Hen's teeth with enamel cap: from dream to impossibility

<p>Abstract</p> <p>Background</p> <p>The ability to form teeth was lost in an ancestor of all modern birds, approximately 100-80 million years ago. However, experiments in chicken have revealed that the oral epithelium can respond to inductive signals from mouse mesenchyme, leading to reactivation of the odontogenic pathway. Recently, tooth germs similar to crocodile rudimentary teeth were found in a chicken mutant. These "chicken teeth" did not develop further, but the question remains whether functional teeth with enamel cap would have been obtained if the experiments had been carried out over a longer time period or if the chicken mutants had survived. The next odontogenetic step would have been tooth differentiation, involving deposition of dental proteins.</p> <p>Results</p> <p>Using bioinformatics, we assessed the fate of the four dental proteins thought to be specific to enamel (amelogenin, AMEL; ameloblastin, AMBN; enamelin, ENAM) and to dentin (dentin sialophosphoprotein, DSPP) in the chicken genome. Conservation of gene synteny in amniotes allowed definition of target DNA regions in which we searched for sequence similarity. We found the full-length chicken AMEL and the only N-terminal region of DSPP, and both are invalidated genes. AMBN and ENAM disappeared after chromosomal rearrangements occurred in the candidate region in a bird ancestor.</p> <p>Conclusion</p> <p>These findings not only imply that functional teeth with enamel covering, as present in ancestral Aves, will never be obtained in birds, but they also indicate that these four protein genes were dental specific, at least in the last toothed ancestor of modern birds, a specificity which has been questioned in recent years.</p

Prototipo de Celula Robotica para Manufactura

[ES] El presente proyecto pretende estructurar el proceso de análisis, diseño, implementación y puesta en marcha de un prototipo robótico, enfocado a procesos de manufactura, utilizando diseños de autómatas aplicados a dispositivos de maquinado industrial, herramientas de mecatrónica y aplicaciones de ingeniería de sistemas, el objetivo es desarrollar una herramienta didáctica, que permita implementar, emular y desarrollar diversos procesos de manufactura, que por medio de interfaces gráficas permitan visualizar y controlar de forma intuitiva procesos industriales de manera automatizada, impulsando el aprendizaje significativo e integral que permita una aproximación a la resolución de problemas en un entorno real, además de reducir sustancialmente la curva de aprendizaje para operadores y técnicos de este tipo de industria, acercando este tipo de tecnologías a micro empresas que sean susceptibles de mejorar sustancialmente la calidad en sus procesos al tener acceso a sistemas automáticos “ a la medida”. Para esto se muestran las fases de implementación de un prototipo que consta de brazos robóticos, los cuales se encargan de manipular, manufacturar en ciertos procesos, seleccionar y/o desechar elementos, así como un conjunto de actuadores neumáticos que funjan como elementos de potencia para otro tipo de maquinado, así todos los parámetros funcionales y operativos sean cargados al sistema desde una aplicación gráfica y de sensores de retroalimentación en actuadores electromecánicos. Para el proceso de operación y maquinado de los autómatas se utilizan parámetros dimensiónales atraves de modelos de aprendizaje por parte del mismo autómata. Se muestran también las etapas que se desea desarrollar en materia de, diseño y construcción del prototipo robótico, así como la implementación de las aplicaciones para la comunicación hombre máquina, que permitan la adquisición de datos y procesen la información.Viveros, I.; Toledo Martínez, S.; Muñoz Delgado, J.; Zamudio Reyes, R. (2019). Prototipo de Celula Robotica para Manufactura. En INNODOCT/18. International Conference on Innovation, Documentation and Education. Editorial Universitat Politècnica de València. 765-774. https://doi.org/10.4995/INN2018.2018.8849OCS76577

Organic substrates in the development of camu-camuzeiro (Myrciaria dubia (H. B. K.) McVaugh) in the amazon region

Amazon is the largest tropical forest on the planet, it has a variety of plant species with emphasis on manyfruit trees, such as the camu-camuzeiro (Myrciaria dubia (H. B. K.) McVaugh), which occurs naturally on thebanks of rivers, lakes, lowlands and flooded forest of the Amazon. The objective of this study is to evaluate thedevelopment of camu-camuzeiro seedlings in different organic substrates. The experiment was conductedin the seedling production nursery of the Federal Rural University of Amazon. The experimental design wasentirely randomized, with ten treatments and five repetitions, each portion was represented by ten plants,totaling 500 seedlings. The substrates evaluated were: T1 - Humus; T2 - Humus + Bird manure; T3 - Humus + Bovinemanure; T4 - Humus + Açaí kernel; T5 - Humus + Chestnut shell; T6 - Humus + Chestnut shell + Poultry manure;T7 - Humus + Bovine manure + Chestnut shell; T8 - Humus + Açaí kernel + Poultry manure; T9 - Humus + Açaíkernel + Bovine manure; T10 - Commercial. The different substrates used influenced the development of camucamuzeiroseedlings evaluated at 180 days. The treatments with a substrate based on Humus (T1), Humus + Açaíkernel (T4), Humus + Chestnut shell (T5), Humus + Chestnut shell + Poultry manure (T6), Humus + Bovine manure +Chestnut shell (T7), Humus + Açaí Kernel + Bovine manure (T9) and the commercial substrate (T10) are the bestfor a satisfactory development of this crop in the production field.Amazon is the largest tropical forest on the planet, it has a variety of plant species with emphasis on manyfruit trees, such as the camu-camuzeiro (Myrciaria dubia (H. B. K.) McVaugh), which occurs naturally on thebanks of rivers, lakes, lowlands and flooded forest of the Amazon. The objective of this study is to evaluate thedevelopment of camu-camuzeiro seedlings in different organic substrates. The experiment was conductedin the seedling production nursery of the Federal Rural University of Amazon. The experimental design wasentirely randomized, with ten treatments and five repetitions, each portion was represented by ten plants,totaling 500 seedlings. The substrates evaluated were: T1 - Humus; T2 - Humus + Bird manure; T3 - Humus + Bovinemanure; T4 - Humus + Açaí kernel; T5 - Humus + Chestnut shell; T6 - Humus + Chestnut shell + Poultry manure;T7 - Humus + Bovine manure + Chestnut shell; T8 - Humus + Açaí kernel + Poultry manure; T9 - Humus + Açaíkernel + Bovine manure; T10 - Commercial. The different substrates used influenced the development of camucamuzeiroseedlings evaluated at 180 days. The treatments with a substrate based on Humus (T1), Humus + Açaíkernel (T4), Humus + Chestnut shell (T5), Humus + Chestnut shell + Poultry manure (T6), Humus + Bovine manure +Chestnut shell (T7), Humus + Açaí Kernel + Bovine manure (T9) and the commercial substrate (T10) are the bestfor a satisfactory development of this crop in the production field

A Multivalent and Cross-Protective Vaccine Strategy against Arenaviruses Associated with Human Disease

Arenaviruses are the causative pathogens of severe hemorrhagic fever and aseptic meningitis in humans, for which no licensed vaccines are currently available. Pathogen heterogeneity within the Arenaviridae family poses a significant challenge for vaccine development. The main hypothesis we tested in the present study was whether it is possible to design a universal vaccine strategy capable of inducing simultaneous HLA-restricted CD8+ T cell responses against 7 pathogenic arenaviruses (including the lymphocytic choriomeningitis, Lassa, Guanarito, Junin, Machupo, Sabia, and Whitewater Arroyo viruses), either through the identification of widely conserved epitopes, or by the identification of a collection of epitopes derived from multiple arenavirus species. By inoculating HLA transgenic mice with a panel of recombinant vaccinia viruses (rVACVs) expressing the different arenavirus proteins, we identified 10 HLA-A02 and 10 HLA-A03-restricted epitopes that are naturally processed in human antigen-presenting cells. For some of these epitopes we were able to demonstrate cross-reactive CD8+ T cell responses, further increasing the coverage afforded by the epitope set against each different arenavirus species. Importantly, we showed that immunization of HLA transgenic mice with an epitope cocktail generated simultaneous CD8+ T cell responses against all 7 arenaviruses, and protected mice against challenge with rVACVs expressing either Old or New World arenavirus glycoproteins. In conclusion, the set of identified epitopes allows broad, non-ethnically biased coverage of all 7 viral species targeted by our studies

LSST Science Book, Version 2.0

A survey that can cover the sky in optical bands over wide fields to faint magnitudes with a fast cadence will enable many of the exciting science opportunities of the next decade. The Large Synoptic Survey Telescope (LSST) will have an effective aperture of 6.7 meters and an imaging camera with field of view of 9.6 deg^2, and will be devoted to a ten-year imaging survey over 20,000 deg^2 south of +15 deg. Each pointing will be imaged 2000 times with fifteen second exposures in six broad bands from 0.35 to 1.1 microns, to a total point-source depth of r~27.5. The LSST Science Book describes the basic parameters of the LSST hardware, software, and observing plans. The book discusses educational and outreach opportunities, then goes on to describe a broad range of science that LSST will revolutionize: mapping the inner and outer Solar System, stellar populations in the Milky Way and nearby galaxies, the structure of the Milky Way disk and halo and other objects in the Local Volume, transient and variable objects both at low and high redshift, and the properties of normal and active galaxies at low and high redshift. It then turns to far-field cosmological topics, exploring properties of supernovae to z~1, strong and weak lensing, the large-scale distribution of galaxies and baryon oscillations, and how these different probes may be combined to constrain cosmological models and the physics of dark energy.Comment: 596 pages. Also available at full resolution at http://www.lsst.org/lsst/sciboo

LSST: from Science Drivers to Reference Design and Anticipated Data Products

(Abridged) We describe here the most ambitious survey currently planned in the optical, the Large Synoptic Survey Telescope (LSST). A vast array of science will be enabled by a single wide-deep-fast sky survey, and LSST will have unique survey capability in the faint time domain. The LSST design is driven by four main science themes: probing dark energy and dark matter, taking an inventory of the Solar System, exploring the transient optical sky, and mapping the Milky Way. LSST will be a wide-field ground-based system sited at Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m effective) primary mirror, a 9.6 deg$^2$ field of view, and a 3.2 Gigapixel camera. The standard observing sequence will consist of pairs of 15-second exposures in a given field, with two such visits in each pointing in a given night. With these repeats, the LSST system is capable of imaging about 10,000 square degrees of sky in a single filter in three nights. The typical 5$\sigma$ point-source depth in a single visit in $r$ will be $\sim 24.5$ (AB). The project is in the construction phase and will begin regular survey operations by 2022. The survey area will be contained within 30,000 deg$^2$ with $\delta<+34.5^\circ$, and will be imaged multiple times in six bands, $ugrizy$, covering the wavelength range 320--1050 nm. About 90\% of the observing time will be devoted to a deep-wide-fast survey mode which will uniformly observe a 18,000 deg$^2$ region about 800 times (summed over all six bands) during the anticipated 10 years of operations, and yield a coadded map to $r\sim27.5$. The remaining 10\% of the observing time will be allocated to projects such as a Very Deep and Fast time domain survey. The goal is to make LSST data products, including a relational database of about 32 trillion observations of 40 billion objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures available from https://www.lsst.org/overvie

Evolutionary Analysis Predicts Sensitive Positions of MMP20 and Validates Newly- and Previously-Identified MMP20 Mutations Causing Amelogenesis Imperfecta

Amelogenesis imperfecta (AI) designates a group of genetic diseases characterized by a large range of enamel disorders causing important social and health problems. These defects can result from mutations in enamel matrix proteins or protease encoding genes. A range of mutations in the enamel cleavage enzyme matrix metalloproteinase-20 gene (MMP20) produce enamel defects of varying severity. To address how various alterations produce a range of AI phenotypes, we performed a targeted analysis to find MMP20 mutations in French patients diagnosed with non-syndromic AI. Genomic DNA was isolated from saliva and MMP20 exons and exon-intron boundaries sequenced. We identified several homozygous or heterozygous mutations, putatively involved in the AI phenotypes. To validate missense mutations and predict sensitive positions in the MMP20 sequence, we evolutionarily compared 75 sequences extracted from the public databases using the Datamonkey webserver. These sequences were representative of mammalian lineages, covering more than 150 million years of evolution. This analysis allowed us to find 324 sensitive positions (out of the 483 MMP20 residues), pinpoint functionally important domains, and build an evolutionary chart of important conserved MMP20 regions. This is an efficient tool to identify new- and previously-identified mutations. We thus identified six functional MMP20 mutations in unrelated families, finding two novel mutated sites. The genotypes and phenotypes of these six mutations are described and compared. To date, 13 MMP20 mutations causing AI have been reported, making these genotypes and associated hypomature enamel phenotypes the most frequent in AI

Interhospital Transfer Before Thrombectomy Is Associated With Delayed Treatment and Worse Outcome in the STRATIS Registry (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke).

BACKGROUND: Endovascular treatment with mechanical thrombectomy (MT) is beneficial for patients with acute stroke suffering a large-vessel occlusion, although treatment efficacy is highly time-dependent. We hypothesized that interhospital transfer to endovascular-capable centers would result in treatment delays and worse clinical outcomes compared with direct presentation. METHODS: STRATIS (Systematic Evaluation of Patients Treated With Neurothrombectomy Devices for Acute Ischemic Stroke) was a prospective, multicenter, observational, single-arm study of real-world MT for acute stroke because of anterior-circulation large-vessel occlusion performed at 55 sites over 2 years, including 1000 patients with severe stroke and treated within 8 hours. Patients underwent MT with or without intravenous tissue plasminogen activator and were admitted to endovascular-capable centers via either interhospital transfer or direct presentation. The primary clinical outcome was functional independence (modified Rankin Score 0-2) at 90 days. We assessed (1) real-world time metrics of stroke care delivery, (2) outcome differences between direct and transfer patients undergoing MT, and (3) the potential impact of local hospital bypass. RESULTS: A total of 984 patients were analyzed. Median onset-to-revascularization time was 202.0 minutes for direct versus 311.5 minutes for transfer patients ( CONCLUSIONS: In this large, real-world study, interhospital transfer was associated with significant treatment delays and lower chance of good outcome. Strategies to facilitate more rapid identification of large-vessel occlusion and direct routing to endovascular-capable centers for patients with severe stroke may improve outcomes. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02239640

Genome-wide physical activity interactions in adiposity. A meta-analysis of 200,452 adults

Physical activity (PA) may modify the genetic effects that give rise to increased risk of obesity. To identify adiposity loci whose effects are modified by PA, we performed genome-wide interaction meta-analyses of BMI and BMI-adjusted waist circumference and waist-hip ratio from up to 200,452 adults of European (n = 180,423) or other ancestry (n = 20,029). We standardized PA by categorizing it into a dichotomous variable where, on average, 23% of participants were categorized as inactive and 77% as physically active. While we replicate the interaction with PA for the strongest known obesity-risk locus in the FTO gene, of which the effect is attenuated by similar to 30% in physically active individuals compared to inactive individuals, we do not identify additional loci that are sensitive to PA. In additional genome-wide meta-analyses adjusting for PA and interaction with PA, we identify 11 novel adiposity loci, suggesting that accounting for PA or other environmental factors that contribute to variation in adiposity may facilitate gene discovery.Peer reviewe