How Much Lox Is a Grizzly Bear Worth?

Using grizzly bears as surrogates for “salmon ecosystem” function, the authors develop a generalizable ecosystem-based management framework that enables decision makers to quantify ecosystem-harvest tradeoffs between wild and human recipients of natural resources like fish

Examining Soil Based Construction Materials through X-Ray Computed Tomography

X-ray computed tomography (XRCT) enables the non-destructive analysis of samples internal structures down to a sub-micron resolution and has been used to examine the macrostructure of unstabilized soil based construction materials (SBCMs) alongside experiments on the materials unconfined compressive strength. SBCMs are manufactured mixtures of clay, sand and gravel which should be considered as highly unsaturated compacted soil where suction is the key source of strength. The use of XRCT in geotechnical literature is comprehensively reviewed before three laboratory investigations are described. Firstly crack propagation in SBCMs following unconfined compression is investigated and key lessons about XRCT scanning highlighted. Secondly the impact of altering sample size to match optimum XRCT scanning conditions is explored through experiments on void size distribution and unconfined compressive strength. Finally the effects of adding expansive clay to SBCM mixes on macrostructure are investigated and insights on how the unconfined compressive strength develops as SBCM dries are given. Conclusions from this thesis have applicability to both the SBCM industry, as the insights into the fundamental behaviour of SBCM can be used to inform building practice, and geotechnical researchers where the extensive use and development of XRCT can be applied to investigate the internal structure of a wide range of geotechnical materials

Using Nonhydrostatic XBeach to Simulate Wave Transformations in Fringing Reef Environments

M.S

Disturbance alters beta-diversity but not the relative importance of community assembly mechanisms

Ecological disturbances are often hypothesized to alter community assembly processes that influence variation in community composition (β-diversity). Disturbance can cause convergence in community composition (low β-diversity) by increasing niche selection of disturbance-tolerant species. Alternatively, disturbance can cause divergence in community composition (high β-diversity) by increasing habitat filtering across environmental gradients. However, because disturbance may also influence β-diversity through random sampling effects owing to changes in the number of individuals in local communities (community size) or abundances in the regional species pool, observed patterns of β-diversity alone cannot be used to unambiguously discern the relative importance of community assembly mechanisms. We compared β-diversity of woody plants and inferred assembly mechanisms among unburned forests and forests managed with prescribed fires in the Missouri Ozarks, USA. Using a null-model approach, we compared how environmental gradients influenced β-diversity after controlling for differences in local community size and regional species abundances between unburned and burned landscapes. Observed β-diversity was higher in burned landscapes. However, this pattern disappeared or reversed after controlling for smaller community size in burned landscapes. β-diversity was higher than expected by chance in both landscapes, indicating an important role for processes that create clumped species distributions. Moreover, fire appeared to decrease clumping of species at broader spatial scales, suggesting homogenization of community composition through niche selection of disturbance-tolerant species. Environmental variables, however, explained similar amounts of variation in β-diversity in both landscapes, suggesting that disturbance did not alter the relative importance of habitat filtering. Our results indicate that contingent responses of communities to fire reflect a combination of fire-induced changes in local community size and scale-dependent effects of fire on species clumping across landscapes. Synthesis. Although niche-based mechanisms of community assembly are often invoked to explain changes in community composition following disturbance, our results suggest that these changes also arise through random sampling effects owing to the influence of disturbance on community size. Comparative studies of these processes across disturbed ecosystems will provide important insights into the ecological conditions that determine when disturbance alters the interplay of deterministic and stochastic processes in natural and human-modified landscapes

Rare plant stabilization projects at Hawai`i Volcanoes National Park, 1998-2008

Reports were scanned in black and white at a resolution of 600 dots per inch and were converted to text using Adobe Paper Capture Plug-in.Approximately 15% of the native vascular plant flora of Hawai`i Volcanoes National Park (HAVO) is listed by the US Fish and Wildlife Service (USFWS) as endangered, threatened, candidate endangered, or species of concern. Another 15% is considered to be rare in HAVO by park botanists. Restoration actions including alien ungulate and invasive plant control are underway in many areas of the park, and common native vegetation is noticeably recovering in some areas. However, rare plant surveys in the 1990’s indicated that little recovery of rare plant species populations was occurring in spite of partial recovery of park ecosystems. This is understandable in that rare plant research in the park indicates that rare plants in recovering ecosystems are limited by rodents, slugs, loss of pollinators, small population size, and other factors not affected by landscape-level restoration. From 1998-2008, HAVO implemented a program of 10 projects to stabilize populations of 42 of the 62 species in HAVO listed by the USFWS, 12 species not listed but rare throughout the park, and seven species rare in one of the seven ecosystems targeted for rare plant species stabilization. An additional 26 uncommon and common species were outplanted in conjunction with rare plant stabilization, largely for the purpose of restoring plant communities or plant community diversity. Stabilization through augmentation and reintroduction involves establishing enough individuals and small populations to maintain species until recovery efforts could be formulated and implemented. Stabilization was carried out by greenhouse propagation and outplanting with the goal of meeting the Hawai`i/Pacific Plant Restoration Coordinating Committee (HPPRCC) standards of three populations of 25 reproductive individuals per population for long-lived perennials or 50 individuals per population of short-lived perennials. Seed additions were used in three sites. Plantings were placed in 31 locations across seven ecosystems of the park including coastal strand, lowland dry-mesic forest, mid-elevation woodland, montane rain forest, montane mesic forest, upper montane, and subalpine. Plantings were monitored for growth, vigor, and the presence of flowers or fruits, typically one of more times for 1-4 years; all plantings except those in the montane mesic forest were monitored in 2009 or 2010, after 6-12 years

A synthesis of plant invasion effects on biodiversity across spatial scales

PREMISE OF THE STUDY: Invasive plant species are typically thought to pose a large threat to native biodiversity, and local-scale studies typically confirm this view. However, plant invaders rarely cause regional extirpations or global extinctions, causing some to suggest that invasive species\u27 influence on native biodiversity may not be so dire. We aim to synthesize the seemingly conflicting literature in plant invasion biology by evaluating the effects of invasive plant species across spatial scales. METHODS: We first conducted a meta-analysis on the effects of invasive plants on the species richness of invaded communities across a range of spatial extents. We then discuss studies that consider the role of invasive plants on regional spatial scales for which such meta-analyses are not possible. Finally, we develop a conceptual framework to synthesize the influence of invasive species across spatial scales by explicitly recognizing how invasive species alter species-occupancy distributions. KEY RESULTS: We found a negative relationship between the spatial extent of the study and the effect size of invasive plants on species richness. Our simulation models suggest that this result can occur if invaders, either proportionately or disproportionately, reduce the occupancy of common species to a greater degree than rare species. CONCLUSIONS: Future studies should consider the influence of invaders on the abundance and occupancy-level changes in native species to inform how invasive plants will influence native species richness relationships across spatial scales. This approach will allow greater predictive ability for forecasting changes in biodiversity in the face of anthropogenic biological invasions and will inform invasive species management and restoration

Improving law enforcement daily deployment through machine learning-informed optimization under uncertainty

National Research Foundation (NRF) Singapore under Corp Lab @ University scheme; Fujitsu Lt

Cognitive processes that indirectly affect olfactory dysfunction in Parkinson\u27s disease

Introduction Accurate early diagnosis of Parkinson\u27s disease is hampered by its long prodromal period and the variable manifestations of its motor symptoms. While olfactory dysfunction can occur before motor-symptom onset and serve as a non-disease-specific diagnostic aid, its underlying causes are incompletely understood. Methods Correlation analyses, univariate density estimates, ANOVA and regression evaluated relationships between scores on the Montreal Cognitive Assessment and Hopkins Verbal Learning Test and those on the University of Pennsylvania Smell Identification Test in 1280 Parkinson\u27s Progression Markers Initiative subjects placed into five diagnostic categories. Structural equation modeling identified cognitive measures having significant indirect effects on olfactory-function-test scores. Results Global cognition, verbal learning and memory, attention, delayed-recall, and visuospatial/executive function scores show weak-to-moderate, significant associations with olfactory-function-test scores. Associations are stronger in symptomatic than asymptomatic subjects having mutations in LRRK2, GBA or SNCA. Score distributions are nonuniform across diagnostic categories. Linear regression found that all cognitive measures except attention predicted olfactory-function-test scores. Three structural equation models assessing indirect effects of verbal learning/memory with either global cognition, visuospatial/executive function, or delayed-recall had a good statistical fit to the data. Only verbal learning/memory scores significantly help explain olfactory-function-test scores in all symptomatic diagnostic categories (−0.56 \u3c b \u3c −0.23, 0.001 \u3c P \u3c .005). Visuospatial/executive-function test scores help explain olfactory-function-test scores in both genetic Parkinson\u27s disease diagnostic categories (−0.25 \u3c b \u3c −0.17, 0.032 \u3c P \u3c .033). Conclusion Impaired verbal learning/memory and visuospatial/executive function contributes to lower performance on olfactory function tests in Parkinson\u27s disease. As both of these domains impact decision-making, decision-making in turn may impact olfactory assessment in Parkinson\u27s disease

All together now : limitations and recommendations for the simultaneous analysis of all eukaryotic soil sequences

The soil environment contains a large, but historically underexplored, reservoir of biodiversity. Sequencing prokaryotic marker genes has become commonplace for the discovery and characterization of soil bacteria and archaea. Increasingly, this approach is also applied to eukaryotic marker genes to characterize the diversity and distribution of soil eukaryotes. However, understanding the properties and limitations of eukaryotic marker sequences is essential for correctly analysing, interpreting, and synthesizing the resulting data. Here, we illustrate several biases from sequencing data that affect measurements of biodiversity that arise from variation in morphology, taxonomy and phylogeny between organisms, as well as from sampling designs. We recommend analytical approaches to overcome these limitations, and outline how the benchmarking and standardization of sequencing protocols may improve the comparability of the data