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Scholarly Works (8 results)

  • Thesis
  • Peer Reviewed
UC Santa Cruz Electronic Theses and Dissertations (2020)

Biodiversity and ecosystem function conservation face unprecedented challenges. Underfunding, incomplete policies, and backlogged assessments hinder conservation planning (Myers et al., 2000; James et al., 1999). In this dissertation, I seek to develop data-driven methods to inform strategic conservation of water and seabirds. Fresh water shortages threaten ecosystem function and human health (Georgakakos et al., 2014; Jiménez Cisneros et al., 2015). In Chapter 2, I addressed effective water conservation by consumers across the contiguous United States. I determined county-level water stress by relating annual water withdrawal to availability. I adjusted water stress by the potential savings from full adoption of common domestic water conservation actions, such as installing low-flow showerheads. I projected that, during a drought year, the majority of counties would remain water-stressed despite savings. Further, I identified the agriculture sector as the most common dominant water user, suggesting that meaningful consumer water savings should reduce dietary water use. Biodiversity loss is threatened with an average population decline of 68% for assessed species since 1970 (Almond et al., 2020). A foundational step in conservation is determining species’ relative extinction risk. In Chapter 3 I applied a metapopulation viability analysis (mPVA), engineered in partnership with the Conservation Action Lab and Tim Tinker, to 99 threatened seabird species. I indexed species by relative extinction risk and identified extremely threatened species. I compared the mPVA projections with IUCN Red List threat statuses to identify species that should be prioritized for reassessment and to inform resource allocations. After species have been targeted and prior to implementation, interventions should be evaluated for potential benefit. In Chapter 4 I used the mPVA to analyze the prescribed actions in New Zealand’s national recovery plan for 27 threatened seabird species. I simulated common conservation actions, such as translocation and invasive species removals, at the breeding population level and compared this to status quo scenarios. I found that the majority of species were not predicted to significantly benefit from prescribed interventions. This dissertation guides effective conservation planning by demonstrating means to assess current risk and project the benefits of conservation actions.

    Cover page: Strategic planning for biodiversity and ecosystem services: Assessing targets and actions in seabird and water conservation
    • Article
    • Peer Reviewed
    UC Santa Cruz Previously Published Works (2022)
    The seabird meta-population viability model (mPVA) uses a generalized approach to project abundance and quasi-extinction risk for 102 seabird species under various conservation scenarios. The mPVA is a stage-structured projection matrix that tracks abundance of multiple populations linked by dispersal, accounting for breeding island characteristics and spatial distribution. Data are derived from published studies, grey literature, and expert review (with over 500 contributions). Invasive species impacts were generalized to stage-specific vital rates by fitting a Bayesian state-space model to trend data from Islands where invasive removals had occurred, while accounting for characteristics of seabird biology, breeding islands and invasive species. Survival rates were estimated using a competing hazards formulation to account for impacts of multiple threats, while also allowing for environmental and demographic stochasticity, density dependence and parameter uncertainty.•The mPVA provides resource managers with a tool to quantitatively assess potential benefits of alternative management actions, for multiple species•The mPVA compares projected abundance and quasi-extinction risk under current conditions (no intervention) and various conservation scenarios, including removal of invasive species from specified breeding islands, translocation or reintroduction of individuals to an island of specified location and size, and at-sea mortality amelioration via reduction in annual at-sea deaths.
      Cover page: Seabird meta-Population Viability Model (mPVA) methods.
      • Article
      • Peer Reviewed
      UC Santa Cruz Previously Published Works (2020)
      Climate change is exacerbating drought and water stress in several global regions, including some parts of the United States. During times of drought in the U.S., municipal governments, private water suppliers and non-profits commonly deploy advocacy campaigns and incentive programs targeting reductions in residential water use through actions including: repairing leaks, shutting off taps, and installing new water-saving appliances. We asked whether these campaigns have the potential to alleviate water stress during drought at the county scale by estimating the potential impact of full adoption of such actions. In 2010, we show that the maximum potential use reductions from these residential actions may only alleviate water stress in 6% (174) of U.S. counties. The potential impact of domestic programs is limited by the relative dominance of agriculture water withdrawal, the primary water user in 50% of U.S. counties. While residential actions do achieve some water demand savings, they are not sufficient to alter water stress in the majority of the continental U.S. We recommend redirecting advocacy efforts and incentives to individual behaviors that can influence agricultural water use.
        Cover page: Turning off the tap: Common domestic water conservation actions insufficient to alleviate drought in the United States of America.
        • Article
        • Peer Reviewed
        UC San Diego Previously Published Works (2012)
        The mechanism of chronic rejection of transplanted human kidneys is unknown. An understanding of this process is important because, chronic rejection ultimately leads to loss of the kidney allograft in most transplants. One feature of chronic rejection is the infiltration of ectopic B-cell clusters that are clonal into the transplanted kidney. We now show that the antibodies produced by these B-cells react strongly with the core carbohydrate region of LPS. Since LPS is a costimulatory immunogen that can react with both the B-cell receptor (BCR) and the Toll-like receptor 4 (TLR4), these results suggest a mechanism for the selective pressure that leads to clonality of these B-cell clusters and opens the possibility that infection and the attendant exposure to LPS plays a role in the chronic rejection of human kidney transplants. If confirmed by clinical studies, these results suggest that treating patients with signs of chronic rejection with antibiotics may improve kidney allograft survival.
          Cover page: The costimulatory immunogen LPS induces the B-Cell clones that infiltrate transplanted human kidneys
          • Article
          • Peer Reviewed
          UC San Diego Previously Published Works (2016)
            Cover page: Correction for Grover et al., The costimulatory immunogen LPS induces the B-Cell clones that infiltrate transplanted human kidneys
            • Article
            • Peer Reviewed
            UC Santa Cruz Previously Published Works (2018)
              Cover page: Best practices: social research methods to inform biological conservationCreative Commons 'BY' version 4.0 license
              • Article
              • Peer Reviewed
              UC San Francisco Previously Published Works (2015)

              Background

              Few studies have systematically investigated the association between PARKIN genotype and psychiatric co-morbidities of Parkison's disease (PD). PARKIN-associated PD is characterized by severe nigral dopaminergic neuronal loss, a finding that may have implications for behaviors rooted in dopaminergic circuits such as obsessive-compulsive symptoms (OCS).

              Methods

              The Schedule of Compulsions and Obsessions Patient Inventory (SCOPI) was administered to 104 patients with early-onset PD and 257 asymptomatic first-degree relatives. Carriers of one and two PARKIN mutations were compared with noncarriers.

              Results

              Among patients, carriers scored lower than noncarriers in adjusted models (one-mutation: 13.9 point difference, P = 0.03; two-mutation: 24.1, P = 0.001), where lower scores indicate less OCS. Among asymptomatic relatives, a trend toward the opposite was seen: mutation carriers scored higher than noncarriers (one mutation, P = 0.05; two mutations, P = 0.13).

              Conclusions

              First, a significant association was found between PARKIN mutation status and obsessive-compulsive symptom level in both PD and asymptomatic patients, suggesting that OCS might represent an early non-motor dopamine-dependent feature. Second, irrespective of disease status, heterozygotes were significantly different from noncarriers, suggesting that PARKIN heterozygosity may contribute to phenotype. © 2014 International Parkinson and Movement Disorder Society.
                Cover page: The relationship between obsessive‐compulsive symptoms and PARKIN genotype: The CORE‐PD study
                • Article
                • Peer Reviewed
                UC San Francisco Previously Published Works (2014)

                Importance

                Data on the long-term cognitive outcomes of patients with PARKIN-associated Parkinson disease (PD) are unknown but may be useful when counseling these patients.

                Objective

                Among patients with early-onset PD of long duration, we assessed cognitive and motor performances, comparing homozygotes and compound heterozygotes who carry 2 PARKIN mutations with noncarriers.

                Design, setting, and participants

                Cross-sectional study of 44 participants at 17 different movement disorder centers who were in the Consortium on Risk for Early-Onset PD study with a duration of PD greater than the median duration (>14 years): 4 homozygotes and 17 compound heterozygotes (hereafter referred to as carriers) and 23 noncarriers.

                Main outcomes and measures

                Unified Parkinson Disease Rating Scale Part III (UPDRS-III) and Clinical Dementia Rating scores and neuropsychological performance. Linear regression models were applied to assess the association between PARKIN mutation status and cognitive domain scores and UPDRS-III scores. Models were adjusted for age, education, disease duration, language, and levodopa equivalent daily dose.

                Results

                Carriers had an earlier age at onset of PD (P < .001) and were younger (P = .004) at time of examination than noncarriers. They performed better than noncarriers on the Mini-Mental State Examination (P = .010) and were more likely to receive lower scores on the Clinical Dementia Rating (P = .003). In multivariate analyses, carriers performed better than noncarriers on the UPDRS-III (P = .02) and on tests of attention (P = .03), memory (P = .03), and visuospatial (P = .02) cognitive domains.

                Conclusions and relevance

                In cross-sectional analyses, carriers demonstrated better cognitive and motor performance than did noncarriers with long disease duration, suggesting slower disease progression. A longitudinal follow-up study is required to confirm these findings.
                  Cover page: Cognitive and Motor Function in Long-Duration PARKIN-Associated Parkinson Disease
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