938 research outputs found
Phylogeny and Geographic History of Annonaceae
Whereas Takhtajan and Smith situated the origin of angiosperms between Southeast Asia and Australia, Walker and Le Thomas emphasized the concentration of primitive pollen types of Annonaceae in South America and Africa, suggesting instead a Northern Gondwanan origin for this family of primitive angiosperms. A cladistic analysis of Annonaceae shows a basal split of the family into Anaxagorea, the only genus with an Asian and Neotropical distribution, and a basically African and Neotropical line that includes the rest of the family. Several advanced lines occur in both Africa and Asia, one of which reaches Australia. This pattern may reflect the following history: (a) disjunction of Laurasian (Anaxagorea) and Northern Gondwanan lines in the Early Cretaceous, when interchanges across the Tethys were still easy and the major lines of Magnoliidae are documented by paleobotany; (b) radiation of the Northern Gondwanan line during the Late Cretaceous, while oceanic barriers were widening; (c) dispersal of African lines into Laurasia due to northward movement of Africa and India in the Early Tertiary, attested by the presence of fossil seeds of Annonaceae in Europe, and interchanges between North and South America at the end of the Tertiary.Alors que Takhtajan et Smith situaient l'origine des Angiospermes entre le Sud-Est asiatique et l'Australie. Walker et Le Thomas ont souligné la concentration des types polliniques primitifs d'Annonaceae en Amérique du Sud et en Afrique, laissant plutôt supposer une origine nord-gondwanienne pour cette famille d'Angiospermes primitives. Une analyse cladistique des Annonaceae révèle une division basale de la famille en Anaxagorea, seul genre de répartition asiatique et néotropicale, et une lignée fondamentalement africaine et néotropicale qui comprend le reste de la famille. Plusieurs lignées évoluées sont partagées entre l'Afrique et l'Asie, dont une atteint l'Australie. Ce schéma pourrait traduire l'histoire suivante : (a) la disjonction des lignées laurasienne (Anaxagorea) et nord-gondwanienne au Crétacé inférieur, alors que les échanges à travers la Téthys étaient encore faciles et que les grandes lignées de Magnoliidae sont établies par la paléobotanique; (b) la radiation de la lignée nord-gondwanienne pendant le Crétacé supérieur, lorsque les barrières océaniques s'élargissaient; (c) la dispersion de lignées africaines en Laurasie due au mouvement de l'Afrique et de l'Inde vers le nord au début du Tertiaire, attestée par la présence de graines fossiles d'Annonaceae en Europe, et des échanges entre l'Amérique du Nord et l'Amérique du Sud à la fin du Tertiaire.Wà hrend Takhtajan und Smith den Ursprung der Angiospermen zwischen Sùdostasien und Australien ansiedelten. haben Walker und Le Thomas die Konzentration primitiver Pollen-Typen von Annonaceae in Sùdamerika und Afrika hervorgehoben und so stattdessen einen Ursprung in Nord-Gondwanaland fur dièse Familie primitiver Angiospermen vorgeschlagen. Eine kladistische Analyse der Annonaceae zeigt eine Basis-Aufspaltung der Familie in Anaxagorea. die einzige Gattung mit asiatischer und neotropischer Verteilung und in eine grundsâtzlich afrikanische und neotropische Linie, welche den Rest der Familie einschliesst. Mehrere entwickelte Linien treten sowohl in Afrika wie Asien auf und eine davon erreicht Australien. Dies Schema kônnte die folgende Geschichte spiegeln: (a) Trennung der laurasischen (Anaxagorea) und der Nord-Godwanaland-Linien in derfrùhen Kreidezeit, zu einer Zeit als der Austausch ùber das Tethys noch einfach war und die Hauptlinien von Magnoliidae durch die Paieobotanik dokumentiert sind; (b) Radiation der Nord-Gondwanaland-Linie wà hrend der spâten Kreidezeit, als die Ozeanbarrieren sich verbreiterten; (c) Verbreitung der afrikanischen Linie ùber Laurasia aufgrund der Nordwà rts-Verschiebung von Afrika und Indien im frùhen Tertiâr, welche durch das Vorkommen fossiler Samen von Annonaceae in Europa bezeugt wird, und Austausch zwischen Nord- und Sùdamerika am Ende des Tertiârs
Reproducibility of deep inspiration breath hold for prone left-sided whole breast irradiation
Background: Investigating reproducibility and instability of deep inspiration breath hold (DIBH) in the prone position to reduce heart dose for left-sided whole breast irradiation.
Methods: Thirty patients were included and underwent 2 prone DIBH CT-scans during simulation. Overlap indices were calculated for the ipsilateral breast, heart and lungs to evaluate the anatomical reproducibility of the DIBH maneuver. The breathing motion of 21 patients treated with prone DIBH were registered using magnetic probes. These breathing curves were investigated to gain data on intra-fraction reproducibility and instability of the different DIBH cycles during treatment.
Results: Overlap index was 0.98 for the ipsilateral breast and 0.96 for heart and both lungs between the 2 prone DIBH-scans. The magnetic sensors reported population amplitudes of 2.8 +/- 1.3 mm for shallow breathing and 11.7 +/- 4.7 mm for DIBH, an intra-fraction standard deviation of 1.0 +/- 0.4 mm for DIBH, an intra-breath hold instability of 1.0 +/- 0.6 mm and a treatment time of 300 +/- 69 s.
Conclusion: Prone DIBH can be accurately clinically implemented with acceptable reproducibility and instability
Factors modifying the risk for developing acute skin toxicity after whole-breast intensity modulated radiotherapy
Background: After breast-conserving radiation therapy most patients experience acute skin toxicity to some degree. This may impair patients' quality of life, cause pain and discomfort. In this study, we investigated treatment and patient-related factors, including genetic polymorphisms, that can modify the risk for severe radiation-induced skin toxicity in breast cancer patients.
Methods: We studied 377 patients treated at Ghent University Hospital and at ST.-Elisabeth Clinic and Maternity in Namur, with adjuvant intensity modulated radiotherapy (IMRT) after breast-conserving surgery for breast cancer. Women were treated in a prone or supine position with normofractionated (25 x 2 Gy) or hypofractionated (15 x 2.67 Gy) IMRT alone or in combination with other adjuvant therapies. Patient-and treatment-related factors and genetic markers in regulatory regions of radioresponsive genes and in LIG3, MLH1 and XRCC3 genes were considered as variables. Acute dermatitis was scored using the CTCAEv3.0 scoring system. Desquamation was scored separately on a 3-point scale (0-none, 1-dry, 2-moist).
Results: Two-hundred and twenty patients (58%) developed G2+ dermatitis whereas moist desquamation occurred in 56 patients (15%). Normofractionation (both p = D (p = 0.001 and p = 0.043) and concurrent hormone therapy (p = 0.001 and p = 0.037) were significantly associated with occurrence of acute dermatitis and moist desquamation, respectively. Additional factors associated with an increased risk of acute dermatitis were the genetic variation in MLH1 rs1800734 (p=0.008), smoking during RT (p = 0.010) and supine IMRT (p = 0.004). Patients receiving trastuzumab showed decreased risk of acute dermatitis (p < 0.001).
Conclusions: The normofractionation schedule, supine IMRT, concomitant hormone treatment and patient related factors (high BMI, large breast, smoking during treatment and the genetic variation in MLH1 rs1800734) were associated with increased acute skin toxicity in patients receiving radiation therapy after breast-conserving surgery. Trastuzumab seemed to be protective
Mycoplasma bovis shares insertion sequences with Mycoplasma agalactiae and Mycoplasma mycoides subsp. mycoides SC: Evolutionary and developmental aspects
Three new insertion elements, ISMbov1, ISMbov2 and ISMbov3, which are closely related to ISMag1 (Mycoplasma agalactiae), ISMmy1 and IS1634 (both Mycoplasma mycoides subsp. mycoides SC), respectively, have been discovered in Mycoplasma bovis, an important pathogen of cattle. Southern blotting showed that the genome of M. bovis harbours 6-12 copies of ISMbov1, 11-15 copies of ISMbov2 and 4-10 copies of ISMbov3, depending on the strain. A fourth insertion element, the IS30-like element, is present in 4-8 copies. This high number of IS elements in M. bovis, which represent a substantial part of its genome, and their relatedness with IS elements of both M. agalactiae and M. mycoides subsp. mycoides SC suggest the occurrence of two evolutionary events: (i) a divergent evolution into M. agalactiae and M. bovis upon infection of different hosts; (ii) a horizontal transfer of IS elements during co-infection with M. mycoides subsp. mycoides SC and M. bovis of a same bovine hos
Bridge over Troubled Water: Linking Capacities of Sport and Non-Sport Organizations
Community Sport Development Programs (CSDPs) that use an intersectoral capacity building approach have shown potential in reaching individuals in disadvantaged situations. This study has investigated how the application of capacity building principles in disadvantaged communities results in higher sport participation rates in these communities. A multiple case design was used, including six similar disadvantaged communities in Antwerp, Belgium; four communities implemented the CSDP, two communities served as control communities without CSDP. In total, 52 face-to-face interviews were held with sport, social, health, cultural, and youth organizations in these communities. Four key findings were crucial to explain the success of the CSDP according to the principles of capacity building. First, the CSDP appeared to be the missing link between sport organizations on the one hand and health, social, youth, and cultural organizations on the other hand. Second, shifting from a sport-oriented staff to a mix of sport staff, social workers and representatives of people in disadvantaged situations helped increase trust through a participatory approach. Third, CSDPs assisted sport clubs to deal with financial, organizational, and cultural pressures that arose from the influx of new members in disadvantaged situations. Finally, the CSDPs developed well-planned and integrated strategies focusing on reinforcing the existing local organizations already using sport to reach their goals. These capacity building principles were key in attaining higher sport participation for people living in disadvantaged communities
Prognostic Value of Viremia in Patients with Long-Standing Human Immunodeficiency Virus Infection
Human immunodeficiency virus (HIV) viremia was evaluated in 73 patients with long-standing infection to investigate its relationship with clinical or biologic parameters and to assess its use as a predictor of clinical progression and death. After adjustment for other parameters, baseline HIV RNA level was significantly associated with baseline clinical stage and CD4 cell count. During follow-up (mean, 14.6 months), 16 patients died; 34 others had clinical progression of disease. In multivariate analysis, mortality was better predicted by baseline CD4 cell count (relative hazard [RH] for 100-cell decrease, 3.5; 95% confidence interval [CI], 1.5-8.2; P = .003) than by HIV RNA (P = .28) or clinical stage. HIV RNA level was the best predictor of clinical progression (RH for 1 log increase, 2.8; 95% CI, 1.6-4.9; P < .001). Monitoring of HIV RNA level may help to identify patients who might benefit from antiretroviral or prophylactic therap
Accounting for end-user preferences in earthquake early warning systems
Earthquake early warning systems (EEWSs) that rapidly trigger risk-reduction actions after a potentially-damaging earthquake is detected are an attractive tool to reduce seismic losses. One brake on their implementation in practice is the difficulty in setting the threshold required to trigger pre-defined actions: set the level too high and the action is not triggered before potentially-damaging shaking occurs and set the level too low and the action is triggered too readily. Balancing these conflicting requirements of an EEWS requires a consideration of the preferences of its potential end users. In this article a framework to define these preferences, as part of a participatory decision making procedure, is presented. An aspect of this framework is illustrated for a hypothetical toll bridge in a seismically-active region, where the bridge owners wish to balance the risk to people crossing the bridge with the loss of toll revenue and additional travel costs in case of bridge closure. Multi-attribute utility theory (MAUT) is used to constrain the trigger threshold for four owners with different preferences. We find that MAUT is an appealing and transparent way of aiding the potentially controversial decision of what level of risk to accept in EEW
La colonisation des prairies par le frĂŞne. Processus et moyens de contrĂ´le dans les Montagnes de Bigorre
focus PSDR3Le projet CHAPAY a contribué à produire des connaissances, des méthodes et des outils pour prendre en compte les relations entre le changement des activités agricoles et des paysages dans l’action publique et la gouvernance des territoires. Au niveau des vallées, la connaissance de l’histoire des paysages pastoraux permet d’identifier les terroirs colonisables par le frêne. Dans ces terroirs, le maintien de la fauche empêche le frêne de s’installer. Par contre, pour les prairies pâturées, il existe un seuil d’intensité de pâturage au-dessus duquel le frêne ne s’installe pas et au-dessous duquel il s’installe de manière irréversible en développant une stratégie de reproduction végétative souterraine
- …