Cone in Cone Concretions of the Stanley Group in southeastern Oklahoma

Cone in cone concretions found in the Stanley Group of Southeastern Oklahoma have a variety of external and internal attributes which allow diagenetic and theoretical models of formation to be hypothesized. Stanley Group carbonate cone in cone concretions are initially formed in sulfur reducing horizons at shallow burial depths in a poorly circulated possibly deep trough containing siliceous sediments and organic matter. Collected concretions near the town of Smithville, Oklahoma displayed four different external morphologies and four variations of mineral constituents. All concretions contained microscopic cones which initiated diffusion and/or fluid patterns and is an early cementation process that directly altered the sediment compared to the surrounding deposits. The patterns initiated ultimately controlled and recorded diagenic alterations to mineral content and structure of the concretions. Concretion mineralogy consisted of microgranular calcite, twinned lamellae calcite and siliceous precipitates which dissolved carbonates from the inside out

Brazilian Consensus on Photoprotection

Brazil is a country of continental dimensions with a large heterogeneity of climates and massive mixing of the population. Almost the entire national territory is located between the Equator and the Tropic of Capricorn, and the Earth axial tilt to the south certainly makes Brazil one of the countries of the world with greater extent of land in proximity to the sun. The Brazilian coastline, where most of its population lives, is more than 8,500 km long. Due to geographic characteristics and cultural trends, Brazilians are among the peoples with the highest annual exposure to the sun. Epidemiological data show a continuing increase in the incidence of nonmelanoma and melanoma skin cancers. Photoprotection can be understood as a set of measures aimed at reducing sun exposure and at preventing the development of acute and chronic actinic damage. Due to the peculiarities of Brazilian territory and culture, it would not be advisable to replicate the concepts of photoprotection from other developed countries, places with completely different climates and populations. Thus the Brazilian Society of Dermatology has developed the Brazilian Consensus on Photoprotection, the first official document on photoprotection developed in Brazil for Brazilians, with recommendations on matters involving photoprotection

The Economic Value of Secure Water: Landowner Returns to Defining Groundwater Property Rights

Groundwater is a prime example of a common-pool resource subject to over-extraction and rent dissipation under open access. To avoid this, users can assign groundwater rights: a cap is set on the volume of groundwater that can be pumped annually, and rights are allocated among users. Although this process restricts pumping, it also improves long-term resource availability, grants a fungible asset that can be traded, and reduces uncertainty for urban developers. We investigate the effect on land values by exploiting a plausibly exogenous discontinuity in the definition of rights in the Mojave groundwater basin in California. Because both the long-term stream of agricultural rents and the value of tradable permits are capitalized into land value, spatial regression discontinuity designs identify the difference between the value of interior parcels with water rights and those of free riders on the exterior, who can drain from the regulated area with no restrictions. We find that the value of rights outweighs gains realized by free riders and that property rights increase land value by half. The large gains estimated here support the idea that the allocation of rights may be instrumental in convincing otherwise recalcitrant users to accept restrictions

Implementing SGMA Collectively: The Role of Bargaining and Markets

The paper outlines some of the collective action problems involved in implementing SGMA