94 research outputs found
Genetic Characterization of Fine-Leaved \u3ci\u3eFestuca valesiaca\u3c/i\u3e Germplasm and Evaluation of Their Relationship to the \u3ci\u3eFestuca ovina\u3c/i\u3e Complex
Fine-leaved Festuca valesiaca possesses abiotic stress tolerances. However, their agronomic performances in the western United States and its genetic relationship to species of the Festuca ovina complex have not been investigated. Also, natural hybridization due to open pollination presents difficulties in distinguishing them for closely related taxa using morphological analysis. Given the species’ agronomic potentials, a project was designed to identify Festuca valesiaca accessions possessing high biomass production and seed yield for possible low-maintenance applications and to examine their relatedness to taxa of the Festuca ovina complex by multi-locus AFLP genotyping and chloroplast DNA sequence analysis using primer combinations designed from three intergenic spacers.
Plant vigor, height and width, total biomass, and seed weight and seed number of Festuca valesiaca accessions were evaluated from 2009 to 2011 at Blue Creek, Utah in a random complete block design with six replications. The Festuca valesiaca accessions examined produced abundance of small seeds. Seed production was significantly (P = 0.001) correlated (r2 = 0.84) with the total biomass, plant height, and plant vigor rating. The Festuca valesiaca accessions examined possessed lower height than the control ‘Cascade’ but higher biomass, spring green-up, and seed production. Given their morphological attributes, Festuca valesiaca accessions PI 659923, W6 30575, and W6 30588 should be considered for low-maintenance applications and use in plant improvement.
The AFLP-based neighbor-joining analysis indicated that Festuca valesiaca is a closely related subcluster of Festuca ovina and should be considered as one species. Festuca trachyphylla is a subcluster under Festuca ovina and Festuca valesiaca. Festuca idahoensis has a close relationship with Festuca roemeri but not with Festuca ovina. Low admixture was detected between the Festuca rubra and Festuca trachyphylla accessions examined, while a comparative high admixture was detected among the commercial cultivars examined.
Chloroplast sequences data reconfirmed that the Festuca ovina complex genetically differed from Festuca rubra and the other reference taxa examined. Festuca valesiaca and Festuca ovina possessed the same maternal lineage based on chloroplast DNA sequence analysis. One Festuca valesiaca accession, W6 30537, was genetically similar to the Festuca rubra examined and should be putatively reclassified as Festuca rubra pending further taxonomic analysis
Prediction of interesting ferromagnetism in Janus semiconducting CrAsP monolayer
Two-dimensional (2D) half-metallic materials that have sparked intense
interest in advanced spintronic applications are essential to the developing
next-generation nanospintronic devices. Here we have adopted a first-principles
calculation method to predict the magnetic properties of intrinsic, Se-doped,
and biaxial strain tuning CrAsP monolayer. The Janus CrAsP monolayer is
proved to be an intrinsic ferromagnetic (FM) semiconductor with a exchange
splitting bandgap of 0.15 eV at the PBE+U level. Concentration-dependent Se
doping such as CrAsSeP (x = 0.25, 0.50, 0.75) can regulate
CrAsP from FM semiconductor to FM half-metallicity. Specifically, the
spin-up channel crosses the Fermi level, while the spin-down channel has a
bandgap. More interestingly, the wide half-metallic bandgaps and spin bandgaps
make them have important implications for the preparation of spintronic
devices. At last, we also explore the effect of biaxial strain from -14% to 10%
on the magnetism of the CrAsP monolayer. There appears a transition from FM
to antiferromagnetic (AFM) at a compressive strain of -10.7%, originating from
the competition between the indirect FM superexchange interaction and the
direct AFM interaction between the nearest-neighbor Cr atoms. Additionally,
when the compressive strain to -2% or the tensile strain to 6%, the
semiconducting CrAsP becomes a half-metallic material. These charming
properties render the Janus CrAsP monolayer with great potential for
applications in spintronic devices.Comment: 14 pages, 4 figure
First-principles calculations on the mechanical, electronic, magnetic and optical properties of two-dimensional Janus CrTeX (X= P, As, Sb) monolayers
Janus materials possess extraordinary physical, chemical, and mechanical
properties caused by symmetry breaking. Here, the mechanic properties,
electronic structure, magnetic properties, and optical properties of Janus
CrTeX (X= P, As, Sb) monolayers are systematically investigated by the
density functional theory. Janus CrTeP, CrTeAs, and CrTeSb are
intrinsic ferromagnetic (FM) half-metals with wide spin gaps and half-metallic
gaps. Monte Carlo simulations based on the Heisenberg model estimate the Curie
temperature (\emph{T}) of these monolayers are about 583, 608, and 597 K,
respectively. Additionally, it is found that CrTeX (X= P, As, Sb)
monolayers still exhibit FM half-metallic properties under biaxial strain from
-6% to 6%. At last, the CrTeP monolayer has a higher absorption coefficient
than the CrTeAs and CrTeSb monolayers in the visible region. The
results predict that Janus CrTeX (X= P, As, Sb) monolayers with novel
properties have good potential for applications in future nanodevices.Comment: 14 pages, 5 figure
Impact of cod skin peptide-ι-carrageenan conjugates prepared via the Maillard reaction on the physical and oxidative stability of Antarctic krill oil emulsions
This research aimed to construct an emulsifier by the Maillard reaction at various times using cod fish skin collagen peptide (CSCP) and ι-carrageenan (ι-car) to stabilize an Antarctic krill oil (AKO) emulsion. This emulsion was then investigated for physicochemical stability, oxidative stability, and gastrointestinal digestibility. The emulsion stability index and emulsifying activity index of Maillard reaction products (MRPs) were increased by 36.32 % and 66.30 %, respectively, at the appropriate graft degree (25.58 %) compared with the mixture of ι-car and CSCP. In vitro digestibility suggested the higher release of free fatty acids (FFAs) of 10d-MRPs-AKO-emulsion, and the highest bioavailability of AST in 10d-MRPs-AKO was found to be 28.48 %. The findings of this study showed the potential of MRPs to improve peptide function, serve as delivery vehicles for bioactive chemicals, and possibly serve as a valuable emulsifier to be used in the food industry
Posterior hemivertebra resection without internal fixation in the treatment of congenital scoliosis in very young children
ObjectiveTo retrospectively analyze the feasibility and efficacy of posterior hemivertebra resection without internal fixation in the treatment of congenital scoliosis in very young children.MethodsSixteen cases of very young children with congenital scoliosis treated at our hospital from April 2000 to July 2019 were collected, including 8 cases of each sex, all of whom had type I/III congenital scoliosis and were operated on at a median (interquartile range) of 9.00 (7.75) months (range, 0.5–48 months) of age. All cases underwent posterior hemivertebra resection without internal fixation and wore orthopedic braces or plaster undershirts for more than six months after surgery, with a mean follow-up of 94.31 ± 65.63 months (range, 36–222 months).ResultsCoronal plane: the preoperative Cobb angle for the segmental curve was 39.50 ± 9.70° compared to postoperative (19.19 ± 8.56°) and last follow-up (14.94 ± 12.11°) (both P < 0.01); the preoperative Cobb angle for the main curve was 34.19 ± 14.34° compared to postoperative (17.00 ± 11.70°) and last follow-up (17.56 ± 16.31°) (both P < 0.01); the preoperative Cobb angle of the proximal compensated curve was 14.88 ± 9.62° compared to postoperative (7.88 ± 4.66°) and last follow-up (8.38 ± 8.36°) (both P < 0.05); and the preoperative Cobb angle of the distal compensated curve was 13.50° (10.50°) (range, 4°–30°) compared with postoperative 4.50° (9.25°) (range, −3° to 25°) and final follow-up 5.50° (9.50°) (range, −3° to 33°) (both P < 0.01). Sagittal plane: the difference in the preoperative Cobb angle was 10.00° (14.00°) (range, −31° to 41°) for segmental kyphosis compared to postoperative 14.00° (24.50°) (range, −6° to 46°) and last follow-up 17.00° (22.55°) (range, −40° to 56°), and these were not statistically significant (both P > 0.05). There was a tendency for the thoracolumbar kyphosis to worsen and the lumbosacral kyphosis to improve during the follow-up period.ConclusionPosterior hemivertebra resection without internal fixation is a feasible treatment for type I/III congenital scoliosis in very young children, but the correction of the sagittal deformity of the thoracolumbar spine is not satisfactory, and postoperative external fixation may require further improvement
Hypercholesterolemia Tunes Hematopoietic Stem/Progenitor Cells for Inflammation and Atherosclerosis
As the pathological basis of cardiovascular disease (CVD), atherosclerosis is featured as a chronic inflammation. Hypercholesterolemia is an independent risk factor for CVD. Accumulated studies have shown that hypercholesterolemia is associated with myeloid cell expansion, which stimulates innate and adaptive immune responses, strengthens inflammation, and accelerates atherosclerosis progression. Hematopoietic stem/progenitor cells (HSPC) in bone marrow (BM) expresses a panel of lipoprotein receptors to control cholesterol homeostasis. Deficiency of these receptors abrogates cellular cholesterol efflux, resulting in HSPC proliferation and differentiation in hypercholesterolemic mice. Reduction of the cholesterol level in the lipid rafts by infusion of reconstituted high-density lipoprotein (HDL) or its major apolipoprotein, apoA-I, reverses hypercholesterolemia-induced HSPC expansion. Apart from impaired cholesterol metabolism, inhibition of reactive oxygen species production suppresses HSPC activation and leukocytosis. These data indicate that the mechanisms underlying the effects of hypercholesterolemia on HSPC proliferation and differentiation could be multifaceted. Furthermore, dyslipidemia also regulates HSPC-neighboring cells, resulting in HSPC mobilization. In the article, we review how hypercholesterolemia evokes HSPC activation and mobilization directly or via its modification of BM microenvironment. We hope this review will bring light to finding key molecules to control HSPC expansion, inflammation, and atherosclerosis for the treatment of CVD
Transcriptome analysis of creeping bentgrass exposed to drought stress and polyamine treatment
<div><p>Creeping bentgrass is an important cool-season turfgrass species sensitive to drought. Treatment with polyamines (PAs) has been shown to improve drought tolerance; however, the mechanism is not yet fully understood. Therefore, this study aimed to evaluate transcriptome changes of creeping bentgrass in response to drought and exogenous spermidine (Spd) application using RNA sequencing (RNA-Seq). The high-quality sequences were assembled and 18,682 out of 49,190 (38%) were detected as coding sequences. A total of 22% and 19% of genes were found to be either up- or down-regulated due to drought while 20% and 34% genes were either up- or down- regulated in response to Spd application under drought conditions, respectively. Gene ontology (GO) and enrichment analysis were used to interpret the biological processes of transcripts and relative transcript abundance. Enriched or differentially expressed transcripts due to drought stress and/or Spd application were primarily associated with energy metabolism, transport, antioxidants, photosynthesis, signaling, stress defense, and cellular response to water deprivation. This research is the first to provide transcriptome data for creeping bentgrass under an abiotic stress using RNA-Seq analysis. Differentially expressed transcripts identified here could be further investigated for use as molecular markers or for functional analysis in responses to drought and Spd.</p></div
Phenotypic and Genotypic Analysis of a U.S. Native Fine-leaved Festuca Population Reveals Its Potential Use for Low-input Urban Landscapes
Continued reduction in limited natural resources worldwide increasingly necessitates the incorporation of low-maintenance and low-input plant materials into urban landscapes. Some fine-leaved Festuca grass species have been used in formal gardens and native urban landscapes because of their inherent tolerance to abiotic stresses, but native, ornamental types (tall and non-spreading with multicolored culms and panicles) are not common in landscapes of the western United States. A native fine-leaved Festuca collection made in Montana (designated FEID 9025897) by the U.S. Natural Resources Conservation Services possesses such ornamental characteristics but has not been evaluated for its horticultural potential. Therefore, a study was designed to assess its phenotypic and genotypic attributes by cloning 270 FEID 9025897 plants and evaluating them along with native F. idahoensis and F. ovina PIs (five) and commercial checks (five) for genetic diversity and plant morphology for 2 years (2010–11). Plant genetic constitution was determined using amplified fragment length polymorphism (AFLP) analysis. Plant height, width, biomass, relative vigor (visual rating of 0 = dead to 5 = green, abundant growth), persistence (number of plants alive per plot), and regrowth after clipping (visual rating of 0 = none to 5 = most) were estimated by evaluation of plants under replication at Hyde Park, UT. Based on AFLP-based coancestry analysis, FEID 9025897 plants possessed considerable genetic affinities with F. idahoensis. Morphological traits as averaged over both years varied in height (13.9 to 105.0 cm), width (9.9 to 66.2 cm), biomass (0 to 170.4 g), vigor (0.2 to 4.7), persistence (0 to 3.9), and regrowth (0 to 4.0). Based on these differences, 19 (7%) FEID 9025897 plants were identified for their ornamental potential that possessed multicolored (red, orange, and yellow) culms and varied in morphology with 2-year means of height (79.8 cm), width (45.2 cm), biomass (88.5 g), vigor (2.9), persistence (1.8), and regrowth (3.7)
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