Calcite fibre formation in modern brachiopod shells

The fibrous calcite layer of modern brachiopod shells is a hybrid composite material and forms a substantial part of the hard tissue. We investigated how cells of the outer mantle epithelium (OME) secrete calcite material and generate the characteristic fibre morphology and composite microstructure of the shell. We employed AFM, FE-SEM, and TEM imaging of embedded/etched, chemically fixed/ decalcified and high-pressure frozen/freeze substituted samples. Calcite fibres are secreted by outer mantle epithelium (OME) cells. Biometric analysis of TEM micrographs indicates that about 50% of these cells are attached via hemidesmosomes to an extracellular organic membrane present at the proximal, convex surface of the fibres. At these sites, mineral secretion is not active. Instead, ion transport from OME cells to developing fibres occurs at regions of closest contact between cells and fibres, however only at sites where the extracellular membrane at the proximal fibre surface is not developed yet. Fibre formation requires the cooperation of several adjacent OME cells. It is a spatially and temporally changing process comprising of detachment of OME cells from the extracellular organic membrane, mineral secretion at detachment sites, termination of secretion with formation of the extracellular organic membrane, and attachment of cells via hemidesmosomes to this membrane.This is a BASE-LINE Earth project supported by the European Union’s Horizon 2020 research and innovation program under grant agreement No. 643084. This is publication nr. 159 of Huinay Scientific Field Station

Chloroplast damage induced by the inhibition of fatty acid synthesis triggers autophagy in chlamydomonas

Fatty acids are synthesized in the stroma of plant and algal chloroplasts by the fatty acid synthase complex. Newly synthesized fatty acids are then used to generate plastidial lipids that are essential for chloroplast structure and function. Here, we show that inhibition of fatty acid synthesis in the model alga Chlamydomonas reinhardtii activates autophagy, a highly conserved catabolic process by which cells degrade intracellular material under adverse conditions to maintain cell homeostasis. Treatment of Chlamydomonas cells with cerulenin, a specific fatty acid synthase inhibitor, stimulated lipidation of the autophagosome protein ATG8 and enhanced autophagic flux. We found that inhibition of fatty acid synthesis decreased monogalactosyldiacylglycerol abundance, increased lutein content, down-regulated photosynthesis, and increased the production of reactive oxygen species. Electron microscopy revealed a high degree of thylakoid membrane stacking in cerulenin-treated cells. Moreover, global transcriptomic analysis of these cells showed an up-regulation of genes encoding chloroplast proteins involved in protein folding and oxidative stress and the induction of major catabolic processes, including autophagy and proteasome pathways. Thus, our results uncovered a link between lipid metabolism, chloroplast integrity, and autophagy through a mechanism that involves the activation of a chloroplast quality control system.Ministerio de Economía y Competitividad BFU2015-68216-PJunta de Andalucía CVI-7336, BIO2015-74432-JI

Conceptions of acculturation: A review and statement of critical issues

http://dx.doi.org/10.1016/j.socscimed.2011.03.01

Phosphorus Availability Regulates TORC1 Signaling via LST8 in Chlamydomonas

Target of rapamycin complex 1 (TORC1) is a central regulator of cell growth. It balances anabolic and catabolic processes in response to nutrients, growth factors, and energy availability. Nitrogen- and carbon-containing metabolites have been shown to activate TORC1 in yeast, animals, and plants. Here, we show that phosphorus (P) regulates TORC1 signaling in the model green alga Chlamydomonas (Chlamydomonas reinhardtii) via LST8, a conserved TORC1 subunit that interacts with the kinase domain of TOR. P starvation results in a sharp decrease in LST8 abundance and downregulation of TORC1 activity. A hypomorphic lst8 mutation resulted in decreased LST8 abundance, and it both reduced TORC1 signaling and altered the cellular response to P starvation. Additionally, we found that LST8 levels and TORC1 activity were not properly regulated in a mutant defective in the transcription factor PSR1, which is the major mediator of P deprivation responses in Chlamydomonas. Unlike wild-type cells, the psr1 mutant failed to downregulate LST8 abundance and TORC1 activity when under P limitation. These results identify PSR1 as an upstream regulator of TORC1 and demonstrate that TORC1 is a key component in P signaling in Chlamydomonas.España Ministerio de Economía y Competitividad (grants BFU2015-68216-P and PGC2018-099048- B-100 to J.L.C. and grant BIO2015-74432-JIN to M.E.P.-P.)National Science Foundation (CAREER award MCB-1552522 to L.M.H. and grant MCB-1616820 to J.G.U.)European Commission (grant number 750996

El papel de las características textuales en la comprensión lectora de alumnado de Educación Primaria en lengua española

During the early grades of primary school, texts are mainly narrative and focus on technical aspects such as decoding words and understanding simple syntax. However, from 4th grade onwards, texts become increasingly more difficult and expository texts become the main source of knowledge from which children will have to extract and learn new information while creating their mental model. This article examined the influences of two main text characteristics: text genre and level of representation (text base and mental model), in the reading comprehension scores of 313 Spanish primary school children aged 8 to 11 to study the relationship between these variables as well as the differences between grades. Comprehension of each text genre was assessed through a validated multiple-choice questionnaire and each variable was compared through a series of correlational methods, such as Pearson’s correlation, Spearman’s rho and ANOVAs. The results showed that all grades obtained significant higher scores on the text base than the mental model but only the expository texts exhibited better results when passing from 4th to 5th and 6th grade. This study provides findings that may contribute to the topic of literacy education during primary school.Durante los primeros cursos de primaria, los textos son principalmente narrativos y se centran en aspectos técnicos como la decodificación y la comprensión de sintaxis simple. Sin embargo, a partir de 4º curso, los textos se vuelven cada vez más difíciles y los expositivos se convierten en la principal fuente de conocimiento a partir de la cual los estudiantes tendrán que extraer y aprender nueva información mientras crean su modelo mental. El presente artículo se centra en examinar las influencias de dos características principales de cualquier texto: el género textual y el nivel de representación (base textual y modelo mental) en las puntuaciones obtenidas en las pruebas de comprensión lectora de 313 estudiantes españoles de educación primaria con edades entre 8 y 11 años para averiguar la relación existente entre estas variables, así como las diferencias entre cursos. La comprensión de cada género textual se evaluó mediante un cuestionario de opción múltiple y cada variable se comparó mediante una serie de métodos correlacionales (correlación de Pearson, rho de Spearman y ANOVAs). Los resultados muestran que todos los cursos obtuvieron puntuaciones significativamente más altas en la base textual que en el modelo mental, pero solo se apreciaron mejores resultados con el paso de 4º a 5º y 6º curso en los textos expositivos. Los hallazgos de este estudio suponen una contribución relevante para la alfabetización en la educación primaria

Occurrence of tetrodotoxin in bivalves and gastropods from harvesting areas and other natural spaces in Spain

Tetrodotoxin (TTX) is a potent neurotoxin that is receiving increasing interest in the European Union because it has been found in different fishery products (fish, bivalves and gastropods) captured in European waters. Since available information is scarce, further analytical data regarding the incidence of this toxin in European fishery products is needed in order to perform an appropriate risk assessment devoted to protecting consumers’ health. Hence, samples of bivalves and gastropods were collected at different points of the Spanish coast and analyzed by high-performance hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) to evaluate the presence of TTX. None of the analyzed samples showed TTX above an internal threshold of 10 µg/kg or even showed a peak under it. Our results on TTX occurrence obtained in bivalve molluscs and gastropods did not show, at least in the studied areas, a risk for public health. However, taking into account previous positive results obtained by other research groups, and since we did not detect TTX in our samples, a more completed study increasing sampling frequency is needed to ensure proper risk evaluation towards the food safety of these products.info:eu-repo/semantics/publishedVersio

Extracellular Vesicles, the Road toward the Improvement of ART Outcomes

Nowadays, farm animal industries use assisted reproductive technologies (ART) as a tool to manage herds’ reproductive outcomes, for a fast dissemination of genetic improvement as well as to bypass subfertility issues. ART comprise at least one of the following procedures: collection and handling of oocytes, sperm, and embryos in in vitro conditions. Therefore, in these conditions, the interaction with the oviductal environment of gametes and early embryos during fertilization and the first stages of embryo development is lost. As a result, embryos obtained in in vitro fertilization (IVF) have less quality in comparison with those obtained in vivo, and have lower chances to implant and develop into viable offspring. In addition, media currently used for IVF are very similar to those empirically developed more than five decades ago. Recently, the importance of extracellular vesicles (EVs) in the fertility process has flourished. EVs are recognized as effective intercellular vehicles for communication as they deliver their cargo of proteins, lipids, and genetic material. Thus, during their transit through the female reproductive tract both gametes, oocyte and spermatozoa (that previously encountered EVs produced by male reproductive tract) interact with EVs produced by the female reproductive tract, passing them important information that contributes to a successful fertilization and embryo development. This fact highlights that the reproductive tract EVs cargo has an important role in reproductive events, which is missing in current ART media. This review aims to recapitulate recent advances in EVs functions on the fertilization process, highlighting the latest proposals with an applied approach to enhance ART outcome through EV utilization as an additive to the media of current ART procedures

Lupus eritematoso tumidus y leishmaniasis: A propósito de un caso

Pocas veces se tiene en cuenta que la Leishmaniasis (enfermedad producida por un protozoo) y otras enfermedades de clínica similar como el Lupus Eritematoso (enfermedad de origen autoinmune) pueden presentarse en forma concomitante. El presente trabajo reporta el caso de una paciente a la cual se le diagnosticó en un primer momento Lupus Eritematoso Tumidus (LET) y posteriormente, ante la remisión parcial frente al tratamiento específico y debido a la procedencia de zona endémica de la paciente, se sospechó y se detectó la concomitancia con Leishmaniasis Mucosa (LM). OBJETIVO: Presentar el caso de una paciente a la cual se realizó diagnóstico de LET y LM. DISEÑO: Reporte de Caso. MATERIAL Y MÉTODO: Mujer de 47 años de edad procedente de Embarcación (departamento. San Martín, Salta), presentó lesión infiltrativa, costrosa y ulcerada en la mucosa nasal, dolorosa, con bordes no definidos, y perforación septal con bordes infiltrados, eritematosos y cubiertos con costras serohematicas. El diagnóstico en un primer momento se realizó a través de examen histopatológico de biopsia de piel nasal tomada con sacabocados, que resultó positivo para LET, y también mediante serología anti-Ro, anti-La y anti-ADN, con resultados negativos. Frente al tratamiento con hidrocloroquina (200mg/día-30 días) hubo mejoría parcial. Ante la sospecha de una posible concomitancia con LM, se realizaron raspados y aspirados de borde de septum nasal para microscopía, PCR (reacción en cadena de la polimerasa) y cultivo. Tanto la microscopía como la PCR resultaron positivas, permitiendo identificar como especie involucrada Leishmania (Leishmania) amazonensis. Al aplicar el tratamiento específico para LM (antimoniato de meglumina I.M., 425mg cada 12 hs. durante 29 días) se logró la remisión completa de la sintomatología. CONCLUSIONES: La amplia variedad de manifestaciones clínicas en la Leishmaniasis obligan a realizar el diagnóstico diferencial con numerosas enfermedades.Fil: Monroig, Sibila. Hospital San Bernardo;Fil: Garcia Bustos, Maria Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: González Prieto, G. Universidad Nacional de Salta. Facultad de Ciencias de la Salud; ArgentinaFil: Ramos, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta. Instituto de Patología Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de Patología Experimental; ArgentinaFil: Segura, Graciela. Hospital San Bernardo;Fil: Barrio. Alejandra Beatriz. Universidad Nacional de Salta. Facultad de Ciencias de la Salud; Argentin

Artificial Intelligence in Orthodontics: Where Are We Now? A Scoping Review

Objective: This scoping review aims to determine the applications of Artificial Intelligence (AI) that are extensively employed in the field of Orthodontics, to evaluate its benefits, and to discuss its potential implications in this speciality. Recent decades have witnessed enormous changes in our profession. The arrival of new and more aesthetic options in orthodontic treatment, the transition to a fully digital workflow, the emergence of temporary anchorage devices and new imaging methods all provide both patients and professionals with a new focus in orthodontic care. Materials and methods: This review was performed following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The electronic literature search was performed through MEDLINE/PubMed, Scopus, Web of Science, Cochrane and IEEE Xplore databases with a 11-year time restriction: January 2010 till March 2021. No additional manual searches were performed. Results: The electronic literature search initially returned 311 records, and 115 after removing duplicate references. Finally, the application of the inclusion criteria resulted in 17 eligible publications in the qualitative synthesis review. Conclusion: The analysed studies demonstrated that Convolution Neural Networks can be used for the automatic detection of anatomical reference points on radiological images. In the growth and development research area, the Cervical Vertebral Maturation stage can be determined using an Artificial Neural Network model and obtain the same results as expert human observers. AI technology can also improve the diagnostic accuracy for orthodontic treatments, thereby helping the orthodontist work more accurately and efficiently

Is tagging with visual implant elastomer a reliable technique for marking earthworms?

Visual implant elastomer (VIE) has recently been employed to investigate different aspects of earthworm ecology. However, a number of fundamental questions relating to the detection and positioning of the tag, its persistence and potential effects on earthworms remain unknown. Seven earthworm species belonging to three ecological groupings, with different pigmentation and burrowing behaviour, were tagged using different coloured VIE. External inspection after two days, one week and 1, 10 and 27 months were followed by preservation, dissection and internal inspection. Tags could be seen in living specimens to 27 months, and dissection revealed that in most cases they were lodged in the coelomic cavity, held in place by septa. However, over longer time periods (more than two years), the chlorogogenous tissue tended to bind to the tags and made external observation increasingly difficult. Migration of the VIE material towards the posterior of the earthworm and potential loss of the tag were only observed on rare occasions, and a recovery rate in excess of 98% was recorded. By introducing a reasonable amount of VIE into segments, just after the clitellum, this technique can become a valuable tool in earthworm ecology and life history studies, particularly in short-medium term laboratory and field experiments