Objectives: During the past decade, the number and proportion of reported HIV cases in the United States acquired through heterosexual contact has increased markedly. CDC employs the National HIV Behavioral Surveillance System (NHBS) to monitor risk behaviors and HIV prevalence in high-risk populations. To identify a target population for conducting NHBS among heterosexuals at increased risk for HIV (NHBS-HET), CDC designed, implemented and evaluated a pilot study.Methods:The pilot study was conducted in 25 US metropolitan statistical areas in 2006-7. We recruited men and women who reported sex with at least one opposite-sex partner during the past year for a behavioral survey and HIV test. We investigated the relationship between newly diagnosed HIV infection and individual risk behaviors, sexual network characteristics, and social-structural characteristics to arrive at a definition of a heterosexual at increased risk of HIV.Results:Of 14,750 participants in the analysis, 207 (1.4%) had newly diagnosed HIV infection. Using low socioeconomic status (SES) as a criterion for defining a heterosexual at increased risk for HIV resulted in optimal rates of HIV prevalence, specificity, sensitivity and practicality.Conclusions:Results from the NHBS pilot study underscore the key role of social factors as determinants of HIV infection risk among U.S. heterosexuals, and low SES was incorporated into the definition of a heterosexual at increased risk for HIV in NHBS-HET cycles. Future cycles of NHBS-HET will help tailor prevention programs for those populations most at risk of HIV in the US.

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Stratigraphic column of the Roan Group exposed in the Zambian part of the Central African Copperbelt showing the stratigraphic distribution of reduced-facies (argillite-hosted and mixed argillite-arenite) and sandstone (arenite-hosted

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Acronyms and Abbreviations UsedA.D. Anno Domini-a designation used to label or number years used with the Gregorian calendar AGI American Geosciences Institute Ar-Ar argon-argon ArcGIS Esri's ArcGIS is a geographic information system (GIS) for working with maps and geographic information ASCII American Standard Code for Information Interchange BOMZ black ore main zone C.M.N. Calcaire à Minerais Noiŕ-Kambove Dolomite CACB Central African Copperbelt CAMEC Central African Mining and Exploration Company CAMI Cadastre Minier Corp. corporation CSK Comite Special du Katanga D. Strat. Dolomites stratifies-stratified, fine grained dolomites DEM digital elevation model DRC Democratic Republic of the Congo EMINERS Economic Mineral Resource Simulator Esri A software development and services company providing geographic information system software and geodatabase management applications g/t grams per metric ton Gécamines La Générale des Carrières et des Mines-a state-owned mining company in the Democratic Republic of the Congo GIS geographic information system ID identifier Inc. incorporated km kilometer km 2 square kilometers kml keyhole markup language-an extensible markup language notation for expressing geographic annotation and visualization within Internet-based, twodimensional maps and three-dimensional Earthbrowsers KOV Kamoto-Oliveira-Virgule area Ltd limited m meter Ma million of years before the present M.Sc. Master of Science xi Acronyms and Abbreviations Used n.b. nonbrecciated NGOs non-governmental organizations NI 43-101 National Instrument 43-101-guidelines developed by the Canadian Securities Administration for preparation of technical reports that summarize scientific and technical information concerning mineral exploration, development and production activities on a mineral property that is material to an issuer Plc public limited company R.A.T. Roches Argilo-Talqueuses Subgroup-red, massive-to irregularly bedded, terrigenous and dolomitic rocks R.S.C. Roches Siliceuses Cellulaires-massive and generally stromatolitic dolomites R.S.F. Roches Siliceuses Feuilletées-siliceous, laminated dolomites RCM Roan Consolidated Mines Ltd Re-Os rhenium-osmium S.D. Shales Dolomitiques-dolomitic shales S.D.B. Schistes Dolomitiques De Base-basal dolomitic shales S.D.S. Schistes Dolomitiques Supérieures-upper dolomitic shales Sprl société privée à responsabilité limitée-private limited liability company TCL Tanganyika Concessions Ltd UMHK Union Minière du Haut Katanga U-Pb uranium-lead USGS United States Geological Survey VTEM versatile time domain electromagnetic WGS World Geodetic System ZCCM Zambia Consolidated Copper Mines ZCCM-IH ZCCM Investments Holdings Plc.