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"Henson, Michael"
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Evaluating employee performance through Christian virtues
In this book the authors create a statistically validated scale measuring the display of each of the nine fruit of the spirit in employees. The authors will discuss how biblical values are applicable to contemporary organizational leadership and management. These nine virtues span a wide breadth of important personal and organizational attributes including benevolence, affection, gladness, relational harmony, tranquility, perseverance, helpfulness, caring for the welfare of others, adherence to the beliefs and value of others, power used soberly, and mastering one's desires. While diverse in nature, the list also suggests a holistic development of personal and organizational character. Understanding the manner in which these traits can be measured will be a significant benefit to HRM and HRD scholars conducting research in Christian servant leadership.
Computational modeling of the gut microbiota reveals putative metabolic mechanisms of recurrent Clostridioides difficile infection
2021
Approximately 30% of patients who have Clostridioides difficile infection (CDI) will suffer at least one incident of reinfection. While the underlying causes of CDI recurrence are poorly understood, interactions between C . difficile and commensal gut bacteria are thought to play an important role. In this study, an in silico pipeline was used to process 16S rRNA gene amplicon sequence data of 225 stool samples from 93 CDI patients into sample-specific models of bacterial community metabolism. Clustered metabolite production rates generated from post-diagnosis samples generated a high Enterobacteriaceae abundance cluster containing disproportionately large numbers of recurrent samples and patients. This cluster was predicted to have significantly reduced capabilities for secondary bile acid synthesis but elevated capabilities for aromatic amino acid catabolism. When applied to 16S sequence data of 40 samples from fecal microbiota transplantation (FMT) patients suffering from recurrent CDI and their stool donors, the community modeling method generated a high Enterobacteriaceae abundance cluster with a disproportionate large number of pre-FMT samples. This cluster also was predicted to exhibit reduced secondary bile acid synthesis and elevated aromatic amino acid catabolism. Collectively, these in silico predictions suggest that Enterobacteriaceae may create a gut environment favorable for C . difficile spore germination and/or toxin synthesis.
Journal Article
Jim Henson's Labyrinth : coronation
The untold origin of the Goblin King from Jim Henson's cult-classic film, Labyrinth. Long before Sarah ventured to save her baby brother from the clutches of the Goblin King, another young woman sought to save her child from an unknown fate within the Labyrinth. Set in 18th-century Venice, Jim Henson's Labyrinth: Coronation is a striking look into the mysteries of the Labyrinth itself, uncovering the fate of a small boy named Jareth who would one day be King. Simon Spurrier (The Spire, Jim Henson's The Power of the Dark Crystal) and Daniel Bayliss (Jim Henson's The Storyteller: Dragons, Big Trouble in Little China/Escape from New York) present a look into a magical world where nothing is as it seems and introduce Maria, a heroine instilled with courage, hope, and determination.
Suboptimal community growth mediated through metabolite crossfeeding promotes species diversity in the gut microbiota
2018
The gut microbiota represent a highly complex ecosystem comprised of approximately 1000 species that forms a mutualistic relationship with the human host. A critical attribute of the microbiota is high species diversity, which provides system robustness through overlapping and redundant metabolic capabilities. The gradual loss of bacterial diversity has been associated with a broad array of gut pathologies and diseases including malnutrition, obesity, diabetes and inflammatory bowel disease. We formulated an in silico community model of the gut microbiota by combining genome-scale metabolic reconstructions of 28 representative species to explore the relationship between species diversity and community growth. While the individual species offered a broad range of metabolic capabilities, communities optimized for maximal growth on simulated Western and high-fiber diets had low diversities and imbalances in short-chain fatty acid (SCFA) synthesis characterized by acetate overproduction. Community flux variability analysis performed with the 28-species model and a reduced 20-species model suggested that enhanced species diversity and more balanced SCFA production were achievable at suboptimal growth rates. We developed a simple method for constraining species abundances to sample the growth-diversity tradeoff and used the 20-species model to show that tradeoff curves for Western and high-fiber diets resembled Pareto-optimal surfaces. Compared to maximal growth solutions, suboptimal growth solutions were characterized by higher species diversity, more balanced SCFA synthesis and lower exchange rates of crossfed metabolites between more species. We hypothesized that modulation of crossfeeding relationships through host-microbiota interactions could be an important means for maintaining species diversity and suggest that community metabolic modeling approaches that allow multiobjective optimization of growth and diversity are needed for more realistic simulation of complex communities.
Journal Article
Interrogation of the perturbed gut microbiota in gouty arthritis patients through in silico metabolic modeling
2021
Recent studies have shown perturbed gut microbiota associated with gouty arthritis, a metabolic disease characterized by an imbalance between uric acid production and excretion. To mechanistically investigate altered microbiota metabolism associated with gout disease, 16S rRNA gene amplicon sequence data from stool samples of gout patients and healthy controls were computationally analyzed through bacterial community metabolic models. Patient‐specific community models constructed with the metagenomics modeling pipeline, mgPipe, were used to perform k‐means clustering of samples according to their metabolic capabilities. The clustering analysis generated statistically significant partitioning of samples into a Bacteroides‐dominated, high gout cluster and a Faecalibacterium‐elevated, low gout cluster. The high gout cluster was predicted to allow elevated synthesis of the amino acids D‐alanine and L‐alanine and byproducts of branched‐chain amino acid catabolism, while the low gout cluster allowed higher production of butyrate, the sulfur‐containing amino acids L‐cysteine and L‐methionine, and the L‐cysteine catabolic product H2S. By expanding the capabilities of mgPipe to provide taxa‐level resolution of metabolite exchange rates, acetate, D‐lactate and succinate exchanged from Bacteroides to Faecalibacterium were predicted to enhance butyrate production in the low gout cluster. Model predictions suggested that sulfur‐containing amino acid metabolism generally and H2S more specifically could be novel gout disease markers.
Journal Article
Microbiota dysbiosis in inflammatory bowel diseases: in silico investigation of the oxygen hypothesis
2017
Background
Inflammatory bowel diseases (IBD), which include ulcerative colitis and Crohn’s disease, cause chronic inflammation of the digestive tract in approximately 1.6 million Americans. A signature of IBD is dysbiosis of the gut microbiota marked by a significant reduction of obligate anaerobes and a sharp increase in facultative anaerobes. Numerous experimental studies have shown that IBD is strongly correlated with a decrease of
Faecalibacterium prausnitzii
and an increase of
Escherichia coli
. One hypothesis is that chronic inflammation induces increased oxygen levels in the gut, which in turn causes an imbalance between obligate and facultative anaerobes.
Results
To computationally investigate the oxygen hypothesis, we developed a multispecies biofilm model based on genome-scale metabolic reconstructions of
F. prausnitzii
,
E. coli
and the common gut anaerobe
Bacteroides thetaiotaomicron
. Application of low bulk oxygen concentrations at the biofilm boundary reproduced experimentally observed behavior characterized by a sharp decrease of
F. prausnitzii
and a large increase of
E. coli
, demonstrating that dysbiosis consistent with IBD disease progression could be qualitatively predicted solely based on metabolic differences between the species. A diet with balanced carbohydrate and protein content was predicted to represent a metabolic “sweet spot” that increased the oxygen range over which
F. prausnitzii
could remain competitive and IBD could be sublimated. Host-microbiota feedback incorporated via a simple linear feedback between the average
F. prausnitzii
concentration and the bulk oxygen concentration did not substantially change the range of oxygen concentrations where dysbiosis was predicted, but the transition from normal species abundances to severe dysbiosis was much more dramatic and occurred over a much longer timescale. Similar predictions were obtained with sustained antibiotic treatment replacing a sustained oxygen perturbation, demonstrating how IBD might progress over several years with few noticeable effects and then suddenly produce severe disease symptoms.
Conclusions
The multispecies biofilm metabolic model predicted that oxygen concentrations of ∼1 micromolar within the gut could cause microbiota dysbiosis consistent with those observed experimentally for inflammatory bowel diseases. Our model predictions could be tested directly through the development of an appropriate in vitro system of the three species community and testing of microbiota-host interactions in gnotobiotic mice.
Journal Article
Cultivation and genomics of the first freshwater SAR11 (LD12) isolate
2018
Evolutionary transitions between fresh and salt water happen infrequently among bacterioplankton. Within the ubiquitous and highly abundant heterotrophic Alphaproteobacteria order
Pelagibacterales
(SAR11), most members live in marine habitats, but the LD12 subclade has evolved as a unique freshwater lineage. LD12 cells occur as some of the most dominant freshwater bacterioplankton, yet this group has remained elusive to cultivation, hampering a more thorough understanding of its biology. Here, we report the first successful isolation of an LD12 representative, strain LSUCC0530, using high-throughput dilution-to-extinction cultivation methods, and its complete genome sequence. Growth experiments corroborate ecological data suggesting active populations of LD12 in brackish water up to salinities of ~5. LSUCC0530 has the smallest closed genome thus far reported for a SAR11 strain (1.16 Mbp). The genome affirms many previous metabolic predictions from cultivation-independent analyses, like a complete Embden–Meyerhof–Parnas glycolysis pathway, but also provides novel insights, such as the first isocitrate dehydrogenase in LD12, a likely homologous recombination of malate synthase from outside of the SAR11 clade, and analogous substitutions of ion transporters with others that occur throughout the rest of the SAR11 clade. Growth data support metagenomic recruitment results suggesting temperature-based ecotype diversification within LD12. Key gene losses for osmolyte uptake provide a succinct hypothesis for the evolutionary transition of LD12 from salt to freshwater. For strain LSUCC0530, we propose the provisional nomenclature
Candidatus
fonsibacter ubiquis.
Journal Article
Ecophysiology and genomics of the brackish water adapted SAR11 subclade IIIa
2023
The Order Pelagibacterales (SAR11) is the most abundant group of heterotrophic bacterioplankton in global oceans and comprises multiple subclades with unique spatiotemporal distributions. Subclade IIIa is the primary SAR11 group in brackish waters and shares a common ancestor with the dominant freshwater IIIb (LD12) subclade. Despite its dominance in brackish environments, subclade IIIa lacks systematic genomic or ecological studies. Here, we combine closed genomes from new IIIa isolates, new IIIa MAGS from San Francisco Bay (SFB), and 460 highly complete publicly available SAR11 genomes for the most comprehensive pangenomic study of subclade IIIa to date. Subclade IIIa represents a taxonomic family containing three genera (denoted as subgroups IIIa.1, IIIa.2, and IIIa.3) that had distinct ecological distributions related to salinity. The expansion of taxon selection within subclade IIIa also established previously noted metabolic differentiation in subclade IIIa compared to other SAR11 subclades such as glycine/serine prototrophy, mosaic glyoxylate shunt presence, and polyhydroxyalkanoate synthesis potential. Our analysis further shows metabolic flexibility among subgroups within IIIa. Additionally, we find that subclade IIIa.3 bridges the marine and freshwater clades based on its potential for compatible solute transport, iron utilization, and bicarbonate management potential. Pure culture experimentation validated differential salinity ranges in IIIa.1 and IIIa.3 and provided detailed IIIa cell size and volume data. This study is an important step forward for understanding the genomic, ecological, and physiological differentiation of subclade IIIa and the overall evolutionary history of SAR11.
Journal Article
Pseudomonas aeruginosa reverse diauxie is a multidimensional, optimized, resource utilization strategy
2021
Pseudomonas aeruginosa
is a globally-distributed bacterium often found in medical infections. The opportunistic pathogen uses a different, carbon catabolite repression (CCR) strategy than many, model microorganisms. It does not utilize a classic diauxie phenotype, nor does it follow common systems biology assumptions including preferential consumption of glucose with an ‘overflow’ metabolism. Despite these contradictions,
P. aeruginosa
is competitive in many, disparate environments underscoring knowledge gaps in microbial ecology and systems biology. Physiological, omics, and in silico analyses were used to quantify the
P. aeruginosa
CCR strategy known as ‘reverse diauxie’. An ecological basis of reverse diauxie was identified using a genome-scale, metabolic model interrogated with in vitro omics data. Reverse diauxie preference for lower energy, nonfermentable carbon sources, such as acetate or succinate over glucose, was predicted using a multidimensional strategy which minimized resource investment into central metabolism while completely oxidizing substrates. Application of a common, in silico optimization criterion, which maximizes growth rate, did not predict the reverse diauxie phenotypes. This study quantifies
P. aeruginosa
metabolic strategies foundational to its wide distribution and virulence including its potentially, mutualistic interactions with microorganisms found commonly in the environment and in medical infections.
Journal Article
Microbial ecology of northern Gulf of Mexico estuarine waters
by
Henson, Michael W.
,
Thrash, J. Cameron
in
Bacteria - classification
,
Bacteria - genetics
,
Bacteria - isolation & purification
2024
Estuarine and coastal waters are diverse ecosystems influenced by tidal fluxes, interconnected wetlands, and river outflows, which are of high economic and ecological importance. Microorganisms play a pivotal role in estuaries as “first responders” and ecosystem architects, yet despite their ecological importance, they remain underrepresented in microbial studies compared to open ocean environments. This leads to substantial knowledge gaps that are important for understanding global biogeochemical cycling and making decisions about conservation and management strategies in these environments. Our study makes key contributions to the microbial ecology of estuarine and coastal habitats in the northern Gulf of Mexico. Our microbial community data support the concept of a globally distributed, core brackish microbiome and emphasize previously underrecognized brackish-water taxa. Given the projected worsening of land loss, oil spills, and natural disasters in this region, our results will serve as important baseline data for researchers investigating the microbial communities found across estuaries.
Journal Article