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A General Meta-graph Strategy for Shape Evolution under Mechanical Stress
(Taylor and Francis Inc., 2019-01-01) Montoya-Zapata D.; Acosta D.A.; Ruiz-Salguero O.; Posada J.; Sanchez-Londono D.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
The challenges that a shape or design stands are central in its evolution. In the particular domain of stress/strain challenges, existing approaches eliminate under-demanded neighborhoods from the shape, thus producing the evolution. This strategy alone incorrectly (a) conserves disconnected parts of the shape and (b) eliminates neighborhoods which are essential to maintain the boundary conditions (supports, loads). The existing analyses preventing (a) and (b) are conducted in an ad-hoc manner, by using graph connectivity. This manuscript presents the implementation of a meta-graph methodology, which systematically lumps together finite element subsets of the current shape. By considering this meta-graph connectivity, the method impedes situations (a) and (b), while maintaining the pruning of under-demanded neighborhoods. Research opportunities are open in the application of this methodology with other types of demand on the shape (e.g., friction, temperature, drag, and abrasion). © 2019, © 2019 Taylor & Francis Group, LLC.
Acetyl-L-carnitine supplementation reverses the age-related decline in carnitine palmitoyltransferase 1 (CPT1) activity in interfibrillar mitochondria without changing the L-carnitine content in the rat heart
(Elsevier BV, 2012-02-01) Gómez, Luis A.; Du Heath, Shi-Hua; Hagen, Tory M.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
The aging heart displays a loss of bioenergetic reserve capacity partially mediated through lower fatty acid utilization. We investigated whether the age-related impairment of cardiac fatty acid catabolism occurs, at least partially, through diminished le
Age-related decline in mitochondrial bioenergetics: Does supercomplex destabilization determine lower oxidative capacity and higher superoxide production
(Copyright, 2012-09-01) Gómez, Luis A.; Hagen, Tory M.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Mitochondrial decay plays a central role in the aging process. Although certainly multifactorial in nature, defective operation of the electron transport chain (ETC) constitutes a key mechanism involved in the age-associated loss of mitochondrial energy m
Análisis de la sensibilidad paramétrica del proceso de producción de ciclo-trimetileno-triamina
(Centro de Informacion Tecnologica, 2014-01-01) Ojeda, J.C.; Gilpavas, E.; Dobrosz-Gómez, I.; Gómez, M.Á.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
Analyses of temperature, conversion, and their sensitivity with respect to the initial temperature were investigated by parametric sensitivity analysis using a dimensionless batch reactor model for the cyclotrimethylene- triamine synthesis. At first, an expression for its reaction rate was fitted from experimental data available in the literature. Then, a new simple sensitivity-based criterion was used to determine critical operating conditions analyzing temperature sensitivity trajectories. The critical condition of runaway reaction corresponds to a Semenov number (F) equals to 0.684, a heat of reaction parameter (B) equals to 15 and an Arrhenius-type number (?) of 20.
Analytical orientation human management: A path to responsibilization
(FUNDACAO GETULIO VARGAS, 2016-01-01) Perez Patino, Juan David; Lopera Arbelaz, Isabel Cristina; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
The present paper proposes an approach to human management that privileges conversational spaces in the organization through verbalization, which results in symbolization, socialization and responsibilization of individuals in the organization groups. Our special concern is responsibilization, emphasizing that participation through conversation generates commitment, inclusion and a sense of belonging in individuals. In the cases studied, we have privileged the analytical method, understood as the method of discourse analysis, which underlies the attitude of the professional who grounds his work on listening, analyzing and intervening. The research findings allow the set out of a path to corporate responsibility.
Antimycotic activity of fengycin C biosurfactant and its interaction with phosphatidylcholine model membranes
(ELSEVIER SCIENCE BV, 2017-08-01) González-Jaramillo LM; Aranda FJ; Teruel JA; Villegas-Escobar V; Ortiz A; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Lipopeptide biosurfactants constitute one of the most promising groups of compounds for the treatment and prevention of fungal diseases in plants. Bacillus subtilis strain EA-CB0015 produces iturin A, fengycin C and surfactin and it has been proven useful for the treatment of black Sigatoka disease in banana plants, an important pathology caused by the fungus Mycosphaerella fijiensis (Morelet). We have found that B. subtilis EA-CB0015 cell free supernatants and purified fractions inhibit M. fijiensis cellular growth. The effect of the purified lipopeptides mentioned above on fungal growth has been also evaluated, observing that iturin A and fengycin C inhibit mycelial growth and ascospore germination, whereas surfactin is not effective. On the hypothesis that the antifungal action of the lipopeptides is associated to their incorporation into biological membranes, ultimately leading to membrane permeabilization, a detailed biophysical study on the interaction of a new isoform of fengycin C with model dipalmitoyphosphatidylcholine (DPPC) membranes has been carried out. Differential scanning calorimetry shows that fengycin C alters the thermotropic phase transitions of DPPC, and is laterally segregated in the fluid bilayer forming domains. Fluorescent probe polarization measurements show that fengycin C does not affect the hydrophobic interior of the membrane. This latter perturbation is concomitant with a strong dehydration of the polar region of DPPC, as shown by FTIR. Fengycin-rich domains, where the surrounding DPPC molecules are highly dehydrated, may well constitute sites of membrane permeabilization leading to a leaky target membrane. These results are a solid support to explain the membrane perturbing action of fengycin, which has been related to its antifungal activity. (C) 2017 Elsevier B.V. All rights reserved.
Aplicaciones del pululano en la conservación de alimentos y bioempaques: vigilancia tecnológica e inteligencia competitiva
(Universidad Nacional de Colombia, 2016-09-21) Catalina Giraldo E; Posada, Juan Pablo; Bustamante, Ana Maria; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Se presenta el ejercicio de Vigilancia Tecnológica e Inteligencia Competitiva (VT&IC) para las aplicaciones del polisacárido pululano en el campo de los alimentos y empaques
Approximation of the Mechanical Response of Large Lattice Domains Using Homogenization and Design of Experiments
(Universitatea Politehnica Bucuresti, 2020-06-01) Montoya, D.; Acosta, D.; Cortes, C.; Pareja, J.; Moreno, Aitor; Posada, Jorge; Ruiz, O.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
Approximation of the mechanical response of large lattice domains using homogenization and design of experiments
(Universitatea Politehnica Bucuresti, 2020-01-01) Montoya-Zapata D.; Acosta D.A.; Cortés C.; Pareja-Corcho J.; Moreno A.; Posada J.; Ruiz-Salguero O.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
Lattice-based workpieces contain patterned repetition of individuals of a basic topology (Schwarz, ortho-walls, gyroid, etc.) with each individual having distinct geometric grading. In the context of the design, analysis and manufacturing of lattice workpieces, the problem of rapidly assessing the mechanical behavior of large domains is relevant for pre-evaluation of designs. In this realm, two approaches can be identified: (1) numerical simulations which usually bring accuracy but limit the size of the domains that can be studied due to intractable data sizes, and (2) material homogenization strategies that sacrifice precision to favor efficiency and allow for simulations of large domains. Material homogenization synthesizes diluted material properties in a lattice, according to the volume occupancy factor of such a lattice. Preliminary publications show that material homogenization is reasonable in predicting displacements, but is not in predicting stresses (highly sensitive to local geometry). As a response to such shortcomings, this paper presents a methodology that systematically uses design of experiments (DOE) to produce simple mathematical expressions (meta-models) that relate the stress-strain behavior of the lattice domain and the displacements of the homogeneous domain. The implementation in this paper estimates the von Mises stress in large Schwarz primitive lattice domains under compressive loads. The results of our experiments show that (1) material homogenization can efficiently and accurately approximate the displacements field, even in complex lattice domains, and (2) material homogenization and DOE can produce rough estimations of the von Mises stress in large domains (more than 100 cells). The errors in the von Mises stress estimations reach 42% for domains of up to 24 cells. This result means that coarse stress-strain estimations may be possible in lattice domains by combining DOE and homogenized material properties. This option is not suitable for precise stress prediction in sensitive contexts wherein high accuracy is needed. Future work is required to refine the meta-models to improve the accuracies of the estimations. © 2020 by the authors.
Assessment of the optimized treatment of indigo-polluted industrial textile wastewater by a sequential electrocoagulation-activated carbon adsorption process
(Elsevier Ltd, 2020-01-01) GilPavas E.; Correa-Sanchez S.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
Wastewater collected from a local jean manufacturing plant was treated using an electrocoagulation process (EC) coupled with activated carbon (AC) adsorption. The process variables were optimized using multivariate regression coupled with nonlinear programming with nonlinear restrictions to achieve the lowest possible cost while keeping a high enough degradation rate for chemical oxygen demand (COD), color, and turbidity to fulfill the Colombian environmental regulation requirements. Under optimal conditions (pH = 5.4, s =2 mS/cm, j =14 mA/cm2, and t = 11 min) color, COD, and TOC removals of 95%, 63%, and 51%, respectively, were achieved. The biodegradability index also increased from 0.13 to 0.29, whereas toxicity tests showed a remaining toxicity of 45%. A kinetic study was conducted for the EC process. The activated carbon (AC) adsorption process was successfully used to completely remove toxicity, while further increasing color, COD, and TOC removals to 96%, 72%, and 61%, respectively. The conditions for the AC adsorption process (20 g/L of AC and 1 h) were determined by experimental adsorption isotherms and kinetic studies. The optimized EC/AC process led to an effluent satisfying the Colombian regulations and seems technologically viable with lower costs than other similar process that were reported in previous works. © 2020 Elsevier Ltd
Bacillus subtilis EA-CB0575 genome reveals clues for plant growth promotion and potential for sustainable agriculture
(Springer, 2020-01-01) Franco-Sierra, N.D.; Posada, L.F.; Santa-María, G.; Romero-Tabarez, M.; Villegas-Escobar, V.; Álvarez, J.C.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Bacillus subtilis is a remarkably diverse bacterial species that displays many ecological functions. Given its genomic diversity, the strain Bacillus subtilis EA-CB0575, isolated from the rhizosphere of a banana plant, was sequenced and assembled to determine the genomic potential associated with its plant growth promotion potential. The genome was sequenced by Illumina technology and assembled using Velvet 1.2.10, resulting in a whole genome of 4.09 Mb with 4332 genes. Genes involved in the production of indoles, siderophores, lipopeptides, volatile compounds, phytase, bacilibactin, and nitrogenase were predicted by gene annotation or by metabolic pathway prediction by RAST. These potential traits were determined using in vitro biochemical tests, finding that B. subtilis EA-CB0575 produces two families of lipopeptides (surfactin and fengycin), solubilizes phosphate, fixes nitrogen, and produces indole and siderophores compounds. Finally, strain EA-CB0575 increased 34.60% the total dry weight (TDW) of tomato plants with respect to non-inoculated plants at greenhouse level. These results suggest that the identification of strain-specific genes and predicted metabolic pathways might explain the strain potential to promote plant growth by several mechanisms of action, accelerating the development of plant biostimulants for sustainable agricultural. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.
Biocontrol activity of Bacillus subtilis EA-CB0015 cells and lipopeptides against postharvest fungal pathogens
(Academic Press Inc., 2017-11-01) Arroyave-Toro J.J.; Mosquera S.; Villegas-Escobar V.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Post-harvest diseases are responsible for significant losses worldwide, especially the plant pathogenic fungi Botrytis cinerea and Colletotrichum sp. are particularly severe and devastating. In this study, nine fungal pathogens were screened for growth inhibition by Bacillus subtilis EA-CB0015 strain and its metabolites. In vitro inhibitory assays showed that B. subtilis EA-CB0015 cells and the cell free supernatant (CFS) inhibited the growth of the tested fungal pathogens with different susceptibilities. Therefore, the antifungal activities of lipopeptides iturin A and fengycin C contained in the CFS, were tested against C. acutatum and B. cinerea. C. acutatum was more susceptible with minimal inhibitory concentrations (MIC) of 32 ppm (iturin A) and 128 ppm (fengycin C). Fruit and flower trials confirmed that B. subtilis EA-CB0015 cells and its lipopeptides reduced postharvest disease development but to differing degrees. Anthracnose symptoms caused by C. acutatum in tamarillo fruits were completely abolished by CFS, iturin A and fengycin C and reduced by 76% when treated with B. subtilis cells. In contrast, grey mold disease symptoms caused by B. cinerea in chrysanthemum flowers were inhibited by 72% when treated with lipopeptides and by 39% when applied with B. subtilis EA-CB0015 cells. Our results indicate that lipopeptides and cells of B. subtilis EA-CB0015 have a broad antifungal spectrum and control postharvest diseases caused by susceptible fungal pathogens. Our findings open the possibility of incorporating this biological control agent into different disease management programs.
Biodegradation of vegetable residues by polygalacturonase-agar using a trickle-bed bioreactor
(Institution of Chemical Engineers, 2018-09-01) Ramírez-Tapias, Y.A.; Rivero, C.W.; Giraldo-Estrada, C.; Britos, C.N.; Trelles, J.A.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Bacterial pectinases degrade the pectic substances present in plant tissues and particularly, polygalacturonases catalyze the hydrolysis of a-(1,4) glycosidic bonds linking D-galacturonic acid units. In this study, polygalacturonase from Streptomyces halstedii ATCC 10897 was immobilized by the matrix entrapment technique using different thermogels. Bacteriological agar added with magnesium cation produced beads with a more stabilized microstructure for enzyme retention, monitored by oscillatory measurements of storage and loss modulus. Agar concentration and protein content were optimized to maximize protein entrapment, product conversion, and reaction yield. Results showed that the mixture at 10:90% (v/v) of protein (2 mg/mL) and agar (4% w/v) was the best immobilization condition to retain 91% of protein and hydrolyze 38% of pectin to allow the highest reaction yield (9.279 g/g) and increase stability up to 48 h of successive reactions. Agarose bead biocatalysts were used in a trickle-bed column operated with recirculation, and this bioreactor allowed the degradation of pear and cucumber residues by enzymatic liquefaction to enhance sugar content up to 15.33 and 9.35 mg/mL, respectively, and decrease viscosity by 92.3%. The scale-up of this process adds value to vegetable residues such as fructooligosaccharides or fermentable sugars, which become a sustainable source of fuels and chemicals. © 2018 Institution of Chemical Engineers
Biodegradation of vegetable residues by polygalacturonase-agar using a trickle-bed bioreactor. En: Food and Bioproducts Processing
(Institution of Chemical Engineers, 2018-09-01) GIRALDO, CATALINA; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Biology stage of Moniliophthora roreri in Colombia
(Universidad Nacional de Colombia, 2014) Correa Álvarez, Javier; Castro Martínez, Sergio; Coy, Jairo; Universidad EAFIT. Departamento de Ciencias; Javier Correa Álvarez (jcorre38@eafit.edu.co); Ciencias Biológicas y Bioprocesos (CIBIOP)
Frosty pod rot disease of cocoa plants is caused by the basiodiomycete Moniliophthora roreri -- Nowadays, this disease is present in almost all Latin American countries producers of cocoa beans, exhibiting high adaptation to diverse environments -- In Colombia, it is the most important disease attacking cocoa crops and the traditional strategies for control have generated side results as strengthening in genetic resistance of strains in some regions -- In this review, we collected the most relevant biological and agricultural aspects of this disease such as origin and distribution of the disease, life cycle, forms of disease control and research projects oriented to understand the genetic and evolution of this pathogen -- Finally, we suggest increasing the number of basic researches, aiming to understand, how this pathogen has evolved its genome in different habitats, favoring its genetic variation -- Thus, with all this knowledge, we could advance in biotechnology programs for control and prevention of the Frosty rod pot
Bioprospecting of aerobic endospore-forming bacteria with biotechnological potential for growth promotion of banana plants
(Elsevier, 2016-11-22) Posada, L.F.; Ramírez, M.; Ochoa-Gómez, N.; Cuellar-Gaviria, T.Z.; Argel-Roldan, L.E.; Ramírez, C.A.; Villegas-Escobar, V.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
High amounts of agrochemicals are regularly used for increasing yields in cultivation of banana. The use of plant growth-promoting rhizobacteria (PGPR) could represent an environmentally friendly alternative that can improve productivity. In this study, we tested a funnel-like strategy to bioprospect aerobic endospore-forming bacteria (AEFB) that could be useful to develop a biotechnological product to promote the growth of banana plants. First, 837 aerobic endospore-forming bacteria were obtained from the rhizosphere of banana and plantain. Then, the isolates were assessed for both: their capacity to promote growth of maize seedlings (used as a model plant) and to display specific biochemical PGPR-associated traits. Twenty-two of these strains significantly increased the dry weight of maize seedlings, some of them showing in vitro PGPR traits. Based on this screening, four isolates were selected to conduct evaluations on banana plants, from which, the bacterial strain Bacillus subtilis EA-CB0575 was chosen as a promising plant growth -promoting isolate. Further studies with this strain showed that the application of either spores, vegetative cells (both at concentrations 1 x 10(7) and 1 x 10(8) CFU/mL), or the cell-free supernatant (CFS) of its fermentation significantly increased the dry weight of banana plants, compared with the non-treated control. Our results suggest that both cellular structures of B. subtilis EA-CB0575 and the metabolites and/or elements contained in its CFS enhance the growth and development of banana plants. (C) 2016 Elsevier B.V. All rights reserved.
Ceratocystis cacaofunesta genome analysis reveals a large expansion of extracellular phosphatidylinositol-specific phospholipase-C genes (PI-PLC)
(BioMed Central Ltd., 2018-01-17) Molano, E.P.L.; Cabrera, O.G.; Jose, J.; do Nascimento, L.C.; Carazzolle, M.F.; Teixeira, P.J.P.L.; Alvarez, J.C.; Tiburcio, R.A.; Tokimatu Filho, P.M.; de Lima, G.M.A.; Guido, R.V.C.; Corrêa, T.L.R.; Leme, A.F.P.; Mieczkowski, P.; Pereira, G.A.G.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Background: The Ceratocystis genus harbors a large number of phytopathogenic fungi that cause xylem parenchyma degradation and vascular destruction on a broad range of economically important plants. Ceratocystis cacaofunesta is a necrotrophic fungus responsible for lethal wilt disease in cacao. The aim of this work is to analyze the genome of C. cacaofunesta through a comparative approach with genomes of other Sordariomycetes in order to better understand the molecular basis of pathogenicity in the Ceratocystis genus. Results: We present an analysis of the C. cacaofunesta genome focusing on secreted proteins that might constitute pathogenicity factors. Comparative genome analyses among five Ceratocystidaceae species and 23 other Sordariomycetes fungi showed a strong reduction in gene content of the Ceratocystis genus. However, some gene families displayed a remarkable expansion, in particular, the Phosphatidylinositol specific phospholipases-C (PI-PLC) family. Also, evolutionary rate calculations suggest that the evolution process of this family was guided by positive selection. Interestingly, among the 82 PI-PLCs genes identified in the C. cacaofunesta genome, 70 genes encoding extracellular PI-PLCs are grouped in eight small scaffolds surrounded by transposon fragments and scars that could be involved in the rapid evolution of the PI-PLC family. Experimental secretome using LC-MS/MS validated 24% (86 proteins) of the total predicted secretome (342 proteins), including four PI-PLCs and other important pathogenicity factors. Conclusion: Analysis of the Ceratocystis cacaofunesta genome provides evidence that PI-PLCs may play a role in pathogenicity. Subsequent functional studies will be aimed at evaluating this hypothesis. The observed genetic arsenals, together with the analysis of the PI-PLC family shown in this work, reveal significant differences in the Ceratocystis genome compared to the classical vascular fungi, Verticillium and Fusarium. Altogether, our analyses provide new insights into the evolution and the molecular basis of plant pathogenicity. © 2018 The Author(s).
Characteristics of the Rat Cardiac Sphingolipid Pool in Two Mitochondrial Subpopulations
(Elsevier Inc., 2010-06-01) Monette, Jeffrey S.; Gómez, Luis A.; Moreau, Regis; Taylor, Alan; Hagen, Tory M.; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Mitochondrial sphingolipids play a diverse role in normal cardiac function and diseases, yet a precise quantification of cardiac mitochondrial sphingolipids has never been performed. Therefore, rat heart interfibrillary mitochondria (IFM) and subsarcolemm
Coagulation-flocculation sequential with Fenton or Photo-Fenton processes as an alternative for the industrial textile wastewater treatment
(Editorial Board, 2017-04-15) GilPavas, E.; Dobrosz-Gómez, I.; Gómez-García, M.Á.; Universidad EAFIT. Departamento de Ingeniería de Procesos; Procesos Ambientales (GIPAB)
In this study, the industrial textile wastewater was treated using a chemical-based technique (coagulation-flocculation, C-F) sequential with an advanced oxidation process (AOP: Fenton or Photo-Fenton). During the C-F, Al2(SO4)3 was used as coagulant and its optimal dose was determined using the jar test. The following operational conditions of C-F, maximizing the organic matter removal, were determined: 700 mg/L of Al2(SO4)3 at pH = 9.96. Thus, the C-F allowed to remove 98% of turbidity, 48% of Chemical Oxygen Demand (COD), and let to increase in the BOD5/COD ratio from 0.137 to 0.212. Subsequently, the C-F effluent was treated using each of AOPs. Their performances were optimized by the Response Surface Methodology (RSM) coupled with a Box-Behnken experimental design (BBD). The following optimal conditions of both Fenton (Fe2+/H2O2) and Photo-Fenton (Fe2+/H2O2/UV) processes were found: Fe2+ concentration = 1 mM, H2O2 dose = 2 mL/L (19.6 mM), and pH = 3. The combination of C-F pre-treatment with the Fenton reagent, at optimized conditions, let to remove 74% of COD during 90 min of the process. The C-F sequential with Photo-Fenton process let to reach 87% of COD removal, in the same time. Moreover, the BOD5/COD ratio increased from 0.212 to 0.68 and from 0.212 to 0.74 using Fenton and Photo-Fenton processes, respectively. Thus, the enhancement of biodegradability with the physico-chemical treatment was proved. The depletion of H2O2 was monitored during kinetic study. Strategies for improving the reaction efficiency, based on the H2O2 evolution, were also tested. © 2017 Elsevier Ltd
Colombia's cyberinfrastructure for biodiversity: Building data infrastructure in emerging countries to foster socioeconomic growth
(2019-12-22) De Vega, Jose J.; Davey, Robert P.; Duitama, Jorge; Escobar, Dairo; Cristancho, Marco A.; Etherington, Graham J.; Minotto, Alice; Pineda J.D.; Correa Alvarez J; Camargo, Anyela V.; Haerty, Wilfried; Mallarino, Juan P.; Barreto, Emiliano; Fuentes, Narcis; Di, Federica; Universidad EAFIT. Departamento de Ciencias; Ciencias Biológicas y Bioprocesos (CIBIOP)
Science and innovation are not a luxury but a prerequisite for social and economic development (Annan, 2003).

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