Based on isotope-geochemical study of mineral-forming fluid of the gold and uranium deposits of two megablocks of the Ukrainian shield, a significant difference between the hydrothermal systems of ...the Archean and Proterozoic (3042—1750 million years) has been established. The study included the experimental determination of the hydrogen, oxygen and carbon isotopic composition, and the ratio of water and carbon dioxide of fluids of gas—liquid inclusions in quartz, pyrite and feldspars.
Time series of cell size evolution in unicellular marine algae (division Haptophyta; Coccolithus lineage), covering 57 million years, are studied by a system of linear stochastic differential ...equations of hierarchical structure. The data consists of size measurements of fossilized calcite platelets (coccoliths) that cover the living cell, found in deep-sea sediment cores from six sites in the world oceans and dated to irregular points in time. To accommodate biological theory of populations tracking their fitness optima, and to allow potentially interprétable correlations in time and space, the model framework allows for an upper layer of partially observed site-specific population means, a layer of site-specific theoretical fitness optima and a bottom layer representing environmental and ecological processes. While the modeled process has many components, it is Gaussian and analytically tractable. A total of 710 model specifications within this framework are compared and inference is drawn with respect to model structure, evolutionary speed and the effect of global temperature.
Phenomena such as air pollution levels are of greatest interest when observations are large, but standard prediction methods are not specifically designed for large observations. We propose a method, ...rooted in extreme value theory, which approximates the conditional distribution of an unobserved component of a random vector given large observed values. Specifically, for Z = (Z₁, . . . , Z d ) T and Z -d = (Z₁, . . . , Z d-1 ) T , the method approximates the conditional distribution of Z d |Z -d = z -d when ║z -d ║ > r * . The approach is based on the assumption that Z is a multivariate regularly varying random vector of dimension d. The conditional distribution approximation relies on knowledge of the angular measure of Z, which provides explicit structure for dependence in the distribution's tail. As the method produces a predictive distribution rather than just a point predictor, one can answer any question posed about the quantity being predicted, and, in particular, one can assess how well the extreme behavior is represented. Using a fitted model for the angular measure, we apply our method to nitrogen dioxide measurements in metropolitan Washington DC. We obtain a predictive distribution for the air pollutant at a location given the air pollutant's measurements at four nearby locations and given that the norm of the vector of the observed measurements is large.
We consider parameter estimation for the spread of the Neolithic incipient farming across Europe using radiocarbon dates. We model the arrival time of farming at radiocarbon-dated, early Neolithic ...sites by a numerical solution to an advancing wavefront. We allow for (technical) uncertainty in the radiocarbon data, lack-of-fit of the deterministic model and use a Gaussian process to smooth spatial deviations from the model. Inference for the parameters in the wavefront model is complicated by the computational cost required to produce a single numerical solution. We therefore employ Gaussian process emulators for the arrival time of the advancing wavefront at each radiocarbon-dated site. We validate our model using predictive simulations.
We propose a method to merge several paleoclimate time series into one that exhibits a consensus on the features of the individual times series. The paleoclimate time series can be noisy, ...nonuniformly sampled and the dates at which the paleoclimate is reconstructed can have errors. Bayesian inference is used to model the various sources of uncertainty and smoothing of the posterior distribution of the consensus is used to capture its credible features in different time scales. The technique is demonstrated by analyzing a collection of six Holocene temperature reconstructions from Finnish Lapland based on various biological proxies. Although the paper focuses on paleoclimate time series, the proposed method can be applied in other contexts where one seeks to infer features that are jointly supported by an ensemble of irregularly sampled noisy time series.
Methods in forest canopy research Lowman, Margaret D; Schowalter, Timothy D; Franklin, Jerry F
2012., 20121124, 2012, 2012-11-26
eBook
Poised between soil and sky, forest canopies represent a critical point of exchange between the atmosphere and the earth, yet until recently, they remained a largely unexplored frontier. For a long ...time, problems with access and the lack of tools and methods suitable for monitoring these complex bioscapes made canopy analysis extremely difficult. Fortunately, canopy research has advanced dramatically in recent decades. Methods in Forest Canopy Research is a comprehensive overview of these developments for explorers of this astonishing environment. The authors describe methods for reaching the canopy and the best ways to measure how the canopy, atmosphere, and forest floor interact. They address how to replicate experiments in challenging environments and lay the groundwork for creating standardized measurements in the canopy—essential tools for for understanding our changing world.
In this paper we describe two bootstrap methods for massive data sets. Naive applications of common resampling methodology are often impractical for massive data sets due to computational burden and ...due to complex patterns of inhomogeneity. In contrast, the proposed methods exploit certain structural properties of a large class of massive data sets to break up the original problem into a set of simpler subproblems, solve each subproblem separately where the data exhibit approximate uniformity and where computational complexity can be reduced to a manageable level, and then combine the results through certain analytical considerations. The validity of the proposed methods is proved and their finite sample properties are studied through a moderately large simulation study. The methodology is illustrated with a real data example from Transportation Engineering, which motivated the development of the proposed methods.
Christ Sahinidou, Ioanna
The Ecumenical review,
December 2018, Volume:
70, Issue:
4
Journal Article
The model of God as creation’s ΟΙΚΟΣ or oikos opens up an ecological, panentheistic view of creation within God. God ‘εν’‐in whom the cosmos unfolds – echoes the trinitarian insight of relationality, ...immanent in God personalized in the oikonomia of creation. A holistic theology realizes that, together with all beings, we must live responsibly. This idea can evoke the religious sense that every being is valuable and that the whole forms a unity. No being can be known as inferior to another. A retrieved eco‐theological view of the scheme of things and our place in it can be a call to respect all life. To know the world neither anthropocentrically nor as isolated beings displaces humans as the central goal of creation and repositions them as partners in its process. New science helps us realize our cosmic interrelated being and a sense of the whole.
Investigation of children's knowledge of the Earth can reveal much about the origins, content and structure of scientific knowledge, and the processes of conceptual change and development. Vosniadou ...and Brewer (1992, claim that children construct coherent mental models of a flat, flattened, or hollow Earth based on a framework theory and intuitive constraints of flatness and support. To examine this account, 62 children, aged 5–10 years, and 31 adults ranked 16 pictures according to how well they were thought to represent the Earth. Even young children showed scientific knowledge of the shape of the Earth. There was little or no evidence of naïve mental models, indicating that any intuitions or constraints must be very weak. Instead, before they acquire the scientific view, children's knowledge of the Earth appears to be incoherent and fragmented.
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