title: Historical museum samples reveal signals of selection and drift in response to changing insecticide use in an agricultural pest moth

authors: Parvizi, Elahe

subjects: cotton bollworm

abstract: In response to environmental and human-imposed selective pressures, agroecosystem pests frequently undergo rapid evolution, with some species having a remarkable capacity to rapidly develop pesticide resistance. Temporal sampling of genomic data can comprehensively capture such adaptive changes over time, for example, by elucidating allele frequency shifts in pesticide resistance loci in response to different pesticides. Here, we leveraged museum specimens spanning over a century of collections to generate temporal contrasts between pre- and post-insecticide populations of an agricultural pest moth, Helicoverpa armigera. We used targeted exon sequencing of 254 samples collected across Australia from the pre-1950s (prior to insecticide introduction) to the 1990s, encompassing decades of changing insecticide use. Our sequencing approach focused on genes that are known to be involved in insecticide resistance, environmental sensation, and stress tolerance. We found an overall lack of spatial and temporal population structure change across Australia. In some decades (e.g., 1960s and 1970s), we found a moderate reduction of genetic diversity, implying stochasticity in evolutionary trajectories due to genetic drift. Temporal genome scans showed extensive evidence of selection following insecticide use, although the majority of selected variants were low impact. Finally, alternating trajectories of allele frequency change were suggestive of potential antagonistic pleiotropy. Our results provide new insights into recent evolutionary responses in an agricultural pest and show how temporal contrasts using museum specimens can improve mechanistic understanding of rapid evolution.

text: Historical museum samples reveal signals of selection and drift in response to changing insecticide use in an agricultural pest moth In response to environmental and human-imposed selective pressures, agroecosystem pests frequently undergo rapid evolution, with some species having a remarkable capacity to rapidly develop pesticide resistance. Temporal sampling of genomic data can comprehensively capture such adaptive changes over time, for example, by elucidating allele frequency shifts in pesticide resistance loci in response to different pesticides. Here, we leveraged museum specimens spanning over a century of collections to generate temporal contrasts between pre- and post-insecticide populations of an agricultural pest moth, Helicoverpa armigera. We used targeted exon sequencing of 254 samples collected across Australia from the pre-1950s (prior to insecticide introduction) to the 1990s, encompassing decades of changing insecticide use. Our sequencing approach focused on genes that are known to be involved in insecticide resistance, environmental sensation, and stress tolerance. We found an overall lack of spatial and temporal population structure change across Australia. In some decades (e.g., 1960s and 1970s), we found a moderate reduction of genetic diversity, implying stochasticity in evolutionary trajectories due to genetic drift. Temporal genome scans showed extensive evidence of selection following insecticide use, although the majority of selected variants were low impact. Finally, alternating trajectories of allele frequency change were suggestive of potential antagonistic pleiotropy. Our results provide new insights into recent evolutionary responses in an agricultural pest and show how temporal contrasts using museum specimens can improve mechanistic understanding of rapid evolution.

year: 2024

title: Synthesis observation equivalence and weak synthesis observation equivalence

authors: Mohajerani, Sahar

subjects: computer science

abstract: This working paper proposes an algorithm to simplify automata in such a way that compositional synthesis results are preserved in every possible context. It relaxes some requirements of synthesis observation equivalence from previous work, so that better abstractions can be obtained. The paper describes the algorithm, adapted from known bisimulation equivalence algorithms, for the improved abstraction method. The algorithm has been implemented in the DES software tool Supremica and has been used to compute modular supervisors for several large benchmark examples. It successfully computes modular supervisors for systems with more than 10¹² reachable states.

text: Synthesis observation equivalence and weak synthesis observation equivalence This working paper proposes an algorithm to simplify automata in such a way that compositional synthesis results are preserved in every possible context. It relaxes some requirements of synthesis observation equivalence from previous work, so that better abstractions can be obtained. The paper describes the algorithm, adapted from known bisimulation equivalence algorithms, for the improved abstraction method. The algorithm has been implemented in the DES software tool Supremica and has been used to compute modular supervisors for several large benchmark examples. It successfully computes modular supervisors for systems with more than 10¹² reachable states.

year: 2012-07-30

title: Language switching in a digital library: Does it make a difference if the default language is set to Maori?

authors: Keegan, Te Taka Adrian Gregory

abstract: In this paper we investigate the effect of default interface language on usage patterns of the Niupepa digital library (a collection of historic Māori language newspapers), by switching the default interface language between Māori and English in alternate weeks.
Transaction analysis of the Niupepa collection logs indicates that changing default language affects the length of user
sessions and the number of actions within sessions, and that the English language interface was used most frequently.

text: Language switching in a digital library: Does it make a difference if the default language is set to Maori? In this paper we investigate the effect of default interface language on usage patterns of the Niupepa digital library (a collection of historic Māori language newspapers), by switching the default interface language between Māori and English in alternate weeks.
Transaction analysis of the Niupepa collection logs indicates that changing default language affects the length of user
sessions and the number of actions within sessions, and that the English language interface was used most frequently.

year: 2004-01-01