1,413 research outputs found

    Sequence variation in the haemagglutinin-neuraminidase gene of human parainfluenza virus type 3 isolates in the UK

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    The sequence variation in a 934 base-pair region of the gene encoding the haemagglutinin-neuraminidase of five human parainfluenza virus type 3 (HPIV3) isolates was determined together with that of a prototype UK strain. All of the clinical isolates were from the Manchester area of the UK and were obtained in 1990. 1991 and 1993. The gene segment was amplified by the polymerase chain reaction using HPIVB-specific oligonucleotide primers. The nucleotide homology of the strains was high, around 99% and specific differences in the UK sequences when compared with that of the US prototype strain were identified. In addition, a number of isolate-specific differences were seen. No correlation was detected between the observed nucleotide mutations and the year of isolation, which supports the hypothesis that HPIV3 shows cocirculation of a heterogeneous population of viruses rather than varying with time in a linear fashion. However, the data suggested that geographically-defined genetic lineages of HPIV3 may exist

    Wie wirken "effektive Mikroorganismen" auf EM-Bokashi in der Bananenproduktion (Musa ssp.)?

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    In Costa Rica, ‘effective microorganisms’ (EM) are used to produce organic fertiliser in the form of Bokashi. This study aimed at investigating the effects of EM addition on the decomposition of banana residues during Bokashi production in comparison to different non-EM control variants (Bokashi produced with: W= water, M= molasses as an EM additive, EMst= sterilized EM). Furthermore, the effects of the above mentioned Bokashi variants on the growth of young banana plants and their effects on the secondary root growth of adult banana plants were evaluated. In comparison to non-EM controls, no increasing effects of EM on the N-mineralization of banana material were observed. All nutrient concentrations were similar for all treatments as well as the weight loss of approximately 77.9 %. The ergosterol concentration was significantly highest in EM Bokashi (77 µg g-1 dry soil), whereas it was lowest in EMst (29 µg g-1 dry soil). Application of all Bokashi variants significantly increased shoot growth of young banana plants under greenhouse conditions compared to a control grown in unamended soil. EM Bokashi and Bokashi produced with molasses significantly decreased the number of root nematodes under greenhouse conditions if compared to the control (nematodes per 100 g: C = 254; W = 143; EMst = 143; M = 67; EM = 38). Furthermore, EM Bokashi increased secondary root growth of adult banana plants in the field (186.7 g) compared to non-composted fresh banana leaves (134.6 g) and a control without mulch application (147 g)

    Protective Efficacy of Menthol Propylene Glycol Carbonate Compared to N, N-diethyl-Methylbenzamide Against Mosquito Bites in Northern Tanzania.

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    The reduction of malaria parasite transmission by preventing human-vector contact is critical in lowering disease transmission and its outcomes. This underscores the need for effective and long lasting arthropod/insect repellents. Despite the reduction in malaria transmission and outcomes in Tanzania, personal protection against mosquito bites is still not well investigated. This study sought to determine the efficacy of menthol propylene glycol carbonate (MR08), Ocimum suave as compared to the gold standard repellent N, N-diethyl-methylbenzamide (DEET), either as a single dose or in combination (blend), both in the laboratory and in the field against Anopheles gambiae s.l and Culex quinquefasciatus. In the laboratory evaluations, repellents were applied on one arm while the other arm of the same individual was treated with a base cream. Each arm was separately exposed in cages with unfed female mosquitoes. Repellents were evaluated either as a single dose or as a blend. Efficacy of each repellent was determined by the number of mosquitoes that landed and fed on treated arms as compared to the control or among them. In the field, evaluations were performed by human landing catches at hourly intervals from 18:00  hr to 01:00  hr. A total of 2,442 mosquitoes were collected during field evaluations, of which 2,376 (97.30%) were An. gambiae s.l while 66 (2.70%) were Cx. quinquefaciatus. MR08 and DEET had comparatively similar protective efficacy ranging from 92% to 100 for both single compound and blends. These findings indicate that MR08 has a similar protective efficacy as DEET for personal protection outside bed nets when used singly and in blends. Because of the personal protection provided by MR08, DEET and blends as topical applicants in laboratory and field situations, these findings suggest that, these repellents could be used efficiently in the community to complement existing tools. Overall, Cx. quinquefasciatus were significantly prevented from blood feeding compared to An. gambiae s.l. The incorporation of these topical repellents for protection against insect bites can be of additional value in the absence or presence of IRS and ITNs coverage. However, a combination of both the physical (bed nets) and the repellent should be used in an integrated manner for maximum protection, especially before going to bed. Additional research is needed to develop repellents with longer duration of protection

    Effect of Delta Operator on Umbral Composition in Finite Operator calculus

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    The main objective of this paper is to propose the matrix representation of umbral composition and investigate the effect of delta operator on umbral composition by using the sequential representation of delta operator in finite operator calculus

    An Optimized Intelligent Deep Network for Herbal Leaf Classification

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    In recent times, a variety of industries have made extensive use of image processing techniques for tasks including segmentation and classification. However, the traditional image processing and ensemble learning approaches face challenges in feature selection and classification. To overcome the demerits of the conventional image processing and boosting algorithm, a novel hybrid Chimp-based Boltzmann Prediction Network (CbBPN) was developed in this article. The presented work was designed and verified in MATLAB software with the herbal leaf dataset. In the model development, the pre-processing and feature extraction module is responsible for extracting valuable features that are pertinent to the classification process. Furthermore, the chimp fitness function increases the classification rate by removing unwanted elements during the classification stage. Additionally, the developed model uses the matching operation to specify the types of the leaf. Furthermore, a case study was created to explain the ways the suggested approach operates. Moreover, a comparison of the projected findings with the existing categorization approaches validates the effectiveness of the constructed model. The comparative analysis shows that the new methods outperformed previously available ones in terms of outpu

    Midgut microbiota of the malaria mosquito vector Anopheles gambiae and Interactions with plasmodium falciparum Infection

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    The susceptibility of Anopheles mosquitoes to Plasmodium infections relies on complex interactions between the insect vector and the malaria parasite. A number of studies have shown that the mosquito innate immune responses play an important role in controlling the malaria infection and that the strength of parasite clearance is under genetic control, but little is known about the influence of environmental factors on the transmission success. We present here evidence that the composition of the vector gut microbiota is one of the major components that determine the outcome of mosquito infections. A. gambiae mosquitoes collected in natural breeding sites from Cameroon were experimentally challenged with a wild P. falciparum isolate, and their gut bacterial content was submitted for pyrosequencing analysis. The meta-taxogenomic approach revealed a broader richness of the midgut bacterial flora than previously described. Unexpectedly, the majority of bacterial species were found in only a small proportion of mosquitoes, and only 20 genera were shared by 80% of individuals. We show that observed differences in gut bacterial flora of adult mosquitoes is a result of breeding in distinct sites, suggesting that the native aquatic source where larvae were grown determines the composition of the midgut microbiota. Importantly, the abundance of Enterobacteriaceae in the mosquito midgut correlates significantly with the Plasmodium infection status. This striking relationship highlights the role of natural gut environment in parasite transmission. Deciphering microbe-pathogen interactions offers new perspectives to control disease transmission.Institut de Recherche pour le Developpement (IRD); French Agence Nationale pour la Recherche [ANR-11-BSV7-009-01]; European Community [242095, 223601]info:eu-repo/semantics/publishedVersio

    Guidelines for DNA recombination and repair studies: Cellular assays of DNA repair pathways

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    Understanding the plasticity of genomes has been greatly aided by assays for recombination, repair and mutagenesis. These assays have been developed in microbial systems that provide the advantages of genetic and molecular reporters that can readily be manipulated. Cellular assays comprise genetic, molecular, and cytological reporters. The assays are powerful tools but each comes with its particular advantages and limitations. Here the most commonly used assays are reviewed, discussed, and presented as the guidelines for future studies.European Research Council ERC2014-ADG669898 TARLOOPMinisterio de Economía y Competitividad BFU2016-75058-PJunta de Andalucía BIO123

    Proposing new variables for the identification of strategic groups in franchising

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    The identification of strategic groups in the Spanish franchising area is the main aim of this study. The authors have added some new strategic variables (not used before) to the study and have classified franchisors between sectors and distribution strategy. The results reveal the existence of four perfectly differentiated strategic groups (types of franchisors). One of the major implications of this study is that the variables that build a strategic group vary depending on the respective sector the network operates in and its distribution strategy. This fact indicates that including sector and distribution strategy is absolutely necessary to achieve good classifications of franchisor type
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