Search Results (436)

Carrier-based aircraft landing is a critical element in generating aircraft carrier combat capability. Traditional landing control suffers from inherent drawbacks including strong trajectory–attitude coupling, high pilot workload, and insufficient disturbance rejection in complex environments. The MAGIC CARPET precision landing technology achieves decoupled manipulation via direct lift control, providing a feasible technical path to address these bottlenecks. However, existing schemes still have limitations in multi-channel dynamic decoupling performance and controller parameter tuning efficiency. This paper designs a three-channel (flap, stabilator, throttle) active disturbance rejection control landing system based on direct lift technology, with an adaptive decoupling module introduced to counteract the pitching moment coupling caused by flap deflection, so as to maintain stable attitude and velocity during trajectory adjustment. An enhanced pigeon-inspired optimization algorithm is proposed with full-process improvements in population initialization, global search operator and local search operator, and a global collaborative tuning scheme for controller parameters is constructed. Verified by multiple groups of comparative simulations and Monte Carlo statistical experiments, the proposed system outperforms comparative schemes in tracking accuracy, decoupling effect and disturbance suppression capability, and exhibits favorable robust stability under uncertain conditions. This study offers a useful reference for the design and practical implementation of direct-lift landing control systems for carrier-based aircraft. Full article

The study evaluated the effects of dietary compound enzyme preparations (CEPs) supplementation on antioxidant capacity, immune response, and intestinal health of pigeons. A total of 288 White King parent pigeons were randomly assigned to four treatments, with six replications of 12 pigeons each. The control (CK) group received a basal diet, whereas the CEP groups were fed a basal diet with 0.25 g/kg (low compound enzyme preparation group, LCEP), 0.5 g/kg (middle compound enzyme preparation group, MCEP), and 1.0 g/kg (high compound enzyme preparation group, HCEP) CEPs. Results showed that supplementation with 0.25 g/kg of CEPs significantly increased duodenal crypt depth (CD), as well as jejunal villus height (VH) and the villus height-to-crypt depth ratio (VCR) (p < 0.05). It also increased the immunoglobulins of serum, such as IgA, IgG, and IgM, as well as enhanced antioxidant capacity by increasing superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities of serum (p < 0.05). Furthermore, we found that CEPs altered ileum content microbiota composition, increasing the relative abundance of p_Bacteroidota and g_Bifidobacterium (p < 0.05). In addition, untargeted metabolomics analysis identified 92 upregulated and 95 downregulated metabolites. Pathway enrichment analysis of these differential metabolites revealed that CEP supplementation altered the metabolomic profile of the ileum contents, with differential metabolites mainly enriched in alanine, aspartate and glutamate metabolism, fatty acid biosynthesis, and unsaturated fatty acid biosynthesis pathways. These results demonstrated that dietary supplementation with CEPs at different doses improved antioxidant capacity to varying degrees and maintained intestinal immune balance by modulating microbiota, which provides a theoretical basis for the rational application of compound enzyme preparations in breeding pigeon feed. Moreover, this study provides mechanistic evidence that CEPs can improve intestinal health, immunity, and antioxidant capacity. It also fills a key knowledge gap in pigeon nutrition by linking enzyme use with gut microbiota and metabolic regulation. Full article

The Tumbler pigeon, a genetic resource of pigeons, exhibits diverse feather colors and distinct flight characteristics compared with other pigeon species, but the genetic basis of these traits remains unclear. Using whole-genome resequencing technology with Illumina NovaSeq X Plus paired-end sequencing (PE150, read length 150 bp) at an average genome coverage of 14.5×, this study analyzed the genetic structure, genetic diversity, and genetic differentiation of 80 individual Tumbler pigeons, Tarim pigeons and homing pigeons, collected from different regions of Xinjiang. In principal component analysis, the Tarim pigeon (TP) and the homing pigeon (XY) each formed relatively independent clusters, and there is a detectable genetic distance between them and the Tumbler pigeon (FC, FY) from the two regions. Moreover, there is an individual overlap phenomenon between the two Tumbler pigeon populations. In the analysis of genetic diversity, N_a ranged from 1.93 to 1.97 and N_e from 1.55 to 1.56 across populations, with the TP population exhibiting the highest N_a. PIC values ranged between 0.251 and 0.256, and H_E values were lower than H_O values in all four pigeon populations, indicating that moderate levels of genetic polymorphism were retained. In phylogenetic tree and population structure analyses, TP and XY formed relatively independent clusters. At the same time, individuals from the two Tumbler pigeon regions showed intermixing, resulting in the most distinct clustering pattern. Based on these findings, detectable genetic differentiation exists among the Tumbler pigeon, Tarim pigeon, and homing pigeon, suggesting that Tumbler pigeons may represent a locally differentiated genetic resource. The findings of this study will enhance our understanding of the population genetic structure of Tumbler pigeon resources, which is of great significance for promoting the conservation of Tumbler pigeon genetic resources and facilitating breed innovation and genetic improvement. Full article

Early-weaned squabs are sensitive to dietary energy–protein supply, but combined effects remain unclear. We tested metabolizable energy (ME; 11.9, 12.2, and 12.5 MJ/kg) and crude protein (CP; 18, 19, and 20%) in 216 15-day-old gray-feathered King pigeon (Columba livia domestica) squabs using a 3 × 3 factorial design. Higher ME increased abdominal fat percentage, whereas CP affected slaughter traits. ME × CP interactions occurred for live weight, liver index, breast and leg muscle quality, and most digestive enzyme activities. At 18% CP, live weight was significantly higher at 12.5 than at 12.2 MJ/kg ME, whereas the opposite numerical trend occurred at 19% CP. Liver index was lower at 18% CP + 11.9 MJ/kg ME than at 18% CP + 12.2 MJ/kg ME. At 12.5 MJ/kg ME, breast muscle a* was lower at 20% CP than at 18% or 19% CP. Enzyme activities were generally highest at 20% CP + 11.9 MJ/kg ME. Targeted 16S rRNA sequencing associated the highest-energy/lowest-protein treatment with Lactobacillus-related taxa, whereas the opposite treatment showed higher diversity and greater contributions of Pseudomonadota- and Enterobacterales-related taxa. Responses were trait-specific; microbial findings represent associations between two contrasting diets. Full article

Cryptococcus neoformans and Cryptococcus gatti are the two most common pathogenic species of the encapsulated yeast genus Cryptococcus and have been linked to fatal neurologic infections in both immunocompromised and healthy individuals. Cryptococcosis, which includes AIDS-defining diseases such as cryptococcal meningitis and meningoencephalitis, is the most frequent fungal infection of the central nervous system, with Africa having the greatest fatality rate. The goal of this study was to identify and characterize C. neoformans from pigeon and bat droppings, which are thought to be environmental reservoirs for the yeast and to determine their relatedness to clinical species. A total of 588 dried and 55 moist pigeon droppings, as well as 50 moist bat droppings, were collected from 18 sites in Ghana’s Greater Accra and Western regions, from sources which included markets, a church, households, and a public park. Seven clinical archived C. neoformans isolates were also retrieved from the Central Laboratory of the Korle-Bu Teaching Hospital (KBTH), Greater Accra. Using conventional methods and partial Multi-Locus Sequence Typing (MLST), 49 Cryptococcus neoformans var grubii were isolated from dried pigeon droppings only, yielding a prevalence of 7%. The sequence type (ST)/MLST group could not be defined based on the available data, although the allele types of the housekeeping genes in some of the isolates were identified. Some clinical strains had allele types that were found among the environmental strains, giving preliminary evidence of possible genetic relatedness, highlighting the need for more comprehensive genomic surveillance approaches, to better characterize environmental and clinical cryptococcal isolate transmission patterns and genetic relationships. This work also adds to the global literature supporting pigeon droppings as favorable ecological niches for Cryptococcus. This study was conducted within a One Health framework, recognizing the interconnected roles of environmental reservoirs, animal-associated sources, and human health in the epidemiology of Cryptococcus infections. Full article

The current study aims to assess the effects of coated sodium butyrate (CSB) on the weaning transition of White King pigeons. A total of 336 1-month-old White King pigeons were assigned randomly to four groups, including the Control group fed basal health sandand without CSB and test groups fed the basal health sand with 0.1%, 0.2%, and 0.4% CSB, respectively. The results showed that, compared with the Control group, the average daily feed intake (ADFI) was significantly increased in the 0.1% and 0.2% CSB groups (p < 0.05). The 0.1% CSB group exhibited a higher immune organ index (IOI) than the Control group (p < 0.05). The total protein (TP) and albumin (ALB) levels in the 0.1% CSB and 0.4% CSB groups significantly increased compared with the Control group (p < 0.05). In contrast, the 0.2% CSB group exhibited lower serum ALB, TP, and total cholesterol (TC) levels; TNF-α and IL-6 concentrations were reduced compared with the other groups (p < 0.05), and the 0.4% CSB group showed significantly increased serum TNF-α, IL-6, and D-lactic acid levels (p < 0.05). The ratio of villus height to crypt depth (VH/CD) of the jejunum (p < 0.05) was significantly increased in the 0.2% CSB group. In addition, the CD and VH/CD of the ileum were significantly increased in the 0.1% CSB group (p < 0.05). Firmicutes was the predominant phylum across all treatment groups, while Bacteroidota showed a more sensitive response to CSB supplementation. The 0.1% CSB group showed a significant enrichment of Oscillospiraceae and Muribaculaceae, fiber-fermenting, SCFA-producing taxa, Enterobacterales and Klebsiella, suggesting CSB-mediated alterations in luminal oxygen tension that favor the coexistence of facultative and obligate anaerobic taxa. Collectively, these data revealed that CSB supplementation efficiently improves growth performance and intestinal health of weaning pigeons by ameliorating the intestinal environment. Full article

The purpose of this experiment is to investigate the differences in blood gas indicators, antioxidant indicators, and lactate content between high- and low-performance tumbler pigeons after exercise, and to use metabolomics and metagenomics techniques to screen for differential metabolites and bacteria related to tumbler pigeon exercise. This experiment selected 12 high-performing (HP) and 12 low-performing (LP) tumbler pigeons, half male and half female, and all pigeons were raised under the same conditions. Three experimental pigeons were grouped for exercise training, with a 20 min training session. The results showed significant differences (p < 0.05) in multiple blood gas parameters related to acid–base balance and gas exchange between the HP and LP groups after tumbler pigeon exercise. In addition, the content of glutathione peroxidase (GSH Px), superoxide dismutase (SOD), and catalase (CAT) in the liver of the HP group of tumbler pigeons was significantly lower than that of the LP group (p < 0.05). In comparison, the content of malondialdehyde (MDA) was significantly higher than that of the LP group (p < 0.05). The content of lactate (Lac) was significantly higher than that of the LP group (p < 0.05). Non-targeted metabolomics analysis revealed that differential metabolites were mainly enriched in pathways such as biosynthesis of unsaturated fatty acids, starch and sucrose metabolism, and fatty acid synthesis. Intestinal metagenomics analysis revealed that the Corynebacteriaceae, Bacillus, Pseudomonad phylum and Corynebacterium were significant biomarkers with significant differences in the gut microbiota of the HP group of tumbler pigeons (p < 0.05). In summary, there are significant differences in blood physiological parameters, antioxidant capacity, lactate content, intestinal metabolites, and gut microbiota between high- and low-performance tumbler pigeons after exercise. This result provides theoretical guidance and data support for cultivating high-performance tumbler pigeons. Full article

The increasing global demand for affordable, nutrient-dense plant-based foods highlights the need to valorize underutilized legumes through suitable processing technologies. This study developed extruded chunk products from blends of fermented and unfermented pigeon pea (Cajanus cajan L.) flour, button mushroom powder, and cassava starch at ratios of 90:2.5:7.5, 90:5.0:5.0, and 90:7.5:2.5 (w/w/w) using a single-screw extruder. Button mushroom powder was incorporated to increase dietary fiber and mineral content due to its abundance of β-glucans and chitin, whereas cassava starch served as a texturizing and binding agent, promoting melt cohesion and expansion during extrusion. Optimal processing conditions were 13–15% feed moisture and a barrel temperature gradient of 100–140 °C. Fermentation significantly improved textural properties, increasing hardness (up to 22,802 g) and crispness (up to 55,099 g/s), likely due to protein modifications that enhanced matrix formation. In contrast, unfermented samples exhibited higher water holding capacity (264–286 g/100 g). All formulations showed low water activity (0.426–0.524), indicating good shelf stability. Protein content remained consistent (18.80–19.45%), while crude fiber ranged from 18.15 to 21.80%. These results showed that the integration of fermentation and extrusion provides an effective, low-cost approach for improving the structural, nutritional, and storage properties of pigeon pea-based products, supporting the development of nutrient-dense plant-based foods industry that are acceptable and sustainable, thereby supporting sustainable agriculture. Full article

Mycotoxin contamination in feed poses a major threat to animal health and productivity, particularly in pigeons. This study evaluated the protective effects of three mycotoxin biodegradation agents (MBAs) in pigeons subchronically co-exposed to a mycotoxin-contaminated (MYC) diet for 60 days. The MYC diet was prepared by mixing 3% naturally mold-contaminated corn with 97% basal diet, yielding final dietary concentrations of fumonisin B1 (7829.41 µg/kg), aflatoxin B1 (201.16 µg/kg), zearalenone (1675.46 µg/kg), T-2 toxin (7721.41 µg/kg), and deoxynivalenol (1211.77 µg/kg). Birds were allocated to five groups (n = 18/group): CON (basal diet); MYC (MYC diet alone); and TRT1–TRT3 fed the MYC diet supplemented with 1.5 g/kg of MBA I (Bacillus subtilis + Bacillus licheniformis + Devosia sp.), MBA II (Bacillus licheniformis + Saccharomyces cerevisiae), or MBA III (Bacillus subtilis + glucose oxidase), respectively. Subchronic co-exposure to the MYC diet significantly increased serum pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), whereas all three MBAs effectively attenuated these elevations. Histopathological examination revealed inflammatory infiltration and tissue damage in the jejunum and liver of MYC birds, which were markedly alleviated by MBA supplementation. Gut microbiota analysis showed that mycotoxins decreased Firmicutes and Lactobacillus and increased Proteobacteria and Streptococcus, whereas MBAs partially restored microbial balance. Among the three MBAs, MBA II exhibited the strongest protective effect, as reflected by the greatest improvements in serum biochemistry, intestinal morphology, and microbial composition. Liver transcriptome analysis showed that mycotoxin mainly affected pathways related to cell cycle and DNA replication, whereas MBA II enhanced pathways associated with intestinal immune function and antigen processing and presentation. Collectively, these findings suggest that MBA II offers effective protection against combined mycotoxin-induced toxicity in pigeons and may serve as a promising feed additive for mitigating mycotoxin contamination in poultry production. Full article

The dissemination of New Delhi metallo-β-lactamase (NDM)-producing Escherichia coli poses a serious threat to public health. Although increasing attention has been paid to the relationship between temperature and antimicrobial resistance (AMR) transmission, research in China’s Xinjiang region remains scarce. In this study, we conducted a cross-sectional survey of 1914 samples from intensive livestock farms across Xinjiang to characterize the detection rate and antimicrobial resistance profiles of bla_NDM-positive E. coli. Using selective culture, PCR, and 16S rRNA sequencing, we identified 140 bla_NDM-positive E. coli (7.3%), predominantly in northern Xinjiang. The highest detection rate of bla_NDM-positive E. coli was found in Tacheng Prefecture (24.0%), followed by Changji Hui Autonomous Prefecture (4.3%) and Bortala Mongol Autonomous Prefecture (0.6%). No bla_NDM-positive E. coli isolates were detected in Bayingolin Mongol Autonomous Prefecture, Kashgar Prefecture, or from pigeon samples. Binomial logistic regression analysis revealed a significant positive association between regional temperature and the detection rate of bla_NDM-positive E. coli. Genotypic analysis identified 35 distinct resistance gene profiles, with predominant resistance genes including bla_TEM (87.9%), ant(3″)-Ia (97.1%), qnrS (92.9%), tet(A) (95.0%), sul1 (70.0%), sul3 (85.0%), and floR (97.1%); mcr-1 and mcr-8 were not detected. Antibiotic susceptibility tests showed that all isolates were resistant to imipenem and exhibited universal resistance to ampicillin, ceftiofur, tetracycline, florfenicol, and enrofloxacin, whereas the majority remained susceptible to amikacin (99.3%), tigecycline (94.3%), and polymyxin (77.1%). These findings indicate that livestock farms, particularly laying-hen systems in northern Xinjiang, may serve as reservoirs of multidrug-resistant bla_NDM-positive E. coli, and that elevated regional temperature is an environmental factor associated with higher detection rates, underscoring a potential climate-associated risk for the spread of AMR. Full article

Urban pigeons (Columba livia) are widely distributed synanthropic birds closely associated with environments of intense human activity, raising interest in their role in urban microbial dynamics. Here, we characterized the fecal bacterial microbiota of urban pigeons from northern Mexico using 16S rRNA gene amplicon sequencing (V3–V4). A total of 1479 amplicon sequence variants (ASVs) were identified across five pooled samples. Alpha diversity varied among pools, with observed richness ranging from 228 to 514 ASVs. The bacterial community was dominated by Proteobacteria and Firmicutes, particularly Escherichia–Shigella and Enterococcus. PICRUSt2-based functional predictions suggested a predominance of predicted metabolic pathways related to carbohydrate degradation and energy acquisition. Conservative taxonomic screening identified 58 gut-associated taxa, including 15 bacteria previously reported in association with humans; however, only three (Clostridium perfringens, Enterococcus faecalis, and Proteus mirabilis) showed reported zoonotic associations, all at very low relative abundances (<0.07%). These findings indicate that the fecal bacterial communities characterized in this study were dominated by taxa commonly associated with the avian gastrointestinal tract, whereas taxa that could be conservatively linked to documented zoonotic reports represented only a minor fraction of the detected microbiota. Overall, the results contribute to a more ecologically informed understanding of urban pigeon-associated microbiota within a One Health framework. Full article

Pigeon homing provides an important model for studying navigation after displacement, yet how large-scale brain activity is organized across different phases of homing flight remains unclear. In this study, we recorded 16-channel epidural electrocorticographic signals from freely flying pigeons during outdoor homing flights initiated approximately 6 km from the home loft. GPS trajectories were used to divide the homing process into waiting, hovering, fuzzy positioning, precise positioning, and home stages. Correlation-based inter-channel functional networks were constructed across alpha, beta, gamma, and high-gamma frequency bands, and their topological properties were quantified using the clustering coefficient and global efficiency. The results showed that ECoG functional network topology varied across homing stages. Network measures were generally higher during the precise positioning stage near the home loft and lower during the fuzzy positioning stage. Gamma-band networks showed a relatively stronger tendency toward the precise positioning stage, whereas alpha-band networks showed a relatively stronger tendency toward the hovering stage. Together, these findings suggest that natural pigeon homing flight is accompanied by stage-associated reorganization of epidural ECoG functional networks. Full article

To tackle the dynamic assignment problem of unmanned aerial vehicle (UAV) swarms, a merged coordination-optimized pigeon-inspired optimization (MCOPIO) algorithm based on the pigeon-inspired optimization (PIO) algorithm is proposed in this paper. The algorithm disrupts the original pigeon distribution via random grouping and performs mutual learning and optimization within the new groups. After dynamic optimization, the underperforming pigeons are discarded, and the flock is reorganized. Subsequently, the two stages of the basic PIO are integrated through a dynamic factor. These improvements overcome the limitations of the basic PIO algorithm, such as insufficient global search capability, poor stability, and disconnection between the two algorithm stages. Comparative experiments are conducted with the state-of-the-art intelligent computing algorithms, such as the basic PIO, particle swarm optimization (PSO), genetic algorithm (GA), and improved consensus-based bundle algorithm (ICBBA), the comparative results verify the feasibility and effectiveness of our improved PIO for UAV swarm dynamic task allocation. Full article

Wild and synanthropic birds harbour a diverse range of yeasts, including species of recognised clinical relevance. Given their close interaction with human activities, these birds represent a valuable source for investigating environmental yeasts and assessing the performance of identification methods. We investigated yeasts recovered from cloacal and crop samples of birds from Gran Canaria and compared routine identification methods with molecular sequencing. Twenty-four isolates were examined by biochemical profiling (API ID32C) and MALDI-TOF MS. Molecular identification based on ITS sequencing was carried out only for the sixteen isolates for which the two routine methods yielded discordant results, allowing resolution of their taxonomic identification. Phenotypic and proteomic methods showed limited agreement at the species level (8/24; 33.3%), with 16 discordant identifications resolved by sequencing. Pigeon isolates were dominated by members of the Kazachstania telluris complex, chiefly K. bovina (11/24; 45.8%), while partridges yielded taxa of clinical importance, including Candida parapsilosis and Pichia kudriavzevii (formerly Candida krusei). Rhodotorula mucilaginosa, Debaryomyces spp., and Saccharomyces cerevisiae were also detected. Comparative tests confirmed significant host-associated differences in species distribution (p < 0.05), and Cohen’s kappa indicated substantial agreement between API and MALDI-TOF at the genus level when benchmarked against ITS (κ = 0.71), although concordance was lower at the species level. In conclusion, these findings strengthen the case for integrating sequencing into diagnostic workflows, highlight the potential One Health relevance of yeast carriage by wild birds, and underscore the need for targeted surveillance at urban and game-handling interfaces where human exposure is likely. Full article

This study investigated the effects of dietary sodium butyrate supplementation on blood gas profiles, biochemical parameters, and untargeted plasma metabolomics in tumbler pigeons. Eighty tumbler pigeons of similar age, body weight, and training intensity were randomly allocated into four groups: a control group without sodium butyrate supplementation (CON) and three sodium butyrate-supplemented groups receiving 6 mg/d (T1), 12 mg/d (T2), and 18 mg/d (T3), respectively. All birds were maintained under identical husbandry conditions and fed the same basal diet throughout a 40-day experimental period consisting of a 10-day acclimation phase and a 30-day feeding trial. Results showed that dietary sodium butyrate supplementation significantly improved dry matter digestibility, with T2 and T3 exhibiting higher values than CON (p < 0.05), while metabolizable energy utilization was significantly increased in T3 compared with CON (p < 0.05). Sodium butyrate supplementation also significantly altered several blood gas parameters associated with acid–base balance and gas exchange. In addition, antioxidant enzyme activities were enhanced, with SOD, CAT, GSH-Px, and T-AOC activities significantly increased in supplemented groups compared with CON (p < 0.01). Furthermore, sodium butyrate supplementation significantly modulated inflammatory responses, increasing IL-10 concentrations (p < 0.01) while decreasing IL-6 and IL-8 levels (p < 0.01). Untargeted metabolomic analysis revealed significant alterations in pathways related to lipid metabolism, amino acid metabolism, and inflammatory regulation. In conclusion, dietary sodium butyrate supplementation influenced nutrient utilization, blood physiological parameters, antioxidant capacity, inflammatory status, and plasma metabolic profiles in tumbler pigeons. Among the tested supplementation levels, 18 mg/d sodium butyrate was associated with the most favorable overall physiological responses. These findings provide a basis for future investigations into the physiological and metabolic effects of sodium butyrate supplementation in competitive pigeons. Full article