ENV-610: EFFECT OF NUTRIENTS ON METHANOTROPHIC OXIDATION ACTIVITY IN BATCH EXPERIMENTAL STUDIES

Methane biofiltration (MBF) has been proposed as an effective and cost efficient method for mitigating methane emissions from anthropogenic sources. Previous MBF studies have successfully demonstrated effective methane oxidation using compost, soil and biodegradable organic materials as the filter medium because they are a natural source of nutrients, organic matter content, and provide adequate space to support microbiological growth. However, these media types will inevitably decompose over time and lose their effectiveness. This study investigates the use of biologically stable media mixtures of lava rock and biochar in batch oxidation studies to determine their ability to support a methanotrophic bacterial population for the oxidation of methane. A screening experiment was performed using an unreplicated 23 factorial design to understand the influence of nutrient content, water holding capacity (WHC), and mixture ratios of lava rock and biochar, by volume, on the methane oxidation rate (MOR). Virtually no activity was observed when 3300 ppm of nitrogen were added to the batches. Methane oxidation activities were only observed when lower nutrient additions were made at 96 ppm of nitrogen with values reaching 2.2 - 2.5 mol/mL∙hr when the WHC was adjusted to 50% regardless of the media composition. Subsequent replicates performed at the lower nitrogen level additions and 30% WHC demonstrated similar MORs. Results demonstrate the supplementation of nutrients to a mixture of lava rock and biochar is possible in supporting a methanotrophic population and that lava rock can be used as a bulking agent

A Comprehensive Model for Anaerobic Degradation in Bio-Reactor Landfills

A new generation of sustainable landfill was designed and constructed in the City of Calgary, Canada to achieve sustainable municipal solid waste (MSW) management. This sustainable landfill called “biocell” involves sequential operation of a landfill cell to produce methane gas during the first stage of anaerobic degradation and in-situ composting within the cell footprint. Once methane recovery is minimal, the second stage aerobic degradation initiated by injecting air through methane recovery system and finally landfill is mined for resource and space recovery in the third stage. The resources that can be recovered include compost like material and recyclables such as plastics, metal, and glass. Non-recovered waste but with high energy content can be used as refuse derived fuel. The practice of this approach will no longer require the need to allocate valuable land for new landfills on an on-going basis. There is leachate re-circulation and environmental monitoring to enhance biodegradation in the biocell. The biocell eliminate problems of ground/surface water contamination, landfill gas emission and the need for new land to use for waste disposal. However, currently there is limited knowledge on landfill mining and in order to estimate the best time to initiate landfill mining a comprehensive mathematical model was developed. The model developed solves the mass and energy balance of waste decay, which computes the rate of gas generation, change of gas and gas flux through the system. This study focuses on anaerobic phase of biodegradation of biomass and the degradation of the biomass was assumed to follow first order kinetics. The decomposing bio mass is represented as cellulose for energy balance computation, which is a major constitution of the MSW. The degradation of bio mass due to micro-organisms generates methane, carbon dioxide and water as the final products and the reaction is exothermic. In this model using the decay of waste computed from mass balance and cellulose as equivalent chemical representing the waste a relationship between the mass degraded with time was established. The heat released due to anaerobic decay is computed and hence computes the increase in biocell temperature. Then selecting the representative decay constant for the computed biocell temperature, the decomposition of waste was computed for the next time step. The above computation is continued in order to obtain the landfill settlement, temperature and the movement of landfill gas and leachate

ENV-623: ANALYSIS OF REACTION KINETIC PARAMETERS IN ENZYME CATALYSED AEROBIC WASTE DEGRADATION

The study discussed here is an attempt at comparing three of the most important kinetic parameters in an enzyme catalysed aerobic system; overall reaction kinetic constant, hydrolysis rate constant and oxygen assimilation constant. The kinetic parameters are compared with each other as well as between uncatalyzed and enzyme catalyzed reactions. Theatrical reaction kinetic models were developed for the analysis. Batch experiments were conducted to characterize solid waste behaviour and the results used to calibrate the developed models. Lignin content, cellulose/hemicellulose content, total organic content, oxygen depletion and CO2 production was used as responses in the experiments. Manganese peroxidase from white-rot-fungi is used as the enzyme for catalysing treatments. The catalyzed reactions showed higher reaction rates than the un-catalyzed reactions. Further analysis revealed that catalyzed reactions have higher hydrolysis rates compared to the overall rates of metabolism. The O2 assimilation analysis revealed that catalyzed reactions require 1.66 times more O2 than un-catalyzed reactions

Probabilistic Fragmentation and Effective Power Law

A simple fragmentation model is introduced and analysed. We show that, under very general conditions, an effective power law for the mass distribution arises with realistic exponent. This exponent has a universal limit, but in practice the effective exponent depends on the detailed breaking mechanism and the initial conditions. This dependence is in good agreement with experimental results of fragmentation.Comment: 4 pages Revtex, 2 figures, zipped and uuencode

A finite strain fibre-reinforced viscoelasto-viscoplastic model of plant cell wall growth

A finite strain fibre-reinforced viscoelasto-viscoplastic model implemented in a finite element (FE) analysis is presented to study the expansive growth of plant cell walls. Three components of the deformation of growing cell wall, i.e. elasticity, viscoelasticity and viscoplasticity-like growth, are modelled within a consistent framework aiming to present an integrative growth model. The two aspects of growth—turgor-driven creep and new material deposition—and the interplay between them are considered by presenting a yield function, flow rule and hardening law. A fibre-reinforcement formulation is used to account for the role of cellulose microfibrils in the anisotropic growth. Mechanisms in in vivo growth are taken into account to represent the corresponding biologycontrolled behaviour of a cell wall. A viscoelastic formulation is proposed to capture the viscoelastic response in the cell wall. The proposed constitutive model provides a unique framework for modelling both the in vivo growth of cell wall dominated by viscoplasticity-like behaviour and in vitro deformation dominated by elastic or viscoelastic responses. A numerical scheme is devised, and FE case studies are reported and compared with experimental data

Association between promoter -1607 polymorphism of MMP1 and Lumbar Disc Disease in Southern Chinese

<p>Abstract</p> <p>Background</p> <p>Matrix metalloproteinases (MMPs) are involved in the degradation of the extracellular matrix of the intervertebral disc. A SNP for guanine insertion/deletion (G/D), the -1607 promoter polymorphism, of the <it>MMP1 </it>gene was found significantly affecting promoter activity and corresponding transcription level. Hence it is a good candidate for genetic studies in DDD.</p> <p>Methods</p> <p>Southern Chinese volunteers between 18 and 55 years were recruited from the population. DDD in the lumbar spine was defined by MRI using Schneiderman's classification. Genomic DNA was isolated from the leukocytes and genotyping was performed using the Sequenom^®platform. Association and Hardy-Weinberg equilibrium checking were assessed by Chi-square test and Mann-Whitney U test.</p> <p>Results</p> <p>Our results showed substantial evidence of association between -1607 promoter polymorphism of <it>MMP1 </it>and DDD in the Southern Chinese subjects. D allelic was significantly associated with DDD (p value = 0.027, odds ratio = 1.41 with 95% CI = 1.04–1.90) while Genotypic association on the presence of D allele was also significantly associated with DDD (p value = 0.046, odds ratio = 1.50 with 95% CI = 1.01–2.24). Further age stratification showed significant genotypic as well as allelic association in the group of over 40 years (genotypic: p value = 0.035, odds ratio = 1.617 with 95% CI = 1.033–2.529; allelic: p value = 0.033, odds ratio = 1.445 with 95% CI = 1.029–2.029). Disc bulge, annular tears and the Schmorl's nodes were not associated with the D allele.</p> <p>Conclusion</p> <p>We demonstrated that individuals with the presence of D allele for the -1607 promoter polymorphism of <it>MMP1 </it>are about 1.5 times more susceptible to develop DDD when compared with those having G allele only. Further association was identified in individuals over 40 years of age. Disc bulge, annular tear as well as Schmorl's nodes were not associated with this polymorphism.</p

Gene expression profiling of mucinous ovarian tumors and comparison with upper and lower gastrointestinal tumors identifies markers associated with adverse outcomes.

PURPOSE: Advanced-stage mucinous ovarian carcinoma (MOC) has poor chemotherapy response and prognosis and lacks biomarkers to aid stage I adjuvant treatment. Differentiating primary MOC from gastrointestinal (GI) metastases to the ovary is also challenging due to phenotypic similarities. Clinicopathologic and gene-expression data were analyzed to identify prognostic and diagnostic features. EXPERIMENTAL DESIGN: Discovery analyses selected 19 genes with prognostic/diagnostic potential. Validation was performed through the Ovarian Tumor Tissue Analysis consortium and GI cancer biobanks comprising 604 patients with MOC (n = 333), mucinous borderline ovarian tumors (MBOT, n = 151), and upper GI (n = 65) and lower GI tumors (n = 55). RESULTS: Infiltrative pattern of invasion was associated with decreased overall survival (OS) within 2 years from diagnosis, compared with expansile pattern in stage I MOC [hazard ratio (HR), 2.77; 95% confidence interval (CI), 1.04–7.41, P = 0.042]. Increased expression of THBS2 and TAGLN was associated with shorter OS in MOC patients (HR, 1.25; 95% CI, 1.04–1.51, P = 0.016) and (HR, 1.21; 95% CI, 1.01–1.45, P = 0.043), respectively. ERBB2 (HER2) amplification or high mRNA expression was evident in 64 of 243 (26%) of MOCs, but only 8 of 243 (3%) were also infiltrative (4/39, 10%) or stage III/IV (4/31, 13%). CONCLUSIONS: An infiltrative growth pattern infers poor prognosis within 2 years from diagnosis and may help select stage I patients for adjuvant therapy. High expression of THBS2 and TAGLN in MOC confers an adverse prognosis and is upregulated in the infiltrative subtype, which warrants further investigation. Anti-HER2 therapy should be investigated in a subset of patients. MOC samples clustered with upper GI, yet markers to differentiate these entities remain elusive, suggesting similar underlying biology and shared treatment strategies

Enhanced Immunosuppression of T Cells by Sustained Presentation of Bioactive Interferon-γ Within Three-Dimensional Mesenchymal Stem Cell Constructs.

The immunomodulatory activity of mesenchymal stem/stromal cells (MSCs) to suppress innate and adaptive immune responses offers a potent cell therapy for modulating inflammation and promoting tissue regeneration. However, the inflammatory cytokine milieu plays a critical role in stimulating MSC immunomodulatory activity. In particular, interferon-γ (IFN-γ)-induced expression of indoleamine 2,3-dioxygenase (IDO) is primarily responsible for MSC suppression of T-cell proliferation and activation. Although pretreatment with IFN-γ is commonly used to prime MSCs for immunomodulatory activity prior to transplantation, the transient effects of pretreatment may limit the potential of MSCs to potently modulate immune responses. Therefore, the objective of this study was to investigate whether microparticle-mediated presentation of bioactive IFN-γ within three-dimensional spheroidal MSC aggregates could precisely regulate and induce sustained immunomodulatory activity. Delivery of IFN-γ via heparin-microparticles within MSC aggregates induced sustained IDO expression during 1 week of culture, whereas IDO expression by IFN-γ-pretreated MSC spheroids rapidly decreased during 2 days. Furthermore, sustained IDO expression induced by IFN-γ-loaded microparticles resulted in an increased and sustained suppression of T-cell activation and proliferation in MSC cocultures with CD3/CD28-activated peripheral blood mononuclear cells. The increased suppression of T cells by MSC spheroids containing IFN-γ-loaded microparticles was dependent on induction of IDO and supported by affecting monocyte secretion from pro- to anti-inflammatory cytokines. Altogether, microparticle delivery of IFN-γ within MSC spheroids provides a potent means of enhancing and sustaining immunomodulatory activity to control MSC immunomodulation after transplantation and thereby improve the efficacy of MSC-based therapies aimed at treating inflammatory and immune diseases. Stem Cells Translational Medicine 2017;6:223-237

Enhanced Immunosuppression of T Cells by Sustained Presentation of Bioactive Interferon-γ Within Three-Dimensional Mesenchymal Stem Cell Constructs.

: The immunomodulatory activity of mesenchymal stem/stromal cells (MSCs) to suppress innate and adaptive immune responses offers a potent cell therapy for modulating inflammation and promoting tissue regeneration. However, the inflammatory cytokine milieu plays a critical role in stimulating MSC immunomodulatory activity. In particular, interferon-γ (IFN-γ)-induced expression of indoleamine 2,3-dioxygenase (IDO) is primarily responsible for MSC suppression of T-cell proliferation and activation. Although pretreatment with IFN-γ is commonly used to prime MSCs for immunomodulatory activity prior to transplantation, the transient effects of pretreatment may limit the potential of MSCs to potently modulate immune responses. Therefore, the objective of this study was to investigate whether microparticle-mediated presentation of bioactive IFN-γ within three-dimensional spheroidal MSC aggregates could precisely regulate and induce sustained immunomodulatory activity. Delivery of IFN-γ via heparin-microparticles within MSC aggregates induced sustained IDO expression during 1 week of culture, whereas IDO expression by IFN-γ-pretreated MSC spheroids rapidly decreased during 2 days. Furthermore, sustained IDO expression induced by IFN-γ-loaded microparticles resulted in an increased and sustained suppression of T-cell activation and proliferation in MSC cocultures with CD3/CD28-activated peripheral blood mononuclear cells. The increased suppression of T cells by MSC spheroids containing IFN-γ-loaded microparticles was dependent on induction of IDO and supported by affecting monocyte secretion from pro- to anti-inflammatory cytokines. Altogether, microparticle delivery of IFN-γ within MSC spheroids provides a potent means of enhancing and sustaining immunomodulatory activity to control MSC immunomodulation after transplantation and thereby improve the efficacy of MSC-based therapies aimed at treating inflammatory and immune diseases.This study demonstrates that biomaterial-based presentation of cytokines within spheroidal mesenchymal stem/stromal cell (MSC) aggregates provides a means of locally concentrating and sustaining presentation of cytokines to potentiate MSC immunomodulatory activity. Overall, this approach could aid in overcoming the limitations of transient pretreatment strategies by continuously presenting cytokines within the MSC microenvironment and thereby maximizing the immunomodulatory potential of transplanted MSCs. Furthermore, this approach provides a means of inducing potent MSC immunomodulation, irrespective of unknown or ill-defined environmental inflammatory milieu, such as in chronic inflammation or when administered with immunosuppressants. Altogether, biomaterial-based engineering of the MSC microenvironment provides a means of controlling the function of transplanted cells to specifically direct their therapeutic activity and may improve MSC-based therapies aimed at treating a number of inflammatory and immune diseases