291 research outputs found
Data from: Adverse effects of inbreeding on the transgenerational expression of herbivore-induced defense traits in Solanum carolinense
No full textPlease cite as: Chad Nihranz, Anjel Helms, John Tooker, Mark Mescher, Consuelo De Moraes, and Andrew G. Stephenson. (2022) Data from: Adverse effects of inbreeding on the transgenerational expression of herbivore-induced defense traits in Solanum carolinense. [Dataset] Cornell University eCommons Repository. https://doi.org/10.7298/eshc-b463These files contain data supporting all results reported in Nihranz et al. "Adverse effects of inbreeding on the transgenerational expression of herbivore-induced defense traits in Solanum carolinense". In Nihranz et al. we found: We found that feeding by Manduca sexta caterpillars on maternal Solanum carolinense plants had a positive influence on trichome and spine production in offspring and that caterpillar development on offspring of herbivore- damaged maternal plants was delayed relative to that on offspring of undamaged plants. Offspring of inbred maternal plants had reduced spine production, compared to those of outbred plants, and caterpillars performed better on these plants. Both herbivory and inbreeding in the maternal generation altered volatile emissions of offspring. In general, maternal plant inbreeding dampened transgenerational effects of herbivory on offspring defensive traits and herbivore resistance. Taken together, this study demonstrates that inducible defenses in S. carolinense can persist across generations and that inbreeding compromises transgenerational resistance in S. carolinense.National Science Foundation grant, DEB-105099
Étienne Gilson, Duns Scotus, and Actual Existence: Weighing the Charge of ‘Essentialism’
No full textÉtienne Gilson juxtaposes what he calls Aquinas’s “existentialism” to what he calls Scotus’s “essentialism.” For Gilson, “existentialism” is philosophical truth, the only view compatible with an authentically Christian metaphysic, while “essentialism” is a Hellenic mistake that seduces Christian philosophers by appealing to the idolatrous desire to reduce reality to what is intelligible. In this paper, the author attempts to describe the difference between “essentialism” and “existentialism” as understood by Gilson. Then, he assesses the case for attributing “essentialism” to Scotus, based on an assessment of Scotus texts and secondary scholarship
Augmenting endogenous wnt signaling improves skin wound healing
No full textWnt signaling is required for both the development and homeostasis of the skin, yet its contribution to skin wound repair remains controversial. By employing Axin2(LacZ/+) reporter mice we evaluated the spatial and temporal distribution patterns of Wnt responsive cells, and found that the pattern of Wnt responsiveness varies with the hair cycle, and correlates with wound healing potential. Using Axin2(LacZ/LacZ) mice and an ear wound model, we demonstrate that amplified Wnt signaling leads to improved healing. Utilizing a biochemical approach that mimics the amplified Wnt response of Axin2(LacZ/LacZ) mice, we show that topical application of liposomal Wnt3a to a non-healing wound enhances endogenous Wnt signaling, and results in better skin wound healing. Given the importance of Wnt signaling in the maintenance and repair of skin, liposomal Wnt3a may have widespread application in clinical practice
Effect of Thermal Stress across Development in Drosophila melanogaster
No full textAnimal development is a complex process that requires successful completion of multiple steps at different developmental stages to produce adult organs and systems. Environmental stress experienced during crucial developmental stages could therefore disrupt the proper functioning and survival of individuals as adults long after the stressor has passed. Early embryonic stages may be particularly susceptible to long-lasting effects because cellular mechanisms of stress resistance are relatively underdeveloped. In chronically cold or hot environments, such stress may impose significant natural selection on early embryonic developmental systems to improve developmental resilience in the face of temperature extremes. In this study, I tested the impact of thermal stress on development in the fruit fly Drosophila melanogaster, for which the sequence of development has been well-described and is known to experience significant heat stress during embryogenesis in the field. I asked two main questions: 1) Are early embryonic stages of development more sensitive to thermal stress than later developmental stages, and 2) have hotter climates resulted in adaptive resilience to thermal stress during early embryonic development? To test whether early embryos are more sensitive to thermal stress, I compared survival, morphological and performance metrics of flies of the Canton-S strain exposed to cold or heat stress at 1, 24, or 60 hours in development. To test whether high temperatures result in adaptive resilience, two tropical and two temperate populations of D. melanogaster from around the globe were tested. The tropical populations originated from Chiapas, Mexico and Guam, and the temperate populations both originated from northern Vermont. The eggs of these populations were reared at 25°C for 1 hour before being transferred to 18°C, 25°C, 30°C, and 32°C incubators and tested to see if they also showed defects seen in Canton-S flies under thermal stress. I found that later developmental stages acclimated better to moderate thermal stress and incurred fewer lasting phenotypic consequences because of that thermal stress compared to early developmental stages. Early embryos experienced a high proportion of deformed wings and many of the pupae failed to eclose into adults. Twenty four-hour flies were found to have a greater proportion of properly developed wings, eclosed from pupae into adults at a higher proportion, and displayed superior upper and lower thermal limits than 1-hour flies. When testing for thermal adaptation during early development between tropical and temperate populations, I found substantial variation between the tropical populations, with only the Chiapas population displaying evidence for thermal adaptation. Chiapas routinely performed better in eclosion success, climbing success, and CTmax. The Guam population, however, frequently performed equally or worse than the temperate populations. Thus, thermal adaptation during development may not have acted equally or even similarly on populations from the same climate. Both parts of this research have important implications for the future of D. melanogaster populations as climate change will continue to affect daily and seasonal temperatures for many D. melanogaster populations. Because flies in early embryonic development are highly sensitive to moderate thermal stress, D. melanogaster populations need to have sufficient adaptive potential to adapt to changing climates during early development. Results from the Chiapas population illustrate how thermal adaptation during early development can buffer populations against moderate thermal stress, possibly allowing populations of D. melanogaster around the globe to adapt to hotter temperatures that arise from climate change.Department of Biolog
Effect of Thermal Stress across Development in Drosophila melanogaster
No full textAnimal development is a complex process that requires successful completion of multiple steps at different developmental stages to produce adult organs and systems. Environmental stress experienced during crucial developmental stages could therefore disrupt the proper functioning and survival of individuals as adults long after the stressor has passed. Early embryonic stages may be particularly susceptible to long-lasting effects because cellular mechanisms of stress resistance are relatively underdeveloped. In chronically cold or hot environments, such stress may impose significant natural selection on early embryonic developmental systems to improve developmental resilience in the face of temperature extremes. In this study, I tested the impact of thermal stress on development in the fruit fly Drosophila melanogaster, for which the sequence of development has been well-described and is known to experience significant heat stress during embryogenesis in the field. I asked two main questions: 1) Are early embryonic stages of development more sensitive to thermal stress than later developmental stages, and 2) have hotter climates resulted in adaptive resilience to thermal stress during early embryonic development? To test whether early embryos are more sensitive to thermal stress, I compared survival, morphological and performance metrics of flies of the Canton-S strain exposed to cold or heat stress at 1, 24, or 60 hours in development. To test whether high temperatures result in adaptive resilience, two tropical and two temperate populations of D. melanogaster from around the globe were tested. The tropical populations originated from Chiapas, Mexico and Guam, and the temperate populations both originated from northern Vermont. The eggs of these populations were reared at 25°C for 1 hour before being transferred to 18°C, 25°C, 30°C, and 32°C incubators and tested to see if they also showed defects seen in Canton-S flies under thermal stress. I found that later developmental stages acclimated better to moderate thermal stress and incurred fewer lasting phenotypic consequences because of that thermal stress compared to early developmental stages. Early embryos experienced a high proportion of deformed wings and many of the pupae failed to eclose into adults. Twenty four-hour flies were found to have a greater proportion of properly developed wings, eclosed from pupae into adults at a higher proportion, and displayed superior upper and lower thermal limits than 1-hour flies. When testing for thermal adaptation during early development between tropical and temperate populations, I found substantial variation between the tropical populations, with only the Chiapas population displaying evidence for thermal adaptation. Chiapas routinely performed better in eclosion success, climbing success, and CTmax. The Guam population, however, frequently performed equally or worse than the temperate populations. Thus, thermal adaptation during development may not have acted equally or even similarly on populations from the same climate. Both parts of this research have important implications for the future of D. melanogaster populations as climate change will continue to affect daily and seasonal temperatures for many D. melanogaster populations. Because flies in early embryonic development are highly sensitive to moderate thermal stress, D. melanogaster populations need to have sufficient adaptive potential to adapt to changing climates during early development. Results from the Chiapas population illustrate how thermal adaptation during early development can buffer populations against moderate thermal stress, possibly allowing populations of D. melanogaster around the globe to adapt to hotter temperatures that arise from climate change.Department of Biolog
Later developmental stages of Drosophila melanogaster acclimate and function better in response to thermal stress than early developmental stages.
No full textUndergraduateAnimal development is a complex process that requires successful completion of multiple steps at different developmental stages to produce adult organs and systems. Environmental stress experienced during crucial developmental stages could therefore disrupt the proper functioning and survival of individuals as adults long after the stressor has passed. Early embryonic stages, in particular, may be particularly susceptible to long-lasting effects because cellular mechanisms of stress resistance are relatively underdeveloped. Drosophila melanogaster acts as a model species, developing important structures like wings and heat resistance systems over time after embryogenesis. In this study, I tested the impact of when thermal stress is applied to pre-adult flies and what impact that had on performance and phenotypic traits as adults. This was accomplished by placing flies in incubators with abnormal temperatures during later developmental stages, including 24 hours post laying, and testing whether later developmental stages acclimated better to thermal stress than early developmental stages. When eggs were laid, they were reared at 25°C for 1 or 24 hours before being transferred to incubators that applied thermal stress that mimicked natural hyperthermia and hypothermia experienced in nature. Moderate thermal stress applied to eggs one hour after laying caused many phenotypic consequences in adulthood. Flies with this treatment experienced a high proportion of deformed wings and many of the pupae failed to eclose into adults. It is expected that thermal stress applied during early embryonic stages disrupts the proper growth and functioning of flies and results in lasting phenotypic consequences. 24-hour flies were found to have a greater proportion of properly developed wings, eclosed from pupae into adults at a higher proportion, and displayed superior upper and lower thermal limits than 1-hour flies. Later developmental stages acclimated better to moderate thermal stress and incurred fewer lasting phenotypic consequences as a result of that thermal stress compared to early developmental stages. By understanding how various developmental stages resisted the deleterious effects of thermal stress, we learned more about when crucial stages in development occur and when D. melanogaster’s ability to resist the effects of thermal stress becomes effective. Due to temperature being an integral factor of D. melanogaster development, female flies should select locations for laying their eggs in nature that are around 25°C, whether that means seeking out shade in hotter climates or seeking out areas constantly exposed to the sun in colder climates
Drawing the Line: How African, Caribbean and White British Women Live Out Psychologically Abusive Experiences
No full textThe final, definitive version of this paper has been published in Violence Against Women, 19 (9):1104-32, Sept 2013 by SAGE Publications Ltd, All rights reserved. © The Author(s) 2013.
The online version of this article can be found at: http://vaw.sagepub.com/content/19/9/110
Later developmental stages of Drosophila melanogaster acclimate and function better in response to thermal stress compared to early developmental stages.
No full text11:00am-1:00pmUndergraduateMost species need to develop many complex organs and systems before they can live as independent adults. Solar thermal stress, provided during crucial developmental stages could disrupt the proper functioning and survival of individuals as adults. Many species utilize heat-shock proteins to resist different types of stress on the cellular level. Drosophila melanogaster acts as a model species and develops important structures like wings and heat resistance systems over time after embryogenesis. Moderate thermal stress applied to eggs one hour after laying caused many phenotypic consequences in adulthood. Flies with this treatment experienced a high proportion of deformed wings and many of the pupae failed to eclose into adults. It is expected that thermal stress applied during early embryonic stages disrupts the proper growth and functioning of flies and results in lasting phenotypic consequences. Later developmental stages have a more developed heat-response system and should acclimate better to thermal stress than early developmental stages and experience fewer lasting deleterious phenotypic effects. We focused on detecting and analyzing the impact of when thermal stress is applied to pre-adult flies and what impact that had on performance and phenotypic traits as adults. This was accomplished by placing flies in incubators with abnormal temperatures during later developmental stages, including 24 hours post laying, and concluding whether later developmental stages acclimated better to thermal stress than early developmental stages. When eggs were laid they were reared at 25°C for 1 or 24 hours before being transferred to incubators that applied thermal stress that mimicked natural hyperthermia and hypothermia experienced in nature. 24 hour flies were found to have a greater proportion of properly developed wings, eclosed from pupae into adults at a higher proportion, and displayed superior upper and lower thermal limits than 1 hour flies. Later developmental stages acclimated better to moderate thermal stress and incurred fewer lasting phenotypic consequences as a result of that thermal stress compared to early developmental stages. By understanding how various developmental stages resisted the deleterious effects of thermal stress, we learned more about when crucial stages in development occur and when D. melanogaster’s ability to resist the effects of thermal stress becomes effective
Duns Scotus on Common Natures and Carving at the Joints of Reality
No full textDespite the puzzles of interpretation it engenders, John Duns Scotus’s theory of common natures is widely cited as an example of scholastic “realism.” Common natures serve a variety of functions in Scotus’s system, providing the “real unity” which serves as the subject for Aristotelian science. The “proper passions” of substances – characteristics which serve to identify substances by type, but do not formally belong to the essence of a subject – are ontologically dependent on common natures according to kind. And Scotus operates on the assumption that it is the description of created subjects according to their common natures which is the most fundamental description of them.Thus, for Scotus, common natures and their relations determine what we might call the “structure” of reality. But not every “subject of a science” is a common nature. According to Scotus, “being,” the subject of “metaphysics,” does not have the same real unity as the natural groupings under the ten categories of Aristotle. As a consequence of this, the “transcendental passions of being” include predicates which do not possess the “real unity” of a common nature, because they are too abstract or generic to do so. I will undertake three primary tasks in this dissertation. First, I will provide a description of the role of common natures in Scotus’s system. Then, I will discuss the rule or criterion by which Scotus posits common natures to account for certain cases of univocal predication – as opposed to cases of univocal predication for which he doesn’t posit common natures. Ultimately, I will discuss the difference between two types of “structure” in Scotus’s system: the case of distinct “quidditative components” in the essence of a subject, and the case of a subject and its passion. In both cases, the relata are “formally distinct.” In the former case but not the latter, they are related by “act-potency composition.” Ultimately, common natures explain the structure in the created world, but not every relatum in a structural relation is a common nature. </p
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