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IntroductionIn this study, we investigated the metabolic profiles of yak (Bos grunniens) follicles during the development period from the perspective of metabolomics, aiming to screen out the differential metabolites of yak follicles in different sizes and potential pathways during yak follicle development and to provide a basis for the study of follicle development and developmental mechanisms in the further stage of development.MethodsA total of 20 four-year-old female yaks were selected, and follicles of different sizes were collected after slaughter and divided into d 6 mm. The follicular fluid was collected, 6 replicates per group and subjected to LC–MS assay, combined with multidimensional and unidimensional statistical analyses to screen the differential metabolites between follicles of different sizes. Differential metabolites enriched KEGG pathways to screen the pathways that might be related to follicle development.ResultsWe found that most of the metabolites were mainly enriched in amino acid metabolism pathways, energy metabolism pathways and other pathways of cofactor synthesis, and that during the development of the small follicle to the large follicle, 2-Lysophosphatidylcholine, PC (17:0/0:0), PC (16:0/0:0), and LysoPC (18:0/0:0) were down-regulated; Dioctyl succinate, P-Coumaraldehyde, ISOPRENE, L-Isoleucine, Dioctyl succinate up-regulated.ConclusionThese results suggest that amino acid metabolism, the production of steroid hormones and their metabolites, and the metabolic activity of granulosa cells play important roles in follicle development. The results provide a theoretical basis for further exploration of follicular development in yak.

IntroductionThe CDO1 gene is an important gene in the taurine synthesis pathway and has been observed to have high expression in ovaries of female mammals. This study aims to explore the conservation of CDO1 gene in domestic yaks, as well as to examine the fundamental characteristics of CDO1 gene and its expression in female yaks.MethodsOvarian samples were collected from yaks in the follicular phase, luteal phase and gestation period in this experiment, and their total RNA and protein were extracted. Then Polymerase Chain Reaction (PCR) and bioinformatics online software were used to clone and analyze the CDO1 gene. The relative expression of CDO1 in yak ovaries was detected by Quantitative Real-time PCR (RT-qPCR) and Western blotting. The distribution and localization of CDO1 protein in ovary were detected by immunohistochemistry.ResultsWe have successfully cloned the coding region of CDO1 gene in yak. The results showed that the CDS region of CDO1 gene was 603 bp, encoding 200 amino acids, and was a relatively stable hydrophilic protein. CDO1 is relatively conservative in species evolution. The protein encoded by CDO1 gene does not have a signaling peptide or a transmembrane structure. It is a protein that is not involved in transmembrane transport and is mainly located in the cytoplasm. The secondary structure of the protein is dominated by the random coil. CDO1 is estimated to interact with 10 proteins. The results of RT-qPCR and Western blotting showed that the CDO1 gene exhibited the highest expression in the ovary during the luteal phase and the lowest expression in the ovary during the follicular phase (P < 0.01). The results of immunohistochemistry showed that CDO1 was mainly expressed in granular cells, theca cells and lutein cells of ovarian tissue.ConclusionThese results suggest that the CDO1 gene has undergone minimal evolutionary changes during the course of animal evolution. The results provide a reference for further investigation of the function of CDO1 gene in reproduction and production in yaks.

In this paper, an in-fiber composite modal interferometer (CMI) is proposed and experimentally demonstrated based on cascaded no-cladding fiber (NCF) and thin-core fiber (TCF) structure, which respectively corresponds to multimode interferometer (MMI) and Mach-Zehnder interferometer (MZI). The self-image effect of MMI is deeply analyzed and the interference fringes distribution of CMI is accurately designed by the selective the length of NCF and TCF. The comprehensive tests are then conducted and the experimental results show that interference fringes present similar temperature response but the apparent differences in strain and refractive index (RI) tests owing to the asymmetrical structure. MMI has a nearzero intensity sensitivity of strain and red-shifts with the increased RI. But MZI has the sensitivity of -19.3nm/RIU and a 4.94 dB increment in the range of 300-1100 με. Thus high-discrimination simultaneous triple-parameter measurement is achieved by means of joint wavelength and intensity demodulation. The proposed CMI has the merits of high sensitivity, low cost and ease of fabrication, and is very promising and potential for the engineering monitoring and sensing applications.

In this paper, we report a tapered thin-core fiber based in-line Mach-Zehnder interferometer to improve the response of axial-strain. With the varied diameters of taper waist, the light field distributions are studied by beam propagation method, and the structures are fabricated by arc-discharged lateral offset splicing and tapering techniques. The comprehensive tests are then conducted and compared in terms of axial-strain and temperature. The experimental results show that, by reducing the diameter of taper waist, more than 400% enhancement of wavelength sensitivity can be gained, and the maximum reaches 4.07 pm/µε with the measured error of 3.6%. Moreover, owing to high consistency of temperature response, the near-zero crosstalk is presented by differential compensation method. Furthermore, owing to the merit of high repeatability and stability, our sensor is very practical and promising in the high-precision measurement and engineering monitoring.

In this paper, to enhance practicality, a novel tapered thin-core fiber (t-TCF) based modal interferometer is proposed and demonstrated experimentally. The light field distribution of t-TCF structure is investigated by a beam propagation method, and the quantitative relationship is gained between light intensity loss and waist diameter. Under ~30 μm waist diameter, multiple t-TCF based sensor heads are fabricated by arc-discharged splicing and taper techniques, and comprehensive tests are performed with respects to axial strain and temperature. The experimental results show that, with near-zero wavelength shift, obvious intensity strain response is exhibited and negative-proportional to the reduced length of TCF. Thus, the maximum sensitivity reaches 0.119 dB/με when the TCF length is equal to 15 mm, and a sub-micro-strain detection resolution (about 0.084 με) is obtained. Besides, owing to the flat red-shifted temperature response, the calculated cross-sensitivity of our sensor is compressed within 0.32 με/°C, which is promising for high precision strain related engineering applications.

Virtual channel (VC) flow control proves to be an alternative way to promote network performance, but uniform VC allocation in the network may be at the cost of chip area and power consumption. We propose a novel VC number allocation algorithm customizing the VCs in network based on the characteristic of the target application. Given the characteristic of target application and total VC number budget, the block probability for each port of nodes in the network can be obtained with an analytical model. Then VCs are added to the port with the highest block probability one by one. The simulation results indicate that the proposed algorithm reduces buffer consumption by 14.58%~51.04% under diverse traffic patterns and VC depth, while keeping similar network performance.

In this paper, a novel in-line modal interferometer for refractive index (RI) sensing is proposed and experimentally fabricated by cascading single-taper and multimode-double- cladding-multimode (MDM) fiber structure. Owing to evanescent field in taper area, the ultra-sensitive and linear intensity-responses to the varied surrounding RI are gained in both single- and double-pass structures. Moreover, the crosstalk from temperature can be effectively discriminated and compensated by means of the RI-free nature of MDM. The experimental results show that the RI sensitivities in single- and double-pass structures, respectively, reach 516.02 and 965.46 dB/RIU (RIU: refractive index unit), both with the slight wavelength shift (~0.2 nm). The temperature responses with respect to wavelength and intensity are 68.9 pm°C−1/0.103 dB°C−1 (single-pass structure) and 103 pm°C−1/0.082 dB·°C−1 (double-pass structure). So the calculated cross-sensitivity of intensity is constrained within 8.49 × 10−5 RIU/°C. In addition, our sensor presents high measurement-stability (~0.99) and low repeatability error (

In this paper, a comprehensive passive torsion measurement is performed firstly in a 40-cm-long polarization maintaining fiber-based Sagnac interferometer (PMF-SI), and the non-linear torsion response is found and investigated. Then, a fiber laser torsion sensor (FLTS) with a dual-ring-cavity structure is proposed and experimentally demonstrated, in which the PMF-SI is utilized as the optical filter as well as the sensing unit. In particular, the highly sensitive linear range is adjusted through fine phase modulation, and owing to the flat-top feature of fringes, an ~83.6% sensitivity difference is effectively compressed by the generated lasing. The experimental results show that, without any pre-twisting, the ultra-wide linear response from −175 to 175 rad/m is gained, and the torsion sensitivities are 2.46 and 1.55 nm/rad with high linearity (>0.99) in the clockwise and anti-clockwise directions, respectively. Additionally, a high extinction ratio (>42 dB) and small line-width (~0.14 nm) are obtained in the proposed FLTS, and the corresponding detection limit reaches 0.015 rad/m.

A novel intensity demodulated refractive index (RI) sensor is theoretically and experimentally demonstrated based on the front-tapered single-mode-multimode-single-mode (FT-SMS) fiber structure. The front taper is fabricated in a section of multimode fiber by flame-heated drawing technique. The intensity feature in the taper area is analyzed through the beam propagation method and the comprehensive tests are then conducted in terms of RI and temperature. The experimental results show that, in FT-SMS, the relative sensitivity is −342.815 dB/RIU in the range of 1.33~1.37. The corresponding resolution reaches 2.92 × 10−5 RIU, which is more than four times higher than that in wavelength demodulation. The temperature sensitivity is 0.307 dB/°C and the measurement error from cross-sensitivity is less than 2 × 10−4. In addition, fabricated RI sensor presents high stability in terms of wavelength (±0.045 nm) and intensity (±0.386 dB) within 2 h of continuous operation.

In order to enhance the practicality of multi-wavelength erbium-doped fiber lasers (MWEDFLs), a novel hybrid dual-ring configuration is proposed in this article, which can flatten the outputs through an optical nonlinear-polarization-rotation-based ring cavity and stabilize the shifts of power and central wavelength of oscillations through an electrical fuzzy-control-based feedback. The experiment results show that, our scheme achieves more than 10 stable oscillations with the dramatic improvements in flatness and working stability. Under dual-ring configuration, the output intensity of MWEDFL reaches ~−7.5 dBm with the flatness of ±0.42 dB. And the in-stabilities in terms of power and central wavelength are respectively constrained ±0.182 dBm and ±0.029 nm within 10-h continuous operation.