Integrated constraints on explosive eruption intensification at Santiaguito dome complex, Guatemala
Protracted volcanic eruptions may exhibit unanticipated intensifications in explosive behaviour and attendant hazards. Santiaguito dome complex, Guatemala, has been characterised by century-long effusion interspersed with frequent, small-to-moderate (<2 km high plumes) gas-and-ash explosions. During 2015–2016, explosions intensified generating hazardous ash-rich plumes (up to 7 km high) and pyroclastic flows. Here, we integrate petrological, geochemical and geophysical evidence to evaluate the causes of explosion intensification. Seismic and infrasound signals reveal progressively longer repose intervals between explosions and deeper fragmentation levels as the seismic energy of these events increased by up to four orders of magnitude. Evidence from geothermobarometry, bulk geochemistry and groundmass microlite textures reveal that the onset of large explosions was concordant with a relatively fast ascent of a deeper-sourced (∼17–24 km), higher temperature (∼960–1020 °C) and relatively volatile-rich magma compared to the previous erupted lavas, which stalled at ∼2 km depth and mingled with the left-over mush that resided beneath the pre-2015 lava dome. We interpret that purging driven by the injection of this deep-sourced magma disrupted the long-term activity, driving a transition from low energy shallow shear-driven fragmentation, to high energy deeper overpressure-driven fragmentation that excavated significant portions of the conduit and intensified local volcanic hazards. Our findings demonstrate the value of multi-parametric approaches for understanding volcanic processes and the triggers for enigmatic shifts in eruption style, with the detection of vicissitudes in both monitoring signals and petrological signatures of the eruptive products proving paramount.
Wallace, Paul A.; Lamb, Oliver D.; De Angelis, Silvio; Kendrick, Jackie E.; Hornby, Adrian J.; Díaz-Moreno, Alejandro; González, Pablo J.; von Aulock, Felix W.; Lamur, Anthony; Utley, James E.P.; Rietbrock, Andreas; Chigna, Gustavo; Lavallée, Yan
The Unethical Enterprise of the Past: Lessons from the Collapse of Archaeological Heritage Management in Spain
This paper explores the underlying factors behind the collapse of commercial archaeology in Spain, with implications for other international contexts. It contributes to the current global debate about heritage ethics, adding nuance and conceptual depth to critical management studies and cultural heritage management in their approach to business ethics. Similar to other European contexts, Spanish archaeological management thrived during the 1990s and 2000s as a business model based on policies directed at safeguarding cultural heritage. The model had controversial ethical implications at academic, policy and business levels. However, the global financial crisis of 2008 had a huge impact on this sector, and more than 70% of the Spanish archaeological companies closed by 2017. Drawing on the concepts of abstract narratives, functional stupidity and corporatist neoliberalism, this paper illustrates the need to examine ethical issues from a pragmatic standpoint, beyond epistemological and moralistic critiques of profit-oriented businesses in the cultural realm. In doing so, it connects the fields of cultural heritage and management studies, opening up hitherto unexplored strands of research and debate.
Parga Dans, Eva; Alonso González, Pablo
Natural wine: do consumers know what it is, and how natural it really is?
Natural wine is a small but rapidly growing sector within the wine industry. Expertise in the field has been advanced by wine experts and professionals, while publications to aid in further understanding the topic lag behind. This manuscript highlights the need to develop more rigorous methodologies to better understand the market segment of natural wine, its consumers, and their composition and behaviour. Moreover, it calls for a deeper theoretical engagement with the notion of natural wine, which positions it among other sustainable and ecological certifications, including organic, biodynamic or sulphite-free. This would allow researchers to advance from the current state of knowledge, which continues to limit our ‘practical’ capacity for advice to policy makers but not to winemakers and marketers. These theoretical and methodological developments would allow scholars to catch up with debates being held by different social actors in the natural wine scene, including winemakers’ and consumer associations, bloggers, writers and professional marketers.
Alonso González, Pablo; Parga-Dans, Eva
Phylogeographic and phenotypic outcomes of brown anole colonization across the Caribbean provide insight into the beginning stages of an adaptive radiation
Some of the most important insights into the ecological and evolutionary processes of diversification and speciation have come from studies of island adaptive radiations, yet relatively little research has examined how these radiations initiate. We suggest that Anolis sagrei is a candidate for understanding the origins of the Caribbean Anolis adaptive radiation and how a colonizing anole species begins to undergo allopatric diversification, phenotypic divergence and, potentially, speciation. We undertook a genomic and morphological analysis of representative populations across the entire native range of A. sagrei, finding that the species originated in the early Pliocene, with the deepest divergence occurring between western and eastern Cuba. Lineages from these two regions subsequently colonized the northern Caribbean. We find that at the broadest scale, populations colonizing areas with fewer closely related competitors tend to evolve larger body size and more lamellae on their toepads. This trend follows expectations for post‐colonization divergence from progenitors and convergence in allopatry, whereby populations freed from competition with close relatives evolve towards common morphological and ecological optima. Taken together, our results show a complex history of ancient and recent Cuban diaspora with populations on competitor‐poor islands evolving away from their ancestral Cuban populations regardless of their phylogenetic relationships, thus providing insight into the original diversification of colonist anoles at the beginning of the radiation. Our research also supplies an evolutionary framework for the many studies of this increasingly important species in ecological and evolutionary research.
Graham Reynolds, Robert; Kolbe, Jason J.; Glor, Richard E.; López-Darias, Marta; Gómez Pourroy, Verónica C.; Harrison, Alexis S.; de Queiroz, Kevin; J. Revell, Liam; B. Losos, Jonathan
Six new non-native ants (Formicidae) in the Canary Islands and their possible impacts
Biological invasions are one of the main causes of biodiversity loss, especially on oceanic islands. Ants are among the most damaging pests in the world. After systematic sampling of more than 1,000 localities in the Canary Islands, six new exotic ant species are reported for the first time: Pheidole bilimeki (Myrmicinae), Pheidole navigans (Myrmicinae), Strumigenys membranifera (Myrmicinae), Brachymyrmex cordemoyi (Formicinae), Tapinoma darioi (Dolichoderinae) and Technomyrmex pallipes (Dolichoderinae). Moreover, another two recently reported species have been genetically confirmed. Morphological and genetic data were analysed to confirm the identity of the new records. For each species, information regarding identification, distribution, global invasive records and possible impacts is given. The arrival of these species may endanger local biodiversity.
Hernández-Teixidor, David; Pérez-Delgado, Antonio José; Suárez, Daniel; Reyes-López, Joaquin
Effect of diurnal vs. nocturnal pollinators and flower position on the reproductive success of Echium simplex
Nocturnal pollination plays an important role in sexual plant reproduction but has been overlooked, partially because of intrinsic difficulties in field experimentation. Even less attention has received the effect of within-inflorescence spatial position (distal or proximal) on nocturnal pollinators of columnar plants, despite numerous studies examining the relationship between such position and reproductive success. Woody endemic Echium simplex possesses large erect inflorescences bearing thousands of flowers which are visited by a wide array of diurnal and nocturnal animals. In this study, we identified nocturnal visitors and compared their pollination effectiveness with that of diurnal pollinators in different inflorescence sections by means of selective exclosures in NE Tenerife (Canary Islands). Nocturnal visitors included at least ten morphospecies of moths (such as Paradrina rebeli and Eupithecia sp.), two coleopteran species (mainly Alloxantha sp.), neuropterans (Chrysoperla carnea), dictyopterans (Phyllodromica brullei), dermapterans (Guanchia sp.) and julidans (Ommatoiulus moreletii). In general, plants excluded from pollinators set less fruits than open-pollination (control) plants which set fruits homogeneously across sections. Diurnally pollinated plants set more fruit in their upper parts whereas nocturnally pollinated plants set fruit in both upper and bottom sections. We conclude that although the frequency and diversity of diurnal pollinators is far higher than that of nocturnal pollinators, both exhibit different foraging behaviour that generates complementary effects on the reproductive success of E. simplex.
Jaca, Julia; Nogales, Manuel; Traveset, Anna
Genetic Diversity of Local Peach (Prunus persica) Accessions from La Palma Island (Canary Islands, Spain)
Peach (Prunus persica) is an economically important temperate fruit crop due to its edible fruits. Due to the need to develop new varieties better adapted to climate change, it is of great interest to find germplasm adapted to warmer conditions, such as those found in the Canary Islands. Peach was an important crop during the last century in one of those islands (La Palma), but its cultivation has been abandoned in recent years. Currently, commercial production is relict and isolated trees are relegated to family orchards with little management. With the objective to characterize and prevent the loss of local varieties of this crop, peach trees were sampled along La Palma. A total of 89 local peach accessions were prospected and analyzed with 10 single-sequence repeat (SSR) loci, which permitted 28 different genotype profiles to be detected. These genotypes were compared to 95 Spanish peach landraces conserved in an ex situ collection, and 26 additional samples from eight different countries. Results showed that the peach genetic diversity found in La Palma was low. In addition, a relation between La Palma samples and other Spanish peaches was observed, which could indicate the arrival of genetic material from the Iberian Peninsula and subsequent intercrossing and local selection of the genotypes more adapted to the subtropical climate of the island. The population structure reflects a grouping of the samples based on fruit type and geographic origin.
Pérez, Verónica; Larrañaga, Nerea; Abdallah, Donia; Wünsch, Ana; Hormaza Urroz, José Ignacio
Two new dipluran species unearthed from subterranean habitats of the Canary Islands (Arthropoda, Hexapoda, Entognatha)
Two new dipluran species of the family Campodeidae have been unearthed in the Canary Islands. Remycampa herbanica sp. nov. was found in a highly threatened lava tube on Fuerteventura island. It is related to the soil-dwelling northwest African Remycampa launeyi that also inhabits four of the Canary Islands. The two known Remycampa species are characterized by a torsion of the labial palps. They differ chiefly in the distribution of macrosetae and in the features of cave adaptation of R. herbanica, i.e. elongation of body and appendages, and a higher number of olfactory chemoreceptors with a coniform shape unique within campodeids. Spaniocampa relicta sp. nov. was collected in the mesovoid shallow substratum (MSS) and has been assigned to a formerly monotypic genus that includes the soil-dwelling Spaniocampa prima from the Republic of Guinea. The two species differ in the number of abdominal macrosetae. Females of S. relicta sp. nov. have small setae arranged in groups along the posterior border of the first urosternite. These structures of unknown function have never been described in other campodeid species. Sequencing the COI barcode region of R. herbanica has been produced but it proved insufficient to identify closest relatives. The two new hexapods from subterranean habitats raise the Canarian campodeid fauna to six species. Five of them are living in soil and/or MSS, whereas the cave-adapted R. herbanica is known only from a single, particularly endangered lava tube distant from other caves.
Sendra, Alberto; López, Heriberto; Selfa, Jesús; Oromí, Pedro
Chemical Composition of an Aphid Antifeedant Extract from an Endophytic Fungus, Trichoderma sp. EFI671
Botanical and fungal biopesticides, including endophytes, are in high demand given the current restrictive legislations on the use of chemical pesticides. As part of an ongoing search for new biopesticides, a series of fungal endophytes have been isolated from selected medicinal plants including Lauraceae species. In the current study, an extract from the endophytic fungus Trichoderma sp. EFI 671, isolated from the stem parts of the medicinal plant Laurus sp., was screened for bioactivity against plant pathogens (Fusarium graminearum, Rhizoctonia solani, Sclerotinia sclerotiorum and Botrytis cinerea), insect pests (Spodoptera littoralis, Myzus persicae, Rhopalosiphum padi) and plant parasites (Meloidogyne javanica), with positive results against M. persicae. The chemical study of the neutral fraction of the active hexane extract resulted in the isolation of a triglyceride mixture (m1), eburicol (2), β-sitostenone (3), ergosterol (4) and ergosterol peroxide (5). The free fatty acids present in the acid fraction of the extract and in m1 (oleic, linoleic, palmitic and stearic) showed strong dose-dependent antifeedant effects against M. persicae. Liquid (potato dextrose broth, PDB and Sabouraud Broth, SDB) and solid (corn, sorghum, pearl millet and rice) growth media were tested in order to optimize the yield and bioactivity of the fungal extracts. Pearl millet and corn gave the highest extract yields. All the extracts from these solid media had strong effects against M. persicae, with sorghum being the most active. Corn media increased the methyl linoleate content of the extract, pearl millet media increased the oleic acid and sorghum media increased the oleic and linoleic acids compared to rice. The antifeedant effects of these extracts correlated with their content in methyl linoleate and linoleic acid. The phytotoxic effects of these extracts against ryegrass, Lolium perenne, and lettuce, Lactuca sativa, varied with culture media, with sorghum being non- toxic.
Kaushik, Nutan; Díaz, Carmen E.; Chhipa, Hemraj; Fernando Julio, L.; Fe Andrés, M.; González-Coloma, Azucena
Synthetic Approaches to Phosphasugars (2-oxo-1,2-oxaphosphacyclanes) Using the Anomeric Alkoxyl Radical β-Fragmentation Reaction as the Key Step
The anomeric alkoxyl radical β-fragmentation (ARF) of carbohydrates possessing an electron-withdrawing group (EWG) at C2, promoted by PhI(OAc)2/I2, gives rise to an acyclic iodide through which a pentavalent atom of phosphorus can be introduced via the Arbuzov reaction. After selective hydrolysis and subsequent cyclization, the phosphonate or phosphinate intermediates can be converted into 2-deoxy-1-phosphahexopyranose and 2-deoxy-1-phosphapentopyranose sugars. The ARF of carbohydrates with an electron-donor group (EDG) at C2 proceeds by a radical-polar crossover mechanism, and the cyclization occurs by nucleophilic attack of a conveniently positioned phosphonate or phosphinate group to the transient oxocarbenium ion. This alternative methodology leads to 5-phosphasugars with a 4-deoxy-5-phosphapentopyranose framework. The structure and conformation of the 2-oxo-1,2-oxaphosphinane and 2-oxo-1,2-oxaphospholane ring systems in different carbohydrate models have been studied by NMR and X-ray crystallography.
Hernández-Guerra, Daniel; Kennedy, Alan R.; León, Elisa I.; Martín, Ángeles; Pérez-Martín, Inés; Rodríguez Morales, María S.; Suárez, Ernesto