3,628 research outputs found
Selected bioelements in bark and wood of native tree species from Central-Amazonian inundation forests
The chemical differences between tree foliage from várzea- and igapó forests are confirmed by respective analyses of bark and wood. While generally bark presents higher concentrations than wood, bark and wood of trees from the várzea have higher concentrations than those from the igapó forest. Species composition as well as river water chemistry and soil quality account for the differences between várzea and igapó
Foliar nutrient levels of native tree species from Central Amazonia. I. Inundation forests
The study of the leaf size spectra and foliar concentrations of N, P, K, Ca, Mg and Na of 52 species sampled in three Central-Amazon inundation forests (2 várzea sites, 1 igapó site) yielded signifìcant differences between várzea and igapó forests. The várzea foliage consists of larger and less heavy leaves with elemental concentrations being high even by tropical standards. The igapó foliage consists of relatively small leaves which are heavier, but much lower in the studied elements. The igapó leaves are supposed to be sclerophyllous and evergreen
Detecting the Cosmic Gravitational Wave Background with the Big Bang Observer
The detection of the Cosmic Microwave Background Radiation (CMB) was one of
the most important cosmological discoveries of the last century. With the
development of interferometric gravitational wave detectors, we may be in a
position to detect the gravitational equivalent of the CMB in this century. The
Cosmic Gravitational Background (CGB) is likely to be isotropic and stochastic,
making it difficult to distinguish from instrument noise. The contribution from
the CGB can be isolated by cross-correlating the signals from two or more
independent detectors. Here we extend previous studies that considered the
cross-correlation of two Michelson channels by calculating the optimal signal
to noise ratio that can be achieved by combining the full set of interferometry
variables that are available with a six link triangular interferometer. In
contrast to the two channel case, we find that the relative orientation of a
pair of coplanar detectors does not affect the signal to noise ratio. We apply
our results to the detector design described in the Big Bang Observer (BBO)
mission concept study and find that BBO could detect a background with
.Comment: 15 pages, 12 Figure
The role of pre-school quality in promoting resilience in the cognitive development of young children
The study reported here investigates the role of pre-school education as a protective factor in the development of children who are at risk due to environmental and individual factors. This investigation builds upon earlier research by examining different kinds of 'quality' in early education and tests the hypothesis that pre-schools of high quality can moderate the impacts of risks upon cognitive development. Cognitive development was measured in 2857 English pre-schoolers at 36 and 58 months of age, together with 22 individual risks to children's development, and assessments were made of the quality of their pre-school provision. Multilevel Structural Equation Modelling revealed that: the global quality of pre-school can moderate the effects of familial risk (such as poverty); the relationships between staff and children can moderate the effects of child level risk (such as low birth weight); and the specific quality of curricular provision can moderate the effects of both. Policy makers need to take quality into account in their efforts to promote resilience in young 'at risk' children through early childhood services
Correction to: Microbial communities associated with distance- and density-dependent seedling mortality in a tropical rainforest (Plant Ecology, (2020), 221, 1, (41-54), 10.1007/s11258-019-00989-y)
© 2020, Springer Nature B.V. The article entitled “Microbial communities associated with distance- and density-dependent seedling mortality in a tropical rainforest”, which is part of the special issue on “Applying microbial communities to improve restoration and conservation outcomes” was published prematurely in Volume 221, Issue 1, January 2020
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