27 results on '"Carmen Solana"'
Search Results
2. Antimicrobial Activity and Cytotoxicity of Nonsteroidal Anti-Inflammatory Drugs against Endodontic Biofilms
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Carmen María Ferrer-Luque, Carmen Solana, Beatriz Aguado, and Matilde Ruiz-Linares
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antimicrobial activity ,endodontic biofilms ,diclofenac ,ibuprofen ,non-steroidal anti-inflammatory drugs ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Persistent infections have become a challenge in dentistry because of growing antibiotic resistance. Nonsteroidal anti-inflammatory drugs (NSAIDs) appear to be a therapeutic alternative to control biofilm infection. The objective of this work is to evaluate the antimicrobial activity and cytotoxicity of sodium diclofenac (DCS), ibuprofen (IBP) and ibuprofen arginine (IBP-arginine) solutions against endodontic polymicrobial biofilms. Sterile radicular dentin blocks of 4 mm × 4 mm × 0.7 mm were used as substrate to grow biofilm. The dentin blocks were submerged into solutions for 5 min. The antimicrobial activity was evaluated by means of the adenosine triphosphate (ATP) assay and confocal laser scanning microscopy (CLSM). Fibroblasts 3T3-L1 (ECACC 86052701) were used to test the cytotoxicity of irrigating solutions. The antibiofilm effects determined by the ATP assay showed that 4% IBP-arginine solution exerted the highest antibiofilm activity, followed by 4% DCS and 4% IBP, with statistical differences among groups (p < 0.001). As for CLSM, 4% DCS and 4% IBP-arginine solutions gave the lowest viable cell percentages, without significant differences between them. Cytotoxicity results at 1/10 dilution were similar for all solutions. At 1/100 dilution, a 4% DCS solution obtained the lowest cell viability for both time periods assayed, 1 h and 24 h. The IBP-arginine group showed the highest cell viability at 24 h. In this preliminary study, in terms of antibiofilm activity and cytotoxicity, a mixed 4% IBP-arginine solution gave the most promising results. NSAID solutions could be recommendable drugs for endodontic disinfection procedures.
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- 2023
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3. Root Canal Disinfection Articles with the Highest Relative Citation Ratios. A Bibliometric Analysis from 1990 to 2019
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Pilar Valderrama, Pilar Baca, Carmen Solana, and Carmen María Ferrer-Luque
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bibliometrics ,citations ,endodontics ,National Institutes of Health ,relative citation ratio ,root canal disinfection ,Therapeutics. Pharmacology ,RM1-950 - Abstract
The relative citation rate (RCR) is a normalized article-level metric useful to assess the impact of research articles. The objective of this bibliometric study is to identify and analyze, in root canal disinfection, the 100 articles having the highest RCRs in the period 1990–2019, then compare them with the top 100 articles most cited. A cross-sectional study was performed, and the search strategy ((Disinfection AND root canal) AND ((“1990/01/01”[Date-Publication]: “2019/12/31”[Date-Publication]))) relied on PubMed (n = 4294 documents), and article data were downloaded from the iCite database. The 100 articles with the highest RCRs and the top 100 cited were selected and evaluated in bibliometric terms. Among the 100 articles with the highest RCRs, there were no differences in the three decades for RCRs values, but there were in citations, being 2000–2009 the most cited. The USA was the predominant country (n = 30), followed by Brazil (n = 14). The most frequent study designs were reviews (n = 27) and in vitro (n = 25) and ex vivo (n = 24) studies. All subfields were well represented, although they varied over time. In 2010–2019, regenerative procedures and irrigation/disinfection techniques were predominant. Considering the RCR’s top 100 articles, 76 were common with the 100 most cited articles. Using the RCR metric allowed us to identify influential articles in root canal disinfection, a research field with topics of significance that fluctuate over time. Compared to citations, RCR reduces the time from publication to detection of its importance for the readership and could be a valid alternative to citation counts.
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- 2021
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4. Impact of Environmental Factors on the Spectral Characteristics of Lava Surfaces: Field Spectrometry of Basaltic Lava Flows on Tenerife, Canary Islands, Spain
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Long Li, Carmen Solana, Frank Canters, Jonathan C.-W. Chan, and Matthieu Kervyn
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lava flow surfaces ,field spectrometry ,weathering ,oxidation ,lichen ,Hyperion ,Tenerife ,Science - Abstract
We report on spectral reflectance measurements of basaltic lava flows on Tenerife Island, Spain. Lava flow surfaces of different ages, surface roughness and elevations were systematically measured using a field spectroradiometer operating in the range of 350–2500 nm. Surface roughness, oxidation and lichen coverage were documented at each measured site. Spectral properties vary with age and morphology of lava. Pre-historical lavas with no biological coverage show a prominent increase in spectral reflectance in the 400–760 nm range and a decrease in the 2140–2210 nm range. Pāhoehoe surfaces have higher reflectance values than ʻaʻā ones and attain a maximum reflectance at wavelengths < 760 nm. Lichen-covered lavas are characterized by multiple lichen-related absorption and reflection features. We demonstrate that oxidation and lichen growth are two major factors controlling spectra of Tenerife lava surfaces and, therefore, propose an oxidation index and a lichen index to quantify surface alterations of lava flows: (1) the oxidation index is based on the increase of the slope of the spectral profile from blue to red as the field-observed oxidation level strengthens; and (2) the lichen index is based on the spectral reflectance in the 1660–1725 nm range, which proves to be highly correlated with lichen coverage documented in the field. The two spectral indices are applied to Landsat ETM+ and Hyperion imagery of the study area for mapping oxidation and lichen coverage on lava surfaces, respectively. Hyperion is shown to be capable of discriminating different volcanic surfaces, i.e., tephra vs. lava and oxidized lava vs. lichen-covered lava. Our study highlights the value of field spectroscopic measurements to aid interpretation of lava flow characterization using satellite images and of the effects of environmental factors on lava surface evolution over time, and, therefore, has the potential to contribute to the mapping as well as dating of lava surfaces.
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- 2015
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5. Crowd-sourcing observations of volcanic eruptions during the 2021 Fagradalsfjall and Cumbre Vieja events
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Fabian B. Wadsworth, Edward W. Llewellin, Jamie I. Farquharson, Janina K. Gillies, Ariane Loisel, Léon Frey, Evgenia Ilyinskaya, Thor Thordarson, Samantha Tramontano, Einat Lev, Matthew J. Pankhurst, Alejandro Galdeano Rull, María Asensio-Ramos, Nemesio M. Pérez, Pedro A. Hernández, David Calvo, M. Carmen Solana, Ulrich Kueppers, and Alejandro Polo Santabárbara
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Science - Abstract
This study explores the scientific potential of crowdsourced observations during volcanic eruptions, using the 2021 Fagradalsfjall (Iceland) and Cumbre Vieja (Canary Islands) events as case studies.
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- 2022
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6. India en el camino de los dioses
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María del Carmen Solana Valdés
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- 2022
7. Microbiome in paired root apices and periapical lesions and its association with clinical signs in persistent apical periodontitis using next‐generation sequencing
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Virginia Pérez‐Carrasco, David Uroz‐Torres, Miguel Soriano, Carmen Solana, Matilde Ruiz‐Linares, Jose Antonio Garcia‐Salcedo, and Maria Teresa Arias‐Moliz
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General Dentistry - Published
- 2023
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8. Journalists, Communication and Volcanic Risk Managment in Spain
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Claudia Rodríguez-Pérez, Nemesio M. Pérez, Fátima Rodríguez, and Carmen Solana
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An effective volcanic risk management is a collective responsibility for all individuals and groups who work or live in areas with volcanic activity. This includes scientists, authorities, civil protection specialists, communication professionals, sociologists, psychologists, health specialists, urban and territorial planners, economists, educators, and the general public. While some may have more specific roles and responsibilities in this effort, communication professionals can make a significant contribution to volcanic risk management efforts.Journalists and the media have the ability to impact the success of volcanic risk management efforts and can potentially save lives by accurately reporting on and informing the public about volcanic hazards. In order to fulfill this role effectively, media professionals should be knowledgeable about the unique characteristics of volcanoes and the methods used to volcanic risk management. However, it is important to note that the media also has a responsibility to critically evaluate and report on the effectiveness of risk management efforts. This dual role of the media can be complex, but it is essential for ensuring transparency and accountability.This research aims to assess the level of understanding and interest that media professionals have about volcanoes and volcanic risk managment in Spain, and to examine the potential and desired role of the media in enhancing the effectiveness of volcanic risk management efforts. In order to evaluate the knowledge, attitudes, and practices of journalists regarding volcanoes, volcanic risk management, and communication in Spain, we developed an online questionnaire. The questionnaire consists of approximately 25 questions and can be completed in about 15 minutes. Approximately 24% of the questionnaire consists of general questions such as residence, gender, age, education level, etc. Questions and comments related to volcanoes and volcanic risk management make up approximately 42% of the questionnaire, while the remaining 32% focus on communication and the role of the media in volcanic risk management in Spain. The questionnaire was released on December 26 and by the end of the year 2022, a total of 105 journalists had completed it. Here we present some preliminary results obtained including qualitative data on needs and sentiment towards volcanic risk.
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- 2023
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9. Effectiveness of conservative instrumentation in root canal disinfection
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Sıla Nur Usta, Carmen Solana, Matilde Ruiz-Linares, Pilar Baca, Carmen María Ferrer-Luque, Monica Cabeo, and Maria Teresa Arias-Moliz
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Disinfection ,Conservative instrumentation ,Polymicrobial infection ,Root canal preparation ,General Dentistry - Abstract
The authors acknowledge Francisca Castillo Pérez for her technical assistance, Ethical approval. This study was performed in line with the principles of the Declaration of Helsinki. The study protocol was approved by the ethics committee of the university where the study was conducted (no. 1076 CEIH/2020)., Objectives: The impact of conservative instrumentation on the disinfection of root canals with different curvatures has not yet been determined. This ex vivo study aimed to evaluate and compare the effect of conservative instrumentation with TruNatomy (TN) and Rotate and a conventional rotary system, ProTaper Gold (PTG), on root canal disinfection during chemomechanical preparation of straight and curved canals. Materials and methods: Ninety mandibular molars with straight (n = 45) and curved (n = 45) mesiobuccal root canals were contaminated with polymicrobial clinical samples. Teeth were divided into three subgroups (n = 14) according to the file systems and the curvature. Canals were instrumented with TN, Rotate, and PTG, respectively. Sodium hypochlorite and EDTA were used as irrigants. Intracanal samples were taken before (S1) and after (S2) instrumentation. Six uninfected teeth were used as negative controls. The bacterial reduction between S1 and S2 was measured by ATP assay, flow cytometry, and culture methods. Kruskal-Wallis and ANOVA tests were followed by the Duncan post hoc test (p < 0.05). Results: Bacterial reduction percentages were similar for the three file systems in straight canals (p > 0.05). However, PTG showed a lower reduction percentage of intact membrane cells in flow cytometry than TN and Rotate (p = 0.036). For the curved canals, no significant differences were obtained (p > 0.05). Conclusion: Conservative instrumentation of straight and curved canals using TN and Rotate files resulted in similar bacterial reduction compared to PTG. Clinical relevance: The disinfection efficacy of conservative instrumentation is similar to conventional instrumentation in straight and curved root canals., Universidad de Granada/CBUA., Research Group CTS‑167 of the Junta de Andalucía, Spain.
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- 2023
10. Current status on antimicrobial activity of a tricalcium silicate cement
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Matilde, Ruiz-Linares, Juliana, de Oliveira Fagundes, Carmen, Solana, Pilar, Baca, and Carmen M, Ferrer-Luque
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Anti-Infective Agents ,Silicates ,Materials Testing ,Calcium Compounds ,General Dentistry ,Silicate Cement - Abstract
Biodentine (BD) is a bioactive material with many indications in endodontic therapy. The purpose of this study was to compile and review the outcomes of in vitro and in vivo studies of BD in terms of antimicrobial effectiveness. An electronic search was carried out in PubMed, from January 2009-April 2021 using the keywords: (Biodentine or dentine substitute or "Ca
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- 2022
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11. Antimicrobial potential of new diclofenac hydrogels for disinfection in regenerative endodontics: An in vitro and ex vivo study
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Matilde Ruiz‐Linares, Javier F. Monroy‐Rojas, Carmen Solana, Pilar Baca, Beatriz Aguado, Ana Soriano‐Lerma, María Teresa Arias‐Moliz, and Carmen María Ferrer‐Luque
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General Dentistry - Abstract
There is a need to explore new alternatives for root canal disinfection in regenerative endodontics, since the current strategies are far from ideal. Currently, the potential use of diclofenac (DC) is being investigated for controlling root canal infections. The objective was to evaluate the antimicrobial efficacy of novel DC-based hydrogels (DCHs) against polymicrobial biofilms grown in radicular dentine and root canals and to compare results with triantibiotic (TAH) and diantibiotic (DAH) hydrogels, and calcium hydroxide (Ca[OH]The in vitro antimicrobial activity of intracanal medicaments was evaluated against 3-week-old polymicrobial root canal biofilms grown on human radicular dentine. Dentine samples were obtained and randomly divided into the study groups (n = 4/group): (1) 1 mg/ml TAH; (2) 1 mg/ml DAH; (3) 5% diclofenac (DCH); (4) 2.5% DCH; (5) 1.25% DCH; (6) 1 mg/ml DAH + 5% DCH; (7) Ca(OH)Confocal scanning laser microscopy analysis indicated that the greatest effectiveness was obtained with 5% DCH, showing significant differences with respect to the other groups (p .001). In root canals, the highest LogSodium DC hydrogels demonstrate antimicrobial efficacy against endodontic biofilms.
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- 2022
12. A laboratory study of root canal and isthmus disinfection in extracted teeth using various activation methods with a mixture of sodium hypochlorite and etidronic acid
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María Teresa Arias-Moliz, Manuel Bravo, Matilde Ruiz-Linares, N Villalta-Briones, Pilar Baca, Carmen Solana, and B. Aguado-Pérez
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Molar ,Sodium Hypochlorite ,Root canal ,0206 medical engineering ,Dentistry ,02 engineering and technology ,Enterococcus faecalis ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine ,Confocal laser scanning microscopy ,Humans ,Therapeutic Irrigation ,General Dentistry ,Root Canal Irrigants ,biology ,business.industry ,Etidronic Acid ,030206 dentistry ,Etidronic acid ,biology.organism_classification ,020601 biomedical engineering ,Disinfection ,medicine.anatomical_structure ,chemistry ,Sodium hypochlorite ,Dental Pulp Cavity ,Activation method ,Laboratories ,business ,Mandibular molar ,Root Canal Preparation ,medicine.drug - Abstract
To evaluate in a laboratory setting the antibiofilm activity of several irrigating protocols including conventional irrigation, ultrasonic activation and XP-endo Finisher, with a mixture of sodium hypochlorite and etidronic acid in infected isthmuses and root canals of extracted human mandibular molar teeth.Fifty-six mesial roots of mandibular molars, half of them with a continuous isthmus from the cervical to the apical third between the two root canals (type 1), and the other half with a continuous isthmus from the cervical to the middle third and one canal in the apical third (type 2), were included. The root canals were contaminated for 7 days with an Enterococcus faecalis suspension. There were three experimental groups plus a control group (n = 7 per type of root canal anatomy). All the root canals, except for the control group that was not treated, were chemomechanically prepared and then assigned to one of the experimental groups according to the final adjunctive procedure: conventional irrigation, ultrasonic activation or XP-endo Finisher activation. The irrigating solution used was a combination of 2.5% sodium hypochlorite and 9% etidronic acid, and the final protocols were applied for three cycles of 30 s with a 3 mL volume. The antibiofilm activity was evaluated at each location (root canal and isthmus) and third (cervical, middle and apical) using confocal laser scanning microscopy and the live/dead technique. Statistical analysis was performed using SPSS (descriptive statistics) and SUDAAN (P-value calculations).Root canals had significantly lower biovolume values than the isthmuses (P 0.05). The biovolume in the root canals was significantly reduced in all the experimental groups in all the thirds except for conventional irrigation in the apical third (P 0.05). In the cervical and middle thirds, ultrasonic activation was associated with the lowest biovolumes (P 0.05), followed by XP-endo Finisher. In the isthmus, disinfection was similar in all the thirds for all the protocols. Conventional irrigation was associated with intermediate values with no significant differences from the control group or from the activated protocols (P 0.05), although the latter were significantly different from the control group (P 0.05). No differences were found between ultrasonic activation and XP-endo Finisher in the middle and apical thirds (P 0.05) in the isthmuses.In this laboratory study on extracted teeth, the isthmus was more difficult to disinfect than root canals. In the root canals, ultrasonic activation and XP-endo Finisher had a greater effectiveness than conventional irrigation. In the isthmuses, no differences were observed between the two activation techniques and conventional irrigation.
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- 2020
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13. Translating research into operational procedures for reducing the risk from volcanic eruptions
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Carmen Solana and Christopher R. J. Kilburn
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Geochemistry and Petrology - Abstract
In this perspective piece, we reflect on scientific progress in volcanic risk reduction and its prospects for future development. In spite of recent advances, a dichotomy still exists between the products of academic research and the desire for practical applications. The main themes to emerge are (1) the need to find the most effective ways to explain the ever growing amount and complexity of volcanological data to non-specialist stakeholders, and (2) how to transfer to future generations of applied scientists the lessons from practical experience that are often missed by theoretical guidelines. Recommendations for sustaining progress in these fields include improving the accessibility of knowledge and data, embracing novel tools to communicate volcanic risk and uncertainty for decision making, and investing effort on transferring practical experience across generations.En este breve artículo, reflexionamos sobre los adelantos científicos para la reducción del riesgo de erupciones volcánicas y en las oportunidades para continuar progresando. A pesar de avances recientes, todavía existe un desfase entre los resultados de investigaciones científicas y su aplicación práctica. Los temas clave que identificamos son (1) la necesidad de encontrar maneras más efectivas de explicar la cantidad incremental de información volcanológica (y su creciente complejidad) a todos los grupos interesados, especialmente los no-especialistas y (2) cómo transmitir y transferir, a futuras generaciones de cientificos, la experiencia y los aprendizajes prácticos que no figuran en directrices y manuales. Recomendaciones para mantener avances en estos campos incluyen: mejorar la accesibilidad de la información y datos científicos, adoptar nuevas técnicas para comunicar: el riesgo volcánico, la incertidumbre en información científica y para apoyar la toma de decisiones, e invertir en transferir experiencia práctica a las generaciones futuras.
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- 2022
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14. The initial phase of the 2021 Cumbre Vieja ridge eruption (Canary Islands): Products and dynamics controlling edifice growth and collapse
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Jorge E. Romero, Mike Burton, Francisco Cáceres, Jacopo Taddeucci, Riccardo Civico, Tullio Ricci, Matthew J. Pankhurst, Pedro A. Hernández, Costanza Bonadonna, Edward W. Llewellin, Marco Pistolesi, Margherita Polacci, Carmen Solana, Luca D'Auria, Fabio Arzilli, Daniele Andronico, Fátima Rodríguez, Maria Asensio-Ramos, Alba Martín-Lorenzo, Catherine Hayer, Piergiorgio Scarlato, and Nemesio M. Perez
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Geophysics ,Geochemistry and Petrology - Abstract
Tajogaite cone in the Cumbre Vieja ridge (La Palma, Canary Islands) erupted between 19 September and 13 December 2021. The tephra and lava sourced from the newly formed fissure rapidly built a pyroclastic cone. During the early days of eruption and after several small-scale landslides, the west flank of the edifice partially collapsed on 25 September, breaching the cone and emplacing a prominent raft-bearing lava flow. Our research combines direct observations, digital elevation models, thermal and visible imaging, and textural and compositional investigation of the explosive products to describe and characterize the edifice growth and collapse. The cone built over a steep slope (26°) and its failure occurred after an intense phase of lava fountaining (up to 30 m3 s−1) that produced rapid pyroclastic accumulation. We suggest that an increased magma supply, to an ascent rate of 0.30 m s−1, led to the rapid growth of the cone (at 2.4 × 106 m3 day−1). Simultaneously, the SW lava flow reactivated and formed a lava ‘seep’ that undercut the flank of the cone, triggering a lateral collapse via rotational rockslide that moved at minimum speeds of 34–70 m h−1. The lateral collapse formed a ~ 200 m wide scar, involving 5.5 × 106 m3 of material, and covered 1.17 km2 with decametric edifice portions and raft-bearing lava. The collapse produced a modest change in the vent geometry, but did not affect eruptive activity long term. A short pause in the eruption after the collapse may have been favored by rapid emptying of the shallower magma system, reducing ascent rates and increasing crystallization times. These results reveal the complex chain of events related to the growth and destruction of newly formed volcanic cones and highlight hazards when situated close to inhabited areas.
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- 2022
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15. Root Canal Disinfection Articles with the Highest Relative Citation Ratios. A Bibliometric Analysis from 1990 to 2019
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Carmen María Ferrer-Luque, Pilar Valderrama, Pilar Baca, and Carmen Solana
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Microbiology (medical) ,field-normalization ,Bibliometric analysis ,Root canal ,Citations ,RM1-950 ,Bibliometrics ,Relative citation ratio ,Citation impact ,Biochemistry ,Microbiology ,Article ,Endodontics ,time-normalization ,Citation rate ,Field-normalization ,Statistics ,medicine ,National Institutes of Health ,Pharmacology (medical) ,Article-level metrics ,General Pharmacology, Toxicology and Pharmaceutics ,Mathematics ,root canal disinfection ,citation impact ,citations ,endodontics ,Infectious Diseases ,medicine.anatomical_structure ,article-level ,Time-normalization ,relative citation ratio ,Therapeutics. Pharmacology ,bibliometrics ,Citation ,Root canal disinfection - Abstract
The relative citation rate (RCR) is a normalized article-level metric useful to assess the impact of research articles. The objective of this bibliometric study is to identify and analyze, in root canal disinfection, the 100 articles having the highest RCRs in the period 1990–2019, then compare them with the top 100 articles most cited. A cross-sectional study was performed, and the search strategy ((Disinfection AND root canal) AND ((“1990/01/01”[Date-Publication]: “2019/12/31”[DatePublication]))) relied on PubMed (n = 4294 documents), and article data were downloaded from the iCite database. The 100 articles with the highest RCRs and the top 100 cited were selected and evaluated in bibliometric terms. Among the 100 articles with the highest RCRs, there were no differences in the three decades for RCRs values, but there were in citations, being 2000–2009 the most cited. The USA was the predominant country (n = 30), followed by Brazil (n = 14). The most frequent study designs were reviews (n = 27) and in vitro (n = 25) and ex vivo (n = 24) studies. All subfields were well represented, although they varied over time. In 2010–2019, regenerative procedures and irrigation/disinfection techniques were predominant. Considering the RCR’s top 100 articles, 76 were common with the 100 most cited articles. Using the RCR metric allowed us to identify influential articles in root canal disinfection, a research field with topics of significance that fluctuate over time. Compared to citations, RCR reduces the time from publication to detection of its importance for the readership and could be a valid alternative to citation counts., Research Groups CTS-167 and HUM-777 of Junta de Andalucía, Spain
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- 2021
16. Antibiofilm Activity of Diclofenac and Antibiotic Solutions in Endodontic Therapy
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María Teresa Arias-Moliz, Carmen Solana, Pilar Baca, Matilde Ruiz-Linares, Alberto Rodriguez-Archilla, and Carmen María Ferrer-Luque
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0301 basic medicine ,medicine.medical_specialty ,Diclofenac ,medicine.drug_class ,medicine.medical_treatment ,Population ,Antibiotics ,Minocycline ,Gastroenterology ,Enterococcus faecalis ,03 medical and health sciences ,0302 clinical medicine ,Ciprofloxacin ,Internal medicine ,medicine ,education ,General Dentistry ,Saline ,education.field_of_study ,Microscopy, Confocal ,biology ,Chemistry ,030206 dentistry ,biology.organism_classification ,Antimicrobial ,Anti-Bacterial Agents ,Metronidazole ,030104 developmental biology ,Biofilms ,Dentin ,medicine.drug - Abstract
Introduction The aim of this study was to compare the antibiofilm effects of a triple antibiotic solution (TAS); a double antibiotic solution (DAS); and 5%, 2.5%, and 1.25% diclofenac solutions (DCSs) against Enteroccocus faecalis biofilm. Methods Eighty-four sterile radicular dentin blocks were used as biofilm substrate for 3 weeks. The study groups were as follows: (1) 1 mg/mL TAS (minocycline, metronidazole, and ciprofloxacin), (2) 1 mg/mL DAS (metronidazole and ciprofloxacin), (3) 5% DCS, (4) 2.5% DCS, (5) 1.25% DCS, and (6) 0.9% saline solution. The antimicrobial activity was evaluated by bacterial count determinations and confocal laser scanning microscopy. The contact time for the antimicrobial tests was 5 minutes. Bacterial counts were expressed as the reduction percentage of colony-forming units; for the confocal laser scanning microscopic evaluation, the log10 total biovolume and percentage of green population (live cells) were calculated. Results The colony-forming unit reduction percentage ranged between 62.98 and 98.62, respectively, for TAS and 5% DCS. The DCS showed a concentration-dependent effect.For the confocal laser scanning microscopy, the log10 total biovolume in all groups was very similar and showed a scarce (1.39–1.02) but significant reduction with respect to the control; 5% and 2.5% DCSs gave the lowest viable cell percentage. The TAS and DAS groups showed intermediate values without significant differences between them. Conclusions DCSs at 5% and 2.5% have greater antimicrobial effects than TAS and DAS and may be considered a valid alternative for controlling the infection of teeth with apical periodontitis.
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- 2020
17. Doxycycline NPs harm E. faecalis
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Pilar Baca, Carmen Solana, Antonio L. Medina-Castillo, Raquel Osorio, Manuel Toledano-Osorio, María Teresa Arias-Moliz, and Manuel Toledano
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Root canal ,0206 medical engineering ,02 engineering and technology ,Enterococcus faecalis ,Microbiology ,Endodontics ,03 medical and health sciences ,0302 clinical medicine ,Nanoparticle ,medicine ,Humans ,General Dentistry ,Doxycycline ,Microscopy, Confocal ,biology ,Root Canal Irrigants ,Chemistry ,Biofilm ,technology, industry, and agriculture ,Dentine ,030206 dentistry ,biology.organism_classification ,Antimicrobial ,020601 biomedical engineering ,Anti-Bacterial Agents ,medicine.anatomical_structure ,Dentinal Tubule ,Biofilms ,Dentin ,Surface modification ,Nanoparticles ,Antibacterial activity ,medicine.drug - Abstract
Reinfection and tooth fracture are the most common causes of failure after endodontical treatment. Aim:The purposes of this study were to evaluate the antimicrobial and inhibition of biofilmformation potential of novel remineralizing polymeric nanoparticles (NPs) when applied on the dentinesurface;and to ascertain the effectof the functionalization of these NPs with zinc, calcium or doxycycline.Methodology: The antimicrobial activity and the inhibition of biofilm formation have beenanalyzed on human dentineblocks that were infected with Enterococcus faecalisbefore orafter NPs application. LIVE/DEAD ®testing under the confocal laser scanning microscopy and bacterial culturing were employed to analyse the biofilm biovolume and the bacterial viability. Field Emission Scanning Electron Microscopy was also employed to assess thebiofilm morphology. One-way ANOVA with Welch’s correction and post-hoccomparison by the Games-Howell test were performed for comparisons between groups. Results:The un-functionalizedNPs displayed the highest antimicrobial activity against E. faecalisbiofilms as they provided the lowest biovolume (3,865.7 μm3) and the highest dead/injured cellspercentage (79.93%), followed by Dox-NPs (biovolume:19,041.55μm3, dead/injured cells: 45.53%). Doxycycline loaded NPs showed the highest values of inhibition of biofilm formation with the lowest biofilm biovolume (8,517.65 μm3) and a high dead/injured bacterial percentage (68.68%).Un-functionalizedNPs did not reduce biomass growth, but exerted the highest percentage of compromised cells (93%), being able to disrupt biofilm formation. It also produced occlusion of dentinal tubules, probably interfering with bacterial tubule penetration. Conclusions:Anew generation of bioactive nano-fillers (doxycycline-functionalizedpolymeric NPs) which may be included as primers in endodontic sealers, promoting antibacterial activity and dentinal tubules occlusionis proposed., This work was supported by the Spanish Ministry of Economy and Competitiveness and European Regional Development Fund [MAT2017-85999P MINECO/AEI/FEDER/UE] and by RegionalGovernmentofAndalusiaResearch Fund, Spain [#CTS-167].
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- 2020
18. Antibiofilm Activity of Sodium Hypochlorite and Alkaline Tetrasodium EDTA Solutions
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María Teresa Arias-Moliz, Carmen María Ferrer-Luque, Mariano J. Valderrama, Matilde Ruiz-Linares, Carmen Solana, and Pilar Baca
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Sodium Hypochlorite ,medicine.medical_treatment ,0206 medical engineering ,Cetrimide ,02 engineering and technology ,Bacterial growth ,Enterococcus faecalis ,Microbiology ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,medicine ,General Dentistry ,Saline ,Edetic Acid ,Root Canal Irrigants ,biology ,Cetrimonium ,030206 dentistry ,biology.organism_classification ,Antimicrobial ,020601 biomedical engineering ,Radicular dentin ,chemistry ,Biofilms ,Sodium hypochlorite ,Anti-Infective Agents, Local ,Cetrimonium Compounds ,IRRIGATING SOLUTIONS ,Disinfectants ,Nuclear chemistry - Abstract
Introduction The aim of this study was to determine the antimicrobial activity of mixed alkaline tetrasodium EDTA (EDTANa4)/sodium hypochlorite (NaOCl) solutions with and without the addition of cetrimide (CTR) against Enterococcus faecalis biofilms. Methods The antimicrobial solutions were evaluated on a 3-week biofilm of E. faecalis grown on radicular dentin blocks. The irrigating solutions were 2.5% NaOCl group, 20% EDTANa4 group, 10% EDTANa4 group, 2.5% NaOCl/10% EDTANa4 group, 2.5% NaOCl/5% EDTANa4 group, 2.5% NaOCl/10% EDTANa4/0.2% CTR group, 2.5% NaOCl/5% EDTANa4/0.2% CTR group, and 0.9% saline solution group. Cell viability was determined by adenosine triphosphate assay, and culture techniques were used to determine colony-forming unit (CFU) counts. In groups with positive growth, the Pearson linear correlation coefficient r (−1 ≤ r ≤ 1) between relative light units (RLUs) and log10 (CFUs + 1) was calculated. The results of the bioluminescence adenosine triphosphate assay and CFUs of the groups were analyzed by means of analysis of variance and the Duncan test. Results There was Pearson correlation between RLUs and log10 (CFUs + 1). A similar reduction of RLUs in all NaOCl groups was seen, giving statistical differences with respect to the control. In the NaOCl groups there was no bacterial growth. The lowest antimicrobial efficacy was found for the EDTANa4 groups. Conclusions Mixed alkaline EDTANa4/NaOCl solutions with and without the addition of CTR do not interfere with the antimicrobial activity of NaOCl.
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- 2017
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19. Cytotoxic effects of alkaline tetrasodium EDTA irrigating solutions
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Xu Wang, Carmen María Ferrer-Luque, Teresa Cabrera, Matilde Ruiz-Linares, Carmen Solana, and Pilar Baca
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Alkaline EDTANa4 ,Root Canal Irrigants ,Cetrimonium ,Sodium Hypochlorite ,Cytotoxicity ,Cetrimide ,Ethylenediaminetetraacetic acid ,Methyl thiazol tetrazolium ,chemistry.chemical_compound ,chemistry ,Irrigating solutions ,Sodium hypochlorite ,Anti-Infective Agents, Local ,IRRIGATING SOLUTIONS ,Cytotoxic T cell ,Humans ,Chelation ,Viability assay ,NaOCl ,General Dentistry ,Edetic Acid ,Nuclear chemistry - Abstract
The aim of this study is to determine the cytotoxic effects of tetrasodium ethylenediaminetetraacetic acid (EDTANa4) when used alone or when combined with sodium hypochlorite (NaOCl), with and without the addition of cetrimide (CTR). Human pulmonary fibroblast cell line was exposed to the following irrigating solutions: group 1, 2.5% NaOCl; group 2, 10% EDTANa4; group 3, 20% EDTANa4; group 4, 2.5% NaOCl/5% EDTANa4; group 5, 2.5% NaOCl/10% EDTANa4; group 6, 2.5% NaOCl/5% EDTANa4/0.2% CTR; group 7, 2.5% NaOCl/10% EDTANa4/0.2% CTR; group 8, control, cells in Dulbecco’s modified Eagle’s medium. Methyl thiazol tetrazolium assay was used to determine the viability of cells after 1 and 24 h. Viability percentages were analyzed for global comparison using the Welch test followed by the Games-Howell test to determine groups with similar viability, and the Student’s t test was used to compare the two times. The lowest viability was obtained with a 2.5% NaOCl solution at both time periods. The association of NaOCl with EDTANa4 increased the cellular viability in direct relation with the concentration of the chelating agent. Globally, after 24 h of exposure, cell viability reduced. The solutions of EDTANa4 showed moderate cytotoxic effects when compared with NaOCl alone., Junta de Andalucía CTS-167
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- 2020
20. India en el camino de los dioses
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María del Carmen Solana Valdés and María del Carmen Solana Valdés
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India es una tierra donde conviven diferentes religiones y es común a sus habitantes la sabiduría de la tolerancia, afirmó Mahatma Gandhi. El presente estudio ofrece al lector un recorrido histórico por las más diversas vías del quehacer espiritual y religioso de India e intenta sistematizar, en lo posible, un caudal inmenso de información, a la vez que presenta la excelente oportunidad –para los estudiosos ávidos de temas culturales, filosóficos y eminentemente humanos- de aquilatar las necesarias notas aclaratorias y bibliográficas como apoyo insustituible de esta obra. Pero hay otra fuente que nutre a la autora de este libro: el sabor de la experiencia, haber tenido la posibilidad de la vivencia directa, la oportunidad de “ver” y “sentir”, de ser protagonista de una historia. Vivir en familia, asistir a clases, participar en toda suerte de ritos y ceremonias, visitar los templos permitidos, sentarse a orillas del Ganga (Ganges) o recorrer el Taj Mahal, ofrecen la mejor de las visiones, un testimonio irremplazable.
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- 2020
21. Quantifying the impact of educational methods for disaster risk reduction: A longitudinal study assessing the impact of teaching methods on student hazard perceptions
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Carmen Solana, Simon Day, Richard Teeuw, and Martin Parham
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Longitudinal study ,Disaster risk reduction ,Teaching method ,media_common.quotation_subject ,Applied psychology ,Geology ,Citizen journalism ,Building and Construction ,Geotechnical Engineering and Engineering Geology ,Hazard ,Risk perception ,Survey methodology ,Perception ,Psychology ,Safety Research ,media_common - Abstract
Disaster Risk Reduction (DRR) education programmes are essential for raising awareness of the factors driving the risk of disaster. Criticism of past DRR education studies emphasises two key issues; short-termism and an inability to assess impact of outcomes. We use the Pictorial Representation of Individual Self Measure (PRISM) survey method to quantify changing student perception of multi-disaster risk in response to different educational methods. From two secondary schools in Roseau, Dominica, we have carried out a longitudinal study, comparing the perceptions of the same student cohort during a 3-year period. Results show a relatively constant perception of disaster risk over time, influenced by experience of low frequency, high impact events, causing either intensification or decay of disaster risk perception. Understanding links between disaster risks is poorly understood. Participatory field-based decision-making exercises had the greatest impact on student awareness of disaster risk, particularly toward low-frequency geophysical risks. Context-relevant practical exercises, bespoke-designed for local use, are necessary for high-impact CCDRR educational approaches.
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- 2021
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22. Human responses to the 1906 eruption of Vesuvius, southern Italy
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Heather Sangster, Christopher R. J. Kilburn, David K. Chester, Angus M. Duncan, and Carmen Solana
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geography ,geography.geographical_feature_category ,Lava ,Diaspora ,Appeasement ,Politics ,Geophysics ,Economy ,Volcano ,Geochemistry and Petrology ,Earth Sciences ,Population growth ,Line of communication ,Tephra ,Seismology ,Geology - Abstract
Cultural and political contexts are important in determining the ways in which communities respond to volcanic eruptions. Understanding the manner in which communities and the State apparatus have coped with historic eruptions can provide insights into how responses have influenced vulnerability and resilience. The 1906 eruption of Vesuvius is well suited for such a study as it was one of the first major eruptions in which there was a significant element of State control, and this worked alongside more traditional pre-industrial responses. This eruption was extensively reported in the regional, national and international press and in archives which include still photography. One feature is the rich archive of material published in English language newspapers of record which are analysed fully in the paper for the first time. Many of these data sources are now accessible on-line. The eruption started on April 4th with mild explosive activity and the eruption of lava from 5th to 7th April. On the night of the 7th/8th, activity intensified when a vigorous lava fountain inclined obliquely to the north east, deposited a thick layer of tephra on the towns of Ottaviano and San Giuseppe. This led to roof collapse and a large number of fatalities. There was increased lava emission and a flow progressed south through the outskirts of Boscotrecase cutting the Circumvesuviana railway line and almost reaching Torre Annunziata. Following April 8th the eruption declined and ended on April 21st. In the initial responses to the eruption pre-industrial features were prominent, with the local communities showing social cohesion, self-reliance and little panic. A more negative aspect was the traditional religious response that involved the use of liturgies of divine appeasement and which included the use of saintly relics and images. There is interesting evidence, however, that this coping strategy was driven by the populace rather than by the clergy. The inhabitants of San Giuseppe, for instance, insisted in taking refuge in a church and this led to over 100 fatalities when the roof collapsed. Intervention by the State included: the effective deployment of troops to handle evacuation, to re-open lines of communication and to distribute food and other relief. Management of the disaster was enhanced when prefectural commissioners were given executive powers. We argue that increased State intervention appears to have reduced self-reliance. In the short-term recovery was supported by regional/state aid and by charitable donations particularly from other governments and members of Neapolitan diaspora in other parts of Italy and abroad. This enabled land clearance, agriculture was re-established and roads/rail links were restored. Long-term recovery was slow with affected local-authorities (i.e., comuni) showing low rates of population growth for more than 15 years.
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- 2015
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23. Dating lava flows of tropical volcanoes by means of spatial modeling of vegetation recovery
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Lien Bakelants, Carmen Solana, Long Li, Frank Canters, Matthieu Kervyn, Geography, Faculty of Sciences and Bioengineering Sciences, Cartography and Geographical Information Science, Earth System Sciences, and Physical Geography
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010504 meteorology & atmospheric sciences ,Lava ,NDVI ,Economics ,Geography, Planning and Development ,Mt Cameroon ,010502 geochemistry & geophysics ,01 natural sciences ,Normalized Difference Vegetation Index ,Vegetation cover ,remote sensing ,Earth and Planetary Sciences (miscellaneous) ,dating lava flows ,Spatial analysis ,Geomorphology ,0105 earth and related environmental sciences ,Earth-Surface Processes ,geography ,geography.geographical_feature_category ,Physics ,Nyamuragira ,Statistical model ,Regression analysis ,Karthala ,Volcano ,Earth Sciences ,Geology - Abstract
The age of past lava flows is crucial information for evaluating the hazards and risks posed by effusive volcanoes, but traditional dating methods are expensive and time-consuming. This study proposes an alternative statistical dating method based on remote sensing observations of tropical volcanoes by exploiting the relationship between lava flow age and vegetation cover. First, the factors controlling vegetation density on lava flows, represented by the normalized difference vegetation index (NDVI), were investigated. These factors were then integrated into pixel-based multi-variable regression models of lava flow age to derive lava flow age maps. The method was tested at a pixel scale on three tropical African volcanoes with considerable recent effusive activity: Nyamuragira (Democratic Republic of Congo), Mt Cameroon (Cameroon) and Karthala (the Comoros). Due to different climatic and topographic conditions, the parameters of the spatial modeling are volcano-specific. Validation suggests that the obtained statistical models are robust and can thus be applied for estimating the age of unmodified undated lava flow surfaces for these volcanoes. When the models are applied to fully vegetated lava flows, the results should be interpreted with caution due to the saturation of NDVI. In order to improve the accuracy of the models, when available, spatial data on temperature and precipitation should be included to directly represent climatic variation. Copyright (c) 2017 John Wiley & Sons, Ltd.
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- 2018
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24. Testing random forest classification for identifying lava flows and mapping age groups on a single Landsat 8 image
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Frank Canters, Long Li, Carmen Solana, Matthieu Kervyn, Geography, Faculty of Sciences and Bioengineering Sciences, Cartography and Geographical Information Science, and Earth System Sciences
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010504 meteorology & atmospheric sciences ,Lava ,Lava flows ,010502 geochemistry & geophysics ,01 natural sciences ,Geochemistry and Petrology ,Radar imaging ,Object-based classification ,lava flows ,object-based classification ,Image resolution ,0105 earth and related environmental sciences ,Remote sensing ,pixel-based classification ,geography ,Random Forest ,geography.geographical_feature_category ,Pixel ,Contextual image classification ,Nyamuragira ,Volcanology ,Random forest ,Geophysics ,Volcano ,Earth Sciences ,Geology ,random forest - Abstract
Mapping lava flows using satellite images is an important application of remote sensing in volcanology. Several volcanoes have been mapped through remote sensing using a wide range of data, from optical to thermal infrared and radar images, using techniques such as manual mapping, supervised/unsupervised classification, and elevation subtraction. So far, spectral-based mapping applications mainly focus on the use of traditional pixel-based classifiers, without much investigation into the added value of object-based approaches and into advantages of using machine learning algorithms. In this study, Nyamuragira, characterized by a series of > 20 overlapping lava flows erupted over the last century, was used as a case study. The random forest classifier was tested to map lava flows based on pixels and objects. Image classification was conducted for the 20 individual flows and for 8 groups of flows of similar age using a Landsat 8 image and a DEM of the volcano, both at 30-meter spatial resolution. Results show that object-based classification produces maps with continuous and homogeneous lava surfaces, in agreement with the physical characteristics of lava flows, while lava flows mapped through the pixel-based classification are heterogeneous and fragmented including much “salt and pepper noise”. In terms of accuracy, both pixel-based and object-based classification performs well but the former results in higher accuracies than the latter except for mapping lava flow age groups without using topographic features. It is concluded that despite spectral similarity, lava flows of contrasting age can be well discriminated and mapped by means of image classification. The classification approach demonstrated in this study only requires easily accessible image data and can be applied to other volcanoes as well if there is sufficient information to calibrate the mapping.
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- 2017
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25. Translations of volcanological terms: cross-cultural standards for teaching, communication, and reporting
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Sonia Calvari, Estuning Tyas Wulan Mei, Alexander Belousov, Benjamin van Wyk de Vries, Andrew J. L. Harris, Þorvaldur Þórðarson, Kenneth T. Koga, Hugo Delgado-Granados, Jean-Claude Thouret, José Pacheco, Matthias Hort, Jean-Marie Prival, Carmen Solana, Agung Harijoko, University of Illinois at Chicago ( UIC ), Earth Observatory of Singapore, Nanyang Technological University [Singapour], Instituto Nazionale di Geofisica e Vulcanologia, Institut für Geophysik, Universität Hamburg ( UHH ), Laboratoire Magmas et Volcans ( LMV ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Institut de Recherche pour le Développement et la société-Université Clermont Auvergne ( UCA ) -Centre National de la Recherche Scientifique ( CNRS ), University of Illinois [Chicago] (UIC), University of Illinois System, Earth Observatory of Singapore (EOS), Istituto Nazionale di Geofisica e Vulcanologia, Institut für Geophysik [Hamburg], Universität Hamburg (UHH), Laboratoire Magmas et Volcans (LMV), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement et la société-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Université Jean Monnet [Saint-Étienne] (UJM), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)
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Translation ,010504 meteorology & atmospheric sciences ,First language ,[SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography ,Volcanology ,[ SDU.STU.VO ] Sciences of the Universe [physics]/Earth Sciences/Volcanology ,010502 geochemistry & geophysics ,01 natural sciences ,Terminology ,German ,Geochemistry and Petrology ,[SDU.STU.VO]Sciences of the Universe [physics]/Earth Sciences/Volcanology ,Language industry ,0105 earth and related environmental sciences ,[ SDU.STU.PE ] Sciences of the Universe [physics]/Earth Sciences/Petrography ,Communication ,Teaching ,language.human_language ,Linguistics ,Language transfer ,Earth Sciences ,language ,Language education ,Icelandic ,Geology ,Meaning (linguistics) - Abstract
International audience; When teaching at a non-English language university, we often argue that because English is the international language, students need to become familiar with English terms, even if the bulk of the class is in the native language. However, to make the meaning of the terms clear, a translation into the native language is always useful. Correct translation of terminology is even more crucial for emergency managers and decision makers who can be confronted with a confusing and inconsistently applied mix of terminology. Thus, it is imperative to have a translation that appropriately converts the meaning of a term, while being grammatically and lexicologically correct, before the need for use. If terms are not consistently defined across all languages following industry standards and norms, what one person believes to be a dog, to another is a cat. However, definitions and translations of English scientific and technical terms are not always available, and language is constantly evolving. We live and work in an international world where English is the common language of multi-cultural exchange. As a result, while finding the correct translation can be difficult because we are too used to the English language terms, translated equivalents that are available may not have been through the peer review process. We have explored this issue by discussing grammatically and lexicologically correct French, German, Icelandic, Indonesian, Italian, Portuguese, Russian, Spanish, and Japanese versions for terms involved in communicating effusive eruption intensity.
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- 2017
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26. Use of PRISM to evaluate changes in secondary school children's perception of multiple hazards in Dominica
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Parham, Martin Ian, Day, Simon, Richard. M. Teeuw, and M. Carmen Solana
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- 2016
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27. Discriminating lava flows of different age within Nyamuragira’s volcanic field using spectral mixture analysis
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Long Li, Weiwei Ma, Frank Canters, Matthieu Kervyn, Carmen Solana, Longqian Chen, Geography, Physical Geography, Cartography and Geographical Information Science, and Earth System Sciences
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Global and Planetary Change ,geography ,geography.geographical_feature_category ,Lava ,Pleiades ,Vegetation fraction ,Nyamuragira ,Weathering ,Vegetation ,vegetation fraction ,Management, Monitoring, Policy and Law ,spectral mixture analysis ,Field (geography) ,ALI ,Volcano ,Thematic Mapper ,Earth Sciences ,lava flow ,Computers in Earth Sciences ,Geomorphology ,Geology ,Earth-Surface Processes - Abstract
In this study, linear spectral mixture analysis (LSMA) is used to characterize the spectral heterogeneity of lava flows from Nyamuragira volcano, Democratic Republic of Congo, where vegetation and lava are the two main land covers. In order to estimate fractions of vegetation and lava through satellite remote sensing, we made use of 30 m resolution Landsat Enhanced Thematic Mapper Plus (ETM+) and Advanced Land Imager (ALI) imagery. 2 m Pleiades data was used for validation. From the results, we conclude that (1) LSMA is capable of characterizing volcanic fields and discriminating between different types of lava surfaces; (2) three lava endmembers can be identified as lava of old, intermediate and young age, corresponding to different stages in lichen growth and chemical weathering; (3) a strong relationship is observed between vegetation fraction and lava age, where vegetation at Nyamuragira starts to significantly colonize lava flows ∼15 years after eruption and occupies over 50% of the lava surfaces ∼40 years after eruption. Our study demonstrates the capability of spectral unmixing to characterize lava surfaces and vegetation colonization over time, which is particularly useful for poorly known volcanoes or those not accessible for physical or political reasons.
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- 2015
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