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Fluorescence lateral flow assays (FLFA) based on quantum dot probes have attracted significant attention in recent years due to their high sensitivity and quantitative detection capabilities. FLFA requires the use of a straightforward fluorescence reader for quantitative detection. Most fluorescence readers employ narrowband filters for auxiliary imaging, which facilitates the acquisition of high-contrast signals. However, during trace detection, the weak signal from FLFA can be easily lost due to optical flux loss associated with narrowband filters, thereby indirectly diminishing detection sensitivity. To address this issue, we developed a fluorescence signal reader that employs CMOS imaging without optical filters and proposed a highly sensitive signal detection algorithm based on continuous wavelet transform (CWT) to identify weak fluorescence signals with low contrast. Experimental results demonstrate that the method achieves a fluorescence detection sensitivity for quantum dots of 10−10 mol/L, with a relative standard deviation (RSD) of < 1.45%. The designed filter-free detection system and CWT analysis algorithm were applied to various FLFA systems (including the sandwich method and the competition method), with the correlation coefficient (R2) between all detection results and sample concentration exceeding 0.997. The findings of this study offer a highly sensitive signal detection method for the precise quantification of FLFA.

Pathogen infection has been progressively recognized as a potential driver of animal migration, and the infection pattern in a certain host may be related to its migration status. Nestling viability can be a crucial life stage in the evolution of the migration cycle but have been irregularly studied to date. In this study, we tested the ‘migratory exposure' hypothesis by comparing the prevalence and diversity of avian haemosporidian parasites in the breeding area between two dominant species including adults and nestlings: yellow‐rumped flycatcher Ficedula zanthopygia, which is a summer migratory species, and Japanese tit Parus minor, which is a local resident species. The yellow‐rumped flycatcher harboured more diverse parasite lineages than the Japanese tit, which is in line with the expectation of the ‘migratory exposure' hypothesis, while nestlings present a similar but more applicable pattern. Among the 40 unique identified parasite lineages, only one was shared between host species and three between age classes. Nestlings suffered a high parasite diversity with plenty of age‐specific lineages in the breeding area, mainly Leucocytozoon, which may suggest an extraordinary selection pressure in early life‐stages during migration. However, the most common lineages in adults were not detected in nestlings, and the prevalence of infection is significantly lower in nestlings than in adults. Our results suggest that migratory birds may have suffered from more frequent parasite infections during migration, but escaped from more virulent lineages at the same time. The difference in susceptibility and parasite assembly between adults and nestlings in migrants may result from an intricate interaction along the evolution of life history. Our investigations have revealed the significance of avian haemosporidian parasite infection patterns in nestlings in breeding areas, and provide a novel insight into the driving forces of migration.

Products such as cattles and pigs can be processed into several types of products (parts) targeting different segments of customers, which belong to the so called coproducts. Mismatch risk is a significant issue in such coproduct supply chains. Under the Stackelberg game setting, we consider a coproduct supply chain consisting of one producer acting as the leader and one retailer being the follower and establish a stylized model to study how the mismatch risk should be allocated. Two supply chain modes are considered, i.e., the P-chain mode under which the producer is responsible for the processing activity and hence holds the mismatch risk, and the R-chain under which the retailer is responsible for the processing activity. We use the unbalanced ratio to reflect the degree of mismatch between supply and demand among different parts of the coproduct and study how the tradeoff between the bargaining power and the mismatch cost, by different mismatch risk allocations, influences the optimal decisions and the performances of the two parties as well as the whole supply chain. Our main findings include: (1) P-chain dominates R-chain from the perspective of the chain performance; and (2) the upstream producer is not always better off in the P-chain under which he bears more mismatch risk. Numerical study shows the robustness of our main results and further studies the effect of demand uncertainty and the processing cost on the performance of P-chain as compared to R-chain.

Quartic solitons in ultrafast fibre lasers (intra-cavity optical fibre modulation systems) have been theoretically and experimentally analysed in recent years. However, there are few reports about extra-cavity modulating quartic solitons. In this situation, the purpose of this work is to investigate a quartic soliton’s extra-cavity modulation. In this paper, we theoretically simulate an extra-cavity-modulating quartic soliton with negative fourth-order dispersion at 1550 nm. The simulation relies on a physical model of a single-mode optical fibre system. Through controlling soliton parameters in an extra-cavity modulation system, a quartic soliton’s orthogonal polarisation modes will show unique characteristics depending on which kind of parameter is changed (seven parameters are considered for variation). For example, through the variation in the projection angle, only a horizontally polarised quartic soliton pulse is generated. These results explore the dynamics of quartic solitons in single-mode optical fibre modulation systems and are applicable to optical soliton transmission techniques in the field of optical fibre communication.

ABSTRACT During the evolution of parasites, co‐speciation and host‐range expansion are thought to play roles in establishing associations with hosts, while sorting events can lead to dissolution of those associations. To address the roles of these processes, we focus on avian haemosporidian parasites infecting hosts of the intensively studied great tit species complex. We estimated the phylogeography of lineages detected in the species complex, and quantified their transition probabilities among hosts. Lineages detected in different host species presented a strong geographical signal but did not form monophyletic groups. Yet, distributions of lineages are not merely the result of their dispersal limitations, as many lineages that infect only one focal species can be found in birds sympatric with other focal species. Besides, closely related lineages that infect the same host species reach more similar rates of infection than expected by chance. Finally, Haemoproteus and Leucocytozoon lineages infecting P. major, the most recently dispersed species, were more generalized than others, consistent with a pattern of generalist parasites expanding their host ranges by infecting newly encountered host species. Our results suggest that host–parasite associations in this system are mainly the result of sorting events and host‐range expansion of parasites, rather than co‐speciation. In this work, we investigated the global phylogeographic pattern of host–parasite associations in a well‐studied common bird species complex, and the role of different ecological processes in establishing the patterns. We found that the parasite distributions are not merely the result of geographical restriction, but mainly shaped by sorting events and host range expansion during the host dispersal. It appears that co‐speciation, which is frequently overestimated, is less important in the establishment of host–parasite associations.

Oudemansiella raphanipes is valued for its rich nutritional content and medicinal properties, but traditional manual grading methods are time-consuming and labor-intensive. To address this, deep learning techniques are employed to automate the grading process, and knowledge distillation (KD) is used to enhance the accuracy of a small-parameter model while maintaining a low resource occupation and fast response speed in resource-limited devices. This study employs a three-teacher KD framework and investigates three cascaded structures: the parallel model, the standard series model, and the series model with residual connections (residual-series model). The student model used is a lightweight ShuffleNet V2 0.5x, while the teacher models are VGG16, ResNet50, and Xception. Our experiments show that the cascaded structures result in improved performance indices, compared with the traditional ensemble model with equal weights; in particular, the residual-series model outperforms the other models, achieving a grading accuracy of 99.7% on the testing dataset with an average inference time of 5.51 ms. The findings of this study have the potential for broader application of KD in resource-limited environments for automated quality grading.

Background Accurate quantification of infection intensity is essential to estimate infection patterns of avian haemosporidian parasites in order to understand the evolution of host-parasite associations. Traditional microscopy is cost-effective but requires high-quality blood smears and considerable experience, while the widely used semi-quantitative qPCR methods are mostly employed with ideal, laboratory-based golden samples and standard curves, which may limit the comparison of parasitemia from different laboratories. Methods Here we present a digital droplet PCR (ddPCR) protocol for absolute quantification of avian haemosporidians in raptors. Novel primers were designed that target a conserved fragment of a rRNA region of the mitochondrial genome of the parasites. Sensitivity and repeatability were evaluated compared to qPCR and other assays. Results This ddPCR assay enables accurate quantification of haemosporidian parasites belonging to Plasmodium , Haemoproteus and Leucocytozoon with minimum infection quantities of 10 −5 (i.e. one parasite copy in 10 5 host genomes) without the use of standard curves. Quantities assessed by ddPCR were more accurate than qPCR using the same primers through reduction of non-specific amplification in low-intensity samples. The ddPCR technique was more consistent among technical duplicates and reactions, especially when infection intensities were low, and this technique demonstrated equal sensitivity with high correspondence ( R 2  = 0.97) compared to the widely used qPCR assay. Both ddPCR and qPCR identified more positive samples than the standard nested PCR protocol for the cytb gene used for barcoding avian haemosporidians. Conclusions We developed a novel ddPCR assay enabling accurate quantification of avian haemosporidians without golden samples or standard curves. This assay can be used as a robust method for investigating infection patterns in different host-parasite assemblages and can facilitate the comparison of results from different laboratories.

Water pollution seriously affects the development of society and human life. There are various kinds of pollutants, including soluble pollutants and insoluble floaters on the water surface. Herein, the photocatalyst semiconductor BiOCl and superhydrophobic functional particles Mg(OH)2 were deposited on the surfaces of canvas and polyester felt to construct superhydrophobic canvas and polyester felt. The contact angles of the synthetic superhydrophobic canvas and polyester felt were measured as 152° and 155.3°, respectively. The selective adsorption of hexadecane was achieved using the wetting difference between the surface of water and pollutants floating on the surface. For dissolved pollutants, the surface wettability needed to be changed with the help of ethanol. The degradation efficiencies were all greater than 90%, demonstrating the versatility of the synthetic superhydrophobic canvas and polyester felt.

As one of the most nutritious and delicious mushroom varieties, Volvariella volvacea has always been popular among people around the world. Different from other artificially cultivated mushrooms, Volvariella volvacea is mostly planted on non-sterile substrates. As the cultivation time increases, the yield of mushroom houses continues to decrease. In our experiment, we selected two groups of samples from the old and new mushroom houses, environmental samples and substrate samples. The results showed that the diversity and abundance of microorganisms in the culture environment of the old mushroom room were consistent with that of the new mushroom room, but the proportion of actinomycetes in the former was significantly higher than that of the new mushroom room. The metabolic activity of microorganisms in the old mushroom room was enhanced compared with the new mushroom room. The microbial diversity in the growth substrate was investigated, and it was found that the structure and diversity of the microbial community in the substrate had changed. In conclusion, the interplay between mushrooms, the culture environment, and the host bacterial community may be the cause of the changes in the yield of Volvariella volvacea.

In this work, we theoretically simulate the modulation of a soliton molecule that has an initial chirped Gaussian pulse shape in a 1 μm extra-cavity optical fiber modulation system. Different soliton parameters in orthogonal polarizations are applied to achieve controllable optical solitons’ output with specific properties in the time/frequency domain. For instance, when the phase difference is changed, both pulse shapes’ and corresponding optical spectra’s peak intensities will have a sudden change when the orthogonal phase difference is π/2. These simulation results provide a beneficial reference value for extra-cavity shaping of different solitons that come from nonlinear optical systems. Optimally, the reported results could pave the groundwork for industrial growth in ultrafast laser design.