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.

Masting in animal-dispersed pines facilitates seed dispersal

Abstract: Masting increases the efficiency of wind pollination and satiates seed predators, but there is little evidence that masting facilitates seed dispersal by animals. Masting in pines was studied over three field seasons by simulating seed crops in synchrony (mast years, autumn 1998 and 1999) or out of synchrony (non-mast year, autumn 2000) with the local population. Rodents removed simulated wind-dispersed Jeffrey pine (Pinus jeffreyi) and sugar pine (Pinus lambertiana) seeds significantly more rapidly in mast years than in the non-mast year. Radioisotopes were used to follow the fates of individual pine seeds taken from three source trees. Rodents cached nearly all experimental seeds in mast and non-mast years, making 562 caches in 1998, 510 caches in 1999, and 1034 caches in 2000. Mean dispersal distances of seeds in primary caches were 5.9 and 4.6 m (28.6% and 22.1%) farther in the two mast years than in the non-mast year. Rodents often excavated cached seeds and moved them to new sites (secondary caching). During mast years, some seeds were found in as many as three cache sites, but during the non-mast year, the level of secondary caching approximately tripled, with some seeds being found in five or six separate cache sites. Large seed crops were associated with reduced secondary caching of seeds, reduced seed consumption, and greater seed survival in the following spring. Animal-mediated seed dispersal may be a selective force, along with predator satiation and increased efficiency of wind pollination, driving temporal variation in seed production in some large-seeded pines.

Magnet hospitals: Part II. Institutions of excellence.

Abstract: The oft repeated charge today is "focus on those who are succeeding!" That's what this report does. Using the eight characteristics identified by Peters and Waterman in their book In Search of Excellence (New York: Harper & Row, 1982), the study analyzes 16 magnet hospitals to ascertain to what extent they possessed characteristics similar to the best run companies in the corporate community. Analysis indicates many areas of strong correspondence. The authors suggest that these magnet hospitals may be dealing effectively with the nursing shortage by creating organizational conditions conducive to eliminating internal nurse shortage.

Accuracy of screening mammography interpretation by characteristics of radiologists.

Abstract: Background: Radiologists differ in their ability to interpret screening mammograms accurately. We investigated the relationship of radiologist characteristics to actual performance from 1996 to 2001. Methods: Screening mammograms (n 469 512) interpreted by 124 radiologists were linked to cancer outcome data. The radiologists completed a survey that included questions on demographics, malpractice concerns, years of experience interpreting mammograms, and the number of mammograms read annually. We used receiver operating characteristics (ROC) analysis to analyze variables associated with sensitivity, specificity, and the combination of the two, adjusting for patient variables that affect performance. All P values are two-sided. Results: Within 1 year of the mammogram, 2402 breast cancers were identified. Relative to low annual interpretive volume ( 2000] 1.89, 95% CI 1.36 to 2.63). Specificity decreased with volume (OR for 1001‐2000 0.65, 95% CI 0.52 to 0.83; OR for more than 2000 0.76, 95% CI 0.60 to 0.96), compared with 1000 or less (P .002). Greater number of years of experience interpreting mammograms was associated with lower sensitivity (P .001), but higher specificity (P .003). ROC analysis using the ordinal BI-RADS interpretation showed an association between accuracy and both previous mammographic history (P .012) and breast density (P<.001). No association was observed between accuracy and years interpreting mammograms (P .34) or mammography volume (P .94), after adjusting for variables that affect the threshold for calling a mammogram positive. Conclusions: We found no evidence that greater volume or experience at interpreting mammograms is associated with better performance. However, they may affect sensitivity and specificity, possibly by determining the threshold for calling a mammogram positive. Increasing volume requirements is unlikely to improve overall mammography performance. [J Natl Cancer Inst 2004;96: 1840‐50]