716 research outputs found

    Glycosylation of cyclooxygenase-2 (COX-2) influences the migratory and invasive potential of cells

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    Prostaglandins are bioactive lipids involved in many physiological functions such as maintenance of the cardiovascular, immune, renal, and central nervous systems. They also play a role in certain diseases like arthritis, cancer, and Alzheimer’s. Cyclooxygenase-2 (COX-2) is the enzyme that catalyzes the initial rate-limiting step in the pathway that converts arachidonic acid to prostaglandins. COX-2 exists as two glycoforms with the molecular weights of 72 and 74 kDa, the latter resulting from the addition of a high mannose chain to the Asn580 residue ~50% of the time. The over-expression of COX-2 is believed to be linked to cancer progression and specifically appears to promote the metastatic phenotype. The objective of this study is to determine the effect of the variable glycosylation of COX-2 at Asn580 on the migratory and invasive potential of cells. COS-1 cells and the breast cancer cell line MCF7 were first transfected with either the wild type or Asn580-mutant human COX-2 gene. Boyden chambers were used to determine the ability of transfected cells to migrate through the membrane, approximately 5x104 cells were plated onto the chambers, and cells were incubated for 16-18 h. Cells were then fixed, stained, visualized and counted. In a previous study, our lab showed that COS-1 cells transfected with the Asn580-mutant COX-2 gene migrated faster through the membrane. In this current study, COS-1 cells transfected with the Asn580-mutant COX-2 gene also had a greater invasive potential; however, MCF7 cells transfected with the wild-type human COX-2 gene migrated faster and also had a greater tendency to invade. The results indicate that the ability of this additional or the lack of glycosylation of COX-2 at Asn580 to either enhance or inhibit the migratory and invasive potential of cells depends greatly on cell type. To confirm this, future studies will be carried out to determine the effect of COX-2 glycosylation on the invasive and the migratory potential of PC-3 and T-47D cancer cell lines.https://scholar.dominican.edu/natural-sciences-and-mathematics-faculty-research-posters/1000/thumbnail.jp

    Modelling the effects of awareness-based interventions to control the mosaic disease of Jatropha curcas

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    Plant diseases are responsible for substantial and sometimes devastating economic and societal costs and thus are a major limiting factor for stable and sustainable agricultural production. Diseases of crops are particular crippling in developing countries that are heavily dependent on agriculture for food security and income. Various techniques have been developed to reduce the negative impact of plant diseases and eliminate the associated parasites, but the success of these approaches strongly depends on population awareness and the degree of engagement with disease control and prevention programs. In this paper we derive and analyse a mathematical model of mosaic disease of Jatropha curcas, an important biofuel plant, with particular emphasis on the effects of interventions in the form of nutrients and insecticides, whose use depends on the level of population awareness. Two contributions to disease awareness are considered in the model: global awareness campaigns, and awareness from observing infected plants. All steady states of the model are found, and their stability is analysed in terms of system parameters. We identify parameter regions associated with eradication of disease, stable endemic infection, and periodic oscillations in the level of infection. Analytical results are supported by numerical simulations that illustrate the behaviour of the model in different dynamical regimes. Implications of theoretical results for practical implementation of disease control are discussed

    Phase equilibrium data and modeling of ethylic biodiesel, with application to a non-edible vegetable oil

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    Contributing to extending the knowledge for the design and operation of biodiesel production processes, isobaric PTxy vapor-liquid equilibria data of ethanol + ethyl hexanoate, 1-pentanol + ethyl hexanoate and 1-pentanol + ethyl octanoate at two different pressures are reported for the first time. Consistency tests were applied to attest the quality of the collected data, for these especially complex measurements. Besides that, vapor pressures of the pure ethyl esters have also been measured. For modeling purposes, the Lyngby and Dortmund UNIFAC variants were used to predict the VLE phase diagrams. Generally, the predictions are of very good quality, being the UNIFAC-Do (Dortmund) better, as the deviations in temperature and vapor compositions are always lower to 1.0 K and 0.020, respectively. Checking for the viability for extrapolations in pressure, CPA EoS was also applied to the modeling of the experimental data with very good results. Finally, aiming at examining the model capabilities to describe multicomponent systems, VLE measurements involving two alcohols and the fatty acid ethyl ester mixture obtained from non-edible vegetable oil have been carried out showing the good performance of the predictive models.This work was developed in the scope of the Projects POCI-01- 0145-FEDER-006984 – Associate Laboratory LSRE-LCM and POCI- 01-0145-FEDER-007679 – CICECO-Aveiro Institute of Materials (FCT Ref. UID/CTM /50011/2013), funded by FEDER (European Union) through COMPETE2020 – Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT (Portugal) – Fundação para a Ciência e a Tecnologia. Also, the authors express their acknowledgment to Frédéric Roze from Université de Lorraine – ENSIC (France) for his technical support during the work.info:eu-repo/semantics/publishedVersio

    CONVERTING THEORY AND WAR DOCTRINE TO REALISTIC TRAINING FOR ENSURING THE SUCCESS OF MILITARY CAMPAIGN PLANNING

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    Military campaigns in the 21st Century are extremely complex multi-dimensional undertakings. In today’s globalized reality, influence of wars will go beyond the theatre of operations into issues of international economy, human migration, airspace and sea lanes, thus adding new dimensions to campaign planning.  Converting theory and doctrine to practice is never easy.  Realistic training may be the best bridge to ensure that classroom knowledge is correctly applied to the real battlefield.  This paper looks at this challenge through the combined experience of six foreign exchange students who graduated from Indonesia’s Air Command and Staff College, 2018.  The purpose of this paper is to highlight some of the challenges to campaign planning, especially in light of multinational influences, extract lessons learned from recent military campaigns and then provide feedback for Indonesia’s wargaming training methodology as practiced in the air command and staff college.  The foundation to Indonesia’s wargaming exercises is the 14-step Military Decision Making Process (MDMP).  MDMP in its general form is part of the campaign planning processes for the authors’ respective countries too, varying only in the sequence and emphasis on steps and tasks within the process and strategies for exercising the process.  This paper will conclude that even the most theoretically sound campaign planning process would lead to operational failure, unless critical thinking & planning abilities are developed in upcoming military leaders through a sound understanding of theory, realistic wargaming, and deep analysis. This requires realistic training in an open learning environment, and a willingness to analyse one’s own country-specific mistakes and successes

    Modification and Characterization of Biodegradable Chitosan/ Starch-Based Films with Monomer 1,4-Butanediol Diacrylate (BDDA) by Gamma Radiation

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    Chitosan reinforced starch-based biodegradable films were prepared by solution casting. Tensile strength (TS), tensile modulus (TM), elongation at break (%), and water vapor permeability (WVP) of the 50% chitosan containing starch-based films were found to be 47 MPa, 550 MPa, 16%, and 2.45 g·mm/m2·day·kPa, respectively.Monomer 1,4 butanediol diacrylate (BDDA) was added (0.25-1% by wt) to the starch/chitosan (50:50) based film formulation. Then, films were cast and gamma irradiated from a radiation dose varied from 1 kGy to 25 kGy. Then mechanical and barrier properties were evaluated. The highest TS (80 MPa) and TM (880 MPa) of the films were found by using 0.5% monomer at 5 kGy dose. The WVP of the films were found to be 1.50 g·mm/m2·day·kPa which is 38.77% lower than control starch/chitosan-based films. Molecular interactions due to incorporation of BDDA were supported by Fourier transform infra red (FTIR) spectroscopy. The water uptake of the films pointed out better hydrophobic character due to incorporation of BDDA in starch/chitosan-based films. Surface morphologies of BDDA treated films were examined by scanning electron microscope (SEM) and suggested better morphologies due to BDDA treatment with starch/chitosan-based biodegradable films
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