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Abstract Numerous genetic studies have contributed to reconstructing the human history of the Canary Islands population. The recent use of new ancient DNA targeted enrichment and next-generation sequencing techniques on new Canary Islands samples have greatly improved these molecular results. However, the bulk of the available data is still provided by the classic mitochondrial DNA phylogenetic and phylogeographic studies carried out on the indigenous, historical, and extant human populations of the Canary Islands. In the present study, making use of all the accumulated mitochondrial information, the existence of DNA contamination and archaeological sample misidentification in those samples is evidenced. Following a thorough review of these cases, the new phylogeographic analysis revealed the existence of a heterogeneous indigenous Canarian population, asymmetrically distributed across the various islands, which most likely descended from a unique mainland settlement. These new results and new proposed coalescent ages are compatible with a Roman-mediated arrival driven by the exploitation of the purple dye manufacture in the Canary Islands.

The synthesis of materials of high added value from a natural kaolin has been studied. The kaolin was pre-activated by means of calcination to obtain the metakaolins, which are amorphous solids capable of being modified by simple and non expensive chemical treatments. These solids were then submitted to acid and basic treatments to modify their structure and properties. The acid activation under specific conditions gave place to the synthesis of solids mainly constituted by silica with good textural properties, developing so much their external and internal surface, these solids may be used like adsorbentes and catalytic supports. On the other hand, the basic activation produced the modification of the metakaolins and it gave place to the crystallisation of the zeolite K-F (Z), appearing as a simple and effective method for the synthesis of this material.En este trabajo se ha estudiado la síntesis de materiales de alto valor añadido a partir de un caolín natural. Para ello el caolín fue pre-activado mediante calcinación para dar lugar a la formación de metacaolines, sólidos amorfos susceptibles de ser modificados por tratamientos químicos de una manera sencilla y poco costosa. Estos sólidos fueron posteriormente sometidos a tratamientos ácidos y básicos para modificar su estructura y propiedades. La activación ácida bajo unas condiciones específicas dio lugar a la síntesis de sólidos constituidos mayoritariamente por sílice con buenas propiedades superficiales, desarrollándose tanto su superficie externa como interna, revelándose como sólidos que pueden ser empleados como adsorbentes y soportes catalíticos. Por su parte, la modificación causada por la activación básica dio lugar a la cristalización de la zeolita K-F (Z), presentándose como un método sencillo y eficaz para la síntesis de este material.

The texture development of a saponite and a montmorillonite, intercalated with zirconium and aluminium oligomers, after calcination at 500 ºC has been studied. Remarkable differences were observed among samples, depending on the source of the intercalating polycations and the parent material. On calcining, the alumina pillared clays suffered noticeable specific surface area and micropore volume losses, which have been related to the interlayer and interpillar distances of the samples. On the contrary, the zirconia pillared clays showed a slight surface area increase, which affected both micropores and mesopores and could be due to the combined effect of the thermal decomposition of the zirconium oligomers and the possible presence of mesoporous ZrO2 particles.En este trabajo se ha estudiado la evolución de las propiedades texturales de una saponita y una montmorillonita intercaladas con disoluciones de circonio y aluminio tras calcinación a 500 ºC. Los sólidos presentaron un diferente comportamiento en función de la naturaleza de la disolución de intercalación y de la arcilla empleada. Tras calcinación, la superficie específica y el volumen microporoso de las arcillas intercaladas con disoluciones de aluminio disminuyeron de manera importante, lo cual se ha relacionado con las distancias interlaminar e interpilar que presentaron los materiales intercalados. Por contra, las superficies específicas de las arcillas intercaladas con disoluciones de circonio aumentaron, probablemente gracias al efecto combinado de la descomposición térmica de los ligandos orgánicos unidos al circonio en los policationes y la posible presencia de partículas mesoporosas de ZrO2 sobre la superficie de los sólidos.

Despite the worldwide importance of disease complexes involving root-feeding nematodes and soilborne fungi, there have been few in-depth studies on how these organisms interact at the molecular level. Previous studies of guava decline have shown that root exudates from Meloidogyne enterolobii-parasitized guava plants (NP plants), but not from nematode-free plants (NF plants), enable the fungus Neocosmospora falciformis to rot guava roots, leading to plant death. To further characterize this interaction, NP and NF root exudates were lyophilized; extracted with distinct solvents; quantified regarding amino acids, soluble carbohydrates, sucrose, phenols, and alkaloids; and submitted to a bioassay to determine their ability to enable N. falciformis to rot the guava seedlings’ roots. NP root exudates were richer than NF root exudates in amino acids, carbohydrates, and sucrose. Only the fractions NP-03 and NP-04 enabled fungal root rotting. NP-03 was then sequentially fractionated through chromatographic silica columns. At each step, the main fractions were reassessed in bioassay. The final fraction that enabled fungal root rotting was submitted to analysis using high performance liquid chromatography, nuclear magnetic resonance, mass spectrometry, energy-dispersive X-ray fluorescence, and computational calculations, leading to the identification of 1,5-dinitrobiuret as the predominant substance. In conclusion, parasitism by M. enterolobii causes an enrichment of guava root exudates that likely favors microorganisms capable of producing 1,5-dinitrobiuret in the rhizosphere. The accumulation of biuret, a known phytotoxic substance, possibly hampers root physiology and the innate immunity of guava to N. falciformis.

Abstract The introgression of M. enterolobii resistance-related genes in guava breeding programs can be compromised by incompatibility among Psidium species. This study aimed to evaluate the female parent preference and genetic diversity of Psidium interspecific hybrids using morphoagronomic traits and resistance to M. enterolobii. There were evaluated cross successes and germination from crosses between accesses of P. cattleyanum, P. guineense and P. guajava and the genetic diversity by Ward-MLM method of hybrids according to descriptors developed for the genus. Crosses were more successful when P. cattleyanum was the female parent. Germination was more successful in crosses involving P. cattleyanum and P. guajava. Four groups were formed. The group IV clustered the most resistant genotypes, composed by genotypes of P. cattleyanum x P. guineense, while the group II was the most susceptible. The groups I and III grouped some genotypes of P. cattleyanum x P. guajava with low levels of susceptibility. There are preferences of female parent species among crosses. Some individuals of groups I and III can be used as source of resistance genes for the breeding program, due the presence of favorable alleles inherited from guava parent. The high susceptibility leads to reduction in root development.

Abstract A global pandemic is underway caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The SARS-CoV-2 genome, like its predecessor SARS-CoV, contains open reading frames that encode accessory proteins involved in virus-host interactions active during infection and which likely contribute to pathogenesis. One of these accessory proteins is 7b, with only 44 (SARS-CoV) and 43 (SARS-CoV-2) residues. It has one predicted transmembrane domain fully conserved, which suggests a functional role, whereas most variability is contained in the predicted cytoplasmic C-terminus. In SARS-CoV, 7b protein is expressed in infected cells, and the transmembrane domain was necessary and sufficient for Golgi localization. Also, anti-p7b antibodies have been found in the sera of SARS-CoV convalescent patients. In the present study, we have investigated the hypothesis that SARS-2 7b protein forms oligomers with ion channel activity. We show that in both SARS viruses 7b is almost completely α-helical and has a single transmembrane domain. In SDS, 7b forms various oligomers, from monomers to tetramers, but only monomers when exposed to reductants. Combination of SDS gel electrophoresis and analytical ultracentrifugation (AUC) in both equilibrium and velocity modes suggests a dimer-tetramer equilibrium, but a monomer–dimer–tetramer equilibrium in the presence of reductant. This data suggests that although disulfide-linked dimers may be present, they are not essential to form tetramers. Inclusion of pentamers or higher oligomers in the SARS-2 7b model were detrimental to fit quality. Preliminary models of this association was generated with AlphaFold2, and two alternative models were exposed to a molecular dynamics simulation in presence of a model lipid membrane. However, neither of the two models provided any evident pathway for ions. To confirm this, SARS-2 p7b was studied using Planar Bilayer Electrophysiology. Addition of p7b to model membranes produced occasional membrane permeabilization, but this was not consistent with bona fide ion channels made of a tetrameric assembly of α-helices.

The Canary Islands' indigenous people have been the subject of substantial archaeological, anthropological, linguistic and genetic research pointing to a most probable North African Berber source. However, neither agreement about the exact point of origin nor a model for the indigenous colonization of the islands has been established. To shed light on these questions, we analyzed 48 ancient mitogenomes from 25 archaeological sites from the seven main islands. Most lineages observed in the ancient samples have a Mediterranean distribution, and belong to lineages associated with the Neolithic expansion in the Near East and Europe (T2c, J2a, X3a…). This phylogeographic analysis of Canarian ancient mitogenomes, the first of its kind, shows that some lineages are restricted to Central North Africa (H1cf, J2a2d and T2c1d3), while others have a wider distribution, including both West and Central North Africa, and, in some cases, Europe and the Near East (U6a1a1, U6a7a1, U6b, X3a, U6c1). In addition, we identify four new Canarian-specific lineages (H1e1a9, H4a1e, J2a2d1a and L3b1a12) whose coalescence dates correlate with the estimated time for the colonization of the islands (1st millennia CE). Additionally, we observe an asymmetrical distribution of mtDNA haplogroups in the ancient population, with certain haplogroups appearing more frequently in the islands closer to the continent. This reinforces results based on modern mtDNA and Y-chromosome data, and archaeological evidence suggesting the existence of two distinct migrations. Comparisons between insular populations show that some populations had high genetic diversity, while others were probably affected by genetic drift and/or bottlenecks. In spite of observing interinsular differences in the survival of indigenous lineages, modern populations, with the sole exception of La Gomera, are homogenous across the islands, supporting the theory of extensive human mobility after the European conquest.

El valle de Salientes (norte de León, España) es un área situada inmediatamente al sur del eje principal de la Cordillera Cantábrica, de la que se halla relativamente aislada debido a los procesos erosivos producidos entre las cabeceras de los ríos Sil y Luna. Este hecho histórico/geológico convierte a este valle en un enclave muy singular y a su biota en un interesante objetivo de estudio. Este trabajo, con un enfoque faunístico, aporta información sobre Carabidae (Insecta, Coleoptera) que habitan en esta área. Se realizaron cuatro campañas entomológicas en tres años consecutivos, donde se recogieron 1255 especímenes, pertenecientes a 101 especies, en 61 puntos de muestreo, mediante captura activa e instalación de trampas pitfall. Los resultados revelan que, en términos de diversidad específica y abundancia, la mayoría de los ejemplares pertenecen a la subfamilia Harpalinae, teniendo especial relevancia Harpalini (18 spp, 167 exx), Zabrini (11 spp, 55 exx), Pterostichini (10 spp, 200 exx), Sphodrini (9 spp, 150 exx) y Platynini (6 spp, 83 exx). Además, se realizó un análisis biogeográfico que puso de manifiesto la elevada contribución que hacen los endemismos ibéricos en la composición faunística de los Carabidae de este enclave geográfico. Finalmente, se discuten aspectos taxonómicos de algunas especies colectadas: 1) el caso de Trechus (Trechus) suturalis Putzeys, 1870 y Trechus (Trechus) gallaecus Jeannel, 1921, cuya morfologíadel edeago, ilustrada en este trabajo, es clave para la distinción inequívoca de ambas especies; 2) también se pone de manifiesto la gran variabilidad observada respecto a los caracteres externos de dos especies ibéricas de Oreophilus Chaudoir, 1838, Pterostichus (O.) cantaber (Chaudoir, 1868) y Pterostichus (O.) franzi Nègre, 1955, concluyendo que no son lo suficientemente consistentes, teniendo que recurrir a la morfología del edeago como único carácter totalmente fiable para identificar ambas especies. Además, se aportan comentarios en relación con la autoecología y preferencia de hábitat (áreas forestales, riparias/palustres, ruderales y subterráneas) de las especies más representativas. Por último, se amplía el rango de distribución del microendemismo Trechus teverganus Toribio, 2015, a pesar de las aparentes barreras geográficas y geológicas que podrían existir para esta especie de vida subterránea.

Summary: The conquest of the Canary Islands by Europeans began at the beginning of the 15th century and culminated in 1496 with the surrender of the aborigines. The collapse of the aboriginal population during the conquest and the arrival of settlers caused a drastic change in the demographic composition of the archipelago. To shed light on this historical process, we analyzed 896 mitogenomes of current inhabitants from the seven main islands. Our findings confirm the continuity of aboriginal maternal contributions and the persistence of their genetic footprints in the current population, even at higher levels (>60% on average) than previously evidenced. Moreover, the age estimates for most autochthonous founder lineages support a first aboriginal arrival to the islands at the beginning of the first millennium. We also revealed for the first time that the main recognizable genetic influences from Europe are from Portuguese and Galicians.

In the Iberian Peninsula and the Balearic Islands, Pogonini (Coleoptera, Carabidae) is the least species-rich tribe of Trechinae. Nevertheless, the taxon is relatively poorly studied in this territory, and the available records are mostly published in old and/or faunistic works. The present study provides a taxonomic revision of the 3 genera and 11 species of Pogonini occurring in the Ibero-Balearic region, with an identification key, diagnoses and illustrations of their external morphology and aedeagus. The chorology of the species was also studied, and was assessed by obtaining precise records from published papers and the collection localities of the examined material. These data were used to make updated distribution maps (with several new occurrence points) that reveal a strong regionalization of the tribe in the Ibero-Balearic territory. The species occur in humid and saline environments, especially along the meridional and Mediterranean coasts of the Iberian Peninsula and in inner arid localities of eastern Spain. This result agrees with the widely accepted halobiont condition of the group. However, sampling bias must be considered, and new records are expected to be provided from future revisions of collections and new samplings.

ABSTRACT One of the main costs in agriculture is related to mechanized operations, which, in turn, are associated with the capital invested in machinery and equipment, the scale of production, and the operating efficiency. Thus, the choice of technology to carry out these operations must take these factors into account to minimize the production cost. In this context, this study aimed to evaluate the most economical investment option for the set of sprayings on a farm located in the municipality of Mineiros, Goiás, Brazil, by comparing two technologies (ground and aerial spraying) and identifying the scale of production that makes each of the technologies more feasible. This study covers the period of one year with the soybean crop in the summer season, followed by the cultivation of corn in the off-season. Economic feasibility indicators were calculated, and the total average costs of both technologies were compared. The results allowed concluding that the investment in aerial spraying with the aircraft acquisition is assertive, as it reduced losses due to crushing. Contracting the service via third parties is feasible and can be used not only in cases of emergency, as it allows for increased profitability.