Guidelines on Conducting and Reporting on CALL Research

These slides are based on workshops presented at CALICO Conferences by (current and previous) editors of LLT

Eruption frequency patterns through time for the current (1999–2018) activity cycle at Volcán de Fuego derived from remote sensing data:Evidence for an accelerating cycle of explosive paroxysms and potential implications of eruptive activity

Volcán de Fuego is a stratovolcano in Guatemala that has produced over 50 VEI ≥ 2 eruptions since 1524. After two decades of quiescence, in 1999 Fuego entered a new period of eruptive activity that continues until the present day, characterized by persistent Strombolian activity interspersed with occasional “paroxysmal” eruptions of greater magnitude, the most recent of which occurred in 2018. The land surrounding Fuego accommodates tens of thousands of people, so greater understanding of its eruptive behaviour has important implications for hazard assessment. Nevertheless, there is relatively little literature that studies recent (since 1999) activity of Fuego in detail. Using time-series analysis of remote sensing thermal data during the period 2000–2018 combined with recent bulletin reports, we present evidence for a new eruptive regime beginning in 2015. We find that this regime is defined by a greater frequency of paroxysmal eruptions than in previous years and is characterized by the following sequence of events: (i) effusion of lava flows and increase in summit explosive activity, followed by (ii) an intense eruptive phase lasting 24–48 h, producing a sustained eruptive column, continuous explosions, and occasional pyroclastic flows, followed by (iii) decrease in explosive activity. We discuss various models that explain this increase in paroxysmal frequency, and consider its implications for hazard assessment at Fuego. We advocate the pairing of remote sensing data with monitoring reports for understanding long-term changes in behaviour of poorly-instrumented volcanoes. The results that we present here provide a standard for informed assessment of future episodes of unrest and paroxysmal eruptions of Fuego

The Influence of the Electron Density in Acyl Protecting Groups on the Selectivity of Galactose Formation

The stereoselective formation of 1,2-cis-glycosidic bonds is a major bottleneck in the synthesis of carbohydrates. We here investigate how the electron density in acyl protecting groups influences the stereoselectivity by fine-tuning the efficiency of remote participation. Electron-rich C4-pivaloylated galactose building blocks show an unprecedented α-selectivity. The trifluoroacetylated counterpart with electron-withdrawing groups, on the other hand, exhibits a lower selectivity. Cryogenic infrared spectroscopy in helium nanodroplets and density functional theory calculations revealed the existence of dioxolenium-type intermediates for this reaction, which suggests that remote participation of the pivaloyl protecting group is the origin of the high α-selectivity of the pivaloylated building blocks. According to these findings, an α-selective galactose building block for glycosynthesis is developed based on rational considerations and is subsequently employed in automated glycan assembly exhibiting complete stereoselectivity. Based on the obtained selectivities in the glycosylation reactions and the results from infrared spectroscopy and density functional theory, we suggest a mechanism by which these reactions could proceed

Resolvin E1 Reverses Experimental Periodontitis and Dysbiosis

Periodontitis is a biofilm-induced inflammatory disease characterized by dysbiosis of the commensal periodontal microbiota. It is unclear how natural regulation of inflammation affects the periodontal biofilm. Promoters of active resolution of inflammation including Resolvin E1 (RvE1) effectively treat inflammatory periodontitis in animal models. The goals of this study were 1) to compare periodontal tissue gene expression in different clinical conditions, 2) to determine the impact of local inflammation on the composition of subgingival bacteria, and 3) to understand how inflammation impacts these changes. Two clinically-relevant experiments were performed in rats: prevention and treatment of ligature-induced periodontitis with RvE1 topical treatment. The gingival transcriptome was evaluated by RNA-seq sequencing of mRNA. The composition of the subgingival microbiota was characterized by 16S rDNA sequencing. Periodontitis was assessed by bone morphometric measurements and histomorphometry of block sections. H&E and, tartrate resistant acid phosphatase staining were used to characterize and quantify inflammatory changes. RvE1 treatment prevented bone loss in ligature induced periodontitis. Osteoclast density and inflammatory cell infiltration in the RvE1 groups were lower than those in the placebo group. RvE1 treatment reduced expression of inflammation-related genes returning the expression profile to one more similar to health. Treatment of established periodontitis with RvE1 reversed bone loss, reversed inflammatory gene expression and reduced osteoclast density. Assessment of the rat subgingival microbiota after RvE1 treatment revealed marked changes in both prevention and treatment experiments. The data suggest that modulation of local inflammation has a major role in shaping the composition of the subgingival microbiota

Cultivation-independent screening revealed hot spots of IncP-1, IncP-7 and IncP-9 plasmid occurrence in different environmental habitats

IncP-1, IncP-7 and IncP-9 plasmids often carry genes encoding enzymes involved in the degradation of man-made and natural contaminants, thus contributing to bacterial survival in polluted environments. However, the lack of suitable molecular tools often limits the detection of these plasmids in the environment. In this study, PCR followed by Southern blot hybridization detected the presence of plasmid-specific sequences in total community (TC-) DNA or fosmid DNA from samples originating from different environments and geographic regions. A novel primer system targeting IncP-9 plasmids was developed and applied along with established primers for IncP-1 and IncP-7. Screening TC-DNA from biopurification systems (BPS) which are used on farms for the purification of pesticide-contaminated water revealed high abundances of IncP-1 plasmids belonging to different subgroups as well as IncP-7 and IncP-9. The novel IncP-9 primer-system targeting the rep gene of nine IncP-9 subgroups allowed the detection of a high diversity of IncP-9 plasmid specific sequences in environments with different sources of pollution. Thus polluted sites are "hot spots" of plasmids potentially carrying catabolic genes.Facultad de Ciencias ExactasInstituto de Biotecnologia y Biologia Molecula

Cultivation-independent screening revealed hot spots of IncP-1, IncP-7 and IncP-9 plasmid occurrence in different environmental habitats

IncP-1, IncP-7 and IncP-9 plasmids often carry genes encoding enzymes involved in the degradation of man-made and natural contaminants, thus contributing to bacterial survival in polluted environments. However, the lack of suitable molecular tools often limits the detection of these plasmids in the environment. In this study, PCR followed by Southern blot hybridization detected the presence of plasmid-specific sequences in total community (TC-) DNA or fosmid DNA from samples originating from different environments and geographic regions. A novel primer system targeting IncP-9 plasmids was developed and applied along with established primers for IncP-1 and IncP-7. Screening TC-DNA from biopurification systems (BPS) which are used on farms for the purification of pesticide-contaminated water revealed high abundances of IncP-1 plasmids belonging to different subgroups as well as IncP-7 and IncP-9. The novel IncP-9 primer-system targeting the rep gene of nine IncP-9 subgroups allowed the detection of a high diversity of IncP-9 plasmid specific sequences in environments with different sources of pollution. Thus polluted sites are "hot spots" of plasmids potentially carrying catabolic genes.Facultad de Ciencias ExactasInstituto de Biotecnologia y Biologia Molecula

LA ALVO: Un camino de cooperación

La Asociación Latinoamericana de Volcanología (ALVO) fue fundada el día 7 de noviembre del año 2010 en Manizales, Departamento de Caldas, Colombia (Granados et al., 2015a, b; Rodríguez et al., 2019). Con un grupo reducido de miembros fundadores, la ALVO quedó establecida e inició operaciones con un primer Consejo Directivo que sentó las bases para un camino de colaboración, reflexión y oportunidades en la región latinoamericana. Hoy en día la asociación cuenta con más de 1500 miembros, repartidos en toda la región Latinoamericana. En números aproximados, se registran 540 miembros para la región de Sudamérica Sur (Argentina, Brasil, Bolivia, Chile, Paraguay y Uruguay), 460 para la región de Sudamérica Norte (Colombia, Ecuador, Guyana, Perú, Surinam y Venezuela), 310 para la región de Centroamérica y el Caribe (Guatemala, Honduras, El Salvador, Nicaragua, Costa Rica, Puerto Rico, Cuba, República Dominicana y demás Antillas), y 260 para la región Norteamérica (México). De los cuales, cerca de un 50% está representado por miembros estudiantes, un 45% por miembros ordinarios y un porcentaje menor por miembros extraordinarios, fundadores y honorarios. No obstante, es importante destacar que se reciben solicitudes de membresía de forma regular, por lo que las características del padrón descritas arriba varían regularmente. Por su parte, la gestión y organización interna de la ALVO se rige por miembros activos que forman parte de un Consejo Directivo conformado por: presidente, vicepresidente, un representante regional por cada una de las regiones, representante estudiantil, secretario general, presidente exoficio y tesorero. Los puestos de representantes regionales, estudiantil y vicepresidente son cargos de elección. El vicepresidente inmediato anterior asume el cargo de presidente en la gestión subsecuente. Los cargos de tesorero y secretario general son asignados por el presidente

Thermal Remote Sensing for Global Volcano Monitoring: Experiences From the MIROVA System

Volcanic activity is always accompanied by the transfer of heat from the Earth’s crust to the atmosphere. This heat can be measured from space and its measurement is a very useful tool for detecting volcanic activity on a global scale. MIROVA (Middle Infrared Observation of Volcanic Activity) is an automatic volcano hot spot detection system, based on the analysis of MODIS data (Moderate Resolution Imaging Spectroradiometer). The system is able to detect, locate and quantify thermal anomalies in near real-time, by providing, on a dedicated website (www.mirovaweb.it), infrared images and thermal flux time-series on over 200 volcanoes worldwide. Thanks to its simple interface and intuitive representation of the data, MIROVA is currently used by several volcano observatories for daily monitoring activities and reporting. In this paper, we present the architecture of the system and we provide a state of the art on satellite thermal data usage for operational volcano monitoring and research. In particular, we describe the contribution that the thermal data have provided in order to detect volcanic unrest, to forecast eruptions and to depict trends and patterns during eruptive crisis. The current limits and requirements to improve the quality of the data, their distribution and interpretation are also discussed, in the light of the experience gained in recent years within the volcanological community. The results presented clearly demonstrate how the open access of satellite thermal data and the sharing of derived products allow a better understanding of ongoing volcanic phenomena, and therefore constitute an essential requirement for the assessment of volcanic hazards