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Summary Within complex ecological systems, identifying animal species likely to play a key role in the emergence of infectious zoonotic diseases remains a major challenge. One approach consists of using information on current ecological and parasitological similarities among host species in order to predict the most likely pathways for future pathogen spillover. Using field data acquired from 15 sympatric rodent species in various habitats in Thailand, Cambodia and Laos, we built networks based on shared parasites (17 helminth and 15 microparasite species) and shared habitats among rodent species and humans. We investigated the architectures of bipartite and unipartite networks using modularity, subgroups partitioning or node centrality, to assess the relative epidemiological importance of particular rodent species. Our results showed that Rattus tanezumi, Bandicota savilei and R. exulans were consistently found to be members of subgroups that included humans in unipartite and bipartite networks on zoonotic agents and shared habitats. High values of centrality in shared zoonotic agents were found for the same three rodent species, whereas high values of shared habitats were observed for two of them. Although phylogenetically related rodent species likely shared both habitats and parasites, a lack of habitat specialization was associated with increased zoonotic parasite sharing. Our results emphasize the disproportionate importance of these three rodent species, through their high degree of connectivity with humans, which may represent a high risk for direct zoonotic spillover. Moreover, due to its high centrality in habitats, R. tanezumi may also play a key role as a bridge host. The recent discovery of new arenaviruses in rodents in South‐East Asia, with associated disease in humans in Cambodia, provides an opportunity to test this empirically. The three rodent species identified using our network approach are some of the potential maintenance hosts for these new emerging arenaviruses. Synthesis and applications. Our results on rodents and their pathogens in South‐East Asia show that network analysis has a high potential to improve the surveillance of emerging zoonotic pathogens by targeting key host species and potential ‘emerging’ pathogen–rodent interactions in complex and heterogeneous landscapes.

Prevention of malaria transmission throughout much of Africa is dependent on bednets that are impregnated with pyrethroid insecticides. Anopheles arabiensis is the major malaria vector in Chad and efforts to control this vector are threatened by the emergence of pyrethroid resistance. WHO bioassays revealed that An. arabiensis from Ndjamena is resistant to pyrethroids and dichlorodiphenyltrichloroethane (DDT) but fully susceptible to carbamates and organophosphates. No 1014F or 1014S kdr alleles were detected in this population. To determine the mechanisms that are responsible for resistance, genetic crosses were established between the Ndja strain and an insecticide susceptible population from Mozambique. Resistance was inherited as an autosomal trait and quantitative trait locus (QTL) mapping identified a single major locus on chromosome 2R, which explained 24.4% of the variance in resistance. This QTL is enriched in P450 genes including 25 cytochrome P450s in total. One of these, Cyp6p4 is 22-fold upregulated in the Ndja strain compared with the susceptible. Piperonyl butoxide (PBO) synergist and biochemical assays further support a role for P450s in conferring pyrethroid resistance in this population.

Objetivo: considerando el elevado uso de plaguicidas en Colombia y los efectos nocivos que produce la exposición a estas sustancias para la salud humana y el ambiente, se realizó un estudio para la determinación de biomarcadores de exposición y efecto de plaguicidas en la población de Suesca que habita en la ribera del río Bogotá, de los niveles de plaguicidas en muestras de agua del río tomadas en el mismo municipio y en muestras de pez "Capitán de la sabana" (Eremophylus mutisii) capturado en dicha zona. Materiales y métodos: se realizaron determinaciones para organofosforados, carbamatos, ditiocarbamatos y organoclorados También se exploró, mediante una encuesta, la exposición ocupacional a plaguicidas y el conocimiento y utilización de medidas de protección personal en su actividad laboral. Adicionalmente, se examinó el hábito de la pesca de pez Capitán y su consumo en la dieta de los habitantes de esta zona del río. Resultados: los resultados muestran la presencia de plaguicidas organoclorados y organofosforados en el río y en el tejido de los peces y organoclorados y etilentiourea en las muestras biológicas humanas. En el estudio participaron trabajadores directamente expuestos a plaguicidas, quienes manipulan productos de alta toxicidad; en su mayoría conocen y emplean las medidas de protección personal e higiene industrial. Conclusiones: existe contaminación por plaguicidas en la cuenca alta del río Bogotá que afecta a la fauna y a las poblaciones ribereñas. Es necesario promover mejores medidas para el cuidado del ambiente, para la protección y para el autocuidado de las personas que manipulan plaguicidas en la zona. Objective: Considering the high use of pesticides in Colombia and the harmful effects resulting from exposure to these substances on human health and the environment, a study for the determination of biomarkers of exposure and effect of pesticides in population of the banks of the Río Bogotá in Suesca, the levels of pesticides in river water samples taken in the same city and in samples of fish, "Capitán de la Sabana" (Eremophylus mutisii) caught in this area. Materials and methods: We measured for organophosphates, carbamates, dithiocarbamates and organochlorines. We also explored through a survey of occupational exposure to pesticides in the population and knowledge and use of personal protective measures in their work. Additionally, we explored the habit of fishing for captain and consumption in the diet of the inhabitants of the riverbank. Results: The results show the presence of organochlorine and organophosphorus pesticides in the river and in fish tissue and organochlorine and ethylene thiourea in human biological samples. Participated in the study workers directly exposed to pesticides, highly toxic handlers, most know and use personal protective measures and industrial hygiene. Conclusions: Pollution such as pesticides in the upper basin of Bogotá that affects wildlife and coastal populations. Best action is necessary to promote environmental care, protection and self-care of persons using pesticides in the area. Objetivos: Considerando o elevado uso de praguicidas na Colômbia e os efeitos nocivos que produz a exposição a estas sustancias para a saúde humana e o ambiente, se realizou um estudo para a determinação de biomarcadores de exposição e efeito de praguicidas na população de Suesca que habita na ribeira do rio Bogotá, dos níveis de praguicidas em amostras de água do rio tomadas no mesmo município e em amostras do peixe "Capitan de la sabana" (Eremophylus mutisii) caçado nesta zona. Materiais e métodos: se realizaram determinações para organofosforados, carbamates, ditiocarbamatos e organoclorados. Também explorou-se, mediante uma pesquisa, a exposição ocupacional a praguicidas e o conhecimento e utilização de medidas de proteção pessoal em sua atividade laboral. Adicionalmente, examinou-se o hábito da pesca de peixe "Capitan de la sabana" e seu consumo na dieta dos habitantes desta zona do rio. Resultados: os resultados mostram a presencia de praguicidas organoclorados e organofosforados no rio e no tecido dos peixes e organoclorados e etilentiouréia nas amostras biológicas humanas. No estudo participaram trabalhadores diretamente expostos a praguicidas, os quais manipulam produtos de alta toxicidade; na sua maioria conhecem e empregam as medidas de proteção pessoal e higiene industrial. Conclusões: existe contaminação por praguicidas na bacia alta do rio Bogotá que afeita à fauna e às populações da ribeira. É necessário promover melhores medidas para o cuidado do ambiente, para a proteção e para o autocuidado das pessoas que manipulam praguicidas na zona.

International audience; During the Eocene-Oligocene transition (EOT), a major palaeoenvironmental change took place in the Paratethys Sea of central Eurasia. Restricted connectivity and increased stratification resulted in wide-spread deposition of organic-rich sediments which nowadays make up important hydrocarbon source rocks. The North Alpine Foreland Basin (NAFB) was a major gateway of the Paratethys Sea to the open ocean during the Eocene, but the age of closure of this gateway is still uncertain. The Ammer section in southern Germany documents the shallowing of this connection and subsequent disappearance of marine environments in the NAFB, as reflected in its sedimentary succession of turbidites to marls (Deutenhausen to Tonmergel beds), via coastal sediments (Baustein beds) to continental conglomerates (Weißach beds). Here, we apply organic geochemistry and date the lithological transitions in the Ammer section using integrated stratigraphy, including magnetostratigraphy and biostratigraphy. Nannoplankton and dinocyst results can be reconciled when dinoflagellate species Wetzeliella symmetrica is of late Eocene age. Our magnetostratigraphy then records C13r-C13n-C12r and allows calculation of sediment accumulation rates and estimation of ages of lithological transitions. We show that the shallowing from turbiditic slope deposits (Deutenhausen beds) to shelf sediments (Tonmergel beds) coincides with the Eocene-Oligocene boundary at 33.9 Ma. The transition to continental sediments is dated at ca. 33.15 Ma, significantly older than suggested by previous studies. We conclude that the transition from marine to continental sediments drastically reduced the marine connection through the western part of the NAFB and influenced the oxygen conditions of the Paratethys Sea.

While gene flow between distantly related populations is increasingly recognized as a potentially important source of adaptive genetic variation for humans, fully characterized examples are rare. In addition, the role that natural selection for resistance to vivax malaria may have played in the extreme distribution of the protective Duffy-null allele, which is nearly completely fixed in mainland sub-Saharan Africa and absent elsewhere, is controversial. We address both these issues by investigating the evolution of the Duffy-null allele in the Malagasy, a recently admixed population with major ancestry components from both East Asia and mainland sub-Saharan Africa. We used genome-wide genetic data and extensive computer simulations to show that the high frequency of the Duffy-null allele in Madagascar can only be explained in the absence of positive natural selection under extreme demographic scenarios involving high genetic drift. However, the observed genomic single nucleotide polymorphism diversity in the Malagasy is incompatible with such extreme demographic scenarios, indicating that positive selection for the Duffy-null allele best explains the high frequency of the allele in Madagascar. We estimate the selection coefficient to be 0.066. Because vivax malaria is endemic to Madagascar, this result supports the hypothesis that malaria resistance drove fixation of the Duffy-null allele in mainland sub-Saharan Africa.

Parasites and environmental features could synergistically act as stressors to the health of their hosts. The objectives of this study were to evaluate the effect of: (i) water quality, host sex, size and body condition on adult digenean parasite infections; (ii) digenean infections and host sex and size on the oxidative stress biomarkers and body condition of hosts; and (iii) water quality on the oxidative stress biomarkers and body condition in Clarias gariepinus. Water quality variables were measured and C. gariepinus were collected each month for a year for examination of two intestinal digeneans, Masenia nkomatiensis and Glossidium pedatum, and determination of body condition and measurement of biomarkers in the host. The results indicated that the intensity of M. nkomatiensis was positively correlated with electrical conductivity and total dissolved solids. Prevalence of G. pedatum was negatively correlated with electrical conductivity, salinity and total dissolved solids. High summer water temperature was strongly associated with high digenean infections. There was no host body condition, sex or size bias for any of the parasite infection variables. Differences in the biomarker levels and body condition between uninfected fish and those infected with M. nkomatiensis or G. pedatum were insignificant indicating a low effect of the digenean parasites on oxidative stress biomarkers and body condition in the fish. However, total protein levels were positively associated with host size, and lipid peroxidation was negatively related to host body condition; total protein levels were also positively correlated with temperature and negatively correlated with dissolved oxygen. Host body condition was only negatively correlated with dissolved oxygen. Overall the trends observed in the data showed that the parasites have a negligible effect on oxidative stress in host fish and the trends observed for all variables (water quality, stress biomarkers, body condition and parasite infections) showed a strong seasonal pattern.

In the marine environment, metals can be present dissolved or adsorbed to suspended particles. In the last decades a new type of particle has been introduced, microplastics (MPs). The exposure route of pollutants influences their accumulation and distribution into tissues. A pulse-chase experiment was conducted in which mussels were exposed to Hg: adsorbed onto MPs and microalgae (MA) and dissolved (WB). Mussels accumulated the same amount of Hg independently of particle, due to the Hg loading in both particles and their acceptability were similar. The highest Hg accumulation occurred in gill when the Hg exposure was through water and in digestive gland when Hg was adsorbed to particles. More than 70% of the Hg uptake through MPs was quickly eliminated due to: i) part of the cleared MPs might not really be ingested but adhered to body surfaces of mussels, ii) MPs ingested were eliminated through faeces as they are non-nutritive particles which may be rejected in stomach preventing their entry into digestive gland and iii) high affinity of Hg on surface of MPs which meant that Hg was mainly eliminated jointly to MPs. The organic nature of MA facilitates the entry of Hg into digestive gland where MA are intracellularly digested releasing the Hg adsorbed onto their surfaces. In this case, Hg may reach deeper levels by translocation of the Hg incorporated into gland towards foot and remaining tissues, a process that might occur through haemolymph. All of the Hg accumulated in WB during the exposure was internally absorbed into tissues, and later translocated from gill to gland. Although Hg elimination rate in MPs mussels was greater than in the other exposure pathways, an important amount of Hg was maintained through the depuration period, thus we cannot and should not neglect the risk of MPs as vectors for mercury. Sí

Abstract Biofouling causes massive economical losses in the maritime sector creating an urgent need for effective and ecologically non-harmful antifouling materials. Zinc oxide (ZnO) nanorod coatings show promise as an antifouling material; however, the toxicity of ZnO nanorods to marine organisms is not known. We compared the toxicity of suspended ZnO nanorods (NR) with that of ZnO nanoparticles (NP) and ionic Zn2+ in a marine bivalve Mytilus edulis exposed for two weeks to 10 or 100 μg Zn L−1 of ZnO NPs, NRs or Zn2+, or to immobilized NRs. The multi-biomarker assessment included bioenergetics markers (tissue energy reserves, activity of mitochondrial electron transport system and autophagic enzymes), expression of apoptotic and inflammatory genes, and general stress biomarkers (oxidative lesions, lysosomal membrane stability and metallothionein expression). Exposure to ZnO NPs, NRs and Zn2+ caused accumulation of oxidative lesions in proteins and lipids, stimulated autophagy, and led to lysosomal membrane destabilization indicating toxicity. However, these responses were not specific for the form of Zn (NPs, NR or Zn2+) and showed no monotonous increase with increasing Zn concentrations in the experimental exposures. No major disturbance of the energy status was found in the mussels exposed to ZnO NPs, NRs, or Zn2+. Exposure to ZnO NPs and NRs led to a strong induction of apoptosis- and inflammation-related genes, which was not seen in Zn2+ exposures. Based on the integrated biomarker response, the overall toxicity as well as the pro-apoptotic and pro-inflammatory action was stronger in ZnO NPs compared with the NRs. Given the stability of ZnO NR coatings and the relatively low toxicity of suspended ZnO NR, ZnO NR coating might be considered a promising low-toxicity material for antifouling paints.