164 research outputs found

    Preservation: Competently Navigating Between All and Nothing

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    Merriam-Webster defines competent as having requisite or adequate ability or qualities. \u27 All professions require competence to be successful-from chefs, to tailors, to NFL quarterbacks. Without the adequate ability to poach an egg, alter suits, or read defenses, they lose patrons, customers, or-in the case of a quarterback-games and fans. Lawyers are no different. Without competence, they may not be successful. However, lawyers are different than the NFL quarterback in that they have an explicit duty of competence to their clients

    Factors Affecting Plant Responses to Arbuscular Mycorrhizal Fungi and Soil Fungal Communities

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    Arbuscular mycorrhizal (AM) fungi are ancient mutualists that associate with the majority of plants. However, the factors that influence how much a plant benefits from AM fungi, or the factors that influence other root-associated fungi are unclear. I examined how plant traits related to nutrient availability can explain variation in AMresponsiveness and whether native species differ from exotics in these relationships. Leaf mass per unit of area (LMA) correlated positively with mycorrhizal growth responsiveness (MGR) and root colonization (RC) among native species. This indicates that native species with more conservative traits more strongly benefit, and benefit from, AM fungi. Furthermore, exotic species did not share this relationship, suggesting that ecological filtering can influence associations between plants and MGR. I also investigated whether populations of the exotic plant, Centaurea solstitialis, collected from native versus non-native ranges, differed in AM-responsiveness. Grown alone, C. solstitialis from both ranges considered together derived a weak benefit from AM fungi, but in competition with the North American native S. pulchra, AM fungi ii i suppressed the biomass of C. solstitialis. The magnitude of this suppressive effect was greater on native versus non-native populations, suggesting that rapid evolutionary changes in how exotic plants respond to interacting AM fungal partners can affect their competitive tolerance in recipient communities. Additions of N and of N and P can have strong effects on soil fungal community composition. However, it is unclear how individual guilds of fungi change along these gradients. I performed high-throughput sequencing on soils from the rhizosphere of Andropogon gerardii, the dominant C4 grass in the Konza Tallgrass Prairie Reserve, to investigate how long-term fertilization with N and N and P affect soil fungi. Fertilization increased pathogen abundance and diversity, but AM fungal abundance and diversity was only decreased when high amounts of P were added. Further, although most AM fungal species decreased along the fertility gradient, the dominant AM fungal species increased, suggesting potential shifts in the functional attributes of those communities. These results suggest that additions of N and P can increase rhizosphere pathogen loads and increases in P can shift the composition and abundance of AM fungi

    The African penguin Spheniscus demersus : conservation and management issues

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    Includes bibliographical references.The African penguin is a southern African endemic, with its breeding distribution within the Benguela Upwelling Ecosystem. The IUCN conservation status of this species was re-classified from ‘Vulnerable’ to ‘Endangered’ in 2010. This thesis investigated some aspects pertinent to the species’ conservation and management. Time series of population estimates of African penguins and fish biomass were available in South Africa since the late 1980s. This study analysed the fish biomass at a stratum scale, which is a finer scale to that of previous studies which looked at biomass estimates as a whole. The strata range in length from c. 155 km to c. 280 km in length. The number of African penguin breeders and adult moulters were found to be positively correlated with fish biomass estimates, although results of the spatial relationships were unexpected. The islands which displayed the strongest relationships were Dassen Island and Robben Island. These islands are only c. 50 km apart, and it is expected that they would experience similar oceanographic conditions. However, the colonies at these islands were found to respond differently to fish biomass estimates. While the number of Dassen Island birds were found to be positively correlated with biomass estimates within the strata in which the island is found, the number of Robben Island birds were correlated with biomass estimates of the stratum to the south and east of the island. Weaker relationships were found for the remaining colonies. This study suggested that the period of moult is of critical importance to the survival of the penguin, an aspect that needs to be incorporated into the Ecosystem Approach to Fisheries modelling

    A cursory look at the fishmeal/oil industry from an ecosystem perspective

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    By supporting the fishmeal industry, are we competing with marine predators? Should we be taking away food from marine predators to subsidize agriculture? If not for human consumption, should forage fish be left in the sea for predators? Are there more sustainable alternatives to fishmeal; can the fishing industry be part of developing these? These are all pressing questions being posed by marine scientists, particularly in the light of the increasing aquaculture industry and associated increasing demand in recent decades for fishmeal and oil to sustain cultured fish. We concisely summarize the global context of marine sourced fishmeal and then use the South African marine ecosystem as a working example. This article draws on research into the trophic role of forage fish in marine ecosystems and ponders whether a reduced demand for fishmeal, given increasing global pressures such as climate change, could benefit marine ecosystems, fisheries on predatory species, and vulnerable marine predators

    A Predictive Spatial Model to Quantify the Risk of Air-Travel-Associated Dengue Importation into the United States and Europe

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    The number of travel-acquired dengue infections has been on a constant rise in the United States and Europe over the past decade. An increased volume of international passenger air traffic originating from regions with endemic dengue contributes to the increasing number of dengue cases. This paper reports results from a network-based regression model which uses international passenger travel volumes, travel distances, predictive species distribution models (for the vector species), and infection data to quantify the relative risk of importing travel-acquired dengue infections into the US and Europe from dengue-endemic regions. Given the necessary data, this model can be used to identify optimal locations (origin cities, destination airports, etc.) for dengue surveillance. The model can be extended to other geographical regions and vector-borne diseases, as well as other network-based processes

    We Can Have It All: Improved Surveillance Outcomes and Decreased Personnel Costs Associated With Electronic Reportable Disease Surveillance, North Carolina, 2010

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    Objectives. We assessed the timeliness, accuracy, and cost of a new electronic disease surveillance system at the local health department level. We describe practices associated with lower cost and better surveillance timeliness and accuracy. Methods. Interviews conducted May through August 2010 with local health department (LHD) staff at a simple random sample of 30 of 100 North Carolina counties provided information on surveillance practices and costs; we used surveillance system data to calculate timeliness and accuracy. We identified LHDs with best timeliness and accuracy and used these categories to compare surveillance practices and costs. Results. Local health departments in the top tertiles for surveillance timeliness and accuracy had a lower cost per case reported than LHDs with lower timeliness and accuracy (71and71 and 124 per case reported, respectively; P = .03). Best surveillance practices fell into 2 domains: efficient use of the electronic surveillance system and use of surveillance data for local evaluation and program management. Conclusions. Timely and accurate surveillance can be achieved in the setting of restricted funding experienced by many LHDs. Adopting best surveillance practices may improve both efficiency and public health outcomes

    Oxo-aglaiastatin-mediated inhibition of translation initiation

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    We thank Dr. Elias George (McGill University) for the kind gift of Pgp-1-expressing HeLa cells. RIM was supported by a doctoral fellowship from the Cole Foundation. This research was supported by a grant from the Canadian Institutes of Health Research (FDN-148366) to JP. J.A.P., Jr. is supported by NIH Grant R35 GM118173. Work at the Boston University Center for Molecular Discovery is supported by Grant R24 GM111625. (Cole Foundation; FDN-148366 - Canadian Institutes of Health Research; R35 GM118173 - NIH; R24 GM111625)Published versionSupporting documentatio

    Factors that influence cape fur seal predation on Cape gannets at Lambert’s bay, South Africa

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    Seabird populations experience predation that can impact their breeding density and breeding success. The Cape gannet Morus capensis is endemic to the Benguela upwelling ecosystem and is classified as Endangered by the IUCN. They are affected by several threats, including predation by the Cape fur seal Arctocephalus pusillus pusillus. Many fledglings succumb to predation during their maiden flight across waters around the island. To curb predation, the selective culling of individual predatory seals was implemented in 2014, 2015, and 2018. Our first study objective was to determine if selective culling of Cape fur seals significantly reduced predation probability on Cape gannets. We tested whether predation probability in 2014, 2015, and 2018 was affected by fish biomass, gannet fledgling numbers, and/or the presence/absence of selective culling

    Initial evaluation of the care and rehabilitation success of Cape Cormorants Phalacrocorax capensis rescued from Robben and Jutten islands, South Africa, in January 2021

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    The population of the endangered Cape Cormorant Phalacrocorax capensis more than halved over the last three decades (BirdLife International 2018a). In January 2021, nearly 2 000 Cape Cormorant chicks were found abandoned, suffering from dehydration and heat stress, at two important nesting sites. The chicks were rescued and rehabilitated by the Southern African Foundation for the Conservation of Coastal Birds (SANCCOB, Cape Town, South Africa). About half (53.7%) of the cormorant chicks were successfully rehabilitated and released back into the breeding colonies. This study found a direct link between the initial body mass of cormorant chicks admitted to the rehabilitation centre and their probability of surviving during rehabilitation, with birds that were initially heavier having a greater probability of eventual release. Most cormorant chicks that died (80.7%) did so within the first 5 days of admission. This rescue required SANCCOB to care for and rehabilitate the largest number of Cape Cormorant chicks that has ever been admitted to its rehabilitation centre at one time, making it the first rescue of its kind. Despite the presumably limited positive impact on overall population numbers of Cape Cormorants, the rescue campaign improved SANCCOB’s preparedness to respond successfully to future disaster events and to deal with different species, both locally and globally

    Escape from Competition: Neighbors Reduce Centaurea Stoebe Performance at Home but not Away

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    The greater abundance of some exotic plants in their nonnative ranges might be explained in part by biogeographic differences in the strength of competition, but these competitive effects have not been experimentally examined in the field. We compared the effects of neighbors on the growth and reproduction of spotted knapweed (Centaurea stoebe) in Europe, where it is native, and in Montana, where it is invasive. There were strong negative competitive effects of neighboring vegetation on C. stoebe growth and reproduction in Europe. In contrast, identical experiments in Montana resulted in insignificant impacts on C. stoebe. Although the mechanisms that produce this dramatic biogeographic difference in competitive outcome remain unknown, our results indicate that differences in net competitive interactions between ranges may contribute to the striking dominance of C. stoebe in parts of North America
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