We compared five types of visual mast surveys with seed trap data from 105 white oaks (Quercus alba L.) during 1996-1997 in the Ouachita Mountains of Arkansas. We also evaluated these visual survey methods for their usefulness indetecting differences in acorn density among areas. Indices derived from all five methods were highly correlated with acorn densities derived from traps, and the Koenig...

Background and Aims: When conducting surveys with older adults, it is important that participants have clear comprehension of the questions being asked. It is also important that survey items can be administered efficiently. This paper investigates the effect of providing visual cues to aid participant understanding and speed of completion of three types of health surveys. Methods: Design Pilot...

A key issue facing any ROV or AUV-based benthic visual survey is how to point the camera normal to the terrain during the survey. Though planar terrain surveys can be executed using a constant camera orientation, non-planar terrain surveys require that the commanded camera orientation change during vehicle movement.. This paper proposes a method that generates a smooth camera orientation comman...

This paper addresses the problem of navigating a robotic vehicle over non-planar surfaces for the purpose of performing visual surveys. The key issue lies in generating a spatiallysmooth camera orientation command that will point the camera toward the surface during surface traversal. The proposed solution filters high spatial frequency local surface measurements using a low spatial frequency s...

Gorgona island, the major insular area in the Colombian Pacific Ocean, is characterized by a remarkably high biological and ecosystem diversity for this area of the world. Coral reefs are well developed and their fish communities have been described using conventional visual surveys. These methods, however, are known to be biased towards detecting larger and more mobile species, tending to igno...

Conservation strategies for long-lived vertebrates require accurate estimates of parameters relative to the populations' size, numbers of non-breeding individuals (the "cryptic" fraction of the population) and the age structure. Frequently, visual survey techniques are used to make these estimates but the accuracy of these approaches is questionable, mainly because of the existence of numerous ...

PURPOSE To assess vision-specific quality of life (QOL), based on abbreviated surveys derived from the National Eye Institute Visual Function Questionnaire (NEI-VFQ), in a cohort of United States women who participated in the Study of Osteoporotic Fractures. DESIGN Prospective, observational cohort study. METHODS Age-related macular degeneration (AMD) status, based on a 3-level classificati...