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The mammalian imprinted Dlk1-Gtl2 locus produces multiple non-coding RNAs (ncRNAs) from the maternally inherited allele, including the largest miRNA cluster in the mammalian genome. This locus has characterized functions in some types of stem cell, but its role in hematopoietic stem cells (HSCs) is unknown. Here, we show that the Dlk1-Gtl2 locus plays a critical role in preserving long-term repopulating HSCs (LT-HSCs). Through transcriptome profiling in 17 hematopoietic cell types, we found that ncRNAs expressed from the Dlk1-Gtl2 locus are predominantly enriched in fetal liver HSCs and the adult LT-HSC population and sustain long-term HSC functionality. Mechanistically, the miRNA mega-cluster within the Dlk1-Gtl2 locus suppresses the entire PI3K-mTOR pathway. This regulation in turn inhibits mitochondrial biogenesis and metabolic activity and protects LT-HSCs from excessive reactive oxygen species (ROS) production. Our data therefore show that the imprinted Dlk1-Gtl2 locus preserves LT-HSC function by restricting mitochondrial metabolism.

In order to optimize future transfiguration Air craft store management system hardware/software partition, directed acyclic graph was used to model the heterogeneity multiprocessor system. particle swarm algorithm was introduced to optimize task allocation, thus gets the decision tasks and paths, then tasks were assigned and Scheduled. The simulation results demonstrate that the algorithm is computationally efficient with good performance when compared with other approximate optimization algorithms in solving the multi-task processing problem.

A strain of Klebsiella pneumoniae (NB029) was positive for blaTEM (beta-lactamase gene), aph(3’)Ⅰ(aminoglycoside modifying enzyme gene), gyrA (quinolone resistance gene), trbC (genetic marker of plasmids), tnp513, IS26, IS903 (genetic markers of transposons and insertion sequences), intⅠ1 (genetic marker of integrons), qacE△1 (drug efflux gene) by PCR assays. So these positive genes confer multidrug-resistant phenotype. And the presence of gyrA, confirmed as a novel variant (Genbank accession number: JN232083), was determined by sequencing and Blastsguin algorithm. The double mutations at codon 83 and codon 87 in the quinolone resistance-determining region of the gyrA gene lead to high level quinolone resistance.

To consider disaccord between white Gaussian noise made by measurement noise and long-tail flicker noise measured in practice when target fusion tracking algorithm of multiple sensor calculates the data, a fusion tracking algorithm of fire solution for MMW/Tv combined guidance UCAV based on IMM-PF was presented. The algorithm can be used to multiple sensor information fusion tracking under nonlinear and non-Guassian circumstance. Also, it can be used to track mobile target through transforming the model to match the target mobile model under the interference of flicker noise. The digital simulation results show that the algorithm has better self-adaptation to mobile target and it is important to improve attack effect of MMW/Tv combined guidance UCAV.

When glass is annealed under stressed conditions, its physical properties such as refrac-tive index, density, etc. are subjected to change as compared with similarly annealed glassunder stress free conditions. This phenomenon may be termed "thermal stress effect ". In thispaper various types of optical glasses were studied for this effect by interferometric methodusing beam shaped specimens annealed under externally bending conditions.In the annealing of a bulk of optical glass, when cooling the glass through the annealingrange, thermal stress is generated within the bulk of glass, resulting an uneven distributionof refractive index due to thermal stress effect. Experiments were carried out for varioustypes of optical glasses and their corresponding values were evaluated.j.troductionIt is well known that, glass, being physically considered as a super -cooled liquid, itsphysical properties at room temperature, such as density, refractive index etc., dependsignificantly on the thermal history as to how it has been cooled through the annealing range(4 -6). For example, for an orninary crown or flint glass, the difference in refractive indexat room temperature between a quickly chilled specimen and an optically annealed glass mayamount to 0.002 to 0.003. For a dense barium crown, this difference may amount to 0.003 to0.004. For a borate flint glass this value may go as high as 0.009. Mechanical stresses sub-jected to the glass during annealing also effect its final properties. Glass cooled throughthe annealing range under hydrostatic pressure of 63 atmospheres was found to yield an in-crease of refrcative index amounting to 15 X 105(1), The latter phenomenon may be termed thethermal stress effect.In the present paper, an experimental method was set up which allows the thermal stresseffect of glass to be studied much more conveniently than the previous authors (1+14. This all-ows the present authors to study this effect more in detail for a number of types of opticalglasses.In consequence, to ensure optical homogeneity, it is deemed important not to introduceextraneous uneven external stresses to the glass while carrying out the annealing process.Hereby, annealing experiments were carried out showing that pronounced thermal stress wasgenerated in course of cooling the glass through the annealing range, and as the result,the thermal stress effect renders a bulk variation in refractive index within theglass. It is further shown that this effect plays an important role towards the existence ofresidual optical inhomoger'ty of annealed optical glasses.The thermal stress effectExperimental method. Glass specimens in slab form of dimensions 130X2OX20 mm3 were subject-ed to external stressing by the four -point bending method as shown in Fig.1. Fused quartzrods were used as supporting points so that no extraneous stress would be introduced due todifference,in thermal contraction between the specimen and the supporting frame. The wholeset up was placed in a muffle furnace to carry out the annealing procedure. Temperature with-in the furnace near the set up was continuously recorded and rate of cooling controlledthroughout the annealing range.After annealing, the glass specimen was examined for variation in refrcative index by in-terference method on a Twyman -Green interferometer. As a usual practice in our Laboratory,when a glass block is to be examined for optical homogeneity, in order to save the tediousprocessing of polishing the end faces to a highly finished optical flat, we back the two endfaces of the test block with two pieces of optically worked parallel glass plates, one oneach face, made of well annealed optical glass, selected for high quality in optical homoge-neity, as shown in Fig.2. In between the backing plate and the specimen surface is wet withan immersion liquid with its refractive index matched to that of the test piece to 10"