This paper concentrates on developing a missile terminal guidance law against a highly maneuvering target whose maneuvering acceleration is very close to that of the missile or even exceeds the ...missile normal acceleration in a finite period of time. A new saturated super-twisting algorithm is proposed and applied to the design of missile guidance law. The proposed algorithm has the advantages of simple structure, easy parameter tuning rules and a full utilization of the limit control input. The designed saturated super-twisting sliding mode guidance law is then employed in a missile guidance system. Simulation and its superior performance against strong maneuvering targets is demonstrated.
The exceptionally rich fossil record available for the equid family has provided textbook examples of macroevolutionary changes. Horses, asses, and zebras represent three extant subgenera of
lineage, ...while the
subgenus is another remarkable
lineage ranging from North America to Ethiopia in the Pleistocene. We sequenced 26 archaeological specimens from Northern China in the Holocene that could be assigned morphologically and genetically to
, a species representative of
. We present the first high-quality complete genome of the
lineage, which was sequenced to 13.4× depth of coverage. Radiocarbon dating demonstrates that this lineage survived until ~3500 years ago, despite continued demographic collapse during the Last Glacial Maximum and the great human expansion in East Asia. We also confirmed the
phylogenetic tree and found that
diverged from the ancestor of non-caballine equids ~2.3-2.7 million years ago and possibly remained affected by secondary gene flow post-divergence. We found that the small genetic diversity, rather than enhanced inbreeding, limited the species' chances of survival. Our work adds to the growing literature illustrating how ancient DNA can inform on extinction dynamics and the long-term resilience of species surviving in cryptic population pockets.
Abstract
Goats are one of the most widespread farmed animals across the world; however, their migration route to East Asia and local evolutionary history remain poorly understood. Here, we sequenced ...27 ancient Chinese goat genomes dating from the Late Neolithic period to the Iron Age. We found close genetic affinities between ancient and modern Chinese goats, demonstrating their genetic continuity. We found that Chinese goats originated from the eastern regions around the Fertile Crescent, and we estimated that the ancestors of Chinese goats diverged from this population in the Chalcolithic period. Modern Chinese goats were divided into a northern and a southern group, coinciding with the most prominent climatic division in China, and two genes related to hair follicle development, FGF5 and EDA2R, were highly divergent between these populations. We identified a likely causal de novo deletion near FGF5 in northern Chinese goats that increased to high frequency over time, whereas EDA2R harbored standing variation dating to the Neolithic. Our findings add to our understanding of the genetic composition and local evolutionary process of Chinese goats.
Goat domestication was critical for agriculture and civilization, but its underlying genetic changes and selection regimes remain unclear. Here, we analyze the genomes of worldwide domestic goats, ...wild caprid species, and historical remains, providing evidence of an ancient introgression event from a West Caucasian tur-like species to the ancestor of domestic goats. One introgressed locus with a strong signature of selection harbors the
gene, which encodes a gastrointestinally secreted mucin. Experiments revealed that the nearly fixed introgressed haplotype confers enhanced immune resistance to gastrointestinal pathogens. Another locus with a strong signal of selection may be related to behavior. The selected alleles at these two loci emerged in domestic goats at least 7200 and 8100 years ago, respectively, and increased to high frequencies concurrent with the expansion of the ubiquitous modern mitochondrial haplogroup A. Tracking these archaeologically cryptic evolutionary transformations provides new insights into the mechanisms of animal domestication.
Low‐coverage whole genome sequencing (lcWGS) has great potential to effectively genotype large‐scale population and to provide solid data for imputation; however, the time for imputation needs to be ...optimized. There is also no publicly available reference panel for whole genome selection in cattle. Here, we proposed a combination of Beagle v5.4 for phasing and GLIMPSE2 for imputation, which is fast and accurate for cattle lcWGS data. Furthermore, we established a multi‐breed reference panel with 61.8 million SNPs based on 2976 worldwide cattle, of which 1766 were bulls, by evaluating diversity and the size of the reference panel. The evaluation of imputation accuracy was conducted using new reference panel for both lcWGS and Bovine BeadChip data. The average concordance rate in Holstein was 99.6%, 99.6%, and 99.5% for 1X, 0.5X, and 0.1X lcWGS data, 99.5% and 99.0% for 777K and 50K chip data, and it was 98.8% for 1X lcWGS data in Simmental. We further investigated the factors affecting the imputation accuracy of lcWGS data and discovered that segmental duplication, structural variant, and guanine‐cytosine content were the top three factors. Interestingly, we found that 10 regions longer than 0.5 Mb showed low imputation accuracy enriched with immune function, such as 96.1% characterized genes in regions of chromosome 10, with more attention being paid on downstream immune‐related analysis. Our study provides the workflow of imputing lcWGS data and establishes the first high‐quality cattle reference panel with free access, which provides a resource to conduct subsequent large‐scale genome‐wide association studies and genomic selection.
This paper proposes a novel trajectory tracking controller for an underactuated unmanned surface vessel (USV) with multiple uncertainties and input constraints. Unlike previous dynamic surface ...control (DSC) methods that utilize a first-order filter to obtain derivatives and avoid “explosion of complexity”, we introduce nonlinear tracking differentiators (NTDs) that achieve satisfactory differential performance and fast tracking response and control the vessel to converge to the pseudo-yaw angle and surge. First, a new guidance law for yaw angle and surge is constructed. Second, inner and outer disturbances caused by uncertainties can be observed by reduced-order extended state observers. With the new guidance law, the design process of the controller is simplified and easy to implement. The simulation results show the trajectory tracking error can be stabilized to a certain extent under the parameter perturbations and other uncertainties, which verified the effectiveness of the proposed algorithm.
Separating proteins from their mixtures is an important process in a great variety of applications, but it faces difficult challenges as soon as the proteins are simultaneously of similar sizes and ...carry comparable net charges. To develop both efficient and sustainable strategies for the selective separation of similar proteins and to understand the underlying molecular mechanisms to enable the separation are crucial. In this work, we propose a novel strategy where the cholinium-based amino acid ChoPro ionic liquid (IL) is used as the trace additive and loaded physically on a mesoporous TiO
surface for separating two similar proteins (lysozyme and cytochrome
). The observed selective adsorption behavior is explained by the hydration properties of the ChoPro loaded on the TiO
surface and their partially dissociated ions under different pH conditions. As the pH is increased from 5.0 to 9.8, the degree of hydration of IL ions also increases, gradually weakening the interaction strength of the proteins with the substrates, more for lysozymes, leading to their effective separation. These findings were further used to guide the detection of the retention behavior of a binary mixture of proteins in high-performance liquid chromatography, where the introduction of ILs did effectively separate the two similar proteins. Our results should further stimulate the use of ILs in the separation of proteins with a high degree of mutual similarity.
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