[1] In recent decades, the diatom Didymosphenia geminata has emerged as nuisance species in river systems around the world. This periphytic alga forms large "blooms" in temperate streams, presenting a counterintuitive result: the blooms occur primarily in oligotrophic streams and rivers, where phosphorus (P) availability typically limits primary production. The goal of this study is to examine how high algal biomass is formed under low P conditions. We reveal a biogeochemical process by which D. geminata mats concentrate P from flowing waters. First, the mucopolysaccaride stalks of D. geminata adsorb both iron (Fe) and P. Second, enzymatic and bacterial processes interact with Fe to increase the biological availability of P. We propose that a positive feedback between total stalk biomass and high growth rate is created, which results in abundant P for cell division. The affinity of stalks for Fe in association with ironphosphorus biogeochemistry suggest a resolution to the paradox of algal blooms in oliogotrophic streams and rivers.

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Ninety‐one sediment oxygen demand (SOD) samples from six designated sites along the stretch of Lower Rapid Creek, South Dakota, were conducted using an in‐situ SOD chamber. Inside the chamber, readings of dissolved oxygen (DO), water temperature, pH, and specific conductance were recorded every minute for more than one hour using the Datasonde 3 Hydrolab. Initial readings of such parameters were recorded for the overlaying water before the deployment of the SOD chamber. Characteristics of the stream conditions, air temperature, barometric pressure, average flow velocity of the stream, depth of the stream, and the flow velocity by the chamber were recorded. Single and multiple linear regression analyses on all parameters indicated that the velocity of the stream is the least critical parameter for SOD in shallow streams.

Dry deposition samples were collected from 28 residential rooftops in Fuhais, Jordan, during the dry seasons of the year 2004. The samples were analyzed for trace and heavy metal concentrations to investigate the impact of total suspended particles emitted from the cement industry in the city of Fuhais. The cement factory has been operational for the past 50 years, and the management was evaluating the use of petcoke blending to reduce fuel costs. No baseline data on heavy metals due to the current operations existed prior to this study. The present study showed that lead (Pb) and copper (Cu) concentrations were statistically significant in the northwest sector of the city compared with the other quadrants. This significance was attributed to the heavy traffic of trucks carrying raw materials and cement in and out of the cement factory as the main route of transportation to the factory runs through this quadrant of the city. Cadmium (Cd), aluminum (Al), iron (Fe), zinc (Zn), manganese (Mn), nickel (Ni), molybdenum (Mo), and chromium (Cr) concentrations were high in all sampled areas. The overall average concentrations of all elements except Mo were found to be higher on the rooftops of the residential areas in Fuhais City in comparison with a remote reference site near Amman where no anthropogenic activity exists. The trace and heavy metal concentrations and the mineralogical composition of dry deposition samples collected from residential rooftops are representative of the current cement industry operations, which dominate the air quality of Fuhais City.

We present modern-day uses of traditionally used wild fruits among the Lakota on Rosebud Reservation as determined from interviews conducted in 2012. We quantify modern-day uses of wild fruits for food, beverages, tonics, medicines (physical and/or spiritual), and crafts. Use of buffaloberries, buffalo currants, chokecherries, riverbank grapes, plums, rosehips, and other plant parts remain as customs among the Lakota although the knowledge and practice of using wild fruits may be waning. Many interviewees implied that traditional uses of wild fruits could help sustain cultural identity.