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"viability"
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Implicit Cognitive Vulnerability Through Nudges, Boosts, and Bounces
Implicit Cognitive Vulnerability is a developing theoretical understanding, wherein feeling safe within an instructional environment is of significant impact upon short-term and long-term memory’s cognitive acquisition of information so as to embed new information within a learner’s conceptual framework of understanding. Towards successfully individualizing a learner’s implicit cognitive vulnerability, the primary focus has been upon the larger community environment in which the learner is housed, yet the viability of the learner’s ability and cognitive viability must also be addressed through nudges, boosts and bounces of motivational support. Recognizing this individualized need of learners, this discussion revolves around the ability of a learner to embed implicit cognitive vulnerability within their own cognitive viability through structured and unstructured synchronous and asynchronous nudges and boosts that support self-regulatory and self-efficacy understandings.
Journal Article
The Tri - Sigma Test: The Triple - Sigma Trichotomous Summation Triostatistic for the Viability, Verifiability, and Validityof Multiple Tri - Squared Test Outcomes
This paper provides a novel statistical methodology called Triple or Tri - Sigma ( Tri-£ ) that is designed to conceptually add to the research that has been conducted on and with the Tri - Squared Test (Osler, 2012a). The Tri - Sigma Test is an advanced statistical procedure that is used to analyze multiple Tri - Squared Tests that have been delivered at different times. Tripleseries summation provides an innovative way of investigating the data derived from a series of researchbased investigative instruments that are known as Trichotomous Tri-Squared Test Triple-I's (Osler and Mansaray, 2013b). The Triple - I is directly derived from specific research questions as an in-depth associated instrument [first introduced in the i-manager's Journal on Mathematics as a part of the Tri-Squared Test (Osler, 2012a)]. This new approach to research inquiry lends additional strength to trichotomous research designs. Trichotomous tests can now be offered at multiple stages, multiple times, and in multiple ways with multiple research questions.
Journal Article
Probiotics in Food Systems: Significance and Emerging Strategies Towards Improved Viability and Delivery of Enhanced Beneficial Value
Preserving the efficacy of probiotic bacteria exhibits paramount challenges that need to be addressed during the development of functional food products. Several factors have been claimed to be responsible for reducing the viability of probiotics including matrix acidity, level of oxygen in products, presence of other lactic acid bacteria, and sensitivity to metabolites produced by other competing bacteria. Several approaches are undertaken to improve and sustain microbial cell viability, like strain selection, immobilization technologies, synbiotics development etc. Among them, cell immobilization in various carriers, including composite carrier matrix systems has recently attracted interest targeting to protect probiotics from different types of environmental stress (e.g., pH and heat treatments). Likewise, to successfully deliver the probiotics in the large intestine, cells must survive food processing and storage, and withstand the stress conditions encountered in the upper gastrointestinal tract. Hence, the appropriate selection of probiotics and their effective delivery remains a technological challenge with special focus on sustaining the viability of the probiotic culture in the formulated product. Development of synbiotic combinations exhibits another approach of functional food to stimulate the growth of probiotics. The aim of the current review is to summarize the strategies and the novel techniques adopted to enhance the viability of probiotics.
Journal Article
Heat stress during flowering in cereals – effects and adaptation strategies
Heat stress during flowering has differential impact on male and female reproductive organ viability leading to yield losses in field crops. Unlike flooded rice, dryland cereals such as sorghum, pearl millet and wheat have optimised their flower opening during cooler early morning or late evening hours to lower heat stress damage during flowering. Although previous studies have concluded that pollen viability determines seed set under heat stress, recent findings have revealed pearl millet and sorghum pistils to be equally sensitive to heat stress. Integrating flower opening time during cooler hours with increased pollen and pistil viability will overcome heat stress-induced damage during flowering under current and future hotter climatic conditions.
Journal Article
Development of a human skin commensal microbe for bacteriotherapy of atopic dermatitis and use in a phase 1 randomized clinical trial
Staphylococcus aureus
colonizes patients with atopic dermatitis (AD) and exacerbates disease by promoting inflammation. The present study investigated the safety and mechanisms of action of
Staphylococcus hominis
A9 (
Sh
A9), a bacterium isolated from healthy human skin, as a topical therapy for AD.
Sh
A9 killed
S. aureus
on the skin of mice and inhibited expression of a toxin from
S. aureus
(
psm
α) that promotes inflammation. A first-in-human, phase 1, double-blinded, randomized 1-week trial of topical
Sh
A9 or vehicle on the forearm skin of 54 adults with
S. aureus
-positive AD (NCT03151148) met its primary endpoint of safety, and participants receiving
Sh
A9 had fewer adverse events associated with AD. Eczema severity was not significantly different when evaluated in all participants treated with
Sh
A9 but a significant decrease in
S. aureus
and increased
Sh
A9 DNA were seen and met secondary endpoints. Some
S. aureus
strains on participants were not directly killed by
Sh
A9, but expression of mRNA for
psm
α was inhibited in all strains. Improvement in local eczema severity was suggested by post-hoc analysis of participants with
S. aureus
directly killed by
Sh
A9. These observations demonstrate the safety and potential benefits of bacteriotherapy for AD.
First-in-human test of topical application of a commensal bacterium on skin of individuals with atopic dermatitis reduces colonization by proinflammatory
Staphylococcus aureus
.
Journal Article
Comparison of methods used for assessing the viability and vitality of yeast cells
Determination of cell viability is the most commonly used method for assessing the impact of various types of stressors in toxicity research and in industrial microbiology studies. Viability is defined as a percentage of live cells in a whole population. Although cell death is one of the consequences of toxicity, chemical or physical factors may exert their toxic effects through a number of cellular alterations that may compromise cell ability to divide without necessarily leading to cell death. This aspect represents the term ‘cell vitality’ defined as physiological capabilities of cells. It is important to note that cell viability and cell vitality represent two different aspects of cell functions, and both are required for the estimation of the physiological state of a cell after exposure to various types of stressors and chemical or physical factors. In this paper, we introduced a classification of available methods for estimating both viability and vitality in Saccharomyces cerevisiae yeast cells (wild‐type and Δsod1 mutant) in which the effects of selected oxidants causing oxidative stress is evaluated. We present the advantages as well as disadvantages of the selected methods and assess their usefulness in different types of research.
Journal Article
Evaluating stress resilience of cyanobacteria through flow cytometry and fluorescent viability assessment
Cyanobacteria are prokaryotic organisms characterised by their complex structures and a wide range of pigments. With their ability to fix CO
2
, cyanobacteria are interesting for white biotechnology as cell factories to produce various high-value metabolites such as polyhydroxyalkanoates, pigments, or proteins. White biotechnology is the industrial production and processing of chemicals, materials, and energy using microorganisms. It is known that exposing cyanobacteria to low levels of stressors can induce the production of secondary metabolites. Understanding of this phenomenon, known as hormesis, can involve the strategic application of controlled stressors to enhance the production of specific metabolites. Consequently, precise measurement of cyanobacterial viability becomes crucial for process control. However, there is no established reliable and quick viability assay protocol for cyanobacteria since the task is challenging due to strong interferences of autofluorescence signals of intercellular pigments and fluorescent viability probes when flow cytometry is used. We performed the screening of selected fluorescent viability probes used frequently in bacteria viability assays. The results of our investigation demonstrated the efficacy and reliability of three widely utilised types of viability probes for the assessment of the viability of
Synechocystis
strains. The developed technique can be possibly utilised for the evaluation of the importance of polyhydroxyalkanoates for cyanobacterial cultures with respect to selected stressor—repeated freezing and thawing. The results indicated that the presence of polyhydroxyalkanoate granules in cyanobacterial cells could hypothetically contribute to the survival of repeated freezing and thawing.
Journal Article
Spatiotemporal microbial evolution on antibiotic landscapes
A key aspect of bacterial survival is the ability to evolve while migrating across spatially varying environmental challenges. Laboratory experiments, however, often study evolution in well-mixed systems. Here, we introduce an experimental device, the microbial evolution and growth arena (MEGA)-plate, in which bacteria spread and evolved on a large antibiotic landscape (120×60 centimeters) that allowed visual observation of mutation and selection in a migrating bacterial front. While resistance increased consistently, multiple coexisting lineages diversified both phenotypically and genotypically. Analyzing mutants at and behind the propagating front, we found that evolution is not always led by the most resistant mutants; highly resistant mutants may be trapped behind more sensitive lineages. The MEGA-plate provides a versatile platform for studying microbial adaption and directly visualizing evolutionary dynamics.
Journal Article
Droplet microfluidic technology for single-cell high-throughput screening
We present a droplet-based microfluidic technology that enables high-throughput screening of single mammalian cells. This integrated platform allows for the encapsulation of single cells and reagents in independent aqueous microdroplets (1 pL to 10 nL volumes) dispersed in an immiscible carrier oil and enables the digital manipulation of these reactors at a very high-throughput. Here, we validate a full droplet screening workflow by conducting a droplet-based cytotoxicity screen. To perform this screen, we first developed a droplet viability assay that permits the quantitative scoring of cell viability and growth within intact droplets. Next, we demonstrated the high viability of encapsulated human monocytic U937 cells over a period of 4 days. Finally, we developed an optically-coded droplet library enabling the identification of the droplets composition during the assay read-out. Using the integrated droplet technology, we screened a drug library for its cytotoxic effect against U937 cells. Taken together our droplet microfluidic platform is modular, robust, uses no moving parts, and has a wide range of potential applications including high-throughput single-cell analyses, combinatorial screening, and facilitating small sample analyses.
Journal Article