Adriana Gomez | Universidad Politécnica de Nicaragua (original) (raw)

Papers by Adriana Gomez

Research paper thumbnail of Open Access Examining the Potential of Using Information on Fire Detected by MODIS and Socio-Economic Variables to Highlight Potential Coca Cultivations in Forest Areas in Colombia

Abstract: Fires in forest areas are considered an important threat to the Andean Region and the A... more Abstract: Fires in forest areas are considered an important threat to the Andean Region and the Amazon rainforest. In Colombia, fire is used to expand the agricultural frontier (including illicit crops) which results in deforestation. Given the importance of avoiding deforestation and to control coca expansion, this paper aims to: 1) understand the relationship between fires and deforestation, coca and deforestation and hence coca and fires; 2) examine the potential of using fire data from remote sensing and socio-economic variables to predict the occurrence of new coca fields in forest areas in Colombia. The analysis was undertaken over a ten year period (2000-2010) at a municipality level in two areas with high coca dynamics (Central Region and Putumayo – Caquetá) using Pearson correlation and three different models: a Linear Probability model, a Logit model and a Probit model. The results show that there is a positive relationship between fire and deforestation. Although in gener...

Research paper thumbnail of The Use of Aerial Photographs as a Tool for Landscape Analysis in an Oil Palm Plantation

In Colombia, the oil palm sector is growing as an important economic sector. Its challenge is to ... more In Colombia, the oil palm sector is growing as an important economic sector. Its challenge is to ensure the growth of the palm oil production and maintain or improve the environment and the local landscape. The Macondo oil palm plantation is located in in Mapiripán, Meta, and is 5800 ha large. Landscape analysis is done to show the diversity of natural elements, the complexity and connectivity of the oil palm plantation. The aim of this paper is to explore the use of aerial pictures in landscape analysis. Using the aerial pictures to reduce time in ground-truthing, and simultaneously, collecting useful information for landscape analysis. Besides, it allows us to obtain “real time” pictures in spatio-temporal scales. The landscape analysis was based on a GIS analysis of the land cover maps of 2009. Using landscape metrics, we applied a raster of squares of 500x500 meters over the plantation area. The squares were classified using the cluster analysis according to similarities in land...

Research paper thumbnail of Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: the ZIKAlliance consortium

BMC Infectious Diseases, Dec 1, 2019

BackgroundThe European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designe... more BackgroundThe European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic.MethodsRecruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS).After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1–3, 4–6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems.Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites.Substudies of ZIKV seroprevalence, transmission clustering, disabilities and health economics, viral kinetics, the potential role of antibody enhancement, and co-infections will be linked to the cohort studies.DiscussionResults of these large cohort studies will provide better risk estimates for birth defects and other developmental abnormalities associated with ZIKV infection including possible co-factors for the variability of risk estimates between other countries and regions. Additional outcomes include incidence and transmission estimates of ZIKV during and after pregnancy, characterization of short and long-term clinical course following infection and viral kinetics of ZIKV.Study registrationsclinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03188731","term_id":"NCT03188731"}}NCT03188731 (PW cohort), June 15, 2017; clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03393286","term_id":"NCT03393286"}}NCT03393286 (CH cohort), January 8, 2018; clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03204409","term_id":"NCT03204409"}}NCT03204409 (NH cohort), July 2, 2017.

Research paper thumbnail of Evaluación del efecto del plasma rico en plaquetas en diferentes tiempos y concentraciones sobre la viabilidad de fibroblastos de ligamento periodontal y osteoblastos / Evaluation of Platelet-Rich Plasma Effect at different times and concentrations

Universitas Odontologica

ABSTRACT. Background: Growth factors used in health treatments can be obtained from a first-gener... more ABSTRACT. Background: Growth factors used in health treatments can be obtained from a first-generation source called platelet-rich plasma. The variety of protocols to prepare PRP produces variable results regarding PRP activation time and its effects on cell proliferation and viability. Purpose: To evaluate proliferation and cell viability of periodontal ligament fibroblasts and osteoblasts stimulated with PRP in several concentrations and times after PRP activation. Methods: An in vitro study was carried out using periodontal ligament fibroblast and osteoblast cell cultures. PRP from venous blood of a healthy adult was prepared through centrifugation and activated with 10 % CaCl2. The effect on cell proliferation after application of 1 %, 3 %, and 5% PRP and platelet-poor plasma was evaluated at 0, 12, 24, 48, and 72 hours after activation through MTS. The control group consisted of culture that did not receive any treatment. Data were analyzed using Chi square, Fisher, and McNemar...

Research paper thumbnail of Hospital-Associated Multicenter Outbreak of Emerging Fungus Candida auris, Colombia, 2016

Emerging Infectious Diseases

In support of improving patient care, this activity has been planned and implemented by Medscape,... more In support of improving patient care, this activity has been planned and implemented by Medscape, LLC and Emerging Infectious Diseases. Medscape, LLC is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team. Medscape, LLC designates this Journal-based CME activity for a maximum of 1.00 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 1.0 MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program. Participants will earn MOC points equivalent to the amount of CME credits claimed for the activity. It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit. All other clinicians completing this activity will be issued a certificate of participation. To participate in this journal CME activity: (1) review the learning objectives and author disclosures; (2) study the education content; (3) take the post-test with a 75% minimum passing score and complete the evaluation at

Research paper thumbnail of Human Three-Dimensional Endometrial Epithelial Cell Model To Study Host Interactions with Vaginal Bacteria and Neisseria gonorrhoeae

Infection and immunity, Mar 1, 2017

Colonization of the endometrium by pathogenic bacteria ascending from the lower female reproducti... more Colonization of the endometrium by pathogenic bacteria ascending from the lower female reproductive tract (FRT) is associated with many gynecologic and obstetric health complications. To study these host-microbe interactions in vitro, we developed a human three-dimensional (3-D) endometrial epithelial cell (EEC) model using the HEC-1A cell line and the rotating wall vessel (RWV) bioreactor technology. Our model, composed of 3-D EEC aggregates, recapitulates several functional/structural characteristics of human endometrial epithelial tissue, including cell differentiation, the presence of junctional complexes/desmosomes and microvilli, and the production of membrane-associated mucins and Toll-like receptors (TLRs). TLR function was evaluated by exposing the EEC aggregates to viral and bacterial products. Treatment with poly(I·C) and flagellin but not with synthetic lipoprotein (fibroblast-stimulating lipoprotein 1 [FSL-1]) or lipopolysaccharide (LPS) significantly induced proinflamm...

Research paper thumbnail of Biosolids and biosolid ashes as inputs for producing construction materials such as bricks

TECCIENCIA, 2016

Wastewater treatment plant biosolids in two states, With No Treatment (WNT) and Ashes (A), were a... more Wastewater treatment plant biosolids in two states, With No Treatment (WNT) and Ashes (A), were added to ceramic paste for brick manufacturing. The elements were cooked at three different temperatures (950°, 1000° and 1050°C) and the percentages of the content Clay-Biosolid WNT and Clay-Biosolid A, were 0, 5, 10 and 15%. Bricks manufactured with 15% ashes at 950°C were found to have a resistance to compression close to 26 MPa, meeting the Colombian Technical Norm 4205 (NTC) for structural and non-structural masonry of internal use and closing or divisory walls that support their own weight. We carried out a chemical, structural and thermic characterization of the raw materials that were used (clay and biosolid). We also performed a leaching test (TCLP) to evaluate toxicity characteristics to determine the safety values for heavy metals (Cr and Zn) in the biosolid. By meeting the requirements indicated in NTC 4205, we proved that the total percentage of biosolid that can be used as an addition in construction materials such as bricks is at least 15%, representing a substantial positive impact on the environment. These results open the path to the proposal of even larger percentages of ceramic paste replacement.

Research paper thumbnail of Microbiological Confirmation of a Focus of Active Trachoma in Amerindians of Colombia, South America

Vision Pan-America, The Pan-American Journal of Ophthalmology, 2015

Prupose: To confirm the microbiological presence of C. trachomatis in indigenous communities of C... more Prupose: To confirm the microbiological presence of C. trachomatis in indigenous communities of Colombia found to have cases of active trachoma. Method: An ophthalmic evaluation was performed in order to identify the active forms of the disease. Ocular swabs were taken from the conjunctiva and analyzed by real-time PCR "in house" for the detection of C. trachomatis. Positive samples were confirmed with a commercial real time PCR and DNA sequencing.

Research paper thumbnail of Digital Modeling, Integrated Project Delivery and Industry Transformation: An Australian Case Study

Research paper thumbnail of Simulación de eventos discretos y líneas de balance, aplicadas al mejoramiento del proceso constructivo de la cimentación de un edificio

ing.ciencía., Jan 30, 2015

El objeto de este trabajo fue establecer propuestas de mejoramiento al proceso de planeación de t... more El objeto de este trabajo fue establecer propuestas de mejoramiento al proceso de planeación de tiempos y costos en la etapa de cimentación de un edificio, a partir de la integración de herramientas como simulación de eventos discretos, programación con líneas de balance y metodologías Building Information Modeling - BIM. A partir de mediciones en campo se levantó información para la elaboración de un modelo de simulación de eventos discretos que imitara el proceso constructivo real. Se propusieron y modelaron alternativas de mejora, a partir de los principios de la filosofía Lean Construction y la programación de líneas de balance encontrando reducciones en tiempo y costo. También se realizó la animación virtual de las alternativas a partir de metodologías BIM. Se concluye que la integración de las herramientas utilizadas es de gran utilidad en la planeación y toma de decisiones en un proyecto civil.

Research paper thumbnail of Mapping global cropland and field size

Global Change Biology, 2015

Research paper thumbnail of Estimación del costo del primer raleo de algarrobo blanco (Prosopis alba): metodología aplicada al caso de una plantación en Herrera, Santiago del Estero, Argentina

Ingeniería solidaria, 2014

Se analizó la operación del primer raleo forestal en una plantación comercial de algarrobo blanco... more Se analizó la operación del primer raleo forestal en una plantación comercial de algarrobo blanco (Prosopis alba) de 5 años de edad, en la localidad de Herrera (Dpto. Avellaneda) de la provincia de Santiago del Estero, Argentina, mediante un estudio de tiempos y movimientos para conocer la productividad operacional y los costos asociados al proceso de apeo con motosierra. Se midieron tiempos efectivos y operativos y se calculó volumen con corteza, eficiencia, productividad y costo directo del raleo. La muestra de 226 árboles completó un volumen abatido de 1,19 m3. El tiempo operativo promedio fue 77 s/árbol y el tiempo efectivo medio de 49 s/árbol. Se verificó una fuerte correlación entre el tiempo efectivo de trabajo de la herramienta y las variables diámetro mayor y volumen de los árboles. La eficiencia operacional fue del 63,3%. La productividad horaria en el derribo fue de 0,25 m3/h (47 árboles/h). El costo diario de la operación fue de 781 $/día, mientras que el costo unitario ...

Research paper thumbnail of Estudio de la tecnología de concretos de contracción compensada aplicada a la construcción de pisos industriales

Research paper thumbnail of Examining the Potential of Using Information on Fire Detected by MODIS and Socio-Economic Variables to Highlight Potential Coca Cultivations in Forest Areas in Colombia

The Open Geography Journal, 2014

Research paper thumbnail of Tempering temperature effects on abrasive wear of mottled cast iron

Wear, 2009

The effects of different tempering temperatures (300-600 • C) on abrasive wear resistance of mott... more The effects of different tempering temperatures (300-600 • C) on abrasive wear resistance of mottled cast iron were studied. Abrasive wear tests were carried out using the rubber-wheel test on quartz sand and the pin test on Al 2 O 3 abrasive cloths. The retained austenite content of the matrix was determined by X-ray diffraction. The wear surface of the specimens was examined by scanning electron microscopy for identifying the wear micromechanism. Bulk hardness and matrix hardness before and after the tests were measured. The results showed that in the two-body (pin-on-disc test) system, the main wear mechanism was microcutting and high matrix hardening was presented. The wear rates presented higher correlation with the retained austenite than with the bulk and matrix hardness. In the three-body system (sand-rubber wheel), the wear surfaces presented indentations due to abrasive rolling. The wear rates had better correlation with both the bulk and matrix hardness (before and after the wear test) than with the retained austenite content. There are two groups of results, high and low wear rates corresponding to each tribosystem, two-body abrasive wear and three-body abrasive wear, respectively.

Research paper thumbnail of Reversible polynomial automorphisms of the plane: the involutory case

Research paper thumbnail of Efecto de la furosemida en ratas sometidas a hipoxia crónica severa

Revista …, 1999

Efecto de la furosemida en ratas sometidas a hipoxia crónica severa.

Research paper thumbnail of Assessing available sight distance: an indirect tool to evaluate geometric design consistency

4th International …, 2010

Any highway should be able to offer driving safety. In this sense, it is especially valued that r... more Any highway should be able to offer driving safety. In this sense, it is especially valued that roadways satisfy drivers' needs of riding with safety and render an adequate workload. Available sight distance along a road alters drivers' expectancies and the way ...

Research paper thumbnail of Volume-preserving maps with an invariant

Chaos: An Interdisciplinary Journal of Nonlinear Science, 2002

Research paper thumbnail of Critical points of solutions to elliptic problems in planar domains

… on Pure and Applied Analysis (CPAA), 2011

ABSTRACT Given a planar domain Ω, and an analytic function f, we describe the set of critical poi... more ABSTRACT Given a planar domain Ω, and an analytic function f, we describe the set of critical points for the solution u of the semilinear elliptic problem Δu=f(u) in Ω, u=0 on ∂Ω. For simply connected domains we establish that the set of critical points is finite while for non–simply connected domains we show that this set is made up of finitely many isolated points and finitely many analytic Jordan curves. Further results are given in the case that Ω is an annular domain whose border has nonzero curvature.

Research paper thumbnail of Open Access Examining the Potential of Using Information on Fire Detected by MODIS and Socio-Economic Variables to Highlight Potential Coca Cultivations in Forest Areas in Colombia

Abstract: Fires in forest areas are considered an important threat to the Andean Region and the A... more Abstract: Fires in forest areas are considered an important threat to the Andean Region and the Amazon rainforest. In Colombia, fire is used to expand the agricultural frontier (including illicit crops) which results in deforestation. Given the importance of avoiding deforestation and to control coca expansion, this paper aims to: 1) understand the relationship between fires and deforestation, coca and deforestation and hence coca and fires; 2) examine the potential of using fire data from remote sensing and socio-economic variables to predict the occurrence of new coca fields in forest areas in Colombia. The analysis was undertaken over a ten year period (2000-2010) at a municipality level in two areas with high coca dynamics (Central Region and Putumayo – Caquetá) using Pearson correlation and three different models: a Linear Probability model, a Logit model and a Probit model. The results show that there is a positive relationship between fire and deforestation. Although in gener...

Research paper thumbnail of The Use of Aerial Photographs as a Tool for Landscape Analysis in an Oil Palm Plantation

In Colombia, the oil palm sector is growing as an important economic sector. Its challenge is to ... more In Colombia, the oil palm sector is growing as an important economic sector. Its challenge is to ensure the growth of the palm oil production and maintain or improve the environment and the local landscape. The Macondo oil palm plantation is located in in Mapiripán, Meta, and is 5800 ha large. Landscape analysis is done to show the diversity of natural elements, the complexity and connectivity of the oil palm plantation. The aim of this paper is to explore the use of aerial pictures in landscape analysis. Using the aerial pictures to reduce time in ground-truthing, and simultaneously, collecting useful information for landscape analysis. Besides, it allows us to obtain “real time” pictures in spatio-temporal scales. The landscape analysis was based on a GIS analysis of the land cover maps of 2009. Using landscape metrics, we applied a raster of squares of 500x500 meters over the plantation area. The squares were classified using the cluster analysis according to similarities in land...

Research paper thumbnail of Study protocol for the multicentre cohorts of Zika virus infection in pregnant women, infants, and acute clinical cases in Latin America and the Caribbean: the ZIKAlliance consortium

BMC Infectious Diseases, Dec 1, 2019

BackgroundThe European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designe... more BackgroundThe European Commission (EC) Horizon 2020 (H2020)-funded ZIKAlliance Consortium designed a multicentre study including pregnant women (PW), children (CH) and natural history (NH) cohorts. Clinical sites were selected over a wide geographic range within Latin America and the Caribbean, taking into account the dynamic course of the ZIKV epidemic.MethodsRecruitment to the PW cohort will take place in antenatal care clinics. PW will be enrolled regardless of symptoms and followed over the course of pregnancy, approximately every 4 weeks. PW will be revisited at delivery (or after miscarriage/abortion) to assess birth outcomes, including microcephaly and other congenital abnormalities according to the evolving definition of congenital Zika syndrome (CZS).After birth, children will be followed for 2 years in the CH cohort. Follow-up visits are scheduled at ages 1–3, 4–6, 12, and 24 months to assess neurocognitive and developmental milestones. In addition, a NH cohort for the characterization of symptomatic rash/fever illness was designed, including follow-up to capture persisting health problems.Blood, urine, and other biological materials will be collected, and tested for ZIKV and other relevant arboviral diseases (dengue, chikungunya, yellow fever) using RT-PCR or serological methods. A virtual, decentralized biobank will be created. Reciprocal clinical monitoring has been established between partner sites.Substudies of ZIKV seroprevalence, transmission clustering, disabilities and health economics, viral kinetics, the potential role of antibody enhancement, and co-infections will be linked to the cohort studies.DiscussionResults of these large cohort studies will provide better risk estimates for birth defects and other developmental abnormalities associated with ZIKV infection including possible co-factors for the variability of risk estimates between other countries and regions. Additional outcomes include incidence and transmission estimates of ZIKV during and after pregnancy, characterization of short and long-term clinical course following infection and viral kinetics of ZIKV.Study registrationsclinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03188731","term_id":"NCT03188731"}}NCT03188731 (PW cohort), June 15, 2017; clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03393286","term_id":"NCT03393286"}}NCT03393286 (CH cohort), January 8, 2018; clinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT03204409","term_id":"NCT03204409"}}NCT03204409 (NH cohort), July 2, 2017.

Research paper thumbnail of Evaluación del efecto del plasma rico en plaquetas en diferentes tiempos y concentraciones sobre la viabilidad de fibroblastos de ligamento periodontal y osteoblastos / Evaluation of Platelet-Rich Plasma Effect at different times and concentrations

Universitas Odontologica

ABSTRACT. Background: Growth factors used in health treatments can be obtained from a first-gener... more ABSTRACT. Background: Growth factors used in health treatments can be obtained from a first-generation source called platelet-rich plasma. The variety of protocols to prepare PRP produces variable results regarding PRP activation time and its effects on cell proliferation and viability. Purpose: To evaluate proliferation and cell viability of periodontal ligament fibroblasts and osteoblasts stimulated with PRP in several concentrations and times after PRP activation. Methods: An in vitro study was carried out using periodontal ligament fibroblast and osteoblast cell cultures. PRP from venous blood of a healthy adult was prepared through centrifugation and activated with 10 % CaCl2. The effect on cell proliferation after application of 1 %, 3 %, and 5% PRP and platelet-poor plasma was evaluated at 0, 12, 24, 48, and 72 hours after activation through MTS. The control group consisted of culture that did not receive any treatment. Data were analyzed using Chi square, Fisher, and McNemar...

Research paper thumbnail of Hospital-Associated Multicenter Outbreak of Emerging Fungus Candida auris, Colombia, 2016

Emerging Infectious Diseases

In support of improving patient care, this activity has been planned and implemented by Medscape,... more In support of improving patient care, this activity has been planned and implemented by Medscape, LLC and Emerging Infectious Diseases. Medscape, LLC is jointly accredited by the Accreditation Council for Continuing Medical Education (ACCME), the Accreditation Council for Pharmacy Education (ACPE), and the American Nurses Credentialing Center (ANCC), to provide continuing education for the healthcare team. Medscape, LLC designates this Journal-based CME activity for a maximum of 1.00 AMA PRA Category 1 Credit(s)™. Physicians should claim only the credit commensurate with the extent of their participation in the activity. Successful completion of this CME activity, which includes participation in the evaluation component, enables the participant to earn up to 1.0 MOC points in the American Board of Internal Medicine's (ABIM) Maintenance of Certification (MOC) program. Participants will earn MOC points equivalent to the amount of CME credits claimed for the activity. It is the CME activity provider's responsibility to submit participant completion information to ACCME for the purpose of granting ABIM MOC credit. All other clinicians completing this activity will be issued a certificate of participation. To participate in this journal CME activity: (1) review the learning objectives and author disclosures; (2) study the education content; (3) take the post-test with a 75% minimum passing score and complete the evaluation at

Research paper thumbnail of Human Three-Dimensional Endometrial Epithelial Cell Model To Study Host Interactions with Vaginal Bacteria and Neisseria gonorrhoeae

Infection and immunity, Mar 1, 2017

Colonization of the endometrium by pathogenic bacteria ascending from the lower female reproducti... more Colonization of the endometrium by pathogenic bacteria ascending from the lower female reproductive tract (FRT) is associated with many gynecologic and obstetric health complications. To study these host-microbe interactions in vitro, we developed a human three-dimensional (3-D) endometrial epithelial cell (EEC) model using the HEC-1A cell line and the rotating wall vessel (RWV) bioreactor technology. Our model, composed of 3-D EEC aggregates, recapitulates several functional/structural characteristics of human endometrial epithelial tissue, including cell differentiation, the presence of junctional complexes/desmosomes and microvilli, and the production of membrane-associated mucins and Toll-like receptors (TLRs). TLR function was evaluated by exposing the EEC aggregates to viral and bacterial products. Treatment with poly(I·C) and flagellin but not with synthetic lipoprotein (fibroblast-stimulating lipoprotein 1 [FSL-1]) or lipopolysaccharide (LPS) significantly induced proinflamm...

Research paper thumbnail of Biosolids and biosolid ashes as inputs for producing construction materials such as bricks

TECCIENCIA, 2016

Wastewater treatment plant biosolids in two states, With No Treatment (WNT) and Ashes (A), were a... more Wastewater treatment plant biosolids in two states, With No Treatment (WNT) and Ashes (A), were added to ceramic paste for brick manufacturing. The elements were cooked at three different temperatures (950°, 1000° and 1050°C) and the percentages of the content Clay-Biosolid WNT and Clay-Biosolid A, were 0, 5, 10 and 15%. Bricks manufactured with 15% ashes at 950°C were found to have a resistance to compression close to 26 MPa, meeting the Colombian Technical Norm 4205 (NTC) for structural and non-structural masonry of internal use and closing or divisory walls that support their own weight. We carried out a chemical, structural and thermic characterization of the raw materials that were used (clay and biosolid). We also performed a leaching test (TCLP) to evaluate toxicity characteristics to determine the safety values for heavy metals (Cr and Zn) in the biosolid. By meeting the requirements indicated in NTC 4205, we proved that the total percentage of biosolid that can be used as an addition in construction materials such as bricks is at least 15%, representing a substantial positive impact on the environment. These results open the path to the proposal of even larger percentages of ceramic paste replacement.

Research paper thumbnail of Microbiological Confirmation of a Focus of Active Trachoma in Amerindians of Colombia, South America

Vision Pan-America, The Pan-American Journal of Ophthalmology, 2015

Prupose: To confirm the microbiological presence of C. trachomatis in indigenous communities of C... more Prupose: To confirm the microbiological presence of C. trachomatis in indigenous communities of Colombia found to have cases of active trachoma. Method: An ophthalmic evaluation was performed in order to identify the active forms of the disease. Ocular swabs were taken from the conjunctiva and analyzed by real-time PCR "in house" for the detection of C. trachomatis. Positive samples were confirmed with a commercial real time PCR and DNA sequencing.

Research paper thumbnail of Digital Modeling, Integrated Project Delivery and Industry Transformation: An Australian Case Study

Research paper thumbnail of Simulación de eventos discretos y líneas de balance, aplicadas al mejoramiento del proceso constructivo de la cimentación de un edificio

ing.ciencía., Jan 30, 2015

El objeto de este trabajo fue establecer propuestas de mejoramiento al proceso de planeación de t... more El objeto de este trabajo fue establecer propuestas de mejoramiento al proceso de planeación de tiempos y costos en la etapa de cimentación de un edificio, a partir de la integración de herramientas como simulación de eventos discretos, programación con líneas de balance y metodologías Building Information Modeling - BIM. A partir de mediciones en campo se levantó información para la elaboración de un modelo de simulación de eventos discretos que imitara el proceso constructivo real. Se propusieron y modelaron alternativas de mejora, a partir de los principios de la filosofía Lean Construction y la programación de líneas de balance encontrando reducciones en tiempo y costo. También se realizó la animación virtual de las alternativas a partir de metodologías BIM. Se concluye que la integración de las herramientas utilizadas es de gran utilidad en la planeación y toma de decisiones en un proyecto civil.

Research paper thumbnail of Mapping global cropland and field size

Global Change Biology, 2015

Research paper thumbnail of Estimación del costo del primer raleo de algarrobo blanco (Prosopis alba): metodología aplicada al caso de una plantación en Herrera, Santiago del Estero, Argentina

Ingeniería solidaria, 2014

Se analizó la operación del primer raleo forestal en una plantación comercial de algarrobo blanco... more Se analizó la operación del primer raleo forestal en una plantación comercial de algarrobo blanco (Prosopis alba) de 5 años de edad, en la localidad de Herrera (Dpto. Avellaneda) de la provincia de Santiago del Estero, Argentina, mediante un estudio de tiempos y movimientos para conocer la productividad operacional y los costos asociados al proceso de apeo con motosierra. Se midieron tiempos efectivos y operativos y se calculó volumen con corteza, eficiencia, productividad y costo directo del raleo. La muestra de 226 árboles completó un volumen abatido de 1,19 m3. El tiempo operativo promedio fue 77 s/árbol y el tiempo efectivo medio de 49 s/árbol. Se verificó una fuerte correlación entre el tiempo efectivo de trabajo de la herramienta y las variables diámetro mayor y volumen de los árboles. La eficiencia operacional fue del 63,3%. La productividad horaria en el derribo fue de 0,25 m3/h (47 árboles/h). El costo diario de la operación fue de 781 $/día, mientras que el costo unitario ...

Research paper thumbnail of Estudio de la tecnología de concretos de contracción compensada aplicada a la construcción de pisos industriales

Research paper thumbnail of Examining the Potential of Using Information on Fire Detected by MODIS and Socio-Economic Variables to Highlight Potential Coca Cultivations in Forest Areas in Colombia

The Open Geography Journal, 2014

Research paper thumbnail of Tempering temperature effects on abrasive wear of mottled cast iron

Wear, 2009

The effects of different tempering temperatures (300-600 • C) on abrasive wear resistance of mott... more The effects of different tempering temperatures (300-600 • C) on abrasive wear resistance of mottled cast iron were studied. Abrasive wear tests were carried out using the rubber-wheel test on quartz sand and the pin test on Al 2 O 3 abrasive cloths. The retained austenite content of the matrix was determined by X-ray diffraction. The wear surface of the specimens was examined by scanning electron microscopy for identifying the wear micromechanism. Bulk hardness and matrix hardness before and after the tests were measured. The results showed that in the two-body (pin-on-disc test) system, the main wear mechanism was microcutting and high matrix hardening was presented. The wear rates presented higher correlation with the retained austenite than with the bulk and matrix hardness. In the three-body system (sand-rubber wheel), the wear surfaces presented indentations due to abrasive rolling. The wear rates had better correlation with both the bulk and matrix hardness (before and after the wear test) than with the retained austenite content. There are two groups of results, high and low wear rates corresponding to each tribosystem, two-body abrasive wear and three-body abrasive wear, respectively.

Research paper thumbnail of Reversible polynomial automorphisms of the plane: the involutory case

Research paper thumbnail of Efecto de la furosemida en ratas sometidas a hipoxia crónica severa

Revista …, 1999

Efecto de la furosemida en ratas sometidas a hipoxia crónica severa.

Research paper thumbnail of Assessing available sight distance: an indirect tool to evaluate geometric design consistency

4th International …, 2010

Any highway should be able to offer driving safety. In this sense, it is especially valued that r... more Any highway should be able to offer driving safety. In this sense, it is especially valued that roadways satisfy drivers' needs of riding with safety and render an adequate workload. Available sight distance along a road alters drivers' expectancies and the way ...

Research paper thumbnail of Volume-preserving maps with an invariant

Chaos: An Interdisciplinary Journal of Nonlinear Science, 2002

Research paper thumbnail of Critical points of solutions to elliptic problems in planar domains

… on Pure and Applied Analysis (CPAA), 2011

ABSTRACT Given a planar domain Ω, and an analytic function f, we describe the set of critical poi... more ABSTRACT Given a planar domain Ω, and an analytic function f, we describe the set of critical points for the solution u of the semilinear elliptic problem Δu=f(u) in Ω, u=0 on ∂Ω. For simply connected domains we establish that the set of critical points is finite while for non–simply connected domains we show that this set is made up of finitely many isolated points and finitely many analytic Jordan curves. Further results are given in the case that Ω is an annular domain whose border has nonzero curvature.