Magnetic Nanoparticles Enhanced Surface Plasmon Resonance Biosensor for Rapid Detection of Salmonella Typhimurium in Romaine Lettuce

Salmonella is one of the major foodborne pathogens responsible for many cases of illnesses, hospitalizations and deaths worldwide. Although different methods are available to timely detect Salmonella in foods, surface plasmon resonance (SPR) has the benefit of real-time detection with a high sensitivity and specificity. The purpose of this study was to develop an SPR method in conjunction with magnetic nanoparticles (MNPs) for the rapid detection of Salmonella Typhimurium. The assay utilizes a pair of well-characterized, flagellin-specific monoclonal antibodies; one is immobilized on the sensor surface and the other is coupled to the MNPs. Samples of romaine lettuce contaminated with Salmonella Typhimurium were washed with deionized water, and bacterial cells were captured on a filter membrane by vacuum filtration. SPR assays were compared in three different formats—direct assay, sequential two-step sandwich assay, and preincubation one-step sandwich assay. The interaction of flagellin and MNPs with the antibody-immobilized sensor surface were analyzed. SPR signals from a sequential two-step sandwich assay and preincubation one-step sandwich assay were 7.5 times and 14.0 times higher than the direct assay. The detection limits of the assay were 4.7 log cfu/mL in the buffer and 5.2 log cfu/g in romaine lettuce samples

Down Drag on an Instrumental Bored Pile in Soft Clay

The paper reports result of a comprehensive full scale field study expressly undertaken to monitor negative drag on a large diameter, bored cast-in-place reinforced concrete pile installed to rock in a deep deposit of soft marine clay of pleistaceae to recent origin. The pile was instrumented with load cells and the ground around the pile with piezometers and settlement gauges. The negative drag was generated by loading the ground around the pile in stages. The ground settlements were accelerated by providing vertical sand drains. The observational data were utilized in figuring out the influence of surcharge on the depth of clay responsible for generating the negative drag. The study has provided computational methodology for estimation of negative drag in terms of total and effective stresses. The inevitability of large ground settlement with respect to the pile brought out the non-importance of precisely ascertaining the magnitude of relative displacement necessary for mobilization of negative drag

Diversity rich solutions

Every household is diverse and diversity can be observed within household in terms of crops, varieties and landraces, soil type, food preferences and preparation methods, knowledge and practices related with production management of agrobiodiversity and other genetic resources. Farmers are practicing agricultural practices that promotes the use of diversity such as growing mixture of landraces, composting, fertigation. Modern agriculture focuses on developing large scale uniform technology eg use of urea, mono-genotype variety. Such system puts pressure and disturbs the ecological balance causing high risk for crop failure and genetic erosion. Any technological option with greater diversity is less risky, more sustainable and higher adaptability in agriculture. Diversity rich solution is any technology or problem associated solution that considers diversity as an option and address problems with inter and intra level diversity as well as combinations of different components. it also includes multiple technology for a single problem. Some examples are broad genetic base variety, cultivar mixtures, compost (made from different species), biopesticide (made from different species), etc. Diversity rich solution is in practice since 2014 in Nepal with the objective of conserving agrobiodiversity, promoting ecologically oriented sustainable agriculture that also enhances ecosystem services

Good practices for agrobiodiversity management

Native agricultural genetic resources have been generally under-valued, therefore, some initiatives have been taken through Global In-situ agrobiodiversity project joinly implemented by NARC, LI-BIRD and Bioversity International since 1997 in Nepal for conservation and sustainable use of agrobiodiversity on-farm. Global in-situ project (1997-2006) has developed many good practices for agrobiodiversity management which are published in On-farm Management of Agricultural Biodiversity in Nepal: Good Practices 2006 (B Sthapit, P Shrestha and M Upadyay, eds). A good practice is a process or methodology or action that is effective and successful; environmentally, economically and socially sustainable; technically feasible; inherently participatory; replicable and adaptable, that has been proven to work well and produce good results. It is a successful experience tested and validated in achieving its objective. For further widening the scope of good practices in the country, NAGRC, LI-BIRD and Bioversity International have generated, tested and adapted a number of good practices in four sites, Jungu, Dolakha; Ghapanpokhara, Lamjung; Hanku, Jumla; and Chippra, Humla through a project Integrating Traditional Crop Genetic Diversity into Technology: Using a Biodiversity Portfolio Approach to Buffer against Unpredictable Environmental Change in the Nepal Himalayas , commonly called as Local Crop Project (LCP) from 2014 to 2019. Good practices listed here are well tested and adapted by the communtiies in the fields, shown their positive impact, shared and discussed among the relevant stakholders. Project team have tested and validated many good practices, however, we have included 22 good practices that are worth sharing for its dessimination and mainstreaming. These practices, though specially based on eight crops (rice, bean, barley, foxtail millet, proso millet, amaranth and buckwheat), can be widely applicable to other agricultural genetic ressources in different locations, national and globally

Kinetic Analysis and Epitope Mapping of Monoclonal Antibodies to Salmonella Typhimurium Flagellin Using a Surface Plasmon Resonance Biosensor

Salmonella Typhimurium is one of the leading causes of foodborne diseases worldwide. Biosensors and immunoassays utilizing monoclonal antibodies are widely used for the detection and subtyping of S. Typhimurium. However, due to insufficient information on the nature of binding with S. Typhimurium flagellin, the selection of appropriate antibodies for assay development is a cumbersome task. Hence, we aimed to compare the binding kinetics of a panel of monoclonal antibodies and their relative binding sites to flagellin antigen using a surface plasmon resonance biosensor. Initially, the flagellin was captured on the sensor surface through an immobilized anti-flagellin antibody. The interactions of different concentrations of monoclonal antibodies to flagellin were determined, and binding curves were fitted using 1:1 bio-interaction model to calculate the kinetic parameters. For epitope mapping, pairwise comparisons were completed to determine the binding inhibition of each paired combination of monoclonal antibodies. It was found that these monoclonal antibodies differed significantly (p \u3c 0.05) in association rate, dissociation rate, and equilibrium dissociation constants. Of the five monoclonal antibodies, only two interfered with the binding of each other. Four distinct epitopes located within a 23 kDa domain of flagellin were identified. Findings from this study provide crucial information needed for the further development and optimization of biosensors and other immunoassays for the detection and subtyping of Salmonella

An educational intervention’s effect on healthcare professionals’ attitudes towards pharmacovigilance

BackgroundPharmacovigilance concerns the detection, assessment, understanding, and prevention of adverse effects or any other drug-related problems. Consumer pharmacovigilance is the involvement of consumers in adverse drug reaction (ADR) reporting. Assessing healthcare professionals’ (HCPs) knowledge of and attitude towards pharmacovigilance and consumer pharmacovigilance is integral to strengthening adverse drug reaction reporting systems. AimsTo study knowledge of and attitude towards pharmacovigilance and consumer pharmacovigilance among HCPs from KIST Medical College, Lalitpur, Nepal, and to plan an appropriate educational intervention to address deficiencies noted.Methods The study was conducted from February 2013 to December 2013 at KIST Medical College using a self-administered, pretested, structured questionnaire. The maximum possible scores for knowledge, attitude, and total were 100, 95, and 195, respectively. Baseline knowledge and attitude were studied. Two months after the questionnaire, an intervention that used a combination of methods about pharmacovigilance and consumer pharmacovigilance was undertaken. Knowledge and attitudes were studied immediately after the intervention. Scores before and after the intervention were compared using Wilcoxon signed-rank test.Results A total of 105 HCPs participated. The median (interquartile range) knowledge, attitude, and total scores before the intervention were 56 (7), 72 (9), and 127 (16), respectively. After the intervention the scores increased significantly to 72 (8), 75 (11.5), and 146 (16.5) (

The COVID‐19 Pandemic Not Only Poses Challenges, but Also Opens Opportunities for Sustainable Transformation

The COVID-19 pandemic has impacted social, economic, and environmental systems worldwide, slowing down and reversing the progress made in achieving the Sustainable Development Goals (SDGs). SDGs belong to the 2030 Agenda to transform our world by tackling humankind's challenges to ensure well-being, economic prosperity, and environmental protection. We explore the potential impacts of the pandemic on SDGs for Nepal. We followed a knowledge co-creation process with experts from various professional backgrounds, involving five steps: online survey, online workshop, assessment of expert's opinions, review and validation, and revision and synthesis. The pandemic has negatively impacted most SDGs in the short term. Particularly, the targets of SDG 1, 4, 5, 8, 9, 10, 11, and 13 have and will continue to have weakly to moderately restricting impacts. However, a few targets of SDG 2, 3, 6, and 11 could also have weakly promoting impacts. The negative impacts have resulted from impeding factors linked to the pandemic. Many of the negative impacts may subside in the medium and long terms. The key five impeding factors are lockdowns, underemployment and unemployment, closure of institutions and facilities, diluted focus and funds for non-COVID-19-related issues, and anticipated reduction in support from development partners. The pandemic has also opened a window of opportunity for sustainable transformation, which is short-lived and narrow. These opportunities are lessons learned for planning and action, socio-economic recovery plan, use of information and communication technologies and the digital economy, reverse migration and “brain gain,” and local governments' exercising authorities

Detection of Salmonella Typhimurium in Romaine Lettuce Using a Surface Plasmon Resonance Biosensor

Leafy vegetables have been associated with high-profile outbreaks causing severe illnesses. Timely and accurate identification of potential contamination is essential to ensure food safety. A surface plasmon resonance (SPR) assay has been developed for the detection of Salmonella Typhimurium in leafy vegetables. The assay utilizes a pair of well characterized monoclonal antibodies specific to the flagellin of S. Typhimurium. Samples of romaine lettuce contaminated with S. Typhimurium at different levels (between 0.9 and 5.9 log cfu/g) were pre-enriched in buffered peptone water. Three SPR assay formats, direct assay, sequential two-step sandwich assay, and pre-incubation one-step sandwich assay were evaluated. All three assay formats detect well even at a low level of contamination (0.9 log cfu/g). The SPR assay showed a high specificity for the detection of S. Typhimurium in the presence of other commensal bacteria in the romaine lettuce samples. The results also suggested that further purification of flagellin from the sample preparation using immunomagnetic separation did not improve the detection sensitivity of the SPR assay. The functional protocol developed in this study can be readily used for the detection of S. Typhimurium in leafy vegetables with high sensitivity and specificity