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Cover page of Psychoactive plant- and mushroom-associated alkaloids from two behavior modifying cicada pathogens

Psychoactive plant- and mushroom-associated alkaloids from two behavior modifying cicada pathogens

(2019)

© 2019 The Authors Entomopathogenic fungi routinely kill their hosts before releasing infectious spores, but a few species keep insects alive while sporulating, which enhances dispersal. Transcriptomics- and metabolomics-based studies of entomopathogens with post-mortem dissemination from their parasitized hosts have unraveled infection processes and host responses. However, the mechanisms underlying active spore transmission by Entomophthoralean fungi in living insects remain elusive. Here we report the discovery, through metabolomics, of the plant-associated amphetamine, cathinone, in four Massospora cicadina-infected periodical cicada populations, and the mushroom-associated tryptamine, psilocybin, in annual cicadas infected with Massospora platypediae or Massospora levispora, which likely represent a single fungal species. The absence of some fungal enzymes necessary for cathinone and psilocybin biosynthesis along with the inability to detect intermediate metabolites or gene orthologs are consistent with possibly novel biosynthesis pathways in Massospora. The neurogenic activities of these compounds suggest the extended phenotype of Massospora that modifies cicada behavior to maximize dissemination is chemically-induced.

Cover page of Power Relations, Coalitions, and Rent Control: Reforming the Military's Natural Resource Levies

Power Relations, Coalitions, and Rent Control: Reforming the Military's Natural Resource Levies

(2019)

Levies imposed on the export earnings of natural resource producers provide the armed forces with sizeable off-budget revenue not subject to oversight or scrutiny. Why do some nations succeed at reforming or eliminating these levies, while others do not? This article argues that outcomes have to do with the balance of coalition strength between civilians and the armed forces. In the contemporary period, the military can no longer go at it alone, relying on tactics of coercive intimidation. Like civilians, it must find political party allies who can compete legislatively on its behalf. How coalitions either congeal, come unraveled, or fail to develop is assessed through a small-N comparative study of Ecuador and Chile.

Cover page of Delegation or Dereliction? When Governments Assign Too Many Defense Posts to Military Officials

Delegation or Dereliction? When Governments Assign Too Many Defense Posts to Military Officials

(2019)

Sometimes democratic political leaders voluntarily cede the armed forces too much authority, assigning them positions that should have gone to civilians. The over-delegation of posts to soldiers can invite problems of dependency, as civilians grow accustomed to the military handling defense policy. This study investigates the delegation of leadership positions in six advanced democracies: Israel, Taiwan, Spain, the US, the UK, and France. It finds that in the first three countries officers dominate many top-tier positions within the defense ministries, while in the latter three, civilians do. Deficiencies in civilian control are unexpected since these countries either face serious external threats or are members of NATO. It is argued that what links the three countries with civilian deficiencies is the presence of wide and longstanding gaps between military and civilian expertise and an absence of incentives to close them. Where civilians suffer from serious knowledge deficits, there is often a temptation to defer to the generals by delegating key ministerial posts to them.

Cover page of Effects of corexit 9500A and Corexit-crude oil mixtures on transcriptomic pathways and developmental toxicity in early life stage mahi-mahi (Coryphaena hippurus).

Effects of corexit 9500A and Corexit-crude oil mixtures on transcriptomic pathways and developmental toxicity in early life stage mahi-mahi (Coryphaena hippurus).

(2019)

Crude oil and polycyclic aromatic hydrocarbon (PAH) exposure in early life stage fish has been well-characterized to induce phenotypic malformations such as altered heart development and other morphological impacts. The effects of chemical oil dispersants on toxicity are more controversial. To better understand how chemical dispersion of oil can impact toxicity in pelagic fish, embryos of mahi-mahi (Coryphaena hippurus) were exposed to three concentrations of the chemical dispersant Corexit 9500A, or Corexit 9500A-oil mixtures (chemically enhanced water accommodated fractions: CEWAF) of Deepwater Horizon crude oil for 48 h. RNA sequencing, gene ontology enrichment, and phenotypic measurements were conducted to assess toxicity. Exposure to Corexit 9500A altered expression of less than 50 genes at all concentrations (2.5, 5, and 10 mg/L nominal concentration) and did not induce acute mortality or phenotypic malformations, corroborating other studies showing minimal effects of Corexit 9500A on developing mahi-mahi embryos. CEWAF preparations contained environmentally relevant ∑PAH concentrations ranging from 1.4 to 3.1 μg/L and similarly did not alter larval morphology. Differentially expressed genes and significantly altered pathways related to cardiotoxicity, visual impairments, and Ca2+ homeostasis reinforced previous work that expression of genes associated with the heart and eye are highly sensitive molecular endpoints in oil-exposed early life stage fish. Differential expression and gene ontology pathways were similar across the three CEWAF treatments, indicating that increased chemical dispersion did not alter molecular outcomes within the range tested here. In addition, significant sublethal molecular responses occurred in the absence of observable phenotypic changes to the heart, indicating that effects of oil on early life stage fish may not be completely dependent on cardiac function.