517 resultados para Magnolia
Resumo:
The new genus Aposphragisma (Araneae, Oonopidae, Oonopinae) comprising the new species A. baltenspergerae, A. borgulai, A. brunomanseri, A. confluens, A. dayak, A. dentatum, A. draconigenum, A. hausammannae, A. helvetiorum, A. kolleri, A. menzi, A. monoceros, A. nocturnum, A. retifer, A. rimba, A. salewskii, A. scimitar, A. sepilok and A. stannum is described. It is characterised by very hard bodied, strongly sclerotized species with completely armoured prosoma and strongly sclerotized ventral and dorsal abdominal scuta. Aposphragisma gen. nov. is placed within the Gamasomorpha-group sensu Saaristo (2001). Descriptions and illustrations are given for all new species. A phylogenetic analysis based on 40 characters using Prethopalpus fosuma, Gamasomorpha asterobothros, G. cataphracta, G. seximpressa, Xestaspis biflocci, X. kandy and X. paulina as outgroup-taxa and Cortestina thaleri (Oonopidae, Sulsulinae) as the root is presented and discussed. Furthermore it is shown that females of Aposphragisma gen. nov. possess complex internal genitalia. The members of the new genus are ground-dwelling litter inhabitants restricted to Southeast Asian lowland and montane forests, with more than 60% of the species only known from single localities. They are presumed to be negatively affected by the massive destruction of pristine forest habitats within their range. This work has been conducted within the framework of the Planetary Biodiversity Inventory (PBI) of Oonopidae (see http://research.amnh.org/oonopidae).
Resumo:
BACKGROUND Magnolia bark preparations from Magnolia officinalis of Asian medicinal systems are known for their muscle relaxant effect and anticonvulsant activity. These CNS related effects are ascribed to the presence of the biphenyl-type neolignans honokiol and magnolol that exert a potentiating effect on GABAA receptors. 4-O-methylhonokiol isolated from seeds of the North-American M. grandiflora was compared to honokiol for its activity to potentiate GABAA receptors and its GABAA receptor subtype-specificity was established. METHODS Different recombinant GABAA receptors were functionally expressed in Xenopus oocytes and electrophysiological techniques were used determine to their modulation by 4-O-methylhonokiol. RESULTS 3μM 4-O-methylhonokiol is shown here to potentiate responses of the α₁β₂γ₂ GABAA receptor about 20-fold stronger than the same concentration of honokiol. In the present study potentiation by 4-O-methylhonokiol is also detailed for 12 GABAA receptor subtypes to assess GABAA receptor subunits that are responsible for the potentiating effect. CONCLUSION The much higher potentiation of GABAA receptors at identical concentrations of 4-O-methylhonokiol as compared to honokiol parallels previous observations made in other systems of potentiated pharmacological activity of 4-O-methylhonokiol over honokiol. GENERAL SIGNIFICANCE The results point to the use of 4-O-methylhonokiol as a lead for GABAA receptor potentiation and corroborate the use of M. grandiflora seeds against convulsions in Mexican folk medicine.
Resumo:
Objetivos: Conocer las interacciones entrenador-atleta y comprender las practicas de liderazgo, de generación de climas motivacionales y de comunicación entre líderes deportivos y jugadores. Metodología: Metodología de cohorte mixto. Se realizó correlación de variables cuantitativas y se analizaron las experiencias y los sentidos del contexto deportivo con una aproximación cualitativa. Se aplicaron a 31 deportistas universitarios los instrumentos: Clima Motivacional Percibido en el Deporte (PMCSQ-2), Clima en el Deporte (SCQ) y Orientación al Ego y a la Tarea en el Deporte. Para profundizar la información obtenida, se realizaron entrevistas semi-estructuradas a 6 deportistas y 2 entrenadores universitarios. RESULTADOS: Que el deportista sienta confianza en su entrenador se encuentra asociado a que se sienta comprendido y aceptado por él. Que el entrenador genere un clima motivacional orientado hacia el ego está relacionado con que los deportistas tengan orientaciones de meta ego. Los entrenadores utilizan dos estilos de liderazgo opuestos: liderazgo democrático (entrenamientos) y liderazgo autocrático (competiciones) Conclusiones: Cuando el atleta confía en la persona que lo dirige deportivamente, presenta mayor satisfacción deportiva. También, que el entrenador fomente un ambiente de comparación social propicia que los deportistas rivalicen con compañeros de equipo y basen su rendimiento en resultados deportivos obtenidos
Resumo:
Objetivos: Conocer las interacciones entrenador-atleta y comprender las practicas de liderazgo, de generación de climas motivacionales y de comunicación entre líderes deportivos y jugadores. Metodología: Metodología de cohorte mixto. Se realizó correlación de variables cuantitativas y se analizaron las experiencias y los sentidos del contexto deportivo con una aproximación cualitativa. Se aplicaron a 31 deportistas universitarios los instrumentos: Clima Motivacional Percibido en el Deporte (PMCSQ-2), Clima en el Deporte (SCQ) y Orientación al Ego y a la Tarea en el Deporte. Para profundizar la información obtenida, se realizaron entrevistas semi-estructuradas a 6 deportistas y 2 entrenadores universitarios. RESULTADOS: Que el deportista sienta confianza en su entrenador se encuentra asociado a que se sienta comprendido y aceptado por él. Que el entrenador genere un clima motivacional orientado hacia el ego está relacionado con que los deportistas tengan orientaciones de meta ego. Los entrenadores utilizan dos estilos de liderazgo opuestos: liderazgo democrático (entrenamientos) y liderazgo autocrático (competiciones) Conclusiones: Cuando el atleta confía en la persona que lo dirige deportivamente, presenta mayor satisfacción deportiva. También, que el entrenador fomente un ambiente de comparación social propicia que los deportistas rivalicen con compañeros de equipo y basen su rendimiento en resultados deportivos obtenidos
Resumo:
Objetivos: Conocer las interacciones entrenador-atleta y comprender las practicas de liderazgo, de generación de climas motivacionales y de comunicación entre líderes deportivos y jugadores. Metodología: Metodología de cohorte mixto. Se realizó correlación de variables cuantitativas y se analizaron las experiencias y los sentidos del contexto deportivo con una aproximación cualitativa. Se aplicaron a 31 deportistas universitarios los instrumentos: Clima Motivacional Percibido en el Deporte (PMCSQ-2), Clima en el Deporte (SCQ) y Orientación al Ego y a la Tarea en el Deporte. Para profundizar la información obtenida, se realizaron entrevistas semi-estructuradas a 6 deportistas y 2 entrenadores universitarios. RESULTADOS: Que el deportista sienta confianza en su entrenador se encuentra asociado a que se sienta comprendido y aceptado por él. Que el entrenador genere un clima motivacional orientado hacia el ego está relacionado con que los deportistas tengan orientaciones de meta ego. Los entrenadores utilizan dos estilos de liderazgo opuestos: liderazgo democrático (entrenamientos) y liderazgo autocrático (competiciones) Conclusiones: Cuando el atleta confía en la persona que lo dirige deportivamente, presenta mayor satisfacción deportiva. También, que el entrenador fomente un ambiente de comparación social propicia que los deportistas rivalicen con compañeros de equipo y basen su rendimiento en resultados deportivos obtenidos
Resumo:
Objetivos: Conocer las interacciones entrenador-atleta y comprender las practicas de liderazgo, de generación de climas motivacionales y de comunicación entre líderes deportivos y jugadores. Metodología: Metodología de cohorte mixto. Se realizó correlación de variables cuantitativas y se analizaron las experiencias y los sentidos del contexto deportivo con una aproximación cualitativa. Se aplicaron a 31 deportistas universitarios los instrumentos: Clima Motivacional Percibido en el Deporte (PMCSQ-2), Clima en el Deporte (SCQ) y Orientación al Ego y a la Tarea en el Deporte. Para profundizar la información obtenida, se realizaron entrevistas semi-estructuradas a 6 deportistas y 2 entrenadores universitarios. RESULTADOS: Que el deportista sienta confianza en su entrenador se encuentra asociado a que se sienta comprendido y aceptado por él. Que el entrenador genere un clima motivacional orientado hacia el ego está relacionado con que los deportistas tengan orientaciones de meta ego. Los entrenadores utilizan dos estilos de liderazgo opuestos: liderazgo democrático (entrenamientos) y liderazgo autocrático (competiciones) Conclusiones: Cuando el atleta confía en la persona que lo dirige deportivamente, presenta mayor satisfacción deportiva. También, que el entrenador fomente un ambiente de comparación social propicia que los deportistas rivalicen con compañeros de equipo y basen su rendimiento en resultados deportivos obtenidos
Resumo:
Palynological investigation of a 410 cm long core section from Tso Kar (33°10'N, 78°E, 4527 m a.s.l.), an alpine lake situated in the arid Ladakh area of NW India at the limit of the present-day Indian summer monsoon, was performed in order to reconstruct post-glacial regional vegetation and climate dynamics. The area was covered with alpine desert vegetation from ca. 15.2 to 14 kyr BP (1 kyr=1000 cal. years), reflecting dry and cold conditions. High influx values of long-distance transported Pinus sylvestris type pollen suggest prevailing air flow from the west and northwest. The spread of alpine meadow communities and local aquatic vegetation is a weak sign of climate amelioration after ca. 14 kyr BP. Pollen data (e.g. influx values of Pinus roxburghii type and Quercus) suggest that this was due to a strengthening of the summer monsoon and the reduced activity of westerly winds. The further spread of Artemisia and species-rich meadows occurred in response to improved moisture conditions between ca. 12.9 and 12.5 kyr BP. The subsequent change towards drier desert-steppe vegetation likely indicates more frequent westerly disturbances and associated snowfalls, which favoured the persistence of alpine meadows on edaphically moist sites. The spread of Chenopodiaceae-dominated vegetation associated with an extremely weak monsoon occurred at ca. 12.2-11.8 kyr BP during the Younger Dryas interstadial. A major increase in humidity is inferred from the development of Artemisia-dominated steppe and wet alpine meadows with Gentianaceae after the late glacial/early Holocene transition in response to the strengthening of the summer monsoon. Monsoonal influence reached maximum activity in the Tso Kar region between ca. 10.9 and 9.2 kyr BP. The subsequent development of the alpine meadow, steppe and desert-steppe vegetation points to a moderate reduction in the moisture supply, which can be linked to the weaker summer monsoon and the accompanying enhancement of the winter westerly flow from ca. 9.2 to 4.8 kyr BP. The highest water levels of Tso Kar around 8 kyr BP probably reflect combined effect of both monsoonal and westerly influence in the region. An abrupt shift towards aridity in the Tso Kar region occurred after ca. 4.8 kyr BP, as evidenced by an expansion of Chenopodiaceae-dominated desert-steppe. Low pollen influx values registered ca. 2.8-1.3 kyr BP suggest scarce vegetation cover and unfavourable growing conditions likely associated with a further weakening of the Indian Monsoon.
Resumo:
Southern China, especially Yunnan, has undergone high tectonic activity caused by the uplift of Himalayan Mountains during the Neogene, which led to a fast changing palaeogeography. Previous study shows that Southern China has been influenced by the Asian Monsoon since at least the Early Miocene. However, it is yet not well understood how intense the Miocene monsoon system was. In the present study, 63 fossil floras of 16 localities from Southern China are compiled and evaluated for obtaining available information concerning floristic composition, stratigraphic age, sedimentology, etc. Based on such reliable information, selected mega- and micro-floras have been analysed with the coexistence approach to obtain quantitative palaeoclimate data. Visualization of climate results in maps shows a distinct spatial differentiation in Southern China during the Miocene. Higher seasonalities of temperature and precipitation occur in the north and south parts of Southern China, respectively. During the Miocene, most regions of Southern China and Europe were both warm and humid. Central Eurasia was likely to be an arid center, which gradually spread westward and eastward. Our data provide information about Miocene climate patterns in Southern China and about the evolution of these patterns throughout the Miocene, and is also crucial to unravel and understand the climatic signals of global cooling and tectonic uplift.
Resumo:
We present a detailed palaeoclimate analysis of the Middle Miocene (uppermost Badenian-lowermost Sarmatian) Schrotzburg locality in S Germany, based on the fossil macro- and micro-flora, using four different methods for the estimation of palaeoclimate parameters: the coexistence approach (CA), leaf margin analysis (LMA), the Climate-Leaf Analysis Multivariate Program (CLAMP), as well as a recently developed multivariate leaf physiognomic approach based on an European calibration dataset (ELPA). Considering results of all methods used, the following palaeoclimate estimates seem to be most likely: mean annual temperature ~15-16°C (MAT), coldest month mean temperature ~7°C (CMMT), warmest month mean temperature between 25 and 26°C, and mean annual precipiation ~1,300 mm, although CMMT values may have been colder as indicated by the disappearance of the crocodile Diplocynodon and the temperature thresholds derived from modern alligators. For most palaeoclimatic parameters, estimates derived by CLAMP significantly differ from those derived by most other methods. With respect to the consistency of the results obtained by CA, LMA and ELPA, it is suggested that for the Schrotzburg locality CLAMP is probably less reliable than most other methods. A possible explanation may be attributed to the correlation between leaf physiognomy and climate as represented by the CLAMP calibration data set which is largely based on extant floras from N America and E Asia and which may be not suitable for application to the European Neogene. All physiognomic methods used here were affected by taphonomic biasses. Especially the number of taxa had a great influence on the reliability of the palaeoclimate estimates. Both multivariate leaf physiognomic approaches are less influenced by such biasses than the univariate LMA. In combination with previously published results from the European and Asian Neogene, our data suggest that during the Neogene in Eurasia CLAMP may produce temperature estimates, which are systematically too cold as compared to other evidence. This pattern, however, has to be further investigated using additional palaeofloras.