209 research outputs found
Variable rewards and discrimination ability in an insect herbivore: what and how does a hungry locust learn?
Urticarial Rash in a Patient with Alpha-Gal Syndrome Caused by Subcutaneous Heparin at Prophylactic Dosing: A Case Report
Introduction: We report a patient with a history of red meat allergy, or alpha-gal syndrome, who had an urticarial rash after exposure to unfractionated heparin at a dose typically used for prophylaxis of deep venous thrombosis. Although anaphylactic reactions have been reported with systemic intravenous heparin, we believe this case is the first report of an immunoglobulin E–mediated reaction to subcutaneous heparin at prophylactic dosing.
Clinical Findings: An 85-year-old male had a 3-year history of red meat allergy and was intolerant of pork and beef. He developed an immunoglobulin E–mediated allergic reaction to subcutaneous heparin at a dose of 5000 units twice daily.
Clinical Course: The patient presented to the emergency department after a fall. He had back pain and was diagnosed with a compression fracture. He was admitted to the hospital because he was unable to safely ambulate. He was treated with subcutaneous unfractionated heparin to prevent deep venous thrombosis as part of routine care. Twenty-four hours after exposure to heparin, he developed an urticarial rash. The rash resolved promptly after discontinuing heparin and excluding other potential allergic triggers.
Conclusions: In patients with alpha-gal syndrome, unfractionated heparin via a subcutaneous route at prophylactic dosing can precipitate immunoglobulin E–mediated systemic reactions and should be avoided
The effectiveness of digital storytelling in the classrooms: a comprehensive study
In recent years the use of new technologies in educational systems has increased worldwide as digital cameras, personal computers, scanners, and easy-to-use software have become available to educators to harness the digital world. The impact of new technologies in educational contexts has been mostly positive as new technologies have given educators the opportunity to enhance their knowledge, skills, and therefore enhance the standard of education. Researchers have found that student engagement, achievement and motivation are enhanced through integration of such technologies. However, education systems still face many challenges: one of these challenges is how to enhance student engagement to provide better educational outcomes. It has become increasingly important to use innovative pedagogical models to engage learners. Digital storytelling is one of the innovative pedagogical approaches that can engage students in deep and meaningful learning. This research project aimed to create a constructivist learning environment with digital storytelling. The research investigated the pedagogical aspects of digital storytelling and the impact of digital storytelling on student learning when teachers and students use digital stories. A multi-site case study was conducted in one Australian school at primary and secondary levels. In selected classrooms, students and teachers had the opportunity to engage in innovative learning experiences based on digital storytelling. In order to enhance the reliability and validity of the research, multiple methods of data collection and analysis were used. Data was collected with qualitative and quantitative methods. An evaluation rubric was used to collect quantitative data, while interviews and observation were used to collect qualitative data. Data collection was guided by a mixed methods research design in order to evaluate if and how digital storytelling enhances teaching and learning outcomes. The findings from this study suggest that digital storytelling is a powerful tool to integrate instructional messages with learning activities to create more engaging and exciting learning environments. It is a meaningful approach for creating a constructivist learning environment based on novel principles of teaching and learning. Thus, this approach has the potential to enhance student engagement and provide better educational outcomes for learners
Host plant range of a fruit fly community (Diptera: Tephritidae): Does fruit composition influence larval performance?
Background: Phytophagous insects differ in their degree of specialisation on host plants, and range from strictly monophagous species that can develop on only one host plant to extremely polyphagous species that can develop on hundreds of plant species in many families. Nutritional compounds in host fruits affect several larval traits that may be related to adult fitness. In this study, we determined the relationship between fruit nutrient composition and the degree of host specialisation of seven of the eight tephritid species present in La Réunion; these species are known to have very different host ranges in natura. In the laboratory, larval survival, larval developmental time, and pupal weight were assessed on 22 fruit species occurring in La Réunion. In addition, data on fruit nutritional composition were obtained from existing databases. Results: For each tephritid, the three larval traits were significantly affected by fruit species and the effects of fruits on larval traits differed among tephritids. As expected, the polyphagous species Bactrocera zonata, Ceratitis catoirii, C. rosa, and C. capitata were able to survive on a larger range of fruits than the oligophagous species Zeugodacus cucurbitae, Dacus demmerezi, and Neoceratitis cyanescens. Pupal weight was positively correlated with larval survival and was negatively correlated with developmental time for polyphagous species. Canonical correspondence analysis of the relationship between fruit nutrient composition and tephritid survival showed that polyphagous species survived better than oligophagous ones in fruits containing higher concentrations of carbohydrate, fibre, and lipid. Conclusion: Nutrient composition of host fruit at least partly explains the suitability of host fruits for larvae. Completed with female preferences experiments these results will increase our understanding of factors affecting tephritid host range. (Résumé d'auteur
Nutritional correlates of koala persistence in a low-density population
It is widely postulated that nutritional factors drive bottom-up, resource-based patterns in herbivore ecology and distribution. There is, however, much controversy over the roles of different plant constituents and how these influence individual herbivores and herbivore populations. The density of koala (Phascolarctos cinereus) populations varies widely and many attribute population trends to variation in the nutritional quality of the eucalypt leaves of their diet, but there is little evidence to support this hypothesis. We used a nested design that involved sampling of trees at two spatial scales to investigate how leaf chemistry influences free-living koalas from a low-density population in south east New South Wales, Australia. Using koala faecal pellets as a proxy for koala visitation to trees, we found an interaction between toxins and nutrients in leaves at a small spatial scale, whereby koalas preferred trees with leaves of higher concentrations of available nitrogen but lower concentrations of sideroxylonals (secondary metabolites found exclusively in eucalypts) compared to neighbouring trees of the same species. We argue that taxonomic and phenotypic diversity is likely to be important when foraging in habitats of low nutritional quality in providing diet choice to tradeoff nutrients and toxins and minimise movement costs. Our findings suggest that immediate nutritional concerns are an important priority of folivores in low-quality habitats and imply that nutritional limitations play an important role in constraining folivore populations. We show that, with a careful experimental design, it is possible to make inferences about populations of herbivores that exist at extremely low densities and thus achieve a better understanding about how plant composition influences herbivore ecology and persistence.IW and WF received a grant from New
South Wales (NSW) Department of Environment,
Climate Change & Water
Cropping Systems Research Summary 2019: Agroecosystems Entomology Project Research Reports
Investigating the role of spiders in integrated pest Management for biological control of Nebraska crop pests, Samantha R. Daniel. Advisors: Julie A. Peterson and Robert Wright
Simulating larval movement of Western bean cutworm in blended refuges by laboratory feeding on non-Bt, Cry1F and Vip3A maize, Andrea Rilaković and Katharine Swoboda Bhattrai
Determining western bean cutworm Striacosta albicosta (Lepidoptera: Noctuidae) optimal nutritional intake via choice studies, M. G. Sacilotto, Katharine Swosoda Battharai, C. A. Deans, S. Behmer, and Julie A. Peterso
Evaluation of a Microbial Inhibitor in Artificial Diets of a Generalist Caterpillar, Heliothis virescens
Controlling microbial growth in artificial diets is a key component in the rearing of laboratory insects. In this study an antimicrobial agent, Diet Antimicrobial Agent (DAA), was tested for its ability to suppress microbial growth on a range of different diets, and for its effect on larval and pupal performance of individuals from two different strains of Heliothis virescens Fabricus (Lepidoptera: Noctuidae). In the first experiment, it was found that the presence of DAA in a pinto bean-based diet was highly effective at suppressing microbial growth relative to other methods, and that survival of caterpillars on diets with DAA was superior to other treatments. Caterpillars also performed best on diets with DAA, although this may have been the result of laboratory selection pressure as these caterpillars had been reared on pinto bean-based diets with DAA for several hundred generations. A second experiment was conducted, using different diets and a different strain of H. virescens to more fully evaluate DAA. Here it was found that DAA significantly suppressed microbial growth and development, particularly in synthetic diets. There was no significant effect of DAA on pupal development time or mass gain. There was a statistically significant effect of DAA on eclosion time for two of the diets, although the effect did not seem to be biologically meaningful. The findings suggest that DAA is an effective suppressor of microbial growth on artificial diets, and that its net effect on developing diet-reared insects is neutral
Long-Chain n-3 Fatty Acids Attenuate Oncogenic KRas-Driven Proliferation by Altering Plasma Membrane Nanoscale Proteolipid Composition
Ras signaling originates from transient nanoscale compartmentalized regions of the plasma membrane composed of specific proteins and lipids. The highly specific lipid composition of these nanodomains, termed nanoclusters, facilitates effector recruitment and therefore influences signal transduction. This suggests that Ras nanocluster proteolipid composition could represent a novel target for future chemoprevention interventions. There is evidence that consumption of fish oil containing long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) such as eicosapentaenoic acid (EPA, 20:5Δ5,8,11,14,17) and docosahexaenoic acid (DHA, 22:6Δ4,7,10,13,16,19) may reduce colon cancer risk in humans, yet the mechanism underlying this effect is unknown. Here, we demonstrate that dietary n-3 PUFA reduce the lateral segregation of cholesterol-dependent and -independent nanoclusters, suppressing phosphatidic acid-dependent oncogenic KRas effector interactions, via their physical incorporation into plasma membrane phospholipids. This results in attenuation of oncogenic Ras-driven colonic hyperproliferation in both Drosophila and murine models. These findings demonstrate the unique properties of dietary n-3 PUFA in the shaping of Ras nanoscale proteolipid complexes and support the emerging role of plasma membrane-targeted therapies. Significance: The influence of dietary long chain n-3 polyunsaturated fatty acids on plasma membrane protein nanoscale organization and KRas signaling supports development of plasma membrane-targeted therapies in colon cancer
The Effect of Plant Inbreeding and Stoichiometry on Interactions with Herbivores in Nature: Echinacea angustifolia and Its Specialist Aphid
Fragmentation of once widespread communities may alter interspecific interactions by changing genetic composition of interacting populations as well as their abundances and spatial distributions. In a long-term study of a fragmented population of Echinacea angustifolia, a perennial plant native to the North American prairie, we investigated influences on its interaction with a specialist aphid and tending ants. We grew plant progeny of sib-matings (I), and of random pairings within (W) and between (B) seven remnants in a common field within 8 km of the source remnants. During the fifth growing season, we determined each plant's burden of aphids and ants, as well as its size and foliar elemental composition (C, N, P). We also assayed composition (C, N) of aphids and ants. Early in the season, progeny from genotypic classes B and I were twice as likely to harbor aphids, and in greater abundance, than genotypic class W; aphid loads were inversely related to foliar concentration of P and positively related to leaf N and plant size. At the end of the season, aphid loads were indistinguishable among genotypic classes. Ant abundance tracked aphid abundance throughout the season but showed no direct relationship with plant traits. Through its potential to alter the genotypic composition of remnant populations of Echinacea, fragmentation can increase Echinacea's susceptibility to herbivory by its specialist aphid and, in turn, perturb the abundance and distribution of aphids
Successional Change in Phosphorus Stoichiometry Explains the Inverse Relationship between Herbivory and Lupin Density on Mount St. Helens
The average nitrogen-to-phosphorus ratio (N?P) of insect herbivores is less than that of leaves, suggesting that P may mediate plant-insect interactions more often than appreciated. We investigated whether succession-related heterogeneity in N and P stoichiometry influences herbivore performance on N-fixing lupin (Lupinus lepidus) colonizing primary successional volcanic surfaces, where the abundances of several specialist lepidopteran herbivores are inversely related to lupin density and are known to alter lupin colonization dynamics. We examined larval performance in response to leaf nutritional characteristics using gelechiid and pyralid leaf-tiers, and a noctuid leaf-cutter.Apple JL, Wink M, Wills SE, Bishop JG (2009) Successional Change in Phosphorus Stoichiometry Explains the Inverse Relationship between Herbivory and Lupin Density on Mount St. Helens. PLoS ONE 4(11): e7807. doi:10.1371/journal.pone.000780
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