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Africa is the poorest continent, with the fastest population growth, the most acute food shortages, and overfishing. Meeting rising food demand while preserving sustainable production is challenging. We evaluated the full fishery supply chain over the previous 70 years in search of sustainable growth paths, from fish resource status and fishery production to trade and human consumption. Our data show that Africa had the lowest per capita fish consumption of any continent in 2017, with international imports accounting for 35% of this low fish consumption. Meanwhile, foreign vessels fish legally or illegally in African waters, landing 3.1 million tonnes of fish outside of Africa each year. Current fishing practises have resulted in 40% of fish populations being overexploited, causing a loss of 2 million tonnes of fish production per year. Improved management can reduce non-trade fish outflows from foreign vessels fishing and restore overfished stocks to maximum sustainable levels, increasing Africa's fish consumption by 42% and the commercial value of marine fisheries by 53%. Aside from food supply and economic benefits, there are also various social and environmental benefits including job opportunities, support for local livelihoods, and environmental health. These findings can help inform policy and the development of long-term sustainable solutions to challenges in Africa such as overfishing, low fish consumption, hunger, and poverty. [ABSTRACT FROM AUTHOR]

The present study provides the first ultrastructural data on the digenean Gonocerca phycidis belonging to the family Gonocercidae. Live adults digenean were collected from the stomach of the marine fish Gephyroberyx darwinii (Teleostei: Trachichthyidae) caught in the Atlantic Ocean, off Dakar (Senegal). This is also the first report of G. phycidis from Senegal and from this fish. The mature spermatozoon exhibits (i) two axonemes with the 9 + '1' pattern of the Trepaxonemata, (ii) a lateral expansion associated with external ornamentations and without cortical microtubules, (iii) two types of external ornamentation of the plasma membrane located in the anterior region of the spermatozoon, (iv) two bundles of cortical microtubules in the mitochondrial and nuclear areas of the spermatozoon, (v) one mitochondrion and (vi) a nucleus. The maximum number of cortical microtubules is located in the median part of the spermatozoon. Moreover, the mature spermatozoon of G. phycidis presents some peculiarities. The presence of a lateral expansion without cortical microtubules associated with external ornamentations is described here, for the first time, in digenean spermatozoa. The presence of two elongated bundles of cortical microtubules is also reported for the first time in the superfamily of Hemiuroidea. However, the ultrastructure of the posterior spermatozoon extremity confirms that already described in other hemiuroidean species. [ABSTRACT FROM AUTHOR]

The distribution of ticks is essentially determined by the presence of climatic conditions and ecological contexts suitable for their survival and development. We build a model that explicitly takes into account each physiological state through a system of infinite differential equations where tick population density are structured on an infinite discrete set. We suppose that intrastage development process is temperature dependent (Arrhenius temperatures function) and that larvae hatching and adult mortality are temperature and water vapor deficit dependent. We analysed mathematically the model and have explicit the R 0 of the tick population. [ABSTRACT FROM AUTHOR]

This paper presents the quality improvement of electric power and the optimization of the switching transient states. We have used a hybrid power generating network by combining the AHP (Hierarchical Process Analysis) and SASV (Automated Variable Structured Automation Systems) methods. This combination revisits the interest of the use of decision support methods in the management of the problem of source switching instants in a hybrid network. The results ensure not only optimal control, supervision, but also a considerable reduction in the repetitive switching that exists in such network and which is detrimental to sensitive loads; because it is perceived as power micro-interruptions. All data collected from different sources (photovoltaic field, battery, generator set and public electricity network), the models of this network and interconexion of different buses are presented. [ABSTRACT FROM AUTHOR]

Polo-like kinase 1 (Plk1) expression is inversely correlated with survival advantages in many cancers. However, molecular mechanisms that underlie Plk1 expression are poorly understood. Here, we uncover a hypoxia-regulated mechanism of Plk1-mediated cancer metastasis and drug resistance. We demonstrated that a HIF-2-dependent regulatory pathway drives Plk1 expression in clear cell renal cell carcinoma (ccRCC). Mechanistically, HIF-2 transcriptionally targets the hypoxia response element of the Plk1 promoter. In ccRCC patients, high expression of Plk1 was correlated to poor disease-free survival and overall survival. Loss-of-function of Plk1 in vivo markedly attenuated ccRCC growth and metastasis. High Plk1 expression conferred a resistant phenotype of ccRCC to targeted therapeutics such as sunitinib, in vitro, in vivo, and in metastatic ccRCC patients. Importantly, high Plk1 expression was defined in a subpopulation of ccRCC patients that are refractory to current therapies. Hence, we propose a therapeutic paradigm for improving outcomes of ccRCC patients. Dufies et al. find high Plk1 expression levels in aggressive clear cell renal cell carcinoma and discover that Plk1 is transcriptionally upregulated in a manner dependent on HIF-2. They also find that high Plk1 expression is correlated to a poor prognosis and resistance to tyrosine kinase inhibitor against VEGF receptor, suggesting a critical role for hypoxia/HIF-2-induced Plk1 in disease progression. [ABSTRACT FROM AUTHOR]

This study shows the ultrastructure of the mature spermatozoon of Lecithostaphylus parexocoeti (Digenea, Microphalloidea, Zoogonidae) parasite of the flying fish Cheilopogon pinnatibarbatus (Exocoetidae) captured in the Atlantic Ocean near Dakar (Senegal). This is the first report of L. parexocoeti from Senegal and from this host species. The mature spermatozoon is filiform and exhibits two axonemes of the 9+"1" pattern of the Trepaxonemata, an external ornamentation associated with spine-like bodies, parallel cortical microtubules, a nucleus, two mitochondria and granules of glycogen. The particularities of the spermatozoon of L. parexocoeti are the location of the first mitochondrion and the morphology of its anterior extremity with only cortical microtubules and external ornamentations of the plasma membrane. To our knowledge, this type of anterior extremity has never been described in the superfamily Microphalloidea. However, the ultrastructure of the posterior extremity of the spermatozoon corresponds to the fasciolidean type that was previously described in the Zoogonidae. [ABSTRACT FROM AUTHOR]

Background: Sunitinib is one of the first-line standard treatments for metastatic clear cell renal cell carcinoma (ccRCC) with a median time to progression shorter than 1 year. The objective is to discover predictive markers of response to adapt the treatment at diagnosis.Methods: Prospective phase 2 multi-centre trials were conducted in ccRCC patients initiating sunitinib (54 patients) or bevacizumab (45 patients) in the first-line metastatic setting (SUVEGIL and TORAVA trials). The plasmatic level of CXCL7 at baseline was correlated with progression-free survival (PFS).Results: The cut-off value of CXCL7 for PFS was 250 ng ml-1. Patients with CXCL7 plasmatic levels above the cut-off at baseline (250 ng ml-1) had a significantly longer PFS (hazard ratio 0.323 (95% confidence interval 0.147-0.707), P=0.001). These results were confirmed in a retrospective validation cohort. The levels of CXCL7 did not influence PFS of the bevacizumab-treated patients.Conclusions: CXCL7 may be considered as a predictive marker of sunitinib efficacy for ccRCC patients. [ABSTRACT FROM AUTHOR]

We present in this paper the first ultrastructural study of the spermatozoon of species of the genus Bianium Stunkard, 1930, namely Bianium plicitum and Bianium arabicum belonging to the family Lepocreadiidae . Specimens are parasites of the tetraodontid teleosts Lagocephalus laevigatus caught in the Atlantic Ocean and Lagocephalus sceleratus caught in Pacific Ocean, respectively. Live worms were fixed and processed for transmission electron microscopy. Observations of numerous cross and longitudinal sections of the spermatozoa of B. plicitum and B. arabicum demonstrated the general pattern described in all previously studied Lepocreadioidea, namely two axonemes with 9+ '1' pattern of Trepaxonemata, two mitochondria, a nucleus, parallel cortical microtubules, and an external ornamentation of the plasma membrane associated with spine-like bodies. The maximum number of cortical microtubules and the external ornamentation were not located at the anterior extremity of the spermatozoon but at a more posterior level, as in all the species of Lepocreadioidea studied to date. Differences observed between spermatozoa of B. plicitum and B. arabicum were observed in: (1) the location of the first mitochondrion, (2) size of cortical microtubules which were longer in B. arabicum than in B. plicitum, and (3) the order of the disappearance of the axonemes, mitochondrion, and cortical microtubules toward the posterior region of the spermatozoon. Only the nucleus reaches into the posterior extremity of the spermatozoon in these two species. The general pattern of the spermatozoon described in these two species exhibit the general model in the genus Bianium. [ABSTRACT FROM AUTHOR]

Heterakis is a genus of parasitic nematodes, the majority of which are found in ground-feeding birds and only rarely in mammals. The best-known species is Heterakis spumosa, a parasite associated with the cosmopolitan invasive rodent Rattus rattus of Asiatic origin. Heterakis dahomensis was described in 1911 as a parasite of the Gambian giant rat ( Cricetomys gambianus) from Benin (Africa), subsequently synonymized to H. spumosa by Hall (1916). The study of helminths in African rodents is scarce and patchy. Since the original description of H. dahomensis, there have been only a few reports from Africa of species belonging to the genus Heterakis and the validity of this species has never in fact been confirmed or rejected. In the present study individual Heterakis spp. were collected from C. gambianus from Senegal. The morphological data taken point to differences between Heterakis dahomensis and H. spumosa, specifically in the number of tail papillae in males and in the vulva cuticular processes of females. In addition, molecular data revealed differences between these taxa and so H. dahomensis should be considered as a valid species. Moreover, recent changes in the systematics of the genus Cricetomys mean that it is now necessary to study the morphology and genetics of the Heterakis specimens collected from Cricetomys spp. (previously assigned to C. gambianus) in order to determine their taxonomic status as either H. dahomensis o H. spumosa. [ABSTRACT FROM AUTHOR]

The study highlights the potential of the black-chinned tilapia to be used as a sentinel to assess environmental contaminants based on the use of a set of biomarkers. The usefulness of fish species as sentinels for assessing aquatic environment contamination was tested using a set of biomarkers in Senegalese environments characterized by multi-pollution sources. The black-chinned tilapia ( Sarotherodon melanotheron) was selected as a sentinel because of its abundance, wide distribution in all coastal aquatic ecosystems and physiological properties. The potential influence of confounding factors such as salinity on biomarker in the tilapia has been examined. Individuals were sampled during two seasons (dry and wet) in eight sites characterized by various degrees of anthropogenic contamination and different salinities (from 0 to 102 psu). Biomarkers-including growth rate (GR), condition factor (CF), biotransformation enzymes such as 7-ethoxyresorufin- O-deethylase (EROD) and glutathione- S-transferase (GST), lipid peroxidation (TBARS) and acetylcholinesterase (AChE)-were measured. Chemical contaminant [polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs)] levels showed different sources of contamination with relatively high concentrations of PAHs in the Hann Bay and Foundiougne locations. The most sensitive biomarker present in different sites according to the principal component analysis is EROD. Few variations of the AChE activity and TBARS levels were found. No clear relationship was found between biomarker responses and salinity, but GR and CF were lower in hypersaline conditions. Tilapia is responsive to environmental contaminants such as PAHs, OCPs and PCBs. The S. melanotheron multiparametric approach showed a better discrimination of sites. [ABSTRACT FROM AUTHOR]

This study describes the ultrastructural organisation of the spermatozoon of a digenean Enodiotrema reductum (Pligiorchiida: Plagiorchiidae) from the green turtle Chelonia mydas (Linnaeus, 1758). This is the first report of E. reductum from Senegal. The mature spermatozoon of E. reductum is filiform and exhibits two axonemes of the 9 + '1' pattern of the Trepaxonemata, a nucleus, parallel cortical microtubules, an extramembranar ornamentation associated with spine-like bodies and granules of glycogen, among other ultrastructural features. The spermatozoon of E. reductum is distinguished by the presence of a moniliform mitochondrion composed of a bulge associated with a long cord and of a central cytoplasmic expansion. This work represents the first utrastructural study of any representative of the large family Plagiorchiidae. Our results are compared with previously published data on spermatozoa of other digenean taxa. [ABSTRACT FROM AUTHOR]

The spermiogenesis process in Wardula capitellata begins with the formation of a differentiation zone containing two centrioles associated with striated rootlets and an intercentriolar body. Each centriole develops into a free flagellum orthogonal to a median cytoplasmic process. Later these flagella rotate and become parallel to the median cytoplasmic process, which already exhibits two electron-dense areas and spinelike bodies before its proximodistal fusion with the flagella. The final stage of the spermiogenesis is characterized by the constriction of the ring of arched membranes, giving rise to the young spermatozoon, which detaches from the residual cytoplasm. The mature spermatozoon of W. capitellata presents most of the classical characters reported in digenean spermatozoa such as two axonemes of different lengths of the 9 + '1' trepaxonematan pattern, nucleus, mitochondrion, two bundles of parallel cortical microtubules and granules of glycogen. However, some peculiarities such as two lateral expansions accompanied by external ornamentation of the plasma membrane and spinelike bodies characterize the mature sperm. Moreover, a new spermatological character is described for the first time, the so-called cytoplasmic ornamented buttons. [ABSTRACT FROM AUTHOR]

The mature Holorchis micracanthum spermatozoon exhibits an apical cone of electron-dense material forming a lateral extension, extramembranar ornamentations, and two fields of cortical microtubules, delimited by attachment zones. The axonemes, of the 9 + '1' pattern of the Platyhelminthes, are shifted longitudinally, one compared to the other. The nucleus, with a fibrous chromatin and a more or less circular section, granules of electron-dense material, and a moniliform mitochondrion are present. The latter, in longitudinal sections, appears in the form of successive bulges, connected to each other by a fine mitochondrial cord, and extends along almost the whole length of the gamete. To our knowledge, a moniliform mitochondrion has never been described before in a digenean. Likewise, the presence of a lateral extension of an apical cone of electron-dense material has never been previously reported in the Lepocreadioidea. In addition, in this work, we show for the first time the existence of extramembranar ornamentations in a species of the Lepocreadiidae. [ABSTRACT FROM AUTHOR]

This work describes the first ultrastructural results on spermiogenesis and on the mature spermatozoon of Dicrocoelium hospes (Trematoda, Digenea) collected in Bos indicus from Senegal (Africa). Examination of this species was processed by TEM. Spermiogenesis follows the general pattern found in the digenean, but reveals a particularity consisting of the appearance of glycogen granules in the late spermatids within the testes. The mature spermatozoon possesses five distinct regions and presents all features found in Digenea gametes: two axonemes, mitochondria, nucleus and parallel cortical microtubules. However, several characters allow us to distinguish D. hospes from other digenetic trematodes within the Dicrocoeliidae family. In fact, we observed several structures that are absent in the other species of Dicrocoeliidae studied until now, such as: a cytoplasmic expansion, extramembranar ornamentation, spine-like bodies and two parallel mitochondria in the mature sperm. Moreover, additional particular characteristics were observed in this species in both extremities of the spermatozoon. This work produced new data on the ultrastructure of this trematode family which may be useful for phylogenetic purposes. [ABSTRACT FROM AUTHOR]