Mycosporine-Like Amino Acids and Marine Toxins - The Common and the Different

Marine microorganisms harbor a multitude of secondary metabolites. Among these are toxins of different chemical classes as well as the UV-protective mycosporine-like amino acids (MAAs). The latter form a group of water-soluble, low molecular-weight (generally < 400) compounds composed of either an aminocyclohexenone or an aminocyclohexenimine ring, carrying amino acid or amino alcohol substituents. So far there has been no report of toxicity in MAAs but nevertheless there are some features they have in common with marine toxins. Among the organisms producing MAAs are cyanobacteria, dinoflagellates and diatoms that also synthesize toxins. As in cyclic peptide toxins found in cyanobacteria, amino acids are the main building blocks of MAAs. Both, MAAs and some marine toxins are transferred to other organisms e.g. via the food chains, and chemical modifications can take place in secondary consumers. In contrast to algal toxins, the physiological role of MAAs is clearly the protection from harmful UV radiation by physical screening. However, other roles, e.g. as osmolytes and antioxidants, are also considered. In this paper the common characteristics of MAAs and marine toxins are discussed as well as the differences

Genome mining of mycosporine-like amino acid (MAA) synthesizing and non-synthesizing cyanobacteria: A bioinformatics study

AbstractMycosporine-like amino acids (MAAs) are a family of more than 20 compounds having absorption maxima between 310 and 362 nm. These compounds are well known for their UV-absorbing/screening role in various organisms and seem to have evolutionary significance. In the present investigation we tested four cyanobacteria, e.g., Anabaena variabilis PCC 7937, Anabaena sp. PCC 7120, Synechocystis sp. PCC 6803 and Synechococcus sp. PCC 6301, for their ability to synthesize MAA and conducted genomic and phylogenetic analysis to identify the possible set of genes that might be involved in the biosynthesis of these compounds. Out of the four investigated species, only A. variabilis PCC 7937 was able to synthesize MAA. Genome mining identified a combination of genes, YP_324358 (predicted DHQ synthase) and YP_324357 (O-methyltransferase), which were present only in A. variabilis PCC 7937 and missing in the other studied cyanobacteria. Phylogenetic analysis revealed that these two genes are transferred from a cyanobacterial donor to dinoflagellates and finally to metazoa by a lateral gene transfer event. All other cyanobacteria, which have these two genes, also had another copy of the DHQ synthase gene. The predicted protein structure for YP_324358 also suggested that this product is different from the chemically characterized DHQ synthase of Aspergillus nidulans contrary to the YP_324879, which was predicted to be similar to the DHQ synthase. The present study provides a first insight into the genes of cyanobacteria involved in MAA biosynthesis and thus widens the field of research for molecular, bioinformatics and phylogenetic analysis of these evolutionary and industrially important compounds. Based on the results we propose that YP_324358 and YP_324357 gene products are involved in the biosynthesis of the common core (deoxygadusol) of all MAAs

Semiclassical Asymptotics for the Maxwell - Dirac System

We study the coupled system of Maxwell and Dirac equations from a semiclassical point of view. A rigorous nonlinear WKB-analysis, locally in time, for solutions of (critical) order $O(\sqrt{\epsilon})$ is performed, where the small semiclassical parameter $\epsilon$ denotes the microscopic/macroscopic scale ratio

A new subspecies of Peucedanum officinale L. subsp. album (Apiaceae) from the eastern part of the Iberian Peninsula

[EN] We describe Peucedanum officinale L. subsp. album Martinez-Fort & Donat-Torres subsp. nov., in which we grouped the thermomediterranean populations scattered along the eastern part of the Iberian Peninsula. The characters that differentiate this new subspecies from other infraspecific taxa in Peucedanum officinale are its canaliculated leaflet, the inflorescences much branched and lack of dominant terminal umbels, the umbels are few rayed, sometimes sessile and lateral, the petals are white and the fruit pedicels short, the same or shorter in length than the fruit. We provide here a full description of the new subspecies based on herbarium specimens and field measurements, as well as providing dichotomous keys to the subspecies within P. officinale. In addition, we provide a comparison of the ITS sequences of nrDNA with the most closely related taxons.Martínez-Fort, J.; León Santana, M.; Donat-Torres, MP. (2019). A new subspecies of Peucedanum officinale L. subsp. album (Apiaceae) from the eastern part of the Iberian Peninsula. PhytoKeys (Online). (131):37-55. https://doi.org/10.3897/phytokeys.131.321733755131Altschul, S. F., Gish, W., Miller, W., Myers, E. W., & Lipman, D. J. (1990). Basic local alignment search tool. Journal of Molecular Biology, 215(3), 403-410. doi:10.1016/s0022-2836(05)80360-2Darriba, D., Taboada, G. L., Doallo, R., & Posada, D. (2012). jModelTest 2: more models, new heuristics and parallel computing. Nature Methods, 9(8), 772-772. doi:10.1038/nmeth.2109Downie, S. R., Watson, M. F., Spalik, K., & Katz-Downie, D. S. (2000). Molecular systematics of Old World Apioideae (Apiaceae): relationships among some members of tribe Peucedaneae sensu lato, the placement of several island-endemic species, and resolution within the apioid superclade. Canadian Journal of Botany, 78(4), 506-528. doi:10.1139/b00-029Downie, S. R., Spalik, K., Katz-Downie, D. S., & Reduron, J.-P. (2010). Major clades within Apiaceae subfamily Apioideae as inferred by phylogenetic analysis of nrDNA ITS sequences. Plant Diversity and Evolution, 128(1-2), 111-136. doi:10.1127/1869-6155/2010/0128-0005Engler, A., Krause, K., Pilger, R. K. F., & Prantl, K. A. E. (1887). Die Natürlichen Pflanzenfamilien nebst ihren Gattungen und wichtigeren Arten, insbesondere den Nutzpflanzen, unter Mitwirkung zahlreicher hervorragender Fachgelehrten begründet von A. Engler und K. Prantl, fortgesetzt von A. Engler ... doi:10.5962/bhl.title.4635García Martín, F., & Silvestre, S. (1992). Peucedanum officinale L. subsp. brachyradium García-Martín y Silvestre: nuevo taxon de Umbelliferae. Acta Botanica Malacitana, 17, 119-121. doi:10.24310/abm.v17i.9022Kljuykov, E. V., Liu, M., Ostroumova, T. A., Pimenov, M. G., Tilney, P. M., van Wyk, B.-E., & van Staden, J. (2004). Towards a standardised terminology for taxonomically important morphological characters in the Umbelliferae. South African Journal of Botany, 70(3), 488-496. doi:10.1016/s0254-6299(15)30233-7Kumar, S., Stecher, G., Li, M., Knyaz, C., & Tamura, K. (2018). MEGA X: Molecular Evolutionary Genetics Analysis across Computing Platforms. Molecular Biology and Evolution, 35(6), 1547-1549. doi:10.1093/molbev/msy096Spalik, K., Reduron, J.-P., & Downie, S. R. (2004). The phylogenetic position of Peucedanum sensu lato and allied genera and their placement in tribe Selineae (Apiaceae, subfamily Apioideae). Plant Systematics and Evolution, 243(3-4), 189-210. doi:10.1007/s00606-003-0066-2White, T. J., Bruns, T., Lee, S., & Taylor, J. (1990). AMPLIFICATION AND DIRECT SEQUENCING OF FUNGAL RIBOSOMAL RNA GENES FOR PHYLOGENETICS. PCR Protocols, 315-322. doi:10.1016/b978-0-12-372180-8.50042-1Magee, A. R., Van Wyk, B.-E., Tilney, P. M., & Downie, S. R. (2007). New generic circumscriptions of Cape peucedanoid species (Apiaceae). South African Journal of Botany, 73(2), 298-299. doi:10.1016/j.sajb.2007.02.07

Dinámicas de fotoinhibición y reorganización pigmentaria bajo ciclos de luz/oscuridad como mecanismos de fotoprotección en Porphyra umbilicales frente a los efectos dañinos de la radiación ultravioleta

Porphyra umbilicalis L. Kutzing collected from the upper intertidal zone at Helgoland, North Sea, was exposed to different spectral ranges of UV radiation under both 12/12 h light/dark cycles and continuous irradiation. In light/dark cycles, oscillations of the optimal quantum yield (Fv /Fm) were observed during the experiments, reaching maximal values at the end of the light phase followed by lower values during the dark phase. Decreased Fv /Fm was observed in thalli illuminated with photosynthetic active radiation (PAR) plus UV-A and PAR+UV-A+UV-B, compared with the PAR control, indicating a certain degree of UV-induced photoinhibition. In addition, a decrease in the percentage of change of the linear initial slope and maximum electron transport rate (ETR) estimated from ETR vs. irradiance curves was induced by UV radiation during the light phase. Recovery during the 12 h dark phase was almost completed in UV-A treated plants. PAR+UV-A seemed not to affect the photosynthesis, measured as O2 production. However, a decrease in O2 production was observed in the PAR+UV-A+UV-B treatment, but it recovered to initial values after 48 h of culture. No changes in total content of photosynthetic pigments were observed. However, thallus absorptance and the in vivo absorption cross-section in the PAR range (400-700 nm) normalised to Chl a (a* parameter) fluctuated during light/dark cycles and were positively correlated with changes in the optimum quantum yield, thus indicating that daily pigment reorganisation in the light-harvesting complex may play a key role in the photosynthetic performance of the algae. Both UV-A and UV-B treatments under continuous irradiation induced a significant reduction in the optimal quantum yield, ETR efficiency and photosynthetic oxygen production during the first 36 h to values around 30% of the initial ones. Thus, different protective mechanisms against UV stress can be observed in P. umbilicalis: dynamic photoinhibition when UVA is combined with PAR, followed by full recovery of photosynthesis during the dark phase, and a more pronounced photoinhibition under UV-B, with only partial recovery after longer time periods, in which photosynthetic pigment reorganisation plays an important role.Talos del alga roja Porphyra umbilicales L. Kutzing fueron cultivados bajo diferentes condiciones espectrales de radiación ultravioleta en condiciones de ciclos de luz/oscuridad de 12 horas y bajo luz continua. El rendimiento cuántico óptimo (Fv /Fm), estimado a través de la fluorescencia de la clorofila a del fotosistema II, evolucionó con oscilaciones en los ciclos de luz/oscuridad, con valores máximos al final de cada fase de luz seguida de valores bajos a lo largo de la fase de oscuridad. Los cultivos iluminados bajo radiación fotosintéticamente activa (PAR)+UV-A y la PAR+UV-A+UV-B disminuyeron los valores de la relación (Fv /Fm) respecto a los cultivos bajo PAR. Los cultivos bajo radiación UV provocaron además una caída, durante la fase de luz, tanto de la pendiente inicial como de los valores máximos de la tasa de transporte electrónico (ETR) estimados a partir de las curvas ETR vs. irradiancia. En el caso de los cultivos bajo PAR + UV-A la recuperación de los valores fotosintéticos fue casi completa durante la fase de oscuridad. Dicho tratamiento no afectó a la producción fotosintética de O2 mientras que el cultivo bajo PAR+UV-A+UV-B disminuyó significativamente dicha tasa, la cual recuperó los valores iniciales tras 48 h de cultivo. No se observaron cambios en el contenido total de los pigmentos fotosintéticos. No obstante, los ciclos de luz/oscuridad afectaron tanto a la absorptancia de los talos como a los valores de corte transversal in vivo en el rango del PAR (400-700 podría implicar un papel clave en el mantenimiento de la actividad fotosintética del alga. En cambio, el cultivo de los talos en luz continua bajo los tratamientos de radiación UV-A y UV-B provocó una disminución del rendimiento cuántico óptimo, de la eficiencia del ETR y de la tasa fotosintética por producción de oxígeno durante las primeras 36 h llegando a valores del 30% de los valores iniciales. Por tanto, diferentes mecanismos están implicados en la protección frente al estrés por radiación ultravioleta en P. umbilicales; un mecanismo de fotoinhibición dinámica cuando el UV-A se combina con el PAR, el cual es seguido por una recuperación completa de los parámetros fotosintéticos durante la posterior fase de oscuridad, y una fotoinhibición más patente en el caso del cultivo bajo UV-B, la cual se recupera sólo parcialmente tras un período largo. En ambos casos, la reorganización de los pigmentos fotosintéticos juega un papel fundamental en dicha recuperación

PBM Implementation Group, Making patient blood management the new norm(al) as experienced by implementors in diverse countries

Background: Patient blood management (PBM) describes a set of evidence-based practices to optimize medical and surgical patient outcomes by clinically managing and preserving a patient's own blood. This concepts aims to detect and treat anemia, minimize the risk for blood loss and the need for blood replacement for each patient through a coordinated multidisciplinary care process. In combination with blood loss, anemia is the main driver for transfusion and all three are independent risk factors for adverse outcomes including morbidity and mortality. Evidence demonstrates that PBM significantly improves outcomes and safety while reducing cost by macroeconomic magnitudes. Despite its huge potential to improve healthcare systems, PBM is not yet adopted broadly. The aim of this study is to analyze the collective experiences of a diverse group of PBM implementors across countries reflecting different healthcare contexts and to use these experiences to develop a guidance for initiating and orchestrating PBM implementation for stakeholders from diverse professional backgrounds. Methods: Semi-structured interviews were conducted with 1-4 PBM implementors from 12 countries in Asia, Latin America, Australia, Central and Eastern Europe, the Middle East, and Africa. Responses reflecting the drivers, barriers, measures, and stakeholders regarding the implementation of PBM were summarized per country and underwent qualitative content analysis. Clustering the resulting implementation measures by levels of intervention for PBM implementation informed a PBM implementation framework. Results: A set of PBM implementation measures were extracted from the interviews with the implementors. Most of these measures relate to one of six levels of implementation including government, healthcare providers, funding, research, training/education, and patients/public. Essential cross-level measures are multi-stakeholder communication and collaboration. Conclusion: The implementation matrix resulting from this research helps to decompose the complexity of PBM implementation into concrete measures on each implementation level. It provides guidance for diverse stakeholders to design, initiate and develop strategies and plans to make PBM a national standard of care, thus closing current practice gaps and matching this unmet public health need

Study of the volume and spin collapse in orthoferrite LuFeO_3 using LDA+U

Rare earth (R) orthoferrites RFeO_3 exhibit large volume transitions associated with a spin collapse. We present here ab initio calculations on LuFeO_3. We show that taking into account the strong correlation among the Fe-3d electrons is necessary. Indeed, with the LDA+U method in the Projector Augmented Wave (PAW), we are able to describe the isostructural phase transition at 50 GPa, as well as a volume discontinuity of 6.0% at the transition and the considerable reduction of the magnetic moment on the Fe ions. We further investigate the effect of the variation of U and J and find a linear dependence of the transition pressure on these parameters. We give an interpretation for the non-intuitive effect of J. This emphasizes the need for a correct determination of these parameters especially when the LDA+U is applied to systems (e.g in geophysical investigations) where the transition pressure is a priori unknown

Community next steps for making globally unique identifiers work for biocollections data

Biodiversity data is being digitized and made available online at a rapidly increasing rate but current practices typically do not preserve linkages between these data, which impedes interoperation, provenance tracking, and assembly of larger datasets. For data associated with biocollections, the biodiversity community has long recognized that an essential part of establishing and preserving linkages is to apply globally unique identifiers at the point when data are generated in the field and to persist these identifiers downstream, but this is seldom implemented in practice. There has neither been coalescence towards one single identifier solution (as in some other domains), nor even a set of recommended best practices and standards to support multiple identifier schemes sharing consistent responses. In order to further progress towards a broader community consensus, a group of biocollections and informatics experts assembled in Stockholm in October 2014 to discuss community next steps to overcome current roadblocks. The workshop participants divided into four groups focusing on: identifier practice in current field biocollections; identifier application for legacy biocollections; identifiers as applied to biodiversity data records as they are published and made available in semantically marked-up publications; and cross-cutting identifier solutions that bridge across these domains. The main outcome was consensus on key issues, including recognition of differences between legacy and new biocollections processes, the need for identifier metadata profiles that can report information on identifier persistence missions, and the unambiguous indication of the type of object associated with the identifier. Current identifier characteristics are also summarized, and an overview of available schemes and practices is provided