Mixing in Circular and Non-circular Jets in Crossflow

Coherent structures and mixing in the flow field of a jet in crossflow have been studied using computational (large eddy simulation) and experimental (particle image velocimetry and laser-induced fluorescence) techniques. The mean scalar fields and turbulence statistics as determined by both are compared for circular, elliptic, and square nozzles. For the latter configurations, effects of orientation are considered. The computations reveal that the distribution of a passive scalar in a cross-sectional plane can be single- or double-peaked, depending on the nozzle shape and orientation. A proper orthogonal decomposition of the transverse velocity indicates that coherent structures may be responsible for this phenomenon. Nozzles which have a single-peaked distribution have stronger modes in transverse direction. The global mixing performance is superior for these nozzle types. This is the case for the blunt square nozzle and for the elliptic nozzle with high aspect ratio. It is further demonstrated that the flow field contains large regions in which a passive scalar is transported up the mean gradient (counter-gradient transport) which implies failure of the gradient diffusion hypothesis

SOX9 Governs Differentiation Stage-Specific Gene Expression in Growth Plate Chondrocytes via Direct Concomitant Transactivation and Repression

Cartilage and endochondral bone development require SOX9 activity to regulate chondrogenesis, chondrocyte proliferation, and transition to a non-mitotic hypertrophic state. The restricted and reciprocal expression of the collagen X gene, Col10a1, in hypertrophic chondrocytes and Sox9 in immature chondrocytes epitomise the precise spatiotemporal control of gene expression as chondrocytes progress through phases of differentiation, but how this is achieved is not clear. Here, we have identified a regulatory element upstream of Col10a1 that enhances its expression in hypertrophic chondrocytes in vivo. In immature chondrocytes, where Col10a1 is not expressed, SOX9 interacts with a conserved sequence within this element that is analogous to that within the intronic enhancer of the collagen II gene Col2a1, the known transactivation target of SOX9. By analysing a series of Col10a1 reporter genes in transgenic mice, we show that the SOX9 binding consensus in this element is required to repress expression of the transgene in non-hypertrophic chondrocytes. Forced ectopic Sox9 expression in hypertrophic chondrocytes in vitro and in mice resulted in down-regulation of Col10a1. Mutation of a binding consensus motif for GLI transcription factors, which are the effectors of Indian hedgehog signaling, close to the SOX9 site in the Col10a1 regulatory element, also derepressed transgene expression in non-hypertrophic chondrocytes. GLI2 and GLI3 bound to the Col10a1 regulatory element but not to the enhancer of Col2a1. In addition to Col10a1, paired SOX9–GLI binding motifs are present in the conserved non-coding regions of several genes that are preferentially expressed in hypertrophic chondrocytes and the occurrence of pairing is unlikely to be by chance. We propose a regulatory paradigm whereby direct concomitant positive and negative transcriptional control by SOX9 ensures differentiation phase-specific gene expression in chondrocytes. Discrimination between these opposing modes of transcriptional control by SOX9 may be mediated by cooperation with different partners such as GLI factors

Multiomic analysis of stretched osteocytes reveals processes and signalling linked to bone regeneration and cancer

Exercise is a non-pharmacological intervention that can enhance bone regeneration and improve the management of bone conditions like osteoporosis or metastatic bone cancer. Therefore, it is gaining increasing importance in an emerging area of regenerative medicine—regenerative rehabilitation (RR). Osteocytes are mechanosensitive and secretory bone cells that orchestrate bone anabolism and hence postulated to be an attractive target of regenerative exercise interventions. However, the human osteocyte signalling pathways and processes evoked upon exercise remain to be fully identified. Making use of a computer-controlled bioreactor that mimics exercise and the latest omics approaches, RNA sequencing (RNA-seq) and tandem liquid chromatography-mass spectrometry (LC-MS), we mapped the transcriptome and secretome of mechanically stretched human osteocytic cells. We discovered that a single bout of cyclic stretch activated network processes and signalling pathways likely to modulate bone regeneration and cancer. Furthermore, a comparison between the transcriptome and secretome of stretched human and mouse osteocytic cells revealed dissimilar results, despite both species sharing evolutionarily conserved signalling pathways. These findings suggest that osteocytes can be targeted by exercise-driven RR protocols aiming to modulate bone regeneration or metastatic bone cancer

Aptamers for pharmaceuticals and their application in environmental analytics

Aptamers are single-stranded DNA or RNA oligonucleotides, which are able to bind with high affinity and specificity to their target. This property is used for a multitude of applications, for instance as molecular recognition elements in biosensors and other assays. Biosensor application of aptamers offers the possibility for fast and easy detection of environmental relevant substances. Pharmaceutical residues, deriving from human or animal medical treatment, are found in surface, ground, and drinking water. At least the whole range of frequently administered drugs can be detected in noticeable concentrations. Biosensors and assays based on aptamers as specific recognition elements are very convenient for this application because aptamer development is possible for toxic targets. Commonly used biological receptors for biosensors like enzymes or antibodies are mostly unavailable for the detection of pharmaceuticals. This review describes the research activities of aptamer and sensor developments for pharmaceutical detection, with focus on environmental applications

Highly conserved structure in the promoter region of the gene for muscle-specific calpain, p94

p94 belongs to the calcium-dependent cysteine protease (calpain) family which has been detected from human to mold. In contrast to the conventional m- and mu-calpains which are expressed ubiquitously, expression of p94 predominates in skeletal muscle, and the mRNA for p94 is at least 10-times more abundant than mRNAs encoding in the m- and mu-types. The unique feature of p94 is that it undergoes rapid and exhaustive autolysis with a half-life of less than half an hour. To elucidate the nature of specific and abundant expression in skeletal muscle, and to proceed toward gene targeting p94, we have cloned and characterized mouse and rat genes for p94, and compared them with that of the human sequence. The sequence comparison among three mammalian species revealed several conserved regions including possible transcription factor binding sites. Furthermore, mouse and rat upstream regions of p94 are conserved over 3 kb suggesting that expression of p94 in skeletal muscle of both rodents is similarly regulated

INFLUENCE OF TEMPERAMENT AND ANXIETY ON ATHLETIC PERFORMANCE

Our research aimed to conduct basic descriptions of temperamental traits and the level of state and trait anxiety of young male athletes, and to compare them by type of sports. Study participants were 277 athletes and 152 non-athletes who were all high school boys. The Korean version of the Temperament and Character Inventory (TCI) was used for checking temperamental traits while the Korean version of the State and Trait Anxiety Inventory form Y (STAI-KY) was used to estimate anxiety levels. Harm Avoidance score of athletes was higher than that of non-athletes. Harm Avoidance score of golfers was lowest and that of swimmers was highest. The state anxiety score of baseball players was lowest and that of Taekwondo players was highest. The trait anxiety score of baseball players was also lowest and that of golfers was highest. Both trait and state anxieties of the 'winner' group were lower than those of the 'no winner' group. While prior research mainly focused on athletes' environment and phenotypic characteristics, we studied the pattern of temperaments in athletes along with its potential influence on athletic performanc

WNT7B promotes bone formation in part through mTORC1

WNT signaling has been implicated in both embryonic and postnatal bone formation. However, the pertinent WNT ligands and their downstream signaling mechanisms are not well understood. To investigate the osteogenic capacity of WNT7B and WNT5A, both normally expressed in the developing bone, we engineered mouse strains to express either protein in a Cre-dependent manner. Targeted induction of WNT7B, but not WNT5A, in the osteoblast lineage dramatically enhanced bone mass due to increased osteoblast number and activity; this phenotype began in the late-stage embryo and intensified postnatally. Similarly, postnatal induction of WNT7B in Runx2-lineage cells greatly stimulated bone formation. WNT7B activated mTORC1 through PI3K-AKT signaling. Genetic disruption of mTORC1 signaling by deleting Raptor in the osteoblast lineage alleviated the WNT7B-induced high-bone-mass phenotype. Thus, WNT7B promotes bone formation in part through mTORC1 activation