Chicken Or The Egg Research Articles

From RNA world to RNA-peptide world: A review

How life starts from small molecules to RNAs and further to modern life is an unanswered question. Cyanosulfitic chemistry established the synthesis of building blocks, including 12 proteinogenic amino acids, 4 ribo- and deoxyribo-nucleosides, and phospholipids, from hydrogen cyanide and hydrogen sulfite under prebiotically plausible conditions. Later on, the non-enzymatic monomer extension of nucleotides provided a plausible pathway from mononucleotides to RNAs giving rise to the RNA world. RNA is one of the key components for the origin of life, firstly, the sequence information can be heritage by template copying reaction. Secondly, RNA is able to fold into a secondary structure which has the capability to catalyze chemical reactions. The RNA world scenario has perfectly overcome the chicken-egg problem, but it still cannot explain why peptides are involved in modern life. Most recently, with the establishment of the reaction between RNA and peptides, the trajectory to the RNA-peptide world theory has opened up a new era of the origin of life research. Here I will discuss the current results relevant to the RNA world to RNA-peptide world theory.

Solution to the Chicken-Egg Dilemma of Electric Mobility for Indian Cities: A Roadmap to Clean Energy

Solution to the Chicken-Egg Dilemma of Electric Mobility for Indian Cities: A Roadmap to Clean Energy

Corporate social (ir)responsibility towards employees and financial performance: using time to solve the chicken-egg problem

Corporate social (ir)responsibility towards employees and financial performance: using time to solve the chicken-egg problem

Comparison of deep learning-based emission-only attenuation correction methods for positron emission tomography.

This study aims to compare two approaches using only emission PET data and a convolution neural network (CNN) to correct the attenuation (μ) of the annihilation photons in PET. One of the approaches uses a CNN to generate μ-maps from the non-attenuation-corrected (NAC) PET images (μ-CNNNAC). In the other method, CNN is used to improve the accuracy of μ-maps generated using maximum likelihood estimation of activity and attenuation (MLAA) reconstruction (μ-CNNMLAA). We investigated the improvement in the CNN performance by combining the two methods (μ-CNNMLAA+NAC) and the suitability of μ-CNNNAC for providing the scatter distribution required for MLAA reconstruction. Image data from 18F-FDG (n = 100) or 68Ga-DOTATOC (n = 50) PET/CT scans were used for neural network training and testing. The error of the attenuation correction factors estimated using μ-CT and μ-CNNNAC was over 7%, but that of scatter estimates was only 2.5%, indicating the validity of the scatter estimation from μ-CNNNAC. However, CNNNAC provided less accurate bone structures in the μ-maps, while the best results in recovering the fine bone structures were obtained by applying CNNMLAA+NAC. Additionally, the μ-values in the lungs were overestimated by CNNNAC. Activity images (λ) corrected for attenuation using μ-CNNMLAA and μ-CNNMLAA+NAC were superior to those corrected using μ-CNNNAC, in terms of their similarity to λ-CT. However, the improvement in the similarity with λ-CT by combining the CNNNAC and CNNMLAA approaches was insignificant (percent error for lung cancer lesions, λ-CNNNAC = 5.45% ± 7.88%; λ-CNNMLAA = 1.21% ± 5.74%; λ-CNNMLAA+NAC = 1.91% ± 4.78%; percent error for bone cancer lesions, λ-CNNNAC = 1.37% ± 5.16%; λ-CNNMLAA = 0.23% ± 3.81%; λ-CNNMLAA+NAC = 0.05% ± 3.49%). The use of CNNNAC was feasible for scatter estimation to address the chicken-egg dilemma in MLAA reconstruction, but CNNMLAA outperformed CNNNAC.

Cysteine and iron accelerate the formation of ribose-5-phosphate, providing insights into the evolutionary origins of the metabolic network structure.

The structure of the metabolic network is highly conserved, but we know little about its evolutionary origins. Key for explaining the early evolution of metabolism is solving a chicken–egg dilemma, which describes that enzymes are made from the very same molecules they produce. The recent discovery of several nonenzymatic reaction sequences that topologically resemble central metabolism has provided experimental support for a “metabolism first” theory, in which at least part of the extant metabolic network emerged on the basis of nonenzymatic reactions. But how could evolution kick-start on the basis of a metal catalyzed reaction sequence, and how could the structure of nonenzymatic reaction sequences be imprinted on the metabolic network to remain conserved for billions of years? We performed an in vitro screening where we add the simplest components of metabolic enzymes, proteinogenic amino acids, to a nonenzymatic, iron-driven reaction network that resembles glycolysis and the pentose phosphate pathway (PPP). We observe that the presence of the amino acids enhanced several of the nonenzymatic reactions. Particular attention was triggered by a reaction that resembles a rate-limiting step in the oxidative PPP. A prebiotically available, proteinogenic amino acid cysteine accelerated the formation of RNA nucleoside precursor ribose-5-phosphate from 6-phosphogluconate. We report that iron and cysteine interact and have additive effects on the reaction rate so that ribose-5-phosphate forms at high specificity under mild, metabolism typical temperature and environmental conditions. We speculate that accelerating effects of amino acids on rate-limiting nonenzymatic reactions could have facilitated a stepwise enzymatization of nonenzymatic reaction sequences, imprinting their structure on the evolving metabolic network.

The Chicken or the Egg: Causality Between Trade and Innovation

The Chicken or the Egg: Causality Between Trade and Innovation

Linking stress and infertility-more than a chicken and egg conundrum.

Linking stress and infertility-more than a chicken and egg conundrum.

Improving crowd labeling using Stackelberg models

Crowdsourcing systems provide an easy means of acquiring labeled training data for supervised learning. However, the labels provided by non-expert crowd workers (labelers) often appear low quality. In order to solve this problem, in practice each sample always obtains a multiple noisy label set from multiple different labelers, then ground truth inference algorithms are employed to obtain integrated labels of samples. So ground truth inference methods directly determine the label quality of samples. In this paper, we propose a novel label integration method based on game theory. We assume that there is an adversary in crowdsourcing system who intentionally provides incorrect integrated labels. We model the interaction between the data miner and the adversary as a Stackelberg game in which one player (the data miner) controls the predictive model whereas another (the adversary) tries to choose the integrated labels which would be most harmful for the current classifier. On this basis, we transform the label integration problem into a repeated Stackelberg model. We call our method Stackelberg label inference (SLI). SLI does not need to estimate the quality of labelers, and avoids the chicken-egg problem that can lead to poor result. Moreover, because SLI has little involvement of multiple noisy label sets on the noise data set, it is not very sensitive to the number of labelers. SLI shows better performance when the number of labelers is relatively small. In term of both label quality and model quality, the experimental results show that SLI is superior to the other state-of-the-art ground truth inference methods used to compare.

Chicken or the egg?: question

Chicken or the egg?: question

A solution to renewable hydrogen economy for fuel cell buses – A case study for Zhangjiakou in North China

Fuel cell vehicles fueled with renewable hydrogen is recognized as a life-cycle carbon-free option for the transport sector, however, the profitability of the H2 pathway becomes a key issue for the FCV commercialization. By analyzing the actual data from the Zhangjiakou fuel cell transit bus project, this research reveals it is economically feasible to commercialize FCV in areas with abundant renewable resources. Low electricity for water electrolysis, localization of H2 supply, and curtailed end price of H2 refueling effectively reduce the hydrogen production, delivery and refueling cost, and render a chance for the profitability of refueling stations. After the fulfillment of the intense deployment of both vehicles and hydrogen stations for the 2022 Winter Olympics, the H2 pathway starts to make a profit thereafter. The practices in the Zhangjiakou FCB project offer a solution to the hydrogen economy, which helps to break the chicken-egg dilemma of vehicles and hydrogen infrastructure.

A comprehensive charging network planning scheme for promoting EV charging infrastructure considering the Chicken-Eggs dilemma

The development of electric vehicles (EVs) cannot separated with the support of charging infrastructures. However, there has always been a paradox between them, especially in the initial phase of EVs development: the low uptake of EVs often hinders the investment enthusiasm of investors for charging infrastructure and vice versa, making them drop into a chicken-egg dilemma. For resolving the problem, a comprehensive planning scheme for EV charging networks is proposed in this paper. In the scheme, the influence mechanism of charging networks along with the developing of EVs is analyzed theoretically first, in which an inclusive analysis framework is proposed; and then around how to solve the current chicken-egg dilemma, a series of propositions and planning models are set forth and built, which not only consider the impact of charging network layout on the EVs’ charging convenience, but also discuss the cost pressure brought by the charging network construction on investors and the subsequent impact on the charging price; last, based on analytic results, aiming to promote the social uptake of EVs effectively, a relevant government subsidy scheme is proposed for charging facilities.

The chicken-or-egg dilemma with nocturia: Which matters most, the water or the salt?

The chicken-or-egg dilemma with nocturia: Which matters most, the water or the salt?

A Stacked Deep MEMC Network for Frame Rate Up Conversion and its Application to HEVC

Optical flows and video frame interpolation are considered as a chicken-egg problem such that one problem affects the other and vice versa. This paper presents a stack of deep networks to estimate intermediate optical flows from the very first intermediate synthesized frame and later generate the very end interpolated frame by combining the very first one and two learned intermediate optical flows based warped frames. The primary benefit is that it glues two problems into a single comprehensive framework that learns altogether by using both an analysis-by-synthesis technique for optical flow estimation and Convolutional Neural Networks (CNN) kernels-based frame synthesis. The proposed network is the first attempt to merge two previous branches of previous approaches, optical flow-based synthesis and CNN kernels-based synthesis into a comprehensive network. Experiments are carried out with various challenging datasets, all showing that the proposed network outperforms the state-of-the-art methods with significant margins for video frame interpolation and the estimated optical flows are more accurate for challenging movements. Furthermore, the proposed Motion Estimation Motion Compensation (MEMC) network shows its outstanding enhancement of the quality of compressed videos.

The Study of Chicken Egg Problem in Subspecies of Software Product

The Study of Chicken Egg Problem in Subspecies of Software Product

Back to the future: dynamic full carbon accounting applied to prospective bioenergy scenarios

Ongoing debates focus on the role of forest-sourced bioenergy within climate mitigation efforts, due to the long rotation lengths of forest biomass. Valuing sequestration is debated due to its reversibility; however, dynamic modelling of biogenic carbon (Cbio) flows captures both negative and positive emissions. The objective of this work is to respond to the key issue of timing sequestration associated with two opposed modelling choices (historic vs. future) in the context of dynamic life cycle assessment (LCA). The outputs of a partial-equilibrium model are used to inform prospective evaluations of the use of forest wood residues in response to an energy transition policy. Dynamic forest carbon modelling represents the carbon cycle between the atmosphere and technosphere: Cbio fixation and release through combustion and/or decay. Time-dependent characterization is used to assess the time-sensitive climate change effects. The two Cbio sequestration perspectives for bioenergy (forest biomass use) and reference (no use) scenarios are contrasted to assess (i) their temporal profiles, (ii) their climatic consequences concerning C-complete (fossil + biogenic C) vs. C-neutral (fossil C) approaches, and (iii) the implications of comparing the two approaches with dynamic LCA. Full lifetime carbon accounting confirms that Cbio entering the bioenergy system equals the Cbio leaving it in the net balance, but not within annual dynamic balances, which alter the atmospheric greenhouse gas composition. The impacts of the historic approach differed considerably from those of the future. Moreover, the “no use” scenario yielded higher forcing effects than the “bioenergy” due to the higher methane proportions. The chicken-egg dilemma arises in attributional LCA: as the forcing depends on the timing of the Cbio sequestration and its allocation to a harvest activity. A decision tree supported by case study applications provides general rules for selecting the adequate time-related modelling approach based the criteria of provision of wood and regrowth from managed and unmanaged forests, determined by the origin of biotic resources and related spheres. Excluding dynamic Cbio introduces under- (future) or over- (historic) estimation of the results, misleading mitigation decisions. Further research is needed to close the gap between forest stand and landscape level, addressing issues beyond the chicken-egg dilemma and developing complete dynamic LCA studies.

The Role of Traits in the Leadership Process

The cliches, “leaders are born, not made and leaders are made, not born” have been on the social sphere of leadership for quite a while. Is this a chicken-egg dilemma? Leadership generally has certain qualities that humans can point at, acting as conspicuous factors to be emulated. These qualities can either be innate or acquired. This paper looks at the role of traits in the leadership process. It focuses mainly on the trait theory, distinguishing the desired and the not so admired ones in as far as leadership is a concern. We also employ the great man theory to historically give flesh to where and how leadership has evolved to the 21st century. Transformational/charismatic leadership comes forth as the lottery winning mode to a sure way to a successful and productive form that leaders should have to deliver in this technologically advancing planet. We touched on Narcissist and Machiavellian types of leadership but only as contrary examples to the recommended. The paper is, therefore, a handy requirement for today’s leaders. A snapshot for those wishing to guide others in the visionary path of leadership. Commitment, passion, empathy, honesty, integrity communication skills and decision-making capabilities can be learned and used to better the leader-follower relationship process. The business world and other forms of social governance are out of the stagnation of the great man theory of leadership. Flexibility in behavior, actions and thought make the best of a leader.

The Chicken-and-Egg Quandry [President's Corner

The Chicken-and-Egg Quandry [President's Corner

Preprocessing of GIS data for electric vehicle charging stations analysis and evaluation of the predictors significance

Abstract When a government or a municipality intends to incentivize electromobility a chicken-egg problem arises: shall citizens first buy electric vehicles or should the charging stations be installed first? Often, a charging infrastructure is deployed, even if the number of electric vehicles is small, in the hope to stimulate a larger interest in electric mobility. In such cases, charging station operators in collaboration with municipalities have to make appropriate decisions, including finding the placement of charging stations that meets the demands of electric vehicles (EVs) while expending the resources efficiently. In this paper, a data set coming from a large network of charging stations, located in one of the worlds electromobility leading countries the Netherlands, is analysed. Dataset comprises over one million charging transactions, more than 1700 charging stations and spans over four years. First, methodological tools to describe the urban context by data are introduced. Publicly available GIS data are collected and exploited to assess the geographical locations of charging stations. Data preprocessing procedures are described and their limitations are discussed. Finally, using correlation analysis the ability of the gathered GIS predictors to explain the utilization characteristics of EV charging stations is evaluated.

Quantum chicken-or-egg experiment blurs the distinction between before and after

Quantum chicken-or-egg experiment blurs the distinction between before and after

A hydrogen refuelling stations infrastructure deployment for cities supported on fuel cell taxi roll-out

A shift towards lower-carbon fuels is mandatory to achieve the decarbonisation of the transport sector, which is responsible of 14% of world greenhouse gas emissions. Despite to the fact that fuel cell electric vehicles are zero tail-pipe emissions vehicles, their use is presently residual. A massive integration of fuel cell vehicles faces a “chicken-egg dilemma”: vehicles need a proper refuelling infrastructure to provide a safe and continuous hydrogen supply, but a viable deployment of the refuelling infrastructure needs the support of an initial market of vehicles.In this article, we design a feasible strategy for overcoming the dilemma, using the local taxi fleet as a stable market of hydrogen consumers to start up a retail hydrogen supply infrastructure in high-populated cities. The design is based on three objectives: ensuring hydrogen supply, having throughout the city a nearby alternative for refuelling and maximizing the infrastructure utilisation rate.The strategy applied to the city of Madrid show that $415 million of public funds allocated along 25 years would provide in six years a network of 112 hydrogen refuelling stations, able to supply the hydrogen needs of 15,000 new fuel cell electric taxis what would cut the emissions of 300 kt CO2 yearly.