218 research outputs found

    Mapping performance of irrigation schemes in Turkey

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    Water is a crucial resource and approximately 70% usage of it in the agriculture sector in Turkey. Water user associations are in charge of irrigation water management. The core aim of this study is to assess water user associations have command area more than 1,000 ha (WUAs) within the districts of DSI (State Hydraulic Works) and to create spatial maps to show the distribution of the performance indicators used constantly by researchers especially around Mediterranean countries during the period from 2011 to 2015. Frequency and panel data analysis are used to figure out the relationship among performance indicators and attributes such as water diversion type, management type, source of water and district no. Panel data analysis was applied to examine statistical assessment over time. As a result, current performance indicators show that excessive irrigation water used due to low technology and management problem. Performance indicators show high differences among districts due to climate, water resources, and crop pattern. Moreover, low irrigation efficiency can be increased with a transition to pressurized irrigation systems, so more are can be irrigated with less water

    Preterm infants harbour diverse Klebsiella populations, including atypical species that encode and produce an array of antimicrobial resistance- and virulence-associated factors

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    Klebsiella spp. are frequently enriched in the gut microbiota of preterm neonates, and overgrowth is associated with necrotizing enterocolitis (NEC), nosocomial infections and late-onset sepsis. Little is known about the genomic and phenotypic characteristics of preterm-associated Klebsiella as previous studies have focussed on recovery of antimicrobial-resistant isolates or culture independent molecular analyses. The aim of this study was to better characterize preterm-associated Klebsiella populations using phenotypic and genotypic approaches. Faecal samples from a UK cohort of healthy and sick preterm neonates (n=109) were screened on MacConkey agar to isolate lactose positive Enterobacteriaceae. Whole-genome sequences were generated for Klebsiella spp., and virulence and antimicrobial resistance genes identified. Antibiotic susceptibility profiling, and in vitro macrophage and iron assays were undertaken for the Klebsiella strains. Metapangenome analyses with a manually curated genome dataset were undertaken to examine diversity of Klebsiella oxytoca and related bacteria in a publicly available shotgun metagenome dataset. Approximately one-tenth of faecal samples harboured Klebsiella spp. (Klebsiella pneumoniae, 7.3 %; Klebsiella quasipneumoniae, 0.9 %; Klebsiella grimontii, 2.8 %; Klebsiella michiganensis, 1.8 %). Isolates recovered from NEC- and sepsis-affected infants and those showing no signs of clinical infection (i.e. 'healthy') encoded multiple -lactamases. No difference was observed between isolates recovered from ‘healthy’ and sick infants with respect to in vitro siderophore production (all encoded enterobactin in their genomes). All K. pneumoniae, K. quasipneumoniae, K. grimontii and K. michiganensis faecal isolates tested were able to reside and persist in macrophages, indicating their immune evasion abilities. Metapangenome analyses of published metagenomic data confirmed our findings regarding the presence of K. michiganensis in the preterm gut. There is little difference in the phenotypic and genomic characteristics of Klebsiella isolates recovered from 'healthy' and sick infants. Identification of -lactamases in all isolates may prove problematic when defining treatment regimens for NEC or sepsis, and suggests ‘healthy’ preterm infants contribute to the resistome. Refined analyses with curated sequence databases are required when studying closely related species present in metagenomic data

    Bifidobacterium breve reduces apoptotic epithelial cell shedding in an exopolysaccharide and MyD88-dependent manner

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    Certain members of the microbiota genus Bifidobacterium are known to positively influence host well-being. Importantly, reduced bifidobacterial levels are associated with inflammatory bowel disease (IBD) patients, who also have impaired epithelial barrier function, including elevated rates of apoptotic extrusion of small intestinal epithelial cells (IECs) from villi—a process termed ‘cell shedding’. Using a mouse model of pathological cell shedding, we show that mice receiving Bifidobacterium breve UCC2003 exhibit significantly reduced rates of small IEC shedding. Bifidobacterial-induced protection appears to be mediated by a specific bifidobacterial surface exopolysaccharide and interactions with host MyD88 resulting in downregulation of intrinsic and extrinsic apoptotic responses to protect epithelial cells under highly inflammatory conditions. Our results reveal an important and previously undescribed role for B. breve, in positively modulating epithelial cell shedding outcomes via bacterial- and host-dependent factors, supporting the notion that manipulation of the microbiota affects intestinal disease outcomes

    Next generation of selenocyanate and diselenides with upgraded leishmanicidal activity

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    Nowadays, leishmaniasis is still treated with outdated drugs that present several obstacles related to their high toxicity, long duration, parenteral administration, high costs and drug resistance. Therefore, there is an urgent demand for safer and more effective novel drugs. Previous studies indicated that selenium compounds are promising derivatives for innovative therapy in leishmaniasis treatment. With this background, a new library of 20 selenocyanate and diselenide derivatives were designed based on structural features present in the leishmanicidal drug miltefosine. Compounds were initially screened against promastigotes of L. major and L. infantum and their cytotoxicity was evaluated in THP-1 cells. Compounds B8 and B9 were the most potent and less cytotoxic and were further screened for the intracellular back transformation assay. The results obtained revealed that B8 and B9 showed EC50 values of 7.7 µM and 5.7 µM, respectively, in L. major amastigotes, while they presented values of 6.0 µM and 7.4 µM, respectively, against L. infantum amastigotes. Furthermore, they exerted high selectivity (60 70) towards bone marrow-derived macrophages. Finally, these compounds exhibited higher TryR inhibitory activity than mepacrine (IC50 7.6 and 9.2 µM, respectively), and induced nitric oxide (NO) and reactive oxygen species (ROS) production in macrophages. These results suggest that the compounds B8 and B9 could not only exert a direct leishmanicidal activity against the parasite but also present an indirect action by activating the microbicidal arsenal of the macrophage. Overall, these new generation of diselenides could constitute promising leishmanicidal drug candidates for further studies
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