scholarly journals Man-made habitats - hotspots of evolutionary game between grass, fungus and fly

2009 ◽  
Vol 15 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Marlena Lembicz ◽  
Paweł Olejniczak ◽  
Ziemowit Olszanowski ◽  
Karolina Górzyńska ◽  
Adrian Leuchtmann

Man-made habitats - hotspots of evolutionary game between grass, fungus and flyThe origin and effects of an evolutionary game between species from three different kingdoms (plants, fungi and animals) are presented. We provide scientific evidence that the interaction discovered in man-made habitats leads to an early stage of coevolution. The grassPuccinellia distanswas observed to rapidly spread in new man-made habitats, while at the same time, it was colonised by the fungusEpichloë typhina.The invasion of infected grasses is accompanied by alterations in life histories of both species:P. distansdeveloped features promoting long-distance spreading, whereasE. typhinachanged its life cycle by forming sexual structures for the second time, later in the vegetative season. This enables the fungus to make use of the late shoots of the grass for sexual reproduction, even though it cannot be completed because the vector of spermatia necessary for fertilisation, femaleBotanophilaflies, is not present at that time. This indicates that such uncoordinated evolutionary processes had taken place before interactions between organisms became so specialised that it is difficult to presume they were the result of natural selection. Moreover, these processes could have been initiated in man-made habitats that, in particular circumstances, can become coevolutionary hotspots.

Author(s):  
Jianming Cai ◽  
Yue Liang

A marriage between dockless bike-sharing systems and rail transit presents new opportunities for sustainable transportation in Chinese cities. However, how to promote the bicycle–metro integration mode remains largely unstudied. This paper designs a public–private partnership program to promote bicycle–metro integration. We consider the cooperation between bike-sharing companies and rail transit companies to improve both services and attract long-distance travelers to choose the bicycle–metro integration mode, with government subsidies. To analyze the proportion of each population participating in this public–private partnership program, we establish an evolutionary game model considering bike-sharing companies, rail transit companies, and long-distance travelers, and obtain eight scenarios of equilibriums and corresponding stable conditions. To prove the evolutionary game analysis, we construct a system dynamics simulation model and confirm that the public–private partnership project can be achieved in reality. We discuss key parameters that affect the final stable state through sensitivity analysis. The results demonstrate that by reasonably adjusting the values of parameters, each equilibrium can be changed into an optimal evolutionary stable strategy. This study can provide useful policy implications and operational recommendations for government agencies, bike-sharing companies, and transit authorities to promote bicycle–metro integration.


Biomedicines ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 884
Author(s):  
Hideyuki Maeda ◽  
Noritoshi Fukushima ◽  
Akihiro Hasumi

Zebrafish are easy to breed in a laboratory setting as they are extremely fertile and produce dozens of eggs per set. Because zebrafish eggs and the skin of the early-stage larvae are transparent, their embryos and the hearts and muscles of their larvae can be easily observed. Multiple rapid analyses of heart rate and behavior can be performed on these larvae simultaneously, enabling investigation of the influence of neuroactive substances on abnormal behavior, death, and associated pathogenetic mechanisms. Zebrafish larvae are becoming increasingly popular among researchers and are used in laboratories worldwide to study various vertebrate life phenomena; more experimental systems using zebrafish will undoubtedly be developed in the future. However, based on the available literature, we believe that the conceptualization of a protocol based on scientific evidence is necessary to achieve standardization. We exposed zebrafish larvae at 6–7 days post-fertilization to 50 repeated light–dark stimuli at either 15-min or 5-min intervals. We measured the traveled distance and habituation time through a video tracking apparatus. The traveled distance stabilized after the 16th repetition when the zebrafish were exposed to light–dark stimuli at 15-min intervals and after the 5th repetition when exposed at 5-min intervals. Additionally, at 15-min intervals, the peak of the traveled distance was reached within the first minute in a dark environment, whereas at 5-min intervals, it did not reach the peak even after 5 min. The traveled distance was more stable at 5-min intervals of light/dark stimuli than at 15-min intervals. Therefore, if one acclimatizes zebrafish larvae for 1 h and collects data from the 5th repetition of light/dark stimuli at intervals of 5 min in the light/dark test, a stable traveled distance result can be obtained. The establishment of this standardized method would be beneficial for investigating substances of unknown lethal concentration.


Botany ◽  
2010 ◽  
Vol 88 (10) ◽  
pp. 875-885 ◽  
Author(s):  
Angela Maria Schäfer ◽  
Martin Kemler ◽  
Robert Bauer ◽  
Dominik Begerow

The plant-parasitic genus Microbotryum (Pucciniomycotina) has been used as a model for various biological studies, but fundamental aspects of its life history have not been documented in detail. The smut fungus is characterized by a dimorphic life cycle with a haploid saprophytic yeast-like stage and a dikaryotic plant-parasitic stage, which bears the teliospores as dispersal agents. In this study, seedlings and flowers of Silene latifolia Poir. (Caryophyllaceae) were inoculated with teliospores or sporidial cells of Microbotryum lychnidis-dioicae (DC. ex Liro) G. Deml & Oberw. and the germination of teliospores, the infection process, and the proliferation in the host tissue were documented in vivo using light and electron microscopy. Although germination of the teliospore is crucial for the establishment of Microbotryum, basidium development is variable under natural conditions. In flowers, where the amount of nutrients is thought to be high, the fungus propagates as sporidia, and mating of compatible cells takes place only when flowers are withering and nutrients are decreasing. On cotyledons (i.e., nutrient-depleted conditions), conjugation occurs shortly after teliospore germination, often via intrapromycelial mating. After formation of an infectious hypha with an appressorium, the invasion of the host occurs by direct penetration of the epidermis. While the growth in the plant is typically intercellular, long distance proliferation seems mediated through xylem tracheary elements. At the beginning of the vegetation period, fungal cells were found between meristematic shoot host cells, indicating a dormant phase inside the plant. By using different microscopy techniques, many life stages of Microbotryum are illustrated for the first time, thereby allowing new interpretations of laboratory data.


2018 ◽  
Vol 200 ◽  
pp. 100-109 ◽  
Author(s):  
Ranbin Liu ◽  
Yaqian Zhao ◽  
Yan Yang ◽  
Olumide Wesley Awe

2016 ◽  
Vol 15 (3) ◽  
pp. 31-48
Author(s):  
Yasheng Chen ◽  
Johnny Jermias

ABSTRACT Based on the four major challenges firms face in the early stage of their life cycle, we identify and use financial and non-financial performance measures to predict the survivability of new international ventures. We use a sample of 3,729 new manufacturing ventures from the Chinese Foreign Invested Enterprises Database. The study sample consists of wholly owned ventures of multi-national corporations (MNCs) and joint ventures between pairs comprising foreign and local investors in China. The results are consistent with the study's hypotheses. Using the Cox (1972) survival model, we find that employee training, employee productivity, accounts receivable collection period, export intensity, and sales growth are positively related to new venture survival. This study contributes to the existing business venturing and accounting literature in three ways. First, it fills the gap in the existing literature on bankruptcy prediction by focusing on firms in the early stage of their life cycle. Second, it uses survivability as a measure of business success. Survivability is a more comprehensive measure of firm performance than traditional financial measures during the start-up stage because during this stage firms tend to carry large losses that make financial measures inappropriate. Finally, this study has the potential to help new venture managers improve a firm's chances of success by using customized performance measures that fit its unique situation. JEL Classifications: D21; G32; M41.


Gamification ◽  
2015 ◽  
pp. 1212-1222
Author(s):  
Sajjad Mahmood ◽  
Moataz Ahmed ◽  
Mohammad Alshayeb

Software reuse enables the development of software that is of better quality and at lower cost. Software reuse environments are sought to enhance the reuse of software artifacts especially when done at early-stage of the software life cycle. A number of software reuse environments have been proposed, however, there is no framework that helps in analyzing and evaluating such environments. In this paper the authors provide an attribute-based framework to analyze, evaluate, classify and compare the reuse environments in order to aid practitioners and researchers to select the appropriate reuse environments for their use. The authors first present a survey of existing reuse environments for systematic reuse of software artifacts. Then, they use the framework to analyze those reuse environments. The evaluation of existing environments provides an understanding of current reuse approaches and identifies gaps for future research.


<em>Abstract</em>.-In the study of species life histories and the structure of diadromous populations, an emerging trend is the prevalence of life cycle diversity-that is, individuals within populations that do not conform to a single life cycle pattern. A rapid rise in publications documenting within-population variability in life cycles has resulted in the use of numerous terms and phrases. We argue that myriad terms specific to taxa, ecosystem types, and applications are in fact describing the same phenomenon-life cycle diversity. This phenomenon has been obscured by the use of multiple terms across applications, but also by the overuse of typologies (i.e., anadromy, catadromy) that fail to convey the extent of life cycle variations that underlay population, metapopulation, and species dynamics. To illustrate this, we review migration and habitat-use terms that have been used to describe life cycles and life cycle variation. Using a citation index (Cambridge Scientific Abstracts © Aquatic Sciences and Fisheries Abstracts), terms were tallied across taxonomic family, ecosystem, type of application, analytical approach, and country of study. Studies on life cycle diversity have increased threefold during the past 15 years, with a total of 336 papers identified in this review. Most of the 40 terms we identified described either sedentary or migratory lifetime behaviors. The sedentary-migratory dichotomy fits well with the phenomenon of partial migration, which has been commonly reported for birds and Salmonidae and is postulated to be the result of early life thresholds (switch-points). On the other hand, the lexicon supports alternate modes of migration, beyond the simple sedentary-migratory dichotomy. Here more elaborate causal mechanisms such as the entrainment hypothesis may have application. Diversity of life cycles in fish populations, whether due to partial migration, entrainment, or other mechanisms, is increasingly recognized as having the effect of offsetting environmental stochasticity and contributing to long-term persistence.


Author(s):  
David Edward Jones ◽  
Chris Snider ◽  
Lee Kent ◽  
Ben Hicks

ABSTRACTWhile extensive modelling - both physical and virtual - is imperative to develop right-first-time products, the parallel use of virtual and physical models gives rise to two interrelated issues: the lack of revision control for physical prototypes; and the need for designers to manually inspect, measure, and interpret modifications to either virtual or physical models, for subsequent update of the other. The Digital Twin paradigm addresses similar problems later in the product life-cycle, and while these digital twins, or the “twinning” process, have shown significant value, there is little work to date on their implementation in the earlier design stages. With large prospective benefits in increased product understanding, performance, and reduced design cycle time and cost, this paper explores the concept of using the Digital Twin in early design, including an introduction to digital twinning, examination of opportunities for and challenges of their implementation, a presentation of the structure of Early Stage Twins, and evaluation via two implementation cases.


2019 ◽  
Vol 887 ◽  
pp. 353-360 ◽  
Author(s):  
Sören Eikemeier ◽  
Ardeshir Mahdavi ◽  
Robert Wimmer

To reduce the energy and resource consumption in the building sector this study is focusing on a design optimisation of life cycle oriented buildings. In order to optimise the performance of the buildings and in consequence also to achieve improved results for the mandatory Austrian energy certificate a simulation-based rapid design approach is used for the early stage design phase of the buildings, in particular for the architectural design of the buildings.Methods like the Window to Wall Ratio, at the very beginning of the design process, a parametric simulation with EnergyPlus or a more detailed optimisation approach with GenOpt are integrated in this study applied to example buildings. The results are showing that the method can be used in a circular approach for improving the heating demand of the Austrian energy certificate for this case study by more than 25 % compared to the preliminary design


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