The ecology of host-parasitoid-pathogen interactions in natural lepidopteran populations

Understanding population dynamics and the biotic and abiotic processes that drive and influence them is one the most fundamental issues in ecology, and is vital for successful ecological management of populations in the face of global environmental change. Species interactions influence population processes, and natural enemies in particular can have important impacts on vital rates, and are thought to be capable of population regulation. This thesis investigated the host-natural enemy interactions and spatio-temporal dynamics of two Lepidoptera-parasitoid-pathogen communities, which were used as model systems in which to explore these issues. Using multi-year field data, potentially regulatory delayed density-dependent pathogen mortality was demonstrated in both the cyclical Operophtera brumata, but also unexpectedly in the non-cyclical Abraxas grossulariata. In addition, there was evidence that increasing temperature-related climatic conditions negatively influenced the interactions of O. brumata and its pathogen. Immune functioning was investigated in wild populations of the non-cyclical A. grossulariata, and unexpectedly found to be influenced by population density. Evidence consistent with trans-generational immune costs from defence against parasitism were also found. Scale-dependent effects of habitat fragmentation were investigated in the A. grossulariata-natural enemy community, and were found to have direct negative effects on host density at both small and large spatial scales, indirect negative effects on virus mortality at the largest scale, and, unexpectedly, direct positive effects on parasitism at small and medium scales. Finally, it was found that spatial population synchrony in O. brumata at the scale of Britain may be due to spatially correlated environmental processes, but that unlike O. brumata populations within mainland Europe there was no evidence for travelling waves in abundance within British populations, either driven by the mainland European travelling waves or occurring separately. The significance of these findings is discussed in the context of current research, and potential areas for future research are also addressed

Cyclic strain upregulates VEGF and attenuates proliferation of vascular smooth muscle cells

OBJECTIVE:Vascular smooth muscle cell (VSMC) hypertrophy and proliferation occur in response to strain-induced local and systemic inflammatory cytokines and growth factors which may contribute to hypertension, atherosclerosis, and restenosis. We hypothesize VSMC strain, modeling normotensive arterial pressure waveforms in vitro, results in attenuated proliferative and increased hypertrophic responses 48 hrs post-strain.METHODS:Using Flexcell Bioflex Systems we determined the morphological, hyperplastic and hypertrophic responses of non-strained and biomechanically strained cultured rat A7R5 VSMC. We measured secretion of nitric oxide, key cytokine/growth factors and intracellular mediators involved in VSMC proliferation via fluorescence spectroscopy and protein microarrays. We also investigated the potential roles of VEGF on VSMC strain-induced proliferation.RESULTS:Protein microarrays revealed significant increases in VEGF secretion in response to 18 hours mechanical strain, a result that ELISA data corroborated. Apoptosis-inducing nitric oxide (NO) levels also increased 43% 48 hrs post-strain. Non-strained cells incubated with exogenous VEGF did not reproduce the antimitogenic effect. However, anti-VEGF reversed the antimitogenic effect of mechanical strain. Antibody microarrays of strained VSMC lysates revealed MEK1, MEK2, phospo-MEK1T385, T291, T298, phospho-Erk1/2T202+Y204/T185+T187, and PKC isoforms expression were universally increased, suggesting a proliferative/inflammatory signaling state. Conversely, VSMC strain decreased expression levels of Cdk1, Cdk2, Cdk4, and Cdk6 by 25-50% suggesting a partially inhibited proliferative signaling cascade.CONCLUSIONS:Subjecting VSMC to cyclic biomechanical strain in vitro promotes cell hypertrophy while attenuating cellular proliferation. We also report an upregulation of MEK and ERK activation suggestive of a proliferative phenotype. Hhowever, the proliferative response appears to be aborogated by enhanced antimitogenic cytokine VEGF, NO secretion and downregulation of Cdk expression. Although exogenous VEGF alone is not sufficient to promote the quiescent VSMC phenotype, we provide evidence suggesting that strain is a necessary component to induce VSMC response to the antimitogenic effects of VEGF. Taken together these data indicate that VEGF plays a critical role in mechanical strain-induced VSMC proliferation and vessel wall remodeling. Whether VEGF and/or NO inhibit signaling distal to Erk 1/2 is currently under investigation.This item is part of the UA Faculty Publications collection. For more information this item or other items in the UA Campus Repository, contact the University of Arizona Libraries at [email protected]

Addressing unintentional exclusion of vulnerable and mobile households in traditional surveys in Kathmandu, Dhaka and Hanoi : a mixed methods feasibility study

The methods used in low- and middle-income countries’ (LMICs) household surveys have not changed in four decades; however, LMIC societies have changed substantially and now face unprecedented rates of urbanization and urbanization of poverty. This mismatch may result in unintentional exclusion of vulnerable and mobile urban populations. We compare three survey method innovations with standard survey methods in Kathmandu, Dhaka, and Hanoi and summarize feasibility of our innovative methods in terms of time, cost, skill requirements, and experiences. We used descriptive statistics and regression techniques to compare respondent characteristics in samples drawn with innovative versus standard survey designs and household definitions, adjusting for sample probability weights and clustering. Feasibility of innovative methods was evaluated using a thematic framework analysis of focus group discussions with survey field staff, and via survey planner budgets. We found that a common household definition excluded single adults (46.9%) and migrant-headed households (6.7%), as well as non-married (8.5%), unemployed (10.5%), disabled (9.3%), and studying adults (14.3%). Further, standard two-stage sampling resulted in fewer single adult and non-family households than an innovative area-microcensus design; however, two-stage sampling resulted in more tent and shack dwellers. Our survey innovations provided good value for money, and field staff experiences were neutral or positive. Staff recommended streamlining field tools and pairing technical and survey content experts during fieldwork. This evidence of exclusion of vulnerable and mobile urban populations in LMIC household surveys is deeply concerning and underscores the need to modernize survey methods and practices

To what extent can decommissioning options for marine artificial structures move us toward environmental targets?

Switching from fossil fuels to renewable energy is key to international energy transition efforts and the move toward net zero. For many nations, this requires decommissioning of hundreds of oil and gas infrastructure in the marine environment. Current international, regional and national legislation largely dictates that structures must be completely removed at end-of-life although, increasingly, alternative decommissioning options are being promoted and implemented. Yet, a paucity of real-world case studies describing the impacts of decommissioning on the environment make decision-making with respect to which option(s) might be optimal for meeting international and regional strategic environmental targets challenging. To address this gap, we draw together international expertise and judgment from marine environmental scientists on marine artificial structures as an alternative source of evidence that explores how different decommissioning options might ameliorate pressures that drive environmental status toward (or away) from environmental objectives. Synthesis reveals that for 37 United Nations and Oslo-Paris Commissions (OSPAR) global and regional environmental targets, experts consider repurposing or abandoning individual structures, or abandoning multiple structures across a region, as the options that would most strongly contribute toward targets. This collective view suggests complete removal may not be best for the environment or society. However, different decommissioning options act in different ways and make variable contributions toward environmental targets, such that policy makers and managers would likely need to prioritise some targets over others considering political, social, economic, and ecological contexts. Current policy may not result in optimal outcomes for the environment or society

Knowledge, Technology Adoption and Financial Innovation

Why are new financial instruments created? This paper proposes the view that financial development arises as a response to the contractual needs of emerging technologies. Exogenous technological progress generates a demand for new fi-nancial instruments in order to share risk or overcome private information, for example. A model of the dynamics of technology adoption and the evolution of financial instruments that support such adoption is presented. Early adoption may be required for financial markets to learn the technology; once learned, finan-cial innovation boosts adoption further. Financial learning emerges as a source of technological diffusion. The analysis identifies a causality link from technology to finance which is nonetheless consistent with empirical findings of a positive effect of current financial development on future growth

Developing expert scientific consensus on the environmental and societal effects of marine artificial structures prior to decommissioning

This work was supported by the UK Natural Environment Research Council and the INSITE programme [INSITE SYNTHESIS project, grant number NE/W009889/1].Thousands of artificial (‘human-made’) structures are present in the marine environment, many at or approaching end-of-life and requiring urgent decisions regarding their decommissioning. No consensus has been reached on which decommissioning option(s) result in optimal environmental and societal outcomes, in part, owing to a paucity of evidence from real-world decommissioning case studies. To address this significant challenge, we asked a worldwide panel of scientists to provide their expert opinion. They were asked to identify and characterise the ecosystem effects of artificial structures in the sea, their causes and consequences, and to identify which, if any, should be retained following decommissioning. Experts considered that most of the pressures driving ecological and societal effects from marine artificial structures (MAS) were of medium severity, occur frequently, and are dependent on spatial scale with local-scale effects of greater magnitude than regional effects. The duration of many effects following decommissioning were considered to be relatively short, in the order of days. Overall, environmental effects of structures were considered marginally undesirable, while societal effects marginally desirable. Experts therefore indicated that any decision to leave MAS in place at end-of-life to be more beneficial to society than the natural environment. However, some individual environmental effects were considered desirable and worthy of retention, especially in certain geographic locations, where structures can support improved trophic linkages, increases in tourism, habitat provision, and population size, and provide stability in population dynamics. The expert analysis consensus that the effects of MAS are both negative and positive for the environment and society, gives no strong support for policy change whether removal or retention is favoured until further empirical evidence is available to justify change to the status quo. The combination of desirable and undesirable effects associated with MAS present a significant challenge for policy- and decision-makers in their justification to implement decommissioning options. Decisions may need to be decided on a case-by-case basis accounting for the trade-off in costs and benefits at a local level.Publisher PDFPeer reviewe

An open-source database for the synthesis of soil radiocarbon data: International Soil Radiocarbon Database (ISRaD) version 1.0

Radiocarbon is a critical constraint on our estimates of the timescales of soil carbon cycling that can aid in identifying mechanisms of carbon stabilization and destabilization and improve the forecast of soil carbon response to management or environmental change. Despite the wealth of soil radiocarbon data that have been reported over the past 75 years, the ability to apply these data to global-scale questions is limited by our capacity to synthesize and compare measurements generated using a variety of methods. Here, we present the International Soil Radiocarbon Database (ISRaD; http://soilradiocarbon.org, last access: 16 December 2019), an open-source archive of soil data that include reported measurements from bulk soils, distinct soil carbon pools isolated in the laboratory by a variety of soil fractionation methods, samples of soil gas or water collected interstitially from within an intact soil profile, CO2 gas isolated from laboratory soil incubations, and fluxes collected in situ from a soil profile. The core of ISRaD is a relational database structured around individual datasets (entries) and organized hierarchically to report soil radiocarbon data, measured at different physical and temporal scales as well as other soil or environmental properties that may also be measured and may assist with interpretation and context. Anyone may contribute their own data to the database by entering it into the ISRaD template and subjecting it to quality assurance protocols. ISRaD can be accessed through (1) a web-based interface, (2) an R package (ISRaD), or (3) direct access to code and data through the GitHub repository, which hosts both code and data. The design of ISRaD allows for participants to become directly involved in the management, design, and application of ISRaD data. The synthesized dataset is available in two forms: the original data as reported by the authors of the datasets and an enhanced dataset that includes ancillary geospatial data calculated within the ISRaD framework. ISRaD also provides data management tools in the ISRaD-R package that provide a starting point for data analysis; as an open-source project, the broader soil community is invited and encouraged to add data, tools, and ideas for improvement. As a whole, ISRaD provides resources to aid our evaluation of soil dynamics across a range of spatial and temporal scales. The ISRaD v1.0 dataset is archived and freely available at https://doi.org/10.5281/zenodo.2613911 (Lawrence et al., 2019).Max Planck Institute for Biogeochemistry; European Research CouncilEuropean Research Council (ERC) [695101]; USGS Land Change Science mission area; US Department of AgricultureUnited States Department of Agriculture (USDA) [2018-67003-27935]; US Geological Survey Powell Center for the working group on Soil Carbon Storage and FeedbacksOpen access journalThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Pathways from research to sustainable development: insights from ten research projects in sustainability and resilience

Drawing on collective experience from ten collaborative research projects focused on the Global South, we identify three major challenges that impede the translation of research on sustainability and resilience into better-informed choices by individuals and policy-makers that in turn can support transformation to a sustainable future. The three challenges comprise: (i) converting knowledge produced during research projects into successful knowledge application; (ii) scaling up knowledge in time when research projects are short-term and potential impacts are long-term; and (iii) scaling up knowledge across space, from local research sites to larger-scale or even global impact. Some potential pathways for funding agencies to overcome these challenges include providing targeted prolonged funding for dissemination and outreach, and facilitating collaboration and coordination across different sites, research teams, and partner organizations. By systematically documenting these challenges, we hope to pave the way for further innovations in the research cycle