Earticle

Parkinson's disease (PD) is one of the most prevalent age-related neurodegenerative disorders. The rotenone-induced mouse model has been widely utilized in research as it effectively recapitulates key pathological features of PD. However, the precise mechanisms by which rotenone causes dopaminergic neuron damage and its associated symptoms are not yet fully elucidated. Our previous study demonstrated that rotenone induces microtubule instability. This study investigated the subsequent changes in the microtubule-associated protein tau and in astrocytes, which are critical for neuronal survival and function. We first confirmed that rotenone administration in mice led to a significant loss of dopaminergic neurons and a reduction of dopaminergic nerve terminals in the striatum. Concurrently, we observed a marked increase in the phosphorylation of the microtubule-regulating protein tau. Such tau hyperphosphorylation is a well-established pathological hallmark of neurodegenerative diseases like Alzheimer's disease and is known to cause microtubule instability. Therefore, it is likely that rotenone-induced tau hyperphosphorylation contributes to microtubule destabilization and consequent neuronal dysfunction. Furthermore, analysis of brain tissue from rotenone-treated mice revealed a reactive astrogliosis, characterized by an activated morphology with increased branching. The results indicate that tau hyperphosphorylation and astrocyte overactivation are key mechanisms driving rotenone-induced dopaminergic cell death. Further research focused on modulating these pathways is expected to contribute significantly to elucidating the pathogenesis of Parkinson's disease.

Rural population dynamics in Mongolia are shaped by strong climatic variability, long-term drying trends, and the vulnerability of pastoral livelihoods to environmental stress. This study examines how desertification related indicators, quarterly climate anomalies, and socioeconomic conditions influence rural population patterns across 21 provinces except Ulaanbaatar from 2006 to 2025. Using a quarterly provincial-level panel dataset, the analysis integrates vegetation conditions (NDVI), soil moisture, long-term drought severity (SPEI-12), temperature anomalies, wind speed, livestock density, and real income. A fixed-effects panel regression framework is employed to control for unobserved provincial characteristics and isolate the temporal effects of environmental and economic variables on rural population. The national-level model shows that cooling anomalies significantly reduce rural population, while warming exerts a modest positive influence. To capture spatial heterogeneity in climate impacts, provinces are separated into drying and stable groups based on long-term SPEI-12 trends. Results indicate that drying regions react more strongly to climate stress: soil moisture becomes significant only in these areas, and livestock density has nearly four times stronger demographic influence than in stable regions. Quarterly temperature models reveal that the positive warming effect originates from winter and spring, while summer cooling intensifies drought stress and reduces rural population. Overall, the findings highlight the combined importance of quarterly climate variability, long-term drying, and rural economic resilience in shaping population dynamics in Mongolia.

Report on the propagation characteristics of terahertz (THz) dielectric slab waveguides affected by laterally misaligned coupling conditions. The TM₀ mode is effectively launched when THz waves are coupled near the lateral center of the waveguide, On the other hand, if the coupling position is shifted laterally, higher-order asymmetric modes such as TM₁ and TM₃ become dominant. The coupling of incident THz waves at the center results in leaky mode behavior for longer wavelengths, whereas shorter wavelengths remain guided. In contrast, off-center coupling induces leaky mode characteristics over nearly the entire spectral ranges. These differences are distinguishable in the time-domain signals measured by THz time-domain spectroscopy, thus allowing the implementation of a time-domain prism for spectroscopy. The systematic investigation of THz slab waveguides may contribute to the realization of multifunctional optical devices for Tz sensing, imaging, and high-speed wireless communications, as well as to the analysis of optical properties in THz measurement systems.

We investigated Panax ginseng , a traditional Korean medicinal plant recognized for its antimicrobial, anti-inflammatory, and antioxidant properties, to evaluate its potential in combating P. gingivalis . The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined under anaerobic conditions based on the years old of the Panax ginseng . Additionally, its efficacy in reducing oral malodor was assessed by measuring hydrogen sulfide (H₂S) and ammonia (NH₃) levels using detection tubes. Experimental results confirmed the significant antimicrobial activity of Panax ginseng against P. gingivalis . Furthermore, treatments notably reduced the production of hydrogen sulfide and ammonia gases. Observations through field emission scanning electron microscopy (FE-SEM) revealed that cell wall damage commenced at MIC conditions, progressing to complete destruction at MBC conditions. These findings provide substantial evidence of the antimicrobial and malodor-reducing properties of Panax ginseng , emphasizing its potential in the development of oral hygiene products.

This study investigated the relationship between benthic macroinvertebrate communities and physicochemical factors in the Micheon Stream, Andong. Three surveys were conducted in 2020. Water temperature ranged from 19.5 to 24.3℃, pH from 7.77 to 8.23, and dissolved oxygen (DO) from 7.87 to 8.77 mg·L⁻¹, indicating generally good water quality. A total of 121 species (47,286.5 inds./㎡) belonging to 61 families and 20 orders were identified. The EPT group (Ephemeroptera, Plecoptera, Trichoptera) comprised 35 species (28.9%) and 27,495.8 inds./㎡ (58.2%), while the OCH group (Odonata, Coleoptera, Hemiptera) accounted for 48 species (39.8%) and 6,500.2 inds./㎡ (13.7%). Community indices showed a mean dominance index (DI) of 0.48, diversity index (H′) of 3.23, richness index (R₁) of 3.23, and evenness index (J′) of 0.70. Predators were the most species-rich feeding group, and clingers were dominant in habitat groups. The TESB index averaged 122, corresponding to water quality grade Ⅰa (“very good”). Similarity and correlation analyses showed that St.1 and St.2 displayed similar patterns, while St.4 showed distinct community differences from other sites. pH and EC were identified as significant environmental factors influencing community composition.

Declining response rates and resulting increases in costs for face-to-face surveys are common worldwide. Therefore, there is a need to refine mixed-mode surveys, which are considered the most suitable survey method for the current survey environment. This study aimed to identify the characteristics of respondents who choose survey modes from the 2024 Social Survey of Statistics Korea, and identify ways to improve survey efficiency, reduce nonresponse rates and survey costs. We used gender, age, number of household members, housing type, and education level as explanatory variables to identify groups that prefer specific survey modes. As a result, when looking at it by age group, both men and women in their 60s and older preferred the face-to-face interview, while the remaining groups preferred the non-face-to-face methods (self-administered or internet). By household size and age group, the following groups, both men and women, preferred the face-to-face interview : single-person households aged 50 and older; single- or two- person households aged 60 and older, and those aged 70 and older regardless of household size. The preference for the face-to-face interview among single-person female teens was particularly noteworthy. By gender, education level, and age group, both men and women aged 70 and over, regardless of educational background, preferred the face-to-face interview. Those aged 60 and over with a high school diploma or lower, and those aged 40 to 50 with a middle school diploma or lower, preferred the face-to-face interview. By education level and household size, those with a college degree or higher and those with three or more household members preferred the non-face-to-face methods.