scholarly journals Synergistic and Additive Effects of Chromosomal and Plasmid-Encoded Hemolysins Contribute to Hemolysis and Virulence in Photobacterium damselae subsp. damselae

2013 ◽  
Vol 81 (9) ◽  
pp. 3287-3299 ◽  
Author(s):  
Amable J. Rivas ◽  
Miguel Balado ◽  
Manuel L. Lemos ◽  
Carlos R. Osorio
Keyword(s):  
Animal Species ◽  
Synergistic Effects ◽  
Additive Effects ◽  
Iron Starvation ◽  
Triple Mutant ◽  
Marine Animals ◽  
Content Type ◽  
Photobacterium Damselae ◽  
The One ◽  
The Individual

ABSTRACTPhotobacterium damselaesubsp.damselaecauses infections and fatal disease in marine animals and in humans. Highly hemolytic strains produce damselysin (Dly) and plasmid-encoded HlyA (HlyApl). These hemolysins are encoded by plasmid pPHDD1 and contribute to hemolysis and virulence for fish and mice. In this study, we report that all the hemolytic strains produce a hitherto uncharacterized chromosome-encoded HlyA (HlyAch). Hemolysis was completely abolished in a singlehlyAchmutant of a plasmidless strain and in adly hlyAplhlyAchtriple mutant. We found that Dly, HlyApl, and HlyAchare needed for full hemolytic values in strains harboring pPHDD1, and these values are the result of the additive effects between HlyApland HlyAch, on the one hand, and of the synergistic effect of Dly with HlyApland HlyAch, on the other hand. Interestingly, Dly-producing strains produced synergistic effects with strains lacking Dly production but secreting HlyA, constituting a case of the CAMP (Christie,Atkins, andMunch-Petersen) reaction. Environmental factors such as iron starvation and salt concentration were found to regulate the expression of the three hemolysins. We found that the contributions, in terms of the individual and combined effects, of the three hemolysins to hemolysis and virulence varied depending on the animal species tested. While Dly and HlyAplwere found to be main contributors in the virulence for mice, we observed that the contribution of hemolysins to virulence for fish was mainly based on the synergistic effects between Dly and either of the two HlyA hemolysins rather than on their individual effects.

scholarly journals Evaluating the individual- and country-level variations in tax morale

2017 ◽  
Vol 44 (5) ◽  
pp. 816-832 ◽  
Author(s):  
Colin C. Williams ◽  
Besnik Krasniqi
Keyword(s):  
Tax Compliance ◽  
State Intervention ◽  
Developed Countries ◽  
Social Actor ◽  
Actor Model ◽  
Tax Morale ◽  
Content Type ◽  
Country Level ◽  
The One ◽  
The Individual

Purpose Recently, a small but burgeoning literature has argued that tax non-compliance cannot be fully explained using the conventional rational economic actor approach which views non-compliance as occurring when the pay-off is greater than the expected cost of being caught and punished. Instead, a social actor approach has emerged which views tax non-compliance as higher when “tax morale”, defined as the intrinsic motivation to pay taxes, is low. To advance this social actor model, the purpose of this paper is to evaluate the individual and national heterogeneity in tax morale, which is crucial if tax compliance is to be improved. Design/methodology/approach To do this, the authors report data from the 2010 Life in Transition Survey on tax morale in 35 Eurasian countries. Findings Logit econometric analysis reveals, on the one hand, that there is higher tax morale among middle-aged, married, homeowners with children, with a university degree and employed, and on the other hand, that there is higher tax morale in more developed countries with stronger legal systems and less corruption, and higher levels of state intervention in the form of both taxation and expenditure. Research limitations/implications Rather than continue with the rational actor approach, this paper reveals that how an emergent social actor approach can help to more fully explain tax non-compliance and results in a different policy approach focused upon changing country-level economic and social conditions associated with low tax morale and thus non-compliance. Practical implications These results display the specific populations with low tax morale which need targeting when seeking to tackle tax non-compliance. Originality/value This paper provides a new way of explaining and tackling tax non-compliance in Eurasian countries.

scholarly journals Characteristics of the endometrium in menstruating species: lessons learned from the animal kingdom†

2020 ◽  
Vol 102 (6) ◽  
pp. 1160-1169
Author(s):  
Laura Catalini ◽  
Jens Fedder
Keyword(s):  
Menstrual Cycle ◽  
Animal Species ◽  
Lessons Learned ◽  
Primate Species ◽  
Fruit Bat ◽  
Laboratory Facilities ◽  
Elephant Shrew ◽  
The One ◽  
The Individual ◽  
Rats And Mice

Abstract Here we have summarized what is currently known about menstruating animal species with special emphasis on non-primate species: length of their menstrual cycle, ovulation, implantation, placentation, decidualization, and endometrial characteristics. Having an overview of all the possible animal models that can be used to study menstruation and the menstrual cycle could be useful to select the one that better matches the needs of the individual research projects. The most promising species to study menstruation seems to be the spiny mouse Acomys cahirinus. It is a rodent that could be easily held in the existing laboratory facilities for rats and mice but with the great advantage of having spontaneous menstruation and several human-like menstrual cycle characteristics. Among the species of menstruating bats, the black mastiff bat Molossus ater and wild fulvous fruit bat Rousettus leschenaultii are the ones presenting the most human-like characteristics. The elephant shrew seems to be the less suitable species among the ones analyzed. The induced mouse model of menstruation is also presented as an adaptable alternative to study menstruation.

scholarly journals Phobalysin, a Small β-Pore-Forming Toxin of Photobacterium damselae subsp. damselae

2015 ◽  
Vol 83 (11) ◽  
pp. 4335-4348 ◽  
Author(s):  
Amable J. Rivas ◽  
Gisela von Hoven ◽  
Claudia Neukirch ◽  
Martina Meyenburg ◽  
Qianqian Qin ◽  
...  
Keyword(s):  
Lactate Dehydrogenase ◽  
Epithelial Cells ◽  
Necrotizing Fasciitis ◽  
Vibrio Cholerae ◽  
Gene Product ◽  
Morphological Changes ◽  
Marine Animals ◽  
Content Type ◽  
Membrane Pores ◽  
Photobacterium Damselae

ABSTRACTPhotobacterium damselaesubsp.damselae, an important pathogen of marine animals, may also cause septicemia or hyperaggressive necrotizing fasciitis in humans. We previously showed that hemolysin genes are critical for virulence of this organism in mice and fish. In the present study, we characterized thehlyAgene product, a putative small β-pore-forming toxin, and termed it phobalysin P (PhlyP), for “photobacterial lysin encoded on a plasmid.” PhlyP formed stable oligomers and small membrane pores, causing efflux of K+, with no significant leakage of lactate dehydrogenase but entry of vital dyes. The latter feature distinguished PhlyP from the relatedVibrio choleraecytolysin. Attack by PhlyP provoked a loss of cellular ATP, attenuated translation, and caused profound morphological changes in epithelial cells. In coculture experiments with epithelial cells,Photobacterium damselaesubsp.damselaeled to rapid hemolysin-dependent membrane permeabilization. Unexpectedly, hemolysins also promoted the association ofP. damselaesubsp.damselaewith epithelial cells. The collective observations of this study suggest that membrane-damaging toxins commonly enhance bacterial adherence.

The impact of age on innovation

2015 ◽  
Vol 38 (4) ◽  
pp. 404-420 ◽  
Author(s):  
Richard A Parsons
Keyword(s):  
Older Workers ◽  
Content Type ◽  
Older Employees ◽  
Human Resource Department ◽  
Age Diversity ◽  
Independent Variable ◽  
The One ◽  
The Individual ◽  
The Cost ◽  
The Impact

Purpose – This paper aims to develop a model of individual innovation based on an employee’s innate propensity to innovate and the specific costs and benefits expected to the individual from the innovation. This model is then used to study the way an employees’ age will impact innovation. Design/methodology/approach – This paper proposes variables which drive an individual’s innovative behavior based on a literature review. This theoretical model is then maximized to show how age drives an employees’ innovation output in three ways. A small survey is used to substantiate the theory. Findings – In this model, the age of the employee becomes an important independent variable with negative elements associated with both the cost and benefit the employee will receive from their innovation efforts. However, age will be positively associated with an employee’s ability to implement and capitalize on their innovation. Practical implications – Firm’s must pay attention to the career life cycle of their employees. The human resource department must take on the task of focusing on delivering the programs needed to support older employees’ particular needs relative to producing innovation. Social implications – As the Western workforce ages, considerations for dealing with older workers and age diversity will become more important. Models such as the one developed in this paper will be important for understanding and managing the changing workforce. Originality/value – This model develops a theory of how age can impact an employee’s innovation in three specific ways that have not previously been addressed in the literature. This model also proposes an explanation for surprising results found in several prior studies.

The unexpected cybernetics life of collectivities: the combinatory systems approach

Kybernetes ◽  
2017 ◽  
Vol 46 (7) ◽  
pp. 1086-1111 ◽  
Author(s):  
Piero Mella
Keyword(s):  
Internal Control ◽  
Path Dependence ◽  
Systems Approach ◽  
Formal Model ◽  
External Control ◽  
Level Control ◽  
Content Type ◽  
Global Variable ◽  
The One ◽  
The Individual

Purpose The purpose of this study is to show how simple “collectivities” of non-interconnected similar agents, which the author has termed “combinatory systems” and which produce analogous micro behaviors, reveal very interesting forms of micro and macro behaviors and effects attributable to a cybernetic mechanism the author shall call “micro-macro feedback”. On the one hand, the macro behavior of the system as a whole derives from the “combination” of the analogous micro behaviors or effects of the agents, and on the other hand, the macro behavior determines, conditions or directs the subsequent micro behavior, thereby creating observable effects and patterns in the collectivity. Design/methodology/approach This paper proposes a new combinatory system theory (CSysT) by constructing a formal model that explains a vast group of phenomena produced by the cybernetic behavior of the collectivity as if an internal organizer were regulating the micro dynamics of agents, producing self-organization, synchronization, path dependence and chaos. Findings In addition to illustrating the CSysT, this study also proposes a new and powerful tool to simulate combinatory systems: the “combinatory automaton”. This is composed of a lattice, each of whose cells contains a variable representing the state of an agent. The value of each cell at each time depends on a synthetic global variable whose values derive from some operations carried out on the values of the cells and that represents the synthetic state of the automaton. The micro-macro feedback connects the analytical values of the cells and the synthetic state of the automaton. Practical implications The CSysT suggests how to control combinatory systems through external actions aimed at making the macro and micro behaviors conform to the desired behaviors. The control is carried out through suitable strengthening or weakening actions, which operate by acting directly on the macro behavior – the author will define this as macro or external control – or by influencing the micro behaviors; in this case, the control will be called micro or internal control. The macro-level control is achieved through strengthening or weakening actions aimed at modifying some recombining factor. Instead, the micro-level control acts on the necessitating factors. Originality/value The CSysT is original and represents an effective tool for observing collective behavior. Combinatory systems are not easily recognizable; nevertheless, they are widely diffused and produce most of the social and economic collective phenomena involving the accumulation of objects, the spread of features or information, the pursuit of a limit and the achievement of general progress as the consequence of the individual pursuit of particular interests.

Assessing the individual and synergistic effects of quality management practices on operations performance

2019 ◽  
Vol 69 (2) ◽  
pp. 297-320 ◽  
Author(s):  
Sarah Jinhui Wu
Keyword(s):  
Quality Management ◽  
Synergistic Effects ◽  
Empirical Support ◽  
Performance Goals ◽  
Adoption Process ◽  
Strategic Choices ◽  
Content Type ◽  
Individual Effects ◽  
Operations Performance ◽  
The Individual

Purpose Quality management (QM) practices have long been suggested as a package to improve the quality performance of a company. Yet, empirical studies offered little support of this perspective as only a small set of QM practices were found to be conductive to quality improvement. By taking a new approach, the purpose of this paper is simultaneously evaluate the individual and synergistic effects of several key quality practices on operations performance. Design/methodology/approach Survey data were collected and used to test the proposed hypotheses. Hierarchical regression analyses were performed to assess the magnitude of synergistic effects and individual effects. Findings It is found in this study that the synergistic effects across QM practices are substantial in enhancing all operations performance dimensions whereas individual effect varies for different performance goals. Originality/value This study makes theoretical contributes to the field of QM by providing empirical support of the interdependence assumption of QM practices and resolving the inconsistent findings. Practically, the results suggest that in-depth implementation of various QM practices simultaneously can be highly effective to achieve performance improvement on all accounts. In addition, the positive additional individual effects also open up a firm’s strategic choices of where to focus the resource investment in the adoption process as long as the strategic focus can justify its contribution toward the desired performance goals.

scholarly journals Intention to live in a smart city based on its characteristics in the perception by the young public

2019 ◽  
Vol 26 (1) ◽  
pp. 73-92 ◽  
Author(s):  
Luis Hernan Contreras Pinochet ◽  
Giulie Furtani Romani ◽  
Cesar Alexandre de Souza ◽  
Guillermo Rodríguez-Abitia
Keyword(s):  
Smart City ◽  
Structural Equation ◽  
Smart Cities ◽  
Idea Generation ◽  
Partial Least Square ◽  
Least Square ◽  
Equation Modeling ◽  
Content Type ◽  
The One ◽  
The Individual

Purpose The purpose of this paper is to identify the intention of living in a smart city as from its characteristics in the individual perception by the young public based on the proposal of an expanded model. Design/methodology/approach The empirical research carried out herein was based on a survey, consisting of a sample of 380 valid questionnaires. Data analysis was carried out through multivariate quantitative approach using structural equation modeling, with estimation by partial least square. Findings In the model, it was possible to adapt all the characteristics of smart cities. The “environment” characteristic was the one that presented the greatest relationship in contributing to efficiencies that allow the migration of citizens and in reducing the environmental impact in the cities’ quality, and the “economy” characteristic was the one that presented the lowest relationship opening the opportunity that this concept can be more widespread within the economic agents and individuals for the society. Originality/value Finally, it is argued that efficiency in all characteristics will depend on the engagement of citizens in the innovation processes of public living in general. The smart city is distinguished from other typologies due to its success in the field of innovation, essentially depending on the collaborative process that is developed in environments that encourage discovery and idea generation.

scholarly journals Photobacterium damselae subsp. damselae Major Virulence Factors Dly, Plasmid-Encoded HlyA, and Chromosome-Encoded HlyA Are Secreted via the Type II Secretion System

2015 ◽  
Vol 83 (4) ◽  
pp. 1246-1256 ◽  
Author(s):  
Amable J. Rivas ◽  
Ana Vences ◽  
Matthias Husmann ◽  
Manuel L. Lemos ◽  
Carlos R. Osorio
Keyword(s):  
Secretion System ◽  
Transcriptional Level ◽  
Type Ii Secretion ◽  
Type Ii ◽  
Marine Animals ◽  
Content Type ◽  
Type Ii Secretion System ◽  
Photobacterium Damselae ◽  
Prepilin Peptidase

Photobacterium damselaesubsp.damselaeis a marine bacterium that causes septicemia in marine animals and in humans. Previously, we had determined a major role of pPHDD1 plasmid-encoded Dly (damselysin) and HlyA (HlyApl) and the chromosome-encoded HlyA (HlyAch) hemolysins in virulence. However, the mechanisms by which these toxins are secreted remain unknown. In this study, we found that a mini-Tn10transposon mutant in a plasmidless strain showing an impaired hemolytic phenotype contained an insertion inepsL, a component of a type II secretion system (T2SS). Reconstruction of the mutant by allelic exchange confirmed the specific involvement ofepsLin HlyAchsecretion. In addition, mutation ofepsLin a pPHDD1-harboring strain caused an almost complete abolition of hemolytic activity against sheep erythrocytes, indicating thatepsLplays a major role in secretion of the plasmid-encoded HlyApland Dly. This was further demonstrated by analysis of different combinations of hemolysin gene mutants and by strain-strain complementation assays. We also found that mutation of the putative prepilin peptidase genepilDseverely affected hemolysis, which dropped at levels inferior to those ofepsLmutants. Promoter expression analyses suggested that impairment of hemolysin secretion inepsLandpilDmutants might constitute a signal that affects hemolysin and T2SS gene expression at the transcriptional level. In addition, singleepsLandpilDmutations caused a drastic decrease in virulence for mice, demonstrating a major role of T2SS andpilDinP. damselaesubsp.damselaevirulence.

Grades or labels? Beef prices and quality

2016 ◽  
Vol 33 (9) ◽  
pp. 1406-1412 ◽  
Author(s):  
Stefan Mann ◽  
Daniel Erdin
Keyword(s):  
A Priori ◽  
Data Sets ◽  
Policy Makers ◽  
Content Type ◽  
Production Methods ◽  
Grading Systems ◽  
The Difference ◽  
The One ◽  
The Individual ◽  
Price Differences

Purpose The difference between quality grades and quality labels is that the latter are awarded on the basis of production processes, whilst the former are conferred on the strength of the actual production results. In the course of a de-ideologisation of society, it might be assumed that the price differences between quality grades would grow larger and larger, while those between quality labels would tend to shrink. The purpose of this paper is to develop and test this hypothesis. Design/methodology/approach Regressions for the calf market on the one hand and for 4,180 cattle-market data sets on the other are run with Stata. Findings The results largely confirm the rising importance of grades between 2000 and 2014. In the period under consideration, a price spread occurs between the individual grades of the Swiss grading system, whilst the surcharge for organic products shrinks. No price discrimination is identified a priori for conventional labels. Practical implications The focus of both chain management and policy makers should be put on effective grading systems rather than on labelling production methods. Originality/value This is the first econometrical comparison of the price effect of both grades and labels.

Contrasting effects of salespeople’s emotion appraisal ability in a transaction-oriented environment

2018 ◽  
Vol 33 (1) ◽  
pp. 84-94 ◽  
Author(s):  
Elten Briggs ◽  
Ashish Kalra ◽  
Raj Agnihotri
Keyword(s):  
Emotional Intelligence ◽  
Customer Service ◽  
Structural Equation ◽  
Sales Performance ◽  
Equation Modeling ◽  
Sales Managers ◽  
Content Type ◽  
The One ◽  
The Individual

Purpose Although the role of emotions in buyer–seller exchanges is important, it remains understudied, especially in the business-to-business selling context. This paper aims to provide insights into the role of the salespeople’s ability to appraise emotions (EA ability) and its effects on job-related outcomes in a transaction-oriented environment. Design/methodology/approach Multi-source data were gathered from 152 salespeople working for a financial service firm. Customer service and sales performance ratings were reported by supervisors. Hypotheses were tested through structural equation modeling using AMOS. Findings The study finds contrasting effects of EA ability on sales performance in the firm’s transaction-oriented environment. On the one hand, EA ability motivates better salesperson customer service, which then increases their sales performance. On the other hand, EA ability enhances emotional exhaustion, which detracts from sales performance. Practical implications Sales managers should consider the ability of new hires to appraise emotions when determining their fit with the job and the organization. Training programs that develop salesperson emotional abilities should be comprehensive as it may be detrimental to be high in EA ability without the skills to regulate or use emotions. Originality value The study is one of the first to consider the effects of emotional abilities in the context of a transaction-oriented environment. By focusing specifically on EA ability, the study provides greater understanding of the influences of the individual components of emotional intelligence, rather than salesperson’s overall capacity for emotional intelligence.

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