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This study investigates the airborne microbial contamination in three museums located in the dry region of Xinjiang region, China—Bayingolin, Hami, and Turpan. Airborne microbial concentrations in these museums were found to be relatively low, ranging from 7.5 to 38.3 CFU/m³, which is advantageous for the preservation of cultural relics, especially in comparison to humid regions where higher microbial concentrations have been reported. The microbial communities were dominated by bacteria, with Firmicutes being the most abundant phylum, followed by Proteobacteria and Bacteroidetes. Notably, Pseudomonas sp., Bacillus sp., and Staphylococcus hominis were identified as potential threats to the degradation of leather cultural relics. Additionally, Mycobacterium sp., Pantoea sp., and Priestia aryabhattai were first identified in the context of cultural heritage conservation. Metagenomic sequencing revealed a significant presence of salt-tolerant, spore-forming bacteria, which are characteristic of dry environments. Antibacterial tests showed that 0.5% K100 exhibited the best antimicrobial effect. This study provides valuable insights into the microbial ecology of museums in rid climates and suggests the need for targeted preservation strategies to mitigate microbial-induced biodeterioration, particularly through the use of antimicrobial agents and environmental management.

The stable isotope technique provides the possibility to trace ancient textiles because the technique is associated with advantages such as trace indication, fast detection, and accurate results. Since different cocooning conditions may impact cocoons even under identical habitats, it is important to investigate the effects of different cocooning temperatures and humidity on the isotope incorporation values in the cocoons. In this study, silk fibers were reeled under different conditions of temperature and humidity, followed by analysis of the secondary structure of cocoon proteins and isotope incorporation patterns. We found that the deviations in carbon isotope values of silk under different cocooning conditions could reach up to 0.76‰, while the deviation in carbon isotope values at different locations of a single silk was 2.75‰. Further, during the cocooning process, depletion of the 13 C-isotope at different locations of the silk fibers was observed, reducing the δ 13 C values. We proposed that the changes in carbon isotopes in silk were related to the content of sericin and silk fibroin in silk. Finally, we did not observe a significant difference in isotope ratios in degummed cocoons. In summary, the 13 C isotope was enriched in sericin, whereas 15 N was enriched in fibroin, and these findings provide basic information for tracing the provenance of silks.

Silk was the driving force behind the opening of the Silk Road, positioning this material as a global commodity that greatly influenced the progress of human civilization. Due to the natural protein properties of silk, the internal structure and external characteristics of silk cultural relics are irreversibly destroyed during the process of burial or when passed down through the generations until the production information and material components completely disappear, making it difficult to obtain direct archaeological evidence for pinpointing the origin of silk. The sacrificial pits at the Sanxingdui archaeologcal site, located in Guanghan, Sichuan, China, have been found with layers of ash above the layers of artifacts and some bronzes with fabric traces. Among the artifacts, one grid-like ware artifact first appeared in the Bronze Age in China. The two sides of the grid-like ware were grid-like ovals made of bronze material, and inside, there was an oval-shaped complete piece of jade with a bent back. Fabric traces were found on both the jade and bronze surfaces. In order to determine the specific function of fabric at this site, the developed silk fibroin immunoaffinity column (IAC) enrichment technique combined with enzyme-linked immunosorbent assay (ELISA), morphology observation and proteomics were used to identify mineralized fabric material and fabric residues in the ash layer. Silk residues were successfully detected, which confirmed the early use of silk as a material carrier to communicate between Heaven and Earth and provided archaeological evidence for the cultural origins of silk.

Hydrogen, oxygen, carbon, and nitrogen isotopes derived from three different strains of silkworms at different life stages involved in silkworm rearing, were measured to understand the fractionation characteristics of stable isotopes at different stages of silkworm development, and to trace the movement of these isotopes from food to larva to excrement and finally to silk. We found that silkworm strain had little effect on δ 2 H, δ 18 O and δ 13 C values. However, a large difference was found in the δ 15 N levels of newly-hatched silkworms between Jingsong Haoyue and Hua Kang No. 3 orthogonal strains, suggesting that the mating and egg laying differences may result in an inconsistent kinetic nitrogen isotope fractionation. The δ 13 C values of silkworm pupae and silkworm cocoon also displayed significant differences, suggesting that heavy carbon isotopes are greatly fractionated from the larva to the silk during cocoon formation. Overall, these results may be used to clarify the relationship between isotope fractionation and the ecological process of the Bombyx mori and expand our ability to resolve stable isotope anomalies at a small regional-scale level.

A magnetically insulated transmission line (MITL) is an inevitable choice for ultra-high power density energy transmissions. Its working process is complex, with an obvious influence on the working process of electron beam diodes and other load devices. The power coupling process of an electron beam diode driven by an MITL is a difficult problem in pulse power applications. No research is available on the electron beam characteristics of its anode. In this paper, a fast time response full absorption Faraday cup was developed. An intense electron beam measurement waveform showing the multi-stage characteristics was obtained through measurements using the Faraday cup absorber as the anode of the electron beam diode. The stage characteristics of the beam were in good agreement with the vacuum transmission, magnetic insulation formation, and multi-stage process of the stable magnetic insulation. The beam intensity corresponded with the conduction current of the cathode. It was obviously smaller than the current of the anode. The results reflected the influence of the different processes of the magnetic insulation on the transmission line on the beam waveforms in the diode area and provided a reference for the power transmission of the power device and the load system design.

This paper aims to value the cliquet-style equity-linked insurance product with death benefits. Whether the insured dies before the contract maturity or not, a benefit payment to the beneficiary is due. The premium is invested in a financial asset, whose dynamics are assumed to follow an exponential jump diffusion. In addition, the remaining lifetime of an insured is modelled by an independent random variable whose distribution can be approximated by a linear combination of exponential distributions. We found that the valuation problem reduced to calculating certain discounted expectations. The Laplace inverse transform and techniques from existing literature were implemented to obtain analytical valuation formulae.

Phase-type (PH) distributions are defined as distributions of lifetimes of finite continuous-time Markov processes. Their traditional applications are in queueing, insurance risk, and reliability, but more recently, also in finance and, though to a lesser extent, to life and health insurance. The advantage is that PH distributions form a dense class and that problems having explicit solutions for exponential distributions typically become computationally tractable under PH assumptions. In the first part of this paper, fitting of PH distributions to human lifetimes is considered. The class of generalized Coxian distributions is given special attention. In part, some new software is developed. In the second part, pricing of life insurance products such as guaranteed minimum death benefit and high-water benefit is treated for the case where the lifetime distribution is approximated by a PH distribution and the underlying asset price process is described by a jump diffusion with PH jumps. The expressions are typically explicit in terms of matrix-exponentials involving two matrices closely related to the Wiener-Hopf factorization, for which recently, a Lévy process version has been developed for a PH horizon. The computational power of the method of the approach is illustrated via a number of numerical examples.

Conservation tillage and fertilization are widely adopted in agricultural systems to enhance soil fertility and influence fungal communities, thereby improving agroecosystems. However, the effects of no-tillage combined with manure on grain yield, nitrogen use efficiency (NUE), soil fertility, and rhizosphere fungal communities remain poorly understood, particularly in rainfed wheat fields on the Loess Plateau. A 15-year field experiment was conducted at the Niujiawa Experimental Farm of the Cotton Research Institute, Shanxi Agricultural University. Five treatments were assessed: conventional tillage without fertilizer (C), no-tillage with chemical fertilizer (NT), no-tillage with chemical fertilizer and manure (NTM), conventional tillage with chemical fertilizer (T), and conventional tillage with chemical fertilizer and manure (TM). The results demonstrated that the NTM treatment significantly increased grain yield by 124.95%, NT by 65.88%, TM by 68.97%, and T by 41.75%, compared to the C treatment (p < 0.05). NUE in the NTM treatment was improved by 58.73%–200.59%. Compared with the C treatment, NTM significantly enhanced soil nutrients, including organic matter (OM) by 70.68%, total nitrogen (TN) by 8.81%, total phosphorus (TP) by 211.53%, available nitrogen (AN) by 90.00%, available phosphorus (AP) by 769.12%, and available potassium (AK) by 89.01%. Additionally, the NTM treatment altered the rhizosphere fungal community of winter wheat, with Ascomycota (81.36%–90.24%) being the dominant phylum, followed by Mucoromycota (5.40%–12.83%) and Basidiomycota (1.50%–8.53%). At the genus level, NTM significantly increased the abundance of Mortierella and Dendrostilbella. An α-diversity analysis revealed that the richness and diversity of soil fungi were highest under NTM. The unweighted pair-group method with arithmetic mean (UPGMA) and principal coordinates analysis (PCoA) based on Bray-Curtis distances indicated that NTM formed a distinct fungal community with the highest phylogenetic diversity, which differed significantly from other treatments. Redundancy analysis (RDA) demonstrated that soil chemical properties variably influenced fungal community dynamics, with higher abundances of Ascomycota and Zoopagomycota positively correlated with OM, AN, AP, TP, and AK. Correlation analysis showed that wheat yield and NUE were positively correlated with Mortierella and Dendrostilbella, and negatively correlated with Fusarium, Chaetomium, and Alternaria. In conclusion, no-tillage with manure not only enhanced soil fertility but also enhanced soil fungal community structure, leading to greater wheat yield and NUE. These findings provide guidance for agricultural practices in rainfed wheat fields of the Loess Plateau.

The objective of this paper is to propose a novel deep learning methodology to gain pragmatic insights into the behavior of an insured person using unsupervised variable importance. It lays the groundwork for understanding how insights can be gained into the fraudulent behavior of an insured person with minimum effort. Starting with a preliminary investigation of the limitations of the existing fraud detection models, we propose a new variable importance methodology incorporated with two prominent unsupervised deep learning models, namely, the autoencoder and the variational autoencoder. Each model's dynamics is discussed to inform the reader on how models can be adapted for fraud detection and how results can be perceived appropriately. Both qualitative and quantitative performance evaluations are conducted, although a greater emphasis is placed on qualitative evaluation. To broaden the scope of reference of fraud detection setting, various metrics are used in the qualitative evaluation.

We consider the optimal proportional reinsurance and dividend strategy. The surplus process is modeled by the classical compound Poisson risk model with regime switching. Considering a class of utility functions, the object of the insurer is to select the reinsurance and dividend strategy that maximizes the expected total discounted utility of the shareholders until ruin. By adapting the techniques and methods of stochastic control, we study the quasi-variational inequality for this classical and impulse control problem and establish a verification theorem. We show that the optimal value function is characterized as the unique viscosity solution of the corresponding quasi-variational inequality.