Vegetation Structure And Interspecific Interactions Predict Distribution And Abundance Of Solidago Specialist Aphids

Volatile compounds such as terpenes are often used by plants as insect herbivory deterrents, though terpenes broadly act as semiochemicals, both priming nearby plants and providing host recognition for insects. I focused on the interactions of tall goldenrod, Solidago altissima, goldenrod galling insects, and specialist aphids. Gall insects induce a volatile terpene response in Solidago and aphids colonize goldenrod stems with high terpene concentrations. In this system, the goldenrod’s terpene response deters the inducing species while simultaneously promoting aphid colonization. Using spatial mapping techniques, I constructed a biologically-based model of terpene induction, driven by insect galls, in three patches of goldenrod in order to predict areas of aphid colonization. Terpenes were analyzed via gas chromatography in plants sampled at varying distances from insect galls in each patch. Results of terpene sampling were used to develop a spatial model of terpene induction and aphid distribution. Aphid counts were made in each patch and compared to model projections. My analysis revealed that terpenes in the field varied significantly by distance and in a similar way across all patches. My spatial models demonstrated an aphid response to the gall induced terpenes, and when combined with models of vegetation structure, accurately predicted aphid distribution

Perspectives of perception

In this, our age of Higher Education, we have learned that the universe is a function of energy and mass and time. But knowledge of astrophysics makes little difference to most of us mortals because fundamentally we do exactly as our most distant ancestors did: we are born, we hunger, exult, imagine, remember, we are mistaken, we die. The universe that matters, as far as our own lives are concerned, is a perceived universe, whose laws have always been dimly felt and darkly understood. This thesis is about perceptions. The first four parts of it-- a poem, a story, another poem, and the beginning of a novel--are figmental; the last part, which is absolutely factual, is a proem, not to this thesis, but to everything else

Beekeepers' gold: reconstructing tupelo honey yield in northwest Florida using Nyssa ogeche tree-ring data

This dissertation contains three manuscripts that have been either submitted to or accepted by peer-reviewed academic journals. I first examine the U.S. honey industry to determine how the industry is responding to the current multiple challenges facing U.S. beekeepers. I discuss how the industry might survive these challenges by transitioning to a multifunctional system and becoming more economically and environmentally sustainable. I then examine a specific honey type--tupelo--in more detail using tree-rings to expand the honey record. Tupelo honey is derived from the nectar of Ogeechee tupelo (Nyssa ogeche) trees growing in northwest Florida and southern Georgia. I use N. ogeche tree-ring data to reconstruct and expand the honey yield-per-hive record and then place the current decline in a historical context. I also identify the climatic and hydrologic conditions conducive to optimal honey yields. This project is the first to use dendrochronological techniques to expand and analyze honey yields. I use tupelo honey yield as an example of how climatic cycles may cause long-term fluctuations in crop productivity. The results demonstrate the utility of employing tree-rings to extend crop records to allow a broader understanding of yield variations inherent in agriculture and can be implemented for other crop yields

Social and ecological effectiveness of large marine protected areas

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this record.Large marine protected areas are increasingly being established to meet global conservation targets and promote sustainable use of resources. Although the factors affecting the performance of small-scale marine protected areas are relatively well studied, there is no such body of knowledge for large marine protected areas. We conducted a global meta-analysis to systematically investigate social, ecological, and governance characteristics of successful large marine protected areas with respect to several social and ecological outcomes. We included all large (>10,000km2), implemented (>5 years of active management) marine protected areas that had sufficient data for analysis, for a total of twelve cases. We used the Social-Ecological Systems Meta-Analysis Database, and a consistent protocol for using secondary data and key informant interviews, to code proxies for fisheries, ecosystem health, and the wellbeing of user groups (mainly fishers). We tested four sets of hypotheses derived from the literature on smallscale marine protected areas and common-pool resources: (i) the attributes of species and ecosystems to be managed in the marine protected area, (ii) adherence to principles for designing small-scale marine protected areas, (iii) adherence to the design principles for common-pool resource management, and (iv) stakeholder participation. We found varying levels of support for these hypotheses. Improved fisheries were associated with older marine protected areas, and higher levels of enforcement. Declining fisheries were associated with several ecological and economic factors, including low productivity, high mobility, and high market value. High levels of participation were correlated with improvements in wellbeing and ecosystem health trends. Overall, this study constitutes an important first step in identifying factors affecting social wellbeing and ecological performance of large marine protected areas.NCB thanks SSHRC and NSERC. CMB was supported by the Price Fellowship and Stanford University’s Emmett Interdisciplinary Program in Environmental Resources. GE is supported by a SSHRC postdoctoral fellowship. We gratefully acknowledge participants of our key informant interviewsThis is the author accepted manuscript. The final version is available from the publisher via the DOI in this record

Assessing trade-offs in large marine protected areas

This is the final version. Available on open access from Public Library of Science via the DOI in this recordData Availability: Data of coded case-studies can be viewed at: https://sesmad.dartmouth.edu/ses_casesLarge marine protected areas (LMPAs) are increasingly being established and have a high profile in marine conservation. LMPAs are expected to achieve multiple objectives, and because of their size are postulated to avoid trade-offs that are common in smaller MPAs. However, evaluations across multiple outcomes are lacking. We used a systematic approach to code several social and ecological outcomes of 12 LMPAs. We found evidence of three types of trade-offs: trade-offs between different ecological resources (supply trade-offs); trade-offs between ecological resource conditions and the well-being of resource users (supply-demand trade-offs); and trade-offs between the well-being outcomes of different resource users (demand trade-offs). We also found several divergent outcomes that were attributed to influences beyond the scope of the LMPA. We suggest that despite their size, trade-offs can develop in LMPAs and should be considered in planning and design. LMPAs may improve their performance across multiple social and ecological objectives if integrated with larger-scale conservation efforts.Social Science and Humanities Research Council of CanadaNatural Sciences and Engineering Research Council of Canad

New ophthalmosaurid ichthyosaurs from the European lower cretaceous demonstrate extensive ichthyosaur survival across the Jurassic–Cretaceous boundary

Background Ichthyosauria is a diverse clade of marine amniotes that spanned most of the Mesozoic. Until recently, most authors interpreted the fossil record as showing that three major extinction events affected this group during its history: one during the latest Triassic, one at the Jurassic–Cretaceous boundary (JCB), and one (resulting in total extinction) at the Cenomanian-Turonian boundary. The JCB was believed to eradicate most of the peculiar morphotypes found in the Late Jurassic, in favor of apparently less specialized forms in the Cretaceous. However, the record of ichthyosaurs from the Berriasian–Barremian interval is extremely limited, and the effects of the end-Jurassic extinction event on ichthyosaurs remains poorly understood. Methodology/Principal Findings Based on new material from the Hauterivian of England and Germany and on abundant material from the Cambridge Greensand Formation, we name a new ophthalmosaurid, Acamptonectes densus gen. et sp. nov. This taxon shares numerous features with Ophthalmosaurus, a genus now restricted to the Callovian–Berriasian interval. Our phylogenetic analysis indicates that Ophthalmosauridae diverged early in its history into two markedly distinct clades, Ophthalmosaurinae and Platypterygiinae, both of which cross the JCB and persist to the late Albian at least. To evaluate the effect of the JCB extinction event on ichthyosaurs, we calculated cladogenesis, extinction, and survival rates for each stage of the Oxfordian–Barremian interval, under different scenarios. The extinction rate during the JCB never surpasses the background extinction rate for the Oxfordian–Barremian interval and the JCB records one of the highest survival rates of the interval. Conclusions/Significance There is currently no evidence that ichthyosaurs were affected by the JCB extinction event, in contrast to many other marine groups. Ophthalmosaurid ichthyosaurs remained diverse from their rapid radiation in the Middle Jurassic to their total extinction at the beginning of the Late Cretaceous

T-cell subpopulations αβ and γδ in cord blood of very preterm infants : The influence of intrauterine infection

Open Access: This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are creditedPreterm infants are very susceptible to infections. Immune response mechanisms in this group of patients and factors that influence cord blood mononuclear cell populations remain poorly understood and are considered insufficient. However, competent immune functions of the cord blood mononuclear cells are also described. The aim of this work was to evaluate the T-cell population (CD3+) with its subpopulations bearing T-cell receptor (TCR) αβ or TCR γδ in the cord blood of preterm infants born before 32 weeks of gestation by mothers with or without an intrauterine infection. Being a pilot study, it also aimed at feasibility check and assessment of an expected effect size. The cord blood samples of 46 infants age were subjected to direct immunofluorescent staining with monoclonal antibodies and then analyzed by flow cytometry. The percentage of CD3+ cells in neonates born by mothers with diagnosis of intrauterine infection was significantly lower than in neonates born by mothers without infection (p = 0.005; Mann-Whitney U test). The number of cells did not differ between groups. Infection present in the mother did not have an influence on the TCR αβ or TCR γδ subpopulations. Our study contributes to a better understanding of preterm infants' immune mechanisms, and sets the stage for further investigations.Peer reviewedFinal Published versio

Moisture transport by Atlantic tropical cyclones onto the North American continent

Tropical Cyclones (TCs) are an important source of freshwater for the North American continent. Many studies have tried to estimate this contribution by identifying TC-induced precipitation events, but few have explicitly diagnosed the moisture fluxes across continental boundaries. We design a set of attribution schemes to isolate the column-integrated moisture fluxes that are directly associated with TCs and to quantify the flux onto the North American Continent due to TCs. Averaged over the 2004–2012 hurricane seasons and integrated over the western, southern and eastern coasts of North America, the seven schemes attribute 7 to 18 % (mean 14 %) of total net onshore flux to Atlantic TCs. A reduced contribution of 10 % (range 9 to 11 %) was found for the 1980–2003 period, though only two schemes could be applied to this earlier period. Over the whole 1980–2012 period, a further 8 % (range 6 to 9 % from two schemes) was attributed to East Pacific TCs, resulting in a total TC contribution of 19 % (range 17 to 22 %) to the ocean-to-land moisture transport onto the North American continent between May and November. Analysis of the attribution uncertainties suggests that incorporating details of individual TC size and shape adds limited value to a fixed radius approach and TC positional errors in the ERA-Interim reanalysis do not affect the results significantly, but biases in peak wind speeds and TC sizes may lead to underestimates of moisture transport. The interannual variability does not appear to be strongly related to the El Nino-Southern Oscillation phenomenon

Global warming and arctic terns: Estimating climate change impacts on the world's longest migration

This is the final version. Available on open access from Wiley via the DOI in this recordData availability statement: Tracking data: The tracking data that were collected and support the findings of this study are available in the Seabird Tracking Database at 2356146398 https://data.seabirdtracking.org/dataset, reference number 1905. Additional tracking data that support the findings of this study are openly available in Dryad at https://doi.org/10.5061/dryad.d6080nt and available upon request at https://data.seabirdtracking.org/dataset/739. Environmental variables: The data that support the findings of this study are openly available in JASMIN at https://jasmin.ac.uk/. All CMIP6 model output is freely available on the Earth System Grid Federation (https://esgf.llnl.gov/). Global ocean biogeochemistry hindcast simulations are available on the Copernicus Marine Database (https://resources.marine.copernicus.eu/).Climate change is one of the top three global threats to seabirds, particularly species that visit polar regions. Arctic terns migrate between both polar regions annually and rely on productive marine areas to forage, on sea ice for rest and foraging, and prevailing winds during flight. Here, we report 21st-century trends in environmental variables affecting arctic terns at key locations along their Atlantic/Indian Ocean migratory flyway during the non-breeding seasons, identified through tracking data. End-of-century climate change projections were derived from Earth System Models and multi-model means calculated in two Shared Socioeconomic Pathways: ‘middle-of-the-road’ and ‘fossil-fuelled development’ scenarios. Declines in North Atlantic primary production emerge as a major impact to arctic terns likely to affect their foraging during the 21st century under a ‘fossil-fuelled development’ scenario. Minimal changes are, however, projected at three other key regions visited by arctic terns (Benguela Upwelling, Subantarctic Indian Ocean and the Southern Ocean). Southern Ocean sea ice extent is likely to decline, but the magnitude of change and potential impacts on tern survival are uncertain. Small changes (<1 m s−1) in winds are projected in both scenarios, but with minimal likely impacts on migration routes and duration. However, Southern Ocean westerlies are likely to strengthen and contract closer to the continent, which may require arctic terns to shift routes or flight strategies. Overall, we find minor effects of climate change on the migration of arctic terns, with the exception of poorer foraging in the North Atlantic. However, given that arctic terns travel over huge spatial scales and live for decades, they integrate minor changes in conditions along their migration routes such that the sum effect may be greater than the parts. Meeting carbon emission targets is vital to slow these end-of-century climatic changes and minimise extinction risk for a suite of polar species.Natural Environment Research Council (NERC)German Federal Ministry of Education and Research (BMBF)University of BristolScience and Technology Facilities Council (STFC)National Geographi

Induction of interleukin-8 preserves the angiogenic response in HIF-1 alpha-deficient colon cancer cells

authorHypoxia inducible factor-1 (HIF-1) is considered a crucial mediator of the cellular response to hypoxia through its regulation of genes that control angiogenesis^1, ^2, ^3, ^4. It represents an attractive therapeutic target^5, ^6 in colon cancer, one of the few tumor types that shows a clinical response to antiangiogenic therapy^7. But it is unclear whether inhibition of HIF-1 alone is sufficient to block tumor angiogenesis^8, ^9. In HIF-1_α knockdown DLD-1 colon cancer cells (DLD-1^HIF-kd), the hypoxic induction of vascular endothelial growth factor (VEGF) was only partially blocked. Xenografts remained highly vascularized with microvessel densities identical to DLD-1 tumors that had wild-type HIF-1_α (DLD-1^HIF-wt). In addition to the preserved expression of VEGF, the proangiogenic cytokine interleukin (IL)-8 was induced by hypoxia in DLD-1^HIF-kd but not DLD-1^HIF-wt cells. This induction was mediated by the production of hydrogen peroxide and subsequent activation of NF-_KB. Furthermore, the KRAS oncogene, which is commonly mutated in colon cancer, enhanced the hypoxic induction of IL-8. A neutralizing antibody to IL-8 substantially inhibited angiogenesis and tumor growth in DLD-1^HIF-kd but not DLD-1^HIF-wt xenografts, verifying the functional significance of this IL-8 response. Thus, compensatory pathways can be activated to preserve the tumor angiogenic response, and strategies that inhibit HIF-1α may be most effective when IL-8 is simultaneously targeted