3 research outputs found
A Follow-up Study of the 1962-66 Graduates Augustana Academy
The functions of the guidance program in today\u27s schools usually consist of five main services. They are: inventory, information, counseling, placement, and follow-up. This paper will center about the last of these services, namely, follow-up. The follow-up service is to education what the customer relations department is to merchandising by means of a continuing follow-up of former students, the educator learns of their .failures, problems, successes, and--most important--obtains their suggestions for improvement. The purpose of this investigation was to conduct a follow-up study of the 1962-66 graduates of Augustana Academy, Canton, South Dakota. Information concerning their evaluations of their former school, their opinions of it, and their_ present status were sought in this survey. At the present time, Augustana Academy is undergoing a retooling operation. With this in mind, it is necessary to evaluate the present curriculum and guidance services. The main purpose of this study was to aid in these revisions
Trace elements at the intersection of marine biological and geochemical evolution
Life requires a wide variety of bioessential trace elements to act as structural components and reactive centers in metalloenzymes. These requirements differ between organisms and have evolved over geological time, likely guided in some part by environmental conditions. Until recently, most of what was understood regarding trace element concentrations in the Precambrian oceans was inferred by extrapolation, geochemical modeling, and/or genomic studies. However, in the past decade, the increasing availability of trace element and isotopic data for sedimentary rocks of all ages has yielded new, and potentially more direct, insights into secular changes in seawater composition â and ultimately the evolution of the marine biosphere. Compiled records of many bioessential trace elements (including Ni, Mo, P, Zn, Co, Cr, Se, and I) provide new insight into how trace element abundance in Earth's ancient oceans may have been linked to biological evolution. Several of these trace elements display redox-sensitive behavior, while others are redox-sensitive but not bioessential (e.g., Cr, U). Their temporal trends in sedimentary archives provide useful constraints on changes in atmosphere-ocean redox conditions that are linked to biological evolution, for example, the activity of oxygen-producing, photosynthetic cyanobacteria. In this review, we summarize available Precambrian trace element proxy data, and discuss how temporal trends in the seawater concentrations of specific trace elements may be linked to the evolution of both simple and complex life. We also examine several biologically relevant and/or redox-sensitive trace elements that have yet to be fully examined in the sedimentary rock record (e.g., Cu, Cd, W) and suggest several directions for future studies