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The taxonomic history, general description and distribution are provided for Myoxanthus. Morphological characterization of the vegetative and reproductive organs is illustrated with photographs. A list of the 52 accepted species includes synonyms and distribution; most are illustrated with a flower photograph. Lectotypes for M. frutex, M. lonchophyllus, M. neillii, M. pulvinatus, M. punctatus, and M. serripetalus are designated, and a neotype is selected for M. melittanthus. Myoxanthus parvilabius is reported for the first time for Colombia. The circumscription of M. lonchophyllus is reevaluated, Pleurothallis pennellia is recognized as a distinct taxon and transferred to Myoxanthus, and Myoxanthus panamense, a new species related to M. scandens, is described from Pamana.

Este trabajo presenta los primeros avances en el estudio de cuentas de collar prehispánicas de la colección del Museo Nacional de Etnografía y Folklore (MUSEF) empleando técnica de Fluorescencia de Rayos X por Energía Dispersiva (FRX-ED), en una colaboración interdisciplinaria entre el MUSEF y el Instituto Boliviano de Ciencia y Tecnología Nuclear (IBTEN). Se presentan los métodos, muestra y resultados del análisis FRX-ED de 48 cuentas de collar, agrupadas en dos collares líticos, que fueron analizadas por esta técnica no destructiva a fin de avanzar en el conocimiento del origen y conformación de ambos collares. Los resultados permiten sugerir, aunque no confirmar, que la materia prima de ambos collares es lapislázuli, pero sobre todo revelan mayor heterogeneidad química en uno de los collares que en otro. Este resultado permite abrir nuevas preguntas, en torno a si estos dos agrupamientos de cuentas son en efecto fenómenos prehispánicos o ensamblajes posteriores, hechos en tiempos del coleccionismo. Asimismo, denota la necesidad de involucrarse a futuro en estudios de procedencia y en interacciones investigativas con países vecinos.

1. Changes in the pollinator assemblage visiting a plant can have consequences for reproductive success and floral evolution. We studied a recent plant trans-continental range expansion to test whether the acquisition of new pollinator functional groups can lead to rapid adaptive evolution of flowers. 2. In Digitalis purpurea, we compared flower visitors, floral traits and natural selection between native European populations and those in two Neotropical regions, naturalised after independent introductions. Bumblebees are the main pollinators in native populations while both bumblebees and hummingbirds are important visitors in the new range. We confirmed that the birds are effective pollinators and deposit more pollen grains on stigmas than bumblebees. 3. We found convergent changes in the two new regions towards larger proximal corolla tubes, a floral trait that restricts access to nectar to visitors with long mouthparts. There was a strong positive linear selection for this trait in the introduced populations, particularly on the length of the proximal corolla tube, consistent with the addition of hummingbirds as pollinators. 4. Synthesis. The addition of new pollinators is likely to happen often as humans influence the ranges of plants and pollinators but it is also a common feature in the long-term evolution of the angiosperms. We show how novel selection followed by very rapid evolutionary change can be an important force behind the extraordinary diversity of flowers. Botanical Society of Britainand Ireland/[]/BSBI/Inglaterra Percy Sladen Memorial Fund/[]//Inglaterra European Union's Horizon 2020 Programme/[706365]//Europa UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigación en Biodiversidad y Ecología Tropical (CIBET) UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

PREMISE: Gypsum soils in the Mediterranean Basin house large numbers of edaphic specialists that are adapted to stressful environments. The evolutionary history and standing genetic variation of these taxa have been influenced by the geological and paleoclimatic complexity of this area and the long-standing effect of human activities. However, little is known about the origin of Mediterranean gypsophiles and the factors affecting their genetic diversity and population structure. METHODS: Using phylogenetic and phylogeographic approaches based on microsatellites and sequence data from nuclear and chloroplast regions, we evaluated the divergence time, genetic diversity, and population structure of 27 different populations of the widespread Iberian gypsophile Lepidium subulatum throughout its entire geographic range. RESULTS: Lepidium subulatum diverged from its nearest relatives ~3 million years ago, and ITS and psbA/matK trees supported the monophyly of the species. These results suggest that both geological and climatic changes in the region around the Plio-Pleistocene promoted its origin, compared to other evolutionary processes. We found high genetic diversity in both nuclear and chloroplast markers, but a greater population structure in the chloroplast data. These results suggest that while seed dispersal is limited, pollen flow may be favored by the presence of numerous habitat patches that enhance the movement of pollinators. CONCLUSIONS: Despite being an edaphic endemic, L. subulatum possesses high genetic diversity probably related to its relatively old age and high population sizes across its range. Our study highlights the value of using different markers to fully understand the phylogeographic history of plant species.

Maize is an important crop worldwide having vital nutritional, medicinal, and economic significance. It is vulnerable to a broad spectrum of emerging infections and diseases caused by Fusarium spec...

Two species of Monstera, apparently endemic to Costa Rica, are newly described and illustrated. Monstera juliusii occurs in the southern Costa Rican portion of the Cordillera de Talamanca at 1600–2250 m, and has been confused with M. standleyana in herbaria. Monstera monteverdensis occurs in the Guanacaste and Tilarán cordilleras, and the northwestern part of the Cordillera Central, at 500–2300 m, and has been confused with M. epipremnoides, M. lentii and M. lechleriana in herbaria. Phenology and suggested conservation categories according to the IUCN Red List criteria are indicated for both new taxa.

Background and Aims Plants experiencing contrasting environmental conditions may accommodate such heterogeneity by expressing phenotypic plasticity, evolving local adaptation or a combination of both. We investigated patterns of genetic differentiation and plasticity in response to drought in populations of the gypsum specialist Lepidium subulatum. Methods We created an outdoor common garden with rain exclusion structures using 60 maternal progenies from four distinct populations that substantially differ in climatic conditions. We characterized fitness, life history and functional plasticity in response to two contrasting treatments that realistically reflect soil moisture variation in gypsum habitats. We also assessed neutral genetic variation and population structure using microsatellite markers. Key Results In response to water stress, plants from all populations flowered earlier, increased allocation to root tissues and advanced leaf senescence, consistent with a drought escape strategy. Remarkably, these probably adaptive responses were common to all populations, as shown by the lack of population × environment interaction for almost all functional traits. This generally common pattern of response was consistent with substantial neutral genetic variation and large differences in population trait means. However, such population-level trait variation was not related to climatic conditions at the sites of origin. Conclusions Our results show that, rather than ecotypes specialized to local climatic conditions, these populations are composed of highly plastic, general-purpose genotypes in relation to climatic heterogeneity. The strikingly similar patterns of plasticity among populations, despite substantial site of origin differences in climate, suggest past selection on a common norm of reaction due to similarly high levels of variation within sites. It is thus likely that plasticity will have a prevalent role in the response of this soil specialist to further environmental change.

14Pág. Centro de Investigación Forestal (CIFOR), Natural selection is the major force driving adaptive evolution in natural populations, varying in strength, direction, and form through space and time, especially in highly variable environments such as Mediterranean ecosystems. Although a conservative resource-use strategy has been hypothesized to be adaptive in Mediterranean taxa, patterns of selection at the intraspecific level, that is, the suite of traits determining individual fitness, are largely unknown. Using a phenotypic selection experiment in natural semi-arid conditions, we measured direct and indirect selection acting through two different fitness components (survival and reproduction), to assess the adaptive value of 20 ecophysiological traits on individuals of two gypsum endemic species, Centaurea hyssopifolia and Helianthemum squamatum, dwelling in environments with contrasting abiotic conditions (south- and north-facing slopes) during two climatically contrasting years (dry and mesic). This allowed quantifying the magnitude and direction of natural selection at different spatiotemporal scales. Our results revealed that different abiotic conditions did not alter selection patterns, being the magnitude of selection more strongly affected by temporal environmental variation. Selection through reproduction indicated consistent selection for early phenology, low water use efficiency, high specific leaf area, low leaf dry matter content, and high leaf N across slopes and years in both species. In contrast, phenotypic trait variation was not linked to survival in either species. Furthermore, while individual reproductive output was higher or similar in environments with higher abiotic stress in both species and years, survival was similar across environmental conditions, and it was neither affected by plant size nor reproductive output. Contrary to our expectations, natural selection via reproductive fitness consistently favoured a drought-escape, acquisitive resource-use strategy in Mediterranean semi-arid plants, rather than a conservative resource-use strategy, even under conditions of higher abiotic stress (i.e. south slopes and dry year). Such acquisitive strategy could allow rapid development by maximizing resource assimilation and reproduction before the most limiting climatic conditions of mid-late summer. Our results shed light on adaptive functional strategies of Mediterranean taxa at the intraspecific level, providing insight on future responses to environmental change, and highlight remarkable differences in selection acting through different fitness components. Read the free Plain Language Summary for this article on the Journal blog., This study was funded by the Spanish Ministerio de Economía y Competitividad (grant GYPSEVOL, CGL2016-75566-P) and the Madrid Regional Government (grant Remedinal3-CM, S2013/MAE-2719). We thank C. Díaz for his assistance during trait measurements, and R. Milla and T.E. Gimeno for their inspiring ideas during the discussion process and insightful comments on the manuscript.

Antecedentes y Objetivos: Aristolochia es el género más grande de Aristolochiaceae y está ampliamente distribuido en el mundo. Una sinopsis reciente de Aristolochia en Costa Rica reconoció 19 especies; sin embargo, una reciente exploración botánica en la parte suroeste de Costa Rica ha revelado otra nueva especie del género.Métodos: La nueva especie resultó del trabajo de campo en Buenos Aires, Provincia de Puntarenas. Se examinaron ejemplares de varios herbarios, así como el material tipo de las especies más similares morfológicamente. Se proporcionan comentarios sobre su distribución, hábitat, fenología, estado de conservación y distinción morfológica de especies relacionadas.Resultados clave: Aristolochia quiricoana, miembro de Aristolochia serie Thyrsicae, se describe e ilustra de la región del Pacífico sur de Costa Rica, donde aparentemente es endémica. Es semejante a A. ornithorhyncha, de la cual se distingue por sus pedicelos más cortos, los limbos del perigonio más anchos y oblongos, con un apéndice más corto, y un patrón diferente de colores de la flor.Conclusiones: El nuevo taxón descrito aquí representa la 22ª especie documentada de Aristolochia serie Thyrsicae, así como la 20ª especie del género para Costa Rica.

Although thousands of lncRNAs are encoded in mammalian genomes, their mechanisms of action are largely uncharacterized because they are often expressed at significantly lower levels than their proposed targets. One such lncRNA is Xist, which mediates chromosome-wide gene silencing on one of the two X chromosomes to achieve gene expression balance between males and females. How a limited number of Xist molecules can mediate robust silencing of a significantly larger number of target genes (∼1 Xist RNA: 10 gene targets) while maintaining specificity to genes on the X within each cell is unknown. Here, we show that Xist drives non-stoichiometric recruitment of the essential silencing protein SHARP (also called Spen) to amplify its abundance across the inactive X, including at regions not directly occupied by Xist. This amplification is achieved through concentration-dependent homotypic assemblies of SHARP on the X and is required for chromosome-wide silencing. We find that expressing Xist at higher levels leads to increased localization at autosomal regions, demonstrating that low levels of Xist are critical for ensuring its specificity to the X chromosome. We show that Xist (through SHARP) acts to suppress production of its own RNA which may act to constrain overall RNA levels and restrict its ability to spread beyond the X. Together, our results demonstrate a spatial amplification mechanism that allows Xist to achieve two essential but countervailing regulatory objectives: chromosome-wide gene silencing and specificity to the X. Our results suggest that this spatial amplification mechanism may be a more general mechanism by which other low abundance lncRNAs can balance specificity to, and robust control of, their regulatory targets.

Matesanz, S., Ramos-Munoz, M., Blanco-Sanchez, M., Garcia-Fernandez, A., Escudero, A. 2019. Migration, genetic variation and phenotypic plasticity of gypsophiles and their role on climate change responses. Ecosistemas 28(1): 48-59. Doi.: 10.7818/ECOS.1525 Gypsum habitats host unique plant communities due to their high richness and abundance of endemic species. Although our knowledge regarding several aspects of their ecology has increased over the last decades, the effects of climate change on gypsophiles, and importantly, their response mechanisms, have been poorly explored. Under the increased aridity foreseen for many regions due to climate change, plants may migrate to more favorable sites, adapt to new environmental conditions or adjust via phenotypic plasticity. In this study, we review the documented effects of climate change on gypsophile populations and evaluate the existing evidence on their potential responses. Despite the stress-tolerant nature of these species, several studies have shown negative effects on their physiology, phenology and demography. Several aspects related to life on gypsum, including natural and anthropogenic fragmentation, gypsophily and lack of active dispersal mechanisms may greatly limit their migration ability. Although there is very little information in population differentiation, evolutionary potential for key functional traits and phenotypic plasticity, our revision suggests that these mechanisms will have a more prominent role than migration in a climate change context. Therefore, we propose future research lines to allow a deeper knowledge on microevolutionary process involved in the response of gypsophiles to climate change.

In recent years, the number of patients with ocular diseases is increasing as a consequence of population aging. Among them, one of the most common is the age-related macular degeneration (AMD), a condition that leads to vision loss if it is not treated. AMD is a multifactorial disorder with two advanced forms, dry and neovascular AMD. Currently, although there is no approved therapy that significantly impacts dry AMD progression, several pharmacologic therapies exist for neovascular AMD. Notwithstanding, evidence suggests a suboptimal result in a high number of patients receiving these therapeutic options. Consequently, finding effective strategies is not only a still unmet medical need in dry AMD but also in neovascular AMD. This underlines the need for new drug delivery technologies that can improve the pharmacological action and drug concentration at the target sites. In this regard, sustained drug delivery systems are presented as the most promising therapeutic options in AMD patients. This review summarized the pathogenesis and the current treatment options for AMD, focusing on the emerging ocular sustained drug delivery approaches undergoing clinical trials.

Understanding constraints to phenotypic plasticity is key given its role on the response of organisms to environmental change. It has been suggested that phenotypic integration, the structure of trait covariation, could limit trait plasticity. However, the relationship between plasticity and integration is far from resolved. Using a database of functional plasticity to drought of a Mediterranean shrub that included 20 ecophysiological traits, we assessed environmentally-induced changes in phenotypic integration and whether integration constrained the expression of plasticity, accounting for thewithin-environment phenotypic variation of traits. Furthermore, we provide the first test of the association between differential trait plasticity and trait integration across an optimumand a stressful environment. Phenotypic plasticity was positively associated with phenotypic integration in both environments, but this relationship was lost when phenotypic variation was considered. The similarityin the plastic response of two traits predicted their integration across environments, with integrated traits having more similar plasticity. Such variation in the plasticity of traits partly explained the lower phenotypic integration found in the stressful environment. We found no evidence that integration may constitute an internal constraint to plasticity. Rather, we present the first empirical demonstration that differences in plastic responses mayinvolve a major reorganization of the relationships among traits, and challenge the notion thatstress generally induces a tighter phenotype., This work was funded by grants GYPSEVOL (CGL2016-75566-P), Remedinal (TE-CM: S2018/EMT-4338), Phenotypes (PGC2018-099115-B-I00) and the Ramon y Cajal Programme of the Spanish Ministry of Economy and Competitiveness.

Innovation is at the heart of scientific and technological success. Without innovation, science stagnates and businesses disappear. Thus, innovation is the common core shared by academic and industry endeavors, a good point of departure for successful collaborations.

Sulphate content in mining wastewater can reach concentrations over 2000 mg/L and, if untreated, is responsible for causing medical problems on humans and animals. Conventional treatment techniques are based on costly and environmentally harmful processes, so it is a need to find a sustainable approach of these methods. For this study, mining wastewater rich in sulphates was used as culture medium for two Arthrospira species. Strains were selected due to their capacity turn contaminants into added value molecules. The focus of this work was to use this wastewater for algal biomass production, as well as to study the biosorption of sulphate on external algal walls. Results showed how Arthrospira maxima could tolerate the presence of 100% of residue and incorporated up to 23.34% of initial sulphate concentration, which is comparable to the pre-treatments currently used in mining industry. SEM-EDX analysis reported no adsorption of sulphates on cellular surface, proving that sulphate descent was due to metabolic up-taking. Our findings suggest that Arthrospira maxima cultures can be used as part of a novel sulphate bioremediation system and for valuable compounds extraction.

Poor morphological and molecular differentiation in recently diversified lineages is a widespread phenomenon in plants. Phylogenetic relationships within such species complexes are often difficult to resolve because of the low variability in traditional molecular loci. Furthermore, biological phenomena responsible for topological incongruence such as Incomplete Lineage Sorting (ILS) and hybridisation complicate the resolution of phylogenetic relationships among closely related taxa. In this study, we employ a Genotyping-by-sequencing (GBS) approach to disentangle evolutionary relationships within a species complex belonging to the Neotropical orchid genus Cycnoches. This complex includes seven taxa distributed through Central America and the Colombian Chocó, and is nested within a clade estimated to have first diversified in the early Quaternary. Previous phylogenies inferred from few loci failed to provide support for internal relationships within the complex. Our Neighbour-net and coalescent-based analyses inferred from ca. 13,000 GBS loci obtained from 31 individuals belonging to six of the seven traditionally accepted Cycnoches taxa provided a robust phylogeny for this group. The genus Cycnoches includes three main clades that are further supported by morphological traits and geographic distributions. Similarly, a topology reconstructed through maximum likelihood (ML) inference of concatenated GBS loci produced results that are comparable with those reconstructed through coalescence and network-based methods. Our comparative phylogenetic informativeness analyses suggest that the low support evident in the ML phylogeny might be attributed to the abundance of uninformative GBS loci, which can account for up to 50% of the total number of loci recovered. The phylogenomic framework provided here, as well as morphological evidence and geographical patterns, suggest that the six entities previously thought to be different species or subspecies might actually represent only three distinct segregates. We further discuss the limited phylogenetic informativeness found in our GBS approach and its utility to disentangle relationships within recent and rapidly evolving species complexes. Our study is the first to demonstrate the utility of GBS data to reconstruct relationships within young (~2 Ma) Neotropical plant clades, opening new avenues for studies of species complexes that populate the species-rich orchid family UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

Subtribe Spiranthinae is the most species-rich lineage of terrestrial Neotropical orchids, encompassing > 500 species and 40 genera. We conducted maximum parsimony and maximum likelihood phylogenetic analyses of DNA sequence data of plastid matK-trnK and trnL-trnF and nuclear ribosomal ITS sequences for 36 genera and 182 species of Spiranthinae plus appropriate outgroups. The results strongly support monophyly of Spiranthinae (minus Discyphus, Discyphinae and Galeottiella, Galeottiellinae) and five major lineages, namely monospecific Cotylolabium (sister to the remaining Spiranthinae) and the Eurystyles, Pelexia, Spiranthes and Stenorrhynchos clades. Eighteen of the 27 genera of Spiranthinae for which more than one species was included in our analyses are monophyletic. Paraphyly of large genera, such as Cyclopogon and Sarcoglottis, resulted from segregation of particular species or groups of species exhibiting minor modifications of structures directly involved in pollination (e.g. nectary, rostellum and viscidium). Conversely, polyphyly has resulted from convergent evolution of floral attributes in distantly related species (e.g. Mesadenus). Some of the morphological characters used traditionally for generic delimitation and in nonmolecular cladistic analyses of Spiranthinae are discussed against the evolutionary framework set by our molecular trees, emphasizing putative synapomorphies and problems derived from inappropriate character coding or incorrect homology assessments. Our ancestral area analysis indicates that Spiranthinae originated in eastern South America, with subsequent migrations and secondary radiations in Mesoamerica and North America, plus a derived migration from the latter region to the Old World (Spiranthes). Universidad Nacional Autónoma de México/[]/UNAM/México American Orchid Society/[]/AOS/Estados Unidos Consejo Nacional de Ciencia y Tecnología/[]/CONACYT/México UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

SUMMARYThe nucleus is a highly organized arrangement of RNA, DNA, and protein molecules that are compartmentalized within three-dimensional (3D) structures involved in shared functional and regulatory processes. Although RNA has long been proposed to play a global role in organizing nuclear structure, exploring the role of RNA in shaping nuclear structure has remained a challenge because no existing methods can simultaneously measure RNA-RNA, RNA-DNA, and DNA-DNA contacts within 3D structures. To address this, we developed RNA & DNA SPRITE (RD-SPRITE) to comprehensively map the location of all RNAs relative to DNA and other RNAs. Using this approach, we identify many RNAs that are localized near their transcriptional loci (RNA-DNA) together with other diffusible ncRNAs (RNA-RNA) within higher-order DNA structures (DNA-DNA). These RNA-chromatin compartments span three major classes of nuclear functions: RNA processing (including ribosome biogenesis, mRNA splicing, snRNA biogenesis, and histone mRNA processing), heterochromatin assembly, and gene regulation. More generally, we identify hundreds of ncRNAs that form stable nuclear compartments in spatial proximity to their transcriptional loci. We find that dozens of nuclear compartments require RNA to guide protein regulators into these 3D structures, and focusing on several ncRNAs, we show that these ncRNAs specifically regulate heterochromatin assembly and the expression of genes contained within these compartments. Together, our results demonstrate a unique mechanism by which RNA acts to shape nuclear structure by forming high concentration territories immediately upon transcription, binding to diffusible regulators, and guiding them into spatial compartments to regulate a wide range of essential nuclear functions.

Fieldwork for this study was done during the field courses OET 2013-18 and OET 2015-18 (“Sistemática de Plantas Tropicales”) of the Organization for Tropical Studies, and during a field trip for the course “Morfología de Flores y Frutos” of the Universidad de Costa Rica. A large colony of duckweeds (Araceae: Lemnoideae) grows on the constantly wet, vertical wall of the rock shelter behind the Llanos de Cortés waterfall of the Potrero River, Guanacaste province, Costa Rica, the first such case ever documented. Its unique hygropetric environment is described. The colony covers several square meters distributed in several different patches, and consists almost entirely of Wolffiella oblonga (Phil.) Hegelm., with much fewer individuals of Lemna valdiviana Phil. and L. aequinoctialis Welw. This also constitutes the first case of the genus Wolffiella Hegelm. growing in a hygropetric manner (an extremely rare condition for duckweeds) and the first record of W. oblonga in Costa Rica. Une vaste colonie de lentilles d’eau (Araceae: Lemnoideae) se développe sur le mur vertical constamment humide de l’abri rocheux situé derrière la cascade Llanos de Cortés de la rivière Potrero, dans la province de Guanacaste, au Costa Rica. C’est le premier cas de ce type jamais documenté. Son environnement hygropétrique unique est décrit. La colonie couvre plusieurs mètres carrés répartis en plusieurs parcelles différentes et consiste presque entièrement en Wolffiella oblonga (Phil.) Hegelm., avec beaucoup moins d’individus de Lemna valdiviana Phil. et L. aequinoctialis Welw. Ceci constitue également la première espèce du genre Wolffiella Hegelm. poussant de manière hygropétrique (une condition extrêmement rare pour les lentilles d’eau) et son premier enregistrement au Costa Rica. UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL)

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a recently identified coronavirus that causes the respiratory disease known as coronavirus disease 2019 (COVID-19). Despite the urgent need, we still do not fully understand the molecular basis of SARS-CoV-2 pathogenesis. Here, we comprehensively define the interactions between SARS-CoV-2 proteins and human RNAs. NSP16 binds to the mRNA recognition domains of the U1 and U2 splicing RNAs and acts to suppress global mRNA splicing upon SARS-CoV-2 infection. NSP1 binds to 18S ribosomal RNA in the mRNA entry channel of the ribosome and leads to global inhibition of mRNA translation upon infection. Finally, NSP8 and NSP9 bind to the 7SL RNA in the signal recognition particle and interfere with protein trafficking to the cell membrane upon infection. Disruption of each of these essential cellular functions acts to suppress the interferon response to viral infection. Our results uncover a multipronged strategy utilized by SARS-CoV-2 to antagonize essential cellular processes to suppress host defenses., Graphical Abstract, Highlights • NSP16 binds mRNA recognition domains of U1/U2 snRNAs and disrupts mRNA splicing • NSP1 binds in the mRNA entry channel of the ribosome to disrupt protein translation • NSP8 and NSP9 bind the signal recognition particle and disrupt protein trafficking • These disruptions of protein production suppress the interferon response to infection, SARS-CoV-2 proteins directly engage host RNAs to dysregulate essential steps of protein production and suppress the interferon response.

Background: This study aimed to (1) describe drug-induced deaths (DIDs) in Southern Spain (Andalusia) in terms of substances involved, sociodemographic characteristics, and circumstances of death, and (2) identify profiles by substances involved and their association with sociodemographic characteristics and circumstances of death. Methods: Observational study of 398 deceased in 2010/2011 in Andalusia suspected of DIDs. Medical examiner diagnoses considered the scene of death, regulatory forensic autopsy, histopathological studies, and toxic-chemical analyses. Latent Class Analysis was applied. Results: The final sample included 360 people diagnosed with DIDs. The mean age was 39.7 and 87.2% were male. The most frequent substances involved were methadone, benzodiazepines, cocaine, and opiates. Two or more substances were involved in 86.7% of deaths. Four profiles were identified: methadone-benzodiazepines, cocaine, benzodiazepines-cocaine-methadone-opiates, and benzodiazepines-alcohol. The methado...

During pre-mRNA splicing, a central step in the expression and regulation of eukaryotic genes, the spliceosome selects splice sites for intron excision and exon ligation. In doing so, the spliceosome must distinguish optimal from suboptimal splice sites. At the catalytic stage of splicing, suboptimal splice sites are repressed by the DEAH-box ATPases Prp16 and Prp22. Here, using budding yeast, we show that these ATPases function further by enabling the spliceosome to search for and utilize alternative branch sites and 3' splice sites. The ATPases facilitate this search by remodeling the splicing substrate to disengage candidate splice sites. Our data support a mechanism involving 3' to 5' translocation of the ATPases along substrate RNA and toward a candidate site, but, surprisingly, not across the site. Thus, our data implicate DEAH-box ATPases in acting at a distance by pulling substrate RNA from the catalytic core of the spliceosome.

Many lncRNAs are thought to interact with the polycomb repressive complex 2 (PRC2) in order to regulate gene expression. A central example of this lncRNA–PRC2 paradigm in gene regulation is HOTAIR . In this issue of The EMBO Journal, a study (Portoso et al, [2017][1]) reports that while HOTAIR binds PRC2 with high affinity, the complex itself is dispensable for HOTAIR ‐mediated transcriptional silencing. This study raises important questions about the role of PRC2 interactions for lncRNA‐mediated functions and argues for a re‐evaluation of this lncRNA–PRC2 functional paradigm. [1]: #ref-8

Chronic social isolation causes severe psychological effects in humans, but their neural bases remain poorly understood. 2 weeks (but not 24 hr) of social isolation stress (SIS) caused multiple behavioral changes in mice and induced brain-wide upregulation of the neuropeptide tachykinin 2 (Tac2)/neurokinin B (NkB). Systemic administration of an Nk3R antagonist prevented virtually all of the behavioral effects of chronic SIS. Conversely, enhancing NkB expression and release phenocopied SIS in group-housed mice, promoting aggression and converting stimulus-locked defensive behaviors to persistent responses. Multiplexed analysis of Tac2/NkB function in multiple brain areas revealed dissociable, region-specific requirements for both the peptide and its receptor in different SIS-induced behavioral changes. Thus, Tac2 coordinates a pleiotropic brain state caused by SIS via a distributed mode of action. These data reveal the profound effects of prolonged social isolation on brain chemistry and function and suggest potential new therapeutic applications for Nk3R antagonists.

Bauhinia proboscidea, a new species from Costa Rica and Panama, is described and illustrated, and compared to the closely related B. pansamalana of southern Mexico, Guatemala and Honduras. It is also compared with B. beguinotii, with which has been confused in herbaria. Bauhinia gorgonae, endemic to Gorgona Island in Colombia and which has been classified as a variety of B. beguinotii, is here considered a separate species. A key to the Neotropical species of Bauhinia with three fertile stamens is provided. Some observations on the morphology and reproductive biology of B. proboscidea are presented. Global-level assessments of the conservation status according to IUCN Red List criteria indicate that B. proboscidea and B. beguinotii (which was previously assessed using some misidentified records) should both be considered as species of Least Concern (LC), B. gorgonae should be considered as Endangered (EN), and B. pansamalana should be considered Not Threatened (NT). Country-level conservation assessments are also provided for all four species. The homology of the “intrastipular spines” of Bauhinia is briefly discussed. Se describe e ilustra Bauhinia proboscidea, una nueva especie de Costa Rica y Panamá, y se compara con la cercanamente emparentada B. pansamalana del sur de México, Guatemala y Honduras. También se compara con B. beguinotii, con la cual se ha confundido en los herbarios. Bauhinia gorgonae, endémica de la Isla Gorgona en Colombia, se considera aquí como una especie independiente de B. beguinotii, de la cual se ha clasificado como una variedad. Se brinda una clave para las especies neotropicales de Bauhinia con tres estambres fértiles. Se presentan algunas observaciones sobre la morfología y biología reproductiva de B. proboscidea. Evaluaciones a nivel global del estado de conservación de acuerdo con los criterios de la Lista Roja de UICN, indica que tanto B. proboscidea como B. beguinotii (que había sido previamente evaluada usando algunos registros mal identificados) deben ser consideradas como especies de Preocupación Menor (LC), B. gorgonae debe considerarse como En Peligro (EN), y B. pansamalana debe considerarse como No Amenazada (NT). También se presentan evaluaciones de conservación a nivel de país para las cuatro especies. Se discute brevemente la homología de las “espinas intraestipulares” de Bauhinia. Universidad de Costa Rica/[]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Jardín Botánico Lankester (JBL) UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología

Bolivia has several nonmetallic occurrences widespread in the country. Unfortunately, they are poorly studied and slightly characterized. In the present work, several nonmetallic occurrences locate ...

The cultivar ?Torrontes Riojano? (Vitis vinifera L.) was derived from a cross of ?Muscat of Alexandria? and ?Criolla Chica?. Its origin was probably not a directed cross in Mendoza Argentina during the colonial period. Related cultivars with common characteristics are called ?criollas?. Some are derived from the same cross, and one is a half-sister with a parent in common. ?Torrontes Riojano? is a productive and vigorous cultivar, and usually is used to produce dry white wines with distinct ?Muscat? flavor. It is spread in the Argentinean northwest wine valleys. Collection trips were made in summer to identify plants with morphologic variations, and others were made during autumn and spring to eliminate plants with viral disease symptoms. Sixty clones were collected from 6 vineyards located in the areas where this cultivar is mostly cultivated, Cafayate (Salta, Argentina) and Chilecito (La Rioja, Argentina). Virus diseases were screened by ELISA tests, and six microsatellites were used to confirm varietal identity: VVMD5, VVMD7, VVMD27, ssrVrZAG 62, ssrVrZAG 79 and VVS2. After that, clones were planted in triplicate in a homogeneous plot. Parameters related to cluster morphology and productivity were measured over 2 growing seasons, 2013 and 2014. The high variability observed in the collection was evidenced through the coefficients of variation. The work is the first contribution of ?Torrontes Riojano?s germplasm and a starting point to hypothesize about the origin of the variability in this cultivar.

Long noncoding RNAs (lncRNAs, which comprise 68% of the human transcriptome with average length of 1,000 nt) interact with various RNA-binding proteins (RBPs) to mediate cellular functions1. Identification of lncRNA interactions through experimental methods is challenging and can be complemented by the use of computational models to predict protein partners. Yet it is currently impractical to calculate RBP–lncRNA interactions for large transcripts2.We introduce Global Score as a means to predict protein interactions with large RNAs (http://service.tartaglialab.com/new_submission/globalscore).

Departamento de Filosofía (Filosofía, Lógica y Filosofía de la Ciencia, Teoría e Historia de la Educación, Filosofía Moral, Estética y Teoría de las Artes), Grado en Filosofía

Utilizing an existing macro-homogeneous porous electrode model developed by John Newman, this paper aims to explore the potential energy density gains which can be realized in lithium-ion battery electrodes fabricated with co-extrusion printing technology. This paper conducts an analysis on two-dimensional electrode cross-sections and presents the electrochemical performance results, including calculated volumetric energy capacity for a general class of lithium cobalt oxide (LiCoO 2 ) co-extruded cathodes, in the presence of a lithium metal anode, polymer separator and liquid ethylene carbonate, propylene carbonate, and dimethyl carbonate (EC:PC:DMC) electrolyte. The impact of structured electrodes on cell performance is investigated by varying the physical distribution of a fixed amount of cathode mass over a space of dimensions which can be fabricated by co-extrusion. By systematically varying the thickness and aspect ratio of the electrode structures, we present an optimal subset of geometries and design rules for co-extruded geometries. Modeling results demonstrate that ultra-thick LiCoO 2 electrodes, on the order of 150–300 μm, can garner a substantial improvement in material utilization and in turn capacity through electrolyte channels and fine width electrode pillars which are 25–100 μm wide.

The spliceosome is a dynamic ribonucleoprotein (RNP) machine that catalyzes the removal of introns during the two transesterification steps of eukaryotic pre-mRNA splicing. Here we used single-molecule fluorescence resonance energy transfer to monitor the distance of the 5' splice site (5' SS) and branch point (BP) of pre-mRNA in affinity-purified spliceosomes stalled by a mutation in the DExD/H-box helicase Prp2 immediately before the first splicing step. Addition of recombinant Prp2 together with NTP and protein cofactor Spp2 rearranges the spliceosome-substrate complex to reversibly explore conformations with proximal 5' SS and BP that accommodate chemistry. Addition of Cwc25, a small heat-stable splicing factor, then strongly biases this equilibrium toward the proximal conformation, promoting efficient first-step splicing. The spliceosome thus functions as a biased Brownian ratchet machine where a helicase unlocks thermal fluctuations subsequently rectified by a cofactor 'pawl', a principle possibly widespread among the many helicase-driven RNPs.

Background and Aims: A significant proportion of orchid species assigned to subtribe Oncidiinae produce floral oil as a food reward that attracts specialized bee pollinators. This oil is produced either by glabrous glands (epithelial elaiophores) or by tufts of secretory hairs (trichomal elaiophores). Although the structure of epithelial elaiophores in the Oncidiinae has been well documented, trichomal elaiophores are less common and have not received as much attention. Only trichomal elaiophores occur in the genus Lockhartia, and their distribution and structure are surveyed here for the first time. Methods: Flowers of 16 species of Lockhartia were studied. The location of floral elaiophores was determined histochemically and their anatomical organization and mode of oil secretionwas investigated by means of light microscopy, scanning electron microscopy and transmission electron microscopy. Key Results and Conclusions: All species of Lockhartia investigated have trichomal elaiophores on the adaxial surface of the labellum. Histochemical tests revealed the presence of lipoidal substances within the labellar trichomes. However, the degree of oil production and the distribution of trichomes differed between the three major groups of species found within the genus. All trichomes were unicellular and, in some species, of two distinct sizes, the larger being either capitate or apically branched. The trichomal cuticle was lamellate, and often appeared distended due to the subcuticular accumulation of oil. The labellar trichomes of the three species examined using transmission electron microscopy contained dense, intensely staining cytoplasm with apically located vacuoles. Oil-laden secretory vesicles fused with the plasmalemma and discharged their contents. Oil eventually accumulated between the cell wall and cuticle of the trichome and contained electron-transparent profiles or droplets. This condition is considered unique to Lockhartia among those species of elaiophore-bearing Oncidiinae studied to date. American Orchid Society/[]AOS/Estados Unidos UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología

The Xist long noncoding RNA orchestrates X chromosome inactivation, a process that entails chromosome-wide silencing and remodeling of the three-dimensional (3D) structure of the X chromosome. Yet, it remains unclear whether these changes in nuclear structure are mediated by Xist and whether they are required for silencing. Here, we show that Xist directly interacts with the Lamin B receptor, an integral component of the nuclear lamina, and that this interaction is required for Xist-mediated silencing by recruiting the inactive X to the nuclear lamina and by doing so enables Xist to spread to actively transcribed genes across the X. Our results demonstrate that lamina recruitment changes the 3D structure of DNA, enabling Xist and its silencing proteins to spread across the X to silence transcription.

Clay minerals are widely distributed in Bolivia; among them, illitic clays are most common in the Altiplano where they are mined for use in the ceramic industry that has been growing in the last few years. In addition to illitic sediments, kaolinitic sediments have been recently discovered in sedimentary units in the Bolivian Altiplano. Residual ball clay occurrences in Devonian sedimentary units were studied as part of this work. Geological mapping and geophysical studies (ERT and GPR) were done for better understanding the origin of the deposits and were part of a preliminary study of the mineral potential to define the relationship with the host rock. Chemical and mineralogical techniques such as X-Ray Diffraction, Scanning Electron Microscopy and Inductively Coupled Plasma analyses were performed in samples from the studied area to verify the presence of kaolinite. Atterberg limits and behaviour of the raw material in ceramic specimens supported by chemical analyses show that this material is suitable for manufacturing tile ceramics. This study provides fundamental knowledge for deposit exploitation and future generation of an alternative source of employment for the inhabitants of Micaya Validerad; 2016; Nivå 2; 20160411 (andbra)

The taxonomic position of Myoxanthus Poepp. & Endl. (Orchidaceae: Pleurothallidinae) i s d i s c u s s e d a n d Silenia L u e r i s m a i n t a i n e d a s a s u b g e n u s o f M y o x a n t h u s. A n e w s p e c i e s o f Myoxanthus is described and illustrated. Myoxanthus vittatus Pupulin & M.A. Blanco is apparently endemic to the low, tropical wet forests of central Pacific Costa Rica, where it has been collected in two different places. It differs from closely related species for the small size of the plant, the whitish flowers, longitudinally striped with purple, the densely pubescent ovary, and the ligulate, obtuse lip. The new combination Myoxanthus tomentosus (Luer) Pupulin & M.A. Blanco is proposed. S e d i s c u t e l a p o s i c i ó n t a x o n ó m i c a d e Myoxanthus P o e p p . & E n d l . ( O r c h i d a c e a e : Pleurothallidinae) y se mantiene a Silenia Luer como subgénero de Myoxanthus. Se describe y se ilustra una nueva especie de Myoxanthus. Myoxanthus vittatus Pupulin & M.A. Blanco es aparente- mente endémico de los bosques tropicales de bajura en el Pacífico Central de Costa Rica, donde ha sido recolectado en dos diferentes localidades. Difiere de las especies afines por el tamaño pequeño de las plantas, por sus flores blanquecinas con estrías longitudinales púrpura, por el ovario densa- mente pubescente y por el labelo ligulado y obtuso. Se propone la nueva combinación Myoxanthus tomentosus (Luer) Pupulin & M.A. Blanco.

S e p r e s e n t a e l p r i m e r i n f o r m e d e l a e x i s t e n c i a d e C y c l o p o g o n o b l i q u u s ( J . J . S m . ) S z l a c h . [= Pelexia obliqua (J. J. Sm.) Garay] en Costa Rica. Se discute su posición taxonómica y se presenta una revisión de su actual distribución geográfica. Se presentan observaciones sobre su hábitat, fenología y repro- ducción.

The new species Stellilabium smaragdinum is described and illustrated from the montane oak f o r e s t s o f t h e C o r d i l l e r a d e T a l a m a n c a , C o s t a R i c a . A m o n g t h e s p e c i e s o f S e c t . T ae ni or hac hi s , S. smaragdinum may be recognized for the inflorescence bearing 1-3 (4) simultaneous flowers, the oblong to ovoid, rounded basal lobules of the lip, the non-ciliate margins of the lip midlobe and the peculiar colour of the column setae, cream banded with purple. S e d e s c r i b e e i l u s t r a S t e l l i l a b i u m s m a r a g d i n u m d e l o s b o s q u e s m o n t a n o s d e e n c i n o d e l a Cordillera de Talamanca. S. smaragdinum se distingue de otras especies de la sección Taeniorhachis por su inflorescencia con 1 a 3 (4) flores simultáneas, los lóbulos basales del labelo oblongos a ovoides y redondeados en el ápice y la peculiar coloración de la setas en los lóbulos laterales de la columna, marfil con bandas púrpura.

In response to intracellular signals in Gram-negative bacteria, translational riboswitches—commonly embedded in messenger RNAs (mRNAs)—regulate gene expression through inhibition of translation initiation. It is generally thought that this regulation originates from occlusion of the Shine-Dalgarno (SD) sequence upon ligand binding; however, little direct evidence exists. Here we develop Single Molecule Kinetic Analysis of RNA Transient Structure (SiM-KARTS) to investigate the ligand-dependent accessibility of the SD sequence of an mRNA hosting the 7-aminomethyl-7-deazaguanine (preQ1)-sensing riboswitch. Spike train analysis reveals that individual mRNA molecules alternate between two conformational states, distinguished by ‘bursts' of probe binding associated with increased SD sequence accessibility. Addition of preQ1 decreases the lifetime of the SD's high-accessibility (bursting) state and prolongs the time between bursts. In addition, ligand-jump experiments reveal imperfect riboswitching of single mRNA molecules. Such complex ligand sensing by individual mRNA molecules rationalizes the nuanced ligand response observed during bulk mRNA translation., In response to intracellular signals, bacterial translational riboswitches embedded in mRNAs can regulate gene expression through inhibition of translation initiation. Here, the authors describe SiM-KARTS, a novel approach for detecting changes in the structure of single RNA molecules in response to a ligand.

The spliceosome is a biomolecular machine that, in all eukaryotes, accomplishes site-specific splicing of introns from precursor messenger RNAs (pre-mRNAs) with high fidelity. Operating at the nanometer scale, where inertia and friction have lost the dominant role they play in the macroscopic realm, the spliceosome is highly dynamic and assembles its active site around each pre-mRNA anew. To understand the structural dynamics underlying the molecular motors, clocks, and ratchets that achieve functional accuracy in the yeast spliceosome (a long-standing model system), we have developed single-molecule fluorescence resonance energy transfer (smFRET) approaches that report changes in intra- and intermolecular interactions in real time. Building on our work using hidden Markov models (HMMs) to extract kinetic and conformational state information from smFRET time trajectories, we recognized that HMM analysis of individual state transitions as independent stochastic events is insufficient for a biomolecular machine as complex as the spliceosome. In this chapter, we elaborate on the recently developed smFRET-based Single-Molecule Cluster Analysis (SiMCAn) that dissects the intricate conformational dynamics of a pre-mRNA through the splicing cycle in a model-free fashion. By leveraging hierarchical clustering techniques developed for Bioinformatics, SiMCAn efficiently analyzes large datasets to first identify common molecular behaviors. Through a second level of clustering based on the abundance of dynamic behaviors exhibited by defined functional intermediates that have been stalled by biochemical or genetic tools, SiMCAn then efficiently assigns pre-mRNA FRET states and transitions to specific splicing complexes, with the potential to find heretofore undescribed conformations. SiMCAn thus arises as a general tool to analyze dynamic cellular machines more broadly.

Resumen El suicidio es la principal causa de muerte violenta en Espana, por delante de los accidentes de trafico, y se estima que cada ano se suicidan cerca de 3.500 personas. Los factores de riesgo identificados de la conducta suicida se basan, principalmente, en estudios de intentos de suicidio. La centralizacion de las autopsias en los Institutos de Medicina Legal facilita la homogenizacion del metodo de trabajo y la consistencia de los resultados a nivel practico-judicial y de investigacion. La medicina forense debe proyectarse en la investigacion en general y de la conducta suicida en particular, en colaboracion con otros equipos de investigacion. La investigacion debe efectuarse segun la normativa etica y administrativa vigente y ser aprobada por el Comite Etico de referencia. Con respecto a la investigacion de los factores de riesgo del suicidio, el reclutamiento de casos y controles, la obtencion de muestras biologicas, la colaboracion en la realizacion de autopsias psicologicas y los estudios epidemiologicos, son aportaciones esenciales de la medicina forense.

The type specimen of Maxillaria grandiflora (Kunth) Lindl. was collected by Alexander von Humboldt and Aimé Bonpland during their scientific expedition to Tropical America. Its type locality, which has been the subject of confusion, is identified as a place on the eastern part of La Cruz municipality in the province of Nariño, Colombia. The type of M. grandiflora is shown to be a mixed collection and a lectotype is designated; the protologue illustration represents an amalgamation of both species. The type of Heterotaxis valenzuelana (A. Rich.) Ojeda & Carnevali was collected by José María Valenzuela but has been erroneously cited as Wright 3314 in the recent literature. Royal Botanic Gardens, Kew/[]//Inglaterra National Science Foundation/[DEB-0234064]/NSF/Estados Unidos UCR::Vicerrectoría de Docencia::Ciencias Básicas::Facultad de Ciencias::Escuela de Biología