A Cam-disc Comb-tooth Chrysanthemum Picking Device

Abstract A quantitative trait locus (QTL) genetic analysis of morphological and reproductive traits distinguishing the sibling species Drosophila simulans and D. sechellia was carried out in a backcross design, using 38 markers with an average spacing of 8.4 cM. The direction of QTL effects for the size of the posterior lobe was consistent across the identified QTL, indicating directional selection for this trait. Directional selection also appears to have acted on testis length, indicating that sexual selection may have influenced many reproductive traits, although other forms of directional selection cannot be ruled out. Sex comb tooth number exhibited high levels of variation both within and among isofemale lines and showed no evidence for directional selection and, therefore, may not have been involved in the early speciation process. A database search for genes associated with significant QTL revealed a set of candidate loci for posterior lobe shape and size, sex comb tooth number, testis length, tibia length, and hybrid male fertility. In particular, decapentaplegic (dpp), a gene known to influence the genital arch, was found to be associated with the largest LOD peak for posterior lobe shape and size.

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Numerical Simulation of Mixing Process in a Splitting-and-Recombination Microreactor

Frontiers in Chemical Engineering ◽

10.3389/fceng.2021.803861 ◽

2022 ◽

Vol 3 ◽

Author(s):

Lifang Yan ◽

Shiteng Wang ◽

Yi Cheng

Keyword(s):

Reynolds Numbers ◽

Mixing Efficiency ◽

Horizontal Distance ◽

Mixing Process ◽

Mixing Rate ◽

Navier Stokes Equation ◽

Vertical Distance ◽

Wide Range ◽

Spacing Distance ◽

Comb Tooth

The mixing process between miscible fluids in a splitting-and-recombination microreactor is analyzed numerically by solving the Navier–Stokes equation and species transfer equation. The commercial microreactor combines rectangular channels with comb-shaped inserts to achieve the splitting-and-recombination effect. The results show that the microreactor with three-layer standard inserts have the highest mixing rate as well as good mixing efficiency within a wide range of Reynolds numbers from 0.1 to 160. The size parameters of the inserts, both the ratio of the width of comb tooth (marked as l) and the spacing distance (marked as s) between two comb teeth, and the ratio of the vertical distance (marked as V) of comb teeth and the horizontal distance (marked as H) are essential for influencing the liquid–liquid mixing process at low Reynolds numbers (e.g., Re ≤ 2). With the increase of s/l from 1 to 4, the mixing efficiency drops from 0.99 to 0.45 at Re = 0.2. Similarly, the increase in V/H is not beneficial to promote the mixing between fluids. When the ratio of V/H changes from 10:10 to 10:4, the splitting and recombination cycles reduce so that the uniform mixing between different fluids can be hardly achieved. The width of comb tooth (marked as l) is 1 mm and the spacing distance (marked as s) between two comb teeth is 2 mm. The vertical distance (marked as V) of comb teeth and the horizontal distance (marked as H) are both 10 mm.

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Comb tooth resolved MIR spectroscopy using a VECSEL frequency comb and a virtually-imaged phased array spectrometer

Vertical External Cavity Surface Emitting Lasers (VECSELs) X ◽

10.1117/12.2546752 ◽

2020 ◽

Author(s):

Robert Rockmore ◽

Ricky Gibson ◽

R. Jason Jones ◽

Jerome V. Moloney

Keyword(s):

Phased Array ◽

Frequency Comb ◽

Mir Spectroscopy ◽

Comb Tooth

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Genetic architecture of variation in sex-comb tooth number in Drosophila simulans

Genetics Research ◽

10.1017/s0016672306008111 ◽

2006 ◽

Vol 87 (2) ◽

pp. 93-107 ◽

Cited By ~ 11

Author(s):

HARUKI TATSUTA ◽

TOSHIYUKI TAKANO-SHIMIZU

Keyword(s):

Interspecific Variation ◽

Drosophila Simulans ◽

Epistatic Interactions ◽

The Third ◽

Sex Comb ◽

Tooth Number ◽

Comb Tooth ◽

Trait Locus ◽

The Relationship ◽

Mapping Populations

The sex comb on the forelegs of Drosophila males is a secondary sexual trait, and the number of teeth on these combs varies greatly within and between species. To understand the relationship between the intra- and interspecific variation, we performed quantitative trait locus (QTL) analyses of the intraspecific variation in sex-comb tooth number. We used five mapping populations derived from two inbred Drosophila simulans strains that were divergent in the number of sex-comb teeth. Although no QTLs were detected on the X chromosome, we identified four QTLs on the second chromosome and three QTLs on the third chromosome. While identification and estimated effects of the second-chromosome QTLs depend on genetic backgrounds, significant and consistent effects of the two third-chromosome QTLs were found in two genetic backgrounds. There were significant epistatic interactions between a second-chromosome QTL and a third-chromosome QTL, as well as between two second-chromosome QTLs. The third-chromosome QTLs are concordant with the locations of the QTLs responsible for the previously observed differences in sex-comb tooth number between D. simulans and D. mauritiana.

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