Pollen-ovule relation in Adesmia tristis and reflections on the seed–ovule ratio by interaction with pollinators in two vertical strata

The vertical distribution of pollinators is an important component in the foraging pattern of plants strata, and it influences the reproductive system (pollen/ovule ratio) and seed/ovule ratio. Niches in two different strata from Adesmia tristis Vogel were evaluated in these aspects. This plant is an endemic shrub from the Campos de Cima da Serra in Southern Brazil. The studies were carried out from January 2010, to January 2011, at Pró-Mata/PUCRS (Catholic University of Rio Grande do Sul) (29°27'-29°35'S and 50°08'-50°15'W), São Francisco de Paula, sate of Rio Grande do Sul, Brazil. Breeding system of A. tristis is mandatory allogamy. The vertical profile in A. tristis has differentiated foraging niches among the most common pollinators. Bees of Megachile genus forage in the upper stratum, and representative bees of the Andrenidae family explore the lower stratum. The upper stratum of the vertical profile had more contribution to seed production. Adesmia tristis showed evidence of pollination deficitA distribuição vertical dos polinizadores é um importante componente no padrão de forrageamento nos estratos das plantas e influencia o sistema reprodutivo (relação pólen/ óvulo) e a razão semente/óvulo. Nichos em dois estratos diferentes de Adesmia tristis Vogel foram avaliados quanto a esses aspectos. Essa planta é um arbusto endêmico dos campos de Cima da Serra no Sul do Brasil. Os estudos ocorreram de janeiro de 2010 a janeiro de 2011, no Pró- Mata/PUCRS (Pontifícia Universidade Católica do Rio Grande do Sul) (29°27'-29°35'S e 50°08'-50°15'W), São Francisco de Paula, estado do Rio Grande do Sul, Brasil. O sistema reprodutivo de A. tristis é alogamia obrigatória. O perfil vertical em A. tristis possui diferentes nichos de forrageamento entre os polinizadores mais comuns. Abelhas do gênero Megachile forrageiam no estrato superior e as abelhas representantes da família Andrenidae exploram o estrato inferior. O estrato superior do perfil vertical contribui mais na produção de sementes. Adesmia tristis apresentou evidências de déficit de polinizaçã

Variaciones intranuales en el espectro polínico de las mieles del valle inferior del río Chubut (Patagonia, Argentina)

Thirty honey samples from the lower valley of the River Chubut, obtained by successive harvests in five apiaries overtwo consecutive apicultural periods (between 1997 and 2000) were analysed. Three hives per apiary were selected, fromwhich three successive harvests were obtained at the end of the following periods: initial (September 1st-December 20th),middle (December 20th-January 30th) and final (January 30th-March 15th). Pollen types were identified by comparisonwith a reference collection. Both reference pollen and sample pollen were subjected to acetolysis. A total of fifty entomophilouspollen types were identified: thirty-six, thirty-five and thirty-seven in initial, middle and final periods,respectively. The most abundant pollen was similar over the whole season, due to the long flowering periods of the taxaproducing dominant and secondary pollen. Tamarix gallica and Medicago sativa were main sources of nectar duringthe entire production period. Significant differences (PSe analizó el contenido polínico de 30 muestras de miel obtenidas de forma secuencial en cinco colmenares del valle inferior del río Chubut durante dos temporadas apícolas consecutivas, entre los años 1997 y 2000. Se seleccionaron tres colmenas por apiario, en las que se efectuaron cosechas sucesivas correspondientes a tres períodos de la temporada apícola: inicial (1 de septiembre-20 de diciembre), medio (20 de diciembre-30 de enero) y final (30 de enero-15 de marzo). Los tipos polínicos fueron reconocidos por comparación con una colección de referencia de polen provenientes de plantas del lugar. En todos los casos el polen fue acetolizado. Se identificó un total de 50 tipos de polen entomófilo, 36 en el período inicial, 35 en el período medio y 37 en el período final. Al comparar los períodos de cosechas se detectaron diferencias significativas (

Intraannual variations in teh pollinic spectrum of honey from the lower valley of the River Chubut (Patagonia, Argentina)

Se analizó el contenido polínico de 30 muestras de miel obtenidas de forma secuencial en cinco colmenares del valle inferior del río Chubut durante dos temporadas apícolas consecutivas, entre los años 1997 y 2000. Se seleccionaron tres colmenas por apiario, en las que se efectuaron cosechas sucesivas correspondientes a tres períodos de la temporada apícola: inicial (1 de septiembre-20 de diciembre), medio (20 de diciembre-30 de enero) y final (30 de enero-15 de marzo). Los tipos polínicos fueron reconocidos por comparación con una colección de referencia de polen proveniente de plantas del lugar. En todos los casos el polen fue acetolizado. Se identificó un total de 50 tipos de polen entomófilo, 36 en el período inicial, 35 en el período medio y 37 en el período final. Al comparar los períodos de cosechas se detectaron diferencias significativas (P<0,001) en la composición polínica. En la primavera se obtuvo el mayor número y variedad de mieles monoflorales y se registró el mayor aporte del distrito austral del Monte. La composición del polen mayoritario fue similar en toda la estación, en concordancia con los extensos períodos de floración de los taxa representados en el polen dominante y secundario. Tamarix gallica y Medicago sativa fueron las principales fuentes de néctar durante todo el período de producción. La presencia de polen anemófilo fue constante en todas las muestras. El número de granos de polen por gramo de miel fue inferior a 10.000 en los tres períodos considerado

EMOTIONAL FLUCTUATIONS OF BLOOD PRESSURE IN ADOLESCENTS: INFLUENCE OF THE REPETITION OF THE MEASUREMENT

Background. The optimal methodology to measure blood pressure (BP) in children remains controversial. Particularly relevant is the concern that anxiety may trigger a rising in BP during the first measurement, while the second and/or the third reading is lower because the child is more relaxed. However, experimental data concerning the pattern of repeated readings of BP are almost non existent. Therefore we accurately examined, by a repeated measures ANOVA design, the pressor response of a large group of healthy children, during the adolescent growth, to three consecutive BP measurements separated by one minute. Method. From a larger group of 719 well-being children aged 5-15 years examined in our hospital between July 2004 and March 2005, a cohort of 145 age-eligible children (11-14 years) was selected for this study. In each subject, BP readings were carried out in the supine position placing size-appropriate cuffies on the right arm and by making use of an oscillometric monitor, whose reliability is unaffected by the enviromental noise. Anthropometric parameters also were acquired. Data were analysed with a PC based statistic package (SPSS for Windows) testing the within-subjects differences. Results and conclusions. Data from the study are shown in the figure

Spin-On thin films of YBa₂Cu₃O_7-y and La_2−xSr_xCuO_4-y from Citrate-Polymer Precursors

ABSTRACTThin films of La2−xSrxCuO4 and YBa2Cu3O7-y superconductors have been prepared from citrate-polymer precursors. By a simple spin-coating and pyrolysis process, films which are dense and continuous at greater than 0.5 μm thickness have been prepared. For YBa2Cu3O7-y films deposited on SrTiO3, a large degree of epitaxial orientation has been observed, with the a-b plane of the superconductor parallel to the (100) plane of the substrate. Microstructural characterization and electrical properties measurements of these films are presented.</jats:p

La sensibilizzazione al gatto non è correlata alla presenza del gatto in casa.

Siena, Itali