Infection-acquired versus vaccine-acquired immunity in an SIRWS model

Despite high vaccine coverage, pertussis has re-emerged as a public health concern in many countries. One hypothesis posed for re-emergence is the waning of immunity. In some disease systems, the process of waning immunity can be non-linear, involving a complex relationship between the duration of immunity and subsequent boosting of immunity through asymptomatic re-exposure. We present and analyse a model of infectious disease transmission to examine the interplay between infection and immunity. By allowing the duration of infection-acquired immunity to differ from that of vaccine-acquired immunity, we explore the impact of the difference in durations on long-term disease patterns and prevalence of infection. Our model demonstrates that vaccination may induce cyclic behaviour, and its ability to reduce the infection prevalence increases with both the duration of infection-acquired immunity and duration of vaccine-acquired immunity. We find that increasing vaccine coverage, while capable of leading to an increase in overall transmission, always results in a reduction in prevalence of primary infections, with epidemic cycles characterised by a longer interepidemic period and taller peaks. Our results show that the epidemiological patterns of an infectious disease may change considerably when the duration of vaccine-acquired immunity differs from that of infection-acquired immunity. Our study highlights that for any particular disease and associated vaccine, a detailed understanding of the duration of protection and how that duration is influenced by infection prevalence is important as we seek to optimise vaccination strategies.Comment: 21 pages, 5 figure

Community Acquired Pneumonia

Community acquired pneumonia is discussed, including the pathophysiology, treatment, patient education, and nursing practice points

"Acquired wit" and Hobbesian education

This thesis analyzes and evaluates the scheme for civil education discussed in Thomas Hobbes’ political works. Hobbes argues in The Elements of Law, De Cive, and Leviathan that the preservation of political order requires that all subjects learn the rationally grounded principles of political theory. Some contemporary scholarship on this aspect of Hobbes’ political philosophy has confined its understanding of “Hobbesian education” to this: the sovereign’s system of true civil doctrines and the means for their dissemination. I argue that for the system of Hobbesian civil doctrines to function as it is intended, a public must also receive instruction in formal argumentation, a skill Hobbes calls “acquired wit” (L viii.13). I will show that the subjects’ cultivation of their individual reasoning abilities is required so the subjects are able to (1) understand the philosophical foundations of the sovereign’s power, (2) sufficiently resist the allure of obfuscating eloquence and other falsehoods, and (3) conduct themselves in accordance with Hobbes’ natural laws. Civil peace in a Hobbesian system requires that the public be able to tell the difference between sound and unsound inferences. If Hobbes did intend for the sovereign to instruct the public in “acquired wit,” contemporary scholars who have offered sympathetic appraisals of Hobbesian education are further vindicated

Uncertainty Modeling for AUV Acquired Bathymetry

Abstract Autonomous Underwater Vehicles (AUVs) are used across a wide range of mission scenarios and from an increasingly diverse set of operators. Use of AUVs for shallow water (less than 200 meters) mapping applications is of increasing interest. However, an update of the total propagated uncertainty TPU model is required to properly attribute bathymetry data acquired from an AUV platform compared with surface platform acquired data. An overview of the parameters that should be considered for data acquired from an AUV platform is discussed. Data acquired in August 2014 using NOAA’s Remote Environmental Measuring UnitS (REMUS) 600 AUV in the vicinity of Portsmouth, NH were processed and analyzed through Leidos’ Survey Analysis and Area Based EditoR (SABER) software. Variability in depth and position of seafloor features observed multiple times from repeat passes of the AUV, and junctioning of the AUV acquired bathymetry with bathymetry acquired from a surface platform are used to evaluate the TPU model and to characterize the AUV acquired data

Acquired versus Non-Acquired Subsidiaries - Which Entry Mode do Parent Firms Prefer

Despite the economic importance of international foreign direct investment (FDI) flows, investment decisions of multinational firms are not well understood. A multinational firm can establish a subsidiary in a foreign country through greenfield investment or through acquiring an existing firm in the target country. The goal of this paper is to shed some light on the determinants of foreign market entry modes. In particular to analyze the systematic variation in the mode choice of FDI, namely acquisition versus non-acquisition (greenfield) investments. We propose a transparent and general applicable method to construct a data base. This database includes information about parent firms and their majority owned affiliates in foreign countries. A particular feature is the construction of a variable which allows to differentiate the establishment mode of parent firms into foreign markets. For this purpose two databases from the Bureau van Dijk are interlinked: Osiris and Zephyr. We provide evidence that firm heterogeneity is important for U.S. multinational firms in determining their entry mode choice. However, this is not a distinguishing feature for European multinational firms. For both sets of parent firms the host country characteristics play an important role in deciding on the entry mode. Higher institutional quality increases the likelihood of acquisitions versus greenfield investments.Acquisition, Greenfield, Subsidiaries, Mode Choice, FDI, Institutions;

Political connection heterogeneity and firm value in Vietnam

The observation of firms’ political connections (PCs) in both types of ascribed and acquired PCs has raised the question of their benefits to firms’ operation. Based on 1,365 Vietnamese listed firm-year observations from 2010 to 2014, we find that although firms with both ascribed and acquired PCs have lower firm value (FV) than firms without any PCs, firms with acquired PCs exhibit better FV than those with ascribed PCs. The paper also reveals that concentrated ownership (CO) has a mediation impact on the association between acquired PCs and FV while it can help firms with acquired PCs in improving FV

Characterization of extended-spectrum β-lactamases produced by Escherichia coli isolated from hospitalized and nonhospitalized patients : emergence of CTX-M-15-producing strains causing urinary tract infections

Extended-spectrum β-lactamase-producing Escherichia coli isolates were obtained from hospitalised and non-hospitalised patients in Belgium between August 2006 and November 2007. The antimicrobial susceptibility of these isolates was determined and their ESBL genes were characterized. Clonal relationships between the CTX-M-producing E. coli isolates causing urinary tract infections were also studied. A total of 90 hospital- and 45 community-acquired cephalosporin-resistant E. coli isolates were obtained. Tetracycline, enrofloxacine, gentamicin and trimethoprim-sulfamethaxozole resistance rates were significantly different between the community-onset and hospital-acquired isolates. A high diversity of different ESBLs was observed among the hospital-acquired E. coli isolates whereas CTX-M-15 was dominating among the community-acquired E. coli isolates (n=28). Thirtheen different PFGE profiles were observed in the community-acquired CTX-M-15-producing E. coli indicating that multiple clones have acquired the blaCTX-M-15 gene. All community-acquired CTX-M-15-producing E. coli isolates of phylogroups B2 and D were assigned to the sequence type ST131. The hospital-acquired CTX-M-15-producing E. coli isolates of phylogroups B2, B1, A and D corresponded to ST131, ST617, ST48 and ST405, respectively. In conclusion, CTX-M-type ESBLs have emerged as the predominant class of ESBLs produced by E. coli isolates in the hospital and community in Belgium. Of particular concern is the predominant presence of the CTX-M-15 enzyme in ST131 community-acquired E. coli

The evolution of resistance through costly acquired immunity

We examine the evolutionary dynamics of resistance to parasites through acquired immunity. Resistance can be achieved through the innate mechanisms of avoidance of infection and reduced pathogenicity once infected, through recovery from infection and through remaining immune to infection: acquired immunity. We assume that each of these mechanisms is costly to the host and find that the evolutionary dynamics of innate immunity in hosts that also have acquired immunity are quantitatively the same as in hosts that possess only innate immunity. However, compared with resistance through avoidance or recovery, there is less likely to be polymorphism in the length of acquired immunity within populations. Long-lived organisms that can recover at intermediate rates faced with fast-transmitting pathogens that cause intermediate pathogenicity (mortality of infected individuals) are most likely to evolve long-lived acquired immunity. Our work emphasizes that because whether or not acquired immunity is beneficial depends on the characteristics of the disease, organisms may be selected to only develop acquired immunity to some of the diseases that they encounter