scholarly journals Caprellid amphipods (Caprella spp.) are vulnerable to both physiological and habitat-mediated effects of ocean acidification

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5327 ◽  
Author(s):  
Emily G. Lim ◽  
Christopher D.G. Harley
Keyword(s):  
Ocean Acidification ◽  
Indirect Effects ◽  
Species Interactions ◽  
Positive Association ◽  
Direct And Indirect Effects ◽  
Metabolic Demand ◽  
Mediated Effects ◽  
Biogenic Habitat ◽  
Experimental Acidification ◽  
Caprella Mutica

Ocean acidification (OA) is one of the most significant threats to marine life, and is predicted to drive important changes in marine communities. Although OA impacts will be the sum of direct effects mediated by alterations of physiological rates and indirect effects mediated by shifts in species interactions and biogenic habitat provision, direct and indirect effects are rarely considered together for any given species. Here, we assess the potential direct and indirect effects of OA on a ubiquitous group of crustaceans: caprellid amphipods (Caprella laeviuscula and Caprella mutica). Direct physiological effects were assessed by measuring caprellid heart rate in response to acidification in the laboratory. Indirect effects were explored by quantifying caprellid habitat dependence on the hydroid Obelia dichotoma, which has been shown to be less abundant under experimental acidification. We found that OA resulted in elevated caprellid heart rates, suggestive of increased metabolic demand. We also found a strong, positive association between caprellid population size and the availability of OA-vulnerable O. dichotoma, suggesting that future losses of biogenic habitat may be an important indirect effect of OA on caprellids. For species such as caprellid amphipods, which have strong associations with biogenic habitat, a consideration of only direct or indirect effects could potentially misestimate the full impact of ocean acidification.

Direct and indirect effects of near-future pCO2 levels on zooplankton dynamics

2017 ◽  
Vol 68 (2) ◽  
pp. 373 ◽  
Author(s):  
Cédric L. Meunier ◽  
María Algueró-Muñiz ◽  
Henriette G. Horn ◽  
Julia A. F. Lange ◽  
Maarten Boersma
Keyword(s):  
Ocean Acidification ◽  
Indirect Effects ◽  
Trophic Levels ◽  
Model Organisms ◽  
High Pco2 ◽  
Direct And Indirect Effects ◽  
Oxyrrhis Marina ◽  
Short Term Exposure ◽  
Zooplankton Growth ◽  
Seawater Pco2

Ocean acidification has direct physiological effects on organisms, for example by dissolving the calcium carbonate structures of calcifying species. However, non-calcifiers may also be affected by changes in seawater chemistry. To disentangle the direct and indirect effects of ocean acidification on zooplankton growth, we undertook a study with two model organisms. Specifically, we investigated the individual effects of short-term exposure to high and low seawater pCO2, and different phytoplankton qualities as a result of different CO2 incubations on the growth of a heterotrophic dinoflagellate (Oxyrrhis marina) and a copepod species (Acartia tonsa). It was observed previously that higher CO2 concentrations can decrease phytoplankton food quality in terms of carbon:nutrient ratios. We therefore expected both seawater pCO2 (pH) and phytoplankton quality to result in decreased zooplankton growth. Although we expected lowest growth rates for all zooplankton under high seawater pCO2 and low algal quality, we found that direct pH effects on consumers seem to be of lesser importance than the associated decrease in algal quality. The decrease in the quality of primary producers under high pCO2 conditions negatively affected zooplankton growth, which may lead to lower availability of food for the next trophic level and thus potentially affect the recruitment of higher trophic levels.

Dimensions and Types of Supervisory Control: Effects on Salesperson Performance and Satisfaction

1996 ◽  
Vol 60 (1) ◽  
pp. 89-105 ◽  
Author(s):  
Goutam N. Challagalla ◽  
Tasadduq A. Shervani
Keyword(s):  
Supervisory Control ◽  
Indirect Effects ◽  
Fortune 500 ◽  
Direct And Indirect Effects ◽  
Behavior Control ◽  
Salesperson Performance ◽  
Mediated Effects ◽  
Fortune 500 Companies ◽  
Independent Effects ◽  
Conceptual Work

The authors extend the conceptual work of Anderson and Oliver (1987) and Jaworski (1988) on control in three ways. First, they account for the independent effects of the reinforcement dimension of control, in addition to the information dimension traditionally studied. Second, to reflect the varied behaviors that supervisors attempt to control, they disaggregate behavior control into activity control and capability control. Third, they delineate the direct and mediated effects of control on salespeople. Their proposed framework was tested with data collected from 270 salespeople in five industrial product divisions of two Fortune 500 companies. The findings suggest that managers must carefully match controls-in-use with desired results. Overall, the results show that information and reinforcement effects vary, which suggests the need to distinguish between the information provided and the actual reinforcements administered to salespeople. They also show that activity and capability control have different effects and draw a sharp distinction between two types of behavior control. Finally, the results suggest that supervisory controls primarily have indirect effects on salesperson performance, but both direct and indirect effects on satisfaction

Direct and indirect effects of ocean acidification and warming on a marine plant–herbivore interaction

Oecologia ◽  
2013 ◽  
Vol 173 (3) ◽  
pp. 1113-1124 ◽  
Author(s):  
Alistair G. B. Poore ◽  
Alexia Graba-Landry ◽  
Margaux Favret ◽  
Hannah Sheppard Brennand ◽  
Maria Byrne ◽  
...  
Keyword(s):  
Ocean Acidification ◽  
Indirect Effects ◽  
Direct And Indirect Effects ◽  
Marine Plant ◽  
Plant Herbivore Interaction ◽  
Plant Herbivore ◽  
Herbivore Interaction

Correlation and Path Analysis Studies for Various Yield and Component Traits in the Segregating Generations of Blackgram [Vigna mungo (L). Hepper]

2021 ◽  
Author(s):  
Rhitisha Sood ◽  
R.K. Mittal ◽  
V.K. Sood ◽  
Shailja Sharma
Keyword(s):  
Path Analysis ◽  
Indirect Effects ◽  
Block Design ◽  
Positive Association ◽  
Direct And Indirect Effects ◽  
Legume Crop ◽  
Component Traits ◽  
Biological Yield ◽  
Correlation And Path Analysis ◽  
Positive Direct

Background: Blackgram despite of being a highly nutritious and short duration legume crop, it is not cultivated on large scales due to many constraints. Considering this, the research was aimed to develop blackgram genotypes with wider adaptability, genetic variability and high yielding potential by studying nature and magnitude of association among yield and related traits for effective production. Methods: The present investigation was carried out at Experimental Farm of the Department of Genetics and Plant Breeding, College of Agriculture, CSK HPKV, Palampur (H.P.) to assess the character association and direct and indirect effects among yield and related traits in 14 crosses and ten parents for 11 quantitative characters during Kharif 2018 and 2019 in randomized complete block design with three replications. Result: Correlation studies highlighted that seed yield per plant had significant and positive association with pods per plant, biological yield per plant, pod length, plant height and 100 seed-weight at genotypic and phenotypic levels in both generations. Study of path analysis revealed that biological yield per plant and pods per plant exhibited maximum positive direct and indirect effects to the total association between yield and other component traits in both the generations. These traits could be suggested as best selection indices on priority basis which would be commendable to improve the performance of genotypes during breeding programme.

scholarly journals Invasion in a Community Context: Genetic Variation in the Strength of Direct and Indirect Effects

2021 ◽  
Author(s):  
Carmen Hoffbeck ◽  
Nicole Cammisa ◽  
Casey P terHorst
Keyword(s):  
Indirect Effects ◽  
Species Interactions ◽  
Local Environment ◽  
Community Context ◽  
Invasion Success ◽  
Plant Performance ◽  
Direct And Indirect Effects ◽  
Effects Of Drought ◽  
Abiotic And Biotic Factors ◽  
Widely Invasive

Abstract Predicting invasion success requires understanding how abiotic and biotic factors in the local environment interact with the particular traits of potential invaders. Relative to studies of direct antagonistic effects, fewer studies have examined how positive species interactions, such as facilitation or mutualism, or indirect interactions in multispecies communities, can affect invasion success. We examined the effects of drought and mutualisms with rhizobia bacteria on the performance of a widely invasive legume, Medicago polymorpha. In a greenhouse experiment, we found that watering regime affected plant performance, but non-linear patterns in response to decreasing water were dependent on the specific plant genotype. In a second experiment, we found that the effects of drought on plant performance were dependent on the presence of rhizobia, particularly for genotypes collected from the invasive range. This suggests that indirect ecological effects may have important consequences for invasion success. We contextualize the strength of these direct and indirect effects by comparing this study to effect sizes in other studies of the same species. In this species, predicting invasion into a natural community context will require understanding multiple direct and indirect effects in the local environment, as well as their effects on the specific genetic composition of the invading population.

scholarly journals Direct and latent effects of ocean acidification on the transition of a sea urchin from planktonic larva to benthic juvenile

2021 ◽  
Author(s):  
Narimane Dorey ◽  
Emanuela Butera ◽  
Nadjejda Espinel-Velasco ◽  
Sam Dupont
Keyword(s):  
Life History ◽  
Ocean Acidification ◽  
Sea Urchin ◽  
Indirect Effects ◽  
Strongylocentrotus Droebachiensis ◽  
Energetic Cost ◽  
Continuous Exposure ◽  
Direct And Indirect Effects ◽  
Life History Stages ◽  
Latent Effects

Ongoing ocean acidification (OA) is expected to affect marine organisms and ecosystems. While sea urchins can survive a wide range of pH, this comes at a high energetic cost, and early life stages are particularly vulnerable. Information on how OA affects transitions between life-history stages is scarce. We evaluated the direct and indirect effects of pH (pHT 8.0, 7.6 and 7.2) on the development and transition between life-history stages of the sea urchin Strongylocentrotus droebachiensis, from fertilization to early juvenile. Continuous exposure to low pH negatively affected larval mortality and growth. At pH 7.2, formation of the rudiment (the primordial juvenile) was delayed by two days. Larvae raised at pH 8.0 and transferred to 7.2 after competency had mortality rates five to six times lower than those kept at 8.0, indicating that pH also has a direct effect on older, competent larvae. Latent effects were visible on the larvae raised at pH 7.6: they were more successful in settling (45%) and metamorphosing (30%) than larvae raised at 8.0 (17 and 1% respectively). These direct and indirect effects of OA on settlement and metamorphosis have important implications for population survival.

scholarly journals Exploring the Environmental Manifestation of Types of Music on Reinforcing Mindfulness and Concurrent Calorie Intake

2020 ◽  
pp. 003329412096727
Author(s):  
Misba Hussain ◽  
Helen Egan ◽  
Rebecca Keyte ◽  
Michail Mantzios
Keyword(s):  
Indirect Effects ◽  
Classical Music ◽  
Positive Association ◽  
Calorie Intake ◽  
Future Research ◽  
Music Listening ◽  
Direct And Indirect Effects ◽  
State Mindfulness ◽  
Sweet Foods

Background The role of music on energy intake is conflicting, and recent research has suggested a positive association between classical music listening and mindfulness. Objective The purpose of the present study was to investigate the effect of music, specifically classical music on state mindfulness and calorie intake of energy-dense foods. Method One hundred participants were randomly assigned to either a classical, popular or no music condition, and were served a variety of sweet (i.e., chocolate and cookies) and savoury (i.e., crisps) energy-dense foods. Results: The results found no significant differences in state mindfulness, overall calorie intake, or intake of sweet foods across the three conditions. However, participants in the classical music condition did consume significantly less savoury food than those in the no music condition. Conclusion Playing classical music may be beneficial in reducing intake of savoury foods, but not through the association to changes in state mindfulness. Future research should explore extended sessions of music listening on state mindfulness and other experiential evaluations of mindfulness to conclude on the direct and indirect effects of music on sweet and savoury foods.

scholarly journals Potential impacts of ocean acidification on the Puget Sound food web

2013 ◽  
Vol 70 (4) ◽  
pp. 823-833 ◽  
Author(s):  
D. Shallin Busch ◽  
Chris J. Harvey ◽  
Paul McElhany
Keyword(s):  
Ocean Acidification ◽  
Food Web ◽  
Indirect Effects ◽  
Puget Sound ◽  
Direct And Indirect Effects ◽  
Direct Effects ◽  
Ecosystem Impacts ◽  
Complex Interactions ◽  
Species Groups ◽  
Food Web Model

Abstract Busch, D. S., Harvey, C. J., and McElhany, P. 2013. Potential impacts of ocean acidification on the Puget Sound food web. – ICES Journal of Marine Science, 70: 823–833. Ecosystem impacts of ocean acidification (OA) were explored by imposing scenarios designed to mimic OA on a food web model of Puget Sound, a large estuary in northwestern USA. The productivity of functional groups containing mostly calcifiers was decreased while still allowing other species groups to respond to the scenarios in a dynamic way through indirect effects. Results focus on changes in ecosystem services and structure. Sometimes the direct and indirect effects of OA countered each other due to interactions between predators and prey within the food web, leading to little change in the food web. In other cases, direct and indirect effects caused greater change in the food web than anticipated from direct effects alone. Results were strongly affected by the group on which OA was directly imposed, with changes in copepod productivity being the most influential. While there is much uncertainty in our predictions, focusing on the complex interactions among species, and between species and their environment, will yield better understanding of how ecosystems may respond to OA.

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