Measuring event concentration in empirical networks with different types of degree distributions.

Measuring event concentration often involves identifying clusters of events at various scales of resolution and across different regions. In the context of a city, for example, clusters may be characterized by the proximity of events in the metric space. However, events may also occur over urban structures such as public transportation and infrastructure systems, which are naturally represented as networks. Our work provides a theoretical framework to determine whether events distributed over a set of interconnected nodes are concentrated on a particular subset. Our main analysis shows how the proposed or any other measure of event concentration on a network must explicitly take into account its degree distribution. We apply the framework to measure event concentration (i) on a street network (i.e., approximated as a regular network where events represent criminal activities); and (ii) on a social network (i.e., a power law network where events represent users who are dissatisfied after purchasing the same product).

Planetary health in the Anthropocene.

The idea that the Holocene is over and a new human-dominated geological epoch, the Anthropocene, is in progress has been widely discussed. The article aims to outline the published definitions and current patterns on the Anthropocene, highlighting an agenda of emerging risks, challenges and possibilities for the health of the world's population in this new era. We performed a review on the complexities of planetary health in the Anthropocene, which generated 42 initial references for full-text reading; we selected 25 of them and carried out analysis and interpretation. Anthropogenic activities have increasing impacts on the environment and a fundamental change in the relationship between humans and the terrestrial system, in many ways that exert intentional and unintentional influences on natural and social processes. The burgeoning literature on health promotion and global public health talks about the anthropogenic forces, claiming a solid critical theory of action to confront, modify and reduce the deleterious effects of such forces. For that reason, the 23rd IUHPE World Conference on Health Promotion, scheduled to be held in New Zealand in 2019, emphasizes the theme 'Promoting Planetary Health and Sustainable Development for All'. It recognizes that the current paradigm of economic unlimited growth and exploitation of limited natural resources is unfair and unsustainable, leading to geopopulational and temporal inequities between generations.

Optimization of roadway layout in ultra-close coal seams: A case study.

Most coal mines in China are currently mining close coal seams. Roadways in close coal seams, especially ultra-close coal seams, confronted difficulties in maintaining, including large deformation of the roadway, roof caving, rib spalling and floor heaving. This is mainly caused by the complicated stress and geological conditions, shattered roof, improper layout and support. To explore the issues mentioned above, the theoretical analysis was used to build a mechanical model and study the stress distribution under coal pillars, and FLAC3D modelling was adopted to build numerical models with different staggered distances. The optimal roadway layout was brought forward combining the result of numerical simulation and coal recovery rate. The field practice was carried out in the tailgate of panel 25301 to investigate the effect of the layout scheme. The results of field monitoring show that the roadway's stability is well maintained in the mining process.

The Anthropocene concept in ecology and conservation.

The term 'Anthropocene' was first used in the year 2000 to refer to the current time period in which human impacts are at least as important as natural processes. It is currently being considered as a potential geological epoch, following on from the Holocene. While most environmental scientists accept that many key environmental parameters are now outside their Holocene ranges, there is no agreement on when the Anthropocene started, with plausible dates ranging from the Late Pleistocene megafaunal extinctions to the recent globalization of industrial impacts. In ecology, the Anthropocene concept has focused attention on human-dominated habitats and novel ecosystems, while in conservation biology it has sparked a divisive debate on the continued relevance of the traditional biocentric aims.

Contaminant geochemistry--a new perspective.

To date, the field of contaminant geochemistry--which deals with the study of chemical interactions in soil and aquifer environments--has focused mainly on pollutant toxicity, retention, persistence, and transport and/or on remediation of contaminated sites. Alteration of subsurface physicochemical properties by anthropogenic chemicals, which reach the land surface as a result of human activity, has been essentially neglected. Contaminant-induced changes in subsurface properties are usually considered as deviations from a normal geological environment, which will disappear under natural attenuation or following remediation procedures. However, contaminants may in many cases cause irreversible changes in both structure and properties of the soil-subsurface geosystem between the land surface and groundwater. The time scales associated with these changes are on a "human time scale", far shorter than geological scales relevant for geochemical processes. In this review, we draw attention to a new perspective of contaminant geochemistry, namely, irreversible changes in the subsurface as a result of anthropogenic chemical pollution. We begin by briefly reviewing processes governing contaminant-subsurface interactions. We then survey how chemical contamination causes irreversible changes in subsurface structure and properties. The magnitude of the anthropogenic impact on the soil and subsurface is linked directly to the amounts of chemical contaminants applied and/or disposed of on the land surface. This particular aspect is of major importance when examining the effects of humans on global environmental changes. Consideration of these phenomena opens new perspectives for the field of contaminant geochemistry and for research of human impacts on the soil and subsurface regimes.

Geophysics and nutritional science: toward a novel, unified paradigm.

This article discusses a few basic geophysical processes, which collectively indicate that several nutritionally adverse elements of current Western diets also yield environmentally harmful food consumption patterns. We address oceanic dead zones, which are at the confluence of oceanography, aquatic chemistry, and agronomy and which are a clear environmental problem, and agriculture's effects on the surface heat budget. These exemplify the unknown, complex, and sometimes unexpected large-scale environmental effects of agriculture. We delineate the significant alignment in purpose between nutritional and environmental sciences. We identify red meat, and to a lesser extent the broader animal-based portion of the diet, as having the greatest environmental effect, with clear nutritional parallels.

Towards the development of a multidisciplinary understanding of the effects of toxic chemical mixtures on health.

Mixtures can be divided into simple (chemicals with comparable properties--health risk assessments on the chemicals) and complex, which can be further subdivided into defined (a reasonably distinct composition, created at a specific time and place despite dissimilar components--risk assessments on the common source) and coincidental (chemicals without similar properties or constant composition in time or space-risk assessments on the receptor). Interactions recognized are: independent action, dose addition (additivity), and potentiation (synergy and antagonism). Unpredicted outcomes need recognition. New approaches in higher education and multidisciplinary investigations are essential. The community of the Society for Environmental Geochemistry and Health should help clarify points such as when transformations in mixtures may become important enough to alter the classification and the risk assessment. The multidisciplinary community is also well placed to support the integration of non-chemical influences into mixture analysis and to contribute to the investigation of cumulative and multiple exposures.

A religion for Darwinians?

A review of Philip Kitcher's book, Living with Darwinism: evolution, design, and the future of faith.