Effect of Ciprofloxacin on the Composition of Intestinal Microbiota in Sarcophaga peregrina (Diptera: Sarcophagidae).

The intestinal bacteria of insects are crucial to the growth and development of the host. It has been found that various physiological processes of insects, such as immune response, metabolism, reproductive ability, and growth and development, involve the gastrointestinal flora. However, many external factors affect the composition of insects' intestinal microorganisms, such as the type of dietary substrate. Sarcophaga peregrina (Robineau-Desvoidy, 1830) (Diptera: Sarcophagidae) is of great significance in medicine and forensic science. In this study, we investigated the effects of ciprofloxacin on the growth and gut microbiota of S. peregrina. The results demonstrated that the maximum body length of larvae was not affected by ciprofloxacin, while the growth rate of body length quickened as the concentration of the drug increased. The weight of the pupa and adult was reduced significantly due to the effect of ciprofloxacin. After analyzing the gut microbiota composition of S. peregrina in different drug groups, it was indicated that Ignatzschineria, Providencia, Wohlfahrtiimonas, Proteus, Myroides, and Bacteroides play important roles in the growth of S. peregrina. However, they still need to be further studied. In general, ciprofloxacin can affect the gut microbial community structure, which in turn affects the fitness of the host.

Interpretation of the coupling mechanism of ecological security and urbanization based on a Computation-Verification-Coupling framework: Quantitative analysis of sustainable development.

In recent decades, China's rapid urbanization has produced numerous economic benefits while simultaneously creating substantial risks to ecological security. China's 14th Five-Year Plan and the United Nations Sustainable Development Goals (SDGs) have recently explicitly called for the coordinated development of ecological security and urbanization. Given this context, it is important to explore the mechanism by which ecological security and urbanization are coupled and coordinated to promote sustainable development. In this study, an index of the relationship between ecological security and urbanization was established via high-resolution data, and a "Computation-Verification-Coupling" (CVC) framework was constructed. The accuracy of the ecological security index was verified using a linear regression model, and the coordination level between ecological security and urbanization was analyzed via a coupled coordination model (CCM). The results revealed a steady increase in the ecological security index from 2010 to 2020; the proportion of the area above the medium level increased from 63.1 % to 74.1 %. The urbanization index in core counties exhibited rapid growth, with level V urbanized areas expanding from 5.5 % to 9.9 %. The ecological security verification model produced a coefficient of determination (R²) of 0.75685, indicating a satisfactory degree of predictive capability. From 2010-2020, the coupled coordination improved, with the high coordination area accounting for 48.8 % and the extreme discoordination area decreasing from 1.8 % to 1.0 %. Coordinated development exhibited a stable progression, characterized by a cyclical evolution from initial coupling to antagonistic coupling and finally to coordinated development. This framework can be used not only to investigate the relationship between ecological security and urbanization but also to provide a quantifiable measure of progress toward achieving the SDGs.

Development and Determinants of Topsoil Bacterial and Fungal Communities of Afforestation by Aerial Sowing in Tengger Desert, China.

It was previously reported that afforestation in the desert can help improve soil texture, carbon accumulation, and nutrient status. However, the effects of afforestation on soil microbial composition, diversity, and microbial interactions with soil physicochemical properties have been rarely evaluated quantitatively. Using the method of space-for-time substitutions, we assessed the development and determinants of topsoil bacterial and fungal communities over nearly 40 years of successive afforestation by aerial sowing in Tengger Desert, China. The results showed that afforestation by aerial sowing comprised a considerable proportion of Chloroflexi and Acidobacteria in the bacterial community in addition to the ubiquitous phyla found in desert but had fewer effects on the dominant phyla of the fungal community. At the phylum level, the bacterial community was clearly clustered into two groups. However, it was difficult to differentiate the constituents of the fungal community based on principal coordinate analysis. The richness of the bacterial and fungal communities was significantly higher after five years than at zero years and three years. Additionally, the bacterial community varied parabolically and reached its largest size at twenty years, while the fungal community increased exponentially. Soil physicochemical properties were found to have divergent effects on the abundance and diversity of bacterial and fungal communities, among which salt- and carbon-associated properties (e.g., electrical conductivity, calcium, magnesium, total carbon, and organic carbon) were closely related with the abundance of bacterial-dominant phyla and the diversity of bacteria and fungi, but nutrient-associated properties (e.g., total phosphorus and available phosphorus) were not. The results indicate that afforestation through the salt secretions of plants leaves and carbon inputs from litter promote the development of topsoil bacterial and fungal communities in the desert.

The evolution process of ecological vulnerability and its quantitative analysis of influencing factors: a case study of Longdong area.

Ecological vulnerability is the main index to evaluate areal environmental stability and monitor the development of ecological environment. Longdong area is a typical Loess Plateau area with complex terrain, serious soil erosion, mineral resource development, and other human activities leading to the ecological vulnerability evolution of the area, but the monitoring of its ecological status and the determination of its factors are still lacking. Based on the ecological characteristics of Longdong area, this study constructed an ecological vulnerability system including natural, social, and economic data and used the fuzzy analytic hierarchy process (FAHP) to study the temporal and spatial evolution of ecological vulnerability from 2006 to 2018. A model for quantitative analysis of the evolution of ecological vulnerability and correlation of influencing factors was ultimately developed. The results showed that (1) from 2006 to 2018, the ecological vulnerability index (EVI) had a minimum value of 0.232 and a maximum value of 0.695. EVI was high in the northeast and southwest of Longdong area and low in the central region. (2) At the same time, the areas of potential vulnerability and mild vulnerability increased, and the areas of slight vulnerability, moderate vulnerability, and severe vulnerability decreased. (3) The correlation coefficient between average annual temperature and EVI exceeded 0.5 in four years, and the correlation coefficient between population density and per capita arable land area and EVI exceeded 0.5 in two years showed significant correlation. The results reflect the spatial pattern and influencing factors of ecological vulnerability in typical arid areas of northern China. Additionally, it served as a resource for researching the interrelationships of the variables affecting ecological vulnerability.

A spatial distribution - Principal component analysis (SD-PCA) model to assess pollution of heavy metals in soil.

With the rapid development of urbanization, heavy metal pollution of soil has received great attention. Over-enrichment of heavy metals in soil may endanger human health. Assessing soil pollution and identifying potential sources of heavy metals are crucial for prevention and control of soil heavy metal pollution. This study introduced a spatial distribution - principal component analysis (SD-PCA) model that couples the spatial attributes of soil pollution with linear data transformation by the eigenvector-based principal component analysis. By evaluating soil pollution in the spatial dimension it identifies the potential sources of heavy metals more easily. In this study, soil contamination by eight heavy metals was investigated in the Lintong District, a typical multi-source urban area in Northwest China. In general, the soils in the study area were lightly contaminated by Cr and Pb. Pearson correlation analysis showed that Cr was negatively correlated with other heavy metals, whereas the spatial autocorrelation analysis revealed that there was strong association in the spatial distribution of eight heavy metals. The aggregation forms were more varied and the correlation between Cr contamination and other heavy metals was lower. The aggregation forms of Mn and Cu, Zn and Pb, on the other hand, were remarkably comparable. Agriculture was the largest pollution source, contributing 65.5 % to soil pollution, which was caused by the superposition of multiple heavy metals. Additionally, traffic and natural pollution sources contributed 17.9 % and 11.1 %, respectively. The ability of this model to track pollution of heavy metals has important practical significance for the assessment and control of multi-source soil pollution.

The complete mitochondrial genome of Sarcophaga gracilior (Diptera: Sarcophagidae).

Sarcophaga gracilior Chen, 1975 (Diptera: Sarcophagidae) plays a significant role in epidemiology and medicine. In this study, we first report the complete mitochondrial genome (mitogenome) of S. gracilior. This mitogenome was 15,534 bp in length (GenBank No. MW531675), comprising 13 protein-coding genes (PCGs), two ribosomal RNAs (rRNAs), 22 transfer RNAs (tRNAs), and a non-coding control region. The arrangement of genes was identical to that of ancestral metazoan. Nucleotide composition revealed a strong A + T bias, accounting for 76.7% (A 39.6%, G 9.3%, C 14.0%, T 37.1%). The phylogenetic relationships indicated that the species of S. gracilior emerged as sister to Sarcophaga melanura. This study provides important mitochondrial data for further studying evolutionary relationships and species identification of flesh flies.

Enhanced 2,4,6-trichlorophenol anaerobic degradation by Fe3O4 supported on water hyacinth biochar for triggering direct interspecies electron transfer and its use in coal gasification wastewater treatment.

Fe3O4 supported on water hyacinth biochar (Fe3O4/WHB) was successfully used in anaerobic degradation of 2,4,6-trichlorophenol and coal gasification wastewater (CGW). Chemical oxygen demand removal efficiency and methane production were significantly improved to 98.9% and 2.0 L with Fe3O4/WHB assisted. Fe3O4/WHB facilitated the conversion of CO2 to methane and reduce H2 production. A higher coenzyme F420 concentration of 1.32 µmol/(g-mixed liquor volatile suspended solids) was found with the presence of Fe3O4/WHB, which might result in a faster conversion of acetate to methane. More interspecific signal molecules, lower diffusible signal factor, and higher mean particle size indicated that Fe3O4/WHB accelerated the sludge granulation process. Microbial community analysis revealed that enriched bacteria Geobacter along with archaea Methanothrix and Methanosarcina may be involved in direct interspecies electron transfer by Fe3O4/WHB stimulation, enhancing the performance of 2,4,6-trichlorophenol fermentation. It is shown that use of Fe3O4/WHB is feasible for enhanced CGW treatment.

Dynamic compensation based adaptive control of thermo-acoustic instabilities in Rijke tube: an experimental validation.

This paper describes experimental investigations of an adaptive control for suppressing thermo-acoustic instabilities in Rijke tube. Strong coupling between pressure oscillations and unsteady heat release excites a self-sustained acoustic wave which results in a loud, annoyed sound and may also lead to a structural damage to the combustion chamber. Adaptive controller based on dynamic compensation is adopted to suppress the instabilities in Rijke tube. The controller provides proper control action in response to pressure changes in combustors. Unknown noise and disturbance will be estimated and compensated actively by adaptive controller, which makes the feedback control less dependent on the precise model of the complex thermo-acoustic processes in Rijke tube. Experiment results confirm the controller employed is effective in breaking up the oscillations in Rijke tube.