University of Nevada, Reno

About: University of Nevada, Reno is a education organization based out in Reno, Nevada, United States. It is known for research contribution in the topics: Population & Poison control. The organization has 13561 authors who have published 28217 publications receiving 882002 citations. The organization is also known as: University of Nevada & Nevada State University.

Lagged effects of experimental warming and doubled precipitation on annual and seasonal aboveground biomass production in a tallgrass prairie

Abstract: Global climate change is expected to result in a greater frequency of extreme weather, which can cause lag effects on aboveground net primary production (ANPP). However, our understanding of lag effects is limited. To explore lag effects following extreme weather, we applied four treatments (control, doubled precipitation, 41C warming, and warming plus doubled precipitation) for 1 year in a randomized block design and monitored changes in ecosystem processes for 3 years in an old-field tallgrass prairie in central Oklahoma. Biomass was estimated twice in the pretreatment year, and three times during the treatment and posttreatment years. Total plant biomass was increased by warming in spring of the treatment year and by doubled precipitation in summer. However, double precipitation suppressed fall production. During the following spring, biomass production was significantly suppressed in the formerly warmed plots 2 months after treatments ceased. Nine months after the end of treatments, fall production remained suppressed in double precipitation and warming plus double precipitation treatments. Also, the formerly warmed plots still had a significantly greater proportion of C4 plants, while the warmed plus double precipitation plots retained a high proportion of C3 plants. The lag effects of warming on biomass did not match the temporal patterns of soil nitrogen availability determined by plant root simulator probes, but coincided with warming-induced decreases in available soil moisture in the deepest layers of soil which recovered to the pretreatment pattern approximately 10 months after the treatments ceased. Analyzing the data with an ecosystem model showed that the lagged temporal patterns of effects of warming and precipitation on biomass can be fully explained by warming-induced differences in soil moisture. Thus, both the experimental results and modeling analysis indicate that water availability regulates lag effects of warming on biomass production.

The Effects of Engineering Modules on Student Learning in Middle School Science Classrooms

Abstract: The Teachers Integrating Engineering into Science (TIES) Program is a collaborative project among faculty from the College of Education and the College of Engineering at the University of Nevada, Reno. The TIES project paired university faculty with middle school science teachers to create three units that included engineering design using a variety of interactive learning activities in order to engage a wide range of students. The units included a Web-based simulation activity, lesson plans, a design project, and three types of assessments that were standardized across schools. Results of assessments were disaggregated by gender, ethnicity, special education, and socio-economic level. Mean scores for these student population groups were compared to mean scores for the same groups on the 2004 Nevada eighth grade science criterion referenced test. These results indicate that engaging students in engineering curriculum activities may diminish achievement gaps in science for some student populations.

Improved outcome with early fixation of skeletally unstable pelvic fractures

Abstract: Thirty-seven consecutive patients with unstable pelvic fractures were divided into two groups: Group 1 (July 1981 to December 1984; n = 18), when early fixation was not routinely used, and Group 2 (January 1985 to March 1988; n = 19), when early fixation was performed unless contraindicated. Hospital stay decreased by 37.8% in Group 2 (p = 0.04). Of Group 1 patients, 60% were disabled for at least 6 months versus 15.7% in Group 2 (p = 0.001), and 45% were discharged to a rehabilitation facility versus 26.4% in Group 2. Group 1 had more complications, 1.3 per patient, versus 1.0. Patients in Group 2 (undergoing early fixation) required 27.2% fewer units of blood than those in Group 1 in whom fracture surgery was delayed. Survival was better in Group 2, 100% versus 83.3% (p = 0.06). Early pelvic fracture fixation reduces hospital stay, long-term disability, and may result in fewer complications, decreased blood loss, and better survival.

An Improved RNA Isolation Method for Succulent Plant Species Rich in Polyphenols and Polysaccharides

Abstract: Isolation of high quality, high molecular weight RNA from plant tissues is complicated by high levels of polyphenols and polysaccharides which bind to and/or co-precipitate with RNA. Using high molecular weight polyethylene glycol (HMW-PEG), RNA was successfully isolated from plant species in which other RNA extraction methods and commercially available kits failed to deliver suitable results. We tested various buffer systems and isolation conditions with and without PEG or PVP (polyvinylpyrrolidone) using tissue from species ofAloe, Ananas, Clusia, Euphorbia, Kalanchoe, Opuntia, andPyrrosia, all of which contain high amounts of phenolic compounds and/or polysaccharides. HMW-PEG was found to be more effective than PVP in removing these compounds. RNA extraction using HMW-PEG resulted in RNA of high quality from all species investigated, as indicated by UV light absorption profiles, and also yielded PCR amplification products after reverse transcription.