214 research outputs found
Effects of Rising Temperature on Interactions between Monarch Butterflies and their Parasites
During the last few decades, global climate change has been one of the major
drivers of species extinction, and has altered many ecological interactions. Monarch
butterflies, which represent a cultural icon in North America, have been experiencing
population declines due to several anthropogenic forces associated with environmental
change. In addition, a monarch protozoan neogregarine parasite, Ophryocystis
elektroscirrha (OE), aggravates their situation by decreasing the reproductive success
and longevity of adult butterflies. Previous studies have shown that global warming can
modify the interaction between parasites and their hosts. This study aimed to assess
how a rise in temperature affects the virulence and transmission potential of OE. I
hypothesized that an increase in temperature would result in shorter adult life spans
and higher parasite loads. A total of 154 larvae were reared on artificial diet in
incubators at three temperatures, 22°C, 25°C and 28°C until adult emergence or
premature death. Approximately 30 larvae from each temperature were inoculated with
10 OE spores and 20 larvae were un-inoculated controls. Developmental time, pupal
weight and spore loads were measured and data were analyzed using generalized linear
models. Unexpected co-infection with an unknown pathogen resulted in high larval
mortality in both OE-inoculated and control treatments, preventing an independent
assessment of the effect of temperature on the monarch-OE interaction. As a result of
co-infection, monarchs inoculated with OE were more likely to die during the larval
stage. As expected, the total developmental time of butterflies declined at higher
temperatures. Importantly, only 8 out of 42 OE-inoculated larvae that survived to
adulthood produced OE spores, suggesting an antagonistic interaction between the
unknown pathogen and OE. Overall, higher temperatures appeared to have a largely
positive effect on monarch performance, since butterflies reared at warmer
temperatures had shorter developmental times, resulting in a decrease in exposure time
to the unknown pathogen. In conclusion, the unknown pathogen interacted in complex
ways with OE, affecting monarch performance more than the increase in temperature
itself. In this changing world, temperature sensitive host-parasite interactions could
potentially be altered by global warming. However, they need to be studied within the
context of how multiple pathogens will interact with their hosts under elevated
temperature scenarios.Master of ScienceFrontiers Bridging Masters ProgramUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/120240/1/Final Thesis Nifosi.pd
The key to the yellow-to-cyan tuning in the green fluorescent protein family is polarisation
Computational approaches have to date failed to fully capture the large (about 0.4 eV) excitation energy tuning displayed by the nearly identical anionic chromophore in different green fluorescent protein (GFP) variants. Here, we present a thorough comparative study of a set of proteins in this sub-family, including the most red- (phiYFP) and blue-shifted (mTFP0.7) ones. We employ a classical polarisable embedding through induced dipoles and combine it with time-dependent density functional theory and multireference perturbation theory in order to capture both state-specific induction contributions and the coupling of the polarisation of the protein to the chromophore transition density. The obtained results show that only upon inclusion of both these two effects generated by the mutual polarisation between the chromophore and the protein can the full spectral tuning be replicated. We finally discuss how this mutual polarisation affects the correlation between excitation energies, dipole moment variation, and molecular electrostatic field
Cent ans de jalousie proustienne, éds. Erika Fülöp et Philippe Chardin
Il volume raccoglie gli interventi presentati al convegno One Hundred Years of Jealousy: Homage to Swann, tenutasi a Oxford dal 31 maggio al primo giugno del 2013. La collettanea offre ulteriori chiavi di lettura rispetto al tema, dominante nella narrazione proustiana, della gelosia. Come affermato da Erika Fülöp nell’Introduction (pp. 11-19), gli autori si propongono un duplice obiettivo: innanzitutto, il motivo ricorrente della gelosia invita a una rivisitazione di Du côté de chez Swann, di..
Son et traduction dans l’œuvre de Proust, sous la direction d’Emily Eells et Naomi Toth
Il presente volume è il risultato dei lavori svolti durante un convegno del giugno 2015 tenutosi tra l’università di Paris Nanterre e l’Hôtel de Lauzun, sede dell’Institut d’études avancées di Parigi. Il titolo del convegno, Traduire la sonorité proustienne, unisce i due temi cardine della traduzione e delle molteplici riverberazioni dell’elemento sonoro all’interno del romanzo proustiano. La miscellanea si compone di una parte dedicata agli interventi dei relatori e di un’altra che raccoglie..
L'Area Archeologica della Villa romana di San Vincenzino a Cecina (LI): Aspetti della musealizzazione in situ.
Lo straordinario potenziale della villa romana di San Vincenzino e l’importanza che essa rivestiva all'interno del territorio cecinese sono stati immediatamente percepiti sin dalla sua scoperta. In questo progetto di tesi si sono quindi avanzate alcune proposte per il recupero e la musealizzazione al fine di rendere il sito archeologico fruibile e attrezzato non soltanto al fine di valorizzare e conservare il patrimonio archeologico emerso, ma anche di trasmettere nel giusto modo i risultati delle ricerche sia alla popolazione residente, così da avvicinarla al suo glorioso passato, sia al flusso sempre maggiore di turisti, vista l’avvenuta trasformazione della città di Cecina da centro rurale a centro balneare
Jean-Pierre Ollivier, Proust et les sciences
Questa volta è un professore di medicina ad avvicinare con estrema competenza e dedizione il testo proustiano, per evidenziarne ancora una volta la spiccata vocazione interdisciplinare. Nel presente volume, infatti, Jean-Pierre Ollivier prende in esame il discorso scientifico all’interno della Recherche, a partire da tre domande fondamentali relative alla sua ragion d’essere, alla sua pertinenza e alla sua funzione nel tessuto narrativo del romanzo («Introduction», p. 14). Il saggio, organizz..
Energy, Structures, and Response Properties with a Fully Coupled QM/AMOEBA/ddCOSMO Implementation
We present the implementation of a fully coupled polarizable QM/MM/continuum model based on the AMOEBA polarizable force field and the domain decomposition implementation of the conductor-like screening model. Energies, response properties, and analytical gradients with respect to both QM and MM nuclear positions are available, and a generic, atomistic cavity can be employed. The model is linear scaling in memory requirements and computational cost with respect to the number of classical atoms and is therefore suited to model large, complex systems. Using three variants of the green-fluorescent protein, we investigate the overall computational cost of such calculations and the effect of the continuum model on the convergence of the computed properties with respect to the size of the embedding. We also demonstrate the fundamental role of polarization effects by comparing polarizable and nonpolarizable embeddings to fully QM ones
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