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Root Damage (root + damage)

Distribution by Scientific Domains

Life Sciences	55%
Medical Sciences	44%

Selected Abstracts

Root defects following air polishing

JOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2003
An in vitro study on the effects of working parameters
Abstract Aim: Air-polishing devices (APDs) are highly effective in removing plaque and extrinsic staining. Their application on root surfaces, however, may result in clinically relevant substance removal, limiting the use in patients with periodontitis, where denuded root surfaces are frequently found. Therefore, the purpose of the study was to assess the influence of different working parameters on root damage and to identify those minimizing root damage. Material and methods: Defect depth and defect volume after instrumentation of roots with an APD (Dentsply Prophy-Jet®) using conventional NaHCO3 powder at instrumentation times of 5, 10 and 20 s, combinations of low, medium and high powder and water settings, distances of 2, 4 and 6 mm, and angulations of 45° and 90° were quantified laseroptically. A total of 297 roots were instrumented and parameter combinations were performed in triplicate. The influence of each working parameter on substance loss was determined by multiple regression analysis. Results: Time had the greatest influence on defect volume and depth (,-weights 0.6 and 0.57, respectively), when compared with powder setting (,-weights 0.49 and 0.3) and water setting (,-weights 0.28 and 0.3). Variations in distance affected defect depth (,-weight 0.44), but not volume (,-weight 0.04). No major differences were found at 45° and 90°. Various parameter combinations led to maximal defect depths of 473.5 ± 26.2 µm within 20 s. Conclusion: Root damage varies among combinations of working parameters. Using the APD with the assessed NaHCO3 powder, all parameter combinations led to substantial root damage. Thus, APDs using NaHCO3 may not be safely utilized on exposed root surfaces. Zusammenfassung Wurzeldefekte nach Pulverstrahlpolitur , Eine In-vitro-Untersuchung zur Auswirkung der Arbeitsparameter Hintergrund: Pulverstrahlgeräte sind sehr wirksam in der Entfernung von Plaque und externen Zahnverfärbungen. Die Bearbeitung von Wurzeloberflächen kann aber zu klinisch relevanten Hartsubstanzabträgen führen, die den Einsatz bei Parodontitispatienten einschränken, bei denen häufig entblößte Wurzeloberflächen gefunden werden. Zielsetzung: Untersuchung des Einflusses verschiedener Arbeitsparameter auf die Wurzeloberflächenschädigung mit dem Ziel diese zu reduzieren. Material und Methoden: Defekttiefe und ,volumen wurden nach Instrumentierung der Wurzeloberflächen mit einem Pulverstahlgerät (Dentsply Prophy-Jet®) bei Verwendung von konventionellem NaHCO3 -Pulver bei Bearbeitungszeiten von 5, 10 and 20 Sekunden, Kombinationen von niedrigen, mittleren und hohen Pulver- und Wassereinstellungen, Abständen von 2, 4 und 6 mm sowie Arbeitswinkeln von 45° und 90° laseroptisch quantifiziert. Insgesamt 297 Wurzeln extrahierter Zähne wurden bearbeitet und die Parameterkombinationen dreimal wiederholt. Der Einfluss der Arbeitsparameter auf den Substanzabtrag wurde für jeden Parameter mittels multipler Regressionsanalyse bestimmt. Ergebnisse: Zeit hatte den größten Einfluss auf Defektvolumen und -tiefe (ß-Gewichte 0,6 und 0,57) im Vergleich zur Pulver- (,-Gewichte 0,49 und 0,3) und Wassereinstellung (,-Gewichte 0,28 und 0,3). Veränderungen des Arbeitsabstandes beeinflussten die Defekttiefe (,-Gewicht 0,44), aber nicht das Volumen (,-Gewicht 0,04). Keine wesentlichen Unterschiede wurden zwischen den Arbeitswinkeln 45° und 90° gefunden. Die verschiedenen Parameterkombinationen führten zu maximalen Defekttiefen von 473,5±26,2 ,m innerhalb von 20 s. Schlussfolgerung: Der Substanzabtrag von Wurzeloberflächen unterscheidet sich für die verschiedenen Kombinationen der Arbeitsparameter. Bei Verwendung von Pulverstrahlgeräten mit dem untersuchten NaHCO3 -Pulver führten alle Kombinationen der Arbeitsparameter zu wesentlichen Substanzverlusten. Deshalb können Pulverstrahlgeräte mit NaHCO3 nicht sicher zur Reinigung freiliegender Wurzeloberflächen verwendet werden. Résumé Lésions radiculaires après aéro-polissage- une étude in vitro sur les effets des paramètres de travail. But de l'étude: Les aéro-polisseurs (APDs) sont très efficace pour l'élimination de la plaque et des colorations extrinsèques. Leur application sur les surfaces radiculaires, cependant, peut résulter en l'élimination cliniquement significative de substance ce qui limite leur utilisation chez les patients souffrant de parodontite, chez lesquels on observe fréquemment des dénudations radiculaires C'est pourquoi cette étude se propose de mettre en évidence l'influence des divers paramètres de travail sur les dommages radiculaires et d'identifier ceux qui limiteraient ces dommages. Matériels et Méthodes: La profondeur des lésions et le volume après instrumentation des racines avec un APD (Dentsply Prophy-Jet®) utilisant une poudre classique de NaHCO3 sur des durées d'utilisation de 5, 10 et 20 secondes, avec des combinaisons de réglages d'eau et de poudre bas, moyen et fort, à des distances de 2, 4 et 6 mm, et avec des angulations de 45° et 90° furent quantifiées par laser-optique. 297 racines furent instrumentées et les combinaisons de paramètres furent appliquées trois fois. L'influence de chaque paramètre de travail sur la perte de substance fut déterminée par analyse de régression multiple. Resultats: La durée avait la plus grande influence sur le volume des lésions et sur leurs profondeurs (,-poids 0.6 et 0.57 respectivement), lorsqu'on la comparait avec les réglages de poudre (,-poids 0.49 et 0.3) et d'eau (,-poids 0.28 et 0.3). Les variations de distance affectait les profondeurs des lésions (,-poids 0.44), mais pas le volume (,-poids 0.04). Aucune différence majeure ne put être trouvée entre les angulations. Les diverses combinaisons de paramètre entraînaient des profondeur de défaut maximales de 473.5±26.2 ,m en 20 s. Conclusion: les dommages radiculaires varient selon les combinaisons de paramétres de travail. Lors de l'utilisation de l'APD avec sa poudre de NaHCO3, toutes les combinaisons entraînaient des dommages radiculaires substantiels. Ainsi, les APDs à NaHCO3 ne peuvent pas être utilises en toute sécurité sur les surfaces radiculaires exposées. [source]

Hosts and distribution of Collybia fusipes in France and factors related to the disease's severity

FOREST PATHOLOGY, Issue 1 2002
D. PIOU
Using data collected by two different observation networks, it was possible to clarify the distribution of Collybia fusipes in France. It is frequently found in the western and northern parts of France, mainly on Quercus rubra and Quercus robur, and to a somewhat lesser extent on Quercus petraea. When the relative areas covered by these species are compared, it is evident that Q. rubra is much the most susceptible of the three species. The fungus has been less frequently reported in the south-eastern quarter of France, where Quercus ilex and Quercus pubescens are the dominant species. Complementary observations carried out at the National Arboretum of Les Barres indicate that a large number of oak species are susceptible to infection by this fungus, particularly those in the subgenus Erythrobalanus. These observations are discussed with reference to reports of this fungus throughout Europe. In a Q. rubra stand, fruit-body clumps were monitored and root damage was assessed on 73 final-crop trees and 40 codominant trees. The results suggest that C. fusipes does not preferentially infect weakened trees. Both the severity of root damage and the number of fruit-body clumps increased with increasing depth to signs of waterlogging. Répartition et hôtes de Collybia fusipes en France et facteurs de gravité de la maladie D'après les données collectées par deux réseaux de surveillance distincts, la répartition de Collybia fusipes en France a été précisée. Le champignon est fréquent dans les moitiés ouest et nord du pays, principalement sur Quercus rubra et Q. robur, et dans une moindre mesure sur Q. petraea. Quand on considère la surface relative occupée par ces espèces, il apparaît évident que Q. rubra est le plus sensible. Il a été moins souvent signalé dans le quart sud-est oùQ. ilex et Q. pubescens sont dominants. Des observations complémentaires réalisées à l'Arboretum National des Barres indiquent qu'un grand nombre d'espèces de chênes sont susceptibles d'être attaquées par ce champignon, particulièrement celles du sous-genre Erythrobalanus. Ces observations sont discutées et comparées avec les données disponibles en Europe. L'apparition des carpophores a été suivie dans un peuplement de Q. rubra, et les dégâts aux racines ont étéévalués sur 73 arbres de place et 40 arbres codominants. Les résultats indiquent que C. fusipes n'infecte pas plus gravement les arbres affaiblis. Le degré d'hydromorphie influence significativement l'importance des dégâts racinaires ainsi que le nombre de carpophores produits. Cette étude confirme que C. fusipes se développe préférentiellement dans les sites où l'hydromorphie n'est pas trop sévère. Wirtspflanzen und Verbreitung von Collybia fusipes in Frankreich sowie mit der Krankheitsintensität assoziierte Umweltfaktoren Mit Hilfe der Daten von zwei unterschiedlichen Beobachtungsnetzwerken konnte die Verbreitung von Collybia fusipes in Frankreich präzisiert werden. Der Pilz ist im Westen und Norden des Landes häufig auf Quercus rubra und Quercus robur zu finden, etwas weniger häufig auf Quercus petraea. Beim Vergleich der von diesen Arten bestockten Flächen wird deutlich, dass Q. rubra die anfälligste der drei Eichenarten ist. Im südöstlichen Teil Frankreichs, wo Quercus ilex und Quercus pubescens dominieren, wurde der Pilz weniger häufig nachgewiesen. Ergänzende Beobachtungen im Arboretum National des Barres ergaben, dass zahlreiche Eichenarten gegen C. fusipes anfällig sind, insbesondere die des Subgenus Erythrobalanus. Diese Ergebnisse werden im Vergleich mit der aus Europa über diesen Pilz verfügbaren Literatur diskutiert. In einem Q. rubra, Bestand wurde das Auftreten von Fruchtkörpern und von Wurzelschäden an 73 herrschenden und 40 mitherrschenden Bäumen registriert. Die Ergebnisse zeigen, dass C. fusipes geschwächte Bäume nicht bevorzugt befällt. Sowohl die Intensität der Wurzelschäden als auch die Anzahl der Fruchtkörper erhöhte sich mit zunehmender Tiefe der Anzeichen für Staunässe im Bodenprofil. [source]

Relationship between presence of basidiomes, above-ground symptoms and root infection by Collybia fusipes in oaks

FOREST PATHOLOGY, Issue 1 2000
B. Marçis
Summary Collybia fusipes is a common cause of root rot on oak in the north of France. Collybia fusipes basidiomes can be as frequent on oaks in stands where no decline of the trees occurs compared with stands where the decline is chronic. This might be explained by differences in the amount of roots damaged by the parasite. To test that hypothesis, 430 oak trees, Quercus petraea, Quercus robur and Quercus rubra, located in six forests were selected. Half of them showed C. fusipes basidiomes at the trunk base. The association between presence of basidiomes and decline of affected trees depended on the forest. The level of infection of each tree by C. fusipes, as well as the crown appearance, the tree height : diameter at breast height ratio, age and sapwood width were determined. The presence of C. fusipes basidiomes was always associated with significant root infections. The crowns of the trees deteriorated with increasing level of root infection and the decline was severe only when the root damage was heavy. Although the decline of trees that were heavily damaged by C. fusipes was severe in some of the stands, in others, it was only mild, and so the differences in tree decline between the stands could not be attributed solely to differences in root infection severity. Trees damaged by C. fusipes seemed not to be subjected to more competition than their undamaged neighbour as reflected by a similar tree height: diameter at breast height ratio. [source]

Controlling western corn rootworm larvae with entomopathogenic nematodes: effect of application techniques on plant-scale efficacy

JOURNAL OF APPLIED ENTOMOLOGY, Issue 5 2010
S. Toepfer
Abstract The three larval instars of western corn rootworm (Diabrotica virgifera virgifera LeConte, Coleoptera: Chrysomelidae) feed on the roots of maize, Zea mays (L.). The effects of six application techniques on the plant-scale efficacy of the entomopathogenic nematode species, Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), in controlling D. v. virgifera populations were assessed in seven field plot experiments in southern Hungary between 2004 and 2007. Approximately 230 000 nematodes were applied per row metre using four different stream spray techniques; or, alternatively 400 000 nematodes per square metre using two different flat spray techniques. Nematode efficacy was assessed by comparing the number of emerging adult D. v. virgifera, and root damage between treatments and untreated controls. All tested nematode application techniques reduced D. v. virgifera density by at least 50% (on average across fields and years). The highest reduction in D. v. virgifera density was 68% and occurred when nematodes were applied into the soil together with maize sowing using a fluid solid stream. Rainfall, the day before application likely increased the control efficacy of H. bacteriophora. Using the 0.00,3.00 node injury damage rating scale, we estimated that potential root damage was prevented by 25,79% when H. bacteriophora was applied. Although, H. bacteriophora can effectively be applied with all of the techniques tested, for optimum performance and minimum costs, it is suggested that the nematodes be applied as follows: (i) as a stream requiring 8,10 times less volume of water than flat sprays, or as a granule requiring no water, and (ii) into the soil when sowing maize, requiring less water than soil surface sprays and avoiding the destruction of nematodes by UV radiation and additional machinery use. [source]

Root defects following air polishing

Mental rotation of body parts and sensory temporal discrimination in fixed dystonia,

MOVEMENT DISORDERS, Issue 8 2010
Petra Katschnig MD
Abstract Fixed dystonia is an uncommon but severely disabling condition typically affecting young women following a minor peripheral injury. There is no evidence of any structural lesions of the central nervous system nor any clear peripheral nerve or root damage. Electrophysiological techniques such as short intracortical inhibition, cortical silent period and a plasticity inducing protocol have revealed similarities but also differences compared to classical mobile dystonia. To further explore the pathophysiology of fixed dystonia we compared mental rotation of body parts and sensory temporal discrimination in 11 patients with fixed dystonia, 11 patients with classical mobile dystonia and 10 healthy controls. In the mental rotation task subjects were presented with realistic photos of left or right hands, feet and the head of a young women with a black patch covering the left or the right eye in six different orientations. Subjects had to verbally report the laterality of the presented stimuli. To assess sensory temporal discrimination subjects were asked to discriminate whether pairs of visual, tactile (electrical), or visuo-tactile stimuli were simultaneous or sequential (temporal discrimination threshold) and in the latter case which stimulus preceded the other (temporal order judgement). In accordance with previous studies patients with mobile dystonia were abnormal in mental rotation and temporal discrimination, whereas patients with fixed dystonia were only impaired in mental rotation. Possible explanations for this deficit may include the influence of the abnormal body posture itself, a shared predisposing pathophysiology for mobile and fixed dystonia, or a body image disturbance. These findings add information to the developing pathophysiological picture of fixed dystonia. © 2010 Movement Disorder Society [source]

Prioritising potential guilds of specialist herbivores as biological control agents for prickly acacia through simulated herbivory

ANNALS OF APPLIED BIOLOGY, Issue 1 2009
K. Dhileepan
Abstract Understanding plant response to herbivory facilitates the prioritisation of guilds of specialist herbivores as biological control agents based on their potential impacts. Prickly acacia (Acacia nilotica ssp. indica) is a weed of national significance in Australia and is a target for biological control. Information on the susceptibility of prickly acacia to herbivory is limited, and there is no information available on the plant organ (i.e. leaf, shoot and root in isolation or in combination) most susceptible to herbivory. We evaluated the ability of prickly acacia seedlings, to respond to different types of simulated herbivory (defoliation, shoot damage, root damage and combinations), at varying frequencies (no herbivory, single, two and three events of herbivory) to identify the type and frequency of herbivory that will be required to reduce the growth and vigour. Defoliation and shoot damage, individually, had a significant negative impact on prickly acacia seedlings. For the defoliation to be effective, more than two defoliation events were required, whereas a single bout of shoot damage was enough to cause a significant reduction in plant vigour. A combination of defoliation + shoot damage had the greatest negative impact. The study highlights the need to prioritise specialist leaf and shoot herbivores as potential biological control agents for prickly acacia. [source]