60 research outputs found
Pollination of Pagamea duckei Standl. (Rubiaceae): a functionally dioecious species
The floral biology, pollination and breeding system of Pagamea duckei Standl. (Rubiaceae) were studied at the Reserva BiolĂłgica da Campina, Manaus, Amazonas, Brazil. Floral morphology suggested that P. duckei is a distylous species. However, crossing experiments revealed that it is functionally dioecious. The flowers are actinomorphic, yellowish, produce nectar and a sweet odor, which is more intense in the morning. Anthesis started in the morning between 5.00 and 6.00 AM and extended until dusk, when the corolla tube abscissed. The flowers were visited mostly by bees of the genus Melipona. Pagamea duckei is not agamospermic and thus needs pollen vectors for effective pollination. The results of this study strengthen the idea that, in Pagamea, species with distylous flower morphology are actually functionally dioecious
Glicerina bruta em suplementos para bovinos de corte a pasto no perĂodo seco
O objetivo deste trabalho foi avaliar o efeito da substituição do milho pela glicerina bruta (GB) sobre os parĂąmetros nutricionais e o desempenho de bovinos de corte em pastagem de Urochloa brizantha 'Marandu', no perĂodo seco. Para a avaliação dos parĂąmetros ruminais, foram utilizados cinco bovinos da raça Nelore nĂŁo fistulados, com peso corporal (PC) inicial de 331,7±29,6 kg, distribuĂdos em delineamento em quadrado latino 5x5. Para a avaliação do desempenho, foram utilizados 30 bovinos, com PC mĂ©dio de 312,4±23,3 kg, distribuĂdos em delineamento inteiramente casualizado. Avaliaram-se suplementos concentrados (20% de proteĂna bruta) com 0, 33, 66 e 100% de GB em substituição ao milho, fornecidos na quantidade de 4,0 kg por animal por dia. Os consumos de matĂ©ria seca (MS) de suplemento, total e de pasto, bem como o de matĂ©ria orgĂąnica (MO) digestĂvel, apresentaram comportamento quadrĂĄtico frente aos nĂveis de substituição. As digestibilidades aparentes de MS, MO, fibra em detergente neutro e MO digerida, bem como o ganho mĂ©dio diĂĄrio, tambĂ©m apresentaram comportamento quadrĂĄtico. Em suplementos concentrados fornecidos na quantidade de 10 g kg-1 de peso corporal, a substituição total do milho pela glicerina bruta reduz o consumo de suplemento e de matĂ©ria orgĂąnica digerida, alĂ©m do desempenho de bovinos de corte em pastejo
New insights into the genetic etiology of Alzheimer's disease and related dementias.
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE Δ4 allele
New insights into the genetic etiology of Alzheimer's disease and related dementias
Characterization of the genetic landscape of Alzheimer's disease (AD) and related dementias (ADD) provides a unique opportunity for a better understanding of the associated pathophysiological processes. We performed a two-stage genome-wide association study totaling 111,326 clinically diagnosed/'proxy' AD cases and 677,663 controls. We found 75 risk loci, of which 42 were new at the time of analysis. Pathway enrichment analyses confirmed the involvement of amyloid/tau pathways and highlighted microglia implication. Gene prioritization in the new loci identified 31 genes that were suggestive of new genetically associated processes, including the tumor necrosis factor alpha pathway through the linear ubiquitin chain assembly complex. We also built a new genetic risk score associated with the risk of future AD/dementia or progression from mild cognitive impairment to AD/dementia. The improvement in prediction led to a 1.6- to 1.9-fold increase in AD risk from the lowest to the highest decile, in addition to effects of age and the APOE Δ4 allele
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