Hasil untuk "Evolution"

Elena Rovenskaya, Alexey Ivanov, Sarah Hathiari et al.

Abstract Economic and social interactions are shifting to digital platforms which grow into vast ecosystems where user engagement creates value for members while ecosystem orchestrators harvest massive revenue. The digital ecosystem business model succeeds by adeptly navigating fast-changing environments, including new technologies and volatile demands, through dynamic innovation in a decentralized decision-making setting. This renders digital platform ecosystems complex adaptive systems. Recognizing that natural ecosystems are a prime example of complex adaptive systems, we propose a systematic hierarchical framework for describing and understanding digital ecosystems, rooted in ecology and evolution. Our framework compares digital ecosystems hosted by societies to natural ecosystems embedded in biomes, products to species, and technologies and elements of business strategy to the genetic makeup of a species. As digital platforms face heightened scrutiny about their socio-economic power and societal value, our approach contributes to the development of deeper understanding and sustainable governance of the digital economy.

Yannan Zhou, Jingyun Jiang, Yushun Wang et al.

Abstract The ternary Cu/ZnO/Al2O3 catalyst is widely used in the industry for renewable methanol synthesis. The tenuous trade‐off between the strong metal–support interaction (SMSI)‐induced Cu–ZnOx interface and the accessible Cu surface strongly affects the activity of the final catalyst. Successes in the control of oxide migration on adsorbate‐induced SMSI catalysts have motivated this to develop a supercritical CO2 activation strategy to synchronously perfect the Cu0–O–Znδ+ interface and Cu0–Cu+ surface sites through the manipulation of the adsorbate diffusion kinetics, which involves *OC2H5 and “side‐on” fixed CO2 species. This findings illustrate that the adsorbate on ZnOx can facilitate its secondary uniform nucleation and induce a ZnxAl2Oy spinel phase and that CO2 adsorption on metallic Cu0 produces an activated CuxO amorphous shell. Such a structural evolution unlocks a dual‐response pathway in methanol synthesis, thus enabling Cu/ZnO/Al2O3 with a twofold increase in catalytic activity. This atomic‐level design of active sites and understanding of supercritical CO2‐induced structural evolution will guide the future development of high‐performance supported metal catalysts.

Guangli Wang, Weijun Li, Jiazhan Wu et al.

<i>Bactrocera dorsalis</i> (Hendel) is an invasive fruit and vegetable pest, infesting citrus, mango, carambola, etc. We observed that the posterior thoracic scutella of some <i>B. dorsalis</i> adults are yellow, some light yellow, and some white in China. Compared with the <i>B. dorsalis</i> races with a yellow scutellum (YS) and white scutellum (WS), the race with a light-yellow scutellum (LYS) is dominant in citrus and carambola orchards. To reveal genetic correlates among the three races, the genomes of 22 samples (8 with YS, 7 with LYS, and 7 with WS) were sequenced by high-throughput sequencing technology. Single-nucleotide polymorphism (SNP) annotation showed that there were 17,580 non-synonymous mutation sites located in the exonic region. Principal component analysis based on independent SNP data revealed that the SNPs with LYS were more similar to that with YS when compared with WS. Most genes associated with scutellum color variation were involved in three pathways: oxidative phosphorylation, porphyrin and chlorophyll metabolism, and terpenoid backbone biosynthesis. By comparing the sequences among the three races, we screened out 276 differential genes (DGs) in YS vs. WS, 185 DGs in LYS vs. WS, and 104 DGs in YS vs. LYS. Most genes determining color variation in <i>B. dorsalis</i> scutella were located on chromosomes 2–5. Biochemical analysis showed that β-carotene content in YS and LYS was significantly higher than that in WS at any stage of adult days 1, 10, and 20. No significant differences were observed in cytochrome P450 or melanin content in YS, LYS, or WS. Our study provides results on aspects of scutellum color variation in <i>B. dorsalis</i> adults, providing molecular and physiological information for revealing the adaptation and evolution of the <i>B. dorsalis</i> population.

Cameron Beetar, Nitin Gupta, S. Shajidul Haque et al.

Abstract Krylov complexity is a measure of operator growth in quantum systems, based on the number of orthogonal basis vectors needed to approximate the time evolution of an operator. In this paper, we study the Krylov complexity of a PT-symmetric system of oscillators, which exhibits two phase transitions that separate a dissipative state, a Rabi-oscillation state, and an ultra-strongly coupled regime. We use a generalization of the su(1) algebra associated to the Bateman oscillator to describe the Hamiltonian of the coupled system, and construct a set of coherent states associated with this algebra. We compute the Krylov (spread) complexity using these coherent states, and find that it can distinguish between the PT-symmetric and PT symmetry-broken phases. We also show that the Krylov complexity reveals the ill-defined nature of the vacuum of the Bateman oscillator, which is a special case of our system. Our results demonstrate the utility of Krylov complexity as a tool to probe the properties and transitions of PT-symmetric systems.

Sofiene Ben Kaab, Juan Antonio Fernández Pierna, Berenice Foncoux et al.

The use of chemical herbicides induces negative impacts on the environment, animals, and human health. It also leads to the development of herbicide-resistant weeds. In this context, natural and efficacious herbicides are highly sought after. Essential oils are natural compounds with antibacterial, fungicidal, and phytotoxic properties. For this reason, we studied the post-emergence phytotoxic effect of cinnamon essential oil (cinnamon EO) from <i>Cinnamomum cassia</i> under greenhouse conditions, testing it against <i>Trifolium incarnatum</i> (<i>T. incarnatum</i>) and <i>Lolium perenne</i> (<i>L. perenne</i>). The content of malondialdehyde (MDA), percentage of water loss, electrolyte leakage, and the fluorescence of treated leaves by cinnamon EO were determined in order to understand the physiological and biochemical responses. In addition, transmission electron microscopy (TEM) was used to study the effect of cinnamon EO on cellular organelles in different tissues of <i>T. incarnatum</i> leaves. Results showed that cinnamon EO quickly induced oxidative stress in treated leaves by increasing MDA content, impacting membrane integrity and causing water loss. TEM observations confirmed the cell desiccation by cellular plasmolysis and showed an alteration of the membrane integrity and chloroplast damages. Moreover, Raman analysis confirms the disturbance of the plant metabolism by the disappearance of some scattering bands which correspond to primary metabolites. Through our finding, we confirm that cinnamon essential oil (EO) could be proposed in the future as a potential bioherbicide and a suitable source of natural phytotoxic compounds with a multisite action on weeds.

Michael Daniels, Adam Smith, Conceicao Bettencourt et al.

Background Effective development and retention of talented early-career researchers (ECRs) is essential to the continued success of biomedical science research fields. To this end, formal mentorship programmes (where researchers are paired with one or more mentors beyond their direct manager) have proven to be successful in providing support and expanding career development opportunities. However, many programmes are limited to pools of mentors and mentees within one institute or geographical area, highlighting that cross-regional connections may be a missed opportunity in many mentorship schemes. Methods Here, we aimed to address this limitation through our pilot cross-regional mentorship scheme, creating reciprocal mentor-mentee pairings between two pre-established networks of Alzheimer’s Research UK (ARUK) Network-associated researchers. We carefully created 21 mentor-mentee pairings between the Scotland and University College London (UCL) networks in 2021, with surveys conducted to assess mentor/mentee satisfaction with the programme. Results Participants reported very high satisfaction with the nature of the pairings and the mentors’ contribution to the career development of mentees; a majority also reported that the mentorship scheme increased their connections outside of their home network. Our assessment of this pilot programme is that it supports the utility of cross-regional mentorship schemes for ECR development. At the same time, we highlight the limitations of our programme and recommend areas for improvement in future programmes, including greater consideration of support for minoritized groups and the need for additional training for mentors. Conclusions In conclusion, our pilot scheme generated successful and novel mentor-mentee pairings across pre-existing networks; both of which reported high satisfaction with pairings, ECR career and personal development, and the formation of new cross-network connections. This pilot may serve as a model for other networks of biomedical researchers, where existing networks within medical research charities can act as a scaffold to build new cross-regional career development opportunities for researchers.

Bin Bai, Yuan-Qing Wang, Yuan-Qing Wang et al.

Artiodactyls diversified during the Eocene and Oligocene in North America and Europe after their first Holarctic appearance at the beginning of the Eocene. However, the relationships among early artiodactyls, European endemic forms, and later derived suiforms, tylopods, and ruminants remain unclear. Early artiodactyls are relatively rare in Asia compared to those known from North America and Europe; thus, investigation of Eocene artiodactyls from Asia is important to resolve these issues. Here we report two new genera and three new species of small early artiodactyls from middle Eocene deposits of the Erlian Basin, Inner Mongolia, China. The new materials represent a morphologically gradational series from Asian Land Mammal Ages Irdinmanhan to Sharamurunian, characterized by a trend towards bilophodonty in the lower molars. Morphologic and phylogenetic analyses suggest that these new taxa have a close relationship with the enigmatic European Tapirulus, which currently consists of five species that range from the middle Eocene to the early Oligocene. The close relationship between the Erlian specimens and Tapirulus suggests possible faunal exchanges between Europe and Asia during the middle Eocene, a view that has been supported by other mammalian groups across the two continents. The evolution of bilophodonty in Tapirulidae and Raoellidae is probably attributable to convergence.

David Merino-Millan, Claudio J. Múnez, Miguel Ángel Garrido-Maneiro et al.

The current developments in concentrating solar power are focused in the third generation. Increase the working temperature of the plants is the main objective for this new generation. For this new condition, alternative materials for the receivers must be explored. In this work, a nickel alloy coating has been fabricated using a compact plasma spray system to be used on the receiver. This thermal spray system could be used for in-situ maintenance and overhaul as it is portable. Then the coatings have been exposed at high temperature of 800 ºC, as expected in the third generation, during different exposure times. The evolution of the coating solar absorptivity and adherence have been studied over the selected exposure times. A maximum value of solar absorptivity 0.93 was reported for the longer exposure time studied. The adherence increment was remarkable reaching a value of about 57 MPa. These results show that these coatings could represent a durable alternative while the solar absorptivity maintains high values.

Jiang Yuqi, Yang Yikang, Tian Wenbo et al.

[Objective] The spatial differences and dynamic evolution of carbon ecological security level were analyzed to optimize the overall plan of carbon ecological security in the Yellow River basin (an important “energy basin” in China) in order to objectively reflect the current status and evolution trend of carbon ecological security, and to provide a reference for optimizing the carbon ecological security pattern. [Methods] An evaluation index system for carbon ecological security in the Yellow River basin was constructed under the framework of driving-pressure-state-impact-response (DPSIR) analysis. The technique for order preference by similarity to ideal solution (TOPSIS) model was used to evaluate the level of carbon ecological security, and the spatial-temporal evolution characteristics were analyzed by the kernel density estimation method. [Results] ① Carbon sinks and carbon emissions increased from 2012 to 2021 in the Yellow River basin, and the growth rate of carbon emissions was faster than that of carbon sinks. Carbon sinks were spatially characterized as “higher in the west and lower in the east”, while carbon emissions were “lower in the west and higher in the east”. ② The carbon ecological security level in the Yellow River basin increased over time, from 0.356 in 2012 to 0.639 in 2021. In terms of spatial distribution, the carbon ecological security level in the upstream region was higher than in the middle and downstream regions, and was characterized as “upstream leading, midstream catching up, and downstream surpassing”. In addition, the level of carbon ecological security tended to be good. ③ Based on the kernel density estimation results, the differences in carbon security levels among different regions in the Yellow River basin were gradually narrowing, and were decreasing in the upstream region faster than in the middle and downstream regions. [Conclusion] Based on the current status of carbon ecological security in the Yellow River basin, carbon sink capacity in the upstream region is expected to increase over time, while clean energy industries and technology-intensive industries with high added value should be developed to promote green GDP growth in the middle and downstream regions. In addition, a carbon ecological compensation mechanism should be established to coordinate and resolve cross-regional security issues, and to improve the carbon ecological security level of the entire basin.

S. Salvadori, F. Deidda, L. Carugati et al.

AbstractLobsters are ubiquitous, economically important decapod crustaceans with apparently conflicting evolutionary relationships. Here, we describe the chromosomal location of the major (45S rDNA) and minor (5S rDNA) ribosomal gene families in four species of Astacidea and five of Achelata, using two-color FISH. The major ribosomal family is located in 4–16 sites per diploid chromosome set, with Nephrops norvegicus (Nephropidae) showing the highest number described so far in Decapoda. The 5S rDNA is located in two sites in eight species; only in the crayfish Procambarus clarkii the 5S FISH signals were detected in four sites together with additional weaker signals. Furthermore, in N. norvegicus the minor ribosomal genes are syntenic with one major ribosomal cluster. Moreover, we located by two-color FISH the pentanucleotide (TTAGG)n telomeric repeat in the Nephropidae studied, showing the occurrence of a colocalization with 45S ribosomal sequences in Homarus gammarus. The comparison of chromosomal locations of repetitive sequences in Mediterranean, Atlantic, and South African lobster species as well as in marine and freshwater ones provides information on chromosomal evolution and cytotaxonomy of Decapoda.

Anders Tranberg, Gerhard Ungersbäck

Abstract Classical-statistical lattice simulations provide a useful approximation to out-of-equilibrium quantum field theory, but only for systems exhibiting large occupation numbers, and only for phenomena that are not intrinsically quantum mechanical in nature. In certain special circumstances, it can be appropriate to initialize such real-time simulations with quantum-like zero-point fluctuations. We will revisit these points, and investigate reports that quantum bubble nucleation rates in 1+1 dimensions can be computed through the classical evolution of such a quantum-like initial condition [1]. We find that although intriguing, the reported numerical agreement between classical-statistical simulations and the quantum nucleation rate in 1+1 dimensions is a coincidence, which is not specific to this choice of initialisation, is parameter and lattice cut-off dependent and disappears as the number of space-dimensions increases from 1+1 to 2+1.

Shanshan He, Sanghu Park, Do-sik Shim et al.

Additive manufacturing enables the development of high-performance materials by in-situ alloying of multiple components. In this study, Inconel 718-based composite, reinforced with tungsten carbide (WC), was synthesized on a 316L stainless steel substrate using laser directed energy deposition (DED). The microstructural evolution, distribution density of WC particles, and strengthening mechanisms of the DED-processed metal matrix composite (MMC) with different WC particle sizes and ratios are systematically investigated. It illustrated that increasing laser power enables the microstructure transforming from equiaxed to dendritic, which is attributed to the different cooling rates and temperature gradients. In addition, the morphology of the 60% WC ratio of the particle composite shows macrocracks. The incorporation of different sized WC affects retained WC distribution density and tailors a gradient layer around the edge of the WC particle. The in-situ WC-W2C phases precipitated in the deposited layer and the evenly distributed high level of ex-situ retained WC particles induce solid solution strengthening and dispersion strengthening, respectively. As a result, the optimal size of the 90 μm WC/Inconel 718 shows the highest wear resistance. The underlying strengthening mechanisms are elucidated. Consequently, the wear mechanism of Inconel 718-based composite reveals the typical abrasive wear characteristics in the presence of WC particles.

Bryce Morsky, Dervis Can Vural

Ecology and evolution under changing environments are important in many subfields of biology with implications for medicine. Here, we explore an example: the consequences of fluctuating environments on the emergence of antibiotic resistance, which is an immense and growing problem. Typically, high doses of antibiotics are employed to eliminate the infection quickly and minimize the time under which resistance may emerge. However, this strategy may not be optimal. Since competition can reduce fitness and resistance typically has a reproductive cost, resistant mutants' fitness can depend on their environment. Here we show conditions under which environmental varying fitness can be exploited to prevent the emergence of resistance. We develop a stochastic Lotka-Volterra model of a microbial system with competing phenotypes: a wild strain susceptible to the antibiotic, and a mutant strain that is resistant. We investigate the impact of various pulsed applications of antibiotics on population suppression. Leveraging competition, we show how a strategy of environmental switching can suppress the infection while avoiding resistant mutants. We discuss limitations of the procedure depending on the microbe and pharmacodynamics and methods to ameliorate them.

Jacek Miȩkisz, Marek Bodnar

We study effects of strategy-dependent time delays on equilibria of evolving populations. It is well known that time delays may cause oscillations in dynamical systems. Here we report a novel behavior. We show that microscopic models of evolutionary games with strategy-dependent time delays lead to a new type of replicator dynamics. It describes the time evolution of fractions of the population playing given strategies and the size of the population. Unlike in all previous models, stationary states of such dynamics depend continuously on time delays. We show that in games with an interior stationary state (a globally asymptotically stable equilibrium in the standard replicator dynamics), at certain time delays, it may disappear or there may appear another interior stationary state. In the Prisoner's Dilemma game, for time delays of cooperation smaller than time delays of defection, there appears an ustable interior equilibrium and therefore for some initial conditions, the population converges to the homogeneous state with just cooperators.

Daniel B. Cooney, Fernando W. Rossine, Dylan H. Morris et al.

The evolution of complex cellular life involved two major transitions: the encapsulation of self-replicating genetic entities into cellular units and the aggregation of individual genes into a collectively replicating genome. In this paper, we formulate a minimal model of the evolution of proto-chromosomes within protocells. We model a simple protocell composed of two types of genes: a "fast gene" with an advantage for gene-level self-replication and a "slow gene" that replicates more slowly at the gene level, but which confers an advantage for protocell-level reproduction. Protocell-level replication capacity depends on cellular composition of fast and slow genes. We use a partial differential equation to describe how the composition of genes within protocells evolves over time under within-cell and between-cell competition. We find that the gene-level advantage of fast replicators casts a long shadow on the multilevel dynamics of protocell evolution: no level of between-protocell competition can produce coexistence of the fast and slow replicators when the two genes are equally needed for protocell-level reproduction. By introducing a "dimer replicator" consisting of a linked pair of the slow and fast genes, we show analytically that coexistence between the two genes can be promoted in pairwise multilevel competition between fast and dimer replicators, and provide numerical evidence for coexistence in trimorphic competition between fast, slow, and dimer replicators. Our results suggest that dimerization, or the formation of a simple chromosome-like dimer replicator, can help to overcome the shadow of lower-level selection and work in concert with deterministic multilevel selection to allow for the coexistence of two genes that are complementary at the protocell-level but compete at the level of individual gene-level replication.

Vincent Bushong, Amr S. Abdelfattah, Abdullah A. Maruf et al.

Microservice architecture has become the leading design for cloud-native systems. The highly decentralized approach to software development consists of relatively independent services, which provides benefits such as faster deployment cycles, better scalability, and good separation of concerns among services. With this new architecture, one can naturally expect a broad range of advancements and simplifications over legacy systems. However, microservice system design remains challenging, as it is still difficult for engineers to understand the system module boundaries. Thus, understanding and explaining the microservice systems might not be as easy as initially thought. This study aims to classify recently published approaches and techniques to analyze microservice systems. It also looks at the evolutionary perspective of such systems and their analysis. Furthermore, the identified approaches target various challenges and goals, which this study analyzed. Thus, it provides the reader with a roadmap to the discipline, tools, techniques, and open challenges for future work. It provides a guide towards choices when aiming for analyzing cloud-native systems. The results indicate five analytical approaches commonly used in the literature, possibly in combination, towards problems classified into seven categories.

Gengjiao Chen, Mee-mann Chang, Feixiang Wu et al.

A new ellimmichthyiform, Guiclupea superstes, gen. et sp. nov., from the Oligocene Ningming Formation of Ningming Basin, Guangxi Zhuang Autonomous Region, South China is described herein. With relatively large body size, parietals meeting at the midline, anterior ceratohyal with a beryciform foramen in the center, a complete predorsal scutes series of very high number and about equally-size scutes with radiating ridges on dorsal surface, first preural centrum unfused with first uroneural but fused with the parhypural, and first ural centrum of roughly the same size as the preural centrum, Guiclupea superstes cannot be assigned to the order Clupeiformes. The phylogenetic analyses using parsimony and Bayesian inference methods with Chanos/Elops as outgroup respectively suggests that the new form is closer to ellimmichthyiform genus Diplomystus than to any other fishes, although there are some discrepancies between the two criteria and different outgroups used. It shares with Diplomystus the high supraoccipital crest, pelvic-fin insertion in advance of dorsal fin origin, and the number of predorsal scutes more than 20. The new form represents the youngest ellimmichthyiform fish record in the world. Its discovery indicates that the members of the Ellimmichthyiformes had a wider distribution range and a longer evolutional history than previously known.

Javier Gamero, Juan A. Tamayo, Juan A. Martinez-Roman

The outbreak of novel coronavirus (2019-nCoV) in China has caused a viral epidemic affecting tens of thousands of persons. Though the danger of this epidemic is evident, the statistical analysis of data offered in this paper indicates that the increase in new cases in China will stabilize in the coming days or weeks. Our forecast could serve to evaluate risks and control the evolution of this disease.

Ting-ting LU, Rong-bin LI, Hong-liang ZHAO et al.

Spent cathode carbon block (SCCB) is considered to be a kind of hazardous waste, because it contains a large amount of soluble fluoride salts and toxic cyanides. The life of an aluminum electrolytic cell is generally 5−8 years, and the SCCB would be produced during the overhaul of the cell. Currently, most SCCBs are piled in landfills or stored for disposal in China. The unreasonable disposal of SCCBs will cause serious pollution and damage to the ecological environment, and wastage of valuable carbon material and fluoride salts. The key to the safe disposal and resource utilization of SCCBs is to separate the carbon and fluoride salts deeply. In this study, SCCB was treated by the pyrometallurgical process, and the characteristics of volatilization temperature of fluoride salts were firstly experimentally determined. For a laboratory-scale self-designed high temperature resistance furnace, a three-dimensional model was built and numerical calculation was performed. The heat transfer characteristics, temperature control law and effective volatilization region of fluoride salts were analyzed in detail. The experimental results demonstrate that the effective volatilization temperature of fluoride is higher than 1700 ℃, and the volatilization rate is higher than 93.1%. By simulating the evolution of the temperature field in the furnace under different power supply modes, it is obtained that under the power supply condition of heating at 12 V for 24 h and holding 9 V for 12 h, the maximum temperature in the furnace during the heating phase can reach 2250 ℃, and the theoretical volatilization volume of fluoride salts can reach 98%. After optimization, a step-by-step decreasing mode of power supply can improve the efficiency of treating SCCBs. Moreover, the treating temperature can be maintained for 20 h at 1700 ℃, which is beneficial to the deep separation of carbon material and fluoride salts in SCCB.

Shiwei Lan

A large number of scientific studies and engineering problems involve high-dimensional spatiotemporal data with complicated relationships. In this paper, we focus on a type of space-time interaction named \emph{temporal evolution of spatial dependence (TESD)}, which is a zero time-lag spatiotemporal covariance. For this purpose, we propose a novel Bayesian nonparametric method based on non-stationary spatiotemporal Gaussian process (STGP). The classic STGP has a covariance kernel separable in space and time, failed to characterize TESD. More recent works on non-separable STGP treat location and time together as a joint variable, which is unnecessarily inefficient. We generalize STGP (gSTGP) to introduce the time-dependence to the spatial kernel by varying its eigenvalues over time in the Mercer's representation. The resulting non-stationary non-separable covariance model bares a quasi Kronecker sum structure. Finally, a hierarchical Bayesian model for the joint covariance is proposed to allow for full flexibility in learning TESD. A simulation study and a longitudinal neuroimaging analysis on Alzheimer's patients demonstrate that the proposed methodology is (statistically) effective and (computationally) efficient in characterizing TESD. Theoretic properties of gSTGP including posterior contraction (for covariance) are also studied.