Evolutionary Trends Research Articles

Haihun Marquis Tomb in Western Han Dynasty: Social Value and Future Prospects - A Knowledge Graph Analysis with Citespace

This paper uses the CiteSpace knowledge graph visualization tool to analyze the research evolution path and trend of 583 academic papers in the CNKI database in the past ten years. The results show that the unique position of the tomb of the Haihun Marquis in the field of history and cultural heritage of the Han Dynasty, the mainstream of research in the field of Han Dynasty culture, artistic innovation and application, the evolution of cultural heritage research, and the interdisciplinary research of the deep integration of cultural heritage research and advanced technology in the future will provide strong support for promoting the cultural and museum industry and the recreation of traditional Chinese culture.

Trends in the dynamic evolution of blockchain and circular economy: A literature review and bibliometric analysis

AbstractThe intersection of blockchain technology and circular economy (CE) practices holds significant potential for enhancing sustainability, transparency, and efficiency. This study conducts a comprehensive bibliometric analysis to explore the current research landscape in this domain. Key findings indicate a rapid growth in publications, highlighting a burgeoning interest in leveraging blockchain for CE initiatives. The analysis identifies critical approaches such as enhancing supply chain transparency, improving resource management, and facilitating product lifecycle tracking. However, the integration of blockchain into CE practices presents challenges, including technical complexities, scalability issues, and regulatory hurdles. Addressing these challenges requires interdisciplinary and cross‐sectoral collaboration, as well as continuous research and innovation. Future research should focus on the integration of emerging technologies with blockchain, longitudinal studies on long‐term impacts, socio‐economic implications, and the development of regulatory frameworks. This study contributes to the existing body of knowledge by providing unique insights and outlining potential research directions at the intersection of blockchain and CE.

Real-Time Run-Off-Road Risk Prediction Based on Deep Learning Sequence Forecasting Approach

Driving risk prediction is crucial for advanced driving technologies, with deep learning approaches leading the way in driving safety analysis. Current driving risk prediction methods typically establish a mapping between driving features and risk statuses. However, status prediction fails to provide detailed risk sequence information, and existing driving safety analyses seldom focus on run-off-road (ROR) risk. This study extracted 660 near-roadside lane-changing samples from the high-D natural driving dataset. The performance of sequence and status prediction for ROR risk was compared across five mainstream deep learning models: LSTM, CNN, LSTM-CNN, CNN-LSTM-MA, and Transformer. The results indicate the following: (1) The deep learning approach effectively predicts ROR risk. The Macro F1 Score of sequence prediction significantly surpasses that of status prediction, with no notable difference in efficiency; (2) Sequence prediction captures risk evolution trends, such as increases, turns, and declines, providing more comprehensive safety information; (3) The presence of surrounding vehicles significantly impacts lane change duration and ROR risk. This study offers new insights into the quantitative research of ROR risk, demonstrating that risk sequence prediction is superior to status prediction in multiple aspects and can provide theoretical support for the development of roadside safety.

Institutional unlocking or technological unlocking? The logic of carbon unlocking in the new energy vehicle industry in China

As a result of unbalanced energy structure, high carbon emissions, and global climate change, carbon lock-in has gained considerable attention. To achieve carbon unlocking, technological advancements and institutional innovation are essential. This paper uses the new energy vehicle (NEV) industry as its case study, identifying the differences and evolutionary trends between institutional unlocking and technological unlocking logics, and demonstrating how these logics affect industry and enterprise development and eventually advance the process of carbon unlocking. The findings are: (1) Institutional incentives play a critical role in the development of an industry at the beginning. As the industry matures, technological innovation plays a central role in driving industry development, while institutional logic gradually loses influence and technological logic gains influence. (2) Dual logics have undergone a complex transformation of compatibility, mutual exclusivity, partial confrontation, and cooperation during the process of carbon unlocking. It is possible for the complexity of the relationship to range from low to high, with both becoming less complex as the industry matures. (3) Through ongoing gaming and adjustment, the dual logics encourage the NEV industry to realize carbon unlocking and low-carbon transformation at the same time.

Mesoproterozoic (∼1.4 Ga) magmatism in northern Alxa, China: Implications for tectonic affinity of microcontinents in the southern Central Asian Orogenic Belt

The origin and paleogeographic reconstruction of Precambrian microcontinents in the Central Asian Orogenic Belt (CAOB) are crucial for understanding continental crustal evolution, mechanisms of accretionary orogeny, and assemblage and breakup of the supercontinent during the Earth’s early history. The existence and basement nature of the South Gobi microcontinent within the central segment of the southern CAOB remain controversial. This study represents the first work to unveil the presence of Mesoproterozoic (∼1.4 Ga) intrusive rocks in the Zhusileng-Hangwula tectonic zone that is the central segment of the southern CAOB, and is distributed along the border areas between China and Mongolia. It offers pivotal evidence for the existence of the South Gobi microcontinent.Three alkali feldspar granites samples collected from the Zhusileng-Hangwula tectonic zone yielded crystallization ages ranging from 1371 ± 17 Ma to 1420 ± 29 Ma, while detrital zircons from a two-mica quartz schist xenolith yielded similar 206Pb/238U ages clustered around ∼1.4 Ga. The ∼1.4 Ga zircons display depleted Hf isotopic signatures (εHf(t) = 3.2–6.0) and relatively young two-stage Hf model ages (1.9–1.7 Ga), suggesting rapid reworking of juvenile mantle-derived materials. These findings indicate that the Zhusileng-Hangwula tectonic zone constitutes a microcontinental fragment with Mesoproterozoic basement, rather than a Paleozoic accretionary complex as previously postulated. Combining the contemporaneous magmatism data from the microcontinents in the southern CAOB, the 1.48–1.32 Ga arc-related magmatism exhibits a coherent trend of geochemical evolution, potentially indicating a geodynamic transition from a convergent to an extensional environment. Moreover, the temporal, tectonic evolution, and petrological similarities imply a tectonic affinity between these microcontinents and Fennoscandia, and they may have originated from an accretionary belt along the edge of Nuna during the Mesoproterozoic.

Adaptation and innovation in darter fish cranial musculature (Etheostomatinae: Percidae): insights from diceCT

Abstract Fish skulls are often highly kinetic, with multiple linkage and lever systems powered by a diverse suite of muscles. Comparative analysis of the evolution of soft-tissue structures in the fish skull is often limited under traditional approaches, while new imaging techniques like diceCT (diffusible iodine-based contrast-enhanced computed tomography) allow for high-resolution imaging of muscles in situ. Darters (Percidae: Etheostomatinae) are a diminutive and species-rich clade of lotic freshwater fishes, which show diverse head shapes believed to be associated with different foraging strategies. We used diceCT to sample all major cranial adductors and abductors responsible for movement of the jaw, hyoid, operculum, and suspensorium from 29 species. We applied comparative phylogenetic approaches to analyse the evolutionary trends in muscle size across the clade. We found two major patterns: (i) darter cranial muscles show fundamental trade-offs relating to investment in musculature, as well as buccal expansion vs. biting attributes; early divergence in muscle size appears to be associated with shifts in habitat use and foraging; (ii) darter adductor mandibulae show high variation in architecture (fibre orientation, divisions). This study highlights how new imaging techniques can provide novel insights into the anatomy of even well-sampled/represented clades.

Dynamic evolution trend and driving mechanisms of water conservation in the Yellow River Basin, China

Water conservation (WC) is a critical ecological service function in the Yellow River Basin (YRB). There is currently a lack of detailed exploration of WC development processes and the impact mechanisms of driving factors at spatiotemporal scales in the YRB. By collecting data on DEM, land use, soil, meteorology, reservoirs, and observed discharge, this study established a large-scale WC model using the soil and water assessment tool (SWAT). The abrupt change test, empirical orthogonal function (EOF), wavelet analysis, hierarchical partitioning analysis (HPA), geodetectors, and aridity index were employed to analyze the multi-spatiotemporal characteristics and driving forces of WC calculated using the water balance method. The results are as follows: (1) The average WC among the YRB was 9.11 mm (74.68 × 108 m3) from 1960 to 2020. Pasture and forests contributed to 48.65% and 22.05% of the average annual WC, respectively. (2) WC exhibited four forms: less/more in the YRB, more in the southeast (northwest), and less in the northwest (southeast). (3) Forests and pastures in land use had higher average WC capacity, while Gansu, Shaanxi, and Qinghai ranked in the top three for average WC among the nine provinces. (4) Precipitation was the major driving force affecting WC variations, with the interaction between precipitation and actual evapotranspiration being the most significant. (5) Drought was a significant cause of negative WC. Protecting and managing crucial WC areas was essential for improving the ecological environment. This research elucidates the driving forces of WC in the YRB, providing scientific support for improving regional WC and promoting sustainable development.

The mid-Cretaceous Hohonu Batholith (South Island, New Zealand): Identifying magmatic sources and processes during onset of crustal extension

The Hohonu Batholith is an aggregation of mostly mid-Cretaceous granitoid plutons on the West Coast of the South Island of New Zealand emplaced during a transitional period between subduction-related compression and continental lithospheric extension. This study reports an integrated dataset, comprising in-situ UPb, O and Hf isotope compositions and REE, Ti and other trace and major elements (ZrHf, ThU) for zircons extracted from four representative plutons within the batholith. Our results provide detailed insight into the protracted thermal, chronological and geochemical histories. LA-ICPMS UPb zircon ages indicate a primary episode of magma genesis and emplacement from 107 to 113 Ma, confirming published SIMS dating. However, a younger previously unrecognized age population of ~91–96 Ma is identified, primarily (although not exclusively) in zircon rims. This younger age event coincides with the timing of protracted lithospheric extension and crustal thinning of the Zealandia continent. The cryptic younger zircon ages suggest that Hohonu granitoids experienced a partial thermal overprint (accompanied by Pb loss) mostly recorded in rims. Differences in bulk rock geochemistry between plutons are inferred to reflect variable conditions of partial melting controlled by source mineralogy and H2O content. Isotope and trace element compositions, along with Ti-thermometry, measured on the same micro-volume of CL-imaged zircons, are used to test if source characteristics were imparted from melt to minerals in zircon-saturated silicic systems. Similarities are revealed in the zircon record of the selected plutonic rocks, confirming their broadly consanguineous relationship and the fundamental role of open-system behaviour, involving hybridization or assimilation between mantle-derived (or juvenile mafic) and a crustal-derived components, as previously inferred from whole rock NdSr isotope systematics. However, intra-sample decoupling of zircon OHf isotope systematics may also be linked to residual source component unmixing. This possibility, in addition to mafic recharge, may have obscured melt source compositional characteristics, and hence zircon REE appear as unsuitable fingerprints of source(s) and conditions of partial melting in this granitoid system. Simple compositional and thermal magma evolution trends appear punctuated by episodes of mafic recharge, presumably during lithospheric thinning.

Estimating Primary Magmas From Mars With PRIMARSMELT: Implications for the Petrogenesis of Some Martian Rocks and the Thermal Evolution of Mars

AbstractPrimary magmas form by partial melting in the mantle of a terrestrial planet and represent the starting material for building its crust. The compositions of primary magmas are critical for understanding the thermal history of planetary interiors, as they can be used to estimate mantle potential temperatures (TP) and track changes in the conditions of mantle partial melting over time. Here, we introduce PRIMARSMELT, a new member of the PRIMELT software family, calibrated to estimate the composition of Martian primary magmas and their formation conditions. We applied PRIMARSMELT to a comprehensive database of basaltic compositions from Mars. Our results are consistent with their petrology, requiring olivine addition to restore fractionated compositions to their primary parents and olivine subtraction from cumulate rocks. Individual primary magma solutions provide insights into the petrogenesis of specific Martian meteorites, with implications for the near‐primary nature of some primitive meteorites and the relationship between lithologies A and B in meteorite EETA 79001. Taken together, our results suggest nearly constant or potentially increasing mantle potential temperatures throughout the geological history of Mars. The average TP for young shergottite meteorites is ∼1,442 ± 40°C, similar to ambient mantle temperatures inferred from geophysical models. In contrast, older basaltic rocks record potential temperatures as low as ∼1,320 ± 48°C for igneous clasts in meteorites NWA 7034/7533. We suggest that, rather than plume‐related magmatism, shergottite meteorites record ambient mantle temperatures, with the thermal evolution trend possibly resulting from inefficient heat loss, as expected for a planet in stagnant‐lid mode.

Characterization of CL-20/HMX cocrystallization and its effects on GAP-based propellants during thermal aging process

The incorporation of HMX and CL-20 as component particles can greatly improve the energy efficiency of composite propellants. Nevertheless, the occurrence of cocrystallization arises when HMX and CL-20 exists together. Further investigation is needed to determine the effects of the CL-20/HMX cocrystallization on the aging features of the propellants. The present study examines the evolutionary trends and effects of the CL-20/HMX cocrystal on the process of solid propellant aging. Experimental thermal aging studies were carried out on GAP-based composite propellants at temperatures of 60 °C/180-day and 70 °C/90-day. An investigation of density bottle, differential scanning calorimetry, X-ray diffraction, Fourier transform infrared spectroscopy, and uniaxial tensile testing were performed on the samples. The results indicate that the cocrystallization behaviours of CL-20/HMX undergo three distinct stages during propellant aging. The reaction rate accelerates most during the middle aging stage. As the GAP-based propellant ages, the recently developed cocrystal structure deteriorates the interfacial characteristics between the propellant particles and the matrix, leading to the formation of cavities inside the material. This will further enhance the decrease in elastic modulus, ultimate strength, and maximum elongation of the propellants. Among them, the most notable distinction from the aging behaviours of propellants without the addition of particles is the increase of the elastic modulus. Furthermore, a strong linear correlation was observed between variation of the elastic modulus and the cocrystal content of CL-20/HMX. This correlation offers a reliable indicator for monitoring the extent of cocrystallization phenomena.

Multi-scenario simulation and optimization of habitat quality under karst desertification management

IntroductionInvestigation of the evolutionary trend of habitat quality in karst and rocky desertification zones is crucial for enhancing ecological security and conservation.MethodsAnalysis of land use statistics from the years 2000, 2010, and 2020, changes in habitat quality (HQ) and land use (LULC) between 2000 and 2020 were analyzed using Huize County in Yunnan Province as an example. The InVEST and FLUS models were applied to simulate LULC under different scenarios in 2030 and 2040 and assess changes in spatial gradients of habitat quality at each timepoint and factors influencing them.ResultsThe findings indicated that (1) The predominant land use types are grassland and woodland, experiencing the most significant growth in urbanized areas, the main sources of which are paddy fields and high-cover grassland. (2) The habitat quality between 2000 and 2020 was average and displayed a consistent decline. The spatial distribution pattern indicates low HQ in urban areas, high HQ in the outskirts, low HQ in the south-west, and high HQ in the north-east. In all four scenarios, habitat quality predominantly decreases in urban areas and regions with a dense concentration of built-up land. (3) Habitat quality spatial distribution is primarily affected by the type of land use, with NDVI being the secondary determinant.DiscussionThe ecological environment of Huize County must be restored and safeguarded with a focus on ecological priorities and harmonious development scenarios. This study provides methodological lessons for ecorestoration and policymakers in areas of karstic rocky desertification.

Complete Chloroplast Genome of Crassula aquatica: Comparative Genomic Analysis and Phylogenetic Relationships

Background/Objectives: Crassula aquatica (L.) Schonl. is a very small annual plant growing along riverbanks. Chloroplast (cp) genomes, crucial for photosynthesis, are highly conserved and play a key role in understanding plant evolution. In this study, we conducted cp genome analysis of C. aquatica, aiming to elucidate its phylogenetic position and structural variations. We analyzed and described the features of the complete cp genome of C. aquatica and conducted comparative analysis with the cp genomes of closely related taxa. Rsults: The cp genome was 144,503 bp in length and exhibited the typical quadripartite structure, consisting of a large single-copy region (LSC; 77,993 bp), a small single-copy region (SSC; 16,784 bp), and two inverted repeats (24,863 bp). The cp genome of C. aquatica comprised 113 unique genes, including 79 protein-coding genes (PCGs), 30 tRNAs, and 4 rRNA genes. Comparative genomic analysis of 13 other Crassula species and six outgroups demonstrated highly conserved gene content and order among Crassula species. However, notable differences were observed, including the complete loss of the rpoC1 intron in C. aquatica and several closely related species, which may serve as a synapomorphic trait supporting the monophyly of the subgenus Disporocarpa. We analyzed the nucleotide diversity among 14 Crassula cp genomes and identified five highly variable regions (pi > 0.08) in the IGS regions. Phylogenetic analysis based on 78 PCGs confirmed the monophyly of Crassula and its division into two subgenera: Crassula and Disporocarpa. Although the phylogenetic tree supported the subgeneric classification system, the sectional classification system requires reassessment. Conclusions: In this study, we conducted a comparative analysis of the cp genome of the genus Crassula. We inferred evolutionary trends within the Crassula cp genome and provided molecular evidence supporting the integration of the genus Tillaea into the genus Crassula. However, as this study does not represent all species within the genus Tillaea, further comprehensive phylogenetic analyses are requrired.

Genetic polymorphism of merozoite surface protein 1 and merozoite surface protein 2 in the Vietnam Plasmodium falciparum population

BackgroundPlasmodium falciparum merozoite surface proteins 1 (PfMSP1) and 2 (PfMSP2) are potential candidates for malaria vaccine development. However, the genetic diversity of these genes in the global P. falciparum population presents a significant challenge in developing an effective vaccine. Hence, understanding the genetic diversity and evolutionary trends in the global P. falciparum population is crucial.MethodsThis study analyzed the genetic variations and evolutionary changes of pfmsp1 and pfmsp2 in P. falciparum isolates from the Central Highland and South-Central regions of Vietnam. DNASTAR and MEGA7 programs were utilized for analyses. The polymorphic nature of global pfmsp1 and pfmsp2 was also investigated.ResultsA total of 337 sequences of pfmsp1 and 289 sequences of pfmsp2 were obtained. The pfmsp1 and pfmsp2 from Vietnam revealed a higher degree of genetic homogeneity compared to those from other malaria-endemic countries. Remarkably, the allele diversity patterns of Vietnam pfmsp1 and pfmsp2 differed significantly from those of neighboring countries in the Greater Mekong Subregion. Declines in allele diversity and polymorphic patterns of Vietnam pfmsp1 and pfmsp2 were observed.ConclusionsThe Vietnam P. falciparum population might be genetically isolated from the parasite populations in other neighboring GMS countries, likely due to geographical barriers and distinct evolutionary pressures. Furthermore, bottleneck effects or selective sweeps may have contributed to the genetic homogeneity of Vietnam pfmsp1 and pfmsp2.

Analysis of control measures inducing the evolution of infectious viral diseases

With the continuation of the infectious disease, pathogens mutate and interact with the resident pathogen. In this paper, we develop an SIR model that considers the evolution of viral virulence under the regulation of different defense strengths. By using infectious disease dynamics and evolutionary adaptive dynamics, we obtain the evolutionary criteria allowing for evolutionary branching and continuously stable strategy across varying intensities of prevention and control measures. Our study finds that robust prevention and control measures can contribute to a rapid evolutionary trend toward higher virulence. We perform a critical function analysis to reveal the evolutionary consequences of trade-offs of arbitrary shape and analyze a diverse range of evolutionary dynamics. Furthermore, we investigate the coexistence of two different strains and construct an evolutionary model to obtain their invasion fitness functions and the evolutionarily singular coalition of the dimorphism. We contemplate the presence of secondary branching on a significantly extended evolutionary time scale. Last, we conduct the numerical simulations to prove our theoretical findings. This reveals the law that the evolutionary state of pathogens is affected by the intensity of prevention and control strategies. The results and methods can be used as references for studying the effects of other factors on virus evolution.

Understanding floods and droughts in the Yangtze River Basin: a historical perspective (1470–2022)

ABSTRACT The Yangtze River basin plays a crucial role in China’s economy, and the impacts of drought and flood in the basin are becoming more uncertain due to climate change. Thus, a study was conducted to analyse the flood–drought rating sequence for the Yangtze River basin in 1470–2022. The frequency of flood and drought occurrences during the flood season followed a normal distribution. Extreme drought and flood accounted for 2–4% of occurrences. Partial and extreme floods increased notably in the 19th and 20th centuries, while droughts became more frequent after the 20th century. Furthermore, the Three Gorges Reservoir area’s storage capacity did not significantly impact flood season precipitation in the upper reaches of the Yangtze River and the reservoir area. This comprehensive study serves to uncover evolutionary patterns and trends of drought and flood, providing valuable insights for effectively managing water resources in the basin.

Leaf architecture and functional traits for 122 species at the University of California Botanical Garden at Berkeley.

The dataset contains leaf venation architecture and functional traits for a phylogenetically diverse set of 122 plant species (including ferns, basal angiosperms, monocots, basal eudicots, asterids, and rosids) collected from the living collections of the University of California Botanical Garden at Berkeley (37.87° N, 122.23° W; CA, USA) from February to September 2021. The sampled species originated from all continents, except Antarctica, and are distributed in different growth forms (aquatic, herb, climbing, tree, shrub). The functional dataset comprises 31 traits (mechanical, hydraulic, anatomical, physiological, economical, and chemical) and describes six main leaf functional axes (hydraulic conductance, resistance and resilience to damages caused by drought and herbivory, mechanical support, and construction cost). It also describes how architecture features vary across venation networks. Our trait dataset is suitable for (1) functional and architectural characterization of plant species; (2) identification of venation architecture-function trade-offs; (3) investigation of evolutionary trends in leaf venation networks; and (4) mechanistic modeling of leaf function. Data are made available under the Open Data Commons Attribution License.

Советский социализм: о природе и уроках проекта

Abstract. This article explores the prerequisites, content, and outcomes of the Soviet project. The term refers to the predominance of arbitrary organization of social reality over its naturally-historical self-determination. Unlike the utopian denial of existing social being, the project is viewed as a technological compensation for the mediating disruptions and interruptions in evolutionary trends. The Soviet period of national history is examined as the largest known endeavor to create a new society, vividly illustrating the inherent internal dialectics that underscore the stability and viability of a constructed consciousness of existence. However, this dual nature imposes a strict limit on such a construction: the act of historical arbitrariness is incapable of transcending the nearest state of stable equilibrium within the social system, where the objective laws of social development reclaim their unlimited authority. Moreover, the earlier inability to impose self-restraint leads arbitrariness to its own negation.

Zircon Typology : a synthesis. Applications to Magmatic, Metamorphic and Sedimentary Rocks

Abstract The study of more than 101,000 zircon crystals from 1105 different magmatic rocks (anatectic crustal, calc-alkaline, alkaline or tholeiitic) enables a general synthesis to be established which is useful for arguments in petrology. Populations are defined in typological distributions, mean points and typological evolutionary trends according to genetic groups. The overall logic obtained confirms the essential factors (temperature, chemistry) responsible for typological variations. The Hf contents of zircons, in substitution for Zr, make it possible to refine their origins (crustal, hybrid or mantle-derived), in particular by considering the early phase of crystallization, in equilibrium with the initial magma. They support the typological arguments and underline the role of the fluid phase in the magmatic evolution. Zircon crystals first formed in a given environment and subsequently immersed in a new medium of different chemical composition, temperature and fluid content show a spectacular readjustment of their typology. All the data obtained from the magmatic rocks are directly usable on ortho-derived metamorphic rocks with preserved zircon populations. For migmatites affected by partial melting, inherited zircon nuclei provide evidence (morphology, geochemistry notably Hf, Y) to constrain the nature of the protolith. Synthetic tables are proposed to help in the search for the origin of zircons found in sedimentary or volcano-sedimentary rocks, with a special mention for the most significant types and subtypes.

Quantitative assessment of PM2.5-related human health impacts at the provincial level in China and analysis of its heterogeneity affected by economic structural transformation

Rapid economic development has led to massive fossil energy consumption and emissions of air pollutants such as PM2.5, which have severely impacted human health and the environment. By uncovering the primary regions and pivotal sectors of PM2.5-related human health impacts (PM2.5-HHI) and evaluating the influence of economic structural factors on them, we can facilitate a more targeted strategy for managing PM2.5 pollution sources. This study employs a structural decomposition analysis method based on input–output analysis to evaluate the impact of China’s provincial economic structural transformation and changes in final demand on PM2.5-HHI in the years 2012, 2015, and 2017. Results indicated that PM2.5-HHI is primarily concentrated in economically developed provinces (e.g., Shandong and Guangdong), which is compared to Shanghai, Heilongjiang, Liaoning, and Hebei experienced negative growth in PM2.5-HHI during 2007–2017. The production-based PM2.5-HHI is primarily driven by energy-intensive sectors such as the production and distribution of electric power and heat power. By contrast, the building sector is key to driving consumption-based PM2.5-HHI. An increasing number of regions are reducing PM2.5-HHI by implementing production structure changes. Moreover, the driving effect of production structure changes on PM2.5-HHI growth is strengthening in Beijing and Tianjin. Changes in the final demand structure mainly led to the growth of PM2.5-HHI in areas with higher economic development levels, such as Beijing and Shandong, but this driving effect is weakening. The final demand–driven PM2.5-HHI shows an evolutionary trend of an increasing share driven by fixed capital formation and exports and a decreasing share driven by household consumption. Changes in emission intensity play a key role in decreasing PM2.5-HHI in each region. Alternatively, changes in the structure of emission sources have a relatively minor impact on PM2.5-HHI. To mitigate PM2.5-HHI, regional economic and resource endowment advantages should be used to promote regional coordinated development and strengthen green production-process innovation in energy-intensive industries. Meanwhcile, it is necessary to optimize urban construction planning and improve the energy efficiency of buildings.

Common Hippopotamus, Hippopotamus Amphibian (Linnaeus, 1758) in the Kouoptamo Subdivision-Cameroon

The Kouoptamo subdivision is one of the localities of the Noun Division that adjoins the Noun River. It served as a study area because of the presence of hippopotamus. This study carried out from January to July 2017, aimed to contribute to the sustainable management of wildlife by improving the observation of hippopotamuses (Hippopotamus amphibius) along the Noun River in the Kouoptamo subdivision. The data were obtained by administering a semi-structured survey form to fishermen, farmers, and local authorities. The results show that the average number of hippopotamuses observed along the River Noun in Kouoptamo is 10. On average, Mefuh records a very abundant potential with 13 individuals. This is followed by Buea and Mangouhnoun (7), Upstream of the dam (5), Makoumahou (4), and Downstream of the dam (3). According to habitat types, megaherbivores are highest in herbaceous savannah (6), followed by forest gallery (5), and finally shrub savannah (3). The months of observation are January and April with the greatest potential (20) and (15), followed by February and June (9) respectively, then March, May, and July (7) respectively. These pachyderms are most frequently observed in the afternoon between 2 p.m. and 6 p.m. (7), followed by the morning between 5 a.m. and 10 a.m. (6), then at midday between 11 a.m. and 1 p.m. (5) and finally at night between 7 p.m. and 4 a.m. (4). Very few studies have been carried out on hippopotamuses in Cameroon, so aspects of their biology and ecology remain unknown; precise estimates of population size and evolutionary trends are still incomplete. However, according to the CBD, knowledge of these resources is essential for better management.