scholarly journals Patterns of Evolutionary Speed: In Search of a Causal Mechanism

Diversity ◽  
2013 ◽  
Vol 5 (4) ◽  
pp. 811-823 ◽  
Author(s):  
Len Gillman ◽  
Shane Wright
Keyword(s):  
Causal Mechanism ◽  
Evolutionary Speed

scholarly journals Support for the evolutionary speed hypothesis from intraspecific population genetic data in the non-biting midge Chironomus riparius

2016 ◽  
Vol 283 (1825) ◽  
pp. 20152413 ◽  
Author(s):  
Ann-Marie Oppold ◽  
João A. M. Pedrosa ◽  
Miklós Bálint ◽  
João B. Diogo ◽  
Julia Ilkova ◽  
...  
Keyword(s):  
Sequence Data ◽  
Chironomus Riparius ◽  
Mutation Rates ◽  
Causal Mechanism ◽  
Ambient Temperatures ◽  
Biting Midge ◽  
Diversity Gradient ◽  
Generation Times ◽  
Show Evidence ◽  
Evolutionary Speed

The evolutionary speed hypothesis (ESH) proposes a causal mechanism for the latitudinal diversity gradient. The central idea of the ESH is that warmer temperatures lead to shorter generation times and increased mutation rates. On an absolute time scale, both should lead to an acceleration of selection and drift. Based on the ESH, we developed predictions regarding the distribution of intraspecific genetic diversity: populations of ectothermic species with more generations per year owing to warmer ambient temperatures should be more differentiated from each other, accumulate more mutations and show evidence for increased mutation rates compared with populations in colder regions. We used the multivoltine insect species Chironomus riparius to test these predictions with cytochrome oxidase I (COI) sequence data and found that populations from warmer regions are indeed significantly more differentiated and have significantly more derived haplotypes than populations from colder regions. We also found a significant correlation of the annual mean temperature with the population mutation parameter θ that serves as a proxy for the per generation mutation rate under certain assumptions. This pattern could be corroborated with two nuclear loci. Overall, our results support the ESH and indicate that the thermal regime experienced may be crucially driving the evolution of ectotherms and may thus ultimately govern their speciation rate.

Symptoms of Alcohol Dependence Predict Suicide Ideation Among Alaskan Undergraduates

Crisis ◽  
2016 ◽  
Vol 37 (3) ◽  
pp. 232-235 ◽  
Author(s):  
Christopher R. DeCou ◽  
Monica C. Skewes
Keyword(s):  
Depressive Symptoms ◽  
Alcohol Consumption ◽  
Alcohol Dependence ◽  
Suicide Ideation ◽  
Alcohol Problems ◽  
Future Research ◽  
Causal Mechanism ◽  
Students At Risk ◽  
The Relationship ◽  
Alcohol Related Problems

Abstract. Background: Previous research has demonstrated an association between alcohol-related problems and suicidal ideation (SI). Aims: The present study evaluated, simultaneously, alcohol consequences and symptoms of alcohol dependence as predictors of SI after adjusting for depressive symptoms and alcohol consumption. Method: A sample of 298 Alaskan undergraduates completed survey measures, including the Young Adult Alcohol Consequences Questionnaire, the Short Alcohol Dependence Data Questionnaire, and the Beck Depression Inventory – II. The association between alcohol problems and SI status was evaluated using sequential logistic regression. Results: Symptoms of alcohol dependence (OR = 1.88, p < .05), but not alcohol-related consequences (OR = 1.01, p = .95), emerged as an independent predictor of SI status above and beyond depressive symptoms (OR = 2.39, p < .001) and alcohol consumption (OR = 1.08, p = .39). Conclusion: Alcohol dependence symptoms represented a unique risk for SI relative to alcohol-related consequences and alcohol consumption. Future research should examine the causal mechanism behind the relationship between alcohol dependence and suicidality among university students. Assessing the presence of dependence symptoms may improve the accuracy of identifying students at risk of SI.

scholarly journals The Hippo Pathway Is Activated and Is a Causal Mechanism for Adipogenesis in Arrhythmogenic Cardiomyopathy

2014 ◽  
Vol 114 (3) ◽  
pp. 454-468 ◽  
Author(s):  
Suet Nee Chen ◽  
Priyatansh Gurha ◽  
Raffaella Lombardi ◽  
Alessandra Ruggiero ◽  
James T. Willerson ◽  
...  
Keyword(s):  
Hippo Pathway ◽  
Causal Mechanism ◽  
Arrhythmogenic Cardiomyopathy ◽  
The Hippo Pathway

Flexibility and Firmness in Crisis Bargaining

2021 ◽  
pp. 002200272199417
Author(s):  
Vesna Danilovic ◽  
Joe Clare
Keyword(s):  
Empirical Analysis ◽  
Causal Mechanism ◽  
Mixed Strategies ◽  
Bargaining Process ◽  
Theoretical Rationale ◽  
Crisis Bargaining ◽  
Peaceful Resolution ◽  
Tit For Tat

Our study compares the efficacy of mixed bargaining strategies to strict coercion or accommodation. While mixed strategies can be approached from different conceptual angles, we focus on flexible and/or firm postures as signaling properties of bargaining. In our theory and empirical analysis, we show that the combination of firmness with flexibility on both sides, without necessarily scripted rules as in tit-for-tat, leads to peaceful resolution without unilateral concessions. Its opposite, resolute firmness is unlikely to make the opponent yield, as assumed in influential literature of the traditional canon. If anything, war is most likely when both sides opt for it. We provide the theoretical rationale for these expectations, which are validated in our empirical analysis of the ICB crisis dataset for the 1918 to 2015 period. Our study also points to the bargaining process as a potential causal mechanism between democracy and peace, and therefore has relevant implications for several research strands.

scholarly journals Induced Empathy Moderates Emotional Responses to Expressive Qualities in Music

2020 ◽  
pp. 102986492097472
Author(s):  
Katherine O’Neill ◽  
Hauke Egermann
Keyword(s):  
Ecological Validity ◽  
Emotional Responses ◽  
Control Group ◽  
Causal Mechanism ◽  
Music Listening ◽  
Psychological Mechanisms ◽  
Priming Paradigm ◽  
Valence And Arousal ◽  
Experimental Group

Recent research has explored the role of empathy in the context of music listening. Here, through an empathy priming paradigm, situational empathy was shown to act as a causal mechanism in inducing emotion, although the way empathy was primed had low levels of ecological validity. We therefore conducted an online experiment to explore the extent to which information about a composer’s expressive intentions when writing a piece of music would significantly affect the degree to which participants reportedly empathise with the composer and in turn influence emotional responses to expressive music. A total of 229 participants were randomly assigned to three groups. The experimental group read short texts describing the emotions felt by the composer during the process of composition. To control for the effect of text regardless of its content, one control group read texts describing the characteristics of the music they were to hear, and a second control group was not given any textual information. Participants listened to 30-second excerpts of four pieces of music, selected to express emotions from the four quadrants of the circumplex theory of emotion. Having heard each music excerpt, participants rated the valence and arousal they experienced and completed a measure of situational empathy. Results show that situational empathy in response to music is significantly associated with trait empathy. As opposed to those in the control conditions, participants in the experimental group responded with significantly higher levels of situational empathy. Receiving this text significantly moderated the effect of the expressiveness of stimuli on induced emotion, indicating that it induced empathy. We conclude that empathy can be induced during music listening through the provision of information about the specific emotions of a person relating to the music. These findings contribute to an understanding of the psychological mechanisms that underlie emotional responses to music.

scholarly journals An overview of psychological and social factors in Charles Bonnet syndrome

2021 ◽  
Vol 13 ◽  
pp. 251584142110347
Author(s):  
Lee Jones ◽  
Lara Ditzel-Finn ◽  
Jamie Enoch ◽  
Mariya Moosajee
Keyword(s):  
Emotional Response ◽  
Causal Mechanism ◽  
Visual Hallucinations ◽  
Cognitively Normal ◽  
Charles Bonnet Syndrome ◽  
Raising Awareness ◽  
Normal Individuals ◽  
The Social ◽  
Recent Developments ◽  
Insight Into

Charles Bonnet syndrome (CBS) is a condition where cognitively normal individuals with sight impairment experience simple and/or complex visual hallucinations. The exact pathogenesis of CBS is unknown; however, deafferentation is often recognised as a causal mechanism. Studies have provided insight into the multifaceted impact of CBS on wellbeing. Onset of CBS may cause distress among those believing visual hallucinations are indicative of a neurological condition. Hallucinatory content is often congruent with the emotional response. For example, hallucinations of a macabre nature typically result in a fearful response. Visual hallucinations may be highly disruptive, causing everyday tasks to become challenging. Clinical management relies on forewarning and pre-emptive questioning. Yet, knowledge and awareness of CBS is typically low. In this review, we provide a summary of the social and psychological implications of CBS and explore recent developments aimed at raising awareness and improving patient management.

The role of the Pacific Decadal Oscillation and ocean-atmosphere interactions in driving United States heatwaves

2021 ◽  
Author(s):  
Sem Vijverberg ◽  
Dim Coumou
Keyword(s):  
Rossby Wave ◽  
Rossby Waves ◽  
Low Frequency ◽  
Causal Link ◽  
Causal Mechanism ◽  
Temperature Forecast ◽  
The Pacific ◽  
Ocean Atmosphere ◽  
The Waves

&lt;p&gt;Heatwaves can have devastating impact on society and reliable early warnings at several weeks lead time are needed. Heatwaves are often associated with quasi-stationary Rossby waves, which interact with sea surface temperature (SST). Previous studies showed that north-Pacific SST can provide long-lead predictability for eastern U.S. temperature, moderated by an atmospheric Rossby wave. The exact mechanisms, however, are not well understood. Here we analyze Rossby waves associated with heatwaves in western and eastern US. Causal inference analyses reveal that both waves are characterized by positive ocean-atmosphere feedbacks at synoptic timescales, amplifying the waves. However, this positive feedback on short timescales is not the causal mechanism that leads to a long-lead SST signal. Only the eastern US shows a long-lead causal link from SSTs to the Rossby wave. We show that the long-lead SST signal derives from low-frequency PDO variability, providing the source of eastern US temperature predictability. We use this improved physical understanding to identify more reliable long-lead predictions. When, at the onset of summer, the Pacific is in a pronounced PDO phase, the SST signal is expected to persist throughout summer. These summers are characterized by a stronger ocean-boundary forcing, thereby more than doubling the eastern US temperature forecast skill, providing a temporary window of enhanced predictability.&lt;/p&gt;

Within-Individual Effects of Dropping out of School on Violent Victimization Among Serious Adolescent Offenders

2021 ◽  
pp. 088626052110500
Author(s):  
Chongmin Na
Keyword(s):  
School Dropout ◽  
Routine Activities ◽  
Dropping Out ◽  
Causal Mechanism ◽  
Violent Victimization ◽  
Adolescent Offenders ◽  
Opportunity Structure ◽  
Risky Lifestyles ◽  
The Impact ◽  
Out Of School

Despite a recent decrease in both school dropout and victimization rates, many harsh and exclusionary school policies continue to push school-aged adolescents out of school. This study combines two research areas—school dropout and violent victimization—by investigating if dropping out of school increases the chance of violent victimization. It is hypothesized that a change in the opportunity structure associated with risky lifestyles and routine activities accounts for the link between school dropout and violent victimization. Drawing on longitudinal panel data collected from a relatively homogenous sample of 1354 serious adolescent offenders who are predominantly minorities (75%) and males (86%) and fixed-effects models which enhance the causal validity of the findings by using the same individuals as their own counterfactuals over time, this study shows that dropping out of school leads to the perpetuation of violent victimization, primarily due to a change in the opportunity structure associated with risky lifestyles and routine activities. By uncovering the pathway between school dropout and victimization, this study contributes to the knowledge base on the impact of school dropouts, the source of violent victimization, and the causal mechanism underlying the link between dropping out of school and violent victimization—all of which are relatively understudied despite their significant implications for theory and policy.

scholarly journals Fault “Corrosion” by Fluid Injection: A Potential Cause of the November 2017 MW 5.5 Korean Earthquake

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-23 ◽  
Author(s):  
Rob Westaway ◽  
Neil M. Burnside
Keyword(s):  
Time Delays ◽  
Chemical Properties ◽  
Fluid Injection ◽  
Anthropogenic Activity ◽  
Geothermal System ◽  
Causal Mechanism ◽  
Seismogenic Fault ◽  
Subsurface Environment ◽  
Anthropogenic Seismicity ◽  
Physical And Chemical

The November 2017 MW 5.5 Pohang earthquake is one of the largest and most damaging seismic events to have occurred in the Korean peninsula over the last century. Its close proximity to an Enhanced Geothermal System (EGS) site, where hydraulic injection into granite had taken place over the previous two years, has raised the possibility that it was anthropogenic; if so, it was by far the largest earthquake caused by any EGS project worldwide. However, a potential argument that this earthquake was independent of anthropogenic activity considers the delay of two or three months before its occurrence, following the most recent injection into each of the wells. A better understanding of the physical and chemical processes that occur following fluid injection into granite is thus warranted. We show that hydrochemical changes occurring while surface water, injected into granite, reequilibrates chemically with its subsurface environment, can account for time delays for earthquake occurrence of such duration, provided the seismogenic fault was already critically stressed, or very close to the condition for slip. This candidate causal mechanism counters the potential argument that the time delay militates against an anthropogenic cause of the Pohang earthquake and can account for its relatively large magnitude as a consequence of a relatively small-volume injection. The resulting analysis places bounds on combinations of physical and chemical properties of rocks, injected volume, and potential postinjection time delays for significant anthropogenic seismicity during future EGS projects in granite.

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