607 research outputs found
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Creativity and education : some theories and procedures to enhance the development of creativity within a classroom setting.
Abstract not availabl
Synthetic Regulation of Eukaryotic Gene Expression by Noncoding RNA
Synthetic biological systems promise to combine the spectacular diversity of biological functionality with engineering principles to design new life to address many pressing needs. As these engineered systems advance in sophistication, there is ever-greater need for customizable, situation-specific expression of desired genes. However, existing gene control platforms are generally not modular, or do not display performance requirements required for robust phenotypic responses to input signals. This work expands the capabilities of eukaryotic gene control in two important directions.
For development of greater modularity, we extend the use of synthetic self-cleaving ribozyme switches to detect changes in input protein levels and convey that information into programmed gene expression in eukaryotic cells. We demonstrate both up- and down-regulation of levels of an output transgene by more than 4-fold in response to rising input protein levels, with maximal output gene expression approaching the highest levels observed in yeast. In vitro experiments demonstrate protein-dependent ribozyme activity modulation. We further demonstrate the platform in mammalian cells. Our switch devices do not depend on special input protein activity, and can be tailored to respond to any input protein to which a suitable RNA aptamer can be developed. This platform can potentially be employed to regulate the expression of any transgene or any endogenous gene by 3’ UTR replacement, allowing for more complex cell state-specific reprogramming.
We also address an important concern with ribozyme switches, and riboswitch performance in general, their dynamic range. While riboswitches have generally allowed for versatile and modular regulation, so far their dynamic ranges of output gene modulation have been modest, generally at most 10-fold. We address this shortcoming by developing a modular genetic amplifier for near-digital control of eukaryotic gene expression. We combine ribozyme switch-mediated regulation of a synthetic TF with TF-mediated regulation of an output gene. The amplifier platform allows for as much as 20-fold regulation of output gene expression in response to input signal, with maximal expression approaching the highest levels observed in yeast, yet being tunable to intermediate and lower expression levels. EC50 values are more than 4 times lower than in previously best-performing non-amplifier ribozyme switches. The system design retains the modular-input architecture of the ribozyme switch platform, and the near-digital dynamic ranges of TF-based gene control.
Together, these developments suggest great potential for the wide applicability of these platforms for better-performing eukaryotic gene regulation, and more sophisticated, customizable reprogramming of cellular activity.</p
Genome-Based Targeted Sequencing as a Reproducible Microbial Community Profiling Assay.
Current sequencing-based methods for profiling microbial communities rely on marker gene (e.g., 16S rRNA) or metagenome shotgun sequencing (mWGS) analysis. We present an approach based on a single-primer extension reaction using a highly multiplexed oligonucleotide probe pool. This approach, termed MA-GenTA (microbial abundances from genome tagged analysis), enables quantitative, straightforward, cost-effective microbiome profiling that combines desirable features of both 16S rRNA and mWGS strategies. The use of multiple probes per target genome and rigorous probe design criteria enabled robust determination of relative abundance. To test the utility of the MA-GenTA assay, probes were designed for 830 genome sequences representing bacteria present in mouse stool specimens. Comparison of the MA-GenTA data with mWGS data demonstrated excellent correlation down to 0.01% relative abundance and a similar number of organisms detected per sample. Despite the incompleteness of the reference database, nonmetric multidimensional scaling (NMDS) clustering based on the Bray-Curtis dissimilarity metric of sample groups was consistent between MA-GenTA, mWGS, and 16S rRNA data sets. MA-GenTA represents a potentially useful new method for microbiome community profiling based on reference genomes
Genome-Based Targeted Sequencing as a Reproducible Microbial Community Profiling Assay.
Current sequencing-based methods for profiling microbial communities rely on marker gene (e.g., 16S rRNA) or metagenome shotgun sequencing (mWGS) analysis. We present an approach based on a single-primer extension reaction using a highly multiplexed oligonucleotide probe pool. This approach, termed MA-GenTA (microbial abundances from genome tagged analysis), enables quantitative, straightforward, cost-effective microbiome profiling that combines desirable features of both 16S rRNA and mWGS strategies. The use of multiple probes per target genome and rigorous probe design criteria enabled robust determination of relative abundance. To test the utility of the MA-GenTA assay, probes were designed for 830 genome sequences representing bacteria present in mouse stool specimens. Comparison of the MA-GenTA data with mWGS data demonstrated excellent correlation down to 0.01% relative abundance and a similar number of organisms detected per sample. Despite the incompleteness of the reference database, nonmetric multidimensional scaling (NMDS) clustering based on the Bray-Curtis dissimilarity metric of sample groups was consistent between MA-GenTA, mWGS, and 16S rRNA data sets. MA-GenTA represents a potentially useful new method for microbiome community profiling based on reference genomes
Vacuum drying soil samples is a low-temperature alternative to conventional oven drying when determining soil water repellence
Here we investigated a low-temperature (20˚C) soil drying technique to generate soil water contents equivalent to those achieved by conventional oven drying (105˚C). The effect of drying temperature, plus aeration status (oxic or anoxic), on SWR was also investigated
Integrative transcriptome and proteome analysis of the tube foot and adhesive secretions of the sea urchin paracentrotus lividus
IF/00006/2015/CP1276/CT0001
P 25404-B25
P 30347Echinoderms, such as the rock-boring sea urchin Paracentrotus lividus, attach temporarily to surfaces during locomotion using their tube feet. They can attach firmly to any substrate and release from it within seconds through the secretion of unknown molecules. The composition of the adhesive, as well as the releasing secretion, remains largely unknown. This study re-analyzed a differential proteome dataset from Lebesgue et al. by mapping mass spectrometry-derived peptides to a P. lividus de novo transcriptome generated in this study. This resulted in a drastic increase in mapped proteins in comparison to the previous publication. The data were subsequently combined with a differential RNAseq approach to identify potential adhesion candidate genes. A gene expression analysis of 59 transcripts using whole mount in situ hybridization led to the identification of 16 transcripts potentially involved in bioadhesion. In the future these data could be useful for the production of synthetic reversible adhesives for industrial and medical purposes.publishersversionpublishe
Detection of mechanical stress in the steel structure of a bridge crane
A significant negative aspect in the operation of bridge-type cranes are the technical problems associated with wear of the wheels and the crane track, which causes crane skewing. The main causes of crane skewing include unevenness of the crane track, unequal loading of the traction drives depending on the position of the crane trolley, slips and different sizes of travel wheels and combinations of these causes. Firstly, this paper presents a design solution that can be used to detect the magnitude of mechanical stress and deformation of the steel structure of the crane, caused by the effects of skewing. The mechanical stress generated by the transverse forces of the deformed geometric shape of the crane bridge structure is recorded by mechanical stress detectors installed in the inner corners of the crane bridge. The resulting electrical signal from element mechanical voltage detectors, loaded by axial forces, can be used for feedback control of separate crane travel drives controlled by frequency converters. Secondly, this paper presents the calculation of the lateral transverse forces according to CSN 27 0103 and the determination of the values of mechanical stresses of the deformed steel structure of the crane bridge of a two-girder bridge crane using the finite element method in the program MSC.MARC 2019. Finally, this paper presents the structural and strength design of mechanical stress detectors and the conclusions of laboratory tests of axial force loading of mechanical stress detectors on the test equipment. At the same time, it presents records of the measured axial forces acting in the mechanical stress detectors, arising from the deformation and warping of the crane bridge by the known magnitude of the axial force acting on the crossbeam and from the deformation of the crane bridge caused by the crane operating modes.Web of Science116art. no. 10029
Scaled Monocular Visual SLAM
The fundamental shortcoming underlying monocular-based localizationand mapping solutions (SfM, Visual SLAM) is the fact thatthe obtained maps and motion are solved up to an unknown scale.Yet, the literature provides interesting solutions to scale estimationusing cues from focus or defocus of a camera. In this paper, wetake advantage of the scale offered by image focus to properly initializeVisual SLAM with a correct metric scale. We provide experimentsshowing the success of the proposed method and discussits limitations
Short Assessment of Health Literacy for Portuguese-speaking Adults
OBJETIVO: Desarrollar y validar un instrumento breve para evaluación de alfabetismo en salud en el idioma portugués. MÉTODOS: El instrumento desarrollado consiste de 50 itens que evalúan la capacidad del individuo de pronunciar y comprender términos médicos comunes. Las propiedades psicométricas se evaluaron en una muestra de 226 ancianos brasileños. La validez del constructo se estableció por la correlación con el número de años de escolaridad, relato de alfabetismo funcional y desempeño cognitivo global. La validez discriminatoria fue establecida por la exactitud del instrumento en la detección de alfabetismo en salud inadecuado, definido como la incapacidad de comprender correctamente prescripciones médicas estandarizadas. RESULTADOS: Las correlaciones con los criterios de constructo presentaron magnitud moderada a alta (coeficientes de Spearman = 0,63 a 0,76). El instrumento presentó también consistencia interna satisfactoria (Cronbach = 0,93) y buena confiabilidad examen-reexamen (coeficiente de correlación intra-clase = 0,95). El área bajo la curva característica de operación del receptor para detección de alfabetismo inadecuado fue 0,82. Una versión con 18 itens fue derivada y presentó propiedades psicométricas similares. CONCLUSIONES: El instrumento desarrollado presentó buena validez y consistencia en una muestra de ancianos brasileños y puede ser utilizado en ambientes clínicos o de investigación con la finalidad de detectar alfabetismo en salud inadecuado.OBJECTIVE: To develop and validate a short health literacy assessment tool for Portuguese-speaking adults. METHODS: The Short Assessment of Health Literacy for Portuguese-speaking Adults is an assessment tool which consists of 50 items that assess an individual's ability to correctly pronounce and understand common medical terms. We evaluated the instrument's psychometric properties in a convenience sample of 226 Brazilian older adults. Construct validity was assessed by correlating the tool scores with years of schooling, self-reported literacy, and global cognitive functioning. Discrimination validity was assessed by testing the tool's accuracy in detecting inadequate health literacy, defined as failure to fully understand standard medical prescriptions. RESULTS: Moderate to high correlations were found in the assessment of construct validity (Spearman's coefficients ranging from 0.63 to 0.76). The instrument showed adequate internal consistency (Cronbach's alpha=0.93) and adequate test-retest reliability (intraclass correlation coefficient=0.95). The area under the receiver operating characteristic curve for detection of inadequate health literacy was 0.82. A version consisting of 18 items was tested and showed similar psychometric properties. CONCLUSIONS: The instrument developed showed good validity and reliability in a sample of Brazilian older adults. It can be used in research and clinical settings for screening inadequate health literacy.OBJETIVO: Desenvolver e validar um instrumento breve para avaliação de alfabetismo em saúde na língua portuguesa. MÉTODOS: O instrumento desenvolvido consiste de 50 itens que avaliam a capacidade do indivíduo de pronunciar e compreender termos médicos comuns. As propriedades psicométricas foram avaliadas em uma amostra de 226 idosos brasileiros. A validade de construto foi estabelecida pela correlação com o número de anos de escolaridade, relato de alfabetismo funcional e desempenho cognitivo global. A validade discriminativa foi estabelecida pela acurácia do instrumento na detecção de alfabetismo em saúde inadequado, definido como a incapacidade de compreender corretamente prescrições médicas padronizadas. RESULTADOS: As correlações com os critérios de construto apresentaram magnitude moderada a alta (coeficientes de Spearman = 0,63 a 0,76). O instrumento apresentou ainda consistência interna satisfatória (Cronbach = 0,93) e boa confiabilidade teste-reteste (coeficiente de correlação intraclasse = 0,95). A área sob a curva característica de operação do receptor para detecção de alfabetismo inadequado foi 0,82. Uma versão com 18 itens foi derivada e apresentou propriedades psicométricas similares. CONCLUSÕES: O instrumento desenvolvido apresentou boa validade e consistência em uma amostra de idosos brasileiros e pode ser utilizado em ambientes clínicos ou de pesquisa com a finalidade de detectar alfabetismo em saúde inadequado
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