991 resultados para Leg.


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During ODP Leg 123, abundant and well-preserved Neocomian radiolarians were recovered at Site 765 (Argo Abyssal Plain) and Site 766 (lower Exmouth Plateau). Assemblages are characterized by the numerical dominance of a small number of non-tethyan forms and by the scarcity of tethyan taxa. Remarkable contrasts exist between radiolarian assemblages extracted from claystones of Site 765 and reexamined DSDP Site 26 1, and faunas recovered from radiolarian sand layers, only found at Site 765. Clay faunas are unusual in their low diversity of apparently ecologically tolerant (or solution resistant?), ubiquist species, whereas sand faunas are dominated by non-tethyan taxa. Comparisons with Sites 766 and 26 1, as well as sedimentological observations, lead to the conclusion that this faunal contrast resulted from a difference in provenance, rather than from hydraulic sorting or selective dissolution. The ranges of 27 tethyan taxa from Site 765 were compared to the tethyan radiolarian zonation by Jud (1992) by means of the Unitary Associations Method. This calculation allows to directly date the Site 765 assemblages and to estimate the amount of truncation of ranges for tethyan taxa. Over 70% of the already few tethyan species of Site 765, have truncated ranges during the Valanginian-Hauterivian. Radiolarian assemblages recovered from claystones at Sites 765 and 261 in the Argo Basin apparently reflect restricted oceanic conditions during the latest Jurassic-Barremian. Neither sedimentary facies nor faunal associations bear any resemblance to what we know from typical tethyan sequences. We conclude that the Argo Basin was paleoceanographically separated from the Tethys during the Late Jurassic and part of the Early Cretaceous by its position at higher paleolatitudes and/or by enclosing land masses. Assemblages recovered from radiolarian sand layers are dominated by non-tethyan species that are interpreted as circumantarctic. Their first appearance in the late Berriasian-early Valanginian predates the oceanization of the Indo-Australian breakup (M11, late Valanginian), but coincides with a sharp increase in margin-derived pelagic turbidites. The Indo-Australian rift zone and the adjacent margins must have been submerged deeply enough to allow an intermittent influx of circumantarctic cold water into the Argo Basin, creating increased bottom current activity. Cold-water radiolarians carried into the Argo Basin upwelled along the margin, died, and accumulated in radiolarite layers due to winnowing by bottom currents. High rates of faunal change and the sharp increase of bottom current activity are thought to be synchronous with possible pronounced late Berriasian-early Valanginian lowstands in sea level. Hypothetically, both phenomena might have been.caused by a tendency to glaciation on the Antarctic-Australian continent, which was for the first time isolated from the rest of Gondwana by oceanic seaways as a result of Jurassic-Early Cretaceous sea-floor spreading. The absence of most typical tethyan radiolarian species during the Valanginian-Hauterivian is interpreted as reflecting a time of strong influx of circumantarctic cold water following oceanization (M11) and rapid spreading between Southeast India and West Australia. The reappearance and gradual abundance/diversity increase of tethyan taxa, along with the still dominant circumantarctic species are thought to result from overall more equitable climatic conditions during the Barremian-early Aptian and from the establishment of an oceanic connection with the Tethys Ocean during the early Aptian.

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A 77-year-old man with a 5-year history of mycosis fungoides (MF) who had received several lines of therapy, including intravenous courses of Methotrexate (MTX) for the past 2 years, went on to develop several ulcerated cutaneous nodules on the left leg. Biopsy revealed diffuse sheets of EBV-positive large B cells (CD20+ CD30 ± IgM Lambda), with an angiocentric distribution and a monoclonal IGH gene rearrangement. Although the pathological features were diagnostic for an EBV-positive diffuse large B-cell lymphoma (DLBCL), several possibilities could be considered for assignment to a specific entity: EBV-positive DLBCL of the elderly, methotrexate-induced lymphoproliferative disorder (LPD), lymphomatoid granulomatosis, or the more recently described EBV-positive mucocutaneous ulcer. The development of EBV+ lymphoproliferations has been reported in two other patients with MF under MTX, and occurred as skin lesions of the leg in one of these and in the current case, which may question the relatedness to primary cutaneous DLCBL, leg-type.

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A survey of the leg exocrine glands in the termite workers of 16 species of the families Kalotermitidae and Termitidae was carried out through scanning electron microscope. Glandular openings were not found in the legs of Anoplotermes sp., Ruptitermes sp. (Apicotermitinae, Termitidae) or Glyptotermes planus (Kalotermitidae), but they are present, spread over the ventral surface of the first, second and third tarsomeres of other Termitidae such as Armitermes euamignathus, Cornitermes cumulans, Nasutitermes coxipoensis, Rhynchotermes nasutissimus, Syntermes nanus, Embiratermes festivellus (Nasutitermitinae), Amitermes beaumonti, Hoplotermes amplus, Microcerotermes sp., Neocapritermes opacus, Orthognathotermes sp., Spinitermes brevicornutus and Termes sp. (Termitinae). The pores are usually isolated but they can also be grouped inside a round depression. The occurrence of leg exocrine glands in the family Termitidae is reported for the first time.

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Summary Aims.-To explore whether fatigue-induced changes in spring-mass behavior during a 5000m self-paced run varied according to the runner's training status. Methods and results.-Six highly- and six well-trained triathletes completed a 5000m time trial. Running velocity and vertical stiffness decreased significantly (P < 0.05) with fatigue, whereas leg stiffness remained constant. None of these parameters displayed a significant interaction between fatigue and training status, despite vertical stiffness being higher (P < 0.05) in highly-trained triathletes. Conclusions.-During a 5000m self-paced run, impairments in leg-spring behavior that occur with fatigue are not affected by athletes' training status. © 2009 Elsevier Masson SAS. All rights reserved. Objectifs.-Étudier, chez des athlètes de niveaux différents, les modifications de raideur mécanique liées à l'apparition de la fatigue lors d'une course de 5000 m. Synthèse des faits.-Six triathlètes très entraînés et six autres bien entraînés ont réalisé une course de 5000 m. La vitesse de course et la raideur verticale diminuaient significativement (p < 0,05) avec la fatigue, alors que la raideur de la jambe demeurait inchangée. Aucune interaction entre la fatigue et le niveau d'entraînement n'a été détectée, malgré des niveaux de raideur verticale plus élevés (p < 0,05) chez les sujets les mieux entraînés.

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Despite the key importance of altered oceanic mantle as a repository and carrier of light elements (B, Li, and Be) to depth, its inventory of these elements has hardly been explored and quantified. In order to constrain the systematics and budget of these elements we have studied samples of highly serpentinized (>50%) spinel harzburgite drilled at the Mid-Atlantic Ridge (Fifteen-Twenty Fracture zone, ODP Leg 209, Sites 1272A and 1274A). In-situ analysis by secondary ion mass spectrometry reveals that the B, Li and Be contents of mantle minerals (olivine, orthopyroxene, and clinopyroxene) remain unchanged during serpentinization. B and Li abundances largely correspond to those of unaltered mantle minerals whereas Be is close to the detection limit. The Li contents of clinopyroxene are slightly higher (0.44-2.8 mu g g(-1)) compared to unaltered mantle clinopyroxene, and olivine and clinopyroxene show an inverse Li partitioning compared to literature data. These findings along with textural observations and major element composition obtained from microprobe analysis suggest reaction of the peridotites with a mafic silicate melt before serpentinization. Serpentine minerals are enriched in B (most values between 10 and 100 mu g g(-1)), depleted in Li (most values below I mu g g(-1)) compared to the primary phases, with considerable variation within and between samples. Be is at the detection limit. Analysis of whole rock samples by prompt gamma activation shows that serpentinization tends to increase B (10.4-65.0 mu g g(-1)), H2O and Cl contents and to lower Li contents (0.07-3.37 mu g g(-1)) of peridotites, implying that-contrary to alteration of oceanic crust-B is fractionated from Li and that the B and Li inventory should depend essentially on rock-water ratios. Based on our results and on literature data, we calculate the inventory of B and Li contained in the oceanic lithosphere, and its partitioning between crust and mantle as a function of plate characteristics. We model four cases, an ODP Leg 209-type lithosphere with almost no igneous crust, and a Semail-type lithosphere with a thick igneous crust, both at I and 75 Ma, respectively. The results show that the Li contents of the oceanic lithosphere are highly variable (17-307 kg in a column of I m x I m x thickness of the lithosphere (kg/col)). They are controlled by the primary mantle phases and by altered crust, whereas the B contents (25-904 kg/col) depend entirely on serpentinization. In all cases, large quantities of B reside in the uppermost part of the plate and could hence be easily liberated during slab dehydration. The most prominent input of Li into subduction zones is to be expected from Semail-type lithosphere because most of the Li is stored at shallow levels in the plate. Subducting an ODP Leg 209-type lithosphere would mean only very little Li contribution from the slab. Serpentinized mantle thus plays an important role in B recycling in subduction zones, but it is of lesser importance for Li. (C) 2008 Elsevier Ltd. All rights reserved.

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OBJECTIVES: This study aimed to determine adjustments in spring-mass model characteristics, plantar loading and foot mobility induced by an exhaustive run. DESIGN: Within-participants repeated measures. METHODS: Eleven highly-trained adolescent middle-distance runners ran to exhaustion on a treadmill at a constant velocity corresponding to 95% of velocity associated with VO₂max (17.8 ± 1.4 kmh(-1), time to exhaustion=8.8 ± 3.4 min). Contact time obtained from plantar pressure sensors was used to estimate spring-mass model characteristics, which were recorded (during 30 s) 1 min after the start and prior to exhaustion using pressure insoles. Foot mobility magnitude (a composite measure of vertical and medial-lateral mobility of the midfoot) was measured before and after the run. RESULTS: Mean contact area (foot to ground), contact time, peak vertical ground reaction force, centre of mass vertical displacement and leg compression increased significantly with fatigue, while flight time, leg stiffness and mean pressure decreased. Leg stiffness decreased because leg compression increased to a larger extent than peak vertical ground reaction forces. Step length, step frequency and foot mobility magnitude did not change at exhaustion. CONCLUSIONS: The stride pattern of adolescents when running on a treadmill at high constant velocity deteriorates near exhaustion, as evidenced by impaired leg-spring behaviour (leg stiffness) and altered plantar loading.

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BACKGROUND: Multislice CT (MSCT) combined with D-dimer measurement can safely exclude pulmonary embolism in patients with a low or intermediate clinical probability of this disease. We compared this combination with a strategy in which both a negative venous ultrasonography of the leg and MSCT were needed to exclude pulmonary embolism. METHODS: We included 1819 consecutive outpatients with clinically suspected pulmonary embolism in a multicentre non-inferiority randomised controlled trial comparing two strategies: clinical probability assessment and either D-dimer measurement and MSCT (DD-CT strategy [n=903]) or D-dimer measurement, venous compression ultrasonography of the leg, and MSCT (DD-US-CT strategy [n=916]). Randomisation was by computer-generated blocks with stratification according to centre. Patients with a high clinical probability according to the revised Geneva score and a negative work-up for pulmonary embolism were further investigated in both groups. The primary outcome was the 3-month thromboembolic risk in patients who were left untreated on the basis of the exclusion of pulmonary embolism by diagnostic strategy. Clinicians assessing outcome were blinded to group assignment. Analysis was per protocol. This study is registered with ClinicalTrials.gov, number NCT00117169. FINDINGS: The prevalence of pulmonary embolism was 20.6% in both groups (189 cases in DD-US-CT group and 186 in DD-CT group). We analysed 855 patients in the DD-US-CT group and 838 in the DD-CT group per protocol. The 3-month thromboembolic risk was 0.3% (95% CI 0.1-1.1) in the DD-US-CT group and 0.3% (0.1-1.2) in the DD-CT group (difference 0.0% [-0.9 to 0.8]). In the DD-US-CT group, ultrasonography showed a deep-venous thrombosis in 53 (9% [7-12]) of 574 patients, and thus MSCT was not undertaken. INTERPRETATION: The strategy combining D-dimer and MSCT is as safe as the strategy using D-dimer followed by venous compression ultrasonography of the leg and MSCT for exclusion of pulmonary embolism. An ultrasound could be of use in patients with a contraindication to CT.

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Ormosia arborea (Vell.) Harms e Ormosia fastigiata Tul. são espécies similares em muitos caracteres morfológicos, o que resulta em dificuldade na sua identificação, tanto em campo quanto em material herborizado. Neste estudo foram descritas as características morfológicas das sementes e morfoanatômicas das plântulas e plantas jovens de O. arborea e O. fastigiata, coletadas em restinga e em mata ciliar, respectivamente. Sementes e plântulas foram processadas segundo técnicas usuais. As sementes de O. arborea são mais pesadas e têm germinação hipógea criptocotiledonar. O caule contém tricomas tectores esparsos e grande quantidade de lenticelas e, na raiz, nodulações. A folha apresenta parênquima paliçádico de células mais curtas, com base mais larga e presença de pigmentos vacuolares, espaços intercelulares conspícuos no parênquima esponjoso, tricomas tectores restritos à nervura principal e células epidérmicas da face adaxial maiores que as da face abaxial. A germinação de O. fastigiata é fanerocotiledonar, e a plântula possui muitos tricomas ao longo do caule e lenticelas restritas à região basal deste. As folhas apresentam tricomas tectores em todas as nervuras, com parênquima paliçádico de células tipicamente alongadas e parênquima esponjoso com espaços intercelulares reduzidos. Tais características são consistentes para separar as plântulas e sementes dessas espécies, que têm a mesma denominação popular e contribuem com informações úteis para o meio produtivo.

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Locomotor problems prevent the bird to move freely, jeopardizing the welfare and productivity, besides generating injuries on the legs of chickens. The objective of this study was to evaluate the influence of age, use of vitamin D, the asymmetry of limbs and gait score, the degree of leg injuries in broilers, using data mining. The analysis was performed on a data set obtained from a field experiment in which it was used two groups of birds with 30 birds each, a control group and one treated with vitamin D. It was evaluated the gait score, the asymmetry between the right and left toes, and the degree of leg injuries. The Weka ® software was used in data mining. In particular, C4.5 algorithm (also known as J48 in Weka environment) was used for the generation of a decision tree. The results showed that age is the factor that most influences the degree of leg injuries and that the data from assessments of gait score were not reliable to estimate leg weakness in broilers.

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Objective: To evaluate the use of the medial gastrocnemius muscle and/or soleus muscle flaps as surgical treatment of the leg bone exposure.Methods: We retrospectively analyzed the medical records of patients undergoing transposition of the medial gastrocnemius and / or soleus for treating exposed bone in the leg, from January 1976 to July 2009, gathering information on epidemiological data, the etiology the lesion, the time between the initial injury and muscle transposition, the muscle used to cover the lesion, the healing evolution of the skin coverage and the function of the gastrocnemius-soleus unit.Results: 53 patients were operated, the ages varying between nine and 84 years (mean age 41); 42 were male and 11 female. The main initial injury was trauma (84.8%), consisting of tibia and / or fibula fracture. The most frequently used muscle was the soleus, in 40 cases (75.5%). The rank of 49 patients (92.5%) was excellent or good outcome, of three (5.6%) as regular and of one (1.9%) as unsatisfactory.Conclusion: the treatment of bone exposure with local muscle flaps (gastrocnemius and/or soleus) enables obtaining satisfactory results in covering of exposed structures, favoring local vascularization and improving the initial injury. It offers the advantage of providing a treatment in only one surgical procedure, an earlier recovery and reduced hospital stay.