Interactive effects of road salt and sediment disturbance on the productivity of seven common aquatic macrophytes

2018 ◽  
Vol 63 (7) ◽  
pp. 709-720 ◽  
Author(s):  
Aaron Stoler ◽  
Kelsey Sudol ◽  
Joseph Mruzek ◽  
Rick Relyea
2017 ◽  
Vol 74 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Max R. Lambert ◽  
Aaron B. Stoler ◽  
Meredith S. Smylie ◽  
Rick A. Relyea ◽  
David K. Skelly

Myriad natural and anthropogenic chemicals alter aquatic vertebrate sex ratios, with implications for population dynamics. Despite 22 million metric tons of salt applied to US roads annually, with much of it entering aquatic environments, it is unknown whether salt impacts sex ratios. Moreover, changes in forest composition co-occur with increased road salt application, dramatically changing ecosystems. We explore how road salt (sodium chloride) and two leaf litter types might influence amphibian development. By examining wood frog (Rana sylvatica = Lithobates sylvaticus) metamorphs reared with different combinations of salt (114 and 867 mg Cl·L−1) and litter species (none, maple (Acer rubrum), oak (Quercus spp.)), we show that salt masculinizes tadpole sex ratios, whereas oak, but not maple, litter feminizes populations. Road salt addition eliminates sexual dimorphism in oak-reared tadpoles, but enhances sexual size dimorphisms in maple-reared tadpoles, producing larger females. We are the first to show that road salt and native tree leaf litter manipulates vertebrate sex ratios and sex-specific development. Human land use might therefore influence vertebrate development through direct effects of contamination and indirect effects of altered botanical composition.


2021 ◽  
Author(s):  
Jéssica Airisse Guimarães Sampaio ◽  
Carla Roberta Gonçalves Reis ◽  
Marília Cunha Lignon ◽  
Gabriela Bielefeld Nardoto ◽  
Luiz Felippe Salemi

Abstract The colonization and spread of non-native species are recognized as a critical driver of environmental change in mangrove ecosystems. However, environmental factors that favor non-native plant colonization in mangroves are still poorly understood. To contribute to filling this gap, we investigated the effect of selected abiotic factors associated controlling aquatic macrophytes colonization in mangroves in Southeastern Brazil. Furthermore, we also assessed foliar attributes of native and non-native species to evaluate whether biotic attributes favored the colonization. We selected 18 plots in mangrove forests under different levels of anthropogenic N inputs, both colonized and non-colonized by aquatic macrophytes in the Estuarine-Lagoon Complex of Cananeia-Iguape, southeastern Brazil. We measured interstitial salinity, sediment nitrate and ammonium concentrations, and sediment physicochemical properties. We also measured foliar nitrogen (N) concentrations, foliar C:N, and foliar δ13C of both native and non-native species. We found that interstitial salinity at 10 cm depth followed by nitrate concentrations in sediment were the main factors associated with the occurrence of aquatic macrophytes in the studied mangrove areas. Moreover, non-native species had about 2-fold higher foliar N concentrations as well as about a 1.5-fold lower C:N ratios compared to native species. Low salinity and increased N availability in sediment allowed for the success of aquatic macrophytes into mangrove forests, also resulting in high amount of dead mangrove trunks (up 53% of basal area).


2013 ◽  
Vol 27 (3) ◽  
pp. 142-148 ◽  
Author(s):  
Konstantinos Trochidis ◽  
Emmanuel Bigand

The combined interactions of mode and tempo on emotional responses to music were investigated using both self-reports and electroencephalogram (EEG) activity. A musical excerpt was performed in three different modes and tempi. Participants rated the emotional content of the resulting nine stimuli and their EEG activity was recorded. Musical modes influence the valence of emotion with major mode being evaluated happier and more serene, than minor and locrian modes. In EEG frontal activity, major mode was associated with an increased alpha activation in the left hemisphere compared to minor and locrian modes, which, in turn, induced increased activation in the right hemisphere. The tempo modulates the arousal value of emotion with faster tempi associated with stronger feeling of happiness and anger and this effect is associated in EEG with an increase of frontal activation in the left hemisphere. By contrast, slow tempo induced decreased frontal activation in the left hemisphere. Some interactive effects were found between mode and tempo: An increase of tempo modulated the emotion differently depending on the mode of the piece.


Crisis ◽  
2019 ◽  
Vol 40 (6) ◽  
pp. 413-421 ◽  
Author(s):  
Megan L. Rogers ◽  
Thomas E. Joiner

Abstract. Background: Acute suicidal affective disturbance (ASAD) has been proposed as a suicide-specific entity that confers risk for imminent suicidal behavior. Preliminary evidence suggests that ASAD is associated with suicidal behavior beyond a number of factors; however, no study to date has examined potential moderating variables.  Aims: The present study tested the hypotheses that physical pain persistence would moderate the relationship between ASAD and (1) lifetime suicide attempts and (2) attempt lethality. Method: Students ( N = 167) with a history of suicidality completed self-report measures assessing the lifetime worst-point ASAD episode and the presence of a lifetime suicide attempt, a clinical interview about attempt lethality, and a physical pain tolerance task. Results: Physical pain persistence was a significant moderator of the association between ASAD and lifetime suicide attempts ( B = 0.00001, SE = 0.000004, p = .032), such that the relationship between ASAD and suicide attempts strengthened at increasing levels of pain persistence. The interaction between ASAD and pain persistence in relation to attempt lethality was nonsignificant ( B = 0.000004, SE = 0.00001, p = .765). Limitations: This study included a cross-sectional/retrospective analysis of worst-point ASAD symptoms, current physical pain perception, and lifetime suicide attempts. Conclusion: ASAD may confer risk for suicidal behavior most strongly at higher levels of pain persistence, whereas ASAD and pain perception do not influence attempt lethality.


2015 ◽  
Vol 36 (3) ◽  
pp. 170-176 ◽  
Author(s):  
Erin N. Stevens ◽  
Joseph R. Bardeen ◽  
Kyle W. Murdock

Parenting behaviors – specifically behaviors characterized by high control, intrusiveness, rejection, and overprotection – and effortful control have each been implicated in the development of anxiety pathology. However, little research has examined the protective role of effortful control in the relation between parenting and anxiety symptoms, specifically among adults. Thus, we sought to explore the unique and interactive effects of parenting and effortful control on anxiety among adults (N = 162). Results suggest that effortful control uniquely contributes to anxiety symptoms above and beyond that of any parenting behavior. Furthermore, effortful control acted as a moderator of the relationship between parental overprotection and anxiety, such that overprotection is associated with anxiety only in individuals with lower levels of effortful control. Implications for potential prevention and intervention efforts which specifically target effortful control are discussed. These findings underscore the importance of considering individual differences in self-regulatory abilities when examining associations between putative early-life risk factors, such as parenting, and anxiety symptoms.


2018 ◽  
Vol 39 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Giulia Fuochi ◽  
Chiara A. Veneziani ◽  
Alberto Voci

Abstract. This paper aimed to assess whether differences in the way to conceive happiness, measured by the Orientations to Happiness measure, were associated with specific reactions to negative events. We hypothesized that among orientations to pleasure (portraying hedonism), to meaning (representing a eudaimonic approach to life), and to engagement (derived from the experience of flow), orientation to meaning would have displayed a stronger protective role against recent negative and potentially stressful events. After providing a validation of the Italian version of the Orientations to Happiness measure (Study 1), we performed regression analyses of the three orientations on positive and negative emotions linked to a self-relevant negative event (Study 2), and moderation analyses assessing the interactive effects of orientations to happiness and stressful events on well-being indicators (Study 3). Our findings supported the hypotheses. In Study 2, meaning was associated with positive emotions characterized by a lower activation (contentment and interest) compared to the positive emotions associated with pleasure (amusement, eagerness, and happiness). In Study 3, only meaning buffered the effect of recent potentially stressful events on satisfaction with life and positive affect. Results suggest that orientation to meaning might help individuals to better react to negative events.


Sign in / Sign up

Export Citation Format

Share Document