Introduced Wildlife of Oregon and Washington

Each species of wildlife occurs as part of an ecosystem, interacting in many ways with other plant and animal species in that system as well as with the abiotic components such as soil, air, water, and other substrates. The array of wildlife species around the globe has been shaped by geological and climatological events as well as by eons of evolution and natural selection. Species have come and gone and those remaining have, in most cases, co-evolved or co-adapted with many other species so that relatively stable, and often complex, relationships exist. Usually, a great many niches have been carved out and occupied, creating a distinct flora and fauna in each region of the globe that is maintained under conditions of relative stability over time. Natural disturbances (wind, fire) and large-scale events (volcanic eruptions, drought) may occasionally alter that stability and the relationships between species, but an overall homeostatis a return to the climatic community steady state usually prevails. These and other concepts of biogeography have been discussed in detail

Introduced Wildlife of Oregon and Washington

Each species of wildlife occurs as part of an ecosystem, interacting in many ways with other plant and animal species in that system as well as with the abiotic components such as soil, air, water, and other substrates. The array of wildlife species around the globe has been shaped by geological and climatological events as well as by eons of evolution and natural selection. Species have come and gone and those remaining have, in most cases, co-evolved or co-adapted with many other species so that relatively stable, and often complex, relationships exist. Usually, a great many niches have been carved out and occupied, creating a distinct flora and fauna in each region of the globe that is maintained under conditions of relative stability over time. Natural disturbances (wind, fire) and large-scale events (volcanic eruptions, drought) may occasionally alter that stability and the relationships between species, but an overall homeostatis a return to the climatic community steady state usually prevails. These and other concepts of biogeography have been discussed in detail

Convergence of the restricted Nelder-Mead algorithm in two dimensions

The Nelder-Mead algorithm, a longstanding direct search method for unconstrained optimization published in 1965, is designed to minimize a scalar-valued function f of n real variables using only function values, without any derivative information. Each Nelder-Mead iteration is associated with a nondegenerate simplex defined by n+1 vertices and their function values; a typical iteration produces a new simplex by replacing the worst vertex by a new point. Despite the method's widespread use, theoretical results have been limited: for strictly convex objective functions of one variable with bounded level sets, the algorithm always converges to the minimizer; for such functions of two variables, the diameter of the simplex converges to zero, but examples constructed by McKinnon show that the algorithm may converge to a nonminimizing point. This paper considers the restricted Nelder-Mead algorithm, a variant that does not allow expansion steps. In two dimensions we show that, for any nondegenerate starting simplex and any twice-continuously differentiable function with positive definite Hessian and bounded level sets, the algorithm always converges to the minimizer. The proof is based on treating the method as a discrete dynamical system, and relies on several techniques that are non-standard in convergence proofs for unconstrained optimization.Comment: 27 page

Geriatrics Attitudes and Knowledge Among Surgical and Medical Subspecialty House Officers

To examine geriatrics knowledge and attitudes of non-primary care house officers (HOs) before and after a multidisciplinary faculty development program. DESIGN : Serial cross-sectional surveys. PARTICIPANTS : HOs. SETTING : A large midwestern academic medical center. INTERVENTION : Faculty from seven surgical and six medical subspecialties participated in weekly seminars for 9 months and implemented geriatrics curricula in their HO programs. MEASUREMENTS : HO geriatrics attitudes and knowledge were measured using the University of California at Los Angeles Geriatrics Attitudes Scale (GAS; 14 items), two scales of the Maxwell Sullivan test (Therapeutic Potential and Time/Energy; six items each; lower scores denote more-favorable attitudes), and the Geriatrics Clinical Knowledge Assessment (20 multiple choice items; range 0–100%). Repeat surveys were administered in seven disciplines after geriatrics curriculum implementation. RESULTS : Baseline (n=175) geriatrics attitudes were favorable (e.g., 3.7 for GAS; 2.1 for Time/Energy), with more-favorable attitudes among medical subspecialty than surgical HOs (e.g., mean GAS 3.8 and 3.6, respectively; P =.001), and with advanced training. Mean baseline knowledge scores were 65.1% among all HOs. No differences in attitudes or knowledge were observed between the first (n=100) and second (n=90) cohorts in the seven disciplines that administered subsequent tests. CONCLUSION : Geriatrics attitudes of non-primary care HOs are positive, and knowledge is moderate, suggesting need for and potential effect of geriatrics curricula. Demonstrating effects on learner outcomes of faculty development programs may require more than one faculty member per discipline and measures that are curriculum-specific and detailed rather than general and brief.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66180/1/j.1532-5415.2007.01475.x.pd

Biotic homogenization or riparian refugia? Urban and wild land snail assemblages along a subtropical precipitation gradient

A noted impact of urbanization is the tendency for biotic homogenization, or the increase of similarity of geographically disparate communities. On the other hand, some urban habitats harbor biodiversity native to their region, a role potentially important in xeric landscapes, with irrigation increasing the coverage and availability of mesic habitats in an otherwise water-limited landscape. We assessed the relative importance of urban yards as agents of biotic homogenization or riparian refugia by characterizing community composition of Tamaulipan thornforest land snail assemblages across a pronounced precipitation gradient in far south Texas, USA. We quantified α- and β-diversity and assessed whether the land snail fauna of urban yards are more similar to each other across a precipitation gradient than they are to their wild counterparts, as well as determined the significance of moisture in driving Tamaulipan thornforest β-diversity, both in terms of turnover (changing species composition) and nestedness (species loss). Sites with both the wild and wet conditions had the highest values of species richness and abundance. Urban land snail communities were significantly homogenized, outweighing the influence of the precipitation gradient. We did not find urban yards served as a refuge for native, moisture-dependent, riparian snails. Our analyses find that turnover, not nestedness, is the largest contributor to β-diversity in these assemblages. Studies of urbanization should address regional spatial scales to quantify how urbanization modifies regional biodiversity arising from background environmental gradients. Such an approach could lead to improved understanding of how large metroplex areas could be used to maintain and even promote biodiversity

FOOD HABITS AND MANAGEMENT OF INTRODUCED RED FOX IN SOUTHERN CALIFORNIA

Introduced red fox in urban Orange County, California ate a wide variety of foods. Mammals and birds were consumed at all times of the year and both taxa appeared in approximately half or more of the fecal samples at all times of the year. Human supplied food remains were also common and supplemental feeding occurred at all study sites. Supplemental feeding has the potential to exacerbate problems for management of introduced red fox and several endangered species

Component-Level Electronic-Assembly Repair (CLEAR) Analysis of the Problem Reporting and Corrective Action (PRACA) Database of the International Space Station On-Orbit Electrical Systems

The NASA Constellation Program is investigating and developing technologies to support human exploration of the Moon and Mars. The Component-Level Electronic-Assembly Repair (CLEAR) task is part of the Supportability Project managed by the Exploration Technology Development Program. CLEAR is aimed at enabling a flight crew to diagnose and repair electronic circuits in space yet minimize logistics spares, equipment, and crew time and training. For insight into actual space repair needs, in early 2008 the project examined the operational experience of the International Space Station (ISS) program. CLEAR examined the ISS on-orbit Problem Reporting and Corrective Action database for electrical and electronic system problems. The ISS has higher than predicted reliability yet, as expected, it has persistent problems. A goal was to identify which on-orbit electrical problems could be resolved by a component-level replacement. A further goal was to identify problems that could benefit from the additional diagnostic and test capability that a component-level repair capability could provide. The study indicated that many problems stem from a small set of root causes that also represent distinct component problems. The study also determined that there are certain recurring problems where the current telemetry instrumentation and built-in tests are unable to completely resolve the problem. As a result, the root cause is listed as unknown. Overall, roughly 42 percent of on-orbit electrical problems on ISS could be addressed with a component-level repair. Furthermore, 63 percent of on-orbit electrical problems on ISS could benefit from additional external diagnostic and test capability. These results indicate that in situ component-level repair in combination with diagnostic and test capability can be expected to increase system availability and reduce logistics. The CLEAR approach can increase the flight crew s ability to act decisively to resolve problems while reducing dependency on Earth-supplied logistics for future Constellation Program missions