Search Results (569)

Hepatitis B virus (HBV), belonging to the genus Orthohepadnavirus, can cause chronic hepatitis and hepatocarcinoma in humans. HBV ensures optimal replication by encoding X, a multifunctional protein responsible for degrading the structural maintenance of chromosomes (Smc) 5/6 complex, an anti-HBV factor in hepatocytes. Previous studies suggest that degradation of the Smc5/6 complex is conserved among viruses from the genus Orthohepadnavirus. Recently, a novel hepadnavirus in cats, domestic cat HBV (DCHBV), has been identified as genetically close to HBV. However, it remains unclear whether the DCHBV X protein possesses similar Smc5/6 complex-degrading properties. Here, we investigated the degradation of the Smc5/6 complex by X proteins from viruses of the genus Orthohepadnavirus, including DCHBV, in cells derived from primates and cats. We found that the DCHBV X protein degraded the Smc5/6 complex in the cells of several host species, and the degree of its anti-Smc5/6 complex activity differed depending on the host species. Furthermore, the DCHBV X protein degraded Smc6 independently of DNA-binding protein 1 (DDB1), which is a critical host factor for HBV X-mediated Smc6 degradation. Our findings highlight the conserved yet divergent degradation machinery for Smc6 of mammalian hepatitis B virus X proteins. Full article

In recent years, under the influence of climate change and human activities, droughts and floods have occurred frequently in the Yangtze River Basin (YRB), seriously threatening socioeconomic development and ecological security. The topography and climate of the YRB are complex, so it is crucial to develop appropriate drought and flood policies based on the drought and flood characteristics of different sub-basins. This study calculated the water storage deficit index (WSDI) based on the Gravity Recovery and Climate Experiment (GRACE) and GRACE-Follow On (GFO) mascon model, extended WSDI to the bidirectional monitoring of droughts and floods in the YRB, and verified the reliability of WSDI in monitoring hydrological events through historical documented events. Combined with the wavelet method, it revealed the heterogeneity of climate responses in the three sub-basins of the upper, middle, and lower reaches. The results showed the following. (1) Compared and verified with the Standardized Precipitation Evapotranspiration Index (SPEI), self-calibrating Palmer Drought Severity Index (scPDSI), and documented events, WSDI overcame the limitations of traditional indices and had higher reliability. A total of 21 drought events and 18 flood events were identified in the three sub-basins, with the lowest frequency of drought and flood events in the upper reaches. (2) Most areas of the YRB showed different degrees of wetting on the monthly and seasonal scales, and the slowest trend of wetting was in the lower reaches of the YRB. (3) The degree of influence of teleconnection factors in the upper, middle, and lower reaches of the YRB had gradually increased over time, and, in particular, El Niño Southern Oscillation (ENSO) had a significant impact on the droughts and floods. This study provided a new basis for the early warning of droughts and floods in different sub-basins of the YRB. Full article

The promotion of sustainability, especially with regard to social and urban sustainability (e.g., well-being and neighborhood revitalization), is mainly linked to human activities and behaviors. Notably, pro-environmental behaviors and actions that promote sustainability depend on the degree to which the individual attributes responsibility, namely, internal and external environmental locus of control (E-LOC). Moreover, from a collectivist perspective, the well-being of communities may also depend on their ability to take action to achieve sustainability goals. In keeping with this, we conducted two different studies to develop and validate (internally and externally) a new instrument that is able to assess internal and external E-LOC by also capturing a third dimension in respect of community E-LOC. In the first study, we performed exploratory factor analysis (EFA) by collecting data from 694 subjects (55.3% cis females; mean age = 30.1, sd = 12.6). In the second study, we conducted confirmatory factor analysis (CFA) on a sample of 1.852 subjects (57% cis females; mean age = 27.6, sd = 11.4), which demonstrated an adequate fit to the theorized model. The final form of the instrument comprises nine items subdivided into internal, external, and community NE-LOC factors. Moreover, the results pointed out significant correlations between the NE-LOC scale and engagement in pro-environmental behaviors and attitudes, pro-environmental self-identity, readiness to change for sustainability, and eco-anxiety. Therefore, the NE-LOC scale can be considered a suitable instrument for the assessment of internal and external NE-LOC, as well as to measure the attribution of collective environmental responsibility. Full article

Scientifically and accurately assessing the interaction between changes in human activity intensity and the surrounding ecological environment along the Qinghai–Tibet Railway is of great significance for the optimized construction of the railway and the restoration of the regional ecological environment. Based on different spatial distribution scales and construction phases of the Qinghai–Tibet Railway, this study integrates multi-source remote sensing data to construct a long-term spatiotemporal dataset of human activity intensity in the region. Drawing on analytical methods from production theory, a coupling theoretical framework based on remote sensing ecological models is proposed to quantitatively reveal the coupling relationships between the ecological environment and human activities across varying spatiotemporal scales along the Qinghai–Tibet Railway. The study finds that (1) the spatiotemporal distribution of human activity intensity along the Qinghai–Tibet Railway demonstrates clear patterns, with expansion primarily radiating from transportation corridors and their intersections, and marked spatial heterogeneity across different segments. Overall, human activity intensity increased slowly between 1990 and 2002, followed by a significant rise during the construction and opening of the Golmud–Lhasa section (2001–2007). From 2013 to 2020, the growth rate began to slow. Within a 0–30 km buffer zone centered on railway station locations (with a 15 km radius), the growth rate of human activity intensity generally decreased with increasing distance from the railway. In the 30–60 km buffer zone, this trend tended to stabilize. (2) The coupling process between ecological quality and human activity intensity across different spatiotemporal scales along the railway exhibits considerable spatial and temporal heterogeneity and complexity. The decoupling relationship is dominated by strong and weak decoupling patterns, with strong decoupling being the most prevalent. Weak decoupling is mainly distributed along the sides of the railway. Overall, in most areas along the railway, ecological quality has shown a certain degree of improvement alongside increasing human activity intensity; however, the rate of ecological improvement is generally lower than the rate of increase in human activity intensity. In some areas adjacent to the railway, intensified human activities have led to a decline in ecological quality, though the resulting ecological pressure remains relatively low. Full article

The use of animal models of idiopathic generalized epilepsy (IGE) is of great importance in the field of epilepsy research, with IGE affecting more than 20 million people worldwide. IGEs are characterized by a high degree of genetic heterogeneity, which makes it difficult to understand the underlying mechanisms leading to seizures. The development of animal models, whether spontaneous or resulting from genetic manipulation, has significantly contributed to our understanding of the pathological processes underlying certain IGEs, notably absence epilepsy. Research suggests that the concept of generalized epilepsy covering the whole brain should be replaced by a model in which the thalamus and its various nuclei are integrated into thalamo-cortical loops. These then assume distinct roles in the generation and generalization of seizures, which may differ across the spectrum of IGE disorders. The study of epileptogenesis is also essential: this area of research, grounded in systematic developmental neuroscience, examines the intermediate stages of neuronal activity to determine when, and how, functional development diverges between healthy and pathological states. Understanding nervous system development requires a comprehensive view of how anatomic, molecular, and genetics factors relate to neuronal activity. The emerging use of optogenetic methods and human assembloids will greatly aid our understanding of the mechanisms underlying these processes. Full article

In view of the issues including the incomplete identification of alternatives and difficulty in tracing pollution sources in PFAS pollution monitoring in surface water, this study took typical surface waters with intensive human activities as the object to perform PFAS screening. A nontarget analysis based on high-resolution mass spectrometry was developed, coupled with a modified solid phase extraction pretreatment method, to achieve the comprehensive screening of 12 legacy carboxylic acids and sulfonic acids, as well as 2 novel alternatives in water. Surface water samples were collected from typical functional areas of human activity to reveal the spatial differential distribution of PFAS concentrations. The long-chain PFASs showed a high detected concentration, among which PFOS, PFUnDA, and PFOA concentrations were especially high in urban complex pollution areas, while PFDA, PFOS, and PFOA were the main components in agricultural areas. The two exposure patterns showed a certain degree of differentiation, which may be related to different pollution sources. PFASs with a long carbon chain, especially chlorine-substituted sulfonic acid, are high-persistent-risk substances. This study provided the data basis for the prevention and control of PFAS pollution in surface water, and supported the treatment of emerging pollutants in the region. Full article

T40214 (STAT) and its recently investigated analogue STATB are G-quadruplex (G4) forming aptamers characterized by an unusually high percentage of C. The therapeutic potential of T40214 relies on its ability to inhibit the signalling pathway of STAT3, a protein frequently overexpressed in tumor cells. STAT adopts a dimeric 5′-5′ end-stacked quadruplex structure, characterized by parallel strands, three G-tetrads and three propeller-shaped loops formed by a cytidine residue. STATB folds in a very similar structure, apart from an additional cytidine bulge loop. Many studies suggest that thermal stability and topology of G4 can be significantly affected by C methylation, thus resulting in altered interaction of G4-binding proteins with these structures. Considering this, two series of STAT and STATB analogues containing a single 5-methyl-2′-deoxycytidine (mC) residue instead of canonical C nucleotide in the loop have been prepared and investigated by a combination of spectroscopic and electrophoretic techniques. CD, NMR and PAGE data clearly indicate that all derivatives adopt dimeric G4 strictly similar to that assumed by parent aptamers, but with higher stabilities. Furthermore, the resistance to nucleases and the antiproliferative activity of these mC-containing derivatives against HCT116 (human colorectal carcinoma) and T24 (human bladder carcinoma) cell lines have been evaluated. In most of the cases, STAT and STATB derivatives inhibit cell proliferation to different extents, although to a lesser degree than the unmodified parent sequences. All the data highlight the key role of the loops and indicate mC as a useful tool to contribute favorably to the stability of G4-forming aptamers without alteration of their topology, required for the biological activity. Full article

Vegetation plays an important role in carbon sequestration in terrestrial ecosystems and is affected by climate change and human activities. As a major factor affecting vegetation growth, the role of soil moisture in the impacts of climate change on vegetation is not well understood. Therefore, the effects of climate change on net primary productivity (NPP) may be underestimated. In this study, we analyzed the spatial distribution of NPP and land use degree comprehensive index (LDCI) in China from 2001 to 2020. The actual and relative contributions of climate change and human activities to NPP variation were explored. The findings indicated that NPP trended upward in 73.12%, 66.78%, and 81.34% of woodland, grassland, and cropland areas, respectively. Most of the woodland and grassland showed a decreasing trend in LDCI, while 48.63% of the cropland showed an increasing trend. The positive joint effects of climate change and human activities increased the NPP of woodlands, grasslands, and croplands by 42.83%, 53.49%, and 45.22%, respectively. Human activities (55.04%) contributed more to NPP than did climate change (44.96%). Analyzing the response of NPP (woodlands, grasslands, and croplands) to climate change and human activities in China is conducive to taking more targeted measures for different land use types to increase carbon sinks in terrestrial ecosystems. Full article

This study aimed to evaluate the physicochemical and mechanical properties of a modified adhesive system containing resveratrol by assessing its microtensile bond strength (µTBS), degree of conversion (DC), mini-flexural strength (MFS), and antibacterial activity. The modified etch-and-rinse adhesive system was prepared by resveratrol (RES) incorporation in different concentrations: adhesive with 0.5% RES (RES0.5), adhesive with 1% RES (RES1), adhesive with 2% RES (RES2), and adhesive with no RES incorporation (RES0—control group). The µTBS test was conducted on 40 human molars with dentin exposure, which were etched, bonded with the adhesives (n = 10), and restored with resin composite. Fourier Transform Infrared Spectroscopy (FTIR) measured the DC for the MFS; ten adhesive sticks were made for each group. Antibacterial activity was assessed using colony-forming unit (CFU) counts. For µTBS, no difference between the groups was found (mean ± SD): RES0.5—42.93 ± 15.49^A; RES1—42.61 ± 13.97^A and RES2—39.43 ± 9.14^A; RES0—41.01 ± 2.64^A. The DC (% ± SD) of the experimental groups was similar: RES0.5—81.02 ± 1.95^A; RES1—76.02 ± 9.00^A; RES2—58.86 ± 15.94^A; RES0—77.75 ± 3.22^A. For MFS (mean ± SD): RES0.5—33.14 ± 13.83^A; RES1—31.1 ± 12.21^A; RES2—19.72 ± 5.43^B; RES0—29.72 ± 11.95^A. For CFU (mean ± SD): RES0.5—0.67 × 10⁷ ± 0.37^B; RES1—0.68 × 10⁷ ± 0.34^B; RES2—0.60 × 10⁷ ± 0.02^C; RES0—0.75 × 10⁷ ± 0.03^A. The incorporation of resveratrol into the adhesive system at low concentrations (0.5 and 1%) does not alter the bond strength of the adhesive interface, the degree of conversion, or the flexural strength. Additionally, both concentrations exhibited antibacterial properties by reducing the colony-forming units of S. mutans. Full article

Wilderness areas are declining worldwide. A major reason is large-scale forestry activities like logging. At the same time, wilderness offers unique opportunities for recreation in natural and remote environments, enabling communities to gather economic income based on wilderness tourism. An outstanding element of wilderness areas is primary forests. Wilderness is often understood as untouched nature, unchanged by human intervention. For visitors, wilderness resembles a counter-world, enabling them to escape from everyday life. The present study investigates whether forestry activities have an effect on the attractiveness of primary forests for wilderness tourism. This question is answered based on a case study in the Făgăraş Mountains (Southern Carpathians, Romania). The findings show that primary forests are a unique selling point in tourism. Forestry activities are associated with direct (loss of biodiversity) and indirect (change of target group) effects. Forestry activities not only cause changes in forests as a tourism attractor, but also change the attractor’s contexts, by rendering access difficult or by destroying hiking trails. This paper makes theoretical and practical contributions. From a theoretical point of view, it reflects the concept of wilderness tourism and highlights the importance of contexts (i.e., access paths) for the attractiveness of wild forests. From a practical point of view, it highlights the importance of distinguishing various target groups and different degrees of naturalness to maintain a nuanced portfolio of recreational opportunities in wild forests, for example by referring to established management tools like the recreation opportunity spectrum. Full article

This investigation focuses on anthropogenic impacts on metallic element distribution within coal mining ecosystems, particularly addressing soil contamination risks in the Linhuan region. Researchers conducted comprehensive sampling and analysis of surface soil contaminants, specifically quantifying mercury, copper, zinc, iron, aluminum, and lead concentrations. Through integrated application of receptor modeling (PMF) and mercury isotopic fingerprinting methodology, this study established a quantitative assessment framework for pollution source apportionment. The multi-technique approach enables precise identification of contamination pathways and proportional contributions from different anthropogenic activities in the mining environment. Coupled with a human health risk assessment model, the health risks associated with specific sources were evaluated. The results indicate that the concentrations of Hg, Cu, Zn, Fe, Al, and Pb in the soil of the study area are 9.49, 2.80, 4.01, 11.79, 6.32, and 1.03 times the soil background values, respectively, suggesting a certain degree of enrichment of these six heavy metals in the soil. The PMF source contribution results show that the soil heavy metals in the study area have three sources: natural soil formation, a mixture of coal combustion and traffic activities, and coal mining activities, with contribution rates of 31.23%, 31.59%, and 37.18%, respectively. The health risk assessment results for specific sources indicate that the non-carcinogenic risks of soil heavy metals in the local area require sufficient attention. Hg is the main cause of non-carcinogenic health risks for both groups, making it a priority element for controlling soil heavy metal health risks. Coal mining activities are the main source (52.4%) of non-carcinogenic risks, making them a priority control source for soil heavy metal health risks in the study area. These findings provide a theoretical basis for enhancing the refined management of heavy metal pollution and the prevention of health risks in soils of coal mining areas. Full article

Uncovering the characteristics of groundwater pollution and its driving mechanisms are crucial for maintaining its ecological functions. This study focuses on hydrochemical changes and their driving factors in groundwater from different aquifers in industrial zones, taking Zibo City, Shandong Province, China, as the research area. During the dry and flood seasons of 2022, samples of phreatic water in pore media (17 sites) and karst confined water (23 sites) were collected and monitored. Piper trilinear diagrams, Gibbs diagrams, ion ratio diagrams, and a principal component analysis (PCA) were used for in-depth analyses. Pore phreatic water had higher excess rates of Na⁺, Cl⁻, and NO₃⁻ than karst confined water, which indicated a greater degree of human impact compared with karst confined water. The main hydrochemical type was HCO₃·SO₄-Ca, but in the dry season, pore phreatic water shifted to HCO₃·SO₄·Cl-Ca. The ion ratios and PCA indicated that the groundwater quality was mainly controlled by water–rock interactions and industrial activities. In the flood season, pore phreatic water was influenced by evaporite dissolution, industrial activities, and domestic sewage, while in the dry season, it was affected by halite and carbonate weathering dissolution and domestic sewage. Karst confined water was controlled by water–rock interactions and industrial activities in both seasons. The findings reveal that the key drivers of groundwater quality displayed significant differences depending on the aquifer type and seasonal variations. As such, customized approaches are essential to efficiently address and counteract the decline in groundwater quality. Full article

The interaction between rural household livelihood strategies and land use behavior constitutes the core of the human–land relationship in a region, especially in protected area villages with high ecological sensitivity that require the integration of social–economic and ecological benefits. This study, grounded in the concept of sustainable livelihoods, utilizes survey data from 399 households in the Chang-Zhu-Tan Green Heart Ecological Protection Zone. By employing the entropy method to calculate indicator weights, a coupling coordination degree model is constructed to analyze the coupling degree, coordination degree, and spatial differentiation patterns between household livelihood strategies and land use behavior. The findings reveal that (1) there is a coupling relationship between household livelihood strategies and land use behavior in the protected area, characterized by moderate coupling coordination. (2) Agricultural sideline households exhibit the highest degree of coupling coordination. The sideline activities of these households not only enhance income but also exert positive impacts on the ecological environment while they are engaged in agricultural production. (3) There is a significant spatial differentiation in the coupling coordination degree of different types of households in the protected area: it increases with the distance from the urban center, with higher values in the central areas than in the peripheral regions. The results of this study provide a basis for understanding micro-level land use changes and guiding household land use behavior, as well as offering theoretical and practical references for improving sustainable livelihoods of households in the study area, promoting rural revitalization, and implementing ecological protection policies. Full article

Sediment is a core part of lake ecosystems, and its organic matter (OM) content is a key indicator of lake ecological health and regional carbon cycling. OM provides nutrients for phytoplankton and algae in water, thereby influencing the degree of lake eutrophication. However, excessively high OM content may trigger water eutrophication, alter sediment’s physical and chemical properties, and ultimately threaten the stability and health of ecosystems. This study innovatively selected Poyang Lake, Taihu Lake, Qinghai Lake, and Hulun Lake from China’s four major geographical regions to systematically investigate sediments’ OM content, sources, and distribution characteristics at different times. The results showed that the organic matter content of sediments in lakes from different regions varied significantly and was influenced by multiple factors, such as watershed characteristics, eutrophication levels, human activities, and climate change. Poyang Lake and Taihu Lake, characterized by high levels of agricultural activities and urbanization within their basins, exhibit significant fluctuations in organic matter content, with total organic carbon (TOC) levels ranging from 0.35% to 2.9% and 0.7% to 2.4%, respectively. In contrast, Qinghai Lake and Hulun Lake, influenced by natural conditions and ecological policies, show relatively stable TOC levels, ranging from 1.3% to 2.75% and 1.25% to 3.58%, respectively. By analyzing sediments’ OM content and combining methods such as organic carbon, nitrogen isotopes, and organic C/N ratios, it is possible to effectively assess the ecological health of lakes, provide critical data support for pollution control, and play a significant role in carbon cycle management. Full article

Human activities have increased the imbalance in atmospheric N and P deposition, which changes soil nutrient availability and subsequently affects the structure and function of terrestrial ecosystems. Dioecious plants are important parts of terrestrial ecosystems and are characterized by sex-related differences in their response to the external environment and always exhibit a skewed sex ratio, which makes them more vulnerable to climate change and increases their risk of extinction. However, little attention has been paid to the effects of unbalanced N and P deposition on these plants, especially on their defense traits. In this study, we used dioecious Populus cathayana to investigate the influence of gradient N and P deposition on the correlation between growth and defense traits. The results showed that although the different rates of N and P deposition enhanced biomass accumulation in both sexes to varying degrees, the most substantial biomass increment was noted under a lower-nitrogen and higher-phosphorus (LNHP) treatment regimen, with females showing an approximately 112% increase and males a 47% increase in total biomass. In response to varying levels of simulated N and P deposition, males and females adopt distinct strategies for biomass allocation. Although declines in root biomass were observed in both sexes as nutrient availability increased, the decrement was more marked in males; under the LNHP treatment, it dropped by about 11%, while under a high-nitrogen and high-phosphorus (HNHP) treatment, the decrease was about 35%. Conversely, females demonstrated a heightened propensity to allocate biomass towards leaf development. Furthermore, with increasing N and P deposition, there was a general reduction in the concentrations of physical and chemical defense substances within the leaves of both sexes. Nonetheless, the correlations between defense substances, nutrient element content, non-structural carbohydrate (NSC) content, and dry biomass were more pronounced in males, suggesting a greater sensitivity to defense substance responses in males than in females. Overall, these results indicate that there is sexual dimorphism in the accumulation of chemical substances in male and female P. cathayana under unbalanced N and P deposition and they provide a technical and theoretical basis for predicting the population dynamics of dioecious plants, maintaining the stability of poplar populations, and constructing high-productivity poplar plantations globally in the future. Full article