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Sample records for mesiodistal root angulation

  1. Mesiodistal root angulation of permanent teeth in children with mixed dentition and normal occlusion

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    Flávia A. S. Jesuino

    2010-12-01

    Full Text Available OBJECTIVE: There is little information regarding the mesiodistal angulation of permanent teeth in mixed dentition. The aim of this study was to evaluate mesiodistal root angulation of permanent incisors, canines and first molars of 100 Brazilian children, using a new horizontal reference plane based on the midpoint of the intercuspation of primary canines and permanent first molars in panoramic radiographs during the mixed-dentition phase. MATERIAL AND METHODS: Children were equally divided between the genders with a mean age of 8.9 years (SD=0.76, normal occlusion and no eruptive disturbances. RESULTS: The angulation of the permanent maxillary first molars was close to the vertical, whereas the mandibular molars presented approximately 25 degrees of distal root angulation. The maxillary canines were the most distally angulated teeth, whereas the permanent mandibular canines were vertically positioned. The evaluation of the anterior maxillary area showed vertical position of permanent lateral, and central incisors with a slight distal angulation, whereas the permanent mandibular incisors tended to a mesial radicular convergence. CONCLUSIONS: The proposed reference line could be useful in mixed dentition root angulation evaluation; there was a slight asymmetry in the mesiodistal angulation among homologous teeth, and also a small variation between the male and the female groups, but no difference between 8-and 10-year-old children.

  2. Comparison of mesiodistal root angulation with posttreatment panoramic radiographs and cone-beam computed tomography

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    Bouwens, Daniel G.; Cevidanes, Lucia; Ludlow, John B.; Phillips, Ceib

    2011-01-01

    Introduction Orthodontists assess mesiodistal root angulations before, during, and after orthodontic treatment as an aid in establishing proper root position. Panoramic imaging has been useful for this purpose and is a valuable screening tool in diagnosis and planning treatment of orthodontic patients. Cone-beam computed tomography (CBCT) for imaging of the craniofacial complex creates the opportunity to evaluate 3-dimensional images compared with traditional 2-dimensional images. The purpose of this project was to compare mesiodistal root angulations by using posttreatment panoramic radiographic images and CBCT scans. Methods Mesiodistal root angulations from panoramic images and CBCT scans of 35 orthognathic surgery patients after orthodontic treatment were compared. The panoramic images were measured by using VixWin (Gendex Dental Systems, Des Plaines, Ill), and the CBCT scans by using InvivoDental 3D (version 4.1, Anatomage, San Jose, Calif). The mesiodistal root angulation of each maxillary and mandibular tooth was measured by using the occlusal plane as the reference line. With an intercept-only linear regression for correlated data (with an unstructured covariance structure), the global test of whether the mean vector of all differences for the teeth is zero was performed separately for the 2 arches. Results The global test for both arches was statistically significant (P<0.001), indicating an overall difference in root angulation between measurements from panoramic and CBCT images. There was no discernible pattern in the average differences between panoramic and CBCT measurements. Conclusions The assessment of mesiodistal tooth angulation with panoramic radiography should be approached with caution and reinforced by a thorough clinical examination of the dentition. PMID:21195286

  3. Analysis of mesiodistal angulations of preadjusted brackets

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    Marcos Rogério de MENDONÇA

    2014-08-01

    Full Text Available Manufacturers offer various prescriptions of preadjusted brackets for use in the “straight-wire” orthodontic technique. However, the need to incorporate bends in the rectangular wires during orthodontic finishing has led to concerns regarding the type of prescription chosen and the credibility of information provided by the manufacturer. The aim of this study was to compare the slot angulations of Roth prescription preadjusted metallic brackets for the maxillary left central incisor and maxillary left canine. For each tooth type, 10 brackets of three commercial brands (GAC, Forestadent and Morelli were selected. Two individual metal matrices for brackets and tooth positioning were made for each group of teeth. Captured images were obtained by standardized ortho-radial photography with a digital camera. Images were exported and analyzed with the Image J software package. One-way ANOVA and Tukey statistical analyses were performed at the 5% significance level. For brackets of the maxillary left central incisor, differences in mean angulation were observed between the Morelli and GAC groups (p < 0.01 and between the Forestadent and GAC groups (p < 0.01. For brackets of the maxillary left canine, differences in mean angulation were found between the Morelli and GAC groups (p < 0.01 and between the Morelli and Forestadent groups (p < 0.05. In conclusion, despite their same prescription name, the different brands exhibited significantly different angulation measurements.

  4. 全景片和锥形束 CT 评价牙根近远中倾斜度的现状和进展%Current situation and progress of evaluating mesiodistal root angulation by panoramic radiography & nbsp;and cone beam computed tomography

    Institute of Scientific and Technical Information of China (English)

    刘太琪; 周力; 王艳民

    2013-01-01

    A fundamental goal in comprehensive orthodontic treatment is the correct angulation of all teeth in three planes of space, and this calls for proper mesiodistal root angulation. Nowadays the main available methods to evaluate mesiodistal root angulation are panoramic radiography and cone beam computed tomography(CBCT). Each one of them has its own benefit and limitation with different efficacy. This article is to review the current situation and progress of these two methods in evaluating mesiodistal root angulation.%  正畸综合治疗的基本目标之一是将牙齿定位于正确的三维空间位置,合适的牙根近远中倾斜度是其要求之一。现有临床评估牙根近远中倾斜度的方法主要有全景片和锥形束CT(CBCT),两者效能不同,各有优缺点。本文就全景片和 CBCT 用于评价牙根近远中倾斜度的现况和进展进行综述。

  5. Mesiodistal angulation of the lateral teeth to the functional occlusal plane in normal occlusions

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    Hiroshi Ueda

    2016-01-01

    Full Text Available Introduction: Crowding is a malocclusion with irregularly positioned teeth caused by arch length discrepancy (ALD. Its incidence is high compared with the various malocclusions. In a previous study the crowns of the maxillary lateral teeth had erupted mesially in relation to the functional occlusal plane (FOP in patients with Angle Class I malocclusion and highly erupted canines, which had been uprighted by non-extraction orthodontic treatment, yet these results were based on only two cases evaluated by using plaster models. Therefore, the aim of this study was to assess the mesiodistal angulations of both maxillary and mandibular teeth relative to the FOP in normal occlusion by means of cephalograms and identifying the teeth axial factors contributing to the normal dentitions with the least ALD. Materials and Methods: Thirty Japanese young adult patients (6 males, 24 females with normal occlusion were selected to participate in this study; cephalograms were procured from each and the FOP was used as a reference plane for measuring the changes in the axial angulation along with other indicators of vertical growth. Results: Progressive mesial tipping of the maxillary lateral teeth was observed. First premolars tended to express this more than the second premolars but the tipping values were roughly 90° relative to the FOP on the first molars. Conclusion: The maxillary lateral teeth are more mesially angulated compared to the mandibular ones relative to the FOP. Furthermore, progressive mesial tipping of the maxillary lateral teeth was detected, of which axial angulations were significantly correlated to each other, in spite the mandibular premolars and molars being angulated in a similar fashion.

  6. Análise da correlação entre a angulação (mesiodistal dos caninos e a inclinação (vestibulolingual dos incisivos Analysis of the correlation between mesiodistal angulation of canines and labiolingual inclination of incisors

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    Amanda Sayuri Cardoso Ohashi

    2011-06-01

    Full Text Available OBJETIVO: avaliar o nível de correlação entre a angulação dos caninos e a inclinação dos incisivos. MÉTODOS: a angulação mesiodistal dos caninos e a inclinação vestibulolingual dos incisivos foram obtidas em um programa digital gráfico (Imagetool®, a partir de fotografias padronizadas dos modelos de 60 pacientes. A inclinação dos incisivos foi, ainda, avaliada pela cefalometria lateral. RESULTADOS: o erro casual mostrou uma variação em torno de 2° nas medidas feitas nos modelos (1,8-2,5º, enquanto o erro sistemático, avaliado pela teste de correlação intraclasse, revelou uma excelente reprodutibilidade para ambos os métodos empregados (p0,05 e variou bastante na arcada inferior (r=0,14-0,50, dependendo da grandeza correlacionada. CONCLUSÃO: ratifica-se a introdução de mudanças na angulação dos caninos com o intuito de acompanhar as compensações observadas na inclinação dos incisivos, principalmente na arcada inferior.OBJECTIVE: To assess the degree of correlation between canine angulation and incisor inclination. METHODS: Mesiodistal angulation of canines and labiolingual inclination of incisors were obtained by means of digital graphics software (ImageTool® from standardized photographs of the casts of 60 patients. Incisor inclination was also assessed by lateral cephalometric radiographs. RESULTS: Random error showed a variation of around 2° in measurements made on the casts (1.8-2.5, while systematic error, measured by the intraclass correlation test, displayed excellent reproducibility for both methods used in this study (p0.05 and varied widely in the mandibular arch (r=0.14 to 0.50. CONCLUSIONS: The introduction of changes in the angulation of canines with the aim of monitoring compensations observed in incisor inclination is warranted, especially in the lower arch.

  7. Compensation trends of the angulation of first molars: retrospective study of 1 403 malocclusion cases

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    Su, Hong; Han, Bing; Li, Sa; Na, Bin; Ma, Wen; Xu, Tian-Min

    2014-01-01

    We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1 403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First, angulation of the upper first molar varied significantly with age and tipped most distally in cases aged 16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability. PMID:24699185

  8. Compensation trends of the angulation of first molars: retrospective study of 1403 malocclusion cases.

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    Su, Hong; Han, Bing; Li, Sa; Na, Bin; Ma, Wen; Xu, Tian-Min

    2014-09-01

    We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First, angulation of the upper first molar varied significantly with age and tipped most distally in cases aged 16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.

  9. Compensation trends of the angulation of first molars:retrospective study of 1 403 malocclusion cases

    Institute of Scientific and Technical Information of China (English)

    Hong Su; Bing Han; Sa Li; Bin Na; Wen Ma; Tian-Min Xu

    2014-01-01

    We investigated the compensatory trends of mesiodistal angulation of first molars in malocclusion cases. We compared differences in the angulation of first molars in different developmental stages, malocclusion classifications and skeletal patterns. The medical records and lateral cephalogrammes of 1 403 malocclusion cases taken before treatment were measured to evaluate compensation of molar angulation in relation to the skeletal jaw. The cases were stratified by age, Angle classification and skeletal patterns. Differences in the mesiodistal angulation of the first molars were compared among the stratifications. We observed three main phenomena. First, angulation of the upper first molar varied significantly with age and tipped most distally in cases aged ,12 years and least distally in cases aged .16 years. The lower first molar did not show such differences. Second, in Angle Class II or skeletal Class II cases, the upper first molar was the most distally tipped, the lower first molar was the most mesially tipped, and opposite angulation compensation was observed in Class III cases. Third, in high-angle cases, the upper and lower first molars were the most distally tipped, and opposite angulation compensation was observed in low-angle cases. These data suggest that the angulation of the molars compensated for various growth patterns and malocclusion types. Hence, awareness of molar angulation compensation would help to adjust occlusal relationships, control anchorage and increase the chances of long-term stability.

  10. Compensatory canine angulation in angle Class II and III patients

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    Mauro Carlos Agner Busato

    2009-09-01

    Full Text Available The aim of this study was to evaluate the occurence of compensation in mesiodistal axial inclinations of canines in skeletal malocclusions patients. The sample consisted of 25 Angle Class II, division 1 malocclusion (group 1 and 19 Angle Class III malocclusion patients (group 2. After measurement of dental angulations through a method that associates plaster model photography and AutoCad software, comparisons between the groups were performed by T-test for independent samples. Results showed that there was no statistically significant difference (p < 0.05 between groups, when maxillary canine angulations were compared. Regarding the mandibular canines, there was a statistically significant difference in dental angulation, expressed by 3.2° for group 1 and 0.15° for group 2. An upright position tendency for mandibular canines was observed in the Angle Class III sample. This configures a pattern of compensatory coronary positioning, since the angulation of these teeth makes them occupy less space in the dental arch and consequently mandibular incisors can be in a more retracted position in the sagittal plane.

  11. Morphometrical analysis of cleaning capacity using nickel-titanium rotary instrumentation associated with irrigating solutions in mesio-distal flattened root canals Análise morfológica da capacidade de limpeza promovida pela instrumentação rotatória, associada à soluções irrigantes, com limas de níquel-titânio em canais radiculares com achatamento mesio-distal

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    Melissa Andréia Marchesan

    2003-03-01

    Full Text Available Variations in the internal anatomy of root canals may interfere with the success of root canal because tissue remnants may remain in the isthmus, re-entrances and ramifications of flattened root canals making instrumentation more difficult. Successful root canal treatment depends fundamentally on shaping, cleaning, disinfection and obturation. This study verified the quality of cleaning of ProFile .04 rotary technique associated with different irrigating solutions: 0.5% sodium hypochlorite, calcium hydroxide + Tergentol and 2% chlorhexidine in canals with mesio-distal flattening. Twelve human mandibular central incisors were randomly divided into 3 groups and instrumented up to ProFile 0.4 #35 file after cervical preparation, and processed histologically. After optical microscopic evaluation, statistical analysis showed that the percentage of cleaning of the three irrigating solutions was statistically different. Two-by-two comparisons classified the irrigating solutions in increasing order of cleaning: calcium hydroxide + Tergentol As variações da anatomia interna de cada canal radicular podem interferir no sucesso da terapêutica endodôntica devido ao fato de que em canais radiculares achatados, pode persistir remanescentes teciduais em istmos, reentrâncias e ramificações dificultando a execução das técnicas de instrumentação. O sucesso do tratamento dos canais radiculares depende fundamentalmente do preparo da forma, limpeza, desinfecção e obturação. Poucos trabalhos avaliaram a limpeza dos canais radiculares após a instrumentação rotatória. O presente trabalho verificou a qualidade de limpeza dos canais radiculares, por meio da microscopia óptica, promovida pela técnica de instrumentação rotatória associada ao hipoclorito de sódio 0,5%, HCT20 e clorexidina, em canais achatados no sentido mésio-distal. Doze incisivos centrais inferiores humanos foram divididos aleatoriamente em três grupos para que fossem

  12. Influence of Preadjusted Bracket Shape and Positioning Reference on Angulation of Upper Central Incisor.

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    Topolski, Francielle; de O Accorsi, Mauricio A; Trevisi, Hugo J; Cuoghi, Osmar A; Moresca, Ricardo

    2016-10-01

    To verify the influence of different bracket shapes and placement references according to Andrews and MBT systems on the expression of angulation in upper central incisors (UCI). Bracket positioning and mesiodistal dental movement simulations were performed and the angulations produced in the dental crown were evaluated, based on computed tomography scan images of 30 UCI and AutoCAD software analysis. Rectangular (Andrews) and rhomboid (MBT) brackets were placed according to the references recommended by Andrews and MBT systems - long axis of the clinical crown (LACC) and incisal edge (IE) respectively. Data showed that the use of LACC as reference for bracket positioning produced 5° and 4° UCI angulations in Andrews and MBT brackets respectively. The use of IE produced a 1.2° mean angulation in UCI for both brackets. When the LACC was used as reference for bracket positioning, the UCI crown angulation corresponded to the angulation built into the brackets, regardless of shape, while the use of IE resulted in natural crown angulation, regardless of bracket shape. This research contributes to guide the orthodontist in relation to the different treatment techniques based on the use of preadjusted brackets.

  13. Effect of Incisor Angulation on Overjet and Overbite in Class II Camouflage Treatment. A typodont study.

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    Sangcharearn, Yasinee; Ho, Christopher

    2007-11-01

    To determine the amount of variation in overjet and overbite that may result from changes in upper and lower incisor angulations following upper first premolar extraction treatment in Class II malocclusions. Typodonts were set up to simulate a skeletal Class II occlusion treated with upper first premolar extractions. The upper incisor angulation was altered through a range from 100 degrees to 120 degrees to the palatal plane by 2 degrees increments. The overjet and overbite were measured with every 2 degrees of upper incisor angulation change. A regression analysis was performed on the experimental data, and the regression coefficients, slope, and intercept were estimated. Excessive proclination of the lower incisors will result in an abnormal overjet and overbite relationship for any magnitude of upper incisor angulation. A normal lower incisor angulation facilitates the attainment of an optimal occlusion. Excessive palatal root torque of the upper incisors will result in an increase in overjet and a consequent decrease in overbite. If the upper incisors are excessively retroclined, an edge-to-edge incisor relationship will result. Class II camouflage treatment with upper first premolar extractions requires correctly angulated incisors to achieve optimal buccal segment interdigitation and incisor relationship. Labial root torque and interproximal reduction of the lower anterior teeth should be considered when the lower incisors are excessively proclined.

  14. Effects of different angulation radiograph on the recognition of the mesiobuccal root canal of maxillary permanent first molar%多角度投照技术在上颌第一恒磨牙近颊根管识别中作用的研究

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    汪敏; 孙虹; 李桥; 潘乙怀; 邓辉; 欧阳玉玲

    2012-01-01

    Objective This study was undertaken to investigate the efficiency of different angulation radiograph in diagnosing twin canals in the mesiobuccal roots of maxillary permanent first molars. Methods Forty extracted maxillary permanent first molars were collected. Two kinds of radiographs were taken of each tooth,and they were periapical radiographs with files or not. 14 photographs were taken of each tooth at 5°intervals between 0°and 30°. The teeth were made into transparent specimens to identify the number of canals in the mesiobuccal roots. Results The percentage of MB2 in the 40 maxillary first molars was 67. 50% . The detection rate of MB2 in the periapical radiographs with files was higher than that in the ones without files. The optimum beam angulations in periapical radiographs with files and without files were mesio-15° and raesio-20° respectively. Conclusions Periapical angulated radiographs with or without files in canals are useful for detection and diagnosis of MB2 canals in the maxillary permanent first morlars.%目的 探讨X线不同投照角度对上颌第一恒磨牙近中颊根双根管的识别作用.方法 选取临床拔除的上颌第一恒磨牙40个,在无诊断丝和存在诊断丝情况下分别进行X线投照,从0°到30°每间隔5°拍摄1张,每个牙齿拍摄14张X线片.将离体牙制成透明牙标本以提供金标准确定近颊根根管数目.结果 40个上颌第一恒磨牙MB2的发现率为67.50%;诊断丝投照对根管识别的正确率高于无诊断丝投照;诊断丝近中水平偏移15°与无诊断丝近中水平偏移20°投照具有最好的双根管检出率.结论 利用诊断丝及偏移角度X线投照能提高上颌第一恒磨牙近中颊根双根管的检出率.

  15. Influence of treatment including second molars on final and postretention molar angulation

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    Luiz Filiphe Gonçalves Canuto

    2013-10-01

    Full Text Available OBJECTIVE: Evaluate axial mesiodistal inclinations of the mandibular molars in orthodontically treated cases, analyzing whether inclusion of second mandibular molars in treatment mechanics has any influence on final and postretention molars angulations. METHODS: The sample comprised 150 panoramic radiographs of 50 patients. Patients were treated with extraction of four first premolars and divided into 2 groups: Group 1 comprised 25 subjects without inclusion of mandibular second molars during orthodontic treatment, whereas Group 2 comprised 25 subjects with inclusion of mandibular second molars. Panoramic radiographs at three observation times were evaluated: pretreatment, posttreatment and postretention. The statistical analysis included one-way analysis of variance (ANOVA for intragroup evaluation and independent t-tests for intergroup comparisons. RESULTS: Intragroup analysis demonstrated significant uprighting of mandibular first and second molars during treatment in Group 2, which remained stable during the postretention stage. Intergroup comparison demonstrated that Group 2 presented first and second molars significantly more uprighted in relation to Group 1 in both post-treatment and postretention stages. CONCLUSIONS: It was concluded that inclusion of mandibular second molars in the orthodontic mechanics is relevant not only to correct the angulation of these teeth, but also to aid mandibular first molars uprighting.

  16. Mesiodistal width and proximal enamel thickness of maxillary first bicuspids

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    Aurélio de Carvalho Macha

    2010-03-01

    Full Text Available This study aimed at evaluating measurements relative to the mesiodistal crown width and enamel thickness of maxillary first bicuspids. The sample consisted of 40 extracted sound bicuspids (20 right and 20 left, selected from white patients (mean age: 23.7 ± 4.2 years, who were treated orthodontically with tooth extraction at a private clinic in São Paulo, SP, Brazil. All teeth were embedded in acrylic resin and cut along their long axis through the proximal surfaces, parallel to the buccal side, to obtain 0.6-mm central sections. The mesiodistal crown width and proximal enamel thickness were measured using a stereoscopic microscope connected to a computer. Measurements for right and left teeth, as well as the mesial and distal enamel thicknesses in the total sample, were compared by the Wilcoxon test (α = 0.05. The mesiodistal crown width mean values found were 7.51 mm (± 0.54 on the right side and 7.53 mm (± 0.35 on the left side. The mean enamel thickness on the distal surfaces for both sides was 1.29 mm (right: s.d. = 0.12 and left: s.d. = 0.18. The mean values for the mesial surfaces were 1.08 mm (± 0.14 and 1.19 mm (± 0.25, on the right and the left sides, respectively. No significant differences were found between the crown measurements and enamel thicknesses on the left and right sides. However, enamel thickness was significantly greater on the distal surfaces. Reliable measurements of enamel thickness are useful to guide stripping, which may be an attractive alternative to tooth extraction because it allows the transverse arch dimension to be maintained.

  17. Mesiodistal crown diameters of permanent dentition in schoolchildren from Lima

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    Pineda-Mejia, Martha; Departamento Académico de Estomatología Rehabilitadora, Facultad Odontología de la Universidad Nacional Mayor de San Marco, Perú.; Petkova- Gueorguieva, Marieta; Facultad Odontología de la Universidad Nacional Mayor de San Marcos.

    2015-01-01

    The purpose of this study was to determine the size of mesiodistal diameters of permanent teeth in a school population of the city of Lima, to analyze the differences between homologous teeth, sexual dimorphism of permanent teeth as well as the degree of variability of the measurements. Methodology: The study was conducted on 400 students of mestizos (200 men and 200 women) 10 to 12 years, from three schools in the districts of la Victoria and Barrios Altos, Lima city. The procedure was perfo...

  18. HUBUNGAN LEBAR DASAR HIDUNG DAN LEBAR MULUT TERHADAP LEBAR MESIODISTAL GIGI INSISIVUS SENTRALISATAS PADA SUKU BUTON

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    ALVIONITA, LENNY

    2015-01-01

    2015 LENNY ALVIONITA. Hubungan Lebar Dasar Hidung dan Lebar Mulut terhadap Lebar Mesiodistal Gigi Insisivus Sentralis Atas pada Suku Buton. Tujuan : Tujuan dari penelitian ini yaitu untuk mengetahui hubungan antara lebar dasar hidung dan lebar mulut terhadap lebar mesiodistal gigi insisivus sentralis atas pada Suku Buton. Bahan dan metode : Sembilan puluh lima orang suku Buton yang berumur 17-25 tahun. Lebar dasar hidung dan lebar mulut diukur meggunakan jangka sorong da...

  19. Assessment of the associated symptoms, pathologies, positions and angulations of bilateral occurring mandibular third molars: is there any similarity?

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    Akarslan, Zühre Zafersoy; Kocabay, Ceyda

    2009-09-01

    The aim of this study was to evaluate and establish any similarity between the associated symptoms, pathologies, positions, and angulation types of bilateral occurring mandibular third molars among a group of young adult patients. A total of 342 patients (167 females, 175 males), aged between 20 and 25 years (mean: 22.2, SD: 1.8) participated in the study. Clinical and radiographic examinations were performed. Eruption status, mucosal and bony coverage type, presence of pain, pericoronitis, suppuration, ulceration, caries in third molar, distal caries in second molar, bone loss, root resorption, or cyst or tumor formation was investigated in addition to the position and the angulation of each tooth. Patients having at least one completely or partially erupted mandibular third molar were classified as group 1 and patients having bilateral impacted mandibular third molars were classified as group 2. No significant difference was found between the symptoms and pathologies related with the mandibular right third molar (RM) and the left third molar (LM) among both groups and genders (P > .05). In the total sample, no significant difference was found between the RM and the LM in terms of mucosal coverage type, bony coverage type, and position both in group 1 and group 2 (P > .05); but gender had an influence on the bony coverage type and ramus distance of the RM and the LM in group 2 (P < .05). In the total the sample, symmetry was present for horizontal or distoangular and vertical or distoangular angulations in group 1 and group 2, respectively. Gender was found to also have an impact on angulation symmetry. In most cases, a similarity was present between the symptoms and pathologies related with the bilateral mandibular third molars; but symmetry in position and angulation differed according to eruption status, angulation type, and gender.

  20. The mesiodistal crown diameters of primary dentition in Indonesian Javanese children.

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    Kuswandari, Sri; Nishino, Mizuho

    2004-03-01

    Dentition analysis of primary teeth is necessary for recognising and correcting occlusal problems in every stage of dental development to enable normal adult occlusion. To do this, normative data of mesiodistal tooth crown diameters from the same ethnic population are needed. The aims of this study were to gather normative data of mesiodistal crown diameters of primary dentition in Indonesian Javanese children and to compare this normative data with published data of other ethnic populations. Dental casts of 160 males and 137 females with acceptable occlusion, aged 3.25-6.58 years, were taken in Yogyakarta, Indonesia. Mesiodistal diameter was measured as the distance between the anatomic contact points using calipers with accuracy to within 0.05 mm. Each measurement was taken twice on different occasions. The results indicated that the magnitude of asymmetry between right and left teeth was larger in distal teeth within a tooth field, larger in males than females, and larger in mandibular than maxillary teeth. The stability of mesiodistal tooth crown diameters was less in males than in females, and was most prominent in the mandibular central incisor. Sexual dimorphisms were found in, the lateral incisor and first molar in the maxilla, and the canine, first and second molars in the mandible. Compared with other ethnic populations, Indonesian Javanese falls between Hong Kong Chinese and Australian Aboriginal.

  1. Sex determination using mesiodistal dimension of permanent maxillary incisors and canines

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    Rajbir Kaur Khangura

    2011-01-01

    Full Text Available Background: Sexual dimorphism refers to the differences in size, shape, etc., between males and females. The dentition′s use in sex assessment has been explored and advocated owing to its strength and resistance to peri- and post-mortem insults. Objectives: The study evaluated permanent maxillary incisors and canines for sexual dimorphism and estimated the level of accuracy with which they could be used for sex determination. Materials and Methods: The study was conducted on 100 subjects (50 males, 50 females. The mesiodistal dimension of permanent maxillary incisors and canines was measured and the data were subjected to statistical analysis. Result: Univariate analysis revealed that all permanent maxillary incisors and canines exhibited larger mean values of mesiodistal dimension in males compared to females but only canines were found to be statistically significant for sexual dimorphism. Conclusion: The study showed maxillary canines exhibiting significant sexual dimorphism and can be used for sex determination along with other procedures.

  2. Correlation between interalar width and intercommisural width against mesiodistal width of central upper incisor in Buginese tribe

    Directory of Open Access Journals (Sweden)

    Bahruddin Thalib

    2016-04-01

    Full Text Available Various types of anatomical landmarks of the face should match its proportions with the size of the teeth which is the interalar width, intercomissural width, interpupillary width, Intercanthal width, and byzigomatic width. Some of face landmarks can be used as a guide in the selection of anterior teeth in complete denture, especially if the pre extraction record such as radiography image, extracted teeth, model study, the remaining teeth, face shape, and the shape of the curved jaw have been lost. The objective of this study was to evaluate the correlation between interalar width and intercommisural width against mesiodistal incisivus centralis width in a group of Buginese tribe. Ninety nine Buginese tribe subjects aged 17-25 were selected. The interalar width, intercommisural width, and mesiodistal incisor centralis teeth were measured using caliper about three times for accuracy and precision. Mean of interalar width and mesiodistal incisor centralis maxilla width in males more width than females (p0.05. The degree of correlation between interalar width against mesiodistal incisor centralis maxilla width was 0.030, -0.246, 0,225 in Buginese tribe, males, and females (p>0.05. : The degree of correlation between intercommisural width against  mesiodistal incisor centralis maxilla width in Buginese tribe was 0,054, 0,013, 0,153 in Buginese tribe, males, and females (p>0.05. The degree of correlation between interalar width and intercommisural width was 0.301 and 0.356 in Buginese tribe and males (p0.05. In conclusion, there is no significant correlation between interalar width and intercommisural width against mesiodistal incisor centralis maxilla width in a group of Buginese tribe. Interalar width and intercommisural width  directly proportional to mesiodistal incisor centralis maxilla in a group of Buginese tribe. Interalar width and intercommisural width  inversely proportional to mesiodistal incisor centralis maxilla in males and directly

  3. Spiral Tomography for Determining Implant Angulation: An In Vitro Study

    Directory of Open Access Journals (Sweden)

    Z. Dalili Kajan

    2008-06-01

    Full Text Available Objective: To study the accuracy of spiral tomography in the determination of implant angulation.Materials and Methods: Eighteen gutta-percha filled points on dry mandibles were se-lected for implant placement. A translucent acrylic template was fabricated for each man-dible. After preparing tomographic images (2 mmslice thickness, Cranex Tome, the ideal axis of the implant was traced. The angle between the ideal axis and the tangent line on the alveolar crest in the buccal side was measured and transferred to aluminum sleeves by a protractor. After implant placement, tomographic images were taken again and angles of the actual implants were estimated. In addition, thedistances from the tip of the actual and the supposed implants to the buccal cortex were measured. The data were analyzed by paired sample t test with 95% confidence.Results: Less than two-degreedifference between angles of the supposed and the actual implants was found in 44.4% of the cases, whilst 33.3% revealed more than five-degreedifference. There was a significant statistical difference between the angle of the actual and the supposed implants. There was also a significant statistical difference between the linear distances from the tip of the actual and the supposed implants to buccal cortex(P=0.015Conclusion: Spiral tomography in combination with template may provide acceptable re-sults concerning implant angulation and prediction of cortical perforation risk.

  4. Effects of implant angulation, material selection, and impression technique on impression accuracy: a preliminary laboratory study.

    Science.gov (United States)

    Rutkunas, Vygandas; Sveikata, Kestutis; Savickas, Raimondas

    2012-01-01

    The aim of this preliminary laboratory study was to evaluate the effects of 5- and 25-degree implant angulations in simulated clinical casts on an impression's accuracy when using different impression materials and tray selections. A convenience sample of each implant angulation group was selected for both open and closed trays in combination with one polyether and two polyvinyl siloxane impression materials. The influence of material and technique appeared to be significant for both 5- and 25-degree angulations (P impression accuracy. The open-tray technique was more accurate with highly nonaxially oriented implants for the small sample size investigated.

  5. Correlation between some facial indexes and mesiodistal width of maxillary anterior teeth

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    Leila Ahmadian

    2012-01-01

    Full Text Available Background: Both tooth size and shape of the anterior maxilla play important role in complete denture and facial esthetics. Tooth selection for an edentulous patient with no pre-extraction is very difficult. The purpose of this study was to analyze mesio-distal width of maxillary anterior teeth and to determine the presence of any relationship between them and other facial measurements.Materials and Method: In this cross-sectional study, after enrolment of 100 high school students, full-face standardized digital images of them were taken in frontal view. Bizaygomatic, interpupilary and interalar distance were measured by images. Width of teeth was determined on the casts. T-test and pearson correlation coefficient were performed to analyze the data.Results: Maxillary central incisor is the widest anterior tooth in both male and female. Correlation between bizaygomatic and interpupillay distances and central incisor width were not significant but between interalar and intercanine were significant.Conclusion: Based on this study, interalar distance is a better index to estimate the width of anterior teeth of maxilla in an edentulous patient

  6. Prediction of Mesiodistal Width of Unerupted Lateral Incisors, Canines and Premolars in Orthodontic Patients in Early Mixed Dentition Period

    Science.gov (United States)

    Toodehzaeim, Mohammad Hossein; Haerian, Alireza

    2016-01-01

    Objectives: Proper diagnosis and prevention of malocclusion are superior to treatment. Discrepancy between arch length and tooth size in mixed dentition period is a condition requiring timely diagnosis. Estimating the mesiodistal width of unerupted teeth according to the size of erupted ones can lead to earlier diagnosis of malocclusion. On the other hand, the best timing for serial extractions is before the eruption of lateral incisors. The aim of this study was to present prediction formulas for mesiodistal width of unerupted lateral incisors, canines and premolars in an Iranian population based on the width of erupted permanent mandibular central incisors and maxillary first molars. Materials and Methods: A total of 120 dental models (60 males, 60 females) of orthodontic patients between 11–25 years were evaluated in Yazd city. The measurements were made by a digital caliper on the widest mesiodistal width of teeth at the interproximal contacts. Data were analyzed to calculate the prediction equation. Results: The prediction equation in the upper jaw was y=0.57x+10.82 for males, y=0.7x+6.37 for females and y=0.64x+8.46 for both sexes. The equation for the lower jaw was y=0.76x+2.86 for males, y=0.74x+3.53 for females and y=0.77x+2.7 for both sexes. Conclusions: The prediction equations suggested in this study can predict the mesiodistal width of unerupted lateral incisors, canines and premolars in an Iranian population in early mixed dentition period without taking radiographs. PMID:28243298

  7. Effect of tooth preparation on microleakage of stainless steel crowns placed on primary mandibular first molars with reduced mesiodistal dimension.

    Directory of Open Access Journals (Sweden)

    Nahid Ramazani

    2015-02-01

    Full Text Available Incomplete adaptation of stainless steel crown margins leads to microleakage. The aim of this study was to evaluate the effect of tooth preparation on microleakage of stainless steel crowns (SSCs placed on mesiodistally reduced primary mandibular first molars.In this In vitro study, 60 primary mandibular first molars with reduced mesiodistal dimension were selected. Pulp cavities were filled with amalgam and occlusal surfaces were reduced. The samples were randomly divided into two groups (groups P and BLP. Standard preparation was done in group P with only proximal reduction. In group BLP, after reducing the proximal undercuts, buccal and lingual surfaces were slightly reduced. Occlusal one-third of the buccal surfaces was beveled in both groups. Then, the SSCs of the primary maxillary and mandibular first molars were fitted and cemented in P and BLP groups, respectively. After immersing the samples into deionized water, thermo-cycling, and immersion in 2% basic fuchsin, the samples were sectioned buccolingually. The mesial halves were evaluated microscopically for microleakage in both buccal and lingual margins. Data were analyzed using Mann-Whitney U test in SPSS 19 at the significant level of 0.05.There was a significant difference in microleakage of the buccal margin (P=0.003; whereas, the difference observed in the lingual margin was not significant (P=0.54.We suggest reduction of buccal and lingual surfaces of mesiodistally reduced primary mandibular first molars and placing lower (mandibular crowns.

  8. Effect of Incisor Angulation on Overjet and Overbite in Class II Camouflage Treatment. A typodont study

    National Research Council Canada - National Science Library

    Sangcharearn, Yasinee; Ho, Christopher

    2007-01-01

    To determine the amount of variation in overjet and overbite that may result from changes in upper and lower incisor angulations following upper first premolar extraction treatment in Class II malocclusions...

  9. Severe cases of ectopically erupting maxillary canine with excessive mesial angulation

    OpenAIRE

    Taguchi, Yo; Hayashi-Sakai, Sachiko; TSUDA, takashi

    2008-01-01

    The aim of the present study was to examine retrospectively how best to treat severe cases of ectopically erupting maxillary canines with mesial angulation exceeding 50 degrees. From the ectopically erupting canines diagnosed at the Pediatric Dental Clinic of Niigata University Hospital, we selected for our study 14 severe cases in which mesial angulation exceeded 50 degrees. Nine ectopically erupting canines could be aligned within the arch after traction, and two canines are in the course o...

  10. Mesiodistal crown diameters of the primary and permanent teeth in southern Chinese--a longitudinal study.

    Science.gov (United States)

    Yuen, K K; So, L L; Tang, E L

    1997-12-01

    The mesiodistal crown diameters of the primary and permanent teeth were measured on serial casts of 112 Hong Kong Southern Chinese (61 males and 51 females) taken at 5.68 and 12.31 years of age. None of the teeth showed significant sex difference in bilateral asymmetry, and significant bilateral asymmetry was found only for the upper primary second molars. The asymmetries were small and the sizes of the antimeres were averaged. Posterior teeth were generally less variable than anterior teeth in both dentitions in Chinese, which is contrary to other reports, but the anterior tooth of each morphological class was, in general, less variable than the posterior member. Male teeth were larger than those of females except for the lower central and lateral incisors in both dentitions, but the difference was not statistically significant. None of the primary teeth nor three of the permanent teeth were found to have significant sex differences in size. Percentage sexual dimorphism ranged from 0.06 to 1.97 per cent for the primary teeth and from 0.36 to 5.27 per cent for the permanent teeth. In the primary dentition, molars were the most dimorphic teeth in both arches, while upper incisors and lower canine were the least dimorphic teeth in their own arch. Among the permanent teeth, the canines were the most dimorphic and the incisors were among the least dimorphic teeth in both arches. Tooth sizes in both dentitions were, in general, larger than those of the Caucasians, comparable with Northern Chinese, but smaller than those of Australian Aboriginals.

  11. What is important for continent catheterizable stomas: angulations or extension?

    Directory of Open Access Journals (Sweden)

    Marcelo L. Vilela

    2007-04-01

    Full Text Available OBJECTIVE: We developed an experimental ex-vivo model to define factors that may influence continence of catheterizable channels by urinary and colonic stomas based on the principle of imbrication of the outlet tube. MATERIALS AND METHODS: From 20 pigs, colon specimens with 25 cm length were obtained and a transverse flap with 3.0 cm length x 1.5 cm width in the average point of the intestine was tubulated to create an efferent tube. With the tube configured, it was embedded by 3 seromuscular stitches far 0.5 cm each other. A pressure study of both intra-luminal surface and channel was then conducted during the filling of the submerse piece with environmental air in a water container, to define the efferent channel continence. The study was repeated after the progressive release of suture stitches until only one stitch remains. RESULTS: Channel continence analyzed in each segment in three different valve length situations, making a total of 20 segments, revealed that with 3 stitches (1.5 cm valve the maximum average pressure prior to overflow was 54 cm H2O; 53.65 cm H2O with 2 stitches (1.0 cm of valve, and 55.45 cm H2O with only one stitch (0.5 cm of valve, which are the same values. The record at the segment explosion pressure was 67.87 cm H2O. CONCLUSION: The study showed that angulation of channel with colon, maintained by only one stitch (0.5 cm imbrication was more important than a larger extension of the valve, represented by 3 suture stitches (1.5 cm imbrication in order to allow continence to the efferent channel.

  12. Influence of third molar space on angulation and dental arch crowding.

    Science.gov (United States)

    Hasegawa, Yuh; Terada, Kazuto; Kageyama, Ikuo; Tsuchimochi, Takashi; Ishikawa, Fujiro; Nakahara, Sen

    2013-01-01

    The influence of the third molars on mandibular incisor crowding has been extensively studied but remains controversial. The purpose of this study was to ascertain whether, in Mongolian subjects, the lower third molar can affect anterior crowding and/or the inclination of teeth in the lower lateral segments. Panoramic radiographs, 45° oblique cephalograms, and dental casts were taken from Mongolian subjects (age range 18.3-24.1 years, mean 21.0 years) exhibiting impaction of all four third molars and an Angle Class I molar relationship. The Ganss ratio was calculated using panoramic radiographs, whereas the gonial angle and angulation of lower canines, premolars and molars were measured using 45° oblique cephalograms. Little's index of irregularity was calculated using dental casts. Significant relationships between the angulation of the third and second molars and between the first molars and second premolars were found. Conversely, there was no significant correlation between the angulation of third molars, first premolars and canines. The Ganss ratio calculations showed that the lower first and second molars and the second premolars inclined mesially if there was insufficient space for the lower third molars. However, there was no significant correlation between Little's index of irregularity and third molar angulation. Furthermore, although the third molar influences the lateral segments, no obvious relationship between the third molar and anterior crowding was observed. Therefore, the angulation of the third molar appears not to cause anterior crowding.

  13. The angulation and the position change of the planned implant after tomographic imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Byung Cheol [Chonnam National Univ. Hospital, Gwangju (Korea, Republic of)

    2007-09-15

    To measure the differences of the splint pin angulation and the position of the planned implant site after conventional tomographic analysis. The angulation and the location of the metal splint pin retained in acrylic stent were compared with the corrected angulation and the location of the implant fixture on the 331 tomographic images. The stent pins were located buccal in 40%, lingual in 10% to the corrected implant site after analysis of the conventional tomographic image. The angle and the location of the maxillary splint pin were mainly directed buccal on incisor and canine regions. The angle and the location of the splint pins in premolar and molar regions needed less corrections in both maxilla and mandible. This study demonstrated that the use of tomographs was essential for successful dental implant planning.

  14. Sex determination using the mesio-distal dimension of permanent maxillary incisors and canines in a modern Chilean population.

    Science.gov (United States)

    Peckmann, Tanya R; Logar, Ciara; Garrido-Varas, Claudia E; Meek, Susan; Pinto, Ximena Toledo

    2016-03-01

    The pelvis and skull have been shown to be the most accurate skeletal elements for the determination of sex. Incomplete or fragmentary bones are frequently found at forensic sites however teeth are often recovered in forensic cases due to their postmortem longevity. The goal of the present research was to investigate sexual dimorphism between the mesio-distal dimension of the permanent maxillary incisors and canines for the determination of sex in a contemporary Chilean population. Three hundred and three dental models (126 males and 177 females) from individuals ranging in age from 13 years to 37 years old were used from the School of Dentistry, University of Chile. The statistical analyses showed that only the central incisors and canines were sexually dimorphic. Discriminant function score equations were generated for use in sex determination. The average accuracy of sex classification ranged from 59.7% to 65.0% for the univariate analysis and 60.1% to 66.7% for the multivariate analysis. Comparisons to other populations were made. Overall, the accuracies ranged from 54.4% to 63.3% with males most often identified correctly and females most often misidentified. The determination of sex from the mesio-distal width of incisors and canines in Chilean populations does not adhere to the Mohan and Daubert criteria and therefore would not be presented as evidence in court.

  15. Effect of vertical angulation to dose of thyroid glands in periapical radiography

    Energy Technology Data Exchange (ETDEWEB)

    Hosoi, Keitaro; Satoh, Keiji; Furumoto, Keiichi (Nippon Dental Univ., Tokyo (Japan). School of Dentistry)

    1992-10-01

    Much attention has been given to reducing the dose of radiation in dental radiography in terms of the highest risk for the head and neck. Organ doses in intraoral radiography vary greatly with subtle differences in vertical angulation. Quantitative determination of doses delivered to the thyroid gland is thus necessary in determining adequate doses and risk for dental radiography. A personal computer program, prepared for estimating organ doses under various radiographic conditions, was used to evaluate the effect of vertical angulation on the dose delivered to the thyroid gland in radiography of the maxillary and mandibular incisors. Review of the literature revealed that the calculated dose delivered to the thyroid gland is approximately in accordance with the data of the actual determination under the same radiographic conditions. The dose-dependence of radiation delivered to the thyroid gland on vertical angulation of the maxilla was much more than that of the mandible. In the mandible, the dose delivered to the thyroid gland increased about three fold at a field size of 6 cm[phi] and about 1.5 fold at 8 cm[phi] when the vertical angulation changed from -40deg to 0deg. In the maxilla, the delivered dose increased about 480 times at a field size of 6 cm[phi] when vertical angulation changed from 0deg to 50deg and rapidly increased about 280 times at 8 cm[phi] when the angulation changed from 0deg to 40deg. The dose of radiation delivered to the thyroid gland was evaluated as a function of product of the irradiated volume within the primary beam directed at the thyroid gland and the inverse square of the distance between a subject's surface and the thyroid gland. (N.K.).

  16. Impact of abutment rotation and angulation on marginal fit: theoretical considerations.

    Science.gov (United States)

    Semper, Wiebke; Kraft, Silvan; Mehrhof, Jurgen; Nelson, Katja

    2010-01-01

    Rotational freedom of various implant positional index designs has been previously calculated. To investigate its clinical relevance, a three-dimensional simulation was performed to demonstrate the influence of rotational displacements of the abutment on the marginal fit of prosthetic superstructures. Idealized abutments with different angulations (0, 5, 10, 15, and 20 degrees) were virtually constructed (SolidWorks Office Premium 2007). Then, rotational displacement was simulated with various degrees of rotational freedom (0.7, 0.95, 1.5, 1.65, and 1.85 degrees). The resulting horizontal displacement of the abutment from the original position was quantified in microns, followed by a simulated pressure-less positioning of superstructures with defined internal gaps (5 µm, 60 µm, and 100 µm). The resulting marginal gap between the abutment and the superstructure was measured vertically with the SolidWorks measurement tool. Rotation resulted in a displacement of the abutment of up to 157 µm at maximum rotation and angulation. Interference of a superstructure with a defined internal gap of 5 µm placed on the abutment resulted in marginal gaps up to 2.33 mm at maximum rotation and angulation; with a 60-µm internal gap, the marginal gaps reached a maximum of 802 µm. Simulation using a superstructure with an internal gap of 100 µm revealed a marginal gap of 162 µm at abutment angulation of 20 degrees and rotation of 1.85 degrees. The marginal gaps increased with the degree of abutment angulation and the extent of rotational freedom. Rotational displacement of the abutment influenced prosthesis misfit. The marginal gaps between the abutment and the superstructure increased with the rotational freedom of the index and the angulation of the abutment.

  17. Anatomical evaluation of the root canal diameter and root thickness on the apical third of mesial roots of molars.

    Science.gov (United States)

    Martos, Josué; Tatsch, Gustavo Henrique; Tatsch, Augusto César; Silveira, Luiz Fernando Machado; Ferrer-Luque, Carmen María

    2011-09-01

    The purpose was to determine the diameter of the main root canal and wall thickness in the apical dentin in mesial roots of maxillary and mandibular molars. Forty mesiobuccal and mesial root specimens were sectioned horizontally at 1, 2 and 3 mm from the apex, and measured at each top surface by using optical microscopy to an accuracy of ×20 magnification. The anatomical parameters were established as the following points of reference: AB, two points connected by a line from the outer edge of the mesial wall to the outer edge of the distal one through the center of the root canal to measure the thickness of the root and mesiodistal diameter of the root canal (CD). A second line (EF) was designed to evaluate the diameter of the root canal in the buccolingual direction. All data were summarized, and values were assessed statistically by ANOVA and Bonferroni multiple comparisons. The buccolingual (BL) root canal diameters at 1, 2 and 3 mm in the mandibular and maxillary molars were greater than in the mesiodistal (MD), showing statistically significant differences (p maxillary molars were statistically significant (p maxillary molars was 1.741 mm. The BL diameters in maxillary and mandibular molars were higher than the MD diameter. The thickness (MD) of maxillary and mandibular molars decreased as a function of apical proximity.

  18. Post-extraction mesio-distal gap reduction assessment by confocal laser scanning microscopy - a clinical 3-month follow-up study.

    Science.gov (United States)

    García-Herraiz, Ariadna; Silvestre, Francisco Javier; Leiva-García, Rafael; Crespo-Abril, Fortunato; García-Antón, José

    2017-05-01

    The aim of this 3-month follow-up study is to quantify the reduction in the mesio-distal gap dimension (MDGD) that occurs after tooth extraction through image analysis of three-dimensional images obtained with the confocal laser scanning microscopy (CLSM) technique. Following tooth extraction, impressions of 79 patients 1 month and 72 patients 3 months after tooth extraction were obtained. Cast models were processed by CLSM, and MDGD changes between time points were measured. The mean mesio-distal gap reduction 1 month after tooth extraction was 343.4 μm and 3 months after tooth extraction was 672.3 μm. The daily mean gap reduction rate during the first term (between baseline and 1 month post-extraction measurements) was 10.3 μm/day and during the second term (between 1 and 3 months) was 5.4 μm/day. The mesio-distal gap reduction is higher during the first month following the extraction and continues in time, but to a lesser extent. When the inter-dental contacts were absent, the mesio-distal gap reduction is lower. When a molar tooth is extracted or the distal tooth to the edentulous space does not occlude with an antagonist, the mesio-distal gap reduction is larger. The consideration of mesio-distal gap dimension changes can help improve dental treatment planning. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Normative segment-specific axial and coronal angulation corridors of subaxial cervical column in axial rotation.

    Science.gov (United States)

    Yoganandan, Narayan; Stemper, Brian D; Pintar, Frank A; Baisden, Jamie L; Shender, Barry S; Paskoff, Glenn

    2008-03-01

    In contrast to clinical studies wherein loading magnitudes are indeterminate, experiments permit controlled and quantifiable moment applications, record kinematics in multiple planes, and allow derivation of moment-angulation corridors. Axial and coronal moment-angulation corridors were determined at every level of the subaxial cervical spine, expressed as logarithmic functions, and level-specificity of range of motion and neutral zones were evaluated. segmental primary axial and coupled coronal motions do not vary by level. Although it is known that cervical spine responses are coupled, segment-specific corridors of axial and coronal kinematics under axial twisting moments from healthy normal spines are not reported. Ten human cadaver columns (23-44 years, mean: 34 +/- 6.8) were fixed at the ends and targets were inserted to each vertebra to obtain kinematics in axial and coronal planes. The columns were subjected to pure axial twisting moments. Range of motion and neutral zone for primary-axial and coupled-coronal rotation components were determined at each spinal level. Data were analyzed using factorial analysis of variance. Moment-rotation angulations were expressed using logarithmic functions, and mean +/-1 standard deviation corridors were derived at each level for both components. Moment-angulations responses were nonlinear. Each segmental curve for both components was well represented by a logarithmic function (r2 > 0.95). Factorial analysis of variance indicated that the biomechanical metrics are spinal level-specific (P specific responses. The presentation of moment-angulation corridors for both metrics forms a dataset for the normal population. These segment-specific nonlinear corridors may help clinicians assess dysfunction or instability. These data will assist mathematical models of the spine in improved validation and lead to efficacious design of stabilizing systems.

  20. Transverse morphology of the sacroiliac joint: effect of angulation and implications for fluoroscopically guided sacroiliac joint injection

    Energy Technology Data Exchange (ETDEWEB)

    Ling, B.C.; Lee, J.W.; Man, H.S.J.; Grace, M.G.A.; Lambert, R.G.W. [Department of Radiology and Diagnostic Imaging, University of Alberta Hospital, Edmonton (Canada); Jhangri, G.S. [Department of Public Health Sciences, University of Alberta Hospital, Edmonton (Canada)

    2006-11-15

    Effects of angulation of computed tomography (CT) reconstruction plane on sacroiliac (SI) joint morphology were studied, and factors influencing the approach to fluoroscopically guided SI joint injection were assessed. CT scans of pelvises were reformatted on 41 subjects, aged 51.7 ({+-}15.1) years. Transverse images were reconstructed at the caudal 3 cm of the SI joint tilting plane of reconstruction from -30 to +30 at 15 increments. Anteroposterior diameter of joint (depth), angle from sagittal plane (orientation angle), and distance from skin were measured. Joint contour was classified, and presence of bone blocking access to the joint was recorded. Comparison between angles were analysed by t-test. Relationships between variables were assessed by a Pearson correlation test. Depth was shorter with angulation in the inferior direction (P<0.01). Orientation angle increased with superior angulation (P<0.01). Distance from skin increased (P<0.01) with angulation in either direction. Joint contour was significantly different from baseline at each angle (P<0.001) but highly variable. Inferior angulation resulted in interposition of ilium between skin and SI joint, and superior angulation caused bone block due to the lower sacrum. None of these features was identified without tilting of the reconstruction plane, and effects were more pronounced with steeper angulation.

  1. Using a dental operating microscope for endodontic management of a mandibular central incisor with 3 root canals.

    Science.gov (United States)

    Aswinkumar, Vijayakumar; Nandini, Suresh; Velmurgan, Natanasabapathy

    2013-08-01

    Endodontic management of teeth with aberrant root canal morphology can be challenging. This article presents a case in which multiple angulated radiographs and a dental operating microscope clearly revealed the presence of 3 root canals in a right mandibular central incisor with 2 different canal patterns. This case report emphasizes the importance of utilizing a dental operating microscope to understand unusual root canal morphology.

  2. Clinical Study of 23 Male Patients with Congenital Ventral Penile Angulation without Hypospadias

    Directory of Open Access Journals (Sweden)

    Ioannis Patoulias

    2017-02-01

    Full Text Available Congenital ventral penile angulation without hypospadias is a rare disease and causes great anxiety to the parents. The aim of our study is the presentation of this disease, especially the indications of surgical treatment and the protocol applied in our clinic. We retrospectively studied 23 male patients aged 2.5 to 7 years old (av 5.2 y with important penile angulation (over 45° without hypospadias, treated during the past 15 years in our department. In 9 patients the cause was the skin chordee (fibrosis of the ventral part of the prepuce, in 4 the fibrotic fascia (incomplete development of dartos and Buck’s fascia and in 10 the disproportion of the corpora cavernosa. No case of congenital short urethra was reported. In our opinion, the appliance of the algorithm suggested by Donnahoo KK et al. in uncomplicated cases, along with the experience of the surgical team, results in satisfactory treatment and avoidance of complications.

  3. Effects of Self-Adjusting File, Mtwo, and ProTaper on the root canal wall

    NARCIS (Netherlands)

    Hin, E.S.; Wu, M.K.; Wesselink, P.R.; Shemesh, H.

    2013-01-01

    Introduction The purpose of this ex vivo study was to observe the incidence of cracks in root dentin after root canal preparation with hand files, self-adjusting file (SAF), ProTaper, and Mtwo. Methods One hundred extracted mandibular premolars with single canals were randomly selected. Two angulate

  4. Influence of ligation method on friction resistance of lingual brackets with different second-order angulations: an in vitro study

    Science.gov (United States)

    Pereira, Graziane Olímpio; Gimenez, Carla Maria Melleiro; Prieto, Lucas; Prieto, Marcos Gabriel do Lago; Basting, Roberta Tarkany

    2016-01-01

    ABSTRACT Objective: To evaluate stainless steel archwire static friction in active and passive self-ligating lingual and conventional brackets with second-order angulations. Methods: Two conventional lingual brackets for canines (STb light/Ormco; PSWb/Tecnident), and two self-ligating brackets, one active (In-Ovation L/GAC) and the other passive (3D/ Forestadent), were evaluated. A stainless steel archwire was used at 0°, 3° and 5° angulations. Metal ligatures, conventional elastic ligatures, and low friction elastic ligatures were also tested. A universal testing machine applied friction between brackets and wires, simulating sliding mechanics, to produce 2-mm sliding at 3 mm/minute speed. Results: Two-way analysis of variance demonstrated a significant effect of the interaction between brackets and angulations (p < 0.001). Tukey test indicated that the highest frictional resistance values were observed at 5° angulation for In-Ovation L, PSWb bracket with non conventional ligature, and STb bracket with metal ligature. As for 3D, PSWb with conventional or metal ligatures, and STb brackets with non conventional ligature, showed significantly lower static frictional resistance with 0° angulation. At 0° angulation, STb brackets with metal ties, In-Ovation L brackets and 3D brackets had the lowest frictional resistance. Conclusions: As the angulation increased from 0° to 3°, static friction resistance increased. When angulation increased from 3° to 5°, static friction resistance increased or remained the same. Self-ligating 3D and In-Ovation L brackets, as well as conventional STb brackets, seem to be the best option when sliding mechanics is used to perform lingual orthodontic treatment. PMID:27653262

  5. Prevalence and features of distolingual roots in mandibular molars analyzed by cone-beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Mi Ree; Moon, Young Mi; Seo, Min Seock [Dept. of Conservative Dentistry, Wonkang University Daejeon Dental Hospital, Daejeon (Korea, Republic of)

    2015-12-15

    This study evaluated the prevalence of distolingual roots in mandibular molars among Koreans, the root canal system associated with distolingual roots, and the concurrent appearance of a distolingual root in the mandibular first molar and a C-shaped canal in the mandibular second molar. Cone-beam computed tomographic images of 264 patients were screened and examined. Axial sections of 1056 mandibular molars were evaluated to determine the number of roots. The interorifice distances from the distolingual canal to the distobuccal canal were also estimated. Using an image analysis program, the root canal curvature was calculated. Pearson's chi-square test, the paired t-test, one-way analysis of variance, and post-hoc analysis were performed. Distolingual roots were observed in 26.1% of the subjects. In cases where a distolingual root was observed in the mandibular molar, a significant difference was observed in the root canal curvature between the buccolingual and mesiodistal orientations. The maximum root canal curvature was most commonly observed in the mesiodistal orientation in the coronal portion, but in the apical portion, maximum root canal curvature was most often observed in the buccolingual orientation. The canal curvature of distolingual roots was found to be very complex, with a different direction in each portion. No correlation was found between the presence of a distolingual root in the mandibular first molar and the presence of a C-shaped canal in the mandibular second molar.

  6. Radiological assessment of cervical lateral mass screw angulations in Asian patients

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    Mariapan Sureisen

    2011-01-01

    Full Text Available Background: Various lateral mass screw fixation methods have been described in the literature with various levels of safety in relation to the anterior neurovascular structures. This study was designed to radiologically determine the minimum lateral angulations of the screw to avoid penetration of the vertebral artery canalusing three of the most common techniques: Roy-Camille, An, and Magerl. Materials and Methods: Sixty normal cervical CT scans were reviewed. A minimum lateral angulation of a 3.5 mm lateral mass screw which was required to avoid penetration of the vertebral artery canal at each level of vertebra were measured. Results: The mean lateral angulations of the lateral mass screws (with 95% confidence interval to avoid vertebral artery canal penetration, in relation to the starting point at the midpoint (Roy-Camille, 1 mm medial (An, and 2 mm medial (Magerl to the midpoint of lateral mass were 6.8° (range, 6.3-7.4°, 10.3° (range, 9.8-10.8°, and 14.1° (range, 13.6-14.6° at C3 vertebrae; 6.8° (range, 6.2-7.5°, 10.7° (range, 10.0-11.5°, and 14.1° (range, 13.4-14.8° at C4 vertebrae; 6.6° (range, 6.0-7.2°, 10.1° (range, 9.3-10.8°, and 13.5° (range, 12.8-14.3° at C5 vertebrae and 7.6° (range, 6.9-8.3°, 10.9° (range, 10.3-11.6°, and 14.3° (range, 13.7-15.0° at C6 vertebrae. The recommended lateral angulations for Roy-Camille, Magerl, and An are 10°, 25°,and 30°, respectively. Statistically, there is a higher risk of vertebral foramen violation with the Roy-Camille technique at C3, C4 and C6 levels, P < 0.05. Conclusions: Magerl and An techniques have a wide margin of safety. Caution should be practised with Roy-Camille′s technique at C3, C4, and C6 levels to avoid vertebral vessels injury in Asian population.

  7. An unusual form of congenital anterolateral tibial angulation - the delta tibia

    Energy Technology Data Exchange (ETDEWEB)

    Currarino, Guido [Department of Radiology, Texas Scottish Rite Hospital for Children, Dallas, TX (United States); Department of Radiology, University of Texas, Southwestern Medical Center, Dallas, TX (United States); Herring, John A.; Johnston II, Charles E.; Birch, John G. [Department of Orthopaedic Surgery, Texas Scottish Rite Hospital for Children, Dallas, TX (United States)

    2003-05-01

    We report three infants with a poorly known form of congenital anterolateral angulation of the tibia with distinctive features seen on lateral roentgenograms. In these films the affected tibia appears to be divided into two segments, one proximal and the other distal, which taper as they approach each other at the site of the angulation, and end separately at the apex of the curve with an intervening radiolucent gap in the anterior tibial cortex. The two tibial segments are originally bridged and held firmly in that position by a well-defined triangular osseous structure located in the concavity of the tibial bow. It appears from the three cases reported in this paper and a few comparable cases in the literature that this form of tibial bowing is not prone to fracture followed by pseudoarthrosis and that it tends to improve (and resolve) spontaneously, with a resorption of the intramedullary bony structures at the apex of the curve resulting in the formation of a normal medullary cavity. A limb length discrepancy of varying degree is the main residual change of the anomaly. (orig.)

  8. Effect of orthodontic treatment involving first premolar extractions on mandibular third molar angulation and retromolar space

    Science.gov (United States)

    Vaillard-Jiménez, Esther; García-Rocha, Araceli; Bellot-Arcís, Carlos; Paredes-Gallardo, Vanessa

    2017-01-01

    Background Third molars present more problems than other teeth because they are the last teeth to erupt, and so it is important to assess their development when designing an orthodontic treatment plan. The aim of this study was to compare the angulation of the mandibular third molar and retromolar space before and after orthodontic treatment in cases involving first premolar extraction. Material and Methods 76 patients, 59 women (77.63%) and 17 men (22.36%), were recruited from the Orthodontics Clinic at Benemérita Universidad Autónoma de Puebla (Mexico). Panoramic radiographs were analyzed before and after orthodontic treatment that included first premolar extractions, measuring retromolar space (RS) and the angles formed by the intersection of the axes of the third and second molar (α) and the intersection of the axis of the mandibular plane and third molar (β). Results The data obtained underwent statistical analysis. The angle α and β showed statistically significant differences on the left side in women. In men, only the right side α angle showed significant differences. Retromolar space increased significantly on both sides for both sexes. Conclusions Third molar angulation presents different behaviors between men and women, with greater verticalization in women. Key words:Third molar, retromolar space, orthodontics. PMID:28298970

  9. Angulação dos caninos em indivíduos portadores de má oclusão de Classe I e de Classe III: análise comparativa através de um novo método utilizando imagens digitalizadas Canine angulation in Class I and Class III individuals: a comparative analysis with a new method using digital images

    Directory of Open Access Journals (Sweden)

    Lucyana Ramos Azevedo

    2010-10-01

    Full Text Available OBJETIVO: determinar as angulações mesiodistais das coroas dos caninos em indivíduos portadores de má oclusão de Classe III, comparando-os a indivíduos Classe I. MÉTODOS: foram empregadas medidas tomadas em fotografias digitalizadas de modelos de gesso e transportadas para um programa gráfico para leitura das medidas (Image Tool. Tais procedimentos foram repetidos para avaliação do erro do método casual (fórmula de Dahlberg e para a análise da reprodutibilidade através da Correlação intraclasse. A amostra constituiu-se de 57 pacientes com dentição permanente completa e não tratados ortodonticamente, dividida em dois grupos, de acordo com a má oclusão apresentada: o grupo I foi constituído por 33 pacientes portadores de má oclusão de Classe I, sendo 16 do sexo masculino e 17 do feminino, com média de idades de 27 anos; o grupo II era representado por 24 pacientes portadores de má oclusão de Classe III, 20 do sexo masculino e 4 do feminino, com média de idades de 22 anos. RESULTADOS: o erro casual mostrou-se com uma variação de 1,54 a 1,96 graus para a angulação dos caninos. A análise estatística revelou que o método apresenta uma excelente reprodutibilidade (pOBJECTIVES: This study aimed to determine the mesiodistal angulation of canine crowns in individuals with Class III malocclusion in comparison with Class I individuals. METHODS: Measurements were taken from digital photographs of plaster models and imported into an imaging program (Image Tool. These procedures were repeated to assess random method error (Dahlberg's formula, and analyze reproducibility by intraclass correlation. The sample consisted of 57 patients with complete permanent dentition, untreated orthodontically and divided into two groups according to their malocclusion: Group I consisted of 33 patients with Class I malocclusion, 16 males and 17 females, mean age 27 years; Group II comprised 24 patients with Class III malocclusion, 20 males and

  10. Posterior odontoid process angulation in pediatric Chiari I malformation: an MRI morphometric external validation study.

    Science.gov (United States)

    Ladner, Travis R; Dewan, Michael C; Day, Matthew A; Shannon, Chevis N; Tomycz, Luke; Tulipan, Noel; Wellons, John C

    2015-08-01

    OBJECT Osseous anomalies of the craniocervical junction are hypothesized to precipitate the hindbrain herniation observed in Chiari I malformation (CM-I). Previous work by Tubbs et al. showed that posterior angulation of the odontoid process is more prevalent in children with CM-I than in healthy controls. The present study is an external validation of that report. The goals of our study were 3-fold: 1) to externally validate the results of Tubbs et al. in a different patient population; 2) to compare how morphometric parameters vary with age, sex, and symptomatology; and 3) to develop a correlative model for tonsillar ectopia in CM-I based on these measurements. METHODS The authors performed a retrospective review of 119 patients who underwent posterior fossa decompression with duraplasty at the Monroe Carell Jr. Children's Hospital at Vanderbilt University; 78 of these patients had imaging available for review. Demographic and clinical variables were collected. A neuroradiologist retrospectively evaluated preoperative MRI examinations in these 78 patients and recorded the following measurements: McRae line length; obex displacement length; odontoid process parameters (height, angle of retroflexion, and angle of retroversion); perpendicular distance to the basion-C2 line (pB-C2 line); length of cerebellar tonsillar ectopia; caudal extent of the cerebellar tonsils; and presence, location, and size of syringomyelia. Odontoid retroflexion grade was classified as Grade 0, > 90°; Grade I,85°-89°; Grade II, 80°-84°; and Grade III, < 80°. Age groups were defined as 0-6 years, 7-12 years, and 13-17 years at the time of surgery. Univariate and multivariate linear regression analyses, Kruskal-Wallis 1-way ANOVA, and Fisher's exact test were performed to assess the relationship between age, sex, and symptomatology with these craniometric variables. RESULTS The prevalence of posterior odontoid angulation was 81%, which is almost identical to that in the previous report

  11. Complete Remodeling after Conservative Treatment of a Severely Angulated Odontoid Fracture in a Patient with Osteogenesis Imperfecta : A Case Report

    NARCIS (Netherlands)

    Colo, Dino; Schlösser, Tom P C; Oostenbroek, Hubert J.; Castelein, RM|info:eu-repo/dai/nl/074344943

    2015-01-01

    Study Design. Case report. Objective. This is the first case report describing successful healing and remodeling of a traumatic odontoid fracture that was dislocated and severely angulated in a patient with osteogenesis imperfecta who was treated conservatively. Summary of Background Data. Osteogene

  12. Complete Remodeling after Conservative Treatment of a Severely Angulated Odontoid Fracture in a Patient with Osteogenesis Imperfecta : A Case Report

    NARCIS (Netherlands)

    Colo, Dino; Schlösser, Tom P C; Oostenbroek, Hubert J.; Castelein, RM

    2015-01-01

    Study Design. Case report. Objective. This is the first case report describing successful healing and remodeling of a traumatic odontoid fracture that was dislocated and severely angulated in a patient with osteogenesis imperfecta who was treated conservatively. Summary of Background Data.

  13. Complete Remodeling after Conservative Treatment of a Severely Angulated Odontoid Fracture in a Patient with Osteogenesis Imperfecta : A Case Report

    NARCIS (Netherlands)

    Colo, Dino; Schlösser, Tom P C; Oostenbroek, Hubert J.; Castelein, RM

    2015-01-01

    Study Design. Case report. Objective. This is the first case report describing successful healing and remodeling of a traumatic odontoid fracture that was dislocated and severely angulated in a patient with osteogenesis imperfecta who was treated conservatively. Summary of Background Data. Osteogene

  14. Subtalar arthrodesis stabilisation with screws in an angulated configuration is superior to the parallel disposition: a biomechanical study.

    Science.gov (United States)

    Eichinger, Martin; Schmölz, Werner; Brunner, Alexander; Mayr, Raul; Bölderl, Andreas

    2015-11-01

    The purpose of this study was to compare the stability of two established screw configurations (SC) for subtalar arthrodesis using a cyclic loading model. Eight paired human cadaver hindfoot specimens underwent subtalar arthrodesis with either parallel or angulated SC. The instrumented specimens were subjected to a cyclic loading protocol (1000 cycles: ±5 Nm rotation moment, 50 N axial force). The joint range of motion (ROM) was quantified before and after cyclic loading, in the three principal motion planes of the subtalar joint using pure bending moments of ±3 Nm. After instrumentation, the angulated SC showed significantly less mean ROM compared to the parallel SC in internal/external rotation (1.4° ± 2.2° vs. 3.3° ± 2.8°, P = 0.006) and in inversion/eversion (0.9° ± 1.4° vs. 1.5° ± 1.1°, P = 0.049). After cyclic loading, the angulated SC resulted in significantly less mean ROM compared to the parallel SC in internal/external rotation (3.3° ± 4.6° vs. 8.8° ± 8.0°, P = 0.006) and in inversion/eversion (1.9° ± 2.3° vs. 3.9° ± 3.9°, P = 0.017). No significant differences in the mean ROM were found between the angulated and parallel SC in dorsal extension/plantar flexion. The angulated SC resulted in decreased ROM in the subtalar arthrodesis construct after instrumentation and after cyclic loading compared to the parallel SC. The data from our study suggest that the clinical use of the angulated SC for subtalar arthrodesis might be superior to the parallel SC.

  15. 影响曲面断层片上颌尖牙长轴角度的部分因素分析%The analysis of factors affecting the canine angulation in panoramic radiograph

    Institute of Scientific and Technical Information of China (English)

    陈桦; 许天民

    2010-01-01

    目的 研究上颌尖牙区三维方向上多种因素变化对曲面断层片中牙长轴角度影响.方法 用干颅骨标本、模型牙制作模型模拟拔牙矫治后理想牙颌状态,从初始状态开始,依次改变右上尖牙的轴倾度、右上尖牙的转矩、上颌右侧弓形以及曲断选层位置,并在精确定位状态下分别拍摄颅骨模型的曲面断层片,测量右上尖牙牙长轴影像与固定参照平面的夹角.结果 尖牙实际轴倾度与曲断片牙长轴角度呈同方向变化;尖牙根颊向转矩使牙根影像趋于后倾,根腭向转矩使牙根影像趋于前倾;弓形尖圆时牙根影像趋于前倾,弓形方圆时牙根影像趋于后倾;选层位置靠后时牙根影像趋于前倾,选层靠前时牙根影像趋于后倾,二者相差1.8°.结论 曲面断层片所示的牙齿长轴角度受局部多种三维因素的共同影响,且具有一定的规律性.%Objective To examine the effect of variable 3D factors of maxillary teeth position on the angulation of the canine axis in panoramic image. Methods A dry skull and a set of model teeth served as the typodont testing device to simulate the ideal occlusion after orthodontic treatment with four premolars extraction. The tip and torque of the upper right canine, the archform of the righ tdental arch and the position of the focal trough were altered in sequence, and panoramic films at each status were taken. The angulations of maxillary canines in each film were measured. Results The true tip of the upper canine and its image angulation in panoramic changed by the same direction. As the root buccal torque increased, the root image tilt distally. As the archform and the position of the focal changed, the angulations of the tooth image were distorted relatively, and the difference was as big as 1.8°. Conclusions The angulations of the long axis of teeth in panoramic images wereimpacted by a series of local 3D factors, and some laws were found about their

  16. Rare Root Morphology of a Maxillary Central Incisor Associated With Gingival Hyperplasia

    OpenAIRE

    Monea, Monica; Moldovan, Cosmin

    2016-01-01

    Abstract Dilaceration is a developmental disturbance characterized by the angulation of the crown or root of a permanent tooth, which is often related to trauma of primary dentition. We report a case of a dilacerated root in a maxillary central incisor associated with gingival hyperplasia in a patient under fixed orthodontic treatment, a combination of pathological conditions that had never been mentioned before in the scientific literature. A 10-year-old female patient presented to the Depar...

  17. Evaluation of the Mesiodistal Crown Sizes of the Remaining Dentition in Patients with Hypodontia, between 12 and 16 Years of Age

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    Albena Reshitaj

    2013-09-01

    Full Text Available Objective: This study evaluated the mesiodistal crown sizes of the remaining dentition in patients affected with hypodontia, compared with the control group possessing complete dentition. Methods: Panoramic radiographs of the patients treated in the Department of Orthodontics, Dental School - branch of Medical Faculty – University of Pristina, were reviewed to select a sample of 22 cases with agenesis of one or more permanent teeth, except the third molars (hypodontia group. A control group included 22 patients with complete dentition. Dental casts were measured for both groups. The patients ranged in age from 12 to 16 years. Mesiodistal crown dimensions were recorded by measuring all erupted teeth on study models with a manual caliper. Statistical calculation was performed using SPSS 15.0. Paired samples t-test was used to detect the statistical differences in tooth width measurements between the two groups. The significance level was predetermined at α = 0.05.Results: The mean age of the patients in the hypodontia group was 14.55±1.57 years, while that of the control group was 14.23±1.11. The most common congenital missing teeth were the upper lateral incisors (46.16% followed by the upper first premolars (11.54%. We found significant differences between the groups in tooth size for the maxillary arch central incisors and the maxillary arch molar right quadrant, while in the left quadrant differences between the two groups were observed in the central incisor (P<0.05. However, we did not observe any significant differences between the groups with respect to tooth size for the lower jaw. Conclusion: The reduced tooth size was evident except in the posterior segment right molar in the hypodontia group. This should be taken into consideration during treatment planning and deciding upon the treatment mechanics in order to achieve functional occlusion and an esthetic dentition at the culmination of the orthodontic treatment.

  18. Introduction of an alternative standardized radiographic measurement method to evaluate volar angulation in subcapital fractures of the 5th metacarpal

    Energy Technology Data Exchange (ETDEWEB)

    Hoffelner, Thomas; Resch, Herbert; Moroder, Philipp; Korn, Gundobert; Steinhauer, Felix [University of Salzburg, Department of Traumatology and Sports Injuries, Salzburg (Austria); Atzwanger, Joerg [University of Salzburg, Department of Radiology, Salzburg (Austria); Minnich, Bernd [University of Salzburg, Department of Organismic Biology, Salzburg (Austria); Tauber, Mark [Shoulder and Elbow Surgery ATOS Clinic Munich, Munich (Germany)

    2012-10-15

    The purpose of the present study was to compare the intra- and interobserver reliability of two different measurement methods for volar angulation of the 5th metacarpal (MC) in an attempt to establish a new standard measurement method to reduce interobserver discrepancies for therapeutic decisions. Twenty patients with subcapital fractures of the 5th MC were radiologically investigated. Imaging consisted of a radiographs in antero-posterior and precise lateral view in addition to a CT scan of the 5th MC. Measurement of volar angulation was accomplished using the conventional and the shaft articular surface (SAS) method. The measurements of five investigators were exported to a spreadsheet for statistical analysis to evaluate the intra-and interobserver reliability. The conventional technique showed large differences among the investigators and poor interobserver reliability (W = 0.328 and 0.307) both at injury (p = 0.001) and at follow-up (p = 0.189). The intraobserver concordance of all investigators showed better results with the SAS than with the conventional technique. With the SAS technique, no statistically significant difference among the investigators could be detected at either the time of injury (p = 0.418) or at follow-up (p = 0.526) with excellent interobserver reliability (W = 0.051 and W = 0.041). Evaluation of volar angulation at follow-up using CT scans did not show any statistically significant difference between the techniques with better correlation among the observers with the SAS technique (p = 0.838). The interobserver correlation of volar angulation with lateral radiographs using the conventional technique was insufficient. Therefore, we recommend the use of the novel SAS technique as standardized measurement method which showed higher accuracy and interobserver reliability in order to facilitate the choice of adequate treatment option. (orig.)

  19. Complete Remodeling After Conservative Treatment of a Severely Angulated Odontoid Fracture in a Patient With Osteogenesis Imperfecta: A Case Report.

    Science.gov (United States)

    Colo, Dino; Schlösser, Tom P C; Oostenbroek, Hubert J; Castelein, René M

    2015-09-15

    Case report. This is the first case report describing successful healing and remodeling of a traumatic odontoid fracture that was dislocated and severely angulated in a patient with osteogenesis imperfecta who was treated conservatively. Osteogenesis imperfecta (OI) is a rare genetic disorder resulting in a low bone mass and bone fragility, predisposing these patients to fractures that often occur at a young age. Although any bone in the body may be involved, odontoid fractures are uncommon in this population. Because of a very high fusion rate, conservative management is accepted as a safe and efficient treatment of fractures of the odontoid in children. Several authors, however, recommend surgical treatment of patients who have failure of conservative treatment and have severe angulation or displacement of the odontoid. A 5-year-old female, diagnosed with OI type I, presented with neck pain without any neurological deficits after falling out of a rocking chair backward, with her head landing first on the ground. Computed tomography confirmed a type III odontoid fracture without dislocation and she was initially treated with a rigid cervical orthosis. At 1 and 2 months of follow-up, progressive severe angulation of the odontoid was observed but conservative treatment was maintained as the space available for the spinal cord was sufficient and also considering the patient's history of OI. Eight months postinjury, she had no clinical symptoms and there was osseous healing of the fracture with remodeling of the odontoid to normal morphology. Even in patients with OI, severely angulated odontoid fractures might have the capacity for osseous healing and complete remodeling under conservative treatment. 5.

  20. A normative study to evaluate inclination and angulation of teeth in North Indian population and comparision of expression of torque in preadjusted appliances

    OpenAIRE

    Verma, Sanjeev; Singh, SP; Utreja, Ashok

    2014-01-01

    Aim: The aim of this study was to evaluate angulation and inclination of teeth from the study models of individuals with normal occlusion and evaluation of actual expression of torque expressed by three different bracket systems. Materials and Methods: In this study, the inclination and angulation were measured on 30 study models of North Indian individuals. A self-developed instrument (torque angle gauge) was used for the measurement. Fifteen study models were duplicated for the evaluation o...

  1. Thickness of cementum/dentin in mesial roots of mandibular first molars.

    Science.gov (United States)

    Berutti, E; Fedon, G

    1992-11-01

    The mesial roots of 15 human first lower molars, along with the corresponding half of the tooth crown, were studied to determine the thickness of dentin-cementum. A device was developed whereby these could be embedded in resin with a precisely known orientation in space. The roots were radiographed in mesiodistal and vestibular-lingual projections, then sectioned perpendicular to the canal axis in the coronal third. Thickness of dentin-cementum was compared on sections and radiograms; results showed that the amount of hard tissue is effectively about one fifth less than that appearing on the radiogram.

  2. Endovascular Treatment of Infrarenal Abdominal Aortic Aneurysm with Short and Angulated Neck in High-Risk Patient

    Directory of Open Access Journals (Sweden)

    Stylianos Koutsias

    2013-01-01

    Full Text Available Endovascular treatment of abdominal aortic aneurysms (AAA is an established alternative to open repair. However lifelong surveillance is still required to monitor endograft function and signal the need for secondary interventions (Hobo and Buth 2006. Aortic morphology, especially related to the proximal neck, often complicates the procedure or increases the risk for late device-related complications (Hobo et al. 2007 and Chisci et al. 2009. The definition of a short and angulated neck is based on length (60° (Hobo et al. 2007 and Chisci et al. 2009. A challenging neck also offers difficulties during open repairs (OR, necessitating extensive dissection with juxta- or suprarenal aortic cross-clamping. Patients with extensive aneurysmal disease typically have more comorbidities and may not tolerate extensive surgical trauma (Sarac et al. 2002. It is, therefore, unclear whether aneurysms with a challenging proximal neck should be offered EVAR or OR (Cox et al. 2006, Choke et al. 2006, Robbins et al. 2005, Sternbergh III et al. 2002, Dillavou et al. 2003, and Greenberg et al. 2003. In our case the insertion of a thoracic endograft followed by the placement of a bifurcated aortic endograft for the treatment of a very short and severely angulated neck proved to be feasible offering acceptable duration of aneurysm exclusion. This adds up to our armamentarium in the treatment of high-risk patients, and it should be considered in emergency cases when the fenestrated and branched endografts are not available.

  3. A comparison between radiovisiography and clearing technique in the study of the root canal types

    Institute of Scientific and Technical Information of China (English)

    Daming Wu; Younong Wu

    2005-01-01

    Objective: To compare the radiovisiography (RVG) with the clearing technique using Kappa value in the study of the root canal types. Methods: One hundred recently extracted human maxillary first premolars were used. Standard periapical RVG images were taken from a buccolingual and mesiodistal direction. The specimens were then accessed, injected with ink, demineralized,dehydrated, and finally were cleared. The RVG images and the transparent teeth were examined by a trained endodontist, and the date of root canal types following Wu's classification was collected. Results: The reliability of RVG was high for studies on simple root canals,but was poor for the studies on the multiple root canals. The Kappa value between the two techniques was 0.3793, indicating the agreement was poor. Conclusion: It is concluded that the limited value of RVG alone when studying certain aspect of the root canal system. The resolution of the RVG system should be enhanced.

  4. Análisis de la simetría del tamaño dentario mesiodistal de la misma muestra en dentición mixta y permanente: Estudio longitudinal Analysis of symmetry mesiodistal size teeth in mixed and permanent dentition in the same sample: A longitudinal study

    Directory of Open Access Journals (Sweden)

    M.D. Austro Martínez

    2004-12-01

    Full Text Available En el presente trabajo se estudian los diámetros mesiodistales de los dientes temporales y permanentes de la misma muestra y se analiza la existencia de simetría entre dientes homólogos. Dicho estudio fue realizado inicialmente sobre una muestra de 267 niños con dentición mixta, 90 (34% niñas y 177 (66% niños, de Andalucía Oriental, con edades comprendidas entre 8 y 10 años, transcurridos cuatro años volvimos a analizar a los mismos niños con dentición permanente, y sólo obtuvimos una muestra de 171, de los cuales 69 (40% eran niñas y el 102 (60% niños, con una edad media de 12 años y un rango de 11 a 13 años, el 21 % de la muestra tenía 11 años, el 46,29% presentaba una edad de 12 y el 32% de 13 años, utilizándose como criterios de selección, que no tuvieran alteraciones morfológicas, pérdida dentarias, apiñamientos importantes, entre otros factores. El tamaño dentario se midió, como la máxima distancia entre los puntos de contacto mesial-distal de la corona, utilizándose un calibre de punta fina, con una precisión de 0,1 mm. Todas las mediciones fueron realizadas por el mismo observador, directamente en boca, utilizando luz natural y espejos desechables. El análisis estadístico incluyó pruebas como la "t" de Student, con un nivel de significación estadística de pIn the present work is analysed the mesiodistal diameters of the temporal and permanent teeth of the same sampie to calculate the symmetry. The first sample was 267 children, 90 girls (34% and 177 (66% boys from Oriental Andalusia, aged between 8 and 10 years old. After four years, we analysed the same children with permanent teething and we obtained just a sample of 171, 69 girls (40% and 102 (60% boys, with an average age of 12 years and a range from 11 to 13 years, using as criteria selection not having morphological alteration, teeth loss, important congestions, between other elements. The teething dimension was measured as the maximum distance

  5. Automated 3D Analysis of Pre-Procedural MDCT to Predict Annulus Plane Angulation and C-Arm Positioning Benefit on Procedural Outcome in Patients Referred for TAVR

    NARCIS (Netherlands)

    Samim, Mariam; Stella, Pieter R.; Agostoni, Pierfrancesco; Kluin, Jolanda; Ramjankhan, Faiez; Budde, Ricardo P. J.; Sieswerda, Gertjan; Algeri, Emanuela; van Belle, Camille; Elkalioubie, Ahmed; Juthier, Francis; Belkacemi, Anouar; Bertrand, Michel E.; Doevendans, Pieter A.; Van Belle, Eric

    2013-01-01

    OBJECTIVES The aim of this study was to determine whether pre-procedural analysis of multidetector row computed tomography (MDCT) scans could accurately predict the "line of perpendicularity" (LP) of the aortic annulus and corresponding C-arm angulations required for prosthesis delivery and impact t

  6. Evaluation of the effect of the residual bone angulation on implant-supported fixed prosthesis in mandibular posterior edentulism. Part II: 3-D finite element stress analysis.

    Science.gov (United States)

    Akça, K; Iplikçioğlu, H

    2001-01-01

    Buccolingual angulation of the mandibular posterior edentulous region may affect the prosthetic load conditions, so as to cause high stress concentrated areas that may easily lead to failure. The aim of this study was to evaluate the effect of various predetermined buccolingual angulation values on stress distribution in the mandibular posterior edentulous region restored with implant-supported fixed partial dentures, using three-dimensional finite element analysis. Stress analyses were performed applying 400N oblique force to implant-supported fixed prosthesis. Stress analyses indicated tensile stress values on the buccal surface and compressive stress values on the lingual surface of cortical bone were increased as the angulation of the edentulous bone increased (especially corresponding to the cervical region of the implants). Compressive stress values, observed where two implants were placed at the second premolar and second molar regions (5-7 design) and first and second molar regions (6-7 design), respectively, were very close to or even exceeded the ultimate compressive strength of bone. It is concluded that when a definite buccolingual angulation is added to other existing risk factors such as bruxism, placing an implant for every missing tooth might reduce the high stress concentration areas.

  7. A comparative study of frictional force in self-ligating brackets according to the bracket-archwire angulation, bracket material, and wire type.

    Science.gov (United States)

    Lee, Souk Min; Hwang, Chung-Ju

    2015-01-01

    This study aimed to compare the frictional force (FR) in self-ligating brackets among different bracket-archwire angles, bracket materials, and archwire types. Passive and active metal self-ligating brackets and active ceramic self-ligating brackets were included as experimental groups, while conventional twin metal brackets served as a control group. All brackets were maxillary premolar brackets with 0.022 inch [in] slots and a -7° torque. The orthodontic wires used included 0.018 round and 0.019 × 0.025 in rectangular stainless steel wires. The FR was measured at 0°, 5°, and 10° angulations as the wire was drawn through the bracket slots after attaching brackets from each group to the universal testing machine. Static and kinetic FRs were also measured. The passive self-ligating brackets generated a lower FR than all the other brackets. Static and kinetic FRs generally increased with an increase in the bracket-archwire angulation, and the rectangular wire caused significantly higher static and kinetic FRs than the round wire (p self-ligating brackets exhibited the lowest static FR at the 0° angulation and a lower increase in static and kinetic FRs with an increase in bracket-archwire angulation than the other brackets, while the conventional twin brackets showed a greater increase than all three experimental brackets. The passive self-ligating brackets showed the lowest FR in this study. Self-ligating brackets can generate varying FRs in vitro according to the wire size, surface characteristics, and bracket-archwire angulation.

  8. Root hairs

    NARCIS (Netherlands)

    Grierson, C.; Nielsen, E.; Ketelaar, T.; Schiefelbein, J.

    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

  9. Root Canal Anatomy and Morphology of Mandibular First Molars in a Selected Iranian Population: An In Vitro Study

    Science.gov (United States)

    Mohammadzadeh Akhlaghi, Nahid; Khalilak, Zohreh; Vatanpour, Mehdi; Mohammadi, Saman; Pirmoradi, Sakineh; Fazlyab, Mahta; Safavi, Kamran

    2017-01-01

    Introduction: The aim of this study was to evaluate root canal anatomy of mandibular first molars (MFM) in a selected Iranian Population using clearing technique. Methods and Materials: A total of 150 extracted MFMs were cleared. The root canal morphology (including the root numbers and root length) and the anatomy of the root canal system (including is the number and type of canals based on Vertucci’s classification, canal curvature according to Schneider's method and the presence of isthmus) was evaluated using the buccolingual and mesiodistal parallel x-rays and stereomicroscope. The data were analyzed using the chi-square test. Results: Two and three roots were present in 96.7% and 33% of the teeth, respectively (P=0.0001). All the teeth (100%) had two canals in the mesial root, while 61.3% of the samples had one distal root canal (P=0.006). The root canal configuration in the mesial canal included type IV (55.3%) and type II (41.3%) (P=0.0001). In doubled-canalled distal roots, 68.8% and 24.3% were type II and type IV, respectively (P=0.0001). Isthmii were observed in 44.6% of mesial and 27.3% of distal roots (P=0.0001). Conclusion: The notable prevalence of type IV configuration in both roots of mandibular first molars, presence of isthmus and root curvature, necessitates the careful negotiation and cleaning of all accessible canal spaces. PMID:28179932

  10. Late results after intertrochanteric varus angulation in aseptic femoral head necrosis in adults. Spaetergebnisse nach intertrochanterer Varisierungsosteotomie bei der aseptischen Hueftkopfnekrose Erwachsener

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, E.; Ahrendt, J.; Niethard, F.U.; Blaesius, K. (Heidelberg Univ. (Germany, F.R.). Orthopaedische Klinik und Poliklinik)

    1989-04-01

    25 patients suffering from femoral head necrosis in 30 hip joints were radiologically studied for an average of 11.6 years following intertrochanteric varus angulation osteotomy. Preoperatively only stages 2 and 3 according to Meyers were seen. The follow-up results could be distributed into 4 groups. At best the osteonecrosis was reconstructed within 6 to 9 years while the trabeculae started to become rearranged within 2 to 4 years. At worst, rapid destruction in absence of bony reaction was observed. The ability of the bone outside the osteonecrosis to react to changed circumstances following angulation osteotomy correlates with long-term results. This may indicate a general osteopathy even outside the necrotic area. (orig.).

  11. A comparison of profilometer and AutoCAD software techniques in evaluation of implant angulation in vitro.

    Science.gov (United States)

    Assunção, Wirley Gonçalves; Gomes, Erica Alves; Tabata, Lucas Fernando; Gennari-Filho, Humberto

    2008-01-01

    The aim of this study was to compare 2 different methods of assessment of implants at different inclinations (90 degrees and 65 degrees)--with a profilometer and AutoCAD software. Impressions (n = 5) of a metal matrix containing 2 implants, 1 at 90 degrees to the surface and 1 at 65 degrees to the surface, were obtained with square impression copings joined together with dental floss splinting covered with autopolymerizing acrylic resin, an open custom tray, and vinyl polysiloxane impression material. Measurement of the angles (in degrees) of the implant analogs were assessed by the same blinded operator with a profilometer and through analysis of digitized images by AutoCAD software. For each implant analog, 3 readings were performed with each method. The results were subjected to a nonparametric Kruskal-Wallis test, with P AutoCAD (89.95 degrees; P = .9142). In the analyses of the angled implants at 65 degrees in relation to the horizontal surface of the specimen, significant differences were observed (P = .0472) between the mean readings with the profilometer (65.73 degrees) and AutoCAD (66.25 degrees). The degrees of accuracy of implant angulation recording vary among the techniques available and may vary depending on the angle of the implant. Further investigation is needed to determine the best test conditions and the best measuring technique for determination of the angle of the implant in vitro.

  12. Comparison of 2D radiography and a semi-automatic CT-based 3D method for measuring change in dorsal angulation over time in distal radius fractures

    Energy Technology Data Exchange (ETDEWEB)

    Christersson, Albert; Larsson, Sune [Uppsala University, Department of Orthopaedics, Uppsala (Sweden); Nysjoe, Johan; Malmberg, Filip; Sintorn, Ida-Maria; Nystroem, Ingela [Uppsala University, Centre for Image Analysis, Uppsala (Sweden); Berglund, Lars [Uppsala University, Uppsala Clinical Research Centre, UCR Statistics, Uppsala (Sweden)

    2016-06-15

    The aim of the present study was to compare the reliability and agreement between a computer tomography-based method (CT) and digitalised 2D radiographs (XR) when measuring change in dorsal angulation over time in distal radius fractures. Radiographs from 33 distal radius fractures treated with external fixation were retrospectively analysed. All fractures had been examined using both XR and CT at six times over 6 months postoperatively. The changes in dorsal angulation between the first reference images and the following examinations in every patient were calculated from 133 follow-up measurements by two assessors and repeated at two different time points. The measurements were analysed using Bland-Altman plots, comparing intra- and inter-observer agreement within and between XR and CT. The mean differences in intra- and inter-observer measurements for XR, CT, and between XR and CT were close to zero, implying equal validity. The average intra- and inter-observer limits of agreement for XR, CT, and between XR and CT were ± 4.4 , ± 1.9 and ± 6.8 respectively. For scientific purpose, the reliability of XR seems unacceptably low when measuring changes in dorsal angulation in distal radius fractures, whereas the reliability for the semi-automatic CT-based method was higher and is therefore preferable when a more precise method is requested. (orig.)

  13. Root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed.......The purpose of this study was to analyze tooth loss after root fractures and to assess the influence of the type of healing and the location of the root fracture. Furthermore, the actual cause of tooth loss was analyzed....

  14. Root canal preparation in endodontics: conventional versus laser methods

    Science.gov (United States)

    Goodis, Harold E.; White, Joel M.; Marshall, Sally J.; Marshall, Grayson W.; Moskowitz, Emrey

    1992-06-01

    Conventional cleaning and shaping of root canal systems employs hand and/or rotary instrumentation to remove the contents of the canal and shape the canal to receive a filling material. With the advent of the Nd:YAG laser system another method of accomplishing proper cleaning and shaping is evaluated. Single rooted teeth were radiographed bucco- lingually and mesio-distally and were divided into 2 groups. The first group was accessed and the root canal systems cleaned and shaped with a step back technique utilizing hand files and gates glidden burs. At completion of the procedure the teeth were again radiographed at the same positions as those prior to the procedure. The teeth were split longitudinally and examined under scanning electron microscopy to assess cleaning. The second group of teeth were accessed, and cleaning and shaping was accomplished using the Nd:YAG laser in combination with hand files and rotary instruments. These teeth were subjected to the same analysis as those in the first group. The before and after radiographs of each group were subjected to image analysis to determine effectiveness of the two methods in shaping the canal systems. We will discuss the ability of Nd:YAG to clean and shape root canal spaces and remove smear layer and organic tissue remnants from those areas.

  15. Location and angulation of curvatures of mesiobucal canals of mandibular molars debrided by three endodontic techniques Posição e angulação de curvaturas radiculares em canais mesiobucais de molares inferiores preparados por três técnicas endodônticas

    Directory of Open Access Journals (Sweden)

    Isa Geralda Teixeira Constante

    2007-03-01

    Full Text Available The aim of this study was to assess the correlation between the degree of angulation and the position of root curvatures and their influence on the comparative results between the performances of the Progressive, Staged and Serial Preparation Techniques. The mesiobucal canals of 70 extracted mandibular molars were filled with a radiological contrast of 100% Barium sulphate and radiographed with a direct digital radiographic system, in an apparatus that guarantees that the samples remain in the same spatial position at all times. The images were then analyzed in the Coreldraw 10 program (MicroSafe, RJ, Brasil in accordance with two criteria: the methods of Berbert, Nishiyama¹ (1994 and Schneider11 (1971 to determine the position and the angle of the root curvatures, respectively. Initially, the possibility of correlation between these two variables was studied. The teeth were then selected according to angulation (greater than 25 degrees and position of root curvatures (cervical, median and apical in order to perform the endodontic techniques. After preparation, the samples were radiographed again and the images were superimposed in order to compare the pre- and post-operative areas. The difference between them showed the percentage of widening for each technique. The results showed that there was no correlation between the angulations and the root curvature positions, and that the different positions did not interfere in the performance of the techniques. The Progressive Preparation technique produced the highest widening values for all the groups, irrespective of the root curvature position.O objetivo deste trabalho foi verificar a correlação entre o grau de angulação e a posição das curvaturas radiculares, e a sua influência nos resultados comparativos entre os desempenhos das técnicas do Preparo Progressivo, Escalonada e Seriada. Os canais mésio-vestibulares de 70 dentes molares inferiores extraídos foram preenchidos com um

  16. Root resorption associated with an impacted mesiodens: a surgical and endodontic approach to treatment.

    Science.gov (United States)

    Zmener, Osvaldo

    2006-10-01

    This article describes a case of root resorption of a maxillary non-vital immature incisor associated with an impacted and angulated mesiodens. The impacted tooth was surgically removed and the compromised incisor was subsequently endodontically treated. Over a period of 27 months the tooth was medicated with repeated applications of calcium hydroxide. Radiographically after 18 months, an incomplete hard tissue barrier was observed with full apical closure at the conclusion of 27 months of treatment. Once the patient was comfortable after surgical removal of the mesiodens, the tooth was asymptomatic and remained so for the duration of the treatment and after definitive restorative work had been completed.

  17. Assessment and management of rotation and angulation of lower limbs in children%儿童下肢“弯曲”的评估与处理

    Institute of Scientific and Technical Information of China (English)

    胡燕; 黎海芪

    2011-01-01

    儿童早期下肢旋转和成角问题常常困扰家长及儿科医生,但多数症状可以自行缓解.为正确理解儿童下肢发育的旋转和成角过程,儿科医生需有相关下肢发育的生理解剖知识,并结合儿童发育的特点及详细的病史体检进行综合评估及处理.%Most rotational and angulational variations in young children are benign and resolved spontaneously. However, they may cause great concerns to parents. In order to provide a deliberate assessment and management of lower limb rotational and angulational problems, it is necessary for pediatricians to understand the normal variations of lower limb development in healthy children combined with the features of child growth and development and detail physical examinations.

  18. Single Balloon Enteroscopy-Assisted ERCP Using Rendezvous Technique for Sharp Angulation of Roux-en-Y Limb in a Patient with Bile Duct Stones

    Directory of Open Access Journals (Sweden)

    Takao Itoi

    2009-01-01

    Full Text Available The acute angulation of Roux-en-Y (R-Y limb precludes endoscopic access for endoscopic retrograde cholangiopancreatography (ERCP even using a balloon enteroscopy. Here, we describe a case of successful single balloon enteroscopy (SBE-assisted ERCP using a rendezvous technique in a patient with sharply angulated R-Y limb in a 79-year-old woman who had bile duct stones. Method. At first, a guidewire was passed antegradely through the major papilla after the needle puncture using percutaneous transhepatic biliary drainage technique. A hydrophilic guidewire with an ERCP catheter was antegradely advanced beyond the Roux limb. After a guidewire was firmly grasped by a snare forceps, it was pulled out of the body, resulting that the enteroscope could advance to the papilla. After papillary dilation, complete removal of bile duct stones was achieved without any procedure-related complication. In conclusion, although further study is needed, SBE-assisted ERCP using a rendezvous technique may have a potential for selected patients.

  19. Personal operator dose in invasive cardiology as a function of body height and tube angulation; Hoehe und Roehrenangulation als die Determinanten der moeglichen Untersucher-Ortsdosisleistung in der invasiven Kardiologie

    Energy Technology Data Exchange (ETDEWEB)

    Kuon, E.; Reuter, G. [Kardiologische Abt., Klinik Fraenkische Schweiz, Ebermannstadt (Germany); Empen, K.; Dahm, J.B. [Kardiologische Klinik, Ernst-Moritz-Arndt-Univ., Greifswald (Germany)

    2004-05-01

    Purpose: to map in an experimental setting of the local personal operator dose for 55 selected tube angulations as a function of body height above ground. Materials and methods: on an alderson-rando phantom representing the patient, we performed measurements of fluoroscopy scatter radiation ({mu}Sv/h) at the operator's position, for the range of 20 - 200 cm body height, for all tube angulations in 30 steps from right anterior oblique (RAO) 90 to left anterior oblique (LAO) 90 position, and for planes angulated cranially (+) and caudally (-) by 10 , 20 , 30 , and 40 , unless rendered unfeasible by geometric circumstances. Results: radiation exposure to the operator is lowest between posteroanterior (PA) 0 and RAO 30 angulation, and continuously increases by a factor of approx. 2 towards steep RAO, and to factors of 5 - 10 towards steep LAO views. Craniocaudal angulation at 30 likewise generates personal dose levels 2 - 3 times as high. For all body heights and all LAO tube angulations, the corridor between 0 - 10 caudal angulation generates the least personal scatter dose, likewise irrespective of body height and craniocaudal tube angulations, the corridor between 0 PA - 30 RAO angulation. RAO angulations, however, being inverse to the respective 90 LAO angulations, are generally 4 to 5 times less radiation extensive. Peak levels of the local personal dose vary from 160 cm body height for steep cranial LAO 90 /30 + views (3,500 {mu}Sv/h), to 50 cm for cranial PA 0 /30 + (400 {mu}Sv/h), and to {>=} 170 cm (600 {mu}Sv/h) and {<=} 40 cm (300 {mu}Sv/h) for steep cranial RAO 90 /30 + views. Caudal angulations generate slightly lower doses, with peak levels at 120 cm for LAO 90 /30 - views (3,000 {mu}Sv/h), at 50 cm for PA 0 /30 - views (300 {mu}Sv/h), and above 170 cm (900 {mu}Sv/h) and below 40 cm (500 {mu}Sv/h) for steep caudal RAO 90 /30 - views. (orig.) [German] Ziel: Experimentelle Bestimmung der Ortsdosisleistung des Untersuchers in der invasiven Kardiologie

  20. Study in the mesiodistal width of teeth and Bolton index of Angle's Class Ⅱ malocclusion patient%安氏Ⅱ类错(牙合)畸形牙冠宽度和Bolton指数测量分析

    Institute of Scientific and Technical Information of China (English)

    陈沐; 李正明; 刘学; 冯志才; 黄永谦

    2013-01-01

    目的 分析安氏Ⅱ类错(牙合)畸形患者的Bolton指数,并探讨其上下牙量关系对其症状及疗效的影响.方法 以安氏Ⅱ类1分类和2分类错(牙合)畸形患者各100例为研究对象,分别进行牙冠宽度测量并计算Bolton指数.结果 安氏Ⅱ类1分类错(牙合)的前牙宽度比安氏Ⅱ类2分类错(牙合)大,差异有统计学意义.Bolton指数不调的基本分布情况为:指数正常组>指数过小组>指数过大组.Bolton指数前牙比和全牙比呈现安氏Ⅱ类2分类错(牙合)>安氏Ⅱ类1分类错(牙合),但其差异无统计学意义.结论 安氏Ⅱ类错(牙合)中有约50%病例Bolton指数在正常值范围之外,存在上下牙量不协调.%Objective To investigate Bolton index of Angle's Class Ⅱ malocclusion patients and to study the influences of an upper and lower tooth size relations on the symptoms and curative effect.Methods 100 casts of Class Ⅱ division 1 and Class Ⅱ division 2 malocclusion were selected,respectively.Mesiodistal width of teeth was measured and Bolton Index was calculated.Results The results indicated that the sum of mesiodistal width of maxillary anterior teeth in Class Ⅱ division 1 malocclusion were larger than that in Class Ⅱ division 2 malocclusion with significant differentce.The ratio of Bolton Index among the normal ranges was larger than that among lower ranges and among higher ranges.Bolton Index of Class Ⅱ division 2 malocclusion was larger than that Class Ⅱ division 1 malocclusion without ignificant differentce.Conclusion More than half of all patients have the Bolton ratio outside the normal ranges and the maxillary and mandibular teeth size discrepancy.

  1. Root resorption

    DEFF Research Database (Denmark)

    Kjaer, Inger

    2014-01-01

    Introduction: This paper summarizes the different conditions, which have a well-known influence on the resorption of tooth roots, exemplified by trauma and orthodontic treatment. The concept of the paper is to summarize and explain symptoms and signs of importance for avoiding resorption during...... orthodontic treatment. The Hypothesis: The hypothesis in this paper is that three different tissue layers covering the root in the so-called periroot sheet can explain signs and symptoms of importance for avoiding root resorption during orthodontic treatment. These different tissue layers are; outermost...... processes provoked by trauma and orthodontic pressure. Inflammatory reactions are followed by resorptive processes in the periroot sheet and along the root surface. Evaluation of the Hypothesis: Different morphologies in the dentition are signs of abnormal epithelium or an abnormal mesodermal layer. It has...

  2. Possibilty of the lower third molar eruption: Radiographic analysis

    Directory of Open Access Journals (Sweden)

    Nedeljković Nenad

    2006-01-01

    Full Text Available Backgraund/Aim. To assess the possibility of the eruption of the lower third molar on the basis of the measured parameters: retromolar space, mesiodistal crown width of a molar and the third molar angulation. Methods. The investigation included 104 patients both sexes (43 boys, and 61 girls, 16 to 25 years old (meanage, 18 years. It was performed using the orthopanthomographic radiographs analysis of those patients. Each radiograph was covered by tracing paper, and the contoures of the followiny anatomic details were drawn: a the crown and root contours of third molars, upper and lower central incisors, distal molars in occlusion, anterior edge of ramus mandible, b lines: 1. the occlusal plane, 2. the line of retromolar space, 3. the mesiodistal crown width of third molar, 4. the axial shaft of the third molar and the distal angle between occlusal plane and the axial shaft of the third molar. The values were measured with an orthodontic caliper: the diameter of retromolar space, diameter of mesiodistal width, the value of distal angle between occlusal plane and axial shaft of molar. Results. A favourable angulation of the lower third molar (more than 60° was found in, boys (left 27.90%, right 32.55%, girls (left 39.34%, right 37.77%. A favourable relationship between the diameters of mesiodistal width of the third molar and retromolar space was found in, boys, (left 13.59%, right 16.27%, girls, (left 8.19%, right 14.75%. A favorable relationship between the diameters of mesiodistal width of the third molar and the retromolar space and the angulation was found in boys, (left 9.30%, right 11.62%, girls, (left 6.56%, right 9.83%. Conclusion. There was not any statistically significant difference found between the relation of the retromolar value, third molar mesiodistal diameter, or of the third molar angulation to the left and the right side nor of their mutual relations in comparing boys and girls. A favorable prognosis was found in 9.33% of the

  3. Evaluation of imaging reformation for root and pulp canal shapes of permanent teeth using a cone beam computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Jong Hyun; Kim, Gyu Tae; Choi, Yong Suk; Hwang, Eui Hwan [Kyung Hee Univ., Seoul (Korea, Republic of)

    2007-09-15

    To estimate the shape of root and pulp canal using a dental cone beam computed tomography (CBCT) and to evaluate the accuracy of imaging reformation. CBCT images were obtained with incisors, premolars, and molars as the destination by using PSR 9000N {sup TM} Dental CT system (Asahi Roentgen Ind. Co., Ltd, Kyoto, Japan) and i-CAT (Imaging Sciences International, Inc, USA) cone beam CT unit that have different kind of detector and field of view, and compared these with the shape and the size of actual root and root canal. When the measuring value of cone beam computed tomography concerning to each root's bucco-lingual diameter and mesio-distal diameter was compared with the value of the actual root, it reveals an error range -0.49 {approx} +0.63 mm at PSR900N and -0.97 {approx} +1.14 mm at i-CAT (P>0.05). It was possible to identify and measure PSR 9000N {sup T}M Dental CT system to the limit 0.48{+-}0.06 mm (P>0.05) and i-CAT CBCT to the limit 0.86{+-}0.09 mm (P<0.05) on estimating the size and the shape of root canal. Two kinds of CBCT images revealed the useful reproducibility to estimate the shape of root, but there was the difference to estimate the shape of root according to apparatus. The reproducibility of root shape in the image of three-dimensions at PSR 900N is low such as 0.65 mm in a case of minute root canal. CBCT images revealed higher accuracy of the imaging reformation for root and pulp and clinically CBCT is a useful diagnostic tool for the assessment of root and canal. However, these are different qualities of imaging reformation according to CBCT apparatus and limitation of reproducibility for minute root canals.

  4. Comparison of the Root End Sealing Ability of Four Different Retrograde Filling Materials in Teeth with Root Apices Resected at Different Angles – An Invitro Study

    Science.gov (United States)

    Ponnappa, K.C.; Yadav, Pankaj; Rao, Yogesh; Relhan, Nikhil; Gupta, Priyanka; Choubey, Ashish; Bhardwaj, Shivanshu

    2016-01-01

    Introduction Insufficient apical seal is the significant reason for surgical endodontic disappointment. The root-end filling material utilized should avoid egress of potential contaminants into periapical tissue. Aim The aim of this study was to compare the sealing ability of four root-end filling materials MTA, Portland cement, IRM, RMGIC in teeth with root apices resected at 0 and 45 angle using dye penetration method under fluorescent microscope. Materials and Methods Hundred extracted human maxillary anterior teeth were sectioned horizontally at the cement-enamel junction. After cleaning, shaping and obturation with gutta-percha and AH Plus sealer, the tooth samples were randomly divided in two groups (the root apices resected at 0° and 45° to the long axis of the root). The root resections were carried out by removing 2 mm and 1 mm in both the groups. Following which 3 mm deep root-end cavities were prepared at the apices and the root were coated with nail varnish except the tip. The teeth in both the group were randomly divided into four subgroups each (Pro root MTA, Portland cement, IRM and Light cure nano GIC Ketac N-100). All the retrofilled samples were stored in acrydine orange for 24 hours after which they were cleaned and vertically sectioned buccolingually. The sectioned root samples were observed under fluorescent microscope. Results The root apex sealing ability of Mineral Trioxide Aggregate (MTA) was superior to Portland cement, Intermediate Restorative Material (IRM) and LC GIC. IRM demonstrated the maximum apical leakage value among all the materials. Portland cement and LC GIC showed comparable sealing ability. Conclusion The angulation whether 0° or 45° angle did not affect the sealing ability of all the four materials used, MTA proved to be one of the superior materials for root-end filling. PMID:26894168

  5. Critical Values of Facet Joint Angulation and Tropism in the Development of Lumbar Degenerative Spondylolisthesis: An International, Large-Scale Multicenter Study by the AOSpine Asia Pacific Research Collaboration Consortium

    Science.gov (United States)

    Samartzis, Dino; Cheung, Jason Pui Yin; Rajasekaran, Shanmuganathan; Kawaguchi, Yoshiharu; Acharya, Shankar; Kawakami, Mamoru; Satoh, Shigenobu; Chen, Wen-Jer; Park, Chun-Kun; Lee, Chong-Suh; Foocharoen, Thanit; Nagashima, Hideki; Kuh, Sunguk; Zheng, Zhaomin; Condor, Richard; Ito, Manabu; Iwasaki, Motoki; Jeong, Je Hoon; Luk, Keith D. K.; Prijambodo, Bambang; Rege, Amol; Jahng, Tae-Ahn; Luo, Zhuojing; Tassanawipas, Warat; Acharya, Narayana; Pokharel, Rohit; Shen, Yong; Ito, Takui; Zhang, Zhihai; Aithala P, Janardhana; Kumar, Gomatam Vijay; Jabir, Rahyussalim Ahmad; Basu, Saumyajit; Li, Baojun; Moudgil, Vishal; Goss, Ben; Sham, Phoebe; Williams, Richard

    2015-01-01

    Study Design  An international, multicenter cross-sectional image-based study performed in 33 institutions in the Asia Pacific region. Objective  The study addressed the role of facet joint angulation and tropism in relation to L4–L5 degenerative spondylolisthesis (DS). Methods  The study included 349 patients (63% females; mean age: 61.8 years) with single-level DS; 82 had no L4–L5 DS (group A) and 267 had L4–L5 DS (group B). Axial computed tomography and magnetic resonance imaging were utilized to assess facet joint angulations and tropism (i.e., asymmetry between facet joint angulations) between groups. Results  There was a statistically significant difference between group A (left mean: 46.1 degrees; right mean: 48.2 degrees) and group B (left mean: 55.4 degrees; right mean: 57.5 degrees) in relation to bilateral L4–L5 facet joint angulations (p < 0.001). The mean bilateral angulation difference was 7.4 and 9.6 degrees in groups A and B, respectively (p = 0.025). A critical value of 58 degrees or greater significantly increased the likelihood of DS if unilateral (adjusted OR: 2.5; 95% CI: 1.2 to 5.5; p = 0.021) or bilateral facets (adjusted OR: 5.9; 95% CI: 2.7 to 13.2; p < 0.001) were involved. Facet joint tropism was found to be relevant between 16 and 24 degrees angulation difference (adjusted OR: 5.6; 95% CI: 1.2 to 26.1; p = 0.027). Conclusions  In one of the largest studies assessing facet joint orientation in patients with DS, greater sagittal facet joint angulation was associated with L4-L5 DS, with a critical value of 58 degrees or greater increasing the likelihood of the condition for unilateral and bilateral facet joint involvement. Specific facet joint tropism categories were noted to be associated with DS. PMID:27433424

  6. The influence of metallic posts in the detection of vertical root fractures using different imaging examinations.

    Science.gov (United States)

    Jakobson, S J M; Westphalen, V P D; Silva Neto, U X; Fariniuk, L F; Schroeder, A G D; Carneiro, E

    2014-01-01

    To assess the influence of metallic posts in the detection of simulated vertical root fractures (VRFs) using the following imaging examinations: 2 cone beam CT (CBCT) systems [CBCT1: NewTom(®) 3G (QR Srl, Verona, Italy) and CBCT2: i-CAT Next Generation(®) (Imaging Sciences International, Hatfield, PA)] and film and digital radiographs. Additionally, the influence of the orientation of the fracture line in the detection of VRFs was evaluated. 100, human, single-rooted endodontically treated premolars were divided into 5 groups (Group 1: with posts and buccolingual VRFs, Group 2: with posts and mesiodistal VRFs, Group 3: without posts and with buccolingual VRFs, Group 4: without posts and with mesiodistal VRFs, and Group 5: with posts and without VRFs). The premolars were placed in human mandibles and imaged using the four examination modalities. The sensitivity and the specificity of each examination in the experimental groups were calculated. The data were analysed using Student's t-test. The presence of metallic posts reduced the sensitivity of the CBCT1 system (p = 0.0244). Digital radiographs and the CBCT1 and CBCT2 systems had a higher sensitivity in detecting buccolingual fractures in teeth with posts, whereas film and digital radiographs had a higher sensitivity in detecting buccolingual fractures in teeth without posts (p < 0.05). The CBCT1 examination demonstrated the lowest specificity (p < 0.05). The presence of metallic posts did not influence the sensitivity of most of the examinations, excluding the CBCT1 system. The fracture line orientation may influence VRF detection.

  7. Influence of the endodontic irrigation needle and root canal enlargement on endodontic cleaning efficacy

    Directory of Open Access Journals (Sweden)

    Livia Etchebehere de Loiola

    2011-04-01

    Full Text Available ntroduction: The irrigation of root canals aims to their cleaning and disinfection, improving endodontic treatment success. Objective: To investigate the influence of the diameter and type of irrigation needle and the root canal enlargement on the mechanical efficacy of endodontic irrigation. Material and methods: Twelve human single-rooted mandibular incisors were used. During some instrumentation stages (enlargement by #20, #30, and #40 K file, root canals were filled with radiographic contrast solution mixed to propyleneglycol and zinc oxide. Needles with different diameters and designs were employed: G1 – 23G and lateral opening; G2 – 22G and apical opening; G3 – 30G and lateral opening; G4 – 30G and apical opening. The needles were inserted up to resistance, with 1 mm step-back to avoid root canal obliteration. The irrigation was performed with 2 mL of distilled water. Before and after irrigation/aspiration, teeth were radiographed at bucco-lingual and mesiodistal direction, using a digital radiographic system. Then, root canal areas, before (filled by contrast solution and after irrigation (remnant of contrast solution, were submitted to image subtraction with Adobe Photoshop CS4 software. Subsequently, the areas were measured by Image Tool 3.0 software, allowing the obtaining of the cleaning percentage for each modality. Data were analysed byusing Anova and Tukey’s test. The level of significance was set at P < 0.05. Results: For all root canal enlargements, 30G needles (G3 e G4 presented a better cleaning efficacy. In all groups, higher cleaning efficacy percentage was observed at #30 and #40 K file enlargement. Conclusion: Regardless their design, thinner needles were more effective; a better cleaning efficacy occurred in more enlarged root canals.

  8. Positive Root Bounds and Root Separation Bounds

    Science.gov (United States)

    Herman, Aaron Paul

    In this thesis, we study two classes of bounds on the roots of a polynomial (or polynomial system). A positive root bound of a polynomial is an upper bound on the largest positive root. A root separation bound of a polynomial is a lower bound on the distance between the roots. Both classes of bounds are fundamental tools in computer algebra and computational real algebraic geometry, with numerous applications. In the first part of the thesis, we study the quality of positive root bounds. Higher quality means that the relative over-estimation (the ratio of the bound and the largest positive root) is smaller. We find that all known positive root bounds can be arbitrarily bad. We then show that a particular positive root bound is tight for certain important classes of polynomials. In the remainder of the thesis, we turn to root separation bounds. We observe that known root separation bounds are usually very pessimistic. To our surprise, we also find that known root separation bounds are not compatible with the geometry of the roots (unlike positive root bounds). This motivates us to derive new root separation bounds. In the second part of this thesis, we derive a new root separation for univariate polynomials by transforming a known bound into a new improved bound. In the third part of this thesis, we use a similar strategy to derive a new improved root separation bound for polynomial systems.

  9. Impacted maxillary canines and root resorption of adjacent teeth: A retrospective observational study

    Science.gov (United States)

    Cavallini, Costanza; Vernucci, Roberto; Vichi, Maurizio; Leonardi, Rosalia; Barbato, Ersilia

    2016-01-01

    Background The prevalence of impacted maxillary canine is reported to be between 1% and 3%. The lack of monitoring and the delay in the treatment of the impacted canine can cause different complications such as: displacement of adjacent teeth, loss of vitality of neighbouring teeth, shortening of the dental arch, follicular cysts, canine ankylosis, recurrent infections, recurrent pain, internal resorption of the canine and the adjacent teeth, external resorption of the canine and the adjacent teeth, combination of these factors. An appropriate diagnosis, accurate predictive analysis and early intervention are likely to prevent such undesirable effects. The objective is to evaluate, by means of a retrospective observational study, the possibility of carrying out a predictive analysis of root resorption adjacent to the impacted canines by means of orthopantomographs, so as to limit the prescription of additional 3D radiography. Material and Methods 120 subjects with unilateral or bilateral maxillary impacted canine were examined and 50 patients with 69 impacted maxillary canine (22 male, 28 female; mean age: 11.7 years) satisfied the inclusion criteria of the study. These patients were subjected to a basic clinical and radiographic investigation (orthopantomographs and computerized tomography). All panoramic films were viewed under standardized conditions for the evaluation of two main variables: maxillary canine angulations (a, b, g angles) and the overlapping between the impacted teeth and the lateral incisor (Analysis of Lindauer). Binary logistic regression was used to estimate the likelihood of resorbed lateral incisors depending on sector location and angle measurements. Results Results indicated that b angle has the greatest influence on the prediction of root resorption (predictive value of b angle = 76%). If β angle resorption is 0.06. Conclusions Evaluation of b angle and superimposition lateral incisor/impacted canine analysed on orthopantomographs could

  10. Syndrome of short stature, widow's peak, ptosis, posteriorly angulated ears, and joint problems: exclusion of the Aarskog (FGD1) gene as a candidate gene.

    Science.gov (United States)

    LaDine, B J; Simmons, J A; Shrimpton, A E; Hoo, J J

    2001-03-15

    A syndrome encompassing postnatal onset of short stature, widow's peak, ptosis, posteriorly angulated ears, and limitation of forearm supination is reported in a boy and his mother. The boy has not yet experienced dislocation of patella or other joint anomaly except for limitation of supination of the forearms. On the other hand, the mother has a milder limitation of supination only on the left arm and is devoid of ptosis. Their condition is reminiscent of that described in the family reported by Kapur et al. [1989: Am. J. Med. Genet. 33: 357-363.], which showed an X-linked dominant mode of inheritance. DNA study on our family using an intragenic polymorphism of the Aarskog syndrome (FGD1) gene and four other adjacent markers convincingly excludes the possibility that their condition could be caused by a mutation of the FGD1 gene. Our family and the family reported by Kapur et al. may suggest segregation of a novel X-linked dominant condition.

  11. Present and future in the use of micro-CT scanner 3D analysis for the study of dental and root canal morphology

    Directory of Open Access Journals (Sweden)

    Nicola M. Grande

    2012-01-01

    Full Text Available The goal of the present article is to illustrate and analyze the applications and the potential of microcomputed tomography (micro-CT in the analysis of tooth anatomy and root canal morphology. The authors performed a micro-CT analysis of the following different teeth: maxillary first molars with a second canal in the mesiobuccal (MB root, mandibular first molars with complex anatomy in the mesial root, premolars with single and double roots and with complicated apical anatomy. The hardware device used in this study was a desktop X-ray microfocus CT scanner (SkyScan 1072, SkyScan bvba, Aartselaar, Belgium. A specific software ResolveRT Amira (Visage Imaging was used for the 3D analysis and imaging. The authors obtained three-dimensional images from 15 teeth. It was possible to precisely visualize and analyze external and internal anatomy of teeth, showing the finest details. Among the 5 upper molars analyzed, in three cases, the MB canals joined into one canal, while in the other two molars the two mesial canals were separate. Among the lower molars two of the five samples exhibited a single canal in the mesial root, which had a broad, flat appearance in a mesiodistal dimension. In the five premolar teeth, the canals were independent; however, the apical delta and ramifications of the root canals were quite complex. Micro-CT offers a simple and reproducible technique for 3D noninvasive assessment of the anatomy of root canal systems.

  12. Present and future in the use of micro-CT scanner 3D analysis for the study of dental and root canal morphology.

    Science.gov (United States)

    Grande, Nicola M; Plotino, Gianluca; Gambarini, Gianluca; Testarelli, Luca; D'Ambrosio, Ferdinando; Pecci, Raffaella; Bedini, Rossella

    2012-01-01

    The goal of the present article is to illustrate and analyze the applications and the potential of microcomputed tomography (micro-CT) in the analysis of tooth anatomy and root canal morphology. The authors performed a micro-CT analysis of the following different teeth: maxillary first molars with a second canal in the mesiobuccal (MB) root, mandibular first molars with complex anatomy in the mesial root, premolars with single and double roots and with complicated apical anatomy. The hardware device used in this study was a desktop X-ray microfocus CT scanner (SkyScan 1072, SkyScan bvba, Aartselaar, Belgium). A specific software ResolveRT Amira (Visage Imaging) was used for the 3D analysis and imaging. The authors obtained three-dimensional images from 15 teeth. It was possible to precisely visualize and analyze external and internal anatomy of teeth, showing the finest details. Among the 5 upper molars analyzed, in three cases, the MB canals joined into one canal, while in the other two molars the two mesial canals were separate. Among the lower molars two of the five samples exhibited a single canal in the mesial root, which had a broad, flat appearance in a mesiodistal dimension. In the five premolar teeth, the canals were independent; however, the apical delta and ramifications of the root canals were quite complex. Micro-CT offers a simple and reproducible technique for 3D noninvasive assessment of the anatomy of root canal systems.

  13. Afrokoko Roots

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Give us a little background information about Afrokoko Roots.How long have you been performing together?It's an international Afrobeat outfit that I founded in Beijing three years ago.I founded it in order to show Chinese people that Africa is beyond what they see and hear on TV.For the purpose of cultural exchange,I hope it can help the Chinese learn about African culture,music,fashion,history and much more.Our band features two dancers,two backup singers,two percussionists,four brass players,a keyboard player,a guitar player and a drummer- and me as the lead vocal,drummer and dancer,which makes for live performances that are equally exciting sonically as they are visually.We have been traveling around,and so far,we have toured and performed in many Chinese cities such as Dalian (Liaoning Province),Hohhot (Inner Mongolia Autonomous Region) and Haikou (Hainan Province).

  14. Evaluation of the maxillary premolar roots dissociation using radiographic holders with conventional and digital radiography

    Directory of Open Access Journals (Sweden)

    Marcia Regina Ramalho da Silva Bardauil

    2010-09-01

    Full Text Available This in vivo study evaluated the dissociation quality of maxillary premolar roots combining variations of vertical and horizontal angulations by using X-ray holders (Rinn -XCP, and made a comparison between two types of intraoral radiography systems - conventional film (Kodak Insight, Rochester, USA and digital radiography (Kodak RVG 6100, Kodak, Rochester, USA. The study sample was comprised of 20 patients with a total of 20 maxillary premolars that were radiographed, using the paralleling angle technique (GP, with a 20º variation of the horizontal angle (GM and 25º variation of the horizontal angle combined with 15º vertical angle (GMV. Each image was independently analyzed by two experienced examiners. These examiners assigned a score to the diagnostic capability of root dissociation and the measurement of the distance between the apexes. Statistical data was derived using the Wilcoxon Signed Rank test, Friedman and T test. The means of the measured distances between buccal and lingual root apexes were greater for the GMV, which ranged from 2.3 mm to 3.3 mm. A statistically significant difference was found between GM and GMV when compared to GP with p < 0.01. An established best diagnostic dissociation roots image was found in the GMV. These results support the use of the anterior X-ray holders which offer a better combined deviation (GMV to dissociate maxillary premolar roots in both radiography systems.

  15. Rare Root Morphology of a Maxillary Central Incisor Associated With Gingival Hyperplasia

    Science.gov (United States)

    Monea, Monica; Moldovan, Cosmin

    2016-01-01

    Abstract Dilaceration is a developmental disturbance characterized by the angulation of the crown or root of a permanent tooth, which is often related to trauma of primary dentition. We report a case of a dilacerated root in a maxillary central incisor associated with gingival hyperplasia in a patient under fixed orthodontic treatment, a combination of pathological conditions that had never been mentioned before in the scientific literature. A 10-year-old female patient presented to the Department of Odontology and Oral Pathology with tenderness to palpation and bleeding from the oral aspect of the central incisor, alerted by the proliferation of the gingiva. During clinical examination, the palpation performed with a dental probe revealed a carious lesion with dental pulp exposure on the distal aspect of right central incisor and the presence of a sessile mass of inflamed gingival tissue that proliferated inside the defect. On the preoperative radiograph a dilacerated root canal was noted, without periapical bone resorption. The main diagnosis was irreversible pulpitis and gingival hyperplasia and the treatment option was surgical removal of the inflamed tissue with histopathological examination and root canal treatment. Successful endodontic treatment with a good prognosis was recorded. The measurement of the root curvature proved to be extremely helpful in choosing the right endodontic technique and made the treatment easier than expected. An important observation was that, despite the rare clinical and radiographic aspect of this dilacerated tooth, the endodontic treatment proved to be relatively easy to perform and, therefore, the prognosis was considered favorable. PMID:27149498

  16. Root fractures in children and adolescents: diagnostic considerations.

    Science.gov (United States)

    Molina, Julie R; Vann, William F; McIntyre, Judy D; Trope, Martin; Lee, Jessica Y

    2008-10-01

    The objectives of this study were to (i) characterize epidemiologic trends in anterior permanent tooth trauma in a sample of children and adolescents (ii) examine the relationship of crown fractures (CF) and concomitant root fractures (RF) to determine if CFs are protective against RFs and (iii) examine the radiographic evidence of RFs to determine the value of obtaining three vertical periapical radiographic projections. This was an 8-year cross-sectional study of patients aged 6-18 with anterior permanent tooth trauma. We examined cases involving maxillary central/lateral incisors for which three clearly diagnostic periapical radiographs were obtained during the initial emergency visit. Two trained and calibrated dentists served as expert examiners for the radiographic assessments. Kappa statistics were used to determine reliability. Tests for association of concomitant crown and root fractures were performed using Likelihood Ratio Chi-Square tests. The final sample included 185 teeth in 114 children. Our demographic and epidemiologic findings were comparable to those of previous studies. Experts reached this consensus: 22 RFs were detected, 9.6% (eight out of 83) teeth exhibited root fractures when no CFs was documented, and 13.7% (14 out of 102) teeth had both CFs and RFs as separate entities. Good examiner reliability was reached confirming the presence of RFs (Kappa = 0.81). The association of concomitant RFs and CFs was odds ratio = 1.97 (P = 0.052). CFs were not protective against RFs; indeed, teeth with CFs were twice as likely to have an RF as those without CFs. As the number of radiographic projections increased, RFs were identified more often; however, our data suggest that there is no reason to suspect a complete RF in preteen children unless the root exhibits clinical signs such as luxation or severe mobility. This study provides solid evidence to support obtaining multiple radiographic projections at different vertical angulations to rule out RFs in

  17. Endodontic and Esthetic Management of a Dilacerated Maxillary Central Incisor Having Two Root Canals Using Cone Beam Computed Tomography as a Diagnostic Aid

    Directory of Open Access Journals (Sweden)

    Sarang Sharma

    2014-01-01

    Full Text Available Traumatic injuries to the primary dentition are quite common. When primary teeth are subjected to trauma, force transmission and/or invasion of the underlying tooth germs lying in close proximity can result in a variety of disturbances in the permanent successors. Few of these disturbances include hypoplasia, dilaceration, or alteration in the eruption sequence and pattern. Dilaceration is defined as an angulation or sharp bend or curve in the linear relationship of the crown of a tooth to its root. A rare case of maxillary left central incisor having crown dilaceration and Vertucci’s type II canal configuration with symptomatic periapical periodontitis is reported. Cone beam computed tomography was used for better understanding of the anomaly and complicated root canal morphology. The tooth was successfully managed by nonsurgical root canal therapy and restoration with resin composite to restore esthetics.

  18. Endodontic and esthetic management of a dilacerated maxillary central incisor having two root canals using cone beam computed tomography as a diagnostic aid.

    Science.gov (United States)

    Sharma, Sarang; Grover, Shibani; Sharma, Vivek; Srivastava, Dhirendra; Mittal, Meenu

    2014-01-01

    Traumatic injuries to the primary dentition are quite common. When primary teeth are subjected to trauma, force transmission and/or invasion of the underlying tooth germs lying in close proximity can result in a variety of disturbances in the permanent successors. Few of these disturbances include hypoplasia, dilaceration, or alteration in the eruption sequence and pattern. Dilaceration is defined as an angulation or sharp bend or curve in the linear relationship of the crown of a tooth to its root. A rare case of maxillary left central incisor having crown dilaceration and Vertucci's type II canal configuration with symptomatic periapical periodontitis is reported. Cone beam computed tomography was used for better understanding of the anomaly and complicated root canal morphology. The tooth was successfully managed by nonsurgical root canal therapy and restoration with resin composite to restore esthetics.

  19. ROOT Reference Documentation

    CERN Document Server

    Fuakye, Eric Gyabeng

    2017-01-01

    A ROOT Reference Documentation has been implemented to generate all the lists of libraries needed for each ROOT class. Doxygen has no option to generate or add the lists of libraries for each ROOT class. Therefore shell scripting and a basic C++ program was employed to import the lists of libraries needed by each ROOT class.

  20. Three dimensional-magnetic resonance imaging of dorsal root. Ganglion in lumbosacral disease

    Energy Technology Data Exchange (ETDEWEB)

    Taira, Gaku [Tokyo Medical Coll. (Japan)

    1997-07-01

    Magnetic resonance imaging (MRI) is commonly used for the diagnosis of lumbosacral disease. However, there are certain pitfalls in the use of this imaging technique. In particular, MRI is inadequate for accurate diagnosis of lateral spinal root lesions. Furthermore, it is also difficult to show the root ganglion of both sides on a plane by classical 2D-MRI. Moreover 2D-coronal views do not show several roots in one image because each lumbosacral nerve root is on a different plane. We have developed a new method of three-dimensional MRI (3D-MRI) which enables a stereoscopic view of the spinal cord and both sides of spinal nerve roots in one image. We evaluated three techniques of 3D-MRI, including rapid imaging spin echo (RISE), small tip angle gradient echo (STAGE) and short TI inversion recovery (STIR), in 30 patients with lumbar disc herniation. In a separate anatomical study lumbosacral nerve roots and dorsal root ganglion (DRG) were investigated by 3D-MRI in 20 normal subjects. In a pathophysiological study the use of 3D-MRI defects the signal changes following damage to the spinal nerve roots or ganglion in 70 patients. Our results indicated that the STIR method is the best for identifying abnormalities of the spinal cord, roots and intervertebral disc. It was possible to image the lateral part of damaged nerve roots. The S1 angulations and length were significantly smaller than those of others (p<0.05). The S1 DRG was oval and was the largest. With regard to signal changes in damaged root ganglion, a good correlation between root compression and root edema was detected by basic experiments. We are currently examining the relationship between the damaged root ganglion, pain and sensory disturbance. This study showed that the dorsal root ganglion plays an important role in sensory control of radiculopathy. In conclusion, our new data show a close relationship between sensory loss, pain and DRG finding on 3D-MRI. (author)

  1. Maxillary canine substitution for the severely resorbed root of central incisor: 12-year follow-up.

    Science.gov (United States)

    Koga, Yoshiyuki; Park, Jae Hyun; Tai, Kiyoshi

    2013-01-01

    Ectopically erupting maxillary canines can cause problems that necessitate surgical, orthodontic, and restorative treatment. When a canine eruption disturbance causes resorption and requires subsequent extraction of the affected teeth, the resulting spaces are candidates for orthodontic repositioning and recontouring of the remaining teeth. To achieve successful results, the clinician must have a proper knowledge of tooth anatomy, root angulation, gingival margin position, restorative techniques, and occlusion. A collaborative effort from the pediatric dentist, orthodontist, and surgeon is required to produce an esthetic and functional result. This case report describes the substitution of maxillary canines for both the left central and right lateral incisors and substitution of the maxillary right lateral incisor for the maxillary right central incisor.

  2. Esthetic evaluation of axial maxillary dental midline angulations by orthodontic patients%正畸患者对上颌牙列中线轴向倾斜的审美评价

    Institute of Scientific and Technical Information of China (English)

    周晨; 郭丛丛; 王媛媛; 范明玲; 王伟财; 包柏成

    2012-01-01

    Objective: To analyze the esthetic evaluation of maxillary dental midline angulation by orthodontic patients. Methods: Photographs of smiling man and woman were altered to produce models with left or right maxillary dental midline angulations in 2 ° increments. An electronic questionnaire was developed and applied in 203 orthodontic patients (79 males and 124 famales) who met the inclusion criteria. The survey was based on three standards including ideal value, detectable value and tolerable value of dental midline angulation. Results: The mean left and right detectable values and tolerable values for the female model were 4. 7° , 4. 9° and 9. 7° , 9. 5° ; while 4. 1° , 5.1° and 9. 0° , 9. 7° for the male model. Statistical analysis showed that the degree of the angulations was not significantly variable ( P > 0. 05 ) except in the detectable values for male model ( P 0.05). Female patients'detectable value for right angulation in male model was lower than that of male patients. Conclusion: Esthetic evaluation of axial maxillary dental midline angulation by ideal, detectable and tolerable values is feasible for clinical application in orthodontic treatment.%目的:探讨正畸患者对不同程度上颌牙列中线轴向倾斜的审美评价.方法:采用上颌牙列中线不同程度轴向倾斜的图片模型,制作电子问卷软件,对203位符合条件的正畸患者(男79人,女124人)分理想值、觉察值和容忍值3个层次进行问卷调查.结果:受试对象对女性图片上颌牙列中线轴向向左、右倾斜的平均觉察值分别是4.7°、4.9°,容忍值是9.7°、9.5°;男性图片则为4.1°、5.1°和9.0°、9.7°.其中除了男性图片左、右侧的觉察值之间有统计学差异之外(P0.05).觉察值的中位数和四分位数间距均为4.0°,2.0°;容忍值则均为10.0°,6.0°.女性和男性图片平均理想值分别为0.1°和0.4°,且与总体均数μ=0间无统计学差异(P>0.05).女性受试者对男性图片

  3. Analysis of angulation rotation traction in the treatment of 30 protrusion of lumbar intervertebral disc cases%成角度牵引治疗腰椎间盘突出症30例分析

    Institute of Scientific and Technical Information of China (English)

    郑丹

    2016-01-01

    ObjectiveTo investigate curative effect by angulation rotation traction in the treatment of protrusion of lumbar intervertebral disc.MethodsA total of 60 patients with protrusion of lumbar intervertebral disc were randomly divided into treatment group and control group, with 30 cases in each group. The treatment group received angulation rotation traction for treatment, and the control group received continuous horizontal traction for treatment. Curative effects of the two groups were compared.ResultsAfter treatment for 3 courses, the treatment group had better total effective rate as 83.3% than 66.7% of the control group (P<0.05).Conclusion Angulation rotation traction provides precisely curative effect in treating protrusion of lumbar intervertebral disc.%目的:探讨成角度牵引治疗腰椎间盘突出症的疗效。方法60例腰椎间盘突出症患者,随机分为治疗组与对照组,各30例。治疗组给予持续成角度牵引治疗,对照组给予持续水平牵引治疗。比较两组治疗效果。结果经过3个疗程治疗后,治疗组总有效率为83.3%,优于对照组的66.7%(P<0.05)。结论成角度牵引治疗腰椎间盘突出症临床疗效良好。

  4. An evaluation of the left atrial/aortic root ratio in children with ventricular septal defect.

    Science.gov (United States)

    Lester, L A; Vitullo, D; Sodt, P; Hutcheon, N; Arcilla, R

    1979-08-01

    Echocardiograms were performed in 80 infants and children with isolated ventricular septal defect (VSD) who underwent cardiac catheterization. The pulmonary-to-systemic flow ratio (Qp/Qs) was correlated with the echocardiographic left atrial-to-aortic root diameter ratio (LA/Ao), and a relatively poor correlation (r = 0.62) was found. The end-systolic diameters of the left atrium and aorta at the level of the aortic root, obtained from lateral cineangiograms of 55 of the 80 patients, were compared with the corresponding echocardiographic dimensions. To assess the possible effect of transducer beam angulation upon the echocardiographic determinations, the angiographic measurements were made at 0 degrees position (perpendicular to the frontal plane) and at angles of 5 degrees, 10 degrees, 15 degrees and 20 degrees from zero, using the aortic root center as the point of intersection. The echocardiographic and angiographic aortic root measurements were comparable (r = 0.95), and the angiographically derived aortic diameter did not vary with different angle projections. However, the left atrial angiographic dimensions were significantly influenced by the angle of projection. We conclude that the echocardiographic LA/Ao ratio cannot reliably estimate the severity of the shunt flow in VSD.

  5. 安氏Ⅱ1类错前牙宽度厚度与Bolton 指数测量分析%STUDY IN THE MESIODISTAL WIDTH AND THE CROWN THICKNESS OF ANTERIOR TEETH AND BONLTON INDEX IN CLASS Ⅱ1 MALOCCLUSION

    Institute of Scientific and Technical Information of China (English)

    徐佳瑛; 马超

    2015-01-01

    目的:通过对正常与安氏Ⅱ1类错模型的比较,分析上下颌牙冠宽度、上颌牙冠厚度、Bolton指数差异,为安氏Ⅱ1类错矫治设计提供参考。方法以正常,安氏Ⅱ1类错各50例为研究对象,分别进行牙冠宽度、牙冠厚度的测量并计算。结果安氏Ⅱ1类错上下颌侧切牙和下颌中切牙的牙冠宽度比正常大,差异有统计学意义(P<0.05)。 Bolton 指数前牙比:正常>安氏Ⅱ1类错。安氏Ⅱ1类错上前牙牙冠厚度均大于正常,差异有统计学意义(P <0.05)。 结论上下颌牙量不调和上前牙牙冠厚度变化会对安氏Ⅱ1类错矫治后期正常前牙咬合关系的建立产生影响。%Objective To compare the mesiodistal width and the crown thickness of anterior teeth and Bolt‐on Index of Class Ⅱ 1 and normal occlusion casts in order to provide reference for the diagnosis and treat‐ment of Class Ⅱ 1 malocclusion .Methods Fifty cases of normal occlusion ,Class Ⅱ 1 malocclusion were selected ,respectively .Mesiodistal width of anterior teeth and the upper anterior teeth's thickness were measured and Bolton Index was calculated .Results The results indicated that mesiodistal width of maxil‐lary and mandibular lateral incisors and mandibular central incisors in Class Ⅱ 1 malocclusion were larger than that in normal occlusion with significant difference(P< 0 .05) .Bolton Index of normal occlusion was larger than that of Class Ⅱ 1 malocclusion .The crown thickness of upper anterior teeth in Class Ⅱ 1 maloc‐clusion were larger than that in normal occlusion with significant difference(P < 0 .05) .Conclusion The maxillary and mandibular teeth size discrepancy and the change of the upper anterior teeth's thickness can have effect on the ultimate occlusion of Class Ⅱ 1 malocclusion after orthodontic treatmeant .

  6. Comparing root architectural models

    Science.gov (United States)

    Schnepf, Andrea; Javaux, Mathieu; Vanderborght, Jan

    2017-04-01

    Plant roots play an important role in several soil processes (Gregory 2006). Root architecture development determines the sites in soil where roots provide input of carbon and energy and take up water and solutes. However, root architecture is difficult to determine experimentally when grown in opaque soil. Thus, root architectural models have been widely used and been further developed into functional-structural models that are able to simulate the fate of water and solutes in the soil-root system (Dunbabin et al. 2013). Still, a systematic comparison of the different root architectural models is missing. In this work, we focus on discrete root architecture models where roots are described by connected line segments. These models differ (a) in their model concepts, such as the description of distance between branches based on a prescribed distance (inter-nodal distance) or based on a prescribed time interval. Furthermore, these models differ (b) in the implementation of the same concept, such as the time step size, the spatial discretization along the root axes or the way stochasticity of parameters such as root growth direction, growth rate, branch spacing, branching angles are treated. Based on the example of two such different root models, the root growth module of R-SWMS and RootBox, we show the impact of these differences on simulated root architecture and aggregated information computed from this detailed simulation results, taking into account the stochastic nature of those models. References Dunbabin, V.M., Postma, J.A., Schnepf, A., Pagès, L., Javaux, M., Wu, L., Leitner, D., Chen, Y.L., Rengel, Z., Diggle, A.J. Modelling root-soil interactions using three-dimensional models of root growth, architecture and function (2013) Plant and Soil, 372 (1-2), pp. 93 - 124. Gregory (2006) Roots, rhizosphere and soil: the route to a better understanding of soil science? European Journal of Soil Science 57: 2-12.

  7. Determinação das medidas dentárias mésio-distais em indivíduos brasileiros leucodermas com oclusão normal Determination of mesiodistal dental measures in white brazilian individuals with normal occlusion

    Directory of Open Access Journals (Sweden)

    Osvaldo Tatsuo Yamaguto

    2005-10-01

    Full Text Available Em 60 modelos de gesso ortodônticos foram medidas as larguras mésio-distais dos dentes, de segundo molar a segundo molar, em ambos os arcos, utilizando um paquímetro digital modificado. Este trabalho teve como objetivos determinar o valor médio para a largura de cada dente e observar a presença de dimorfismo sexual, em indivíduos brasileiros leucodermas, com a média de idade de 16,03 anos (25 do gênero masculino e 35 do gênero feminino, não tratados ortodonticamente e portadores de oclusão normal, apresentando no mínimo quatro das seis chaves de oclusão, conforme descrito por Andrews. Os valores das médias individuais dos dentes estudados foram utilizados para a elaboração de uma tabela, correspondentes aos arcos superior e inferior.In 60 (sixty orthodontics models of plaster, it was measured the width mesio-distals of the teeth, from second molar to second molar, in both arches, using a modified sliding caliper. This project had as an objective to determine the average value for the width of each tooth and to observe the presence of sexual dimorphism, in white brazilians individuals, with an average age of 16.03 years old (25 male and 35 female, who were not treated orthodontically and that had normal occlusion, as it was described by Andrews. People's average values of the studied teeth were used to create a table, related to the superior and inferior arches. While analyzing the changes statistically changed, it was noticed a bigger mesio-distal width of the teeth from the male youngsters, related to the female ones.

  8. The Root Pressure Phenomenon

    Science.gov (United States)

    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. The Root Canal Biofilm

    NARCIS (Netherlands)

    Sluis, van der L.W.M.; Boutsioukis, C.; Jiang, L.M.; Macedo, R.; Verhaagen, B.; Versluis, M.; Chávez de Paz, E.; Sedgley, C.M.; Kishen, A.

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  10. WHY ROOTING FAILS.

    Energy Technology Data Exchange (ETDEWEB)

    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.

  11. Root canal irrigation

    NARCIS (Netherlands)

    L. van der Sluis; C. Boutsioukis; L.M. Jiang; R. Macedo; B. Verhaagen; M. Versluis

    2015-01-01

    The aims of root canal irrigation are the chemical dissolution or disruption and the mechanical detachment of pulp tissue, dentin debris and smear layer (instrumentation products), microorganisms (planktonic or biofilm), and their products from the root canal wall, their removal out of the root cana

  12. Rooting gene trees without outgroups: EP rooting.

    Science.gov (United States)

    Sinsheimer, Janet S; Little, Roderick J A; Lake, James A

    2012-01-01

    Gene sequences are routinely used to determine the topologies of unrooted phylogenetic trees, but many of the most important questions in evolution require knowing both the topologies and the roots of trees. However, general algorithms for calculating rooted trees from gene and genomic sequences in the absence of gene paralogs are few. Using the principles of evolutionary parsimony (EP) (Lake JA. 1987a. A rate-independent technique for analysis of nucleic acid sequences: evolutionary parsimony. Mol Biol Evol. 4:167-181) and its extensions (Cavender, J. 1989. Mechanized derivation of linear invariants. Mol Biol Evol. 6:301-316; Nguyen T, Speed TP. 1992. A derivation of all linear invariants for a nonbalanced transversion model. J Mol Evol. 35:60-76), we explicitly enumerate all linear invariants that solely contain rooting information and derive algorithms for rooting gene trees directly from gene and genomic sequences. These new EP linear rooting invariants allow one to determine rooted trees, even in the complete absence of outgroups and gene paralogs. EP rooting invariants are explicitly derived for three taxon trees, and rules for their extension to four or more taxa are provided. The method is demonstrated using 18S ribosomal DNA to illustrate how the new animal phylogeny (Aguinaldo AMA et al. 1997. Evidence for a clade of nematodes, arthropods, and other moulting animals. Nature 387:489-493; Lake JA. 1990. Origin of the metazoa. Proc Natl Acad Sci USA 87:763-766) may be rooted directly from sequences, even when they are short and paralogs are unavailable. These results are consistent with the current root (Philippe H et al. 2011. Acoelomorph flatworms are deuterostomes related to Xenoturbella. Nature 470:255-260).

  13. Screw angulation affects bone-screw stresses and bone graft load sharing in anterior cervical corpectomy fusion with a rigid screw-plate construct: a finite element model study.

    Science.gov (United States)

    Hussain, Mozammil; Natarajan, Raghu N; Fayyazi, Amir H; Braaksma, Brian R; Andersson, Gunnar B J; An, Howard S

    2009-12-01

    Anterior corpectomy and reconstruction with bone graft and a rigid screw-plate construct is an established procedure for treatment of cervical neural compression. Despite its reliability in relieving symptoms, there is a high rate of construct failure, especially in multilevel cases. There has been no study evaluating the biomechanical effects of screw angulation on construct stability; this study investigates the C4-C7 construct stability and load-sharing properties among varying screw angulations in a rigid plate-screw construct. A finite element model of a two-level cervical corpectomy with static anterior cervical plate. A three-dimensional finite element (FE) model of an intact C3-T1 segment was developed and validated. From this intact model, a fusion model (two-level [C5, C6] anterior corpectomy) was developed and validated. After corpectomy, allograft interbody fusion with a rigid anterior screw-plate construct was created from C4 to C7. Five additional FE models were developed from the fusion model corresponding to five different combinations of screw angulations within the vertebral bodies (C4, C7): (0 degrees, 0 degrees), (5 degrees, 5 degrees), (10 degrees, 10 degrees), (15 degrees, 15 degrees), and (15 degrees, 0 degrees). The fifth fusion model was termed as a hybrid fusion model. The stability of a two-level corpectomy reconstruction is not dependent on the position of the screws. Despite the locked screw-plate interface, some degree of load sharing is transmitted to the graft. The load seen by the graft and the shear stress at the bone-screw junction is dependent on the angle of the screws with respect to the end plate. Higher stresses are seen at more divergent angles, particularly at the lower level of the construct. This study suggests that screw divergence from the end plates not only increases load transmission to the graft but also predisposes the screws to higher shear forces after corpectomy reconstruction. In particular, the inferior screw

  14. Application of angulated periapical radiography and cone beam computed tomography in detection of missing root canals%偏位投照与锥形束CT在寻找遗漏根管中的准确性比较

    Institute of Scientific and Technical Information of China (English)

    方朱嫕; 王庆; 余优成

    2014-01-01

    目的:分析比较偏位投照与锥形束CT(CBCT)在根管治疗中发现遗漏根管的应用.方法:对200例患牙常规拍摄术前正位根尖片和CBCT,术中插诊断丝拍摄20°~30°偏位投照根尖片,完善根管治疗.比较偏位投照与CBCT发现的遗漏根管数,采用SPSS 19.0软件包对数据进行统计学分析.结果:200例患牙中,偏位投照发现8例患牙有遗漏根管,前牙及前磨牙3例,磨牙5例.而CBCT扫描显示有15例,其中,前牙及前磨牙4例,磨牙11例.CBCT发现数量大于偏位投照,但差异无显著性(P>0.05).结论:偏位投照与CBCT有利于发现遗漏根管,帮助临床完善根管治疗.

  15. Root canal irrigants.

    Science.gov (United States)

    Kandaswamy, Deivanayagam; Venkateshbabu, Nagendrababu

    2010-10-01

    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.

  16. Conjoined lumbosacral nerve roots

    Directory of Open Access Journals (Sweden)

    Atila Yılmaz

    2012-03-01

    Full Text Available Lumbosacral nerve root anomalies are a rare group ofcongenital anatomical anomalies. Various types of anomaliesof the lumbosacral nerve roots have been documentedin the available international literature. Ttheseanomalies may consist of a bifid, conjoined structure, ofa transverse course or of a characteristic anastomizedappearance. Firstly described as an incidental findingduring autopsies or surgical procedures performed forlumbar disk herniations and often asymptomatic, lumbosacralnerve root anomalies have been more frequentlydescribed in the last years due to the advances made inradiological diagnosis.

  17. The position of maxillary canine impactions and the influenced factors to adjacent root resorption in the Korean population.

    Science.gov (United States)

    Kim, Yoojun; Hyun, Hong-Keun; Jang, Ki-Taeg

    2012-06-01

    The purpose of this study was to evaluate the position and aspects of maxillary canine impactions in the Korean population and investigate its comparison with the previous reports, while aiding in the establishment of diagnosis and treatment planning by revealing the influential factors of root resorption associated with such impactions. The subjects of this study consisted of 186 teeth from 148 patients, who had visited Seoul National University Dental Hospital due to impacted canines and had taken computerized tomographic images and panorama radiographic images. As a result, maxillary canine impaction in the Korean population occurred 1.5 times more often in females (F:M = 89:59) than males. Regarding the position of impaction, there were three times more buccal impactions (B:P = 140:46) than palatal impactions. The occurrence of root resorption was as high as 49.5 per cent. In evaluating the influential factors affecting adjacent root resorption, the significance of the impacted angulation was insufficient (P = 0.652). However, the buccopalatal position (P resorption caused by impacted maxillary canines can be stated to exhibit a greater amount of resorption as the positional proximity of the canine crown and lateral incisor root increases.

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

    Science.gov (United States)

    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 perspective on our understanding of the root economics spectrum.

  19. Optimal C-arm angulation during transcatheter aortic valve replacement: Accuracy of a rotational C-arm computed tomography based three dimensional heart model.

    Science.gov (United States)

    Veulemans, Verena; Mollus, Sabine; Saalbach, Axel; Pietsch, Max; Hellhammer, Katharina; Zeus, Tobias; Westenfeld, Ralf; Weese, Jürgen; Kelm, Malte; Balzer, Jan

    2016-10-26

    To investigate the accuracy of a rotational C-arm CT-based 3D heart model to predict an optimal C-arm configuration during transcatheter aortic valve replacement (TAVR). Rotational C-arm CT (RCT) under rapid ventricular pacing was performed in 57 consecutive patients with severe aortic stenosis as part of the pre-procedural cardiac catheterization. With prototype software each RCT data set was segmented using a 3D heart model. From that the line of perpendicularity curve was obtained that generates a perpendicular view of the aortic annulus according to the right-cusp rule. To evaluate the accuracy of a model-based overlay we compared model- and expert-derived aortic root diameters. For all 57 patients in the RCT cohort diameter measurements were obtained from two independent operators and were compared to the model-based measurements. The inter-observer variability was measured to be in the range of 0°-12.96° of angular C-arm displacement for two independent operators. The model-to-operator agreement was 0°-13.82°. The model-based and expert measurements of aortic root diameters evaluated at the aortic annulus (r = 0.79, P r = 0.93, P r = 0.92, P < 0.01) correlated on a high level and the Bland-Altman analysis showed good agreement. The interobserver measurements did not show a significant bias. Automatic segmentation of the aortic root using an anatomical model can accurately predict an optimal C-arm configuration, potentially simplifying current clinical workflows before and during TAVR.

  20. Chromatic roots and hamiltonian paths

    DEFF Research Database (Denmark)

    Thomassen, Carsten

    2000-01-01

    We present a new connection between colorings and hamiltonian paths: If the chromatic polynomial of a graph has a noninteger root less than or equal to t(n) = 2/3 + 1/3 (3)root (26 + 6 root (33)) + 1/3 (3)root (26 - 6 root (33)) = 1.29559.... then the graph has no hamiltonian path. This result...

  1. ROOT User Workshop 2013

    CERN Document Server

    2013-01-01

    Since almost two decades, ROOT has established itself as the framework for HENP data processing and analysis. The LHC upgrade program and the new experiments being designed at CERN and elsewhere will pose even more formidable challenges in terms of data complexity and size. The new parallel and heterogeneous computing architectures that are either announced or already available will call for a deep rethinking of the code and the data structures to be exploited efficiently. This workshop, following from a successful series of such events, will allow you to learn in detail about the new ROOT 6 and will help shape the future evolution of ROOT.

  2. Genetic association among root morphology, root quality and root yield in ashwagandha (Withania somnifera

    Directory of Open Access Journals (Sweden)

    Kumar Ramesh R.

    2011-01-01

    Full Text Available Ashwagandha (Withania somnifera is a dryland medicinal crop and roots are used as valuable drug in traditional systems of medicine. Morphological variants (morphotypes and the parental populations were evaluated for root - morphometric, quality and yield traits to study genetic association among them. Root morphometric traits (root length, root diameter, number of secondary roots/ plant and crude fiber content exhibited strong association among them and showed significant positive genotypic correlation with yield. Starch-fiber ratio (SFR, determinant of brittle root texture showed strong negative association with root yield. The total alkaloid content had positive genotypic correlation with root yield. So genetic upgradation should aim at optimum balance between two divergent groups of traits i.e. root yield traits (root morphometric traits and crude fiber content and root textural quality traits (starch content and SFR to develop superior genotypes with better yield and quality.

  3. 利用锥形束 CT 分析上颌第一磨牙根尖片的最佳拍摄角度%Optimal Imaging Angulation for the Maxillary First Molar:A Cone Beam Computed Tomography(CBCT)Study

    Institute of Scientific and Technical Information of China (English)

    韦健; 万盼; 马威; 丁蕾

    2015-01-01

    arch to the palatal root apices of the maxillary first molar(angle 3)and the angle between the horizontal plane and the line across the top of palatine crest and the palatal root apices of the maxillary first molar(angle 4) . Results The average distance of the mesial lingual cusp of the maxillary first molars was(40.48 ± 2.05)mm.The average height of the palatine crest to the upper jaw plane was(20.28 ± 2.12)mm.The average value of angles 1 to 4 was(15.83 ± 4.95)° ,(11.75 ± 3.71)° ,(21.66 ± 6.22)° and(-2.62 ± 7.17)° ,respectively.There was no significant difference in these varia‐bles between different sex and age groups.Conclusion The appropriate horizontal angle for X‐ray tube is about 16° in taking a maxillary molar periapical radiograph.The appropriate vertical angles are between-3° and 22°.The optimal imaging angulation is theoretically 22.5°.These findings are not in accordance with the data recommended by the textbook.

  4. Root lattices and quasicrystals

    Science.gov (United States)

    Baake, M.; Joseph, D.; Kramer, P.; Schlottmann, M.

    1990-10-01

    It is shown that root lattices and their reciprocals might serve as the right pool for the construction of quasicrystalline structure models. All noncrystallographic symmetries observed so far are covered in minimal embedding with maximal symmetry.

  5. Simultaneous occurrence of compound odontoma and arrested root formation as developmental disturbances after maxillofacial trauma: a case report.

    Science.gov (United States)

    Güngörmüş, Metin; Yolcu, Umit; Aras, Mutan-Hamdi; Halicioğlu, Koray

    2010-03-01

    Traumatic injury to a primary tooth and/or a bone fracture has the potential to damage the underlying permanent tooth germ which may disturb its development. The extent of the malformation depends on the developmental stage of the permanent tooth and the intensity of the trauma. The presence of infection may be a predictive factor for these abnormalities. Open surgical procedures can also potentially cause impaction and developmental disturbances. Several developmental alterations such as discolouration, hypoplasia, crown dilaceration, root angulation or dilaceration, sequestration of permanent tooth buds and disturbance in eruption have been reported in permanent teeth after trauma. However, odontoma-like malformations and partial or complete arrest of root formation are rare complications developed after trauma. This article presents a rare case with simultaneous occurrence of an odontoma-like malformation and complete and partial arrested root formations as the results of maxillofacial trauma. Almost all pediatric fractures must be managed with closed reduction as much as possible. However, if it is necessary to perform an open reduction, careful attention must be paid during placement of the osteosynthetic plates and screws; and tooth bud development must be followed periodically.

  6. Aflatoxins in ginseng roots.

    Science.gov (United States)

    D'Ovidio, Kathleen; Trucksess, Mary; Weaver, Carol; Horn, Erin; McIntosh, Marla; Bean, George

    2006-02-01

    Ginseng roots can be infected by molds during growth, harvest and storage and result in contamination with mycotoxins. In this study, an analytical method for the determination of aflatoxins B(1), B(2), G(1) and G(2), a group of structurally similar mycotoxins, in ginseng root was developed. Test samples were extracted with methanol-water (8?+?2), diluted and passed through an immunoaffinity column packed with antibodies specific for aflatoxins. The purified extract was then derivatized with a mixture of water, trifluoroacetic acid and acetic acid. Aflatoxins were then separated and quantified by reverse phase liquid chromatography (LC) with fluorescence detection. Recoveries of total aflatoxins at 2, 4, 8 and 16 ng/g added to toxin-free 4 to 5-year old dried sliced Wisconsin ginseng were 92, 77, 91 and 83% respectively; and relative standard deviations were 3.6, 8.0, 6.9 and 2.0% respectively. A total of 11 wild simulated and 12 cultivated ginseng root samples were analysed for aflatoxins. All cultivated roots were found to be free of aflatoxin contamination. Two of the wild simulated roots contained total aflatoxins B(1), B(2), G(1) and G(2) at 15.1 and 15.2 ng/g. One moldy ginseng root purchased from a grocery store was found to be contaminated with aflatoxins at 16 ng/g.

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

    Directory of Open Access Journals (Sweden)

    M. Schwarz

    2013-03-01

    Full Text Available 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

  8. Root architecture simulation improves the inference from seedling root phenotyping towards mature root systems.

    Science.gov (United States)

    Zhao, Jiangsan; Bodner, Gernot; Rewald, Boris; Leitner, Daniel; Nagel, Kerstin A; Nakhforoosh, Alireza

    2017-02-01

    Root phenotyping provides trait information for plant breeding. A shortcoming of high-throughput root phenotyping is the limitation to seedling plants and failure to make inferences on mature root systems. We suggest root system architecture (RSA) models to predict mature root traits and overcome the inference problem. Sixteen pea genotypes were phenotyped in (i) seedling (Petri dishes) and (ii) mature (sand-filled columns) root phenotyping platforms. The RSA model RootBox was parameterized with seedling traits to simulate the fully developed root systems. Measured and modelled root length, first-order lateral number, and root distribution were compared to determine key traits for model-based prediction. No direct relationship in root traits (tap, lateral length, interbranch distance) was evident between phenotyping systems. RootBox significantly improved the inference over phenotyping platforms. Seedling plant tap and lateral root elongation rates and interbranch distance were sufficient model parameters to predict genotype ranking in total root length with an RSpearman of 0.83. Parameterization including uneven lateral spacing via a scaling function substantially improved the prediction of architectures underlying the differently sized root systems. We conclude that RSA models can solve the inference problem of seedling root phenotyping. RSA models should be included in the phenotyping pipeline to provide reliable information on mature root systems to breeding research. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  9. The "Green" Root Beer Laboratory

    Science.gov (United States)

    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…

  10. The "Green" Root Beer Laboratory

    Science.gov (United States)

    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…

  11. Impacted maxillary canines and root resorption of adjacent teeth: A retrospective observational study.

    Science.gov (United States)

    Guarnieri, R; Cavallini, C; Vernucci, R; Vichi, M; Leonardi, R; Barbato, E

    2016-11-01

    The prevalence of impacted maxillary canine is reported to be between 1% and 3%. The lack of monitoring and the delay in the treatment of the impacted canine can cause different complications such as: displacement of adjacent teeth, loss of vitality of neighbouring teeth, shortening of the dental arch, follicular cysts, canine ankylosis, recurrent infections, recurrent pain, internal resorption of the canine and the adjacent teeth, external resorption of the canine and the adjacent teeth, combination of these factors. An appropriate diagnosis, accurate predictive analysis and early intervention are likely to prevent such undesirable effects. The objective is to evaluate, by means of a retrospective observational study, the possibility of carrying out a predictive analysis of root resorption adjacent to the impacted canines by means of orthopantomographs, so as to limit the prescription of additional 3D radiography. 120 subjects with unilateral or bilateral maxillary impacted canine were examined and 50 patients with 69 impacted maxillary canine (22 male, 28 female; mean age: 11.7 years) satisfied the inclusion criteria of the study. These patients were subjected to a basic clinical and radiographic investigation (orthopantomographs and computerized tomography). All panoramic films were viewed under standardized conditions for the evaluation of two main variables: maxillary canine angulations (a, b, g angles) and the overlapping between the impacted teeth and the lateral incisor (Analysis of Lindauer). Binary logistic regression was used to estimate the likelihood of resorbed lateral incisors depending on sector location and angle measurements. Results indicated that b angle has the greatest influence on the prediction of root resorption (predictive value of b angle = 76%). If β angle <18° and Lindauer = I, the probability of resorption is 0.06. Evaluation of b angle and superimposition lateral incisor/impacted canine analysed on orthopantomographs could be one of

  12. The Roots Of Alienation

    Science.gov (United States)

    Bronfenbrenner, Urie

    1973-01-01

    Alienation in our society takes several forms--withdrawal, hostility, or efforts to reform. The author traces the roots of alienation to our neglect of many of the needs of children, particularly their need for interaction with adults. Among his many recommendations are: modified work schedules to permit more time with children and systems for…

  13. Multiple external root resorption.

    Science.gov (United States)

    Yusof, W Z; Ghazali, M N

    1989-04-01

    Presented is an unusual case of multiple external root resorption. Although the cause of this resorption was not determined, several possibilities are presented. Trauma from occlusion, periodontal and pulpal inflammation, and resorption of idiopathic origin are all discussed as possible causes.

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

    OpenAIRE

    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 exo...

  15. Variation in root wood anatomy

    NARCIS (Netherlands)

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  16. Variation in root wood anatomy

    NARCIS (Netherlands)

    Cutler, D.F.

    1976-01-01

    Variability in the anatomy of root wood of selected specimens particularly Fraxinus excelsior L. and Acer pseudoplatanus L. in the Kew reference microscope slide collection is discussed in relation to generalised statements in the literature on root wood anatomy.

  17. Function of root apical meristem

    OpenAIRE

    Benešová, Šárka

    2013-01-01

    A root apical meristem is the only source of cells for all tissues in the root. The root growth relies on its function. Regulation of a cell division frequency and cell differentiation affects organization and function of the differentiated tissues and the proper meristem function. If the cell differentiation overbalances the cell proliferation, the meristem exhaustion occurs and the root growth irreversibly terminates. This thesis describes existing knowledge about regulation of the primary ...

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

    Science.gov (United States)

    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

  19. Adventitious root formation in Arabidopsis

    NARCIS (Netherlands)

    Massoumi, Mehdi

    2016-01-01

    Adventitious root (AR) formation is indispensable in vegetative propagation and is widely used. A better understanding of the underlying mechanisms is needed to improve rooting treatments. We first established a system to study rooting in Arabidopsis, the model organism in plant biology but only occ

  20. Negative phototropism of rice root

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@It is often believed that the stem of higher plants has characteristics of positive phototropism, and the root shows no phototropism or no sensitivity to light though the root of Arabdopsis was reported possessing characteristics of negative phototropism. In this study, a distinct negative phototropism of the root system of rice seedlings was observed.

  1. Metagenomics at Grass Roots

    Indian Academy of Sciences (India)

    Sudeshna Mazumdar-Leighton; Vivek K Choudhary

    2017-03-01

    Metagenomics is a robust, interdisciplinary approach for studyingmicrobial community composition, function, and dynamics.It typically involves a core of molecular biology, microbiology,ecology, statistics, and computational biology. Excitingoutcomes anticipated from these studies include unravelingof complex interactions that characterize the ecologicalmilieu of microbial communities. Diverse habitats fromwhich metagenomes have been reported include human guts,caterpillar guts, thermal vents in oceans, ore deposits, polarcaps, and even soils that adhere to plant roots. Knowledgegenerated from metagenomic projects has tremendous potentialto benefit human health, agriculture, and ecosystemfunctions. This article provides a brief history of technicaladvances in metagenomics, including DNA sequencing methods,and some case studies. A specific example is providedof microbial metagenomes found at the roots of native grassspecies (family Poaceae) that can grow on degraded lands undergoingrevegetation.

  2. Rooting an Android Device

    Science.gov (United States)

    2015-09-01

    tools that grant root privileges for both Windows and Linux . For the Linux system, open a shell window and use “cd” command to change the directory...defined as a process of gaining administrative commands and functions of an operating system (OS). In order to monitor live network traffic on any... Linux -based or, in this case, Android system, it is necessary to have administrative rights to gain access to any of the hardware devices, such as the

  3. Back to the roots!

    DEFF Research Database (Denmark)

    Woermann, Niklas

    2017-01-01

    This article argues that one can revive the critical edge that postmodernist theory has brought to marketing, thinking without subscribing to any particular school of (critical) theory by following the principle of methodological situationalism. The roots of postmodernist critique lie in careful...... of social order into account, hence fail to provide sensible insight. I propose the principle of methodological situationalism as a litmus test to the analytical strength of a theory or piece of research. The principle states that theoretically adequate accounts of social phenomena must be grounded...

  4. The Roots of Beowulf

    Science.gov (United States)

    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.

  5. Matching roots to their environment.

    Science.gov (United States)

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

    2013-07-01

    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. 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.

  6. 影响口腔正畸治疗患者下颌第三磨牙状态改变的因素分析%Factors influencing the changes of lower third molars' angulation and space/crown width ratio by orthodontic treatment

    Institute of Scientific and Technical Information of China (English)

    李小彤; 张东姝; 杨雁琪

    2011-01-01

    Objective : To investigate the factors which influence the changes of lower third molars ' angulation and space/crown width ratio by orthodontic treatment. Methods : Pretreatment and posttreatment panoramic radiographs of 120 orthodontically treated cases were taken. The lower third molars ' angulation and space/crown width ratio were examined and the relative factors on changes were analyzed. Results : ( 1 ) The changes of the lower third molars' angulation and space/crown width ratio after orthodontic treatment were quite different among the cases. ( 2) The factors which influenced these changes mainly included extraction, mandibular plane angle, angulation and space/crown width ratio of lower third molar before orthodontic treatment. (3) Extraction was the most significantly variable associated with lower third molars' upright ( angulation < 30°) after orthodontic treatment. Conclusion: Orthodontic extraction is helpful to upright the lower third molars and to increase the space for third molars; and the pre-treatment lower third molars ' angulation and space/crown width ratio are important variables for the changes after treatment; cases with lower mandibular plane angle are apt to greater possibility for the lower third molars' upright.%目的:研究影响口腔正畸患者治疗前、后下颌第三磨牙状态改变的因素.方法:利用正畸治疗前、后的全口曲面断层片,测量120例正畸患者的120颗下颌第三磨牙[男37例,女83例,年龄在10~24岁,平均(14.1±3.3)岁]前倾角度和间隙/宽度比值的改变,统计分析影响正畸治疗前、后改变的因素.结果:(1)正畸治疗前、后下颌第三磨牙前倾角度和间隙/宽度比值的改变个体差别较大;(2)影响正畸治疗前、后下颌第三磨牙前倾角度和间隙/宽度比值改变的因素主要有拔牙、下颌平面角、治疗前的前倾角度和间隙/宽度比值(P<0.05),而骨龄和牙龄等因素对下颌第三磨牙状态的

  7. RootNav: navigating images of complex root architectures.

    Science.gov (United States)

    Pound, Michael P; French, Andrew P; Atkinson, Jonathan A; Wells, Darren M; Bennett, Malcolm J; Pridmore, Tony

    2013-08-01

    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.

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

    Science.gov (United States)

    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

  9. Perennial roots to immortality.

    Science.gov (United States)

    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. © 2014 American Society of Plant Biologists. All Rights Reserved.

  10. [Flexible root posts].

    Science.gov (United States)

    Vadachkoriia, N R; Mandzhavidze, N A; Gumberidze, N Sh

    2009-02-01

    The article discusses the current state of restoration techniques of root canal treatment. Nowadays, technical progress allows manufacturers to develop flexible fiberglass posts, aspiring not only to an excellent aesthetics and mechanical properties (first of all, in comparison with metal and cast posts), but also to maintenance of their radio density and a wide range of forms. Growth of fiberglass posts popularity testifies to their clinical efficiency that also is confirmed by results of long-term researches. Introduction of fiberglass posts in a dental practice has rendered huge influence on restoration techniques of root canal treatment. Convincing factors of fiberglass posts superiority provide restoration the appearance similar with the natural dentition; possess close to dentine elasticity; creation of monolithic structure with hard tooth tissues and composite cement, posts, in case of need, can be easily adjusted on length, adhesive linkage of posts gives them additional stability. Modern researches have confirmed that only elastic, namely carbon fiber and the fiberglass posts made of modern technologies possess similar physical properties, as tooth structure. They can create reliable biomimetic design; solve a complex of aesthetic and functional restoration problems.

  11. Multivariate ultrametric root counting

    CERN Document Server

    Avendano, Martin

    2011-01-01

    Let $K$ be a field, complete with respect to a discrete non-archimedian valuation and let $k$ be the residue field. Consider a system $F$ of $n$ polynomial equations in $K\\vars$. Our first result is a reformulation of the classical Hensel's Lemma in the language of tropical geometry: we show sufficient conditions (semiregularity at $w$) that guarantee that the first digit map $\\delta:(K^\\ast)^n\\to(k^\\ast)^n$ is a one to one correspondence between the solutions of $F$ in $(K^\\ast)^n$ with valuation $w$ and the solutions in $(k^\\ast)^n$ of the initial form system ${\\rm in}_w(F)$. Using this result, we provide an explicit formula for the number of solutions in $(K^\\ast)^n$ of a certain class of systems of polynomial equations (called regular), characterized by having finite tropical prevariety, by having initial forms consisting only of binomials, and by being semiregular at any point in the tropical prevariety. Finally, as a consequence of the root counting formula, we obtain the expected number of roots in $(K...

  12. ROOT Tutorial for Summer Students

    CERN Document Server

    CERN. Geneva; Piparo, Danilo

    2015-01-01

    ROOT is a "batteries-included" tool kit for data analysis, storage and visualization. It is widely used in High Energy Physics and other disciplines such as Biology, Finance and Astrophysics. This event is an introductory tutorial to ROOT and comprises a front lecture and hands on exercises. IMPORTANT NOTE: The tutorial is based on ROOT 6.04 and NOT on the ROOT5 series.  IMPORTANT NOTE: if you have ROOT 6.04 installed on your laptop, you will not need to install any virtual machine. The instructions showing how to install the virtual machine on which you can find ROOT 6.04 can be found under "Material" on this page.

  13. Auxin control of root development.

    Science.gov (United States)

    Overvoorde, Paul; Fukaki, Hidehiro; Beeckman, Tom

    2010-06-01

    A plant's roots system determines both the capacity of a sessile organism to acquire nutrients and water, as well as providing a means to monitor the soil for a range of environmental conditions. Since auxins were first described, there has been a tight connection between this class of hormones and root development. Here we review some of the latest genetic, molecular, and cellular experiments that demonstrate the importance of generating and maintaining auxin gradients during root development. Refinements in the ability to monitor and measure auxin levels in root cells coupled with advances in our understanding of the sources of auxin that contribute to these pools represent important contributions to our understanding of how this class of hormones participates in the control of root development. In addition, we review the role of identified molecular components that convert auxin gradients into local differentiation events, which ultimately defines the root architecture.

  14. Removal of root filling materials.

    LENUS (Irish Health Repository)

    Duncan, H.F. Chong, B.S.

    2011-05-01

    Safe, successful and effective removal of root filling materials is an integral component of non-surgical root canal re-treatment. Access to the root canal system must be achieved in order to negotiate to the canal terminus so that deficiencies in the original treatment can be rectified. Since a range of materials have been advocated for filling root canals, different techniques are required for their removal. The management of commonly encountered root filling materials during non-surgical re-treatment, including the clinical procedures necessary for removal and the associated risks, are reviewed. As gutta-percha is the most widely used and accepted root filling material, there is a greater emphasis on its removal in this review.

  15. Properties of Estimated Characteristic Roots

    DEFF Research Database (Denmark)

    Nielsen, Bent; Nielsen, Heino Bohn

    Estimated characteristic roots in stationary autoregressions are shown to give rather noisy information about their population equivalents. This is remarkable given the central role of the characteristic roots in the theory of autoregressive processes. In the asymptotic analysis the problems appear...... when multiple roots are present as this imply a non-differentiability so the d-method does not apply, convergence rates are slow, and the asymptotic distribution is non-normal. In finite samples this has a considerable influence on the finite sample distribution unless the roots are far apart....... With increasing order of the autoregressions it becomes increasingly difficult to place the roots far apart giving a very noisy signal from the characteristic roots....

  16. Comparing Leaf and Root Insertion

    Directory of Open Access Journals (Sweden)

    Jaco Geldenhuys

    2010-07-01

    Full Text Available We consider two ways of inserting a key into a binary search tree: leaf insertion which is the standard method, and root insertion which involves additional rotations. Although the respective cost of constructing leaf and root insertion binary search trees trees, in terms of comparisons, are the same in the average case, we show that in the worst case the construction of a root insertion binary search tree needs approximately 50% of the number of comparisons required by leaf insertion.

  17. Roots of the Chromatic Polynomial

    DEFF Research Database (Denmark)

    Perrett, Thomas

    a tight lower bound on the smallest non-trivial chromatic root of a graph admitting a spanning tree with at most three leaves. Here, non-trivial means different from 0 or 1. This extends a theorem of Thomassen on graphs with Hamiltonian paths. We also prove similar lower bounds on the chromatic roots...... of several graph families. In particular, we show that the chromatic roots of planar graphs are dense in the interval (3; 4), except for a small interval around _ + 2 _ 3:618, where _ denotes the golden ratio. We also investigate the chromatic roots of related minor-closed classes of graphs and bipartite...

  18. The roots of human destructiveness

    National Research Council Canada - National Science Library

    Sabby Sagall

    2014-01-01

    .... I emphasise the contributions of the Frankfurt School, particularly Erich Fromm, and Wilhelm Reich, to our understanding of individual and class consciousness, and of the roots of destructiveness...

  19. Root Scaling Study ; Description of the DNS Root Scaling Model

    NARCIS (Netherlands)

    Gijsen, B.; Jamakovic, A.; Roijers, F.

    2009-01-01

    In opdracht van de Internet Corporation for Assigned Names and Numbers (ICANN), de organisatie verantwoordelijk voor het beheren van de Root zone, heeft TNO onderzoek gedaan naar de schaalbaarheid van de Root zone. Welke impact kunnen de invoering van secure DNS (DNSSEC) en IPv6 en de uitbreiding

  20. Searching for Roots / Pierre Gervasoni

    Index Scriptorium Estoniae

    Gervasoni, Pierre

    1997-01-01

    Uuest heliplaadist "Searching for Roots. Eduard Tubin: Symphonie no 11; Arvo Pärt: Nekrolog-Symphonie no 1; Erkki-Sven Tüür: Searching for Roots - Insula deserta - Zeitraum; Orchestre philharmonique royal de Stockholm, Paavo Järvi (direction)" Virgin Classics 5 45212 2 (distribue par EMI)

  1. Properties of Estimated Characteristic Roots

    DEFF Research Database (Denmark)

    Nielsen, Bent; Nielsen, Heino Bohn

    Estimated characteristic roots in stationary autoregressions are shown to give rather noisy information about their population equivalents. This is remarkable given the central role of the characteristic roots in the theory of autoregressive processes. In the asymptotic analysis the problems appear...

  2. Determinants and Polynomial Root Structure

    Science.gov (United States)

    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…

  3. Project Work on Plant Roots.

    Science.gov (United States)

    Devonald, V. G.

    1986-01-01

    Methods of investigating plant root growth developed for research purposes can be adopted for student use. Investigations of the effect of water table level and of ethylene concentration are described, and techniques of measuring root growth are explained. (Author/ML)

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

    Science.gov (United States)

    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.

  5. Medico-legal aspects of vertical root fractures in root filled teeth

    DEFF Research Database (Denmark)

    Rosen, E; Tsesis, I; Tamse, A

    2012-01-01

    To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT).......To analyse the medico-legal aspects of vertical root fracture (VRF) following root canal treatment (RCT)....

  6. Rooted in Movement

    DEFF Research Database (Denmark)

    The result of the synergy between four doctoral projects and an advanced MA-level course on Bronze Age Europe, this integrated assemblage of articles represents a variety of different subjects united by a single theme: movement. Ranging from theoretical discussion of the various responses to and ...... period of European prehistory. In so doing, the text not only addresses transmission and reception, but also the conceptualization of mobility within a world which was literally Rooted in Movement.......The result of the synergy between four doctoral projects and an advanced MA-level course on Bronze Age Europe, this integrated assemblage of articles represents a variety of different subjects united by a single theme: movement. Ranging from theoretical discussion of the various responses...... to and reactions from the circulation of people, objects and ideas to the transmission of the spiral and the ‚trade’ in crafting expertise, this volume takes a fresh look at old questions. Each article within this monograph represents a different approach to mobility framed within a highly mobile and dynamic...

  7. Conventional versus storage phosphor-plate digital images to visualize the root canal system contrasted with a radiopaque medium.

    Science.gov (United States)

    Naoum, Hani J; Chandler, Nicholas P; Love, Robert M

    2003-05-01

    The pulp tissue was removed from 20 mandibular first molar teeth using 2.5% NaOCl irrigation and hand files. The dried canals were infused with radiopaque contrast medium. Standardized conventional and Digora digital images were obtained of each tooth positioned in a dried mandible at 0- and 30-degree horizontal angulations. Three evaluators rated the image clarity of the 0- and 30-degree original, enhanced, three-dimensional, zoom, and reverse digital image modes as superior, equal, or inferior to corresponding 0- and 30-degree conventional radiographs. The ratings were compared using the Wilcoxon signed rank test. The original, three-dimensional, zoom, or reverse digital images were inferior to the conventional radiographs for clarity of canal anatomy. The enhanced digital images were not always inferior to the conventional radiographs and were the only images superior to the original digital images. Overall, evaluators rated the image clarity of root canal anatomy on conventional radiographs better than on Digora images. However, factors in the experimental design may have contributed to this result.

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

    Science.gov (United States)

    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. Non-canonical WOX11-mediated root branching contributes to plasticity in arabidopsis root system architecture

    NARCIS (Netherlands)

    Sheng, Lihong; Hu, Xiaomei; Du, Yujuan; Zhang, Guifang; Huang, Hai; Scheres, Ben; Xu, Lin

    2017-01-01

    Lateral roots (LRs), which originate from the growing root, and adventitious roots (ARs), which are formed from non-root organs, are the main contributors to the post-embryonic root system in Arabidopsis. However, our knowledge of how formation of the root system is altered in response to diverse

  10. 下颌切牙根管解剖显微CT研究%Study of root canal morphology of mandibular incisors by micro-computed tomography in vitro

    Institute of Scientific and Technical Information of China (English)

    朱艳玲; 杨健

    2014-01-01

    Objective:To investigate the anatomy of mandibular incisors using microcomputed tomography(Micro-CT).Methods:62 extracted mandibular incisors were selected from dental clinic and observed by Micro-CT.The anatomy of the teeth was analyzed. Results:83.9% of mandibular incisors had a single canal,72.6% had no accessory canal.The location of the apical foramen varied considerably.The mean distance from the root apex to the major lateral apical foramen was (0.613 ±0.298)mm.Of the canals the bucco-lingual diameter were greater than the mesio-distal diameters and the root bucco-lingual canal tapers were greater than the me-sio-distal.Conclusion:The morphology data of mandibular incisors were obtained using Micro-CT.%目的:采用高分辨率的显微CT观察离体下颌切牙根管解剖结构。方法:收集62颗离体下颌切牙,使用显微CT扫描及三维重建获取每颗牙的解剖数据。结果:83.9%下颌切牙为单根管,72.6%无侧副根管,根尖孔位于旁侧者占56.5%,侧方根尖孔至解剖根尖的距离为(0.613±0.298)mm,下颌切牙根管颊舌向直径及锥度大于近远中向。结论:利用显微CT获得了下颌切牙根管复杂解剖结构的解剖数据。

  11. Review on Mutation in Lateral Root of Rice

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xia; ZHANG Da; HAO Zaibin

    2011-01-01

    Rice roots include seminal roots, adventitious roots, lateral roots and root hairs, At present, progresses in the research of rice roots have been achieved in many aspects, such as root morphology, root activity, root reaction to various environmental factors as a contribution of root growth and rice yield, the relationship between root growth and stems/leaves/flowers/rice, genetic laws of root characters, etc. However, there are very few researches on lateral root mutant. This paper reviewed progresses of the lateral root mutant of rice from the perspectives of phytomorphology to plant physiology and biochemistry to the gene mapping, consisting of mechanism of developing lateral root of rice, gene cloning and functional analysis of lateral root development, the relationship between auxin and lateral roots, agronomic traits of lateral roots mutant, structure and morphology of root hairs, gravity anomaly of root, redox metabolism and proteomics researches of the mutation in lateral root of rice.

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

    Science.gov (United States)

    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.

  13. Avaliação da efetividade do método de Tanaka-Johnston para predição do diâmetro mésio-distal de caninos e pré-molares não-irrompidos Evaluation of the effectiveness of the Tanaka-Johnston method for prediction of the mesiodistal diameter of unerupted canines and premolars

    Directory of Open Access Journals (Sweden)

    Viviane Maria Teixeira MARCHIONNI

    2001-03-01

    Full Text Available No presente estudo, os autores avaliaram o método de predição de Tanaka-Johnston com o objetivo de verificar sua efetividade para os lados direito e esquerdo, para ambos os sexos e para as raças branca, mulato claro, mulato médio, mulato escuro e negra, na cidade de Salvador - Bahia. Com o auxílio de um paquímetro digital, mediu-se o diâmetro mésio-distal dos incisivos inferiores permanentes, caninos e pré-molares, já irrompidos na cavidade bucal, de 98 indivíduos (45 do sexo masculino e 53 do sexo feminino, com idade variando entre 13 e 29 anos. Através de testes estatísticos, compararam-se os resultados obtidos a partir da aplicação das fórmulas de Tanaka-Johnston com os valores reais. Após análise dos resultados, observou-se que a correlação entre os valores estimados pela técnica de Tanaka-Johnston e os valores reais foram maiores para o sexo feminino que para o sexo masculino. Em relação à raça, os coeficientes de correlação foram satisfatórios para todas, sendo maior no arco dentário superior para a raça mulato escuro (0,67 e no arco dentário inferior para a raça mulato claro (0,74. Considerando-se os lados, os achados revelaram um maior coeficiente de correlação para o arco dentário inferior do lado esquerdo (0,61. Pôde-se concluir, neste trabalho, que o método de Tanaka-Johnston, apesar de ter sido preconizado a partir de uma amostra de descendentes europeus, é indicado para predição do diâmetro mésio-distal de caninos e pré-molares não-irrompidos para diferentes raças, sexos e lados dos arcos dentários na amostra estudada.In the present study, the authors evaluated the Tanaka-Johnston method of prediction, with the objective of verifying its effectiveness for the right and left sides, for both genders and for the white, light mulatto, medium mulatto, dark mulatto and black races in the city of Salvador, Bahia. The mesiodistal diameter of the inferior permanent incisors, canines and

  14. How Can Science Education Foster Students' Rooting?

    Science.gov (United States)

    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…

  15. MES buffer affects Arabidopsis root apex zonation and root growth by suppressing superoxide generation in root apex

    Directory of Open Access Journals (Sweden)

    Tomoko eKagenishi

    2016-02-01

    Full Text Available In plants, growth of roots and root hairs is regulated by the fine cellular control of pH and reactive oxygen species. MES, 2-(N-morpholinoethanesulfonic 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 reactive oxygen species (ROS homeostasis in root apex.

  16. Advances in experimental methods for root system architecture and root development

    Institute of Scientific and Technical Information of China (English)

    Jun-bang Wang; Xiu-juan Zhang; Chu Wu

    2015-01-01

    Plant roots play important roles in acquisition of water and nutrients, storage, anchoring, transport, and symbiosis with soil microorganisms, thus quantitative researches on root developmental processes are essential to understand root functions and root turnover in ecosystems, and at the same time such researches are the most difficult because roots are hidden underground. Therefore, how to investigate efficiently root functions and root dynamics is the core aspect in underground ecology. In this article, we reviewed some experimental methods used in root resear-ches on root development and root system architecture, and summarized the advantages and shortages of these meth-ods. Based on the analyses, we proposed three new ways to more understand root processes: (1) new experimental materials for root development; (2) a new observatory system comprised of multiple components, including many observatory windows installed in field, analysis software, and automatic data transport devices; (3) new techniques used to analyze quantitatively functional roots.

  17. Magnetophoretic Induction of Root Curvature

    Science.gov (United States)

    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.

  18. Assessment of surface friction of self-ligating brackets under conditions of angulated traction Avaliação da fricção superficial apresentada por braquetes autoligáveis em condições de tracionamento sob angulação

    Directory of Open Access Journals (Sweden)

    Roberta Buzzoni

    2012-08-01

    Full Text Available OBJECTIVE: The aim of this study was to assess resistance to sliding of stainless steel passive self-ligating brackets with 0° and 2.5° angulations and to compare them to active self-ligating brackets at zero angulation. The hypothesis to be tested was that passive self-ligating brackets produce lower frictional forces than active self-ligating brackets. METHODS: Twenty five 0.022 x 0.028-in slot maxillary canine brackets were divided into 5 groups of 5 brackets: Damon SL II (Ormco, CA, USA self-ligating bracket and Gemini (3M/Unitek, CA, USA conventional bracket with angulation of 0 and 2.5° and a group of Speed 2 (American Orthodontics, WI, USA active clip self-ligating system with zero angulation. Twenty five segments of stainless steel 0.020-in archwire (TP Orthodontics, IN, USA were tested and each bracket/wire interface was evaluated at 4 successive points during sliding. Overall, 100 frictional values were analyzed by parametric analysis of variance and Bonferroni tests. RESULTS AND CONCLUSION: Frictional tests were performed with an Emic DL 10000 testing machine (Emic, Brazil with a load cell of one kilogram. Passive self-ligating brackets produced lower frictional forces than active self-ligating brackets (p OBJETIVO: avaliar a fricção apresentada por braquetes autoligáveis de aço inoxidável com sistema passivo de tampa deslizante sob angulação de 0 grau e 2,5 graus, e comparar o comportamento desse grupo sob angulação nula com o de um grupo de braquetes autoligáveis com sistema ativo de tampa resiliente. MÉTODOS: foram utilizados 25 braquetes de caninos superiores, divididos em 5 grupos - braquetes autoligáveis passivos Damon SL II sob angulação de 0 grau e de 2,5 graus; braquetes convencionais Gemini amarrados com ligaduras elásticas sob as mesmas angulações; e um grupo formado pelo sistema ativo Time 2, sob angulação nula. A hipótese a ser testada é se artefatos autoligáveis com sistema de tampa passiva s

  19. Capturing Arabidopsis Root Architecture Dynamics with root-fit Reveals Diversity in Responses to Salinity

    NARCIS (Netherlands)

    Julkowska, M.M.; Hoefsloot, H.C.J.; Mol, S.; Feron, R.; de Boer, G.J.; Haring, M.A.; Testerink, C.

    2014-01-01

    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 i

  20. Retention of Root Canal Posts

    DEFF Research Database (Denmark)

    Sahafi, A; Benetti, Ana Raquel; Flury, S;

    2015-01-01

    The aim of this study was to investigate the effect of the cement film thickness of a zinc phosphate or a resin cement on retention of untreated and pretreated root canal posts. Prefabricated zirconia posts (CosmoPost: 1.4 mm) and two types of luting cements (a zinc phosphate cement [DeTrey Zinc......] and a self-etch adhesive resin cement [Panavia F2.0]) were used. After removal of the crowns of 360 extracted premolars, canines, or incisors, the root canals were prepared with a parallel-sided drill system to three different final diameters. Half the posts did not receive any pretreatment. The other half...... received tribochemical silicate coating according to the manufacturer's instructions. Posts were then luted in the prepared root canals (n=30 per group). Following water storage at 37°C for seven days, retention of the posts was determined by the pull-out method. Irrespective of the luting cement...

  1. Adventitious Roots and Secondary Metabolism

    Institute of Scientific and Technical Information of China (English)

    Hosakatte Niranjana Murthy; Eun Joo Hahn; Kee Yoeup Paek

    2008-01-01

    Plants are a rich source of valuable secondary metabolites and in the recent years plant cell, tissue and organ cultures have been developed as an important alternative sources for the production of these compounds. Adventitious roots have been successfully induced in many plant species and cultured for the production of high value secondary metabolites of pharmaceutical, nutraceutical and industrial importance. Adoption of elicitation methods have shown improved synthesis of secondary metabolites in adventitious root cultures. Development of large-scale culture methods using bioreactors has opened up feasibilities of production of secondary metabolites at the industrial levels. In the present review we summarize the progress made in recent past in the area of adventitious root cultures for the production of secondary metabolites.

  2. Grass Roots War on Poverty

    OpenAIRE

    Amsden, Alice H

    2012-01-01

    Sub-Saharan Africa’s failure to slay the dragon of poverty is due to a logical flaw in its policies: the remedies to reduce poverty don’t address the causes. Poverty is caused by unemployment, owing to a scarcity of jobs that pay above bare subsistence, but grass-roots poverty alleviation measures are exclusively designed to make job-seekers more capable although no jobs are available. The ‘appropriate’ technologies of the grass roots movement that dominates anti-poverty policies are ...

  3. Root justifications for ontology repair

    CSIR Research Space (South Africa)

    Moodley, K

    2011-08-01

    Full Text Available stream_source_info Moodley_2011.pdf.txt stream_content_type text/plain stream_size 32328 Content-Encoding ISO-8859-1 stream_name Moodley_2011.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Root Justi cations... the ontology, based on the no- tion of root justi cations [8, 9]. In Section 5, we discuss the implementation of a Prot eg e3 plugin which demonstrates our approach to ontology repair. In this section we also discuss some experimental results comparing...

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

    Science.gov (United States)

    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.

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

    Directory of Open Access Journals (Sweden)

    Parul Bansal

    2016-01-01

    Full Text Available 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.

  6. [Effects nutrients on the seedlings root hair development and root growth of Poncirus trifoliata under hydroponics condition].

    Science.gov (United States)

    Cao, Xiu; Xia, Ren-Xue; Zhang, De-Jian; Shu, Bo

    2013-06-01

    Ahydroponics experiment was conducted to study the effects of nutrients (N, P, K, Ca, Mg, Fe, and Mn) deficiency on the length of primary root, the number of lateral roots, and the root hair density, length, and diameter on the primary root and lateral roots of Poncirus trifoliata seedlings. Under the deficiency of each test nutrient, root hair could generate, but was mainly concentrated on the root base and fewer on the root tip. The root hair density on lateral roots was significantly larger than that on primary root, but the root hair length was in adverse. The deficiency of each test nutrient had greater effects on the growth and development of root hairs, with the root hair density on primary root varied from 55.0 to 174.3 mm(-2). As compared with the control, Ca deficiency induced the significant increase of root hair density and length on primary root, P deficiency promoted the root hair density and length on the base and middle part of primary root and on the lateral roots significantly, Fe deficiency increased the root hair density but decreased the root hair length on the tip of primary root significantly, K deficiency significantly decreased the root hair density, length, and diameter on primary root and lateral roots, whereas Mg deficiency increased the root hair length of primary root significantly. In all treatments of nutrient deficiency, the primary root had the similar growth rate, but, with the exceptions of N and Mg deficiency, the lateral roots exhibited shedding and regeneration.

  7. Disease notes - Bacterial root rot

    Science.gov (United States)

    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...

  8. [Lumbosciatica and nerve root anomalies].

    Science.gov (United States)

    Sacchi, A; Rouaud, J P; Caroit, M; George, B; Cophignon, J

    1982-04-01

    The authors report 3 cases of lumbar pain and sciatica where operation revealed the existence of abnormalities in the distribution of L5 and S1 roots. In one case, the L5 root was not recognised within fibrous tissue also surrounding S1 and S2 and histological examination of this "fibrosis" led to the identification of nerve structures. Development of postoperative L5 paralysis showed that the L5 root was contained within the tissue non-individualised, consisting of multiple rootlets. In the other two cases the L5 and S1 roots arose from a common trunk. There was an associated herniated disc in all three cases. A review of the literature revealed the rarity of such abnormalities, as well as the fact that they were not recognised before surgery. They are difficult to recognise, even at the time of operation. The prognosis is less good than in typical lumbar pain and sciatica, essentially because of surgical difficulties of the disc curettage.

  9. Cutting the Roots of Violence.

    Science.gov (United States)

    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…

  10. The Roots of School Leadership.

    Science.gov (United States)

    Sergiovanni, Thomas J.

    1994-01-01

    The Pyramid, Railroad, and High Performance theories of leadership are inappropriate for school settings. At root, school leadership is about connecting people morally to each other and to their work. The work of leadership involves developing shared purposes, beliefs, values, and conceptions associated with teaching and learning,…

  11. Rapid shoot‐to‐root signalling regulates root hydraulic conductance via aquaporins

    National Research Council Canada - National Science Library

    VANDELEUR, REBECCA K; SULLIVAN, WENDY; ATHMAN, ASMINI; JORDANS, CHARLOTTE; GILLIHAM, MATTHEW; KAISER, BRENT N; TYERMAN, STEPHEN D

    2014-01-01

    Investigating the relationship between transpiration and root hydraulic conductance Vandeleur et al report that leaf area reduction reduces root hydraulic conductance in grapevine, soybean and maize...

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

    Science.gov (United States)

    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.

  13. Root formation in ethylene-insensitive plants.

    Science.gov (United States)

    Clark, D G; Gubrium, E K; Barrett, J E; Nell, T A; Klee, H J

    1999-09-01

    Experiments with ethylene-insensitive tomato (Lycopersicon esculentum) and petunia (Petunia x hybrida) plants were conducted to determine if normal or adventitious root formation is affected by ethylene insensitivity. Ethylene-insensitive Never ripe (NR) tomato plants produced more below-ground root mass but fewer above-ground adventitious roots than wild-type Pearson plants. Applied auxin (indole-3-butyric acid) increased adventitious root formation on vegetative stem cuttings of wild-type plants but had little or no effect on rooting of NR plants. Reduced adventitious root formation was also observed in ethylene-insensitive transgenic petunia plants. Applied 1-aminocyclopropane-1-carboxylic acid increased adventitious root formation on vegetative stem cuttings from NR and wild-type plants, but NR cuttings produced fewer adventitious roots than wild-type cuttings. These data suggest that the promotive effect of auxin on adventitious rooting is influenced by ethylene responsiveness. Seedling root growth of tomato in response to mechanical impedance was also influenced by ethylene sensitivity. Ninety-six percent of wild-type seedlings germinated and grown on sand for 7 d grew normal roots into the medium, whereas 47% of NR seedlings displayed elongated tap-roots, shortened hypocotyls, and did not penetrate the medium. These data indicate that ethylene has a critical role in various responses of roots to environmental stimuli.

  14. Dynamics of heterorhizic root systems: protoxylem groups within the fine-root system of Chamaecyparis obtusa.

    Science.gov (United States)

    Hishi, Takuo; Takeda, Hiroshi

    2005-08-01

    To understand the physiology of fine-root functions in relation to soil organic sources, the heterogeneity of individual root functions within a fine-root system requires investigation. Here the heterogeneous dynamics within fine-root systems are reported. The fine roots of Chamaecyparis obtusa were sampled using a sequential ingrowth core method over 2 yr. After color categorization, roots were classified into protoxylem groups from anatomical observations. The root lengths with diarch and triarch groups fluctuated seasonally, whereas the tetrarch root length increased. The percentage of secondary root mortality to total mortality increased with increasing amounts of protoxylem. The carbon : nitrogen ratio indicated that the decomposability of primary roots might be greater than that of secondary roots. The position of diarch roots was mostly apical, whereas tetrarch roots tended to be distributed in basal positions within the root architecture. We demonstrate the heterogeneous dynamics within a fine-root system of C. obtusa. Fine-root heterogeneity should affect soil C dynamics. This heterogeneity is determined by the branching position within the root architecture.

  15. Environmental Control of Root System Biology.

    Science.gov (United States)

    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.

  16. Meromorphic iterative roots of linear fractional functions

    Institute of Scientific and Technical Information of China (English)

    SHI YongGuo; CHEN Li

    2009-01-01

    Iterative root problem can be regarded as a weak version of the problem of embedding a homeomorphism into a flow. There are many results on iterative roots of monotone functions. However, this problem gets more difficult in non-monotone cases. Therefore, it is interesting to find iterative roots of linear fractional functions (abbreviated as LFFs), a class of non-monotone functions on R. In this paper, iterative roots of LFFs are studied on C. An equivalence between the iterative functional equation for non-constant LFFs and the matrix equation is given. By means of a method of finding matrix roots, general formulae of all meromorphic iterative roots of LFFs are obtained and the precise number of roots is also determined in various cases. As applications, we present all meromorphic iterative roots for functions z and 1/z.

  17. Single-rooted primary first mandibular molar

    OpenAIRE

    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 ro...

  18. Counting Rooted Nearly 2-regular Planar Maps

    Institute of Scientific and Technical Information of China (English)

    郝荣霞; 蔡俊亮

    2004-01-01

    The number of rooted nearly 2-regular maps with the valency of rootvertex, the number of non-rooted vertices and the valency of root-face as three parameters is obtained. Furthermore, the explicit expressions of the special cases including loopless nearly 2-regular maps and simple nearly 2-regular maps in terms of the above three parameters are derived.

  19. Rooting of microcuttings: Theory and practice

    NARCIS (Netherlands)

    Klerk, de G.J.M.

    2002-01-01

    Poor adventitious root formation is a major obstacle in micropropagation and in conventional propagation. This paper reviews recent progress in the understanding of adventitious root formation as a developmental process focusing on the role of plant hormones and on the effect of rooting conditions o

  20. Rooting of microcuttings: Theory and practice

    NARCIS (Netherlands)

    Klerk, de G.J.M.

    2002-01-01

    Poor adventitious root formation is a major obstacle in micropropagation and in conventional propagation. This paper reviews recent progress in the understanding of adventitious root formation as a developmental process focusing on the role of plant hormones and on the effect of rooting conditions o

  1. Doubling bialgebras of rooted trees

    Science.gov (United States)

    Mohamed, Mohamed Belhaj; Manchon, Dominique

    2017-01-01

    The vector space spanned by rooted forests admits two graded bialgebra structures. The first is defined by Connes and Kreimer using admissible cuts, and the second is defined by Calaque, Ebrahimi-Fard and the second author using contraction of trees. In this article, we define the doubling of these two spaces. We construct two bialgebra structures on these spaces which are in interaction, as well as two related associative products obtained by dualization. We also show that these two bialgebras verify a commutative diagram similar to the diagram verified Calaque, Ebrahimi-Fard and the second author in the case of rooted trees Hopf algebra, and by the second author in the case of cycle-free oriented graphs.

  2. The rhizosphere revisited: root microbiomics

    Directory of Open Access Journals (Sweden)

    Peter A.H.M. Bakker

    2013-05-01

    Full Text Available 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

  3. Automatic Schema Evolution in Root

    Institute of Scientific and Technical Information of China (English)

    ReneBrun; FonsRademakers

    2001-01-01

    ROOT version 3(spring 2001) supports automatic class schema evolution.In addition this version also produces files that are self-describing.This is achieved by storing in each file a record with the description of all the persistent classes in the file.Being self-describing guarantees that a file can always be read later,its structure browsed and objects inspected.also when the library with the compiled code of these classes is missing The schema evolution mechanism supports the frequent case when multiple data sets generated with many different class versions must be analyzed in the same session.ROOT supports the automatic generation of C++ code describing the data objects in a file.

  4. Evaluation of bacterial leakage of four root- end filling materials: Gray Pro Root MTA, White Pro Root MTA, Root MTA and Portland Cement (type I

    Directory of Open Access Journals (Sweden)

    Zarabian M.

    2005-07-01

    Full Text Available Background and Aim: Today several materials have been used for root- end filling in endodontic surgery. Optimal properties of Pro Root MTA in in-vitro and in-vivo studies has been proven. On the other hand, based on some studies, Root MTA (Iranian Pro Root MTA and Portland cement are similar to Pro Root MTA in physical and biologic properties. The aim of this study was to evaluate bacterial leakage (amount and mean leakage time of four root- end filling materials. Materials and Methods: In this experimental in-vitro study, seventy six extracted single- rooted human teeth were randomly divided into six groups for root-end filling with gray Pro Root MTA, white Pro Root MTA, Root MTA (Iranian Pro Root MTA, Portland Cement (type I and positive and negative control groups. Root canals were instrumented using the step- back technique. Root- end filling materials were placed in 3mm ultra sonic retro preparations. Samples and microleakage model system were sterilized in autoclave. The apical 3-4 mm of the roots were immersed in phenol red with 3% lactose broth culture medium. The coronal access of each specimen was inoculated every 24h with a suspension of Streptococcus sanguis (ATCC 10556. Culture media were observed every 24h for colour change indicating bacterial contamination for 60 days. Statistical analysis was performed using log- rank test with P<0.05 as the limit of significance. Results: At the end of study 50%, 56.25%, 56.25% and 50% of specimens filled with Gray Pro Root MTA, White Pro Root MTA. Root MTA and Portland Cement (type I had evidence of leakage respectively. The mean leakage time was 37.19±6.29, 36.44±5.81, 37.69±5.97 and 34.81±6.67 days respectively. Statistical analysis of data showed no significant difference among the leakage (amount and mean leakage time of the four tested root- end filling materials (P=0.9958. Conclusion: Based on the results of this study, there were no significant differences in leakage among the four

  5. Archimedes' calculations of square roots

    CERN Document Server

    Davies, E B

    2011-01-01

    We reconsider Archimedes' evaluations of several square roots in 'Measurement of a Circle'. We show that several methods proposed over the last century or so for his evaluations fail one or more criteria of plausibility. We also provide internal evidence that he probably used an interpolation technique. The conclusions are relevant to the precise calculations by which he obtained upper and lower bounds on pi.

  6. Facilitative root interactions in intercrops

    DEFF Research Database (Denmark)

    Hauggaard-Nielsen, H.; Jensen, E.S.

    2005-01-01

    Facilitation takes place when plants ameliorate the environment of their neighbours, and increase their growth and survival. Facilitation occurs in natural ecosystems as well as in agroecosystems. We discuss examples of facilitative root interactions in intercropped agroecosystems; including...... intensified cropping systems using chemical and mechanical inputs also show that facilitative interactions definitely can be of significance. It is concluded that a better understanding of the mechanisms behind facilitative interactions may allow us to benefit more from these phenomena in agriculture...

  7. Phene synergism between root hair length and basal root growth angle for phosphorus acquisition.

    Science.gov (United States)

    Miguel, Magalhaes Amade; Postma, Johannes Auke; Lynch, Jonathan Paul

    2015-04-01

    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.

  8. The quality of root fillings remaining in mandibular incisors after root-end cavity preparation

    NARCIS (Netherlands)

    Wu, MK; de Schwartz, FBC; van der Sluis, LWM; Wesselink, PR

    2001-01-01

    Aim The aim of this study was to determine the quality of root fillings remaining in mandibular incisors after root-end resection and root-end cavity preparation. Methodology Roots of 40 mandibular incisors. 12 mm in length. were divided into two groups and instrumented using a balanced force techni

  9. The quality of root fillings remaining in mandibular incisors after root-end cavity preparation

    NARCIS (Netherlands)

    Wu, MK; de Schwartz, FBC; van der Sluis, LWM; Wesselink, PR

    2001-01-01

    Aim The aim of this study was to determine the quality of root fillings remaining in mandibular incisors after root-end resection and root-end cavity preparation. Methodology Roots of 40 mandibular incisors. 12 mm in length. were divided into two groups and instrumented using a balanced force techni

  10. Using coloured roots to study root interaction and competition in intercropped legumes and non-legumes

    DEFF Research Database (Denmark)

    Tosti, Giacomo; Thorup-Kristensen, Kristian

    2010-01-01

    if a species with coloured roots can be used to examine the interaction in a legume-non-legume intercropping system; (ii) to verify the importance of initial root growth on the successive root development of mixture component plants; (iii) to test if the root interaction in the shallow layers has consequences...

  11. OpenSimRoot: widening the scope and application of root architectural models.

    Science.gov (United States)

    Postma, Johannes A; Kuppe, Christian; Owen, Markus R; Mellor, Nathan; Griffiths, Marcus; Bennett, Malcolm J; Lynch, Jonathan P; Watt, Michelle

    2017-08-01

    OpenSimRoot is an open-source, functional-structural plant model and mathematical description of root growth and function. We describe OpenSimRoot and its functionality to broaden the benefits of root modeling to the plant science community. OpenSimRoot is an extended version of SimRoot, established to simulate root system architecture, nutrient acquisition and plant growth. OpenSimRoot has a plugin, modular infrastructure, coupling single plant and crop stands to soil nutrient and water transport models. It estimates the value of root traits for water and nutrient acquisition in environments and plant species. The flexible OpenSimRoot design allows upscaling from root anatomy to plant community to estimate the following: resource costs of developmental and anatomical traits; trait synergisms; and (interspecies) root competition. OpenSimRoot can model three-dimensional images from magnetic resonance imaging (MRI) and X-ray computed tomography (CT) of roots in soil. New modules include: soil water-dependent water uptake and xylem flow; tiller formation; evapotranspiration; simultaneous simulation of mobile solutes; mesh refinement; and root growth plasticity. OpenSimRoot integrates plant phenotypic data with environmental metadata to support experimental designs and to gain a mechanistic understanding at system scales. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  12. ROOT Status and Future Developments

    CERN Document Server

    Brun, R; Canal, P; Rademakers, Fons; Goto, Masaharu; Canal, Philippe; Brun, Rene

    2003-01-01

    In this talk we will review the major additions and improvements made to the ROOT system in the last 18 months and present our plans for future developments. The additons and improvements range from modifications to the I/O sub-system to allow users to save and restore objects of classes that have not been instrumented by special ROOT macros, to the addition of a geometry package designed for building, browsing, tracking and visualizing detector geometries. Other improvements include enhancements to the quick analysis sub-system (TTree::Draw()), the addition of classes that allow inter-file object references (TRef, TRefArray), better support for templated and STL classes, amelioration of the Automatic Script Compiler and the incorporation of new fitting and mathematical tools. Efforts have also been made to increase the modularity of the ROOT system with the introduction of more abstract interfaces and the development of a plug-in manager. In the near future, we intend to continue the development of PROOF and...

  13. Printing Values In Interactive ROOT

    CERN Document Server

    Perovic, Boris

    2015-01-01

    This project report summarizes the work I have been performing during the past twelve weeks as a Summer Student intern working on ROOT project in the SFT group, PH department, under the supervision of Axel Naumann and Danilo Piparo. One of the widely requested features for ROOT was improved interactive shell experience as well as improved printing of object values. Solving this issue was the goal of this project. Primarily, we have enabled printing of the collections. Secondly, we have unified the printing interface, making it much more robust and extendible. Thirdly, we have implemented printing of nested collections in a flexible and user-friendly manner. Finally, we have added an interactive mode, allowing for paginated output. At the beginning of the report, ROOT is presented with examples of where it is used and how important it is. Then, the motivation behind the project is elaborated, by presenting the previous state of the software package and its potential for improvement. Further, the process in wh...

  14. Light as stress factor to plant roots - case of root halotropism.

    Science.gov (United States)

    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.

  15. Injerto columelar extendido angulado. Método para prevenir la rotación cefálica y lateral de los injertos de cartílago en la punta nasal Angulated extended collumelar graft. A method to prevent the cephalic and lateral rotation of the cartilage graft in the nasal tip

    Directory of Open Access Journals (Sweden)

    Y. Castro Govea

    2011-06-01

    Full Text Available El paciente mestizo generalmente posee una nariz pequeña, de base ancha, con fosas nasales redondas y dorso convexo. Los cartílagos alares son débiles, delgados y cortos, proporcionando un soporte estructural deficiente y pobre definición de la punta nasal. Los injertos de cartílago de la punta nasal se usan frecuentemente para corregir esta condición; sin embargo un problema común es la rotación cefálica, caudal y lateral de estos cartílagos. Empleamos un injerto columelar extendido angulado (ICEA para proporcionar elongación y soporte columelar; la extensión angulada nos brinda a su vez un mejor control y predicción de la posición de los injertos de la punta nasal al prevenir su desplazamiento cefálico y lateral. El protocolo quirúrgico empleado incluyó historia clínica completa, desarrollo de un plan quirúrgico mediante análisis de la deformidad y fotografías pre y postoperatorias para el control de los pacientes a medio y largo plazo. Tratamos 95 pacientes usando este procedimiento; 75 con rinoplastia abierta y 20 con técnica cerrada. El rango del periodo de seguimiento fue de 6 meses a 4 años. Los resultados obtenidos fueron satisfactorios, mostrando mejor control y predicción de la forma de la punta nasal. En conclusión, creemos que el injerto columelar extendido angulado proporciona un mejor control de la proyección y angularidad de los injertos colocados en la punta nasal.The mestizo patient usually has a small nose, with wide base, round nostrils and convex dorsum. The alar cartilages are weak, thin and short, providing a deficient structural support and poor definition of the nasal tip. Cartilage graft in the nasal tip are very often used to correct this condition, but a commun problem of this procedure is the cephalic or lateral rotation of these grafts. We used an angulated extended collumalar graft to give collumelar support and elongation. The angulated extension of the graft provides a better control and

  16. Asteroidal Quadruples in non Rooted Path Graphs

    Directory of Open Access Journals (Sweden)

    Gutierrez Marisa

    2015-11-01

    Full Text Available A directed path graph is the intersection graph of a family of directed subpaths of a directed tree. A rooted path graph is the intersection graph of a family of directed subpaths of a rooted tree. Rooted path graphs are directed path graphs. Several characterizations are known for directed path graphs: one by forbidden induced subgraphs and one by forbidden asteroids. It is an open problem to find such characterizations for rooted path graphs. For this purpose, we are studying in this paper directed path graphs that are non rooted path graphs. We prove that such graphs always contain an asteroidal quadruple.

  17. Fate of HERS during Tooth Root Development

    OpenAIRE

    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 c...

  18. Penis-root perception of Koro patients.

    Science.gov (United States)

    Chowdhury, A N

    1991-07-01

    Koro is an acute anxiety reaction in which the perception of decreased penis length because of intra-abdominal traction is the main feature. This study attempts to explore the penis-root perception of the Koro patients by a graphomotor projective test--the Draw-a-penis Test (DAPT). This controlled DAPT investigation shows that Koro patients perceived the penis as a detached organ with root-boundary definiteness as evidenced from their close penis-root perception. They also displayed reduced volumetric perception of penis-root than the normal subjects. These perceptual deviations in penis-root image are discussed in relation to their Koro vulnerability.

  19. Medicolegal aspects of iatrogenic root perforations

    DEFF Research Database (Denmark)

    Tsesis, I; Rosen, E; Bjørndal, L

    2014-01-01

    AIM: To retrospectively analyze the medico-legal aspects of iatrogenic root perforations (IRP) that occurred during endodontic treatments. METHODOLOGY: A comprehensive search in a professional liability insurance database was conducted to retrospectively identify cases of IRP following root canal...... treatment (p root perforation is a complication of root canal treatment and may result in tooth extraction...... and in legal actions against the treating practitioner. Mandibular molars are more prone to medico-legal claims related to root perforations. The patient should be informed of the risks during RCT and should get information on alternative treatments and their risks and prognosis...

  20. Lateral root organogenesis - from cell to organ.

    Science.gov (United States)

    Benková, Eva; Bielach, Agnieszka

    2010-12-01

    Unlike locomotive organisms capable of actively approaching essential resources, sessile plants must efficiently exploit their habitat for water and nutrients. This involves root-mediated underground interactions allowing plants to adapt to soils of diverse qualities. The root system of plants is a dynamic structure that modulates primary root growth and root branching by continuous integration of environmental inputs, such as nutrition availability, soil aeration, humidity, or salinity. Root branching is an extremely flexible means to rapidly adjust the overall surface of the root system and plants have evolved efficient control mechanisms, including, firstly initiation, when and where to start lateral root formation; secondly lateral root primordia organogenesis, during which the development of primordia can be arrested for a certain time; and thirdly lateral root emergence. Our review will focus on the most recent advances in understanding the molecular mechanisms involved in the regulation of lateral root initiation and organogenesis with the main focus on root system of the model plant Arabidopsis thaliana. Copyright © 2010 Elsevier Ltd. All rights reserved.

  1. Correlations of Vegetative and Reproductive Characters with Root ...

    African Journals Online (AJOL)

    jummy

    exception of root branching and grain weight per plant. Heritability estimates were ... Keywords: Root volume, root thickness, root dry weight, drought, grain yield. Correspondence: ..... Whole plant responses, key processes, and adaptation to ...

  2. Optimal root arrangement of cereal crops

    Science.gov (United States)

    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.

  3. Hydraulic responses of whole vines and individual roots of kiwifruit (Actinidia chinensis) following root severance.

    Science.gov (United States)

    Black, Marykate Z; Patterson, Kevin J; Minchin, Peter E H; Gould, Kevin S; Clearwater, Michael J

    2011-05-01

    Whole vine (K(plant)) and individual root (K(root)) hydraulic conductances were measured in kiwifruit (Actinidia chinensis Planch. var. chinensis 'Hort16A') vines to observe hydraulic responses following partial root system excision. Heat dissipation and compensation heat pulse techniques were used to measure sap flow in trunks and individual roots, respectively. Sap flux and measurements of xylem pressure potential (Ψ) were used to calculate K(plant) and K(root) in vines with zero and ∼80% of roots severed. Whole vine transpiration (E), Ψ and K(plant) were significantly reduced within 24 h of root pruning, and did not recover within 6 weeks. Sap flux in intact roots increased within 24 h of root pruning, driven by an increase in the pressure gradient between the soil and canopy and without any change in root hydraulic conductance. Photosynthesis (A) and stomatal conductance (g(s)) were reduced, without significant effects on leaf internal CO(2) concentration (c(i)). Shoot growth rates were maintained; fruit growth and dry matter content were increased following pruning. The woody roots of kiwifruit did not demonstrate a rapid dynamic response to root system damage as has been observed previously in monocot seedlings. Increased sap flux in intact roots with no change in K(root) and only a moderate decline in shoot A suggests that under normal growing conditions root hydraulic conductance greatly exceeds requirements for adequate shoot hydration.

  4. Effects of fine root length density and root biomass on soil preferential flow in forest ecosystems

    Directory of Open Access Journals (Sweden)

    Yinghu Zhang

    2015-04-01

    Full Text Available Aim of study: The study was conducted to characterize the impacts of plant roots systems (e.g., root length density and root biomass on soil preferential flow in forest ecosystems. Area of study: The study was carried out in Jiufeng National Forest Park, Beijing, China. Material and methods: The flow patterns were measured by field dye tracing experiments. Different species (Sophora japonica Linn,Platycladus orientalis Franco, Quercus dentata Thunbwere quantified in two replicates, and 12 soil depth were applied. Plant roots were sampled in the sieving methods. Root length density and root biomass were measured by WinRHIZO. Dye coverage was implied in the image analysis, and maximum depth of dye infiltration by direct measurement. Main results: Root length density and root biomass decreased with the increasing distance from soil surface, and root length density was 81.6% higher in preferential pathways than in soil matrix, and 66.7% for root biomass with respect to all experimental plots. Plant roots were densely distributed in the upper soil layers. Dye coverage was almost 100% in the upper 5-10 cm, but then decreased rapidly with soil depth. Root length density and root biomass were different from species: Platycladus orientalis Franco > Quercus dentata Thunb > Sophora japonica Linn. Research highlights: The results indicated that fine roots systems had strong effects on soil preferential flow, particularly root channels enhancing nutrition transport across soil profiles in forest dynamics.

  5. Root cap removal increases root penetration resistance in maize (Zea mays L).

    Science.gov (United States)

    Iijima, Morio; Higuchi, Toshifumi; Barlow, Peter W; Bengough, A Glyn

    2003-09-01

    The root cap assists the passage of the root through soil by means of its slimy mucilage secretion and by the sloughing of its outer cells. The root penetration resistance of decapped primary roots of maize (Zea mays L. cv. Mephisto) was compared with that of intact roots in loose (dry bulk density 1.0 g cm-3; penetration resistance 0.06 MPa) and compact soil (1.4 g cm-3; penetration resistance 1.0 MPa), to evaluate the contribution of the cap to decreasing the impedance to root growth. Root elongation rate and diameter were the same for decapped and intact roots when the plants were grown in loose soil. In compacted soil, however, the elongation rate of decapped roots was only about half that of intact roots, whilst the diameter was 30% larger. Root penetration resistances of intact and decapped seminal axis were 0.31 and 0.52 MPa, respectively, when the roots were grown in compacted soil. These results indicated that the presence of a root cap alleviates much of the mechanical impedance to root penetration, and enables roots to grow faster in compacted soils.

  6. Assessment of the nonoperated root after apical surgery of the other root in mandibular molars

    DEFF Research Database (Denmark)

    Kraus, Riccardo D; von Arx, Thomas; Gfeller, David

    2015-01-01

    INTRODUCTION: If a surgical approach is chosen to treat a multirooted tooth affected by persistent periapical pathosis, usually only the affected roots are operated on. The present study assessed the periapical status of the nonoperated root 5 years after apical surgery of the other root...... and radiographs 5 years after surgery were examined. The following data were collected: tooth, operated root, type and quality of the coronal restoration, marginal bone level, length and homogeneity of the root canal filling, presence of a post/screw, periapical index (PAI) of each root, and radiographic healing...... of the operated root. The presence of apical pathosis of the nonoperated root was analyzed statistically in relation to the recorded variables. RESULTS: Thirty-seven patients fulfilled the inclusion criteria. Signs of periapical pathosis in the nonoperated root 5 years after surgery (PAI ≥ 3) could be observed...

  7. In Vitro Comparison of Cone Beam Computed Tomography with Digital Periapical Radiography for Detection of Vertical Root Fracture in Posterior Teeth

    Science.gov (United States)

    Abdinian, Mehrdad; Razavian, Hamid; Jenabi, Nastaran

    2016-01-01

    Statement of the Problem The diagnosis of vertical root fracture (VRF) is a challenging task. Purpose This in vitro study compared cone beam computed tomography (CBCT) imaging with digital periapical radiography (DPR) made by three different horizontal angels (20°mesial, 0° and 20° distal) for accurate diagnosis of VRF. Materials and Method Among 120 posterior teeth included in this study, 60 were vertically fractured. Fractured and non-fractured teeth were randomly distributed into three groups defined as group 1 with no filling in the root canal, group 2 with gutta-percha in the canal, and group 3 with the intracanal post. All samples were placed in a dry mandible and imaged with CBCT and DPR techniques. Two blind observers investigated the images. Results CBCT had higher sensitivity but lower specificity compared with DPR, except for the intracanal post group in which the sensitivity of DPR was higher; though the chi-square test showed the differences to be statistically insignificant. The sensitivity, specificity, and accuracy of CBCT and DPR were reduced in the cases that gutta-percha or post were present in the canal. Inter-observer agreement was higher for CBCT. A set of three DPRs with different horizontal angels were significantly more sensitive for VRF recognition than a single orthogonal DPR. Conclusion Based on our results, there was no significant difference between CBCT and a set of three DPRs with different angulations for VRF detection in posterior teeth. Therefore, it is suggested to consider DPRs with three different horizontal angels (20°mesial, 0° and 20° distal) for radiographic evaluation before CBCT examination. PMID:27284552

  8. In Vitro Comparison of Cone Beam Computed Tomography with Digital Periapical Radiography for Detection of Vertical Root Fracture in Posterior Teeth

    Directory of Open Access Journals (Sweden)

    Mehrdad Abdinian

    2016-06-01

    Full Text Available Statement of the Problem: The diagnosis of vertical root fracture (VRF is a challenging task. Purpose: This in vitro study compared cone beam computed tomography (CBCT imaging with digital periapical radi-ography (DPR made by three different horizontal angels (20°mesial, 0° and 20° distal for accurate diagnosis of VRF. Materials and Method: Among 120 posterior teeth included in this study, 60 were vertically fractured. Fractured and non-fractured teeth were randomly distributed into three groups defined as group 1 with no filling in the root canal, group 2 with gutta-percha in the canal, and group 3 with the intracanal post. All samples were placed in a dry mandible and imaged with CBCT and DPR techniques. Two blind observers investigated the images. Results: CBCT had higher sensitivity but lower specificity compared with DPR, except for the intracanal post group in which the sensitivity of DPR was higher; though the chi-square test showed the differences to be statistically insignifi-cant. The sensitivity, specificity, and accuracy of CBCT and DPR were reduced in the cases that gutta-percha or post were present in the canal. Inter-observer agreement was higher for CBCT. A set of three DPRs with different horizontal angels were significantly more sensitive for VRF recognition than a single orthogonal DPR. Conclusion: Based on our results, there was no significant difference between CBCT and a set of three DPRs with dif-ferent angulations for VRF detection in posterior teeth. Therefore, it is suggested to consider DPRs with three different horizontal angels (20°mesial, 0° and 20° distal for radiographic evaluation before CBCT examination.

  9. 偏移投照技术与显微治疗诊治遗漏根管的疗效分析%Effectiveness analysis of augulated periapical radiography and micro-endodontics in the detection and treatment of missing root canals

    Institute of Scientific and Technical Information of China (English)

    闫雪冰; 彭红; 孙凤

    2011-01-01

    目的 分析根管治疗术后偏移投照技术与显微根管治疗的应用对遗漏根管的发现与治疗的临床疗效.方法 选择需行初次牙髓治疗的下颌前牙、下颌前磨牙、下颌第一、二磨牙及上颌第一、二磨牙共360颗(分别为49、68、62、50、85、46颗).常规拍摄术前正位根尖片,并于根治后拍摄正位及20°~30°偏位根尖片,通过对比分析,对可疑遗漏根管的患牙,在显微镜下寻找及治疗遗漏根管.结果 经显微治疗,360颗患牙中25颗(6.9%)确诊为遗漏根管,各牙位依次为3、5、5、4、6、2颗,其中23颗患牙发现并成功充填遗漏根管,2颗根管可找到但不完全通畅;正位发现8颗(2.2%),偏位发现23颗(6.4%),术后偏移投照发现率明显高于正位(P<0.05).结论 根治术后偏移投照技术与显微根管治疗对遗漏根管的发现与治疗有较大的帮助.%Objective To analyze the clinical effectiveness of angulated periapical radiography and micro-endodontics in the detection and treatment of missing root canals after endodontic treatment. Methods Three hundred and sixty nonendodontically treated teeth, including 49 mandibular anterior teeth, 68 mandibular premolars, 62 mandibular first molars, 50 mandibular second molars, 85 maxillary first molars and 46 maxillary second molars, were selected. Before the endodontic treatment, conventional periapical radiographs were taken at the routine angle. After root canal obturation, both routine and 20-30 degree horizontally angulated periapical radiographs were taken. The suspected teeth were explored and treated under dental operating microscope. Results Among the 360 teeth, 25 teeth (6.9%) were found to have missing root canals after endodontic treatment by using routine and augulated periapical radiographs and micro-endodontics (3, 5, 5, 4, 6 and 2 respectively). The 23 missing root canals were identified and filled successfully and 2 canals can not achieve the full length

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

    Science.gov (United States)

    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.

  11. Patterns in soil fertility and root herbivory interact to influence fine-root dynamics.

    Science.gov (United States)

    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 (root biomass, were the only ones to respond significantly to both treatments, increasing when fertilizer and when insecticide were added (each P 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.

  12. A statistical approach to root system classification.

    Science.gov (United States)

    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.

  13. A statistical approach to root system classification.

    Directory of Open Access Journals (Sweden)

    Gernot eBodner

    2013-08-01

    Full Text Available 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. We demonstrate that combining principal component and cluster analysis yields a meaningful classification of rooting types based on morphological traits. The classification method presented is based on a data-defined statistical procedure without a priori decision on the classifiers. Biplot inspection is used to determine key traits and to ensure stability in cluster based grouping. 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. Three rooting types emerged from measured data, distinguished by diameter/weight, density and spatial distribution respectively. 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

  14. Towards understanding tree root profiles: simulating hydrologically optimal strategies for root distribution

    Directory of Open Access Journals (Sweden)

    M. T. van Wijk

    2001-01-01

    Full Text Available In this modelling study differences in vertical root distributions measured in four contrasting forest locations in the Netherlands were investigated. Root distributions are seen as a reflection of the plant’s optimisation strategy, based on hydrological grounds. The 'optimal' root distribution is defined as the one that maximises the water uptake from the root zone over a period of ten years. The optimal root distributions of four forest locations with completely different soil physical characteristics are calculated using the soil hydrological model SWIF. Two different model configurations for root interactions were tested: the standard model configuration in which one single root profile was used (SWIF-NC, and a model configuration in which two root profiles compete for the same available water (SWIF-C. The root profiles were parameterised with genetic algorithms. The fitness of a certain root profile was defined as the amount of water uptake over a simulation period of ten years. The root profiles of SWIF-C were optimised using an evolutionary game. The results showed clear differences in optimal root distributions between the various sites and also between the two model configurations. Optimisation with SWIF-C resulted in root profiles that were easier to interpret in terms of feasible biological strategies. Preferential water uptake in wetter soil regions was an important factor for interpretation of the simulated root distributions. As the optimised root profiles still showed differences with measured profiles, this analysis is presented, not as the final solution for explaining differences in root profiles of vegetation but as a first step using an optimisation theory to increase understanding of the root profiles of trees. Keywords: forest hydrology, optimisation, roots

  15. Root canal treatment of bilateral three-rooted maxillary first premolars

    Directory of Open Access Journals (Sweden)

    Bhavana Gandhi

    2012-01-01

    Full Text Available In endodontics, several anatomic variations occur in teeth, both externally and in the internal root morphology, which play a very significant role in the diagnosis and treatment outcome. A thorough knowledge of the root canal anatomy, careful interpretation of the angled radiographs, proper endodontic access cavity preparation, and exploration of the root canal are the prerequisites for endodontic success. In a maxillary first premolar, it is rare to find extra roots and canals, and the aim of the present article is to report a case about the successful diagnosis and clinical management of bilateral three-rooted maxillary first premolars, with three independent root canals.

  16. Systems approaches to study root architecture dynamics

    Directory of Open Access Journals (Sweden)

    Candela eCuesta

    2013-12-01

    Full Text Available 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 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 lateral roots and thereby root system architecture is established and developed.

  17. Thermotropism by primary roots of maize

    Energy Technology Data Exchange (ETDEWEB)

    Fortin, M.-C.; Poff, K.L. (MSU-DOE Plant Research Laboratory, East Lansing, MI (USA))

    1990-05-01

    Sensing in the roots of higher plants has long been recognized to be restricted mainly to gravitropism and thigmotropism. However, root responses to temperature gradients have not been extensively studied. We have designed experiments under controlled conditions to test if and how root direction of maize can be altered by thermal gradients perpendicular to the gravity vector. Primary roots of maize grown on agar plates exhibit positive thermotropism (curvature toward the warmer temperature) when exposed to gradients of 0.5 to 4.2{degree}C cm{sup {minus}1}. The extent of thermotropism depends on the temperature gradient and the temperature at which the root is placed within the gradient. The curvature cannot be accounted for by differential growth as a direct effect of temperature on each side of the root.

  18. Winter Wheat Root Growth and Nitrogen Relations

    DEFF Research Database (Denmark)

    Rasmussen, Irene Skovby

    Root growth is an essential parameter regarding nitrogen (N) uptake efficiency, as more and deeper roots may improve the uptake from deeper soil layers and reduce nitrate leaching losses. During this PhD project, it was studied how different agronomic practices influence root growth and N relations...... in winter wheat (Triticum aestivum L). Field experiments on the effect of sowing date, N fertilization and cultivars were conducted on a sandy loam soil in Taastrup, Denmark. The root studies were conducted by means of the minirhizotron method. Also, a field experiment on the effect of defoliation and N...... fertilization was conducted in Canberra, Australia. Here the root studies were done by means of the core-break method and root washing....

  19. Tree-root control of shallow landslides

    Directory of Open Access Journals (Sweden)

    D. Cohen

    2017-08-01

    Full Text Available Tree roots have long been recognized to increase slope stability by reinforcing the strength of soils. Slope stability models usually include the effects of roots by adding an apparent cohesion to the soil to simulate root strength. No model includes the combined effects of root distribution heterogeneity, stress-strain behavior of root reinforcement, or root strength in compression. Recent field observations, however, indicate that shallow landslide triggering mechanisms are characterized by differential deformation that indicates localized activation of zones in tension, compression, and shear in the soil. Here we describe a new model for slope stability that specifically considers these effects. The model is a strain-step discrete element model that reproduces the self-organized redistribution of forces on a slope during rainfall-triggered shallow landslides. We use a conceptual sigmoidal-shaped hillslope with a clearing in its center to explore the effects of tree size, spacing, weak zones, maximum root-size diameter, and different root strength configurations. Simulation results indicate that tree roots can stabilize slopes that would otherwise fail without them and, in general, higher root density with higher root reinforcement results in a more stable slope. The variation in root stiffness with diameter can, in some cases, invert this relationship. Root tension provides more resistance to failure than root compression but roots with both tension and compression offer the best resistance to failure. Lateral (slope-parallel tension can be important in cases when the magnitude of this force is comparable to the slope-perpendicular tensile force. In this case, lateral forces can bring to failure tree-covered areas with high root reinforcement. Slope failure occurs when downslope soil compression reaches the soil maximum strength. When this occurs depends on the amount of root tension upslope in both the slope-perpendicular and slope

  20. Winter Wheat Root Growth and Nitrogen Relations

    DEFF Research Database (Denmark)

    Rasmussen, Irene Skovby

    Root growth is an essential parameter regarding nitrogen (N) uptake efficiency, as more and deeper roots may improve the uptake from deeper soil layers and reduce nitrate leaching losses. During this PhD project, it was studied how different agronomic practices influence root growth and N relations...... in winter wheat (Triticum aestivum L). Field experiments on the effect of sowing date, N fertilization and cultivars were conducted on a sandy loam soil in Taastrup, Denmark. The root studies were conducted by means of the minirhizotron method. Also, a field experiment on the effect of defoliation and N...... fertilization was conducted in Canberra, Australia. Here the root studies were done by means of the core-break method and root washing....

  1. Tree-root control of shallow landslides

    Science.gov (United States)

    Cohen, Denis; Schwarz, Massimiliano

    2017-08-01

    Tree roots have long been recognized to increase slope stability by reinforcing the strength of soils. Slope stability models usually include the effects of roots by adding an apparent cohesion to the soil to simulate root strength. No model includes the combined effects of root distribution heterogeneity, stress-strain behavior of root reinforcement, or root strength in compression. Recent field observations, however, indicate that shallow landslide triggering mechanisms are characterized by differential deformation that indicates localized activation of zones in tension, compression, and shear in the soil. Here we describe a new model for slope stability that specifically considers these effects. The model is a strain-step discrete element model that reproduces the self-organized redistribution of forces on a slope during rainfall-triggered shallow landslides. We use a conceptual sigmoidal-shaped hillslope with a clearing in its center to explore the effects of tree size, spacing, weak zones, maximum root-size diameter, and different root strength configurations. Simulation results indicate that tree roots can stabilize slopes that would otherwise fail without them and, in general, higher root density with higher root reinforcement results in a more stable slope. The variation in root stiffness with diameter can, in some cases, invert this relationship. Root tension provides more resistance to failure than root compression but roots with both tension and compression offer the best resistance to failure. Lateral (slope-parallel) tension can be important in cases when the magnitude of this force is comparable to the slope-perpendicular tensile force. In this case, lateral forces can bring to failure tree-covered areas with high root reinforcement. Slope failure occurs when downslope soil compression reaches the soil maximum strength. When this occurs depends on the amount of root tension upslope in both the slope-perpendicular and slope-parallel directions. Roots

  2. INDUSTRIAL ENGINEERING : ROOTING FOR ROOTS, HANKERING FOR HEROES

    Directory of Open Access Journals (Sweden)

    P.S. Kruger

    2012-01-01

    Full Text Available

    ENGLISH ABSTRACT: The “roots” of Industrial Engineering are certainly extensive, diverse and deep. Similarly, there are numerous historical “heroes” that made significant contributions to the development of the Industrial Engineering discipline. For the sake of argument, this article will assume that Industrial Engineering has at least two identifiable main roots, namely Determinism and Stochastism. The article attempts to trace the early history1 of the stochastic root which is very closely linked to the history of probability and statistics and hence games of chance, gambling and divinity. Therefore, the life and times, contributions and personalities of some of the heroes and villains, champions and sad cases of the stochastic world, will be briefly discussed in a somewhat light-hearted, but not necessarily flippant, manner.

    AFRIKAANSE OPSOMMING: Die “wortel en tak” van Bedryfsingenieurswese is sekerlik van groot omvang, van diverse aard en diep gesetel. Verskeie historiese “helde” het betekenisvolle bydraes gemaak tot die ontwikkeling van die Bedryfsingenieurswesevakgebied. Ter wille van betoogvoering sal in hierdie artikel aanvaar word dat Bedryfsingenieurswese uit minstens twee identifiseerbare sub-vakgebiede bestaan naamlik : Die Determinisme en die Stogasme. ’n Poging word aangewend om die vroeë geskiedenis van die stogasme na te speur wat op sy beurt aaneengesnoer is met die geskiedenis van die waarskynlikheidsleer en statistiek en dus toevalspelle, dobbelary en wiggelary. Die lewenswyse, tydsgewrig, bydraes en persoonlikheidseienskappe van ’n aantal helde en skurke, kampioene en prulle van die stogastiese wêreld word kortliks bespreek, op ’n ietwat lighartige maar nie noodwendig ligsinnige wyse.

  3. Rooting of carnation cuttings: The auxin signal

    OpenAIRE

    Acosta, Manuel; Oliveros-Valenzuela, M Rocío; Nicolás, Carlos; Sánchez-Bravo, José

    2009-01-01

    The rooting of stem cuttings is a common vegetative propagation practice in many ornamental species. Among other signals, auxin polarly transported through the stem plays a key role in the formation and growth of adventitious roots. Unlike in other plant species, auxin from mature leaves plays a decisive role in the rooting of carnation (Dianthus caryophyllus. L) cuttings. The gene DcAUX1, which codifies an auxin influx carrier involved in polar auxin transport, has now been cloned and charac...

  4. Root phenology in a changing climate.

    Science.gov (United States)

    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.

  5. Signaling Pathways Critical for Tooth Root Formation.

    Science.gov (United States)

    Wang, J; Feng, J Q

    2017-10-01

    Tooth is made of an enamel-covered crown and a cementum-covered root. Studies on crown dentin formation have been a major focus in tooth development for several decades. Interestingly, the population prevalence for genetic short root anomaly (SRA) with no apparent defects in crown is close to 1.3%. Furthermore, people with SRA itself are predisposed to root resorption during orthodontic treatment. The discovery of the unique role of Nfic (nuclear factor I C; a transcriptional factor) in controlling root but not crown dentin formation points to a new concept: tooth crown and root have different control mechanisms. Further genetic mechanism studies have identified more key molecules (including Osterix, β-catenin, and sonic hedgehog) that play a critical role in root formation. Extensive studies have also revealed the critical role of Hertwig's epithelial root sheath in tooth root formation. In addition, Wnt10a has recently been found to be linked to multirooted tooth furcation formation. These exciting findings not only fill the critical gaps in our understanding about tooth root formation but will aid future research regarding the identifying factors controlling tooth root size and the generation of a whole "bio-tooth" for therapeutic purposes. This review starts with human SRA and mainly focuses on recent progress on the roles of NFIC-dependent and NFIC-independent signaling pathways in tooth root formation. Finally, this review includes a list of the various Cre transgenic mouse lines used to achieve tooth root formation-related gene deletion or overexpression, as well as strengths and limitations of each line.

  6. Power Efficient Division and Square Root Unit

    DEFF Research Database (Denmark)

    Liu, Wei; Nannarelli, Alberto

    2012-01-01

    shows that division and square root units based on the digit-recurrence algorithm offer the best tradeoff delay-area-power. Moreover, the two operations can be combined in a single unit. Here, we present a radix-16 combined division and square root unit obtained by overlapping two radix-4 stages......Although division and square root are not frequent operations, most processors implement them in hardware to not compromise the overall performance. Two classes of algorithms implement division or square root: digit-recurrence and multiplicative (e.g., Newton-Raphson) algorithms. Previous work...

  7. Comprehensive analysis of Panax ginseng root transcriptomes

    National Research Council Canada - National Science Library

    Jayakodi, Murukarthick; Lee, Sang-Choon; Lee, Yun Sun; Park, Hyun-Seung; Kim, Nam-Hoon; Jang, Woojong; Lee, Hyun Oh; Joh, Ho Jun; Yang, Tae-Jin

    2015-01-01

    Korean ginseng (Panax ginseng C.A. Meyer) is a highly effective medicinal plant containing ginsenosides with various pharmacological activities, whose roots are produced commercially for crude drugs...

  8. Mandibular second premolar with four roots

    Directory of Open Access Journals (Sweden)

    Sefika Nur Akyuz

    2012-01-01

    Full Text Available Detection of normal and abnormal variation in tooth anatomy is essential for clinical success. It is generally well known that the mandibular second premolar teeth have a single root and canal. However, the mandibular second premolar teeth have sometimes more than one root and root canal. The endodontic treatment of a mandibular second premolar with four roots which separated at different levels along the middle third of the root is presented in this case report. Preoperative radiographs appeared radiolucency and different root anatomy in the region of the mandibular second premolar. The root canals were prepared using Mtwo rotary system (VDW, Munich, Germany and obturated laterally condensed gutta percha and AH plus (Dentsply De Trey, Konstanz, Germany. After the completion of root canal treatment, the tooth was restored with a posterior composite filling material. On follow-up, the tooth was clinically and radiographically asymptomatic for two years. Clinicians should be aware of the importance of careful clinical and radiographic examination of mandibular premolars during the endodontic treatment. Radiographs exposed at two different horizontal angles and their careful interpretation facilitates the search of additional root canals.

  9. Designing new interfaces for ROOT data processing

    CERN Document Server

    Vuorinen, Kalle Elmer

    2016-01-01

    ROOT is a C++ framework for data analysis provided with a Python interface (PyRoot). ROOT is used in every Large Hadron Collider experiment. This project presents a way of reading ROOT TTree by using a new class called DataFrame, which allows the usage of cache and functional chains. Reading TTrees in Python has been quite slow compared to the C++ way of doing it and for this reason we also bring the possibility to read them with just-in-time (JIT) compiled C++ code, using another new Python class called TreeReader.

  10. Mineral nutrition and adventitious rooting in microcuttings of Eucalyptus globulus.

    Science.gov (United States)

    Schwambach, Joséli; Fadanelli, Cristina; Fett-Neto, Arthur G

    2005-04-01

    We characterized the adventitious rooting response of Eucalyptus globulus Labill. to various concentrations of calcium, nitrogen, phosphorus, iron, manganese, zinc, boron and copper. The parameters analyzed were percent rooting, root number, root length and mean rooting time. Root number and root length were significantly affected by mineral nutrition, whereas mean rooting time and rooting percentage seemed to be closely related to auxin availability. Root number was affected by calcium, nitrogen source and zinc, whereas root length was influenced by concentrations of phosphorus, iron and manganese, and by nitrogen source. Based on these results, we evaluated various combinations of several concentrations of these minerals in each rooting phase. Cuttings that were rooted in an optimized mineral nutrient medium and acclimatized to ex-vitro conditions for two months showed significantly higher survival after transplanting and drought stress than cuttings rooted in basal medium and treated in the same way.

  11. ROOT HYDRAULIC CONDUCTIVITY AND PHOTOSYNTHETIC CAPACITY OF EUCALYPT CLONAL CUTTINGS WITH ROOT MALFORMATION INDUCTIONS

    Directory of Open Access Journals (Sweden)

    Fábio Afonso Mazzei Moura de Assis Figueiredo

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814566The gain reduction of wood biomass in trees has been assigned to root deformations even in the nursery phase. The objective of this work was the evaluation of the root system hydraulic conductivity, gas exchanges and photochemical efficiency of eucalypt clonal cuttings with and without root deformation inductions. The treatments were: 1 operational cuttings without root malformation inductions (grown according to the used methodology of Fibria Cellulose S.A.; 2 root deformation inductions. These inductions did not promote decrease in the root volume. However, the deformations brought reduction of the root system hydraulic conductivity. Lower photosynthetic rates were also observed along the day in the cuttings in the root deformed cuttings. This decreasing rate is connected to stomatal and non stomatal factors.

  12. Variations of fine root diameter with root order in Manchurian ash and Dahurian larch plantations

    Institute of Scientific and Technical Information of China (English)

    WANG Xiangrong; WANG Zhengquan; HAN Youzhi; GU Jiacun; GUO Dali; MEI Li

    2007-01-01

    Fine root lifespan and turnover play an important role in carbon allocation and nutrient cycling in forest ecosystems.Fine roots are typically defined as less than 1 or 2mm in diameter.However,when categorizing roots by this diameter size,the position of an individual root on the complex lateral branching pattern has often been ignored,and our knowledge about relationships between branching order and root function thus remains limited.More recently,studies on root survivals found that longevity was remarkably different in the same branching level due to diameter variations.The objectives of this study were:(1) To examine variations of fine root diameter from the first-to fifth-orders in Fraxinus mandshurica Rupr and Larix gmelinii Rupr roots;and (2) To reveal how the season,soil nutrient,and water availability affect root diameter in different branch order in two species.This study was conducted at Maoershan Forest Research Station (45°21'-45°25'N,127°30'-127°34'E) owned by Northeast Forestry University in Harbin,northeast China.Both F.mandshurica and L.gmelinii were planted in 1986.In each plantation,fine roots of two species by sampling up to five fine root branch orders three times during the 2003 growing season from two soil depths (i.e.,0-10 and 10-20 cm)were obtained.The results showed that average diameters of fine roots were significantly different among the five branch orders.The first-order had the thinner roots and the fifth order had the thickest roots,the diameter increasing regularly with the ascending branch orders in both species.If the diameter of fine roots was defined as being smaller than 0.5 mm,the first three orders ofF.mandshurica roots and the first two orders of L.gmelinii roots would be included in the fine root population.The diameter ranges of the fine roots from first-order to fifth-order were 0.15-0.58,0.18-0.70,0.26-1.05,0.36-1.43,and 0.71-2.96 mm for F.mandshurica,and 0.17-0.76,0.23-1.02,0.26-1.10,0.38-1.77,and 0.84-2.80 mm for L

  13. Piriformospora indica root colonization triggers local and systemic root responses and inhibits secondary colonization of distal roots.

    Directory of Open Access Journals (Sweden)

    Lorenzo Pedrotti

    Full Text Available Piriformosporaindica is a basidiomycete fungus colonizing roots of a wide range of higher plants, including crop plants and the model plant Arabidopsis thaliana. Previous studies have shown that P. indica improves growth, and enhances systemic pathogen resistance in leaves of host plants. To investigate systemic effects within the root system, we established a hydroponic split-root cultivation system for Arabidopsis. Using quantitative real-time PCR, we show that initial P. indica colonization triggers a local, transient response of several defense-related transcripts, of which some were also induced in shoots and in distal, non-colonized roots of the same plant. Systemic effects on distal roots included the inhibition of secondary P. indica colonization. Faster and stronger induction of defense-related transcripts during secondary inoculation revealed that a P. indica pretreatment triggers root-wide priming of defense responses, which could cause the observed reduction of secondary colonization levels. Secondary P. indica colonization also induced defense responses in distant, already colonized parts of the root. Endophytic fungi therefore trigger a spatially specific response in directly colonized and in systemic root tissues of host plants.

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

    OpenAIRE

    Galkovskyi Taras; Mileyko Yuriy; Bucksch Alexander; Moore Brad; Symonova Olga; Price Charles A; Topp Christopher N; Iyer-Pascuzzi Anjali S; Zurek Paul R; Fang Suqin; Harer John; Benfey Philip N; Weitz Joshua S

    2012-01-01

    Abstract 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...

  15. Root-soil relationships and terroir

    Science.gov (United States)

    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.

  16. Malformations of the tooth root in humans

    Directory of Open Access Journals (Sweden)

    Hans Ulrich eLuder

    2015-10-01

    Full Text Available 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

  17. Root selection methods in flood analysis

    Directory of Open Access Journals (Sweden)

    B. Parmentier

    2003-01-01

    Full Text Available In the 1970s, de Laine developed a root-matching procedure for estimating unit hydrograph ordinates from estimates of the fast component of the total runoff from multiple storms. Later, Turner produced a root selection method which required only data from one storm event and was based on recognising a pattern typical of unit hydrograph roots. Both methods required direct runoff data, i.e. prior separation of the slow response. This paper introduces a further refinement, called root separation, which allows the estimation of both the unit hydrograph ordinates and the effective precipitation from the full discharge hydrograph. It is based on recognising and separating the quicker component of the response from the much slower components due to interflow and/or baseflow. The method analyses the z-transform roots of carefully selected segments of the full hydrograph. The root patterns of these separate segments tend to be dominated by either the fast response or the slow response. This paper shows how their respective time-scales can be distinguished with an accuracy sufficient for practical purposes. As an illustration, theoretical equations are derived for a conceptual rainfall-runoff system with the input split between fast and slow reservoirs in parallel. These are solved analytically to identify the reservoir constants and the input splitting parameter. The proposed method, called 'root separation', avoids the subjective selection of rainfall roots in the Turner method as well as the subjective matching of roots in the original de Laine method. Keywords: unit hydrograph,identification methods, z-transform, polynomial roots, root separation, fast andslow response, Nash cascade

  18. Fine root production at drained peatland sites

    Energy Technology Data Exchange (ETDEWEB)

    Finer, L. [Finnish Forest Research Inst. (Finland). Joensuu Research Station; Laine, J. [Helsinki Univ. (Finland). Dept. of Forest Ecology

    1996-12-31

    The preliminary results of the Finnish project `Carbon balance of peatlands and climate change` show that fine roots play an important role in carbon cycling on peat soils. After drainage the roots of mire species are gradually replaced by the roots of trees and other forest species. Pine fine root biomass reaches a maximum level by the time of crown closure, some 20 years after drainage on pine mire. The aim of this study is to compare the results of the sequential coring method and the ingrowth bag method used for estimating fine root production on three drained peatland sites of different fertility. The results are preliminary and continuation to the work done in the study Pine root production on drained peatlands, which is part of the Finnish project `Carbon cycling on peatlands and climate change`. In this study the fine root biomass was greater on the poor site than on the rich sites. Pine fine root production increased with the decrease in fertility. Root turnover and the production of field layer species were greater on the rich sites than on the poor site. The results suggested that the in growth bag method measured more root activity than the magnitude of production. More than two growing seasons would have been needed to balance the root dynamics in the in growth bags with the surrounding soil. That time would probably have been longer on the poor site than on the rich ones and longer for pine and field layer consisting of dwarf shrubs than for field layer consisting of sedge like species and birch. (11 refs.)

  19. Changes of Root Length and Root-to-Crown Ratio after Apical Surgery

    DEFF Research Database (Denmark)

    von Arx, Thomas; Jensen, Simon S; Bornstein, Michael M

    2015-01-01

    the length of apicectomy and calculated the loss of root length and changes of RCR after apical surgery. METHODS: In a prospective clinical study, cone-beam computed tomography scans were taken preoperatively and postoperatively. From these images, the crown and root lengths of 61 roots (54 teeth in 47...

  20. X-ray computed tomography uncovers root-root interactions: quantifying spatial relationships between interacting root systems in three dimensions

    Directory of Open Access Journals (Sweden)

    Alexander Martin Paya

    2015-04-01

    Full Text Available Research in the field of plant biology has recently demonstrated that inter- and intra-specific interactions belowground can dramatically alter root growth. Our aim was to answer questions related to the effect of inter- vs. intra-specific interactions on the growth and utilization of undisturbed space by fine roots within three dimensions (3D using micro X-ray computed tomography. To achieve this, Populus tremuloides (quaking aspen and Picea mariana (black spruce seedlings were planted into containers as either solitary individuals, or inter-/intra-specific pairs, allowed to grow for two months, and 3D metrics developed in order to quantify their use of belowground space. In both aspen and spruce, inter-specific root interactions produced a shift in the vertical distribution of the root system volume, and deepened the average position of root tips when compared to intra-specifically growing seedlings. Inter-specific interactions also increased the minimum distance between root tips belonging to the same root system. There was no effect of belowground interactions on the radial distribution of roots, or the directionality of lateral root growth for either species. In conclusion, we found that significant differences were observed more often when comparing controls (solitary individuals and paired seedlings (inter- or intra-specific, than when comparing inter- and intra-specifically growing seedlings. This would indicate that competition between neighboring seedlings was more responsible for shifting fine root growth in both species than was neighbor identity. However, significant inter- vs. intra-specific differences were observed, which further emphasizes the importance of biological interactions in competition studies.

  1. Compounds from the roots of Jasminum sambac.

    Science.gov (United States)

    Zeng, Lin-Hong; Hu, Min; Yan, Yong-Ming; Lu, Qing; Cheng, Yong-Xian

    2012-01-01

    Four new compounds (+)-jasminoids A, B, C, and D, together with seven known compounds, were isolated from the roots of Jasminum sambac. Their structures were identified using spectroscopic methods. This study provides a better understanding to the chemical composition of J. sambac roots that have been thought to be one ingredient of an ancient prescription 'Ma-Fei-San'.

  2. Sugarbeet root rot in drought conditions

    Directory of Open Access Journals (Sweden)

    Jasnić Stevan M.

    2005-01-01

    Full Text Available In recent years several types of sugarbeet root rot have occurred in our country causing significant economic damage. The most frequent symptoms are leaf chlorosis and brown-black wet necrosis of the root. The necrosis spread through the entire root and vascular strands. In the course of this study F. oxysporum was the most frequently isolated from infected sugar beet roots. The incidence of other fungi (Fusarium solani, Rhizoctonia solani and Macrophomina phaseolina was much lower and it depended on weather conditions. High temperatures occurring during dry years encourage the development of F. oxysporum, the causer of sugar beet root rot. In 2000, an extremely dry year, plant vitality was satisfactory in the experiment with irrigation and the average root rot incidence was low (2,91%. In the nonirrigated variant the average incidence was high (71,02%. It may be concluded on the basis of the results from five years (2000-2004 that the major causal agents of sugarbeet root rot in our country are species from genus Fusarium, especially F. oxysporum. Fusarium wilt and root rot are due to the increased frequency of dry and warm years.

  3. Cytological and ultrastructural studies on root tissues

    Science.gov (United States)

    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.

  4. A histochemical study of root nodule development.

    NARCIS (Netherlands)

    Wiel, van de C.C.M.

    1991-01-01

    In cooperation with soil bacteria of the genera Rhizobium , Bradyrhizobium or Azorhizobium , many members of the legume family are able to form specialized organs on their roots, called root nodules. The bacteria, wrapped up inside a plant membrane, are accomodated in large parenchymatic cells locat

  5. Improving rooting uniformity in rose cuttings

    NARCIS (Netherlands)

    Telgen, van H.J.; Eveleens-Clark, B.A.; Garcia Victoria, N.

    2007-01-01

    Studies to improve rooting uniformity of single node stem cuttings for rose are reported. We found that the variation in shoot growth in a young rose crop depended on the variation in root number of the cuttings, which, in turn, was related to the auxin concentration applied to the cutting before ro

  6. Graphing Powers and Roots of Complex Numbers.

    Science.gov (United States)

    Embse, Charles Vonder

    1993-01-01

    Using De Moivre's theorem and a parametric graphing utility, examines powers and roots of complex numbers and allows students to establish connections between the visual and numerical representations of complex numbers. Provides a program to numerically verify the roots of complex numbers. (MDH)

  7. On König's root finding algorithms

    DEFF Research Database (Denmark)

    Buff, Xavier; Henriksen, Christian

    2003-01-01

    In this paper, we first recall the definition of a family of root-finding algorithms known as König's algorithms. We establish some local and some global properties of those algorithms. We give a characterization of rational maps which arise as König's methods of polynomials with simple roots. We...

  8. Layers of root nouns in Germanic

    DEFF Research Database (Denmark)

    Hansen, Bjarne Simmelkjær Sandgaard

    2015-01-01

    The root-noun declension became productive in early Germanic, containing (I) inherited root nouns, (IIa) original substrate or loan words, and transitions from other declensions in (IIb) Proto-Germanic and (III) North Germanic. As ablaut was abolished, the inherited type would display ablaut grad...

  9. On the Denesting of Nested Square Roots

    Science.gov (United States)

    Gkioulekas, Eleftherios

    2017-01-01

    We present the basic theory of denesting nested square roots, from an elementary point of view, suitable for lower level coursework. Necessary and sufficient conditions are given for direct denesting, where the nested expression is rewritten as a sum of square roots of rational numbers, and for indirect denesting, where the nested expression is…

  10. On König's root finding algorithms

    DEFF Research Database (Denmark)

    Buff, Xavier; Henriksen, Christian

    2003-01-01

    In this paper, we first recall the definition of a family of root-finding algorithms known as König's algorithms. We establish some local and some global properties of those algorithms. We give a characterization of rational maps which arise as König's methods of polynomials with simple roots. We...

  11. Salt stress signals shape the plant root

    NARCIS (Netherlands)

    C.S. Galvan-Ampudia; C. Testerink

    2011-01-01

    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 avo

  12. Tree root mapping with ground penetrating radar

    CSIR Research Space (South Africa)

    Van Schoor, Abraham M

    2009-09-01

    Full Text Available roots is required a detailed 3D survey approach is recommended. REFERENCES Butnor, J.R., Doolittle, J.A., Johnsen, K.H., Samuelson, L., Stokes, T. and Kress, L., 2003, Utility of Ground-Penetrating Radar as a Root Biomass Survey Tool in Forest...

  13. Rapid phenotyping of alfalfa root system architecture

    Science.gov (United States)

    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...

  14. Clinical management of infected root canal dentin.

    Science.gov (United States)

    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.

  15. Effect of lead on root growth.

    Science.gov (United States)

    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.

  16. Effect of lead on root growth

    Science.gov (United States)

    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

  17. The Complexity of Rooted Phylogeny Problems

    CERN Document Server

    Bodirsky, Manuel

    2011-01-01

    Several computational problems in phylogenetic reconstruction can be formulated as restrictions of the following general problem: given a formula in conjunctive normal form where the literals are rooted triples, is there a rooted binary tree that satisfies the formula? If the formulas do not contain disjunctions, the problem becomes the famous rooted triple consistency problem, which can be solved in polynomial time by an algorithm of Aho, Sagiv, Szymanski, and Ullman. If the clauses in the formulas are restricted to disjunctions of negated triples, Ng, Steel, and Wormald showed that the problem remains NP-complete. We systematically study the computational complexity of the problem for all such restrictions of the clauses in the input formula. For certain restricted disjunctions of triples we present an algorithm that has sub-quadratic running time and is asymptotically as fast as the fastest known algorithm for the rooted triple consistency problem. We also show that any restriction of the general rooted ph...

  18. Tissue engineering in endodontics: root canal revascularization.

    Science.gov (United States)

    Palit Madhu Chanda; Hegde, K Sundeep; Bhat, Sham S; Sargod, Sharan S; Mantha, Somasundar; Chattopadhyay, Sayan

    2014-01-01

    Root canal revascularization attempts to make necrotic tooth alive by the use of certain simple clinical protocols. Earlier apexification was the treatment of choice for treating and preserving immature permanent teeth that have lost pulp vitality. This procedure promoted the formation of apical barrier to seal the root canal of immature teeth and nonvital filling materials contained within root canal space. However with the success of root canal revascularization to regenerate the pulp dentin complex of necrotic immature tooth has made us to rethink if apexification is at the beginning of its end. The objective of this review is to discuss the new concepts of tissue engineering in endodontics and the clinical steps of root canal revascularization.

  19. Formation and separation of root border cells.

    Science.gov (United States)

    Driouich, Azeddine; Durand, Caroline; Vicré-Gibouin, Maïté

    2007-01-01

    Plant roots release a large number of border cells into the rhizosphere, which are believed to play a key role in root development and health. The formation and loss of these cells from the root cap region is a developmentally regulated process that is also controlled by phytohormones and environmental factors. The separation of border cells involves the complete dissociation of individual cells from each other and from root tissue. This process requires the activity of cell wall-degrading enzymes that solubilize the cell wall connections between cells. We present and discuss the solubilization process with an emphasis on pectin-degrading enzymes as well as the recently discovered root border-like cells of Arabidopsis thaliana.

  20. Methane and Root Dynamics in Arctic Soil

    DEFF Research Database (Denmark)

    D'Imperio, Ludovica

    on the global climate. We investigated two aspects of arctic ecosystem dynamics which are not well represented in climatic models: i) soil methane (CH4) oxidation in dry heath tundra and barren soils and ii) root dynamics in wetlands. Field measurements were carried out during the growing season in Disko Island......, West Greenland, and CH4 and root dynamics were assessed in response to experimentally increased winter snow precipitation, summer warming and their interaction to better understand their contribution to the C balance of the Arctic. Our results indicate that both the dry heath and barren soils have...... from wetlands in a future warmer climate. At the wet fen increased winter snow precipitation delayed the onset of the growing season of about a week and reduced the relative fine root production. The use of minirhizotrons improved our understanding of root growth and phenology. Total root number...

  1. Nutrition and adventitious rooting in woody plants

    Directory of Open Access Journals (Sweden)

    Fernanda Bortolanza Pereira

    2016-09-01

    Full Text Available Vegetative propagation success of commercial genotypes via cutting techniques is related to several factors, including nutritional status of mother trees and of propagation material. The nutritional status determines the carbohydrate quantities, auxins and other compounds of plant essential metabolism for root initiation and development. Each nutrient has specific functions in plant, acting on plant structure or on plant physiology. Although the importance of mineral nutrition for success of woody plants vegetative propagation and its relation with adventitious rooting is recognized, the role of some mineral nutrients is still unknown. Due to biochemical and physiological complexity of adventitious rooting process, there are few researches to determine de role of nutrients on development of adventitious roots. This review intends to explore de state of the art about the effect of mineral nutrition on adventitious rooting of woody plants.

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

    Directory of Open Access Journals (Sweden)

    Lucas Villaça Zogheib

    2011-12-01

    Full Text Available 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.

  3. PHIV-RootCell: a supervised image analysis tool for rice root anatomical parameter quantification

    Directory of Open Access Journals (Sweden)

    Marc eLartaud

    2015-01-01

    Full Text Available We developed the PHIV-RootCell software to quantify anatomical traits of rice roots transverse section images. Combined with an efficient root sample processing method for image acquisition, this program permits supervised measurements of areas (those of whole root section, stele, cortex and central metaxylem vessels, number of cell layers and number of cells per cell layer. The PHIV-RootCell toolset runs under ImageJ, an independent operating system that has a license-free status. To demonstrate the usefulness of PHIV-RootCell, we conducted a genetic diversity study and an analysis of salt-stress responses of root anatomical parameters in rice (Oryza sativa L.. Using 16 cultivars, we showed that we could discriminate between some of the varieties even at the 6 day-old stage, and that tropical japonica varieties had larger root sections due to an increase in cell number. We observed, as described previously, that root sections become enlarged under salt stress. However, our results show an increase in cell number in ground tissues (endodermis and cortex but a decrease in external (peripheral tissues (sclerenchyma, exodermis and epidermis. Thus, the PHIV-RootCell program is a user-friendly tool that will be helpful for future genetic and physiological studies that investigate root anatomical trait variations.

  4. Aerenchyma Formed Under Phosphorus Deficiency Contributes to the Reduced Root Hydraulic Conductivity in Maize Roots

    Institute of Scientific and Technical Information of China (English)

    Mingshou Fan; Ruiqin Bai; Xuefeng Zhao; Jianhua Zhang

    2007-01-01

    Root hydraulic conductivity has been shown to decrease under phosphorus (P) deficiency. This study investigated how the formation of aerenchyma is related to this change. Root anatomy, as well as root hydraulic conductivity was studied in maize (Zea mays L.) roots under different phosphorus nutrition conditions. Plant roots under P stress showed enhanced degradation of cortical cells and the aerenchyma formation was associated with their reduced root hydraulic conductivity, supporting our hypothesis that air spaces that form in the cortex of phosphorusstressed roots impede the radial transport of water in a root cylinder. Further evidence came from the variation in aerenchyma formation due to genotypic differences. Five maize inbred lines with different porosity in their root cortex showed a significant negative correlation with their root hydraulic conductivity. Shoot relative water content was also found lower in P-deficient maize plants than that in P-sufficient ones when such treatment was prolonged enough, suggesting a limitation of water transport due to lowered root hydraulic conductivity of P-deficient piants.

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

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

    2015-11-01

    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.

  7. Root phenology at Harvard Forest and beyond

    Science.gov (United States)

    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, pGrowth 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 2012 through August 2013 at the Harvard Forest in Petersham, MA, USA. Greenness and stem growth were highest in late May and early June with one clear

  8. Do ectomycorrhizal and arbuscular mycorrhizal temperate tree species systematically differ in root order based fine root morphology and biomass?

    Directory of Open Access Journals (Sweden)

    Petra eKubisch

    2015-02-01

    Full Text Available 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.

  9. Tractography of lumbar nerve roots: initial results

    Energy Technology Data Exchange (ETDEWEB)

    Balbi, Vincent; Budzik, Jean-Francois; Thuc, Vianney le; Cotten, Anne [Hopital Roger Salengro, Service de Radiologie et d' Imagerie musculo-squelettique, Lille Cedex (France); Duhamel, Alain [Universite de Lille 2, UDSL, Lille (France); Bera-Louville, Anne [Service de Rhumatologie, Hopital Roger Salengro, Lille (France)

    2011-06-15

    The aims of this preliminary study were to demonstrate the feasibility of in vivo diffusion tensor imaging (DTI) and fibre tracking (FT) of the lumbar nerve roots, and to assess potential differences in the DTI parameters of the lumbar nerves between healthy volunteers and patients suffering from disc herniation. Nineteen patients with unilateral sciatica related to posterolateral or foraminal disc herniation and 19 healthy volunteers were enrolled in this study. DTI with tractography of the L5 or S1 nerves was performed. Mean fractional anisotropy (FA) and mean diffusivity (MD) values were calculated from tractography images. FA and MD values could be obtained from DTI-FT images in all controls and patients. The mean FA value of the compressed lumbar nerve roots was significantly lower than the FA of the contralateral nerve roots (p=0.0001) and of the nerve roots of volunteers (p=0.0001). MD was significantly higher in compressed nerve roots than in the contralateral nerve root (p=0.0002) and in the nerve roots of volunteers (p=0.04). DTI with tractography of the lumbar nerves is possible. Significant changes in diffusion parameters were found in the compressed lumbar nerves. (orig.)

  10. Spiralizations and tropisms in Arabidopsis roots.

    Science.gov (United States)

    Migliaccio, F; Piconese, S

    2001-12-01

    When Arabidopsis seedlings are grown on a hard-agar plate, their primary roots show characteristic spiralling movements, apparent as waves, coils and torsions, together with a slanting toward the right-hand side. All these movements are believed to be the result of three different processes acting on the roots: circumnutation, positive gravitropism and negative thigmotropism. The basic movement of the roots is described as that of a growing right-handed helix, which, because of the root tip hitting the agar plate, is continuously switched from the right-hand to the left-hand of the growth direction, and vice versa. This movement also produces a slanting root-growth direction toward the right-hand because of the incomplete waves made by the right-handed root to the left-hand. By contrast, the torsions seen in the coils and waves are interpreted as artefacts that form as an adaptation of the three-dimensional root helix to the flat two-dimensional agar surface.

  11. Is pulp regeneration necessary for root maturation?

    Science.gov (United States)

    Nosrat, Ali; Li, Kevin L; Vir, Kunwar; Hicks, M Lamar; Fouad, Ashraf F

    2013-10-01

    True regeneration of the dental pulp-dentin complex in immature teeth with necrotic pulps has not been shown histologically. It is not known to what extent this true tissue regeneration is necessary to achieve clinically acceptable outcomes. This case report describes the treatment of a patient with an immature maxillary right central incisor with a history of impact trauma and enamel-dentin crown fracture. A diagnosis of pulp necrosis with acute apical abscess was established. A regenerative endodontic protocol that used a paste containing Augmentin for 5 weeks as an intracanal medicament was used. Follow-ups at 9, 12, 17, and 31 months revealed complete osseous healing of the periapical lesion and formation of the root apex, but without increase in root length. Clinically, the tooth was functional, asymptomatic, and nonresponsive to pulp vitality tests. The crown discolored over time. On reentering the root canal, no tissues were observed under magnification inside the root canal space. The root canal treatment was completed with mineral trioxide aggregate obturation. Augmentin might be an acceptable choice for root canal disinfection in regenerative endodontic procedures. The protocol for regenerative endodontic treatment is not predictable for pulp-dentin regeneration. Formation of the root apex is possible without pulp regeneration. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  12. How to bond to root canal dentin

    Science.gov (United States)

    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.

  13. Root distribution of rootstocks for 'Tahiti' lime

    Directory of Open Access Journals (Sweden)

    Neves Carmen Silvia Vieira Janeiro

    2004-01-01

    Full Text Available Field studies on citrus roots are important for genetic selection of cultivars and for management practices such as localized irrigation and fertilization. To characterize root systems of six rootstocks, taking into consideration chemical and physical characteristics of a clayey Typic Hapludox of the Northern State of Paraná, this study was performed having as scion the 'IAC-5 Tahiti' lime [Citrus latifolia (Yu. Tanaka]. The rootstocks 'Rangpur' lime (C. limonia Osbeck, 'Africa Rough' lemon (C. jambhiri Lush., 'Sunki' mandarin [C. sunki (Hayata hort. ex Tan.], Poncirus trifoliata (L. Raf., 'C13' citrange [C. sinensis (L. Osb. x P. trifoliata (L. Raf] and 'Catânia 2' Volkamer lemon (C. volkameriana Ten. & Pasq. were used applying the trench profile method and the SIARCS® 3.0 software to determine root distribution. 'C-13' citrange had the largest root system. 'Volkamer' lemon and 'Africa Rough' lemon presented the smallest amount of roots. The effective depth for 80 % of roots was 31-53 cm in rows and 67-68 cm in inter-rows. The effective distance of 80 % of roots measured from the tree trunk exceeded the tree canopy for P. trifoliata, 'Sunki' mandarin, and 'Volkamer' and 'Africa Rough' lemons.

  14. A thermodynamic formulation of root water uptake

    Science.gov (United States)

    Hildebrandt, Anke; Kleidon, Axel; Bechmann, Marcel

    2016-08-01

    By extracting bound water from the soil and lifting it to the canopy, root systems of vegetation perform work. Here we describe how root water uptake can be evaluated thermodynamically and demonstrate that this evaluation provides additional insights into the factors that impede root water uptake. We derive an expression that relates the energy export at the base of the root system to a sum of terms that reflect all fluxes and storage changes along the flow path in thermodynamic terms. We illustrate this thermodynamic formulation using an idealized setup of scenarios with a simple model. In these scenarios, we demonstrate why heterogeneity in soil water distribution and rooting properties affect the impediment of water flow even though the mean soil water content and rooting properties are the same across the scenarios. The effects of heterogeneity can clearly be identified in the thermodynamics of the system in terms of differences in dissipative losses and hydraulic energy, resulting in an earlier start of water limitation in the drying cycle. We conclude that this thermodynamic evaluation of root water uptake conveniently provides insights into the impediments of different processes along the entire flow path, which goes beyond resistances and also accounts for the role of heterogeneity in soil water distribution.

  15. A review on the molecular mechanism of plants rooting modulated ...

    African Journals Online (AJOL)

    A review on the molecular mechanism of plants rooting modulated by auxin. ... rooting modulated by auxin. H Han, S Zhang, X Sun ... Phytohormones, especially auxin, played an essential role in regulating roots developments. This review ...

  16. Effects of acid deposition on tree roots

    Energy Technology Data Exchange (ETDEWEB)

    Persson, H. [Swedish Univ. of Agricultural Sciences (Sweden). Dept. of Ecology and Environmental Research

    1995-12-31

    Large forest regions in SW Sweden have been exposed to high levels of acid deposition for many decades, causing soil acidification in forest soils. Historically, SO{sub 2} has been the major acidification agent, but lately nitrogen compounds increasingly have become important. The amount and chemical form of nitrogen strongly affects the pH in the rhizosphere and rhizoplane. Many forest stands show a positive growth response to increased nitrogen input, even in heavily N-loaded areas. Nitrogen fertilization experiments suggest that part of the increased forest production is caused by a translocation of biomass production from below-ground to above-ground parts. At the same time fine-root growth dynamics are strongly affected by the high N supply. Deficiencies of various nutrients (Mg,Ca,K,Mn and Zn) obtained from needle analyses have been reported from different Picea abies stands. In areas with more extensive acidification and nutrient leaching, a decline in tree vitality has been observed. Although deficiency symptoms in forest trees may be reflected in nitrogen/cation ratios in fine roots, few attempts have been made to explain forest damage symptoms from fine-root chemistry. Root damage is often described as a decline in the amount of living fine roots, an increase in the amount of dead versus live fine roots (a lower live/dead ratio) and an increasing amount of dead medium and coarse roots. The primary objectives of the present presentation were to analyse available data on the effects of high nitrogen and sulphur deposition on mineral nutrient balance in tree fine roots and to evaluate the risk of Al interference with cation uptake by roots

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

    Science.gov (United States)

    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

  18. Pullout tests of root analogs and natural root bundles in soil: Experiments and modeling

    Science.gov (United States)

    Schwarz, M.; Cohen, D.; Or, D.

    2011-06-01

    Root-soil mechanical interactions are key to soil stability on steep hillslopes. Motivated by new advances and applications of the Root Bundle Model (RBM), we conducted a series of experiments in the laboratory and in the field to study the mechanical response of pulled roots. We systematically quantified the influence of different factors such as root geometry and configuration, soil type, and soil water content considering individual roots and root bundles. We developed a novel pullout apparatus for strain-controlled field and laboratory tests of up to 13 parallel roots measured individually and as a bundle. Results highlight the importance of root tortuosity and root branching points for prediction of individual root pullout behavior. Results also confirm the critical role of root diameter distribution for realistic prediction of global pullout behavior of a root bundle. Friction between root and soil matrix varied with soil type and water content and affected the force-displacement behavior. Friction in sand varied from 1 to 17 kPa, with low values obtained in wet sand at a confining pressure of 2 kPa and high values obtained in dry sand with 4.5 kPa confining pressure. In a silty soil matrix, friction ranged between 3 kPa under wet and low confining pressure (2 kPa) and 6 kPa in dry and higher confining pressure (4.5 kPa). Displacement at maximum pullout force increased with increasing root diameter and with tortuosity. Laboratory experiments were used to calibrate the RBM that was later validated using six field measurements with natural root bundles of Norway spruce (Picea abies L.). These tests demonstrate the progressive nature of root bundle failure under strain-controlled pullout force and provide new insights regarding force-displacement behavior of root reinforcement, highlighting the importance of considering displacement in slope stability models. Results show that the magnitude of maximum root pullout forces (1-5 kPa) are important for slope

  19. Negative phototropism of rice root and its influencing factors

    Institute of Scientific and Technical Information of China (English)

    WANG; Zhong(王忠); MO; Yiwei(莫亿伟); QIAN; Shanqin(钱善勤); GU; Yunjie(顾蕴洁)

    2002-01-01

    Some characteristics of the rice (Oryza sativa L.) root were found in the experiment of unilaterally irradiating the roots which were planted in water: (ⅰ) All the seminal roots, adventitious roots and their branched roots bent away from light, and their curvatures ranged from 25° to 60°. The curvature of adventitious root of the higher node was often larger than that of the lower node, and even larger than that of the seminal root. (ⅱ) The negative phototropic bending of the rice root was mainly due to the larger growth increment of root-tip cells of the irradiated side compared with that of the shaded side. (ⅲ) Root cap was the site of light perception. If root cap was shaded while the root was irradiated the root showed no negative phototropism, and the root lost the characteristic of negative phototropism when root cap was divested. Rice root could resume the characteristic of negative phototropism when the new root cap grew up, if the original cells of root cap were well protected while root cap was divested. (ⅳ) The growth increment and curvature of rice root were both influenced by light intensity. Within the range of 0-100μmol@m-2@s-1, the increasing of light intensity resulted in the decreasing of the growth increment and the increasing of the curvature of rice root. (ⅴ) The growth increment and the curvature reached the maximum at 30℃ with the temperature treatment of 10-40℃. (ⅵ) Blue-violet light could prominently induce the negative phototropism of rice root, while red light had no such effect. (ⅶ) The auxin (IAA) in the solution, as a very prominent influencing factor, inhibited the growth, the negative phototropism and the gravitropism of rice root when the concentration of IAA increased. The response of negative phototropism of rice root disappeared when the concentration of IAA was above 10 mg@L-1.

  20. Arabidopsis: an adequate model for dicot root systems?

    OpenAIRE

    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 8 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 th...

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

    OpenAIRE

    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 t...

  2. THttpServer class in ROOT

    Science.gov (United States)

    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.

  3. ANTIARTHRITIC ACTIVITY OF DESMODIUM GANGETICUM ROOT

    Directory of Open Access Journals (Sweden)

    Vedpal

    2013-09-01

    Full Text Available The present study is aimed to evaluate the in-vitro anti-arthritic activity of aqueous extract of Desmodium gangeticum root using inhibition of protein denaturation model and human red blood cell Membrane stabilization model. Diclofenac sodium was used as a standard drug. Results revealed that the aqueous extract of Desmodium gangeticum root at different concentrations possessed significant anti-arthritic activity as compared to standard drug used as Diclofenac sodium. The results obtained in the present investigation Indicate that aqueous extract of Desmodium gangeticum root showed anti-arthritic activity.

  4. A "square-root rule" for reinsurance

    Directory of Open Access Journals (Sweden)

    Michael R. Powers

    2006-12-01

    Full Text Available In previous work, the authors derived a mathematical expression for the optimal (or "saturation" number of reinsurers for a given number of primary insurers (see Powers and Shubik, 2001. In the current article, we show analytically that, for large numbers of primary insurers, this mathematical expression provides a "square-root rule"; i.e., the optimal number of reinsurers in a market is given asymptotically by the square root of the total number of primary insurers. We note further that an analogous "fourth-root rule" applies to markets for retrocession (the reinsurance of reinsurance.

  5. BOREAS TE-2 Root Respiration Data

    Science.gov (United States)

    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).

  6. Clinical technique for invasive cervical root resorption

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Machado Silveira

    2011-01-01

    Full Text Available 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.

  7. Enhancing auxin accumulation in maize root tips improves root growth and dwarfs plant height.

    Science.gov (United States)

    Li, Zhaoxia; Zhang, Xinrui; Zhao, Yajie; Li, Yujie; Zhang, Guangfeng; Peng, Zhenghua; Zhang, Juren

    2017-05-12

    Maize is a globally important food, feed crop and raw material for the food and energy industry. Plant architecture optimization plays important roles in maize yield improvement. PIN-FORMED (PIN) proteins are important for regulating auxin spatiotemporal asymmetric distribution in multiple plant developmental processes. In this study, ZmPIN1a overexpression in maize increased the number of lateral roots and inhibited their elongation, forming a developed root system with longer seminal roots and denser lateral roots. ZmPIN1a overexpression reduced plant height, internode length and ear height. This modification of the maize phenotype increased the yield under high-density cultivation conditions, and the developed root system improved plant resistance to drought, lodging and a low-phosphate environment. IAA concentration, transport capacity determination and application of external IAA indicated that ZmPIN1a overexpression led to increased IAA transport from shoot to root. The increase in auxin in the root enabled the plant to allocate more carbohydrates to the roots, enhanced the growth of the root and improved plant resistance to environmental stress. These findings demonstrate that maize plant architecture can be improved by root breeding to create an ideal phenotype for further yield increases. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  8. The Root Cap Determines Ethylene-Dependent Growth and Development in Maize Roots

    Institute of Scientific and Technical Information of China (English)

    Achim Hahn; Roman Zimmermann; Dierk Wanke; Klaus Harter; Hans G.Edelmann

    2008-01-01

    Besides providing protection against mechanical damage to the root tip,the root cap is involved in the perception and processing of diverse external and internal stimuli resulting in altered growth and development.The transduction of these stimuli includes hormonal signaling pathways such as those of auxin,ethylene and cytokinin.Here,we show that the root cap is essential for the ethylene-induced regulation of elongation growth and root hair formation in maize.Exogenously applied ethylene is no longer able to inhibit elongation growth when the root cap has been surgically removed prior to hormone treatment.Reconstitution of the cap positively correlates with the developing capacity of the roots to respond to ethylene again.In contrast,the removal of the root cap does not per se affect growth inhibition controlled by auxin and cytokinin.Furthermore,our semi-quantitative RT-PCR results support earlier findings that the maize root cap is a site of high gene expression activity with respect to sensing and responding to hormones such as ethylene.From these data,we propose a novel function of the root cap which is the establishment of competence to respond to ethylene in the distal zones of the root.

  9. Phosphate Availability Alters Lateral Root Anatomy and Root Architecture of Fraxinus mandshurica Rupr. Seedlings

    Institute of Scientific and Technical Information of China (English)

    Chu WU; Xing WEI; Hai-Long SUN; Zheng-Quan WANG

    2005-01-01

    Plants have evolved some mechanisms to maximize the efficiency of phosphorus acquisition.Changes in root architecture are one such mechanism. When Fraxinus mandshurica Rupr. seedlings were grown under conditions of low phosphorus availability, the length of cells in the meristem zone of the lateral roots was longer, but the length of cells in the elongation and mature zones of the lateral roots was shorter,compared with seedlings grown under conditions of high phosphorus availability. The elongation rates of primary roots increased as phosphorus availability increased, but the elongation rates of the branched zones of the primary roots decreased. The number of lateral root primordia and the length of the lateral roots decreased as phosphorus availability increased. The topological index (altitude slope) decreased as phosphorus availability increased, suggesting that root architecture tended to be herringbone-like when seedlings were grown under conditions of low phosphate availability. Herringbone-like root systems exploit nutrients more efficiently, but they have higher construction costs than root systems with a branching pattern.

  10. Regenerative Endodontic Procedures for Traumatized Teeth after Horizontal Root Fracture, Avulsion, and Perforating Root Resorption.

    Science.gov (United States)

    Saoud, Tarek Mohamed A; Mistry, Sonali; Kahler, Bill; Sigurdsson, Asgeir; Lin, Louis M

    2016-10-01

    Traumatic injury to the teeth can cause horizontal root fractures and inflammatory root resorptions (external and internal). Traditionally, traumatized teeth with horizontal root fractures resulting in pulp necrosis and inflammatory root resorptions are treated with conventional root canal therapy. A 15-year-old boy had a history of traumatic injury to mature tooth #8 resulting in horizontal root fracture and pulp necrosis of the coronal fragment. A 7-year-old girl suffered an avulsion injury to immature tooth #9, which developed inflammatory replacement resorption and subsequently root fractured 15 months later. Another 16-year-old boy also suffered a history of traumatic injury to mature tooth #8, resulting in perforating root resorption. All teeth were treated with regenerative endodontic procedures using chemomechanical debridement, calcium hydroxide/triple antibiotic paste dressing, EDTA rinse, induction of periapical bleeding into the canal space, and a coronal mineral trioxide aggregate plug. In the tooth presenting with horizontal root fracture, only the coronal fragment was treated to preserve pulp vitality in the apical fragment for possible pulp tissue regeneration. After regenerative endodontic procedures, clinical signs/symptoms subsided, and inflammatory osteolytic lesions resolved in all traumatized teeth. Two teeth were followed for 19 months and 1 tooth for 5 years. At the last review of the teeth with horizontal root fractures, the first case showed healing by calcified tissue and the second case showed healing by fibrous connective and hard tissue. Tooth with perforating root resorption demonstrated a decrease in size of the resorptive defect. Based on these case reports, regenerative endodontic procedures have the potential to be used to treat traumatized teeth with horizontal root fracture and inflammatory root resorption. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  11. Plant roots use a patterning mechanism to position lateral root branches toward available water.

    Science.gov (United States)

    Bao, Yun; Aggarwal, Pooja; Robbins, Neil E; Sturrock, Craig J; Thompson, Mark C; Tan, Han Qi; Tham, Cliff; Duan, Lina; Rodriguez, Pedro L; Vernoux, Teva; Mooney, Sacha J; Bennett, Malcolm J; Dinneny, José R

    2014-06-24

    The architecture of the branched root system of plants is a major determinant of vigor. Water availability is known to impact root physiology and growth; however, the spatial scale at which this stimulus influences root architecture is poorly understood. Here we reveal that differences in the availability of water across the circumferential axis of the root create spatial cues that determine the position of lateral root branches. We show that roots of several plant species can distinguish between a wet surface and air environments and that this also impacts the patterning of root hairs, anthocyanins, and aerenchyma in a phenomenon we describe as hydropatterning. This environmental response is distinct from a touch response and requires available water to induce lateral roots along a contacted surface. X-ray microscale computed tomography and 3D reconstruction of soil-grown root systems demonstrate that such responses also occur under physiologically relevant conditions. Using early-stage lateral root markers, we show that hydropatterning acts before the initiation stage and likely determines the circumferential position at which lateral root founder cells are specified. Hydropatterning is independent of endogenous abscisic acid signaling, distinguishing it from a classic water-stress response. Higher water availability induces the biosynthesis and transport of the lateral root-inductive signal auxin through local regulation of tryptophan aminotransferase of Arabidopsis 1 and PIN-formed 3, both of which are necessary for normal hydropatterning. Our work suggests that water availability is sensed and interpreted at the suborgan level and locally patterns a wide variety of developmental processes in the root.

  12. Rhizosphere interactions: root exudates, microbes and microbial communities

    National Research Council Canada - National Science Library

    Huang, Xing-Feng; Chaparro, Jacqueline M; Reardon, Kenneth F; Zhang, Ruifu; Shen, Qirong; Vivanco, Jorge M

    2014-01-01

    .... In this review, we summarize recent progress made in unraveling the interactions between plants and rhizosphere microbes through plant root exudates, focusing on how root exudate compounds mediate...

  13. Effect of two contemporary root canal sealers on root canal dentin microhardness

    Science.gov (United States)

    2017-01-01

    Background Successful root canal treatment depends on proper cleaning, disinfecting and shaping of the root canal space. Pulpless teeth have lower dentin microhardness value compared to that of vital teeth. A material which can cause change in dentin composition may affect the microhardness. Thus the aim of this study was to evaluate and compare the effect of two root canal sealers on dentin microhardness. Material and Methods Forty two single rooted teeth were selected and divided into 3 equal groups; Apexit, iRootSP and control groups (n=14) Each group was then divided into 2 subgroups according to the post evaluation period; 1 week and 2 months (n=7). Root canal procedure was done in the experimental groups and obturation was made using either; Apexit, iRootSP or left unprepared and unobturated in the control group. Roots were sectioned transversely into cervical, middle and apical segments. The three sections of each root were mounted in a plastic chuck with acrylic resin. The coronal dentin surfaces of the root segments werepolished. Microhardness of each section was measured at 500 µm and 1000 µm from the canal lumen. Results Four way-ANOVA revealed that different tested sealer materials, canal third, measuring distance from the pulp and time as independent variables had statistically non significant effect on mean microhardness values (VHN) at p≤0.001. Among iRootSP groups there was a statistically significant difference between iRoot SP at coronal root portion (87.79±17.83) and iRoot SP at apical root portion (76.26±9.33) groups where (p=0.01). IRoot SP at coronal canal third had higher statistically significant mean microhardness value (87.79±17.83) compared to Apexit at coronal third (73.61±13.47) where (p=0.01). Conclusions Root canal sealers do not affect dentin microhardness. Key words:Root canal, dentin, sealers, microhardness, bioceramic. PMID:28149466

  14. Elements with Square Roots in Finite Groups

    Institute of Scientific and Technical Information of China (English)

    M.S. Lucido; M.R. Pournaki

    2005-01-01

    In this paper, we study the probability that a randomly chosen element in a finite group has a square root, in particular the simple groups of Lie type of rank 1, the sporadic finite simple groups and the alternating groups.

  15. Dechlorodauricumine from cultured roots of Menispermum dauricum.

    Science.gov (United States)

    Sugimoto, Yukihiro; Matsui, Miharu; Takikawa, Hirosato; Sasaki, Mitsuru; Kato, Masako

    2005-11-01

    Dechlorodauricumine, a possible organic substrate for biochlorination, was isolated from cultured roots of Menispermum dauricum, a rich source of chlorinated alkaloids. Its structure was established by spectroscopic and chemical methods.

  16. Naine objektistab meest / Fideelia-Signe Roots

    Index Scriptorium Estoniae

    Roots, Fideelia-Signe, 1976-

    2009-01-01

    Fideelia-Signe Roots Eesti Kunstiakadeemias 2009. a. kevadsemestril enda poolt läbi viidud valikainekursusest "Kunstiteose anatoomiast mehe anatoomiani", mis lõppes näitusega "Tõuseb / ei tõuse" Eesti Tervishoiumuuseumis, avatud 31. maini

  17. Naine objektistab meest / Fideelia-Signe Roots

    Index Scriptorium Estoniae

    Roots, Fideelia-Signe, 1976-

    2009-01-01

    Fideelia-Signe Roots Eesti Kunstiakadeemias 2009. a. kevadsemestril enda poolt läbi viidud valikainekursusest "Kunstiteose anatoomiast mehe anatoomiani", mis lõppes näitusega "Tõuseb / ei tõuse" Eesti Tervishoiumuuseumis, avatud 31. maini

  18. BGP reflection functors in root categories

    Institute of Scientific and Technical Information of China (English)

    XIAO Jie; ZHANG Guanglian; ZHU Bin

    2005-01-01

    We define the BGP-reflection functors in the derived categories and the root categories. By Ringel's Hall algebra approach, the BGP-reflection functor is applicable to obtain the classical Weyl group action on the Lie algebra.

  19. EFFECT OF CALITROPIS PROCERA AQUEOUS ROOT EXTRACT ...

    African Journals Online (AJOL)

    ABUBAKAR

    The hepatocurative effect of aqueous root extract of Calitropis Procera on CCl4 induced hepatotoxicity in rabbits was studied in groups of rabbit and the levels of liver enzymes; aspartate .... and inhibitors and presence of pyridoxine (vitamin.

  20. Cryptographic Protocols Based on Root Extracting

    DEFF Research Database (Denmark)

    Koprowski, Maciej

    In this thesis we design new cryptographic protocols, whose security is based on the hardness of root extracting or more speci cally the RSA problem. First we study the problem of root extraction in nite Abelian groups, where the group order is unknown. This is a natural generalization of the...... complexity of root extraction, even if the algorithm can choose the "public exponent'' itself. In other words, both the standard and the strong RSA assumption are provably true w.r.t. generic algorithms. The results hold for arbitrary groups, so security w.r.t. generic attacks follows for any cryptographic...... construction based on root extracting. As an example of this, we modify Cramer-Shoup signature scheme such that it becomes a genericm algorithm. We discuss then implementing it in RSA groups without the original restriction that the modulus must be a product of safe primes. It can also be implemented in class...

  1. Tree root systems and nutrient mobilization

    DEFF Research Database (Denmark)

    Boyle, Jim; Rob, Harrison; Raulund-Rasmussen, Karsten

    Roots mobilize nutrients via deep penetration and rhizosphere processes inducing weathering of primary minerals. These contribute to C transfer to soils and to tree nutrition. Assessments of these characteristics and processes of root systems are important for understanding long-term supplies...... some of the world’s most productive intensively managed forests, including Brazil and the Southeast and Pacifi c Northwest regions of the United States, have shown that root systems are often several meters in depth, and often extend deeper than soil is sampled. Large amounts of carbon are also...... sometimes stored at depth. Other recent studies on potential release of nutrients due to chemical weathering indicate the importance of root access to deep soil layers. Release profi les clearly indicate depletion in the top layers and a much higher potential in B and C horizons. Review of evaluations...

  2. Transgenic root cultures of Gentiana punctata L.

    Directory of Open Access Journals (Sweden)

    Branka Vinterhalter

    2014-01-01

    Full Text Available Shoot cultures of Gentiana punctata L. were inoculated with suspension of Agrobacterium rhizogenes strain A4 M70GUS. Hairy roots which appeared 2-3 weeks later were cultured on hormone-free, liquid, WPM (Lloyd and McCown 1980 basal medium for more than 5 years (60 subcultures. Growth rate of transformed roots was higher than the growth rate of nontransformed roots. Spontaneous shoot regeneration occured only in three culture vessels in subcultures No. 40 and 42. Plants had phenotype characteristics typical for A. rhizogenes transformed plants including: wrincled leaves, short internodes, plagiotropic roots and in general their growth rate was reduced. These plants also manifested precocious formation of flower buds without vernalization and flowering under in vitro conditions. Flowers were pale yellow, the same as in the standard phenotype.

  3. Tooth mobility changes subsequent to root fractures

    DEFF Research Database (Denmark)

    Andreasen, Jens Ove; Christensen, Søren Steno Ahrensburg; Tsilingaridis, Georgios

    2012-01-01

    The purpose of this study was to analyze tooth mobility changes in root-fractured permanent teeth and relate this to type of interfragment healing (hard tissue healing (HT), interfragment healing with periodontal ligament (PDL) and nonhealing with interposition of granulation tissue (GT) because...... of pulp necrosis in the coronal fragment. Furthermore, the effect of age, location of the fracture on the root, and observation period on mobility values was analyzed. Mobility values were measured for 44 of 95 previous reported root-fractured permanent incisors. Mobility changes were measured...... after 3 months and 1 year, and a normalization of mobility value was usually found after 5 and 10 years. In 17 cases of PDL healing, generally a higher mobility was found in comparison with root fractures healing with hard tissue, and a consistent decrease in mobility value was found in the course...

  4. New Heuristics for Rooted Triplet Consistency

    Directory of Open Access Journals (Sweden)

    Soheil Jahangiri

    2013-07-01

    Full Text Available Rooted triplets are becoming one of the most important types of input for reconstructing rooted phylogenies. A rooted triplet is a phylogenetic tree on three leaves and shows the evolutionary relationship of the corresponding three species. In this paper, we investigate the problem of inferring the maximum consensus evolutionary tree from a set of rooted triplets. This problem is known to be APX-hard. We present two new heuristic algorithms. For a given set of m triplets on n species, the FastTree algorithm runs in O(m + α(nn2 time, where α(n is the functional inverse of Ackermann’s function. This is faster than any other previously known algorithms, although the outcome is less satisfactory. The Best Pair Merge with Total Reconstruction (BPMTR algorithm runs in O(mn3 time and, on average, performs better than any other previously known algorithms for this problem.

  5. DMA thermal analysis of yacon tuberous roots

    Science.gov (United States)

    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.

  6. The inflow of Cs-137 in soil with root litter and root exudates of Scots pine

    Science.gov (United States)

    Shcheglov, Alexey; Tsvetnova, Olga; Popova, Evgenia

    2017-04-01

    In the model experiment on evaluation of Cs-137 inflow in the soil with litter of roots and woody plants root exudates on the example of soil and water cultures of Scots pine (Pinus sylvestris L.) was shown, that through 45 days after the deposit Cs-137 solution on pine needles (specific activity of solution was 3.718*106 Bk) of the radionuclide in all components of model systems has increased significantly: needles, small branches and trunk by Cs-137 surface contamination during the experiment; roots as a result of the internal distribution of the radionuclide in the plant; soil and soil solution due to the of receipt Cs-137 in the composition of root exudates and root litter. Over 99% of the total reserve of Cs-137 accumulated in the components of the soil and water systems, accounted for bodies subjected to external pollution (needles and small branches) and 99.9% was due to root exudates

  7. ROOT I/O in Javascript - Reading ROOT files in a browser

    CERN Document Server

    CERN. Geneva

    2012-01-01

    A JavaScript version of the ROOT I/O subsystem is being developed, in order to be able to browse (inspect) ROOT files in a platform independent way. This allows the content of ROOT files to be displayed in most web browsers, without having to install ROOT or any other software on the server or on the client. This gives a direct access to ROOT files from new (e.g. portable) devices in a light way. It will be possible to display simple graphical objects such as histograms and graphs (TH1, TH2, TH3, TProfile, TGraph, ...). The rendering will first be done with an external JavaScript graphic library, before investigating a way to produce graphics closer to what ROOT supports on other platforms (X11, Windows).

  8. Operating protocols of external root cervical resorption

    OpenAIRE

    Luca Venuti

    2015-01-01

    Aim: Theme of this report is the external cervical root resorption and the sequence of clinical procedures to be implemented during the phases of treatment. The external cervical root resorption (ICR) presents particular pathological conditions such as to classify between resorption of inflammatory origin.1–3 It is generally presented as a complex clinical situation both in the diagnosis in a predictable prognosis.3–6 It's often associated with loss of calcified tissue: dentin, cementum, a...

  9. Sparse DOA estimation with polynomial rooting

    OpenAIRE

    Xenaki, Angeliki; Gerstoft, Peter; Fernandez Grande, Efren

    2015-01-01

    Direction-of-arrival (DOA) estimation involves the localization of a few sources from a limited number of observations on an array of sensors. Thus, DOA estimation can be formulated as a sparse signal reconstruction problem and solved efficiently with compressive sensing (CS) to achieve highresolution imaging. Utilizing the dual optimal variables of the CS optimization problem, it is shown with Monte Carlo simulations that the DOAs are accurately reconstructed through polynomial rooting (Root...

  10. Rational Convolution Roots of Isobaric Polynomials

    OpenAIRE

    Conci, Aura; Li, Huilan; MacHenry, Trueman

    2014-01-01

    In this paper, we exhibit two matrix representations of the rational roots of generalized Fibonacci polynomials (GFPs) under convolution product, in terms of determinants and permanents, respectively. The underlying root formulas for GFPs and for weighted isobaric polynomials (WIPs), which appeared in an earlier paper by MacHenry and Tudose, make use of two types of operators. These operators are derived from the generating functions for Stirling numbers of the first kind and second kind. Hen...

  11. Anatomical aspects of angiosperm root evolution

    Science.gov (United States)

    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

  12. Development of Machine Learning Tools in ROOT

    Science.gov (United States)

    Gleyzer, S. V.; Moneta, L.; Zapata, Omar A.

    2016-10-01

    ROOT is a framework for large-scale data analysis that provides basic and advanced statistical methods used by the LHC experiments. These include machine learning algorithms from the ROOT-integrated Toolkit for Multivariate Analysis (TMVA). We present several recent developments in TMVA, including a new modular design, new algorithms for variable importance and cross-validation, interfaces to other machine-learning software packages and integration of TMVA with Jupyter, making it accessible with a browser.

  13. Operating protocols of external root cervical resorption

    OpenAIRE

    Venuti, Luca

    2015-01-01

    Aim: Theme of this report is the external cervical root resorption and the sequence of clinical procedures to be implemented during the phases of treatment. The external cervical root resorption (ICR) presents particular pathological conditions such as to classify between resorption of inflammatory origin.1–3 It is generally presented as a complex clinical situation both in the diagnosis in a predictable prognosis.3–6 It's often associated with loss of calcified tissue: dentin, cementum, a...

  14. Two root canals in maxillary central incisor

    Directory of Open Access Journals (Sweden)

    Fábio de Almeida Gomes

    2011-07-01

    Full Text Available Introduction and objective: The success of endodontic treatment requires the knowledge of tooth morphology and its variations. Case report: This clinical article reports an unusual root canal configuration that was detected in a maxillary central incisor with two root canals, demonstrated by radiographic and computerized tomography exams. Conclusion: Knowledge of endodontic anatomy as well as the obtainment of both preoperative radiographs and tomography is important to detect abnormal tooth morphology.

  15. Development of TRatioPlot in ROOT

    CERN Document Server

    Gessinger-Befurt, Paul

    2016-01-01

    The ROOT data analysis and visualization framework is a software package which is widely used in physics, especially in high energy physics. A common visualization which has so far been lacking a direct implementation is the ratio plot, as well as a few similar types of plots. The scope and goal of the summer student project at CERN was to implement a class in ROOT itself, that can take care of the most common types of calculations, and produces high quality visuals.

  16. q--Magnetism at roots of unity

    CERN Document Server

    Berkovich, A; Gómez, C

    1993-01-01

    We study the thermodynamic properties of a family of integrable 1D spin chain hamiltonians associated with quantum groups at roots of unity. These hamiltonians depend for each primitive root of unit on a parameter $s$ which plays the role of a continuous spin. The model exhibits ferrimagnetism even though the interaction involved is between nearest neighbors. The latter phenomenon is interpreted as a genuine quantum group effect with no ``classical" analog. The discussion of conformal properties is given.

  17. Immunology of root resorption: A literature review

    Directory of Open Access Journals (Sweden)

    Silva Luciano

    2008-01-01

    Full Text Available Root resorption seems to be related to a complex combination of mechanical factors and biological activity, which comprehends the role of immunologic structures including specialized cells. The aim of this research was to explain the development of the process - from mineralization to the destruction of hard tissues - and the possible relationship between root resorption and immunology, along with discussing current concepts described in the literature.

  18. Relationships between root respiration rate and root morphology, chemistry and anatomy in Larix gmelinii and Fraxinus mandshurica.

    Science.gov (United States)

    Jia, Shuxia; McLaughlin, Neil B; Gu, Jiacun; Li, Xingpeng; Wang, Zhengquan

    2013-06-01

    Tree roots are highly heterogeneous in form and function. Previous studies revealed that fine root respiration was related to root morphology, tissue nitrogen (N) concentration and temperature, and varied with both soil depth and season. The underlying mechanisms governing the relationship between root respiration and root morphology, chemistry and anatomy along the root branch order have not been addressed. Here, we examined these relationships of the first- to fifth-order roots for near surface roots (0-10 cm) of 22-year-old larch (Larix gmelinii L.) and ash (Fraxinus mandshurica L.) plantations. Root respiration rate at 18 °C was measured by gas phase O2 electrodes across the first five branching order roots (the distal roots numbered as first order) at three times of the year. Root parameters of root diameter, specific root length (SRL), tissue N concentration, total non-structural carbohydrates (starch and soluble sugar) concentration (TNC), cortical thickness and stele diameter were also measured concurrently. With increasing root order, root diameter, TNC and the ratio of root TNC to tissue N concentration increased, while the SRL, tissue N concentration and cortical proportion decreased. Root respiration rate also monotonically decreased with increasing root order in both species. Cortical tissue (including exodermis, cortical parenchyma and endodermis) was present in the first three order roots, and cross sections of the cortex for the first-order root accounted for 68% (larch) and 86% (ash) of the total cross section of the root. Root respiration was closely related to root traits such as diameter, SRL, tissue N concentration, root TNC : tissue N ratio and stele-to-root diameter proportion among the first five orders, which explained up to 81-94% of variation in the rate of root respiration for larch and up to 83-93% for ash. These results suggest that the systematic variations of root respiration rate within tree fine root system are possibly due to the

  19. Defining the core Arabidopsis thaliana root microbiome

    Science.gov (United States)

    Gehring, Jase; Malfatti, Stephanie; Tremblay, Julien; Engelbrektson, Anna; Kunin, Victor; del Rio, Tijana Glavina; Edgar, Robert C.; Eickhorst, Thilo; Ley, Ruth E.; Hugenholtz, Philip; Tringe, Susannah Green; Dangl, Jeffery L.

    2014-01-01

    Land plants associate with a root microbiota distinct from the complex microbial community present in surrounding soil. The microbiota colonizing therhizosphere(immediately surroundingthe root) and the endophytic compartment (within the root) contribute to plant growth, productivity, carbon sequestration and phytoremediation1-3. Colonization of the root occurs despite a sophisticated plant immune system4,5, suggesting finely tuned discrimination of mutualists and commensals from pathogens. Genetic principles governing the derivation of host-specific endophyte communities from soil communities are poorly understood. Here we report the pyrosequencing of the bacterial 16S ribosomal RNA gene of more than 600 Arabidopsis thaliana plants to test the hypotheses that the root rhizosphere and endophytic compartment microbiota of plants grown under controlled conditions in natural soils are sufficiently dependent on the host to remain consistent across different soil types and developmental stages, and sufficiently dependent on host genotype to vary between inbred Arabidopsis accessions. We describe different bacterial communities in two geochemically distinct bulk soils and in rhizosphere and endophytic compartments prepared from roots grown in these soils. The communities in each compartment are strongly influenced by soil type. Endophytic compartments from both soils feature overlapping, low-complexity communities that are markedly enriched in Actinobacteria and specific families from other phyla, notably Proteobacteria. Some bacteria vary quantitatively between plants of different developmental stage and genotype. Our rigorous definition of an endophytic compartment microbiome should facilitate controlled dissection of plantmicrobe interactions derived from complex soil communities. PMID:22859206

  20. Gene expression regulation in roots under drought.

    Science.gov (United States)

    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.

  1. Extracellular DNA: the tip of root defenses?

    Science.gov (United States)

    Hawes, Martha C; Curlango-Rivera, Gilberto; Wen, Fushi; White, Gerard J; Vanetten, Hans D; Xiong, Zhongguo

    2011-06-01

    This review discusses how extracellular DNA (exDNA) might function in plant defense, and at what level(s) of innate immunity this process might operate. A new role for extracellular factors in mammalian defense has been described in a series of studies. These studies reveal that cells including neutrophils, eosinophils, and mast cells produce 'extracellular traps' (ETs) consisting of histone-linked exDNA. When pathogens are attracted to such ETs, they are trapped and killed. When the exDNA component of ETs is degraded, trapping is impaired and resistance against invasion is reduced. Conversely, mutation of microbial genes encoding exDNases that degrade exDNA results in loss of virulence. This discovery that exDNases are virulence factors opens new avenues for disease control. In plants, exDNA is required for defense of the root tip. Innate immunity-related proteins are among a group of >100 proteins secreted from the root cap and root border cell populations. Direct tests revealed that exDNA also is rapidly synthesized and exported from the root tip. When this exDNA is degraded by the endonuclease DNase 1, root tip resistance to fungal infection is lost; when the polymeric structure is degraded more slowly, by the exonuclease BAL31, loss of resistance to fungal infection is delayed accordingly. The results suggest that root border cells may function in a manner analogous to that which occurs in mammalian cells.

  2. Roots of Dehn twists about separating curves

    CERN Document Server

    Rajeevsarathy, Kashyap

    2011-01-01

    Let $C$ be a curve in a closed orientable surface $F$ of genus $g \\geq 2$ that separates $F$ into subsurfaces $\\widetilde {F_i}$ of genera $g_i$, for $i = 1,2$. We study the set of roots in $\\Mod(F)$ of the Dehn twist $t_C$ about $C$. All roots arise from pairs of $C_{n_i}$-actions on the $\\widetilde{F_i}$, where $n=\\lcm(n_1,n_2)$ is the degree of the root, that satisfy a certain compatibility condition. The $C_{n_i}$ actions are of a kind that we call nestled actions, and we classify them using tuples that we call data sets. The compatibility condition can be expressed by a simple formula, allowing a classification of all roots of $t_C$ by compatible pairs of data sets. We use these data set pairs to classify all roots for $g = 2$ and $g = 3$. We show that there is always a root of degree at least $2g^2+2g$, while $n \\leq 4g^2+2g$. We also give some additional applications.

  3. Acid protease production in fungal root endophytes.

    Science.gov (United States)

    Mayerhofer, Michael S; Fraser, Erica; Kernaghan, Gavin

    2015-01-01

    Fungal endophytes are ubiquitous in healthy root tissue, but little is known about their ecosystem functions, including their ability to utilize organic nutrient sources such as proteins. Root-associated fungi may secrete proteases to access the carbon and mineral nutrients within proteins in the soil or in the cells of their plant host. We compared the protein utilization patterns of multiple isolates of the root endophytes Phialocephala fortinii s.l., Meliniomyces variabilis and Umbelopsis isabellina with those of two ectomycorrhizal (ECM) fungi, Hebeloma incarnatulum and Laccaria bicolor, and the wood-decay fungus Irpex lacteus at pH values of 2-9 on liquid BSA media. We also assessed protease activity using a fluorescently labeled casein assay and gelatin zymography and characterized proteases using specific protease inhibitors. I. lacteus and U. isabellina utilized protein efficiently, while the ECM fungi exhibited poor protein utilization. ECM fungi secreted metallo-proteases and had pH optima above 4, while other fungi produced aspartic proteases with lower pH optima. The ascomycetous root endophytes M. variabilis and P. fortinii exhibited intermediate levels of protein utilization and M. variabilis exhibited a very low pH optimum. Comparing proteolytic profiles between fungal root endophytes and fungi with well defined ecological roles provides insight into the ecology of these cryptic root associates.

  4. Tomato Root Response to Subsurface Drip Irrigation

    Institute of Scientific and Technical Information of China (English)

    ZHUGE Yu-Ping; ZHANG Xu-Dong; ZHANG Yu-Long; LI Jun; YANG Li-Juan; HUANG Yi; LIU Ming-Da

    2004-01-01

    Four depth treatments of subsurface drip irrigation pipes were designated as 1) at 20,2) 30 and 3) 40 cm depths all with a drip-proof flumes underneath,and 4) at 30 cm without a drip-proof flume to investigate the responses of a tomato root system to different technical parameters of subsurface drip irrigation in a glass greenhouse,to evaluate tomato growth as affected by subsurface drip irrigation,and to develop an integrated subsurface drip irrigation method for optimal tomato yield and water use in a glass greenhouse. Tomato seedlings were planted above the subsurface drip irrigation pipe. Most of the tomato roots in treatment 1 were found in the top 0-20 cm soil depth with weak root activity but with yield and water use efficiency (WUE) significantly less (P ---- 0.05) than treatment 2; root activity and tomato yield were significantly higher (P = 0.05) with treatment 3 compared to treatment 1; and with treatment 2 the tomato roots and shoots grew harmoniously with root activity,nutrient uptake,tomato yield and WUE significantly higher (P= 0.05) or as high as the other treatments. These findings suggested that subsurface drip irrigation with pipes at 30 cm depth with a drip-proof flume placed underneath was best for tomato production in greenhouses. In addition,the irrigation interval should be about 7-8 days and the irrigation rate should be set to 225 m3 ha-1 per event.

  5. Vertical root fractures and their management

    Science.gov (United States)

    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

  6. RootNav: Navigating Images of Complex Root Architectures1[C][W

    Science.gov (United States)

    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

  7. Root caries, root surface restorations and lifestyle factors in adult Danes

    DEFF Research Database (Denmark)

    Christensen, Lisa Bøge; Jensen, Allan Bardow; Ekstrand, Kim

    2015-01-01

    AIM: To investigate selected lifestyle factors in relation to active caries and restored root surface lesions in adults. MATERIALS AND METHODS: Based on clinical examinations and questionnaires, data on root caries, socioeconomic status, body mass index, dietary habits, alcohol consumption, tobacco...... dentures were significantly associated with presence of active root caries (p tobacco use and alcohol...... consumption, as well as wearing dentures, were significantly associated with the occurrence of untreated caries and restored root surface lesions, especially in persons over 45. Thus, such lifestyle factors should be taken into consideration, identifying persons with a need of preventive dental services...

  8. New insights to lateral rooting: Differential responses to heterogeneous nitrogen availability among maize root types.

    Science.gov (United States)

    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.

  9. Capturing Arabidopsis root architecture dynamics with ROOT-FIT reveals diversity in responses to salinity.

    Science.gov (United States)

    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.

  10. Enhanced MRI in compressed lumbosacral nerve root; Alteration of vascular peameability in nerve root

    Energy Technology Data Exchange (ETDEWEB)

    Morita, Tomofumi; Yoshizawa, Hidezo; Nakai, Sadaaki; Kobayashi, Shigeru; Hachiya, Hiromichi; Nakagawa, Masato; Nishimoto, Satoshi (Fujita Health Univ., Toyoake, Aichi (Japan). School of Medicine)

    1993-04-01

    The study was undertaken to assess how enhanced MRI reflects pathophysiology of the nerve root. In fundamental study, the seventh left lumbar nerve root was compressed by a clip for one hour in 10 mongrel dogs. Thirty min after removal of mechanical compression, gadolinium and Evans blue albumin (EBA) were iv injected. Then, the dogs were killed 10 min later. A mass of lumbosacral nerve root was removed for MR imaging. In addition, nerve root slices were prepared to examine changes in vascular permeability of EBA under microscopy. The compression area of nerve root was seen as hyperintensity on enhanced MRI, corresponding to extravascular leakage of EBA that resulted from the damaged blood-nerve barrier, i.e., edema within the root on microscope. In a clinical setting, 27 patients with lumbar disc herniation underwent MRI for the observation of the nerve root. In 8 of these 27 patients, the nerve root was seen as hyperintensity. This suggests that approximately one third of such patients may have edema within the nerve root. (N.K.).

  11. Plant root tortuosity: an indicator of root path formation in soil with different composition and density

    Science.gov (United States)

    Popova, Liyana; van Dusschoten, Dagmar; Nagel, Kerstin A.; Fiorani, Fabio; Mazzolai, Barbara

    2016-01-01

    Background and Aims Root soil penetration and path optimization are fundamental for root development in soil. We describe the influence of soil strength on root elongation rate and diameter, response to gravity, and root-structure tortuosity, estimated by average curvature of primary maize roots. Methods Soils with different densities (1·5, 1·6, 1·7 g cm−3), particle sizes (sandy loam; coarse sand mixed with sandy loam) and layering (monolayer, bilayer) were used. In total, five treatments were performed: Mix_low with mixed sand low density (three pots, 12 plants), Mix_medium - mixed sand medium density (three pots, 12 plants), Mix_high - mixed sand high density (three pots, ten plants), Loam_low sandy loam soil low density (four pots, 16 plants), and Bilayer with top layer of sandy loam and bottom layer mixed sand both of low density (four pots, 16 plants). We used non-invasive three-dimensional magnetic resonance imaging to quantify effects of these treatments. Key Results Roots grew more slowly [root growth rate (mm h–1); decreased 50 %] with increased diameters [root diameter (mm); increased 15 %] in denser soils (1·7 vs. 1·5 g cm–3). Root response to gravity decreased 23 % with increased soil compaction, and tortuosity increased 10 % in mixed sand. Response to gravity increased 39 % and tortuosity decreased 3 % in sandy loam. After crossing a bilayered–soil interface, roots grew more slowly, similar to roots grown in soil with a bulk density of 1·64 g cm–3, whereas the actual experimental density was 1·48±0·02 g cm–3. Elongation rate and tortuosity were higher in Mix_low than in Loam_low. Conclusions The present study increases our existing knowledge of the influence of physical soil properties on root growth and presents new assays for studying root growth dynamics in non-transparent media. We found that root tortuosity is indicative of root path selection, because it could result from both mechanical deflection and

  12. Root cortical senescence decreases root respiration, nutrient content, and radial water and nutrient transport in barley.

    Science.gov (United States)

    Schneider, Hannah M; Wojciechowski, Tobias; Postma, Johannes A; Brown, Kathleen M; Lücke, Andreas; Zeisler, Viktoria; Schreiber, Lukas; Lynch, Jonathan P

    2017-02-06

    The functional implications of root cortical senescence (RCS) are poorly understood. We tested the hypotheses that RCS in barley: (1) reduces the respiration and nutrient content of root tissue; (2) decreases radial water and nutrient transport; (3) is accompanied by increased suberization to protect the stele. Genetic variation for RCS exists between modern germplasm and landraces. Nitrogen and phosphorus deficiency increased the rate of RCS. Maximal RCS, defined as the disappearance of the entire root cortex, reduced root nitrogen content by 66%, phosphorus content by 63%, and respiration by 87% compared to root segments with no RCS. Roots with maximal RCS had 90%, 92%, and 84% less radial water, nitrate, and phosphorus transport, respectively compared to segments with no RCS. The onset of RCS coincided with 30% greater aliphatic suberin in the endodermis. These results support the hypothesis that RCS reduces root carbon and nutrient costs and may therefore have adaptive significance for soil resource acquisition. By reducing root respiration and nutrient content, RCS could permit greater root growth, soil resource acquisition, and resource allocation to other plant processes. RCS merits investigation as a trait for improving the performance of barley, wheat, triticale, and rye under edaphic stress.

  13. A new Approach for Quantifying Root-Reinforcement of Streambanks: the RipRoot Model

    Science.gov (United States)

    Pollen, N. L.; Simon, A.

    2003-12-01

    Riparian vegetation plays an important role in controlling geotechnical and fluvial processes acting along and within streambanks through the binding effects of roots. Quantification of this mechanical effect is therefore essential to accurately model streambank stability. Until now, most attempts to include the effects of root reinforcement by riparian vegetation have used root-cohesion values estimated using the Wu et al. (1979) equation, requiring the tensile strengths and diameters of the roots crossing the potential shear-plane. However, the Wu et al. equation is a static model that assumes that all roots break, and that they all break simultaneously. Field observations and laboratory experiments have shown that in reality the roots do not all break simultaneously, and that the breaking of roots during mass failure is in fact a dynamic process. Static models such as the Wu et al. equation are therefore likely to produce overestimations of cohesion due to roots. As a response to this concern, a dynamic root reinforcement model (RipRoot) was developed, based on the concepts of fiber bundle models (FBM's) used in materials science. Within the model the root-soil system is loaded incrementally resulting in progressive root breaking and redistribution of stresses from the broken roots to the remaining intact roots in the soil matrix. The redistribution and loading process continues until either all of the roots have broken, or equilibrium is reached where the root network supports the driving force imposed on the bank. The increase in bank cohesion using the static Wu et al. equation are 18% to 38% higher than RipRoot for riparian tree species, including Black Willow, Sandbar Willow, Cottonwood, River Birch and Eastern Sycamore, and 49% higher for Switch Grass. These variations in cohesion values can have a significant impact on streambank Factor of Safety (Fs) values calculated using the Simon et al. (2000) bank-stability model. For example, a 3m high silt

  14. Possibilty of the lower third molar eruption: Radiographic analysis

    OpenAIRE

    2006-01-01

    Backgraund/Aim. To assess the possibility of the eruption of the lower third molar on the basis of the measured parameters: retromolar space, mesiodistal crown width of a molar and the third molar angulation. Methods. The investigation included 104 patients both sexes (43 boys, and 61 girls), 16 to 25 years old (meanage, 18 years). It was performed using the orthopanthomographic radiographs analysis of those patients. Each radiograph was covered by tracing paper, and the contoures of the foll...

  15. Model Persamaan Massa Karbon Akar Pohon dan Root-Shoot Ratio Massa Karbon (Equation Models of Tree Root Carbon Mass and Root-Shoot Carbon Mass Ratio

    Directory of Open Access Journals (Sweden)

    Elias .

    2011-03-01

    Full Text Available The case study was conducted in the area of Acacia mangium plantation at BKPH Parung Panjang, KPH Bogor. The objective of the study was to formulate equation models of tree root carbon mass and root to shoot carbon mass ratio of the plantation. It was found that carbon content in the parts of tree biomass (stems, branches, twigs, leaves, and roots was different, in which the highest and the lowest carbon content was in the main stem of the tree and in the leaves, respectively. The main stem and leaves of tree accounted for 70% of tree biomass. The root-shoot ratio of root biomass to tree biomass above the ground and the root-shoot ratio of root biomass to main stem biomass was 0.1443 and 0.25771, respectively, in which 75% of tree carbon mass was in the main stem and roots of tree. It was also found that the root-shoot ratio of root carbon mass to tree carbon mass above the ground and the root-shoot ratio of root carbon mass to tree main stem carbon mass was 0.1442 and 0.2034, respectively. All allometric equation models of tree root carbon mass of A. mangium have a high goodness-of-fit as indicated by its high adjusted R2.Keywords: Acacia mangium, allometric, root-shoot ratio, biomass, carbon mass

  16. Modelling water uptake efficiency of root systems

    Science.gov (United States)

    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

  17. D-Root: a system for cultivating plants with the roots in darkness or under different light conditions.

    Science.gov (United States)

    Silva-Navas, Javier; Moreno-Risueno, Miguel A; Manzano, Concepción; Pallero-Baena, Mercedes; Navarro-Neila, Sara; Téllez-Robledo, Bárbara; Garcia-Mina, Jose M; Baigorri, Roberto; Gallego, Francisco Javier; del Pozo, Juan C

    2015-10-01

    In nature roots grow in the dark and away from light (negative phototropism). However, most current research in root biology has been carried out with the root system grown in the presence of light. Here, we have engineered a device, called Dark-Root (D-Root), to grow plants in vitro with the aerial part exposed to the normal light/dark photoperiod while the roots are in the dark or exposed to specific wavelengths or light intensities. D-Root provides an efficient system for cultivating a large number of seedlings and easily characterizing root architecture in the dark. At the morphological level, root illumination shortens root length and promotes early emergence of lateral roots, therefore inducing expansion of the root system. Surprisingly, root illumination also affects shoot development, including flowering time. Our analyses also show that root illumination alters the proper response to hormones or abiotic stress (e.g. salt or osmotic stress) and nutrient starvation, enhancing inhibition of root growth. In conclusion, D-Root provides a growing system closer to the natural one for assaying Arabidopsis plants, and therefore its use will contribute to a better understanding of the mechanisms involved in root development, hormonal signaling and stress responses.

  18. Mercury content of sprouts and harvested roots from treated sweet potato mother roots. [Ipomoea batatas

    Energy Technology Data Exchange (ETDEWEB)

    Huisingh, D.; Nielsen, L.W.

    1972-01-01

    Mercury containing fungicides have been used extensively for seed and root disease control, but data on the fate of the mercury (Hg) are scarce. Experiments were designed to see if Hg applied to propagative sweet potato roots increased the Hg-content of edible roots. Roots were treated with Semesan Bel(hydroxymercurinitrophenol + hydroxymercurichlorophenol), Mertect (Thiabendazole: 2-(4-Thiazolyl)-benzimidazole), or Botran (2,6-Dichloro-4-nitroanaline) at recommended rates or with water. Treated roots were bedded into sandy loam soil, and the plants were harvested at 2 and 3 months after bedding. Some sprouts transplanted at 2 months were grown to maturity, and the harvested roots were analyzed. Hg analyses were performed by flameless atomic absorption. Roots treated prior to planting with Semesan Bel, Mertect, Botran, and water contained 23.0, 0.05, 0.03 and 0.03 ..mu..g/g dry wt, respectively. At the 2-month harvest, the leaves and stems of the Semesan Bel-treated plants contained 5 times more Hg than those of the other treatments. By the 3-month harvest, the amount of Hg in plant leaves and stems from Hg-treated roots was 2 to 3 times that of the others. Fall harvested fleshy roots contained 0.03, 0.02, 0.03, and 0.03 ..mu..g/g dry wt Hg for the Semesan Bel, Mertect, Botran, and water treatments, respectively. This demonstrates that the Hg applied to the mother root was translocated to the new plant, but little if any was translocated to the new fleshy roots.

  19. In vitro biocompatibility, inflammatory response, and osteogenic potential of 4 root canal sealers: Sealapex, Sankin apatite root sealer, MTA Fillapex, and iRoot SP root canal sealer.

    Science.gov (United States)

    Chang, Seok-Woo; Lee, So-Youn; Kang, Soo-Kyung; Kum, Kee-Yeon; Kim, Eun-Cheol

    2014-10-01

    The objective of this study was to compare the cytotoxicity, inflammatory response, osteogenic effect, and the signaling mechanism of these biologic activities of 4 calcium compound-based root canal sealers (ie, Sealapex [Sybron Kerr, WA], apatite root sealer [ARS; Dentsply Sankin, Tokyo, Japan], MTA Fillapex [Angelus Indústria de Produtos Odontológicos S/A, Londrina, PR, Brazil], and iRoot SP [Innovative BioCreamix Inc, Vancouver, Canada]) in human periodontal ligament cells. Cytotoxicity was assessed using the 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium bromide assay. Levels of inflammatory mediators were measured by enzyme-linked immunosorbent assay, reverse-transcription polymerase chain reaction, and Western blot analysis. Osteogenic potential was evaluated by alkaline phosphatase activity, alizarin red staining, and marker genes by reverse-transcription polymerase chain reaction. The signal transduction pathways were examined by Western blotting. None of the sealers were cytotoxic. ARS, MTA Fillapex, and iRoot SP induced a lower expression of proinflammatory mediators than Sealapex. All sealers increased ALP activity and the formation of mineralized nodules and up-regulated the expression of osteoblastic marker messenger RNA. ARS, MTA Fillapex, and iRoot SP showed superior osteogenic potential compared with Sealapex. The expression and/or activation of integrin receptors and downstream signaling molecules, including focal adhesion kinase, paxillin, Akt, mitogen-activated protein kinase, and nuclear factor κB, was induced by ARS, MTA Fillapex, and iRoot SP treatment but not by Sealapex treatment. We show for the first time that ARS, MTA Fillapex, and iRoot SP induce a lower expression of inflammatory mediators and enhance osteoblastic differentiation of PDLCs via the integrin-mediated signaling pathway compared with Sealapex. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  20. Pharmacognostic study of Lantana camara Linn. root

    Directory of Open Access Journals (Sweden)

    Dinesh Kumar

    2012-05-01

    Full Text Available Objective: The study was carried out to perform the pharmacognostic evaluation of Lantana camara Linn. root. Method: The pharmacognostic evaluation was done in terms of organoleptic, macro-microscopy, fluorescence analysis and physicochemical parameters. Results: The characteristic macroscopic features showed that the root consists of 25-40 cm long, 0.2-4.0 cm thick pieces which are usually branched, shallow, tough, creamish-brown externally, outer surface rough due to longitudinal wrinkles, with hard fracture, characteristic odour and pungent taste. The main microscopic characters of the root shows exfoliating cork, consisting of about 10-15 rows of tangentially elongated, thick-walled cells followed by cortex consisting of polygonal parenchymatous cells, a few containing rhomboidal shaped calcium oxalate crystals. Endodermis consists of 3-4 layers of non-lignified, thick-walled rounded parenchymatous cells followed by a single layer of non-lignified pericycle. Phloem, a wide zone of xylem consisting of lignified pitted vessels and bi-to triseriate medullary rays are also present. Proximate physicochemical analysis of the root power showed loss on drying, total ash, water soluble ash, sulphated ash values as 0.52, 4.26, 3.8 and 5.8 % w/w respectively. Successive extraction of the root powder with petroleum ether, chloroform, alcohol, water yielded 0.19, 0.35, 2.19 and 2.0 % w/w respectively. Fluorescence study imparted characteristic colors to the root powder when observed under visible, short and long wavelength light. Conclusions: Various pharmacognostic parameters evaluated in this study helps in identification and standardization of Lantana camara L. root in crude form.

  1. How can science education foster students' rooting?

    Science.gov (United States)

    Østergaard, Edvin

    2015-06-01

    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 earth as ground, and potential consequences for teaching science in a rooted manner. However, the argumentation raises a number of questions which I try to answer. My argumentation rests on Husserl's critique of science and the "ontological reversal", an ontological position where abstract models from science are considered as more real than the everyday reality itself, where abstract, often mathematical, models are taken to be the real causes behind everyday experiences. In this paper, measures towards an "ontological re-reversal" are discussed by drawing on experiences from phenomenon-based science education. I argue that perhaps the most direct and productive way of promoting rooting in science class is by intentionally cultivating the competencies of sensing and aesthetic experience. An aesthetic experience is defined as a precognitive, sensuous experience, an experience that is opened up for through sensuous perception. Conditions for rooting in science education is discussed against three challenges: Restoring the value of aesthetic experience, allowing time for open inquiry and coping with curriculum. Finally, I raise the question whether dimensions like "reality" or "nature" are self-evident for students. In the era of constructivism, with its focus on cognition and knowledge building, the inquiry process itself has become more important than the object of inquiry. I argue that as educators of science teachers we have to emphasize more explicitly "the nature of nature" as a field of exploration.

  2. Cold temperature delays wound healing in postharvest sugarbeet roots

    Science.gov (United States)

    Storage temperature affects the rate and extent of wound-healing in a number of root and tuber crops. The effect of storage temperature on wound-healing in sugarbeet (Beta vulgaris L.) roots, however, is largely unknown. Wound-healing of sugarbeet roots was investigated using surface-abraded roots s...

  3. Root bacterial endophytes alter plant phenotype, but not physiology

    DEFF Research Database (Denmark)

    Henning, Jeremiah A.; Weston, David J.; Pelletier, Dale A.;

    2016-01-01

    (root:shoot, biomass production, root and leaf growth rates) and physiological traits (chlorophyll content, net photosynthesis, net photosynthesis at saturating light-Asat, and saturating CO2-Amax). Overall, we found that bacterial root endophyte infection increased root growth rate up to 184% and leaf...

  4. [Dimensional fractal of post-paddy wheat root architecture].

    Science.gov (United States)

    Chen, Xin-xin; Ding, Qi-shuo; Li, Yi-nian; Xue, Jin-lin; Lu, Ming-zhou; Qiu, Wei

    2015-06-01

    To evaluate whether crop rooting system was directionally dependent, a field digitizer was used to measure post-paddy wheat root architectures. The acquired data was transferred to Pro-E, in which virtual root architecture was reconstructed and projected to a series of planes each separated in 10° apart. Fractal dimension and fractal abundance of root projections in all the 18 planes were calculated, revealing a distinctive architectural distribution of wheat root in each direction. This strongly proved that post-paddy wheat root architecture was directionally dependent. From seedling to turning green stage, fractal dimension of the 18 projections fluctuated significantly, illustrating a dynamical root developing process in the period. At the jointing stage, however, fractal indices of wheat root architecture resumed its regularity in each dimension. This wheat root architecture recovered its dimensional distinctness. The proposed method was applicable for precision modeling field state root distribution in soil.

  5. Redirection of auxin flow in Arabidopsis thaliana roots after infection by root-knot nematodes

    NARCIS (Netherlands)

    Kyndt, Tina; Goverse, Aska; Haegeman, Annelies; Warmerdam, Sonja; Wanjau, Cecilia; Jahani, Mona; Engler, Gilbert; Almeida Engler, De Janice; Gheysen, Godelieve

    2016-01-01

    Plant-parasitic root-knot nematodes induce the formation of giant cells within the plant root, and it has been recognized that auxin accumulates in these feeding sites. Here, we studied the role of the auxin transport system governed by AUX1/LAX3 influx proteins and different PIN efflux proteins dur

  6. Deep rooting conferred by DEEPER ROOTING 1 enhances rice yield in paddy fields

    Science.gov (United States)

    Arai-Sanoh, Yumiko; Takai, Toshiyuki; Yoshinaga, Satoshi; Nakano, Hiroshi; Kojima, Mikiko; Sakakibara, Hitoshi; Kondo, Motohiko; Uga, Yusaku

    2014-01-01

    To clarify the effect of deep rooting on grain yield in rice (Oryza sativa L.) in an irrigated paddy field with or without fertilizer, we used the shallow-rooting IR64 and the deep-rooting Dro1-NIL (a near-isogenic line homozygous for the Kinandang Patong allele of DEEPER ROOTING 1 (DRO1) in the IR64 genetic background). Although total root length was similar in both lines, more roots were distributed within the lower soil layer of the paddy field in Dro1-NIL than in IR64, irrespective of fertilizer treatment. At maturity, Dro1-NIL showed approximately 10% higher grain yield than IR64, irrespective of fertilizer treatment. Higher grain yield of Dro1-NIL was mainly due to the increased 1000-kernel weight and increased percentage of ripened grains, which resulted in a higher harvest index. After heading, the uptake of nitrogen from soil and leaf nitrogen concentration were higher in Dro1-NIL than in IR64. At the mid-grain-filling stage, Dro1-NIL maintained higher cytokinin fluxes from roots to shoots than IR64. These results suggest that deep rooting by DRO1 enhances nitrogen uptake and cytokinin fluxes at late stages, resulting in better grain filling in Dro1-NIL in a paddy field in this study. PMID:24988911

  7. Root system markup language: toward a unified root architecture description language.

    Science.gov (United States)

    Lobet, Guillaume; Pound, Michael P; Diener, Julien; Pradal, Christophe; Draye, Xavier; Godin, Christophe; Javaux, Mathieu; Leitner, Daniel; Meunier, Félicien; Nacry, Philippe; Pridmore, Tony P; Schnepf, Andrea

    2015-03-01

    The number of image analysis tools supporting the extraction of architectural features of root systems has increased in recent years. These tools offer a handy set of complementary facilities, yet it is widely accepted that none of these software tools is able to extract in an efficient way the growing array of static and dynamic features for different types of images and species. We describe the Root System Markup Language (RSML), which has been designed to overcome two major challenges: (1) to enable portability of root architecture data between different software tools in an easy and interoperable manner, allowing seamless collaborative work; and (2) to provide a standard format upon which to base central repositories that will soon arise following the expanding worldwide root phenotyping effort. RSML follows the XML standard to store two- or three-dimensional image metadata, plant and root properties and geometries, continuous functions along individual root paths, and a suite of annotations at the image, plant, or root scale at one or several time points. Plant ontologies are used to describe botanical entities that are relevant at the scale of root system architecture. An XML schema describes the features and constraints of RSML, and open-source packages have been developed in several languages (R, Excel, Java, Python, and C#) to enable researchers to integrate RSML files into popular research workflow.

  8. Compensation in Root Water Uptake Models Combined with Three-Dimensional Root Length Density Distribution

    NARCIS (Netherlands)

    Heinen, M.

    2014-01-01

    A three-dimensional root length density distribution function is introduced that made it possible to compare two empirical uptake models with a more mechanistic uptake model. Adding a compensation component to the more empirical model resulted in predictions of root water uptake distributions

  9. Pea-root exudates and their effect upon root-nodule bacteria

    NARCIS (Netherlands)

    Egeraat, van A.W.S.M.

    1972-01-01

    The main purpose of this investigation was to study the exudation (mechanism, sites) of various compounds by roots of pea seedlings in relation to the growth of Rhizobium leguminosarum.Chapter 1 gives a survey of the literature pertaining to plant-root exudates and their influence upon soil microorg

  10. Identification of coniferous fine roots to species using ribosomal PCR products of pooled root samples

    Science.gov (United States)

    Background/Question/Methods To inform an individual-based forest stand model emphasizing belowground competition, we explored the potential of using the relative abundances of ribosomal PCR products from pooled and milled roots, to allocate total root biomass to each of the thre...

  11. Triterpene and Flavonoid Biosynthesis and Metabolic Profiling of Hairy Roots, Adventitious Roots, and Seedling Roots of Astragalus membranaceus.

    Science.gov (United States)

    Park, Yun Ji; Thwe, Aye Aye; Li, Xiaohua; Kim, Yeon Jeong; Kim, Jae Kwang; Arasu, Mariadhas Valan; Al-Dhabi, Naif Abdullah; Park, Sang Un

    2015-10-14

    Astragalus membranaceus is an important traditional Chinese herb with various medical applications. Astragalosides (ASTs), calycosin, and calycosin-7-O-β-d-glucoside (CG) are the primary metabolic components in A. membranaceus roots. The dried roots of A. membranaceus have various medicinal properties. The present study aimed to investigate the expression levels of genes related to the biosynthetic pathways of ASTs, calycosin, and CG to investigate the differences between seedling roots (SRs), adventitious roots (ARs), and hairy roots (HRs) using quantitative real-time polymerase chain reaction (qRT-PCR). qRT-PCR study revealed that the transcription level of genes involved in the AST biosynthetic pathway was lowest in ARs and showed similar patterns in HRs and SRs. Moreover, most genes involved in the synthesis of calycosin and CG exhibited the highest expression levels in SRs. High-performance liquid chromatography (HPLC) analysis indicated that the expression level of the genes correlated with the content of ASTs, calycosin, and CG in the three different types of roots. ASTs were the most abundant in SRs. CG accumulation was greater than calycosin accumulation in ARs and HRs, whereas the opposite was true in SRs. Additionally, 40 metabolites were identified using gas chromatography-time-of-flight mass spectrometry (GC-TOF-MS). Principal component analysis (PCA) documented the differences among SRs, ARs, and HRs. PCA comparatively differentiated among the three samples. The results of PCA showed that HRs were distinct from ARs and SRs on the basis of the dominant amounts of sugars and clusters derived from closely similar biochemical pathways. Also, ARs had a higher concentration of phenylalanine, a precursor for the phenylpropanoid biosynthetic pathway, as well as CG. TCA cycle intermediates levels including succinic acid and citric acid indicated a higher amount in SRs than in the others.

  12. Evolution of Root Characters of Soybean Varieties Developed in Different Years

    Institute of Scientific and Technical Information of China (English)

    YANG Xiu-hong; WU Zong-pu; ZHANG Guo-dong

    2002-01-01

    It was studied that the evolution of root characteristics among 42 soybean varieties developed in Heilongjiang and Jilin Province in different years. The results showed that there were differences on the root characteristics among soybean varieties. From 1950s to 1990s, root fresh weight, root volume, root surface, root dry weight, lateral root length of main root characters tendedly increased with the variable development years. The root system of the varieties in 1990s was relatively well developed compared with that in the other years. The evolutionary trend of the root system of soybean varieties was increasing in root weight, root volume, root surface and length of lateral root.

  13. Computing Rooted and Unrooted Maximum Consistent Supertrees

    CERN Document Server

    van Iersel, Leo

    2009-01-01

    A chief problem in phylogenetics and database theory is the computation of a maximum consistent tree from a set of rooted or unrooted trees. A standard input are triplets, rooted binary trees on three leaves, or quartets, unrooted binary trees on four leaves. We give exact algorithms constructing rooted and unrooted maximum consistent supertrees in time O(2^n n^5 m^2 log(m)) for a set of m triplets (quartets), each one distinctly leaf-labeled by some subset of n labels. The algorithms extend to weighted triplets (quartets). We further present fast exact algorithms for constructing rooted and unrooted maximum consistent trees in polynomial space. Finally, for a set T of m rooted or unrooted trees with maximum degree D and distinctly leaf-labeled by some subset of a set L of n labels, we compute, in O(2^{mD} n^m m^5 n^6 log(m)) time, a tree distinctly leaf-labeled by a maximum-size subset X of L that all trees in T, when restricted to X, are consistent with.

  14. How tree roots respond to drought

    Directory of Open Access Journals (Sweden)

    Ivano eBrunner

    2015-07-01

    Full Text Available The ongoing climate change is characterised by increased temperatures and altered precipitation patterns. In addition, there has been an increase in both the frequency and intensity of extreme climatic events such as drought. Episodes of drought induce a series of interconnected effects, all of which have the potential to alter the carbon balance of forest ecosystems profoundly at different scales of plant organisation and ecosystem functioning. During recent years, considerable progress has been made in the understanding of how aboveground parts of trees respond to drought and how these responses affect carbon assimilation. In contrast, processes of belowground parts are relatively underrepresented in research on climate change. In this review, we describe current knowledge about responses of tree roots to drought. Tree roots are capable of responding to drought through a variety of strategies that enable them to avoid and tolerate stress. Responses include root biomass adjustments, anatomical alterations, and physiological acclimations. The molecular mechanisms underlying these responses are characterized to some extent, and involve stress signalling and the induction of numerous genes, leading to the activation of tolerance pathways. In addition, mycorrhizas seem to play important protective roles. The current knowledge compiled in this review supports the view that tree roots are well equipped to withstand drought situations and maintain morphological and physiological functions as long as possible. Further, the reviewed literature demonstrates the important role of tree roots in the functioning of forest ecosystems and highlights the need for more research in this emerging field.

  15. Rooting of stem cuttings of ixora

    Directory of Open Access Journals (Sweden)

    Aline De Souza Silva

    2015-08-01

    Full Text Available The ixora is ornamental plant widely used in landscaping. In order to maximize the propagation of cuts, we evaluated the concentrations of auxin (indolbutiric acid and the presence of leaves on the rooting in cuts of Ixora coccinea L. The experiment was conducted in randomized block design, in factorial design 3x4, with three types of cuts (without leaf, with two or four leaves, four concentrations of indolbutiric acid (0, 1000, 2000 and 4000 mg L-1, with four replications and 10 cuts in each experimental unit. After 53 days of implantation the experiment, evaluated the survival(%, rooting(%, sprouting(%, formation of callus(%, number, length and biomass of roots formed. The interaction of the type of cuts with concentrations of auxin was not significant for any of the variables analyzed. The survival of cuttings was not influenced by the treatments. Cuts with two or four leaves presented rooting and length of roots above the cuttings without leaves. The application of auxin does not substitute the presence of leaf in cuts of ixora in vegetative propagation. The vegetative propagation by cut of ixora can be made without application of auxin, and the leaves must be maintained in the cuttings.

  16. Protein synthesis in geostimulated root caps

    Science.gov (United States)

    Feldman, L. J.

    1982-01-01

    A study is presented of the processes occurring in the root cap of corn which are requisite for the formation of root cap inhibitor and which can be triggered or modulated by both light and gravity. The results of this study indicate the importance of protein synthesis for light-induced gravitropic bending in roots. Root caps in which protein synthesis is prevented are unable to induce downward bending. This suggests that light acts by stimulating proteins which are necessary for the translation of the gravitropic stimulus into a growth response (downward bending). The turnover of protein with time was also examined in order to determine whether light acts by stimulating the synthesis of unique proteins required for downward growth. It is found that auxin in combination with light allows for the translation of the gravitropic stimulus into a growth response at least in part through the modification of protein synthesis. It is concluded that unique proteins are stimulated by light and are involved in promoting the downward growth in roots which are responding to gravity.

  17. Etiology of phomopsis root rot in soybean

    Directory of Open Access Journals (Sweden)

    Valéria Cecília Ghissi

    2014-09-01

    Full Text Available In a survey of damages caused by soybean root rot to crops in the south of Brazil for several years, a root rot caused by Phomopsis sp has been found with increasing frequency. The primary symptoms are seen when the main root is cut longitudinally, including the death of the wood which shows white coloration and well-defined black lines that do not have a defined format. Thus, based on similarity, it has been called geographic root rot due to its aspect resembling irregular lines that separate regions on a map. In isolations, colonies and alpha spores of Phomopsis have prevailed. Pathogenicity test was done by means of inoculation in the crown of plants cultivated in a growth chamber. The geographic symptoms were reproduced in plants and the fungus Phomopsis sp. was reisolated. In soybean stems naturally infected with pod and stem blight, geographic symptoms caused by Phomopsis phaseoli are found. To the known symptoms on stems, pods and grains, that of root rot caused by P. phaseoli is now added.

  18. Chronic nerve root entrapment: compression and degeneration

    Science.gov (United States)

    Vanhoestenberghe, A.

    2013-02-01

    Electrode mounts are being developed to improve electrical stimulation and recording. Some are tight-fitting, or even re-shape the nervous structure they interact with, for a more selective, fascicular, access. If these are to be successfully used chronically with human nerve roots, we need to know more about the possible damage caused by the long-term entrapment and possible compression of the roots following electrode implantation. As there are, to date, no such data published, this paper presents a review of the relevant literature on alternative causes of nerve root compression, and a discussion of the degeneration mechanisms observed. A chronic compression below 40 mmHg would not compromise the functionality of the root as far as electrical stimulation and recording applications are concerned. Additionally, any temporary increase in pressure, due for example to post-operative swelling, should be limited to 20 mmHg below the patient’s mean arterial pressure, with a maximum of 100 mmHg. Connective tissue growth may cause a slower, but sustained, pressure increase. Therefore, mounts large enough to accommodate the root initially without compressing it, or compliant, elastic, mounts, that may stretch to free a larger cross-sectional area in the weeks after implantation, are recommended.

  19. Differences in U root-to-shoot translocation between plant species explained by U distribution in roots

    Energy Technology Data Exchange (ETDEWEB)

    Straczek, Anne; Duquene, Lise [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Wegrzynek, Dariusz [IAEA, Seibersdorf Laboratories, A-2444 Seibersdorf (Austria); Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow (Poland); Chinea-Cano, Ernesto [IAEA, Seibersdorf Laboratories, A-2444 Seibersdorf (Austria); Wannijn, Jean [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium); Navez, Jacques [Royal Museum of Africa, Department of Geology, Leuvensesteenweg 13, 3080 Tervuren (Belgium); Vandenhove, Hildegarde, E-mail: hvandenh@sckcen.b [Belgium Nuclear Research Centre (SCK.CEN), Biosphere Impact Studies, Boeretang 200, 2400 Mol (Belgium)

    2010-03-15

    Accumulation and distribution of uranium in roots and shoots of four plants species differing in their cation exchange capacity of roots (CECR) was investigated. After exposure in hydroponics for seven days to 100 mumol U L{sup -1}, distribution of uranium in roots was investigated through chemical extraction of roots. Higher U concentrations were measured in roots of dicots which showed a higher CECR than monocot species. Chemical extractions indicated that uranium is mostly located in the apoplasm of roots of monocots but that it is predominantly located in the symplasm of roots of dicots. Translocation of U to shoot was not significantly affected by the CECR or distribution of U between symplasm and apoplasm. Distribution of uranium in roots was investigated through chemical extraction of roots for all species. Additionally, longitudinal and radial distribution of U in roots of maize and Indian mustard, respectively showing the lowest and the highest translocation, was studied following X-ray fluorescence (XRF) analysis of specific root sections. Chemical analysis and XRF analysis of roots of maize and Indian mustard clearly indicated a higher longitudinal and radial transport of uranium in roots of Indian mustard than in roots of maize, where uranium mostly accumulated in root tips. These results showed that even if CECR could partly explain U accumulation in roots, other mechanisms like radial and longitudinal transport are implied in the translocation of U to the shoot.

  20. Partical replacement of the rooting procedure of Chrysanthenum merifolium cuttings by pre-rooting storage in the dark.

    NARCIS (Netherlands)

    Pol, van de P.A.

    1988-01-01

    Part of the rooting procedure of Chrysanthemum morifolium 'Pink Boston' and 'Refour' cuttings can be replaced by pre-rooting storage in the dark. Pre-rooting storage of 7 days at temperatures between 9° and 21°C was adequate. Longer periods of dark storage resulted in increase of root growth but als

  1. Variations in the Root Form and Root Canal Morphology of Permanent Mandibular First Molars in a Sri Lankan Population

    Directory of Open Access Journals (Sweden)

    Roshan Peiris

    2015-01-01

    Full Text Available The present study was conducted to determine the number of roots and morphology of the root canal system of permanent mandibular first molars (M1 in a Sri Lankan population. Sample of 529 M1 teeth was used. The number of roots was examined and the lengths of the mesial and distal roots were measured to the nearest 0.01 mm. Vacuum injection protocol was used to inject China ink into the root canal system, making it transparent. Root canal morphology was recorded using Vertucci’s classification. Presence of furcation canals, position of lateral canals, intercanal communications, level of bifurcation, and convergence of the root canal system were recorded. M1 showed three roots in 4.1% of the sample. Commonest root canal morphology of the mesial root was type IV and the distal root was type I. The level of bifurcation of the root canals was commonly observed in the cervical one-third of the root while convergence was observed in the apical one-third in both roots. Prevalence of three rooted mandibular first molars is less than 5%. Mesial root showed the most variable canal morphology. Prevalence of furcation canals was 1.5% while that of middle mesial canals was 0.2%.

  2. Root hair defective4 encodes a phosphatidylinositol-4-phosphate phosphatase required for proper root hair development in Arabidopsis thaliana

    NARCIS (Netherlands)

    Thole, J.M.; Vermeer, J.E.M.; Zhang, Y.; Gadella, Th.W.J.; Nielsen, E.

    2008-01-01

    Polarized expansion of root hair cells in Arabidopsis thaliana is improperly controlled in root hair-defective rhd4-1 mutant plants, resulting in root hairs that are shorter and randomly form bulges along their length. Using time-lapse fluorescence microscopy in rhd4-1 root hairs, we analyzed

  3. Root-soil air gap and resistance to water flow at the soil-root interface of Robinia pseudoacacia.

    Science.gov (United States)

    Liu, X P; Zhang, W J; Wang, X Y; Cai, Y J; Chang, J G

    2015-12-01

    During periods of water deficit, growing roots may shrink, retaining only partial contact with the soil. In this study, known mathematical models were used to calculate the root-soil air gap and water flow resistance at the soil-root interface, respectively, of Robinia pseudoacacia L. under different water conditions. Using a digital camera, the root-soil air gap of R. pseudoacacia was investigated in a root growth chamber; this root-soil air gap and the model-inferred water flow resistance at the soil-root interface were compared with predictions based on a separate outdoor experiment. The results indicated progressively greater root shrinkage and loss of root-soil contact with decreasing soil water potential. The average widths of the root-soil air gap for R. pseudoacacia in open fields and in the root growth chamber were 0.24 and 0.39 mm, respectively. The resistance to water flow at the soil-root interface in both environments increased with decreasing soil water potential. Stepwise regression analysis demonstrated that soil water potential and soil temperature were the best predictors of variation in the root-soil air gap. A combination of soil water potential, soil temperature, root-air water potential difference and soil-root water potential difference best predicted the resistance to water flow at the soil-root interface.

  4. Root biomass, root/shoot ratio, and soil water content under perennial grasses with different nitrogen rates

    Science.gov (United States)

    Roots help in soil water and nutrient uptake and provide C input for soil C sequestration, but information on root biomass of bioenergy perennial grasses is lacking. Root/shoot ratios are used to estimate crop root biomass and C inputs, but the values for perennial grasses are also scanty. We examin...

  5. Surgical management of aortic root disease in Marfan syndrome and other congenital disorders associated with aortic root aneurysms

    NARCIS (Netherlands)

    T. Treasure (Tom); J.J.M. Takkenberg (Hanneke); J. Pepper (John)

    2014-01-01

    textabstractElective root replacement in Marfan syndrome has improved life expectancy in affected patients. Three forms of surgery are now available: total root replacement (TRR) with a valved conduit, valve sparing root replacement (VSRR) and personalised external aortic root support (PEARS) with a

  6. Surgical management of aortic root disease in Marfan syndrome and other congenital disorders associated with aortic root aneurysms

    NARCIS (Netherlands)

    T. Treasure (Tom); J.J.M. Takkenberg (Hanneke); J. Pepper (John)

    2016-01-01

    textabstractElective root replacement in Marfan syndrome has improved life expectancy in affected patients. Three forms of surgery are now available: total root replacement (TRR) with a valved conduit, valve sparing root replacement (VSRR) and personalised external aortic root support (PEARS) with a

  7. A NOTE ON THE STOCHASTIC ROOTS OF STOCHASTIC MATRICES

    Institute of Scientific and Technical Information of China (English)

    Qi-Ming HE; Eldon GUNN

    2003-01-01

    In this paper, we study the stochastic root matrices of stochastic matrices. All stochastic roots of 2×2 stochastic matrices are found explicitly. A method based on characteristic polynomial of matrix is developed to find all real root matrices that are functions of the original 3×3 matrix, including all possible (function) stochastic root matrices. In addition, we comment on some numerical methods for computing stochastic root matrices of stochastic matrices.

  8. Untangling the effects of root age and tissue nitrogen on root respiration in Populus tremuloides at different nitrogen supply.

    Science.gov (United States)

    Ceccon, Christian; Tagliavini, Massimo; Schmitt, Armin Otto; Eissenstat, David M

    2016-05-01

    Root respiration is a major contributor to terrestrial carbon flux. Many studies have shown root respiration to increase with an increase in root tissue nitrogen (N) concentration across species and study sites. Studies have also shown that both root respiration and root N concentration typically decrease with root age. The effects of added N may directly increase respiration of existing roots or may affect respiration by shifting the age structure of a root population by stimulating growth. To the best of our knowledge, no study has ever examined the effect of added N as a function of root age on root respiration. In this study, root respiration of 13-year-old Populus tremuloides Michx. trees grown in the field and 1-year-old P. tremuloides seedlings grown in containers was analyzed for the relative influence of root age and root N concentration independent of root age on root respiration. Field roots were first tracked using root windows and then sampled at known age. Nitrogen was either applied or not to small patches beneath the windows. In a pot experiment, each plant was grown with its root system split between two separate pots and N was applied at three different levels, either at the same or at different rates between pots. Root N concentration ranged between 1.4 and 1.7% in the field experiment and 1.8 and 2.6% in the seedling experiment. We found that addition of N increased root N concentration of only older roots in the field but of roots of all ages in the potted seedlings. In both experiments, the age-dependent decline in root respiration was largely consistent, and could be explained by a negative power function. Respiration decreased ∼50% by 3 weeks of age. Although root age was the dominant factor affecting respiration in both experiments, in the field experiment, root N also contributed to root respiration independent of root age. These results add further insight into respiratory responses of roots to N addition and mechanisms underlying the

  9. The role of root hairs in cadmium acquisition by barley

    Energy Technology Data Exchange (ETDEWEB)

    Zheng Ruilun; Li Huafen [Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Jiang Rongfeng, E-mail: rfjiang@cau.edu.c [Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Roemheld, Volker [Institute of Plant Nutrition, University of Hohenheim, D-70593 Stuttgart (Germany); Zhang Fusuo [Key Laboratory of Plant-Soil Interactions of the Ministry of Education, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100094 (China); Zhao Fangjie [Soil Science Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ (United Kingdom)

    2011-02-15

    The role of root hairs in Cd acquisition from soil was investigated in three pot experiments using a root hairless mutant (bald root barley, brb) and its wild-type (WT) cultivar of barley (Hordeum vulgare). brb had significantly lower concentrations and lower total amounts of Cd in shoots than WT. The Cd uptake efficiency based on total root length was 8-45% lower in brb than in WT. The difference between brb and WT increased with increasing extractable Cd in soil under the experimental conditions used. Additions of phosphate to soil decreased Cd extractability. Both soil and foliar additions of phosphate decreased root length, and root hair formation in WT. These effects resulted in decreased Cd uptake with increasing P supply. Cd uptake in WT correlated significantly with root length, root hair length and density, and soil extractable Cd. Root hairs contribute significantly to Cd uptake by barley. - Research highlights: The Cd uptake efficiency was significantly lower in brb than in WT. Additions of phosphate to soil decreased Cd extractability and Cd uptake. Both soil and foliar additions of phosphate decreased root length, and root hair formation in WT. Root hairs contribute significantly to Cd uptake by barley. - The Cd uptake efficiency based on total root length was 8-45% lower in a barley root hairless mutant than in its wild-type, indicating an important role of root hairs in Cd acquisition.

  10. Genotypic diversity of root and shoot characteristics of

    Directory of Open Access Journals (Sweden)

    ali ganjali

    2009-06-01

    Full Text Available Root and shoot characteristics of chickpea (Cicer arietinum L. genotypes are believed to be important in drought tolerance. There is a little information about the response of genotypes root growth in hydroponics and greenhouse culture, also the relationships between root size and drought tolerance. This study was conducted to observe whether genotypes differ in root size, and to see that root size is associated with drought tolerance during early vegetative growth. We found significant differences (p0.01 in root dry weight, total root length, tap root length, root area, leaf dry weight, leaf area and shoot biomass per plant among 30 genotypes of chickpea grown in hydroponics culture for three weeks. Each of these parameters correlated with all others, positively. Among 30 genotypes, 10 genotypes with different root sizes were selected and were grown in a greenhouse in sand culture experiment under drought stress (FC %30 for three weeks. There were not linear or non-linear significant correlations between root characters in hydroponics and greenhouse environments. It seems that environmental factors are dominant on genetic factors in seedling stage and so, the expression of genotypics potential for root growth characteristics of genotypes are different in hydroponic and greenhouse conditions. In this study, the selection of genotypes with vigorous roots system in hydroponic condition did not lead to genotypes with the same root characters in greenhouse environment. The genotype×drought interactions for root characters of chickpea seedlings in 30 days were not significant (p

  11. Bio-reconstruction of root canal using dentin post

    Directory of Open Access Journals (Sweden)

    Navin Mishra

    2013-01-01

    Full Text Available This case report describes the successful management of complicated crown fracture of left maxillary central incisor (#21 of 23-year-old male using dentin (biological post made from human tooth. Endodontic treatment was initiated and sectional obturation was done using ProTaper gutta-percha and AH Plus sealer. The coronal space was modified to receive a human dentin post. A two-step procedure comprising direct and indirect technique of post fabrication was done to achieve the accuracy of biological post. A maxillary cuspid from an institutional tooth bank was taken, sectioned mesiodistally using a diamond disc simulating the length and thickness of mock post. Dentin post was first verified on the plaster model and then cemented in tooth #21. Core build up was done with composite and porcelain fused to metal (PFM crown was luted. On the follow-up visits, patient was asymptomatic and radiographic evaluation revealed normal periradicular architecture. Biological posts may be good alternatives to conventional post systems as they preserve internal dentin walls, provide excellent adhesion, and resilience similar to natural tooth structure.

  12. Aortic Root Enlargement or Sutureless Valve Implantation?

    Directory of Open Access Journals (Sweden)

    Nikolaos G. Baikoussis

    2016-11-01

    Full Text Available Aortic valve replacement (AVR in patients with a small aortic annulus is a challenging issue. The importance of prosthesis–patient mismatch (PPM post aortic valve replacement (AVR is controversial but has to be avoided. Many studies support the fact that PPM has a negative impact on short and long term survival. In order to avoid PPM, aortic root enlargement may be performed. Alternatively and keeping in mind that often some comorbidities are present in old patients with small aortic root, the Perceval S suturelles valve implantation could be a perfect solution. The Perceval sutureless bioprosthesis provides reasonable hemodynamic performance avoiding the PPM and providing the maximum of aortic orifice area. We would like to see in the near future the role of the aortic root enlargement techniques in the era of surgical implantation of the sutureless valve (SAVR and the transcatheter valve implantation (TAVI.

  13. Cryptographic Protocols Based on Root Extracting

    DEFF Research Database (Denmark)

    Koprowski, Maciej

    In this thesis we design new cryptographic protocols, whose security is based on the hardness of root extracting or more speci cally the RSA problem. First we study the problem of root extraction in nite Abelian groups, where the group order is unknown. This is a natural generalization of the...... construction based on root extracting. As an example of this, we modify Cramer-Shoup signature scheme such that it becomes a genericm algorithm. We discuss then implementing it in RSA groups without the original restriction that the modulus must be a product of safe primes. It can also be implemented in class......,  providing a currently acceptable level of security. This allows us to propose the rst practical blind signature scheme provably secure, without relying on heuristics called random oracle model (ROM). We obtain the protocol for issuing blind signatures by implementing our modi ed Fischlin's signing algorithm...

  14. Tree root systems and nutrient mobilization

    DEFF Research Database (Denmark)

    Boyle, Jim; Rob, Harrison; Raulund-Rasmussen, Karsten;

    Roots mobilize nutrients via deep penetration and rhizosphere processes inducing weathering of primary minerals. These contribute to C transfer to soils and to tree nutrition. Assessments of these characteristics and processes of root systems are important for understanding long-term supplies...... of nutrient elements essential for forest growth and resilience. Research and techniques have signifi cantly advanced since Olof Tamm’s 1934 base mineral index for Swedish forest soils, and basic nutrient budget estimates for whole-tree harvesting systems of the 1970s. Recent research in areas that include...... sometimes stored at depth. Other recent studies on potential release of nutrients due to chemical weathering indicate the importance of root access to deep soil layers. Release profi les clearly indicate depletion in the top layers and a much higher potential in B and C horizons. Review of evaluations...

  15. Nitrogenase Activity Associated with Halodule wrightii Roots.

    Science.gov (United States)

    Smith, G W; Hayasaka, S S

    1982-06-01

    Nitrogen fixation (acetylene reduction) associated with roots of the seagrass Halodule wrightii was measured offshore near Beaufort and Moorhead City, N.C. Rates of acetylene reduction were higher in aerobic than in anaerobic assays and were linear for up to 5 days. The temperature range for acetylene reduction was 15 to 35 degrees C with a maximum activity at 35 degrees C. Nitrogenase activity was shown to vary seasonally with highest activities occurring during warmer summer months (23 mug of N(2) fixed per m per day). At in situ temperature, nitrogenase activities associated with surface-sterilized and non-surface-sterilized roots were similar. One morphological bacterial type was isolated from surface-sterilized roots and identified as Klebsiella pneumoniae type 4B.

  16. Probing allelochemical biosynthesis in sorghum root hairs

    Science.gov (United States)

    Rimando, Agnes M; Pan, Zhiqiang

    2008-01-01

    Allelopathic interaction between plants is thought to involve the release of phytotoxic allelochemicals by one species, thus inhibiting the growth of neighboring species in competition for limited resources. Sorgoleone represents one of the more potent allelochemicals characterized to date, and its prolific production in root hair cells of Sorghum spp. has made the investigation of its biosynthetic pathway ideally-suited for functional genomics investigations. Through the use of a recently-released EST data set generated from isolated Sorghum bicolor root hair cells, significant inroads have been made toward the identification of genes and the corresponding enzymes involved in the biosynthesis of this compound in root hairs. Here we provide additional information concerning our recent report on the identification of a 5-n-alk(en) ylresorcinol utilizing O-methyltransferase, as well as other key enzymes likely to participate in the biosynthesis of this important allelochemical. PMID:19704820

  17. LC/MS profiling of flavonoid glycoconjugates isolated from hairy roots, suspension root cell cultures and seedling roots of Medicago truncatula

    OpenAIRE

    Staszków, Anna; Swarcewicz, Barbara; Banasiak, Joanna; Muth, Dorota; Jasiński, Michał; Stobiecki, Maciej

    2011-01-01

    Hairy roots and suspension cell cultures are commonly used in deciphering different problems related to the biochemistry and physiology of plant secondary metabolites. Here, we address about the issue of possible differences in the profiles of flavonoid compounds and their glycoconjugates derived from various plant materials grown in a standard culture media. We compared profiles of flavonoids isolated from seedling roots, hairy roots, and suspension root cell cultures of a model legume plant...

  18. Effects of nutrition spatial heterogeneity on root traits and carbon usage by roots of Cercis chinensis seedlings in split root rooms

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    In natural ecosystems, nutrition available for plants shows great spatial heterogeneity. Much is known about plant root responses to the spatial heterogeneity of nutrition, but little is known about carbon usage in roots in nutrition-deficient patches and its effect on root longevity. In this study, split-room boxes were used for culture of Cercis chinensis seedlings, and the small rooms were supplied with different nutrition levels. The number of the first-order roots in the rooms with nutrition supply was significantly higher than that in the rooms with deficient nutrition. Specific root length (SRL) of the first-order roots in the rooms with deficient nutrition reached its peak at day 64 after nutrition treatment. There was no significant SRL differences between the two order roots during the experiment. Biomass of the first-order roots in the rooms without nutrition supply was significantly less than that of the first-order roots in the rooms with nutrition supply from day 64 to 96. The total biomass of the lateral roots in the rooms without nu-trition supply decreased from day 64 to 96. The activities of the enzymes in roots in the rooms without nutrition supply increased and the activities of alkaline invertases in roots in the two sides of split box did not change significantly. The activities of the enzymes in roots in the rooms without nutrition supply increased gradually. These results suggest that nutrition spatial heterogeneity induced the changes in root traits and plants actively controlled carbon usage in roots in nutrition-deficient patches by regulating the activities of invertases and sucrose synthases, resulting in the reduction in carbon usage in the roots in nutrition-deficient patches.

  19. Roots Air Management System with Integrated Expander

    Energy Technology Data Exchange (ETDEWEB)

    Stretch, Dale [Eaton Corporation, Menomonee Falls, WI (United States); Wright, Brad [Eaton Corporation, Menomonee Falls, WI (United States); Fortini, Matt [Eaton Corporation, Menomonee Falls, WI (United States); Fink, Neal [Ballard Power Systems, Burnaby, BC (Canada); Ramadan, Bassem [Kettering Univ., Flint, MI (United States); Eybergen, William [Eaton Corporation, Menomonee Falls, WI (United States)

    2016-07-06

    PEM fuel cells remain an emerging technology in the vehicle market with several cost and reliability challenges that must be overcome in order to increase market penetration and acceptance. The DOE has identified the lack of a cost effective, reliable, and efficient air supply system that meets the operational requirements of a pressurized PEM 80kW fuel cell as one of the major technological barriers that must be overcome. This project leveraged Roots positive displacement development advancements and demonstrated an efficient and low cost fuel cell air management system. Eaton built upon its P-Series Roots positive displacement design and shifted the peak efficiency making it ideal for use on an 80kW PEM stack. Advantages to this solution include: • Lower speed of the Roots device eliminates complex air bearings present on other systems. • Broad efficiency map of Roots based systems provides an overall higher drive cycle fuel economy. • Core Roots technology has been developed and validated for other transportation applications. Eaton modified their novel R340 Twin Vortices Series (TVS) Roots-type supercharger for this application. The TVS delivers more power and better fuel economy in a smaller package as compared to other supercharger technologies. By properly matching the helix angle with the rotor’s physical aspect ratio, the supercharger’s peak efficiency can be moved to the operating range where it is most beneficial for the application. The compressor was designed to meet the 90 g/s flow at a pressure ratio of 2.5, similar in design to the P-Series 340. A net shape plastic expander housing with integrated motor and compressor was developed to significantly reduce the cost of the system. This integrated design reduced part count by incorporating an overhung expander and motor rotors into the design such that only four bearings and two shafts were utilized.

  20. Root resorption during orthodontic tooth movements.

    Science.gov (United States)

    Ramanathan, C; Hofman, Z

    2009-12-01

    The aim of the study was to compare the extent of maxillary incisor root resorption during different orthodontic tooth movements using three different techniques, namely the basal intrusion arch, the three component arch, and levelling of the upper dental arch with the straightwire appliance. The radiographs of 49 subjects (20 males and 29 females) with a mean age of 14.5 years were taken at two time points: in groups 1 and 2 after the levelling phase and in group 3 immediately after placement of the archwire (T1) and in all groups after a period of 6 months (T2). The amount of root resorption of the central incisors was determined at T2. The average incisor resorption was different in the three groups, with group 2 (three component arch) showing greater resorption (0.46 mm) than groups 1 (basal arch) and 3 (straightwire) of 0.26 and 0.25 mm, respectively. Analysis of variance (ANOVA) demonstrated that differences in root resorption in the three groups were not significant. Wilcoxon paired test showed that the root resorption occurring between T1 and T2 in the three groups was not significant. There was also no significant difference among the rates of resorption in the three groups. Grouping the subjects on the basis of the extent of root resorption and the biomechanics used showed differences in the percentage of subjects with the least (resorption between the three groups. This again showed that the technique of three component intrusion arch resulted in the greatest increase in root resorption.

  1. Root approach for estimation of statistical distributions

    Science.gov (United States)

    Bogdanov, Yu. I.; Bogdanova, N. A.

    2014-12-01

    Application of root density estimator to problems of statistical data analysis is demonstrated. Four sets of basis functions based on Chebyshev-Hermite, Laguerre, Kravchuk and Charlier polynomials are considered. The sets may be used for numerical analysis in problems of reconstructing statistical distributions by experimental data. Based on the root approach to reconstruction of statistical distributions and quantum states, we study a family of statistical distributions in which the probability density is the product of a Gaussian distribution and an even-degree polynomial. Examples of numerical modeling are given.

  2. Root approach for estimation of statistical distributions

    CERN Document Server

    Bogdanov, Yu I

    2014-01-01

    Application of root density estimator to problems of statistical data analysis is demonstrated. Four sets of basis functions based on Chebyshev-Hermite, Laguerre, Kravchuk and Charlier polynomials are considered. The sets may be used for numerical analysis in problems of reconstructing statistical distributions by experimental data. Based on the root approach to reconstruction of statistical distributions and quantum states, we study a family of statistical distributions in which the probability density is the product of a Gaussian distribution and an even-degree polynomial. Examples of numerical modeling are given. The results of present paper are of interest for the development of tomography of quantum states and processes.

  3. Tonoplast aquaporins facilitate lateral root emergence

    DEFF Research Database (Denmark)

    Reinhardt, Hagen; Hachez, Charles; Bienert, Manuela Désirée

    2016-01-01

    that, in Arabidopsis (Arabidopsis thaliana), the highly abundant tonoplast AQP isoforms AtTIP1;1, AtTIP1;2, and AtTIP2;1 facilitate the emergence of new lateral root primordia (LRPs). The number of lateral roots was strongly reduced in the triple tip mutant, whereas the single, double, and triple tip...... could be fully rescued by expressing AtTIP2;1 under its native promoter. We conclude that TIP isoforms allow the spatial and temporal fine-tuning of cellular water transport, which is critically required during the highly regulated process of LRP morphogenesis and emergence....

  4. A method to minimize complications in endodontic access cavity preparation.

    Science.gov (United States)

    Zelikow, Robert; Cozzarelli-Moldauer, Gina; Keiner, Steven; Hardigan, Patrick C

    2008-06-01

    This article presents a method of avoiding some operative errors in endodontic-access cavity preparation. Utilizing the radiograph, a line representing the coronal extension of the image of the coronal two-thirds of the root canal(s) is drawn on the facial surface of the crown (Fig. 1). This line determines the proper angulation of the bur to facilitate entry into the pulp chamber in proper mesio-distal orientation, thereby reducing the likelihood of mesial and distal gouging and perforating. Marking the tooth to be treated prior to rubber-dam placement help in preventing treatment of an incorrect tooth. Two studies utilizing Nova Southeastern University College of Dental Medicine (NSUCDM) second-year dental students (D-2), one utilizing University of Florida, College of Dentistry (UFCD) second year dental students (D2) and one utilizing NSUCDM Advanced Education in General Dentistry (AEGD) faculty and students were undertaken to evaluate the method. Evaluation was by endodontic teachers. Results indicate use of the line-drawing method may facilitate more ideal access cavities than those prepared without the method. Welch's t-test, chi-square test and estimating equations were employed. One study showed significant difference between control and test groups (p less than 045). All studies indicated a difference. Further testing of the method is indicated. This valuable tool should be considered for use in teaching and practice.

  5. Isolated root caps, border cells, and mucilage from host roots stimulate hyphal branching of the arbuscular mycorrhizal fungus, Gigaspora gigantea.

    Science.gov (United States)

    Nagahashi, Gerald; Douds, David D

    2004-09-01

    Unlike previous reports that have shown that water soluble and volatile compounds from roots or root exudates play an important role in precolonization events during arbuscular mycorrhizal (AM) fungus-host root interactions (Bécard & Piché 1989, Giovannetti et al. 1993), the results shown here deal with particulate and viscous fractions isolated from host roots. Root caps and a slow sedimenting particulate fraction (SSPF) were rapidly isolated and separated from Ri T-DNA transformed carrot roots (D. carota) grown in liquid culture. In addition, border cells (BC) and mucilage were isolated from aseptically grown corn seedlings (Zea mays). Root caps, SSPF (composed mainly of small root cap fragments and some BCs), BCs, and mucilage all had an associated AM fungus hyphal branching stimulator. Root caps stored for 5 d at 4 degrees C appeared to either synthesize or slowly release the branching stimulator. Also, isolated root caps from roots grown in the absence of P contained more branch stimulating activity than those isolated from roots grown in the presence of P. Although the branching stimulation activity in particulate fractions was low compared to that of the exudate, the particulate fractions can stick to the root surface at considerable distances from the root tip. This may be significant during the infection and colonization of host roots at sites far removed from the primary location of exudation.

  6. Arabidopsis alcohol dehydrogenase expression in both shoots and roots is conditioned by root growth environment

    Science.gov (United States)

    Chung, H. J.; Ferl, R. J.

    1999-01-01

    It is widely accepted that the Arabidopsis Adh (alcohol dehydrogenase) gene is constitutively expressed at low levels in the roots of young plants grown on agar media, and that the expression level is greatly induced by anoxic or hypoxic stresses. We questioned whether the agar medium itself created an anaerobic environment for the roots upon their growing into the gel. beta-Glucuronidase (GUS) expression driven by the Adh promoter was examined by growing transgenic Arabidopsis plants in different growing systems. Whereas roots grown on horizontal-positioned plates showed high Adh/GUS expression levels, roots from vertical-positioned plates had no Adh/GUS expression. Additional results indicate that growth on vertical plates closely mimics the Adh/GUS expression observed for soil-grown seedlings, and that growth on horizontal plates results in induction of high Adh/GUS expression that is consistent with hypoxic or anoxic conditions within the agar of the root zone. Adh/GUS expression in the shoot apex is also highly induced by root penetration of the agar medium. This induction of Adh/GUS in shoot apex and roots is due, at least in part, to mechanisms involving Ca2+ signal transduction.

  7. Hairy Root Induction in Helicteres isora L. and Production of Diosgenin in Hairy Roots.

    Science.gov (United States)

    Kumar, Vinay; Desai, Dnyanada; Shriram, Varsha

    2014-04-01

    Mature seeds of Helicteres isora L. were collected from seven geographical locations of Maharashtra and Goa (India) and evaluated for diosgenin (a bioactive steroidal sapogenin of prime importance) extraction and quantification. Chemotypic variations were evidenced with diosgenin quantity ranging from 33 μg g(-1) seeds (Osmanabad forests) to 138 μg g(-1) (Khopoli region). Nodal and leaf explants from in vitro-raised seedlings were used for callus and Agrobacterium-mediated transformation, respectively. Compact, hard, whitish-green callus (2.65 g explant(-1)) was obtained on MS + 13.32 μM BAP + 2.32 μM Kin after 30 days of inoculation. Various parameters including types of explant and Agrobacterium strain, culture density, duration of infection and various medium compositions were optimized for hairy root production. A. rhizogenes strain ATCC-15834 successfully induced hairy roots from leaf explants (1 cm(2)) with 42 % efficiency. Transgenic status of the roots was confirmed by PCR using rolB and VirD specific primers. Hairy roots showed an ability to synthesize diosgenin. Diosgenin yield was increased ~8 times in hairy roots and ~5 times in callus than the seeds of wild plants. Enhanced diosgenin content was associated with proline accumulation in hairy roots. This is the first report on induction of hairy roots in H. isora.

  8. Tissue specific localization of root infection by fungal pathogens: role of root border cells.

    Science.gov (United States)

    Gunawardena, Uvini; Hawes, Martha C

    2002-11-01

    When roots of pea seedlings were inoculated uniformly with spores of Nectria haematocca or other pea pathogenic fungi, more than 90% developed lesions in the region of elongation within 3 days. More mature regions of most roots as well as the tip showed no visible signs of infection. Yet, microscopic observation revealed that 'mantles,' comprised of fungal hyphae intermeshed with populations of border cells, covered the tips of most roots. After physical detachment of the mantle, the underlying tip of most roots was found to be free of infection. Mantle-covered root tips did not respond to invasion of their border cells by activation of known defense genes unless there was invasion of the tip itself, as revealed by the presence of a lesion. Concomitant with the activation of defense genes was the induction of a cell-wall degrading enzyme whose expression is a marker for renewed production of border cells. Mantle formation did not occur in response to nonpathogens. The data are consistent with the hypothesis that border cells serve as a host-specific 'decoy' that protects root meristems by inhibiting fungal infection of the root tip.

  9. Root Traits and Phenotyping Strategies for Plant Improvement

    Directory of Open Access Journals (Sweden)

    Ana Paez-Garcia

    2015-06-01

    Full Text Available Roots are crucial for nutrient and water acquisition and can be targeted to enhance plant productivity under a broad range of growing conditions. A current challenge for plant breeding is the limited ability to phenotype and select for desirable root characteristics due to their underground location. Plant breeding efforts aimed at modifying root traits can result in novel, more stress-tolerant crops and increased yield by enhancing the capacity of the plant for soil exploration and, thus, water and nutrient acquisition. Available approaches for root phenotyping in laboratory, greenhouse and field encompass simple agar plates to labor-intensive root digging (i.e., shovelomics and soil boring methods, the construction of underground root observation stations and sophisticated computer-assisted root imaging. Here, we summarize root architectural traits relevant to crop productivity, survey root phenotyping strategies and describe their advantages, limitations and practical value for crop and forage breeding programs.

  10. Adjustment of Forest Ecosystem Root Respiration as Temperature Warms

    Institute of Scientific and Technical Information of China (English)

    Andrew J. Burton; Jerry M. Melillo; Serita D. Frey

    2008-01-01

    Adjustment of ecosystem root respiration to warmer climatic conditions can alter the autotrophic portion of soil respiration and influence the amount of carbon available for biomass production. We examined 44 published values of annual forest root respiration and found an increase in ecosystem root respiration with increasing mean annual temperature (MAT),but the rate of this cross-ecosystem increase (Q10 = 1.6) is less than published values for short-term responses of root respiration to temperature within ecosystems (Q10 = 2-3). When specific root respiration rates and root biomass values were examined, there was a clear trend for decreasing root metabolic capacity (respiration rate at a standard temperature) with increasing MAT. There also were tradeoffs between root metabolic capacity and root system biomass, such that there were no instances of high growing season respiration rates and high root biomass occurring together. We also examined specific root respiration rates at three soil warming experiments at Harvard Forest, USA, and found decreases in metabolic capacity for roots from the heated plots. This decline could be due to either physiological acclimation or to the effects of co-occurring drier soils on the measurement date. Regardless of the cause, these findings clearly suggest that modeling efforts that allow root respiration to increase exponentially with temperature, with Qt0 values of 2 or more, may over-predict root contributions to ecosystem CO2 efflux for future climates and underestimate the amount of C available for other uses,including net primary productivity.

  11. Mycorrhiza alters the profile of root hairs in trifoliate orange.

    Science.gov (United States)

    Wu, Qiang-Sheng; Liu, Chun-Yan; Zhang, De-Jian; Zou, Ying-Ning; He, Xin-Hua; Wu, Qing-Hua

    2016-04-01

    Root hairs and arbuscular mycorrhiza (AM) coexist in root systems for nutrient and water absorption, but the relation between AM and root hairs is poorly known. A pot study was performed to evaluate the effects of four different AM fungi (AMF), namely, Claroideoglomus etunicatum, Diversispora versiformis, Funneliformis mosseae, and Rhizophagus intraradices on root hair development in trifoliate orange (Poncirus trifoliata) seedlings grown in sand. Mycorrhizal seedlings showed significantly higher root hair density than non-mycorrhizal seedlings, irrespective of AMF species. AMF inoculation generally significantly decreased root hair length in the first- and second-order lateral roots but increased it in the third- and fourth-order lateral roots. AMF colonization induced diverse responses in root hair diameter of different order lateral roots. Considerably greater concentrations of phosphorus (P), nitric oxide (NO), glucose, sucrose, indole-3-acetic acid (IAA), and methyl jasmonate (MeJA) were found in roots of AM seedlings than in non-AM seedlings. Levels of P, NO, carbohydrates, IAA, and MeJA in roots were correlated with AM formation and root hair development. These results suggest that AMF could alter the profile of root hairs in trifoliate orange through modulation of physiological activities. F. mosseae, which had the greatest positive effects, could represent an efficient AM fungus for increasing fruit yields or decreasing fertilizer inputs in citrus production.

  12. [Morphology of wheat roots under low-phosphorus stress].

    Science.gov (United States)

    Sun, Haiguo; Zhang, Fusuo

    2002-03-01

    The morphology of root systems of different wheat (Triticum aestivum L.) genotypes under low-phosphorus stress were studied to determine the effects of external factors on components of root system and the early morphological indicators related to phosphorus efficiency. The number of root axes and the length of lateral root of P-deficient plant were significantly lower than those of P-sufficient plant. The length of root axis and root system, and the number of lateral roots were sharply increased under low-P stress. The number and length of root axis were significantly different under different levels of phosphorus supply and among different wheat genotypes under same phosphorus supply. This implied that the two traits (number and length of root axis) were controlled by genotype and external factors. The difference in the characteristics of lateral root of the given wheat genotypes was significant only between different levels of P supply. It showed that the traits of lateral root mainly depended on external factors. The length and number of root axis, root length, and root angle were significantly different among 6 wheat genotypes. There exited significant linear relationships between relative grain yield and the interaction of the morphological traits, and it implied that the traits could be used as early indicators of selecting high P-efficiency wheat varieties.

  13. Single Plant Root System Modeling under Soil Moisture Variation

    Science.gov (United States)

    Yabusaki, S.; Fang, Y.; Chen, X.; Scheibe, T. D.

    2016-12-01

    A prognostic Virtual Plant-Atmosphere-Soil System (vPASS) model is being developed that integrates comprehensively detailed mechanistic single plant modeling with microbial, atmospheric, and soil system processes in its immediate environment. Three broad areas of process module development are targeted: Incorporating models for root growth and function, rhizosphere interactions with bacteria and other organisms, litter decomposition and soil respiration into established porous media flow and reactive transport models Incorporating root/shoot transport, growth, photosynthesis and carbon allocation process models into an integrated plant physiology model Incorporating transpiration, Volatile Organic Compounds (VOC) emission, particulate deposition and local atmospheric processes into a coupled plant/atmosphere model. The integrated plant ecosystem simulation capability is being developed as open source process modules and associated interfaces under a modeling framework. The initial focus addresses the coupling of root growth, vascular transport system, and soil under drought scenarios. Two types of root water uptake modeling approaches are tested: continuous root distribution and constitutive root system architecture. The continuous root distribution models are based on spatially averaged root development process parameters, which are relatively straightforward to accommodate in the continuum soil flow and reactive transport module. Conversely, the constitutive root system architecture models use root growth rates, root growth direction, and root branching to evolve explicit root geometries. The branching topologies require more complex data structures and additional input parameters. Preliminary results are presented for root model development and the vascular response to temporal and spatial variations in soil conditions.

  14. Anchorage of mature conifers: resistive turning moment, root-soil plate geometry and root growth orientation.

    Science.gov (United States)

    Lundström, Tor; Jonas, Tobias; Stöckli, Veronika; Ammann, Walter

    2007-09-01

    Eighty-four mature Norway spruce (Picea abies L. Karst), silver fir (Abies alba Mill) and Scots pine (Pinus sylvestris L.) trees were winched over to determine the maximum resistive turning moment (M(a)) of the root-soil system, the root-soil plate geometry, the azimuthal orientation of root growth, and the occurrence of root rot. The calculation of M(a), based on digital image tracking of stem deflection, accounted not only for the force application and its changing geometry, but also for the weight of the overhanging tree, representing up to 42% of M(a). Root rot reduced M(a) significantly and was detected in 25% of the Norway spruce and 5% of the silver fir trees. Excluding trees with root rot, differences in M(a) between species were small and insignificant. About 75% of the variance in M(a) could be explained by one of the four variables--tree mass, stem mass, stem diameter at breast height squared times tree height, and stem diameter at breast height squared. Among the seven allometric variables assessed above ground, stem diameter at breast height best described the root-soil plate dimensions, but the correlations were weak and the differences between species were insignificant. The shape of the root-soil plate was well described by a depth-dependent taper model with an elliptical cross section. Roots displayed a preferred azimuthal orientation of growth in the axis of prevailing winds, and the direction of frequent weak winds matched the orientation of growth better than that of rare strong winds. The lack of difference in anchorage parameters among species probably reflects the similar belowground growth conditions of the mature trees.

  15. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots

    NARCIS (Netherlands)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises

  16. Cytokinin-induced promotion of root meristem size in the fern Azolla supports a shoot-like origin of euphyllophyte roots

    NARCIS (Netherlands)

    de Vries, Jan; Fischer, Angela Melanie; Roettger, Mayo; Rommel, Sophie; Schluepmann, Henriette; Bräutigam, Andrea; Carlsbecker, Annelie; Gould, Sven Bernhard

    2016-01-01

    The phytohormones cytokinin and auxin orchestrate the root meristem development in angiosperms by determining embryonic bipolarity. Ferns, having the most basal euphyllophyte root, form neither bipolar embryos nor permanent embryonic primary roots but rather an adventitious root system. This raises

  17. Reproducible hairy root transformation and spot-inoculation methods to study root symbioses of pea

    Directory of Open Access Journals (Sweden)

    Clemow Scott R

    2011-12-01

    Full Text Available Abstract Pea has lagged behind other model legumes in the molecular study of nodulation and mycorrhizae-formation because of the difficulty to transform its roots and its poor growth on agar plates. Here we describe for pea 1 a transformation technique which permits the complementation of two known non-nodulating pea mutants, 2 a rhizobial inoculation method which allows the study of early cellular events giving rise to nodule primordia, and 3 a targeted fungal inoculation method which allows us to study short segments of mycorrhizal roots assured to be infected. These tools are certain to advance our knowledge of pea root symbioses.

  18. Rooting greenwood tip cuttings of several Populus clones hydroponically (hydroponic rooting of Populus cuttings)

    Energy Technology Data Exchange (ETDEWEB)

    Phipps, H.M.; Hansen, E.A.; Tolsted, D.N.

    1980-01-01

    Greenwood cuttings of several Populus clones were successfully rooted with a relatively simple hydroponic method. Indolebutyric acid and naphthaleneacetic acid at concentrations of 500 to 5000 ppM applied as a quick dip to the cutting bases, a complete nutrient solution at 20 to 40% of full strength, and a solution temperature between 27 and 30/sup 0/C generally produced the best rooting performance of most clones. Cuttings propagated by the hydroponic procedure rooted faster and generally outgrew those produced by a standard method after being transplanted to pots and grown in the greenhouse.

  19. Boston: Community Schools from the Grass Roots

    Science.gov (United States)

    O'Neil, William F.

    1974-01-01

    In Boston, grass roots citizen pressure led to the formation of community schools to replace elementary schools. The community schools are operated by the Boston School Committee during the regular school day and by the Department of Public Facilities in the extended day and evening. (Author/DN)

  20. Phytochemical Investigations of Caesalpinia digyna Root

    Directory of Open Access Journals (Sweden)

    R. Srinivasan

    2011-01-01

    Full Text Available Phytochemical examination of petroleum ether extract of Caesalpinia digyna root resulted in the isolation of four compounds namely, friedelin, hexacosanoic acid, β-sitosterol and stigmasterol. These compounds have been characterized on basis of physical and spectral data. All the four compounds are being reported for the first time from this plant

  1. Methane and Root Dynamics in Arctic Soil

    DEFF Research Database (Denmark)

    D'Imperio, Ludovica

    on the global climate. We investigated two aspects of arctic ecosystem dynamics which are not well represented in climatic models: i) soil methane (CH4) oxidation in dry heath tundra and barren soils and ii) root dynamics in wetlands. Field measurements were carried out during the growing season in Disko Island...

  2. Proofs of certain properties of irrational roots

    OpenAIRE

    Belbas, S. A.

    2009-01-01

    We give two elementary proofs, at a level understandable by students with only pre-calculus knowledge of Algebra, of the well known fact that an irreducible irrational n-th root of a positive rational number cannot be solution of a polynomial of degree less than n with rational coefficients. We also state and prove a few simple consequences.

  3. Bacterial proteins pinpoint a single eukaryotic root.

    Science.gov (United States)

    Derelle, Romain; Torruella, Guifré; Klimeš, Vladimír; Brinkmann, Henner; Kim, Eunsoo; Vlček, Čestmír; Lang, B Franz; Eliáš, Marek

    2015-02-17

    The large phylogenetic distance separating eukaryotic genes and their archaeal orthologs has prevented identification of the position of the eukaryotic root in phylogenomic studies. Recently, an innovative approach has been proposed to circumvent this issue: the use as phylogenetic markers of proteins that have been transferred from bacterial donor sources to eukaryotes, after their emergence from Archaea. Using this approach, two recent independent studies have built phylogenomic datasets based on bacterial sequences, leading to different predictions of the eukaryotic root. Taking advantage of additional genome sequences from the jakobid Andalucia godoyi and the two known malawimonad species (Malawimonas jakobiformis and Malawimonas californiana), we reanalyzed these two phylogenomic datasets. We show that both datasets pinpoint the same phylogenetic position of the eukaryotic root that is between "Unikonta" and "Bikonta," with malawimonad and collodictyonid lineages on the Unikonta side of the root. Our results firmly indicate that (i) the supergroup Excavata is not monophyletic and (ii) the last common ancestor of eukaryotes was a biflagellate organism. Based on our results, we propose to rename the two major eukaryotic groups Unikonta and Bikonta as Opimoda and Diphoda, respectively.

  4. Bullying in nursing: roots, rationales, and remedies.

    Science.gov (United States)

    Szutenbach, Mary Pat

    2013-01-01

    Bullying and incivility are sadly, far too common in today's healthcare workplaces. This article reviews early to current literature, identifies types of bullying, offers four root causes, and suggests responses to impact these causes using Gibbs' Reflective Cycle, biblical Scripture, and an allegory "How to Swim with Sharks."

  5. Quest for Continual Growth Takes Root

    Science.gov (United States)

    Surdey, Mary M.; Hashey, Jane M.

    2006-01-01

    In this article, the authors describe how the quest for continual growth has taken its root at Vestal Central School district. Located at the heart of upstate New York, educators at Vestal Central School district have created a spirit of "kaizen," a Japanese word meaning the relentless quest for continual improvement and higher-quality…

  6. Root canal cleaning through cavitation and microstreaming

    NARCIS (Netherlands)

    Verhaagen, B.

    2012-01-01

    We have investigated the flow from a needle using Computational Fluid Dynamics simulations and high-speed imaging experiments on sub-millimeter fluidic channels. These have shown that the flow is not effective in delivering the bleach near the bacteria, due to the complex geometry of the root canal.

  7. FiT gets CLEAN local roots

    Energy Technology Data Exchange (ETDEWEB)

    Meehan, Chris

    2012-07-01

    Feed-in tariffs are starting to take root in the US. While there is little to no hope of a national FiT policy, a growing number of cities, like Los Angeles, Gainesville, and Sacramento and states including California and Vermont are creating their own FiTs. (orig.)

  8. An antileishmanial chalcone from Chinese licorice roots

    DEFF Research Database (Denmark)

    Christensen, S B; Ming, C; Andersen, L

    1994-01-01

    A bioassay guided fractionation of an extract of Chinese licorice roots led to the isolation of (E)-1-[2,4-dihydroxy-3-(3-methyl-2-butenyl)phenyl]-3-[4- hydroxy-3-(3-methyl-2-butenyl]phenyl-2-propen-1-one, which in vitro showed potent antileishmanial activity. In addition, the novel chalcone (E)-...

  9. Dialectical roots for interest prohibition theory

    NARCIS (Netherlands)

    J.A. Bergstra

    2011-01-01

    It is argued that arguments for strict prohibition of interests must be based on the use of arguments from authority. This is carried out by first making a survey of so-called dialectical roots for interest prohibition and then demonstrating that for at least one important positive interest bearing

  10. Alkaloids from the Roots of Saccopetalum prolificum

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A new alkaloid, named prolifine (1), was isolated along with four known alkaloids, liriodenine (2), 6-hydroxyonychine (3), isooncodine (4) and discretamine (5) from the roots of Saccopetalum prolificum. The structure of 1 was elucidated on the basis of spectroscopic and chemical methods.

  11. Parameterizing the soil - water - plant root system

    NARCIS (Netherlands)

    Feddes, R.A.; Raats, P.A.C.

    2004-01-01

    Root water uptake is described from the local scale, to the field scale and to the regional and global scales. The local macroscopic model can be incorporated in Soil-Plant-Atmosphere Continuum (SPAC) numerical models, like the SWAP, HYSWASOR, HYDRUS, ENVIRO-GRO and FUSSIM models. These SPAC models

  12. The bifidogenic effect of Taraxacum officinale root.

    Science.gov (United States)

    Trojanová, I; Rada, V; Kokoska, L; Vlková, E

    2004-12-01

    The infusion of dandelion root (Taraxacum officinale) stimulated in vitro the growth of 14 strains of bifidobacteria. The utilization of oligofructans, glucose, fructose and total saccharides was determined by enzymatic and phenol-sulfuric methods. Dandelion oligofructans were important source of carbon and energy for bifidobacteria tested.

  13. Pharmacognostical Standardization of Tephrosia purpurea Pers Root.

    Science.gov (United States)

    Sandhya, S; Ventaka, Ramana K; Vinod, K R

    2010-07-01

    Wild Indigo or Purple Tephrosia or fish poison occurs throughout the Indian subcontinent. It is widely used in the treatment of inflammation, diabetes, rheumatism, asthma, diarrhoea and many other ailments. But so far the pharmacognostic standardization has not been reported for its proper identification. Hence the present study is a pharmacognosy work carried out for the root part. This may help in the identification of the plant species. A thin transverse section, powder microscopy, measurement of the dimensions of cell structures, fluorescence analysis and physico chemical parameters were conducted for the root. From the TS, the secondary xylem fibres and vessels were found to be the tissues of diagnostic importance. The xylem vessels were of two types: narrow and long; broad and short. The important characters in the powdered microscopy were vessel elements, fibres and xylem parenchyma cells. The different fluorescent light shades were obtained under short and long UV light for both powder as well as the extracts of the root. The proximate analysis values were also obtained in a satisfactory way. Combining all these data a suitable root profile for plant can be constructed which may help in the identification of quality of the plant part.

  14. Occurrence of root parsley pathogens inhabiting seeds

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available The studies on root parsley pathogens inhabiting seeds were conducted during 1981-1988 and in 1993. Filter paper method with prefreezing and keeping under light was used. Each test sample comprised 500 seeds. Pathogenicity of collected fungal isolates was tested following two laboratory methods. 238 seed samples were studied. 18 fungal species were found but only 7 proved to be important pathogens of root parsley. The most common inhabitants of root parsley seeds were Alternaria spp. A.allernata occurred on 74,8% of seeds but only a few isolates showed to be slightly pathogenic while A.petroselini and A.radicina were higly pathogenic and inhabited 11,4 and 4,2% of seeds, respectively. The second group of important pathogens were species of Fusarium found on 3,9% of seeds. F.avenaceum dominated as it comprised 48% of Fusarium isolates, the next were as follow: F.culmorum - 20%, F.equiseti - 15%, F.solani - 8%, F.oxysporum - 7% and F.dimerum -2%. Some fungi like Botrytis cinerea, Septoria petroselini and Phoma spp. inhabited low number of seeds, respectively O,4; 0,5 and 0,8%, but they were highly pathogenic to root parsley. The fungi: Bipolaris sorokiniana, Drechslera biseptata, Stemphylium botryosum and Ulocludium consortiale showed slight pathogenicity. They were isolated from 3,8% of seeds.

  15. Del Pezzo Moduli via Root Systems

    NARCIS (Netherlands)

    Colombo, E.; van Geemen, B.; Looijenga, E.J.N.

    2010-01-01

    Coble defined in his 1929 treatise invariants for cubic surfaces and quartic curves. We reinterpret these in terms of the root systems of type E6 and E7 that are naturally associated to these varieties, thereby giving some of his results a more intrinsic treatment. Our discussion is uniform for all

  16. Hormone symphony during root growth and development.

    Science.gov (United States)

    Garay-Arroyo, Adriana; De La Paz Sánchez, María; García-Ponce, Berenice; Azpeitia, Eugenio; Alvarez-Buylla, Elena R

    2012-12-01

    Hormones regulate plant growth and development in response to external environmental stimuli via complex signal transduction pathways, which in turn form complex networks of interaction. Several classes of hormones have been reported, and their activity depends on their biosynthesis, transport, conjugation, accumulation in the vacuole, and degradation. However, the activity of a given hormone is also dependent on its interaction with other hormones. Indeed, there is a complex crosstalk between hormones that regulates their biosynthesis, transport, and/or signaling functionality, although some hormones have overlapping or opposite functions. The plant root is a particularly useful system in which to study the complex role of plant hormones in the plastic control of plant development. Physiological, cellular, and molecular genetic approaches have been used to study the role of plant hormones in root meristem homeostasis. In this review, we discuss recent findings on the synthesis, signaling, transport of hormones and role during root development and examine the role of hormone crosstalk in maintaining homeostasis in the apical root meristem.

  17. Root resorption after orthodontic intrusion and extrusion:.

    NARCIS (Netherlands)

    Han, G.; Huang, S.; Hoff, J.W. Von den; Zeng, X.; Kuijpers-Jagtman, A.M.

    2005-01-01

    The aim of this investigation was to compare root resorption in the same individual after application of continuous intrusive and extrusive forces. In nine patients (mean age 15.3 years), the maxillary first premolars were randomly intruded or extruded with a continuous force of 100 cN for eight wee

  18. Proofs of certain properties of irrational roots

    OpenAIRE

    Belbas, S. A.

    2009-01-01

    We give two elementary proofs, at a level understandable by students with only pre-calculus knowledge of Algebra, of the well known fact that an irreducible irrational n-th root of a positive rational number cannot be solution of a polynomial of degree less than n with rational coefficients. We also state and prove a few simple consequences.

  19. Aortic root replacement with a pulmonary autograft

    NARCIS (Netherlands)

    R.B. Hokken (Raymond)

    1997-01-01

    textabstractAortic valve disease in the pediatric age group is usually a consequence of congenital aortic stenosis, which may be isolated or may be a part of an anomaly of the left ventricular outflow tract or the aortic root. Management of these patients is difficult. Neonates and infants with seve

  20. Pectate hydrolases of parsley (Petroselinum crispum) roots.

    Science.gov (United States)

    Flodrová, Dana; Dzúrovä, Mária; Lisková, Desana; Mohand, Fairouz Ait; Mislovicová, Danica; Malovícová, Anna; Voburka, Zdenek; Omelková, Jirina; Stratilová, Eva

    2007-01-01

    The presence of various enzyme forms with terminal action pattern on pectate was evaluated in a protein mixture obtained from parsley roots. Enzymes found in the soluble fraction of roots (juice) were purified to homogeneity according to SDS-PAGE, partially separated by preparative isoelectric focusing and characterized. Three forms with pH optima 3.6, 4.2 and 4.6 clearly preferred substrates with a lower degree of polymerization (oligogalacturonates) while the form with pH optimum 5.2 was a typical exopolygalacturonase [EC 3. 2.1.67] with relatively fast cleavage of polymeric substrate. The forms with pH optima 3.6, 4.2 and 5.2 were released from the pulp, too. The form from the pulp with pH optimum 4.6 preferred higher oligogalacturonates and was not described in plants previously. The production of individual forms in roots was compared with that produced by root cells cultivated on solid medium and in liquid one.

  1. Tapping Ancient Roots: Plaited Paper Baskets

    Science.gov (United States)

    Patrick, Jane

    2011-01-01

    With ancient roots, basket making has been practiced since the earliest civilizations, and according to textile experts, probably pre-dates pottery. This is partly conjecture since few baskets remain. It is through evidence found in clay impressions that the earliest baskets reveal themselves. Basically, basketry construction is like flat weaving.…

  2. Root development in relation to impacted mesiodens.

    Science.gov (United States)

    Kalra, N; Chopra, P

    1998-09-01

    Presented here is a case of 7 years 6 month old child with an apically impacted mesiodens in relation to the developing root of right upper central incisor. The removal of mesiodens was deferred in order to avoid disturbance in the natural development of the upper central incisor. Serial X-rays are presented and case is discussed.

  3. Topographic and ecologic controls on root reinforcement

    Science.gov (United States)

    T.C. Hales; C.R. Ford; T. Hwang; J.M. Vose; L.E. Band

    2009-01-01

    Shallow landslides are a significant hazard in steep, soil-mantled landscapes. During intense rainfall events, the distribution of shallow landslides is controlled by variations in landscape gradient, the frictional and cohesive properties of soil and roots, and the subsurface hydrologic response. While gradients can be estimated from digital elevation models,...

  4. Nodal distances for rooted phylogenetic trees.

    Science.gov (United States)

    Cardona, Gabriel; Llabrés, Mercè; Rosselló, Francesc; Valiente, Gabriel

    2010-08-01

    Dissimilarity measures for (possibly weighted) phylogenetic trees based on the comparison of their vectors of path lengths between pairs of taxa, have been present in the systematics literature since the early seventies. For rooted phylogenetic trees, however, these vectors can only separate non-weighted binary trees, and therefore these dissimilarity measures are metrics only on this class of rooted phylogenetic trees. In this paper we overcome this problem, by splitting in a suitable way each path length between two taxa into two lengths. We prove that the resulting splitted path lengths matrices single out arbitrary rooted phylogenetic trees with nested taxa and arcs weighted in the set of positive real numbers. This allows the definition of metrics on this general class of rooted phylogenetic trees by comparing these matrices through metrics in spaces M(n)(R) of real-valued n x n matrices. We conclude this paper by establishing some basic facts about the metrics for non-weighted phylogenetic trees defined in this way using L(p) metrics on M(n)(R), with p [epsilon] R(>0).

  5. Plant Hormones: How They Affect Root Formation.

    Science.gov (United States)

    Reinhard, Diana Hereda

    This science study aid, produced by the U.S. Department of Agriculture, includes a series of plant rooting activities for secondary science classes. The material in the pamphlet is written for students and includes background information on plant hormones, a vocabulary list, and five learning activities. Objectives, needed materials, and…

  6. REAL ROOT ISOLATION OF SPLINE FUNCTIONS

    Institute of Scientific and Technical Information of China (English)

    Renhong Wang; Jinming Wu

    2008-01-01

    In this paper,we propose an algorithm for isolating real roots of a given univariate spline function,which is based on the use of Descartes' rule of signs and de Casteljau algorithm.Numerical examples illustrate the flexibility and effectiveness of the algorithm.

  7. Damage to root dentin during retreatment procedures

    NARCIS (Netherlands)

    Shemesh, H.; Roeleveld, A.C.; Wesselink, P.R.; Wu, M.K.

    2011-01-01

    Introduction: The aim of this study was to explore the influence of retreatment procedures on the appearance of defects on the root canal walls. Methods: Two hundred mandibular premolars were divided into 4 groups. One group was left unprepared. The rest of the teeth were prepared with ProTaper file

  8. Seasonal changes of whole root system conductance by a drought-tolerant grape root system.

    Science.gov (United States)

    Alsina, Maria Mar; Smart, David R; Bauerle, Taryn; de Herralde, Felicidad; Biel, Carme; Stockert, Christine; Negron, Claudia; Save, Robert

    2011-01-01

    The role of root systems in drought tolerance is a subject of very limited information compared with above-ground responses. Adjustments to the ability of roots to supply water relative to shoot transpiration demand is proposed as a major means for woody perennial plants to tolerate drought, and is often expressed as changes in the ratios of leaf to root area (A(L):A(R)). Seasonal root proliferation in a directed manner could increase the water supply function of roots independent of total root area (A(R)) and represents a mechanism whereby water supply to demand could be increased. To address this issue, seasonal root proliferation, stomatal conductance (g(s)) and whole root system hydraulic conductance (k(r)) were investigated for a drought-tolerant grape root system (Vitis berlandieri×V. rupestris cv. 1103P) and a non-drought-tolerant root system (Vitis riparia×V. rupestris cv. 101-14Mgt), upon which had been grafted the same drought-sensitive clone of Vitis vinifera cv. Merlot. Leaf water potentials (ψ(L)) for Merlot grafted onto the 1103P root system (-0.91±0.02 MPa) were +0.15 MPa higher than Merlot on 101-14Mgt (-1.06±0.03 MPa) during spring, but dropped by approximately -0.4 MPa from spring to autumn, and were significantly lower by -0.15 MPa (-1.43±0.02 MPa) than for Merlot on 101-14Mgt (at -1.28±0.02 MPa). Surprisingly, g(s) of Merlot on the drought-tolerant root system (1103P) was less down-regulated and canopies maintained evaporative fluxes ranging from 35-20 mmol vine(-1) s(-1) during the diurnal peak from spring to autumn, respectively, three times greater than those measured for Merlot on the drought-sensitive rootstock 101-14Mgt. The drought-tolerant root system grew more roots at depth during the warm summer dry period, and the whole root system conductance (k(r)) increased from 0.004 to 0.009 kg MPa(-1) s(-1) during that same time period. The changes in k(r) could not be explained by xylem anatomy or conductivity changes of individual root

  9. Seasonal changes of whole root system conductance by a drought-tolerant grape root system

    Science.gov (United States)

    Alsina, Maria Mar; Smart, David R.; Bauerle, Taryn; de Herralde, Felicidad; Biel, Carme; Stockert, Christine; Negron, Claudia; Save, Robert

    2011-01-01

    The role of root systems in drought tolerance is a subject of very limited information compared with above-ground responses. Adjustments to the ability of roots to supply water relative to shoot transpiration demand is proposed as a major means for woody perennial plants to tolerate drought, and is often expressed as changes in the ratios of leaf to root area (AL:AR). Seasonal root proliferation in a directed manner could increase the water supply function of roots independent of total root area (AR) and represents a mechanism whereby water supply to demand could be increased. To address this issue, seasonal root proliferation, stomatal conductance (gs) and whole root system hydraulic conductance (kr) were investigated for a drought-tolerant grape root system (Vitis berlandieri×V. rupestris cv. 1103P) and a non-drought-tolerant root system (Vitis riparia×V. rupestris cv. 101-14Mgt), upon which had been grafted the same drought-sensitive clone of Vitis vinifera cv. Merlot. Leaf water potentials (ψL) for Merlot grafted onto the 1103P root system (–0.91±0.02 MPa) were +0.15 MPa higher than Merlot on 101-14Mgt (–1.06±0.03 MPa) during spring, but dropped by approximately –0.4 MPa from spring to autumn, and were significantly lower by –0.15 MPa (–1.43±0.02 MPa) than for Merlot on 101-14Mgt (at –1.28±0.02 MPa). Surprisingly, gs of Merlot on the drought-tolerant root system (1103P) was less down-regulated and canopies maintained evaporative fluxes ranging from 35–20 mmol vine−1 s−1 during the diurnal peak from spring to autumn, respectively, three times greater than those measured for Merlot on the drought-sensitive rootstock 101-14Mgt. The drought-tolerant root system grew more roots at depth during the warm summer dry period, and the whole root system conductance (kr) increased from 0.004 to 0.009 kg MPa−1 s−1 during that same time period. The changes in kr could not be explained by xylem anatomy or conductivity changes of individual root

  10. Beneficial microbes affect endogenous mechanisms controlling root development

    Science.gov (United States)

    Verbon, Eline H.; Liberman, Louisa M.

    2016-01-01

    Plants have incredible developmental plasticity, enabling them to respond to a wide range of environmental conditions. Among these conditions is the presence of plant growth-promoting rhizobacteria (PGPR) in the soil. Recent studies show that PGPR affect root growth and development within Arabidopsis thaliana root. These effects lead to dramatic changes in root system architecture, that significantly impact aboveground plant growth. Thus, PGPR may promote shoot growth via their effect on root developmental programs. This review focuses on contextualizing root developmental changes elicited by PGPR in light of our understanding of plant-microbe interactions and root developmental biology. PMID:26875056

  11. On Integrable Roots in Split Lie Triple Systems

    Institute of Scientific and Technical Information of China (English)

    A.J.CALDER(O)N MART(I)N

    2009-01-01

    We focus on the notion of an integrable root in the framework of split Lie triple systems T with a coherent 0-root space. As a main result, it is shown that if T has all its nonzero roots integrable, then its standard embedding is a split Lie algebra having all its nonzero roots integrable. As a consequence, a local finiteness theorem for split Lie triple systems, saying that whenever all nonzero roots of T are integrable then T is locally finite, is stated. Finally, a classification theorem for split simple Lie triple systems having all its nonzero roots integrable is given.

  12. Root resorption following periodontally accelerated osteogenic orthodontics

    Directory of Open Access Journals (Sweden)

    Donald J Ferguson

    2016-01-01

    Full Text Available Background: Literature evidence suggests that root resorption, an adverse side effect of orthodontic therapy, may be decreased under conditions of alveolar osteopenia, a condition characterized by diminished bone density and created secondary to alveolar corticotomy (Cort surgery. Purpose: To compare root resorption of the maxillary central incisors following nonextraction orthodontic therapy with and without Cort surgery. Materials and Methods: The sample comprised two groups, with and without Cort and was matched by age and gender: Cort-facilitated nonextraction orthodontics with 27 subjects, 53 central incisors of mean age 24.8 ± 10.2 years, and conventional (Conv nonextraction orthodontics with 27 subjects, 54 incisors with mean age of 19.6 ± 8.8 years. All periapical radiographs were taken with the paralleling technique; total tooth lengths of the right and left central incisors were measured by projecting and enlarging the periapical radiographs exactly 8 times. Results: t-tests revealed a significant decrease in treatment time in the Cort group (6.3 ± 8.0 vs. 17.4 ± 20.2 months, P = 0.000. Pretreatment root lengths were not significantly different (P = 0.11, but Conv had significantly shorter roots at posttreatment when compared with Cort (P = 0.03. Significant root resorption (P < 0.01 occurred in both Cort (0.3 mm and Conv (0.7 mm, but the increment of change was significantly greater in Conv (P < 0.03. The variable SNA increased significantly in the Cort (P = 0.001 group and decreased significantly in the Conv group (P < 0.001. Conclusions: Based on the conditions of this study, it may be concluded that Cort-facilitated nonextraction orthodontic therapy results in less root resorption and enhanced alveolar support within a significantly reduced clinical service delivery time frame. Rapid orthodontic treatment and reduced apical root resorption are probably due to the transient osteopenia induced by the Cort surgery and inspired by

  13. Electrical Imaging of Roots and Trunks

    Science.gov (United States)

    Al Hagrey, S.; Werban, U.; Meissner, R.; Ismaeil, A.; Rabbel, W.

    2005-05-01

    We applied geoelectric and GPR techniques to analyze problems of botanical structures and even processes, e.g., mapping root zones, internal structure of trunks, and water uptake by roots. The dielectric nature of root zones and trunks is generally a consequence of relatively high moisture content. The electric method, applied to root zones, can discriminate between old, thick, isolated roots (high resistivity) and the network of young, active, and hydraulically conductive zones (low resistivity). Both types of roots show low radar velocity and a strong attenuation caused by the dominant effect of moisture (high dielectric constant) on the electromagnetic wave propagation. Single root branches could be observed in radargrams by their reflection and diffraction parabolas. We have perfected the inversion method for perfect and imperfect cylindrical objects, such as trunks, and developed a new multielectrodes (needle or gel) ring array for fast applications on living trees and discs. Using synthetic models we tested the technique successfully and analyzed it as a function of total electrode number and configuration. Measurements at a trunk show a well established inverse relationship between the imaged resistivity and the moisture content determined from cores. The central resistivity maximum of healthy trees strongly decreases toward the rim. This agrees with the moisture decrease to the outside where active sap flow processes take place. Branching, growth anomalies (new or old shoots) and meteorological effects (sunshine and wind direction) lead to deviations of the concentric electric structure. The strongest anomalies are related to infections causing wet, rotting spots or cavities. The heartwood resistivity is highest in olive and oak trunks, intermediate in young fruit trees and lowest in cork oak trunks that are considered to be anomalously wet. Compared to acoustic tomography our electric technique shows a better resolution in imaging internal ring structures

  14. External root resorption: Different etiologies explained from the composition of the human root-close periodontal membrane

    Directory of Open Access Journals (Sweden)

    Inger Kjaer

    2013-01-01

    Full Text Available Introduction: This paper summarizes different conditions, which have a well-known influence on the resorption of tooth roots. It also highlights factors important for individual susceptibility to root resorption. Furthermore, the paper focuses on idiopathic root resorption where the provoking factor is not known. The Hypothesis: The several different disturbances causing root resorption can be either orthodontically provoked or acquired by trauma, virus or congenital diseases. It is presumed that all these conditions lead to inflammatory processes in the three main tissue layers, comprising the peri-root sheet. Evaluation of the Hypothesis: This paper explains how different etiologies behind root resorption and how different phenotypic traits in root resorption can be understood from immunohistochemical studies of the human periodontal membrane close to the root and thus, gain a new understanding of the phenomenon of root resorption.

  15. Root-soil friction: quantification provides evidence for measurable benefits for manipulation of root-tip traits.

    Science.gov (United States)

    McKenzie, Blair M; Mullins, Christopher E; Tisdall, Judith M; Bengough, A Glyn

    2013-06-01

    To penetrate soil, a root requires pressure both to expand the cavity it is to occupy, σn , and to overcome root-soil friction, σf . Difficulties in estimating these two pressures independently have limited our ability to estimate the coefficient of soil-root friction, μsr . We used a rotated penetrometer probe, of similar dimensions to a root, and for the first time entering the soil at a similar rate to a root tip, to estimate σn . Separately we measured root penetration resistance (PR) Qr . Root PR was between two to four times σn . We estimated that the coefficient of root-soil friction (μsr ) was 0.21-0.26, based on the geometry of the root tip. This is slightly larger than the 0.05-0.15 characteristic of boundary lubricants. Scanning electron microscopy showed that turgid border cells lined the root channel, supporting our hypothesis that the lubricant consisted of mucilage sandwiched between border cells and the surface of the root cap and epidermis. This cell-cell lubrication greatly decreased the friction that would otherwise be experienced had the surface of the root proper slid directly past unlubricated soil particles. Because root-soil friction can be a substantial component of root PR, successful manipulation of friction represents a promising opportunity for improving plant performance.

  16. Root cap-dependent gravitropic U-turn of maize root requires light-induced auxin biosynthesis via the YUC pathway in the root apex

    Science.gov (United States)

    Suzuki, Hiromi; Yokawa, Ken; Nakano, Sayuri; Yoshida, Yuriko; Fabrissin, Isabelle; Okamoto, Takashi; Baluška, František; Koshiba, Tomokazu

    2016-01-01

    Gravitropism refers to the growth or movement of plants that is influenced by gravity. Roots exhibit positive gravitropism, and the root cap is thought to be the gravity-sensing site. In some plants, the root cap requires light irradiation for positive gravitropic responses. However, the mechanisms regulating this phenomenon are unknown. We herein report that maize roots exposed to white light continuously for ≥1–2h show increased indole-3-acetic acid (IAA) levels in the root tips, especially in the transition zone (1–3mm from the tip). Treatment with IAA biosynthesis inhibitors yucasin and l-kynurenine prevented any increases in IAA content and root curvature under light conditions. Analyses of the incorporation of a stable isotope label from tryptophan into IAA revealed that some of the IAA in roots was synthesized in the root apex. Furthermore, Zmvt2 and Zmyuc gene transcripts were detected in the root apex. One of the Zmyuc genes (ZM2G141383) was up-regulated by light irradiation in the 0–1mm tip region. Our findings suggest that IAA accumulation in the transition zone is due to light-induced activation of Zmyuc gene expression in the 0–1mm root apex region. Light-induced changes in IAA levels and distributions mediate the maize root gravitropic U-turn. PMID:27307546

  17. Root canal filling using Resilon: a review.

    LENUS (Irish Health Repository)

    Shanahan, D J

    2011-07-01

    Root canal treatment is achieved by chemo-mechanical debridement of the root canal system followed by filling. The filling material \\'entombs\\' residual bacteria and acts as a barrier which prevents the entrance of oral microorganisms and reinfection of the root canal system through microleakage. However, filling with contemporary root filling materials such as gutta-percha offers limited long-term resistance to microorganisms; as a result other materials such as Resilon have been investigated as alternatives. The aim of this review was to analyse the literature to consider whether Resilon is a suitable root canal filling material. A MEDLINE and Cochrane library search including various keyword searches identified several papers which investigated or discussed Resilon or RealSeal\\/Epiphany. Analysis of the literature demonstrated that the bulk of the literature is in vitro in nature, based largely on leakage-type studies, and demonstrates a wide variety of methodologies with conflicting findings; as a result meaningful conclusions are difficult. Within the limit of these in vitro studies Resilon appears to perform adequately in comparison to gutta-percha, however, as a result of the questionable merit of such studies, it cannot presently be considered an evidence-based alternative to the current gold standard gutta-percha. It is imperative that before Resilon is considered as a replacement material, a better understanding of the physical properties of the resin sealer and the reality of the adhesive \\'monoblock\\' are elucidated. The literature also demonstrates a paucity of quality long-term clinical outcome studies which will need to be addressed before firm conclusions can be reached.

  18. Root Induced Heterogeneity In Agricultural Soils

    Science.gov (United States)

    Gomes, C.; Gabai, R.; Weisbrod, N.; Furman, A.

    2012-12-01

    In this study we investigate the role of plant induced heterogeneity on water dynamics in agricultural soils. We conducted three experiments in two sites (one still ongoing) in which a trench was excavated in the root zone of an orchard and the subsurface, to a depth of over 1 m, was instrumented in high resolution with water content, water potential and temperature sensors. High temporal resolution monitoring of soil state was carried for over a year, period that included natural (Mediterranean) climate boundary forcing. In addition, sprinkler, flood, and spray irrigation boundary conditions were forced for short time periods to explore the infiltration process under these conditions. One site was an Avocado orchard planted in red sandy soil while the other, still on-going, is in a grape vineyards irrigated by tap and treated wastewater, planted over alluvial clayey soil. In the vineyard, we are comparing soil irrigated with fresh water to soil irrigated with treated waste water for more than 10 years. Our preliminary results indicate several interesting phenomena. First, the role of plant roots is clearly seen as the major roots act as a conduit for water (and solute), providing a fast bypass of the upper soil. Further, we identified different regions of the subsurface that apparently were of the same texture, but in practice presented very different hydraulic properties. Second, the role of these roots depends on the boundary conditions. That is, the root bypass acts differently when soil is flooded than when flow is strictly unsaturated. As expected, simulation of the experimental results show good fit only if the domain heterogeneity of soil properties was incorporated. Results for the clayey soils were not available at time of abstract submission.

  19. Research on the Slope Protection Mechanism of Roots

    Directory of Open Access Journals (Sweden)

    Juan Wan

    2013-08-01

    Full Text Available This study aims to investigate the slope protection mechanism of roots. In ecological slope protection, plant roots can fix soil and protect slop through biological and mechanical action. However, previous studies on the slope protection mechanism are still not deep enough and inadequate. By taking four kinds of typical plant roots along Wu-Shen Expressway as the research object, through the indoor tensile test and root morphology observation analysis, the tensile strength and ultimate tension were studied and the influence to the stability of the slope was discussed in this study. The results show that the mean ultimate tension of roots is 7.19~29.96 N. The mean tension of shrub roots is 2~4 times greater than that of herb roots. The ultimate tension of the same plant roots increases with the diameter significantly. To the range of improvement, Shrub roots exceed herb ones. It also indicates that the mean tensile strength of roots are 24.48~74.25 MPa. Compared with the steel HRB235, the tensile strength of herb roots is as great as 1/5~1/3, while Shrub roots is about 1/10~1/5. The slope stability coefficient with plant growing is a positive correlation with roots tension and root number through the sliding surface and is a negative correlation with plants weight. In addition, the slope stability coefficient is related to plant density and root morphology. The test results demonstrate that the roots tension with acute angle or right angle to the landslide surface and the roots shear stiffness with obtuse angle can improve the performance of slope’s anti-slide. Four kinds of plants can improve the stability coefficient of shallow soil. As for the slope protection effect, herbage is superior to shrub. In general, grass-shrub mixed community is the ideal system for slope protection.

  20. Root traits contributing to plant productivity under drought.

    Science.gov (United States)

    Comas, Louise H; Becker, Steven R; Cruz, Von Mark V; Byrne, Patrick F; Dierig, David A

    2013-11-05

    Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less "leaky" and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g., functional differences between fine and coarse roots) needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria) and rice (Oryza) show approaches to phenotyping of root traits and current understanding of root trait genetics for breeding.

  1. Root traits contributing to plant productivity under drought

    Directory of Open Access Journals (Sweden)

    Louise eComas

    2013-11-01

    Full Text Available Geneticists and breeders are positioned to breed plants with root traits that improve productivity under drought. However, a better understanding of root functional traits and how traits are related to whole plant strategies to increase crop productivity under different drought conditions is needed. Root traits associated with maintaining plant productivity under drought include small fine root diameters, long specific root length (SRL, and considerable root length density, especially at depths in soil with available water. In environments with late season water deficits, small xylem diameters in targeted seminal roots save soil water deep in the soil profile for use during crop maturation and result in improved yields. Capacity for deep root growth and large xylem diameters in deep roots may also improve root acquisition of water when ample water at depth is available. Xylem pit anatomy that makes xylem less ‘leaky’ and prone to cavitation warrants further exploration holding promise that such traits may improve plant productivity in water-limited environments without negatively impacting yield under adequate water conditions. Rapid resumption of root growth following soil rewetting may improve plant productivity under episodic drought. Genetic control of many of these traits through breeding appears feasible. Several recent reviews have covered methods for screening root traits but an appreciation for the complexity of root systems (e.g. functional differences between fine and coarse roots needs to be paired with these methods to successfully identify relevant traits for crop improvement. Screening of root traits at early stages in plant development can proxy traits at mature stages but verification is needed on a case by case basis that traits are linked to increased crop productivity under drought. Examples in lesquerella (Physaria and rice (Oryza show approaches to phenotyping of root traits and current understanding of root trait

  2. The effect of root preparation technique and instrumentation length on the development of apical root cracks.

    Science.gov (United States)

    Adorno, Carlos G; Yoshioka, Takatomo; Suda, Hideaki

    2009-03-01

    The purpose of this study was to compare the effects of root canal preparation techniques and instrumentation length on the development of apical root cracks. Forty extracted mandibular premolars with straight roots were randomly selected and mounted on resin blocks with simulated periodontal ligaments, and the apex was exposed. The teeth were divided into four groups of 10 teeth each for different canal preparation techniques and instrumentation lengths: group A: step-back preparation (SB) with stainless steel files (SF) using root canal length (RCL) to guide instrumentation length; group B: SB using RCL - 1 mm; group C: crown-down preparation (CD) with Profile using RCL; and group D: CD with PF using RCL - 1 mm. Digital images of the instrumentation sequence were compared for each tooth. Statistical analysis revealed a significant effect of instrumentation length (p 0.05) on the development of apical cracks.

  3. Temperature variation on root surface with three root-end cavity preparation techniques

    Directory of Open Access Journals (Sweden)

    Bodrumlu Emre

    2013-01-01

    Full Text Available Introduction. Thermal changes can occur on the external root surface when root-end cavity preparation is performed, which may damage periodontal ligament cells and alveolar bone. Objective. The purpose of this study was to evaluate the temperature changes during preparation of the root-end cavities at 1 and 3 mm to the sectioned apical root surfaces when either tungsten carbide round bur, diamond round bur or ultrasonic diamond tip was used. Methods. Root-end resection was performed at 90° to the long axis of the root, 3 mm from the apex. Specimens were randomly divided into three groups of 12 teeth each for three different root-end cavity preparation techniques to be used, i.e. tungsten carbide bur, diamond bur and ultrasonic diamond retro tip. Thermocouples were used to measure temperature changes at 1 mm (T1 and 3 mm (T2 to the cutting plane during the preparations. Results. For T1, the lowest and the highest mean temperature increases of 3.53°C and 4.34°C were recorded for the carbide and diamond burs, respectively. For T2, the lowest and the highest mean temperature increases of 2.62°C and 4.39°C where recorded for the carbide and diamond burs, respectively. The mean temperatures with the ultrasonic tip were 3.68 and 3.04 ºC at T1 and T2 region, respectively. For root-end preparation, the ultrasonic preparation technique took the shortest preparation time (10.25 sec and the diamond bur took the longest time (28.17 sec. Conclusion. Ultrasonic retro tips and burs caused temperature to rise from 2.62° to 4.39°C, and these rises were within safety levels.

  4. Root water uptake and lateral interactions among root systems in a temperate forest

    Science.gov (United States)

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

    2016-12-01

    A growing body of research has highlighted the importance of root architecture and hydraulic properties to the maintenance of the transpiration stream under water limitation and drought. Detailed studies of single plant systems have shown the ability of root systems to adjust zones of uptake due to the redistribution of local water potential gradients, thereby delaying the onset of stress under drying conditions. An open question is how lateral interactions and competition among neighboring plants impact individual and community resilience to water stress. While computational complexity has previously hindered the implementation of microscopic root system structure and function in larger scale hydrological models, newer hybrid approaches allow for the resolution of these properties at the plot scale. Using a modified version of the PFLOTRAN model, which represents the 3-D physics of variably saturated soil, we model root water uptake in a one-hectare temperate forest plot under natural and synthetic forcings. Two characteristic hydraulic architectures, tap roots and laterally sprawling roots, are implemented in an ensemble of simulations. Variations of root architecture, their hydraulic properties, and degree of system interactions produce variable local response to water limitation and provide insights on individual and community response to changing meteorological conditions. Results demonstrate the ability of interacting systems to shift areas of active uptake based on local gradients, allowing individuals to meet water demands despite competition from their peers. These results further illustrate how inter- and intra-species variations in root properties may influence not only individual response to water stress, but also help quantify the margins of resilience for forest ecosystems under changing climate.

  5. A case of unusual root morphology: Maxillary canine with two roots

    Directory of Open Access Journals (Sweden)

    Nagesh Bolla

    2009-01-01

    Full Text Available The case describes a 3 months follow-up of the treatment of a maxillary canine with two roots. Clinical examination revealed a maxillary canine with a large carious lesion and an exaggerated response to cold thermal tests. Radiographic examination revealed a large distal carious lesion that appeared to invade the pulp chamber. The radiograph also revealed what appeared to be an extra root in this permanent maxillary canine.

  6. Amyloplast Distribution Directs a Root Gravitropic Reaction

    Science.gov (United States)

    Kordyum, Elizabeth

    Immobile higher plants are oriented in the gravitational field due to gravitropim that is a physiological growth reaction and consists of three phases: reception of a gravitational signal by statocytes, its transduction to the elongation zone, and finally the organ bending. As it is known, roots are characterized with positive gravitropism, i. e. they grow in the direction of a gravitational vector, stems - with negative gravitropism, i. e. they grow in the direction opposite to a gravitational vector. According to the Nemec’s and Haberlandt’s starch-statolith hypothesis, amyloplasts in diameter of 1.5 - 3 μ in average, which appear to act as gravity sensors and fulfill a statolythic function in the specialized graviperceptive cells - statocytes, sediment in the direction of a gravitational vector in the distal part of a cell, while a nucleus is in the proximal one. There are reasonable data that confirm the amyloplasts-statoliths participation in gravity perception: 1) correlation between the statoliths localization and the site of gravity sensing, 2) significant redistribution (sedimentation) of amyloplasts in statocytes under gravistimulation in comparison with other cell organelles, 3) root decreased ability to react on gravity under starch removal from amyloplasts, 4) starchless Arabidopsis thaliana mutants are agravitropic, 5) amyloplasts-statoliths do not sediment in the absence of the gravitational vector and are in different parts or more concentrated in the center of statocytes. Plant tropisms have been intensively studied for many decades and continue to be investigated. Nevertheless, the mechanisms by which plants do so is still not clearly explained and many questions on gravisensing and graviresponse remain unanswered. Even accepted hypotheses are now being questioned and recent data are critically evaluated. Although the available data show the Ca2+ and cytoskeleton participation in graviperception and signal transduction, the clear evidence

  7. Conservation of root regeneration potential of cell aggregates from horseradish hairy roots used as artificial seeds

    Energy Technology Data Exchange (ETDEWEB)

    Repunte, V.; Taya, M.; Tone, S. [Osaka University, Osaka (Japan). Faculty of Engineering Science

    1996-10-20

    The effects of water content in agar gel used as a medium and oxygen level in the gas phase on the adventitious root regeneration of cell aggregates (CA) derived from horseradish hairy roots were investigated in cultures at 25{degree}C. The number of roots emerging from CA was highly dependent on water content of the agar gel and no root regeneration was observed at a gel water content of 66% during culture time of 20 days. CA root regeneration was suppressed when the CA were kept for 20 days in an atmosphere oxygen composition of 10%, but was restored upon transfer of the CA to normal atmosphere of 21% oxygen. On the basis of these findings, an artificial seed was proposed using the CA as a cell inclusion material encapsulated in alginate gels covered with coats. From the perspective of conserving the root regeneration potential of the CA by preventing the drying of alginate gel while keeping oxygen availability to the CA, different coating materials of ethylene vinyl acetate acrylic acid terpolymer, paraffin and polyorganosiloxane were tested. Paraffin was selected as a suitable coating material because of its efficient drying tolerance and adequate permeability to oxygen. A regeneration efficiency of 90% could be obtained from the CA, stored in alginate gel covered with a paraffin coating of 0.40 mm thickness at 25{degree}C for 60 days in air, when sucrose concentration in the gel was over 240 mol m{sup -3}. 25 refs., 8 figs.

  8. Assessment of the wetting behavior of three different root canal sealers on root canal dentin

    Directory of Open Access Journals (Sweden)

    Muralidhar Tummala

    2012-01-01

    Full Text Available Aim: The objective of the present study was to evaluate and compare the wetting behavior of three different root canal sealers on the root canal dentin surface treated with irrigants and their combination. Materials and Methods: Decoronation and apical third resections of 27 extracted single-rooted human mandibular premolars were done. The roots were then split longitudinally into two halves, and randomly assigned into three treatment groups (n=18. The root dentin surfaces in Group1, Group 2 and Group 3 were treated with 17% ethylene diamine tetra acetic acid (EDTA, 3% sodium hypochlorite (NaOCl and combination of 17% EDTA and 3% NaOCl, respectively. Each group was subdivided into three subgroups of 6 specimens each, depending on the the sealer used, i.e. sub group A. zinc oxide (ZnOE, sub group B. AH plus, subgroup C. Guttaflow sealer, respectively. The contact angle was measured using First Ten Angstroms (FTA 200 dynamic contact angle analyzer. Results: The contact angle values for AH Plus sealer were significantly lower when compared to the other two sealer groups. Conclusion: The wettability of AH Plus sealer on the root surface dentin was found to be better than Gutta-Flow and ZnOE sealer.

  9. Flavonoids modify root growth and modulate expression of SHORT-ROOT and HD-ZIP III.

    Science.gov (United States)

    Franco, Danilo Miralha; Silva, Eder Marques; Saldanha, Luiz Leonardo; Adachi, Sérgio Akira; Schley, Thayssa Rabelo; Rodrigues, Tatiane Maria; Dokkedal, Anne Ligia; Nogueira, Fabio Tebaldi Silveira; Rolim de Almeida, Luiz Fernando

    2015-09-01

    Flavonoids are a class of distinct compounds produced by plant secondary metabolism that inhibit or promote plant development and have a relationship with auxin transport. We showed that, in terms of root development, Copaifera langsdorffii leaf extracts has an inhibitory effect on most flavonoid components compared with the application of exogenous flavonoids (glycosides and aglycones). These compounds alter the pattern of expression of the SHORT-ROOT and HD-ZIP III transcription factor gene family and cause morpho-physiological alterations in sorghum roots. In addition, to examine the flavonoid auxin interaction in stress, we correlated the responses with the effects of exogenous application of auxin and an auxin transport inhibitor. The results show that exogenous flavonoids inhibit primary root growth and increase the development of lateral roots. Exogenous flavonoids also change the pattern of expression of specific genes associated with root tissue differentiation. These findings indicate that flavonoid glycosides can influence the polar transport of auxin, leading to stress responses that depend on auxin.

  10. COUNTING ROOTED NEAR-4-REGULAR EULERIAN MAPS ON SOME SURFACES

    Institute of Scientific and Technical Information of China (English)

    RenHan; LiuYanpei

    1999-01-01

    In this article the rooted planar near-4-regular Eulerian trails are enumerated and an explicit formula for such maps is presented. Further, the rooted near-4-regular Eulerian maps on the torus are counted in an exact way.

  11. Bessel functions for root systems via the trigonometric setting

    DEFF Research Database (Denmark)

    Ørsted, Bent; Said, S.B.

    2005-01-01

    In this paper, we study generalized Bessel functions related to root systems and give explicit formulas in several cases.......In this paper, we study generalized Bessel functions related to root systems and give explicit formulas in several cases....

  12. Root dynamics and global change: seeking an ecosystem perspective

    National Research Council Canada - National Science Library

    NORBY, RICHARD J; JACKSON, ROBERT B

    2000-01-01

    ...? What are the consequences of root responses to plant physiological processes? What are the implications of root dynamics to soil microbial communities and the fate of carbon in soil? Ecosystem...

  13. Phototropism and gravitropism in lateral roots of Arabidopsis.

    Science.gov (United States)

    Kiss, John Z; Miller, Kelley M; Ogden, Lisa A; Roth, Kelly K

    2002-01-01

    Gravitropism and, to a lesser extent, phototropism have been characterized in primary roots, but little is known about structural/functional aspects of these tropisms in lateral roots. Therefore, in this study, we report on tropistic responses in lateral roots of Arabidopsis thaliana. Lateral roots initially are plagiogravitropic, but when they reach a length of approximately 10 mm, these roots grow downward and exhibit positive orthogravitropism. Light and electron microscopic studies demonstrate a correlation between positive gravitropism and development of columella cells with large, sedimented amyloplasts in wild-type plants. Lateral roots display negative phototropism in response to white and blue light and positive phototropism in response to red light. As is the case with primary roots, the photoresponse is weak relative to the graviresponse, but phototropism is readily apparent in starchless mutant plants, which are impaired in gravitropism. To our knowledge, this is the first report of phototropism of lateral roots in any plant species.

  14. Nemesia root hair response to paper pulp substrate for micropropagation.

    Science.gov (United States)

    Labrousse, Pascal; Delmail, David; Decou, Raphaël; Carlué, Michel; Lhernould, Sabine; Krausz, Pierre

    2012-01-01

    Agar substrates for in vitro culture are well adapted to plant micropropagation, but not to plant rooting and acclimatization. Conversely, paper-pulp-based substrates appear as potentially well adapted for in vitro culture and functional root production. To reinforce this hypothesis, this study compares in vitro development of nemesia on several substrates. Strong differences between nemesia roots growing in agar or in paper-pulp substrates were evidenced through scanning electron microscopy. Roots developed in agar have shorter hairs, larger rhizodermal cells, and less organized root caps than those growing on paper pulp. In conclusion, it should be noted that in this study, in vitro microporous substrates such as paper pulp lead to the production of similar root hairs to those found in greenhouse peat substrates. Consequently, if agar could be used for micropropagation, rooting, and plant acclimatization, enhancement could be achieved if rooting stage was performed on micro-porous substrates such as paper pulp.

  15. Beyond the Barrier: Communication in the Root through the Endodermis

    National Research Council Canada - National Science Library

    Neil E. Robbins; Charlotte Trontin; Lina Duan; José R. Dinneny

    2014-01-01

    ... of the root and the outer environment. The presence of these barriers and the position of the endodermis between the inner and outer parts of the root require that communication between these two domains acts through the endodermis...

  16. Root–Root Interactions:Towards A Rhizosphere Framework

    NARCIS (Netherlands)

    Mommer, L.; Kirkegaard, John; Ruijven, van J.

    2016-01-01

    Plant scientists have made great progress in understanding molecular mechanisms controlling root responses to nutrients of arabidopsis (Arabidopsis thaliana) plants under controlled conditions. Simultaneously, ecologists and agronomists have demonstrated that root–root interactions involve more than

  17. Selection of direct restorative and rooting filling materials by Kenyan ...

    African Journals Online (AJOL)

    Selection of direct restorative and rooting filling materials by Kenyan dentists in 2014. ... AFRICAN JOURNALS ONLINE (AJOL) · Journals · Advanced Search ... To establish the categories of direct restorative and root filling materials used by ...

  18. Action of plant root exudates in bioremediations: a review

    Directory of Open Access Journals (Sweden)

    Peter Dundek

    2011-01-01

    Full Text Available This work presents a summary of literature dealing with the use of plant root exudates in bioremediations. Bioremediation using plants (phytoremediation or rhizoremediation and associate rhizosphere to decontaminate polluted soil is a method based on the catabolic potential of root-associated microorganisms, which are supported by the organic substrates released from roots. These substrates are called “root exudates”. Root exudates support metabolism of pollutants-decomposing microorganisms in the rhizosphere, and affect sorption / desorption of pollutants. Awareness of exudation rates is necessary for testing soil decontamination. Commonly, water-soluble root exudates of different plants are studied for their qualitative composition which should be related to total carbon of exuded water-soluble compounds. This paper presents the determined rate of plant root exudation and the amount of root exudates carbon used to form artificial rhizosphere.

  19. Role of calcium in gravity perception of plant roots

    Science.gov (United States)

    Evans, Michael L.

    1986-01-01

    Calcium ions may play a key role in linking graviperception by the root cap to the asymmetric growth which occurs in the elongation zone of gravistimulated roots. Application of calcium-chelating agents to the root cap inhibits gravitropic curvature without affecting growth. Asymmetric application of calcium to one side of the root cap induces curvature toward the calcium source, and gravistimulation induces polar movement of applied (Ca-45)(2+) across the root cap toward the lower side. The action of calcium may be linked to auxin movement in roots since: (1) auxin transport inhibitors interfere both with gravitropic curvature and graviinduced polar calcium movement and (2) asymmetric application of calcium enhances auxin movement across the elongation zone of gravistimulated roots. Indirect evidence indicates that the calcium-modulated regulator protein, calmodulin, may be involved in either the transport or action of calcium in the gravitropic response mechanism of roots.

  20. Regeneration of roots from callus reveals stability of the developmental program for determinate root growth in Sonoran Desert Cactaceae.

    Science.gov (United States)

    Shishkova, Svetlana; García-Mendoza, Edith; Castillo-Díaz, Vicente; Moreno, Norma E; Arellano, Jesús; Dubrovsky, Joseph G

    2007-05-01

    In some Sonoran Desert Cactaceae the primary root has a determinate root growth: the cells of the root apical meristem undergo only a few cell division cycles and then differentiate. The determinate growth of primary roots in Cactaceae was found in plants cultivated under various growth conditions, and could not be reverted by any treatment tested. The mechanisms involved in root meristem maintenance and determinate root growth in plants remain poorly understood. In this study, we have shown that roots regenerated from the callus of two Cactaceae species, Stenocereus gummosus and Ferocactus peninsulae, have a determinate growth pattern, similar to that of the primary root. To demonstrate this, a protocol for root regeneration from callus was established. The determinate growth pattern of roots regenerated from callus suggests that the program of root development is very stable in these species. These findings will permit future analysis of the role of certain Cactaceae genes in the determinate pattern of root growth via the regeneration of transgenic roots from transformed calli.

  1. Visualization of root water uptake: quantification of deuterated water transport in roots using neutron radiography and numerical modeling.

    Science.gov (United States)

    Zarebanadkouki, Mohsen; Kroener, Eva; Kaestner, Anders; Carminati, Andrea

    2014-10-01

    Our understanding of soil and plant water relations is limited by the lack of experimental methods to measure water fluxes in soil and plants. Here, we describe a new method to noninvasively quantify water fluxes in roots. To this end, neutron radiography was used to trace the transport of deuterated water (D2O) into roots. The results showed that (1) the radial transport of D2O from soil to the roots depended similarly on diffusive and convective transport and (2) the axial transport of D2O along the root xylem was largely dominated by convection. To quantify the convective fluxes from the radiographs, we introduced a convection-diffusion model to simulate the D2O transport in roots. The model takes into account different pathways of water across the root tissue, the endodermis as a layer with distinct transport properties, and the axial transport of D2O in the xylem. The diffusion coefficients of the root tissues were inversely estimated by simulating the experiments at night under the assumption that the convective fluxes were negligible. Inverse modeling of the experiment at day gave the profile of water fluxes into the roots. For a 24-d-old lupine (Lupinus albus) grown in a soil with uniform water content, root water uptake was higher in the proximal parts of lateral roots and decreased toward the distal parts. The method allows the quantification of the root properties and the regions of root water uptake along the root systems.

  2. How to study deep roots-and why it matters.

    Science.gov (United States)

    Maeght, Jean-Luc; Rewald, Boris; Pierret, Alain

    2013-01-01

    The drivers underlying the development of deep root systems, whether genetic or environmental, are poorly understood but evidence has accumulated that deep rooting could be a more widespread and important trait among plants than commonly anticipated from their share of root biomass. Even though a distinct classification of "deep roots" is missing to date, deep roots provide important functions for individual plants such as nutrient and water uptake but can also shape plant communities by hydraulic lift (HL). Subterranean fauna and microbial communities are highly influenced by resources provided in the deep rhizosphere and deep roots can influence soil pedogenesis and carbon storage.Despite recent technological advances, the study of deep roots and their rhizosphere remains inherently time-consuming, technically demanding and costly, which explains why deep roots have yet to be given the attention they deserve. While state-of-the-art technologies are promising for laboratory studies involving relatively small soil volumes, they remain of limited use for the in situ observation of deep roots. Thus, basic techniques such as destructive sampling or observations at transparent interfaces with the soil (e.g., root windows) which have been known and used for decades to observe roots near the soil surface, must be adapted to the specific requirements of deep root observation. In this review, we successively address major physical, biogeochemical and ecological functions of deep roots to emphasize the significance of deep roots and to illustrate the yet limited knowledge. In the second part we describe the main methodological options to observe and measure deep roots, providing researchers interested in the field of deep root/rhizosphere studies with a comprehensive overview. Addressed methodologies are: excavations, trenches and soil coring approaches, minirhizotrons (MR), access shafts, caves and mines, and indirect approaches such as tracer-based techniques.

  3. Root-Contact/Pressure-Plate Assembly For Hydroponic System

    Science.gov (United States)

    Morris, Carlton E.; Loretan, Philip A.; Bonsi, Conrad K.; Hill, Walter A.

    1994-01-01

    Hydroponic system includes growth channels equipped with rootcontact/pressure-plate assemblies. Pump and associated plumbing circulate nutrient liquid from reservoir, along bottom of growth channels, and back to reservoir. Root-contact/pressure-plate assembly in each growth channel stimulates growth of roots by applying mild contact pressure. Flat plate and plate connectors, together constitute pressure plate, free to move upward to accommodate growth of roots. System used for growing sweetpotatoes and possibly other tuber and root crops.

  4. Distribution of Primitive λ-Roots of Composite Moduli Ⅱ

    Institute of Scientific and Technical Information of China (English)

    Zhiyong ZHENG; Todd COCHRANE

    2006-01-01

    We improve estimates for the distribution of primitive λ-roots of a composite modulus q yielding an asymptotic formula for the number of primitive λ-roots in any interval Ⅰ of length |I| (>>) q1/2+∈. Similar results are obtained for the distribution of ordered pairs (x, x-1) with x a primitive λ-root, and for the number of primitive λ-roots satisfying inequalities such as |x -x-1| ≤ B.

  5. Internal root resorption in the maxillary central incisor

    OpenAIRE

    2010-01-01

    Introduction: Internal root resorption is a chronic inflammatory process initiated within the pulp space with the loss of dentin. The clastic cells present in the pulp tissue trigger a progressive resorption phenomenon. Case report and conclusion: This paper reports a clinical case of an internal root resorption in the permanent central incisor, at the middle third of the root canal. Because it is asymptomatic,internal root resorption needs an early diagnosis in order to institute the endodon...

  6. ROOT ALLOMETRY OF TWO SUBTROPICAL PLANT COMMUNITIES OF NORTHEASTERN MEXICO

    OpenAIRE

    Eduardo de los Ríos-Carrasco; José de Jesús Návar-Cháidez

    2010-01-01

    This research work aimed at the study of the root allometry in sub-tropical Tamaulipan thornscrub and pine forest communities of Nuevo Leon, Mexico. By excavating each individual root of each of 20 trees per plant community, we developed root allometric equations for biomass, volume, total length and diameter. Covariance analysis, ancova, was employed to determine the statistical difference of these variables between plant communities. Results indicate that pine plant trees have larger root v...

  7. Genomic Regions Influencing Seminal Root Traits in Barley

    Directory of Open Access Journals (Sweden)

    Hannah Robinson

    2016-03-01

    Full Text Available Water availability is a major limiting factor for crop production, making drought adaptation and its many component traits a desirable attribute of plant cultivars. Previous studies in cereal crops indicate that root traits expressed at early plant developmental stages, such as seminal root angle and root number, are associated with water extraction at different depths. Here, we conducted the first study to map seminal root traits in barley ( L.. Using a recently developed high-throughput phenotyping method, a panel of 30 barley genotypes and a doubled-haploid (DH population (ND24260 × ‘Flagship’ comprising 330 lines genotyped with diversity array technology (DArT markers were evaluated for seminal root angle (deviation from vertical and root number under controlled environmental conditions. A high degree of phenotypic variation was observed in the panel of 30 genotypes: 13.5 to 82.2 and 3.6 to 6.9° for root angle and root number, respectively. A similar range was observed in the DH population: 16.4 to 70.5 and 3.6 to 6.5° for root angle and number, respectively. Seven quantitative trait loci (QTL for seminal root traits (root angle, two QTL; root number, five QTL were detected in the DH population. A major QTL influencing both root angle and root number (/ was positioned on chromosome 5HL. Across-species analysis identified 10 common genes underlying root trait QTL in barley, wheat ( L., and sorghum [ (L. Moench]. Here, we provide insight into seminal root phenotypes and provide a first look at the genetics controlling these traits in barley.

  8. Distribution of the residual roots in principal components analysis.

    Directory of Open Access Journals (Sweden)

    A. M. Kshirsagar

    1964-10-01

    Full Text Available The latent of distribution of latent roots of the covariance martix of normal variables, when a hypothetical linear function of the variables is eliminated, is derived in this paper. The relation between original roots and the residual roots- after elimination of, is also derived by an analytical method. An exact test for the goodness of fit of a single nonisotropic hypothetical principal components, using the residual roots, is then obtained.

  9. Root Ecological Niche Index and Root Distribution Characteristics of Artificial Phytocommunities in Rehabilitated Fields

    Institute of Scientific and Technical Information of China (English)

    Hu Jianzhong; Zhen Jiali; Shen Jingyu

    2006-01-01

    In the implementation phase of the Conversion of Cropland to Forest and Grassland (CCFG) project in China,it is important,from a scientific point of view,to recognize phytocommunities' characteristics,species compatibility,and ecological function.The ecological niche that roots occupy,their abundance and distribution,and the factors that affect them must be acknowledged.Following the methodology of community ecology,the total root mass of a phytocommunity is measured as cubic volume.Root biomass,length,and the number of roots in every diameter class,for each soil layer and for each plant species,are regarded as observation variables.In the first instance therefore,a new method to calculate the root ecological niche index (REND is proposed,embracing the entire phytocommunity of plantations.Using the new method,the roots of pbytocommunities in Datong County,Qinghai Province (one of the counties selected for the national CCFG experiment),are dealt with in this paper.The results show that most of the vertical distributions of plant roots belong to the type wherein the roots are concentrated in the topsoil layer (0-20 cm),far more than those in the lower soil layers.The RENI of pbytocommunities is higher than that of pure stands or monocultures.The distribution of RENI by root diameter can be divided into four types:J-type,inverse J-type,recumbent S-type,and U-type.RENI is positively correlated with the wet biomass of aboveground level stems,branches,and plant leaves,and with the species richness of phytocommunities.Although the RENIs of plantations in rehabilitated fields are a little lower than those of natural forests,they are higher than those of cultivated crops.The RENIs of three community types (Picea crassifolia+Hippophae rhamnoides ssp.sinensis,H.rhamnoides ssp.sinensis,and P.crassifolia) in rehabilitated fields benefit greatly from the restoration project.The implementation of the CCFG project is important for the increase in RENI and the multiple functions of

  10. Artificial Root Exudate System (ARES): a field approach to simulate tree root exudation in soils

    Science.gov (United States)

    Lopez-Sangil, Luis; Estradera-Gumbau, Eduard; George, Charles; Sayer, Emma

    2016-04-01

    The exudation of labile solutes by fine roots represents an important strategy for plants to promote soil nutrient availability in terrestrial ecosystems. Compounds exuded by roots (mainly sugars, carboxylic and amino acids) provide energy to soil microbes, thus priming the mineralization of soil organic matter (SOM) and the consequent release of inorganic nutrients into the rhizosphere. Studies in several forest ecosystems suggest that tree root exudates represent 1 to 10% of the total photoassimilated C, with exudation rates increasing markedly under elevated CO2 scenarios. Despite their importance in ecosystem functioning, we know little about how tree root exudation affect soil carbon dynamics in situ. This is mainly because there has been no viable method to experimentally control inputs of root exudates at field scale. Here, I present a method to apply artificial root exudates below the soil surface in small field plots. The artificial root exudate system (ARES) consists of a water container with a mixture of labile carbon solutes (mimicking tree root exudate rates and composition), which feeds a system of drip-tips covering an area of 1 m2. The tips are evenly distributed every 20 cm and inserted 4-cm into the soil with minimal disturbance. The system is regulated by a mechanical timer, such that artificial root exudate solution can be applied at frequent, regular daily intervals. We tested ARES from April to September 2015 (growing season) within a leaf-litter manipulation experiment ongoing in temperate deciduous woodland in the UK. Soil respiration was measured monthly, and soil samples were taken at the end of the growing season for PLFA, enzymatic activity and nutrient analyses. First results show a very rapid mineralization of the root exudate compounds and, interestingly, long-term increases in SOM respiration, with negligible effects on soil moisture levels. Large positive priming effects (2.5-fold increase in soil respiration during the growing

  11. [Medicinal plant hairy roots generating and their applications].

    Science.gov (United States)

    Zhang, Meng; Gao, Wei; Wang, Xiu-Juan

    2014-06-01

    As a kind of the plant tissue cultures, hairy root culture is characterized by rapid growth without exogenous hormones source and high yield of secondary metabolites, which attracted the attention of scholars in resent years. This work systematically summarized the research of medicinal plant hairy roots, including the mechanism, current situation of medicinal plant hairy roots, and their applications.

  12. Mechanical properties of tree roots for soil reinforcement models

    NARCIS (Netherlands)

    Cofie, P.

    2001-01-01

    Evidence from forestry has shown that part of the forest floor bearing capacity is delivered by tree roots. The beneficial effect however varies and diminishes with increasing number of vehicle passes. Roots potential for reinforcing the soil is known to depend among others on root mechanical proper

  13. Assessment of root surfaces of apicected teeth: A scanning electron ...

    African Journals Online (AJOL)

    2014-05-15

    May 15, 2014 ... Many dental root canal systems have unreachable fields like isthmi, lateral ... root resection and ultrasonic root‑end preparation, when compared with root ... irrigation with 5 ml of 15% EDTA (Wizard, Rehber Kimya. San. ve Tic ...

  14. Optimizing the chemical aspect of root canal irrigation

    NARCIS (Netherlands)

    R.G. de Macedo

    2013-01-01

    Root canal treatment is aimed at the removal of inflamed and infected tissue present in the root canal system. It will prevent the entrance of new microorganisms or nutrients in order to maintain or create a healthy environment around the root. There is sufficient evidence that shows that traditiona

  15. Deciduous canine and permanent lateral incisor differential root resorption.

    Science.gov (United States)

    Davies, K R; Schneider, G B; Southard, T E; Hillis, S L; Wertz, P W; Finkelstein, M; Hogan, M M

    2001-10-01

    When a permanent maxillary canine erupts apical to the permanent lateral incisor and the deciduous canine, resorption typically takes place only on the deciduous canine root. An understanding of this differential resorption could provide insight into the reasons for excessive iatrogenic root resorption during orthodontic tooth movement. The purpose of the present study was to examine the response of roots of permanent lateral incisors and deciduous canines to simulated resorption, and to acid and enzyme attack, reflecting the physiologic environment of an erupting permanent canine. Groups of maxillary permanent lateral incisor and deciduous canine roots were exposed to 5 combinations of Ten Cate demineralizing solution, Ten Cate demineralizing solution with EDTA, and a Type I collagenase solution. Sections of the roots were examined under a polarized light microscope. Analysis of variation of the resulting root lesions demonstrated that the lesion depths for deciduous canines were greater than those for permanent lateral incisors when averaged across 4 of the conditions (F(1,24) = 7.49, P =.0115). On average, deciduous canine roots demonstrated lesions 10% deeper than did permanent lateral incisor roots. We concluded that when deciduous canine and permanent lateral incisor roots are subjected to acid and enzyme attack, reflecting the physiologic environment of an erupting permanent canine, significantly deeper demineralized lesions are seen in the deciduous roots compared with the permanent roots. This finding may partially explain the differential root resorption during permanent tooth eruption.

  16. 21 CFR 872.3810 - Root canal post.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Root canal post. 872.3810 Section 872.3810 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES DENTAL DEVICES Prosthetic Devices § 872.3810 Root canal post. (a) Identification. A root canal post is a device made of austenitic alloys...

  17. Root rot in sugar beet piles at harvest

    Science.gov (United States)

    Sugar beet root rots are not only a concern because of reduced yields, but can also be associated with losses in storage. Our primary sugar beet root rot disease problem in the Amalgamated production area is Rhizoctonia root rot. However, this rot frequently only penetrates a short distance past t...

  18. Phosphate-dependent root system architecture responses to salt stress

    NARCIS (Netherlands)

    Kawa, D.; Julkowska, M.M.; Montero Sommerfeld, H.; ter Horst, A.; Haring, M.A.; Testerink, C.

    2016-01-01

    Nutrient availability and salinity of the soil affect growth and development of plant roots. Here, we describe how phosphate availability affects root system architecture (RSA) of Arabidopsis and how phosphate levels modulate responses of the root to salt stress. Phosphate (Pi) starvation reduced ma

  19. Effects of Root-Growing Space on Its Absorbing Characteristics

    Institute of Scientific and Technical Information of China (English)

    SONG Hai-xing; LI Sheng-xiu

    2003-01-01

    Influences of root-growing space of maize upon root physiological characteristics, nutrient uptake and crop yields were studied under conditions with and without supply of water and N. Results showed that limitation of the root-growing space greatly affected root growth, decreased total root-absorbing area and TTC-reductive amounts. However, it obviously increased the root active-absorbing area, specific absorbing area (absorbing area per gram root weight) and specific active-absorbing area (actively absorbing area per gram root weight) in addition to promoting the TTC-reductive intensity. This clearly showed that plants were not passively tolerant to stress, but actively regulated their physiological metabolic processes, and strengthened their absorbing ability to increase water and nutrient uptake so that root injury by the environmental stress could be reduced. Supply of water and N stimulated root growth, increased root-absorbing area and activity, promoted nutrient uptake, and therefore increased crop yield and decreased the detrimental effects resulting from the limitation of roots-growing space.

  20. Root water extraction under combined water and osmotic stress

    NARCIS (Netherlands)

    Jong van Lier, de Q.; Dam, van J.C.; Metselaar, K.

    2009-01-01

    Using a numerical implicit model for root water extraction by a single root in a symmetric radial flow problem, based on the Richards equation and the combined convection-dispersion equation, we investigated some aspects of the response of root water uptake to combined water and osmotic stress. The