Article
Optics
Remika S. Gupana, Alexander Damm, Abolfazl Irani Rahaghi, Camille Minaudo, Daniel Odermatt
Summary: Quantum yield of fluorescence (OF) is crucial for understanding the impact of photochemical quenching (PQ) and non-photochemical quenching (NPQ) on sun-induced fluorescence (SIF) signals. However, obtaining accurate OF measurements is challenging due to its high temporal and physiological variability, as well as the need for combined measurements. In this study, we used in-situ measurements in Lake Geneva to investigate the vertical and temporal changes in OF and determine NPQ and PQ conditions. Our findings reveal the presence of NPQ in daytime profiles and the significant influence of downwelling irradiance on OF.
Article
Chemistry, Analytical
Ilaria Cesana, Mariano Bresciani, Sergio Cogliati, Claudia Giardino, Remika Gupana, Dario Manca, Stefano Santabarbara, Monica Pinardi, Martina Austoni, Andrea Lami, Roberto Colombo
Summary: This study tested a series of methods relying on hyperspectral measurements to characterize phytoplankton in clear lake waters. In addition to remote sensed parameters, water samples were collected and analyzed to evaluate in-situ fluorescence and absorbed light, developing and testing several phytoplankton primary production models. Promising results were achieved by replacing F-A with E-PAR or F-FLH in the equation evaluating a PP proxy.
Article
Environmental Sciences
Jing Teng, Tinglu Zhang, Kunpeng Sun, Hong Gao
Summary: In this study, a novel method was proposed to retrieve pigment concentrations of phytoplankton using hyperspectral data. The method, called the ES-SR method, showed strong correlations between pigment concentrations and the derivatives of phytoplankton absorption coefficients. Compared to other methods, the ES-SR method achieved the greatest accuracy and robustness. This method has the potential to effectively monitor phytoplankton community information in global oceans.
Article
Environmental Sciences
Flavien Petit, Julia Uitz, Catherine Schmechtig, Celine Dimier, Josephine Ras, Antoine Poteau, Melek Golbol, Vincenzo Vellucci, Herve Claustre
Summary: This study investigates the main sources of natural variability in the in-situ fluorescence signal in the global open ocean, focusing on the influence of phytoplankton community composition. The results show that the phytoplankton community composition plays a key role in the relationship between the in-situ fluorescence signal and Chla concentration.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Hana Travers-Smith, Fernanda Giannini, Akash R. Sastri, Maycira Costa
Summary: The study demonstrated a method to enhance the accuracy of chlorophyll-a concentration measurement by correcting sensor bias and non-photochemical quenching effects, improving the correspondence between in vivo Chl-a fluorescence and extracted Chl-a measurement. Sensor bias was found to contribute significantly to the error in fluorescence signal, and the NPQ correction method developed by Davis et al. (2008) was identified as the most effective in improving accuracy. The study suggests the use of this correction method along with pre-processing steps for in vivo Chl-a measurements to address potential sensor biofouling and bias.
FRONTIERS IN MARINE SCIENCE
(2021)
Article
Food Science & Technology
Monica Mburu, Clement Komu, Olivier Paquet-Durand, Bernd Hitzmann, Viktoria Zettel
Summary: The study successfully detected the amount of adulterated oils using spectroscopic analysis, with a classification accuracy of 90% for identifying adulterated chia oils. The classification methods showed good results, with SVM being the most effective in identifying the adulteration oil.
Article
Geosciences, Multidisciplinary
Walker O. Smith
Summary: Polar systems are important components of global biogeochemical cycles, but they are undersampled. This study focused on long-term measurements of primary productivity and chlorophyll concentrations in the Ross Sea of Antarctica. The results provide valuable insights into the productivity and composition of polar ecosystems.
EARTH SYSTEM SCIENCE DATA
(2022)
Article
Thermodynamics
Arsalan Taassob, Tarek Echekki
Summary: This study proposes and investigates a method to extract derived scalar statistics using a surrogate composition space. The method parameterizes the statistics of measured scalars using principal components from principal component analysis, and complements them with homogeneous chemistry calculations to recover missing species and evaluate species reaction rates. The results show that the proposed procedure is able to recover unmeasured species and predict the species reaction rates.
COMBUSTION AND FLAME
(2023)
Editorial Material
Biochemistry & Molecular Biology
Kimberlee Thamatrakoln
Summary: The new study shows that phosphorus-limited diatoms activate a rapid calcium-based signaling pathway upon phosphorus resupply, which enhances nitrogen uptake and assimilation, setting the stage for recovery from nutrient deprivation.
Article
Environmental Sciences
Julia K. Marrs, Taylor S. Jones, David W. Allen, Lucy R. Hutyra
Summary: Solar-induced chlorophyll fluorescence (SIF) is commonly used as a proxy for photosynthesis in terrestrial primary productivity models. However, there is wide variability in the magnitude of published SIF retrievals, and inconsistent reporting on calibration procedures and hardware characterizations. Methodological differences in calibration and corrections likely explain some of the observed variability in published SIF retrievals, limiting the utility of SIF in modeling GPP across scales.
REMOTE SENSING OF ENVIRONMENT
(2021)
Article
Chemistry, Multidisciplinary
Hongwei Lu, Yuan Xie, Ziteng Zhang, Zhiming Zhang, Jing Zhi Sun, Haoke Zhang, Ben Zhong Tang
Summary: This study explores a method to modulate the clusteroluminescent properties of non-conjugated systems through the formation of complex compounds, providing a new engineering approach for the construction of efficient clusteroluminescent materials.
CHINESE JOURNAL OF CHEMISTRY
(2023)
Article
Environmental Sciences
Lionel A. Arteaga, Michael J. Behrenfeld, Emmanuel Boss, Toby K. Westberry
Summary: This study combines data from biogeochemical Argo floats with a carbon-based productivity model to compute vertically resolved estimates of marine net primary production (NPP). In the Southern Ocean, the depth-reconstructing implementation of the model overestimates phytoplankton division rates and Chl:C below the mixed layer, but improves by accounting for deep iron limitation.
GLOBAL BIOGEOCHEMICAL CYCLES
(2022)
Article
Environmental Sciences
Xiaolong Li, Yi Yang, Joji Ishizaka, Xiaofeng Li
Summary: Based on global observations and measurements, a DL-PPCE model was developed to estimate concentrations of 17 phytoplankton pigments worldwide. The model utilized a fusion architecture and three different types of input data to achieve robust estimation performance. The results showed strong correlations between estimated pigment concentrations and in-situ observations, and revealed the relationship between phytoplankton community dynamics and El Nino events in the western equatorial Pacific.
REMOTE SENSING OF ENVIRONMENT
(2023)
Article
Environmental Sciences
Hongjin Qiao, Shasha Zang, Fang Yan, Zhiguang Xu, Lei Wang, Hongyan Wu
Summary: The study found that the larger diatom Thalassiosira weissflogii can maintain photosynthetic activity for a longer period under nitrogen starvation compared to the smaller diatom Thalassiosira pseudonana, which is more sensitive to high light. Both diatoms showed inhibited electron transfer reactions, with fast closing of reaction centers promoting the development of non-reducing PSII centers.
MARINE ENVIRONMENTAL RESEARCH
(2021)
Article
Oceanography
Monika Soja-Wozniak, Lesley Clementson, Bozena Wojtasiewicz, Mark Baird
Summary: This paper reconstructs the absorption spectra of phytoplankton using pigment concentration and absorption coefficients. Small phytoplankton samples show no significant difference between calculated and measured absorption. The reconstructed phytoplankton absorption is overestimated at one wavelength and underestimated over a specific range.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2022)
Editorial Material
Oceanography
Jeffrey M. Schell, Deborah S. Goodwin, Amy N. S. Siuda
Article
Engineering, Environmental
Kara Lavender Law, Skye E. Moret-Ferguson, Deborah S. Goodwin, Erik R. Zettler, Emelia De Force, Tobias Kukulka, Giora Proskurowski
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2014)
Article
Environmental Sciences
Ulla von Ammon, Andrew Jeffs, Anastasija Zaiko, Aimee van der Reis, Deb Goodwin, Lynnath E. Beckley, Emmanuel Malpot, Xavier Pochon
FRONTIERS IN MARINE SCIENCE
(2020)
Article
Marine & Freshwater Biology
Lindsay M. Martin, Madalyn Taylor, Grayson Huston, Deborah S. Goodwin, Jeffrey M. Schell, Amy N. S. Siuda
Summary: The different morphotypes of pelagic Sargassum have varying influences on attracting epifauna, with the complex structure of Sargassum fluitans III supporting more individuals and taxa compared to the simpler Sargassum natans VIII or S. natans I. The study of 373 algae samples revealed shifts in dominant epifauna compared to historical studies, highlighting important differences in ecological value between morphotypes and implications for conservation strategies. These findings underscore the significance of considering the distribution of morphotypes and recurring Sargassum inundation events in coastal and pelagic conservation efforts.
Article
Marine & Freshwater Biology
Skye Dibner, Lindsay Martin, Thierry Thibaut, Didier Aurelle, Aurelie Blanfune, Kerry Whittaker, Laura Cooney, Jeffrey M. Schell, Deborah S. Goodwin, Amy N. S. Siuda
Summary: This study examined the genetic divergence among three common pelagic Sargassum morphotypes using mitochondrial genes, confirming evolutionary divergence and differences between these morphologies. The results suggest that taxonomic reclassification of the three most common pelagic morphotypes may be warranted based on genetic divergence compared with benthic Sargassum species.
MARINE ECOLOGY-AN EVOLUTIONARY PERSPECTIVE
(2022)
Article
Multidisciplinary Sciences
Deborah S. Goodwin, Amy N. S. Siuda, Jeffrey M. Schell
Summary: This study focuses on the visual observations of holopelagic Sargassum in the North Atlantic Ocean from 2011 to 2020. It describes the regional distribution, presence, and aggregation state of the Sargassum at hourly and 10 km scales. The study considers the influences of oceanographic region, wind/sea conditions, and temporal trends, and also examines the ecological value of the Sargassum aggregations to marine megafauna associates. The findings reveal the presence of holopelagic Sargassum in the western North Atlantic, with dispersed fragments and clumps being more common than aggregated windrows and mats. The study also identifies similar aggregation state patterns across regions, with windrow proportion increasing with higher wind speeds.