Estimation of the mode of (hornblende-) biotite gneisses and amphibolites with the help of chemical analyses

A method is described to calculate the mineralogical composition of (hornblende-) biotite gneisses and amphibolites on the basis of (1) the chemical analysis of the rock, and (2) some information gained from the thin section, especially the An content of the plagioclase. In the calculations, hornblende and biotite of average chemical composition are used as norm minerals, and for rocks with such average hornblende and/or biotite the calculation gives a close approximation of the mode of the rock. For rocks in which the chemical composition of the hornblende and biotite deviates from the averages, errors result. These ‘random’ errors increase with the amounts of biotite and hornblende present. For rocks with up to approximately 15% biotite and/or hornblende the reliability of the results is as good as, or better than, normally obtained by point counting.     

Chemical contaminant exposure and effects in four fish species from Tampa Bay,Florida

Concentrations of selected anthropogenic chemical contaminants and levels of pollution-related biological effects were measured during three consecutive years (1990–1992) in hardhead catfish (Arius felis), Gulf killifish (Fundulus grandis), longnose killifish (F. majalis), and red drum (Scieaenops ocellatus) from 12 subtidal and intertidal sites in Tampa Bay and nearby Sarasota Bay. Each species was collected from at least four sites. Compared to nonindustrialized sites, concentrations of PCBs, DDTs, and alpha-chlordane in liver, and of fluorescent aromatic compounds in bile, were highest in fish from sites in or near Hillsborough Bay, the most industrialized portion of Tampa Bay. The results of analyses for two biochemical markers of contaminant-induced effects in fish, hepatic cytochrome P4501A activities and levels of hepatic DNA adducts, also showed the highest levels to be in all four fish species from sites in the vicinity of Hillsborough Bay. Liver lesions, considered to be pollution-associated in several other bottom-feeding fish species, were found in hardhead catfish and longnose killifish, exclusively from sites in Hillsborough Bay. Overall, concentrations of selected contaminants and their derivatives in the four target fish species generally reflected concentrations of these contaminants found in sediment. The biochemical and histopathological responses demonstrated that chemical contaminant concentrations in the vicinity of Hillsborough Bay are sufficiently high to cause adverse effects in indigenous fish species. The results, collectively, showed that the extent of contaminant exposure and biological effects in fish from sites in Tampa Bay were low to moderate compared to more urbanized coastal sites of the United States. *** DIRECT SUPPORT *** A01BY073 00009     

Self-organization maps (SOM) in the definition of a “transfer function” for a diatoms-based climate proxy

Climate Dynamics - This study utilizes self-organizing maps (SOM) —a particular type of artificial neural network (ANN) — as a nonlinear analysis tool for identifying species that can...     

From quiet to bold encroachment: contesting dispossession in Accra’s informal sector

This article draws on Asef Bayat’s theory of “quiet encroachment” to analyse the political agency of street hawkers and squatters in Accra, Ghana. It demonstrates how squatters and street hawkers in Ghana’s capital city are engaged in everyday practices of quiet encroachment, whereby they occupy urban space as a means to reproduce themselves. It then explores how encroachers take collective action to defend their access to urban space from state-led dispossession. In a context of competitive partisan politics where the management of urban space has become highly politicized, hawkers and squatters organizations have been empowered to seek active engagement and dialogue with the authorities. Whereas Bayat argues that the informal proletariat in authoritarian contexts desire autonomy and invisibility from the institutions of the state, therefore, the particular characteristics of Ghana’s multiparty system have created the possibility for bold acts of encroachment on urban space.     

National and Community Market Contributions of Wilderness

Wilderness attracts tourists and generates visitor spending in proximate communities as people enjoy Wilderness for outdoor recreation. Wilderness also attracts amenity migrants and out-of-region investments into surrounding regional economies. To investigate the amount and types of employment and income generated by Wilderness visitation, we conducted an economic contribution analysis of aggregate national visitor expenditures. The U.S. Forest Service National Visitor Use and Monitoring (NVUM) economic spending profiles were used to construct types and amounts of Wilderness visitor spending and were applied to an estimated 9.9 million annual visitors across federal agencies. IMPLAN modeling software was used to estimate total effects and multipliers for output, employment, income, and value added. Results show that some $500 million is annually spent in communities adjacent to Wilderness, generating a direct effect of 5,700 jobs and a total output effect over $700 million across numerous industries ($2012 including indirect and induced effects).