scholarly journals Previous oil exposure alters Gulf Killifish Fundulus grandis oil avoidance behavior

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10587
Author(s):  
Charles W. Martin ◽  
Ashley M. McDonald ◽  
Guillaume Rieucau ◽  
Brian J. Roberts
Keyword(s):  
Oil Spills ◽  
Field Studies ◽  
Future Research ◽  
Ecological Communities ◽  
Fundulus Grandis ◽  
High Exposure ◽  
Choice Tests ◽  
Exposure Levels ◽  
And Function ◽  
Oil Exposure

Oil spills threaten the structure and function of ecological communities. The Deepwater Horizon spill was predicted to have catastrophic consequences for nearshore fishes, but field studies indicate resilience in populations and communities. Previous research indicates many marsh fishes exhibit avoidance of oil contaminated areas, representing one potential mechanism for this resilience. Here, we test whether prior oil exposure of Gulf killifish Fundulus grandis alters this avoidance response. Using choice tests between unoiled and oiled sediments at one of three randomized concentrations (low: 0.1 L oil m−2, medium: 0.5 L oil m−2, or high: 3.0 L oil m−2), we found that, even at low prior exposure levels, killifish lose recognition of oiled sediments compared to control, unexposed fish. Preference for unoiled sediments was absent across all oil concentrations after oil exposure, and some evidence for preference of oiled sediments at high exposure was demonstrated. These results highlight the lack of response to toxic environments in exposed individuals, indicating altered behavior despite organism survival. Future research should document additional sublethal consequences that affect ecosystem and food web functioning.

scholarly journals Previous oil exposure alters oil avoidance behavior in a common marsh fish, the Gulf Killifish Fundulus grandis

2020 ◽  
Author(s):  
Charles W. Martin ◽  
Ashley M. McDonald ◽  
Guillaume Rieucau ◽  
Brian J. Roberts
Keyword(s):  
Oil Spills ◽  
Spatial Scales ◽  
Chemical Constituents ◽  
Field Studies ◽  
Future Research ◽  
Ecological Communities ◽  
Fundulus Grandis ◽  
Individual Level ◽  
Marine Disasters ◽  
Oil Exposure

AbstractOil spills threaten the structure and function of ecological communities. In the northern Gulf of Mexico, the 2010 Deepwater Horizon spill was among the largest marine disasters in history. While many predicted catastrophic consequences for nearshore fishes, field studies indicate surprising resilience in populations and communities. One potential mechanism for this resilience is the recognition and behavioral avoidance at small spatial scales of the toxic chemical constituents found in oil. Previous research indicates many marsh fishes have the capacity to avoid oil contaminated areas. Here, we test whether prior oil exposure of a common marsh fish, the Gulf killifish Fundulus grandis, alters this avoidance response. Using choice tests between unoiled and a range of oiled sediments, we found that, even at low levels of previous exposure, killifish lose recognition of oiled sediments. Preference for unoiled sediments was lost across the entire range of oil concentrations tested here after oil exposure, and some evidence for preference of oiled sediments was even demonstrated. These results provide evidence for lack of response to toxic environments in exposed individuals, suggesting sublethal impairment of sensory mechanisms on an individual level despite organism survival. Future research should highlight additional sublethal consequences that affect ecosystem and food web functioning.

Community Ecology of Stream Fishes: Concepts, Approaches, and Techniques

2010 ◽  
Keyword(s):  
Community Ecology ◽  
Fish Assemblages ◽  
Abiotic Factors ◽  
Biotic Interactions ◽  
Theoretical Models ◽  
Field Studies ◽  
Structure And Function ◽  
Activity Levels ◽  
Ecological Communities ◽  
And Function

<em>Abstract</em>.—Ecological communities are structured by a combination of stochastic and deterministic processes, the latter including both abiotic factors and biotic interactions such as predation. Many studies, mostly in relatively stable ecosystems such as lakes, have demonstrated top-down effects on community structure and function. Communities or species in dynamic nonequilibrium ecosystems such as streams may also respond strongly to predation pressure. In this chapter, we review experimental research on effects of predation on fish assemblages in lotic systems, focusing on developments in the decades since Matthews and Heins (1987). Direct experimental evidence indicates that predators strongly affect lotic fish assemblages via direct and indirect pathways of lethal and nonlethal interactions. Across studies, predators consistently reduced prey density, caused changes in prey habitat use, and decreased prey activity levels. Predators may also affect aspects of prey life history and reproduction in streams, and the presence of multiple predator species may result in prey risk enhancement. Our review identified five areas needing additional research that may lead to further advances in stream fish community ecology: (1) linking predation experiments with theoretical models of fish assemblage structure and function, (2) quantifying functional traits of predators and prey, (3) manipulating whole assemblages and testing multispecies interactions, (4) understanding the role of predation in human-modified ecosystems, and (5) application of analytical approaches that facilitate integration among these areas of research as well as with observational field studies.

scholarly journals Learning to live with interfering neighbours: the influence of time of learning and level of encoding on word learning

2019 ◽  
Vol 6 (4) ◽  
pp. 181842 ◽  
Author(s):  
S. Walker ◽  
L. M. Henderson ◽  
F. E. Fletcher ◽  
V. C. P. Knowland ◽  
S. A. Cairney ◽  
...  
Keyword(s):  
Word Learning ◽  
Explicit Memory ◽  
Explicit Knowledge ◽  
Future Research ◽  
Exposure Level ◽  
Lexical Competition ◽  
High Exposure ◽  
Word Memory ◽  
Exposure Levels ◽  
Novel Word Learning

New vocabulary is consolidated offline, particularly during sleep; however, the parameters that influence consolidation remain unclear. Two experiments investigated effects of exposure level and delay between learning and sleep on adults' consolidation of novel competitors (e.g. BANARA) to existing words (e.g. BANANA). Participants made speeded semantic decisions (i.e. a forced choice: natural versus man-made) to the existing words, with the expectation that novel word learning would inhibit responses due to lexical competition. This competition was observed, particularly when assessed after sleep, for both standard and high exposure levels (10 and 20 exposures per word; Experiment 1). Using a lower exposure level (five exposures; Experiment 2), no post-sleep enhancement of competition was observed, despite evidence of consolidation when explicit knowledge of novel word memory was tested. Thus, when encoding is relatively weak, consolidation-related lexical integration is particularly compromised. There was no evidence that going to bed soon after learning is advantageous for overnight consolidation; however, there was some preliminary suggestion that longer gaps between learning and bed-onset were associated with better explicit memory of novel words one week later, but only at higher levels of exposure. These findings suggest that while lexical integration can occur overnight, weaker lexical traces may not be able to access overnight integration processes in the sleeping brain. Furthermore, the finding that longer-term explicit memory of stronger (but not weaker) traces benefit from periods of wake following learning deserves examination in future research.

Parasite defense mechanisms in bees: behavior, immunity, antimicrobials, and symbionts

2019 ◽  
Vol 4 (1) ◽  
pp. 59-76 ◽  
Author(s):  
Alison E. Fowler ◽  
Rebecca E. Irwin ◽  
Lynn S. Adler
Keyword(s):  
Defense Mechanisms ◽  
Poor Quality ◽  
Future Research ◽  
Immune Priming ◽  
Social Bees ◽  
Bee Health ◽  
Landscape Scales ◽  
And Function ◽  
Solitary Species

Parasites are linked to the decline of some bee populations; thus, understanding defense mechanisms has important implications for bee health. Recent advances have improved our understanding of factors mediating bee health ranging from molecular to landscape scales, but often as disparate literatures. Here, we bring together these fields and summarize our current understanding of bee defense mechanisms including immunity, immunization, and transgenerational immune priming in social and solitary species. Additionally, the characterization of microbial diversity and function in some bee taxa has shed light on the importance of microbes for bee health, but we lack information that links microbial communities to parasite infection in most bee species. Studies are beginning to identify how bee defense mechanisms are affected by stressors such as poor-quality diets and pesticides, but further research on this topic is needed. We discuss how integrating research on host traits, microbial partners, and nutrition, as well as improving our knowledge base on wild and semi-social bees, will help inform future research, conservation efforts, and management.

scholarly journals Insect Behavioral Change and the Potential Contributions of Neuroinflammation—A Call for Future Research

Genes ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 465
Author(s):  
Colleen A. Mangold ◽  
David P. Hughes
Keyword(s):  
Behavioral Change ◽  
Potential Role ◽  
Insect Behavior ◽  
Future Research ◽  
Cell Physiology ◽  
Behavioral Manipulation ◽  
Neuroimmune Communication ◽  
And Function ◽  
Neuron Function ◽  
Insect Innate Immunity

Many organisms are able to elicit behavioral change in other organisms. Examples include different microbes (e.g., viruses and fungi), parasites (e.g., hairworms and trematodes), and parasitoid wasps. In most cases, the mechanisms underlying host behavioral change remain relatively unclear. There is a growing body of literature linking alterations in immune signaling with neuron health, communication, and function; however, there is a paucity of data detailing the effects of altered neuroimmune signaling on insect neuron function and how glial cells may contribute toward neuron dysregulation. It is important to consider the potential impacts of altered neuroimmune communication on host behavior and reflect on its potential role as an important tool in the “neuro-engineer” toolkit. In this review, we examine what is known about the relationships between the insect immune and nervous systems. We highlight organisms that are able to influence insect behavior and discuss possible mechanisms of behavioral manipulation, including potentially dysregulated neuroimmune communication. We close by identifying opportunities for integrating research in insect innate immunity, glial cell physiology, and neurobiology in the investigation of behavioral manipulation.

Blame Avoidance in China's Cadre Responsibility System

2021 ◽  
pp. 1-22
Author(s):  
Jiayuan Li ◽  
Xing Ni ◽  
Rui Wang
Keyword(s):  
Qualitative Data ◽  
Performance Standards ◽  
Field Studies ◽  
Future Research ◽  
Limited Attention ◽  
Discursive Strategies ◽  
Conventional View ◽  
Blame Avoidance ◽  
Local Officials ◽  
Responsibility System

Abstract This article contends that prior research on the behaviour of Chinese local cadres pays limited attention to their motivation for avoiding blame. Using qualitative data from three field studies conducted in Guangdong province, the study focuses on blame avoidance in the cadre responsibility system, which is recognized as an important instrument for state capacity building. Our analysis uncovers three major discursive strategies used by grassroots cadres to manage blame either before or after it is apportioned: de-legitimating performance standards, re-attributing blame and transferring blame risk. We find that local cadres have a role as blame makers in shifting blame and accusations. This finding challenges the conventional view, which typically sees local officials as blame takers. The article concludes by elaborating on the wider implications of this finding and proposing avenues for future research.

scholarly journals Discovery of a novel RORγ antagonist with skin-restricted exposure for topical treatment of mild to moderate psoriasis

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Suxing Liu ◽  
Dong Liu ◽  
Ru Shen ◽  
Di Li ◽  
Qiyue Hu ◽  
...  
Keyword(s):  
Topical Treatment ◽  
Clinical Success ◽  
Systemic Exposure ◽  
Skin Inflammation ◽  
Targeted Therapeutics ◽  
High Exposure ◽  
Structure Activity ◽  
Potential Safety ◽  
Systematic Structure ◽  
And Function

AbstractClinical success of IL-17/IL-23 pathway biologics for the treatment of moderate to severe psoriasis suggests that targeting RORγt, a master regulator for the proliferation and function of Th17 cells, could be an effective alternative. However, oral RORγ antagonists (VTP43742, TAK828) with high systemic exposure showed toxicity in phase I/II clinical trials and terminated development. To alleviate the potential safety concerns, identifying compounds with skin-restricted exposure amenable for topical use is of great interest. Systematic structure activity relationship study and multi-parameter optimization led to the discovery of a novel RORγ antagonist (SHR168442) with desired properties for a topical drug. It suppressed the transcription of IL-17 gene, leading to reduction of IL-17 cytokine secretion. It showed high exposure in skin, but low in plasma. Topical application of SHR168442 in Vaseline exhibited excellent efficacy in the imiquimod-induced and IL-23-induced psoriasis-like skin inflammation mouse models and correlated with the reduction of Th17 pathway cytokines, IL-6, TNFα and IL-17A. This work demonstrated restricted skin exposure of RORγ antagonist may provide a new topical treatment option as targeted therapeutics for mild to moderate psoriasis patients and may be suitable for the treatment of any other inflammatory disorders that are accessible locally.

scholarly journals Design of Mechanism and Preliminary Field Validation of Low-Cost Transfemoral Rotator for Use in the Developing World

2016 ◽  
Author(s):  
Matthew L. Cavuto ◽  
Matthew Chun ◽  
Nora Kelsall ◽  
Karl Baranov ◽  
Keriann Durgin ◽  
...  
Keyword(s):  
Developing World ◽  
Low Cost ◽  
Field Studies ◽  
Field Validation ◽  
User Testing ◽  
Common Solution ◽  
Locking Mechanism ◽  
Medial Rotation ◽  
Transfemoral Amputees ◽  
And Function

Transfemoral (above-knee) amputees face a unique and challenging set of restrictions to movement and function. Most notably, they are unable to medially rotate their lower-leg and subsequently cross their legs. The best and most common solution to this issue today is a transfemoral rotator, which allows medial rotation of the leg distal to the knee through a lockable turntable mechanism. However, currently available transfemoral rotators can cost thousands of dollars, and few equivalent technologies exist in the developing world. This paper, supported by the results of field studies and user testing, establishes a framework for the design of a low-cost and easily manufacturable transfemoral rotator for use in the developing world. Two prototypes are presented, each with a unique internal locking mechanism and form. A preliminary field study was conducted on six transfemoral amputees in India and qualitative user and prosthetist feedback was collected. Both prototypes successfully allowed all subjects to complete tasks such as crossing legs, putting on pants, and tying shoes while maintaining functionality of walking and standing. Future iterations of the mechanism will be guided by a combination of the most positively received features of the prototypes and general feedback suggestions from the users.

scholarly journals Sexual dimorphism in a top predator ( Notophthalmus viridescens ) drives aquatic prey community assembly

2018 ◽  
Vol 285 (1890) ◽  
pp. 20181717 ◽  
Author(s):  
Denon Start ◽  
Stephen De Lisle
Keyword(s):  
Sexual Dimorphism ◽  
Sex Ratio ◽  
Intraspecific Variation ◽  
Structure And Function ◽  
Sexually Dimorphic ◽  
Ecological Communities ◽  
Top Predator ◽  
Aquatic Mesocosms ◽  
And Function ◽  
The Impact

Intraspecific variation can have important consequences for the structure and function of ecological communities, and serves to link community ecology to evolutionary processes. Differences between the sexes are an overwhelmingly common form of intraspecific variation, but its community-level consequences have never been experimentally investigated. Here, we manipulate the sex ratio of a sexually dimorphic predacious newt in aquatic mesocosms, then track their impact on prey communities. Female and male newts preferentially forage in the benthic and pelagic zones, respectively, causing corresponding reductions in prey abundances in those habitats. Sex ratio differences also explained a large proportion (33%) of differences in the composition of entire pond communities. Ultimately, we demonstrate the impact of known patterns of sexual dimorphism in a predator on its prey, uncovering overlooked links between evolutionary adaptation and the structure of contemporary communities. Given the extreme prevalence of sexual dimorphism, we argue that the independent evolution of the sexes will often have important consequences for ecological communities.

scholarly journals Normative range parenting and the developing brain: a scoping review of the literature

2019 ◽  
Author(s):  
Madeline Farber ◽  
Dylan Gee ◽  
Ahmad R. Hariri
Keyword(s):  
Mental Health ◽  
Brain Development ◽  
Scoping Review ◽  
Developmental Trajectories ◽  
Future Research ◽  
Risk And Resilience ◽  
Abuse And Neglect ◽  
Brain Structure And Function ◽  
And Function ◽  
The Impact

Studies of early adversity such as trauma, abuse, and neglect highlight the critical importance of quality caregiving in brain development and mental health. However, the impact of normative range variability in caregiving on such biobehavioral processes remains poorly understood. Thus, we lack an essential foundation for understanding broader, population-representative developmental mechanisms of risk and resilience. Here, we conduct a scoping review of the extant literature centered on the question, “Is variability in normative range parenting associated with variability in brain structure and function?” After removing duplicates and screening by title, abstract, and full-text, 23 records were included in a qualitative review. The most striking outcome of this review was not only how few studies have explored associations between brain development and normative range parenting, but also how little methodological consistency exists across published studies. In light of these limitations, we propose recommendations for future research on normative range parenting and brain development. In doing so, we hope to facilitate evidence-based research that will help inform policies and practices that yield optimal developmental trajectories and mental health.

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