Scientific Reports最新文献

The suspended particulate matter (SPM) is a key parameter influencing the quality of aquatic habitats. SPM directly impacts the habitat of the "soft gold" (Artemia) in Ebinur Lake and is a major contributor to saline dust within its watershed. However, significant variations among inversion models present a challenge for SPM monitoring via remote sensing. Using Ebinur Lake as a case study, this study identify an optimal strategy for SPM monitoring. The findings are as follows: (1) Ebinur Lake water shows complete absorption at 695 nm. (2) ESTARFM achieved a Red-band spatiotemporal fusion R² ≥0.79, leading to an SPM inversion R² of 0.75. (3) Compared to the empirical model (R² ≥ 0.72, RMSE ≤ 78.95 mg/L), the QAA (Quasi-Analytical Algorithm) demonstrated superior adaptability (R² ≥ 0.74, RMSE ≤ 61.12 mg/L). (4) The red-band reflectance consistency among Landsat sensors reaches R² ≥ 0.76, with a cross-platform correlation of R²= 0.73 between Landsat 8 and Sentinel 2. (5) The QAA_655(665) model is effective for Landsat 8 and Sentinel 2, whereas the EXPM (the exponential model) is more suitable for Landsat 5/7 and fusion images. This study primarily addresses the challenge of spatiotemporal inadaptability in the long-term SPM inversion process for Ebinur Lake. It can serve as a reference for water color parameter retrieval via remote sensing in globally similar environmental contexts.

Refractive error is the leading cause of correctable visual impairment and preventable blindness worldwide. It is a growing public health concern, particularly among the younger population, including medical students, who represent a vital future workforce for developing countries like Ethiopia. Poor ocular health can negatively impact academic performance, productivity, and overall quality of life, further contributing to the economic burden. Despite the increasing prevalence of REs globally, there is a lack of evidence regarding their prevalence and associated factors among medical students in Ethiopia. Therefore, this study was aimed to assess the prevalence and factors associated with refractive error among medical students. An institutional based cross sectional study design using simple random sampling technique was employed to select 422 undergraduate medical students at Hawassa University College of Medicine and Health Sciences after proportional allocation done for five batches. The study was conducted from September 2023 to October 2023. The data were collected using semi -structured questionnaires and clinical examination check list adapted from previous studies. The collected data were entered by kobo tool and exported and analyzed with Statistical Packages for the Social Science version 26.Variables with p-value < 0.05 in multivariable logistic regression were considered as statistically significant. A total of 417 participants with a response rate of 98.8% were involved in this study. Prevalence of refractive error was 10.3% (95%CI: 7.2%-13.4%). In multivariable logistic regression analysis, lack of outdoor activity [AOR = 2.382(95% CI (1.084-5.234)], no Active rest [AOR = 2.442(95% CI 1.064-5.608)] previous eye operation [AOR = 4.382 (95% CI (1.781-10.784)] and eye trauma (AOR: 7.188; 95%CI: 2.178-23.724)] were significantly associated with refractive error. The study underscores a remarkable prevalence of refractive errors among medical students, consistent with findings from comparable settings and populations. The significant links identified between refractive errors and modifiable lifestyle factors such as reduced outdoor activity, lack of active breaks, prior ocular surgeries, and eye trauma emphasize the influence of demanding academic schedules and limited environmental exposure on visual health. These insights call for proactive screening and the implementation of targeted preventive measures to mitigate refractive error risks. Addressing these factors is critical for preserving the ocular well-being and academic efficacy of medical students.

The establishment of Agricultural Product Quality and Safety Counties not only enhances the quality and safety standards of agricultural products, effectively ensuring food safety and consumption security, but also holds significant implications for accelerating the transformation of agricultural development patterns and advancing modern agriculture. Based on panel data from 1,609 Chinese counties from 2010 to 2023, this study employs the national pilot policy for Agricultural Product Quality and Safety Counties as a quasi-natural experiment and utilizes a multi-period difference-in-differences approach to examine the impact of establishing these counties on agricultural economic growth and its underlying mechanisms. The findings reveal that: (1) the pilot policy significantly promotes county-level agricultural economic growth, a conclusion that remains robust after a series of robustness checks; (2) heterogeneity analysis indicates the policy's effects are more pronounced in central and eastern regions, major grain-producing areas, and regions with higher levels of economic development, digital infrastructure, and transportation facilities; (3) mechanism analysis demonstrates that the policy facilitates agricultural economic development by promoting expanded operational scale and the development of geographical indications. This study provides theoretical support and policy references for further expanding the Agricultural Product Quality and Safety County initiative and for government agencies to formulate development policies tailored to local conditions.

Metastable fluidized granular systems can spontaneously defluidize, forming glass- or crystal-like structures. We performed experiments with polymer spheres of different friction and roughness fluidized in a vertical water pipe flow. Velocity fluctuations were higher for high friction materials. Monodisperse particles form a crystal-like shell on the cylinder wall for a range of flow rates and number of particles. For polytetrafluoroethylene (PTFE) spheres with a friction coefficient near 0.1, structural organization was assessed through nearest-neighbor angle analysis, featuring hexagonal packing with defects. At such low friction, defects decreased, while contact chains became longer and more aligned. These findings highlight the role of surface properties in the emergence of ordered or disordered structures, offering new insights into the mechanisms governing glass- and crystal-like arrangements in fluidized particle systems.