312 research outputs found

    \u3cem\u3eRhaphiolepis indica\u3c/em\u3e Fruit Extracts for Control \u3cem\u3eFusarium solani\u3c/em\u3e and \u3cem\u3eRhizoctonia solani,\u3c/em\u3e the Causal Agents of Bean Root Rot

    Get PDF
    Numerous strategies have been suggested to reduce dependence on synthetic products, such as physical, microbial, and natural methods. Among the natural remedies, plant extracts have emerged as a popular option owing to their eco-friendly character, ease of degradation, and harmless nature to humans. In our study, we used the acetone and hexane extracts of Rhaphiolepis indica fruit to combat two fungal pathogens that were isolated from infected bean plants and showed root rot symptoms. The two pathogens were confirmed to be pathogenic by pathogenicity assays conducted in vivo. The morphological and molecular identification by ITS-region sequencing revealed that the two isolates were Rhizoctonia solani and Fusarium solani, and they were assigned accession numbers OQ880457 and OQ820158, respectively. Our data showed that both hexane and acetone extracts caused a significant decrease in the linear growth of F. solani at all concentrations used (1%, 2%, and 3%), compared to the control. However, at a concentration of 3%, the hexane extract caused much greater inhibition than the acetone extract. For R. solani, the hexane extract, shows a significant inhibition percentage at all concentrations, which further increases to 85.24% at 3% concentration. The HPLC of both extracts indicated the presence and absence of phenolic and flavonoid compounds. The obtained results revealed that five acetonic phenolic extract compounds were ferulic, p-coumaric, gallic, p-OH benzoic, and cinnamic, with concentrations of 5.31, 10.36, 7.24, 6.08, and 0.89 mg/mL, respectively. On the other hand, the five hexanoic phenolic compounds were catechol, caffeic, chlorogenic, p-OH benzoic, and cinnamic acids, with concentrations of 3.66, 5.14, 0.69, 6.31, and 13.47 mg/mL, respectively. The identified acetonic flavonoid extract compounds, namely rutin, chrysin, quercetin, kaempferol, chrysoeriol, 7-OH flavone, and naringin, had respective concentrations of 5.36, 10.23, 4.32, 15.33, 1.06, 0.087, and 0.069 mg/mL, respectively. In contrast, it was observed that the seven hexanoic flavonoid extracts comprised of rutin, quercetin, kampferol, luteolin, chrysoeriol, 7-OH flavone, and catechin exhibited concentrations of 5.36, 7.15, 18.20, 6.04, 2.04, 10.24, and 13.43 mg/mL, respectively. The results of the study suggest that plant extracts may be a useful natural remedy for combating fungal pathogens and reducing dependence on synthetic products

    Application of a central design composed of surface of response for the determination of the flatness in the steel sheets of a Colombian steel

    Get PDF
    In this paper the results of research are shown in which the response surface was applied with central composite design for estimating the values of flatness as shown and accepted by the quality department and production company of the Caribbean region, taking into account factors such as voltage control in the winding sheet and the coefficient of friction. Initially, a first-order model was proposed to estimate the variance of the error and consider a quantitative model that takes into account the effects of combination. The method of steepest descent is used to sequentially move the descent path, i.e., in the direction of the minimum response decrement, until a new interval near optimal experimentation. Subsequently, a model of higher order was developed using a central composite design with center points and stars, taking into account control other variables additional response flatness, such as the roughness and hardness of the sheets in a range of flexible and acceptable tolerances for the company through a canonical model, and that will be the focus of future research

    \u3cem\u3e Swietenia mahagoni \u3c/em\u3e Leaves Extract: Antifungal, Insecticidal, and Phytochemical Analysis

    Get PDF
    In this study, we investigated the antifungal properties of an acetone extract derived from the leaves of Swietenia mahagoni (SMAL) against two isolated fungi, Fusarium equiseti (OQ820153) and Rhizoctonia solani (OQ820152), from rice sheath. The extract was effective in inhibiting the growth of both fungi at the highest concentration tested, 3000 μg·mL−1. Laboratory tests on the LC20 of SMAL extract (49.86 mg·L−1) versus pyriproxyfen 10% EC (1.96 mg·L−1) were accomplished on Aphis gossypii Glover. The extract potently reduced the survival of the nymphs (49.58%) more than the other treatments. The longevity of nymphs treated with the extract had the highest prolongation at 9.67 days. The olfactory choice test exhibited the lowest aphid attraction percentage (23.33%). The HPLC of SMAL extract contained various phenolic compounds, and the most abundant found were catechin (752.64 µg·g−1), gallic acid, and chlorogenic acid, as well as flavonoids such as rutin (585.24 µg·g−1) and naringenin. A GC–MS analysis revealed n-hexadecanoic acid (37.1%) as the major compound, followed by oleic acid. These results suggest that SMAL extract has the potential to help plants fight against fungal and insect infections, making it a promising natural and renewable solution for long-term plant pest regulation

    Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis

    Get PDF
    BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London

    Energy-efficient quantum frequency estimation

    Get PDF
    The problem of estimating the frequency of a two-level atom in a noisy environment is studied. Our interest is to minimise both the energetic cost of the protocol and the statistical uncertainty of the estimate. In particular, we prepare a probe in a `GHZ-diagonal' state by means of a sequence of qubit gates applied on an ensemble of n atoms in thermal equilibrium. Noise is introduced via a phenomenological time-nonlocal quantum master equation, which gives rise to a phase-covariant dissipative dynamics. After an interval of free evolution, the n-atom probe is globally measured at an interrogation time chosen to minimise the error bars of the final estimate. We model explicitly a measurement scheme which becomes optimal in a suitable parameter range, and are thus able to calculate the total energetic expenditure of the protocol. Interestingly, we observe that scaling up our multipartite entangled probes offers no precision enhancement when the total available energy E is limited. This is at stark contrast with standard frequency estimation, where larger probes---more sensitive but also more `expensive' to prepare---are always preferred. Replacing E by the resource that places the most stringent limitation on each specific experimental setup, would thus help to formulate more realistic metrological prescriptions

    Global economic burden of unmet surgical need for appendicitis

    Get PDF
    Background: There is a substantial gap in provision of adequate surgical care in many low-and middle-income countries. This study aimed to identify the economic burden of unmet surgical need for the common condition of appendicitis. Methods: Data on the incidence of appendicitis from 170 countries and two different approaches were used to estimate numbers of patients who do not receive surgery: as a fixed proportion of the total unmet surgical need per country (approach 1); and based on country income status (approach 2). Indirect costs with current levels of access and local quality, and those if quality were at the standards of high-income countries, were estimated. A human capital approach was applied, focusing on the economic burden resulting from premature death and absenteeism. Results: Excess mortality was 4185 per 100 000 cases of appendicitis using approach 1 and 3448 per 100 000 using approach 2. The economic burden of continuing current levels of access and local quality was US 92492millionusingapproach1and92 492 million using approach 1 and 73 141 million using approach 2. The economic burden of not providing surgical care to the standards of high-income countries was 95004millionusingapproach1and95 004 million using approach 1 and 75 666 million using approach 2. The largest share of these costs resulted from premature death (97.7 per cent) and lack of access (97.0 per cent) in contrast to lack of quality. Conclusion: For a comparatively non-complex emergency condition such as appendicitis, increasing access to care should be prioritized. Although improving quality of care should not be neglected, increasing provision of care at current standards could reduce societal costs substantially

    Investigation of the effect of temper rolling on the texture evolution and mechanical behavior of IF steels using multiscale simulation

    Get PDF
    The main objective of this study is to simulate texture and deformation during the temper-rolling process. To this end, a rate-independent crystal plasticity model, based on the self-consistent scale-transition scheme, is adopted to predict texture evolution and deformation heterogeneity during temper-rolling process. For computational efficiency, a decoupled analysis is considered between the polycrystalline plasticity model and the finite element analysis for the temper rolling. The elasto-plastic finite element analysis is first carried out to determine the history of velocity gradient during the numerical simulation of temper rolling. The thus calculated velocity gradient history is subsequently applied to the polycrystalline plasticity model. By following some appropriately selected strain paths (i.e., streamlines) along the rolling process, one can predict the texture evolution of the material at the half thickness of the sheet metal as well as other parameters related to its microstructure. The numerical results obtained by the proposed strategy are compared with experimental data in the case of IF steels.French program “Investment in the future” operated by the National Research Agency (ANR)-11-LABX-0008-01, LabEx DAMAS (LST)
    corecore