Are predatory mites efficient dispersal agents of entomopathogenic fungi? : understanding the process of disease transmission from predators to prey for biological control

Towards the end of my PhD, I decided to combine my two passions together: burlesque and biological control. Here is the link to an eight-minute burlesque video that interprets my PhD. I danced as a predatory mite and my friends danced as thrips. https://www.youtube.com/watch?v=N-UT5engHRcLes acariens prédateurs et les champignons entomopathogènes sont couramment utilisés dans les programmes de lutte biologique contre le thrips des petits fruits, Frankliniella occidentalis. Les acariens prédateurs peuvent localiser les thrips même lorsque ceux-ci se cachent, mais ne consomment que le premier stade larvaire. Les champignons entomopathogènes, quant à eux, peuvent infecter tous les stades, mais leur dispersion est passive. Dans cette thèse, nous avons évalué le potentiel des acariens prédateurs comme agents de dispersion des champignons entomopathogènes dans les colonies de thrips. Le travail expérimental de cette thèse a été divisé en trois sections. Dans la première section, nous avons évalué la pathogénicité de la souche ANT-03 du champignon entomopathogène Beauveria bassiana pour chacun des stades de thrips ainsi que pour trois espèces d'acariens prédateurs: deux espèces principalement actives sur les plantes (Amblyseius swirskii et Neoseiulus cucumeris) et une espèce active dans le sol (Stratiolaelaps scimitus). Nous avons (1) établi que la souche ANT-03, les acariens prédateurs et les thrips forment des associations fonctionnelles d'agent pathogène, de vecteurs et d'hôte, (2) démontré que des spores mélangées aux substrats d'élevage des acariens s'accumulent sur leurs corps au fil du temps, et (3) mis au point une méthode d'application permettant aux acariens de disséminer les spores de B. bassiana directement à partir des substrats d'élevage. Dans la deuxième section, à l'aide d'enregistrements vidéo, nous avons déterminé comment les acariens prédateurs délogent les spores de leurs corps en examinant la relation entre le nombre de spores restant sur les acariens et le temps alloué au toilettage ou à la marche. Nous avons comparé les comportements des acariens prédateurs avec ou sans spores. Nous avons montré que la marche, est plus efficace le toilettage pour déloger les spores. Les acariens prédateurs peuvent percevoir la présence des spores sur leur corps et augmenter le temps alloué à la marche. Dans la troisième section, nous avons déterminé la capacité des acariens prédateurs à acheminer les spores jusqu’aux colonies de thrips. Amblyseius swirskii et N. cucumeris ont été chargés de spores et relâchés sur des plantes infestées de thrips de premier stade et regroupés sur les feuilles. Nous avons caractérisé la distribution spatiale de chaque organisme, calculé l’empiètement spatial entre les spores et les thrips et estimé la proportion de thrips portant des spores. Les deux acariens ont dispersé une quantité similaire de spores sur les plantes, mais A. swirskii a distribué plus de spores sur les feuilles infestées de thrips et a donc augmenté le taux de rencontre entre le pathogène et les thrips. Les différences observées entre les espèces d'acariens prédateurs résultent de leurs différents comportements de chasse. En comprenant le processus de transmission des spores de champignons entomopathogènes des acariens prédateurs vers les proies, nous fournissons une base théorique pour identifier quels prédateurs feraient de bons candidats comme agents de dispersion de spores. Ainsi, nous pourrons augmenter la capacité des acariens prédateurs à réduire les populations de thrips en combinant la prédation et la dispersion d’entomopathogènes dans un contexte de lutte biologique.In biological control programs, predatory mites and entomopathogenic fungi are commonly used against western flower thrips, one of the most challenging pests in food and ornamental crops. Predatory mites can locate thrips even when thrips hide in plant crevices, but they only consume first instar larval thrips. Entomopathogenic fungi can infect all other stages, but their dispersal is passive and host encounter is therefore random. This thesis examines the potential role of predatory mites as dispersal agents of entomopathogenic fungi to thrips colonies. The experimental work has been divided into three sections. In the first section, we evaluated the pathogenicity of the entomopathogenic fungus Beauveria bassiana strain ANT-03 to all stages of the western flower thrips and to three species of predatory mites: Amblyseius swirskii and Neoseiulus cucumeris that are active on plants and Stratiolaelaps scimitus that is active in soil. We established that B. bassiana ANT-03, predatory mites and thrips form appropriate pathogen-vector-host associations. We also developed a commercially applicable method for predatory mites to collect B. bassiana spores directly from the rearing substrates and transport them to the environment. We demonstrated that spores did accumulate on predatory mites over time in the substrates. In the second section, using video recordings, we described how predatory mites dislodged spores by linking the number of spores remaining on a mite to the time spent grooming and walking. We compared behaviors of the predatory mites with and without spores following their release from rearing substrates. Using low-temperature scanning electronic microscopy, we visualized the spore distribution on mites. We showed that walking primarily contributed to predatory mites dislodging spores in our experimental arena, whereas grooming was insufficient. When bearing conidia, all three species of predatory mites extended their walking periods. The duration of grooming behavior was not affected for A. swirskii and N. cucumeris, and was even reduced for S. scimitus. For the third section, we determined the capacity of predatory mites to deliver spores to thrips colonies. Amblyseius swirskii and N. cucumeris were loaded with spores and released on plants that had been previously infested with first instar thrips clustered on leaves. We carefully characterized the spatial distribution of each organism on plants, calculated the spatial co-occurrence index of spores and thrips, and estimated the proportion of thrips with spores. Both mites dispersed similar amounts of spores per plant, but A. swirskii delivered more spores to thrips infested leaves and thereby played a significant role in spreading the fungal disease to thrips populations. The observed differences between predatory mite species resulted from different foraging activity patterns. By understanding how the pathogens can be transferred from foraging predatory mites to prey, we provided a theoretical basis for identifying candidate predators as efficient fungal dispersal agents. These methods, if validated in commercially representative settings, could increase the capacity of predatory mites to suppress thrips populations by combining predation and dispersion of entomopathogens for biological control

An Interview with Eileen A. Olds

It\u27s your job to speak up. And then it\u27s also your job if you see things that don\u27t... feel right, to address them in some way. -- Judge Eileen Olds ------------------------------------ Sharp, quick-witted, and carrying a solemn charm, Judge Olds shares a strong personal narrative portraying her life as one in which she incessantly pursues justice. Her interview begins with stories of a strong sense of right and wrong in her early years. She goes on to share her rather traumatic experience of being isolated by fellow classmates during law school. Nonetheless, she and her fellow African American students (there were only four in her class) supported one another, even advocating for increased diversity among students and faculty at the law school. As the interview progresses, Judge Olds describes her highly successful career. She touches on rejoining the law school community after many years feeling unable to return. Judge Olds describes her “Tell it to the Judge” program, about how judges are trained, what they can do to be better. She discusses advice for her younger self, and for the law school now. She finishes the interview on a hopeful note, describing the law school today as a much better institution in terms of diversity and priorities.https://scholarship.law.wm.edu/oralhist_all/1005/thumbnail.jp

OncoDB: An interactive online database for analysis of gene expression and viral infection in cancer

Large-scale multi-omics datasets, most prominently from the TCGA consortium, have been made available to the public for systematic characterization of human cancers. However, to date, there is a lack of corresponding online resources to utilize these valuable data to study gene expression dysregulation and viral infection, two major causes for cancer development and progression. To address these unmet needs, we established OncoDB, an online database resource to explore abnormal patterns in gene expression as well as viral infection that are correlated to clinical features in cancer. Specifically, OncoDB integrated RNA-seq, DNA methylation, and related clinical data from over 10 000 cancer patients in the TCGA study as well as from normal tissues in the GTEx study. Another unique aspect of OncoDB is its focus on oncoviruses. By mining TCGA RNA-seq data, we have identified six major oncoviruses across cancer types and further correlated viral infection to changes in host gene expression and clinical outcomes. All the analysis results are integratively presented in OncoDB with a flexible web interface to search for data related to RNA expression, DNA methylation, viral infection, and clinical features of the cancer patients. OncoDB is freely accessible at http://oncodb.org

An Interview with Alemante Gebre-Selassie

So when I came here, I wrote back that experience of Law and Development as an important subject... We have to study the actual realities of a country, their culture, their geography, their history, their economic conditions, their social conditions before you propose some kind of recommendation to them. -- Alemante Gebre-Selassie ------------------------------------ The interview starts with Professor Gebre-Selassie’s background and family. He was educated first as a law student at University of Haile Selassie in the 1960s, followed by a J.D. in UW-Madison. He discusses life prior to teaching at W&M and about his home country. Professor Gebre-Selassie emphasizes that the single most important value for the legal profession is dedication. He also stresses the importance of U.S legal scholars to respect regional differences and traditions of other countries before applying “universal” legal doctrines. Professor Gebre-Selassie stresses several times the importance of a closely-knit community of faculty members, which he believes has been diminished, possibly as a result of the global pandemic, during his years as emeritus faculty.https://scholarship.law.wm.edu/oralhist_all/1001/thumbnail.jp

Equity Markets, Financial Integration and Competitive Convergence

We expect a firm's competitive advantage to manifest itself in a return on invested capital that is higher than the opportunity cost of capital. Deviations of returns from the cost of capital are a signal for competitive entry or for exit, while the speed of convergence indicates the strength of competitive forces. It is widely believed that, in some sense, the world is becoming more competitive, and that this is may be the effect of globalisation, facilitated by innovations in information technology. It also be the effect of determined actions by governments over two or three decades, to deregulate and open up markets to competition. So for example, in Europe one purpose of both the common currency and the Single Market project was to accelerate the process of economic convergence and, presumably, of competitive convergence. This paper examines the process of competitive convergence in profitability of listed companies in 7 countries of the European Union. We cast our examination of the convergence process in terms of three questions. The first is whether, and to what extent, we observe convergence in profitability through time. The second question is whether there are national differences in the extent of convergence or the speed at which it takes place. Thirdly, we look at the dynamics of convergence through time to see whether there is evidence that convergence in profitability has become more rapid, by which we mean above average or below average profitability persists for a shorter space of time because of increases in competition. The extent to which this can be related to economic and monetary convergence in the European Union remains an open question

Further Cryptanalysis of a Type of RSA Variants

To enhance the security or the efficiency of the standard RSA cryptosystem, some variants have been proposed based on elliptic curves, Gaussian integers or Lucas sequences. A typical type of these variants which we called Type-A variants have the specified modified Euler\u27s totient function $\psi(N)=(p^2-1)(q^2-1)$. But in 2018, based on cubic Pell equation, Murru and Saettone presented a new RSA-like cryptosystem, and it is another type of RSA variants which we called Type-B variants, since their scheme has $\psi(N)=(p^2+p+1)(q^2+q+1)$. For RSA-like cryptosystems, four key-related attacks have been widely analyzed, i.e., the small private key attack, the multiple private keys attack, the partial key exposure attack and the small prime difference attack. These attacks are well-studied on both standard RSA and Type-A variants. Recently, the small private key attack on Type-B variants has also been analyzed. In this paper, we make further cryptanalysis of Type-B variants, that is, we propose the first theoretical results of multiple private keys attack, partial key exposure attack as well as small prime difference attack on Type-B variants, and the validity of our attacks are verified by experiments. Our results show that for all three attacks, Type-B variants are less secure than standard RSA

カタリ エナイ タイケン ヲ イカニ カタルカ ジョルジュ バタイユ ノ ヘーゲル ヘノ カイキ ヲ テガカリ ニ シテ

本稿で試みられるのは、語りえない体験をいかに語るのかという問いをめぐるジョルジュ・バタイユの思考を考察することである。この問いは主著の『内的体験』から「実存主義から経済の優位性へ」という論文までを貫くバタイユの重要な問題意識の一つであるが、今までの議論は後者の論文に関する考察にとどまっており、「ヘーゲル、死と供犠」という論文の中で、バタイユがヘーゲルとの対決によってこの問いに応えた思索の過程が十分に検討されてこなかった。したがって、本稿はバタイユのヘーゲル読解を考察し、バタイユがいかにヘーゲルとの緊張関係において、語りえない体験を語るための方法を案出したのかについて論じる。This paper examines Georges Bataille’s thought upon the question, that is, how to tell the experience which cannot be told. This question which is one of the most significant interests of Bataille is consistent from his important work, L’expérience intérieur, to the essay ‘De l’existentialisme au primat de l’économie’. Current studies have focused on the statements in ‘De l’existentialisme au primat de l’économie’ but have not sufficiently discussed his later article, ‘Hegel, la mort et le sacrifice’, in which Bataille gave an possible answer to the question in confrontation with Hegel’s philosophy. By examining Bataille’s reading of Hegel, I argue that Bataille works out the approach of telling the experience in the very tension with Hegel.論

Dynamic Optimal Production Strategies Based on the Inventory-Dependent Demand under the Cap-and-Trade Mechanism

Cap-and-trade system is the most popularly applied mechanism that is currently recognized to be effective in stimulating the enterprises to environmentally friendly operate through emission reduction. In this paper, we consider a single company whose carbon emission is generated from not only its production process but also its inventory management activity. A continuous optimal control model is used to find the optimal dynamic production policy on the objective of profit maximization with respect to the cap-and-trade mechanism. Some properties of the strategies are derived concerning the timing of production rate adjustment and the length of the decision duration period. The capacitated strategy is also discussed, in which different combinations of different decision intervals of different production rates are explicitly explored. The impact of various factors on the length of these intervals is qualitatively described. Through the sensitivity analysis, we further discuss the impact of product prices on the positions of the switch time points between the decision intervals. Company’s performance including profit and emission is numerically compared in the situation of joining or not joining the cap-and-trade system