scholarly journals Increased Thermal Sensitivity of a Tropical Marine Gastropod Under Combined CO2 and Temperature Stress

2021 ◽  
Vol 8 ◽  
Author(s):  
Jay J. Minuti ◽  
Charlee A. Corra ◽  
Brian S. Helmuth ◽  
Bayden D. Russell

The ability of an organism to alter its physiology in response to environmental conditions offers a short-term defense mechanism in the face of weather extremes resulting from climate change. These often manifest as multiple, interacting drivers, especially pH and temperature. In particular, decreased pH can impose constraints on the biological mechanisms which define thermal limits by throwing off energetic equilibrium and diminishing physiological functions (e.g., in many marine ectotherms). For many species, however, we do not have a detailed understanding of these interactive effects, especially on short-term acclimation responses. Here, we investigated the metabolic plasticity of a tropical subtidal gastropod (Trochus maculatus) to increased levels of CO2 (700 ppm) and heating (+3°C), measuring metabolic performance (Q10 coefficient) and thermal sensitivity [temperature of maximum metabolic rate (TMMR), and upper lethal temperature (ULT)]. Individuals demonstrated metabolic acclimation in response to the stressors, with TMMR increasing by +4.1°C under higher temperatures, +2.7°C under elevated CO2, and +4.4°C under the combined stressors. In contrast, the ULT only increased marginally in response to heating (+0.3°C), but decreased by −2.3°C under CO2, and −8.7°C under combined stressors. Therefore, although phenotypic plasticity is evident with metabolic acclimation, acute lethal temperature limits seem to be less flexible during short-term acclimation.

Author(s):  
Claudius Härpfer

In recent times we find many plebiscitary acts that seek to democratically legitimize political processes in any direction. They have in common that they interrupt the normal routine of representative democracies to a certain degree and create an extra-daily state of affairs, which entails not only direct but also indirect consequences. The text attempts to systematize some of these mechanisms from a Weberian perspective using Brexit as an example. After a brief overview of Weber’s short-term politically inspired statements on plebiscitary democracy, the text systematizes Weber’s understanding of the state as a bureaucratic apparatus that requires any kind of leader to be controlled. Subsequently, the text discusses the relationship between domination, legality, and rationality in order to finally point out the danger of erosion of truth and legality through the emergence of competing consensus communities in the face of competing conceptions of order.


2021 ◽  
pp. 019459982110042
Author(s):  
Jenny X. Chen ◽  
Shivani A. Shah ◽  
Vinay K. Rathi ◽  
Mark A. Varvares ◽  
Stacey T. Gray

Graduate medical education (GME) is funded by the Centers for Medicare and Medicaid Services through both direct and indirect payments. In recent years, stakeholders have raised concerns about the growth of spending on GME and distribution of payment among hospitals. Key stakeholders have proposed reforms to reduce GME funding such as adjustments to statutory payment formulas and absolute caps on annual payments per resident. Otolaryngology departmental leadership should understand the potential effects of proposed reforms, which could have significant implications for the short-term financial performance and the long-term specialty workforce. Although some hospitals and departments may elect to reduce resident salaries or eliminate positions in the face of GME funding cuts, this approach overlooks the substantial Medicare revenue contributed by resident care and high cost of alternative labor sources. Commitment to resident training is necessary to align both the margin and mission of otolaryngology departments and their sponsoring hospitals.


2021 ◽  
Vol 24 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Dominic Abrams ◽  
Fanny Lalot ◽  
Michael A. Hogg

COVID-19 is a challenge faced by individuals (personal vulnerability and behavior), requiring coordinated policy from national government. However, another critical layer—intergroup relations—frames many decisions about how resources and support should be allocated. Based on theories of self and social identity uncertainty, subjective group dynamics, leadership, and social cohesion, we argue that this intergroup layer has important implications for people’s perceptions of their own and others’ situation, political management of the pandemic, how people are influenced, and how they resolve identity uncertainty. In the face of the pandemic, initial national or global unity is prone to intergroup fractures and competition through which leaders can exploit uncertainties to gain short-term credibility, power, or influence for their own groups, feeding polarization and extremism. Thus, the social and psychological challenge is how to sustain the superordinate objective of surviving and recovering from the pandemic through mutual cross-group effort.


2021 ◽  
pp. 1-26
Author(s):  
Ruth Schmidt ◽  
Katelyn Stenger

Abstract Despite widespread recognition that behavioral public policy (BPP) needs to move beyond nudging if the field is to achieve more significant impact, problem-solving approaches remain optimized to achieve tactical success and are evaluated by short-term metrics with the assumption of stable systems. As a result, current methodologies may contribute to the development of solutions that appear well formed but become ‘brittle’ in the face of more complex contexts if they fail to consider important contextual cues, broader system forces, and emergent conditions, which can take three distinct forms: contextual, systemic, and anticipatory brittleness. The Covid-19 pandemic and vaccination rollout present an opportunity to identify and correct interventional brittleness with a new methodological approach – strategic BPP (SBPP) – that can inform the creation of more resilient solutions by embracing more diverse forms of evidence and applied foresight, designing interventions within ecosystems, and iteratively developing solutions. To advance the case for adopting a SBPP and ‘roughly right’ modes of inquiry, we use the Covid-19 vaccination rollout to define a new methodological roadmap, while also acknowledging that taking a more strategic approach may challenge current BPP norms.


Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1912
Author(s):  
Aleksander Yevtushenko ◽  
Katarzyna Topczewska ◽  
Michal Kuciej

An algorithm to determine the maximum temperature of brake systems during repetitive short-term (RST) braking mode has been proposed. For this purpose, the intermittent mode of braking was given in the form of a few cyclic stages consisting of subsequent braking and acceleration processes. Based on the Chichinadze’s hypothesis of temperature summation, the evolutions of the maximum temperature during each cycle were calculated as the sum of the mean temperature on the nominal contact surface of the friction pair elements and temperature attained on the real contact areas (flash temperature). In order to find the first component, the analytical solution to the one-dimensional thermal problem of friction for two semi-spaces taking into account frictional heat generation was adapted. To find the flash temperature, the solution to the problem for the semi-infinite rod sliding with variable velocity against a smooth surface was used. In both solutions, the temperature-dependent coefficient of friction and thermal sensitivity of materials were taken into account. Numerical calculations were carried out for disc and drum brake systems. The obtained temporal variations of sliding velocity, friction power and temperature were investigated on each stage of braking. It was found that the obtained results agree well with the corresponding data established by finite element and finite-difference methods.


BMC Biology ◽  
2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Isabella Loughland ◽  
Alexander Little ◽  
Frank Seebacher

Abstract Background Thermal plasticity is pivotal for evolution in changing climates and in mediating resilience to its potentially negative effects. The efficacy to respond to environmental change depends on underlying mechanisms. DNA methylation induced by DNA methyltransferase 3 enzymes in the germline or during early embryonic development may be correlated with responses to environmental change. This developmental plasticity can interact with reversible acclimation within adult organisms, which would increase the speed of response and could alleviate potential mismatches between parental or early embryonic environments and those experienced at later life stages. Our aim was to determine whether there is a causative relationship between DNMT3 enzyme and developmental thermal plasticity and whether either or both interact with short-term acclimation to alter fitness and thermal responses in zebrafish (Danio rerio). Results We developed a novel DNMT3a knock-out model to show that sequential knock-out of DNA methyltransferase 3a isoforms (DNMT3aa−/− and DNMT3aa−/−ab−/−) additively decreased survival and increased deformities when cold developmental temperatures in zebrafish offspring mismatched warm temperatures experienced by parents. Interestingly, short-term cold acclimation of parents before breeding rescued DNMT3a knock-out offspring by restoring survival at cold temperatures. DNMT3a knock-out genotype interacted with developmental temperatures to modify thermal performance curves in offspring, where at least one DNMT3a isoform was necessary to buffer locomotion from increasing temperatures. The thermal sensitivity of citrate synthase activity, an indicator of mitochondrial density, was less severely affected by DNMT3a knock-out, but there was nonetheless a significant interaction between genotype and developmental temperatures. Conclusions Our results show that DNMT3a regulates developmental thermal plasticity and that the phenotypic effects of different DNMT3a isoforms are additive. However, DNMT3a interacts with other mechanisms, such as histone (de)acetylation, induced during short-term acclimation to buffer phenotypes from environmental change. Interactions between these mechanisms make phenotypic compensation for climate change more efficient and make it less likely that thermal plasticity incurs a cost resulting from environmental mismatches.


2018 ◽  
Vol 48 (9) ◽  
Author(s):  
Lucas De Ross Marchioretto ◽  
Andrea De Rossi ◽  
Leonardo Oliboni do Amaral ◽  
Ana Maria Alves de Souza Ribeiro

ABSTRACT: Until few years ago there were limited options of apple rootstocks commercially available for Brazilian growers; although, new series of Geneva® rootstocks introduced recently present desirable features such as vigor control and wider lateral branch angle. On the main apple producing regions of Brazil, intermittent rainfall eventually occurs and waterlogged condition is frequent especially in high clay oxisols; in addition, little is known about the tolerance of rootstocks M.9, Marubakaido/M.9 interstock, G.202, G.213 and G.814 to waterlogging. Thus, the objective of this experiment was to evaluate the tolerance of these rootstocks to short-term waterlogging on root and aerial parameters. Potted ‘Maxi Gala’ apple plants were kept under 48 hours of waterlogging weekly throughout 19 weeks to be compared with a normal hydric condition control. The evaluated variables were: leaf, stem and root dry matter, number and length of new root emission, and number of leaves, mean leaf size and chlorophyll content. Rootstocks G.202, G.814 and Marubakaido/M.9 interstock presented more tolerance to waterlogging, and the main defense mechanism was the emission of new adventitious roots.


Religions ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 236
Author(s):  
Joanna Kulska

The increasingly acknowledged post-secular perspective has resulted in the emergence of some new approaches theorizing this phenomenon. One such approach has been the concept of religious engagement, which calls for the redefinition of the perception of religious non-state actors towards including them as important partners in the process of identifying and realizing political goals. According to this view, due to the multidimensional role played by religious communities and non-state religious actors, they need to be recognized as pivotal in creating a new form of knowledge generated through encounter and dialogue of the political decision-makers with these subjects. Among numerous others, the challenge of migration calls for enhanced debate referring to both political and ethical issues. When such a perspective is applied, the question is raised of the duties and limits of nation-states using more or less harsh political measures towards refugees and migrants based on the concept of security, but also short-term political goals. In the face of a state’s lack of will or capacity to deal with the problem of migration, the question of religion serving not only as the service-provider but also as the “trend-setter” with regard to fundamental ethical questions needs to be considered.


1996 ◽  
Vol 26 (4) ◽  
pp. 670-681 ◽  
Author(s):  
S.B. McLaughlin ◽  
D.J. Downing

Seasonal growth patterns of mature loblolly pine (Pinustaeda L.) trees over the interval 1988–1993 have been analyzed to evaluate the effects of ambient ozone on growth of large forest trees. Patterns of stem expansion and contraction of 34 trees were examined using serial measurements with sensitive dendrometer band systems. Study sites, located in eastern Tennessee, varied significantly in soil moisture, soil fertility, and stand density. Levels of ozone, rainfall, and temperature varied widely over the 6-year study interval. Regression analysis identified statistically significant influences of ozone on stem growth patterns, with responses differing widely among trees and across years. Ozone interacted with both soil moisture stress and high temperatures, explaining 63% of the high frequency, climatic variance in stem expansion identified by stepwise regression of the 5-year data set. Observed responses to ozone were rapid, typically occurring within 1–3 days of exposure to ozone at ≥40 ppb and were significantly amplified by low soil moisture and high air temperatures. Both short-term responses, apparently tied to ozone-induced increases in whole-tree water stress, and longer term cumulative responses were identified. These data indicate that relatively low levels of ambient ozone can significantly reduce growth of mature forest trees and that interactions between ambient ozone and climate are likely to be important modifiers of future forest growth and function. Additional studies of mechanisms of short-term response and interspecies comparisons are clearly needed.


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