,4-dichlorophenoxyacetic acid). Springback is prevented if a clinostat treatment is interjected to neutralize gravistimulation during germination, which suggests that the change in curvature is a response to a memory' effect carried over from a prior gravistimulation. PMID:11537456

  6. Diagravitropism in corn roots

    NASA Technical Reports Server (NTRS)

    Leopold, A. C.; Wettlaufer, S. H.

    1988-01-01

    The diagravitropic behavior of Merit corn (Zea mays L.) roots grown in darkness provides an opportunity for comparison of two qualitatively different gravitropic systems. As with positive gravitropism, diagravitropism is shown to require the presence of the root cap, have a similar time course for the onset of curvature, and a similar presentation time. In contrast with positive gravitropism, diagravitropism appears to have a more limited requirement for calcium, for it is insensitive to the elution of calcium by EGTA and insensitive to the subsequent addition of a calcium/EGTA complex. These results are interpreted as indicating that whereas the same sensing system is shared by the two types of gravitropism, separate transductive systems are involved, one for diagravitropism, which is relatively independent of calcium, and one for positive gravitropism, which is markedly dependent on calcium.

  7. Growing Up the Chinese Way: Chinese Child and Adolescent Development.

    ERIC Educational Resources Information Center

    Lau, Sing, Ed.

    This volume is a collection of current research by noted scholars on Chinese child development. The volume re-examines long-held beliefs and preconceptions about Chinese culture, draws forth incompatible pictures and contradictory facts about Chinese children, and draws attention to new problems of the modern Chinese family. The chapters of the…

  8. Chinese Language Guide. Level I.

    ERIC Educational Resources Information Center

    Bay Area Bilingual Education League, Berkeley, CA.

    This comprehensive Chinese language development guide for bilingual Chinese-English educators contains fifteen objectives along with related learning activities to be taught in the Chinese bilingual program. The guide emphasizes audio-lingual skill development and involves Chinese games, songs, foods, and holidays. (Author/AM)

  9. Modern Chinese: History and Sociolinguistics.

    ERIC Educational Resources Information Center

    Chen, Ping

    This book presents a comprehensive and up-to-date account of the development of modern Chinese from the late 19th century up to the 1990s, concentrating on three major aspects: modern spoken Chinese, modern written Chinese, and the modern Chinese writing system. It describes and analyzes in detail, from historical and sociolinguistic perspectives,…

  10. Control of Arabidopsis Root Development

    PubMed Central

    Petricka, Jalean J.; Winter, Cara M.; Benfey, Philip N.

    2013-01-01

    The Arabidopsis root has been the subject of intense research over the past decades. This research has led to significantly improved understanding of the molecular mechanisms underlying root development. Key insights into the specification of individual cell types, cell patterning, growth and differentiation, branching of the primary root, and responses of the root to the environment have been achieved. Transcription factors and plant hormones play key regulatory roles. Recently, mechanisms involving protein movement and the oscillation of gene expression have also been uncovered. Root gene regulatory networks controlling root development have been reconstructed from genome-wide profiling experiments, revealing novel molecular connections and models. Future refinement of these models will lead to a more complete description of the complex molecular interactions that give rise to a simple growing root. PMID:22404466

  11. The Application of the Chinese Sense of "Balance" to Agreements Signed between Chinese and Foreign Institutions in the Chinese Higher Education Sector: Adding Depth to a Popular Cultural Concept

    ERIC Educational Resources Information Center

    Willis, Mike

    2004-01-01

    The Chinese sense of "balance" has been widely researched in the literature from several perspectives including culture (where it has been traced back to Confucian, neo-Confucian and Taoist roots), and business and market entry (where it has been linked to issues such as the development of trust, relationship building, and guanxi between foreign…

  12. Try to Be a Hero: Community Service Learning as a Pedagogy for Moral-Political Education and Leadership Development in the Chinese University

    ERIC Educational Resources Information Center

    Waite, Paul Daniel

    2009-01-01

    Based on ten months of ethnographic fieldwork, including more than 65 in-depth interviews with Chinese university students and higher education administrators, this study examines the roots of an emerging community service learning movement in mainland China. The dissertation focuses on a case study of a pioneering Chinese Party State-sponsored…

  13. A Chinese view of the Western nursing metaparadigm.

    PubMed

    Kao, Hsueh-Fen Sabrina; Reeder, Francelyn M; Hsu, Min-Tao; Cheng, Su-Fen

    2006-06-01

    The purpose of this article is to reveal Chinese-rooted meanings present within the Western nursing metaparadigm and to illustrate some similarities with Rogers's Science of Unitary Human Beings. Confucian and Taoist beliefs have the potential to illuminate the basic constructs inherent in holistic nursing. The Western nursing metaparadigm of four concepts--person, nursing, health, and environment--was explored through the lens of a Chinese worldview and led to the presentation of a broadened view for an integrated model of nursing. Asian and Western worldviews of human beings and health are not mutually exclusive. The Chinese holistic worldview of Taoism and Confucianism resonates theoretically and cosmically with the dynamic nature of the human-environment mutual relationship basic to Rogers' unitary view. This strong, theoretical link, when elaborated for its similarities and implications, can broaden the knowledge base to guide contemporary nursing practice, education, and research, particularly relevant for holistic nursing. PMID:16740897

  14. The Roots of Beowulf

    NASA Technical Reports Server (NTRS)

    Fischer, James R.

    2014-01-01

    The first Beowulf Linux commodity cluster was constructed at NASA's Goddard Space Flight Center in 1994 and its origins are a part of the folklore of high-end computing. In fact, the conditions within Goddard that brought the idea into being were shaped by rich historical roots, strategic pressures brought on by the ramp up of the Federal High-Performance Computing and Communications Program, growth of the open software movement, microprocessor performance trends, and the vision of key technologists. This multifaceted story is told here for the first time from the point of view of NASA project management.

  15. Philosophical Roots of Cosmology

    NASA Astrophysics Data System (ADS)

    Ivanovic, M.

    2008-10-01

    We shall consider the philosophical roots of cosmology in the earlier Greek philosophy. Our goal is to answer the question: Are earlier Greek theories of pure philosophical-mythological character, as often philosophers cited it, or they have scientific character. On the bases of methodological criteria, we shall contend that the latter is the case. In order to answer the question about contemporary situation of the relation philosophy-cosmology, we shall consider the next question: Is contemporary cosmology completely independent of philosophical conjectures? The answer demands consideration of methodological character about scientific status of contemporary cosmology. We also consider some aspects of the relation contemporary philosophy-cosmology.

  16. Matching roots to their environment

    PubMed Central

    White, Philip J.; George, Timothy S.; Gregory, Peter J.; Bengough, A. Glyn; Hallett, Paul D.; McKenzie, Blair M.

    2013-01-01

    Background Plants form the base of the terrestrial food chain and provide medicines, fuel, fibre and industrial materials to humans. Vascular land plants rely on their roots to acquire the water and mineral elements necessary for their survival in nature or their yield and nutritional quality in agriculture. Major biogeochemical fluxes of all elements occur through plant roots, and the roots of agricultural crops have a significant role to play in soil sustainability, carbon sequestration, reducing emissions of greenhouse gasses, and in preventing the eutrophication of water bodies associated with the application of mineral fertilizers. Scope This article provides the context for a Special Issue of Annals of Botany on ‘Matching Roots to Their Environment’. It first examines how land plants and their roots evolved, describes how the ecology of roots and their rhizospheres contributes to the acquisition of soil resources, and discusses the influence of plant roots on biogeochemical cycles. It then describes the role of roots in overcoming the constraints to crop production imposed by hostile or infertile soils, illustrates root phenotypes that improve the acquisition of mineral elements and water, and discusses high-throughput methods to screen for these traits in the laboratory, glasshouse and field. Finally, it considers whether knowledge of adaptations improving the acquisition of resources in natural environments can be used to develop root systems for sustainable agriculture in the future. PMID:23821619

  17. Different attitudes toward humor between Chinese and American students: evidence from the Implicit Association Test.

    PubMed

    Jiang, Feng; Yue, Xiao Dong; Lu, Su

    2011-08-01

    Although cross-cultural research indicates that Chinese people demonstrate less humor than do Americans, little research addresses the reasons. This cross-cultural difference may be largely due to different implicit attitudes toward humor held by Chinese and Americans, deeply rooted in the two cultural traditions. Both self-report evaluation and the Implicit Association Test (IAT) were used to compare Chinese and American attitudes toward humor. Although 60 Chinese undergraduate students showed no significant difference from 33 American exchange students in explicit attitudes toward humor, the former associated humor more frequently with unpleasant adjectives and seriousness with pleasant adjectives on the IAT; the opposite pattern was found for the American group. This indicated a negative implicit attitude toward humor among the Chinese students. PMID:22049652

  18. Traditional Chinese Biotechnology

    NASA Astrophysics Data System (ADS)

    Xu, Yan; Wang, Dong; Fan, Wen Lai; Mu, Xiao Qing; Chen, Jian

    The earliest industrial biotechnology originated in ancient China and developed into a vibrant industry in traditional Chinese liquor, rice wine, soy sauce, and vinegar. It is now a significant component of the Chinese economy valued annually at about 150 billion RMB. Although the production methods had existed and remained basically unchanged for centuries, modern developments in biotechnology and related fields in the last decades have greatly impacted on these industries and led to numerous technological innovations. In this chapter, the main biochemical processes and related technological innovations in traditional Chinese biotechnology are illustrated with recent advances in functional microbiology, microbial ecology, solid-state fermentation, enzymology, chemistry of impact flavor compounds, and improvements made to relevant traditional industrial facilities. Recent biotechnological advances in making Chinese liquor, rice wine, soy sauce, and vinegar are reviewed.

  19. Geophysical Imaging of Root Architecture and Root-soil Interaction

    NASA Astrophysics Data System (ADS)

    Wu, Y.; Dafflon, B.; Hubbard, S. S.

    2015-12-01

    Roots play a critical role in controlling water and nutrient uptake, soil biogeochemical processes, as well as the physical anchorage for plants. While important processes, such as root hydraulic redistribution for optimal growth and survival have been recognized, representation of roots in climate models, e.g. its carbon storage, carbon resilience, root biomass, and role in regulating water and carbon fluxes across the rhizosphere and atmosphere interface is still challenging. Such a challenge is exacerbated because of the large variations of root architecture and function across species and locations due to both genetic and environmental controls and the lack of methods for quantifying root mass, distribution, dynamics and interaction with soils at field scales. The scale, complexity and the dynamic nature of plant roots call for minimally invasive methods capable of providing quantitative estimation of root architecture, dynamics over time and interactions with the soils. We present a study on root architecture and root-soil interactions using geophysical methods. Parameters and processes of interests include (1) moisture dynamics around root zone and its interaction with plant transpiration and environmental controls and (2) estimation of root structure and properties based on geophysical signals. Both pot and field scale studies were conducted. The pot scale experiments were conducted under controlled conditions and were monitored with cross-well electrical resistivity tomography (ERT), TDR moisture sensors and temperature probes. Pots with and without a tree were compared and the moisture conditions were controlled via a self regulated pumping system. Geophysical monitoring revealed interactions between roots and soils under dynamic soil moisture conditions and the role of roots in regulating the response of the soil system to changes of environmental conditions, e.g. drought and precipitation events. Field scale studies were conducted on natural trees using

  20. Perennial roots to immortality.

    PubMed

    Munné-Bosch, Sergi

    2014-10-01

    Maximum lifespan greatly varies among species, and it is not strictly determined; it can change with species evolution. Clonal growth is a major factor governing maximum lifespan. In the plant kingdom, the maximum lifespans described for clonal and nonclonal plants vary by an order of magnitude, with 43,600 and 5,062 years for Lomatia tasmanica and Pinus longaeva, respectively. Nonclonal perennial plants (those plants exclusively using sexual reproduction) also present a huge diversity in maximum lifespans (from a few to thousands of years) and even more interestingly, contrasting differences in aging patterns. Some plants show a clear physiological deterioration with aging, whereas others do not. Indeed, some plants can even improve their physiological performance as they age (a phenomenon called negative senescence). This diversity in aging patterns responds to species-specific life history traits and mechanisms evolved by each species to adapt to its habitat. Particularities of roots in perennial plants, such as meristem indeterminacy, modular growth, stress resistance, and patterns of senescence, are crucial in establishing perenniality and understanding adaptation of perennial plants to their habitats. Here, the key role of roots for perennial plant longevity will be discussed, taking into account current knowledge and highlighting additional aspects that still require investigation. PMID:24563283

  1. The Chinese in Britain.

    PubMed

    Chan, Y M; Chan, C

    1997-01-01

    "This research note offers a brief historical perspective on the relationship between Hong Kong and Britain and describes the demographic profile of the Chinese community in Britain...[using] information obtained from the 1991 [UK] Census.... The data analysis shows that the Chinese population is widely dispersed and increasing rapidly, and is characterised by a high child-bearing capacity and a low rate of unemployment." PMID:12179828

  2. Mexicanolide-Type Limonoids from the Roots of Trichilia sinensis.

    PubMed

    Liu, Shou-Bai; Mei, Wen-Li; Chen, Hui-Qin; Guo, Zhi-Kai; Dai, Hao-Fu; Wang, Zhu-Nian

    2016-01-01

    Four new mexicanolide-type limonoids 1-4, along with two known limonoids 5-6, were isolated from the ethanolic extracts of roots of the Traditional Chinese Medicine Trichilia sinensis. Their structures were unambiguously determined by analysis of spectroscopic data, including 1D and 2D NMR as well as MS, and by comparison with literature data. In addition, the acetylcholinesterase (AChE) inhibitory activity of compounds 1-6 was evaluated by the Ellman method. All these compounds showed weak AChE inhibitory activity, with the inhibition percentages ranging from 18.5% to 27.8%. PMID:27589710

  3. [Changes of root biomass, root surface area, and root length density in a Populus cathayana plantation].

    PubMed

    Yan, Hui; Liu, Guang-quan; Li, Hong-sheng

    2010-11-01

    By using soil core method, the biomass, surface area, and length density of roots < or =2 mm and 2-5 mm in diameter in a 50-year-old Populus cathayana plantation on the northern slope of Qinling Mountains were determined during growth season. Among the roots <5 mm in diameter, those < or =2 mm and 2-5 mm in diameter accounted for 77.8% and 22.2% of the total root biomass, respectively. The surface area and length density of the roots < or =2 mm in diameter accounted for more than 97% of the total, and those of the roots 2-5 mm in diameter only occupied less than 3%. The biomass, surface area, and root length density of roots < or =2 mm in diameter decreased with soil depth, while those of the roots 2-5 mm in diameter were the least in 20-30 cm soil layer. The biomass, surface area, and length density of roots < or =2 mm in diameter were significantly correlated with soil organic matter and available nitrogen, but no significant correlations were found for the roots 2-5 mm in diameter. PMID:21360997

  4. Transgene expression in regenerated roots.

    PubMed

    Malamy, Jocelyn

    2007-01-01

    INTRODUCTIONThis procedure, which uses a root transformation protocol, provides a rapid method for assessing gene expression in Arabidopsis roots. It is useful for testing promoter:reporter gene constructs, for expressing genes, the overexpression of which is lethal in whole plants, and for transforming the roots of plants that are recalcitrant to conventional transformation techniques. The protocol has been used successfully with Ws, No-0, and RLD ecotypes. PMID:21357026

  5. Tense and Aspect in Mandarin Chinese and Spanish: Contrasts Manifested in the Mandarin Translation of Javier Marias' Corazón Tan Blanco

    ERIC Educational Resources Information Center

    Hung, Yu-Ju

    2016-01-01

    Mandarin Chinese and Spanish are both considered aspect languages for the simple reason that they both mark grammatical aspect morphologically: the former attaches a particle expressing only aspectual meaning to the root of a verb, while the latter attaches a suffix expressing both aspectual and tense meaning to the root of a verb. Since tense…

  6. A Split-Root Technique for Measuring Root Water Potential

    PubMed Central

    Adeoye, Kingsley B.; Rawlins, Stephen L.

    1981-01-01

    Water encounters various resistances in moving along a path of decreasing potential energy from the soil through the plant to the atmosphere. The reported relative magnitudes of these pathway resistances vary widely and often these results are conflicting. One reason for such inconsistency is the difficulty in measuring the potential drop across various segments of the soil-plant-atmosphere continuum. The measurement of water potentials at the soil-root interface and in the root xylem of a transpiring plant remains a challenging problem. In the divided root experiment reported here, the measured water potential of an enclosed, nonabsorbing branch of the root system of young corn (Bonanza) plants to infer the water potential of the remaining roots growing in soil was used. The selected root branch of the seedling was grown in a specially constructed Teflon test tube into which a screen-enclosed thermocouple psychrometer was inserted and sealed to monitor the root's water potential. The root and its surrounding atmosphere were assumed to be in vapor equilibrium. Images PMID:16661886

  7. [A case of appendicular supplementary root with external root resorption].

    PubMed

    González Bahillo, J; Martínez Insua, A; Varela Patiño, P; Rivas Lombardero, P; Paz Pumpido, F

    1991-01-01

    The case of a lateral maxillary incisor with a supplementary root fractured by external root resorption, is presented. The role played for the periodontal disease is shown in the clinical and radiographic achievements, and their implications in the pulpal disease. Endodontic therapy was performed and the diagnosis confirmed in the specimen histological research. PMID:1858059

  8. The roots of predictivism.

    PubMed

    Barnes, Eric Christian

    2014-03-01

    In The Paradox of Predictivism (2008, Cambridge University Press) I tried to demonstrate that there is an intimate relationship between predictivism (the thesis that novel predictions sometimes carry more weight than accommodations) and epistemic pluralism (the thesis that one important form of evidence in science is the judgments of other scientists). Here I respond to various published criticisms of some of the key points from Paradox from David Harker, Jarret Leplin, and Clark Glymour. Foci include my account of predictive novelty (endorsement novelty), the claim that predictivism has two roots, the prediction per se and predictive success, and my account of why Mendeleev's predictions carried special weight in confirming the Periodic Law of the Elements. PMID:24984449

  9. New roots for agriculture: exploiting the root phenome

    PubMed Central

    Lynch, Jonathan P.; Brown, Kathleen M.

    2012-01-01

    Recent advances in root biology are making it possible to genetically design root systems with enhanced soil exploration and resource capture. These cultivars would have substantial value for improving food security in developing nations, where yields are limited by drought and low soil fertility, and would enhance the sustainability of intensive agriculture. Many of the phenes controlling soil resource capture are related to root architecture. We propose that a better understanding of the root phenome is needed to effectively translate genetic advances into improved crop cultivars. Elementary, unique root phenes need to be identified. We need to understand the ‘fitness landscape’ for these phenes: how they affect crop performance in an array of environments and phenotypes. Finally, we need to develop methods to measure phene expression rapidly and economically without artefacts. These challenges, especially mapping the fitness landscape, are non-trivial, and may warrant new research and training modalities. PMID:22527403

  10. Chinese health beliefs of older Chinese in Canada.

    PubMed

    Lai, Daniel W L; Surood, Shireen

    2009-02-01

    Objectives. This study examines the cultural health beliefs held by older Chinese in Canada. Methods. Chinese surnames are randomly selected from the local Chinese telephone directories. Telephone screening is then conducted to identify eligible Chinese people 55 years of age or older to take part in a face-to-face interview to complete a structured survey questionnaire. Results. The results of exploratory factor analysis indicate that the health beliefs of the older Chinese are loaded onto three factors related to beliefs about traditional health practices, beliefs about traditional Chinese medicine, and beliefs about preventive diet. Education, religion, country of origin, length of residency in Canada, and city of residency are the major correlates of the various Chinese health beliefs scales. Discussion. The findings support the previous prescriptive knowledge about Chinese health beliefs and illustrate the intragroup sociocultural diversity that health practitioners should acknowledge in their practice. PMID:19144968

  11. Compensatory Root Water Uptake of Overlapping Root Systems

    NASA Astrophysics Data System (ADS)

    Agee, E.; Ivanov, V. Y.; He, L.; Bisht, G.; Shahbaz, P.; Fatichi, S.; Gough, C. M.; Couvreur, V.; Matheny, A. M.; Bohrer, G.

    2015-12-01

    Land-surface models use simplified representations of root water uptake based on biomass distributions and empirical functions that constrain water uptake during unfavorable soil moisture conditions. These models fail to capture the observed hydraulic plasticity that allows plants to regulate root hydraulic conductivity and zones of active uptake based on local gradients. Recent developments in root water uptake modeling have sought to increase its mechanistic representation by bridging the gap between physically based microscopic models and computationally feasible macroscopic approaches. It remains to be demonstrated whether bulk parameterization of microscale characteristics (e.g., root system morphology and root conductivity) can improve process representation at the ecosystem scale. We employ the Couvreur method of microscopic uptake to yield macroscopic representation in a coupled soil-root model. Using a modified version of the PFLOTRAN model, which represents the 3-D physics of variably saturated soil, we model a one-hectare temperate forest stand under natural and synthetic climatic forcing. Our results show that as shallow soil layers dry, uptake at the tree and stand level shift to deeper soil layers, allowing the transpiration stream demanded by the atmosphere. We assess the potential capacity of the model to capture compensatory root water uptake. Further, the hydraulic plasticity of the root system is demonstrated by the quick response of uptake to rainfall pulses. These initial results indicate a promising direction for land surface models in which significant three-dimensional information from large root systems can be feasibly integrated into the forest scale simulations of root water uptake.

  12. Determinants and Polynomial Root Structure

    ERIC Educational Resources Information Center

    De Pillis, L. G.

    2005-01-01

    A little known property of determinants is developed in a manner accessible to beginning undergraduates in linear algebra. Using the language of matrix theory, a classical result by Sylvester that describes when two polynomials have a common root is recaptured. Among results concerning the structure of polynomial roots, polynomials with pairs of…

  13. Ancient Chinese Astronomical Technologies

    NASA Astrophysics Data System (ADS)

    Walsh, Jennifer Robin

    2004-05-01

    I am interested in the astronomical advances of the Ancient Chinese in measuring the solar day. Their development of gnomon & ruler, sundial, and water clock apparatuses enabled Chinese astronomers to measure the annual solar orbit and solar day more precisely than their contemporaries. I have built one of each of these devices to use in collecting data from Olympia, Washington. I will measure the solar day in the Pacific Northwest following the methodology of the ancient Chinese. I will compare with my data, the available historical Chinese astronomical records and current records from the United States Naval Observatory Master Clock. I seek to understand how ancient Chinese investigations into solar patterns enabled them to make accurate predictions about the movement of the celestial sphere and planets, and to develop analytic tests of their theories. Mayall, R. Newton; Sundials: their construction and use. Dover Publications 2000 North, John; The Norton History of Astronomy and Cosmology W.W. Norton& Co. 1995 Zhentao Xu, David W. Pankenier, Yaotiao Jiang; East Asian archaeoastronomy : historical records of astronomical observations of China, Japan and Korea Published on behalf of the Earth Space Institute by Gordon and Breach Science Publishers, c2000

  14. Chinese Visiting Scholars' Academic Socialization in US Institutions of Higher Education: A Qualitative Study

    ERIC Educational Resources Information Center

    Xue, Mo; Chao, Xia; Kuntz, Aaron M.

    2015-01-01

    Socialization as a theoretical concept has been increasingly applied to higher education over the past several decades. However, little research examines international visiting scholars' overseas academic socialization experiences. Rooted in socialization theory, this one-year qualitative study explores 15 Chinese visiting scholars' lived…

  15. On the Problems Existed in Chinese Art Education and the Way Out

    ERIC Educational Resources Information Center

    Yue, Youxi

    2009-01-01

    Nowadays Chinese art education has mostly four problems: The first one is to make art education skilling; The second is to make art education moralization; The third is to make art education mechanization; The fourth is to make art education marginalization. The root of the problems has two aspects: First, the actuality of education system affects…

  16. Shuttle ban for Chinese journalists

    NASA Astrophysics Data System (ADS)

    Gwynne, Peter

    2011-07-01

    A bill passed in April by the US Congress has banned representatives of the Chinese government's news agency Xinhua from the launch site at the Kennedy Space Center as well as preventing NASA from hosting "official Chinese visitors".

  17. Traditional Chinese Medicine: An Introduction

    MedlinePlus

    ... C, eds. A Comprehensive Guide to Chinese Medicine . River Edge, NJ: World Scientific Publishing Co.; 2003. Manheimer ... YC, eds. A Comprehensive Guide to Chinese Medicine . River Edge, NJ: World Scientific Publishing Co.; 2003. Vickers ...

  18. History of Chinese medicinal wine.

    PubMed

    Xia, Xun-Li

    2013-07-01

    Chinese medicinal wine is one type of a favorable food-drug product invented by Chinese ancestors for treating and preventing diseases, promoting people's health and corporeity, and enriching people's restorative culture. In the course of development of the millenary-old Chinese civilization, Chinese medicinal wine has made incessant progress and evolution. In different historical periods, Chinese medicinal wine presented different characteristics in basic wine medical applications, prescriptions, etc. There are many medical and Materia Medica monographs which have systemically and specifically reported on Chinese medicinal wine in past Chinese dynasties. By studying leading medical documents, this article made an outline review on the invention, development, and characteristics of Chinese medicinal wine. PMID:21853349

  19. Cassava root membrane proteome reveals activities during storage root maturation.

    PubMed

    Naconsie, Maliwan; Lertpanyasampatha, Manassawe; Viboonjun, Unchera; Netrphan, Supatcharee; Kuwano, Masayoshi; Ogasawara, Naotake; Narangajavana, Jarunya

    2016-01-01

    Cassava (Manihot esculenta Crantz) is one of the most important crops of Thailand. Its storage roots are used as food, feed, starch production, and be the important source for biofuel and biodegradable plastic production. Despite the importance of cassava storage roots, little is known about the mechanisms involved in their formation. This present study has focused on comparison of the expression profiles of cassava root proteome at various developmental stages using two-dimensional gel electrophoresis and LC-MS/MS. Based on an anatomical study using Toluidine Blue, the secondary growth was confirmed to be essential during the development of cassava storage root. To investigate biochemical processes occurring during storage root maturation, soluble and membrane proteins were isolated from storage roots harvested from 3-, 6-, 9-, and 12-month-old cassava plants. The proteins with differential expression pattern were analysed and identified to be associated with 8 functional groups: protein folding and degradation, energy, metabolism, secondary metabolism, stress response, transport facilitation, cytoskeleton, and unclassified function. The expression profiling of membrane proteins revealed the proteins involved in protein folding and degradation, energy, and cell structure were highly expressed during early stages of development. Integration of these data along with the information available in genome and transcriptome databases is critical to expand knowledge obtained solely from the field of proteomics. Possible role of identified proteins were discussed in relation with the activities during storage root maturation in cassava. PMID:26547558

  20. Knowing Chinese character grammar.

    PubMed

    Myers, James

    2016-02-01

    Chinese character structure has often been described as representing a kind of grammar, but the notion of character grammar has hardly been explored. Patterns in character element reduplication are particularly grammar-like, displaying discrete combinatoriality, binarity, phonology-like final prominence, and potentially the need for symbolic rules (X→XX). To test knowledge of these patterns, Chinese readers were asked to judge the acceptability of fake characters varying both in grammaticality (obeying or violating reduplication constraints) and in lexicality (of the reduplicative configurations). While lexical knowledge was important (lexicality improved acceptability and grammatical configurations were accepted more quickly when also lexical), grammatical knowledge was important as well, with grammaticality improving acceptability equally for lexical and nonlexical configurations. Acceptability was also higher for more frequent reduplicative elements, suggesting that the reduplicative configurations were decomposed. Chinese characters present an as-yet untapped resource for exploring fundamental questions about the nature of the human capacity for grammar. PMID:26684059

  1. Traditional Chinese drug therapy.

    PubMed

    Borchardt, John K

    2003-12-01

    More than 4,000 years old, traditional Chinese medicine continues to be widely practiced in China and in western countries. Traditional Chinese medicine teaches that good health is the result of harmony and balance between five basic elements: earth, water, fire, wood and metal. Also important to health are the two types of energy Yin and Yang, constituting a vital substance that circulates through the body. Drug therapy has been one of the means used in Chinese medicine to keep these elements and the flow of energy in balance. Many of the same herbs used thousands of years ago in China could be the source of new pharmaceuticals in Western medicine. PMID:14747850

  2. On Chinese Culture Curriculum Planning

    ERIC Educational Resources Information Center

    Wang, Catherine

    2006-01-01

    The importance of cultural elements in foreign language teaching has been widely accepted in recent years. This applies particularly to the teaching of Chinese as a foreign language (TCFL) to non-native Chinese speakers at tertiary level in mainland China. However, there is no commonly accepted blueprint that defines the parts of Chinese culture…

  3. The Chinese in Children's Books.

    ERIC Educational Resources Information Center

    New York Public Library, NY.

    This is a selective annotated list of children's books about China and the Chinese. Topics range from dynasties, the era of Western influence, emigration, revolution, to present day affairs. Most of the books have a Chinese setting, but some are about the Chinese in America. Listings are made under categories such as picture books, stories for…

  4. Concepts of Chinese Folk Happiness

    ERIC Educational Resources Information Center

    Ip, Po Keung

    2011-01-01

    Discourses on Chinese folk happiness are often based on anecdotal narratives or qualitative analysis. Two traditional concepts of happiness popular in Chinese culture are introduced. The paper constructs a concept of Chinese folk happiness on basis of the findings of a scientific survey on the Taiwanese people regarding their concepts of…

  5. Ancient Chinese constellations

    NASA Astrophysics Data System (ADS)

    Xu, Junjun

    2011-06-01

    China, a country with a long history and a specific culture, has also a long and specific astronomy. Ancient Chinese astronomers observed the stars, named and distributed them into constellations in a very specific way, which is quite different from the current one. Around the Zodiac, stars are divided into four big regions corresponding with the four orientations, and each is related to a totem, either the Azure Dragon, the Vermilion Bird, the White Tiger or the Murky Warrior. We present a general pattern of the ancient Chinese constellations, including the four totems, their stars and their names.

  6. Distribution of Chinese names

    NASA Astrophysics Data System (ADS)

    Huang, Ding-wei

    2013-03-01

    We present a statistical model for the distribution of Chinese names. Both family names and given names are studied on the same basis. With naive expectation, the distribution of family names can be very different from that of given names. One is affected mostly by genealogy, while the other can be dominated by cultural effects. However, we find that both distributions can be well described by the same model. Various scaling behaviors can be understood as a result of stochastic processes. The exponents of different power-law distributions are controlled by a single parameter. We also comment on the significance of full-name repetition in Chinese population.

  7. Gravisensing in roots

    NASA Astrophysics Data System (ADS)

    Perbal, G.

    1999-01-01

    The mode of gravisensing in higher plants is not yet elucidated. Although, it is generally accepted that the amyloplasts (statoliths) in the root cap cells (statocytes) are responsible for susception of gravity. However, the hypothesis that the whole protoplast acts as gravisusceptor cannot be dismissed. The nature of the sensor that is able to transduce and amplify the mechanical energy into a biochemical factor is even more controversial. Several cell structures could potentially serve as gravireceptors: the endoplasmic reticulum, the actin network, the plasma membrane, or the cytoskeleton associated with this membrane. The nature of the gravisusceptors and gravisensors is discussed by taking into account the characteristics of the gravitropic reaction with respect to the presentation time, the threshold acceleration, the reciprocity rule, the deviation from the sine rule, the movement of the amyloplasts, the pre-inversion effect, the response of starch free and intermediate mutants and the effects of cytochalasin treatment. From this analysis, it can be concluded that both the amyloplasts and the protoplast could be the gravisusceptors, the former being more efficient than the latter since they can focus pressure on limited areas. The receptor should be located in the plasma membrane and could be a stretch-activated ion channel.

  8. Root development during soil genesis: effects of root-root interactions, mycorrhizae, and substrate

    NASA Astrophysics Data System (ADS)

    Salinas, A.; Zaharescu, D. G.

    2015-12-01

    A major driver of soil formation is the colonization and transformation of rock by plants and associated microbiota. In turn, substrate chemical composition can also influence the capacity for plant colonization and development. In order to better define these relationships, a mesocosm study was set up to analyze the effect mycorrhizal fungi, plant density and rock have on root development, and to determine the effect of root morphology on weathering and soil formation. We hypothesized that plant-plant and plant-fungi interactions have a stronger influence on root architecture and rock weathering than the substrate composition alone. Buffalo grass (Bouteloua dactyloides) was grown in a controlled environment in columns filled with either granular granite, schist, rhyolite or basalt. Each substrate was given two different treatments, including grass-microbes and grass-microbes-mycorrhizae and incubated for 120, 240, and 480 days. Columns were then extracted and analyzed for root morphology, fine fraction, and pore water major element content. Preliminary results showed that plants produced more biomass in rhyolite, followed by schist, basalt, and granite, indicating that substrate composition is an important driver of root development. In support of our hypothesis, mycorrhizae was a strong driver of root development by stimulating length growth, biomass production, and branching. However, average root length and branching also appeared to decrease in response to high plant density, though this trend was only present among roots with mycorrhizal fungi. Interestingly, fine fraction production was negatively correlated with average root thickness and volume. There is also slight evidence indicating that fine fraction production is more related to substrate composition than root morphology, though this data needs to be further analyzed. Our hope is that the results of this study can one day be applied to agricultural research in order to promote the production of crops

  9. Random root movements in weightlessness.

    PubMed

    Johnsson, A; Karlsson, C; Iversen, T H; Chapman, D K

    1996-02-01

    The dynamics of root growth was studied in weightlessness. In the absence of the gravitropic reference direction during weightlessness, root movements could be controlled by spontaneous growth processes, without any corrective growth induced by the gravitropic system. If truly random of nature, the bending behavior should follow so-called 'random walk' mathematics during weightlessness. Predictions from this hypothesis were critically tested. In a Spacelab ESA-experiment, denoted RANDOM and carried out during the IML-2 Shuttle flight in July 1994, the growth of garden cress (Lepidium sativum) roots was followed by time lapse photography at 1-h intervals. The growth pattern was recorded for about 20 h. Root growth was significantly smaller in weightlessness as compared to gravity (control) conditions. It was found that the roots performed spontaneous movements in weightlessness. The average direction of deviation of the plants consistently stayed equal to zero, despite these spontaneous movements. The average squared deviation increased linearly with time as predicted theoretically (but only for 8-10 h). Autocorrelation calculations showed that bendings of the roots, as determined from the 1-h photographs, were uncorrelated after about a 2-h interval. It is concluded that random processes play an important role in root growth. Predictions from a random walk hypothesis as to the growth dynamics could explain parts of the growth patterns recorded. This test of the hypothesis required microgravity conditions as provided for in a space experiment. PMID:11541141

  10. Nutritional regulation of root development.

    PubMed

    Ruiz Herrera, León Francisco; Shane, Michael W; López-Bucio, José

    2015-01-01

    Mineral nutrients such as nitrogen (N), phosphorus (P), and iron (Fe) are essential for plant growth, development, and reproduction. Adequate provision of nutrients via the root system impacts greatly on shoot biomass and plant productivity and is therefore of crucial importance for agriculture. Nutrients are taken up at the root surface in ionic form, which is mediated by specific transport proteins. Noteworthy, root tips are able to sense the local and internal concentrations of nutrients to adjust growth and developmental processes, and ultimately, to increase or decrease the exploratory capacity of the root system. Recently, important progress has been achieved in identifying the mechanisms of nutrient sensing in wild- and cultivated species, including Arabidopsis, bean, maize, rice, lupin as well as in members of the Proteaceae and Cyperaceae families, which develop highly sophisticated root clusters as adaptations to survive in soils with very low fertility. Major findings include identification of transporter proteins and transcription factors regulating nutrient sensing, miRNAs as mobile signals and peptides as repressors of lateral root development under heterogeneous nutrient supply. Understanding the roles played by N, P, and Fe in gene expression and biochemical characterization of proteins involved in root developmental responses to homogeneous or heterogeneous N and P sources has gained additional interest due to its potential for improving fertilizer acquisition efficiency in crops. PMID:25760021

  11. Being Chinese or Being Different: Chinese Undergraduates' Use of Discourses of Chineseness

    ERIC Educational Resources Information Center

    Skyrme, Gillian

    2014-01-01

    Myths about "the Chinese learner" developed from an outsider perspective abound in the Western world. The focus of this article, however, is how discourses of Chineseness were used by the Chinese international students themselves who, as undergraduate students in a New Zealand university, were the subjects of my doctoral research. It…

  12. Hypocotyl adventitious root organogenesis differs from lateral root development

    PubMed Central

    Verstraeten, Inge; Schotte, Sébastien; Geelen, Danny

    2014-01-01

    Wound-induced adventitious root (AR) formation is a requirement for plant survival upon root damage inflicted by pathogen attack, but also during the regeneration of plant stem cuttings for clonal propagation of elite plant varieties. Yet, adventitious rooting also takes place without wounding. This happens for example in etiolated Arabidopsis thaliana hypocotyls, in which AR initiate upon de-etiolation or in tomato seedlings, in which AR initiate upon flooding or high water availability. In the hypocotyl AR originate from a cell layer reminiscent to the pericycle in the primary root (PR) and the initiated AR share histological and developmental characteristics with lateral roots (LRs). In contrast to the PR however, the hypocotyl is a determinate structure with an established final number of cells. This points to differences between the induction of hypocotyl AR and LR on the PR, as the latter grows indeterminately. The induction of AR on the hypocotyl takes place in environmental conditions that differ from those that control LR formation. Hence, AR formation depends on differentially regulated gene products. Similarly to AR induction in stem cuttings, the capacity to induce hypocotyl AR is genotype-dependent and the plant growth regulator auxin is a key regulator controlling the rooting response. The hormones cytokinins, ethylene, jasmonic acid, and strigolactones in general reduce the root-inducing capacity. The involvement of this many regulators indicates that a tight control and fine-tuning of the initiation and emergence of AR exists. Recently, several genetic factors, specific to hypocotyl adventitious rooting in A. thaliana, have been uncovered. These factors reveal a dedicated signaling network that drives AR formation in the Arabidopsis hypocotyl. Here we provide an overview of the environmental and genetic factors controlling hypocotyl-born AR and we summarize how AR formation and the regulating factors of this organogenesis are distinct from LR

  13. IAA transport in corn roots includes the root cap

    SciTech Connect

    Hasenstein, K.H. )

    1989-04-01

    In earlier reports we concluded that auxin is the growth regulator that controls gravicurvature in roots and that the redistribution of auxin occurs within the root cap. Since other reports did not detect auxin in the root cap, we attempted to confirm the IAA does move through the cap. Agar blocks containing {sup 3}H-IAA were applied to the cut surface of 5 mm long apical segments of primary roots of corn (mo17xB73). After 30 to 120 min radioactivity (RA) of the cap and root tissue was determined. While segments suspended in water-saturated air accumulated very little RA in the cap, application of 0.5 {mu}1 of dist. water to the cap (=controls) increased RA of the cap dramatically. Application to the cap of 0.5 {mu}1 of sorbitol or the Ca{sup 2+} chelator EGTA reduced cap RA to 46% and 70% respectively compared to water, without affecting uptake. Control root segments gravireacted faster than non-treated or osmoticum or EGTA treated segments. The data indicate that both the degree of hydration and calcium control the amount of auxin moving through the cap.

  14. Towards a multidimensional root trait framework: a tree root review.

    PubMed

    Weemstra, Monique; Mommer, Liesje; Visser, Eric J W; van Ruijven, Jasper; Kuyper, Thomas W; Mohren, Godefridus M J; Sterck, Frank J

    2016-09-01

    Contents 1159 I. 1159 II. 1161 III. 1164 IV. 1166 1167 References 1167 SUMMARY: The search for a root economics spectrum (RES) has been sparked by recent interest in trait-based plant ecology. By analogy with the one-dimensional leaf economics spectrum (LES), fine-root traits are hypothesised to match leaf traits which are coordinated along one axis from resource acquisitive to conservative traits. However, our literature review and meta-level analysis reveal no consistent evidence of an RES mirroring an LES. Instead the RES appears to be multidimensional. We discuss three fundamental differences contributing to the discrepancy between these spectra. First, root traits are simultaneously constrained by various environmental drivers not necessarily related to resource uptake. Second, above- and belowground traits cannot be considered analogues, because they function differently and might not be related to resource uptake in a similar manner. Third, mycorrhizal interactions may offset selection for an RES. Understanding and explaining the belowground mechanisms and trade-offs that drive variation in root traits, resource acquisition and plant performance across species, thus requires a fundamentally different approach than applied aboveground. We therefore call for studies that can functionally incorporate the root traits involved in resource uptake, the complex soil environment and the various soil resource uptake mechanisms - particularly the mycorrhizal pathway - in a multidimensional root trait framework. PMID:27174359

  15. Chinese "Magic" Mirrors.

    ERIC Educational Resources Information Center

    Swinson, Derek B.

    1992-01-01

    Chinese "magic" mirrors are made from bronze with the front side a mirror and the reverse side a molded image. When light is reflected from the mirror,the image on the reverse side appears. Discusses reflections of conventional mirrors, possible explanations for the magic mirror phenomenon, and applications of the phenomenon to semiconductor…

  16. Chinese Festivals and Customs.

    ERIC Educational Resources Information Center

    Green, Sandra Aili

    Traditional festivals and customs of the Chinese people are described in this publication which can be used with secondary level students. In the margins of the text are numbers which indicate slides and cultural objects that relate to the text. The text, however, can be used without the slides and objects. The following festivals are described:…

  17. The Imperative in Chinese.

    ERIC Educational Resources Information Center

    Hashimoto, Anne Yue

    A preliminary study of the syntactic characteristics of the imperative construction in modern Chinese is presented. The term "imperative" is used to refer to the type of syntactic construction which is marked by an implicit or explicit second person subject, and which expresses a direct command. Indirect or implied commands expressed by a…

  18. Chinese New Year Dragons.

    ERIC Educational Resources Information Center

    Balgemann, Linda

    2000-01-01

    Presents an art project, used in a culturally diverse curriculum, in which second grade students create Chinese New Year dragons. Describes the process of creating the dragons, from the two-week construction of the head to the accordion-folded bodies. (CMK)

  19. Cataloging Pirated Chinese Books

    ERIC Educational Resources Information Center

    Wang, Sze-Tseng

    1971-01-01

    Various types of pirated Chinese books are given with specific examples. The basic steps followed for the proper identification of these books is described, and remedies suggested in case the original is discovered after the book has been cataloged according to the information given by the book pirate. (13 references) (Author/NH)

  20. Root hairs improve root penetration, root-soil contact, and phosphorus acquisition in soils of different strength.

    PubMed

    Haling, Rebecca E; Brown, Lawrie K; Bengough, A Glyn; Young, Iain M; Hallett, Paul D; White, Philip J; George, Timothy S

    2013-09-01

    Root hairs are a key trait for improving the acquisition of phosphorus (P) by plants. However, it is not known whether root hairs provide significant advantage for plant growth under combined soil stresses, particularly under conditions that are known to restrict root hair initiation or elongation (e.g. compacted or high-strength soils). To investigate this, the root growth and P uptake of root hair genotypes of barley, Hordeum vulgare L. (i.e. genotypes with and without root hairs), were assessed under combinations of P deficiency and high soil strength. Genotypes with root hairs were found to have an advantage for root penetration into high-strength layers relative to root hairless genotypes. In P-deficient soils, despite a 20% reduction in root hair length under high-strength conditions, genotypes with root hairs were also found to have an advantage for P uptake. However, in fertilized soils, root hairs conferred an advantage for P uptake in low-strength soil but not in high-strength soil. Improved root-soil contact, coupled with an increased supply of P to the root, may decrease the value of root hairs for P acquisition in high-strength, high-P soils. Nevertheless, this work demonstrates that root hairs are a valuable trait for plant growth and nutrient acquisition under combined soil stresses. Selecting plants with superior root hair traits is important for improving P uptake efficiency and hence the sustainability of agricultural systems. PMID:23861547

  1. Power and Roots by Recursion.

    ERIC Educational Resources Information Center

    Aieta, Joseph F.

    1987-01-01

    This article illustrates how questions from elementary finance can serve as motivation for studying high order powers, roots, and exponential functions using Logo procedures. A second discussion addresses a relatively unknown algorithm for the trigonometric exponential and hyperbolic functions. (PK)

  2. Ultrasonic cleaning of root canals

    NASA Astrophysics Data System (ADS)

    Verhaagen, Bram; Boutsioukis, Christos; Jiang, Lei-Meng; Macedo, Ricardo; van der Sluis, Luc; Versluis, Michel

    2011-11-01

    A crucial step during a dental root canal treatment is irrigation, where an antimicrobial fluid is injected into the root canal system to eradicate all bacteria. Agitation of the fluid using an ultrasonically vibrating miniature file has shown significant improvement in cleaning efficacy over conventional syringe irrigation. However, the physical mechanisms underlying the cleaning process, being acoustic streaming, cavitation or chemical activity, and combinations thereof, are not fully understood. High-speed imaging allows us to visualize the flow pattern and cavitation in a root canal model at microscopic scales, at timescales relevant to the cleaning processes (microseconds). MicroPIV measurements of the induced acoustic streaming are coupled to the oscillation characteristics of the file as simulated numerically and measured with a laser vibrometer. The results give new insight into the role of acoustic streaming and the importance of the confinement for the cleaning of root canals.

  3. Root Patterns in Heterogeneous Soils

    NASA Astrophysics Data System (ADS)

    Dara, A.; Moradi, A. B.; Carminati, A.; Oswald, S. E.

    2010-12-01

    Heterogeneous water availability is a typical characteristic of soils in which plant roots grow. Despite the intrinsic heterogeneity of soil-plant water relations, we know little about the ways how plants respond to local environmental quality. Furthermore, increasing use of soil amendments as partial water reservoirs in agriculture calls for a better understanding of plant response to soil heterogeneity. Neutron radiography is a non-invasive imaging that is highly sensitive to water and root distribution and that has high capability for monitoring spatial and temporal soil-plant water relations in heterogeneous systems. Maize plants were grown in 25 x 30 x 1 cm aluminum slabs filled with sandy soil. On the right side of the compartments a commercial water absorbent (Geohumus) was mixed with the soil. Geohumus was distributed with two patterns: mixed homogeneously with the soil, and arranged as 1-cm diameter aggregates (Fig. 1). Two irrigation treatments were applied: sufficient water irrigation and moderate water stress. Neutron radiography started 10 days after planting and has been performed twice a day for one week. At the end of the experiment, the containers were opened, the root were removed and dry root weight in different soil segments were measured. Neutron radiography showed root growth tendency towards Geohumus treated parts and preferential water uptake from Geohumus aggregates. Number and length of fine lateral roots were lower in treated areas compared to the non-treated zone and to control soil. Although corn plants showed an overall high proliferation towards the soil water sources, they decreased production of branches and fine root when water was more available near the main root parts. However there was 50% higher C allocation in roots grown in Geohumus compartments, as derived by the relative dry weight of root. The preferential C allocation in treated regions was higher when plants grew under water stress. We conclude that in addition to the

  4. Root Caries in Older Adults.

    PubMed

    Gregory, Dick; Hyde, Susan

    2015-08-01

    Older adults are retaining an increasing number of natural teeth, and nearly half of all individuals aged 75 and older have experienced root caries. Root caries is a major cause of tooth loss in older adults, and tooth loss is the most significant negative impact on oral health-related quality of life for the elderly. The need for improved preventive efforts and treatment strategies for this population is acute. PMID:26357814

  5. Hong Kong homeopathy: how it arrived and how it connected with Chinese medicine.

    PubMed

    Fan, Ka-wai

    2010-07-01

    Translated as 'Shunshi Liaofa' in Mandarin, homeopathy received considerable attention from local physicians, thanks to Dr Heribert Schmidt who shared his views on the similarities between this western medical therapy and Chinese medicine during his visit to Hong Kong in 1954. Considered widely as non-scientific and superstitious, Chinese medicine was pushed to the periphery during the 1950s. On the contrary, adopted by western advanced countries, homeopathy was generally regarded as scientific and reliable. Schmidt's acknowledgement of the scientific roots of Chinese medicine excited many traditional therapists. The purpose of this paper is to trace the history of how homeopathy was introduced to Hong Kong and discuss its relationship with scientification of Chinese medicine. PMID:20674846

  6. Effect of parameter choice in root water uptake models - the arrangement of root hydraulic properties within the root architecture affects dynamics and efficiency of root water uptake

    NASA Astrophysics Data System (ADS)

    Bechmann, M.; Schneider, C.; Carminati, A.; Vetterlein, D.; Attinger, S.; Hildebrandt, A.

    2014-10-01

    Detailed three-dimensional models of root water uptake have become increasingly popular for investigating the process of root water uptake. However, they suffer from a lack of information on important parameters, particularly on the spatial distribution of root axial and radial conductivities, which vary greatly along a root system. In this paper we explore how the arrangement of those root hydraulic properties and branching within the root system affects modelled uptake dynamics, xylem water potential and the efficiency of root water uptake. We first apply a simple model to illustrate the mechanisms at the scale of single roots. By using two efficiency indices based on (i) the collar xylem potential ("effort") and (ii) the integral amount of unstressed root water uptake ("water yield"), we show that an optimal root length emerges, depending on the ratio between roots axial and radial conductivity. Young roots with high capacity for radial uptake are only efficient when they are short. Branching, in combination with mature transport roots, enables soil exploration and substantially increases active young root length at low collar potentials. Second, we investigate how this shapes uptake dynamics at the plant scale using a comprehensive three-dimensional root water uptake model. Plant-scale dynamics, such as the average uptake depth of entire root systems, were only minimally influenced by the hydraulic parameterization. However, other factors such as hydraulic redistribution, collar potential, internal redistribution patterns and instantaneous uptake depth depended strongly on the arrangement on the arrangement of root hydraulic properties. Root systems were most efficient when assembled of different root types, allowing for separation of root function in uptake (numerous short apical young roots) and transport (longer mature roots). Modelling results became similar when this heterogeneity was accounted for to some degree (i.e. if the root systems contained between

  7. Electrohydrodynamic (EHD) drying of the Chinese wolfberry fruits.

    PubMed

    Yang, Maosheng; Ding, Changjiang

    2016-01-01

    The conventional methods of drying Chinese wolfberry fruits cause loss of active ingredients and the drying time is very long. In order to explore and investigate the new method of drying Chinese wolfberry fruits, electrohydrodynamic (EHD) drying system was used to drying for Chinese wolfberry fruits with a multiple needle-to-plate electrode on five levels alternating voltage at 0, 20, 24, 28 and 32 kV and a multiple needle-to-plate electrode on a level direct voltage at 28 kV. The drying rate, the moisture rate, shrinkage rate, rehydration ratio, and Vitamin C contents of Chinese wolfberry were measured. Ten different mathematical drying models were also determined and compared to simulate drying curves based on the root mean square error, reduced mean square of the deviation and the coefficient of correlation. Each drying treatment was carried out at (25 ± 2) °C, the drying relative humidity was (30 ± 5) % and all samples were dehydrated until they reached the final moisture content (17 ± 1)/100 g. The results showed that the drying rate of Chinese wolfberry was notably greater in the EHD system when compared to control, and improved by 1.8777, 2.0017, 2.3676 and 2.6608 times, respectively, at 20, 24, 28 and 32 kV, compared to that of the control in the 5 h. The drying rate with multiple needles-to-plate electrode under AC electric field is faster than that with a multiple needle-to-plate electrode under DC electric field and the mass transfer enhancement factor heightened with the increase of voltage. The EHD drying treatments have a significant effect on rehydration ratio, and Vitamin C contents of Chinese wolfberry, but no significant differences was observed in shrinkage rate of Chinese wolfberry. The specific energy consumption of EHD drying (kJ·kg(-1) water) were significantly influenced by the alternating voltage, it heightened with the increase of voltage. The Parabolic model was best suited for describing the drying rate curve of

  8. Plant root-microbe communication in shaping root microbiomes.

    PubMed

    Lareen, Andrew; Burton, Frances; Schäfer, Patrick

    2016-04-01

    A growing body of research is highlighting the impacts root-associated microbial communities can have on plant health and development. These impacts can include changes in yield quantity and quality, timing of key developmental stages and tolerance of biotic and abiotic stresses. With such a range of effects it is clear that understanding the factors that contribute to a plant-beneficial root microbiome may prove advantageous. Increasing demands for food by a growing human population increases the importance and urgency of understanding how microbiomes may be exploited to increase crop yields and reduce losses caused by disease. In addition, climate change effects may require novel approaches to overcoming abiotic stresses such as drought and salinity as well as new emerging diseases. This review discusses current knowledge on the formation and maintenance of root-associated microbial communities and plant-microbe interactions with a particular emphasis on the effect of microbe-microbe interactions on the shape of microbial communities at the root surface. Further, we discuss the potential for root microbiome modification to benefit agriculture and food production. PMID:26729479

  9. Root anatomical phenes predict root penetration ability and biomechanical properties in maize (Zea Mays)

    PubMed Central

    Chimungu, Joseph G.; Loades, Kenneth W.; Lynch, Jonathan P.

    2015-01-01

    The ability of roots to penetrate hard soil is important for crop productivity but specific root phenes contributing to this ability are poorly understood. Root penetrability and biomechanical properties are likely to vary in the root system dependent on anatomical structure. No information is available to date on the influence of root anatomical phenes on root penetrability and biomechanics. Root penetration ability was evaluated using a wax layer system. Root tensile and bending strength were evaluated in plant roots grown in the greenhouse and in the field. Root anatomical phenes were found to be better predictors of root penetrability than root diameter per se and associated with smaller distal cortical region cell size. Smaller outer cortical region cells play an important role in stabilizing the root against ovalization and reducing the risk of local buckling and collapse during penetration, thereby increasing root penetration of hard layers. The use of stele diameter was found to be a better predictor of root tensile strength than root diameter. Cortical thickness, cortical cell count, cortical cell wall area and distal cortical cell size were stronger predictors of root bend strength than root diameter. Our results indicate that root anatomical phenes are important predictors for root penetrability of high-strength layers and root biomechanical properties. PMID:25903914

  10. How Can Science Education Foster Students' Rooting?

    ERIC Educational Resources Information Center

    Østergaard, Edvin

    2015-01-01

    The question of how to foster rooting in science education points towards a double challenge; efforts to "prevent" (further) uprooting and efforts to "promote" rooting/re-rooting. Wolff-Michael Roth's paper discusses the uprooting/rooting pair of concepts, students' feeling of alienation and loss of fundamental sense of the…

  11. MES Buffer Affects Arabidopsis Root Apex Zonation and Root Growth by Suppressing Superoxide Generation in Root Apex

    PubMed Central

    Kagenishi, Tomoko; Yokawa, Ken; Baluška, František

    2016-01-01

    In plants, growth of roots and root hairs is regulated by the fine cellular control of pH and reactive oxygen species (ROS). MES, 2-(N-morpholino)ethanesulfonic acid as one of the Good’s buffers has broadly been used for buffering medium, and it is thought to suit for plant growth with the concentration at 0.1% (w/v) because the buffer capacity of MES ranging pH 5.5–7.0 (for Arabidopsis, pH 5.8). However, many reports have shown that, in nature, roots require different pH values on the surface of specific root apex zones, namely meristem, transition zone, and elongation zone. Despite the fact that roots always grow on a media containing buffer molecule, little is known about impact of MES on root growth. Here, we have checked the effects of different concentrations of MES buffer using growing roots of Arabidopsis thaliana. Our results show that 1% of MES significantly inhibited root growth, the number of root hairs and length of meristem, whereas 0.1% promoted root growth and root apex area (region spanning from the root tip up to the transition zone). Furthermore, superoxide generation in root apex disappeared at 1% of MES. These results suggest that MES disturbs normal root morphogenesis by changing the ROS homeostasis in root apex. PMID:26925066

  12. MES Buffer Affects Arabidopsis Root Apex Zonation and Root Growth by Suppressing Superoxide Generation in Root Apex.

    PubMed

    Kagenishi, Tomoko; Yokawa, Ken; Baluška, František

    2016-01-01

    In plants, growth of roots and root hairs is regulated by the fine cellular control of pH and reactive oxygen species (ROS). MES, 2-(N-morpholino)ethanesulfonic acid as one of the Good's buffers has broadly been used for buffering medium, and it is thought to suit for plant growth with the concentration at 0.1% (w/v) because the buffer capacity of MES ranging pH 5.5-7.0 (for Arabidopsis, pH 5.8). However, many reports have shown that, in nature, roots require different pH values on the surface of specific root apex zones, namely meristem, transition zone, and elongation zone. Despite the fact that roots always grow on a media containing buffer molecule, little is known about impact of MES on root growth. Here, we have checked the effects of different concentrations of MES buffer using growing roots of Arabidopsis thaliana. Our results show that 1% of MES significantly inhibited root growth, the number of root hairs and length of meristem, whereas 0.1% promoted root growth and root apex area (region spanning from the root tip up to the transition zone). Furthermore, superoxide generation in root apex disappeared at 1% of MES. These results suggest that MES disturbs normal root morphogenesis by changing the ROS homeostasis in root apex. PMID:26925066

  13. Chinese Experiences on Orthokeratology.

    PubMed

    Xie, Peiying; Guo, Xi

    2016-01-01

    The prevalence of myopia in Chinese children has been rising each year. Research has shown that orthokeratology is a good method for controlling the progression of myopia. In this article, we review the current prevalence of myopia, the development and management of orthokeratology, and the myopia control methods used in China. A physical and health survey release indicated that the ratio of poor vision in every range of ages is still high in China. During the past 17 years, Chinese doctors have developed a standard fitting procedure and medical management of orthokeratology patients. This article also reviews the clinical studies in China for Ortho-K lenses, such as myopia control, effects and safety, corneal change, and lens design and fitting. Finally, we review the development of the International Academy of Orthokeratology Asia in China. PMID:26704137

  14. Chinese Spacesuit Analysis

    NASA Technical Reports Server (NTRS)

    Croog, Lewis

    2010-01-01

    In 2008, China became only the 3rd nation to perform an Extravehicular Activity (EVA) from a spacecraft. An overview of the Chinese spacesuit and life support system were assessed from video downlinks during their EVA; from those assessments, spacesuit characteristics were identified. The spacesuits were compared against the Russian Orlan Spacesuit and the U.S. Extravehicular Mobility Unit (EMU). China's plans for future missions also were presented.

  15. Chinese biobanking initiatives.

    PubMed

    Gan, Rongxing; Wang, Huiyuan; Song, Yutong; Fan, Jinli; Xiong, Yan

    2015-02-01

    Due to the requirement for comprehensive clinical research efforts in China, the importance of biobanking in modern clinical research is outlined in this overview. Hospitals, universities, and research institutes have been well organized as fundamental resources for Chinese biobanking initiatives and the resulting bio-sample collections. Here, a brief history and time line of development of biobanking in China will be introduced, as well as strategic designs for future biobanking development. PMID:25686040

  16. Transmitting Chinese Medicine

    PubMed Central

    Scheid, Volker

    2015-01-01

    Historians of Chinese medicine acknowledge the plurality of Chinese medicine along both synchronic and diachronic dimensions. Yet, there remains a tendency to think of tradition as being defined by some unchanging features. The Chinese medical body is a case in point. This is assumed to have been formalised by the late Han dynasty around a system of internal organs, conduits, collaterals, and associated body structures. Although criticism was voiced from time to time, this body and the micro/macrocosmic cosmological resonances that underpin it are seen to persist until the present day. I challenge this view by attending to attempts by physicians in China and Japan in the period from the mid 16th to the late 18th century to reimagine this body. Working within the domain of cold damage therapeutics and combining philological scholarship, empirical observations, and new hermeneutic strategies these physicians worked their way towards a new territorial understanding of the body and of medicine as warfare that required an intimate familiarity with the body’s topography. In late imperial China this new view of the body and medicine was gradually re-absorbed into the mainstream. In Japan, however, it led to a break with this orthodoxy that in the Republican era became influential in China once more. I argue that attending further to the innovations of this period from a transnational perspective - commonly portrayed as one of decline - may help to go beyond the modern insistence to frame East Asian medicines as traditional. PMID:26869864

  17. How life is associated with colors in Chinese culture: utilizing colors based on Chinese five-essence theory

    NASA Astrophysics Data System (ADS)

    Lee, Tien-Rein

    2002-06-01

    Chinese believe that Feng-shui, Ch'i, Tao, Yin and Yang are major components rooted in Chinese culture. Many people know life has to balance and harmonize with nature and the universe through the Five-essence. Ancient wisdom is successfully interwoven with mankind and the natural world. Elements such as orientation, season, color, sound, facial organs, viscera, stars, and numbers can be associated with life through the Five-essence Theory. Since color is one of the major components of the Five-essence Theory, everything in our life can be associated with colors through a conjoined covering process. Color selection process is part of the interaction between human beings and the universe. Depending on the achievement one is pursuing, the Five- essence Theory model can be treated as an interface between destiny and human beings. This study reports how life is associated with Chinese Five-essence based paradigms. Models were used to explain how Chinese utilize Five-essence Theory to select colors in their daily lives.

  18. Root traits for infertile soils

    PubMed Central

    White, Philip J.; George, Timothy S.; Dupuy, Lionel X.; Karley, Alison J.; Valentine, Tracy A.; Wiesel, Lea; Wishart, Jane

    2013-01-01

    Crop production is often restricted by the availability of essential mineral elements. For example, the availability of N, P, K, and S limits low-input agriculture, the phytoavailability of Fe, Zn, and Cu limits crop production on alkaline and calcareous soils, and P, Mo, Mg, Ca, and K deficiencies, together with proton, Al and Mn toxicities, limit crop production on acid soils. Since essential mineral elements are acquired by the root system, the development of crop genotypes with root traits increasing their acquisition should increase yields on infertile soils. This paper examines root traits likely to improve the acquisition of these elements and observes that, although the efficient acquisition of a particular element requires a specific set of root traits, suites of traits can be identified that benefit the acquisition of a group of mineral elements. Elements can be divided into three Groups based on common trait requirements. Group 1 comprises N, S, K, B, and P. Group 2 comprises Fe, Zn, Cu, Mn, and Ni. Group 3 contains mineral elements that rarely affect crop production. It is argued that breeding for a limited number of distinct root ideotypes, addressing particular combinations of mineral imbalances, should be pursued. PMID:23781228

  19. Electrotropism of Maize Roots 1

    PubMed Central

    Ishikawa, Hideo; Evans, Michael L.

    1990-01-01

    We examined the kinetics of electrotropic curvature in solutions of low electrolyte concentration using primary roots of maize (Zea mays L., variety Merit). When submerged in oxygenated solution across which an electric field was applied, the roots curved rapidly and strongly toward the positive electrode (anode). The strength of the electrotropic response increased and the latent period decreased with increasing field strength. At a field strength of 7.5 volts per centimeter the latent period was 6.6 minutes and curvature reached 60 degrees in about 1 hour. For electric fields greater than 10 volts per centimeter the latent period was less than 1 minute. There was no response to electric fields less than 2.8 volts per centimeter. Both electrotropism and growth were inhibited when indoleacetic acid (10 micromolar) was included in the medium. The auxin transport inhibitor pyrenoylbenzoic acid strongly inhibited electrotropism without inhibiting growth. Electrotropism was enhanced by treatments that interfere with gravitropism, e.g. decapping the roots or pretreating them with ethyleneglycol-bis-[β-ethylether]-N,N,N′,N′-tetraacetic acid. Similarly, roots of agravitropic pea (Pisum sativum, variety Ageotropum) seedlings were more responsive to electrotropic stimulation than roots of normal (variety Alaska) seedlings. The data indicate that the early steps of gravitropism and electrotropism occur by independent mechanisms. However, the motor mechanisms of the two responses may have features in common since auxin and auxin transport inhibitors reduced both gravitropism and electrotropism. PMID:11537481

  20. Magnetophoretic Induction of Root Curvature

    NASA Technical Reports Server (NTRS)

    Hasenstein, Karl H.

    1997-01-01

    The last year of the grant period concerned the consolidation of previous experiments to ascertain that the theoretical premise apply not just to root but also to shoots. In addition, we verified that high gradient magnetic fields do not interfere with regular cellular activities. Previous results have established that: (1) intracellular magnetophoresis is possible; and (2) HGMF lead to root curvature. In order to investigate whether HGMF affect the assembly and/or organization of structural proteins, we examined the arrangement of microtubules in roots exposed to HGMF. The cytoskeletal investigations were performed with fomaldehyde-fixed, nonembedded tissue segments that were cut with a vibratome. Microtubules (MTs) were stained with rat anti-yeast tubulin (YOL 1/34) and DTAF-labeled antibody against rat IgG. Microfilaments (MFs) were visualized by incubation in rhodamine-labeled phalloidin. The distribution and arrangement of both components of the cytoskeleton were examined with a confocal microscope. Measurements of growth rates and graviresponse were done using a video-digitizer. Since HGMF repel diamagnetic substances including starch-filled amyloplasts and most The second aspect of the work includes studies of the effect of cytoskeletal inhibitors on MTs and MFs. The analysis of the effect of micotubular inhibitors on the auxin transport in roots showed that there is very little effect of MT-depolymerizing or stabilizing drugs on auxin transport. This is in line with observations that application of such drugs is not immediately affecting the graviresponsiveness of roots.

  1. Cadmium re-distribution from pod and root zones and accumulation by peanut (Arachis hypogaea L.).

    PubMed

    Wang, Kairong; Song, Ningning; Zhao, Qiaoqiao; van der Zee, S E A T M

    2016-01-01

    Peanut (Arachis hypogaea L.) genotypes may differ greatly with regard to cadmium (Cd) accumulation, but the underlying mechanisms remain unclear. To determine the key factors that may contribute to Cd re-distribution and accumulation in peanut genotypes with different Cd accumulating patterns, a split-pot soil experiment was conducted with three common Chinese peanut cultivars (Fenghua-6, Huayu-20, and Huayu-23). The growth medium was separated into pod and root zones with varied Cd concentrations in each zone to determine the re-distribution of Cd after it is taken up via different routes. The peanut cultivars were divided into two groups based on Cd translocation efficiency as follows: (1) high internal Cd translocation efficiency cultivar (Fenghua-6) and (2) low internal Cd translocation efficiency cultivars (Huayu-20 and Huayu-23). Compared with Fenghua-6, low Cd translocation cultivars Huayu-20 and Huayu-23 showed higher biomass production, especially in stems and leaves, leading to dilution of metal concentrations. Results also showed that Cd concentration in roots increased significantly with increasing Cd concentrations in soils when Cd was applied in the root zone. However, there were no significant differences in the root Cd concentrations between different pod zone Cd treatments and the control, suggesting that root uptake, rather than pod uptake, is responsible for Cd accumulation in the roots of peanuts. Significant differences of Cd distribution were observed between pod and root zone Cd exposure treatments. The three peanut cultivars revealed higher kernel over total Cd fractions for pod than for root zone Cd exposure if only extra applied Cd was considered. This suggests that uptake through peg and pod shell might, at least partially, be responsible for the variation in Cd re-distribution and accumulation among peanut cultivars. Cd uptake by plants via two routes (i.e., via roots and via pegs and pods, respectively) and internal Cd translocation

  2. Descendant root volume varies as a function of root type: estimation of root biomass lost during uprooting in Pinus pinaster

    PubMed Central

    Danjon, Frédéric; Caplan, Joshua S.; Fortin, Mathieu; Meredieu, Céline

    2013-01-01

    Root systems of woody plants generally display a strong relationship between the cross-sectional area or cross-sectional diameter (CSD) of a root and the dry weight of biomass (DWd) or root volume (Vd) that has grown (i.e., is descendent) from a point. Specification of this relationship allows one to quantify root architectural patterns and estimate the amount of material lost when root systems are extracted from the soil. However, specifications of this relationship generally do not account for the fact that root systems are comprised of multiple types of roots. We assessed whether the relationship between CSD and Vd varies as a function of root type. Additionally, we sought to identify a more accurate and time-efficient method for estimating missing root volume than is currently available. We used a database that described the 3D root architecture of Pinus pinaster root systems (5, 12, or 19 years) from a stand in southwest France. We determined the relationship between CSD and Vd for 10,000 root segments from intact root branches. Models were specified that did and did not account for root type. The relationships were then applied to the diameters of 11,000 broken root ends to estimate the volume of missing roots. CSD was nearly linearly related to the square root of Vd, but the slope of the curve varied greatly as a function of root type. Sinkers and deep roots tapered rapidly, as they were limited by available soil depth. Distal shallow roots tapered gradually, as they were less limited spatially. We estimated that younger trees lost an average of 17% of root volume when excavated, while older trees lost 4%. Missing volumes were smallest in the central parts of root systems and largest in distal shallow roots. The slopes of the curves for each root type are synthetic parameters that account for differentiation due to genetics, soil properties, or mechanical stimuli. Accounting for this differentiation is critical to estimating root loss accurately. PMID

  3. Efficient hydraulic properties of root systems

    NASA Astrophysics Data System (ADS)

    Bechmann, Marcel; Schneider, Christoph; Carminati, Andrea; Hildebrandt, Anke

    2013-04-01

    Understanding the mechanisms of ecosystem root water uptake (RWU) is paramount for parameterizing hydrological models. With the increase in computational power it is possible to calculate RWU explicitly up to the single plant scale using physical models. However, application of these models for increasing our understanding of ecosystem root water uptake is hindered by the deficit in knowledge about the detailed hydraulic parameter distribution within root systems. However, those physical models may help us to identify efficient parameterizations and to describe the influence of these hydraulic parameters on RWU profiles. In this research, we investigated the combined influence of root hydraulic parameters and different root topologies on shaping efficient root water uptake. First, we use a conceptual model of simple branching structures to understand the influence of branching location and transitions in root hydraulic properties on the RWU patterns in typical sub root structures. Second, we apply a physical model called "aRoot" to test our conclusions on complex root system architectures of single plants. aRoot calculates the distribution of xylem potential within arbitrary root geometries to satisfy a given water demand depending on the available water in the soil. Redistribution of water within the bulk soil is calculated using the Richards equation. We analyzed results using a measure of uptake efficiency, which describes the effort necessary for transpiration. Simulations with the conceptual model showed that total transpiration in sub root structures is independent of root hydraulic properties over a wide range of hydraulic parameters. On the other hand efficiency of root water uptake depends crucially on distribution hydraulic parameters in line with root topology. At the same time, these parameters shape strongly the distribution of RWU along the roots, and its evolution in time, thus leading to variable individual root water uptake profiles. Calculating

  4. Sensitivity of the "Root Bundle Model" to root mechanical properties and root distribution: Implication for shallow landslide stability.

    NASA Astrophysics Data System (ADS)

    Schwarz, Massimiliano; Giadrossich, Filippo; Cohen, Denis

    2015-04-01

    Root reinforcement is recognized as an important factor for shallow landslides stability. Due to the complexity of root reinforcement mechanisms and the heterogeneity of the root-soil system, the estimation of parameters used in root reinforcement models is difficult, time consuming, and often highly uncertain. For practical applications, it is necessary to focus on the estimation of the most relevant parameters. The objective of the present contribution is to review the state of the art in the development of root reinforcement models and to discuss the sensitivity of the "Root Bundle Model" (RBM) when considering the variability of root mechanical properties and the heterogeneity of root distributions. The RBM is a strain-step loading fiber bundle model extended to include the mechanical and geometrical properties of roots. The model allows the calculation of the force-displacement behavior of a root bundle. In view of new results of field pullout tests performed on coarse roots of spruce (Picea abies) and considering a consistent dataset of root distribution of alpine tree species, we quantify the sensitivity of the RBM and the uncertainty associated with the most important input parameters. Preliminary results show that the extrapolation of force-diameter values from incomplete datasets (i.e., when only small roots are tested and values for coarse roots are extrapolated) may result in considerable errors. In particular, in the case of distributions with root diameters larger than 5 mm, root reinforcement tends to be dominated by coarse roots and their mechanical properties need to be quantified. In addition to the results of the model sensitivity, we present a possible best-practice method for the quantification of root reinforcement in view of its application to slope stability calculations and implementations in numerical models.

  5. Root crops and their biomass potential in Florida

    SciTech Connect

    O'Hair, S.K.; Locascio, S.J.; Forbes, R.R.; White, J.M.; Hensel, D.R.; Shumaker, J.R.; Dangler, J.M.

    1983-01-01

    Root and tuber crops are of particular interest as biofuel crops because of their ability to concentrate and store fermentables including starch and sugars, in enlarged organs at or below the soil surface. In Florida, harvest index, the storage organ biomass divided by total plant biomass, of sweet potato, fodder beet, cassava and potato has approached 0.80. Chicory, fodder beet, cassava and sweet potato produced a total plant yield of 16.0, 14.1, 11.4 and 11.3 t/ha, respectively. Since the crops vary for time to maturity and storage organ chemical composition, a conventional unit to equate yield differences is kilocalorie (kcal) production/ha/day. Of the warm season crops, sweet potato and cassava roots produced an estimated 32 and 14 x 10/sup 4/ kcal/ha/day, respectively. Chinese radish and rutabaga roots produced 18 and 17 x 10/sup 4/ kcal/ha/day. Thus, a year round average of as much as 25 x 10/sup 4/ kcal/ha/day has been demonstrated. In conjunction with the total potential biomass production by a plant, root and tuber crops may be able to surpass grain crops in fermentable productivity on a temporal and spacial basis. The factors that will contribute to this include developing the appropriate cultural practices for biomass production along with breeding and selecting for adaptability and favorable harvest index. Since many of these crops have been neglected from a research standpoint, there is little doubt that improvements can be made by further work. 27 references.

  6. Chinese Songs We Can Sing and Chinese Instrumental Music.

    ERIC Educational Resources Information Center

    Hawaii Univ., Honolulu. Ethnic Resource Center for the Pacific.

    This booklet includes a number of Chinese songs (with English translations) designed for use with a tape recording produced by the Ethnic Resource Center for the Pacific, Educational Foundations, University of Hawaii. A pronunciation key and a listing of cassette recordings of Chinese instrumental music are provided. (EB)

  7. Root branching: mechanisms, robustness, and plasticity.

    PubMed

    Dastidar, Mouli Ghosh; Jouannet, Virginie; Maizel, Alexis

    2012-01-01

    Plants are sessile organisms that must efficiently exploit their habitat for water and nutrients. The degree of root branching impacts the efficiency of water uptake, acquisition of nutrients, and anchorage. The root system of plants is a dynamic structure whose architecture is determined by modulation of primary root growth and root branching. This plasticity relies on the continuous integration of environmental inputs and endogenous developmental programs controlling root branching. This review focuses on the cellular and molecular mechanisms involved in the regulation of lateral root distribution, initiation, and organogenesis with the main focus on the root system of Arabidopsis thaliana. We also examine the mechanisms linking environmental changes to the developmental pathways controlling root branching. Recent progress that emphasizes the parallels to the formation of root branches in other species is discussed. PMID:23801487

  8. New theories of root growth modelling

    NASA Astrophysics Data System (ADS)

    Landl, Magdalena; Schnepf, Andrea; Vanderborght, Jan; Huber, Katrin; Javaux, Mathieu; Bengough, A. Glyn; Vereecken, Harry

    2016-04-01

    In dynamic root architecture models, root growth is represented by moving root tips whose line trajectory results in the creation of new root segments. Typically, the direction of root growth is calculated as the vector sum of various direction-affecting components. However, in our simulations this did not reproduce experimental observations of root growth in structured soil. We therefore developed a new approach to predict the root growth direction. In this approach we distinguish between, firstly, driving forces for root growth, i.e. the force exerted by the root which points in the direction of the previous root segment and gravitropism, and, secondly, the soil mechanical resistance to root growth or penetration resistance. The latter can be anisotropic, i.e. depending on the direction of growth, which leads to a difference between the direction of the driving force and the direction of the root tip movement. Anisotropy of penetration resistance can be caused either by microscale differences in soil structure or by macroscale features, including macropores. Anisotropy at the microscale is neglected in our model. To allow for this, we include a normally distributed random deflection angle α to the force which points in the direction of the previous root segment with zero mean and a standard deviation σ. The standard deviation σ is scaled, so that the deflection from the original root tip location does not depend on the spatial resolution of the root system model. Similarly to the water flow equation, the direction of the root tip movement corresponds to the water flux vector while the driving forces are related to the water potential gradient. The analogue of the hydraulic conductivity tensor is the root penetrability tensor. It is determined by the inverse of soil penetration resistance and describes the ease with which a root can penetrate the soil. By adapting the three dimensional soil and root water uptake model R-SWMS (Javaux et al., 2008) in this way

  9. Analysis of carotenoid accumulation and expression of carotenoid biosynthesis genes in different organs of Chinese cabbage (Brassica rapa subsp. pekinensis)

    PubMed Central

    Tuan, Pham Anh; Kim, Jae Kwang; Lee, Jeongyeo; Park, Woo Tae; Kwon, Do Yeon; Kim, Yeon Bok; Kim, Haeng Hoon; Kim, Hye Ran; Park, Sang Un

    2012-01-01

    The relationship between carotenoid accumulation and expression of carotenoid biosynthesis genes was investigated in the flowers, stems, young leaves, old leaves, and roots of Chinese cabbage (Brassica rapa subsp. pekinensis). Quantitative real-time PCR analysis showed that the mRNA levels of BrPSY, BrPDS, BrZDS, BrLCYB, BrLCYE, BrCHXB, and BrZEP leading to the production of carotenoids were highest in the flowers or the leaves and lowest in the roots of Chinese cabbage. In contrast, the mRNA expression of BrNCED, a gene involved in abscisic acid (ABA) biosynthesis, was highest in the roots. High-performance liquid chromatography revealed that carotenoids, namely, lutein and β-carotene, were distributed predominantly in the flowers and leaves, with very little in the underground organ, the roots. Specifically, old leaves contained 120.3 μg/g lutein and 103.93 μg/g β-carotene, which is the most potent dietary precursor of vitamin A. Moreover, we found a relatively large amount of cis isomers of β-carotene, namely, 9-cis β-carotene and 13-cis β-carotene, in Chinese cabbage. These results provide insight into carotenoid biosynthetic mechanisms in Chinese cabbage and may be helpful in the metabolic engineering of carotenoid biosynthesis in plants.

  10. Root growth, secondary root formation and root gravitropism in carotenoid-deficient seedlings of Zea mays L

    NASA Technical Reports Server (NTRS)

    Ng, Y. K.; Moore, R.

    1985-01-01

    The effect of ABA on root growth, secondary-root formation and root gravitropism in seedlings of Zea mays was investigated by using Fluridone-treated seedlings and a viviparous mutant, both of which lack carotenoids and ABA. Primary roots of seedlings grown in the presence of Fluridone grew significantly slower than those of control (i.e. untreated) roots. Elongation of Fluridone-treated roots was inhibited significantly by the exogenous application of 1 mM ABA. Exogenous application of 1 micromole and 1 nmole ABA had either no effect or only a slight stimulatory effect on root elongation, depending on the method of application. The absence of ABA in Fluridone-treated plants was not an important factor in secondary-root formation in seedlings less than 9-10 d old. However, ABA may suppress secondary-root formation in older seedlings, since 11-d-old control seedlings had significantly fewer secondary roots than Fluridone-treated seedlings. Roots of Fluridone-treated and control seedlings were graviresponsive. Similar data were obtained for vp-9 mutants of Z. mays, which are phenotypically identical to Fluridone-treated seedlings. These results indicate that ABA is necessary for neither secondary-root formation nor for positive gravitropism by primary roots.

  11. Four cuspal maxillary second premolar with single root and three root canals: Case report

    PubMed Central

    Bansal, Parul; Nikhil, Vineeta; Goyal, Ayush; Singh, Ritu

    2016-01-01

    Traditional configuration of maxillary second premolars has been described to have two cusps, one root and one or two root canals. The endodontic literature reports considerable anatomic aberrations in the root canal morphology of maxillary second premolar but the literature available on the variation in cuspal anatomy and its relationship to the root canal anatomy is sparse. The purpose of this clinical report was to describe the root and root canal configuration of a maxillary second premolar with four cusps. PMID:27563190

  12. Four cuspal maxillary second premolar with single root and three root canals: Case report.

    PubMed

    Bansal, Parul; Nikhil, Vineeta; Goyal, Ayush; Singh, Ritu

    2016-01-01

    Traditional configuration of maxillary second premolars has been described to have two cusps, one root and one or two root canals. The endodontic literature reports considerable anatomic aberrations in the root canal morphology of maxillary second premolar but the literature available on the variation in cuspal anatomy and its relationship to the root canal anatomy is sparse. The purpose of this clinical report was to describe the root and root canal configuration of a maxillary second premolar with four cusps. PMID:27563190

  13. Brown Root Rot of Alfalfa

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This bulletin describes the disease of alfalfa called brown root rot (BRR) including: the disease symptoms, the fungal pathogen and its biology, its distribution, and disease management. Since the 1920s, BRR has been regarded as an important disease of forage legumes, including alfalfa, in northern ...

  14. Dry root rot of chickpea

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dry root rot of chickpea is a serious disease under dry hot summer conditions, particularly in the semi-arid tropics of Ethiopia, and in central and southern India. It usually occurs at reproductive stages of the plant. Symptoms include drooping of petioles and leaflets of the tips, but not the low...

  15. Rhizoctonia root rot of lentil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rhizoctonia root rot is a soilborne disease of lentil caused by the fungal pathogen Rhizoctonia solani, and is favored by cool (11-19 C or 52 - 66 F) and wet soil conditions. The disease starts as reddish or dark brown lesions on lentil plants near the soil line, and develops into sunken lesions an...

  16. [Root arthrosis of the thumb].

    PubMed

    Hautefeuille, P; Duquesnoy, B

    1991-12-15

    Root arthrosis of the thumb results from a degenerative lesion of the trapezometacarpal joint. It is particularly frequent in menopausal women. The often prolonged pain it produces sometimes raises therapeutic problems. Treatment is always medical at first, but when it fails several surgical operations will ensure permanent painlessness. PMID:1808686

  17. Disease notes - Bacterial root rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial root rot initiated by lactic acid bacteria, particularly Leuconostoc, occurs every year in Idaho sugarbeet fields. Hot fall weather seems to make the problem worse. Although Leuconostoc initiates the rot, other bacteria and yeast frequently invade the tissue as well. The acetic acid bac...

  18. Cutting the Roots of Violence.

    ERIC Educational Resources Information Center

    Koziey, Paul W.

    1996-01-01

    Violence is rooted in obedience to authority and in comparisons--foundations of our institutions of parenting and schooling. Obedience brings reward and punishment, comparison perpetuates a cycle of competition and conflict. Television violence is especially harmful because children easily understand visual images. The Reality Research approach to…

  19. Excising the Root from STEM

    ERIC Educational Resources Information Center

    Lock, Roger

    2009-01-01

    There are a number of well-intentioned STEM initiatives, some designed to improve the recruitment and retention of science teachers. Sometimes it appears that the initiators are remote from direct contact with the "grass roots" issues that feed the "stem" on which the blossoms of young enthusiastic recruits to the science teaching profession are…

  20. Internationalization of Chinese Higher Education

    ERIC Educational Resources Information Center

    Chen, Linhan; Huang, Danyan

    2013-01-01

    This paper probes into the development of internationalization of higher education in China from ancient times to modern times, including the emergence of international connections in Chinese higher education and the subsequent development of such connections, the further development of internationalization of Chinese higher education, and the…

  1. Contradictions in Chinese Language Reform.

    ERIC Educational Resources Information Center

    Cheng, Chin-Chuan

    The Draft of the Second Chinese Character Simplification Scheme proposed by the Chinese Committee on Language Reform, published in 1977, is discussed. The political history of the draft and current uncertainty about character simplification are examined, and a rigorous methodology for determining the success rate of a script reform is proposed.…

  2. Retroflex Endings in Ancient Chinese

    ERIC Educational Resources Information Center

    Hashimoto, Mantaro J.

    1973-01-01

    Reconstruction of Ancient Chinese retroflex endings (syllable-final consonants) based on internal phonological evidence in Modern Chinese. Paper read at the December 1972 meeting of the Kukeo Hakhoe (The National Language Association of Korea); research supported by the Social Science Research Council, Committee for Korean Studies. (RS)

  3. Nominal Modifiers in Mandarin Chinese.

    ERIC Educational Resources Information Center

    Hou, John Y.

    In the surface structure of Chinese nominal modifiers (quantifiers, determiners, adjectives, measure phrase, relative clause, etc.) may occur either before or after a modified noun. In most of the transformational studies of Chinese syntax (e.g. Cheng 1966; Hashimoto 1966; Mei 1972; Tai 1973; Teng 1974), it has been assumed that such NP's have the…

  4. A Chinese Zodiac Mathematical Structure.

    ERIC Educational Resources Information Center

    Lamb, John F., Jr.

    2000-01-01

    Helps students identify the animal that corresponds to the year of their birth according to the Chinese zodiac. Defines the structure of the Chinese zodiac so that the subsets of compatibles and opposites form closed substructures with interesting mathematical properties. (ASK)

  5. Neuroanatomical markers of speaking Chinese.

    PubMed

    Crinion, Jenny T; Green, David W; Chung, Rita; Ali, Nliufa; Grogan, Alice; Price, Gavin R; Mechelli, Andrea; Price, Cathy J

    2009-12-01

    The aim of this study was to identify regional structural differences in the brains of native speakers of a tonal language (Chinese) compared to nontonal (European) language speakers. Our expectation was that there would be differences in regions implicated in pitch perception and production. We therefore compared structural brain images in three groups of participants: 31 who were native Chinese speakers; 7 who were native English speakers who had learnt Chinese in adulthood; and 21 European multilinguals who did not speak Chinese. The results identified two brain regions in the vicinity of the right anterior temporal lobe and the left insula where speakers of Chinese had significantly greater gray and white matter density compared with those who did not speak Chinese. Importantly, the effects were found in both native Chinese speakers and European subjects who learnt Chinese as a non-native language, illustrating that they were language related and not ethnicity effects. On the basis of prior studies, we suggest that the locations of these gray and white matter changes in speakers of a tonal language are consistent with a role in linking the pitch of words to their meaning. PMID:19530216

  6. Migration Problems of Chinese Women.

    ERIC Educational Resources Information Center

    Lee, Christina C.; Cochran, Larry R.

    1988-01-01

    Used case study approach to focus on adjustment decisions of 15 female Chinese college students who emigrated from Hong Kong to Vancouver, British Columbia. Common themes of conflict involved Chinese and Western value opposition, the need for personal development, and the fear of social isolation. Six different patterns of client adjustment were…

  7. The Commoditization of Chinese Women.

    ERIC Educational Resources Information Center

    Gates, Hill

    1989-01-01

    Documents women's historically low place in Chinese culture as an integral part of a complex economic pattern. Covers the following topics: (1) women, family, and economy; (2) the Chinese modes of production; (3) views of commodity production in China; (4) class relations; (5) women's labor; and (6) textiles, women, and class. (JS)

  8. Chinese English Learners' Strategic Competence

    ERIC Educational Resources Information Center

    Wang, Dianjian; Lai, Hongling; Leslie, Michael

    2015-01-01

    The present study aims to investigate Chinese English learners' ability to use communication strategies (CSs). The subjects are put in a relatively real English referential communication setting and the analyses of the research data show that Chinese English learners, when encountering problems in foreign language (FL) communication, are…

  9. Chinese American Experience: San Francisco.

    ERIC Educational Resources Information Center

    Stanford Univ., CA. Stanford Program on International and Cross Cultural Education.

    This unit encourages students to explore the history and current situation of Chinese Americans. Organized around five lesson plans, the unit's first lesson begins with the students' own perceptions of Chinese Americans, followed by a quiz that provides relevant background information. The second lesson examines the general history of Chinese…

  10. Molecular regulatory mechanism of tooth root development

    PubMed Central

    Huang, Xiao-Feng; Chai, Yang

    2012-01-01

    The root is crucial for the physiological function of the tooth, and a healthy root allows an artificial crown to function as required clinically. Tooth crown development has been studied intensively during the last few decades, but root development remains not well understood. Here we review the root development processes, including cell fate determination, induction of odontoblast and cementoblast differentiation, interaction of root epithelium and mesenchyme, and other molecular mechanisms. This review summarizes our current understanding of the signaling cascades and mechanisms involved in root development. It also sets the stage for de novo tooth regeneration. PMID:23222990

  11. Physical characteristics of Chinese Hakka.

    PubMed

    Zheng, Lianbin; Li, Yonglan; Lu, Shunhua; Bao, Jinping; Wang, Yang; Zhang, Xiaorui; Xue, Hong; Rong, Wenguo

    2013-06-01

    Using standard and internationally validated methods, 86 anthropologic characteristics were determined in 650 male (305 from urban areas and 345 from rural areas) and 704 female (331 from urban areas, 373 from rural areas) Chinese Hakka adults living in Guangdong and Jiangxi. The data were used to calculate 24 anthropologic indices, which were analyzed statistically. The physical characteristics of Hakka subjects were analyzed and compared with reference ethnic data. There were four main findings of this study. First, a small proportion of Hakka adults had an eye fold on the upper eyelid, but a large proportion had a mongoloid fold. The eye slits were narrow in most adults, had a medium nasal root height and straight bridges, and most of the external angles were prominent. The nasal base was upturned in most men. The distributions of the three types of nasal base in women were similar. The proportions of subjects with middle and high alae nasi heights were high and similar. Males with a maximum nostril diameter were mostly classified as transverse and oblique, while many women were classified as transverse and had relatively wide alae nasi. The round lobe type was the most common. Upper lip skin height was mostly classified as medium. Lips were classified as thin. The hair was black, eyes were brown, and the skin was yellowish. Second, the head length was long in male Hakka. The minimum frontal breadth, face breadth, lip height, and interocular breadth were similar to those of North-Asian populations. Meanwhile, head breadth, morphological facial height, nose breadth, mouth breadth, and nose height were similar to those of South-Asian populations. Head length was long in female Hakka. The minimum frontal breadth, face breadth, lip height, and interocular breadth were similar to those of North-Asian populations. Head breadth, nose breadth, and mouth breadth were similar to those of South-Asian populations. Third, the stature of male and female Hakka in urban and

  12. Panax ginseng Adventitious Root Suspension Culture: Protocol for Biomass Production and Analysis of Ginsenosides by High Pressure Liquid Chromatography.

    PubMed

    Murthy, Hosakatte Niranjana; Paek, Kee Yoeup

    2016-01-01

    Panax ginseng C.A. Meyer (Korean ginseng) is a popular herbal medicine. It has been used in Chinese and Oriental medicines since thousands of years. Ginseng products are generally used as a tonic and an adaptogen to resist the adverse influence of a wide range of physical, chemical and biological factors, and to restore homeostasis. Ginsenosides or ginseng saponins are the principal active ingredients of ginseng. Since ginseng cultivation process is very slow and needs specific environment for field cultivation, cell and tissue cultures are sought as alternatives for the production of ginseng biomass and bioactive compounds. In this chapter, we focus on methods of induction of adventitious roots from ginseng roots, establishment of adventitious root suspension cultures using bioreactors, procedures for processing of adventitious roots, and analysis of ginsenosides by high pressure liquid chromatography. PMID:27108314

  13. Characterizing pathways by which gravitropic effectors could move from the root cap to the root of primary roots of Zea mays

    NASA Technical Reports Server (NTRS)

    Moore, R.; McClelen, C. E.

    1989-01-01

    Plasmodesmata linking the root cap and root in primary roots Zea mays are restricted to approx. 400 protodermal cells bordering approx. 110000 microns2 of the calyptrogen of the root cap. This area is less than 10% of the cross-sectional area of the root-tip at the cap junction. Therefore, gravitropic effectors moving from the root cap to the root can move symplastically only through a relatively small area in the centre of the root. Decapped roots are non-responsive to gravity. However, decapped roots whose caps are replaced immediately after decapping are strongly graviresponsive. Thus, gravicurvature occurs only when the root cap contacts the root, and symplastic continuity between the cap and root is not required for gravicurvature. Completely removing mucilage from the root tip renders the root non-responsive to gravity. Taken together, these data suggest that gravitropic effectors move apoplastically through mucilage from the cap to the root.

  14. Investigation of VEGGIE Root Mat

    NASA Technical Reports Server (NTRS)

    Subbiah, Arun M.

    2013-01-01

    VEGGIE is a plant growth facility that utilizes the phenomenon of capillary action as its primary watering system. A cloth made of Meta Aramid fiber, known as Nomex is used to wick water up from a reservoir to the bottom of the plants roots. This root mat system is intended to be low maintenance with no moving parts and requires minimal crew interface time. Unfortunately, the water wicking rates are inconsistent throughout the plant life cycle, thus causing plants to die. Over-wicking of water occurs toward the beginning of the cycle, while under-wicking occurs toward the middle. This inconsistency of wicking has become a major issue, drastically inhibiting plant growth. The primary objective is to determine the root cause of the inconsistent wicking through experimental testing. Suspect causes for the capillary water column to break include: a vacuum effect due to a negative pressure gradient in the water reservoir, contamination of material due to minerals in water and back wash from plant fertilizer, induced air bubbles while using syringe refill method, and material limitations of Nomex's ability to absorb and retain water. Experimental testing will be conducted to systematically determine the cause of under and over-wicking. Pressure gages will be used to determine pressure drop during the course of the plant life cycle and during the water refill process. A debubbler device will be connected to a root mat in order to equalize pressure inside the reservoir. Moisture and evaporation tests will simultaneously be implemented to observe moisture content and wicking rates over the course of a plant cycle. Water retention tests will be performed using strips of Nomex to determine materials wicking rates, porosity, and absorptivity. Through these experimental tests, we will have a better understanding of material properties of Nomex, as well as determine the root cause of water column breakage. With consistent test results, a forward plan can be achieved to resolve

  15. Control of root system architecture by DEEPER ROOTING 1 increases rice yield under drought conditions.

    PubMed

    Uga, Yusaku; Sugimoto, Kazuhiko; Ogawa, Satoshi; Rane, Jagadish; Ishitani, Manabu; Hara, Naho; Kitomi, Yuka; Inukai, Yoshiaki; Ono, Kazuko; Kanno, Noriko; Inoue, Haruhiko; Takehisa, Hinako; Motoyama, Ritsuko; Nagamura, Yoshiaki; Wu, Jianzhong; Matsumoto, Takashi; Takai, Toshiyuki; Okuno, Kazutoshi; Yano, Masahiro

    2013-09-01

    The genetic improvement of drought resistance is essential for stable and adequate crop production in drought-prone areas. Here we demonstrate that alteration of root system architecture improves drought avoidance through the cloning and characterization of DEEPER ROOTING 1 (DRO1), a rice quantitative trait locus controlling root growth angle. DRO1 is negatively regulated by auxin and is involved in cell elongation in the root tip that causes asymmetric root growth and downward bending of the root in response to gravity. Higher expression of DRO1 increases the root growth angle, whereby roots grow in a more downward direction. Introducing DRO1 into a shallow-rooting rice cultivar by backcrossing enabled the resulting line to avoid drought by increasing deep rooting, which maintained high yield performance under drought conditions relative to the recipient cultivar. Our experiments suggest that control of root system architecture will contribute to drought avoidance in crops. PMID:23913002

  16. Nicotiana Roots Recruit Rare Rhizosphere Taxa as Major Root-Inhabiting Microbes.

    PubMed

    Saleem, Muhammad; Law, Audrey D; Moe, Luke A

    2016-02-01

    Root-associated microbes have a profound impact on plant health, yet little is known about the distribution of root-associated microbes among different root morphologies or between rhizosphere and root environments. We explore these issues here with two commercial varieties of burley tobacco (Nicotiana tabacum) using 16S rRNA gene amplicon sequencing from rhizosphere soil, as well as from primary, secondary, and fine roots. While rhizosphere soils exhibited a fairly rich and even distribution, root samples were dominated by Proteobacteria. A comparison of abundant operational taxonomic units (OTUs) between rhizosphere and root samples indicated that Nicotiana roots select for rare taxa (predominantly Proteobacteria, Verrucomicrobia, Actinobacteria, Bacteroidetes, and Acidobacteria) from their corresponding rhizosphere environments. The majority of root-inhabiting OTUs (~80 %) exhibited habitat generalism across the different root morphological habitats, although habitat specialists were noted. These results suggest a specific process whereby roots select rare taxa from a larger community. PMID:26391804

  17. Chinese Armillary Spheres

    NASA Astrophysics Data System (ADS)

    Sun, Xiaochun

    The armillary sphere was perhaps the most important type of astronomical instrument in ancient China. It was first invented by Luoxia Hong in the first century BC. After Han times, the structure of the armillary sphere became increasingly sophisticated by including more and more rings representing various celestial movements as recognized by the Chinese astronomers. By the eighth century, the Chinese armillary sphere consisted of three concentric sets of rings revolving on the south-north polar axis. The relative position of the rings could be adjusted to reflect the precession of the equinoxes and the regression of the Moon's nodes along the ecliptic. To counterbalance the defect caused by too many rings, Guo Shoujing from the late thirteenth century constructed the Simplified Instruments which reorganized the rings of the armillary sphere into separate instruments for measuring equatorial coordinates and horizontal coordinates. The armillary sphere was still preserved because it was a good illustration of celestial movements. A fifteenth-century replica of Guo Shoujing's armillary sphere still exists today.

  18. The role of strigolactones in root development

    PubMed Central

    Sun, Huwei; Tao, Jinyuan; Gu, Pengyuan; Xu, Guohua; Zhang, Yali

    2016-01-01

    Strigolactones (SLs) and their derivatives were recently defined as novel phytohormones that orchestrate shoot and root growth. Levels of SLs, which are produced mainly by plant roots, increase under low nitrogen and phosphate levels to regulate plant responses. Here, we summarize recent work on SL biology by describing their role in the regulation of root development and hormonal crosstalk during root deve-lopment. SLs promote the elongation of seminal/primary roots and adventitious roots (ARs) and they repress lateral root formation. In addition, auxin signaling acts downstream of SLs. AR formation is positively or negatively regulated by SLs depending largely on the plant species and experimental conditions. The relationship between SLs and auxin during AR formation appears to be complex. Most notably, this hormonal response is a key adaption that radically alters rice root architecture in response to nitrogen- and phosphate-deficient conditions. PMID:26515106

  19. Environmental Control of Root System Biology.

    PubMed

    Rellán-Álvarez, Rubén; Lobet, Guillaume; Dinneny, José R

    2016-04-29

    The plant root system traverses one of the most complex environments on earth. Understanding how roots support plant life on land requires knowing how soil properties affect the availability of nutrients and water and how roots manipulate the soil environment to optimize acquisition of these resources. Imaging of roots in soil allows the integrated analysis and modeling of environmental interactions occurring at micro- to macroscales. Advances in phenotyping of root systems is driving innovation in cross-platform-compatible methods for data analysis. Root systems acclimate to the environment through architectural changes that act at the root-type level as well as through tissue-specific changes that affect the metabolic needs of the root and the efficiency of nutrient uptake. A molecular understanding of the signaling mechanisms that guide local and systemic signaling is providing insight into the regulatory logic of environmental responses and has identified points where crosstalk between pathways occurs. PMID:26905656

  20. Bioactivity-Guided Fractionation and GC/MS Fingerprinting of Angelica sinensis and Angelica archangelica Root Components for Antifungal and Mosquito Deterrent Activity

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Angelica sinensis and A. archangelica belong to the Umbelliferae and both are used in traditional Chinese medicine to treat gynecological and intestinal disorders. In this study, oils from three different A. sinensis collections and one A. archangelica root were analyzed by GC and GC/MS. The domin...

  1. Rhizosphere biophysics and root water uptake

    NASA Astrophysics Data System (ADS)

    Carminati, Andrea; Zarebanadkouki, Mohsen; Ahmed, Mutez A.; Passioura, John

    2016-04-01

    The flow of water into the roots and the (putative) presence of a large resistance at the root-soil interface have attracted the attention of plant and soil scientists for decades. Such resistance has been attributed to a partial contact between roots and soil, large gradients in soil matric potential around the roots, or accumulation of solutes at the root surface creating a negative osmotic potential. Our hypothesis is that roots are capable of altering the biophysical properties of the soil around the roots, the rhizosphere, facilitating root water uptake in dry soils. In particular, we expect that root hairs and mucilage optimally connect the roots to the soil maintaining the hydraulic continuity across the rhizosphere. Using a pressure chamber apparatus we measured the relation between transpiration rate and the water potential difference between soil and leaf xylem during drying cycles in barley mutants with and without root hairs. The samples were grown in well structured soils. At low soil moistures and high transpiration rates, large drops in water potential developed around the roots. These drops in water potential recovered very slowly, even after transpiration was severely decreased. The drops in water potential were much bigger in barley mutants without root hairs. These mutants failed to sustain high transpiration rates in dry conditions. To explain the nature of such drops in water potential across the rhizosphere we performed high resolution neutron tomography of the rhizosphere of the barleys with and without root hairs growing in the same soil described above. The tomograms suggested that the hydraulic contact between the soil structures was the highest resistance for the water flow in dry conditions. The tomograms also indicate that root hairs and mucilage improved the hydraulic contact between roots and soil structures. At high transpiration rates and low water contents, roots extracted water from the rhizosphere, while the bulk soil, due its

  2. Transitioning Challenges Faced by Chinese Graduate Students

    ERIC Educational Resources Information Center

    Huang, Ying

    2012-01-01

    This literature review examines transitioning challenges faced by Chinese international students who pursue graduate degrees in the United States. Based on existing research on adulthood in U.S. and Chinese contexts and the features of Chinese graduate students, Chinese adults, and international students as learners in Western countries, the…

  3. Single-rooted primary first mandibular molar

    PubMed Central

    Haridoss, SelvaKumar; Swaminathan, Kavitha; Rajendran, Vijayakumar; Rajendran, Bharathan

    2014-01-01

    Morphological variations like single-rooted molar in primary dentition are scarce. Understanding the root canal anatomy and variations is necessary for successful root canal therapy. The purpose of the present article is to report successful endodontic treatment of primary left mandibular first molar with an abnormal morphology of a single root. This case report highlights the importance of knowledge and its applications in the management of anomalous anatomic variants which play a crucial role in the success of endodontic treatment. PMID:25150245

  4. Root proliferation in decaying roots and old root channels: A nutrient conservation mechanism in oligotrophic mangrove forests?

    USGS Publications Warehouse

    McKee, K.L.

    2001-01-01

    1. In oligotrophic habitats, proliferation of roots in nutrient-rich microsites may contribute to overall nutrient conservation by plants. Peat-based soils on mangrove islands in Belize are characterized by the presence of decaying roots and numerous old root channels (0.1-3.5 cm diameter) that become filled with living and highly branched roots of Rhizophora mangle and Avicennia germinans. The objectives of this study were to quantify the proliferation of roots in these microsites and to determine what causes this response. 2. Channels formed by the refractory remains of mangrove roots accounted for only 1-2% of total soil volume, but the proportion of roots found within channels varied from 9 to 24% of total live mass. Successive generations of roots growing inside increasingly smaller root channels were also found. 3. When artificial channels constructed of PVC pipe were buried in the peat for 2 years, those filled with nutrient-rich organic matter had six times more roots than empty or sand-filled channels, indicating a response to greater nutrient availability rather than to greater space or less impedance to root growth. 4. Root proliferation inside decaying roots may improve recovery of nutrients released from decomposing tissues before they can be leached or immobilized in this intertidal environment. Greatest root proliferation in channels occurred in interior forest zones characterized by greater soil waterlogging, which suggests that this may be a strategy for nutrient capture that minimizes oxygen losses from the whole root system. 5. Improved efficiency of nutrient acquisition at the individual plant level has implications for nutrient economy at the ecosystem level and may explain, in part, how mangroves persist and grow in nutrient-poor environments.

  5. Social Anxiety among Chinese People

    PubMed Central

    Fan, Qianqian; Chang, Weining C.

    2015-01-01

    The experience of social anxiety has largely been investigated among Western populations; much less is known about social anxiety in other cultures. Unlike the Western culture, the Chinese emphasize interdependence and harmony with social others. In addition, it is unclear if Western constructed instruments adequately capture culturally conditioned conceptualizations and manifestations of social anxiety that might be specific to the Chinese. The present study employed a sequence of qualitative and quantitative approaches to examine the assessment of social anxiety among the Chinese people. Interviews and focus group discussions with Chinese participants revealed that some items containing the experience of social anxiety among the Chinese are not present in existing Western measures. Factor analysis was employed to examine the factor structure of the more comprehensive scale. This approach revealed an “other concerned anxiety” factor that appears to be specific to the Chinese. Subsequent analysis found that the new factor—other concerned anxiety—functioned the same as other social anxiety factors in their association with risk factors of social anxiety, such as attachment, parenting, behavioral inhibition/activation, and attitude toward group. The implications of these findings for a more culturally sensitive assessment tool of social anxiety among the Chinese were discussed. PMID:26380367

  6. EFFECTS OF OZONE ON ROOT PROCESSES

    EPA Science Inventory

    Ozone alters root growth and root processes by first reducing photosynthesis and altering foliar metabolic pathways. The alteration in foliar metabolism is reflected in lowered carbohydrate levels in the roots. This can reduce key metabolic processes such as mineral uptake and sy...

  7. Cultivar selection for sugarbeet root rot resistance.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fungal and bacterial root rots in sugar beet caused by Rhizoctonia solani (Rs) and Leuconostoc mesenteroides subsp. dextranicum (Lm) can lead to root yield losses greater than 50%. To reduce the impact of these root rots on sucrose loss in the field, storage, and factories, studies were conducted t...

  8. Effect of scapling on root respiration rate

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Scalping improves root quality at harvest since impurities such as potassium, sodium, amino nitrogen and invert sugars that hinder sugarbeet processing are concentrated in the upper root crown. The effect of scalping on root storage properties, however, is less clear. A small study was conducted t...

  9. [Root caries--scanning electron microscopic observations].

    PubMed

    Heinrich, R; Hornová, J; Kneist, S; Künzel, W

    1990-01-01

    Sound and carious root surfaces of 24 extracted human teeth with extensive periodontal attachment loss were examined by SEM. The microflora covering the radicular surfaces was a complex flora consisting of filamentous and fusiform bacteria, short and long rods. Cocci and coccoid bacteria were observed on root surfaces. Bacterial invasion in the exposed peripheral root dentin was delayed by sclerotic dentin. PMID:2150459

  10. Springback in Root Gravitropism 1

    PubMed Central

    Leopold, A. Carl; Wettlaufer, Scott H.

    1989-01-01

    Conditions under which a gravistimulus of Merit corn roots (Zea mays L.) is withdrawn result in a subsequent loss of gravitropic curvature, an effect which we refer to as `springback.' This loss of curvature begins within 1 to 10 minutes after removal of the gravistimulus. It occurs regardless of the presence or absence of the root cap. It is insensitive to inhibitors of auxin transport (2,3,5-triiodobenzoic acid, naphthylphthalmaic acid) or to added auxin (2,4-dichlorophenoxyacetic acid). Springback is prevented if a clinostat treatment is interjected to neutralize gravistimulation during germination, which suggests that the change in curvature is a response to a `memory' effect carried over from a prior gravistimulation. PMID:11537456

  11. The rhizosphere revisited: root microbiomics

    PubMed Central

    Bakker, Peter A. H. M.; Berendsen, Roeland L.; Doornbos, Rogier F.; Wintermans, Paul C. A.; Pieterse, Corné M. J.

    2013-01-01

    The rhizosphere was defined over 100 years ago as the zone around the root where microorganisms and processes important for plant growth and health are located. Recent studies show that the diversity of microorganisms associated with the root system is enormous. This rhizosphere microbiome extends the functional repertoire of the plant beyond imagination. The rhizosphere microbiome of Arabidopsis thaliana is currently being studied for the obvious reason that it allows the use of the extensive toolbox that comes with this model plant. Deciphering plant traits that drive selection and activities of the microbiome is now a major challenge in which Arabidopsis will undoubtedly be a major research object. Here we review recent microbiome studies and discuss future research directions and applicability of the generated knowledge. PMID:23755059

  12. Phene Synergism between Root Hair Length and Basal Root Growth Angle for Phosphorus Acquisition1[OPEN

    PubMed Central

    Miguel, Magalhaes Amade

    2015-01-01

    Shallow basal root growth angle (BRGA) increases phosphorus acquisition efficiency by enhancing topsoil foraging because in most soils, phosphorus is concentrated in the topsoil. Root hair length and density (RHL/D) increase phosphorus acquisition by expanding the soil volume subject to phosphorus depletion through diffusion. We hypothesized that shallow BRGA and large RHL/D are synergetic for phosphorus acquisition, meaning that their combined effect is greater than the sum of their individual effects. To evaluate this hypothesis, phosphorus acquisition in the field in Mozambique was compared among recombinant inbred lines of common bean (Phaseolus vulgaris) having four distinct root phenotypes: long root hairs and shallow basal roots, long root hairs and deep basal roots, short root hairs and shallow basal roots, and short root hairs and deep basal roots. The results revealed substantial synergism between BRGA and RHL/D. Compared with short-haired, deep-rooted phenotypes, long root hairs increased shoot biomass under phosphorus stress by 89%, while shallow roots increased shoot biomass by 58%. Genotypes with both long root hairs and shallow roots had 298% greater biomass accumulation than short-haired, deep-rooted phenotypes. Therefore, the utility of shallow basal roots and long root hairs for phosphorus acquisition in combination is twice as large as their additive effects. We conclude that the anatomical phene of long, dense root hairs and the architectural phene of shallower basal root growth are synergetic for phosphorus acquisition. Phene synergism may be common in plant biology and can have substantial importance for plant fitness, as shown here. PMID:25699587

  13. Modeling root reinforcement using a root-failure Weibull survival function

    NASA Astrophysics Data System (ADS)

    Schwarz, M.; Giadrossich, F.; Cohen, D.

    2013-11-01

    Root networks contribute to slope stability through complex interactions with soil that include mechanical compression and tension. Due to the spatial heterogeneity of root distribution and the dynamics of root turnover, the quantification of root reinforcement on steep slopes is challenging and consequently the calculation of slope stability also. Although considerable progress has been made, some important aspects of root mechanics remain neglected. In this study we address specifically the role of root-strength variability on the mechanical behavior of a root bundle. Many factors contribute to the variability of root mechanical properties even within a single class of diameter. This work presents a new approach for quantifying root reinforcement that considers the variability of mechanical properties of each root diameter class. Using the data of laboratory tensile tests and field pullout tests, we calibrate the parameters of the Weibull survival function to implement the variability of root strength in a numerical model for the calculation of root reinforcement (RBMw). The results show that, for both laboratory and field data sets, the parameters of the Weibull distribution may be considered constant with the exponent equal to 2 and the normalized failure displacement equal to 1. Moreover, the results show that the variability of root strength in each root diameter class has a major influence on the behavior of a root bundle with important implications when considering different approaches in slope stability calculation. Sensitivity analysis shows that the calibration of the equations of the tensile force, the elasticity of the roots, and the root distribution are the most important steps. The new model allows the characterization of root reinforcement in terms of maximum pullout force, stiffness, and energy. Moreover, it simplifies the implementation of root reinforcement in slope stability models. The realistic quantification of root reinforcement for tensile

  14. Root-cubing and general root-powering methods for finding the zeros of polynomials

    NASA Technical Reports Server (NTRS)

    Bareiss, E. H.

    1969-01-01

    Mathematical analysis technique generalizes a root squaring and root cubing method into a general root powering method. The introduction of partitioned polynomials into this general root powering method simplifies the coding of the polynomial transformations into input data suitable for processing by computer. The method includes analytic functions.

  15. Application of glutathione to roots selectively inhibits cadmium transport from roots to shoots in oilseed rape

    PubMed Central

    Nakamura, Shin-ichi

    2013-01-01

    Glutathione is a tripeptide involved in various aspects of plant metabolism. This study investigated the effects of the reduced form of glutathione (GSH) applied to specific organs (source leaves, sink leaves, and roots) on cadmium (Cd) distribution and behaviour in the roots of oilseed rape plants (Brassica napus) cultured hydroponically. The translocation ratio of Cd from roots to shoots was significantly lower in plants that had root treatment of GSH than in control plants. GSH applied to roots reduced the Cd concentration in the symplast sap of root cells and inhibited root-to-shoot Cd translocation via xylem vessels significantly. GSH applied to roots also activated Cd efflux from root cells to the hydroponic solution. Inhibition of root-to-shoot translocation of Cd was visualized, and the activation of Cd efflux from root cells was also shown by using a positron-emitting tracer imaging system (PETIS). This study investigated a similar inhibitory effect on root-to-shoot translocation of Cd by the oxidized form of glutathione, GSSG. Inhibition of Cd accumulation by GSH was abolished by a low-temperature treatment. Root cells of plants exposed to GSH in the root zone had less Cd available for xylem loading by actively excluding Cd from the roots. Consequently, root-to-shoot translocation of Cd was suppressed and Cd accumulation in the shoot decreased. PMID:23364937

  16. Estimate of fine root production including the impact of decomposed roots in a Bornean tropical rainforest

    NASA Astrophysics Data System (ADS)

    Katayama, Ayumi; Khoon Koh, Lip; Kume, Tomonori; Makita, Naoki; Matsumoto, Kazuho; Ohashi, Mizue

    2016-04-01

    Considerable carbon is allocated belowground and used for respiration and production of roots. It is reported that approximately 40 % of GPP is allocated belowground in a Bornean tropical rainforest, which is much higher than those in Neotropical rainforests. This may be caused by high root production in this forest. Ingrowth core is a popular method for estimating fine root production, but recent study by Osawa et al. (2012) showed potential underestimates of this method because of the lack of consideration of the impact of decomposed roots. It is important to estimate fine root production with consideration for the decomposed roots, especially in tropics where decomposition rate is higher than other regions. Therefore, objective of this study is to estimate fine root production with consideration of decomposed roots using ingrowth cores and root litter-bag in the tropical rainforest. The study was conducted in Lambir Hills National Park in Borneo. Ingrowth cores and litter bags for fine roots were buried in March 2013. Eighteen ingrowth cores and 27 litter bags were collected in May, September 2013, March 2014 and March 2015, respectively. Fine root production was comparable to aboveground biomass increment and litterfall amount, and accounted only 10% of GPP in this study site, suggesting most of the carbon allocated to belowground might be used for other purposes. Fine root production was comparable to those in Neotropics. Decomposed roots accounted for 18% of fine root production. This result suggests that no consideration of decomposed fine roots may cause underestimate of fine root production.

  17. Chinese medicine and martial arts.

    PubMed

    Koh, T C

    1981-01-01

    Wushu (Martial Arts), mistakenly known in the West as Kung-Fu, is a system of Chinese boxing which is closely linked with the traditional practice of Chinese medicine. Many of the masters (Sifu) are Chinese physicians who often recommend health exercises and the soft form of martial arts to their patients, while the hard form is suitable for sport and self-defense. Martial arts is a great discipline for body and mind, suitable for all who treasure physical and mental health. PMID:6764088

  18. The pattern of secondary root formation in curving roots of Arabidopsis thaliana (L.) Heynh

    NASA Technical Reports Server (NTRS)

    Fortin, M. C.; Pierce, F. J.; Poff, K. L.

    1989-01-01

    A gravitational stimulus was used to induce the curvature of the main root of Arabidopsis thaliana. The number of secondary roots increased on the convex side and decreased on the concave side of any curved main root axes in comparison with straight roots used as the control. The same phenomenon was observed with the curved main roots of plants grown on a clinostat and of mutant plants exhibiting random root orientation. The data suggest that the pattern of lateral root formation is associated with curvature but is independent of the environmental stimuli used to induce curvature.

  19. Kudzu Root Extract Does Not Perturb the Sleep/Wake Cycle of Moderate Drinkers

    PubMed Central

    Penetar, David M.; Maclean, Robert Ross; Lukas, Scott E.

    2011-01-01

    Abstract Objectives According to ancient Chinese medicine, kudzu root has been used as an ingredient to treat alcohol intoxication for centuries. Kudzu root extract is effective at reducing alcohol intake in animals and in humans, both in a natural-settings laboratory environment and on an outpatient basis. In dependent populations, withdrawal from alcohol is associated with disturbed sleep. These disturbances to the quantity and quality of sleep likely impact relapse to drinking. Many medications used to treat alcohol dependence also affect sleep. Therefore, as a possible treatment for alcohol dependence, the impact of kudzu root extract on the sleep/wake cycle is an important aspect of its effectiveness. Design This double-blind, placebo-controlled, crossover trial tested the effects of kudzu root extract on the sleep/wake cycles of moderate drinkers. Results Kudzu extract had no effect on any of the sleep parameters measured, including sleep efficiency, sleep latency, total time asleep per night, number of waking episodes, time awake per episode, number of moving minutes, number of sleep episodes, time asleep per episode, and number of immobile minutes. Conclusions These data suggest that the administration of kudzu root extract does not disturb sleep/wake cycles of moderate drinkers, and as such its utility as an adjunct treatment for alcohol dependence remains free of any potential side-effects on sleep. PMID:22010780

  20. Was acupuncture developed by Han Dynasty Chinese anatomists?

    PubMed

    Shaw, Vivien; Mclennan, Amy K

    2016-05-01

    Anatomical dissection has begun to reveal striking similarities between gross anatomical structures and the system of nomenclature used in traditional Chinese acupuncture. This paper argues that acupuncture point nomenclature is rooted in systematic anatomical investigation of cadaveric specimens, and that acupuncture points and meridians are purposefully named to reflect observable physical form. Two types of evidence are compared: observations of physical structures based on anatomical dissection, and translation and analysis of original Chinese texts. Evidence is contextualized through in-depth practical understanding of acupuncture. Points designated as tian (heavenly/superior), xia (below/inferior), liao (bone-hole), fei (flying), wei (bend), and xi (mountain stream/ravine) are investigated. These acupuncture point names: (a) specify position; (b) reflect function and/or form; (c) indicate homologous structures; (d) mark unusual structures; and/or (e) describe the physical appearance of a deep (dissected) structure by likening it to a homologous everyday object. Results raise intriguing possibilities for developing an understanding of acupuncture points and meridians firmly based in the material and functional anatomy of the human body. Such an understanding has the potential to open new fields of thought about functional anatomy. It also has implications for future investigations into the mechanisms of acupuncture, and gives some insights into the possible origins of this iconic area of Chinese medicine. Anat Rec, 299:643-659, 2016. © 2016 Wiley Periodicals, Inc. PMID:26861920

  1. Head-and-face anthropometric survey of Chinese workers.

    PubMed

    Du, Lili; Zhuang, Ziqing; Guan, Hongyu; Xing, Jingcai; Tang, Xianzhi; Wang, Limin; Wang, Zhenglun; Wang, Haijiao; Liu, Yuewei; Su, Wenjin; Benson, Stacey; Gallagher, Sean; Viscusi, Dennis; Chen, Weihong

    2008-11-01

    Millions of workers in China rely on respirators and other personal protective equipment to reduce the risk of injury and occupational diseases. However, it has been >25 years since the first survey of facial dimensions for Chinese adults was published, and it has never been completely updated. Thus, an anthropometric survey of Chinese civilian workers was conducted in 2006. A total of 3000 subjects (2026 males and 974 females) between the ages of 18 and 66 years old was measured using traditional techniques. Nineteen facial dimensions, height, weight, neck circumference, waist circumference and hip circumference were measured. A stratified sampling plan of three age strata and two gender strata was implemented. Linear regression analysis was used to evaluate the possible effects of gender, age, occupation and body size on facial dimensions. The regression coefficients for gender indicated that for all anthropometric dimensions, males had significantly larger measurements than females. As body mass index increased, dimensions measured increased significantly. Construction workers and miners had significantly smaller measurements than individuals employed in healthcare or manufacturing for a majority of dimensions. Five representative indexes of facial dimension (face length, face width, nose protrusion, bigonial breadth and nasal root breadth) were selected based on correlation and cluster analysis of all dimensions. Through comparison with the facial dimensions of American subjects, this study indicated that Chinese civilian workers have shorter face length, smaller nose protrusion, larger face width and longer lip length. PMID:18765398

  2. Biogas: the Chinese experience

    SciTech Connect

    Thorhaug, A.

    1980-10-01

    This article details the history of biogas in China and its development as a renewable energy source. There are 7.2 million biogas plants that benefit directly 35 million rural people. The average family digester costs $20 to $40 and can easily be made by unskilled technical workers. The design of a typical digester is described together with its maintenance and recovery of gas. The uses of biogas in China are numerous and solves most of the major energy problems of rural life such as village cooking, and fuel for irrigation pumps and farm tractors. The utilizing of human, animal and agricultural waste is in itself a large benefit and a list of other benefits to the Chinese is given.

  3. The Chinese healthcare challenge

    PubMed Central

    Fabre, Guilhem

    2015-01-01

    Investments in the extension of health insurance coverage, the strengthening of public health services, as well as primary care and better hospitals, highlights the emerging role of healthcare as part of China’s new growth regime, based on an expansion of services, and redistributive policies. Such investments, apart from their central role in terms of relief for low-income people, serve to rebalance the Chinese economy away from export-led growth toward the domestic market, particularly in megacity-regions as Shanghai and the Pearl River Delta, which confront the challenge of integrating migrant workers. Based on the paper by Gusmano and colleagues, one would expect improvements in population health for permanent residents of China’s cities. The challenge ahead, however, is how to address the growth of inequalities in income, wealth and the social wage. PMID:25774379

  4. Nitrogen in Chinese coals

    USGS Publications Warehouse

    Wu, D.; Lei, J.; Zheng, B.; Tang, X.; Wang, M.; Hu, Jiawen; Li, S.; Wang, B.; Finkelman, R.B.

    2011-01-01

    Three hundred and six coal samples were taken from main coal mines of twenty-six provinces, autonomous regions, and municipalities in China, according to the resource distribution and coal-forming periods as well as the coal ranks and coal yields. Nitrogen was determined by using the Kjeldahl method at U. S. Geological Survey (USGS), which exhibit a normal frequency distribution. The nitrogen contents of over 90% Chinese coal vary from 0.52% to 1.41% and the average nitrogen content is recommended to be 0.98%. Nitrogen in coal exists primarily in organic form. There is a slight positive relationship between nitrogen content and coal ranking. ?? 2011 Science Press, Institute of Geochemistry, CAS and Springer Berlin Heidelberg.

  5. The teacher-disciple tradition and secret teaching in Chinese medicine.

    PubMed

    Solos, Ioannis; Liang, Yuan; Yue, Guang-xin

    2014-01-01

    The ancient teacher-disciple tradition is regarded as one of the most celebrated practices within the Chinese medicine world. Such traditions of secrecy, private wisdom and honor are deeply rooted in the theories of Confucianism. This paper only explores the surface of this ancient culture, by investigating relevant popular ancient texts and common Chinese proverbs, as well as utilizing personal experiences, in order to reflect on how the ancient Chinese perceived such practices within their own society and how secret teaching was passed on from teacher to student, including the revelation of secret formulas and their importance and how that tradition differs from our modern-day perspectives. Various rare manuscripts from the author's personal library are employed in order to provide relative examples of the importance of secret knowledge, and how these secrets applied in the traditional healing. PMID:24126973

  6. Developing a cultural model of caregiving obligations for elderly Chinese wives.

    PubMed

    Holroyd, Eleanor

    2005-06-01

    This article addresses the dilemmas of elderly Chinese women as spousal caregivers in Hong Kong in the 1990s. An in-depth ethnographic approach was used to draw on a convenience sample of 20 elderly wives who were caregivers from Hong Kong. At the conceptual level, the discussion highlights how caregiving is rooted in complex, culturally-based models of contemporary practices, sociohistoric patterns, and gender-specific obligations. The key themes identified were marital duty-bound roles and responsibilities, reciprocity and burden, public guidelines and upholding reputations as Chinese wives, monetary restrictions, affection as an emotional force to sustain caregiving, effects of the caregiving role, and the creation of self-identity through caregiving. The model proposed for interpreting elderly Chinese wives' caregiving obligations highlights the tension-filled links between Confucianism and government guidelines, early and ongoing socializing experiences, and self-identity. PMID:15870240

  7. Metabonomic analysis of water extracts from different angelica roots by ¹H-nuclear magnetic resonance spectroscopy.

    PubMed

    Chan, Pui Hei; Zhang, Wendy L; Lau, Chung-Ho; Cheung, Chi Yuen; Keun, Hector C; Tsim, Karl W K; Lam, Henry

    2014-01-01

    Angelica Radix, the roots of the genus Angelica, has been used for more than 2,000 years as a traditional medicine in Eastern Asia. The Chinese Pharmacopoeia records more than 100 herbal formulae containing Angelica roots. There are two common sources of Angelica roots, Angelica sinensis from China and A. gigas from Korea. The two species of Angelica roots differ in their chemical compositions, pharmacological properties and clinical efficacy. ¹H-NMR metabolic profiling has recently emerged as a promising quality control method for food and herbal chemistry. We explored the use of ¹H-NMR metabolic profiling for the quality control of Angelica Radix. Unlike previous work, we performed the metabolic profiling on hot water extracts, so as to mimic the clinically relevant preparation method. Unsupervised principle component analyses of both the full spectral profile and a selection of targeted molecules revealed a clear differentiation of three types of Angelica roots. In addition, the levels of 13 common metabolites were measured. Statistically significant differences in the levels of glucose, fructose and threonine were found between different sources of Angelica. Ferulic acid, a marker commonly used to evaluate Angelica root, was detected in our samples, but the difference in ferulic acid levels between the samples was not statistically significant. Overall, we successfully applied ¹H-NMR metabolic profiling with water extraction to discriminate all three sources of Angelica roots, and obtained quantitative information of many common metabolites. PMID:24658570

  8. Autonomic Recovery Is Delayed in Chinese Compared with Caucasian following Treadmill Exercise

    PubMed Central

    Sun, Peng; Yan, Huimin; Ranadive, Sushant M.; Lane, Abbi D.; Kappus, Rebecca M.; Bunsawat, Kanokwan; Baynard, Tracy; Hu, Min; Li, Shichang; Fernhall, Bo

    2016-01-01

    Caucasian populations have a higher prevalence of cardiovascular disease (CVD) when compared with their Chinese counterparts and CVD is associated with autonomic function. It is unknown whether autonomic function during exercise recovery differs between Caucasians and Chinese. The present study investigated autonomic recovery following an acute bout of treadmill exercise in healthy Caucasians and Chinese. Sixty-two participants (30 Caucasian and 32 Chinese, 50% male) performed an acute bout of treadmill exercise at 70% of heart rate reserve. Heart rate variability (HRV) and baroreflex sensitivity (BRS) were obtained during 5-min epochs at pre-exercise, 30-min, and 60-min post-exercise. HRV was assessed using frequency [natural logarithm of high (LnHF) and low frequency (LnLF) powers, normalized high (nHF) and low frequency (nLF) powers, and LF/HF ratio] and time domains [Root mean square of successive differences (RMSSD), natural logarithm of RMSSD (LnRMSSD) and R–R interval (RRI)]. Spontaneous BRS included both up-up and down-down sequences. At pre-exercise, no group differences were observed for any HR, HRV and BRS parameters. During exercise recovery, significant race-by-time interactions were observed for LnHF, nHF, nLF, LF/HF, LnRMSSD, RRI, HR, and BRS (up-up). The declines in LnHF, nHF, RMSSD, RRI and BRS (up-up) and the increases in LF/HF, nLF and HR were blunted in Chinese when compared to Caucasians from pre-exercise to 30-min to 60-min post-exercise. Chinese exhibited delayed autonomic recovery following an acute bout of treadmill exercise. This delayed autonomic recovery may result from greater sympathetic dominance and extended vagal withdrawal in Chinese. Trial Registration: Chinese Clinical Trial Register ChiCTR-IPR-15006684 PMID:26784109

  9. Optimal root arrangement of cereal crops

    NASA Astrophysics Data System (ADS)

    Jung, Yeonsu; Park, Keunhwan; Kim, Ho-Young

    2015-11-01

    The plant root absorbs water from the soil and supplies it to the rest part of the plant. It consists of a number of root fibers, through whose surfaces water uptake occurs. There is an intriguing observation that for most of cereal crops such as maize and wheat, the volume density of root in the soil declines exponentially as a function of depth. To understand this empirical finding, we construct a theoretical model of root water uptake, where mass transfer into root surface is modeled just as heat flux around a fin. Agreement between the theoretically predicted optimal root distribution in vertical direction and biological data supports the hypothesis that the plant root has evolved to achieve the optimal water uptake in competition with neighbors. This study has practical implication in the agricultural industry as well as optimal design of water transport networks in both micro- and macroscales. Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 08826, Korea.

  10. Chinese Constellations and Star Maps

    NASA Astrophysics Data System (ADS)

    Sun, Xiaochun

    Star observations can be traced back to as early as the twenty-third century BC in ancient China. By the fifth century BC, the Chinese had named the 28 asterisms that formed the basic reference points for the Chinese equatorial coordinate system. By the first century BC, the Chinese had developed a unique system of constellations that reflected Chinese cosmological ideas with the central theme of the correlation between Heaven and Man. Star charts have been discovered on tomb ceilings dating back to Han times. But most of them are illustrative in their presentation of stars. The Dunhuang star maps from the ninth century, the star maps in the Xin yixiang fa yao of the eleventh century, and the Suzhou Astronomical Planisphere of the thirteenth century are examples of precise star maps from ancient China.

  11. Chinese Swing Back to Science.

    ERIC Educational Resources Information Center

    Swetz, Frank; Yu, Ying-king

    1979-01-01

    Describes the history of science education in the People's Republic of China since the 1950s, and discusses the new Chinese emphasis on "theory" and "expertness" to produce the scientists necessary for China's development and modernization. (GA)

  12. The Chinese Cult of Examinations.

    ERIC Educational Resources Information Center

    Krebs, Sylvia H.

    1996-01-01

    Discusses how the cult of examinations continues to affect both teachers and students in China, and concludes that any serious reform of Chinese education depends on thoroughly rethinking the role of examinations in learning. (SR)

  13. Bulimia nervosa in the Chinese.

    PubMed

    Schmidt, U

    1993-12-01

    Typical DSM-III-R bulimia nervosa with self-induced vomiting was found in 2 women of Hong Kong Chinese origin and a Chinese man from Malaysia. All 3 cases had a family history of obesity. In 2 of the cases a period of weight gain and in the third case frank obesity preceded the onset of the eating disorder. Cultural transition seemed to play an important part in the onset and maintenance of the eating disorder. PMID:8293034

  14. Chinese journals: a guide for epidemiologists

    PubMed Central

    Fung, Isaac CH

    2008-01-01

    Chinese journals in epidemiology, preventive medicine and public health contain much that is of potential international interest. However, few non-Chinese speakers are acquainted with this literature. This article therefore provides an overview of the contemporary scene in Chinese biomedical journal publication, Chinese bibliographic databases and Chinese journals in epidemiology, preventive medicine and public health. The challenge of switching to English as the medium of publication, the development of publishing bibliometric data from Chinese databases, the prospect of an Open Access publication model in China, the issue of language bias in literature reviews and the quality of Chinese journals are discussed. Epidemiologists are encouraged to search the Chinese bibliographic databases for Chinese journal articles. PMID:18826604

  15. Chinese kindergartners learn to read characters analytically.

    PubMed

    Yin, Li; McBride, Catherine

    2015-04-01

    Do Chinese children implicitly extract information from Chinese print before they are formally taught to read? We examined Chinese kindergartners' sensitivity to regularities in Chinese characters and the relationship between such sensitivity and later literacy ability. Eighty-five kindergartners from Beijing were given a character-learning task and assessed on word reading and word writing twice within a 1-year interval. Sensitivity to the structural and phonetic regularities in Chinese appeared in 4-year-olds, and sensitivity to the positions of radicals in Chinese characters emerged in 5-year-olds. Such sensitivities explained unique variance in Chinese word reading and writing 1 year later, with age and nonverbal IQ statistically controlled. Young children detected regularities in written Chinese before they received formal instruction in it, which underscores both the importance of early statistical learning for literacy development and the analytic properties of Chinese print. PMID:25711130

  16. General complex polynomial root solver

    NASA Astrophysics Data System (ADS)

    Skowron, J.; Gould, A.

    2012-12-01

    This general complex polynomial root solver, implemented in Fortran and further optimized for binary microlenses, uses a new algorithm to solve polynomial equations and is 1.6-3 times faster than the ZROOTS subroutine that is commercially available from Numerical Recipes, depending on application. The largest improvement, when compared to naive solvers, comes from a fail-safe procedure that permits skipping the majority of the calculations in the great majority of cases, without risking catastrophic failure in the few cases that these are actually required.

  17. Xanthones from Garcinia propinqua Roots.

    PubMed

    Meesakul, Pornphimol; Pansanit, Acharavadee; Maneerat, Wisanu; Sripisut, Tawanun; Ritthiwigrom, Thunwadee; Machana, Theeraphan; Cheenpracha, Sarot; Laphookhieo, Surat

    2016-01-01

    Phytochemical investigation of Garcinia propinqua roots led to the isolation and identification of a new xanthone, doitunggarcinone D (1), together with 15 known compounds (2-16). Their structures were elucidated by intensive analysis of spectroscopic data. Compounds 3, 6, 7, 14, 15 and 16 exhibited strong antibacterial activity against Bacillus subtilis TISTR 088 with MIC values in the range of 1-4 µg/mL. Compounds 3, 7, 10 and 14 also showed good antibacterial activity against B. cereus TISTR 688 with MIC values ranging from 4-8 µg/mL. PMID:26996028

  18. Morphometric data of canine sacral nerve roots with reference to electrical sacral root stimulation.

    PubMed

    Rijkhoff, N J; Koldewijn, E L; d'Hollosy, W; Debruyne, F M; Wijkstra, H

    1996-01-01

    Experiments to investigate restoration of lower urinary tract control by electrical stimulation of the sacral nerve roots are mostly performed on dogs, yet little morphometric data (such as canine root and fiber diameter distributions) are available. The aim of this study was to acquire morphometric data of the intradural canine sacral dorsal and ventral roots (S1-S3). Cross-sections of sacral roots of two beagle dogs were analyzed using a light microscope and image processing software. The cross-sectional area of each root was measured. The diameters of the fibers and the axons in the cross-sections of the S2 and S3 roots were measured and used to construct nerve fiber diameter frequency distribution histograms. The results show a unimodal diameter distribution for the dorsal roots and a bimodal distribution for the ventral roots. In addition the average ratio g of the axon diameter to fiber diameter was calculated for each root. PMID:8732990

  19. Root canal treatment of a maxillary first premolar with three roots

    PubMed Central

    Mathew, Josey; Devadathan, Aravindan; Syriac, Gibi; Shamini, Sai

    2015-01-01

    Successful root canal treatment needs a thorough knowledge of both internal and external anatomy of a tooth. Variations in root canal anatomy constitute an impressive challenge to the successful completion of endodontic treatment. Undetected extra roots and canals are a major reason for failed root canal treatment. Three separate roots in a maxillary first premolar have a very low incidence of 0.5–6%. Three rooted premolars are anatomically similar to molars and are sometimes called “small molars or radiculous molars.” This article explains the diagnosis and endodontic management of a three rooted maxillary premolar with separate canals in each root highlighting that statistics may indicate a low incidence of abnormal variations in root canal morphology of a tooth, but aberrant anatomy is a possibility in any tooth. Hence, modern diagnostics like cone beam computed tomography, and endodontic operating microscope may have to be used more for predictable endodontic treatment. PMID:26538958

  20. Inhibition of auxin movement from the shoot into the root inhibits lateral root development in Arabidopsis

    NASA Technical Reports Server (NTRS)

    Reed, R. C.; Brady, S. R.; Muday, G. K.

    1998-01-01

    In roots two distinct polar movements of auxin have been reported that may control different developmental and growth events. To test the hypothesis that auxin derived from the shoot and transported toward the root controls lateral root development, the two polarities of auxin transport were uncoupled in Arabidopsis. Local application of the auxin-transport inhibitor naphthylphthalamic acid (NPA) at the root-shoot junction decreased the number and density of lateral roots and reduced the free indoleacetic acid (IAA) levels in the root and [3H]IAA transport into the root. Application of NPA to the basal half of or at several positions along the root only reduced lateral root density in regions that were in contact with NPA or in regions apical to the site of application. Lateral root development was restored by application of IAA apical to NPA application. Lateral root development in Arabidopsis roots was also inhibited by excision of the shoot or dark growth and this inhibition was reversible by IAA. Together, these results are consistent with auxin transport from the shoot into the root controlling lateral root development.

  1. Foraging strategies in trees of different root morphology: the role of root lifespan.

    PubMed

    Adams, Thomas S; McCormack, M Luke; Eissenstat, David M

    2013-09-01

    Resource exploitation of patches is influenced not simply by the rate of root production in the patches but also by the lifespan of the roots inhabiting the patches. We examined the effect of sustained localized nitrogen (N) fertilization on root lifespan in four tree species that varied widely in root morphology and presumed foraging strategy. The study was conducted in a 12-year-old common garden in central Pennsylvania using a combination of data from minirhizotron and root in-growth cores. The two fine-root tree species, Acer negundo L. and Populus tremuloides Michx., exhibited significant increases in root lifespan with local N fertilization; no significant responses were observed in the two coarse-root tree species, Sassafras albidum Nutt. and Liriodendron tulipifera L. Across species, coarse-root tree species had longer median root lifespan than fine-root tree species. Localized N fertilization did not significantly increase the N concentration or the respiration of the roots growing in the N-rich patch. Our results suggest that some plant species appear to regulate the lifespan of different portions of their root system to improve resource acquisition while other species do not. Our results are discussed in the context of different strategies of foraging of nutrient patches in species of different root morphology. PMID:24128849

  2. PATTERNS IN SOIL FERTILITY AND ROOT HERBIVORY INTERACT TO INFLUENCE FINE-ROOT DYNAMICS.

    SciTech Connect

    Stevens, Glen, N.; Jones, Robert, H.

    2006-03-01

    Fine-scale soil nutrient enrichment typically stimulates root growth, but it may also increase root herbivory, resulting in trade-offs for plant species and potentially influencing carbon cycling patterns. We used root ingrowth cores to investigate the effects of microsite fertility and root herbivory on root biomass in an aggrading upland forest in the coastal plain of South Carolina, USA. Treatments were randomly assigned to cores from a factorial combination of fertilizer and insecticide. Soil, soil fauna, and roots were removed from the cores at the end of the experiment (8–9 mo), and roots were separated at harvest into three diameter classes. Each diameter class responded differently to fertilizer and insecticide treatments. The finest roots (,1.0 mm diameter), which comprised well over half of all root biomass, were the only ones to respond significantly to both treatments, increasing when fertilizer and when insecticide were added (each P , 0.0001), with maximum biomass found where the treatments were combined (interaction term significant, P , 0.001). These results suggest that root-feeding insects have a strong influence on root standing crop with stronger herbivore impacts on finer roots and within more fertile microsites. Thus, increased vulnerability to root herbivory is a potentially significant cost of root foraging in nutrient-rich patches.

  3. A statistical approach to root system classification

    PubMed Central

    Bodner, Gernot; Leitner, Daniel; Nakhforoosh, Alireza; Sobotik, Monika; Moder, Karl; Kaul, Hans-Peter

    2013-01-01

    Plant root systems have a key role in ecology and agronomy. In spite of fast increase in root studies, still there is no classification that allows distinguishing among distinctive characteristics within the diversity of rooting strategies. Our hypothesis is that a multivariate approach for “plant functional type” identification in ecology can be applied to the classification of root systems. The classification method presented is based on a data-defined statistical procedure without a priori decision on the classifiers. The study demonstrates that principal component based rooting types provide efficient and meaningful multi-trait classifiers. The classification method is exemplified with simulated root architectures and morphological field data. Simulated root architectures showed that morphological attributes with spatial distribution parameters capture most distinctive features within root system diversity. While developmental type (tap vs. shoot-borne systems) is a strong, but coarse classifier, topological traits provide the most detailed differentiation among distinctive groups. Adequacy of commonly available morphologic traits for classification is supported by field data. Rooting types emerging from measured data, mainly distinguished by diameter/weight and density dominated types. Similarity of root systems within distinctive groups was the joint result of phylogenetic relation and environmental as well as human selection pressure. We concluded that the data-define classification is appropriate for integration of knowledge obtained with different root measurement methods and at various scales. Currently root morphology is the most promising basis for classification due to widely used common measurement protocols. To capture details of root diversity efforts in architectural measurement techniques are essential. PMID:23914200

  4. A statistical approach to root system classification.

    PubMed

    Bodner, Gernot; Leitner, Daniel; Nakhforoosh, Alireza; Sobotik, Monika; Moder, Karl; Kaul, Hans-Peter

    2013-01-01

    Plant root systems have a key role in ecology and agronomy. In spite of fast increase in root studies, still there is no classification that allows distinguishing among distinctive characteristics within the diversity of rooting strategies. Our hypothesis is that a multivariate approach for "plant functional type" identification in ecology can be applied to the classification of root systems. The classification method presented is based on a data-defined statistical procedure without a priori decision on the classifiers. The study demonstrates that principal component based rooting types provide efficient and meaningful multi-trait classifiers. The classification method is exemplified with simulated root architectures and morphological field data. Simulated root architectures showed that morphological attributes with spatial distribution parameters capture most distinctive features within root system diversity. While developmental type (tap vs. shoot-borne systems) is a strong, but coarse classifier, topological traits provide the most detailed differentiation among distinctive groups. Adequacy of commonly available morphologic traits for classification is supported by field data. Rooting types emerging from measured data, mainly distinguished by diameter/weight and density dominated types. Similarity of root systems within distinctive groups was the joint result of phylogenetic relation and environmental as well as human selection pressure. We concluded that the data-define classification is appropriate for integration of knowledge obtained with different root measurement methods and at various scales. Currently root morphology is the most promising basis for classification due to widely used common measurement protocols. To capture details of root diversity efforts in architectural measurement techniques are essential. PMID:23914200

  5. Traditional Chinese Medicines in Treatment of Patients with Type 2 Diabetes Mellitus

    PubMed Central

    Xie, Weidong; Zhao, Yunan; Zhang, Yaou

    2011-01-01

    Type 2 diabetes mellitus (T2DM) occurs in 95% of the diabetic populations. Management of T2DM is a challenge. Traditional Chinese medicines (TCM) are usually served as adjuvants used to improve diabetic syndromes in combination of routine antidiabetic drugs. For single-herb prescriptions, Ginseng, Bitter melon, Golden Thread, Fenugreek, Garlic, and Cinnamon might have antidiabetic effects in T2DM patients. Among 30 antidiabetic formulas approved by the State Food and Drugs Administrator of China, top 10 of the most frequently prescribed herbs are Membranous Milkvetch Root, Rehmannia Root, Mongolian Snakegourd Root, Ginseng, Chinese Magnoliavine Fruit, Kudzuvine Root, Dwarf Lilyturf Tuber, Common Anemarrhena Rhizome, Barbary Wolfberry Fruit, and India Bread, which mainly guided by the theory of TCM. Their action mechanisms are related to improve insulin sensitivity, stimulate insulin secretion, protect pancreatic islets, and even inhibit intake of intestinal carbohydrates. However, it is very difficult to determine antihyperglycemic components of TCM. Nevertheless, TCM are becoming popular complementary and alternative medicine in treatment of syndromes of T2DM. In the future, it requires further validation of phytochemical, pharmacological, and clinical natures of TCM in T2DM in the future studies, especially for those herbs with a high prescription frequency. PMID:21584252

  6. Root hairs aid soil penetration by anchoring the root surface to pore walls

    PubMed Central

    Bengough, A. Glyn; Loades, Kenneth; McKenzie, Blair M.

    2016-01-01

    The physical role of root hairs in anchoring the root tip during soil penetration was examined. Experiments using a hairless maize mutant (Zea mays: rth3–3) and its wild-type counterpart measured the anchorage force between the primary root of maize and the soil to determine whether root hairs enabled seedling roots in artificial biopores to penetrate sandy loam soil (dry bulk density 1.0–1.5g cm−3). Time-lapse imaging was used to analyse root and seedling displacements in soil adjacent to a transparent Perspex interface. Peak anchorage forces were up to five times greater (2.5N cf. 0.5N) for wild-type roots than for hairless mutants in 1.2g cm−3 soil. Root hair anchorage enabled better soil penetration for 1.0 or 1.2g cm−3 soil, but there was no significant advantage of root hairs in the densest soil (1.5g cm−3). The anchorage force was insufficient to allow root penetration of the denser soil, probably because of less root hair penetration into pore walls and, consequently, poorer adhesion between the root hairs and the pore walls. Hairless seedlings took 33h to anchor themselves compared with 16h for wild-type roots in 1.2g cm−3 soil. Caryopses were often pushed several millimetres out of the soil before the roots became anchored and hairless roots often never became anchored securely.The physical role of root hairs in anchoring the root tip may be important in loose seed beds above more compact soil layers and may also assist root tips to emerge from biopores and penetrate the bulk soil. PMID:26798027

  7. Root hairs aid soil penetration by anchoring the root surface to pore walls.

    PubMed

    Bengough, A Glyn; Loades, Kenneth; McKenzie, Blair M

    2016-02-01

    The physical role of root hairs in anchoring the root tip during soil penetration was examined. Experiments using a hairless maize mutant (Zea mays: rth3-3) and its wild-type counterpart measured the anchorage force between the primary root of maize and the soil to determine whether root hairs enabled seedling roots in artificial biopores to penetrate sandy loam soil (dry bulk density 1.0-1.5g cm(-3)). Time-lapse imaging was used to analyse root and seedling displacements in soil adjacent to a transparent Perspex interface. Peak anchorage forces were up to five times greater (2.5N cf. 0.5N) for wild-type roots than for hairless mutants in 1.2g cm(-3) soil. Root hair anchorage enabled better soil penetration for 1.0 or 1.2g cm(-3) soil, but there was no significant advantage of root hairs in the densest soil (1.5g cm(-3)). The anchorage force was insufficient to allow root penetration of the denser soil, probably because of less root hair penetration into pore walls and, consequently, poorer adhesion between the root hairs and the pore walls. Hairless seedlings took 33h to anchor themselves compared with 16h for wild-type roots in 1.2g cm(-3) soil. Caryopses were often pushed several millimetres out of the soil before the roots became anchored and hairless roots often never became anchored securely.The physical role of root hairs in anchoring the root tip may be important in loose seed beds above more compact soil layers and may also assist root tips to emerge from biopores and penetrate the bulk soil. PMID:26798027

  8. Improving prediction of metal uptake by Chinese cabbage (Brassica pekinensis L.) based on a soil-plant stepwise analysis.

    PubMed

    Zhang, Sha; Song, Jing; Gao, Hui; Zhang, Qiang; Lv, Ming-Chao; Wang, Shuang; Liu, Gan; Pan, Yun-Yu; Christie, Peter; Sun, Wenjie

    2016-11-01

    It is crucial to develop predictive soil-plant transfer (SPT) models to derive the threshold values of toxic metals in contaminated arable soils. The present study was designed to examine the heavy metal uptake pattern and to improve the prediction of metal uptake by Chinese cabbage grown in agricultural soils with multiple contamination by Cd, Cu, Ni, Pb, and Zn. Pot experiments were performed with 25 historically contaminated soils to determine metal accumulation in different parts of Chinese cabbage. Different soil bioavailable metal fractions were determined using different extractants (0.43M HNO3, 0.01M CaCl2, 0.005M DTPA, and 0.01M LWMOAs), soil moisture samplers, and diffusive gradients in thin films (DGT), and the fractions were compared with shoot metal uptake using both direct and stepwise multiple regression analysis. The stepwise approach significantly improved the prediction of metal uptake by cabbage over the direct approach. Strongly pH dependent or nonlinear relationships were found for the adsorption of root surfaces and in root-shoot uptake processes. Metals were linearly translocated from the root surface to the root. Therefore, the nonlinearity of uptake pattern is an important explanation for the inadequacy of the direct approach in some cases. The stepwise approach offers an alternative and robust method to study the pattern of metal uptake by Chinese cabbage (Brassica pekinensis L.). PMID:27450258

  9. 1-aminocyclopropane-1-carboxylic acid (ACC) concentration and ACC synthase expression in soybean roots and root tips and soybean cyst nematode (Heterodera glycines) colonized root pieces

    Technology Transfer Automated Retrieval System (TEKTRAN)

    It's fairly well established that a functional ethylene response path is important to root knot and cyst nematode colonization of plant roots. However, ethylene plays many roles in root development and the role of ethylene in nematode colonization of roots may be indirect, e.g. lateral root initiati...

  10. Roots at the percolation threshold

    NASA Astrophysics Data System (ADS)

    Kroener, Eva; Ahmed, Mutez Ali; Carminati, Andrea

    2015-04-01

    The rhizosphere is the layer of soil around the roots where complex and dynamic interactions between plants and soil affect the capacity of plants to take up water. The physical properties of the rhizosphere are affected by mucilage, a gel exuded by roots. Mucilage can absorb large volumes of water, but it becomes hydrophobic after drying. We use a percolation model to describe the rewetting of dry rhizosphere. We find that at a critical mucilage concentration the rhizosphere becomes impermeable. The critical mucilage concentration depends on the radius of the soil particle size. Capillary rise experiments with neutron radiography prove that for concentrations below the critical mucilage concentration water could easily cross the rhizosphere, while above the critical concentration water could no longer percolate through it. Our studies, together with former observations of water dynamics in the rhizosphere, suggest that the rhizosphere is near the percolation threshold, where small variations in mucilage concentration sensitively alter the soil hydraulic conductivity. Is mucilage exudation a plant mechanism to efficiently control the rhizosphere conductivity and the access to water?

  11. Roots at the percolation threshold.

    PubMed

    Kroener, Eva; Ahmed, Mutez Ali; Carminati, Andrea

    2015-04-01

    The rhizosphere is the layer of soil around the roots where complex and dynamic interactions between plants and soil affect the capacity of plants to take up water. The physical properties of the rhizosphere are affected by mucilage, a gel exuded by roots. Mucilage can absorb large volumes of water, but it becomes hydrophobic after drying. We use a percolation model to describe the rewetting of dry rhizosphere. We find that at a critical mucilage concentration the rhizosphere becomes impermeable. The critical mucilage concentration depends on the radius of the soil particle size. Capillary rise experiments with neutron radiography prove that for concentrations below the critical mucilage concentration water could easily cross the rhizosphere, while above the critical concentration water could no longer percolate through it. Our studies, together with former observations of water dynamics in the rhizosphere, suggest that the rhizosphere is near the percolation threshold, where small variations in mucilage concentration sensitively alter the soil hydraulic conductivity. Is mucilage exudation a plant mechanism to efficiently control the rhizosphere conductivity and the access to water? PMID:25974526

  12. Salt stress signals shape the plant root.

    PubMed

    Galvan-Ampudia, Carlos S; Testerink, Christa

    2011-06-01

    Plants use different strategies to deal with high soil salinity. One strategy is activation of pathways that allow the plant to export or compartmentalise salt. Relying on their phenotypic plasticity, plants can also adjust their root system architecture (RSA) and the direction of root growth to avoid locally high salt concentrations. Here, we highlight RSA responses to salt and osmotic stress and the underlying mechanisms. A model is presented that describes how salinity affects auxin distribution in the root. Possible intracellular signalling pathways linking salinity to root development and direction of root growth are discussed. These involve perception of high cytosolic Na+ concentrations in the root, activation of lipid signalling and protein kinase activity and modulation of endocytic pathways. PMID:21511515

  13. High resolution modeling of water and nutrient uptake by plant roots: at a scale from single root to root system

    NASA Astrophysics Data System (ADS)

    Abesha, Betiglu; Vanderborght, Jan; Javaux, Mathieu; Schnepf, Andrea; Vereecken, Harry

    2014-05-01

    The uptake of nutrients by plant roots is a multiscale problem. At the small scale, nutrient fluxes towards single roots lead to strong gradients in nutrient concentrations around single roots. At the scale of the root system and soil profile, nutrient fluxes are generated by water fluxes and variations in nutrient uptake due to spatially varying root density, nutrient concentrations and water contents. In this contribution, we present a numerical simulation model that describes the processes at the scale of a single root and the scale of the entire root system simultaneously. Water flow and nutrient transport in the soil are described by the 3-D Richards and advection-dispersion equations, respectively. Water uptake by a root segment is simulated based on the difference between the soil water potential at the soil root interface and in the xylem tissue. The xylem water potential is derived from solving a set of flow equations that describe flow in the root network (Javaux et al., 2008). Nutrient uptake by a segment is simulated as a function of the nutrient concentration at the soil-root interface using a nonlinear Michaelis-Menten equation. An accurate description of the nutrient concentrations gradients around single roots requires a spatial resolution in the sub mm scale and is therefore not feasible for simulations of the entire root system or soil profile. In order to address this problem, a 1-D axisymmetric model (Barber and Cushman, 1981) was used to describe nutrient transport towards a single root segment. The network of connected cylindrical models was coupled to a 3-D regular grid that was used to solve the flow and transport equations at the root system scale. The coupling was done by matching the fluxes across the interfaces of the voxels of the 3-D grid that contain root segments with the fluxes at the outer boundaries of the cylindrical domains and by matching the sink terms in these voxels with uptake by the root segments. To demonstrate the

  14. Comparative Transcriptome Analysis Reveals Heat-Responsive Genes in Chinese Cabbage (Brassica rapa ssp. chinensis)

    PubMed Central

    Wang, Aihua; Hu, Jihong; Huang, Xingxue; Li, Xia; Zhou, Guolin; Yan, Zhixiang

    2016-01-01

    Chinese cabbage (Brassica rapa ssp. chinensis) is an economically and agriculturally significant vegetable crop and is extensively cultivated throughout the world. Heat stress disturbs cellular homeostasis and causes visible growth inhibition of shoots and roots, severe retardation in growth and development, and even death. However, there are few studies on the transcriptome profiling of heat stress in non-heading Chinese cabbage. In this study, we investigated the transcript profiles of non-heading Chinese cabbage from heat-sensitive and heat-tolerant varieties “GHA” and “XK,” respectively, in response to high temperature using RNA sequencing (RNA seq). Approximately 625 genes were differentially expressed between the two varieties. The responsive genes can be divided into three phases along with the time of heat treatment: response to stimulus, programmed cell death and ribosome biogenesis. Differentially expressed genes (DEGs) were identified in the two varieties, including transcription factors (TFs), kinases/phosphatases, genes related to photosynthesis and effectors of homeostasis. Many TFs were involved in the heat stress response of Chinese cabbage, including NAC069 TF which was up-regulated at all the heat treatment stages. And their expression levels were also validated by quantitative real-time-PCR (qRT-PCR). These candidate genes will provide genetic resources for further improving the heat-tolerant characteristics in non-heading Chinese cabbage. PMID:27443222

  15. Comparative Transcriptome Analysis Reveals Heat-Responsive Genes in Chinese Cabbage (Brassica rapa ssp. chinensis).

    PubMed

    Wang, Aihua; Hu, Jihong; Huang, Xingxue; Li, Xia; Zhou, Guolin; Yan, Zhixiang

    2016-01-01

    Chinese cabbage (Brassica rapa ssp. chinensis) is an economically and agriculturally significant vegetable crop and is extensively cultivated throughout the world. Heat stress disturbs cellular homeostasis and causes visible growth inhibition of shoots and roots, severe retardation in growth and development, and even death. However, there are few studies on the transcriptome profiling of heat stress in non-heading Chinese cabbage. In this study, we investigated the transcript profiles of non-heading Chinese cabbage from heat-sensitive and heat-tolerant varieties "GHA" and "XK," respectively, in response to high temperature using RNA sequencing (RNA seq). Approximately 625 genes were differentially expressed between the two varieties. The responsive genes can be divided into three phases along with the time of heat treatment: response to stimulus, programmed cell death and ribosome biogenesis. Differentially expressed genes (DEGs) were identified in the two varieties, including transcription factors (TFs), kinases/phosphatases, genes related to photosynthesis and effectors of homeostasis. Many TFs were involved in the heat stress response of Chinese cabbage, including NAC069 TF which was up-regulated at all the heat treatment stages. And their expression levels were also validated by quantitative real-time-PCR (qRT-PCR). These candidate genes will provide genetic resources for further improving the heat-tolerant characteristics in non-heading Chinese cabbage. PMID:27443222

  16. A Systematic Review of Single Chinese Herbs for Alzheimer's Disease Treatment

    PubMed Central

    Fu, Li-Min; Li, Ju-Tzu

    2011-01-01

    The objectives here are to provide a systematic review of the current evidence concerning the use of Chinese herbs in the treatment of Alzheimer's disease (AD) and to understand their mechanisms of action with respect to the pathophysiology of the disease. AD, characterized microscopically by deposition of amyloid plaques and formation of neurofibrillary tangles in the brain, has become the most common cause of senile dementia. The limitations of western medications have led us to explore herbal medicine. In particular, many Chinese herbs have demonstrated some interesting therapeutic properties. The following databases were searched from their inception: MEDLINE (PUBMED), ALT HEALTH WATCH (EBSCO), CINAH and Cochrane Central. Only single Chinese herbs are included. Two reviewers independently extracted the data and performed quality assessment. The quality assessment of a clinical trial is based on the Jadad criteria. Seven Chinese herbs and six randomized controlled clinical trials were identified under the predefined criteria. Ginkgo biloba, Huperzine A (Lycopodium serratum) and Ginseng have been assessed for their clinical efficacy with limited favorable evidence. No serious adverse events were reported. Chinese herbs show promise in the treatment of AD in terms of their cognitive benefits and more importantly, their mechanisms of action that deal with the fundamental pathophysiology of the disease. However, the current evidence in support of their use is inconclusive or inadequate. Future research should place emphasis on herbs that can treat the root of the disease. PMID:19737808

  17. New pattern recognition system in the e-nose for Chinese spirit identification

    NASA Astrophysics Data System (ADS)

    Hui, Zeng; Qiang, Li; Yu, Gu

    2016-02-01

    This paper presents a new pattern recognition system for Chinese spirit identification by using the polymer quartz piezoelectric crystal sensor based e-nose. The sensors are designed based on quartz crystal microbalance (QCM) principle, and they could capture different vibration frequency signal values for Chinese spirit identification. For each sensor in an 8-channel sensor array, seven characteristic values of the original vibration frequency signal values, i.e., average value (A), root-mean-square value (RMS), shape factor value (Sf), crest factor value (Cf), impulse factor value (If), clearance factor value (CLf), kurtosis factor value (Kv) are first extracted. Then the dimension of the characteristic values is reduced by the principle components analysis (PCA) method. Finally the back propagation (BP) neutral network algorithm is used to recognize Chinese spirits. The experimental results show that the recognition rate of six kinds of Chinese spirits is 93.33% and our proposed new pattern recognition system can identify Chinese spirits effectively. Project supported by the National High Technology Research and Development Program of China (Grant No. 2013AA030901) and the Fundamental Research Funds for the Central Universities, China (Grant No. FRF-TP-14-120A2).

  18. Ethno-cultural diversity in the experience of widowhood in later life: Chinese widows in Canada.

    PubMed

    Martin-Matthews, Anne; Tong, Catherine E; Rosenthal, Carolyn J; McDonald, Lynn

    2013-12-01

    This paper utilizes Helena Znaniecka Lopata's concept of life frameworks as a lens through which to understand the experience of widowhood amongst elderly Chinese immigrant women living in Toronto, Canada. While Lopata defined life frameworks as including social supports, social relations and social roles, for these widows, personal resources (framed in Chinese cultural context) were also important aspects of life frameworks. In-depth interviews with 20 widows contacted through a Chinese community center were conducted in Mandarin and Cantonese and then transcribed and interpreted through team-based qualitative analyses. These women ranged in age from 69 to 93 years and had been in Canada an average of 17 years, with over half of them widowed following immigration. Our analysis framed the widows' narratives in terms of four types of supports defined by Lopata: social, service, financial and emotional supports. They had fairly extensive social and service supports focused primarily around family and the Chinese community. Although norms of filial piety traditionally dictate sons as primary supports, daughters predominated as providers of supports to these widows. Interpreted from a life course perspective, financial supports were deemed sufficient, despite overall limited financial means. Emotional support was more nuanced and complex for these widows. Loneliness and feelings of social isolation were prevalent. Nevertheless, themes of acceptance and satisfaction dominated our findings, as did reciprocity and exchange. The narrative accounts of these widows depict a complexity of experience rooted in their biographies as Chinese women and as immigrants, rather than primarily in widowhood itself. PMID:24300070

  19. Some reflections on the influence of Chinese thought on Jung and his psychological theory.

    PubMed

    Stein, Murray

    2005-04-01

    Jung claimed that Richard Wilhelm, whose masterful translations of Chinese wisdom literature into a European language (German) and thence into Western consciousness have brought Chinese modes of thinking to so many, was one of the most important influences on his own life and work. The contacts between the two men, which took place from the early 1920's until Wilhelm's death in 1930, were few but intense and for Jung decisive in several ways. Wilhelm's translations of the I Ching and The Secret of the Golden Flower opened new avenues for Jung that had far-reaching consequences on his research and writing after 1930. The latter opened the door to the study of alchemy as a key to the archetypal process of individuation as rooted in the collective unconscious. 'Synchronicity' is a term that grew out of his contact with Chinese thought, in particular with the I Ching. From his contact with Chinese thought, additionally, he received confirmation of the view, independently arrived at, that adult psychological development is not linear but rather circular and spiral-like. The letters between Jung and Wilhelm illuminate the great importance Jung ascribed to Wilhelm's contribution toward bridging East and West and the potential value of Chinese philosophy for psychotherapy. PMID:15817043

  20. Root phenology in a changing climate.

    PubMed

    Radville, Laura; McCormack, M Luke; Post, Eric; Eissenstat, David M

    2016-06-01

    Plant phenology is one of the strongest indicators of ecological responses to climate change, and altered phenology can have pronounced effects on net primary production, species composition in local communities, greenhouse gas fluxes, and ecosystem processes. Although many studies have shown that aboveground plant phenology advances with warmer temperatures, demonstration of a comparable association for belowground phenology has been lacking because the factors that influence root phenology are poorly understood. Because roots can constitute a large fraction of plant biomass, and root phenology may not respond to warming in the same way as shoots, this represents an important knowledge gap in our understanding of how climate change will influence phenology and plant performance. We review studies of root phenology and provide suggestions to direct future research. Only 29% of examined studies approached root phenology quantitatively, strongly limiting interpretation of results across studies. Therefore, we suggest that researchers emphasize quantitative analyses in future phenological studies. We suggest that root initiation, peak growth, and root cessation may be under different controls. Root initiation and cessation may be more constrained by soil temperature and the timing of carbon availability, whereas the timing of peak root growth may represent trade-offs among competing plant sinks. Roots probably do not experience winter dormancy in the same way as shoots: 89% of the studies that examined winter phenology found evidence of growth during winter months. More research is needed to observe root phenology, and future studies should be careful to capture winter and early season phenology. This should be done quantitatively, with direct observations of root growth utilizing rhizotrons or minirhizotrons. PMID:26931171

  1. Root Doctors as Providers of Primary Care

    PubMed Central

    Stitt, Van J.

    1983-01-01

    Physicians in primary care recognize that as many as 65 percent of the patients seen in their offices are there for psychological reasons. In any southern town with a moderate population of blacks, there are at least two “root doctors.” These root doctors have mastered the power of autosuggestion and are treating these patients with various forms of medication and psychological counseling. This paper updates the practicing physician on root doctors who practice primary care. PMID:6887277

  2. Root doctors as providers of primary care.

    PubMed

    Stitt, V J

    1983-07-01

    Physicians in primary care recognize that as many as 65 percent of the patients seen in their offices are there for psychological reasons. In any southern town with a moderate population of blacks, there are at least two "root doctors." These root doctors have mastered the power of autosuggestion and are treating these patients with various forms of medication and psychological counseling. This paper updates the practicing physician on root doctors who practice primary care. PMID:6887277

  3. Temperature sensing by primary roots of maize

    NASA Technical Reports Server (NTRS)

    Poff, K. L.

    1990-01-01

    Zea mays L. seedlings, grown on agar plates at 26 degrees C, reoriented the original vertical direction of their primary root when exposed to a thermal gradient applied perpendicular to the gravity vector. The magnitude and direction of curvature can not be explained simply by either a temperature or a humidity effect on root elongation. It is concluded that primary roots of maize sense temperature gradients in addition to sensing the gravitational force.

  4. Advanced Techniques for Root Cause Analysis

    Energy Science and Technology Software Center (ESTSC)

    2000-09-19

    Five items make up this package, or can be used individually. The Chronological Safety Management Template utilizes a linear adaptation of the Integrated Safety Management System laid out in the form of a template that greatly enhances the ability of the analyst to perform the first step of any investigation which is to gather all pertinent facts and identify causal factors. The Problem Analysis Tree is a simple three (3) level problem analysis tree whichmore » is easier for organizations outside of WSRC to use. Another part is the Systemic Root Cause Tree. One of the most basic and unique features of Expanded Root Cause Analysis is the Systemic Root Cause portion of the Expanded Root Cause Pyramid. The Systemic Root Causes are even more basic than the Programmatic Root Causes and represent Root Causes that cut across multiple (if not all) programs in an organization. the Systemic Root Cause portion contains 51 causes embedded at the bottom level of a three level Systemic Root Cause Tree that is divided into logical, organizationally based categorie to assist the analyst. The Computer Aided Root Cause Analysis that allows the analyst at each level of the Pyramid to a) obtain a brief description of the cause that is being considered, b) record a decision that the item is applicable, c) proceed to the next level of the Pyramid to see only those items at the next level of the tree that are relevant to the particular cause that has been chosen, and d) at the end of the process automatically print out a summary report of the incident, the causal factors as they relate to the safety management system, the probable causes, apparent causes, Programmatic Root Causes and Systemic Root Causes for each causal factor and the associated corrective action.« less

  5. Springback and diagravitropism in Merit corn roots.

    PubMed Central

    Kelly, M O; Leopold, A C

    1992-01-01

    Dark-treated Merit corn (Zea mays L.) roots are diagravitropic and lose curvature upon withdrawal of the gravity stimulus (springback). Springback was not detected in a variety of corn that is orthogravitropic in the dark, nor in Merit roots in which tropistic response was enhanced either with red light or with abscisic acid. A possible interpretation is that springback may be associated with a weak growth response of diagravitropic roots. PMID:11537884

  6. Springback and diagravitropism in Merit corn roots

    NASA Technical Reports Server (NTRS)

    Kelly, M. O.; Leopold, A. C.

    1992-01-01

    Dark-treated Merit corn (Zea mays L.) roots are diagravitropic and lose curvature upon withdrawal of the gravity stimulus (springback). Springback was not detected in a variety of corn that is orthogravitropic in the dark, nor in Merit roots in which tropistic response was enhanced either with red light or with abscisic acid. A possible interpretation is that springback may be associated with a weak growth response of diagravitropic roots.

  7. Springback and diagravitropism in Merit corn roots.

    PubMed

    Kelly, M O; Leopold, A C

    1992-06-01

    Dark-treated Merit corn (Zea mays L.) roots are diagravitropic and lose curvature upon withdrawal of the gravity stimulus (springback). Springback was not detected in a variety of corn that is orthogravitropic in the dark, nor in Merit roots in which tropistic response was enhanced either with red light or with abscisic acid. A possible interpretation is that springback may be associated with a weak growth response of diagravitropic roots. PMID:11537884

  8. Temperature sensing by primary roots of maize

    SciTech Connect

    Fortin, M.C.A.; Poff, K.L. )

    1990-09-01

    Zea mays L. seedlings, grown on agar plates at 26{degree}C, reoriented the original vertical direction of their primary root when exposed to a thermal gradient applied perpendicular to the gravity vector. The magnitude and direction of curvature can not be explained simply by either a temperature or a humidity effect on root elongation. It is concluded that primary roots of maize sense temperature gradients in addition to sensing the gravitational force.

  9. Behavioral response of grape root borer (Lepidoptera: Sesiidae) neonates to grape root volatiles.

    PubMed

    Rijal, J P; Zhang, A; Bergh, J C

    2013-12-01

    Grape root borer, Vitacea polistiformis (Harris), is an oligophagous and potentially destructive pest of grape in commercial vineyards throughout much of the eastern United States. Larvae feed on vine roots, although little is known about their below-ground interactions with host plants. The behavioral response of groups of grape root borer neonates to stimuli from host and nonhost roots was evaluated in single and paired stimuli bioassays in which stimuli were presented in opposing wells attached to the bottom of petri dish arenas. Stimulus sources included root pieces and root headspace volatiles from 3309 and 420-A grape rootstocks (host) and apple (nonhost) and ethanol-based extracts of 3309 and 420-A roots. In single stimulus assays, significantly more larvae were recovered from wells containing grape roots, apple roots, grape extracts, and grape root volatiles than from control wells, but there was no significant response to volatiles collected from the headspace of apple roots. In paired stimuli assays, significantly more larvae were recovered from wells containing grape than apple roots. There was no difference in larval distribution between wells when 420-A and 3309 roots were presented simultaneously, although a significantly greater response to 3309 than 420-A root extract was recorded. When soil was added to the assays, significantly more larvae were recovered from wells containing grape roots than from those containing only soil, but this response was not detected in assays using buried apple roots. These results are discussed in relation to the plant-insect interactions between grape root borer larvae and their Vitaceae hosts. PMID:24216488

  10. Characterization of Pearl Millet Root Architecture and Anatomy Reveals Three Types of Lateral Roots

    PubMed Central

    Passot, Sixtine; Gnacko, Fatoumata; Moukouanga, Daniel; Lucas, Mikaël; Guyomarc’h, Soazig; Ortega, Beatriz Moreno; Atkinson, Jonathan A.; Belko, Marème N.; Bennett, Malcolm J.; Gantet, Pascal; Wells, Darren M.; Guédon, Yann; Vigouroux, Yves; Verdeil, Jean-Luc; Muller, Bertrand; Laplaze, Laurent

    2016-01-01

    Pearl millet plays an important role for food security in arid regions of Africa and India. Nevertheless, it is considered an orphan crop as it lags far behind other cereals in terms of genetic improvement efforts. Breeding pearl millet varieties with improved root traits promises to deliver benefits in water and nutrient acquisition. Here, we characterize early pearl millet root system development using several different root phenotyping approaches that include rhizotrons and microCT. We report that early stage pearl millet root system development is characterized by a fast growing primary root that quickly colonizes deeper soil horizons. We also describe root anatomical studies that revealed three distinct types of lateral roots that form on both primary roots and crown roots. Finally, we detected significant variation for two root architectural traits, primary root lenght and lateral root density, in pearl millet inbred lines. This study provides the basis for subsequent genetic experiments to identify loci associated with interesting early root development traits in this important cereal. PMID:27379124

  11. Root-to-Root Travel of the Beneficial Bacterium Azospirillum brasilense†

    PubMed Central

    Bashan, Yoav; Holguin, Gina

    1994-01-01

    The root-to-root travel of the beneficial bacterium Azospirillum brasilense on wheat and soybean roots in agar, sand, and light-textured soil was monitored. We used a motile wild-type (Mot+) strain and a motility-deficient (Mot-) strain which was derived from the wild-type strain. The colonization levels of inoculated roots were similar for the two strains. Mot+ cells moved from inoculated roots (either natural or artificial roots in agar, sand, or light-textured soil) to noninoculated roots, where they formed a band-type colonization composed of bacterial aggregates encircling a limited part of the root, regardless of the plant species. The Mot- strain did not move toward noninoculated roots of either plant species and usually stayed at the inoculation site and root tips. The effect of attractants and repellents was the primary factor governing the motility of Mot+ cells in the presence of adequate water. We propose that interroot travel of A. brasilense is an essential preliminary step in the root-bacterium recognition mechanism. Bacterial motility might have a general role in getting Azospirillum cells to the site where firmer attachment favors colonization of the root system. Azospirillum travel toward plants is a nonspecific active process which is not directly dependent on nutrient deficiency but is a consequence of a nonspecific bacterial chemotaxis, influenced by the balance between attractants and possibly repellents leaked by the root. PMID:16349297

  12. Characterization of Pearl Millet Root Architecture and Anatomy Reveals Three Types of Lateral Roots.

    PubMed

    Passot, Sixtine; Gnacko, Fatoumata; Moukouanga, Daniel; Lucas, Mikaël; Guyomarc'h, Soazig; Ortega, Beatriz Moreno; Atkinson, Jonathan A; Belko, Marème N; Bennett, Malcolm J; Gantet, Pascal; Wells, Darren M; Guédon, Yann; Vigouroux, Yves; Verdeil, Jean-Luc; Muller, Bertrand; Laplaze, Laurent

    2016-01-01

    Pearl millet plays an important role for food security in arid regions of Africa and India. Nevertheless, it is considered an orphan crop as it lags far behind other cereals in terms of genetic improvement efforts. Breeding pearl millet varieties with improved root traits promises to deliver benefits in water and nutrient acquisition. Here, we characterize early pearl millet root system development using several different root phenotyping approaches that include rhizotrons and microCT. We report that early stage pearl millet root system development is characterized by a fast growing primary root that quickly colonizes deeper soil horizons. We also describe root anatomical studies that revealed three distinct types of lateral roots that form on both primary roots and crown roots. Finally, we detected significant variation for two root architectural traits, primary root lenght and lateral root density, in pearl millet inbred lines. This study provides the basis for subsequent genetic experiments to identify loci associated with interesting early root development traits in this important cereal. PMID:27379124

  13. [Studies on chemical constituents from the root of Coriaria nepalensis wall (Coriaria sinica Maxim)].

    PubMed

    Wei, H; Zeng, F; Lu, M; Tang, R

    1998-09-01

    The root of Coriaria nepalensis Wall (Coriaria sinica Maxim) is a Chinese herbal medicine and has been used to treat numbness, toothache due to wind and heat, phlegm-retention syndrome, traumatic injury and acute conjunctivitis. Nine compounds were isolated from the root of Coriaria nepalensis Wall and they were identified as braylin (I), norbraylin (II), dihydrocoriamyrtin (III), coriamyrtin (IV), tutin (V), coriatin (VI), apotutin (VII), hydroxycoriatin (VIII) and gallic acid (IX) on the basis of their physicochemical properties and IR, UV, MS, 1HNMR, 13CNMR data. I, II were isolated from the title plant for the first time; III was obtained from plant origin for the first time, and VII, VIII were new compounds. PMID:12016873

  14. Measurements of water uptake of maize roots: the key function of lateral roots

    NASA Astrophysics Data System (ADS)

    Ahmed, M. A.; Zarebanadkouki, M.; Kroener, E.; Kaestner, A.; Carminati, A.

    2014-12-01

    Maize (Zea mays L.) is one of the most important crop worldwide. Despite its importance, there is limited information on the function of different root segments and root types of maize in extracting water from soils. Therefore, the aim of this study was to investigate locations of root water uptake in maize. We used neutron radiography to: 1) image the spatial distribution of maize roots in soil and 2) trace the transport of injected deuterated water (D2O) in soil and roots. Maizes were grown in aluminum containers (40×38×1 cm) filled with a sandy soil. When the plants were 16 days old, we injected D2O into selected soil regions containing primary, seminal and lateral roots. The experiments were performed during the day (transpiring plants) and night (not transpiring plants). The transport of D2O into roots was simulated using a new convection-diffusion numerical model of D2O transport into roots. By fitting the observed D2O transport we quantified the diffusional permeability and the water uptake of the different root segments. The maize root architecture consisted of a primary root, 4-5 seminal roots and many lateral roots connected to the primary and seminal roots. Laterals emerged from the proximal 15 cm of the primary and seminal roots. Water uptake occurred primarily in lateral roots. Lateral roots had the highest diffusional permeability (9.4×10-7), which was around six times higher that the diffusional permeability of the old seminal segments (1.4×10-7), and two times higher than the diffusional permeability of the young seminal segments (4.7×10-7). The radial flow of D2O into the lateral (6.7×10-5 ) was much higher than in the young seminal roots (1.1×10-12). The radial flow of D2O into the old seminal was negligible. We concluded that the function of the primary and seminal roots was to collect water from the lateral roots and transport it to the shoot. A maize root system with lateral roots branching from deep primary and seminal roots would be

  15. Chinese herbal medicines for hypercholesterolemia

    PubMed Central

    Liu, Zhao Lan; Liu, Jian Ping; Zhang, Anthony Lin; Wu, Qiong; Ruan, Yao; Lewith, George; Visconte, Denise

    2011-01-01

    Background Hypercholesterolemia is an important key contributory factor for ischemic heart disease and is associated with age, high blood pressure, a family history of hypercholesterolemia, and diabetes. Chinese herbal medicines have been used for a long time as lipid-lowering agents. Objectives To assess the effects of Chinese herbal medicines on hypercholesterolemia. Search strategy We searched the following databases: The Cochrane Library (issue 8, 2010), MEDLINE (until July 2010), EMBASE (until July 2010), Chinese BioMedical Database (until July 2010), Traditional Chinese Medical Literature Analysis and Retrieval System (until July 2010), China National Knowledge Infrastructure (until July 2010), Chinese VIP Information (until July 2010), Chinese Academic Conference Papers Database and Chinese Dissertation Database (until July 2010), and Allied and Complementary Medicine Database (until July 2010). Selection criteria We considered randomized controlled clinical trials in hypercholesterolemic participants comparing Chinese herbal medicines with placebo, no treatment, and pharmacological or non-pharmacological interventions. Data collection and analysis Two review authors independently extracted data and assessed the risk of bias. We resolved any disagreements with this assessment through discussion and a decision was achieved based by consensus. We assessed trials for the risk of bias against key criteria: random sequence generation, allocation concealment, blinding of participants, incomplete outcome data, selective outcome reporting and other sources of bias. Main results We included 22 randomized trials (2130 participants). The mean treatment duration was 2.3 ± 1.3 months (ranging from one to six months). Twenty trials were conducted in China and 18 trials were published in Chinese. Overall, the risk of bias of included trials was high or unclear. Five different herbal medicines were evaluated in the included trials, which compared herbs with conventional

  16. Genetic ablation of root cap cells in Arabidopsis

    NASA Technical Reports Server (NTRS)

    Tsugeki, R.; Fedoroff, N. V.

    1999-01-01

    The root cap is increasingly appreciated as a complex and dynamic plant organ. Root caps sense and transmit environmental signals, synthesize and secrete small molecules and macromolecules, and in some species shed metabolically active cells. However, it is not known whether root caps are essential for normal shoot and root development. We report the identification of a root cap-specific promoter and describe its use to genetically ablate root caps by directing root cap-specific expression of a diphtheria toxin A-chain gene. Transgenic toxin-expressing plants are viable and have normal aerial parts but agravitropic roots, implying loss of root cap function. Several cell layers are missing from the transgenic root caps, and the remaining cells are abnormal. Although the radial organization of the roots is normal in toxin-expressing plants, the root tips have fewer cytoplasmically dense cells than do wild-type root tips, suggesting that root meristematic activity is lower in transgenic than in wild-type plants. The roots of transgenic plants have more lateral roots and these are, in turn, more highly branched than those of wild-type plants. Thus, root cap ablation alters root architecture both by inhibiting root meristematic activity and by stimulating lateral root initiation. These observations imply that the root caps contain essential components of the signaling system that determines root architecture.

  17. Deriving the unit hydrograph by root selection

    NASA Astrophysics Data System (ADS)

    Turner, J. E.; Dooge, J. C. I.; Bree, T.

    1989-09-01

    De Laine's method of deriving the unit hydrograph from the common roots of polynomials corresponding to different storms is used as a basis for proposing a new procedure in which the unit hydrograph roots can be selected from among the polynomial roots for the runoff of a single storm. The selection is made on the basis that the complex unit hydrograph roots form a characteristic "skew circle" pattern when plotted on an Argand diagram. The application of the procedure to field data is illustrated for both a single-peaked and a double-peaked event.

  18. New substitution models for rooting phylogenetic trees

    PubMed Central

    Williams, Tom A.; Heaps, Sarah E.; Cherlin, Svetlana; Nye, Tom M. W.; Boys, Richard J.; Embley, T. Martin

    2015-01-01

    The root of a phylogenetic tree is fundamental to its biological interpretation, but standard substitution models do not provide any information on its position. Here, we describe two recently developed models that relax the usual assumptions of stationarity and reversibility, thereby facilitating root inference without the need for an outgroup. We compare the performance of these models on a classic test case for phylogenetic methods, before considering two highly topical questions in evolutionary biology: the deep structure of the tree of life and the root of the archaeal radiation. We show that all three alignments contain meaningful rooting information that can be harnessed by these new models, thus complementing and extending previous work based on outgroup rooting. In particular, our analyses exclude the root of the tree of life from the eukaryotes or Archaea, placing it on the bacterial stem or within the Bacteria. They also exclude the root of the archaeal radiation from several major clades, consistent with analyses using other rooting methods. Overall, our results demonstrate the utility of non-reversible and non-stationary models for rooting phylogenetic trees, and identify areas where further progress can be made. PMID:26323766

  19. Maxillary First Molar with Two Root Canals

    PubMed Central

    Rahimi, Saeed; Ghasemi, Negin

    2013-01-01

    Knowledge regarding the anatomic morphology of maxillary molars is absolutely essential for the success of endodontic treatment. The morphology of the permanent maxillary first molar has been reviewed extensively; however, the presence of two canals in a two-rooted maxillary first molar has rarely been reported in studies describing tooth and root canal anatomies. This case report presents a patient with a maxillary first molar with two roots and two root canals, who was referred to the Department of Endodontics, Tabriz University of Medical Sciences, Iran. PMID:23862051

  20. The nth root of sequential effect algebras

    NASA Astrophysics Data System (ADS)

    Shen, Jun; Wu, Junde

    2010-06-01

    In 2005, Gudder [Int. J. Theor. Phys. 44, 2219 (2005)] presented 25 problems of sequential effect algebras, the 20th problem asked: In a sequential effect algebra, if the square root of some element exists, is it unique? In this paper, we show that for each given positive integer n >1, there is a sequential effect algebra such that the nth root of its some element c is not unique, and the nth root of c is not the kth root of c (k

  1. New substitution models for rooting phylogenetic trees.

    PubMed

    Williams, Tom A; Heaps, Sarah E; Cherlin, Svetlana; Nye, Tom M W; Boys, Richard J; Embley, T Martin

    2015-09-26

    The root of a phylogenetic tree is fundamental to its biological interpretation, but standard substitution models do not provide any information on its position. Here, we describe two recently developed models that relax the usual assumptions of stationarity and reversibility, thereby facilitating root inference without the need for an outgroup. We compare the performance of these models on a classic test case for phylogenetic methods, before considering two highly topical questions in evolutionary biology: the deep structure of the tree of life and the root of the archaeal radiation. We show that all three alignments contain meaningful rooting information that can be harnessed by these new models, thus complementing and extending previous work based on outgroup rooting. In particular, our analyses exclude the root of the tree of life from the eukaryotes or Archaea, placing it on the bacterial stem or within the Bacteria. They also exclude the root of the archaeal radiation from several major clades, consistent with analyses using other rooting methods. Overall, our results demonstrate the utility of non-reversible and non-stationary models for rooting phylogenetic trees, and identify areas where further progress can be made. PMID:26323766

  2. The Chinese-American Workforce

    SciTech Connect

    Nissen, S.H.

    1990-05-01

    The current study focused on a group of Chinese-American professionals working in a scientific environment in the San Francisco Bay area. One of the goals of the present study is to determine to what extent do the Chinese cultural values impact job performance, interpersonal relationships and perception of job satisfaction. This was carried out by identifying the important motivational factors and optimal working conditions which provided career satisfaction for the Chinese-American professionals. Comparisons were made between the US born and foreign-born respondents to determine differences, if any, in their perceptions relative to career satisfaction due to varying acculturation levels. In addition, this study identified barriers to career advancement and compared these barriers with the results of another survey on the Chinese-American professionals working in government, industry and private sector in the Bay area. A structured survey questionnaire was designed by the investigator and sent to 167 Chinese-American professionals, composed of both US-born and foreign-born. 41 refs., 12 figs., 8 tabs.

  3. Toxicological risks of Chinese herbs.

    PubMed

    Shaw, Debbie

    2010-12-01

    As traditional Chinese medicine (TCM) has become more popular there have been increasing concerns about safety and potential toxicity of the Chinese materia medica (CMM) comprising plants, animal parts and minerals. The potential toxicity of many CMM is well recognised in TCM and to reduce risks use of some herbs is restricted whilst specific processing methods have been developed to modify the activities/toxicity of others. However adverse reactions have been reported, many of these are due misuse or abuse of Chinese medicine. The main problem remains products adulterated with pharmaceuticals for weight loss or erectile dysfunction. But some herbs have narrow therapeutic ranges (e.g., Aconitum species) so toxic effects are frequently reported. Toxic effects from chronic or cumulative dosing are difficult to detect in the traditional setting and recent reports have demonstrated the health problems from Aristolochia species. Despite safety concerns, Chinese medicine appears to be relatively safe with comparatively few reports of adverse reactions compared with overall drug reports. The wealth of information in the Chinese literature needs to be more widely available. As TCM is widely used by patients, improved pharmacovigilance and pharmacoepidemiology can contribute valuable safety information, relevant to clinical use. PMID:21077025

  4. Assessment of Chinese Students' Experience with Foreign Faculty: A Case Study from a Chinese University

    ERIC Educational Resources Information Center

    Ho, Raymond

    2010-01-01

    This article compares Chinese students' responses to local Chinese versus American professors, and the effectiveness of the professors' respective teaching techniques. A case study made at a single university in China, which had a joint academic program with the United States, found that Chinese students preferred local Chinese professors to…

  5. Writing Chinese and Mathematics Achievement: A Study with Chinese-American Undergraduates.

    ERIC Educational Resources Information Center

    Li, Chieh; Nuttall, Ronald

    2001-01-01

    Indicates that writing Chinese is correlated to Chinese-American (CA) students' spatial skills and investigates whether writing Chinese would have the same relationship to mathematics skills. Suggested a strong correlation between writing Chinese and success on SAT-Math. Supports the cultural relativity theory of gender difference on SAT-Math.…

  6. Mothers' Self-Reported Emotional Expression in Mainland Chinese, Chinese American and European American Families

    ERIC Educational Resources Information Center

    Camras, Linda; Kolmodin, Karen; Chen, Yinghe

    2008-01-01

    This study compared Mainland Chinese, Chinese American and European American mothers' self-reported emotional expression within the family. Mothers of 3-year-old European American (n = 40), Chinese American (n = 39) and Mainland Chinese (n = 36) children (n = 20 girls per group) completed the Self-Expressiveness in the Family Questionnaire (SEFQ),…

  7. The Meaning of "Being Chinese" and "Being American." Variation among Chinese American Young Adults.

    ERIC Educational Resources Information Center

    Tsai, Jeanne L.; Ying, Yu-Wen; Lee, Peter A.

    2000-01-01

    Investigated how meanings of being Chinese and being American varied among young adults, examining orientations to Chinese and American cultures and noting cultural domains upon which being Chinese and being American were based. Surveys of Chinese American college students who were American-born or immigrants indicated that the meanings attached…

  8. Translating Chinese Zero Anaphoric Subjects into English.

    ERIC Educational Resources Information Center

    Lee, Cher-leng

    1993-01-01

    Deals with a major difference between European languages and Chinese, namely the sparse use of anaphoric reference in Chinese. Suggests that the translator's way of rendering references will affect the interpretational potential of the text in the target language. (NKA)

  9. Increased symplasmic permeability in barley root epidermal cells correlates with defects in root hair development.

    PubMed

    Marzec, M; Muszynska, A; Melzer, M; Sas-Nowosielska, H; Kurczynska, E U

    2014-03-01

    It is well known that the process of plant cell differentiation depends on the symplasmic isolation of cells. Before starting the differentiation programme, the individual cell or group of cells should restrict symplasmic communication with neighbouring cells. We tested the symplasmic communication between epidermal cells in the different root zones of parental barley plants Hordeum vulgare L., cv. 'Karat' with normal root hair development, and two root hairless mutants (rhl1.a and rhl1.b). The results clearly show that symplasmic communication was limited during root hair differentiation in the parental variety, whereas in both root hairless mutants epidermal cells were still symplasmically connected in the corresponding root zone. This paper is the first report on the role of symplasmic isolation in barley root cell differentiation, and additionally shows that a disturbance in the restriction of symplasmic communication is present in root hairless mutants. PMID:23927737

  10. Increased symplasmic permeability in barley root epidermal cells correlates with defects in root hair development

    PubMed Central

    Marzec, M; Muszynska, A; Melzer, M; Sas-Nowosielska, H; Kurczynska, E U; Wick, S

    2014-01-01

    It is well known that the process of plant cell differentiation depends on the symplasmic isolation of cells. Before starting the differentiation programme, the individual cell or group of cells should restrict symplasmic communication with neighbouring cells. We tested the symplasmic communication between epidermal cells in the different root zones of parental barley plants Hordeum vulgare L., cv. ‘Karat’ with normal root hair development, and two root hairless mutants (rhl1.a and rhl1.b). The results clearly show that symplasmic communication was limited during root hair differentiation in the parental variety, whereas in both root hairless mutants epidermal cells were still symplasmically connected in the corresponding root zone. This paper is the first report on the role of symplasmic isolation in barley root cell differentiation, and additionally shows that a disturbance in the restriction of symplasmic communication is present in root hairless mutants. PMID:23927737

  11. OZONE DECREASES SPRING ROOT GROWTH AND ROOT CARBOHYDRATE CONTENT IN PONDEROSA PINE THE YEAR FOLLOWING EXPOSURE

    EPA Science Inventory

    Storage carbohydrates are extremely important for new shoot and root development following dormancy or during periods of high stress. he hypothesis that ozone decreases carbohydrate storage and decreases new root growth during the year following exposure was investigated. eedling...

  12. Root-growth-inhibiting sheet

    DOEpatents

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene; Van Voris, Peter

    1993-01-01

    In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a "geotextile" and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

  13. Root-growth-inhibiting sheet

    DOEpatents

    Burton, F.G.; Cataldo, D.A.; Cline, J.F.; Skiens, W.E.; Van Voris, P.

    1993-01-26

    In accordance with this invention, a porous sheet material is provided at intervals with bodies of a polymer which contain a 2,6-dinitroaniline. The sheet material is made porous to permit free passage of water. It may be either a perforated sheet or a woven or non-woven textile material. A particularly desirable embodiment is a non-woven fabric of non-biodegradable material. This type of material is known as a geotextile'' and is used for weed control, prevention of erosion on slopes, and other landscaping purposes. In order to obtain a root repelling property, a dinitroaniline is blended with a polymer which is attached to the geotextile or other porous material.

  14. ROOT CAUSE ANALYSIS PROGRAM MANUAL

    SciTech Connect

    Gravois, Melanie C.

    2007-05-02

    Root Cause Analysis (RCA) identifies the cause of an adverse condition that, if corrected, will preclude recurrence or greatly reduce the probability of recurrence of the same or similar adverse conditions and thereby protect the health and safety of the public, the workers, and the environment. This procedure sets forth the requirements for management determination and the selection of RCA methods and implementation of RCAs that are a result of significant findings from Price-Anderson Amendments Act (PAAA) violations, occurrences/events, Significant Adverse Conditions, and external oversight Corrective Action Requests (CARs) generated by the Office of Enforcement (PAAA headquarters), the U.S. Environmental Protection Agency, and other oversight entities against Lawrence Berkeley National Laboratory (LBNL). Performance of an RCA may result in the identification of issues that should be reported in accordance with the Issues Management Program Manual.

  15. Root hair formation in rice (Oryza sativa L.) differs between root types and is altered in artificial growth conditions.

    PubMed

    Nestler, Josefine; Keyes, Samuel David; Wissuwa, Matthias

    2016-06-01

    Root hairs are important sites for nutrient uptake, especially in P limiting conditions. Here we provide first insights into root hair development for the diverse root types of rice grown under different conditions, and show the first in situ images of rice root hairs in intact soil. Roots of plants grown in upland fields produced short root hairs that showed little responsiveness to P deficiency, and had a higher root hair density in the high P condition. These results were reproducible in rhizoboxes under greenhouse conditions. Synchrotron-based in situ analysis of root hairs in intact soil further confirmed this pattern of root hair formation. In contrast, plants grown in nutrient solution produced more and longer root hairs in low P conditions, but these were unequally distributed among the different root types. While nutrient solution-grown main roots had longer hairs compared to upland field-grown main roots, second order lateral roots did not form any root hairs in nutrient solution-grown plants. Furthermore, root hair formation for plants grown in flooded lowland fields revealed few similarities with those grown in nutrient solution, thus defining nutrient solution as a possible measure of maximal, but not natural root hair development. By combining root hair length and density as a measure for root hair impact on the whole soil-grown root system we show that lateral roots provided the majority of root hair surface. PMID:26976815

  16. Root growth and nitrate-nitrogen leaching of catch crops following spring wheat.

    PubMed

    Herrera, Juan M; Feil, Boy; Stamp, Peter; Liedgens, Markus

    2010-01-01

    Growing nitrogen (N) catch crops can reduce NO(3)-N leaching after cultivating cereals. The objective of this study was to relate NO(3)-N leaching to variation in the uptake of N and the size and distribution of the root systems of different catch crops species. In a 3-yr lysimeter experiment, phacelia (Phacelia tanacetifolia Benth.), sunflower (Helianthus annuus L.), and a Brassica species (yellow mustard [Brassica alba L.] or a hybrid of turnip rape [B. rapa L. spp. oleifera (DC.) Metzg.] and Chinese cabbage [B. rapa L. ssp. chinensis (L.) Hanelt]) were grown after the harvest of spring wheat under two levels of N supply. Bare soil lysimeters served as the control. Water percolation from the lysimeters and the NO(3)(-) concentration in the leachate were measured weekly from the sowing until the presumed frost-kill of the catch crops. Minirhizotrons were used to assess the spatial and temporal patterns of root growth from 0.10 to 1.00 m. The catch crop species differed in their shoot biomass, N uptake, total NO(3)-N leaching, and root growth. The results suggested that there was no strict relationship between the total NO(3)-N leaching of each catch crop species and the N uptake or parameters that indicate static characteristics of the root system. In contrast, the ranking of each catch crop species by parameters that indicate early root growth was inversely related to the ranking of each catch crop species in NO(3)-N leaching. The rapid establishment of the root system is essential for a catch crop following spring wheat to reduce the amount of NO(3)-N leaching after the harvest of spring wheat. PMID:20400580

  17. Malformations of the tooth root in humans.

    PubMed

    Luder, Hans U

    2015-01-01

    The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS) which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus, even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on root formation

  18. Malformations of the tooth root in humans

    PubMed Central

    Luder, Hans U.

    2015-01-01

    The most common root malformations in humans arise from either developmental disorders of the root alone or disorders of radicular development as part of a general tooth dysplasia. The aim of this review is to relate the characteristics of these root malformations to potentially disrupted processes involved in radicular morphogenesis. Radicular morphogenesis proceeds under the control of Hertwig's epithelial root sheath (HERS) which determines the number, length, and shape of the root, induces the formation of radicular dentin, and participates in the development of root cementum. Formation of HERS at the transition from crown to root development appears to be very insensitive to adverse effects, with the result that rootless teeth are extremely rare. In contrast, shortened roots as a consequence of impaired or prematurely halted apical growth of HERS constitute the most prevalent radicular dysplasia which occurs due to trauma and unknown reasons as well as in association with dentin disorders. While odontoblast differentiation inevitably stops when growth of HERS is arrested, it seems to be unaffected even in cases of severe dentin dysplasias such as regional odontodysplasia and dentin dysplasia type I. As a result radicular dentin formation is at least initiated and progresses for a limited time. The only condition affecting cementogenesis is hypophosphatasia which disrupts the formation of acellular cementum through an inhibition of mineralization. A process particularly susceptible to adverse effects appears to be the formation of the furcation in multirooted teeth. Impairment or disruption of this process entails taurodontism, single-rooted posterior teeth, and misshapen furcations. Thus, even though many characteristics of human root malformations can be related to disorders of specific processes involved in radicular morphogenesis, precise inferences as to the pathogenesis of these dysplasias are hampered by the still limited knowledge on root formation

  19. Root-soil relationships and terroir

    NASA Astrophysics Data System (ADS)

    Tomasi, Diego

    2015-04-01

    Soil features, along with climate, are among the most important determinants of a succesful grape production in a certain area. Most of the studies, so far, investigated the above-ground vine response to differente edaphic and climate condition, but it is clearly not sufficient to explain the vine whole behaviour. In fact, roots represent an important part of the terroir system (soil-plant-atmosphere-man), and their study can provide better comprehension of vine responses to different environments. The root density and distribution, the ability of deep-rooting and regenerating new roots are good indicators of root well-being, and represents the basis for an efficient physiological activity of the root system. Root deepening and distribution are strongly dependent and sensitive on soil type and soil properties, while root density is affected mostly by canopy size, rootstock and water availability. According to root well-being, soil management strategies should alleviate soil impediments, improving aeration and microbial activity. Moreover, agronomic practices can impact root system performance and influence the above-ground growth. It is well known, for example, that the root system size is largely diminished by high planting densities. Close vine spacings stimulate a more effective utilization of the available soil, water and nutrients, but if the competition for available soil becomes too high, it can repress vine growth, and compromise vineyard longevity, productivity and reaction to growing season weather. Development of resilient rootstocks, more efficient in terms of water and nutrient uptake and capable of dealing with climate and soil extremes (drought, high salinity) are primary goals fore future research. The use of these rootstocks will benefit a more sustainable use of the soil resources and the preservation and valorisation of the terroir.

  20. Root reinforcement of soils under compression

    NASA Astrophysics Data System (ADS)

    Schwarz, M.; Rist, A.; Cohen, D.; Giadrossich, F.; Egorov, P.; Büttner, D.; Stolz, M.; Thormann, J.-J.

    2015-10-01

    It is well recognized that roots reinforce soils and that the distribution of roots within vegetated hillslopes strongly influences the spatial distribution of soil strength. Previous studies have focussed on the contribution of root reinforcement under conditions of tension or shear. However, no systematic investigation into the contribution of root reinforcement to soils experiencing compression, such as the passive Earth forces at the toe of a landslide, is found in the literature. An empirical-analytical model (CoRoS) for the quantification of root reinforcement in soils under compression is presented and tested against experimental data. The CoRoS model describes the force-displacement behavior of compressed, rooted soils and can be used to provide a framework for improving slope stability calculations. Laboratory results showed that the presence of 10 roots with diameters ranging from 6 to 28 mm in a rectangular soil profile 0.72 m by 0.25 m increased the compressive strength of the soil by about 40% (2.5 kN) at a displacement of 0.05 m, while the apparent stiffness of the rooted soil was 38% higher than for root-free soil. The CoRoS model yields good agreement with experimentally determined values of maximum reinforcement force and compression force as a function of displacement. These results indicate that root reinforcement under compression has a major influence on the mechanical behavior of soil and that the force-displacement behavior of roots should be included in analysis of the compressive regimes that commonly are present in the toe of landslides.

  1. Teaching Oral Chinese in the United States

    ERIC Educational Resources Information Center

    Cheng, Chin-Chuan

    1976-01-01

    Because Chinese language textbooks were judged inadequate in teaching vocabulary dealing with everyday life in the U.S. and in China, new methods and materials were introduced into an oral Chinese course. Prepared discussion topics, Chinese films, soap operas, and shortwave radio broadcasts were used. (CHK)

  2. Problems of Textbook in Teaching Chinese Poetry.

    ERIC Educational Resources Information Center

    Kuo, Ta-hsia

    It is proposed that teachers of Chinese expose their students to traditional critical views of Chinese poetics and criticism through careful selection of poems. This approach to language study is based on the assumption that the student may gain insight and appreciation of Chinese poetry as well as a feeling for the culture. Arguments favoring…

  3. Chinese American Students Fight for Their Rights

    ERIC Educational Resources Information Center

    Wang, Yuxiang; Phillion, JoAnn

    2007-01-01

    Parental and community involvement play a key role in the Chinese American students' fight for their rights. In order to understand the reasons behind the parental and community support of Chinese students, a survey was conducted among Chinese parents to assess what they know about language loss, power, knowledge, and democracy. The results…

  4. BIBLIOGRAPHY AND GLOSSARY FOR CHINESE GRAMMAR.

    ERIC Educational Resources Information Center

    LIU, LILLIAN; WANG, W. S-Y

    THIS BIBLIOGRAPHY LISTS 937 TITLES IN THE FIELD OF CHINESE GRAMMAR FROM AMERICAN AND FOREIGN BOOKS, MAGAZINES, AND JOURNALS. THE AUTHORS AND TITLES ARE LISTED IN PINYIN SYSTEM TRANSCRIPTION WITH A TRANSLATION OF THE TITLE IN ENGLISH AND WITH CHINESE LOGOGRAPHS AFTER THE SOURCE CITATION FOR THOSE ENTRIES ORGINALLY WRITTEN IN CHINESE. ENTRIES ARE…

  5. Saving Chinese-Language Education in Singapore

    ERIC Educational Resources Information Center

    Lee, Cher Leng

    2012-01-01

    Three-quarters of Singapore's population consists of ethnic Chinese, and yet, learning Chinese (Mandarin) has been a headache for many Singapore students. Recently, many scholars have argued that the rhetoric of language planning for Mandarin Chinese should be shifted from emphasizing its cultural value to stressing its economic value since…

  6. Animals of the Chinese Zodiac. [Lesson Plan].

    ERIC Educational Resources Information Center

    2002

    The Chinese lunar calendar dates back to the second millennium BC. Unlike the western calendar, which numbers the years progressively from the birth of Jesus Christ, the Chinese calendar is cyclical. Each cycle is made up of 12 years--after the 12th year, the cycle is repeated. The Chinese associate each year of a 12-year cycle with an animal, and…

  7. Chinese Brush Calligraphy Character Retrieval and Learning

    ERIC Educational Resources Information Center

    Zhuang, Yueting; Zhang, Xiafen; Lu, Weiming; Wu, Fei

    2007-01-01

    Chinese brush calligraphy is a valuable civilization legacy and a high art of scholarship. It is still popular in Chinese banners, newspaper mastheads, university names, and celebration gifts. There are Web sites that try to help people enjoy and learn Chinese calligraphy. However, there lacks advanced services such as content-based retrieval or…

  8. Chinese-English Machine Translation System.

    ERIC Educational Resources Information Center

    Wang, William S-Y; And Others

    The report documents results of a two-year R&D effort directed at the completion of a prototype system for Chinese-English machine translation of S&T literature. The system, designated QUINCE, accepts Chinese input exactly as printed, with no pre-editing of any kind, and produces English output on experimental basis. Coding of Chinese text via…

  9. Scientific and Technical Chinese, Volume II. Glossary.

    ERIC Educational Resources Information Center

    Kao, Kung-yi; And Others

    A composite English-to-Chinese glossary of all terms introduced in the individual lessons of "Scientific and Technical Chinese" is presented here. The appendices include lists of weights and measures and chemical elements, and a partial list of Chinese government organizations and research institutes related to science and technology. (AMH)

  10. Young Chinese ESL Children's Home Literacy Experiences.

    ERIC Educational Resources Information Center

    Xu, Hong

    1999-01-01

    Describes home literacy experiences of six Chinese English-as-a-second-language kindergartners. Includes the parents' provision of literate home environments as well as children's functional use of Chinese and English and engagement in Chinese and English literacy activities. Indicates the diverse and cultural nature of the home literacy…

  11. Factors Influencing the Learning of Chinese Characters

    ERIC Educational Resources Information Center

    Sung, Ko-Yin; Wu, Hsiao-Ping

    2011-01-01

    This survey study, which involved 108 language learners enrolled in first-year Chinese as a foreign language classrooms in the United States, intended to address the research questions, "What types of Chinese-character learning strategies do US learners use?" and "Do US learners' Chinese-character learning strategy use differ based on the…

  12. Bilingual Vocational Training Program for Chinese Chefs.

    ERIC Educational Resources Information Center

    China Inst. in America, New York, NY.

    This document contains materials that can be used by instructors in an English-as-a-second-language course for Chinese kitchen workers or chefs. The materials consist of lessons on various topics that occur in the everyday life of Chinese chefs. Topics include: English names for Chinese dishes; phrases to employ when meeting people and when using…

  13. International Curriculum for Chinese Language Education

    ERIC Educational Resources Information Center

    Scrimgeour, Andrew; Wilson, Philip

    2009-01-01

    The International Curriculum for Chinese Language Education (ICCLE) represents a significant initiative by the Office of Chinese Language Council International (Hanban) to organise and describe objectives and content for a standardised Chinese language curriculum around the world. It aims to provide a reference curriculum for planning, a framework…

  14. L2 Chinese: Grammatical Development and Processing

    ERIC Educational Resources Information Center

    Mai, Ziyin

    2016-01-01

    Two recent books (Jiang, 2014, "Advances in Chinese as a second language"; Wang, 2013, "Grammatical development of Chinese among non-native speakers") provide new resources for exploring the role of processing in acquiring Chinese as a second language (L2). This review article summarizes, assesses and compares some of the…

  15. The Rhetoric of Chinese Layoff Memos

    ERIC Educational Resources Information Center

    Sisco, Lisa A.; Yu, Na

    2010-01-01

    In this analysis the authors introduce three memos announcing layoffs in Chinese companies. The three memos, translated from Chinese, are from: (1) Hewlett Packard China, an American company doing business in China; (2) UT Starcom, founded in China; and (3) Rizhao Steel, one of China's largest steel manufacturers. Comparing the Chinese and…

  16. Modern Chinese Punctuation and CSL Reading Pedagogy.

    ERIC Educational Resources Information Center

    Mickel, Stan

    1988-01-01

    Provides a brief history of Chinese punctuation and detailed analysis of modern Chinese punctuation. Three tables show: 1) uniquely Chinese punctuation markers; 2) markers graphemically identical and functionally similar to Western markers; and 3) markers graphemically identical but functionally different from Western markers. Each punctuation…

  17. The Chinese American: Inscrutable to Some.

    ERIC Educational Resources Information Center

    Chan, Carole

    Chinese Americans have been called inscrutable--not open to being understood. More casual, spontaneous, and expressive people find it hard to understand the strict discipline of feelings and highly selective and controlled expressions such as the Chinese American may practice. This paper serves as a social introduction to the Chinese American. For…

  18. Adaptation Processes in Chinese: Word Formation.

    ERIC Educational Resources Information Center

    Pasierbsky, Fritz

    The typical pattern of Chinese word formation is to have native material adapt to changed circumstances. The Chinese language neither borrows nor lends words, but it does occasionally borrow concepts. The larger cultural pattern in which this occurs is that the Chinese culture borrows, if necessary, but ensures that the act of borrowing does not…

  19. Chinese Orthographic Decomposition and Logographic Structure

    ERIC Educational Resources Information Center

    Cheng, Chao-Ming; Lin, Shan-Yuan

    2013-01-01

    "Chinese orthographic decomposition" refers to a sense of uncertainty about the writing of a well-learned Chinese character following a prolonged inspection of the character. This study investigated the decomposition phenomenon in a test situation in which Chinese characters were repeatedly presented in a word context and assessed…

  20. Problems and Prospect of Chinese Communication Study.

    ERIC Educational Resources Information Center

    Chen, Guo-Ming

    Chinese have systematically practiced communication for over two thousand years, but from the Western perspective communication education and research in Chinese societies only began to burgeon in recent decades. In addition to summarizing the Western and traditional Chinese communication study and practice, this paper identified four problems…

  1. Flash Cards: Common Chinese-Cantonese Characters.

    ERIC Educational Resources Information Center

    Defense Language Inst., Monterey, CA.

    This set of flash cards is designed to accompany the Defense Language Institute's instructional programs in Cantonese Chinese. Each card displays six Chinese characters, for a total of 1500 characters. Each character is printed two inches tall. Above each character are transcriptions of the Chinese words represented by the character (marked for…

  2. Chinese Number Words, Culture, and Mathematics Learning

    ERIC Educational Resources Information Center

    Ng, Sharon Sui Ngan; Rao, Nirmala

    2010-01-01

    This review evaluates the role of language--specifically, the Chinese-based system of number words and the simplicity of Chinese mathematical terms--in explaining the relatively superior performance of Chinese and other East Asian students in cross-national studies of mathematics achievement. Relevant research is critically reviewed focusing on…

  3. Managerial Success Factors: A Chinese Profile

    ERIC Educational Resources Information Center

    Stivers, Bonnie P.; Adams, Janet S.; Liu, Bin

    2007-01-01

    This article reports on an exploratory study conducted in the People's Republic of China (PRC) to identify the managerial success factors perceived by Chinese managers to be important in their market economy. The study also looked at how these factors are exhibited by recent graduates of Chinese universities now working in Chinese firms.…

  4. Writing Concepts in Chinese Writing Instruction.

    ERIC Educational Resources Information Center

    Wang, Xia

    1994-01-01

    This study focuses on how Chinese writing instruction can cause negative interference for Chinese English-as-a-Second-Language students writing in English. The study shows that in Chinese writing, the main idea can be more general, as a theme, or specific, as a thesis statement. It can also come at the beginning or end of a paper, and the writer…

  5. Root susceptibility and inoculum production from roots of Eastern United States oak species to Phytophthora ramorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about root susceptibility of eastern U.S. tree species to Phytophthora ramorum. In this study, we examined root susceptibility and inoculum production from roots. Sprouted acorns of Q. rubra, Q. palustrus, Q. coccinia, Q. alba, Q. michauxii and Q. prinus were exposed to motile zoos...

  6. RootScan: Software for high-throughput analysis of root anatomical traits

    Technology Transfer Automated Retrieval System (TEKTRAN)

    RootScan is a program for semi-automated image analysis of anatomical phenes in root cross-sections. RootScan uses pixel value thresholds to separate the cross-section from its background and to visually dissect it into tissue regions. Area measurements and object counts are performed within various...

  7. Effect of Root Moisture Content and Diameter on Root Tensile Properties

    PubMed Central

    Yang, Yuanjun; Chen, Lihua; Li, Ning; Zhang, Qiufen

    2016-01-01

    The stabilization of slopes by vegetation has been a topical issue for many years. Root mechanical characteristics significantly influence soil reinforcement; therefore it is necessary to research into the indicators of root tensile properties. In this study, we explored the influence of root moisture content on tensile resistance and strength with different root diameters and for different tree species. Betula platyphylla, Quercus mongolica, Pinus tabulaeformis, and Larix gmelinii, the most popular tree species used for slope stabilization in the rocky mountainous areas of northern China, were used in this study. A tensile test was conducted after root samples were grouped by diameter and moisture content. The results showedthat:1) root moisture content had a significant influence on tensile properties; 2) slightly loss of root moisture content could enhance tensile strength, but too much loss of water resulted in weaker capacity for root elongation, and consequently reduced tensile strength; 3) root diameter had a strong positive correlation with tensile resistance; and4) the roots of Betula platyphylla had the best tensile properties when both diameter and moisture content being controlled. These findings improve our understanding of root tensile properties with root size and moisture, and could be useful for slope stabilization using vegetation. PMID:27003872

  8. Root susceptibility and inoculum production from roots of eastern oak species to Phytophthora ramorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Little is known about root susceptibility of eastern tree species to Phytophthora ramorum. In this study, we examined root susceptibility and inoculum production from roots. Oak radicles of several eastern oak species were exposed to zoospore suspensions of 1, 10, 100, or 1000 zoospores per ml at ...

  9. Root-Gel Interactions and the Root Waving Behavior of Arabidopsis1[w

    PubMed Central

    Thompson, Matthew V.; Holbrook, N. Michele

    2004-01-01

    Arabidopsis roots grown on inclined agarose gels exhibit a sinusoidal growth pattern known as root waving. While root waving has been attributed to both intrinsic factors (e.g. circumnutation) and growth responses to external signals such as gravity, the potential for physical interactions between the root and its substrate to influence the development of this complex phenotype has been generally ignored. Using a rotating stage microscope and time-lapse digital imaging, we show that (1) root tip mobility is impeded by the gel surface, (2) this impedance causes root tip deflections by amplifying curvature in the elongation zone in a way that is distinctly nontropic, and (3) root tip impedance is augmented by normal gravitropic pressure applied by the root tip against the gel surface. Thus, both lateral corrective bending near the root apex and root tip impedance could be due to different vector components of the same graviresponse. Furthermore, we speculate that coupling between root twisting and bending is a mechanical effect resulting from root tip impedance. PMID:15247406

  10. Kinetics of short-term root-carbon mineralization in roots of biofuel crops in soils

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To better understand and document the rates of root decomposition in biofuel cropping systems, we compared the evolution of CO2 from roots incubated with samples of two Iowa Mollisols. Root samples were collected from experimental plots for four cropping systems: a multispecies reconstructed prairie...

  11. Effect of Root Moisture Content and Diameter on Root Tensile Properties.

    PubMed

    Yang, Yuanjun; Chen, Lihua; Li, Ning; Zhang, Qiufen

    2016-01-01

    The stabilization of slopes by vegetation has been a topical issue for many years. Root mechanical characteristics significantly influence soil reinforcement; therefore it is necessary to research into the indicators of root tensile properties. In this study, we explored the influence of root moisture content on tensile resistance and strength with different root diameters and for different tree species. Betula platyphylla, Quercus mongolica, Pinus tabulaeformis, and Larix gmelinii, the most popular tree species used for slope stabilization in the rocky mountainous areas of northern China, were used in this study. A tensile test was conducted after root samples were grouped by diameter and moisture content. The results showedthat:1) root moisture content had a significant influence on tensile properties; 2) slightly loss of root moisture content could enhance tensile strength, but too much loss of water resulted in weaker capacity for root elongation, and consequently reduced tensile strength; 3) root diameter had a strong positive correlation with tensile resistance; and4) the roots of Betula platyphylla had the best tensile properties when both diameter and moisture content being controlled. These findings improve our understanding of root tensile properties with root size and moisture, and could be useful for slope stabilization using vegetation. PMID:27003872

  12. Relations between Roots and Coefficients of Cubic Equations with One Root Negative the Reciprocal of Another

    ERIC Educational Resources Information Center

    Asiru, M. A.

    2007-01-01

    Under predetermined conditions on the roots and coefficients, necessary and sufficient conditions relating the coefficients of a given cubic equation x[cubed] + ax[squared] + bx + c = 0 can be established so that the roots possess desired properties. In this note, the condition for one root of a cubic equation to be "the negative reciprocal of…

  13. Coupling root architecture and pore network modeling - an attempt towards better understanding root-soil interactions

    NASA Astrophysics Data System (ADS)

    Leitner, Daniel; Bodner, Gernot; Raoof, Amir

    2013-04-01

    Understanding root-soil interactions is of high importance for environmental and agricultural management. Root uptake is an essential component in water and solute transport modeling. The amount of groundwater recharge and solute leaching significantly depends on the demand based plant extraction via its root system. Plant uptake however not only responds to the potential demand, but in most situations is limited by supply form the soil. The ability of the plant to access water and solutes in the soil is governed mainly by root distribution. Particularly under conditions of heterogeneous distribution of water and solutes in the soil, it is essential to capture the interaction between soil and roots. Root architecture models allow studying plant uptake from soil by describing growth and branching of root axes in the soil. Currently root architecture models are able to respond dynamically to water and nutrient distribution in the soil by directed growth (tropism), modified branching and enhanced exudation. The porous soil medium as rooting environment in these models is generally described by classical macroscopic water retention and sorption models, average over the pore scale. In our opinion this simplified description of the root growth medium implies several shortcomings for better understanding root-soil interactions: (i) It is well known that roots grow preferentially in preexisting pores, particularly in more rigid/dry soil. Thus the pore network contributes to the architectural form of the root system; (ii) roots themselves can influence the pore network by creating preferential flow paths (biopores) which are an essential element of structural porosity with strong impact on transport processes; (iii) plant uptake depend on both the spatial location of water/solutes in the pore network as well as the spatial distribution of roots. We therefore consider that for advancing our understanding in root-soil interactions, we need not only to extend our root models

  14. Effect of Root System Morphology on Root-sprouting and Shoot-rooting Abilities in 123 Plant Species from Eroded Lands in North-east Spain

    PubMed Central

    GUERRERO-CAMPO, JOAQUÍN; PALACIO, SARA; PÉREZ-RONTOMÉ, CARMEN; MONTSERRAT-MARTÍ, GABRIEL

    2006-01-01

    • Background and Aims The objective of this study was to test whether the mean values of several root morphological variables were related to the ability to develop root-borne shoots and/or shoot-borne roots in a wide range of vascular plants. • Methods A comparative study was carried out on the 123 most common plant species from eroded lands in north-east Spain. After careful excavations in the field, measurements were taken of the maximum root depth, absolute and relative basal root diameter, specific root length (SRL), and the root depth/root lateral spread ratio on at least three individuals per species. Shoot-rooting and root-sprouting were observed in a large number of individuals in many eroded and sedimentary environments. The effect of life history and phylogeny on shoot-rooting and root-sprouting abilities was also analysed. • Key Results The species with coarse and deep tap-roots tended to be root-sprouting and those with fine, fasciculate and long main roots (which generally spread laterally), tended to be shoot-rooting. Phylogeny had an important influence on root system morphology and shoot-rooting and root-sprouting capacities. However, the above relations stood after applying analyses based on phylogenetically independent contrasts (PICs). • Conclusions The main morphological features of the root system of the study species are related to their ability to sprout from their roots and form roots from their shoots. According to the results, such abilities might only be functionally viable in restricted root system morphologies and ecological strategies. PMID:16790468

  15. Chinese Character Acquisition and Visual Skills in Two Chinese Scripts

    ERIC Educational Resources Information Center

    Mcbride-Chang, Catherine; Chow, Bonnie W. Y.; Zhong, Yiping; Burgess, Stephen; Hayward, William G.

    2005-01-01

    Three different visual skills, along with Chinese character recognition, vocabulary, speeded naming, and syllable deletion skills were tested twice over one school year among 118 Hong Kong and 96 Xiangtan, China kindergartners. Results revealed that a task of Visual Spatial Relationships [Gardner, M. F. (1996). "Test of visual-perceptual skills…

  16. Meniscal Root Tears: Identification and Repair.

    PubMed

    Doherty, David B; Lowe, Walter R

    2016-01-01

    Intact menisci are capable of converting the axial load of tibiofemoral contact into hoop stress that protects the knee joint. Total meniscectomy leads to rapid degeneration of the knee. Strong clinical and biomechanical data show meniscal root tears and avulsions are the functional equivalent of total meniscectomy. Lateral root tears commonly occur with knee ligament sprains and tears. Medial root tears are generally more chronic, and can be caused by preexisting knee arthritis. Meniscal root repair is indicated when there is identification of a meniscal root tear in a knee with minimal to no arthritis. Chronic root tears in the setting of osteoarthritis are treated conservatively. Meniscal root tears can acutely occur with cruciate ligament tears, can exaggerate symptoms of instability, and will have negative ramifications on outcomes of anterior cruciate ligament reconstruction if not addressed concomitantly. In this review, we describe the importance of the menisci for knee joint longevity through anatomy and biomechanics, the diagnostic workup, and ultimately a transosseous technique for repair of meniscal root tears and avulsions. PMID:27004274

  17. ADVANCING FINE ROOT RESEARCH WITH MINIRHIZOTRONS

    EPA Science Inventory

    Minirhizotrons provide a nondestructive, in situ method for directly viewing and studying fine roots. Although many insights into fine roots have been gained using minirhizotrons, it is clear from the literature that there is still wide variation in how minirhizotrons and minirhi...

  18. Fate of HERS during Tooth Root Development

    PubMed Central

    Huang, Xiaofeng; Bringas, Pablo; Slavkin, Harold C.; Chai, Yang

    2009-01-01

    Tooth root development begins after the completion of crown formation in mammals. Previous studies have shown that Hertwig's epithelial root sheath (HERS) plays an important role in root development, but the fate of HERS has remained unknown. In order to investigate the morphological fate and analyze the dynamic movement of HERS cells in vivo, we generated K14-Cre;R26R mice. HERS cells are detectable on the surface of the root throughout root formation and do not disappear. Most of the HERS cells are attached to the surface of the cementum, and others separate to become the epithelial rest of Malasez. HERS cells secrete extracellular matrix components onto the surface of the dentin before dental follicle cells penetrate the HERS network to contact dentin. HERS cells also participate in the cementum development and may differentiate into cementocytes. During root development, the HERS is not interrupted, and instead the HERS cells continue to communicate with each other through the network structure. Furthermore, HERS cells interact with cranial neural crest derived mesenchyme to guide root development. Taken together, the network of HERS cells is crucial for tooth root development. PMID:19576204

  19. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  20. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  1. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  2. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  3. Enhancing Students' Understanding of Square Roots

    ERIC Educational Resources Information Center

    Wiesman, Jeff L.

    2015-01-01

    Students enrolled in a middle school prealgebra or algebra course often struggle to conceptualize and understand the meaning of radical notation when it is introduced. For example, although it is important for students to approximate the decimal value of a number such as [square root of] 30 and estimate the value of a square root in the form of…

  4. Sporulation on plant roots by Phytophthora ramorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Phytophthora ramorum has been shown to infect the roots of many of the pathogen’s foliar hosts. Methods of detecting inoculum in runoff and of quantifying root colonization were tested using Viburnum tinus, Camellia oleifera, Quercus prinus, Umbellularia californica, and Epilobium ciliatum. Plants...

  5. Cytological and ultrastructural studies on root tissues

    NASA Technical Reports Server (NTRS)

    Slocum, R. D.; Gaynor, J. J.; Galston, A. W.

    1984-01-01

    The anatomy and fine structure of roots from oat and mung bean seedlings, grown under microgravity conditions for 8 days aboard the Space Shuttle, was examined and compared to that of roots from ground control plants grown under similar conditions. Roots from both sets of oat seedlings exhibited characteristic monocotyledonous tissue organization and normal ultrastructural features, except for cortex cell mitochondria, which exhibited a 'swollen' morphology. Various stages of cell division were observed in the meristematic tissues of oat roots. Ground control and flight-grown mung bean roots also showed normal tissue organization, but root cap cells in the flight-grown roots were collapsed and degraded in appearance, especially at the cap periphery. At the ultrastructural level, these cells exhibited a loss of organelle integrity and a highly-condensed cytoplasm. This latter observation perhaps suggests a differing tissue sensitivity for the two species to growth conditions employed in space flight. The basis for abnormal root cap cell development is not understood, but the loss of these putative gravity-sensing cells holds potential significance for long term plant growth orientation during space flight.

  6. Growth and development of root system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The growth and development of root systems of cotton plants is under genetic control but may be modified by the environment. There are many factors that influence root development in cotton. These range from abiotic factors such as soil temperature, soil water, and soil aeration to biotic factors ...

  7. Field investigation of rooting potential in sorghum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The differential influence of root systems on plant development under field conditions is very difficult. A field experiment was devised using three different row spacings (101,152 and 203 cm ) to screen sorghum germplasm for rooting potential based on the relative ability to explore additional soil...

  8. Affine root systems and dual numbers

    NASA Astrophysics Data System (ADS)

    Kostyakov, I. V.; Gromov, N. A.; Kuratov, V. V.

    The root systems in Carroll spaces with degenerate metric are defined. It is shown that their Cartan matrices and reflection groups are affine. Due to the geometric consideration the root system structure of affine algebras is determined by a sufficiently simple algorithm.

  9. Black streak root rot of lentil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Black streak root rot of lentil is caused by the soil borne fungus Thielaviopsis basicola. The pathogen is widespread. The disease shows symptoms of black streaking on root, and stunted plants. The disease is favored by cool and moist weather. Management of the disease rely on avoiding fields wi...

  10. Root phenotypic characterization of lesquerella genetic resources

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root systems are crucial for optimizing plant growth and productivity. There has been a push to better understand root morphological and architectural traits and their plasticity because these traits determine the capacity of plants to effectively acquire available water and soil nutrients in the so...

  11. Maize root characteristis that enhance flooding tolerance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant root systems have several cellular and molecular adaptations that are important in reducing stress caused by flooding. Of these, two physical properties of root systems provide an initial barrier toward the avoidance of stress. These are the presence of aerenchyma cells and rapid adventitious ...

  12. Sugarbeet Cultivar Evaluation for Bacterial Root Rot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterial root rot of sugarbeet caused by Leuconostoc mesenteroides subsp. dextranicum is a disease problem recently described in the United States. To ameliorate the impact of bacterial root rot on sucrose loss in the field, storage piles, and factories, studies were conducted to establish an assa...

  13. 33 CFR 117.1095 - Root River.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Root River. 117.1095 Section 117.1095 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES DRAWBRIDGE OPERATION REGULATIONS Specific Requirements Wisconsin § 117.1095 Root River. (a) The draw of the Main...

  14. Rapid phenotyping of alfalfa root system architecture

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root system architecture (RSA) influences the capacity of an alfalfa plant for symbiotic nitrogen fixation, nutrient uptake and water use efficiency, resistance to frost heaving, winterhardiness, and some pest and pathogen resistance. However, we currently lack a basic understanding of root system d...

  15. Roots as a source of food.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Numerous plant species produce edible roots that are an important source of calories and that contribute to human nutrition. This book chapter discusses the origin and domestication, production aspects and nutritional aspects of a number of root crops including; cassava (Manioc), sweetpotato (Ipomo...

  16. A new approach to root formation

    PubMed Central

    Vatanpour, Mehdi; Zarei, Mina; Javidi, Maryam; Shirazian, Shiva

    2008-01-01

    In endodontics, treatment of an open apex tooth with necrotic pulp is a problem. It seems that with promotion of remnants of Hertwig’s epithelial sheath or rest of malassez accompany with a good irrigation of root canal we can expect root formation. (Iranian Endodontic Journal 2008;3:42-43) PMID:24171018

  17. ACETOGENIC BACTERIA ASSOCIATED WITH SEAGRASS ROOTS

    EPA Science Inventory

    Seagrasses are adapted to being rooted in reduced, anoxic sediments with high rates of sulfate reduction. During the day, an oxygen gradient is generated around the roots, becoming anoxic at night. Thus, obligate anaerobic bacteria in the rhizosphere have to tolerate elevated oxy...

  18. Dehydration Accelerates Respiration in Postharvest Sugarbeet Roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sugarbeet (Beta vulgaris L.) roots lose water during storage and often become severely dehydrated after prolonged storage and at the outer regions of storage piles which have greater wind and sun exposure. Sucrose loss is known to be elevated in dehydrated roots, although the metabolic processes re...

  19. Method for Constructing Standardized Simulated Root Canals.

    ERIC Educational Resources Information Center

    Schulz-Bongert, Udo; Weine, Franklin S.

    1990-01-01

    The construction of visual and manipulative aids, clear resin blocks with root-canal-like spaces, for simulation of root canals is explained. Time, materials, and techniques are discussed. The method allows for comparison of canals, creation of any configuration of canals, and easy presentation during instruction. (MSE)

  20. Arabidopsis: An Adequate Model for Dicot Root Systems?

    PubMed

    Zobel, Richard W

    2016-01-01

    The Arabidopsis root system is frequently considered to have only three classes of root: primary, lateral, and adventitious. Research with other plant species has suggested up to eight different developmental/functional classes of root for a given plant root system. If Arabidopsis has only three classes of root, it may not be an adequate model for eudicot plant root systems. Recent research, however, can be interpreted to suggest that pre-flowering Arabidopsis does have at least five (5) of these classes of root. This then suggests that Arabidopsis root research can be considered an adequate model for dicot plant root systems. PMID:26904040

  1. GiA Roots: software for the high throughput analysis of plant root system architecture

    PubMed Central

    2012-01-01

    Background Characterizing root system architecture (RSA) is essential to understanding the development and function of vascular plants. Identifying RSA-associated genes also represents an underexplored opportunity for crop improvement. Software tools are needed to accelerate the pace at which quantitative traits of RSA are estimated from images of root networks. Results We have developed GiA Roots (General Image Analysis of Roots), a semi-automated software tool designed specifically for the high-throughput analysis of root system images. GiA Roots includes user-assisted algorithms to distinguish root from background and a fully automated pipeline that extracts dozens of root system phenotypes. Quantitative information on each phenotype, along with intermediate steps for full reproducibility, is returned to the end-user for downstream analysis. GiA Roots has a GUI front end and a command-line interface for interweaving the software into large-scale workflows. GiA Roots can also be extended to estimate novel phenotypes specified by the end-user. Conclusions We demonstrate the use of GiA Roots on a set of 2393 images of rice roots representing 12 genotypes from the species Oryza sativa. We validate trait measurements against prior analyses of this image set that demonstrated that RSA traits are likely heritable and associated with genotypic differences. Moreover, we demonstrate that GiA Roots is extensible and an end-user can add functionality so that GiA Roots can estimate novel RSA traits. In summary, we show that the software can function as an efficient tool as part of a workflow to move from large numbers of root images to downstream analysis. PMID:22834569

  2. Effect of lead on root growth

    PubMed Central

    Fahr, Mouna; Laplaze, Laurent; Bendaou, Najib; Hocher, Valerie; Mzibri, Mohamed El; Bogusz, Didier; Smouni, Abdelaziz

    2013-01-01

    Lead (Pb) is one of the most widespread heavy metal contaminant in soils. It is highly toxic to living organisms. Pb has no biological function but can cause morphological, physiological, and biochemical dysfunctions in plants. Plants have developed a wide range of tolerance mechanisms that are activated in response to Pb exposure. Pb affects plants primarily through their root systems. Plant roots rapidly respond either (i) by the synthesis and deposition of callose, creating a barrier that stops Pb entering (ii) through the uptake of large amounts of Pb and its sequestration in the vacuole accompanied by changes in root growth and branching pattern or (iii) by its translocation to the aboveground parts of plant in the case of hyperaccumulators plants. Here we review the interactions of roots with the presence of Pb in the rhizosphere and the effect of Pb on the physiological and biochemical mechanisms of root development. PMID:23750165

  3. Systems approaches to study root architecture dynamics

    PubMed Central

    Cuesta, Candela; Wabnik, Krzysztof; Benková, Eva

    2013-01-01

    The plant root system is essential for providing anchorage to the soil, supplying minerals and water, and synthesizing metabolites. It is a dynamic organ modulated by external cues such as environmental signals, water and nutrients availability, salinity and others. Lateral roots (LRs) are initiated from the primary root post-embryonically, after which they progress through discrete developmental stages which can be independently controlled, providing a high level of plasticity during root system formation. Within this review, main contributions are presented, from the classical forward genetic screens to the more recent high-throughput approaches, combined with computer model predictions, dissecting how LRs and thereby root system architecture is established and developed. PMID:24421783

  4. The origin and early evolution of roots.

    PubMed

    Kenrick, Paul; Strullu-Derrien, Christine

    2014-10-01

    Geological sites of exceptional fossil preservation are becoming a focus of research on root evolution because they retain edaphic and ecological context, and the remains of plant soft tissues are preserved in some. New information is emerging on the origins of rooting systems, their interactions with fungi, and their nature and diversity in the earliest forest ecosystems. Remarkably well-preserved fossils prove that mycorrhizal symbionts were diverse in simple rhizoid-based systems. Roots evolved in a piecemeal fashion and independently in several major clades through the Devonian Period (416 to 360 million years ago), rapidly extending functionality and complexity. Evidence from extinct arborescent clades indicates that polar auxin transport was recruited independently in several to regulate wood and root development. The broader impact of root evolution on the geochemical carbon cycle is a developing area and one in which the interests of the plant physiologist intersect with those of the geochemist. PMID:25187527

  5. Long-term control of root growth

    DOEpatents

    Burton, Frederick G.; Cataldo, Dominic A.; Cline, John F.; Skiens, W. Eugene

    1992-05-26

    A method and system for long-term control of root growth without killing the plants bearing those roots involves incorporating a 2,6-dinitroaniline in a polymer and disposing the polymer in an area in which root control is desired. This results in controlled release of the substituted aniline herbicide over a period of many years. Herbicides of this class have the property of preventing root elongation without translocating into other parts of the plant. The herbicide may be encapsulated in the polymer or mixed with it. The polymer-herbicide mixture may be formed into pellets, sheets, pipe gaskets, pipes for carrying water, or various other forms. The invention may be applied to other protection of buried hazardous wastes, protection of underground pipes, prevention of root intrusion beneath slabs, the dwarfing of trees or shrubs and other applications. The preferred herbicide is 4-difluoromethyl-N,N-dipropyl-2,6-dinitro-aniline, commonly known as trifluralin.

  6. Long-term control of root growth

    SciTech Connect

    Burton, F.G.; Cataldo, D.A.; Cline, J.F.; Skiens, W.E.

    1992-05-26

    A method and system for long-term control of root growth without killing the plants bearing those roots involves incorporating a 2,6-dinitroaniline in a polymer and disposing the polymer in an area in which root control is desired. This results in controlled release of the substituted aniline herbicide over a period of many years. Herbicides of this class have the property of preventing root elongation without translocating into other parts of the plant. The herbicide may be encapsulated in the polymer or mixed with it. The polymer-herbicide mixture may be formed into pellets, sheets, pipe gaskets, pipes for carrying water, or various other forms. The invention may be applied to other protection of buried hazardous wastes, protection of underground pipes, prevention of root intrusion beneath slabs, the dwarfing of trees or shrubs and other applications. The preferred herbicide is 4-difluoromethyl-N,N-dipropyl-2,6-dinitro-aniline, commonly known as trifluralin. 7 figs.

  7. Clinical management of infected root canal dentin.

    PubMed

    Love, R M

    1996-08-01

    Several hundred different species of bacteria are present in the human intraoral environment. Bacterial penetration of root canal dentin occurs when bacteria invade the root canal system. These bacteria may constitute a reservoir from which root canal reinfection may occur during or after endodontic treatment. The learning objective of this article is to review endodontic microbiology, update readers on the role of bacteria in pulp and periapical disease, and discuss the principles of management of infected root canal dentin. Complete debridement, removal of microorganisms and affected dentin, and chemomechanical cleansing of the root canal are suggested as being the cornerstones of successful endodontic therapy, followed by intracanal medication to remove residual bacteria, when required. PMID:9242125

  8. Management of Six Root Canals in Mandibular First Molar

    PubMed Central

    Gomes, Fabio de Almeida; Sousa, Bruno Carvalho

    2015-01-01

    Success in root canal treatment is achieved after thorough cleaning, shaping, and obturation of the root canal system. This clinical case describes conventional root canal treatment of an unusual mandibular first molar with six root canals. The prognosis for endodontic treatment in teeth with abnormal morphology is unfavorable if the clinician fails to recognize extra root canals. PMID:25685156

  9. Root Canal Treatment of a Maxillary Second Premolar with Two Palatal Root Canals: A Case Report

    PubMed Central

    Golmohammadi, Maryam; Jafarzadeh, Hamid

    2016-01-01

    Accurate diagnosis of the root canal morphology and anatomy is essential for thorough shaping and cleaning of the entire root canal system and consequent successful treatment. This report describes a case of maxillary second premolar with two roots and three root canals (two mesial and distal palatal canals). The case report underlines the importance of complete knowledge about root canal morphology and possible variations, coupled with clinical and radiographic examination in order to increase the ability of clinicians to treat difficult cases. PMID:27471538

  10. Root Canal Treatment of a Maxillary Second Premolar with Two Palatal Root Canals: A Case Report.

    PubMed

    Golmohammadi, Maryam; Jafarzadeh, Hamid

    2016-01-01

    Accurate diagnosis of the root canal morphology and anatomy is essential for thorough shaping and cleaning of the entire root canal system and consequent successful treatment. This report describes a case of maxillary second premolar with two roots and three root canals (two mesial and distal palatal canals). The case report underlines the importance of complete knowledge about root canal morphology and possible variations, coupled with clinical and radiographic examination in order to increase the ability of clinicians to treat difficult cases. PMID:27471538

  11. Variation in root density along stream banks.

    PubMed

    Wynn, Theresa M; Mostaghimi, Saied; Burger, James A; Harpold, Adrian A; Henderson, Marc B; Henry, Leigh-Anne

    2004-01-01

    While it is recognized that vegetation plays a significant role in stream bank stabilization, the effects are not fully quantified. The study goal was to determine the type and density of vegetation that provides the greatest protection against stream bank erosion by determining the density of roots in stream banks. To quantify the density of roots along alluvial stream banks, 25 field sites in the Appalachian Mountains were sampled. The riparian buffers varied from short turfgrass to mature riparian forests, representing a range of vegetation types. Root length density (RLD) with depth and aboveground vegetation density were measured. The sites were divided into forested and herbaceous groups and differences in root density were evaluated. At the herbaceous sites, very fine roots (diameter < 0.5 mm) were most common and more than 75% of all roots were concentrated in the upper 30 cm of the stream bank. Under forested vegetation, fine roots (0.5 mm < diameter < 2.0 mm) were more common throughout the bank profile, with 55% of all roots in the top 30 cm. In the top 30 cm of the bank, herbaceous sites had significantly greater overall RLD than forested sites (alpha = 0.01). While there were no significant differences in total RLD below 30 cm, forested sites had significantly greater concentrations of fine roots, as compared with herbaceous sites (alpha = 0.01). As research has shown that erosion resistance has a direct relationship with fine root density, forested vegetation may provide better protection against stream bank erosion. PMID:15537925

  12. Root conditioning in periodontology — Revisited

    PubMed Central

    Nanda, Tarun; Jain, Sanjeev; Kaur, Harjit; Kapoor, Daljit; Nanda, Sonia; Jain, Rohit

    2014-01-01

    Objective: Root surfaces of periodontitis-affected teeth are hypermineralized and contaminated with cytotoxic and other biologically active substances. To achieve complete decontamination of the tooth surfaces, various methods including root conditioning following scaling and root planning are present. The main objective of this article is to throw light on the different root conditioning agents used and the goals accomplished by root conditioning in the field of periodontology. Materials and Methods: 20 human maxillary anterior teeth indicated for extraction due to chronic periodontitis were collected and root planned. The teeth were sectioned and specimens were divided into two groups — Group I and II. Group I dentin specimens were treated with EDTA and group II specimens were treated with tetracycline HCl solution at concentration of 10% by active burnishing technique for 3 minutes. The root surface samples were then examined by scanning electron microscope (SEM). Results: The results of the study showed that EDTA and tetracycline HCl were equally effective in removing the smear layer. It was observed that the total and patent dentinal tubules were more in number in teeth treated with tetracycline as compared to EDTA group. However, EDTA was found to be much more effective as root conditioning agent because it enlarged the diameter of dentinal tubules more than that of tetracycline HCl. Conclusion: Results of in-vitro study showed that both the agents are good root conditioning agents if applied in addition to periodontal therapy. However, further studies are required to establish the in-vivo importance of EDTA and tetracycline HCL as root conditioners. PMID:25097414

  13. Maize Varieties Released in Different Eras Have Similar Root Length Density Distributions in the Soil, Which Are Negatively Correlated with Local Concentrations of Soil Mineral Nitrogen

    PubMed Central

    Ning, Peng; Li, Sa; White, Philip J.; Li, Chunjian

    2015-01-01

    Larger, and deeper, root systems of new maize varieties, compared to older varieties, are thought to have enabled improved acquisition of soil resources and, consequently, greater grain yields. To compare the spatial distributions of the root systems of new and old maize varieties and their relationships with spatial variations in soil concentrations of available nitrogen (N), phosphorus (P) and potassium (K), two years of field experiments were performed using six Chinese maize varieties released in different eras. Vertical distributions of roots, and available N, P and K in the 0–60 cm soil profile were determined in excavated soil monoliths at silking and maturity. The results demonstrated that new maize varieties had larger root dry weight, higher grain yield and greater nutrient accumulation than older varieties. All varieties had similar total root length and vertical root distribution at silking, but newer varieties maintained greater total root length and had more roots in the 30–60 cm soil layers at maturity. The spatial variation of soil mineral N (Nmin) in each soil horizon was larger than that of Olsen-P and ammonium-acetate-extractable K, and was inversely correlated with root length density (RLD), especially in the 0–20 cm soil layer. It was concluded that greater acquisition of mineral nutrients and higher yields of newer varieties were associated with greater total root length at maturity. The negative relationship between RLD and soil Nmin at harvest for all varieties suggests the importance of the spatial distribution of the root system for N uptake by maize. PMID:25799291

  14. Accessory roots and root canals in human anterior teeth: a review and clinical considerations.

    PubMed

    Ahmed, H M A; Hashem, A A

    2016-08-01

    Anterior teeth may have aberrant anatomical variations in the number of roots and root canals. A review of the literature was conducted using appropriate key words in major endodontic journals to identify the available reported cases as well as experimental and clinical investigations on accessory roots and root canals in anterior teeth. After retrieving the full text of related articles, cross-citations were identified, and the pooled data were then discussed. Results revealed a higher prevalence in accessory root/root canal variations in mandibular anterior teeth than in maxillary counterparts. However, maxillary incisor teeth revealed the highest tendency for accessory root/root canal aberrations caused by anomalies such as dens invaginatus and palato-gingival groove. Primary anterior teeth may also exhibit external and internal anatomical variations in the root, especially maxillary canines. Therefore, dental practitioners should thoroughly assess all teeth scheduled for root canal treatment to prevent the undesirable consequences caused by inadequate debridement of accessory configurations of the root canal system. PMID:26174943

  15. RootGraph: a graphic optimization tool for automated image analysis of plant roots

    PubMed Central

    Cai, Jinhai; Zeng, Zhanghui; Connor, Jason N.; Huang, Chun Yuan; Melino, Vanessa; Kumar, Pankaj; Miklavcic, Stanley J.

    2015-01-01

    This paper outlines a numerical scheme for accurate, detailed, and high-throughput image analysis of plant roots. In contrast to existing root image analysis tools that focus on root system-average traits, a novel, fully automated and robust approach for the detailed characterization of root traits, based on a graph optimization process is presented. The scheme, firstly, distinguishes primary roots from lateral roots and, secondly, quantifies a broad spectrum of root traits for each identified primary and lateral root. Thirdly, it associates lateral roots and their properties with the specific primary root from which the laterals emerge. The performance of this approach was evaluated through comparisons with other automated and semi-automated software solutions as well as against results based on manual measurements. The comparisons and subsequent application of the algorithm to an array of experimental data demonstrate that this method outperforms existing methods in terms of accuracy, robustness, and the ability to process root images under high-throughput conditions. PMID:26224880

  16. Root hair-specific expansins modulate root hair elongation in rice.

    PubMed

    ZhiMing, Yu; Bo, Kang; XiaoWei, He; ShaoLei, Lv; YouHuang, Bai; WoNa, Ding; Ming, Chen; Hyung-Taeg, Cho; Ping, Wu

    2011-06-01

    Root hair growth requires intensive cell-wall modification. This study demonstrates that root hair-specific expansin As, a sub-clade of the cell wall-loosening expansin proteins, are required for root hair elongation in rice (Oryza sativa L.). We identified a gene encoding EXPA17 (OsEXPA17) from a rice mutant with short root hairs. Promoter::reporter transgenic lines exhibited exclusive OsEXPA17 expression in root hair cells. The OsEXPA17 mutant protein (OsexpA17) contained a point mutation, causing a change in the amino acid sequence (Gly104→Arg). This amino acid alteration is predicted to disrupt a highly conserved disulfide bond in the mutant. Suppression of OsEXPA17 by RNA interference further confirmed requirement for the gene in root hair elongation. Complementation of the OsEXPA17 mutant with other root hair EXPAs (OsEXPA30 and Arabidopsis EXPA7) can restore root hair elongation, indicating functional conservation of these root hair EXPAs in monocots and dicots. These results demonstrate that members of the root hair EXPA sub-clade play a crucial role in root hair cell elongation in Graminaceae. PMID:21309868

  17. GLO-Roots: an imaging platform enabling multidimensional characterization of soil-grown root systems

    PubMed Central

    Rellán-Álvarez, Rubén; Lobet, Guillaume; Lindner, Heike; Pradier, Pierre-Luc; Sebastian, Jose; Yee, Muh-Ching; Geng, Yu; Trontin, Charlotte; LaRue, Therese; Schrager-Lavelle, Amanda; Haney, Cara H; Nieu, Rita; Maloof, Julin; Vogel, John P; Dinneny, José R

    2015-01-01

    Root systems develop different root types that individually sense cues from their local environment and integrate this information with systemic signals. This complex multi-dimensional amalgam of inputs enables continuous adjustment of root growth rates, direction, and metabolic activity that define a dynamic physical network. Current methods for analyzing root biology balance physiological relevance with imaging capability. To bridge this divide, we developed an integrated-imaging system called Growth and Luminescence Observatory for Roots (GLO-Roots) that uses luminescence-based reporters to enable studies of root architecture and gene expression patterns in soil-grown, light-shielded roots. We have developed image analysis algorithms that allow the spatial integration of soil properties, gene expression, and root system architecture traits. We propose GLO-Roots as a system that has great utility in presenting environmental stimuli to roots in ways that evoke natural adaptive responses and in providing tools for studying the multi-dimensional nature of such processes. DOI: http://dx.doi.org/10.7554/eLife.07597.001 PMID:26287479

  18. Resistance to compression of weakened roots subjected to different root reconstruction protocols

    PubMed Central

    ZOGHEIB, Lucas Villaça; SAAVEDRA, Guilherme de Siqueira Ferreira Anzaloni; CARDOSO, Paula Elaine; VALERA, Márcia Carneiro; de ARAÚJO, Maria Amélia Máximo

    2011-01-01

    Objective This study evaluated, in vitro, the fracture resistance of human non-vital teeth restored with different reconstruction protocols. Material and methods Forty human anterior roots of similar shape and dimensions were assigned to four groups (n=10), according to the root reconstruction protocol: Group I (control): non-weakened roots with glass fiber post; Group II: roots with composite resin by incremental technique and glass fiber post; Group III: roots with accessory glass fiber posts and glass fiber post; and Group IV: roots with anatomic glass fiber post technique. Following post cementation and core reconstruction, the roots were embedded in chemically activated acrylic resin and submitted to fracture resistance testing, with a compressive load at an angle of 45º in relation to the long axis of the root at a speed of 0.5 mm/min until fracture. All data were statistically analyzed with bilateral Dunnett's test (α=0.05). Results Group I presented higher mean values of fracture resistance when compared with the three experimental groups, which, in turn, presented similar resistance to fracture among each other. None of the techniques of root reconstruction with intraradicular posts improved root strength, and the incremental technique was suggested as being the most recommendable, since the type of fracture that occurred allowed the remaining dental structure to be repaired. Conclusion The results of this in vitro study suggest that the healthy remaining radicular dentin is more important to increase fracture resistance than the root reconstruction protocol. PMID:22231002

  19. Root cap influences root colonisation by Pseudomonas fluorescens SBW25 on maize.

    PubMed

    Humphris, Sonia N; Bengough, A Glyn; Griffiths, Bryan S; Kilham, Ken; Rodger, Sheena; Stubbs, Vicky; Valentine, Tracy A; Young, Iain M

    2005-09-01

    We investigated the influence of root border cells on the colonisation of seedling Zea mays roots by Pseudomonas fluorescens SBW25 in sandy loam soil packed at two dry bulk densities. Numbers of colony forming units (CFU) were counted on sequential sections of root for intact and decapped inoculated roots grown in loose (1.0 mg m(-3)) and compacted (1.3 mg m(-3)) soil. After two days of root growth, the numbers of P. fluorescens (CFU cm(-1)) were highest on the section of root just below the seed with progressively fewer bacteria near the tip, irrespective of density. The decapped roots had significantly more colonies of P. fluorescens at the tip compared with the intact roots: approximately 100-fold more in the loose and 30-fold more in the compact soil. In addition, confocal images of the root tips grown in agar showed that P. fluorescens could only be detected on the tips of the decapped roots. These results indicated that border cells, and their associated mucilage, prevented complete colonization of the root tip by the biocontrol agent P. fluorescens, possibly by acting as a disposable surface or sheath around the cap. PMID:16329978

  20. Lateral root initiation in Marsilea quadrifolia. I. Origin and histogensis of lateral roots

    NASA Technical Reports Server (NTRS)

    Lin, B. L.; Raghavan, V.

    1991-01-01

    In Marsilea quadrifolia, lateral roots arise from modified single cells of the endodermis located opposite the protoxylem poles within the meristematic region of the parent root. The initial cell divides in four specific planes to establish a five-celled lateral root primordium, with a tetrahedral apical cell in the centre and the oldest merophytes and the root cap along the sides. The cells of the merophyte divide in a precise pattern to give rise to the cells of the cortex, endodermis, pericycle, and vascular tissues of the emerging lateral root. Although the construction of the parent root is more complicated than that of lateral roots, patterns of cell division and tissue formation are similar in both types of roots, with the various tissues being arranged in similar positions in relation to the central axis. Vascular connection between the lateral root primordium and the parent root is derived from the pericycle cells lying between the former and the protoxylem members of the latter. It is proposed that the central axis of the root is not only a geometric centre, but also a physiological centre which determines the fate of the different cell types.

  1. Play Chinese Games. 1987, Revised.

    ERIC Educational Resources Information Center

    White, Caryn

    This document, designed to introduce all ages to a selection of popular Chinese games, describes these games and provides instructions and materials for making the items needed to play most of them. Section 1 suggests class activities that can be related to some of the games. Section 2 presents instructions for the physical or outdoor games of:…

  2. Young Chinese Children's Authority Concepts

    ERIC Educational Resources Information Center

    Yau, Jenny; Smetana, Judith G.; Metzger, Aaron

    2009-01-01

    Using multilevel analyses, we examined the influence of domain (moral, conventional, and personal) and the familiarity of different authority figures (mother, teacher, person in charge, and stranger) in public, school, or home settings in 123 four to seven-year-old Chinese children (M = 5.6 years) in Hong Kong. Children affirmed authority more for…

  3. Instructional Technology: The Chinese Approach.

    ERIC Educational Resources Information Center

    Miller, William F.

    1989-01-01

    Describes the current state of instructional technology in Chinese universities. Topics discussed include organizational patterns in audiovisual centers; the use of various media, including film, videotapes, overhead projectors, and television; the use of technology in language instruction; audiovisual equipment and appropriate technology; and…

  4. School Choice with Chinese Characteristics

    ERIC Educational Resources Information Center

    Wu, Xiaoxin

    2012-01-01

    This paper explores the major characteristics of school choice in the Chinese context. It highlights the involvement of cultural and economic capital, such as choice fees, donations, prize-winning certificates and awards in gaining school admission, as well as the use of social capital in the form of "guanxi". The requirement for these resources…

  5. Organizational Management in Chinese Universities.

    ERIC Educational Resources Information Center

    Kwong, Julia, Ed.

    1987-01-01

    Presents translations of 13 articles on topics of higher education reform in China. Reforms began in 1976 with the purging of supporters of the Gang of Four and continues today with fundamental changes in funding, administration, curriculum, and faculty policies. Notes that many proposed reforms run counter to existing Chinese views and may…

  6. Chinese-Cantonese Basic Course.

    ERIC Educational Resources Information Center

    Defense Language Inst., Washington, DC.

    This nine-volume basic course in Cantonese Chinese is designed for 47 weeks of intense audiolingual instruction. The first book of the series introduces the pronunciation, with emphasis on the tone system, and the basic aspects of the grammar. Also introduced in this volume is the romanization system used in this series (the U.S. Army Language…

  7. Chinese English Learners' Strategic Competence.

    PubMed

    Wang, Dianjian; Lai, Hongling; Leslie, Michael

    2015-12-01

    The present study aims to investigate Chinese English learners' ability to use communication strategies (CSs). The subjects are put in a relatively real English referential communication setting and the analyses of the research data show that Chinese English learners, when encountering problems in foreign language (FL) communication, are characterized by the frequent use of substitution, approximation, circumlocution, literal translation, exemplification, word-coinage, repetition, and the infrequent use of cultural-knowledge and paralinguistic CSs. The rare use of paralinguistic strategies is found to be typical of Chinese English learners. The high frequency of literal translation, one first language (L1)-based strategy in our study sample, suggests that FL learners' use of L1-based CSs may depend more upon the developmental stage of their target language than the typology distance between L1 and the target language. The frequency of repetition reveals one fact that the Chinese English learners lack variety and flexibility in their use of CSs. Based on these findings, it was indicated that learners' use of CSs is influenced by a variety of factors, among which the development stage of their interlanguage and their cultural background are identified as two important factors. Some implications are finally suggested for the English foreign language teaching practice in China. PMID:25134668

  8. American Drama through Chinese Eyes.

    ERIC Educational Resources Information Center

    Brown, Joanne

    An American instructor taught a 5-week course on the family in American drama to a group of graduate English majors on the campus of Hebei Teachers' University in the People's Republic of China. The instructor learned as much about Chinese culture as the students learned about American culture. Lecture is the standard pedagogy even in graduate…

  9. Ancient Chinese Bronzes: Teacher's Packet.

    ERIC Educational Resources Information Center

    Smithsonian Institution, Washington, DC. Arthur M. Sackler Gallery.

    The focus of this teacher's packet is the bronze vessels made for the kings and great families of the early Chinese dynasties between 1700 B.C. and 200 A.D. The materials in the guide are intended for use by teachers and students visiting the exhibition, "The Arts of China," at the Arthur M. Sackler Gallery of the Smithsonian Institution in…

  10. Eye Movements during Chinese Reading

    ERIC Educational Resources Information Center

    Liversedge, Simon P; Hyona, Jukka; Rayner, Keith

    2013-01-01

    respects, and for this reason, interest in the nature of the cognitive processes underlying Chinese reading has flourished over recent years. A number of researchers have used eye movement methodology as a measure of on-line processing to understand more about…

  11. Quantifying Affinity among Chinese Dialects.

    ERIC Educational Resources Information Center

    Cheng, Chin-Chuan

    A study of the relationships between Chinese dialects based on a quantitative measure of dialect affinity is summarized. First, tone values in all the dialect localities available in the early 1970s were used to calculate the dialectal differences in terms of tone height with respect to the "yin and yang" split. In the late 1970s, calculations of…

  12. Writing Quality Predicts Chinese Learning

    ERIC Educational Resources Information Center

    Guan, Connie Qun; Perfetti, Charles A.; Meng, Wanjin

    2015-01-01

    To examine the importance of manual character writing to reading in a new writing system, 48 adult Chinese-as-a-foreign-language students were taught characters in either a character writing-to-read or an alphabet typing-to-read condition, and engaged in corresponding handwriting or typing training for five consecutive days. Prior knowledge of…

  13. Aspects of the Chinese Verb.

    ERIC Educational Resources Information Center

    Thompson, J. Charles

    1968-01-01

    It has long been realized that tense is not a feature of the Chinese verb system, which is controlled by a set of particles attached to the verb or to the sentence as a whole. The various usages involving these particles have been listed and described, the author points out, but the system as a whole has not been clearly defined. He suggests the…

  14. Root phenology at Harvard Forest and beyond

    NASA Astrophysics Data System (ADS)

    Abramoff, R. Z.; Finzi, A.

    2013-12-01

    Roots are hidden from view and heterogeneously distributed making them difficult to study in situ. As a result, the causes and timing of root production are not well understood. Researchers have long assumed that above and belowground phenology is synchronous; for example, most parameterizations of belowground carbon allocation in terrestrial biosphere models are based on allometry and represent a fixed fraction of net C uptake. However, using results from metaanalysis as well as empirical data from oak and hemlock stands at Harvard Forest, we show that synchronous root and shoot growth is the exception rather than the rule. We collected root and shoot phenology measurements from studies across four biomes (boreal, temperate, Mediterranean, and subtropical). General patterns of root phenology varied widely with 1-5 production peaks in a growing season. Surprisingly, in 9 out of the 15 studies, the first root production peak was not the largest peak. In the majority of cases maximum shoot production occurred before root production (Offset>0 in 32 out of 47 plant sample means). The number of days offset between maximum root and shoot growth was negatively correlated with median annual temperature and therefore differs significantly across biomes (ANOVA, F3,43=9.47, p<0.0001). This decline in offset with increasing temperature may reflect greater year-round coupling between air and soil temperature in warm biomes. Growth form (woody or herbaceous) also influenced the relative timing of root and shoot growth. Woody plants had a larger range of days between root and shoot growth peaks as well as a greater number of growth peaks. To explore the range of phenological relationships within woody plants in the temperate biome, we focused on above and belowground phenology in two common northeastern tree species, Quercus rubra and Tsuga canadensis. Greenness index, rate of stem growth, root production and nonstructural carbohydrate content were measured beginning in April

  15. Variation of the Linkage of Root Function with Root Branch Order

    PubMed Central

    Chen, Zhengxia; Zeng, Hui

    2013-01-01

    Mounting evidence has shown strong linkage of root function with root branch order. However, it is not known whether this linkage is consistent in different species. Here, root anatomic traits of the first five branch order were examined in five species differing in plant phylogeny and growth form in tropical and subtropical forests of south China. In Paramichelia baillonii, one tree species in Magnoliaceae, the intact cortex as well as mycorrhizal colonization existed even in the fifth-order root suggesting the preservation of absorption function in the higher-order roots. In contrast, dramatic decreases of cortex thickness and mycorrhizal colonization were observed from lower- to higher-order roots in three other tree species, Cunninghamia lanceolata, Acacia auriculiformis and Gordonia axillaries, which indicate the loss of absorption function. In a fern, Dicranopteris dichotoma, there were several cortex layers with prominently thickened cell wall and no mycorrhizal colonization in the third- and fourth-order roots, also demonstrating the loss of absorptive function in higher-order roots. Cluster analysis using these anatomic traits showed a different classification of root branch order in P. baillonii from other four species. As for the conduit diameter-density relationship in higher-order roots, the mechanism underpinning this relationship in P. baillonii was different from that in other species. In lower-order roots, different patterns of coefficient of variance for conduit diameter and density provided further evidence for the two types of linkage of root function with root branch order. These linkages corresponding to two types of ephemeral root modules have important implication in the prediction of terrestrial carbon cycling, although we caution that this study was pseudo-replicated. Future studies by sampling more species can test the generality of these two types of linkage. PMID:23451168

  16. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order-related fine root morphology and biomass?

    PubMed Central

    Kubisch, Petra; Hertel, Dietrich; Leuschner, Christoph

    2015-01-01

    While most temperate broad-leaved tree species form ectomycorrhizal (EM) symbioses, a few species have arbuscular mycorrhizas (AM). It is not known whether EM and AM tree species differ systematically with respect to fine root morphology, fine root system size and root functioning. In a species-rich temperate mixed forest, we studied the fine root morphology and biomass of three EM and three AM tree species from the genera Acer, Carpinus, Fagus, Fraxinus, and Tilia searching for principal differences between EM and AM trees. We further assessed the evidence of convergence or divergence in root traits among the six co-occurring species. Eight fine root morphological and chemical traits were investigated in root segments of the first to fourth root order in three different soil depths and the relative importance of the factors root order, tree species and soil depth for root morphology was determined. Root order was more influential than tree species while soil depth had only a small effect on root morphology All six species showed similar decreases in specific root length and specific root area from the 1st to the 4th root order, while the species patterns differed considerably in root tissue density, root N concentration, and particularly with respect to root tip abundance. Most root morphological traits were not significantly different between EM and AM species (except for specific root area that was larger in AM species), indicating that mycorrhiza type is not a key factor influencing fine root morphology in these species. The order-based root analysis detected species differences more clearly than the simple analysis of bulked fine root mass. Despite convergence in important root traits among AM and EM species, even congeneric species may differ in certain fine root morphological traits. This suggests that, in general, species identity has a larger influence on fine root morphology than mycorrhiza type. PMID:25717334

  17. Scalable encryption using alpha rooting

    NASA Astrophysics Data System (ADS)

    Wharton, Eric J.; Panetta, Karen A.; Agaian, Sos S.

    2008-04-01

    Full and partial encryption methods are important for subscription based content providers, such as internet and cable TV pay channels. Providers need to be able to protect their products while at the same time being able to provide demonstrations to attract new customers without giving away the full value of the content. If an algorithm were introduced which could provide any level of full or partial encryption in a fast and cost effective manner, the applications to real-time commercial implementation would be numerous. In this paper, we present a novel application of alpha rooting, using it to achieve fast and straightforward scalable encryption with a single algorithm. We further present use of the measure of enhancement, the Logarithmic AME, to select optimal parameters for the partial encryption. When parameters are selected using the measure, the output image achieves a balance between protecting the important data in the image while still containing a good overall representation of the image. We will show results for this encryption method on a number of images, using histograms to evaluate the effectiveness of the encryption.

  18. Chinese women's participation in fertility discussions.

    PubMed

    Li, L

    1993-01-01

    In an attempt to better understand the process through which the family planning (FP) programs and socioeconomic developments in China affect fertility, women's participation in fertility discussions with their husbands are examined as an intermediate factor in a study based on results of a random survey of 6654 ever-married women of reproductive age from 7 cities and 30 counties of Guangdong. First, it must be noted that Chinese couples do have individual choices (albeit quite limited ones) about their fertility; they can choose to follow or ignore government policy or they can choose to remain childless. The present study has 3 major hypotheses: 1) the more a woman is involved in fertility discussions with her husband, the fewer children she will have; 2) urban women with a higher educational status will be more likely to have such discussions; and 3) women who are contacted individually by FP personnel are more likely to be involved in fertility discussions. After a discussion of data collection and variables (number of living children, education of wife and husband, age at marriage, residence, living with parents, contacted by FP personnel, and discussion with husband), the results are presented in terms of zero-order correlation coefficients indicating their relationships. The bivariate analysis supported the hypotheses. Multiple regression analysis showed that age at marriage, education of wives and husbands, FP contacts, and participation in discussions remain significant fertility determinants (but the correlation between fertility and residence becomes trivial). A further regression model indicated that a woman's educational attainment is the most significant positive indication of their participation in fertility discussions. These results imply that as women's status continues to improve in China and the deeply-rooted patriarchal tradition loses hold, increased gender equity and education will influence a fertility decline. FP personnel could also

  19. Antimutagenic property of a Chinese herb

    SciTech Connect

    Hongen Zhang; Te-Hsiu Ma; Byeong-Seon Jeong; Chang-Deok Won

    1994-12-31

    The root extracts of a Chinese herb, Polygonum multiflorum Thunb, has been used as internal medicine to improve liver and kidney functions for centuries. The antimutagenic property of this drug was evaluated with the Tradescantia-micronucleus (Trad-MCN) assay in this study. The Trad-MCN bioassay is a well-established test for chromosome damage induced by physical or chemical agents in terms of micronuclei (MCN) frequency. Inflorescences of the Tradescantia plant cuttings were first exposed to 35 R soft X-rays (80 Kv, 5 ma, 1 mm Al filter, dose rate around 50 R/min) and followed by drug treatments at 1%, 3% and 6% concentrations of the aqueous solution for a total of 24 hr recovery period. The positive (X-rays), negative (nutrient solution) and drug control (3% drug solution) groups were maintained in each of the three series of repeated experiments. Flower buds of the treated and control groups were fixed in aceto-alcohol (1:3 ratio) for preparation of slides to score MCN frequencies in the early tetrads of the meiotic pollen mother cells. The mean MCN frequencies (MCN/100 tetrads + SD) of the positive control (X-irradiated) was 26.67 + 9.62; the negative control was 2.92 + 1.90; the drug control was 2.06 + 1.50 and the 35 R X-ray/6% drug treated was 18.75 + 6.54. A 30% reduction of chromosome damage was observed. Antimutagenic effects were relatively lower at lower concentrations. This antimutagenic effect could be the results of the meiotic inhibition, DNA repair or radical elimination from the X-irradiation plant cells.

  20. Developmental dyscalculia and low numeracy in Chinese children.

    PubMed

    Chan, Winnie Wai Lan; Au, Terry K; Tang, Joey

    2013-05-01

    Children struggle with mathematics for different reasons. Developmental dyscalculia and low numeracy - two kinds of mathematical difficulties - may have their roots, respectively, in poor understanding of exact non-symbolic numerosities and of symbolic numerals. This study was the first to explore whether Chinese children, despite cultural and linguistic factors supporting their mathematical learning, also showed such mathematical difficulties and whether such difficulties have measurable impact on children's early school mathematical performance. First-graders, classified as dyscalculia, low numeracy, or normal achievement, were compared for their performance in various school mathematical tasks requiring a grasp of non-symbolic numerosities (i.e., non-symbolic tasks) or an understanding of symbolic numerals (i.e., symbolic tasks). Children with dyscalculia showed poorer performance than their peers in non-symbolic tasks but not symbolic ones, whereas those with low numeracy showed poorer performance in symbolic tasks but not non-symbolic ones. As hypothesized, these findings suggested that dyscalculia and low numeracy were distinct deficits and caused by deficits in non-symbolic and symbolic processing, respectively. These findings went beyond prior research that only documented generally low mathematical achievements for these two groups of children. Moreover, these deficits appeared to be persistent and could not be remedied simply through day-to-day school mathematical learning. The present findings highlighted the importance of tailoring early learning support for children with these distinct deficits, and pointed to future directions for the screening of such mathematical difficulties among Chinese children. PMID:23475011

  1. [Quantitative Detection of Chinese Cabbage Clubroot Based on FTIR Spectroscopy].

    PubMed

    Wang, Wei-ping; Chai, A-li; Shi, Yan-xia; Xie, Xue-wen; Li, Bao-ju

    2015-05-01

    Clubroot, caused by Plasmodiophora brassicae, is considered the most devastating soilborne disease in Brassica crops. It has emerged as a serious disease threatening the cruciferous crop production industry in China. Nowadays, the detection techniques for P. brassicae are laborious, time-consuming and low sensitivity. Rapid and effective detection methods are needed. The objective of this study is to develop a Fourier transform infrared spectrometer (FTIR) technique for detection of P. brassicae effectively and accurately. FTIR and Real-time PCR techniques were applied in quantitative detection of P. brassicae. Chinese cabbages were inoculated with P. brassicae. By analyzing the FTIR spectra of P. brassicae, infected clubroots and healthy roots, three specific bands 1 105, 1 145 and 1 228 cm-1 were selected. According to the correlation between the peak areas at these sensitive bands and Real-time PCR Ct value, quantitative evaluation model of P. brassicae was established based on FTIR y=34. 17 +12. 24x - 9. 81x2 - 6. 05x3, r=0. 98 (p<0. 05). To validate accuracy of the model, 10 clubroot samples were selected randomly from field, and detected by FTIR spectrum model, the results showed that the average error is 1. 60%. This demonstrated that the FTIR technology is an available one for the quantitative detection of P. brassicae in clubroot, and it provides a new method for quantitative and quickly detection of Chinese cabbage clubroot. PMID:26415436

  2. Ecology of Root Colonizing Massilia (Oxalobacteraceae)

    PubMed Central

    Ofek, Maya; Hadar, Yitzhak; Minz, Dror

    2012-01-01

    Background Ecologically meaningful classification of bacterial populations is essential for understanding the structure and function of bacterial communities. As in soils, the ecological strategy of the majority of root-colonizing bacteria is mostly unknown. Among those are Massilia (Oxalobacteraceae), a major group of rhizosphere and root colonizing bacteria of many plant species. Methodology/Principal Findings The ecology of Massilia was explored in cucumber root and seed, and compared to that of Agrobacterium population, using culture-independent tools, including DNA-based pyrosequencing, fluorescence in situ hybridization and quantitative real-time PCR. Seed- and root-colonizing Massilia were primarily affiliated with other members of the genus described in soil and rhizosphere. Massilia colonized and proliferated on the seed coat, radicle, roots, and also on hyphae of phytopathogenic Pythium aphanidermatum infecting seeds. High variation in Massilia abundance was found in relation to plant developmental stage, along with sensitivity to plant growth medium modification (amendment with organic matter) and potential competitors. Massilia absolute abundance and relative abundance (dominance) were positively related, and peaked (up to 85%) at early stages of succession of the root microbiome. In comparison, variation in abundance of Agrobacterium was moderate and their dominance increased at later stages of succession. Conclusions In accordance with contemporary models for microbial ecology classification, copiotrophic and competition-sensitive root colonization by Massilia is suggested. These bacteria exploit, in a transient way, a window of opportunity within the succession of communities within this niche. PMID:22808103

  3. How to bond to root canal dentin

    NASA Astrophysics Data System (ADS)

    Nica, Luminita; Todea, Carmen; Furtos, Gabriel; Baldea, Bogdan

    2014-01-01

    Bonding to root canal dentin may be difficult due to various factors: the structural characteristic of the root canal dentin, which is different from that of the coronal dentin; the presence of the organic tissue of the dental pulp inside the root canal, which has to be removed during the cleaning-shaping of the root canal system; the smear-layer resulted after mechanical instrumentation, which may interfere with the adhesion of the filling materials; the type of the irrigants used in the cleaning protocol; the type of the sealer and core material used in the obturation of the endodontic space; the type of the materials used for the restoration of the endodontically treated teeth. The influence of the cleaning protocol, of the root canal filling material, of the type of the adhesive system used in the restoration of the treated teeth and of the region of the root canal, on the adhesion of several filling and restorative materials to root canal dentin was evaluated in the push-out bond strength test on 1-mm thick slices of endodontically treated human teeth. The results showed that all these factors have a statistically significant influence on the push-out bond strength. Formation of resin tags between radicular dentin and the investigated materials was observed in some of the samples at SEM analysis.

  4. 13. PHOTOCOPY OF ILLUSTRATED CIRCULAR OF 'ROOTS NEW IRON POSITIVE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. PHOTOCOPY OF ILLUSTRATED CIRCULAR OF 'ROOTS NEW IRON POSITIVE BLAST BLOWER,' CA. JAN. 1880, FROM FILES OF ROOTS-CONNERSVILLE BLOWER CO., CONNERSVILLE, IND. - P. H. & F. M. Roots Company, Eastern Avenue, Connersville, Fayette County, IN

  5. Bitter Root Irrigation district canal, looking east, typical section (canal ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bitter Root Irrigation district canal, looking east, typical section (canal full) - Bitter Root Irrigation Project, Bitter Root Irrigation Canal, Heading at Rock Creek Diversion Dam, West of U.S. Highway 93, Darby, Ravalli County, MT

  6. Bitter Root Irrigation district canal, looking east, typical section and ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Bitter Root Irrigation district canal, looking east, typical section and crossing - Bitter Root Irrigation Project, Bitter Root Irrigation Canal, Heading at Rock Creek Diversion Dam, West of U.S. Highway 93, Darby, Ravalli County, MT

  7. 10. PHOTOCOPY OF 'P. H. & F. M. ROOTS FOUNDARY ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. PHOTOCOPY OF 'P. H. & F. M. ROOTS FOUNDARY MANUFACTURERS OF ROOTS BLOWERS' FROM INDIANAPOLIS STAR, June 13, 1926, Gravure Section, p. 2 - P. H. & F. M. Roots Company, Eastern Avenue, Connersville, Fayette County, IN

  8. A thermodynamic formulation of root water uptake

    NASA Astrophysics Data System (ADS)

    Hildebrandt, A.; Kleidon, A.; Bechmann, M.

    2015-12-01

    By extracting bound water from the soil and lifting it to the canopy, root systems of vegetation perform work. Here we describe how the energetics involved in root water uptake can be quantified. The illustration is done using a simple, four-box model of the soil-root system to represent heterogeneity and a parameterization in which root water uptake is driven by the xylem potential of the plant with a fixed flux boundary condition. We use this approach to evaluate the effects of soil moisture heterogeneity and root system properties on the dissipative losses and export of energy involved in root water uptake. For this, we derive an expression that relates the energy export at the root collar to a sum of terms that reflect all fluxes and storage changes along the flow path in thermodynamic terms. We conclude that such a thermodynamic evaluation of root water uptake conveniently provides insights into the impediments of different processes along the entire flow path and explicitly accounting not only for the resistances along the flow path and those imposed by soil drying but especially the role of heterogenous soil water distribution. The results show that least energy needs to be exported and dissipative losses are minimized by a root system if it extracts water uniformly from the soil. This has implications for plant water relations in forests where canopies generate heterogenous input patterns. Our diagnostic in the energy domain should be useful in future model applications for quantifying how plants can evolve towards greater efficiency in their structure and function, particularly in heterogenous soil environments. Generally, this approach may help to better describe heterogeneous processes in the soil in a simple, yet physically-based way.

  9. Root type matters: measurements of water uptake by seminal, crown and lateral roots of maize

    NASA Astrophysics Data System (ADS)

    Ahmed, Mutez Ali; Zarebanadkouki, Mohsen; Kaestner, Anders; Carminati, Andrea

    2016-04-01

    Roots play a key role in water acquisition and are a significant component of plant adaptation to different environmental conditions. Although maize (Zea mays L.) is one of the most important crops worldwide, there is limited information on the function of different root segments and types in extracting water from soils. Aim of this study was to investigate the location of root water uptake in mature maize. We used neutron radiography to image the spatial distribution of maize roots and trace the transport of injected deuterated water (D2O) in soil and roots. Maize plants were grown in aluminum containers filled with a sandy soil that was kept homogeneously wet throughout the experiment. When the plants were five weeks-old, we injected D2O into selected soil regions. The transport of D2O was simulated using a diffusion-convection numerical model. By fitting the observed D2O transport we quantified the diffusion coefficient and the water uptake of the different root segments. The model was initially developed and tested with two weeks-old maize (Ahmed et. al. 2015), for which we found that water was mainly taken up by lateral roots and the water uptake of the seminal roots was negligible. Here, we used this method to measure root water uptake in a mature maize root system. The root architecture of five weeks-old maize consisted of primary and seminal roots with long laterals and crown (nodal) roots that emerged from the above ground part of the plant two weeks after planting. The crown roots were thicker than the seminal roots and had fewer and shorter laterals. Surprisingly, we found that the water was mainly taken up by the crown roots and their laterals, while the lateral roots of seminal roots, which were the main location of water uptake of younger plants, stopped to take up water. Interestingly, we also found that in contrast to the seminal roots, the crown roots were able to take up water also from their distal segments. We conclude that for the two weeks

  10. Adventitious root induction in Arabidopsis thaliana as a model for in vitro root organogenesis.

    PubMed

    Verstraeten, Inge; Beeckman, Tom; Geelen, Danny

    2013-01-01

    Adventitious root formation, the development of roots on non-root tissue (e.g. leaves, hypocotyls and stems) is a critical step during micropropagation. Although root induction treatments are routinely used for a large number of species micropropagated in vitro as well as for in vivo cuttings, the mechanisms controlling adventitious rooting are still poorly understood. Researchers attempt to gain better insight into the molecular aspects by studying adventitious rooting in Arabidopsis thaliana. The existing assay involves etiolation of seedlings and measurements of de novo formed roots on the elongated hypocotyl. The etiolated hypocotyls express a novel auxin-controlled signal transduction pathway in which auxin response factors (ARFs), microRNAs and environmental conditions that drive adventitious rooting are integrated. An alternative assay makes use of so-called thin cell layers (TCL), excised strips of cells from the inflorescence stem of Arabidopsis thaliana. However, both the etiolated seedling system and the TCL assay are only distantly related to industrial rooting processes in which roots are induced on adult stem tissue. Here, we describe an adventitious root induction system that uses segments of the inflorescence stems of Arabidopsis thaliana, which have a histological structure similar to cuttings or in vitro micropropagated shoots. The system allows multiple treatments with chemicals as well as the evaluation of different environmental conditions on a large number of explants. It is therefore suitable for high throughput chemical screenings and experiments that require numerous data points for statistical analysis. Using this assay, the adventitious root induction capacity of classical auxins was evaluated and a differential response to the different auxins could be demonstrated. NAA, IBA and IAA stimulated adventitious rooting on the stem segment, whereas 2,4-D and picloram did not. Light conditions profoundly influenced the root induction capacity

  11. Clinical technique for invasive cervical root resorption

    PubMed Central

    Silveira, Luiz Fernando Machado; Silveira, Carina Folgearini; Martos, Josué; Piovesan, Edno Moacir; César Neto, João Batista

    2011-01-01

    This clinical case report describes the diagnosis and treatment of an external invasive cervical resorption. A 17-year-old female patient had a confirmed diagnosis of invasive cervical resorption class 4 by cone beam computerized tomography. Although, there was no communication with the root canal, the invasive resorption process was extending into the cervical and middle third of the root. The treatment of the cervical resorption of the lateral incisor interrupted the resorptive process and restored the damaged root surface and the dental functions without any esthetic sequelae. Both the radiographic examination and computed tomography are imperative to reveal the extent of the defect in the differential diagnosis. PMID:22144822

  12. THttpServer class in ROOT

    NASA Astrophysics Data System (ADS)

    Adamczewski-Musch, Joern; Linev, Sergey

    2015-12-01

    The new THttpServer class in ROOT implements HTTP server for arbitrary ROOT applications. It is based on Civetweb embeddable HTTP server and provides direct access to all objects registered for the server. Objects data could be provided in different formats: binary, XML, GIF/PNG, and JSON. A generic user interface for THttpServer has been implemented with HTML/JavaScript based on JavaScript ROOT development. With any modern web browser one could list, display, and monitor objects available on the server. THttpServer is used in Go4 framework to provide HTTP interface to the online analysis.

  13. BOREAS TE-2 Root Respiration Data

    NASA Technical Reports Server (NTRS)

    Ryan, Michael G.; Lavigne, Michael; Hall, Forrest G. (Editor); Papagno, Andrea (Editor)

    2000-01-01

    The BOREAS TE-2 team collected several data sets in support of its efforts to characterize and interpret information on the respiration of the foliage, roots, and wood of boreal vegetation. This data set includes means of tree root respiration measurements on roots having diameters ranging from 0 to 2 mm conducted in the NSA during the growing season of 1994. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

  14. Getting to the roots of it: Genetic and hormonal control of root architecture.

    PubMed

    Jung, Janelle K H; McCouch, Susan

    2013-01-01

    Root system architecture (RSA) - the spatial configuration of a root system - is an important developmental and agronomic trait, with implications for overall plant architecture, growth rate and yield, abiotic stress resistance, nutrient uptake, and developmental plasticity in response to environmental changes. Root architecture is modulated by intrinsic, hormone-mediated pathways, intersecting with pathways that perceive and respond to external, environmental signals. The recent development of several non-invasive 2D and 3D root imaging systems has enhanced our ability to accurately observe and quantify architectural traits on complex whole-root systems. Coupled with the powerful marker-based genotyping and sequencing platforms currently available, these root phenotyping technologies lend themselves to large-scale genome-wide association studies, and can speed the identification and characterization of the genes and pathways involved in root system development. This capability provides the foundation for examining the contribution of root architectural traits to the performance of crop varieties in diverse environments. This review focuses on our current understanding of the genes and pathways involved in determining RSA in response to both intrinsic and extrinsic (environmental) response pathways, and provides a brief overview of the latest root system phenotyping technologies and their potential impact on elucidating the genetic control of root development in plants. PMID:23785372

  15. Light as stress factor to plant roots – case of root halotropism

    PubMed Central

    Yokawa, Ken; Fasano, Rossella; Kagenishi, Tomoko; Baluška, František

    2014-01-01

    Despite growing underground, largely in darkness, roots emerge to be very sensitive to light. Recently, several important papers have been published which reveal that plant roots not only express all known light receptors but also that their growth, physiology and adaptive stress responses are light-sensitive. In Arabidopsis, illumination of roots speeds-up root growth via reactive oxygen species-mediated and F-actin dependent process. On the other hand, keeping Arabidopsis roots in darkness alters F-actin distribution, polar localization of PIN proteins as well as polar transport of auxin. Several signaling components activated by phytohormones are overlapping with light-related signaling cascade. We demonstrated that the sensitivity of roots to salinity is altered in the light-grown Arabidopsis roots. Particularly, light-exposed roots are less effective in their salt-avoidance behavior known as root halotropism. Here we discuss these new aspects of light-mediated root behavior from cellular, physiological and evolutionary perspectives. PMID:25566292

  16. Getting to the roots of it: Genetic and hormonal control of root architecture

    PubMed Central

    Jung, Janelle K. H.; McCouch, Susan

    2013-01-01

    Root system architecture (RSA) – the spatial configuration of a root system – is an important developmental and agronomic trait, with implications for overall plant architecture, growth rate and yield, abiotic stress resistance, nutrient uptake, and developmental plasticity in response to environmental changes. Root architecture is modulated by intrinsic, hormone-mediated pathways, intersecting with pathways that perceive and respond to external, environmental signals. The recent development of several non-invasive 2D and 3D root imaging systems has enhanced our ability to accurately observe and quantify architectural traits on complex whole-root systems. Coupled with the powerful marker-based genotyping and sequencing platforms currently available, these root phenotyping technologies lend themselves to large-scale genome-wide association studies, and can speed the identification and characterization of the genes and pathways involved in root system development. This capability provides the foundation for examining the contribution of root architectural traits to the performance of crop varieties in diverse environments. This review focuses on our current understanding of the genes and pathways involved in determining RSA in response to both intrinsic and extrinsic (environmental) response pathways, and provides a brief overview of the latest root system phenotyping technologies and their potential impact on elucidating the genetic control of root development in plants. PMID:23785372

  17. Arthroscopic Repair of Posterior Meniscal Root Tears

    PubMed Central

    Matheny, Lauren; Moulton, Samuel G.; Dean, Chase S.; LaPrade, Robert F.

    2016-01-01

    Objectives: The purpose of this study was to compare subjective clinical outcomes in patients requiring arthroscopic transtibial pullout repair for posterior meniscus root tears of the medial and lateral menisci. We hypothesized that improvement in function and activity level would be similar among patients undergoing lateral and medial meniscal root repairs. Methods: This study was IRB approved. All patients who underwent posterior meniscal root repair by a single orthopaedic surgeon were included in this study. Detailed operative data were documented at surgery. Patients completed a subjective questionnaire, including Lysholm score, Tegner activity scale, WOMAC, SF-12 and patient satisfaction with outcome, which were collected preoperatively and at a minimum of two years postoperatively. Failure was defined as any patient who underwent revision meniscal root repair or partial meniscectomy following the index surgery. Results: There were 50 patients (16 females, 34 males) with a mean age of 37.8 years (range, 16.6-65.7) and a mean BMI of 27.3 (range, 20.5-49.2) included in this study. Fifteen patients underwent lateral meniscus root repair and 35 patients underwent medial meniscus root repair. Three patients who underwent lateral meniscus root repair required revision meniscus root repair surgery, while no patients who underwent medial meniscus root repair required revision surgery (p=0.26). There was a significant difference in preoperative and postoperative Lysholm score (53 vs. 78) (p<0.001), Tegner activity scale (2.0 vs. 4.0) (p=0.03), SF-12 physical component subscale (38 vs. 50) (p=0.001) and WOMAC (36 vs. 8) (p<0.001) for the total population. Median patient satisfaction with outcome was 9 (range, 1-10). There was no significant difference in mean age between lateral and medial root repair groups (32 vs. 40) (p=0.12) or gender (p=0.19). There was no significant difference in gender between lateral and medial root repair groups (p=0.95). There was a

  18. RootScape: a landmark-based system for rapid screening of root architecture in Arabidopsis.

    PubMed

    Ristova, Daniela; Rosas, Ulises; Krouk, Gabriel; Ruffel, Sandrine; Birnbaum, Kenneth D; Coruzzi, Gloria M

    2013-03-01

    The architecture of plant roots affects essential functions including nutrient and water uptake, soil anchorage, and symbiotic interactions. Root architecture comprises many features that arise from the growth of the primary and lateral roots. These root features are dictated by the genetic background but are also highly responsive to the environment. Thus, root system architecture (RSA) represents an important and complex trait that is highly variable, affected by genotype × environment interactions, and relevant to survival/performance. Quantification of RSA in Arabidopsis (Arabidopsis thaliana) using plate-based tissue culture is a very common and relatively rapid assay, but quantifying RSA represents an experimental bottleneck when it comes to medium- or high-throughput approaches used in mutant or genotype screens. Here, we present RootScape, a landmark-based allometric method for rapid phenotyping of RSA using Arabidopsis as a case study. Using the software AAMToolbox, we created a 20-point landmark model that captures RSA as one integrated trait and used this model to quantify changes in the RSA of Arabidopsis (Columbia) wild-type plants grown under different hormone treatments. Principal component analysis was used to compare RootScape with conventional methods designed to measure root architecture. This analysis showed that RootScape efficiently captured nearly all the variation in root architecture detected by measuring individual root traits and is 5 to 10 times faster than conventional scoring. We validated RootScape by quantifying the plasticity of RSA in several mutant lines affected in hormone signaling. The RootScape analysis recapitulated previous results that described complex phenotypes in the mutants and identified novel gene × environment interactions. PMID:23335624

  19. Allometry of root branching and its relationship to root morphological and functional traits in three range grasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Several studies have documented the existence of correlative mechanisms that control lateral root emergence in plants. To better understand root branching responses to nutrients, root growth in three range grasses [Whitmar cultivar of bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) Love), Hyc...

  20. Rooting depths of plants relative to biological and environmental factors

    SciTech Connect

    Foxx, T S; Tierney, G D; Williams, J M

    1984-11-01

    In 1981 to 1982 an extensive bibliographic study was completed to document rooting depths of native plants in the United States. The data base presently contains 1034 citations with approximately 12,000 data elements. In this paper the data were analyzed for rooting depths as related to life form, soil type, geographical region, root type, family, root depth to shoot height ratios, and root depth to root lateral ratios. Average rooting depth and rooting frequencies were determined and related to present low-level waste site maintenance.

  1. Understanding plant root system influences on soil strength and stability

    NASA Astrophysics Data System (ADS)

    Bengough, A. Glyn; Brown, Jennifer L.; Loades, Kenneth W.; Knappett, Jonathan A.; Meijer, Gertjan; Nicoll, Bruce

    2016-04-01

    Keywords: root growth, soil reinforcement, tensile strength Plant roots modify and reinforce the soil matrix, stabilising it against erosion and shallow landslides. Roots mechanically bind the soil particles together and modify the soil hydrology via water uptake, creation of biopores, and modification of the soil water-release characteristic. Key to understanding the mechanical reinforcement of soil by roots is the relation between root strength and root diameter measured for roots in any given soil horizon. Thin roots have frequently been measured to have a greater tensile strength than thick roots, but their strength is also often much more variable. We consider the factors influencing this strength-diameter relationship, considering relations between root tensile strength and root dry density, root water content, root age, and root turnover in several woody and non-woody species. The role of possible experimental artefacts and measurement techniques will be considered. Tensile strength increased generally with root age and decreased with thermal time after excision as a result of root decomposition. Single factors alone do not appear to explain the strength-diameter relationship, and both strength/stiffness and dry density may vary between different layers of tissue within a single root. Results will be discussed to consider how we can achieve a more comprehensive understanding of the variation in root biomechanical properties, and its consequences for soil reinforcement. Acknowledgements: The James Hutton Institute receives funding from the Scottish Government. AGB and JAK acknowledge part funding from EPSRC (EP/M020355/1).

  2. A large and deep root system underlies high nitrogen-use efficiency in maize production.

    PubMed

    Yu, Peng; Li, Xuexian; White, Philip J; Li, Chunjian

    2015-01-01

    Excessive N fertilization results in low N-use efficiency (NUE) without any yield benefits and can have profound, long-term environmental consequences including soil acidification, N leaching and increased production of greenhouse gases. Improving NUE in crop production has been a longstanding, worldwide challenge. A crucial strategy to improve NUE is to enhance N uptake by roots. Taking maize as a model crop, we have compared root dry weight (RDW), root/shoot biomass ratio (R/S), and NUE of maize grown in the field in China and in western countries using data from 106 studies published since 1959. Detailed analysis revealed that the differences in the RDW and R/S of maize at silking in China and the western countries were not derived from variations in climate, geography, and stress factors. Instead, NUE was positively correlated with R/S and RDW; R/S and NUE of maize varieties grown in western countries were significantly greater than those grown in China. We then testified this conclusion by conducting field trials with representative maize hybrids in China (ZD958 and XY335) and the US (P32D79). We found that US P32D79 had a better root architecture for increased N uptake and removed more mineral N than Chinese cultivars from the 0-60 cm soil profile. Reported data and our field results demonstrate that a large and deep root, with an appropriate architecture and higher stress tolerance (higher plant density, drought and N deficiency), underlies high NUE in maize production. We recommend breeding for these traits to reduce the N-fertilizer use and thus N-leaching in maize production and paying more attention to increase tolerance to stresses in China. PMID:25978356

  3. A Large and Deep Root System Underlies High Nitrogen-Use Efficiency in Maize Production

    PubMed Central

    Yu, Peng; Li, Xuexian; White, Philip J.; Li, Chunjian

    2015-01-01

    Excessive N fertilization results in low N-use efficiency (NUE) without any yield benefits and can have profound, long-term environmental consequences including soil acidification, N leaching and increased production of greenhouse gases. Improving NUE in crop production has been a longstanding, worldwide challenge. A crucial strategy to improve NUE is to enhance N uptake by roots. Taking maize as a model crop, we have compared root dry weight (RDW), root/shoot biomass ratio (R/S), and NUE of maize grown in the field in China and in western countries using data from 106 studies published since 1959. Detailed analysis revealed that the differences in the RDW and R/S of maize at silking in China and the western countries were not derived from variations in climate, geography, and stress factors. Instead, NUE was positively correlated with R/S and RDW; R/S and NUE of maize varieties grown in western countries were significantly greater than those grown in China. We then testified this conclusion by conducting field trials with representative maize hybrids in China (ZD958 and XY335) and the US (P32D79). We found that US P32D79 had a better root architecture for increased N uptake and removed more mineral N than Chinese cultivars from the 0-60 cm soil profile. Reported data and our field results demonstrate that a large and deep root, with an appropriate architecture and higher stress tolerance (higher plant density, drought and N deficiency), underlies high NUE in maize production. We recommend breeding for these traits to reduce the N-fertilizer use and thus N-leaching in maize production and paying more attention to increase tolerance to stresses in China. PMID:25978356

  4. Antioxidant and DNA Repair Stimulating Effect of Extracts from Transformed and Normal Roots of Rhaponticum carthamoides against Induced Oxidative Stress and DNA Damage in CHO Cells

    PubMed Central

    Skała, Ewa; Sitarek, Przemysław; Różalski, Marek; Krajewska, Urszula; Szemraj, Janusz; Wysokińska, Halina; Śliwiński, Tomasz

    2016-01-01

    Rhaponticum carthamoides has a long tradition of use in Siberian folk medicine. The roots and rhizomes of this species are used in various dietary supplements or nutraceutical preparations to increase energy level or eliminate physical weakness. This is the first report to reveal the protective and DNA repair stimulating abilities of R. carthamoides root extracts in Chinese hamster ovary (CHO) cells exposed to an oxidative agent. Both transformed root extract (TR extract) and extract of soil-grown plant roots (NR extract) may be responsible for stimulating CHO cells to repair oxidatively induced DNA damage, but CHO cells stimulated with extract from the transformed roots demonstrated significantly stronger properties than cells treated with the soil-grown plant root extract. These differences in biological activity may be attributed to the differences in the content of phenolic compounds in these root extracts. Preincubation of the CHO cells with TR and NR extracts showed an increase in gene expression and protein levels of catalase (CAT) and superoxide dismutase (SOD2). R. carthamoides may possess antioxidant properties that protect CHO cells against oxidative stress. PMID:27034736

  5. Antioxidant and DNA Repair Stimulating Effect of Extracts from Transformed and Normal Roots of Rhaponticum carthamoides against Induced Oxidative Stress and DNA Damage in CHO Cells.

    PubMed

    Skała, Ewa; Sitarek, Przemysław; Różalski, Marek; Krajewska, Urszula; Szemraj, Janusz; Wysokińska, Halina; Śliwiński, Tomasz

    2016-01-01

    Rhaponticum carthamoides has a long tradition of use in Siberian folk medicine. The roots and rhizomes of this species are used in various dietary supplements or nutraceutical preparations to increase energy level or eliminate physical weakness. This is the first report to reveal the protective and DNA repair stimulating abilities of R. carthamoides root extracts in Chinese hamster ovary (CHO) cells exposed to an oxidative agent. Both transformed root extract (TR extract) and extract of soil-grown plant roots (NR extract) may be responsible for stimulating CHO cells to repair oxidatively induced DNA damage, but CHO cells stimulated with extract from the transformed roots demonstrated significantly stronger properties than cells treated with the soil-grown plant root extract. These differences in biological activity may be attributed to the differences in the content of phenolic compounds in these root extracts. Preincubation of the CHO cells with TR and NR extracts showed an increase in gene expression and protein levels of catalase (CAT) and superoxide dismutase (SOD2). R. carthamoides may possess antioxidant properties that protect CHO cells against oxidative stress. PMID:27034736

  6. Root gravitropism in maize and Arabidopsis

    NASA Technical Reports Server (NTRS)

    Evans, Michael L.

    1993-01-01

    Research during the period 1 March 1992 to 30 November 1993 focused on improvements in a video digitizer system designed to automate the recording of surface extension in plants responding to gravistimulation. The improvements included modification of software to allow detailed analysis of localized extension patterns in roots of Arabidopsis. We used the system to analyze the role of the postmitotic isodiametric growth zone (a region between the meristem and the elongation zone) in the response of maize roots to auxin, calcium, touch and gravity. We also used the system to analyze short-term auxin and gravitropic responses in mutants of Arabidopsis with reduced auxin sensitivity. In a related project, we studied the relationship between growth rate and surface electrical currents in roots by examining the effects of gravity and thigmostimulation on surface potentials in maize roots.

  7. DMA thermal analysis of yacon tuberous roots

    NASA Astrophysics Data System (ADS)

    Blahovec, J.; Lahodová, M.; Kindl, M.; Fernández, E. C.

    2013-12-01

    Specimens prepared from yacon roots in first two weeks after harvest were tested by dynamic mechanical analysis thermal analysis at temperatures between 30 and 90°C. No differences between different parts of roots were proved. There were indicated some differences in the test parameters that were caused by short time storage of the roots. One source of the differences was loss of water during the roots storage. The measured modulus increased during short time storage. Detailed study of changes of the modulus during the specimen dynamic mechanical analysis test provided information about different development of the storage and loss moduli during the specimen heating. The observed results can be caused by changes in cellular membranes observed earlier during vegetable heating, and by composition changes due to less stable components of yacon like inulin.

  8. "Roots" Touched Children: Planned or Not

    ERIC Educational Resources Information Center

    Greathouse, Betty

    1977-01-01

    Explores children's reactions to the televised version of Alex Haley's "Roots" through interviews with thirty 8-year-old third-graders (10 Black, 10 Mexican-American, 10 White) from two classrooms in South Phoenix, Arizona. (BF/JH)

  9. Irregular sesquiterpenoids from Ligusticum grayi roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root oil of Ligusticum grayi (Apiaceae) contains numerous irregular sesquiterpenoids. In addition to the known acyclic sesquilavandulol and a new sesquilavandulyl aldehyde, two thapsanes, one epithapsane, and fourteen sesquiterpenoids representing eight novel carbon skeletons were found. The new sk...

  10. Translation and validation of a Chinese version of the Mandibular Function Impairment Questionnaire.

    PubMed

    Xu, L; Cai, B; Fang, Z

    2016-08-01

    To adapt the English version of the Mandibular Function Impairment Questionnaire (MFIQ) for Chinese-speaking patients with temporomandibular disorder (TMD) and to evaluate its validity and reliability. In total, 352 patients diagnosed with TMD according to the research diagnostic criteria for TMD (RDC/TMD) Axis I were included in this study. The psychometric evaluation included reliability, which was evaluated by internal consistency (Cronbach's alpha coefficient), and test-retest reliability and validity, which were tested by content and construct validity. Because the content validity of item 11 (kissing) was low (0·12), this item was excluded in subsequent analyses. For exploratory factor analysis, three factors were extracted, accounting for 63·6% of the variance. All items had factor loadings above 0·4. Two models were tested by confirmatory factor analysis, and the two-factor model was adopted (χ(2) /df = 2·279, root mean square error of approximation (RMSEA) = 0·086, comparative fit index (CFI) = 0·910). Internal reliability (coefficient alpha values of 0·925 and 0·720 for each factor) and test-retest reliability (ICCfactor1 = 0·895, 95% CIfactor1 = 0·869-0·918, ICCfactor2 = 0·720, 95% CIfactor2 = 0·645-0·783) of the Chinese MFIQ were excellent. A reliable and valid Chinese version of the MFIQ was constructed for the evaluation of Chinese patients with TMD after some modification of the English version of the MFIQ. PMID:27061198

  11. [Textual research on adulteration of Chinese materia medica in ancient China].

    PubMed

    Xie, Jin; Wang, De-Qun

    2013-09-01

    By investigating the mainstream works of herbal classics of successive ages, it is found that adulteration of Chinese materia medica appeared early in ancient China. The main methods of adulteration was producing fraud medicines in the Northern-Southern Dynasties, fake medicines began to appear in the Tang Dynasty, and status of adulteration of Chinese materia medica ran unchecked since the Ming and Qing Dynasty. By statistics, there were 76 kinds of adulteration varieties before the Republican period. The main varieties were precious drugs, animal drugs and artifacts. Commonly methods used in the process included forging and adulterating, dealing with 11 kinds and 68 kinds respectively. Adulteration probably lead to the result of imposing the changes of the used medicinal parts of Herba Pogostemonis; Radix Aconiti Lateralis prepared by adding salt, Radix Angelica Sinensis processed by wine, and Radix Astragalis seu Hedysaris processed with bee honey. However, the root cause of adulteration in Chinese materia medica was the dissociation of professional physician and pharmacist, resulting in the ignorance of medical practitioners became unable to recognize Chinese materia medica; and the immorality of medicinal merchants. Besides, rating the quality of materia medica based on its producing areas without differentiating the false from the genuine may also contribute to this result passively. PMID:24429032

  12. Optimizing prescription of chinese herbal medicine for unstable angina based on partially observable markov decision process.

    PubMed

    Feng, Yan; Qiu, Yu; Zhou, Xuezhong; Wang, Yixin; Xu, Hao; Liu, Baoyan

    2013-01-01

    Objective. Initial optimized prescription of Chinese herb medicine for unstable angina (UA). Methods. Based on partially observable Markov decision process model (POMDP), we choose hospitalized patients of 3 syndrome elements, such as qi deficiency, blood stasis, and turbid phlegm for the data mining, analysis, and objective evaluation of the diagnosis and treatment of UA at a deep level in order to optimize the prescription of Chinese herb medicine for UA. Results. The recommended treatment options of UA for qi deficiency, blood stasis, and phlegm syndrome patients were as follows: Milkvetch Root + Tangshen + Indian Bread + Largehead Atractylodes Rhizome (ADR = 0.96630); Danshen Root + Chinese Angelica + Safflower + Red Peony Root + Szechwan Lovage Rhizome Orange Fruit (ADR = 0.76); Snakegourd Fruit + Longstamen Onion Bulb + Pinellia Tuber + Dried Tangerine peel + Largehead Atractylodes Rhizome + Platycodon Root (ADR = 0.658568). Conclusion. This study initially optimized prescriptions for UA based on POMDP, which can be used as a reference for further development of UA prescription in Chinese herb medicine. PMID:24078826

  13. Three-dimensional facial analysis of Chinese children with repaired unilateral cleft lip and palate

    PubMed Central

    Othman, Siti Adibah; Aidil Koay, Noor Airin

    2016-01-01

    We analyzed the facial features of Chinese children with repaired unilateral cleft lip and palate (UCLP) and compared them with a normal control group using a three-dimensional (3D) stereophotogrammetry camera. This cross-sectional study examined 3D measurements of the facial surfaces of 20 Chinese children with repaired UCLP and 40 unaffected Chinese children aged 7 to 12 years old, which were captured using the VECTRA 3D five-pod photosystem and analyzed using Mirror software. Twenty-five variables and two ratios were compared between both groups using independent t-test. Intra- and inter-observer reliability was determined using ten randomly selected images and analyzed using intra-class correlation coefficient test (ICC). The level of significance was set at p < 0.0018. Intra- and inter-observers’ reliability was considered fair to excellent with an ICC value ranging from 0.54 to 0.99. Statistically significant differences (p < 0.0018) were found mainly in the nasolabial region. The cleft group exhibited wider alar base root width, flattened nose and broader nostril floor width on the cleft side. They tended to have shorter upper lip length and thinner upper vermillion thickness. Faces of Chinese children with repaired UCLP displayed meaningful differences when compared to the normal group especially in the nasolabial regions. PMID:27507713

  14. Three-dimensional facial analysis of Chinese children with repaired unilateral cleft lip and palate.

    PubMed

    Othman, Siti Adibah; Aidil Koay, Noor Airin

    2016-01-01

    We analyzed the facial features of Chinese children with repaired unilateral cleft lip and palate (UCLP) and compared them with a normal control group using a three-dimensional (3D) stereophotogrammetry camera. This cross-sectional study examined 3D measurements of the facial surfaces of 20 Chinese children with repaired UCLP and 40 unaffected Chinese children aged 7 to 12 years old, which were captured using the VECTRA 3D five-pod photosystem and analyzed using Mirror software. Twenty-five variables and two ratios were compared between both groups using independent t-test. Intra- and inter-observer reliability was determined using ten randomly selected images and analyzed using intra-class correlation coefficient test (ICC). The level of significance was set at p < 0.0018. Intra- and inter-observers' reliability was considered fair to excellent with an ICC value ranging from 0.54 to 0.99. Statistically significant differences (p < 0.0018) were found mainly in the nasolabial region. The cleft group exhibited wider alar base root width, flattened nose and broader nostril floor width on the cleft side. They tended to have shorter upper lip length and thinner upper vermillion thickness. Faces of Chinese children with repaired UCLP displayed meaningful differences when compared to the normal group especially in the nasolabial regions. PMID:27507713

  15. Mapping gene activity of Arabidopsis root hairs

    PubMed Central

    2013-01-01

    Background Quantitative information on gene activity at single cell-type resolution is essential for the understanding of how cells work and interact. Root hairs, or trichoblasts, tubular-shaped outgrowths of specialized cells in the epidermis, represent an ideal model for cell fate acquisition and differentiation in plants. Results Here, we provide an atlas of gene and protein expression in Arabidopsis root hair cells, generated by paired-end RNA sequencing and LC/MS-MS analysis of protoplasts from plants containing a pEXP7-GFP reporter construct. In total, transcripts of 23,034 genes were detected in root hairs. High-resolution proteome analysis led to the reliable identification of 2,447 proteins, 129 of which were differentially expressed between root hairs and non-root hair tissue. Dissection of pre-mRNA splicing patterns showed that all types of alternative splicing were cell type-dependent, and less complex in EXP7-expressing cells when compared to non-root hair cells. Intron retention was repressed in several transcripts functionally related to root hair morphogenesis, indicative of a cell type-specific control of gene expression by alternative splicing of pre-mRNA. Concordance between mRNA and protein expression was generally high, but in many cases mRNA expression was not predictive for protein abundance. Conclusions The integrated analysis shows that gene activity in root hairs is dictated by orchestrated, multilayered regulatory mechanisms that allow for a cell type-specific composition of functional components. PMID:23800126

  16. Anatomical aspects of angiosperm root evolution

    PubMed Central

    Seago, James L.; Fernando, Danilo D.

    2013-01-01

    Background and Aims Anatomy had been one of the foundations in our understanding of plant evolutionary trends and, although recent evo-devo concepts are mostly based on molecular genetics, classical structural information remains useful as ever. Of the various plant organs, the roots have been the least studied, primarily because of the difficulty in obtaining materials, particularly from large woody species. Therefore, this review aims to provide an overview of the information that has accumulated on the anatomy of angiosperm roots and to present possible evolutionary trends between representatives of the major angiosperm clades. Scope This review covers an overview of the various aspects of the evolutionary origin of the root. The results and discussion focus on angiosperm root anatomy and evolution covering representatives from basal angiosperms, magnoliids, monocots and eudicots. We use information from the literature as well as new data from our own research. Key Findings The organization of the root apical meristem (RAM) of Nymphaeales allows for the ground meristem and protoderm to be derived from the same group of initials, similar to those of the monocots, whereas in Amborellales, magnoliids and eudicots, it is their protoderm and lateral rootcap which are derived from the same group of initials. Most members of Nymphaeales are similar to monocots in having ephemeral primary roots and so adventitious roots predominate, whereas Amborellales, Austrobaileyales, magnoliids and eudicots are generally characterized by having primary roots that give rise to a taproot system. Nymphaeales and monocots often have polyarch (heptarch or more) steles, whereas the rest of the basal angiosperms, magnoliids and eudicots usually have diarch to hexarch steles. Conclusions Angiosperms exhibit highly varied structural patterns in RAM organization; cortex, epidermis and rootcap origins; and stele patterns. Generally, however, Amborellales, magnoliids and, possibly

  17. Capillary-Effect Root-Environment System

    NASA Technical Reports Server (NTRS)

    Wright, Bruce D.

    1991-01-01

    Capillary-effect root-environment system (CERES) is experimental apparatus for growing plants in nutrient solutions. Solution circulated at slight tension in cavity filled with plastic screen and covered by porous plastic membrane. By adsorptive attraction, root draws solution through membrane. Conceived for use in microgravity of space, also finds terrestrial application in germinating seedlings, because it protects them from extremes of temperature, moisture, and soil pH and from overexposure to fertilizers and herbicides.

  18. Chinese herbs for dementia diseases.

    PubMed

    Hügel, H M; Jackson, N; May, B H; Xue, C C I

    2012-05-01

    In the last twenty years a considerable body of information has accumulated on the chemical constituents of Chinese herbs and their therapeutic potential. Our evaluation/systematic review [1, 2] of well-designed, randomized double blind controlled trials on Chinese herbal medicines beneficial for the improvement of cognitive function revealed a range of either single herbs or herbal mixtures that provided neuroprotective benefits. Oxidative stress may directly initiate neurodegeneration and herbal antioxidant neuroprotection is considered as a preventative and therapeutic approach. We encountered Acoris gramineus rhizome (AGR), Panax ginseng, Polygala tenuifolia and Poria cocos as the four most frequently used herbs as single/herbal mixtures that were associated with positive cognitive enhancing outcomes. This review focuses on the evidence of their medicinal effects attributed to those constituents present in relatively high concentration. PMID:22303969

  19. Recent advances in Chinese palaeontology.

    PubMed

    Xu, Xing; Luo, Zhe-Xi; Rong, Jia-Yu

    2010-01-22

    Discoveries are a driving force for progress in palaeontology. Palaeontology as a discipline of scientific inquiry has gained many fresh insights into the history of life, from the discoveries of many new fossils in China in the last 20 years, and from the new ideas derived from these fossils. This special issue of Proceedings of Royal Society B entitled Recent Advances in Chinese Palaeontology selects some of the very latest studies aimed at resolving the current problems of palaeontology and evolutionary biology based on new fossils from China. These fossils and their studies help to clarify some historical debates about a particular fossil group, or to raise new questions about history of life, or to pose a new challenge in our pursuit of science. These works on new Chinese fossils have covered the whole range of the diversity through the entire Phanerozoic fossil record. PMID:19812080

  20. Capital sought for Chinese development

    SciTech Connect

    Cheng, L.

    1984-03-01

    Foreign investment will be needed to develop China's untapped coal fields. China is the world's third largest coal producer, ranking behind only the USA and the Soviet Union. Bituminous coal predominates, but anthracite and brown coal are also found in considerable quantities. China's raw coal output increased from 32.4 million t in 1949 to 650 million t in 1982. About 96% of Chinese coal comes from underground operations, and 4% from open-pit mines. Mechanized operations contribute about 40% of the national output. To reach the annual production goal of 700 million t by the end of 1985 and 1.2 billion t by the year 2000, the Chinese government is promoting a concentrated development plan for selected major fields, and is calling on foreign investors to join in their exploitation. The investment program for the development of China's coal resources is described.

  1. Taiwanese, Chinese treatment facilities installed

    SciTech Connect

    Not Available

    1990-02-19

    This article reports on water treatment facilities from a U.S. company installed in a major Taiwanese refinery and in two mainland Chinese oil fields. Chinese Petroleum Corp. recently installed a wastewater treatment plant at its Kaohsiung, Taiwan, refinery. The treatment plant was needed because of expansion of the refinery's naphtha-cracking facilities at the 446,500-b/d refinery, the largest refinery, in terms of crude charging capacity, in the Asia/Pacific region. The same system has also gone into two oil field applications in the People's Republic of China: the Zhongyuan and Shengli oil fields. The system is designed for a total wastewater flow rate of 10,000 cu m/hr. The system and its treatment requirements are summarized.

  2. The Efficacy of Chinese Medicinal Herbs towards Grape Phylloxera (Daktulosphaira vitifoliae Fitch) (Hemiptera, Phylloxeridae)

    PubMed Central

    Su, Junping; Liu, Weiwei; Hussain Dhiloo, Khalid; Guo, Yuyuan

    2015-01-01

    Bio-insecticidal effects of seven Chinese medicinal herbs on mortality, fecundity, developmental periods and life table parameters of the grape phylloxera were investigated. In an excised root bioassay experiment aqueous extracts from seven Chinese medicinal herbs increased grape phylloxera first instar mortality (26.00–38.50%) compared to other instars. The intrinsic rate of increase (rm), finite rate of increase (λ), fecundity rate and net reproductive rate (R0) were significantly reduced by A. bidentata, A. tataricus, O. basilicum, P. frutescens and N. cataria. In a glasshouse pot trial, eggs, nymphs, adults and total population were significantly reduced before population establishment compared to those after its population established, by A. bidentata, A. tataricus and O. basilicum. Overall, A. bidentata, A. tataricus and O. basilicum can be used to suppress all life-stages of grape phylloxera. PMID:26186216

  3. The individual-oriented and social-oriented Chinese bicultural self: testing the theory.

    PubMed

    Lu, Luo

    2008-06-01

    The author proposes a bicultural self theory for contemporary Chinese individuals, encompassing 2 main components: the individual-oriented self and the social-oriented self. The social orientation is rooted in traditional Chinese conceptualization of the self, whereas the individual orientation has evolved and developed under Western influences along with recent societal modernization. The author conducted a series of 5 studies to test the theory and relate the model to important issues in current personality and social psychological research, such as cultural individualism-collectivism, self-construals, motivation, cognition, emotion, and well-being. A total of 977 university students in Taiwan participated. The author found that contrasting self-aspects were differentially associated with the aforementioned constructs, as theoretically predicted. This evidence thus generally supported the bicultural self model. PMID:18605182

  4. The Efficacy of Chinese Medicinal Herbs towards Grape Phylloxera (Daktulosphaira vitifoliae Fitch) (Hemiptera, Phylloxeridae).

    PubMed

    Liu, Yongqiang; Wang, Zhongyue; Su, Junping; Liu, Weiwei; Hussain Dhiloo, Khalid; Guo, Yuyuan

    2015-01-01

    Bio-insecticidal effects of seven Chinese medicinal herbs on mortality, fecundity, developmental periods and life table parameters of the grape phylloxera were investigated. In an excised root bioassay experiment aqueous extracts from seven Chinese medicinal herbs increased grape phylloxera first instar mortality (26.00-38.50%) compared to other instars. The intrinsic rate of increase (rm), finite rate of increase (λ), fecundity rate and net reproductive rate (R0) were significantly reduced by A. bidentata, A. tataricus, O. basilicum, P. frutescens and N. cataria. In a glasshouse pot trial, eggs, nymphs, adults and total population were significantly reduced before population establishment compared to those after its population established, by A. bidentata, A. tataricus and O. basilicum. Overall, A. bidentata, A. tataricus and O. basilicum can be used to suppress all life-stages of grape phylloxera. PMID:26186216

  5. [Apical root pins of high-karat gold alloys for resected roots].

    PubMed

    Handtmann, S; Lindemann, W; Sculte, W

    1989-02-01

    Following earlier studies on corrosion of silver pins in the root canal experience will be presented with the use of high-karat gold pins for apical closure of root amputations. The commercially available standardized Ackermann silver pins were replaced by high-karat gold pins of similar Vicker hardness and inserted in 218 patients with 264 root amputations since 1986. A clinical and radiological follow-up demonstrated a success rate of over 90%. PMID:2598876

  6. Lectin Binding to the Root and Root Hair Tips of the Tropical Legume Macroptilium atropurpureum Urb

    PubMed Central

    Ridge, R. W.; Rolfe, B. G.

    1986-01-01

    Ten fluorescein isothiocyanate-labeled lectins were tested on the roots of the tropical legume Macroptilium atropurpureum Urb. Four of these (concanavalin A, peanut agglutinin, Ricinis communis agglutinin I [RCA-I], wheat germ agglutinin) were found to bind to the exterior of root cap cells, the root cap slime, and the channels between epidermal cells in the root elongation zone. One of these lectins, RCA-I, bound to the root hair tips in the mature and emerging hair zones and also to sites at which root hairs were only just emerging. There was no RCA-I binding to immature trichoblasts. Preincubation of these lectins with their hapten sugars eliminated all types of root cell binding. By using a microinoculation technique, preincubation of the root surface with RCA-I lectin was found to inhibit infection and nodulation by Rhizobium spp. Preincubation of the root surface with the RCA-I hapten β-d-galactose or a mixture of RCA-I lectin and its hapten failed to inhibit nodulation. Application of RCA-I lectin to the root surface caused no apparent detrimental effects to the root hair cells and did not prevent the growth of root hairs. The lectin did not prevent Rhizobium sp. motility or viability even after 24 h of incubation. It was concluded that the RCA-I lectin-specific sugar β-d-galactose may be involved in the recognition or early infection stages, or both, in the Rhizobium sp. infection of M. atropurpureum. Images PMID:16346989

  7. ASTROCULTURE (TM) root metabolism and cytochemical analysis.

    PubMed

    Porterfield, D M; Barta, D J; Ming, D W; Morrow, R C; Musgrave, M E

    2000-01-01

    Physiology of the root system is dependent upon oxygen availability and tissue respiration. During hypoxia nutrient and water acquisition may be inhibited, thus affecting the overall biochemical and physiological status of the plant. For the Astroculture (TM) plant growth hardware, the availability of oxygen in the root zone was measured by examining the changes in alcohol dehydrogenase (ADH) activity within the root tissue. ADH activity is a sensitive biochemical indicator of hypoxic conditions in plants and was measured in both spaceflight and control roots. In addition to the biochemical enzyme assays, localization of ADH in the root tissue was examined cytochemically. The results of these analyses showed that ADH activity increased significantly as a result of spaceflight exposure. Enzyme activity increased 248% to 304% in dwarf wheat when compared with the ground controls and Brassica showed increases between 334% and 579% when compared with day zero controls. Cytochemical staining revealed no differences in ADH tissue localization in any of the dwarf wheat treatments. These results show the importance of considering root system oxygenation in designing and building nutrient delivery hardware for spaceflight plant cultivation and confirm previous reports of an ADH response associated with spaceflight exposure. PMID:11543169

  8. Vertical root fractures and their management

    PubMed Central

    Khasnis, Sandhya Anand; Kidiyoor, Krishnamurthy Haridas; Patil, Anand Basavaraj; Kenganal, Smita Basavaraj

    2014-01-01

    Vertical root fractures associated with endodontically treated teeth and less commonly in vital teeth represent one of the most difficult clinical problems to diagnose and treat. In as much as there are no specific symptoms, diagnosis can be difficult. Clinical detection of this condition by endodontists is becoming more frequent, where as it is rather underestimated by the general practitioners. Since, vertical root fractures almost exclusively involve endodontically treated teeth; it often becomes difficult to differentiate a tooth with this condition from an endodontically failed one or one with concomitant periodontal involvement. Also, a tooth diagnosed for vertical root fracture is usually extracted, though attempts to reunite fractured root have been done in various studies with varying success rates. Early detection of a fractured root and extraction of the tooth maintain the integrity of alveolar bone for placement of an implant. Cone beam computed tomography has been shown to be very accurate in this regard. This article focuses on the diagnostic and treatment strategies, and discusses about predisposing factors which can be useful in the prevention of vertical root fractures. PMID:24778502

  9. Gene expression regulation in roots under drought.

    PubMed

    Janiak, Agnieszka; Kwaśniewski, Mirosław; Szarejko, Iwona

    2016-02-01

    Stress signalling and regulatory networks controlling expression of target genes are the basis of plant response to drought. Roots are the first organs exposed to water deficiency in the soil and are the place of drought sensing. Signalling cascades transfer chemical signals toward the shoot and initiate molecular responses that lead to the biochemical and morphological changes that allow plants to be protected against water loss and to tolerate stress conditions. Here, we present an overview of signalling network and gene expression regulation pathways that are actively induced in roots under drought stress. In particular, the role of several transcription factor (TF) families, including DREB, AP2/ERF, NAC, bZIP, MYC, CAMTA, Alfin-like and Q-type ZFP, in the regulation of root response to drought are highlighted. The information provided includes available data on mutual interactions between these TFs together with their regulation by plant hormones and other signalling molecules. The most significant downstream target genes and molecular processes that are controlled by the regulatory factors are given. These data are also coupled with information about the influence of the described regulatory networks on root traits and root development which may translate to enhanced drought tolerance. This is the first literature survey demonstrating the gene expression regulatory machinery that is induced by drought stress, presented from the perspective of roots. PMID:26663562

  10. ASTROCULTURE (TM) root metabolism and cytochemical analysis

    NASA Technical Reports Server (NTRS)

    Porterfield, D. M.; Barta, D. J.; Ming, D. W.; Morrow, R. C.; Musgrave, M. E.

    2000-01-01

    Physiology of the root system is dependent upon oxygen availability and tissue respiration. During hypoxia nutrient and water acquisition may be inhibited, thus affecting the overall biochemical and physiological status of the plant. For the Astroculture (TM) plant growth hardware, the availability of oxygen in the root zone was measured by examining the changes in alcohol dehydrogenase (ADH) activity within the root tissue. ADH activity is a sensitive biochemical indicator of hypoxic conditions in plants and was measured in both spaceflight and control roots. In addition to the biochemical enzyme assays, localization of ADH in the root tissue was examined cytochemically. The results of these analyses showed that ADH activity increased significantly as a result of spaceflight exposure. Enzyme activity increased 248% to 304% in dwarf wheat when compared with the ground controls and Brassica showed increases between 334% and 579% when compared with day zero controls. Cytochemical staining revealed no differences in ADH tissue localization in any of the dwarf wheat treatments. These results show the importance of considering root system oxygenation in designing and building nutrient delivery hardware for spaceflight plant cultivation and confirm previous reports of an ADH response associated with spaceflight exposure.

  11. Competing neighbors: light perception and root function.

    PubMed

    Gundel, Pedro E; Pierik, Ronald; Mommer, Liesje; Ballaré, Carlos L

    2014-09-01

    Plant responses to competition have often been described as passive consequences of reduced resource availability. However, plants have mechanisms to forage for favorable conditions and anticipate competition scenarios. Despite the progresses made in understanding the role of light signaling in modulating plant-plant interactions, little is known about how plants use and integrate information gathered by their photoreceptors aboveground to regulate performance belowground. Given that the phytochrome family of photoreceptors plays a key role in the acquisition of information about the proximity of neighbors and canopy cover, it is tempting to speculate that changes in the red:far-red (R:FR) ratio perceived by aboveground plant parts have important implications shaping plant behavior belowground. Exploring data from published experiments, we assess the neglected role of light signaling in the control of root function. The available evidence indicates that plant exposure to low R:FR ratios affects root growth and morphology, root exudate profiles, and interactions with beneficial soil microorganisms. Although dependent on species identity, signals perceived aboveground are likely to affect root-to-root interactions. Root systems could also be guided to deploy new growth predominantly in open areas by light signals perceived by the shoots. Studying interactions between above- and belowground plant-plant signaling is expected to improve our understanding of the mechanisms of plant competition. PMID:24894371

  12. Adaptive significance of root grafting in trees

    SciTech Connect

    Loehle, C.; Jones, R.

    1988-12-31

    Root grafting has long been observed in forest trees but the adaptive significance of this trait has not been fully explained. Various authors have proposed that root grafting between trees contributes to mechanical support by linking adjacent root systems. Keeley proposes that this trait would be of greatest advantage in swamps where soils provide poor mechanical support. He provides as evidence a greenhouse study of Nyssa sylvatica Marsh in which seedlings of swamp provenance formed between-individual root grafts more frequently than upland provenance seedlings. In agreement with this within-species study, Keeley observed that arid zone species rarely exhibit grafts. Keeley also demonstrated that vines graft less commonly than trees, and herbs never do. Since the need for mechanical support coincides with this trend, these data seem to support his model. In this paper, the authors explore the mechanisms and ecological significance of root grafting, leading to predictions of root grafting incidence. Some observations support and some contradict the mechanical support hypothesis.

  13. [On Chinese medicine quality precision in expectation].

    PubMed

    Shi, Ren-bing; Wang, Yong-yan; Lv, Song-tao

    2015-09-01

    According to the correlative analyses on Chinese medicine essence, dosage forms and quality control level, it expounds the precise concept of Chinese medicine, and its quality advantages and characteristics in this paper, furthermore discusses how to achieve the ideal drugs and Chinese medicine quality precision in expectation. Base on the Chinese medicine essence, using the concept of nature medicine and its drug system to construct Chinese medicine effective material basis and its drugs, with the correlative analyses of whole view and reductionism, the problems of uncertainty quality of original natural medicinal resources and preparations may well be solved, and further with the macroscopic to microcosmic construction of drug system, the precision in expectations of Chinese medicine quality and higher production lever may well be achieved. PMID:26978969

  14. Photoacoustic Spectroscopy Analysis of Traditional Chinese Medicine

    NASA Astrophysics Data System (ADS)

    Chen, Lu; Zhao, Bin-xing; Xiao, Hong-tao; Tong, Rong-sheng; Gao, Chun-ming

    2013-09-01

    Chinese medicine is a historic cultural legacy of China. It has made a significant contribution to medicine and healthcare for generations. The development of Chinese herbal medicine analysis is emphasized by the Chinese pharmaceutical industry. This study has carried out the experimental analysis of ten kinds of Chinese herbal powder including Fritillaria powder, etc., based on the photoacoustic spectroscopy (PAS) method. First, a photoacoustic spectroscopy system was designed and constructed, especially a highly sensitive solid photoacoustic cell was established. Second, the experimental setup was verified through the characteristic emission spectrum of the light source, obtained by using carbon as a sample in the photoacoustic cell. Finally, as the photoacoustic spectroscopy analysis of Fritillaria, etc., was completed, the specificity of the Chinese herb medicine analysis was verified. This study shows that the PAS can provide a valid, highly sensitive analytical method for the specificity of Chinese herb medicine without preparing and damaging samples.

  15. Chlamydial infections in Chinese livestock.

    PubMed

    Yin, L; Kalmar, I D; Boden, J; Vanrompay, D

    2013-12-01

    The occurrence and impact of chlamydial infections in Western livestock is well documented in the international literature, but less is known aboutthese infections in livestock in the People's Republic of China. China's livestock production and its share in the global market have increased significantly in recent decades. In this review, the relevant English and Chinese literature on the epidemiology of chlamydial infections in Chinese livestock is considered, and biosecurity measures, prophylaxis and treatment of these infections in China's livestock are compared with Western practices. Chlamydial infections are highly prevalent in Chinese livestock and cause important economic losses, as they do in the rest of the world. Surveillance data and diagnostic results of abortion outbreaks in cattle, sheep and goats highlight the importance of virulent chlamydial infections in China's major ruminant species in many of China's provinces, autonomous regions and municipalities. Data from many of China's provincial divisions also indicate the widespread presence of chlamydial infections in industrially reared swine across the country. Less is known about chlamydial infections in yak, buffalo and horses, but available reports indicate a high prevalence in China's populations. In these reports, chlamydiosis was related to abortions in yak and pneumonia in horses. In Western countries, chlamydial infections are principally treated with antibiotics. In China, however, traditional medicine is often used in conjunction with antibiotics or used as an alternative treatment. PMID:24761733

  16. Capturing Arabidopsis root architecture dynamics with ROOT-FIT reveals diversity in responses to salinity.

    PubMed

    Julkowska, Magdalena M; Hoefsloot, Huub C J; Mol, Selena; Feron, Richard; de Boer, Gert-Jan; Haring, Michel A; Testerink, Christa

    2014-11-01

    The plant root is the first organ to encounter salinity stress, but the effect of salinity on root system architecture (RSA) remains elusive. Both the reduction in main root (MR) elongation and the redistribution of the root mass between MRs and lateral roots (LRs) are likely to play crucial roles in water extraction efficiency and ion exclusion. To establish which RSA parameters are responsive to salt stress, we performed a detailed time course experiment in which Arabidopsis (Arabidopsis thaliana) seedlings were grown on agar plates under different salt stress conditions. We captured RSA dynamics with quadratic growth functions (root-fit) and summarized the salt-induced differences in RSA dynamics in three growth parameters: MR elongation, average LR elongation, and increase in number of LRs. In the ecotype Columbia-0 accession of Arabidopsis, salt stress affected MR elongation more severely than LR elongation and an increase in LRs, leading to a significantly altered RSA. By quantifying RSA dynamics of 31 different Arabidopsis accessions in control and mild salt stress conditions, different strategies for regulation of MR and LR meristems and root branching were revealed. Different RSA strategies partially correlated with natural variation in abscisic acid sensitivity and different Na(+)/K(+) ratios in shoots of seedlings grown under mild salt stress. Applying root-fit to describe the dynamics of RSA allowed us to uncover the natural diversity in root morphology and cluster it into four response types that otherwise would have been overlooked. PMID:25271266

  17. Comparative behavior of root pathogens in stems and roots of southeastern Pinus species.

    PubMed

    Matusick, George; Nadel, Ryan L; Walker, David M; Hossain, Mohammad J; Eckhardt, Lori G

    2016-04-01

    Root diseases are expected to become a greater threat to trees in the future due to accidental pathogen introductions and predicted climate changes, thus there is a need for accurate and efficient pathogenicity tests. For many root pathogens, these tests have been conducted in stems instead of roots. It, however, remains unclear whether stem and root inoculations are comparable for most fungal species. In this study we compared the growth and damage caused by five root pathogens (Grosmannia huntii, Grosmannia alacris, Leptographium procerum, Leptographium terebrantis, and Heterobasidion irregulare) in root and stem tissue of two Pinus species by inoculating mature trees and tissue amended agar in the laboratory. Most fungal species tested caused greater damage in roots of both pine hosts following inoculation. The relationship between root and stem damage was, however, similar when most combinations of pathogens were compared. These results suggest that although stem inoculations are not suitable for determining the actual damage potential of a given species, they may be viewed as a useful surrogate for root inoculations when comparing the relative pathogenicity of multiple species. When grown on amended agar, fungal species generally had greater growth in stem tissue, contrasting with the findings from tree inoculations. PMID:27020149

  18. Melatonin promotes seminal root elongation and root growth in transgenic rice after germination.

    PubMed

    Park, Sangkyu; Back, Kyoungwhan

    2012-11-01

    The effect of melatonin on root growth after germination was examined in transgenic rice seedlings expressing sheep serotonin N-acetyltransferase (NAT). Enhanced melatonin levels were found in T(3) homozygous seedlings because of the ectopic overexpression of sheep NAT, which is believed to be the rate-limiting enzyme in melatonin biosynthesis in animals. Compared with wild-type rice seeds, the transgenic rice seeds showed enhanced seminal root growth and an analogous number of adventitious roots 4 and 10 days after seeding on half-strength Murashige and Skoog medium. The enhanced initial seminal root growth in the transgenic seedlings matched their increased root biomass well. We also found that treatment with 0.5 and 1 μM melatonin promoted seminal root growth of the wild type under continuous light. These results indicate that melatonin plays an important role in regulating both seminal root length and root growth after germination in monocotyledonous rice plants. This is the first report on the effects of melatonin on root growth in gain-of-function mutant plants that produce high levels of melatonin. PMID:22640001

  19. Earliest rooting system and root : shoot ratio from a new Zosterophyllum plant.

    PubMed

    Hao, Shougang; Xue, Jinzhuang; Guo, Dali; Wang, Deming

    2010-01-01

    The enhanced chemical weathering by rooted vascular plants during the Silurian-Devonian period played a crucial role in altering global biogeochemical cycles and atmospheric environments; however, the documentation of early root morphology and physiology is scarce because the existing fossils are mostly incomplete. Here, we report an entire, uprooted specimen of a new Zosterophyllum Penhallow, named as Z. shengfengense, from the Early Devonian Xitun Formation (Lochkovian, c. 413 Myr old) of Yunnan, south China. This plant has the most ancient known record of a rooting system. The plant consists of aerial axes of 98 mm in height, showing a tufted habit, and a rhizome bearing a fibrous-like rooting system, c. 20 mm in length. The rhizome shows masses of branchings, which produce upwardly directed aerial axes and downwardly directed root-like axes. The completeness of Z. shengfengense made it possible to estimate the biomass allocation and root : shoot ratio. The root : shoot ratio of this early plant is estimated at a mean value of 0.028, and the root-like axes constitute only c. 3% of the total biomass. Zosterophyllum shengfengense was probably a semi-aquatic plant with efficient water use or a strong uptake capacity of the root-like axes. PMID:19825018

  20. New insights to lateral rooting: Differential responses to heterogeneous nitrogen availability among maize root types.

    PubMed

    Yu, Peng; White, Philip J; Li, Chunjian

    2015-01-01

    Historical domestication and the "Green revolution" have both contributed to the evolution of modern, high-performance crops. Together with increased irrigation and application of chemical fertilizers, these efforts have generated sufficient food for the growing global population. Root architecture, and in particular root branching, plays an important role in the acquisition of water and nutrients, plant performance, and crop yield. Better understanding of root growth and responses to the belowground environment could contribute to overcoming the challenges faced by agriculture today. Manipulating the abilities of crop root systems to explore and exploit the soil environment could enable plants to make the most of soil resources, increase stress tolerance and improve grain yields, while simultaneously reducing environmental degradation. In this article it is noted that the control of root branching, and the responses of root architecture to nitrate availability, differ between root types and between plant species. Since the control of root branching depends upon both plant species and root type, further work is urgently required to determine the appropriate genes to manipulate to improve resource acquisition by specific crops. PMID:26443081

  1. RootNav: Navigating Images of Complex Root Architectures1[C][W

    PubMed Central

    Pound, Michael P.; French, Andrew P.; Atkinson, Jonathan A.; Wells, Darren M.; Bennett, Malcolm J.; Pridmore, Tony

    2013-01-01

    We present a novel image analysis tool that allows the semiautomated quantification of complex root system architectures in a range of plant species grown and imaged in a variety of ways. The automatic component of RootNav takes a top-down approach, utilizing the powerful expectation maximization classification algorithm to examine regions of the input image, calculating the likelihood that given pixels correspond to roots. This information is used as the basis for an optimization approach to root detection and quantification, which effectively fits a root model to the image data. The resulting user experience is akin to defining routes on a motorist’s satellite navigation system: RootNav makes an initial optimized estimate of paths from the seed point to root apices, and the user is able to easily and intuitively refine the results using a visual approach. The proposed method is evaluated on winter wheat (Triticum aestivum) images (and demonstrated on Arabidopsis [Arabidopsis thaliana], Brassica napus, and rice [Oryza sativa]), and results are compared with manual analysis. Four exemplar traits are calculated and show clear illustrative differences between some of the wheat accessions. RootNav, however, provides the structural information needed to support extraction of a wider variety of biologically relevant measures. A separate viewer tool is provided to recover a rich set of architectural traits from RootNav’s core representation. PMID:23766367

  2. New insights to lateral rooting: Differential responses to heterogeneous nitrogen availability among maize root types

    PubMed Central

    Yu, Peng; White, Philip J; Li, Chunjian

    2015-01-01

    Historical domestication and the "Green revolution" have both contributed to the evolution of modern, high-performance crops. Together with increased irrigation and application of chemical fertilizers, these efforts have generated sufficient food for the growing global population. Root architecture, and in particular root branching, plays an important role in the acquisition of water and nutrients, plant performance, and crop yield. Better understanding of root growth and responses to the belowground environment could contribute to overcoming the challenges faced by agriculture today. Manipulating the abilities of crop root systems to explore and exploit the soil environment could enable plants to make the most of soil resources, increase stress tolerance and improve grain yields, while simultaneously reducing environmental degradation. In this article it is noted that the control of root branching, and the responses of root architecture to nitrate availability, differ between root types and between plant species. Since the control of root branching depends upon both plant species and root type, further work is urgently required to determine the appropriate genes to manipulate to improve resource acquisition by specific crops. PMID:26443081

  3. Ozone decreases spring root growth and root carbohydrate content in ponderosa pine the year following exposure

    SciTech Connect

    Andersen, C.P.; Hogsett, W.E.; Wessling, R.; Plocher, M.

    1991-01-01

    Storage carbohydrates are extremely important for new shoot and root development following dormancy or during periods of high stress. The hypothesis that ozone decreases carbohydrate storage and decreases new root growth during the year following exposure was investigated. The results suggest that (1) ponderosa pine seedlings exposed to 122 and 169 ppm hrs ozone for one season have significantly less root starch reserves available just prior to and during bud break the following year, and (2) spring root growth is decreased following ozone exposure. The carry-over effects of ozone stress may be important in long-lived perennial species which are annually subjected to ozone.

  4. Antioxidant activity of 45 Chinese herbs and the relationship with their TCM characteristics.

    PubMed

    Liao, Hui; Banbury, Linda K; Leach, David N

    2008-12-01

    Here, 45 Chinese herbs that regulate blood circulation were analyzed for antioxidant activity using the oxygen radical absorbance capacity (ORAC) assay. A recent publication by Ou et al. identified a close relationship between in vitro antioxidant activity and classification of Chinese herbs as yin or yang. The 45 Chinese herbs in this study could be assigned the traditional characteristics of natures (cold, cool, hot and warm), flavors (pungent, sweet, sour, bitter and salty) and functions (arresting bleeding, promoting blood flow to relieve stasis, nourishing blood and clearing away heat from blood). These characteristics are generalized according to the theory of yin and yang. We identified a broad range, 40-1990 micromol Trolox Equivalent/g herbs, of antioxidant activity in water extracts. There was no significant correlation between ORAC values and natures or functions of the herbs. There was a significant relationship between flavors and ORAC values. Bitter and/or sour herbs had the highest ORAC values, pungent and/or sweet herbs the lowest. Other flavors had intermediate values. Flavors also correspond with the yin/yang relationship and our results are supportive of the earlier publication. We reported for the first time antioxidant properties of many Chinese herbs. High antioxidant herbs were identified as Spatholobus suberectus vine (1990 micromol TE/g), Sanguisorba officinalis root (1940 micromol TE/g), Agrimonia pilosa herb (1440 micromol TE/g), Artemisia anomala herb (1400 micromol TE/g), Salvia miltiorrhiza root (1320 micromol TE/g) and Nelembo nucifera leaf (1300 micromol TE/g). Antioxidant capacity appears to correlate with the flavors of herbs identified within the formal TCM classification system and may be a useful guide in describing their utility and biochemical mechanism of action. PMID:18955214

  5. Bioassay-guided separation of the proinflammatory constituents from the roots of Euphorbia kansui.

    PubMed

    Shu, Xiaoyun; Yu, Li; Tang, Yuping; Zhang, Li; Ding, Anwei; Luo, Dan; Duan, Jin-ao; Shen, Xiangchun

    2010-01-01

    In view of the toxic inflammatory reaction induced by Euphorbia kansui roots, a traditional Chinese medicine used for the treatment of edema, ascites, and asthma, the 95% ethanol extract was found to have a significant stimulating effect on inflammatory cells. Bioassay-guided separation of the 95% ethanol extract from the roots of E. kansui led to the isolation of five diterpenoids whose structures were identified by (1)H, (13)C NMR spectroscopy and HR-ESI-MS as kansuinine B (1), kansuinine A (2), kansuiphorin C (3), 3-O-benzoyl-20-deoxyingenol (4), and 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol (5). The proinflammatory effect of compounds 1-5 was evaluated in vitro in models of inflammation using exoteric mice splenic lymphocytes (SPL) and rat peritoneal macrophages (PMphi). Compounds 1, 2, and 5 markedly promoted SPL proliferation and NO production by PMphi at concentrations from 0.78 to 12.50 microg/mL. Hence the three compounds are believed to be important proinflammatory components of the roots of E. kansui. PMID:19844773

  6. Parents' Attitudes Toward Chinese-English Bilingual Education and Chinese-Language Use

    ERIC Educational Resources Information Center

    Lao, Christy

    2004-01-01

    This study surveyed 86 parents who enrolled their children in a Chinese-English bilingual preschool in San Francisco. The participants were asked their opinions on bilingual education, the reasons for sending their children to a Chinese-English bilingual school, their attitudes toward bilingual education, their use of Chinese and English, and…

  7. A Comparison of English and Chinese Reading Proficiency of Primary School Chinese Students

    ERIC Educational Resources Information Center

    Tse, Shek Kam; Loh, Ka Yee Elizabeth; Lam, Yu Hong Raymond; Lam, Wai Ip Joseph

    2010-01-01

    Hong Kong children's comprehension of Chinese and English text is of concern to parents and teachers since school leavers need to be proficient readers both of Chinese and English. Although Chinese has been officially designated the medium of instruction in most secondary schools, many parents want their children to be taught in English-medium…

  8. Chinese Americans Past and Present; A Collection of Chinese American Readings and Learning Activities.

    ERIC Educational Resources Information Center

    Wong, Don; Collier, Irene Dea

    This work consists of twenty reading selections, fiction and non-fiction. It is intended for use in grades 4 through 6 (9-12 year olds), and covers topics dealing with the history of the Chinese in America and contemporary Chinese American experience. These selections emphasize particularly the role the Chinese played in the development of the…

  9. Corpora and Collocations in Chinese-English Dictionaries for Chinese Users

    ERIC Educational Resources Information Center

    Xia, Lixin

    2015-01-01

    The paper identifies the major problems of the Chinese-English dictionary in representing collocational information after an extensive survey of nine dictionaries popular among Chinese users. It is found that the Chinese-English dictionary only provides the collocation types of "v+n" and "v+n," but completely ignores those of…

  10. Chinese Translation Errors in English/Chinese Bilingual Children's Picture Books

    ERIC Educational Resources Information Center

    Huang, Qiaoya; Chen, Xiaoning

    2012-01-01

    The aim of this study was to review the Chinese translation errors in 31 English/Chinese bilingual children's picture books. While bilingual children's books make definite contributions to language acquisition, few studies have examined the quality of these books, and even fewer have specifically focused on English/Chinese bilingual books.…

  11. Modelling water uptake efficiency of root systems

    NASA Astrophysics Data System (ADS)

    Leitner, Daniel; Tron, Stefania; Schröder, Natalie; Bodner, Gernot; Javaux, Mathieu; Vanderborght, Jan; Vereecken, Harry; Schnepf, Andrea

    2016-04-01

    Water uptake is crucial for plant productivity. Trait based breeding for more water efficient crops will enable a sustainable agricultural management under specific pedoclimatic conditions, and can increase drought resistance of plants. Mathematical modelling can be used to find suitable root system traits for better water uptake efficiency defined as amount of water taken up per unit of root biomass. This approach requires large simulation times and large number of simulation runs, since we test different root systems under different pedoclimatic conditions. In this work, we model water movement by the 1-dimensional Richards equation with the soil hydraulic properties described according to the van Genuchten model. Climatic conditions serve as the upper boundary condition. The root system grows during the simulation period and water uptake is calculated via a sink term (after Tron et al. 2015). The goal of this work is to compare different free software tools based on different numerical schemes to solve the model. We compare implementations using DUMUX (based on finite volumes), Hydrus 1D (based on finite elements), and a Matlab implementation of Van Dam, J. C., & Feddes 2000 (based on finite differences). We analyse the methods for accuracy, speed and flexibility. Using this model case study, we can clearly show the impact of various root system traits on water uptake efficiency. Furthermore, we can quantify frequent simplifications that are introduced in the modelling step like considering a static root system instead of a growing one, or considering a sink term based on root density instead of considering the full root hydraulic model (Javaux et al. 2008). References Tron, S., Bodner, G., Laio, F., Ridolfi, L., & Leitner, D. (2015). Can diversity in root architecture explain plant water use efficiency? A modeling study. Ecological modelling, 312, 200-210. Van Dam, J. C., & Feddes, R. A. (2000). Numerical simulation of infiltration, evaporation and shallow

  12. [Consensuses on lung cancer treatment by Chinese medicine experts from Beijing and Guangzhou and medication features in the North and South China].

    PubMed

    Wang, Shu-mei; Lin, Li-zhu; Nie, Hui

    2011-07-01

    To study the consensuses on lung cancer treatment by Chinese medicine experts from North China and South China, and to analyze their medication features from viewpoints such as the medication frequency, combination laws, medication classification by collecting 800 recipes on the treatment of lung cancer patients prescribed by 8 Chinese oncologists from Guanganmen Hospital of China Academy of Chinese Medical Sciences, the Affiliated Hospital of Guangzhou University of Traditional Chinese Medicine, and Guangdong Provincial Hospital of Traditional Chinese Medicine. Results showed that coix seed, poria, pinelliae tuber were the three herbs most commonly used in treatment of lung cancer by all experts. They generally accepted Pi invigorating and phlegm removing method as the basic treatment method for treating lung cancer. Secondly, they usually used white peony root, heterophylla falsestarwort root, and ophiopogonis tuber, etc. (with higher medication frequency) to nourish yin and moisten Fei. Thirdly, consistency was also shown in clearing heat, detoxication, and anticancer. Smilacis glabra, Rhizoma Smilacis Glabrae, Herba Hedyotis diffusae, Herba Scutellariae Barbatae were herbs used by all experts. However, there were differences between oncologists in North China and South China. Oncologists in South China paid more attention to heat toxin and blood stasis, while those in North China paid more attention to supplementing both qi and yin. PMID:21866673

  13. [Studies of the active constituents of the Chinese drug "duhuo" Angelica pubescents].

    PubMed

    Li, R Z; He, Y Q; Chiao, M; Xu, Y; Zhang, Q B; Meng, J R; Gu, Y; Ge, L P

    1989-01-01

    Eight coumarins isolated from the alcohol extract of the Chinese drug "Duhuo", the root of Angelica pubescents Maxim. f. biserrata Shan et Yuan (Umbelliferae) were elucidated to be columbianetin (I), columbianetin acetate (II), columbiadin (III), osthol (IV), isoimperatorin (V), bergapten (VI), xanthotoxin (VII), and columbianetin-beta-D-glucopyranoside (VIII), by chemical and spectral analysis, compound VIII was isolated from plant for the first time. All these coumarins were tested on platelet aggregation induced by 2 microns ADP. I, II, III, IV and VIII showed strong inhibiting activity against platelet aggregation. PMID:2618698

  14. Phytotoxic cis-clerodane diterpenoids from the Chinese liverwort Scapania stephanii.

    PubMed

    Li, Rui-Juan; Sun, Yi; Sun, Bin; Wang, Xiao-Ning; Liu, Shan-Shan; Zhou, Jin-Chuan; Ye, Jian-Ping; Zhao, Yu; Liu, Lei; Lee, Kuo-Hsiung; Lou, Hong-Xiang

    2014-09-01

    Five cis-clerodane diterpenoids, stephanialides A-E, along with seven known cis-clerodanes, scaparvins A-C, parvitexins B and C, 3-chloro-4-hydroxy-parvitexin A, and scapanialide B, were isolated from the Chinese liverwort Scapania stephanii. Their structures were established unequivocally on the basis of spectroscopic data. The absolute configuration of stephanialide A was determined by analysis of CD data using the octant rule. Phytotoxic activity evaluation showed that this type of diterpenoids can significantly inhibit root elongation of the seeds of Arabidopsis thaliana, Lepidium sativum and Brassica pekinensis. PMID:24947338

  15. Body, gender, and disease: the female breast in late imperial Chinese medicine.

    PubMed

    Wu, Yi-Li

    2011-01-01

    This paper examines the diverse ways in which Chinese medical experts historically gendered breast disease as a female ailment. By comparing representations of the female breast from the "Imperially-Compiled Golden Mirror of Medical Learning (Yuzuan yizong jinjian, 1742)" to those from earlier and contemporary texts, this paper analyzes how breast disease was alternately categorized as an ailment of childbearing and as a disease rooted in pathological female emotion. Medical awareness of breast disease in men did somewhat challenge these connections between womanhood and disease. Nevertheless, medical illustrations of women helped to reinforce the idea that breast disease was a characteristically female problem. PMID:22069795

  16. Root Exudates from Grafted-Root Watermelon Showed a Certain Contribution in Inhibiting Fusarium oxysporum f. sp. niveum

    PubMed Central

    Wang, Dongsheng; Mao, Jiugeng; Huang, Qiwei; Guo, Shiwei; Shen, Qirong

    2013-01-01

    Grafting watermelon onto bottle gourd rootstock is commonly used method to generate resistance to Fusarium oxysporum f. sp. niveum (FON), but knowledge of the effect of the root exudates of grafted watermelon on this soil-borne pathogen in rhizosphere remains limited. To investigate the root exudate profiles of the own-root bottle gourd, grafted-root watermelon and own-root watermelon, recirculating hydroponic culture system was developed to continuously trap these root exudates. Both conidial germination and growth of FON were significantly decreased in the presence of root exudates from the grafted-root watermelon compared with the own-root watermelon. HPLC analysis revealed that the composition of the root exudates released by the grafted-root watermelon differed not only from the own-root watermelon but also from the bottle gourd rootstock plants. We identified salicylic acid in all 3 root exudates, chlorogenic acid and caffeic acid in root exudates from own-root bottle gourd and grafted-root watermelon but not own-root watermelon, and abundant cinnamic acid only in own-root watermelon root exudates. The chlorogenic and caffeic acid were candidates for potentiating the enhanced resistance of the grafted watermelon to FON, therefore we tested the effects of the two compounds on the conidial germination and growth of FON. Both phenolic acids inhibited FON conidial germination and growth in a dose-dependent manner, and FON was much more susceptible to chlorogenic acid than to caffeic acid. In conclusion, the key factor in attaining the resistance to Fusarium wilt is grafting on the non-host root stock, however, the root exudates profile also showed some contribution in inhibiting FON. These results will help to better clarify the disease resistance mechanisms of grafted-root watermelon based on plant-microbe communication and will guide the improvement of strategies against Fusarium-mediated wilt of watermelon plants. PMID:23700421

  17. Root exudates from grafted-root watermelon showed a certain contribution in inhibiting Fusarium oxysporum f. sp. niveum.

    PubMed

    Ling, Ning; Zhang, Wenwen; Wang, Dongsheng; Mao, Jiugeng; Huang, Qiwei; Guo, Shiwei; Shen, Qirong

    2013-01-01

    Grafting watermelon onto bottle gourd rootstock is commonly used method to generate resistance to Fusarium oxysporum f. sp. niveum (FON), but knowledge of the effect of the root exudates of grafted watermelon on this soil-borne pathogen in rhizosphere remains limited. To investigate the root exudate profiles of the own-root bottle gourd, grafted-root watermelon and own-root watermelon, recirculating hydroponic culture system was developed to continuously trap these root exudates. Both conidial germination and growth of FON were significantly decreased in the presence of root exudates from the grafted-root watermelon compared with the own-root watermelon. HPLC analysis revealed that the composition of the root exudates released by the grafted-root watermelon differed not only from the own-root watermelon but also from the bottle gourd rootstock plants. We identified salicylic acid in all 3 root exudates, chlorogenic acid and caffeic acid in root exudates from own-root bottle gourd and grafted-root watermelon but not own-root watermelon, and abundant cinnamic acid only in own-root watermelon root exudates. The chlorogenic and caffeic acid were candidates for potentiating the enhanced resistance of the grafted watermelon to FON, therefore we tested the effects of the two compounds on the conidial germination and growth of FON. Both phenolic acids inhibited FON conidial germination and growth in a dose-dependent manner, and FON was much more susceptible to chlorogenic acid than to caffeic acid. In conclusion, the key factor in attaining the resistance to Fusarium wilt is grafting on the non-host root stock, however, the root exudates profile also showed some contribution in inhibiting FON. These results will help to better clarify the disease resistance mechanisms of grafted-root watermelon based on plant-microbe communication and will guide the improvement of strategies against Fusarium-mediated wilt of watermelon plants. PMID:23700421

  18. Disentangling root system responses to neighbours: identification of novel root behavioural strategies.

    PubMed

    Belter, Pamela R; Cahill, James F

    2015-01-01

    Plants live in a social environment, with interactions among neighbours a ubiquitous aspect of life. Though many of these interactions occur in the soil, our understanding of how plants alter root growth and the patterns of soil occupancy in response to neighbours is limited. This is in contrast to a rich literature on the animal behavioural responses to changes in the social environment. For plants, root behavioural changes that alter soil occupancy patterns can influence neighbourhood size and the frequency or intensity of competition for soil resources; issues of fundamental importance to understanding coexistence and community assembly. Here we report a large comparative study in which individuals of 20 species were grown with and without each of two neighbour species. Through repeated root visualization and analyses, we quantified many putative root behaviours, including the extent to which each species altered aspects of root system growth (e.g. rooting breadth, root length, etc.) in response to neighbours. Across all species, there was no consistent behavioural response to neighbours (i.e. no general tendencies towards root over-proliferation nor avoidance). However, there was a substantial interspecific variation showing a continuum of behavioural variation among the 20 species. Multivariate analyses revealed two novel and predominant root behavioural strategies: (i) size-sensitivity, in which focal plants reduced their overall root system size in response to the presence of neighbours, and (ii) location-sensitivity, where focal plants adjusted the horizontal and vertical placement of their roots in response to neighbours. Of these, size-sensitivity represents the commonly assumed response to competitive encounters-reduced growth. However, location sensitivity is not accounted for in classic models and concepts of plant competition, though it is supported from recent work in plant behavioural ecology. We suggest that these different strategies could have

  19. Disentangling root system responses to neighbours: identification of novel root behavioural strategies

    PubMed Central

    Belter, Pamela R.; Cahill, James F.

    2015-01-01

    Plants live in a social environment, with interactions among neighbours a ubiquitous aspect of life. Though many of these interactions occur in the soil, our understanding of how plants alter root growth and the patterns of soil occupancy in response to neighbours is limited. This is in contrast to a rich literature on the animal behavioural responses to changes in the social environment. For plants, root behavioural changes that alter soil occupancy patterns can influence neighbourhood size and the frequency or intensity of competition for soil resources; issues of fundamental importance to understanding coexistence and community assembly. Here we report a large comparative study in which individuals of 20 species were grown with and without each of two neighbour species. Through repeated root visualization and analyses, we quantified many putative root behaviours, including the extent to which each species altered aspects of root system growth (e.g. rooting breadth, root length, etc.) in response to neighbours. Across all species, there was no consistent behavioural response to neighbours (i.e. no general tendencies towards root over-proliferation nor avoidance). However, there was a substantial interspecific variation showing a continuum of behavioural variation among the 20 species. Multivariate analyses revealed two novel and predominant root behavioural strategies: (i) size-sensitivity, in which focal plants reduced their overall root system size in response to the presence of neighbours, and (ii) location-sensitivity, where focal plants adjusted the horizontal and vertical placement of their roots in response to neighbours. Of these, size-sensitivity represents the commonly assumed response to competitive encounters—reduced growth. However, location sensitivity is not accounted for in classic models and concepts of plant competition, though it is supported from recent work in plant behavioural ecology. We suggest that these different strategies could have

  20. How do roots elongate in a structured soil?

    PubMed

    Jin, Kemo; Shen, Jianbo; Ashton, Rhys W; Dodd, Ian C; Parry, Martin A J; Whalley, William R

    2013-11-01

    In this review, we examine how roots penetrate a structured soil. We first examine the relationship between soil water status and its mechanical strength, as well as the ability of the soil to supply water to the root. We identify these as critical soil factors, because it is primarily in drying soil that mechanical constraints limit root elongation. Water supply to the root is important because root water status affects growth pressures and root stiffness. To simplify the bewildering complexity of soil-root interactions, the discussion is focused around the special cases of root elongation in soil with pores much smaller than the root diameter and the penetration of roots at interfaces within the soil. While it is often assumed that the former case is well understood, many unanswered questions remain. While low soil-root friction is often viewed as a trait conferring better penetration of strong soils, it may also increase the axial pressure on the root tip and in so doing reduce the rate of cell division and/or expansion. The precise trade-off between various root traits involved in root elongation in homogeneous soil remains to be determined. There is consensus that the most important factors determining root penetration at an interface are the angle at which the root attempts to penetrate the soil, root stiffness, and the strength of the soil to be penetrated. The effect of growth angle on root penetration implicates gravitropic responses in improved root penetration ability. Although there is no work that has explored the effect of the strength of the gravitropic responses on penetration of hard layers, we attempt to outline possible interactions. Impacts of soil drying and strength on phytohormone concentrations in roots, and consequent root-to-shoot signalling, are also considered. PMID:24043852