This study examines the level of politicization and polarization in COVID-19 news in U.S. newspapers and televised network news from March to May 2020. Using multiple computer-assisted content ...analytic approaches, we find that newspaper coverage is highly politicized, network news coverage somewhat less so, and both newspaper and network news coverage are highly polarized. We find that politicians appear in newspaper coverage more frequently than scientists, whereas politicians and scientists are more equally featured in network news. We suggest that the high degree of politicization and polarization in initial COVID-19 coverage may have contributed to polarization in U.S. COVID-19 attitudes.
Using a national sample, this study experimentally tests the effects of news visuals and texts that emphasize either the causes and impacts of climate change or actions that can be taken to address ...climate change. We test the effects of variations in text and imagery on discrete emotions (i.e., hope, fear, and anger) and, indirectly, on support for climate mitigation policies. Political ideology is examined as a moderator. The findings indicate that news images and texts that focus on climate‐oriented actions can increase hope and, in the case of texts, decrease fear and anger, and these effects generally hold across the ideological spectrum. In turn, the influence of emotions on policy support depends on ideology: Hope and fear increase support for climate policies for all ideological groups but particularly conservatives, whereas anger polarizes the opinions of liberals and conservatives. Implications for climate change communication that appeals to emotions are discussed.
•We evaluate how framing affects support for four low-carbon energy policies among U.S. partisans.•For Republicans, a climate change frame lowers support relative to pollution or security frames.•We ...find framing effects for renewable energy, carbon tax, and fuel efficiency policies, but not nuclear power.•No framing effects are observed among Democrats or Independents.•Results support a motivated reasoning rather than heuristic processing mechanism.
This study examines how public support for four specific low-carbon energy policies (renewable energy investment, revenue-neutral carbon tax, fuel efficiency regulations, expansion of nuclear power) varies when these policies are framed as a way to reduce either climate change, air pollution, or energy dependence. A survey question wording experiment with a nationally representative U.S. sample is utilized. We find framing effects only among Republicans, whose policy support was lower in response to the climate change frame versus the air pollution and energy security frames for all policies except nuclear power. This suggests that framing effects are conditional on political partisanship and policy content. When testing the processing mechanism behind these effects, we find no evidence that the climate change frame functions as a simple heuristic; rather, the findings are consistent with motivated reasoning, whereby the framing effects on policy support are mediated by the policy’s perceived relative benefits and costs.
The deficit-model of science communication assumes increased communication about science issues will move public opinion toward the scientific consensus. However, in the case of climate change, ...public polarization about the issue has increased in recent years, not diminished. In this study, we draw from theories of motivated reasoning, social identity, and persuasion to examine how science-based messages may increase public polarization on controversial science issues such as climate change. Exposing 240 adults to simulated news stories about possible climate change health impacts on different groups, we found the influence of identification with potential victims was contingent on participants’ political partisanship. This partisanship increased the degree of political polarization on support for climate mitigation policies and resulted in a boomerang effect among Republican participants. Implications for understanding the role of motivated reasoning within the context of science communication are discussed.
Under the archaeological canine surrogacy approach (CSA) it is assumed that because dogs were reliant on humans for food, they had similar diets to the people with whom they lived. As a result, the ...stable isotope ratios of their tissues (bone collagen and apatite, tooth enamel and dentine collagen) will be close to those of the humans with whom they cohabited. Therefore, in the absence of human tissue, dog tissue isotopes can be used to help reconstruct past human diets. Here δ
C and δ
N ratios on previously published dog and human bone collagen from fourteenth-seventeenth century AD ancestral Iroquoian village archaeological sites and ossuaries in southern Ontario are used with MixSIAR, a Bayesian dietary mixing model, to determine if the dog stable isotope ratios are good proxies for human isotope ratios in dietary modeling for this context. The modeling results indicate that human dietary protein came primarily from maize and high trophic level fish and dogs from maize, terrestrial animals, low trophic level fish, and human feces. While isotopes from dog tissues can be used as general analogs for human tissue isotopes under CSA, greater insights into dog diets can be achieved with Bayesian dietary mixing models.
Using an online experiment with a national sample, this study tests the effects of political efficacy messages on two types of climate-related political participation via the discrete emotions of ...hope, fear, and anger and compares these effects across ideological groups. Relative to a message that discusses only negative climate impacts, messages that emphasize the internal, external, or response efficacy of political actions to address climate change are found to influence hope and fear but not anger, and these effects vary by political ideology. Furthermore, exposure to efficacy information indirectly increases participation via hope—even, in some cases, among conservatives.
During development and adulthood, brain plasticity is evident at several levels, from synaptic structure and function to the outgrowth of dendrites and axons. Whether and how sex impinges on neuronal ...plasticity is poorly understood. Here we show that the sex-shared GABA (γ-aminobutyric acid)-releasing DVB neuron in Caenorhabditis elegans displays experience-dependent and sexually dimorphic morphological plasticity, characterized by the stochastic and dynamic addition of multiple neurites in adult males. These added neurites enable synaptic rewiring of the DVB neuron and instruct a functional switch of the neuron that directly modifies a step of male mating behaviour. Both DVB neuron function and male mating behaviour can be altered by experience and by manipulation of postsynaptic activity. The outgrowth of DVB neurites is promoted by presynaptic neurexin and antagonized by postsynaptic neuroligin, revealing a non-conventional activity and mode of interaction of these conserved, human-disease-relevant factors.
European metal artifacts in assemblages from sites predating the physical presence of Europeans in Northern Iroquoia in present-day New York, USA and southern Ontario, Canada have been used as ...chronological markers for the mid-sixteenth century AD. In the Mohawk River Valley of New York, European metal artifacts at sites pre-dating the physical presence of Europeans have been used by archaeologists as a terminus post quem (TPQ) of 1525 to 1550 in regional chronologies. This has been done under the assumption that these metals did not begin to circulate until after sustained European presence on the northern Atlantic coast beginning in 1517. Here we use Bayesian chronological modeling of a large set of radiocarbon dates to refine our understanding of early European metal circulation in the Mohawk River Valley. Our results indicate that European iron and cuprous metals arrived earlier than previously thought, by the beginning of the sixteenth century, and cannot be used as TPQs. Together with recent Bayesian chronological analyses of radiocarbon dates from several sites in southern Ontario, these results add to our evolving understanding of intra-regional variation in Northern Iroquoia of sixteenth-century AD circulation and adoption of European goods.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Effects of rapid evolution on species coexistence Hart, Simon P.; Turcotte, Martin M.; Levine, Jonathan M.
Proceedings of the National Academy of Sciences - PNAS,
02/2019, Letnik:
116, Številka:
6
Journal Article
Recenzirano
Odprti dostop
Increasing evidence for rapid evolution suggests that the maintenance of species diversity in ecological communities may be influenced by more than purely ecological processes. Classic theory shows ...that interspecific competition may select for traits that increase niche differentiation, weakening competition and thus promoting species coexistence. While empirical work has demonstrated trait evolution in response to competition, if and how evolution affects the dynamics of the competing species—the key step for completing the required eco-evolutionary feedback—has been difficult to resolve. Here, we show that evolution in response to interspecific competition feeds back to change the course of competitive population dynamics of aquatic plant species over 10–15 generations in the field. By manipulating selection imposed by heterospecific competitors in experimental ponds, we demonstrate that (i) interspecific competition drives rapid genotypic change, and (ii) this evolutionary change in one competitor, while not changing the coexistence outcome, causes the population trajectories of the two competing species to converge. In contrast to the common expectation that interspecific competition should drive the evolution of niche differentiation, our results suggest that genotypic evolution resulted in phenotypic changes that altered population dynamics by affecting the competitive hierarchy. This result is consistent with theory suggesting that competition for essential resources can limit opportunities for the evolution of niche differentiation. Our finding that rapid evolution regulates the dynamics of competing species suggests that ecosystems may rely on continuous feedbacks between ecology and evolution to maintain species diversity.
News organizations increasingly use the terms “climate emergency” and “climate crisis” to convey the urgency of climate change; yet, little is known about how this terminology affects news audiences. ...This study experimentally examined how using “climate emergency,” “climate crisis,” or “climate change” in Twitter-based news stories influences public engagement with climate change and news perceptions, as well as whether the effects depend on the focus of the news (i.e., on climate impacts, actions, or both impacts and actions) and on participants’ political ideology. Results showed no effect of terminology on climate change engagement; however, “climate emergency” reduced perceived news credibility and newsworthiness compared to “climate change.” Both climate engagement and news perceptions were more consistently affected by the focus of the stories: news about climate impacts increased fear, decreased efficacy beliefs and hope, and reduced news credibility compared to news about climate actions. No interactions with political ideology were found.
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