Studies on the relationship between the survival of Schistosoma mansoni larvae in mice and the degree of resistance produced

Parasitology ◽  
1982 ◽  
Vol 84 (1) ◽  
pp. 111-122 ◽  
Author(s):  
Q. D. Bickle
Keyword(s):  
Schistosoma Mansoni ◽  
Key Factors ◽  
Larval Phase ◽  
Post Vaccination ◽  
Induction Of Resistance ◽  
The Relationship

SUMMARYThese studies were aimed at giving a clearer idea of the source of the antigens responsible for the induction of resistance by larval schistosomes. Firstly, the resistance induced by radiation-attenuated (20 krad.) infections was compared with that induced by the larval phase of unirradiated infections. The superiority of the irradiated larvae was demonstrated by infecting mice with 500 female cercariae which were either unirradiated or irradiated, and challenging them 3 weeks later with male cercariae. At perfusion, when primary and challenge worms could be distinguished by sex, significantly greater resistance was demonstrated in the groups vaccinated with irradiated larvae (56 cf. 31% and 48 cf. 26% in two experiments). Secondly, in order to establish how long immunizing larvae need to survive to stimulate optimum resistance, mice were either treated with schistosomulicidal drugs or had the site of infection excised at various intervals post-vaccination. Treatment or excision at up to 24 h did not result in significant resistance to challenge (6–16%). Similar treatments at 1 week did not prevent significant resistance developing (26–37%) but the levels of resistance were significantly lower than those manifest by vaccinated, untreated mice (51–71%). It is concluded that the immunizing larvae need to persist for between 1 and 2 weeks in order to stimulate optimum protection and that antigens released during protracted survival and/or death of the larvae in either the skin or the lungs are probably key factors in the induction of resistance.

Immunization of mice with gamma-irradiated intramuscularly injected schistosomula of Schistosoma mansoni

Parasitology ◽  
1979 ◽  
Vol 79 (2) ◽  
pp. 209-222 ◽  
Author(s):  
Q. D. Bickle ◽  
M. G. Taylor ◽  
M. J. Doenhoff ◽  
G. S. Nelson
Keyword(s):  
Schistosoma Mansoni ◽  
Challenge Infection ◽  
Radiation Doses ◽  
Significant Protection ◽  
Lethal Challenge ◽  
Post Vaccination ◽  
Intramuscular Injections ◽  
Induction Of Resistance ◽  
Gamma Irradiated

SUMMARYThe parameters involved in the induction of resistance against Schistosoma mansoni by injection of irradiated, artificially transformed schistosomula were studied in mice. Single intramuscular injections of 500 schistosomula exposed to radiation doses in the range 2·3 to 160 krad. resulted in significant protection (in the range 20 to 50% as assessed by reduced worm burdens) against a challenge infection administered at intervals from 3 to 24 weeks post-vaccination. However, schistosomula irradiated with 20 krad. consistently resulted in better protection than those exposed to either higher or lower radiation doses despite the persistence of stunted adults from the infections irradiated with 2·3 krad. Vaccination with 40 krad. schistosomula resulted in significant protection in terms of reduced worm and tissue egg burdens and increased survival following lethal challenge. Varying the number of irradiated schistosomula, the frequency and route of their administration, the site of challenge and the strain of host all failed to enhance the level of resistance. However, percutaneously applied, irradiated cercariae were found to be more effective in stimulating resistance (60%) than intramuscularly injected, irradiated schistosomula (40%).

Examining Organizational, Cultural, and Individual-Level Factors Related to Workplace Safety and Health Awareness and Risks: A Systematic Review and Metric Analysis (Preprint)

2018 ◽  
Author(s):  
Edmund W. J. Lee ◽  
Han Zheng ◽  
Htet Htet Aung ◽  
Megha Rani Aroor ◽  
Chen Li ◽  
...  
Keyword(s):  
Systematic Review ◽  
Citation Count ◽  
Workplace Safety ◽  
Key Factors ◽  
Health Awareness ◽  
Individual Level ◽  
Metric Analysis ◽  
Safety And Health ◽  
The Impact ◽  
The Relationship

BACKGROUND Promoting safety and health awareness and mitigating risks are of paramount importance to companies in high-risk industries. Yet, there are very few studies that have synthesized findings from existing online workplace safety and health literature to identify what are the key factors that are related to (a) safety awareness, (b) safety risks, (c) health awareness, and (d) health risks. OBJECTIVE As one of the first systematic reviews in the area of workplace health and safety, this study aims to identify the factors related to safety and health awareness as well as risks, and systematically map these factors within three levels: organizational, cultural, and individual level. Also, this review aims to assess the impact of these workplace safety and health publications in both academic (e.g., academic databases, Mendeley, and PlumX) and non-academic settings (e.g., social media platform). METHODS The systematic review was conducted in line with procedures recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). First, Proquest, ScienceDirect and Scopus were identified as suitable databases for the systematic review. Second, after inputting search queries related to safety and health awareness and risks, the articles were evaluated based on a set of inclusion and exclusion criteria. Third, the factors identified in the included articles were coded systematically. Fourth, the research team assessed the impact of the articles through a combination of traditional and new metric analysis methods: citation count, Altmetric Attention Score, Mendeley readers count, usage count, and capture count. RESULTS Out of a total of 4,831 articles retrieved from the three databases, 51 articles were included in the final sample and were systematically coded. The results revealed six categories of organizational (management commitment, management support, organizational safety communication, safety management systems, physical work environment, and organizational environment), two cultural (interpersonal support and organizational culture), and four individual (perception, motivation, attitude and behavior) level factors that relate to safety and health awareness and risk. In terms of impact, the relationship between citation count and the various metrics measuring academic activity (e.g., Mendeley readers, usage count, and capture count) were mostly significant while the relationship between citation count and Altmetric Attention Score was non-significant. CONCLUSIONS This study provides a macro view of the current state of workplace safety and health research and gives scholars an indication on some of the key factors of safety and health awareness and risks. Researchers should also be cognizant that while their work may receive attention from the scholarly community, it is important to tailor their communication messages for the respective industries they are studying to maximize the receptivity and impact of their findings. CLINICALTRIAL N.A.

scholarly journals Comparison of the sensitivity of Western blotting between PVDF and NC membranes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xiang ◽  
Yuanyuan Zheng ◽  
Shaobo Liu ◽  
Gang Liu ◽  
Zhi Li ◽  
...  
Keyword(s):  
Western Blotting ◽  
Polyvinylidene Fluoride ◽  
Staining Intensity ◽  
Detection Sensitivity ◽  
Key Factors ◽  
Post Translational Modifications ◽  
Factors Affecting ◽  
Molecular Weights ◽  
Direct Blue ◽  
The Relationship

AbstractWestern blotting (WB) is one of the most widely used techniques to identify proteins as well as post translational modifications of proteins. The selection of electroblotted membrane is one of the key factors affecting the detection sensitivity of the protein which is transferred from gel to membrane in WB. The most common used membranes are polyvinylidene fluoride (PVDF) and nitrocellulose (NC) membranes. Which membrane of these two is more suitable for WB has not been reported so far. Here, by incubating proteins which were transferred to PVDF or NC membranes with a series of antibodies and different types of lectins, we investigated the relationship between the binding ability of these two membranes to proteins or glycoproteins and the molecular weight of the target protein. The antibody re-probed ability of the two membranes was also explored. Moreover, we verified the above results by directly incubating proteins having different molecular weights onto PVDF or NC membranes. Bound proteins were stained with direct blue-71, and the staining intensity was quantitated by scanning and densitometry.

scholarly journals High coverage COVID-19 mRNA vaccination rapidly controls SARS-CoV-2 transmission in long-term care facilities

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Pablo M. De Salazar ◽  
Nicholas B. Link ◽  
Karuna Lamarca ◽  
Mauricio Santillana
Keyword(s):  
Long Term Care ◽  
Mitigation Strategies ◽  
Key Factors ◽  
Modeling Framework ◽  
High Coverage ◽  
Term Care ◽  
Early Effect ◽  
Care Facilities ◽  
The Relationship

Abstract Background Residents of Long-Term Care Facilities (LTCFs) represent a major share of COVID-19 deaths worldwide. Measuring the vaccine effectiveness among the most vulnerable in these settings is essential to monitor and improve mitigation strategies. Methods We evaluate the early effect of the administration of BNT162b2-mRNA vaccine to individuals older than 64 years residing in LTCFs in Catalonia, Spain. We monitor all the SARS-CoV-2 documented infections and deaths among LTCFs residents once more than 70% of them were fully vaccinated (February–March 2021). We develop a modeling framework based on the relationship between community and LTCFs transmission during the pre-vaccination period (July–December 2020). We compute the total reduction in SARS-CoV-2 documented infections and deaths among residents of LTCFs over time, as well as the reduction in the detected transmission for all the LTCFs. We compare the true observations with the counterfactual predictions. Results We estimate that once more than 70% of the LTCFs population are fully vaccinated, 74% (58–81%, 90% CI) of COVID-19 deaths and 75% (36–86%, 90% CI) of all expected documented infections among LTCFs residents are prevented. Further, detectable transmission among LTCFs residents is reduced up to 90% (76–93%, 90% CI) relative to that expected given transmission in the community. Conclusions Our findings provide evidence that high-coverage vaccination is the most effective intervention to prevent SARS-CoV-2 transmission and death among LTCFs residents. Widespread vaccination could be a feasible avenue to control the COVID-19 pandemic conditional on key factors such as vaccine escape, roll out and coverage.

The relationship between the age of Schistosoma mansoni cercariae and their ability to penetrate and infect the mammalian host

Parasitology ◽  
1983 ◽  
Vol 87 (3) ◽  
pp. 481-492 ◽  
Author(s):  
J. Ruth Lawson ◽  
R. A. Wilson
Keyword(s):  
Schistosoma Mansoni ◽  
Stratum Corneum ◽  
Mass Mortality ◽  
Mammalian Host ◽  
Energy Reserves ◽  
Age Related ◽  
Abdominal Route ◽  
Relationship Of ◽  
The Relationship ◽  
Related Mortality

SummaryThe ability of the cercariae of Schistosoma mansoni to penetrate the tails of mice was shown to remain constant throughout their lives. However, their capacity to establish themselves and then reach maturity decreased as they aged. The abdominal route of penetration produced consistently higher maturation rates than the tail route. Significantly different maturation rates were obtained by modifying the standard tail infection technique. Evidence is presented that age-related mortality of schisto-somula occurs within 24 h of penetration and may be associated with the exhaustion of energy reserves during the penetration of the stratum corneum. The relationship of this age-related mortality to ‘mass mortality’ is discussed.

scholarly journals CRITICAL FACTORS VARYING CONSTRUCTION COST

2009 ◽  
Vol 12 (1) ◽  
pp. 104-117
Author(s):  
Tam Thi Minh Nguyen ◽  
Thi Hao Cao
Keyword(s):  
Construction Industry ◽  
Construction Projects ◽  
Multiple Linear Regression Model ◽  
Construction Cost ◽  
Ho Chi Minh City ◽  
Cost Overrun ◽  
Key Factors ◽  
Industry Sectors ◽  
The Relationship ◽  
Chronic Problem

Construction industry is considered to be one of the most important industries in Vietnam's economy. But many construction industry sectors have been experienced chronic problem as cost overrun. Therefore, a conceptual model of factors influencing construction cost was developed to determine the key factors that cause difference between budget cost and actual cost and some solutions are recommended to be applied to achieve the best outcome of cost. The result of analyzing 216 construction projects completed from 2002 to 2007 by companies located in Ho Chi Minh City indicated 6 main factors varying construction cost: project planners, project executives, economics, political, natural environment, fraudulent and lost. The results of multiple linear regression model confirmed the relationship between these above 6 factors and construction cost with the theories are supported at the statistically significant level of 0.05.

On the Mechanism and the Rate of Sub-Ground Erosion in the Loess Material

2011 ◽  
Vol 233-235 ◽  
pp. 2528-2531 ◽  
Author(s):  
Xi An Li ◽  
Qiang Xu ◽  
Hong Zhou Lin ◽  
Wan Jun Ye
Keyword(s):  
Critical Condition ◽  
Theoretical Basis ◽  
Field Survey ◽  
Influential Factors ◽  
The Other ◽  
Initial Water Content ◽  
Key Factors ◽  
Erosion Process ◽  
Initial Water ◽  
The Relationship

Sub-ground erosion often resulted in severe problems in various engineering constructions, most of which is due to the sub-erosion in loess. In this paper, the critical condition of “soil bursting” was analyzed and the formula describing the critical condition of soil bursting was derivated by the analytical method. Furthermore, the velocity of tunnel-erosion in loess and its influential factors were studied. A set of tests are designed to study the relationship between the tunnel-erosion velocity and the key influential factors. The key factors considered in the test include soil density as well as the initial water content. The other purpose is to reveal the characteristics of the tunnel-erosion process. Phenomena observed during the tests together with the data from field survey revealed the mechanism of tunneling in loess very well, and the work in this paper formed a theoretical basis for further study about sub-ground erosion in loess.

Internationalization Process of Innovative SMEs in Lebanon

2015 ◽  
pp. 365-388
Author(s):  
Maarouf Ramadan
Keyword(s):  
International Development ◽  
International Cooperation ◽  
Positive Relationship ◽  
Empirical Studies ◽  
Research Proposal ◽  
Internationalization Process ◽  
Key Factors ◽  
Mediterranean Countries ◽  
The Relationship

This chapter aims to highlight the relationship between innovation and internationalization in the context of international development of Lebanese innovative SMEs. The problems of the commitment of these SMEs in a process of internationalization is relevant in the Mediterranean countries in general and Lebanon in particular, but few empirical studies have been done so far to understand their international development (Ramadan, 2008; Ramadan and Levratto, 2011). The role of key factors such as size, age, international cooperation and strategic planning in the international development of Lebanese SMEs has rarely been comprehensively studied. Motivated by the literature that establishes a positive relationship between innovation and internationalization, this study presents a research proposal on these SMEs to bring out certain variables that characterize them. Moreover, the aim of the study is to verify the effect of the above factors and integrates into schools of thought that attempt to demonstrate that the international development of SMEs is influenced by a context that must be identified in the case of Lebanon.

Could Cultural Sustainability Improve Organisational Sustainability in Cloud Environments?

2017 ◽  
pp. 1202-1217 ◽  
Author(s):  
Fawzy Soliman
Keyword(s):  
Organizational Culture ◽  
Stakeholder Involvement ◽  
Management Support ◽  
Key Factors ◽  
Readiness Assessment ◽  
Leadership And Management ◽  
Cultural Sustainability ◽  
Sustainable Culture ◽  
Cloud Environments ◽  
The Relationship

This chapter provides an explorative analysis of cultural factors critical to the sustainable organisational developments within cloud environments. The chapter examines how businesses could improve their sustainability by creating sustainable cultures. The chapter debates sustainability issues such as the relationship between organizational culture and sustainable organisational developments. The chapter provides a list of key areas for creating a sustainable culture, for instance, the Change readiness assessment, Leadership and management support, Stakeholder involvement, and Education, as well as Communication. The chapter also discusses organizational culture and the close relationships between culture and sustainability. The chapter examines the relationships when creating sustainability culture and the key factors that will influence the change process.

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