7,064 research outputs found

    Effects of contrasting irradiances on carbon balance, biomass partition, and leaf nutrient contents in brazilian cerrado woody species.

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    It was evaluated growth and photosynthetic peformance of two leguminosae woody species under contrasting irradiances environments, Anadenanthera falcata (Benth.) Speg. and Stryphnodendron adstringens (Mart.) Coville. Under total irradiance in open area both species presented greater biomass accumulation, height, stem diameter, total leaf area and higher photosynthetic capacity on area bases (Amaxa). Shaded individuals under canopy modified the biomass partition, presenting greater mean values of leaf area rate (LAR), and smaller values of the specific leaf mass (SLM), repiration in dark (Rd), and apparent photorespiration (Pr) , apparent carboxylation efficiency (eletron transport rate (J). High transitory concentrations of CO2 increased the photosynthetic capacity under total irradiance (83%) and under canopy (71%)

    Comportamento sazonal do potencial hídrico e das trocas gasosoas de quatro variedades de coqueiro anão.

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    Estratégia de sobrevivência de panicum maximum tanzânia sob pastejo rotacionado.

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    Foi avaliada a dinâmica de perfilhamento do capim-tanzânia ao longo de um ano, visando caracterizar sua estratégia de sobrevivência em 5 touceiras. As maiores taxas de natalidade ocorreram em janeiro (76,6 p.100) e março (51,3 p.100) e as menores em junho (19,7 p.100) e agosto (13,2 p.100). As maiores taxas de mortalidade ocorreram em janeiro (72,5 p.100) e março (55,2 p.100) e as menores em abril (28,8 p.100) a outubro (24,4 p.100). Houve florescimento quando o fotoperíodo foi inferior a 11,5 horas (abril-agosto), onde as taxas de natalidade foram menores devido à dominância apical. Entre janeiro e abril houve intensa renovação de perfilhos. Grande proporção de perfilhos da geração que surgiu em março sobreviveu durante o período seco. Portanto, nesta geração, devem ser aplicadas técnicas de manejo visando à perenidade do pasto

    Orbital Magnetism in Ensembles of Parabolic Potentials

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    We study the magnetic susceptibility of an ensemble of non-interacting electrons confined by parabolic potentials and subjected to a perpendicular magnetic field at finite temperatures. We show that the behavior of the average susceptibility is qualitatively different from that of billiards. When averaged over the Fermi energy the susceptibility exhibits a large paramagnetic response only at certain special field values, corresponding to comensurate classical frequencies, being negligible elsewhere. We derive approximate analytical formulae for the susceptibility and compare the results with numerical calculations.Comment: 4 pages, 4 figures, REVTE

    Persistence Strategy of \u3cem\u3ePanicum Maximum\u3c/em\u3e cv. Tanzania in Grazed Pastures

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    In many cases, tiller age cohorts survival diagrams show seasonal increases or decreases in rates of tiller birth and death, which may be regarded as persistence strategy (Matthew et al., 2000). The aim of this work was to analyse tiller demographic information of P. maximum cv. Tanzania to determine its persistence strategy

    Foramen caróticoclinoideo en cráneos humanos: incidencia, morfometría y sus implicaciones clínicas

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    The caroticoclinoid foramen is an inconstant structure, formed by the union of the anterior and middle clinoid processes. The aim of this study was to perform an incidence and morphometry of the caroticoclinoid foramen in Brazilian human skulls and discuss its clinical implications. Eighty dry human skulls with sex distinction were used, and 3 groups of incidence were determined: General, sex, and sides. The morphometry was performed using a manual caliper and the major diameter of the foramina was measured; the values were also divided in general, according to sex and sides. The incidence of skulls with at least one foramen was 8.5%. According to the sides, 8.5% of the skulls showed foramen on the right side and 2.5% on the left. We found 2.5% of the skulls with bilateral foramen and 6.25% with unilateral foramen. In relation to sex, the foramens were found in 5% of male skulls and 12.5% of female skulls. The major diameter of this structure presented on mean, values of 5.23 mm on general, 5.18 mm on the right side and 5.35 mm on the left, 5.30 mm in male skulls and 5.18 mm in female skulls. The anatomical characteristics of this foramen should be considered in view of its clinical implications associated with neurosurgery as clinoid process removal, and symptoms as headache due to internal carotid artery alterations in this region. In conclusion knowledge of this structure supports the diagnosis and treatment of clinical complications related to this variation.The caroticoclinoid foramen is an inconstant structure, formed by the union of the anterior and middle clinoid processes. The aim of this study was to perform an incidence and morphometry of the caroticoclinoid foramen in Brazilian human skulls and discuss its clinical implications. Eighty dry human skulls with sex distinction were used, and 3 groups of incidence were determined: General, sex, and sides. The morphometry was performed using a manual caliper and the major diameter of the foramina was measured; the values were also divided in general, according to sex and sides. The incidence of skulls with at least one foramen was 8.5%. According to the sides, 8.5% of the skulls showed foramen on the right side and 2.5% on the left. We found 2.5% of the skulls with bilateral foramen and 6.25% with unilateral foramen. In relation to sex, the foramens were found in 5% of male skulls and 12.5% of female skulls. The major diameter of this structure presented on mean, values of 5.23 mm on general, 5.18 mm on the right side and 5.35 mm on the left, 5.30 mm in male skulls and 5.18 mm in female skulls. The anatomical characteristics of this foramen should be considered in view of its clinical implications associated with neurosurgery as clinoid process removal, and symptoms as headache due to internal carotid artery alterations in this region. In conclusion knowledge of this structure supports the diagnosis and treatment of clinical complications related to this variation292427431Das, S., Suri, R., Kapur, V., Ossification of caroticoclinoid ligament and its clinical importance in skull-based surgery (2007) São Paulo Med. J, 125, pp. 351-353Dodo, Y., Ishida, H., Incidence of nonmetric cranial variant in several population samples from East Asia and North America (1987) J. Anthrop. Soc. Nippon, 95, pp. 161-167Dolenc, V.V., A combined epi and subdural direct approach to carotidophthalmic artery aneurysms (1985) J. Neurosurg, 5, pp. 667-672Donald, P.J., (1998) Surgery of the Skull Base, , Philadelphia, Lippincott- RavenErturk, M., Kayalioglu, G., Govsa, F., Anatomy of the clinoidal region with special emphasis on the caroticoclinoid foramen and interclinoid osseous brid- ge in a recent Turkish population (2004) Neurosurg. Rev, pp. 22-26Gupta, N., Ray, B., Ghosh, S., A study on anterior clinoid process and optic strut with emphasis on variations of caroticoclinoid foramen (2005) Nep. Med. Coll. J, 7, pp. 140-144Hochstetter, F., Über die Taenia interclinoidea,die Commissura alicochlearis und die Cartilago supracochlearis des menschlichen Primordialkraniums.Gegenbaurs Morph (1940) Jahrb, 84, pp. 220-243Inoue, T., Rhoton Jr., A.L., Theele, D., Barry, M.E., Surgical approaches to the cavernous sinus:A microsurgical study (1990) Neurosurg, 6, pp. 903-932Kier, E.L., Embryology of the normal optic canal and its anomalies.An anatomic and roentgenographic stud (1966) Invest. Radiol, 1, pp. 346-362Kobayashi, S., Kyoshima, K., Gibo, H., Hedge, S.A., Takemae, T., Sugita, K., Carotid cave aneurysms of the internal carotid artery (1989) J. Neurosurg, 70, p. 216Lee, H.Y., Chung, I.H., Choi B., Y., Anterior, C., (1997) Yonsei Med. J, 38, pp. 151-154Narolewski, R., Significance of anatomic variants of bony surroundings of the internal carotid artery and their significance for lateral surgical approaches to the cavernous sinus (2003) Ann. Acad. Med. Stetin, 49, pp. 205-229Saka, E., Ozdoǧmus, O., Tulay, C., Gürdal, E., Uzün, I., The anatomy of the carotico-clinoid foramen and its relation with the internal carotid artery (2003) Surg. Radiol. Anat, 25, pp. 241-246Reisch, R., Vutskits, L., Filippi, R., Patonay, L., Fries, G., Perneczky, A., Topographic microsurgical anatomy of the paraclinoid carotid artery (2002) Neurosurg Rev, 25, pp. 177-183Sekhar, L.N., Akin, O., Anatomical study of the cavernous sinus emphasizing operative approaches and related vascular and neural reconstruction (1987) Neurosurg, 21, pp. 806-816Seoane, E., Rhoton, A.L., Oliveira, E., Microsurgical anatomy of the dural collar (carotid collar) and rings around the clinoid segment of the internal carotid artery (1998) Neurosurg, 42, pp. 869-886Sicher, H., du Brul, E.L., (1977) Oral Anatomy, , 6ed. Rio de Janeiro, Guanabara KooganStandring, S., Overview of the Development of the Head and Neck Head: Skull and Mandible Gray's anatomy: The anatomical basis of clinical practice, p. 2005. , New York, ElsevierEl foramen caróticoclinoideo es una estructura inconstante formada por la unión de la procesos clinoides anterior y medio. El objetivo de este estudio fue revisar la incidencia y la morfometría del foramen caróticoclinoideo en cráneos humanos brasileños y discutir sus implicaciones clínicas. Se utilizaron 80 cráneos humanos secos, de ambos sexos, determinando tres variables: sexo y lados derecho e izquierdo. La morfometría se realizó con un cáliper manual midiéndose el diámetro máximo del foramen. La incidencia de cráneos con al menos un foramen fue de 8,5%. El 8,5% de los cráneos presentó un foramen en el lado derecho y el 2,5% en el izquierdo. El 2,5% de los cráneos presentó un foramen bilateral y el 6,25% un foramen unilateral. En relación al sexo, los forámenes se encontraron en el 5% de los cráneos de hombres y el 12,5% de los cráneos de mujeres. El diámetro máximo de esta estructura presentó en promedio, valores de 5,23 mm; 5,18 mm en el lado derecho y 5,35 mm en el izquierdo; 5,30 mm en cráneos de hombres y 5.18 mm en cráneos de mujeres. Las características anatómicas de este foramen deben ser consideradas debido a las implicaciones clínicas asociadas a la neurocirugía, como la eliminación del proceso clinoides y a síntomas como cefaleas producto de alteraciones en la arteria carótida interna en esta región. En conclusión, el conocimiento de esta estructura mejora el diagnóstico y tratamiento de las complicaciones clínicas relacionadas con esta variació
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