scholarly journals Abi Is Required for Modulation and Stability but Not Localization or Activation of the SCAR/WAVE Complex

2013 ◽  
Vol 12 (11) ◽  
pp. 1509-1516 ◽  
Author(s):  
Andrew J. Davidson ◽  
Seiji Ura ◽  
Peter A. Thomason ◽  
Gabriela Kalna ◽  
Robert H. Insall
Keyword(s):  
Cell Separation ◽  
Leading Edge ◽  
Experimental Manipulation ◽  
Exact Role ◽  
Content Type ◽  
Small Complex ◽  
N Terminus ◽  
The Individual ◽  
Wave Complex ◽  
Deletion Series

ABSTRACT The SCAR/WAVE complex drives actin-based protrusion, cell migration, and cell separation during cytokinesis. However, the contribution of the individual complex members to the activity of the whole remains a mystery. This is primarily because complex members depend on one another for stability, which limits the scope for experimental manipulation. Several studies suggest that Abi, a relatively small complex member, connects signaling to SCAR/WAVE complex localization and activation through its polyproline C-terminal tail. We generated a deletion series of the Dictyostelium discoideum Abi to investigate its exact role in regulation of the SCAR complex and identified a minimal fragment that would stabilize the complex. Surprisingly, loss of either the N terminus of Abi or the C-terminal polyproline tail conferred no detectable defect in complex recruitment to the leading edge or the formation of pseudopods. A fragment containing approximately 20% Abi—and none of the sites that couple to known signaling pathways—allowed the SCAR complex to function with normal localization and kinetics. However, expression of N-terminal Abi deletions exacerbated the cytokinesis defect of the Dictyostelium abi mutant, which was earlier shown to be caused by the inappropriate activation of SCAR. This demonstrates, unexpectedly, that Abi does not mediate the SCAR complex's ability to make pseudopods, beyond its role in complex stability. Instead, we propose that Abi has a modulatory role when the SCAR complex is activated through other mechanisms.

Vortex force of an impulsively started plate at high angle of attack

2017 ◽  
Vol 27 (11) ◽  
pp. 2402-2414
Author(s):  
Xiang Fu ◽  
Gaohua Li ◽  
Fuxin Wang
Keyword(s):  
Aerodynamic Force ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Aerodynamic Forces ◽  
Total Drag ◽  
Content Type ◽  
Vortical Structures ◽  
Edge Vortex ◽  
The Individual ◽  
Practical Implications

Purpose A quantitative study that can identify the primary aerodynamic forces and relate them to individual vortical structures is lacking. The paper aims to clarify the quantitative relationships between the aerodynamic forces and vortical structures. Design/methodology/approach The various contributions to the aerodynamic forces on the two-dimensional impulsively started plate are investigated from the perspective of the vorticity moment theorem. The angles of attacks are set to 45°, 58.5° and 72°, while the Reynolds number is 10,000 based on the chord length. Compared with the traditional pressure force analysis, this theorem not only tells us the total aerodynamic force during the motion, but also enables us to quantify the forces contributed from the fluid elements with non-zero vorticity. Findings It is found that the time-dependent force behaviors are dominated by the formations and evolutions of these vortical structures. The analysis of the time-averaged forces demonstrates that the lift contributed from the leading edge vortex (LEV) is nearly four times larger than the total lift and the drag contributed from the starting vortex (SV) is almost equal to the total drag when the angle of attack (AoA) increases to 72°, which means the LEV is “lift structure” whereas the SV is “drag structure”. Practical implications The present method provides a better perspective for flow control and drag reduction by relating the forces directly to the individual vorticity structures. Originality/value In this paper, the Vorticity Moment Theory is first used to study the quantitative relationships between the aerodynamic forces and the vortices.

scholarly journals In VitroAnalyses of the Effects of Heparin and Parabens on Candida albicans Biofilms and Planktonic Cells

2011 ◽  
Vol 56 (1) ◽  
pp. 148-153 ◽  
Author(s):  
Marisa H. Miceli ◽  
Stella M. Bernardo ◽  
T. S. Neil Ku ◽  
Carla Walraven ◽  
Samuel A. Lee
Keyword(s):  
Candida Albicans ◽  
Metabolic Activity ◽  
Biofilm Formation ◽  
High Dose ◽  
Dependent Manner ◽  
Planktonic Cells ◽  
Content Type ◽  
Heparin Sodium ◽  
The Individual

ABSTRACTInfections and thromboses are the most common complications associated with central venous catheters. Suggested strategies for prevention and management of these complications include the use of heparin-coated catheters, heparin locks, and antimicrobial lock therapy. However, the effects of heparin onCandida albicansbiofilms and planktonic cells have not been previously studied. Therefore, we sought to determine thein vitroeffect of a heparin sodium preparation (HP) on biofilms and planktonic cells ofC. albicans. Because HP contains two preservatives, methyl paraben (MP) and propyl paraben (PP), these compounds and heparin sodium without preservatives (Pure-H) were also tested individually. The metabolic activity of the mature biofilm after treatment was assessed using XTT [2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide] reduction and microscopy. Pure-H, MP, and PP caused up to 75, 85, and 60% reductions of metabolic activity of the mature preformedC. albicansbiofilms, respectively. Maximal efficacy against the mature biofilm was observed with HP (up to 90%) compared to the individual compounds (P< 0.0001). Pure-H, MP, and PP each inhibitedC. albicansbiofilm formation up to 90%. A complete inhibition of biofilm formation was observed with HP at 5,000 U/ml and higher. When tested against planktonic cells, each compound inhibited growth in a dose-dependent manner. These data indicated that HP, MP, PP, and Pure-H havein vitroantifungal activity againstC. albicansmature biofilms, formation of biofilms, and planktonic cells. Investigation of high-dose heparin-based strategies (e.g., heparin locks) in combination with traditional antifungal agents for the treatment and/or prevention ofC. albicansbiofilms is warranted.

Gender bias in hospital leadership: a qualitative study on the experiences of women CEOs

2017 ◽  
Vol 31 (2) ◽  
pp. 253-268 ◽  
Author(s):  
Sophie Soklaridis ◽  
Ayelet Kuper ◽  
Cynthia R. Whitehead ◽  
Genevieve Ferguson ◽  
Valerie H. Taylor ◽  
...  
Keyword(s):  
Qualitative Study ◽  
Gender Bias ◽  
Female Leaders ◽  
Content Type ◽  
Hospital Leadership ◽  
Purposeful Sampling ◽  
Women Ceos ◽  
Hospital Ceos ◽  
The Individual ◽  
Systemic Discrimination

Purpose The purpose of this paper is to examine the experiences of gender bias among women hospital CEOs and explore to what these female leaders attribute their success within a male-dominated hospital executive leadership milieu. Design/methodology/approach This qualitative study involved 12 women hospital CEOs from across Ontario, Canada. Purposeful sampling techniques and in-depth qualitative interview methods were used to facilitate discussion around experiences of gender and leadership. Findings Responses fell into two groups: the first group represented the statement “Gender inequality is alive and well”. The second group reflected the statement “Gender inequity is not significant, did not happen to me, and things are better now”. This group contained a sub-group with no consciousness of systemic discrimination and that claimed having no gendered experiences in their leadership journey. The first group described gender issues in various contexts, from the individual to the systemic. The second group was ambivalent about gender as a factor impacting leadership trajectories. Originality/value Representations of women’s leadership have become detached from feminism, with major consequences for women. This study reveals how difficult it is for some women CEOs to identify gender bias. The subtle everyday norms and practices within the workplace make it difficult to name and explain gender bias explicitly and may explain the challenges in understanding how it might affect a woman’s career path.

The role of organizational culture in the knowledge management process

2015 ◽  
Vol 19 (3) ◽  
pp. 433-455 ◽  
Author(s):  
Christina Ling-hsing Chang ◽  
Tung-Ching Lin
Keyword(s):  
Organizational Culture ◽  
Knowledge Management ◽  
Customer Service ◽  
Survey Methodology ◽  
Cultural Dimensions ◽  
Content Type ◽  
Knowledge Resources ◽  
Positive Effects ◽  
Wide Range ◽  
The Individual

Purpose – The purpose of the study is to focus on the enhancement of knowledge management (KM) performance and the relationship between organizational culture and KM process intention of individuals because of the diversity of organizational cultures (which include results-oriented, tightly controlled, job-oriented, closed system and professional-oriented cultures). Knowledge is a primary resource in organizations. If firms are able to effectively manage their knowledge resources, then a wide range of benefits can be reaped such as improved corporate efficiency, effectiveness, innovation and customer service. Design/methodology/approach – The survey methodology, which has the ability to enhance generalization of results (Dooley, 2001), was used to collect the data utilized in the testing of the research hypotheses. Findings – Results- and job-oriented cultures have positive effects on employee intention in the KM process (creation, storage, transfer and application), whereas a tightly controlled culture has negative effects. Research limitations/implications – However, it would have been better to use a longitudinal study to collect useful long-term data to understand how the KM process would be influenced when organizational culture dimensions are changed through/by management. This is the first limitation of this study. According to Mason and Pauleen (2003), KM culture is a powerful predictor of individual knowledge-sharing behavior, which is not included in this study. Thus, this is the second limitation of this paper. Moreover, national culture could be an important issue in the KM process (Jacks et al., 2012), which is the third limitation of this paper for not comprising it. Practical implications – In researchers’ point of view, results- and job-oriented cultures have positive effects, whereas a tightly controlled culture has a negative effect on the KM process intention of the individual. These findings provide evidences that challenge the perspective of Kayworth and Leidner (2003) on this issue. As for practitioners, management has a direction to modify their organizational culture to improve the performance of KM process. Social implications – Both behavioral and value perspectives of the organizational cultural dimensions (results-oriented, tightly control, job-oriented, sociability, solidarity, need for achievement and democracy) should be examined to ascertain their effects firstly on KM culture and then on the KM process intention of the individual. It is hoped that the current study will spawn future investigations that lead to the development of an integrated model which includes organizational culture, KM culture and the KM process intention of the individual. Originality/value – The results-oriented, loosely controlled and job-oriented cultures will improve the effectiveness of the KM process and will also increase employees’ satisfaction and willingness to stay with the organization.

Do information technology (IT) capabilities affect hotel competitiveness?

2020 ◽  
Vol 11 (3) ◽  
pp. 447-460
Author(s):  
Nan Hua
Keyword(s):  
Design Methodology ◽  
Financial Data ◽  
Content Type ◽  
It Systems ◽  
Study Results ◽  
It Capabilities ◽  
The Usa ◽  
Lagged Effects ◽  
The Individual ◽  
Direct Measures

Purpose This paper aims to examine the impacts of IT capabilities on hotel competitiveness. Design/methodology/approach This study adapts and extends Hua et al. (2015) and O’Neill et al. (2008) by incorporating the specific measures of IT expenditures as proxies for the relevant IT capabilities to explore the impacts of IT capabilities on hotel competitiveness. Findings This study finds that expenditures on IT Labor, IT Systems and IT Websites exert different impacts on hotel competitiveness. In addition, IT capabilities exert both contemporary and lagged effects on hotel competitiveness. Originality/value This study is the first that uses financial data to capture direct measures of individual IT capabilities and tests the individual impacts of IT capabilities on hotel competitiveness from both contemporaneous and lagged perspectives. It uses a large same store sample of hotels in the USA from 2011 to 2017; as a result, the study results can be reasonably representative of the hotel population in the USA.

Embeddedness and entrepreneurial traditions

2019 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Maria Elo ◽  
Leo-Paul Dana
Keyword(s):  
Social Ties ◽  
Extended Family ◽  
Business Environment ◽  
Content Type ◽  
Original Culture ◽  
New Locations ◽  
Business Entities ◽  
Time Changes ◽  
The Individual ◽  
Context Specific

Purpose The purpose of this paper is to explore how entrepreneurship traditions evolve in diaspora. Design/methodology/approach A qualitative multiple case study examining the role of diaspora embeddedness, extended family, ethno-religious-, cultural- and social ties and relevant structures shaping diaspora entrepreneurship. Findings The authors found that social ties and diaspora embeddedness create dynamism fostering entrepreneurial identity as a part of the Bukharian culture, and as a preferred career option in the context of Bukharian Jews in diaspora. Diasporic family businesses are products of culture and tradition that migrate to new locations with families and communities, not as disconnected business entities. Research limitations/implications The ways in which families nurture a highly entrepreneurial culture that transfers across generations and contexts are context-specific and not per se generalizable to other diasporas. Practical implications Diasporans often continue their traditions and become again entrepreneurs after their settlement, or they may generate hybrid, circular solutions that allow them to employ their competences in the new contexts or connecting various contexts. This calls for transnational entrepreneurship-policymaking. Social implications Time changes diasporas. A long-term commitment to the business environment evolves and reduces the mobility of the individual diasporan; typically the children of these migrants become more integrated and develop divergent career paths. Hence, their plans are not necessarily including family entrepreneurship creating a challenge for continuation of the original culture of entrepreneurship. Originality/value Despite a notable tradition in Jewish studies, there is limited research on Jewish entrepreneurial diaspora and its contemporary entrepreneurial identity and tradition. Furthermore, the population of Bukharian Jews is an unknown and under-explored highly entrepreneurial group that may offer instrumental views to larger diasporic audiences being concerned about maintaining notions of ethnic heritage and identity.

scholarly journals Improved Antimicrobial Activities of Synthetic-Hybrid Bacteriocins Designed from Enterocin E50-52 and Pediocin PA-1

2014 ◽  
Vol 81 (5) ◽  
pp. 1661-1667 ◽  
Author(s):  
Santosh Kumar Tiwari ◽  
Katia Sutyak Noll ◽  
Veronica L. Cavera ◽  
Michael L. Chikindas
Keyword(s):  
Micrococcus Luteus ◽  
Electrical Potential ◽  
Gram Negative Bacteria ◽  
Additional Advantage ◽  
Gram Negative ◽  
Content Type ◽  
Intracellular Atp ◽  
Hybrid Peptides ◽  
C Terminus ◽  
N Terminus

ABSTRACTTwo hybrid bacteriocins, enterocin E50-52/pediocin PA-1 (EP) and pediocin PA-1/enterocin E50-52 (PE), were designed by combining the N terminus of enterocin E50-52 and the C terminus of pediocin PA-1 and by combining the C terminus of pediocin PA-1 and the N terminus of enterocin E50-52, respectively. Both hybrid bacteriocins showed reduced MICs compared to those of their natural counterparts. The MICs of hybrid PE and EP were 64- and 32-fold lower, respectively, than the MIC of pediocin PA-1 and 8- and 4-fold lower, respectively, than the MIC of enterocin E50-52. In this study, the effect of hybrid as well as wild-type (WT) bacteriocins on the transmembrane electrical potential (ΔΨ) and their ability to induce the efflux of intracellular ATP were investigated. Enterocin E50-52, pediocin PA-1, and hybrid bacteriocin PE were able to dissipate ΔΨ, but EP was unable to deplete this component. Both hybrid bacteriocins caused a loss of the intracellular concentration of ATP. EP, however, caused a faster efflux than PE and enterocin E50-52. Enterocin E50-52 and hybrids PE and EP were active against the Gram-positive and Gram-negative bacteria tested, such asMicrococcus luteus,Salmonella entericaserovar Enteritidis 20E1090, andEscherichia coliO157:H7. The hybrid bacteriocins designed and described herein are antimicrobial peptides with MICs lower those of their natural counterparts. Both hybrid peptides induce the loss of intracellular ATP and are capable of inhibiting Gram-negative bacteria, and PE dissipates the electrical potential. In this study, the MIC of hybrid bacteriocin PE decreased 64-fold compared to the MIC of its natural peptide counterpart, pediocin PA-1. Inhibition of Gram-negative pathogens confers an additional advantage for the application of these peptides in therapeutics.

Entrepreneurship in regions: differentiated impacts of the socio cultural and gender types

2015 ◽  
Vol 28 (1) ◽  
pp. 45-76 ◽  
Author(s):  
Claudio Mancilla ◽  
José Ernesto Amorós
Keyword(s):  
Negative Impact ◽  
Positive Impact ◽  
Fear Of Failure ◽  
Content Type ◽  
Reference Models ◽  
Cultural Aspects ◽  
And Gender ◽  
The Individual ◽  
Practical Implications ◽  
Secondary City

Purpose The purpose of this paper is to study the differentiated impact of factors that influence the propensity to entrepreneur in a sample of people in Chile. A distinction is made between individuals that live in primary cities and secondary cities. The differentiating factors are socio‐cultural aspects (reference models – positive examples of entrepreneurs – and perception of social fear of failure) and the gender of the individual. Design/methodology/approach For the research data from the survey used in Chile by the Global Entrepreneurship Monitor for the years 2010 and 2011 were used. A logit model was used to determine the differentiated impact of the analysed factors and interactions were done using the method proposed by Corneliâen and Sonderhof (2009). Findings These showed that the fact that an individual lives in a secondary city decreases his entrepreneurship probability. The positive impact that the reference models have is weaker in women. Contrary to what was expected, the negative impact of the fear of failure perception is weaker in women. Practical implications These results have the implications to suggest focused public policies and differentiations that consider the socio‐cultural, territorial (focused in cities) and gender aspects. Originality/value The research contributes by giving empirical evidence of the existence of the negative impact of living in a secondary city and of differentiated effects of socio‐cultural factors from the gender perspective.

scholarly journals Secretion of Anti-Plasmodium Effector Proteins from a Natural Pantoea agglomerans Isolate by Using PelB and HlyA Secretion Signals

2011 ◽  
Vol 77 (13) ◽  
pp. 4669-4675 ◽  
Author(s):  
Dawn C. Bisi ◽  
David J. Lampe
Keyword(s):  
Control Strategies ◽  
Pectate Lyase ◽  
Erwinia Carotovora ◽  
Individual Characteristics ◽  
Pantoea Agglomerans ◽  
Effector Proteins ◽  
World Health ◽  
Content Type ◽  
E Coli ◽  
The Individual

ABSTRACTThe insect-vectored disease malaria is a major world health problem. New control strategies are needed to supplement the current use of insecticides and medications. A genetic approach can be used to inhibit development of malaria parasites (Plasmodiumspp.) in the mosquito host. We hypothesized thatPantoea agglomerans, a bacterial symbiont ofAnophelesmosquitoes, could be engineered to express and secrete anti-Plasmodiumeffector proteins, a strategy termed paratransgenesis. To this end, plasmids that include thepelBorhlyAsecretion signals from the genes of related species (pectate lyase fromErwinia carotovoraand hemolysin A fromEscherichia coli, respectively) were created and tested for their efficacy in secreting known anti-Plasmodiumeffector proteins (SM1, anti-Pbs21, and PLA2) inP. agglomeransandE. coli.P. agglomeranssuccessfully secreted HlyA fusions of anti-Pbs21 and PLA2, and these strains are under evaluation for anti-Plasmodiumactivity in infected mosquitoes. Varied expression and/or secretion of the effector proteins was observed, suggesting that the individual characteristics of a particular effector may require empirical testing of several secretion signals. Importantly, those strains that secreted efficiently grew as well as wild-type strains under laboratory conditions and, thus, may be expected to be competitive with the native microbiota in the environment of the mosquito midgut.

The IRS eyes professor's movie: a taxation case exercise

2013 ◽  
Vol 9 (2) ◽  
pp. 58-64
Author(s):  
Jayanti Bandyopadhyay ◽  
Paul F. McGee ◽  
Linda A. Hall
Keyword(s):  
Foreign Country ◽  
Attractive Alternative ◽  
Sufficient Information ◽  
Case Description ◽  
Red Flags ◽  
Content Type ◽  
Accounting Rules ◽  
The Individual ◽  
Tax Accounting

Case description This case illustrates the tax implications of a movie produced in a foreign country that resulted in a loss. Teaching opportunities include the application of tax rules to a Schedule C business loss and a resulting net operating loss (NOL) deduction, the consideration of hobby and passive activity losses, the tax treatment of funds received in a divorce settlement, and how an individual might handle a possible IRS examination. Students are asked to prepare a revised Form 1040 for the movie business loss and the individual NOL deduction based on evidence provided in the case. Sufficient information is provided in the case to identify audit “red flags” in a tax return. Using the tale of an actual movie production in a foreign country and its consequent tax implications can provide an attractive alternative to teaching tax accounting rules that are often considered by students as “dry”.

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