A switch in species dominance of a recovering pelagic ecosystem

2021 ◽  
Author(s):  
Joshua M. Lawrence ◽  
Paul G. Fernandes
Harmful Algae ◽  
2020 ◽  
Vol 99 ◽  
pp. 101921
Author(s):  
M. De Rijcke ◽  
J.M. Baert ◽  
N. Brion ◽  
M.B. Vandegehuchte ◽  
F. De Laender ◽  
...  

2021 ◽  
Vol 496 ◽  
pp. 119430
Author(s):  
Marcela de Castro Nunes Santos Terra ◽  
Jamir Afonso do Prado-Júnior ◽  
Cléber Rodrigo de Souza ◽  
Luiz Otávio Rodrigues Pinto ◽  
Eduarda Martiniano de Oliveira Silveira ◽  
...  

2021 ◽  
Vol 17 ◽  
pp. 174550652110091
Author(s):  
John Garza ◽  
Kushal Gandhi ◽  
Sarah Choi ◽  
Asley Sanchez ◽  
Gary Ventolini

Background and Purpose: Lactobacilli play a vital role in protecting the vagina against pathogens. Cytokines are vital components of defense against infections in women. The genital mycoplasmas, Mycoplasma genitalium and Ureaplasma urealyticum, are associated with various infectious diseases in adults and infants. The objective of our study is to identify differences in cytokine profile and Lactobacillus species dominance between a study group of non-pregnant pre-menopausal women with genital M. genitalium or U. urealyticum colonization and a control group of non-pregnant pre-menopausal women without genital M. genitalium or U. urealyticum colonization. Methods: A real-time polymerase chain reaction was performed to measure Lactobacillus species in vaginal swab samples. Cytokine analysis was performed using multiplex immunoassay techniques. Analysis of variance confirmed a significant difference in cytokine profiles between patient groups, with t-tests identifying the most significantly different cytokines. Categorical data analysis identified significant patterns of relative Lactobacillus species dominance in the study group. Results: Lactobacillus iners was the predominant Lactobacillus species in the control group ( p = 0.005). There were no dominant Lactobacillus species observed in the study group. Vascular endothelial growth factor A ( p = 0.002), interleukin-8 ( p = 0.001), and interleukin-1β ( p = 0.049) were expressed significantly higher in the study group, whereas interleukin-1 receptor antagonist ( p < 0.001), interleukin-10 ( p = 0.001), interleukin-12 ( p = 0.002), and interferon-γ ( p = 0.022) were expressed higher in the control group. Association matrices for cytokines were significantly different between two groups ( p < 0.001), with mostly negative associations in the control group and mostly positive associations in the study group. Conclusion: Cytokine levels, their associations, and the patterns of Lactobacillus species dominance are observed to significantly diverge on the basis of M. genitalium and U. urealyticum colonization among non-pregnant pre-menopausal women.


2004 ◽  
Vol 34 (12) ◽  
pp. 2501-2507 ◽  
Author(s):  
Takahide A Ishida ◽  
Kouhei Hattori ◽  
Masahito T Kimura

We examined responses of phytophagous insects to hybrids between Quercus crispula Blume and Quercus dentata Thunberg in a natural population in northern Japan. The abundance of leafminers and leaf area loss by chewing insects in hybrids were intermediate between those in the parental species (additive mode), close to those of either of the parental species (dominance mode), or similar to those of both parental species (no difference). Hybrids were neither more susceptible nor resistant to the insect herbivores we monitored. In Phyllonorycter (Gracillariidae) species, which are specialized to either of the parental oak species, the mortality of sap-feeding early instar larvae did not differ between hybrids and the parental species. The abundance of four leafminer taxa was correlated with environmental conditions (i.e., distance from the coastal edge of the forest or the timing of budbreak) as well as genetic factors.


2003 ◽  
Vol 60 (9) ◽  
pp. 1161-1175 ◽  
Author(s):  
George M Watters ◽  
Robert J Olson ◽  
Robert C Francis ◽  
Paul C Fiedler ◽  
Jeffrey J Polovina ◽  
...  

We used a model of the pelagic ecosystem in the eastern tropical Pacific Ocean to explore how climate variation at El Niño – Southern Oscillation (ENSO) scales might affect animals at middle and upper trophic levels. We developed two physical-forcing scenarios: (1) physical effects on phytoplankton biomass and (2) simultaneous physical effects on phytoplankton biomass and predator recruitment. We simulated the effects of climate-anomaly pulses, climate cycles, and global warming. Pulses caused oscillations to propagate through the ecosystem; cycles affected the shapes of these oscillations; and warming caused trends. We concluded that biomass trajectories of single populations at middle and upper trophic levels cannot be used to detect bottom-up effects, that direct physical effects on predator recruitment can be the dominant source of interannual variability in pelagic ecosystems, that such direct effects may dampen top-down control by fisheries, and that predictions about the effects of climate change may be misleading if fishing mortality is not considered. Predictions from ecosystem models are sensitive to the relative strengths of indirect and direct physical effects on middle and upper trophic levels.


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