scholarly journals The role of bacterial biofilm in persistent infections and control strategies

2011 ◽  
Vol 3 (2) ◽  
pp. 66-73 ◽  
Author(s):  
Li Chen ◽  
Yu‐mei Wen
Author(s):  
Г.Н. Ланской

Статья посвящена истории связи между развитием исторической науки и политической практики в России. В контексте этого развития представлены, с одной стороны, эволюция исторических исследований и их координации и, с другой стороны, трансформация подхода институциональных структур государства к выбору управленческой стратегии в руководстве работой историков. В качестве примера для исследования обозначенной проблемы выбран период с начала XVIII до начала XXI века, потому что в его рамках была сформирована практика профессиональной деятельности в сфере историографии как процесса человеческой деятельности. Особое внимание в статье адресовано к роли идеологии в формировании различных моделей связи между работой историков и политических деятелей по конструированию образа прошлого, настоящего и будущего развития российской истории. The article reveals the connection between the historical science development and evolution of political practice in Russia.In that context shown are the course of the historical research and the coordination and control strategies implemented by the state, including institutional transformations.As a subject of current research was taken the period from the XVIII – beginning of the XXI centuries, when historiography became a profession and was institutionalized.Special attention is driven to the role of ideology in adopting different models of interaction between historians and political actors, while framing the image of the past, the present and the future of Russia.


2020 ◽  
Vol 3 (4) ◽  
pp. 299-316
Author(s):  
Bo Li ◽  
Huang Kuo ◽  
Xuehui Wang ◽  
Yiyi Chen ◽  
Yangang Wang ◽  
...  

AbstractAn overview of current thermal challenges in transport electrification is introduced in order to underpin the research developments and trends of recent thermal management techniques. Currently, explorations of intelligent thermal management and control strategies prevail among car manufacturers in the context of climate change and global warming impacts. Therefore, major cutting-edge systematic approaches in electrified powertrain are summarized in the first place. In particular, the important role of heating, ventilation and air-condition system (HVAC) is emphasised. The trends in developing efficient HVAC system for future electrified powertrain are analysed. Then electric machine efficiency is under spotlight which could be improved by introducing new thermal management techniques and strengthening the efforts of driveline integrations. The demanded integration efforts are expected to provide better value per volume, or more power output/torque per unit with smaller form factor. Driven by demands, major thermal issues of high-power density machines are raised including the comprehensive understanding of thermal path, and multiphysics challenges are addressed whilst embedding power electronic semiconductors, non-isotropic electromagnetic materials and thermal insulation materials. Last but not least, the present review has listed several typical cooling techniques such as liquid cooling jacket, impingement/spray cooling and immersion cooling that could be applied to facilitate the development of integrated electric machine, and a mechanic-electric-thermal holistic approach is suggested at early design phase. Conclusively, a brief summary of the emerging new cooling techniques is presented and the keys to a successful integration are concluded.


2004 ◽  
Vol 11 (2) ◽  
pp. 100-110 ◽  
Author(s):  
Amparo Belloch ◽  
Carmen Morillo ◽  
Mariela Lucero ◽  
Elena Cabedo ◽  
Carmen Carrió

2021 ◽  
Vol 15 (5) ◽  
pp. e0009449
Author(s):  
Maylis Layan ◽  
Simon Dellicour ◽  
Guy Baele ◽  
Simon Cauchemez ◽  
Hervé Bourhy

Background Rabies is a fatal yet vaccine-preventable disease. In the last two decades, domestic dog populations have been shown to constitute the predominant reservoir of rabies in developing countries, causing 99% of human rabies cases. Despite substantial control efforts, dog rabies is still widely endemic and is spreading across previously rabies-free areas. Developing a detailed understanding of dog rabies dynamics and the impact of vaccination is essential to optimize existing control strategies and developing new ones. In this scoping review, we aimed at disentangling the respective contributions of mathematical models and phylodynamic approaches to advancing the understanding of rabies dynamics and control in domestic dog populations. We also addressed the methodological limitations of both approaches and the remaining issues related to studying rabies spread and how this could be applied to rabies control. Methodology/principal findings We reviewed how mathematical modelling of disease dynamics and phylodynamics have been developed and used to characterize dog rabies dynamics and control. Through a detailed search of the PubMed, Web of Science, and Scopus databases, we identified a total of n = 59 relevant studies using mathematical models (n = 30), phylodynamic inference (n = 22) and interdisciplinary approaches (n = 7). We found that despite often relying on scarce rabies epidemiological data, mathematical models investigated multiple aspects of rabies dynamics and control. These models confirmed the overwhelming efficacy of massive dog vaccination campaigns in all settings and unraveled the role of dog population structure and frequent introductions in dog rabies maintenance. Phylodynamic approaches successfully disentangled the evolutionary and environmental determinants of rabies dispersal and consistently reported support for the role of reintroduction events and human-mediated transportation over long distances in the maintenance of rabies in endemic areas. Potential biases in data collection still need to be properly accounted for in most of these analyses. Finally, interdisciplinary studies were determined to provide the most comprehensive assessments through hypothesis generation and testing. They also represent new avenues, especially concerning the reconstruction of local transmission chains or clusters through data integration. Conclusions/significance Despite advances in rabies knowledge, substantial uncertainty remains regarding the mechanisms of local spread, the role of wildlife in dog rabies maintenance, and the impact of community behavior on the efficacy of control strategies including vaccination of dogs. Future integrative approaches that use phylodynamic analyses and mechanistic models within a single framework could take full advantage of not only viral sequences but also additional epidemiological information as well as dog ecology data to refine our understanding of rabies spread and control. This would represent a significant improvement on past studies and a promising opportunity for canine rabies research in the frame of the One Health concept that aims to achieve better public health outcomes through cross-sector collaboration.


ACTA IMEKO ◽  
2014 ◽  
Vol 3 (1) ◽  
pp. 4
Author(s):  
S. S. Carlisle

<p>This is a reissue of a paper which appeared in ACTA IMEKO 1967, Proceedings of the 4th International Measurement Congress, 1967, Warsaw, vol. 1, pp. 37-50.</p> <p>The paper sets a frame on the role of measurement and control as critical tools to support the automation of manufacturing processes. In this perspective three main requirements for measurement are discussed, i.e., to identify where automation can be most profitably used; to investigate individual process behaviors and hence to formulate process control strategies; and finally to perform quality control of products.</p>


Author(s):  
Rhastin A D Castro ◽  
Sonia Borrell ◽  
Sebastien Gagneux

Abstract Tuberculosis (TB) has been responsible for the greatest number of human deaths due to an infectious disease in general, and due to antimicrobial resistance (AMR) in particular. The etiological agents of human TB are a closely-related group of human-adapted bacteria that belong to the Mycobacterium tuberculosis complex (MTBC). Understanding how MTBC populations evolve within-host may allow for improved TB treatment and control strategies. In this Review, we highlight recent works that have shed light on how AMR evolves in MTBC populations within individual patients. We discuss the role of heteroresistance in AMR evolution, and review the bacterial, patient, and environmental factors that likely modulate the magnitude of heteroresistance within-host. We further highlight recent works on the dynamics of MTBC genetic diversity within-host, and discuss how spatial substructures in patients’ lungs, spatiotemporal heterogeneity in antimicrobial concentrations, and phenotypic drug tolerance likely modulates the dynamics of MTBC genetic diversity in patients during treatment. We note the general characteristics that are shared between how the MTBC and other bacterial pathogens evolve in humans, and highlight the characteristics unique to the MTBC.


2018 ◽  
Vol 23 (3) ◽  
pp. 38
Author(s):  
Dibyendu Biswas ◽  
Suman Dolai ◽  
Jahangir Chowdhury ◽  
Priti Roy ◽  
Ellina Grigorieva

Leishmaniasis is a neglected tropical vector-borne epidemic disease, and its transmission is a complex process. Zoonotic transmission to humans or animals occurs through the bites of female Phlebotominae sand flies. Here, reservoir is considered as a major source of endemic pathogen pool for disease outbreak, and the role of more than one reservoir animal becomes indispensable. To study the role of the reservoir animals on disease dynamics, a mathematical model was constructed consisting of susceptible and infected populations of humans and two types of reservoir (animal) and vector populations, respectively. Our aim is to prevent the disease by applying a control theoretic approach, when more than one type of reservoir animal exists in the region. We use drugs like sodium stibogluconate and meglumine antimoniate to control the disease for humans and spray insecticide to control the sand fly population. Similarly, drugs are applied for infected reservoir animals of Types A and B. We calculated the cost-effectiveness of all possible combinations of the intervention and control policies. One of our findings is that the most cost-effective case for Leishmania control is the spray of insecticides for infected sand fly vector. Alternate strategic cases were compared to address the critical shortcomings of single strategic cases, and a range of control strategies were estimated for effective control and economical benefit of the overall control strategy. Our findings provide the most innovative techniques available for application to the successful eradication of cutaneous leishmaniasis in the future.


2021 ◽  
Author(s):  
Steffen Geisel ◽  
Eleonora Secchi ◽  
Jan Vermant

Biofilms, bacterial communities of cells encased by a self-produced matrix, exhibit a variety of three-dimensional structures. Specifically, channel networks formed within the bulk of the biofilm have been identified to play an important role in the colonies viability by promoting the transport of nutrients and chemicals. Here, we study channel formation and focus on the role of the adhesion of the biofilm matrix to the substrate in Pseudomonas aeruginosa biofilms grown under constant flow in microfluidic channels. We perform phase contrast and confocal laser scanning microscopy to examine the development of the biofilm structure as a function of the substrates surface energy. The formation of the wrinkles and folds is triggered by a mechanical buckling instability, controlled by biofilm growth rate and the film's adhesion to the substrate. The three-dimensional folding gives rise to hollow channels that rapidly increase the overall volume occupied by the biofilm and facilitate bacterial movement inside them. The experiments and analysis on mechanical instabilities for the relevant case of a bacterial biofilm grown during flow enable us to predict and control the biofilm morphology.


Author(s):  
R. F. Zeigel ◽  
W. Munyon

In continuing studies on the role of viruses in biochemical transformation, Dr. Munyon has succeeded in isolating a highly infectious human herpes virus. Fluids of buccal pustular lesions from Sasha Munyon (10 mo. old) uiere introduced into monolayer sheets of human embryonic lung (HEL) cell cultures propagated in Eagles’ medium containing 5% calf serum. After 18 hours the cells exhibited a dramatic C.P.E. (intranuclear vacuoles, peripheral patching of chromatin, intracytoplasmic inclusions). Control HEL cells failed to reflect similar changes. Infected and control HEL cells were scraped from plastic flasks at 18 hrs. of incubation and centrifuged at 1200 × g for 15 min. Resultant cell packs uiere fixed in Dalton's chrome osmium, and post-fixed in aqueous uranyl acetate. Figure 1 illustrates typical hexagonal herpes-type nucleocapsids within the intranuclear virogenic regions. The nucleocapsids are approximately 100 nm in diameter. Nuclear membrane “translocation” (budding) uias observed.


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