scholarly journals A generative bias towards average complexity in artificial cell lineages

2007 ◽  
Vol 274 (1619) ◽  
pp. 1741-1751 ◽  
Author(s):  
Rolf Lohaus ◽  
Nicholas L Geard ◽  
Janet Wiles ◽  
Ricardo B.R Azevedo
Keyword(s):  
Alternative Hypothesis ◽  
Critical Role ◽  
High Complexity ◽  
Average Complexity ◽  
Trade Offs ◽  
Phenotypic Complexity ◽  
Evolution Of Life ◽  
Life On Earth ◽  
Increasing Trends

The evolution of life on earth has been characterized by generalized long-term increases in phenotypic complexity. Although natural selection is a plausible cause for these trends, one alternative hypothesis—generative bias—has been proposed repeatedly based on theoretical considerations. Here, we introduce a computational model of a developmental system and use it to test the hypothesis that long-term increasing trends in phenotypic complexity are caused by a generative bias towards greater complexity. We use our model to generate random organisms with different levels of phenotypic complexity and analyse the distributions of mutational effects on complexity. We show that highly complex organisms are easy to generate but there are trade-offs between different measures of complexity. We also find that only the simplest possible phenotypes show a generative bias towards higher complexity, whereas phenotypes with high complexity display a generative bias towards lower complexity. These results suggest that generative biases alone are not sufficient to explain long-term evolutionary increases in phenotypic complexity. Rather, our finding of a generative bias towards average complexity argues for a critical role of selective biases in driving increases in phenotypic complexity and in maintaining high complexity once it has evolved.

‘Where is everybody?’ An empirical appraisal of occurrence, prevalence and sustainability of technological species in the Universe

2019 ◽  
Vol 18 (6) ◽  
pp. 495-501 ◽  
Author(s):  
John-Oliver Engler ◽  
Henrik von Wehrden
Keyword(s):  
Milky Way ◽  
Current State ◽  
Evolution Of Life ◽  
Interstellar Communication ◽  
Life On Earth ◽  
The Universe

AbstractWe use recent results from astrobiology, particularly the A-form of the Drake equation and combine it with data on the evolution of life on Earth to obtain a new assessment of the prevalence of technological species in our Universe. A species is technological if it is, in theory, capable of interstellar communication. We find that between seven and 300 technological species have likely arisen in the Milky Way until today, the current state of which however unknown. Assuming that we are currently alone in our Galaxy, we estimate that we would need to wait for roughly 26 million years for a 50% chance of another technological species to arise. By relating our results to the much-debated Fermi–Hart paradox, we discuss if and to what extent our results may help quantify the chances of humanity to manage the transition to a long-term sustainable path of existence.

Constraints in the evolution of life histories

1991 ◽  
Vol 332 (1262) ◽  
pp. 3-13 ◽  
Keyword(s):  
Life History ◽  
Life Histories ◽  
Ecological Impact ◽  
Genetic Studies ◽  
Local Optima ◽  
Trade Offs ◽  
Evolution Of Life ◽  
Diversity Of Life ◽  
Irreversible Evolution

The life history favoured by natural selection maximizes fitness, and this implies maximization of fecundity and survival at all ages. The observed diversity in life histories suggests that there are constraints on what can be achieved in practice. Functional constraints occur if only certain combinations of age-specific fertility and survival are possible, either because of the physiology of the organism or because of the ecological impact of its environment. The resulting constrained optimization means that the organism is involved in making trade-offs between life-history characters. A major task for the future is the measurement of trade-off functions in the environment in which the life-history evolved. Natural variation between individuals and populations, genetic studies and experimental manipulations have all been used to detect trade-offs. The last two methods are the most satisfactory, and can be complementary. Experimental manipulations are at their best when based on sound physiological understanding of the traits under manipulation. Constraints can also operate on the long-term. Local optima, evolutionary lags and irreversible evolution may all have contributed to the diversity of life histories.

Configurations to Superior Environmental Innovation Strategy: A Both–And Approach

2021 ◽  
pp. 108602662110316
Author(s):  
Tiziana Russo-Spena ◽  
Nadia Di Paola ◽  
Aidan O’Driscoll
Keyword(s):  
Climate Change ◽  
Value Chain ◽  
Critical Role ◽  
Well Being ◽  
Point Of View ◽  
Future Generations ◽  
Innovation Strategy ◽  
Environmental Innovation ◽  
Data Set

An effective climate change action involves the critical role that companies must play in assuring the long-term human and social well-being of future generations. In our study, we offer a more holistic, inclusive, both–and approach to the challenge of environmental innovation (EI) that uses a novel methodology to identify relevant configurations for firms engaging in a superior EI strategy. A conceptual framework is proposed that identifies six sets of driving characteristics of EI and two sets of beneficial outcomes, all inherently tensional. Our analysis utilizes a complementary rather than an oppositional point of view. A data set of 65 companies in the ICT value chain is analyzed via fuzzy-set comparative analysis (fsQCA) and a post-QCA procedure. The results reveal that achieving a superior EI strategy is possible in several scenarios. Specifically, after close examination, two main configuration groups emerge, referred to as technological environmental innovators and organizational environmental innovators.

scholarly journals Overexpression of MdATG8i improves water use efficiency in transgenic apple by modulating photosynthesis, osmotic balance, and autophagic activity under moderate water deficit

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xin Jia ◽  
Ke Mao ◽  
Ping Wang ◽  
Yu Wang ◽  
Xumei Jia ◽  
...  
Keyword(s):  
Water Use Efficiency ◽  
Water Deficit ◽  
Water Use ◽  
Photosynthetic Capacity ◽  
Critical Role ◽  
Drought Conditions ◽  
Moderate Drought ◽  
Use Efficiency ◽  
Autophagic Activity

AbstractWater deficit is one of the major limiting factors for apple (Malus domestica) production on the Loess Plateau, a major apple cultivation area in China. The identification of genes related to the regulation of water use efficiency (WUE) is a crucial aspect of crop breeding programs. As a conserved degradation and recycling mechanism in eukaryotes, autophagy has been reported to participate in various stress responses. However, the relationship between autophagy and WUE regulation has not been explored. We have shown that a crucial autophagy protein in apple, MdATG8i, plays a role in improving salt tolerance. Here, we explored its biological function in response to long-term moderate drought stress. The results showed that MdATG8i-overexpressing (MdATG8i-OE) apple plants exhibited higher WUE than wild-type (WT) plants under long-term moderate drought conditions. Plant WUE can be increased by improving photosynthetic efficiency. Osmoregulation plays a critical role in plant stress resistance and adaptation. Under long-term drought conditions, the photosynthetic capacity and accumulation of sugar and amino acids were higher in MdATG8i-OE plants than in WT plants. The increased photosynthetic capacity in the OE plants could be attributed to their ability to maintain optimal stomatal aperture, organized chloroplasts, and strong antioxidant activity. MdATG8i overexpression also promoted autophagic activity, which was likely related to the changes described above. In summary, our results demonstrate that MdATG8i-OE apple lines exhibited higher WUE than WT under long-term moderate drought conditions because they maintained robust photosynthesis, effective osmotic adjustment processes, and strong autophagic activity.

scholarly journals Wire-in-Wire TiO2/C Nanofibers Free-Standing Anodes for Li-Ion and K-Ion Batteries with Long Cycling Stability and High Capacity

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Die Su ◽  
Yi Pei ◽  
Li Liu ◽  
Zhixiao Liu ◽  
Junfang Liu ◽  
...  
Keyword(s):  
Critical Role ◽  
Electronic Conductivity ◽  
Specific Capacity ◽  
High Capacity ◽  
Cycling Stability ◽  
Free Standing ◽  
High Specific Capacity ◽  
Tetracarboxylic Dianhydride ◽  
Carbon Network

AbstractWearable and portable mobile phones play a critical role in the market, and one of the key technologies is the flexible electrode with high specific capacity and excellent mechanical flexibility. Herein, a wire-in-wire TiO2/C nanofibers (TiO2 ww/CN) film is synthesized via electrospinning with selenium as a structural inducer. The interconnected carbon network and unique wire-in-wire nanostructure cannot only improve electronic conductivity and induce effective charge transports, but also bring a superior mechanic flexibility. Ultimately, TiO2 ww/CN film shows outstanding electrochemical performance as free-standing electrodes in Li/K ion batteries. It shows a discharge capacity as high as 303 mAh g−1 at 5 A g−1 after 6000 cycles in Li half-cells, and the unique structure is well-reserved after long-term cycling. Moreover, even TiO2 has a large diffusion barrier of K+, TiO2 ww/CN film demonstrates excellent performance (259 mAh g−1 at 0.05 A g−1 after 1000 cycles) in K half-cells owing to extraordinary pseudocapacitive contribution. The Li/K full cells consisted of TiO2 ww/CN film anode and LiFePO4/Perylene-3,4,9,10-tetracarboxylic dianhydride cathode possess outstanding cycling stability and demonstrate practical application from lighting at least 19 LEDs. It is, therefore, expected that this material will find broad applications in portable and wearable Li/K-ion batteries.

scholarly journals A Mixed-Methods Investigation into Barriers for Sharing Geospatial and Resilience Flood Data in the UK

Water ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1235
Author(s):  
Luke Waterman ◽  
Mónica Rivas Casado ◽  
Emma Bergin ◽  
Gary McInally
Keyword(s):  
Data Sharing ◽  
Local Politics ◽  
Critical Role ◽  
Third Sector ◽  
Structured Interviews ◽  
Average Temperature ◽  
Third Sector Organisations ◽  
Data Points ◽  
The Uk

With increases in average temperature and rainfall predicted, more households are expected to be at risk of flooding in the UK by 2050. Data and technologies are increasingly playing a critical role across public-, private- and third-sector organisations. However, barriers and constraints exist across organisations and industries that limit the sharing of data. We examine the international context for data sharing and variations between data-rich and data-sparse countries. We find that local politics and organisational structures influence data sharing. We focus on the case study of the UK, and on geospatial and flood resilience data in particular. We use a series of semi-structured interviews to evaluate data sharing limitations, with particular reference to geospatial and flood resilience data. We identify barriers and constraints when sharing data between organisations. We find technological, security, privacy, cultural and commercial barriers across different use cases and data points. Finally, we provide three long-term recommendations to improve the overall accessibility to flood data and enhance outcomes for organisations and communities.

scholarly journals Radiation Necrosis of the Lateral Skull Base and Temporal Bone

2020 ◽  
Vol 34 (04) ◽  
pp. 265-271
Author(s):  
Marc W. Herr ◽  
Aurora G. Vincent ◽  
Meghan A. Skotnicki ◽  
Yadranko Ducic ◽  
Spiros Manolidis
Keyword(s):  
Radiation Therapy ◽  
Temporal Bone ◽  
Radiation Necrosis ◽  
Critical Role ◽  
Therapeutic Effects ◽  
Normal Tissues ◽  
Lateral Skull Base ◽  
The Many ◽  
Work Up

AbstractRadiation therapy plays a critical role in the treatment of malignancies involving the head and neck. Although the therapeutic effects of ionizing radiation are achieved, normal tissues are also susceptible to injury and significant long-term sequelae. Osteoradionecrosis of the temporal bone (ORNTB) is among the many complications that can arise after therapy. ORNTB is a debilitating and potentially lethal condition that continues to challenge patients and treating physicians. Herein, we review the pathophysiology, presentation, work-up, and management of ORNTB.

Robot‐assisted partial nephrectomy for high‐complexity tumors (PADUA score ≥10): Perioperative, long‐term functional and oncologic outcomes

2021 ◽  
Author(s):  
Periklis Koukourikis ◽  
Ali Abdullah Alqahtani ◽  
Ahmad Almujalhem ◽  
Jongsoo Lee ◽  
Woong Kyu Han ◽  
...  
Keyword(s):  
Partial Nephrectomy ◽  
Oncologic Outcomes ◽  
High Complexity ◽  
Robot Assisted

scholarly journals How Do Trade-Offs and Synergies between Ecosystem Services Change in the Long Period? The Case Study of Uxin, Inner Mongolia, China

2019 ◽  
Vol 11 (21) ◽  
pp. 6041 ◽  
Author(s):  
Zhang ◽  
Li ◽  
Buyantuev ◽  
Bao ◽  
Zhang
Keyword(s):  
Ecosystem Services ◽  
Inner Mongolia ◽  
Stepwise Regression ◽  
Driving Forces ◽  
Extended Period ◽  
Trade Offs ◽  
Development And Utilization ◽  
Long Term Trends

Ecosystem services management should often expect to deal with non-linearities due to trade-offs and synergies between ecosystem services (ES). Therefore, it is important to analyze long-term trends in ES development and utilization to understand their responses to climate change and intensification of human activities. In this paper, the region of Uxin in Inner Mongolia, China, was chosen as a case study area to describe the spatial distribution and trends of 5 ES indicators. Changes in relationships between ES and driving forces of dynamics of ES relationships were analyzed for the period 1979–2016 using a stepwise regression. We found that: the magnitude and directions in ES relationships changed during this extended period; those changes are influenced by climate factors, land use change, technological progress, and population growth.

scholarly journals Trends in the Frequency of Intense Precipitation Events in Southern and Southeastern Brazil during 1960–2004

2011 ◽  
Vol 24 (7) ◽  
pp. 1913-1921 ◽  
Author(s):  
Mateus da Silva Teixeira ◽  
Prakki Satyamurty
Keyword(s):  
Extreme Rainfall ◽  
Southeastern Brazil ◽  
Extreme Rainfall Event ◽  
Southern Brazil ◽  
Extreme Rainfall Events ◽  
Rainfall Events ◽  
Annual Frequency ◽  
Long Term Trends ◽  
Increasing Trends

Abstract A new approach to define heavy and extreme rainfall events based on cluster analysis and area-average rainfall series is presented. The annual frequency of the heavy and extreme rainfall events is obtained for the southeastern and southern Brazil regions. In the 1960–2004 period, 510 (98) and 466 (77) heavy (extreme) rainfall events are identified in the two regions. Monthly distributions of the events closely follow the monthly climatological rainfall in the two regions. In both regions, annual heavy and extreme rainfall event frequencies present increasing trends in the 45-yr period. However, only in southern Brazil is the trend statistically significant. Although longer time series are necessary to ensure the existence of long-term trends, the positive trends are somewhat alarming since they indicate that climate changes, in terms of rainfall regimes, are possibly under way in Brazil.

Sign in / Sign up

Export Citation Format

Share Document