Evolution Of Cycles Research Articles

Depositional facies and cyclic patterns in a subtidal-dominated ramp during the Early-Middle Ordovician in the western Tarim Basin (NW China)

Due to a long-term transgression since the Early Cambrian, an extensive shallow-water carbonate platform was developed in the entire Tarim Basin (NW China). During the deposition of the Yingshan Formation (Early-Middle Ordovician), a carbonate ramp system was formed in the intrashelf basin in the Bachu-Keping area of the western basin. Four well-exposed outcrop sections were selected to investigate their depositional facies, cycles, and sequences, as well as the depositional evolution. Detailed facies analyses permit the recognition of three depositional facies associations, including peritidal, semi-restricted subtidal, and open-marine subtidal facies, and eleven types of lithofacies. These are vertically arranged into meter-scale, shallowing-upward peritidal, semi-restricted subtidal, and open-marine subtidal cycles, in the span of Milankovitch frequency bands, suggesting a dominant control of Earth’s orbital forcing on the cyclic sedimentation on the platform. On the basis of vertical facies (or lithofacies) and cycle stacking patterns, as well as accommodation changes illustrated graphically by Fischer plots at all studied sections, six third-order depositional sequences are recognized and consist of lower transgressive and upper regressive parts. In shallow depositional settings, the transgressive packages are dominated by thicker-than-average, shallow subtidal cycles, whereas the regressive parts are mainly represented by thinner-than-average, relatively shallow subtidal to peritidal cycles. In relatively deep environments, however, the transgressive and regressive successions display the opposite trends of cycle stacking patterns, i.e., thinner-than-average subtidal cycles of transgressive packages. Sequence boundaries are mainly characterized by laterally traceable, transitional zones without apparent subaerial exposure features. Good correlation of the long-term changes in accommodation space inferred from vertical facies and cycle stacking patterns with sea-level fluctuations elsewhere around the world suggests an overriding eustatic control on cycle origination, platform building-up and evolution during the Early-Middle Ordovician, although with localized influences of syndepositional faulting and depositional settings.

Trachylina: The Group That Remains Enigmatic Despite 150 Years of Investigations

Trachylina is a group of cnidarians, a subclass of Hydrozoa. Despite the low species diversity of this group, its representatives are characterized by diversity of life cycles. Trachylina have populated various environments, from deep ocean to fresh water ecosystems. Polyps of Trachylina are either very small or absent in the life cycle, which distinguishes this group from the majority of other Hydrozoa. Trachylina are also highly diverse and have a number of features that are unusual for cnidarians. A number of representatives of this group are characterized by a small number of cells at the embryonic and larval stages. This phenomenon is well known for the representatives of phylogenetically distant taxa—Nematoda and Chordata (Tunicata). In addition, the development of Trachylina is characterized by a number of evolutionary changes that, apparently, make it possible to accelerate the formation of the definitive stage (medusa). Paradoxically, there is no one species among the representatives of this group that is studied in more or less detail. The purpose of our review is to summarize the scanty information on the Trachylina ontogeny and to demonstrate the importance of studying the ontogeny of this group for understanding the general rules of the evolution of development and life cycles of Metazoa.

A deterministic model for forecasting long-term solar activity

A phenomenological model is presented for the quantitative description of individual solar cycles' features, such as onset, intensity, evolution, in terms of the number of M and X-class solar flares. The main elements of the model are the relative ecliptic motion of the planets Jupiter and Saturn, and its synergy with a quasi-periodic component of solar activity. Using as input the temporal distribution of flares during cycle 21, the general evolution of cycles 22–24 is reproduced in notable agreement with the observations, including the resurgence of activity in the last months of 2017, and further predictions are provided for cycle 25. This deterministic description could contribute to elucidating the responsible physical mechanisms and forecasting space weather.

Improvement of Nickel-Rich Lithium Transition-Metal Oxide By Surface Modifications

Nickel-rich lithium transition-metal oxides for Li-ion batteries have been interested under intense commercialization as high-energy cathode materials because of their high specific capacity and relatively low cost. However, it still demands the necessities of higher energy density and more improved thermal stability to compete with requirements of smart mobile applications and x-EVs (extended electric vehicles). Accordingly, further research to increase both Ni content over 60 mol% and the cut off voltage to more than 4.5 V are being carried out to increase the energy density of Li-ion cells. However, two critical problems (structural instability both at >60 °C cycling and fast exothermic oxygen evolution at >200 °C) affecting such Ni contents should be solved. Here, we present electrochemical performance of a nickel-rich lithium transition-metal oxide (Ni content from 60 mol% to 91 mol %. Furthermore, by employing various surface chemistry on the cathode materials such as dry powder mixing, direct precipitation, colloidal deposition, Improvement of structural instability have been studied. The degradation of LiMO2 (M = Co, Ni, and Mn) cathode materials was strongly related to their surface chemistry. Among the proposed degradation mechanisms, the irreversible formation of inactive di- or tri-valant Ni species, particularly those localized in surface regions, are the products of such reactions. In other words, when the cathode materials are charged above 4.3 V, the cathodes could be partially transformed into an electrochemically inactive NiO-like phase or spinel structure with volumetric changes due to the migration of the Ni cations from the original transition metal (TM) layers. Our surface treatment cathode materials suppressed formation of NiO-like phase or spinel structure over 5% compared with bare cathode materials. The experimental results suggest one of way for applications that require high energy, long maintain life and excellent safety.

Regime shift and redevelopment of a mining area’s socio-ecological system under resilience thinking: a case study in Shanxi Province, China

Theory related to resilience thinking proposes that complex systems evolve in nested adaptive cycles. However, concrete examples are needed to instantiate this proposition and show what merit it might have in practice. This empirical study used a mesoscale landscape that has experienced mining activity and has faced challenges related to environmental protection and sustainable development. Adopting the perspective of resilience thinking, this study investigated the historical dynamics of a post-mining area in Shanxi Province and considered its future development. In the studied area, the main income source was found to have shifted from agriculture to coal mining activity between 1983 and 2010, with more than 41% of the land being used for mining operations. Such activity degraded the net primary productivity of the local ecosystem. The socio-ecological system experienced two states: traditional agriculture and mining. The evolution of the past adaptive cycles was mainly driven by coal exploitation and environmental degradation within the mining area, as well as the cross-scale interactions of economic events and coal policy changes outside the mining area. As a result of exhausted coal resources and small-scale mining closures, the socio-ecological system is currently in a poverty trap. Based on an assessment of the socio-ecological system’s strengths, weaknesses, opportunities, and threats, a new eco-agriculture can be considered an option for future transformation. The post-mining landscape is apparently a coupled socio-ecological system characterized by panarchy and temporal dynamics. Internal resources and cross-scale interactions, such as the regional-scale demand for agricultural products, could help reorganize the stagnant system. This case study shows that a mesoscale landscape can be a sally port for the application and operation of resilience-thinking-related theory, such as panarchy. This concrete example manifests the proposition that complex systems undergo cycles of renewal and collapse and can be nested in adaptive cycles. The merit of this proposition is not just that it helps to establish a theoretical understanding of the dynamics of complex systems; more importantly, it also generates practical measures to manage such dynamics. This case study supports the existence and importance of regional resilience in maintaining or restoring local economies. On these grounds, we propose that resilience thinking can act as a mental model and practical tool for understanding the historical dynamics of stagnant systems, such as legacy mining sites, and navigate their transitions.

Processes and patterns of interaction as units of selection: An introduction to ITSNTS thinking

Many practicing biologists accept that nothing in their discipline makes sense except in the light of evolution, and that natural selection is evolution’s principal sense-maker. But what natural selection actually is (a force or a statistical outcome, for example) and the levels of the biological hierarchy (genes, organisms, species, or even ecosystems) at which it operates directly are still actively disputed among philosophers and theoretical biologists. Most formulations of evolution by natural selection emphasize the differential reproduction of entities at one or the other of these levels. Some also recognize differential persistence, but in either case the focus is on lineages of material things: even species can be thought of as spatiotemporally restricted, if dispersed, physical beings. Few consider—as “units of selection” in their own right—the processes implemented by genes, cells, species, or communities. “It’s the song not the singer” (ITSNTS) theory does that, also claiming that evolution by natural selection of processes is more easily understood and explained as differential persistence than as differential reproduction. ITSNTS was formulated as a response to the observation that the collective functions of microbial communities (the songs) are more stably conserved and ecologically relevant than are the taxa that implement them (the singers). It aims to serve as a useful corrective to claims that “holobionts” (microbes and their animal or plant hosts) are aggregate “units of selection,” claims that often conflate meanings of that latter term. But ITSNS also seems broadly applicable, for example, to the evolution of global biogeochemical cycles and the definition of ecosystem function.

Nitrogen fixation sustained productivity in the wake of the Palaeoproterozoic Great Oxygenation Event

The marine nitrogen cycle is dominated by redox-controlled biogeochemical processes and, therefore, is likely to have been revolutionised in response to Earth-surface oxygenation. The details, timing, and trajectory of nitrogen cycle evolution, however, remain elusive. Here we couple nitrogen and carbon isotope records from multiple drillcores through the Rooihoogte–Timeball Hill Formations from across the Carletonville area of the Kaapvaal Craton where the Great Oxygenation Event (GOE) and its aftermath are recorded. Our data reveal that aerobic nitrogen cycling, featuring metabolisms involving nitrogen oxyanions, was well established prior to the GOE and that ammonium may have dominated the dissolved nitrogen inventory. Pronounced signals of diazotrophy imply a stepwise evolution, with a temporary intermediate stage where both ammonium and nitrate may have been scarce. We suggest that the emergence of the modern nitrogen cycle, with metabolic processes that approximate their contemporary balance, was retarded by low environmental oxygen availability.

Loss of metagenesis and evolution of a parasitic life style in a group of open-ocean jellyfish

Loss or stark reduction of the free-swimming medusa or jellyfish stage is common in the cnidarian class Hydrozoa. In the hydrozoan clade Trachylina, however, many species do not possess a sessile polyp or hydroid stage. Trachylines inhabiting freshwater and coastal ecosystems (i.e., Limnomedusae) possess a metagenetic life cycle involving benthic, sessile polyp and free-swimming medusa. In contrast, the paradigm is that open ocean inhabiting, oceanic trachylines (in the orders Narcomedusae and Trachymedusae) develop from zygote to medusa via a free-swimming larva, forgoing the polyp stage. In some open-ocean trachylines, development includes a sessile stage that is an ecto- or endoparasite of other oceanic organisms. We expand the molecular-based phylogenetic hypothesis of trachylines significantly, increasing taxon and molecular marker sampling. Using this comprehensive phylogenetic hypothesis in conjunction with character state reconstructions we enhance understanding of the evolution of life cycles in trachyline hydrozoans. We find that the polyp stage was lost at least twice independently, concurrent with a transition to an oceanic life style. Further, a sessile, polypoid parasitic stage arose once, rather than twice as current classification would imply, in the open ocean inhabiting Narcomedusae. Our results also support the hypothesis that interstitial species of the order Actinulida are directly descended from direct developing, oceanic trachylines.

Joint evolution of dispersal propensity and site selection in structured metapopulation models

We propose a novel mathematical model for a metapopulation in which dispersal occurs on two levels: juvenile dispersal from the natal site is mandatory but it may take place either locally within the natal patch or globally between patches. Within each patch, individuals live in sites. Each site can be inhabited by at most one individual at a time and it may be of high or low quality. A disperser immigrates into a high-quality site whenever it obtains one, but it immigrates into a low-quality site only with a certain probability that depends on the time within the dispersal season. The vector of these low-quality-site-acceptance probabilities is the site-selection strategy of an individual. We derive a proxy for the invasion fitness in this model and study the joint evolution of long-distance-dispersal propensity and site-selection strategy. We focus on the way different ecological changes affect the evolutionary dynamics and study the interplay between global patch-to-patch dispersal and local site-selection. We show that ecological changes affect site-selection mainly via the severeness of competition for sites, which often leads to effects that may appear counterintuitive. Moreover, the metapopulation structure may result in extremely complex site-selection strategies and even in evolutionary cycles. The propensity for long-distance dispersal is mainly determined by the metapopulation-level ecological factors. It is, however, also strongly affected by the winter-survival of the site-holders within patches, which results in surprising non-monotonous effects in the evolution of site-selection due to interplay with long-distance dispersal. Altogether, our results give new additional support to the recent general conclusion that evolution of site-selection is often dominated by the indirect factors that take place via density-dependence, which means that evolutionary responses can rarely be predicted by intuition.

Determining performance criteria of railway market: a case study

This paper classifies a case study on railway clusters allowing analysis of competitiveness performance criteria including the innovation capability of industries via different models. Data are collected from the Turkish railway industrial cluster; where 130 companies are located. Porters’ industries Life Cycle Evolution, Diamond, Five Forces Models and SWOT Analysis are applied to explore which criteria influence at most on the cluster companies’ competitiveness performances and innovation capability based on operational conditions. Porter’s Life Cycle analysis showed that the cluster is between introduction and growth phase. This phase has typical characteristics such as high investment demand on R&D, lack of qualified staff which could be compared to the performance criteria evaluated from the other three models. Another aim was to research the consistency and difference between the applied different dimension scaled models. Delivery time of the suppliers, qualified staff, capital range of the companies and physical enlargement area of the production plants were found to be the most important criteria in operational view of the competitiveness. Another result is that the applied tools are producing similar and consistent results independently from their dimension scales.

Prediction of future evolution of solar cycle 24 using machine learning techniques

AbstractForecasting the solar activity is of great importance not only for its effect on the climate of the Earth but also on the telecommunications, power lines, space missions and satellite safety. In the present work, machine learning using Artificial Neural Networks (ANNs) called Nonlinear Autoregressive Network (NAR) with Exogenous Inputs (NARX) have been applied for the prediction of future evolution of the present sunspot cycle. NARX network is able to combine the performance of ANN algorithm with nonlinear autoregressive method to handle problems such as finding dependencies among solar indices and prediction of solar cycle evolution.

Properties of Coronal Holes in Solar Cycle 21-23 using McIntosh archive

AbstractWe study the properties of coronal holes during solar cycle 21-23 from the McIntosh archive. In the spatial distribution of coronal hole area we find that there is a sharp increase in coronal hole area at high latitude in agreement with expected open flux configuration there. In overall spatiotemporal distribution of coronal hole centroids, we find the dominance of high latitude coronal holes except for the maximum of the solar cycle, when coronal holes mostly appear in low latitudes. This is in agreement with the expected solar cycle evolution of surface magnetic flux.

Rapid phenotypic evolution following shifts in life cycle complexity.

Life cycle strategies have evolved extensively throughout the history of metazoans. The expression of disparate life stages within a single ontogeny can present conflicts to trait evolution, and therefore may have played a major role in shaping metazoan forms. However, few studies have examined the consequences of adding or subtracting life stages on patterns of trait evolution. By analysing trait evolution in a clade of closely related salamander lineages we show that shifts in the number of life cycle stages are associated with rapid phenotypic evolution. Specifically, salamanders with an aquatic-only (paedomorphic) life cycle have frequently added vertebrae to their trunk skeleton compared with closely related lineages with a complex aquatic-to-terrestrial (biphasic) life cycle. The rate of vertebral column evolution is also substantially lower in biphasic lineages, which may reflect the functional compromise of a complex cycle. This study demonstrates that the consequences of life cycle evolution can be detected at very fine scales of divergence. Rapid evolutionary responses can result from shifts in selective regimes following changes in life cycle complexity.

Toward a new (evolutionary) economics of sports

PurposeThe purpose of this paper is to propose a new classification of rules-driven sports and technology-driven sports that suggests different models of how sports develop. This paper outlines some key aspects of an evolutionary view of sports economics research and, separately, an institutional view of sports economic research.Design/methodology/approachThis paper is a conceptual/theoretical piece rather than an empirical analysis of a research question. The authors scaffold a proposed analytic framework that is a combination of evolutionary economics and new institutional economics.FindingsA new dynamic approach to the study of sports industries is called for. The authors observe that sports and sports industries exhibit dynamic qualities but in the study of sports there is no analogue of “industrial dynamics” as in economics. What is missing is the field of “evolutionary sports dynamics.” To build this, the authors frame a new evolutionary approach to the study of the sports economy and sports industries – by examining the evolution of sports, their industries, and the complex industrial ecosystems they operate in, through the lens of institutional and evolutionary economics.Originality/valueThe paper establishes a theoretical basis for a “New Economics of Sports” – as a shift in the types of questions that sports economics seeks to answer. These are away from “sports statics” – as a branch of applied economics of industrial organization and optimal allocation of sports resources (ala Rottenberg, 1956; Neale, 1964) – and toward concern with the economics of “sports dynamics.” The prime questions are less with the optimal organization of existing sports, and more toward understanding the origin of new sports and the evolutionary life cycles of sports.

Watch Out for the "Living Dead": Cell-Free Enzymes and Their Fate.

Microbes are the engines driving biogeochemical cycles. Microbial extracellular enzymatic activities (EEAs) are the “gatekeepers” of the carbon cycle. The total EEA is the sum of cell-bound (i.e., cell-attached), and dissolved (i.e., cell-free) enzyme activities. Cell-free enzymes make up a substantial proportion (up to 100%) of the total marine EEA. Although we are learning more about how microbial diversity and function (including total EEA) will be affected by environmental changes, little is known about what factors control the importance of the abundant cell-free enzymes. Since cell-attached EEAs are linked to the cell, their fate will likely be linked to the factors controlling the cell’s fate. In contrast, cell-free enzymes belong to a kind of “living dead” realm because they are not attached to a living cell but still are able to perform their function away from the cell; and as such, the factors controlling their activity and fate might differ from those affecting cell-attached enzymes. This article aims to place cell-free EEA into the wider context of hydrolysis of organic matter, deal with recent studies assessing what controls the production, activity and lifetime of cell-free EEA, and what their fate might be in response to environmental stressors. This perspective article advocates the need to go “beyond the living things,” studying the response of cells/organisms to different stressors, but also to study cell-free enzymes, in order to fully constrain the future and evolution of marine biogeochemical cycles.

Quantifying Postfire Aeolian Sediment Transport Using Rare Earth Element Tracers

AbstractGrasslands, which provide fundamental ecosystem services in many arid and semiarid regions of the world, are undergoing rapid increases in fire activity and are highly susceptible to postfire‐accelerated soil erosion by wind. A quantitative assessment of physical processes that integrates fire‐wind erosion feedbacks is therefore needed relative to vegetation change, soil biogeochemical cycling, air quality, and landscape evolution. We investigated the applicability of a novel tracer technique—the use of multiple rare earth elements (REE)—to quantify soil transport by wind and to identify sources and sinks of wind‐blown sediments in both burned and unburned shrub‐grass transition zone in the Chihuahuan Desert, NM, USA. Results indicate that the horizontal mass flux of wind‐borne sediment increased approximately threefold following the fire. The REE tracer analysis of wind‐borne sediments shows that the source of the horizontal mass flux in the unburned site was derived from bare microsites (88.5%), while in the burned site it was primarily sourced from shrub (42.3%) and bare (39.1%) microsites. Vegetated microsites which were predominantly sinks of aeolian sediments in the unburned areas became sediment sources following the fire. The burned areas showed a spatial homogenization of sediment tracers, highlighting a potential negative feedback on landscape heterogeneity induced by shrub encroachment into grasslands. Though fires are known to increase aeolian sediment transport, accompanying changes in the sources and sinks of wind‐borne sediments may influence biogeochemical cycling and land degradation dynamics. Furthermore, our experiment demonstrated that REEs can be used as reliable tracers for field‐scale aeolian studies.

Discussion on Core Technique and General Software Platform of River Water Resources Regulation in China

Due to the aggravation of human activities and global climate changes in recent decades, catchment water cycle has experienced strong variation. The world is faced with profound water crisis, and water problems are especially severe and water disasters are of high frequency in China. Water problems have become significant obstacle factors for realizing sustainable development, which greatly threatens national economy and ecological safety. Given the scientific background of catchment water cycle evolution and water resources comprehensive regulation, we propose the method of solving water problems through water resources operation based on dualistic water cycle theory and discuss the developing status and existing problems of current water resources operation in China. On this basis, we also put forward the technical framework and key process of water resources regulation, which integrates the six links of monitoring, simulation, evaluation, forecasting, regulation and control. Furthermore, aiming at the background of the second phase of National Water Monitoring Capacity Building Project, we introduce a nationwide general software platform for water resources regulation. This platform will realize business collaboration and information sharing among three-scale platform of Ministry of Water Resources, basin authorities and provincial level, so as to overall improve the ability of water resources regulation and decision-making.

Latitude Distribution of Sunspots: Analysis Using Sunspot Data and a Dynamo Model

Abstract In this paper, we explore the evolution of sunspot latitude distribution and explore its relations with the cycle strength. With the progress of the solar cycle, the distributions in two hemispheres from mid-latitudes propagate toward the equator and then (before the usual solar minimum) these two distributions touch each other. By visualizing the evolution of the distributions in two hemispheres, we separate the solar cycles by excluding this hemispheric overlap. From these isolated solar cycles in two hemispheres, we generate latitude distributions for each cycle, starting from cycle 8 to cycle 23. We find that the parameters of these distributions, namely the central latitude (C), width (δ), and height (H), evolve with the cycle number, and they show some hemispheric asymmetries. Although the asymmetries in these parameters persist for a few successive cycles, they get corrected within a few cycles, and the new asymmetries appear again. In agreement with the previous study, we find that distribution parameters are correlated with the strengths of the cycles, although these correlations are significantly different in two hemispheres. The general trend features, i.e., (i) stronger cycles that begin sunspot eruptions at relatively higher latitudes, and (ii) stronger cycles that have wider bands of sunspot emergence latitudes, are confirmed when combining the data from two hemispheres. We explore these features using a flux transport dynamo model with stochastic fluctuations. We find that these features are correctly reproduced in this model. The solar cycle evolution of the distribution center is also in good agreement with observations. Possible explanations of the observed features based on this dynamo model are presented.

Climate, topography, and dust influences on the mineral and geochemical evolution of granitic soils in southern Arizona

Mineral weathering transforms rock into soils that supply nutrients to ecosystems, store terrestrial carbon, and provide habitat for organisms. As a result, the mineralogy and geochemistry of soils from contrasting environments are well-studied. The primary objective of this research was to examine how climate, topography, and dust interactively control the mineral and geochemical composition of granitic soils that span an environmental gradient in southern Arizona. Two field sites were selected within the Catalina Critical Zone Observatory that exhibit significant range in precipitation (25 to 85cmyr−1), temperature (24 to 10°C), and vegetation composition (desert scrub→mixed conifer). Within each site, two catena end member pairs were selected to represent variation in local topography which included divergent, water-shedding summits and convergent, water-gathering footslopes. Soils and parent rock were studied using x-ray diffraction and x-ray fluorescence. Dust samples were collected from ridgetop dust traps at the desert scrub site and examined using x-ray fluorescence. The desert scrub soils showed enrichment in biotite, total feldspar, and Fe+Mg whereas the mixed conifer soils were depleted in feldspars and enriched in Fe+Mg. Depletions of Na, Si, and K+Ca occurred in both the desert and mixed conifer ecosystems, with the convergent soils in the conifer sites exhibiting the greatest degree of elemental loss. We examined dust in the regolith after identifying mineral and elemental enrichments in both ecosystems. Dust fraction estimates ranged from 2 to 21% in desert soils and 9 to 19% for the mixed conifer soils. Our results confirm the interactive role of bioclimate, topography, and dust in driving the geochemical evolution of soils and cycling of nutrients in desert and conifer ecosystems.

Fragmentation modes and the evolution of life cycles.

Reproduction is a defining feature of living systems. To reproduce, aggregates of biological units (e.g., multicellular organisms or colonial bacteria) must fragment into smaller parts. Fragmentation modes in nature range from binary fission in bacteria to collective-level fragmentation and the production of unicellular propagules in multicellular organisms. Despite this apparent ubiquity, the adaptive significance of fragmentation modes has received little attention. Here, we develop a model in which groups arise from the division of single cells that do not separate but stay together until the moment of group fragmentation. We allow for all possible fragmentation patterns and calculate the population growth rate of each associated life cycle. Fragmentation modes that maximise growth rate comprise a restrictive set of patterns that include production of unicellular propagules and division into two similar size groups. Life cycles marked by single-cell bottlenecks maximise population growth rate under a wide range of conditions. This surprising result offers a new evolutionary explanation for the widespread occurrence of this mode of reproduction. All in all, our model provides a framework for exploring the adaptive significance of fragmentation modes and their associated life cycles.