Opportunities and challenges for modelling epidemiological and evolutionary dynamics in a multihost, multiparasite system: Zoonotic hybrid schistosomiasis in West Africa

Multihost multiparasite systems are evolutionarily and ecologically dynamic, which presents substantial trans‐disciplinary challenges for elucidating their epidemiology and designing appropriate control. Evidence for hybridizations and introgressions between parasite species is gathering, in part in line with improvements in molecular diagnostics and genome sequencing. One major system where this is becoming apparent is within the Genus Schistosoma, where schistosomiasis represents a disease of considerable medical and veterinary importance, the greatest burden of which occurs in sub‐Saharan Africa. Interspecific hybridizations and introgressions bring an increased level of complexity over and above that already inherent within multihost, multiparasite systems, also representing an additional source of genetic variation that can drive evolution. This has the potential for profound implications for the control of parasitic diseases, including, but not exclusive to, widening host range, increased transmission potential and altered responses to drug therapy. Here, we present the challenging case example of haematobium group Schistosoma spp. hybrids in West Africa, a system involving multiple interacting parasites and multiple definitive hosts, in a region where zoonotic reservoirs of schistosomiasis were not previously considered to be of importance. We consider how existing mathematical model frameworks for schistosome transmission could be expanded and adapted to zoonotic hybrid systems, exploring how such model frameworks can utilize molecular and epidemiological data, as well as the complexities and challenges this presents. We also highlight the opportunities and value such mathematical models could bring to this and a range of similar multihost, multi and cross‐hybridizing parasites systems in our changing world

Altered Behaviour: The Performative Nature of Manufacture Chainsaw Choreographies + Bandsaw Manoeuvres

This paper explores the ventures of the Robotic Fabrications AA Visiting School. Cultivating and implementing radical and innovative modes of architectural fabrication, we borrow from neighbouring creative fields such as choreography, performance and martial arts - efficient code being infected with an exciting spatial complexity and positing an artistic engagement within the world of physical production

Gum Arabic promotes oxidation and ester hydrolysis

We studied the interactions between gum Arabic and select catecholic compounds like caffeic acid, chlorogenic acid and catechol. We observed that GA is capable of promoting the auto-oxidation of the above-mentioned compounds into darkly colored pigments without the addition of redox-sensitive cations. Gum Arabic appeared to be unique among polysaccharide-based materials as many other types of polysaccharides promote the oxidation of the above-mentioned compounds only in the presence of redox cations like Fe2+ or Cu2+. RP-HPLC and SEC chromatographic techniques were employed to monitor the reactions and to observe the formation of high molecular mass, pigmented materials from gum Arabic and all three catecholic compounds. FT-IR spectroscopic analysis revealed that, despite their darkly colored appearances, the gum Arabic/pigment materials synthesized contain mostly gum Arabic and very little pigment. As chlorogenic acid is an ester of caffeic acid, we studied the capacity of gum Arabic to promote ester hydrolysis using acetylsalicylic acid as the model compound. We observed that gum Arabic did promote the hydrolysis of acetylsalicylic acid into salicylic acid. However, in all our experiments involving the pigment formation between gum Arabic and chlorogenic acid, we did not observe any evidence that chlorogenic acid was hydrolyzed leading to the release of caffeic acid during these reactions. In addition, we observed that heat treatment of gum Arabic did not affect its pro-oxidizing capability, but it did negatively affect its capability to hydrolyze salicylic acid. Thus, these two types of chemical reactivity present in the gum Arabic material may be associated with different components of the gum Arabic material

Les Sarcosporidies des petits ruminants au Sénégal

Les Sarcosporidies des petits ruminants rencontrées au Sénégal ont été étudiées. Une prévalence de 82 p. 100 d'infestations à S. ovicanis chez le mouton et de 88 p. 100 à S. capracanis chez la chèvre a été trouvée. Pour S. capracanis une étude est faite au microscope électronique. L'importance de la sarcosporidose dans la pathologie des petits ruminants est discuté

Corrigendum to "GLOWORM-PARA:a flexible framework to simulate the population dynamics of the parasitic phase of gastrointestinal nematodes infecting grazing livestock" [Int. J. Parasitol. 50 (2020) 133-144]

Gastrointestinal (GI) nematodes are a significant threat to the economic and environmental sustainability of keeping livestock, as adequate control becomes increasingly difficult due to the development of anthelmintic resistance (AR) in some systems and climate-driven changes to infection dynamics. To mitigate any negative impacts of climate on GI nematode epidemiology and slow AR development, there is a need to develop effective, targeted control strategies that minimise the unnecessary use of anthelmintic drugs and incorporate alternative strategies such as vaccination and evasive grazing. However, the impacts climate and GI nematode epidemiology may have on the optimal control strategy are generally not considered, due to lack of available evidence to drive recommendations. Parasite transmission models can support control strategy evaluation to target field trials, thus reducing the resources and lead-time required to develop evidence-based control recommendations incorporating climate stochasticity. GI nematode population dynamics arising from natural infections have been difficult to replicate and model applications have often focussed on the free-living stages. A flexible framework is presented for the parasitic phase of GI nematodes, GLOWORM-PARA, which complements an existing model of the free-living stages, GLOWORM-FL. Longitudinal parasitological data for two species that are of major economic importance in cattle, Ostertagia ostertagi and Cooperia oncophora, were obtained from seven cattle farms in Belgium for model validation. The framework replicated the observed seasonal dynamics of infection in cattle on these farms and overall, there was no evidence of systematic under- or over-prediction of faecal egg counts (FECs). However, the model under-predicted the FECs observed on one farm with very young calves, highlighting potential areas of uncertainty that may need further investigation if the model is to be applied to young livestock. The model could be used to drive further research into alternative parasite control strategies such as vaccine development and novel treatment approaches, and to understand GI nematode epidemiology under changing climate and host management

Hopf Categories

We introduce Hopf categories enriched over braided monoidal categories. The notion is linked to several recently developed notions in Hopf algebra theory, such as Hopf group (co)algebras, weak Hopf algebras and duoidal categories. We generalize the fundamental theorem for Hopf modules and some of its applications to Hopf categories.Comment: 47 pages; final version to appear in Algebras and Representation Theor