104 research outputs found
Immunogenicity of Self-Associated Aggregates and Chemically Cross-Linked Conjugates of the 42 kDa Plasmodium falciparum Merozoite Surface Protein-1
Self-associated protein aggregates or cross-linked protein conjugates are, in general, more immunogenic than oligomeric or monomeric forms. In particular, the immunogenicity in mice of a recombinant malaria transmission blocking vaccine candidate, the ookinete specific Plasmodium falciparum 25 kDa protein (Pfs25), was increased more than 1000-fold when evaluated as a chemical cross-linked protein-protein conjugate as compared to a formulated monomer. Whether alternative approaches using protein complexes improve the immunogenicity of other recombinant malaria vaccine candidates is worth assessing. In this work, the immunogenicity of the recombinant 42 kDa processed form of the P. falciparum merozoite surface protein 1 (MSP142) was evaluated as a self-associated, non-covalent aggregate and as a chemical cross-linked protein-protein conjugate to ExoProtein A, which is a recombinant detoxified form of Pseudomonas aeruginosa exotoxin A. MSP142 conjugates were prepared and characterized biochemically and biophysically to determine their molar mass in solution and stoichiometry, when relevant. The immunogenicity of the MSP142 self-associated aggregates, cross-linked chemical conjugates and monomers were compared in BALB/c mice after adsorption to aluminum hydroxide adjuvant, and in one instance in association with the TLR9 agonist CPG7909 with an aluminum hydroxide formulation. Antibody titers were assessed by ELISA. Unlike observations made for Pfs25, no significant enhancement in MSP142 specific antibody titers was observed for any conjugate as compared to the formulated monomer or dimer, except for the addition of the TLR9 agonist CPG7909. Clearly, enhancing the immunogenicity of a recombinant protein vaccine candidate by the formation of protein complexes must be established on an empirical basis
The effect of web advertising visual design on online purchase intention: An examination across gender
With web advertising growing to be a huge industry, it is important to understand the effectiveness of web advertisement. In this study we investigate the effects of web advertising visual design (WAVD) purchasing intention within the framework of an integrated model. Nine hypotheses were developed and tested on a dataset of 316 observations collected via a questionnaire survey. The results of structural equation modeling (SEM) indicate that while web advertising visual cues influence consumers' purchasing intention through advertising attitudes and brand attitudes, they do not have direct effects on purchasing intention. Further results on the moderating role of gender suggest that web advertising visual cues have direct effect on consumers' purchasing intention for male groups but not for female groups. This study contributes to the understanding the role of visual dimensions in forming online purchase intentions
The relationship between consumer ethnocentrism, cosmopolitanism and product country image among younger generation consumers: the moderating role of country development status
Although the differences between developed and developing countries have been extensively studied in the context of globalization strategies, few studies have so far been conducted on the relationship between country development status and the possession by countries of a favorable (or unfavorable) product country image (PCI). Moreover, the results of such studies to date have been inconclusive. The purpose of this paper is to investigate the moderating role of country developmental status on PCI coupled with two antecedents of PCI, namely consumer ethnocentrism and cosmopolitanism. The paper also distinguishes between the PCI of the home and foreign country images of respondents. We test a new model that incorporates these constructs with a sample of 2655 younger generation consumers. The results show that country development status moderates some relationships but does not moderate others. These findings have significant implications for international companies from both developed and developing countries when developing global strategy
Do affective variables make a difference in consumers behavior toward mobile advertising?
Research into permission-based mobile marketing is increasingly common due to the widespread adoption of mobile technology and its use as a communication channel. Yet few studies have attempted to analyze the factors that determine attitudes toward mobile advertising while simultaneously considering: the links among them and consumers' intentions, behavior, and/or cognitive and affective variables simultaneously. The present research therefore sought to deepen understanding of the antecedents and consequences of attitudes toward permission-based mobile advertising. More specifically, it sought to identify the antecedents of attitudes toward mobile advertising and the bridges between these attitudes and consumers' intentions upon receiving advertising on their mobile devices. To this end, a causal model was proposed and tested with a sample of 612 mobile phone users that was collected from a panel of Spanish adults who receive advertising on their mobile phones in the form of SMS text messages. The structural model used was validated using the partial least squares (PLS) regression technique. The results show that the greatest influence was that exerted by positive emotions on feelings, suggesting that positive emotions have an indirect effect on attitude toward mobile advertising. This influence was even greater than their direct effect. Another important, though less powerful, effect was the influence of attitude on behavioral intentions to receive mobile advertising. In contrast, the influence of cognitive variables on attitude was less relevant.This work was funded by the Spanish Ministry of Economy
and Competitiveness under Research Project ECO2014-59688-R,“National Program for Research, Develop and Innovation
Oriented toward Societal Challenges, ”within the context of
the 2013-2016 National Scientific and Technical Research and
Innovation Plan
An Exploratory Study of ISO 9001:2000 Quality Management Systems Using the ISO/IEC 15504 Architecture
The purpose of this paper is to provide an exploratory study on the implementation and issues regarding Quality Management Systems as defined by ISO 9001 :2000 using the architecture of ISO/IEC 15504. The recently published ISO/IEC 15504 series of standards provides a framework to assess processes and determine levels of capability. With the use of this framework, the study will focus on the assessment and identification of problem areas requiring focus for continual improvement within an ISO 9001 :2000 quality management system.
The structure of this paper is as follows: Section 1 provides a background discussion of ISO 9001 :2000. The literature review conducted that resulted in the use of 1SO/IEC 15504 during this study is discussed in section 2. Section 3 provides the methodology used for the research project. Sections 4 and 5 contain information regarding the development, deployment and analysis of the survey conducted. A discussion of the results obtained is provided in section 6. An overall summary of the study is provided in section 7 with concluding remarks in section 8
Geochemical trends in Chesterian (Upper Mississippian) Waltersburg crudes of the Illinois Basin
Cover title.Includes bibliographical references (p. 21-23)
Some factors that influence the acquisition of complex, stereotyped, response sequences in pigeons
Two pigeons were required to peck six to nine illuminated response keys. A response on any one of the keys darkened that key. When each key had been darkened, a reinforcer was delivered. No specific sequence of key pecking was ever required. The keys were presented in various matrices: three by two, three by three, horizontal rows, and vertical columns. The keys either presented the same stimulus, white light; or each key presented a different stimulus, a color or form. The results indicated that although there were 720 to 362,880 different sequences that would produce reinforcement, each bird developed a particular, stereotyped sequence that dominated its behavior. Variability among the birds across phases yielded less than 60 sequences, .0001 to 6 percent of the possible sequences. The data suggest that a reinforcement contingency that includes “free choice” of response sequence will produce stereotypical response sequences that function as complex “units” of behavior
Changeover behavior under pairs of fixed-ratio and variable-ratio schedules of reinforcement
Three pigeons were studied under a pair of equal fixed-ratio schedules and a pair of equal variable-ratio schedules. Each pair was arranged as independent, concurrent schedules and also in a non-independent relation where each peck in a schedule counted toward the response requirement of both schedules. The non-independent pair of variable-ratio schedules maintained much higher changeover rates than any of the other three arrangements. Thus, two factors seemed necessary for generating high changeover rates. Responding on a schedule had to count toward the response requirement of both schedules, and the component schedules had to be variable. These data are consistent with the hypothesis that changeovers are at least partly controlled by the probability of reinforcement following a changeover
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