Maintaining Research Integrity While Balancing Cultural Sensitivity: A Case Study and Lessons From the Field

Contemporary emphasis on creating culturally relevant and context specific knowledge increasingly drives researchers to conduct their work in settings outside their home country. This often requires researchers to build relationships with various stakeholders who may have a vested interest in the research. This case study examines the tension between relationship development with stakeholders and maintaining study integrity, in the context of potential harms, data credibility and cultural sensitivity. We describe an ethical breach in the conduct of global health research by a arising from the ad‐hoc participation of a community stakeholder external to the visiting research group. A framework for reflection is developed from a careful examination of underlying factors and presented with a discussion of consequences and mitigation measures. This framework aims to present lessons learned for researchers working abroad who might face similar situations in their work.     

Invasion genetics of a human commensal rodent: the black rat Rattus rattus in Madagascar

Studies focusing on geographical genetic patterns of commensal species and on human history complement each other and provide proxies to trace common colonization events. On Madagascar, the unintentional introduction and spread of the commensal species Rattus rattus by people may have left a living clue of human colonization patterns and history. In this study, we addressed this question by characterizing the genetic structure of natural populations of R. rattus using both microsatellites and mitochondrial sequences, on an extensive sampling across the island. Such data sets were analysed by a combination of methods using population genetics, phylogeography and approximate Bayesian computation. Our results indicated two introduction events to Madagascar from the same ancestral source of R. rattus, one in the extreme north of the island and the other further south. The latter was the source of a large spatial expansion, which may have initially started from an original point located on the southern coast. The inferred timing of introduction events—several centuries ago—is temporally congruent with the Arabian trade network in the Indian Ocean, which was flourishing from the middle of the first millennium.     

Biosynthesis and physiology of coenzyme Q in bacteria

Ubiquinone, also called coenzyme Q, is a lipid subject to oxido-reduction cycles. It functions in the respiratory electron transport chain and plays a pivotal role in energy generating processes. In this review, we focus on the biosynthetic pathway and physiological role of ubiquinone in bacteria. We present the studies which, within a period of five decades, led to the identification and characterization of the genes named ubi and involved in ubiquinone production in Escherichia coli. When available, the structures of the corresponding enzymes are shown and their biological function is detailed. The phenotypes observed in mutants deficient in ubiquinone biosynthesis are presented, either in model bacteria or in pathogens. A particular attention is given to the role of ubiquinone in respiration, modulation of two-component activity and bacterial virulence. This article is part of a Special Issue entitled: 18th European Bioenergetic Conference.     

Human eosinophils exert TNF-α and granzyme A-mediated tumoricidal activity toward colon carcinoma cells

Peripheral blood and tissue eosinophilia is a prominent feature in allergic diseases and helminth infections. In cancer patients, tumor-associated tissue eosinophilia is frequently observed. Tumor-associated tissue eosinophilia can be associated with a favorable prognosis, notably in colorectal carcinoma. However, underlying mechanisms of eosinophil contribution to antitumor responses are poorly understood. We have in this study investigated the direct interactions of human eosinophils with Colo-205, a colorectal carcinoma cell line, and show that eosinophils induce apoptosis and directly kill tumor cells. Using blocking Abs, we found that CD11a/CD18 complex is involved in the tumoricidal activity. Coculture of eosinophils with Colo-205 led to the release of eosinophil cationic protein and eosinophil-derived neurotoxin as well as TNF-α secretion. Moreover, eosinophils expressed granzyme A, which was released upon interaction with Colo-205, whereas cytotoxicity was partially inhibited by FUT-175, an inhibitor of trypsin-like enzymatic activity. Our data present the first demonstration, to our knowledge, that granzyme A is a cytotoxic mediator of the eosinophil protein arsenal, exerting eosinophil tumoricidal activity toward Colo-205, and provide mechanistic evidence for innate responses of eosinophil against tumor cells.     

Synthesis and properties of red emitter Ru(II) complexes based on 6,6′-disubstituted-4,4′-bipyrimidine

Heteroleptic complexes [Ru(bpy)₂(R₂bpm)]²⁺, where bpy = 2,2′-bipyridine and R₂bpm = 6,6′-diaryl-4,4′-bipyrimidine, have been synthesized and characterized, together with the homoleptic complex [Ru(R₂bpm)₃]²⁺, in which R₂bpm = 6,6′-diphenyl-4,4′-bipyrimidine. The substituent aryl on the bipyrimidine has significant effects on the properties of these complexes as compared to the parent [Ru(bpy)₂(bpm)]²⁺ complex. The complexes exhibit Ru-to-bpm charge transfer (CT) absorptions centered at about 540 nm and Ru-to-bpy CT absorptions centered at about 435 nm. The assignment of the low energy absorptions is supported by the relative ease of the reduction of the new complexes as compared to [Ru(bpy)₃]²⁺. The new complexes exhibit a relatively intense emission at room temperature, with lifetimes in the 10-50 ns range, with the homoleptic species exhibiting the higher-energy (maximum at 724 nm) and the longest-lived (τ = 48 ns) emission among the complexes. Luminescence lifetimes and quantum yields are governed by the energy gap law, indicating that direct deactivation to the ground state is the dominant relaxation pathway for 1-6, while thermally activated processes are inefficient.     

Enantiomer separation of 1,4-sulfanylalcohols by conventional and low-temperature gas chromatography

Since 1990, the family of organosulfur molecules has assumed increasing importance in pheromone, flavour, and fragrance chemistry. Depending on the constitution of the functional groups, various volatile sulfur-containing compounds are chiral. However, hitherto it has been impossible to study the chirality of 1,4-sulfanylalcohols, since no adequate enantioselective analytical technique has been available. Here we report on the enantiomer separation of ten volatile 1,4-sulfanylalcohol homologues by applying an heptakis(6-O-tert-butyldimethylsilyl-2,3-di-O-methyl)-beta-cyclodextrin phase, involving in some cases the use of a low-temperature gas chromatographic (ltGC) technique. The results are expected to open research potential on the asymmetry of volatile organosulfur molecules, particularly in the fields of pheromone, flavour, and fragrance research.     

Synthesis and antiprotozoal activity of some new synthetic substituted quinoxalines

A series of 29 new quinoxalines was synthesized and evaluated in vitro against several parasites (Leishmania donovani, Trypanosoma brucei brucei, and Trichomonas vaginalis). Several of them displayed interesting activities, and particularly four quinoxaline amides showed in vitro antileishmanial properties (IC50 less than 20 microM).     

Rebound in functional distinctiveness following warming and reduced fishing in the North Sea

Functionally distinct species (i.e. species with unique trait combinations in the community) can support important ecological roles and contribute disproportionately to ecosystem functioning. Yet, how functionally distinct species have responded to recent climate change and human exploitation has been widely overlooked. Here, using ecological traits and long-term fish data in the North Sea, we identified functionally distinct and functionally common species, and evaluated their spatial and temporal dynamics in relation to environmental variables and fishing pressure. Functionally distinct species were characterized by late sexual maturity, few, large offspring, and high parental care, many being sharks and skates that play critical roles in structuring food webs. Both functionally distinct and functionally common species increased in abundance as ocean temperatures warmed and fishing pressure decreased over the last three decades; however, functionally distinct species increased throughout the North Sea, but primarily in southern North Sea where fishing was historically most intense, indicating a rebound following fleet decommissioning and reduced harvesting. Yet, some of the most functionally distinct species are currently listed as threatened by the IUCN and considered highly vulnerable to fishing pressure. Alarmingly these species have not rebounded. This work highlights the relevance and potential of integrating functional distinctiveness into ecosystem management and conservation prioritization.