3,597 research outputs found
The Genome of Vibrio orientalis : A Luminous Bacterium.
Vibrio orientalis was first isolated from the Yellow Sea in China and described as a luminous bacterium. Since the bacterium was named, a surprisingly sparse amount of information is available. In this study, the genome of V. orientalis was sequenced; the draft genome consists of five contigs. The genome was explored using a comparative genomics approach to describe the genes that are in the genome. Genes and mobile elements were compared to other Vibrio species to determine the presence of mobile elements related to important cell functions and adaptive functions that provided evidence related to the environments in which the bacterium is able to adapt and survive. The genome also provided insight into nutrients that the bacterium may be able to metabolize
The Implication of Substance P in the Development of Tendinopathy: A Case Control Study.
It was reported that substance P had beneficial effects in the healing of acute tendon injury. However, the relationship between substance P and degenerative tendinopathy development remains unclear. The purpose of this study was to determine the role of substance P in the pathogenesis of tendinopathy. Healthy and tendinopathy tendon were harvested from human and tenocytes were cultured individually. The expression levels of genes associated with tendinopathy were compared. Next, substance P was exogenously administered to the healthy tenocyte and the effect was evaluated. The results showed that tendinopathy tenocytes had higher levels of COL3A1, MMP1, COX2, SCX, ACTA2, and substance P gene expression compared to healthy tenocytes. Next, substance P treatment on the healthy tenocyte displayed similar changes to that of the tendinopathy tenocytes. These differences between the two groups were also determined by Western blot. Additionally, cells with substance P had the tendinopathy change morphologically although cellular proliferation was significantly higher compared to that of the control group. In conclusion, substance P enhanced cellular proliferation, but concomitantly increased immature collagen (type 3 collagen). Substance P plays a crucial role in tendinopathy development and could be a future therapeutic target for treatment
Skeletal Micro-RNA Responses to Simulated Weightlessness
Astronauts lose bone structure during long-duration spaceflight. These changes are due, in part, to insufficient bone formation by the osteoblast cells. Little is known about the role that small (approximately 22 nucleotides), non-coding micro-RNAs (miRNAs) play in the osteoblast response to microgravity. We hypothesize that osteoblast-lineage cells alter their miRNA status during microgravity exposure, contributing to impaired bone formation during weightlessness. To simulate weightlessness, female mice (C57BL/6, Charles River, 10 weeks of age, n = 7) were hindlimb unloaded up to 12 days. Age-matched and normally ambulating mice served as controls (n=7). To assess the expression of miRNAs in skeletal tissue, the tibia was collected ex vivo and cleaned of soft-tissue and marrow. Total RNA was collected from tibial bone and relative abundance was measured for miRNAs of interest using quantitative real time PCR array looking at 372 unique and well-characterized mature miRNAs using the delta-delta Ct method. Transcripts of interest were normalized to an average of 6 reference RNAs. Preliminary results show that hindlimb unloading decreased the expression of 14 miRNAs to less than 0.5 times that of the control levels and increased the expression of 5 miRNAs relative to the control mice between 1.2-1.5-fold (p less than 0.05, respectively). Using the miRSystem we assessed overlapping target genes predicted to be regulated by multiple members of the 19 differentially expressed miRNAs as well as in silico predicted targets of our individual miRNAs. Our miRsystem results indicated that a number of our differentially expressed miRNAs were regulators of genes related to the Wnt-Beta Catenin pathway-a known regulator of bone health-and, interestingly, the estrogen-mediated cell-cycle regulation pathway, which may indicate that simulated weightlessness modulated systemic hormonal levels or hormonal transduction that additionally contributed to bone loss. We plan to follow up these findings by measuring gene expression of miRNA-regulated genes within these two pathways with the aim of furthering our understanding of the function of miRNAs in the skeletal response to spaceflight
Water waves over a rough bottom in the shallow water regime
This is a study of the Euler equations for free surface water waves in the
case of varying bathymetry, considering the problem in the shallow water
scaling regime. In the case of rapidly varying periodic bottom boundaries this
is a problem of homogenization theory. In this setting we derive a new model
system of equations, consisting of the classical shallow water equations
coupled with nonlocal evolution equations for a periodic corrector term. We
also exhibit a new resonance phenomenon between surface waves and a periodic
bottom. This resonance, which gives rise to secular growth of surface wave
patterns, can be viewed as a nonlinear generalization of the classical Bragg
resonance. We justify the derivation of our model with a rigorous mathematical
analysis of the scaling limit and the resulting error terms. The principal
issue is that the shallow water limit and the homogenization process must be
performed simultaneously. Our model equations and the error analysis are valid
for both the two- and the three-dimensional physical problems.Comment: Revised version, to appear in Annales de l'Institut Henri Poincar\'
CFHTLenS: A Weak Lensing Shear Analysis of the 3D-Matched-Filter Galaxy Clusters
We present the cluster mass-richness scaling relation calibrated by a weak
lensing analysis of >18000 galaxy cluster candidates in the
Canada-France-Hawaii Telescope Lensing Survey (CFHTLenS). Detected using the
3D-Matched-Filter cluster-finder of Milkeraitis et al., these cluster
candidates span a wide range of masses, from the small group scale up to
, and redshifts 0.2 0.9. The total
significance of the stacked shear measurement amounts to 54. We compare
cluster masses determined using weak lensing shear and magnification, finding
the measurements in individual richness bins to yield 1 compatibility,
but with magnification estimates biased low. This first direct mass comparison
yields important insights for improving the systematics handling of future
lensing magnification work. In addition, we confirm analyses that suggest
cluster miscentring has an important effect on the observed 3D-MF halo
profiles, and we quantify this by fitting for projected cluster centroid
offsets, which are typically 0.4 arcmin. We bin the cluster candidates
as a function of redshift, finding similar cluster masses and richness across
the full range up to 0.9. We measure the 3D-MF mass-richness scaling
relation . We find a normalization , and a logarithmic slope of
, both of which are in 1 agreement with results
from the magnification analysis. We find no evidence for a redshift-dependence
of the normalization. The CFHTLenS 3D-MF cluster catalogue is now available at
cfhtlens.org.Comment: 3D-MF cluster catalog is NOW AVAILABLE at cfhtlens.org.
Magnification-shear mass comparison in Figure 10. 19 pages, 10 figures.
Accepted to MNRA
How do people search to generate new ideas?
The findings of our study lead us to think about how to evaluate search systems for creativity. Should future evaluation of creativity search tools focus on the final ideas generated as a result of searching, the ultimate outcomes, or the assistance provided throughout each of our identified phases
Identification of Carcass and Meat Quality QTL in an F2 Duroc × Pietrain Pig Resource Population Using Different Least-Squares Analysis Models
A three-generation resource population was constructed by crossing pigs from the Duroc and Pietrain breeds. In this study, 954 F2 animals were used to identify quantitative trait loci (QTL) affecting carcass and meat quality traits. Based on results of the first scan analyzed with a line-cross (LC) model using 124 microsatellite markers and 510 F2 animals, 9 chromosomes were selected for genotyping of additional markers. Twenty additional markers were genotyped for 954 F2 animals and 20 markers used in the first scan were genotyped for 444 additional F2 animals. Three different Mendelian models using least-squares for QTL analysis were applied for the second scan: a LC model, a half-sib (HS) model, and a combined LC and HS model. Significance thresholds were determined by false discovery rate (FDR). In total, 50 QTL using the LC model, 38 QTL using the HS model, and 3 additional QTL using the combined LC and HS model were identified (q < 0.05). The LC and HS models revealed strong evidence for QTL regions on SSC6 for carcass traits (e.g., 10th-rib backfat; q < 0.0001) and on SSC15 for meat quality traits (e.g., tenderness, color, pH; q < 0.01), respectively. QTL for pH (SSC3), dressing percent (SSC7), marbling score and moisture percent (SSC12), CIE a* (SSC16), and carcass length and spareribs weight (SSC18) were also significant (q < 0.01). Additional marker and animal genotypes increased the statistical power for QTL detection, and applying different analysis models allowed confirmation of QTL and detection of new QTL
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