5 resultados para Rock-fall
em DigitalCommons@University of Nebraska - Lincoln
Resumo:
If readers of Great Plains Research are seeking a window on rock art research in North America, this book provides a few clear panes, a few that are hazy, and a few muddy ones. Like many edited volumes, the weaker contributions and lack of a consistent style limit the book's usefulness. Some authors target a general readership; others clearly are addressing colleagues. The book has two stated themes: the history of rock art research in North America and recent approaches to rock art analysis. Articles by Julie Francis and (jointly) David Whitley and Jean Clottes explore why rock art research has long been marginalized in North America. Unfortunately, both of these otherwise observant essays slip into advocacy of shamanism as a unifying or primary explanation for rock art, an interpretive model by no means universally accepted by today's rock art specialists.
Resumo:
I am so pleased to have this opportunity to speak with you today. There is something about the beginning of a semester that always strikes me as hopeful and exciting, and it is a treat to share in hopeful times just as we have shared in the very difficult economic times the Institute, the university, and our state have experienced in the past two years. We have dealt with budget crises and made some tremendously difficult decisions that are felt personally, as well as professionally. We know it often seems that "bad news" grabs the headlines, yet a tremendous number of good things have happened in the past year, as well, thanks to the talent, enthusiasm, and the professionalism of our faculty, staff, and students.
Resumo:
I thought about beginning my time with you this afternoon by asking each of you to turn to the person on your left, shake that person's hand, and say congratulations and thank you. Then I was going to ask you to turn to the person on your right, shake hands, and say congratulations and thank you.
Resumo:
First off, thank you. Thank you for the work you do each day on behalf of the University and for Nebraska. Thank you for the expertise and the passion you bring to your work, for the belief you have in it, and for the dedication you show.
Resumo:
White Rock Lake reservoir in Dallas, Texas contains a 150-cm sediment record of silty clay that documents land-use changes since its construction in 1912. Pollen analysis corroborates historical evidence that between 1912 and 1950 the watershed was primarily agricultural. Land disturbance by plowing coupled with strong and variable spring precipitation caused large amounts of sediment to enter the lake during this period. Diatoms were not preserved at this time probably because of low productivity compared to diatom dissolution by warm, alkaline water prior to burial in the sediments. After 1956, the watershed became progressively urbanized. Erosion decreased, land stabilized, and pollen of riparian trees increased as the lake water became somewhat less turbid. By 1986 the sediment record indicates that diatom productivity had increased beyond rates of diatom destruction. Neither increased nutrients nor reduced pesticides can account for increased diatom productivity, but grain size studies imply that before 1986 diatoms were light limited by high levels of turbidity. This study documents how reservoirs may relate to land-use practices and how watershed management could extend reservoir life and improve water quality.