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Wireless positioning and tracking technology are key technologies in applying wireless sensor networks and have vital research significance and application value. In this paper, in terms of positioning multiple non-coincident dynamic targets, aiming at the problem of low precision and large computational complexity when locating multiple dynamic targets by the two-step least squares algorithm and the constrained total least squares algorithm, an improved constrained total least squares algorithm is proposed. This algorithm fully considers the constraints, introduces the Lagrangian multiplier technology and the quasi-Newton BFGS iterative formula, avoids the calculation of the Hessian matrix, reduces the amount of calculation, and improves the positioning accuracy. Simulation experiments show that when the measurement error and sensor position error are moderate, the ICTLS positioning algorithm has a smaller RMSE than the TSWLS and CTLS positioning algorithms, showing higher positioning accuracy and stronger robustness. Secondly, aiming at the problem that the target is close to the reference node or any coordinate axis causes the positioning error of the traditional positioning algorithm to increase sharply, an optimized two-step least squares algorithm is proposed. This algorithm corrects the defects of the TSWLS algorithm by selecting the reference station and rotating the coordinate system again, and improves the positioning performance of the algorithm while reducing the amount of calculation. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effect of melatonin during the culture of donor cells and cloned embryos on the in vitro developmental competence and quality of cloned porcine embryos. At concentrations of 10-6 m or 10-8 m, melatonin significantly enhanced the proliferation of porcine fetal fibroblasts (PFFs), and the blastocyst rate was significantly increased in the 10-10 m melatonin-treated donor cell group. Cloned embryo development was also improved in embryo culture medium that was supplemented with 10-9 m or 10-12 m melatonin. When both donor cells and cloned embryos were treated with melatonin, the cleavage rate and total cell number of blastocysts were not significantly affected; however, the blastocyst rate was increased significantly (20.0% versus 11.7%). TUNEL assays showed that combined melatonin treatment reduced the rate of apoptotic nuclei (3.6% versus 6.1%). Gene expression analysis of the apoptosis-related genes BAX, BCL2L1, and p53 showed that the expression of BCL2L1 was significantly elevated 2.7-fold relative to the control group, while the expression of BAX and p53 was significantly decreased by 3.7-fold and 23.2-fold, respectively. In addition, we detected the expression of two melatonin receptors (MT1 and MT2) in PFFs but not in porcine cloned embryos. We conclude that exogenous melatonin enhances the development of porcine cloned embryos and improves embryo quality by inhibiting p53-mediated apoptotic pathway. The proliferation of PFFs may be mediated by receptor binding, but the beneficial effects of melatonin on embryonic development may be receptor-independent, possibly through melatonin's ability to directly scavenge free radicals. [ABSTRACT FROM AUTHOR]

Seasonal environmental shifts and improper eating habits are the important causes of diarrhea in children and growing animals. Whether adjusting feeding time at varying temperatures can modify cecal bacterial structure and improve diarrhea remains unknown. Three batches growing rabbits with two groups per batch were raised under different feeding regimens (fed at daytime vs. nighttime) in spring, summer and winter separately, and contents were collected at six time points in 1 day and used 16S rRNA sequencing to investigate the effects of feeding regimens and season on the composition and circadian rhythms of cecum bacteria. Randomized forest regression screened 12 genera that were significantly associated with seasonal ambient temperature changes. Nighttime feeding reduced the abundance of the conditionally pathogenic bacteria Desulfovibrio and Alistipes in summer and Campylobacter in winter. And also increases the circadian rhythmic Amplicon Sequence Variants in the cecum, enhancing the rhythm of bacterial metabolic activity. This rhythmic metabolic profile of cecum bacteria may be conducive to the digestion and absorption of nutrients in the host cecum. In addition, this study has identified 9 genera that were affected by the combination of seasons and feeding time. In general, we found that seasons and feeding time and their combinations affect cecum composition and circadian rhythms, and that daytime feeding during summer and winter disrupts the balance of cecum bacteria of growing rabbits, which may adversely affect cecum health and induce diarrhea risk., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 He, Zhang, Jin, Wang, Huang, Li, Guo, Liu, Liu, Liu, Geng, Li, Li, Liu and Wu.)

Vector injection into the perivitelline space has emerged as the standard delivery method to transduce lentivirus to mammalian oocytes or one-cell embryos, but its application is limited by the need for high titers of lentivirus. Herein we developed a new method by using a Piezo impact micro-manipulator for injecting low titer of lentivirus into the subzonal space of two-cell embryos or the perivitelline space of one-cell embryos that were shrunk with a highly concentrated sucrose solution. The survival rate of embryos was greater than 98% using this micromanipulation strategy, which was increased compared to the normal one-cell embryo injection method. More than 90% of injected embryos were GFP positive after subzonal injection of a lentivirus vector carrying the GFP gene with titers of 2 × 10⁸ I.U./ml. Even when a low titer of lentivirus (2 × 10⁶ I.U./ml) was used, 53.26% and 40.85% transgenic embryos were obtained after two-cell embryonic injection and one-cell sucrose treated embryonic injection, respectively. The GFP-positive rates were also greater than in the conventional method of injecting one-cell embryos (25.39%). In addition, blastocysts from the two-cell embryo injection group displayed stronger GFP fluorescence than the one-cell embryo injection groups treated with or without the sucrose solution. Increased expression of GFP suggests that the embryos obtained from this injection method have higher exogenous gene expression levels compared to previous methods. Therefore, in contrast with the traditional injection method, we have demonstrated a simplified and efficient lentivirus-mediated gene transfer method based on a low-titer virus preparation.