Facultad de Ciencias de la Tierra y el Mar

URI permanente para esta comunidadhttp://10.0.96.45:4000/handle/11056/14052

La Facultad de Ciencias de la Tierra y Mar (FCTM) de la Universidad Nacional (UNA), se crea en el año 1973 y desde sus inicios se ha caracterizado por su compromiso con los principios y valores que sustentan la Universidad Necesaria; la cual en lo fundamental se caracteriza por la búsqueda de nuevos espacios que le permitan seguir aportando a la sociedad profesionales y productos de la investigación, extensión y servicios que contribuyan a la mejora en la calidad de vida de la población costarricense y sus relaciones con la naturaleza.

Decana: Grace Wong Reyes, Ph.D, correo electrónico: grace.wong.reyes@una.cr

Contacto:

Página web: www.tierraymar.una.ac.cr

Correo: fctm@una.cr

Teléfono: (506) 2277-3226 / (506) 2277-3280

Biblioteca Especializada Facultad de Ciencias de la Tierra y el Mar:

Página web: www.bctm.una.ac.cr

Correo: bctm@una.cr

Teléfono: 2562-6490 / 2562-6491

Facebook: @BibliotecaTierrayMar

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Mostrando 1 - 20 de 1345

20 años de monitoreo de cinco especies indicadoras de la salud del Bosque en el Parque Nacional Corcovado, Costa Rica
(2013-08-22) Eduardo Carrillo; Joel Sáenz
Costa Rica es uno de los países más avanzados en América Latina en cuanto a la protección de áreas silvestres y sus recursos naturales. Sin embargo, los datos acerca de si la mayoría de las áreas boscosas costarricenses cumplen con los requisitos mínimos para mantener especies silvestres que requieren áreas extensas para sobrevivir son escasos. Los grandes felinos, como el jaguar y el puma (Puma concolor), sus presas, entre ellas, el chanco de monte (Tayassu pecari), la danta (Tapirus bairdii) y el cabro de monte (Mazama americana) están muy relacionados a los bosques primarios y han desaparecido en la mayor parte del país debido, principalmente, a la destrucción de hábitat y a la presión de cacería. Estas especies pueden ser utilizadas como especies indicadoras para estimar la salud del ecosistema y ayudar a definir rutas de comunicación y límites de corredores biológicos, por ejemplo. Este informe presenta los resultados de los últimos 20 años de monitoreo de cinco especies de mamíferos grandes y medianos en el Parque Nacional Corcovado, PNC. Las especies incluidas en este informe son: el jaguar, el puma, el chancho de monte, el saíno y la danta.
3. Informe Técnico ISA 04 Colaboración Programa ISA Y Asistentes Técnicos de Atención Primaria en Salud del Área de Salud de Talamanca: Aprendizaje y estrategias de difusión sobre el uso de plaguicidas y la salud humana
(Universidad Nacional, Costa Rica, 2014-01) Quesada, Rosario; Romero Boniche, Jenny Raquel; van Wendel de Joode, Berna
In the context of the Infants and Environmental Health Program (ISA - www.isa.una.ac.cr) we started working together with the Primary Care Technical Assistants in Health (ATAPS) in the upper Talamanca area, with the support of the Costa Rican Social Security (CCSS). The collaboration of the ATAPS has allowed us to understand even more the knowledge and population's use of pesticides. The support of the Talamanca Health Area (CCSS) made it possible to implement working meetings with ATAPS in the development of a tool for obtain information on the use, knowledge and experience of the population about pesticides. This instrument was built, validated and piloted by the ATAPS during home visits. Also the development of workshops with the ATAPS, allowed the sharing of information on the types of pesticides, their effects health and research findings that the ISA team develops since 2006 in the area. Through the participation of ATAPS and other social actors in the area (such as the Municipality, women's associations, Biological Corridor, governments among others), it was possible to form a Commission1 (see Annex 01) for attend to the problem of the sky bags that constitute a source of contamination in the communities of the indigenous territory. The ISA Program is very interested in maintaining collaboration with the CCSS and to continue working with ATAPS. The purpose of this document is to report on the main activities carried out with the ATAPS.
5to congreso geológico, Universidad de Costa Rica 2021
(Universidad de Costa Rica, 2021) Mora, Mauricio M.; Soto, Gerardo J.
El Congreso Geológico de la Universidad de Costa Rica, que se celebra desde 2017, se ha consolidado como un espacio académico vital para compartir investigaciones en geociencias. Reúne a estudiantes y docentes para presentar avances científicos y proyectarlos a la sociedad, tanto a nivel nacional como internacional. La pandemia impulsó su adaptación al formato virtual, lo que amplió su alcance y participación. Este congreso no solo fomenta la investigación, sino que también fortalece habilidades de comunicación científica en el estudiantado. A pesar de retos como la pandemia, la crisis económica y el cambio climático, la UCR reafirma su compromiso con la docencia, la investigación y la acción social. El evento demuestra la importancia de las universidades como generadoras de conocimiento útil y como formadoras de buenos ciudadanos, en línea con principios de autonomía, libertad y servicio al país.
9th Latin American Pesticide Residue Workshop (LAPRW 2023) Food and Enviroment, May 18-20, 2021
(Thermo Fisher Scientific, 2021) Universidad Nacional del Litoral (Panamá)
Thermo Fisher Scientific patrocina el 9º Latin American Pesticide Residue Workshop (LAPRW), que se realizará del 21 al 24 de mayo de 2023 en el Sheraton Grand Hotel Panamá. Visítenos en el stand #P2 y descubra nuestras soluciones para el análisis de pesticidas, enfocadas en aumentar la productividad y la confiabilidad de los resultados. El evento abordará temas como métodos analíticos, control de calidad, regulación y análisis de riesgos.
A biogeochemical comparison of three representative lakes of Costa Rica
(INLAND WATERS (Taylor and Francis), 2025-06-09) Esquivel-Hernández, Germain; Sánchez-Gutiérrez, Rolando; Arias, M.; Ugalde-Salazar, Rocío; Echeverría- Sáenz, Silvia
Lakes are widely distributed across Costa Rica, from coasts to the highest elevation regions and located in the main terrestrial biomes, yet updated biogeochemical information about the main types of lakes is still lacking. We present comparative biogeochemistry (water chemistry, stable isotopes, and picoplankton) for a coastal lake (Lake Madre de Dios), a volcanic lake (Lake Barva), and a glacial lake (Lake Ditkevi). Sampling was conducted between February and November 2022, including dry and rainy seasonal conditions. Hydrological and chemical conditions were evaluated using water and carbon stable isotopes, dissolved organic matter, major ions, and microbiota analysis. Isotopic data on water (δ2H and δ18O) and dissolved inorganic carbon (δ13CDIC) confirmed lower evaporative losses for the maar and tarn lakes and productivity response to precipitation inputs. Excitation/emission matrices confirmed the prevalence of fulvic and humic acids in the coastal and glacial lakes, mainly aromatic proteins and soluble microbial byproducts in the volcanic lake. Picophytoplankton (PPP, ∼0.2–10 μm) was mainly represented by phycocyanin-rich picocyanobacteria in the 3 lakes, but maar and tarn lakes had greater representation of phycoerythrin-rich picocyanobacteria. We confirmed fluctuations in PPP cell abundance in the lakes was lower than in comparable temperate lakes. For other eutrophic lakes, abundance of picocyanobacteria dominated over picoeukaryotic algae. This work aimed to promote an ecosystem approach to study the biogeochemical functioning of tropical lakes using a combination of chemical, hydrological, and biological data and to provide baseline information for future studies (e.g., climate change and pollution impacts) on tropical lakes of Costa Rica.
A botanical extract of Souroubea sympetala and its active principle, betulinic acid, attenuate the cortisol response to a stressor in rainbow trout, Oncorhynchus mykiss
(Elsevier, 2016-09-28) Mullally, Martha; Mimeault, Caroline; Otárola Rojas, Marco Antonio; Sanchez Vindas, Pablo; Garcia, Mario; Poveda Alvarez, Luis; Moon, Thomas W.; Gilmour, Kathleen M.; Trudeau, Vance; Arnason, John
The capacity of the traditional anxiolytic plant, Souroubea sympetala, and its bioactive principle, betulinic acid (BA), to lower cortisol levels in rainbow trout, Oncorhynchus mykiss, was investigated. Effects at the level of the cortisol-producing interrenal cells were investigated using an in vitro head kidney preparation. Head kidney tissue incubated with S. sympetala extract or BA produced significantly less cortisol in response to adrenocorticotropic hormone (ACTH) than cells incubated with ACTH alone; a 50% reduction in the cortisol response was predicted to occur at 43 μg mL− 1 extract or 71 μg mL− 1 BA. To investigate whether effects on interrenal cell cortisol production translated into effects at the whole-animal level, the plasma cortisol response to an acute stressor, confinement in a net, was assessed. Fish fed a commercial trout pellet diet supplemented with 1 mg kg− 1 fish BA for six days exhibited a significantly lower plasma cortisol response to the acute stressor than fish fed the unsupplemented diet. Collectively, these results demonstrate that S. sympetala and BA act on the interrenal cells of the hypothalamic-pituitary-interrenal (HPI) axis in rainbow trout to significantly attenuate the cortisol response to an acute stressor. These findings suggest that BA is of potential use in mitigating effects of exposure to the stressors commonly encountered in an aquaculture setting. Statement of relevance • Souroubea sympetala extract and betulinic acid reduced ACTH-stimulated cortisol production by head kidney tissue in vitro, with little or no evidence of cytotoxicity.• The cortisol response to an acute stressor was attenuated in rainbow trout fed a commercial diet supplemented with betulinic acid.• The cortisol-reducing properties of the S. sympetala extract and betulinic acid may be useful in mitigating effects of stress in aquaculture, particularly since, as natural products, they may raise less public concern with respect to human consumption.
A brittle failure model for long-period seismic events recorded at Turrialba Volcano, Costa Rica
(American Geophysical Union, 2015-01-30) Eyre, Thomas; Bean, Christopher; DE BARROS, LOUIS; Martini, Francesca; Lokmer, Ivan; Mora Fernández, Mauricio Manuel; Pacheco, Javier F.; Soto, Gerardo J.
A temporary seismic network, consisting of 23 broadband and six short-period stations, wasinstalled in a dense network at Turrialba Volcano, Costa Rica, between 8 March and 4 May 2011. During thistime 513 long-period (LP) events were observed. Due to their pulse-like waveforms, the hypothesis thatthe events are generated by a slow-failure mechanism, based on a recent new model by Bean et al. (2014), istested. A signiﬁcant number (107) of the LPs are jointly inverted for their source locations and mechanisms,using full-waveform moment tensor inversion. The locations are mostly shallow, with depths < 800 m belowthe active Southwest Crater. The results of the decompositions of the obtained moment tensor solutions showcomplex source mechanisms, composed of high proportions of isotropic and low, but seemingly signiﬁcant,proportions of compensated linear vector dipole and double-couple components. It is demonstrated that thiscan be explained as mode I tensile fracturing with a strong shear component. The source mechanism is furtherinvestigated by exploring scaling laws within the data. The LPs recorded follow relationships very similar tothose of conventional earthquakes, exhibiting frequency-magnitude and corner frequency versus magnituderelationships that can be explained by brittle failure. All of these observations indicate that a slow-failure sourcemodel can successfully describe the generation of short-duration LP events at Turrialba Volcano
A case study on pharmaceutical residues and antimicrobial resistance genes in Costa Rican rivers : a possible route of contamination for feline and other species
(Elsevier, 2023-11-12) Vargas-Villalobos, Seiling; Hernández, Felix; Fabregat-Safont, David; Salas-González, Denis; Quesada-Alvarado, Francisco; Botero-Coy, Ana Maria; Esperón, Fernando; Martín-Maldonado, Bárbara; Monrós-González, Juan; Ruepert, Clemens; Estrada-König, Sandra; Rivera-Castillo, Josué; Chaverri-Fonseca, Fabio; Blanco-Peña, Kinndle
In this investigation, the presence of antibiotics and pharmaceuticals in Costa Rican surface waters, specifically in regions near feline habitats, was examined. The study revealed that 47% of the water samples contained detectable traces of at least one antibiotic. Ciprofloxacin and norfloxacin were the most frequently detected compounds, each with a detection rate of 27%. Other antibiotics, such as erythromycin, roxithromycin, and trimethoprim, were also found but at lower frequencies, around 14%. Notably, all antibiotic concentrations remained below 10 ng/L, with ciprofloxacin, norfloxacin, and erythromycin showing the highest concentrations. Furthermore, the investigation revealed the presence of non-antibiotic pharmaceutical residues in the water samples, typically at concentrations below 64 ng/L. Tramadol was the most frequently detected compound, present in 18% of the samples. The highest concentrations were observed for acetaminophen and tramadol, measuring 64 and 10 ng/L, respectively. Comparing these findings with studies conducted in treated wastewater and urban rivers, it became evident that the concentrations of antibiotics and pharmaceuticals were notably lower in this study. While previous research reported higher values, the limited number of studies conducted in protected areas raises concerns about the potential environmental impact on biodiversity. In summary, these results emphasize the importance of monitoring pharmaceutical residues and antimicrobial resistance genes ARGs in vulnerable ecosystems, especially those in close proximity to feline habitats in Costa Rica. Additionally, the study delved into the detection of (ARGs). All tested water samples were positive for at least one ARG, with the blaTEM gene being the most prevalent at 82%, followed by tetS at 64% and qnrB at 23%. Moreover, this research shed light on the complexity of evaluating ARGs in environmental samples, as their presence does not necessarily indicate their expression. It also highlighted the potential for co-selection and coregulation of ARGs, showcasing the intricate behaviors of these genes in aquatic environments.
A Combined Metagenomics and Metatranscriptomics Approach to Unravel Costa Rican Cocoa Box Fermentation Processes Reveals Yet Unreported Microbial Species and Functionalities
(Frontiers Media, 2021-02-16) Verce, Marko; Schoonejans, Jorn; Hernandez Aguirre, Carlos; Luc De Vuyst; Weckx, Stefan
Cocoa fermentation is the first step in the post-harvest processing chain of cocoa and is important for the removal of the cocoa pulp surrounding the beans and the development of flavor and color precursors. In the present study, metagenomic and metatranscriptomic sequencing were applied to Costa Rican cocoa fermentation processes to unravel the microbial diversity and assess the function and transcription of their genes, thereby increasing the knowledge of this spontaneous fermentation process. Among 97 genera found in these fermentation processes, the major ones were Acetobacter, Komagataeibacter, Limosilactobacillus, Liquorilactobacillus, Lactiplantibacillus, Leuconostoc, Paucilactobacillus, Hanseniaspora, and Saccharomyces. The most prominent species were Limosilactobacillus fermentum, Liquorilactobacillus cacaonum, and Lactiplantibacillus plantarum among the LAB, Acetobacter pasteurianus and Acetobacter ghanensis among the AAB, and Hanseniaspora opuntiae and Saccharomyces cerevisiae among the yeasts. Consumption of glucose, fructose, and citric acid, and the production of ethanol, lactic acid, acetic acid, and mannitol were linked to the major species through metagenomic binning and the application of metatranscriptomic sequencing. By using this approach, it was also found that Lacp. plantarum consumed mannitol and oxidized lactic acid, that A. pasteurianus degraded oxalate, and that species such as Cellvibrio sp., Pectobacterium spp., and Paucilactobacillus vaccinostercus could contribute to pectin degradation. The data generated and results presented in this study could enhance the ability to select and develop appropriate starter cultures to steer the cocoa fermentation process toward a desired course.
A comparison of different indirect techniques to evaluate volcanic intact rock strength
(Springer, 2009) Del Potro, Rodrigo; Hürlimann, Marcel
The efficiency of different methods that are used to evaluate volcanic intact rock strength is compared that includes Schmidt hammers, point load tests and uniaxial compression tests. The Schmidt hammer records the rebound height of the mass (R) on a linear scale and gives an indication of the strength of the material being tested. The two types of Schmidt hammers (L- and N-type), with different impact energies are used that shows results as the rebound height RLand RN for the L- and N-type Schmidt hammers, respectively. The other method used is point load test that provides strength measurements of irregular fragments of rocks or of rock cores, with all rock dimensions being greater than 50 mm. The last method is uniaxial compression that shows little scatter and clear logarithmic increase of uniaxial compressive strength with increasing unit weight. The studies showed that Schmidt hammers can give results similar in quality to uniaxial compression tests.
A comparison of fruit removal in Ficus colubrinae between birds and Ectophylla alba (Chiroptera: Phyllostomidae) in a Costa Rican rain forest
(Taylor and Francis Ltd., 2021-02-02) De la Llata Quiroga, Edna; Ruedas, Luis; Mora, José Manuel
Ectophylla alba almost exclusively feeds on the fruits of Ficus colubrinae therefore significantly contributing to dispersal of its seeds. The objective of this research was to quantify the fruit removal of F. colubrinae by E. alba and compare it with that of birds in a F. colubrinae tree at the La Selva Biological Station, Costa Rica. We established seven quadrats randomly at different heights of the tree. We took photographs of each quadrat, quantified the fruits in each photograph, and compared the number of fruits removed during periods of high and low activity. The on-site persistence time of birds (9:05 min) was higher than that of E. alba (0.32 s). Birds removed more fruits (46) than E. alba (41). Birds defecated on site more times (13.08 feces per day) than E. alba (7.5 feces per day). Thus, E. alba is a more important seed disperser of F. colubrinae than are birds, because it persisted a short time at the feeding site, and consumed food beyond the individual trees’ canopies. Most importantly, by defecating during flight or away from the fruiting tree, E. alba disperse seeds some distance from the F. colubrinae tree, thereby contributes more effectively toward seed dispersal.
A Creep Event on the Shallow Interface of the Nicoya Peninsula, Costa Rica Seismogenic Zone
(American Geophysical Union, 2004) Protti, Marino; González, Victor; Kato, Teruyuki; Iinuma, Takeshi; Miyazaki, Shinichi; Obana, Koichiro; Kaneda, Yoshiyuki; LaFemina, Peter; Dixon, Timothy; Schwartz, Susan
Summary of the paper "A Creep Event on the Shallow Interface of the Nicoya Peninsula, Costa Rica Seismogenic Zone"
A female of Eudorylaimus sp with two vulvae.
(Universidad Nacional, Costa Rica, 2001) Esquivel Hernández, Alejandro
A female of Eudorylaimus sp, with two vulvae was found in Tempisque Conservation Area in Costa Rica. Thousands of nematodes have been prepared in Cobb's slides to study nematode diversity in Costa Rica; nevertheless, only one aberrant female has been found. The two vulvae are very close to each other and vaginal sclerotization plates show abnormal formation. There is no linkage between the uterus and the gonoducts and the ovaries are poorly developed. An absence of sperm and eggs suggests that the genital apparatus is not functional. Because identification at the species level teas not achieved, more specimens and studies are needed
A long-term record of polythionates in the acid crater-lake of Poás volcano: Changes in the subaqueous input of fumarolic gases
(IAVCEI. General Assembly. Pucón-Chile, 2004-01) Martínez, M.; Van Bergen, M. J.; Fernández, E.; Takano, B.; Malavassi, E.; Barboza, V.; Miura, Y.; Van der Laat, R.; Duarte, E.; Valdés, J.; Sáenz, W.
A multidisciplinary approach to analyze the antimicrobial resistance in natural ecosystems
(Universidad Nacional, Costa Rica, 2024-02-25) Blanco-Pena, K; Quesada-Alvarado, Francisco; Salas-González, Denis; Chaverri-Fonseca, Fabio
Antimicrobial Resistance (AMR) poses a global threat to both human health and environmental well-being. Our study delved into Costa Rican wildlife reserves, uncovering a substantial human impact on these ecosystems and underscoring the imperative to pinpoint AMR hotspots. Embracing a One Health perspective, we advocated for a comprehensive landscape analysis that intricately intertwined geographic, climatic, forest, and human factors. This study illuminated the link between laboratory results and observed patterns of antimicrobial use, thereby paving the way for sustainable solutions. Our innovative methodology involved deploying open-ended questions to explore antimicrobial usage across livestock activities, contributing to establishing a comprehensive methodology. Non-invasive sampling in wildlife emerged as a critical aspect, shedding light on areas contaminated by AMR. Feline species, positioned at the apex of the food chain, acted as sentinels for environmental health due to heightened exposure to improperly disposed waste. Regarding laboratory findings, each sample revealed the presence of at least one antimicrobial resistance gene (ARG). Notably, genes encoding resistance to tetracyclines dominated (94.9%), followed by beta-lactams (75.6%), sulfonamides (53.8%), aminoglycosides (51.3%), quinolones (44.9%), phenicols (25.6%), and macrolides (20.5%). Genes encoding polymyxins were not detected. Moreover, 66% of samples carried a multi-resistant microbiome, with 15% exhibiting resistance to three antimicrobial families and 51% to four. The absence of a correlation between forest coverage and ARG presence underscored the profound human impact on wildlife reserves, surpassing previous estimations. This environmental pressure could potentially modify microbiomes and resistomes in unknown ways. As not all antimicrobial families encoding ARGs were utilized by farmers, our next step involved evaluating other human activities to identify the primary sources of contamination. This comprehensive study contributed crucial insights into the intricate dynamics of AMR in natural ecosystems, paving the way for targeted interventions and sustainable coexistence.
A new dagger nematode, Xiphinema tica n. sp. (Nematoda: Longidoridae), from Costa Rica with updating of the polytomous key of Loof and Luc (1990)
(Springer, 2017-05-15) Peraza-Padilla, Walter; Cantalapiedra-Navarrete, Carolina; Zamora-Araya, Tatiana; Palomares-Rius, Juan Emilio; Castillo, Pablo; Archidona Yuste, Antonio
A new dagger nematode, Xiphinema tica n. sp., is described and illustrated from several populations extracted from soil associated with several crops and wild plants in Costa Rica. The new dagger nematode is characterised by a moderate body size (3276–4240 μm), a rounded lip region, ca 13.5 μm wide, separated from body contour by a shallow depression, amphidial fovea large, stirrup-shaped, a moderately long odontostyle ca 135 μm long, stylet guiding ring located at ca 122 μm from anterior end, vulva almost equatorial (50–54%), well-developed Z-organ, with heavy muscularised wall containing in the most of specimens observed two moderately refractive inclusions variable in shape (from round to star-shaped), with uterine spines and crystalloid bodies; female tail short, dorsally convex-conoid, with rounded end and a small peg, with a c’ ratio ca 0.8, bearing two or three pairs of caudal pores and male absent. The unique and novel uterine differentiation based on the coexistence of a well-developed Z-organ mixed with uterine spines and crystalloid bodies in Xiphinema prompted us to update and include this combination of characters in the polytomous key of Loof and Luc (1990). Integrative diagnosis was completed with molecular data obtained, using D2-D3 expansion segments of 28S rDNA, ITS1-rDNA, partial 18S–rDNA and the partial mitochondrial gene cytochrome c oxidase subunit 1 (coxI). The phylogenetic relationships of this species with other Xiphinema spp. indicated that X. tica n. sp. was monophyletic to the other species from the morphospecies Group 4, Xiphinema oleae.
A new nesting record for the jabiru in Costa Rica
(Waterbird Society, 1998) Villarreal Orias, Johnny
I document the first nesting record of theJabiru (Jabiru mycteria) in "Los Guatuzos" forest floodplain, Alajuela province, Costa Rica. The active nest was located in March 1995 at 10°49'23.70"N and 84°47'23.20"W. The nest was 16m high in a 23m high silk-cotton tree (Ceiba pentandra) and contained three chicks. The zone is not protected and active lumbering is underway.
A new ring nematode, Xenocriconemella costaricense sp. nov., (Nematoda: Criconematidae) from Costa Rica
(Universidad Nacional, Costa Rica, 2024-04-20) Peraza-Padilla, Walter; Aráuz Badilla, Jefferson; Cantalapiedra-Navarrete, Carolina; Palomares-Rius, Juan Emilio; Archidona Yuste, Antonio; Castillo, Pablo
During nematode surveys of natural vegetation in forests of La Cima de Copey de Dota, San José, San José province, Costa Rica, a Xenocriconemella species closely resembling X. macrodora and related species was found. Integrative taxonomical approaches demonstrated that it is a new species described herein as X. costaricense sp. nov. The new species is parthenogenetic (only females have been detected) and characterised by a short body (276–404 μm); lip region with two annuli, not offset, not separated from body contour; first lip annulus partially covering the second lip annulus. Stylet thin, very long (113–133 μm) and flexible, occupying 30.5–47.8% of body length. Excretory pore located from one or two annuli anterior to one or two annuli posterior to level of stylet knobs, at 42 (37–45) μm from anterior end. Female genital tract monodelphic, prodelphic, outstretched, and occupying 35–45% of body length, with vagina slightly ventrally curved (14–18 μm long). Anus located 6–11 annuli from the tail terminus. Tail conoid and bluntly rounded terminus, the last 2–3 annuli oriented dorsally. Results of molecular characterisation and phylogenetic analyses of D2-D3 expansion segments of 28S rRNA, ITS, and partial 18S rRNA, as well as cytochrome oxidase c subunit 1 gene sequences further characterised the new species and clearly separated it from X. macrodora and other related species (X. iberica, X. paraiberica, and X. pradense).
A NEW SPECIES OF NEMATODE, SCLERORHABDITIS NEOTROPICALIS SP.N. (RHABDITIDA), ASSOCIATED WITH AZTECA ANTS IN CECROPIA OBTUSIFOLIA
(Nematropica, 2012-06) Esquivel, Alejandro; Abolafia Cobaleda, Joaquín; Hanson, P.; Pinto, A.
Sclerorhabditis neotropicalis sp. n. is described and illustrated. It can be distinguished by its body length (515-560 μm in females and 363-455 μm in males), lip region with crown-shaped lips, having acute three acute thorns, oral aperture one third of lip region width, stoma 15-22 μm long or 1.0-1.6 times as long as diameter of lip region, stomatal tube about 1.5 times longer than wide, bearing rhabdia with slightly rugous walls at lumen side, stegostom lacking glottoid apparatus and denticles, pharynx 125-135 μm long in females and 107-131 μm long in males, excretory pore and hemizonid located at 21-22% of the distance from the anterior end. The female reproductive system is didelphicamphidelphic, with ovaries straight or dorsally reflexed, and the vulva is a transverse slit, 55-61% from the anterior end, female tail conoid elongated, 62-76 μm long, having a posterior hyaline portion very slender and with acute tip. The male reproductive system is monorchic, with testis anterio-ventrally reflexed, spicules free, 36-47 μm long or 1.6-1.8 times longer than anal body width, with rounded manubrium, gubernaculum 15-18 μm long or 38-42% of spicule length, and bursa anteriorly open, peloderan, with scalloped margin and bearing eight pairs of genital papillae (1+1/1+1+1+1+2), tail conoid spicate, 23-30 μm long. The new species was found in close association with an ant colony (Azteca constructor Emery, 1876) inside a Cecropia obtusifolia Bertoloni, 1840 tree in a tropical rain forest in Costa Rica. Certain species of Azteca ants live in mutualistic association with Cecropia trees and preliminary evidence suggests that the new nematode species is invariably present in the colonies of at least some of these Azteca species. It is, therefore, possible that the new nematode species represents a third partner in the mutualism, although its role is still unknown.
A New Sulfur and Carbon Degassing Inventory for the Southern Central American Volcanic Arc: The Importance of Accurate Time-Series Data Sets and Possible Tectonic Processes Responsible for Temporal Variations in Arc-Scale Volatile Emissions
(AGU Publications, 2017-12-12) Muller, C.; Saballos, A.; Ibarra, M.; LaFemina, Peter; de Moor, Joost Maarten; Kern, Christoph; Avard, Geoffroy; AIUPPA, Alessandro; Protti, Marino; Fischer, Tobias
This work presents a new database of SO2 and CO2 fluxes from the Southern Central American Volcanic Arc (SCAVA) for the period 2015–2016. We report 300 SO2 flux measurements from 10 volcanoes and gas ratios from 11 volcanoes in Costa Rica and Nicaragua representing the most extensive available assessment of this 500 km arc segment. The SO2 flux from SCAVA is estimated at 6,24061,150 T/d, about a factor of three higher than previous estimations (1972–2013). We attribute this increase in part to our more complete assessment of the arc. Another consideration in interpreting the difference is the context of increased volcanic activity, as there were more eruptions in 2015–2016 than in any period since 1980. A potential explanation for increased degassing and volcanic activity is a change in crustal stress regime (from compression to extension, opening volcanic conduits) following two large (Mw>7) earthquakes in the region in 2012. The CO2 flux from the arc is estimated at 22,50064,900 T/d, which is equal to or greater than estimates of C input into the SCAVA subduction zone. Time-series data sets for arc degassing need to be improved in temporal and spatial coverage to robustly constrain volatile budgets and tectonic controls. Arc volatile budgets are strongly influenced by short-lived degassing events and arc systems likely display significant short-term variations in volatile output, calling for expansion of nascent geochemical monitoring networks to achieve spatial and temporal coverage similar to traditional geophysical networks.

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