Evolution of Thermal Sensitivity in Changing and Variable Climates

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Lauren B. Buckley ◽  
Joel G. Kingsolver
Keyword(s):  
Thermal Sensitivity ◽  
Experimental Studies ◽  
Thermal Adaptation ◽  
Theoretical Models ◽  
Environmental Variation ◽  
Behavioral Thermoregulation ◽  
Annual Review ◽  
Publication Date ◽  
Evolutionary Adaptation ◽  
Variable Environments

Evolutionary adaptation to temperature and climate depends on both the extent to which organisms experience spatial and temporal environmental variation (exposure) and how responsive they are to the environmental variation (sensitivity). Theoretical models and experiments suggesting substantial potential for thermal adaptation have largely omitted realistic environmental variation. Environmental variation can drive fluctuations in selection that slow adaptive evolution. We review how carefully filtering environmental conditions based on how organisms experience their environment and further considering organismal sensitivity can improve predictions of thermal adaptation. We contrast taxa differing in exposure and sensitivity. Plasticity can increase the rate of evolutionary adaptation in taxa exposed to pronounced environmental variation. However, forms of plasticity that severely limit exposure, such as behavioral thermoregulation and phenological shifts, can hinder thermal adaptation. Despite examples of rapid thermal adaptation, experimental studies often reveal evolutionary constraints. Further investigating these constraints and issues of timescale and thermal history are needed to predict evolutionary adaptation and, consequently, population persistence in changing and variable environments. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 52 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

High-Entropy Ultra-High-Temperature Borides and Carbides: A New Class of Materials for Extreme Environments

2021 ◽  
Vol 51 (1) ◽  
Author(s):  
Lun Feng ◽  
William G. Fahrenholtz ◽  
Donald W. Brenner
Keyword(s):  
High Temperature ◽  
Extreme Environments ◽  
Experimental Studies ◽  
Heat Fluxes ◽  
Annual Review ◽  
Publication Date ◽  
Structure Property ◽  
High Entropy ◽  
Ultra High Temperature Ceramics ◽  
Ultra High Temperature

Herein, we critically evaluate computational and experimental studies in the emerging field of high-entropy ultra-high-temperature ceramics. High-entropy ultra-high-temperature ceramics are candidates for use in extreme environments that include temperatures over 2,000°C, heat fluxes of hundreds of watts per square centimeter, or irradiation from neutrons with energies of several megaelectron volts. Computational studies have been used to predict the ability to synthesize stable high-entropy materials as well as the resulting properties but face challenges such asthe number and complexity of unique bonding environments that are possible for these compositionally complex compounds. Experimental studies have synthesized and densified a large number of different high-entropy borides and carbides, but no systematic studies of composition-structure-property relationships have been completed. Overall, this emerging field presents a number of exciting research challenges and numerous opportunities for future studies. Expected final online publication date for the Annual Review of Materials Science, Volume 51 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Learning to Model G-Quadruplexes: Current Methods and Perspectives

2021 ◽  
Vol 50 (1) ◽  
Author(s):  
Iker Ortiz de Luzuriaga ◽  
Xabier Lopez ◽  
Adrià Gil3
Keyword(s):  
Molecular Dynamics ◽  
Small Molecules ◽  
Molecular Dynamics Simulations ◽  
Density Functional ◽  
Experimental Studies ◽  
Annual Review ◽  
Publication Date ◽  
Square Planar ◽  
Explicit Simulation ◽  
Dynamics Simulations

G-quadruplexes have raised considerable interest during the past years for the development of therapies against cancer. These noncanonical structures of DNA may be found in telomeres and/or oncogene promoters, and it has been observed that the stabilization of such G-quadruplexes may disturb tumor cell growth. Nevertheless, the mechanisms leading to folding and stabilization of these G-quadruplexes are still not well established, and they are the focus of much current work in this field. In seminal works, stabilization was observed to be produced by cations. However, subsequent studies showed that different kinds of small molecules, from planar and nonplanar organic molecules to square-planar and octahedral metal complexes, may also lead to the stabilization of G-quadruplexes. Thus, the comprehension and rationalization of the interaction of these small molecules with G-quadruplexes are also important topics of current interest in medical applications. To shed light on the questions arising from the literature on the formation of G-quadruplexes, their stabilization, and their interaction with small molecules, synergies between experimental studies and computational works are needed. In this review, we mainly focus on in silico approaches and provide a broad compilation of different leading studies carried out to date by different computational methods. We divide these methods into two main categories: ( a) classical methods, which allow for long-timescale molecular dynamics simulations and the corresponding analysis of dynamical information, and ( b) quantum methods (semiempirical, quantum mechanics/molecular mechanics, and density functional theory methods), which allow for the explicit simulation of the electronic structure of the system but, in general, are not capable of being used in long-timescale molecular dynamics simulations and, therefore, give a more static picture of the relevant processes. Expected final online publication date for the Annual Review of Biophysics, Volume 50 is May 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Dynamics of Ecological Communities Following Current Retreat of Glaciers

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Gentile Francesco Ficetola ◽  
Silvio Marta ◽  
Alessia Guerrieri ◽  
Mauro Gobbi ◽  
Roberto Ambrosini ◽  
...  
Keyword(s):  
Community Dynamics ◽  
Abiotic Factors ◽  
Empirical Studies ◽  
Experimental System ◽  
Theoretical Models ◽  
Glacier Retreat ◽  
Community Formation ◽  
Annual Review ◽  
Publication Date ◽  
Ecological Communities

Glaciers are retreating globally, and the resulting ice-free areas provide an experimental system for understanding species colonization patterns, community formation, and dynamics. The last several years have seen crucial advances in our understanding of biotic colonization after glacier retreats, resulting from the integration of methodological innovations and ecological theories. Recent empirical studies have demonstrated how multiple factors can speed up or slow down the velocity of colonization and have helped scientists develop theoretical models that describe spatiotemporal changes in community structure. There is a growing awareness of how different processes (e.g., time since glacier retreat, onset or interruption of surface processes, abiotic factors, dispersal, biotic interactions) interact to shape community formation and, ultimately, their functional structure through succession. Here, we examine how these studies address key theoretical questions about community dynamics and show how classical approaches are increasingly being combined with environmental DNA metabarcoding and functional trait analysis to document the formation of multitrophic communities, revolutionizing our understanding of the biotic processes that occur following glacier retreat. Expected final online publication date for the Annual Review of Ecology, Evolution, and Systematics, Volume 52 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Physiological Consequences of Oceanic Environmental Variation: Life from a Pelagic Organism's Perspective

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Mark W. Denny ◽  
W. Wesley Dowd
Keyword(s):  
Response Times ◽  
Environmental Gradients ◽  
Spatial Scales ◽  
New Technology ◽  
Empirical Work ◽  
Environmental Variation ◽  
Life Forms ◽  
Annual Review ◽  
Publication Date ◽  
Surrounding Water

To better understand life in the sea, marine scientists must first quantify how individual organisms experience their environment, and then describe how organismal performance depends on that experience. In this review, we first explore marine environmental variation from the perspective of pelagic organisms, the most abundant life forms in the ocean. Generation time, the ability to move relative to the surrounding water (even slowly), and the presence of environmental gradients at all spatial scales play dominant roles in determining the variation experienced by individuals, but this variation remains difficult to quantify. We then use this insight to critically examine current understanding of the environmental physiology of pelagic marine organisms. Physiologists have begun to grapple with the complexity presented by environmental variation, and promising frameworks exist for predicting and/or interpreting the consequences for physiological performance. However, new technology needs to be developed and much difficult empirical work remains, especially in quantifying response times to environmental variation and the interactions among multiple covarying factors. We call on the field of global-change biology to undertake these important challenges. Expected final online publication date for the Annual Review of Marine Science, Volume 14 is January 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Countergradient variation in reptiles: thermal sensitivity of developmental and metabolic rates across locally adapted populations

2020 ◽  
Author(s):  
Amanda Kate Pettersen
Keyword(s):  
Genetic Variation ◽  
Environmental Gradients ◽  
Thermal Sensitivity ◽  
Empirical Work ◽  
Thermal Adaptation ◽  
Environmental Variation ◽  
Developmental Time ◽  
Metabolic Rates ◽  
Countergradient Variation ◽  
Developmental Rates

Environmental temperature is a key driver of variation in physiological developmental rates in reptiles. Cooler temperatures extend development time and increase the amount of energy required to achieve hatching success, which can pose fitness consequences later in life. Yet, in locally-adapted populations, genetic variation often opposes environmental variation across ecological gradients, known as countergradient variation (CnGV). It is therefore not only the presence, but the absence of phenotypic variation that can reveal insights into the mechanisms underlying local adaptation across environmental gradients. While evidence for genetic variation opposing environmental variation in physiological rates has been summarised in other taxa, the generality of CnGV variation in reptiles is yet unknown. Here I present a summary of studies measuring developmental time and metabolic rates in locally-adapted populations across thermal clines for 15 species of reptiles across 8 families. CnGV in developmental time is found to be common, while no clear pattern emerges for the thermal sensitivity of metabolic rates across locally-adapted populations. CnGV in developmental time may be an adaptive response in order to decrease the costly development in cool climates, however empirical work is needed to disentangle plastic from genetic responses, and to uncover potentially general mechanisms of local thermal adaptation in reptiles.

Education and Political Participation

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Claire Willeck ◽  
Tali Mendelberg
Keyword(s):  
Political Participation ◽  
Political Science ◽  
Civic Education ◽  
Final Section ◽  
Theoretical Models ◽  
Annual Review ◽  
Publication Date ◽  
Causal Pathways ◽  
Causal Impact ◽  
Clear Support

Whether education affects political participation is a long-standing and central question in political philosophy and political science. In this review, we provide an overview of the three main theoretical models that explain different causal pathways. We then synthesize the surge in research using causal inference strategies and show that this literature has generated mixed results about the causal impact of education, even when using similar methods and data. These findings do not provide clear support for any of the three theories. Our next section covers research on civic education and political participation. The quantity of civic education matters little for political participation, but how civic education is taught does matter. Namely, strategies falling under the rubric of active learning show promise. These strategies seem especially effective for historically marginalized students. Our final section calls for more research on how civic education is taught. Expected final online publication date for the Annual Review of Political Science, Volume 25 is May 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

scholarly journals Comparative Perspectives on Racial Discrimination in Hiring: The Rise of Field Experiments

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Lincoln Quillian ◽  
Arnfinn H. Midtbøen
Keyword(s):  
Race And Ethnicity ◽  
Field Experiments ◽  
Minority Groups ◽  
Experimental Studies ◽  
Ethnic Discrimination ◽  
Future Research ◽  
Annual Review ◽  
Publication Date ◽  
Institutional Rules ◽  
Hiring Discrimination

This article reviews studies of discrimination against racial and ethnic minority groups in hiring in cross-national perspective. We focus on field-experimental studies of hiring discrimination: studies that use fictitious applications from members of different racial and ethnic groups to apply for actual jobs. There are more than 140 field experimental studies of hiring discrimination against ethno-racial minority groups in 30 countries. We outline seventeen empirical findings from this body of studies. We also discuss individual and contextual theories of hiring discrimination, the relative strengths and weaknesses of field experiments to assess discrimination, and the history of such field experiments. The comparative scope of this body of research helps to move beyond micromodels of employer decision-making to better understand the roles of history, social context, institutional rules, and racist ideologies in producing discrimination. These studies show that racial and ethnic discrimination is a pervasive international phenomenon that has hardly declined over time, although levels vary significantly over countries. Evidence indicates that institutional rules regarding race and ethnicity in hiring can have an important influence on levels of discrimination. Suggestions for future research on discrimination are discussed. Expected final online publication date for the Annual Review of Sociology, Volume 47 is July 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

A Relativistic Newtonian Mechanics Predicts with Precision the Results of Recent Neutrino-Velocity Experiments

2014 ◽  
Vol 6 (1) ◽  
pp. 1032-1035 ◽  
Author(s):  
Ramzi Suleiman
Keyword(s):  
Null Hypothesis ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Newtonian Mechanics ◽  
Speed Of Light ◽  
Symmetry Principle ◽  
Proposed Model ◽  
Significant Difference ◽  
The One ◽  
Complete Collapse

The research on quasi-luminal neutrinos has sparked several experimental studies for testing the "speed of light limit" hypothesis. Until today, the overall evidence favors the "null" hypothesis, stating that there is no significant difference between the observed velocities of light and neutrinos. Despite numerous theoretical models proposed to explain the neutrinos behavior, no attempt has been undertaken to predict the experimentally produced results. This paper presents a simple novel extension of Newton's mechanics to the domain of relativistic velocities. For a typical neutrino-velocity experiment, the proposed model is utilized to derive a general expression for . Comparison of the model's prediction with results of six neutrino-velocity experiments, conducted by five collaborations, reveals that the model predicts all the reported results with striking accuracy. Because in the proposed model, the direction of the neutrino flight matters, the model's impressive success in accounting for all the tested data, indicates a complete collapse of the Lorentz symmetry principle in situation involving quasi-luminal particles, moving in two opposite directions. This conclusion is support by previous findings, showing that an identical Sagnac effect to the one documented for radial motion, occurs also in linear motion.

scholarly journals Experimental Evaluation of Airlift Performance for Vertical Pumping of Water in Underground Mines

2021 ◽  
Author(s):  
Parviz Enany ◽  
Oleksandr Shevchenko ◽  
Carsten Drebenstedt
Keyword(s):  
Water Flow ◽  
High Efficiency ◽  
Experimental Studies ◽  
Theoretical Models ◽  
Injection System ◽  
Experimental Investigations ◽  
Flow Mode ◽  
New Device ◽  
Riser Pipe ◽  
Airlift Pump

AbstractThis paper presents experimental studies on the optimization of air–water flow in an airlift pump. Airlift pumps use compressed gas to verticall transport liquids and slurries. Due to the lack of theoretical equations for designing and predicting flow regimes, experimental investigations must be carried out to find the best condition to operate an airlift pump at high efficiency. We used a new air injection system and different submergence ratios to evaluate the output of a simple pump for vertical displacement of water in an underground mine. The tests were carried out in a new device with 5.64 m height and 10.2 cm circular riser pipe. Three air-jacket pipes, at different gas flows in the range of 0.002–0.09 m3/s were investigated with eight submergence ratios. It was found that with the same air flow rate, the most efficient flow of water was achieved when an air jacket with 3 mm diameter holes was used with a submergence ratio between 0.6 and 0.75. In addition, a comparison of practical results with two theoretical models proposed by other investigators showed that neither was able to accurately predict airlift performance in air–water flow mode.

Endogenous Retroviruses Drive Resistance and Promotion of Exogenous Retroviral Homologs

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Elliott S. Chiu ◽  
Sue VandeWoude
Keyword(s):  
Immune Modulation ◽  
Viral Infections ◽  
Viral Evolution ◽  
Endogenous Retroviruses ◽  
Annual Review ◽  
Publication Date ◽  
Biological Functions ◽  
Self Tolerance ◽  
Vertebrate Hosts ◽  
Insight Into

Endogenous retroviruses (ERVs) serve as markers of ancient viral infections and provide invaluable insight into host and viral evolution. ERVs have been exapted to assist in performing basic biological functions, including placentation, immune modulation, and oncogenesis. A subset of ERVs share high nucleotide similarity to circulating horizontally transmitted exogenous retrovirus (XRV) progenitors. In these cases, ERV–XRV interactions have been documented and include ( a) recombination to result in ERV–XRV chimeras, ( b) ERV induction of immune self-tolerance to XRV antigens, ( c) ERV antigen interference with XRV receptor binding, and ( d) interactions resulting in both enhancement and restriction of XRV infections. Whereas the mechanisms governing recombination and immune self-tolerance have been partially determined, enhancement and restriction of XRV infection are virus specific and only partially understood. This review summarizes interactions between six unique ERV–XRV pairs, highlighting important ERV biological functions and potential evolutionary histories in vertebrate hosts. Expected final online publication date for the Annual Review of Animal Biosciences, Volume 9 is February 16, 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

Sign in / Sign up

Export Citation Format

Share Document