148 research outputs found
THE CRISPR/CAS9 EDITING OF A WRKY GENE AND THE OVEREXPRESSION OF A LIPOXYGENASE GENE FOR IMPROVING PATHOGEN RESISTANCE IN MAIZE
Fusarium verticillioides (Fv) is a major cereal pathogen causing stalk rot
and ear rot in maize, negatively affecting crop productivity, and
compromising food safety by producing the secondary metabolites fumonisins.
Several studies were conducted to identify maize genes associated with host
plant resistance to Fv infection and fumonisin accumulation. The maize WRKY
transcription factors and the lipoxygenases (ZmLOXs) are well recognized as
important players in plant defense against pathogens, and it is known that
the host-pathogen lipid cross-talk influences the pathogenesis. In this
regard, previous RNA-seq experiments reported the enhanced expression of
ZmLOX genes in maize resistant genotypes and GWAS resulted in one SNP
significantly associated with ZmWRKY125.
The Clustered Regularly Interspaced Short Palindromic Repeat/associated
Cas9 (CRISPR/Cas9) editing of ZmWRKY125 and the transgenic overexpression
of ZmLOX4 genes were carried out to investigate the possible implication of
these two genes in the resistance mechanisms against Fv. Before cloning
experiments, protein domain conservation and different splicing products
have been analyzed comparing homologues and orthologues for both genes.
As regards ZmWRKY125, the CRISPR cloning was based on a double cloning
using two different guides (sgRNA) for one gene target. Agrobacterium
tumefaciens mediated transformation was used for introducing the construct
under the maize promoter ZmpUBI in the binary vector p1609 in maize A188
line. Mutants from three different transformation events were obtained. For
each event, T2 plants will be genotyped to find homozygous for the mutation
that in turn will be phenotyped for Fv resistance and fumonisin content.
As regards ZmLOX4, the gene was cloned under an overexpressed promoter
involved in kernel development in the vector L1781, and the same
transformation conditions adopted for the CRISPR/Cas9 editing of ZmWRKY125
were used. Mutants from two different transformation events were obtained.
For each event, T2 plants were genotyped in order to find homozygous for
the mutation. Homozygous plants will be further evaluated for Fv
resistance, fumonisin accumulation, oxylipin content as well as for the
expression analysis of the main genes involved in the jasmonic acid pathway
Structure and expression analysis of rice paleo duplications
Having a well-known history of genome duplication, rice is a good model for studying structural and functional evolution of paleo duplications. Improved sequence alignment criteria were used to characterize 10 major chromosome-to-chromosome duplication relationships associated with 1440 paralogous pairs, covering 47.8% of the rice genome, with 12.6% of genes that are conserved within sister blocks. Using a micro-array experiment, a genome-wide expression map has been produced, in which 2382 genes show significant differences of expression in root, leaf and grain. By integrating both structural (1440 paralogous pairs) and functional information (2382 differentially expressed genes), we identified 115 paralogous gene pairs for which at least one copy is differentially expressed in one of the three tissues. A vast majority of the 115 paralogous gene pairs have been neofunctionalized or subfunctionalized as 88%, 89% and 96% of duplicates, respectively, expressed in grain, leaf and root show distinct expression patterns. On the basis of a Gene Ontology analysis, we have identified and characterized the gene families that have been structurally and functionally preferentially retained in the duplication showing that the vast majority (>85%) of duplicated have been either lost or have been subfunctionalized or neofunctionalized during 50–70 million years of evolution
Restriction fragment length polymorphisms between tomato lines sensitive or tolerant to bacterial wilt.
Inclined reinforcement around web opening in concrete beams
YesTwelve reinforced-concrete continuous deep beams
having web openings within interior shear spans were
tested to failure. The main variables investigated were
the opening size and the amount of inclined
reinforcement around openings. An effective inclined
reinforcement factor combining the influence of the
amount of inclined web reinforcement and opening size
is proposed and used to analyse the structural behaviour
of continuous deep beams tested. It was observed that
the end support reaction, diagonal crack width and load
capacity of beams tested were significantly dependent on
the proposed effective inclined reinforcement factor. As
this factor increased, the end support reaction and
increasing rate of diagonal crack width were closer to
those of companion solid deep beams. In addition, a
higher load capacity was exhibited by beams having an
effective inclined reinforcement factor above 0.077 than
the companion solid deep beam. A numerical procedure
based on the upper-bound analysis of the plasticity
theory was proposed to estimate the load capacity of
beams tested. Comparisons between the measured and
predicted load capacities showed good agreement
Application of Plasticity Theory to Reinforced Concrete Deep Beams
yesThis paper reviews the application of the plasticity theory to reinforced concrete deep beams. Both the truss analogy and mechanism approach were employed to predict the capacity of reinforced concrete deep beams. In addition, most current codes of practice, for example Eurocode 1992 and ACI 318-05, recommend the strut-and-tie model for designing reinforced concrete deep beams.
Compared with methods based on empirical or semi-empirical equations, the strut-and-tie model and mechanism analyses are more rational, adequately accurate and sufficiently simple for estimating the load capacity of reinforced concrete deep beams. However, there is a problem of selecting the effectiveness factor of concrete as reflected in the wide range of values reported in the literature for deep beams
Circulating Apoptotic Progenitor Cells in Patients with Congestive Heart Failure
Background: Circulating CD34+ endothelial progenitor cells (EPCs) are capable of differentiating into mature endothelial cells to assist in angiogenesis and vasculogenesis. We sought to quantify the numbers of apoptotic progenitors in patients with congestive heart failure. Methods and Results: Peripheral blood mononuclear cells were isolated by Ficoll density-gradient from 58 patients with various degrees of heart failure and 23 matched controls. Apoptosis in progenitor CD34+ cells was assessed using the Annexin V-PE/PI detection kit, and FACS analysis was performed with triple staining for CD34, annexin-V and propidium iodide. The percentage of early and late apoptotic progenitor cells was determined in the subject groups and was correlated with clinical characteristics. While there was no significant difference in total CD34 positive cells or early apoptotic progenitors between control subjects and CHF patients (p = 0.42) or between severe and mild/moderate CHF groups (p = 0.544), there was an elevated number of late apoptotic progenitors in the severe CHF group compared with the mild/moderate CHF group (p = 0.03). Late apoptotic progenitors were significantly increased in CHF patients as compared to matched controls. There was also an inverse correlation between late apoptotic progenitors and ejection fraction (r = 20.252, p = 0.028) as well as a positive association with NYHA class (r = 0.223, p = 0.046). Conclusion: Severe heart failure patients exhibited higher numbers of late apoptotic progenitors, and this was positivel
The learning styles neuromyth:when the same term means different things to different teachers
Alexia Barrable - ORCID: 0000-0002-5352-8330 https://orcid.org/0000-0002-5352-8330Although learning styles (LS) have been recognised as a neuromyth, they remain a virtual truism within education. A point of concern is that the term LS has been used within theories that describe them using completely different notions and categorisations. This is the first empirical study to investigate education professionals’ conceptualisation, as well as means of identifying and implementing LS in their classroom. A sample of 123 education professionals were administered a questionnaire consisting both closed- and open-ended questions. Responses were analysed using thematic analysis. LS were found to be mainly conceptualised within the Visual-Auditory-(Reading)-Kinaesthetic (VAK/VARK) framework, as well as Gardner’s multiple intelligences. Moreover, a lot of education professionals confused theories of learning (e.g., behavioural or cognitive theories) with LS. In terms of identifying LS, educators reported using a variety of methods, spanning from observation and everyday contact to the use of tests. The ways LS were implemented in the classroom were numerous, comprising various teaching aids, participatory techniques and motor activities. Overall, we argue that the extended use of the term LS gives the illusion of a consensus amongst educators, when a closer examination reveals that the term LS is conceptualised, identified and implemented idiosyncratically by different individuals. This study aims to be of use to pre-service and in-service teacher educators in their effort to debunk the neuromyth of LS and replace it with evidence-based practices.https://doi.org/10.1007/s10212-020-00485-236pubpub
Neural network modelling of RC deep beam shear strength
YesA 9 x 18 x 1 feed-forward neural network (NN) model
trained using a resilient back-propagation algorithm and
early stopping technique is constructed to predict the
shear strength of deep reinforced concrete beams. The
input layer covering geometrical and material properties
of deep beams has nine neurons, and the corresponding output is the shear strength. Training, validation and testing of the developed neural network have been
achieved using a comprehensive database compiled from
362 simple and 71 continuous deep beam specimens.
The shear strength predictions of deep beams obtained
from the developed NN are in better agreement with
test results than those determined from strut-and-tie
models. The mean and standard deviation of the ratio between predicted capacities using the NN and measured shear capacities are 1.028 and 0.154, respectively, for simple deep beams, and 1.0 and 0.122, respectively, for continuous deep beams. In addition, the
trends ascertained from parametric study using the developed NN have a consistent agreement with those observed in other experimental and analytical investigations
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