scholarly journals Characterization of Airborne Bacteria at an Underground Subway Station

2012 ◽  
Vol 78 (6) ◽  
pp. 1917-1929 ◽  
Author(s):  
Marius Dybwad ◽  
Per Einar Granum ◽  
Per Bruheim ◽  
Janet Martha Blatny

ABSTRACTThe reliable detection of airborne biological threat agents depends on several factors, including the performance criteria of the detector and its operational environment. One step in improving the detector's performance is to increase our knowledge of the biological aerosol background in potential operational environments. Subway stations are enclosed public environments, which may be regarded as potential targets for incidents involving biological threat agents. In this study, the airborne bacterial community at a subway station in Norway was characterized (concentration level, diversity, and virulence- and survival-associated properties). In addition, a SASS 3100 high-volume air sampler and a matrix-assisted laser desorption ionization–time of flight mass spectrometry-based isolate screening procedure was used for these studies. The daytime level of airborne bacteria at the station was higher than the nighttime and outdoor levels, and the relative bacterial spore number was higher in outdoor air than at the station. The bacterial content, particle concentration, and size distribution were stable within each environment throughout the study (May to September 2010). The majority of the airborne bacteria belonged to the generaBacillus,Micrococcus, andStaphylococcus, but a total of 37 different genera were identified in the air. These results suggest that anthropogenic sources are major contributors to airborne bacteria at subway stations and that such airborne communities could harbor virulence- and survival-associated properties of potential relevance for biological detection and surveillance, as well as for public health. Our findings also contribute to the development of realistic testing and evaluation schemes for biological detection/surveillance systems by providing information that can be used to mimic real-life operational airborne environments in controlled aerosol test chambers.

2011 ◽  
pp. 2030-2042 ◽  
Author(s):  
Hideyuki Nakanishi ◽  
Toru Ishida ◽  
Satoshi Koizumi

Many research projects have studied various aspects of smart environments including smart rooms, home, and offices. Few projects, however, have studied smart urban public spaces such as smart railway stations and airports due to the lack of an experimental environment. We propose virtual cities as a testbed for examining the design of smart urban public spaces. We developed an intelligent emergency guidance system for subway stations and used the virtual subway station platform to analyze the effects of the system. This experience allows us to argue that simulations in virtual cities are useful to pre-test the design of smart urban public spaces and estimate the possible outcome of real-life scenarios.


Author(s):  
Hideyuki Nakanishi ◽  
Toru Ishida ◽  
Satoshi Koizumi

Many research projects have studied various aspects of smart environments including smart rooms, home, and offices. Few projects, however, have studied smart urban public spaces such as smart railway stations and airports due to the lack of an experimental environment. We propose virtual cities as a testbed for examining the design of smart urban public spaces. We developed an intelligent emergency guidance system for subway stations and used the virtual subway station platform to analyze the effects of the system. This experience allows us to argue that simulations in virtual cities are useful to pre-test the design of smart urban public spaces and estimate the possible outcome of real-life scenarios.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Brenda Cardoso ◽  
Tharcisio Fontainha ◽  
Adriana Leiras ◽  
Patricia Alcantara Cardoso

PurposeThis paper aims to identify the main performance criteria for Humanitarian Operations (HOs) from the beneficiary perspective and to propose a taxonomy to support the evaluation of stakeholders.Design/methodology/approachThe research conducts a Systematic Literature Review to identify the main criteria in HOs from the beneficiary's view. Also, we conduct an empirical study based on a survey and a case study to validate the findings in a real-life setting.FindingsConsidering 25 papers, the identified performance criteria were divided into six categories: health, housing, education, socioeconomic factors, care and risk and disaster management. The empirical discussion considered forty-four responses from beneficiaries, and the main criteria complained about were related to socioeconomic factors. In addition, a case study was developed that examines the perspective of the company responsible for the construction of the building to aid in understanding the areas of dissatisfaction noted by the residents.Practical implicationsThe research contributes organized criteria to support the performance evaluation of organizations. It offers a structured basis for further discussion among academics and professionals about other performance evaluation topics, such as dashboards and the integration of indicators from different stakeholders.Originality/valueLiterature is scarce in questions of performance evaluation in HOs and the analysis of the beneficiary as the main client. Therefore, the paper contributes to both areas by evaluating HOs from the beneficiary's perspective.


2013 ◽  
Vol 80 (1) ◽  
pp. 257-270 ◽  
Author(s):  
Marius Dybwad ◽  
Gunnar Skogan ◽  
Janet Martha Blatny

ABSTRACTNaturally occurring bioaerosol environments may present a challenge to biological detection-identification-monitoring (BIODIM) systems aiming at rapid and reliable warning of bioterrorism incidents. One way to improve the operational performance of BIODIM systems is to increase our understanding of relevant bioaerosol backgrounds. Subway stations are enclosed public environments which may be regarded as potential bioterrorism targets. This study provides novel information concerning the temporal variability of the concentration level, size distribution, and diversity of airborne bacteria in a Norwegian subway station. Three different air samplers were used during a 72-h sampling campaign in February 2011. The results suggested that the airborne bacterial environment was stable between days and seasons, while the intraday variability was found to be substantial, although often following a consistent diurnal pattern. The bacterial levels ranged from not detected to 103CFU m−3and generally showed increased levels during the daytime compared to the nighttime levels, as well as during rush hours compared to non-rush hours. The airborne bacterial levels showed rapid temporal variation (up to 270-fold) on some occasions, both consistent and inconsistent with the diurnal profile. Airborne bacterium-containing particles were distributed between different sizes for particles of >1.1 μm, although ∼50% were between 1.1 and 3.3 μm. Anthropogenic activities (mainly passengers) were demonstrated as major sources of airborne bacteria and predominantly contributed 1.1- to 3.3-μm bacterium-containing particles. Our findings contribute to the development of realistic testing and evaluation schemes for BIODIM equipment by providing information that may be used to simulate operational bioaerosol backgrounds during controlled aerosol chamber-based challenge tests with biological threat agents.


2019 ◽  
Vol 121 (11) ◽  
pp. 2592-2606 ◽  
Author(s):  
Thales Leandro Coutinho de Oliveira ◽  
Gabriela de Barros Silva Haddad ◽  
Alcinéia de Lemos Souza Ramos ◽  
Eduardo Mendes Ramos ◽  
Roberta Hilsdorf Piccoli ◽  
...  

Purpose The purpose of this paper is to evaluate the optimization of high hydrostatic pressure (HHP) processing for the microbial inactivation on low-sodium sliced vacuum-packaged turkey breast supplemented with a natural antimicrobial compound (carvacrol). Design/methodology/approach A response surface methodology was used to model and describe the effects of different pressures (200–650 MPa) and holding times (30–300 s) during HHP processing of low-salt ready-to-eat turkey breast supplemented with 200 mg/kg of carvacrol on survival of the target pathogen (Listeria sp.) and spoilage microflora and on the quality attributes, including pH, syneresis, CIE color and lipid oxidation. Findings The HHP parameters influenced (p<0.05) the lethality rates and syneresis but did not affect the pH values and lipid oxidation of the products evaluated. According to the required performance criteria for Listeria post-lethality treatment, a treatment at 600 MPa/180 s (at 25°C) appears to be suitable for the studied low-sodium product. The HHP bacterial inactivation effects can notably be potentiated via the presence of carvacrol, and is useful at sensory acceptable sub-inhibitory levels. Originality/value This study shows that combined HHP plus additives may produce similar safety and shelf-life extension effects with mild HHP treatments, creating a global increase in the quality of HHP-processed food in addition to reducing costs on equipment maintenance and increasing industry productivity.


Author(s):  
Anuradha Mathrani ◽  
Sanjay Mathrani

Purpose The paper aims to capture the nuances of two client–supplier relationships to offer new insights on the influences of transactional, knowledge and social elements in outsourcing partnerships. Design/methodology/approach The study has used descriptive case studies with narrative storylines. Interviews were conducted with three relationship managers (boundary gatekeepers) to understand preferred governance practices between clients and suppliers in diverse economic markets. Findings Experiences of three real-life cases engaged in offshore outsourcing have helped to identify the market, operational knowledge and social influences in a relational exchange. Findings reveal that offshore partnerships are first constituted with service-level agreements, which set control measures and layout business expectations from both partners. Boundary gatekeepers bring further accountability across firms by designing social networks for capturing and sharing of knowledge, thereby reducing each partner’s perception of risk. As firms evaluate transactional, knowledge and social elements for building a futuristic relational exchange, more disaggregated and dispersed enterprises evolve as new opportunities are explored in foreign markets. Research limitations/implications The retrospective nature of the client–supplier partnership is a limitation in this research study. However, retrospection adds to experience, and to practice perspectives made in hindsight, and therefore has a positive influence in this study. Originality/value This paper shares real-world experiences that can be used by scholars and practitioners to better understand how relational governance practices operate in a global socio-economic setting.


2016 ◽  
Vol 8 (2) ◽  
pp. 130-148
Author(s):  
Carlo Massironi ◽  
Giusy Chesini

Purpose The authors are interested in building descriptive – real life – models of successful investors’ investment reasoning and decision-making. Models designed to be useful for trying to replicate and evolve their reasoning and decision-making. The purpose of this paper, a case study, is to take the substantial material – on innovating the investing tools – published in four books (2006/2012, 2010, 2011, 2015) by a US stock investor named Kenneth Fisher (CEO of Fisher Investments, Woodside, California) and sketch Fisher’s investment innovating reasoning model. Design/methodology/approach To sketch Fisher’s investment innovating reasoning model, the authors used the Radical constructivist theory of knowledge, a framework for analyzing human action and reasoning called Symbolic interactionism and a qualitative analytic technique called Conceptual analysis. The authors have done qualitative research applied to the study of investment decision-making of a single professional investor. Findings In the paper, the authors analyzed and described the heuristics used by Fisher to build subsequent generations of investing tools (called by Fisher “Capital Markets Technology”) to try to make better forecasts to beat the stock market. The authors were interested in studying the evolutive dimensions of the tools to make forecasts of a successful investor: the “how to build it” and “how to evolve it” dimension. Originality/value The paper offers an account of Kenneth Fisher’s framework to reason the innovation of investing tools. The authors believe that this paper could be of interest to professional money managers and to all those who are involved in the study and development of the tools of investing. This work is also an example of the use of the Radical constructivist theory of knowledge, the Symbolic interactionist framework and the Conceptual analysis to build descriptive models of investment reasoning of individual investors, models designed to enable the reproduction/approximation of the conceptual operations of the investor.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Andres Marquez ◽  
Chris Maharaj

Purpose The purpose of this study was to carry out an analysis of the corrosion failure on a chrome-moly pipeline transporting highly concentrated sulfuric acid in a demineralization section at a petrochemical plant, along with the feasibility of using inhibitors to minimize the corrosive effects of sulfuric acid. Design/methodology/approach X-ray fluorescence spectroscopy, high-resolution optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy and accelerated corrosion experiments (ACE) were performed. Findings Erosion-corrosion failure was confirmed by the significant reduction in thickness of the internal surface of the material exposed to sulfuric acid, as well as the formation of an oxide scale/layer. ACE accurately predicted high material loss from exposure to sulfuric acid. Moreover, adding ascorbic acid as a corrosion inhibitor (even at low concentrations) was found to reduce the oxidation by more than 50% in the presence of sulfuric acid. Originality/value The main idea/purpose of this work relies on the analysis of recurrent real-life corrosion-attributed failures that are common in industry but are not properly addressed for a variety of reasons, poor management and lack of corrosion preventive strategies being the main ones. This study once again highlights readily available solutions/implementations that are capable of not only addressing technically the issue investigated but also, and as important, economically. By using microscopic imaging, reliable well-tested and widely used characterization methods, all combined with basic experiments and tests, the nature of the repetitive failure investigated was clearly demonstrated as well as readily available alternatives to minimize it in the short term. Nevertheless, implementing material selection techniques appropriately as effective corrosion prevention/control and cost-saving strategies must be enforced in any process.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Adarsh Anand ◽  
Subhrata Das ◽  
Mohini Agarwal ◽  
Shinji Inoue

PurposeIn the current market scenario, software upgrades and updates have proved to be very handy in improving the reliability of the software in its operational phase. Software upgrades help in reinventing working software through major changes, like functionality addition, feature enhancement, structural changes, etc. In software updates, minor changes are undertaken which help in improving software performance by fixing bugs and security issues in the current version of the software. Through the current proposal, the authors wish to highlight the economic benefits of the combined use of upgrade and update service. A cost analysis model has been proposed for the same.Design/methodology/approachThe article discusses a cost analysis model highlighting the distinction between launch time and time to end the testing process. The number of bugs which have to be catered in each release has been determined which also consists of the count of latent bugs of previous version. Convolution theory has been utilized to incorporate the joint role of tester and user in bug detection into the model. The cost incurred in debugging process was determined. An optimization model was designed which considers the reliability and budget constraints while minimizing the total debugging cost. This optimization was used to determine the release time and testing stop time.FindingsThe proposal is backed by real-life software bug dataset consisting of four releases. The model was able to successfully determine the ideal software release time and the testing stop time. An increased profit is generated by releasing the software earlier and continues testing long after its release.Originality/valueThe work contributes positively to the field by providing an effective optimization model, which was able to determine the economic benefit of the combined use of upgrade and update service. The model can be used by management to determine their timelines and cost that will be incurred depending on their product and available resources.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mohammad Ali Beheshtinia ◽  
Narjes Salmabadi ◽  
Somaye Rahimi

Purpose This paper aims to provide an integrated production-routing model in a three-echelon supply chain containing a two-layer transportation system to minimize the total costs of production, transportation, inventory holding and expired drugs treatment. In the proposed problem, some specifications such as multisite manufacturing, simultaneous pickup and delivery and uncertainty in parameters are considered. Design/methodology/approach At first, a mathematical model has been proposed for the problem. Then, one possibilistic model and one robust possibilistic model equivalent to the initial model are provided regarding the uncertain nature of the model parameters and the inaccessibility of their probability function. Finally, the performance of the proposed model is evaluated using the real data collected from a pharmaceutical production center in Iran. The results reveal the proper performance of the proposed models. Findings The results obtained from applying the proposed model to a real-life production center indicated that the number of expired drugs has decreased because of using this model, also the costs of the system were reduced owing to integrating simultaneous drug pickup and delivery operations. Moreover, regarding the results of simulations, the robust possibilistic model had the best performance among the proposed models. Originality/value This research considers a two-layer vehicle routing in a production-routing problem with inventory planning. Moreover, multisite manufacturing, simultaneous pickup of the expired drugs and delivery of the drugs to the distribution centers are considered. Providing a robust possibilistic model for tackling the uncertainty in demand, costs, production capacity and drug expiration costs is considered as another remarkable feature of the proposed model.


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