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Zooplankton and 210Po/210Pb in Southwest Pacific Waters
Published in Se-Kwon Kim, Marine Biochemistry, 2023
Ross A. Jeffree, Ron Szymczak, Gillian Peck, Scott W. Fowler
The role of zooplankton and their particulate products in the biogeochemical cycling and vertical transport of natural radionuclides, such as 210Po and 210Pb, in the marine environment has been the subject of both field and experimental laboratory studies for many years (Cherry et al., 1975; Heyraud et al., 1976; Beasley et al., 1978; Fowler and Fisher, 2004; Rodriguez y Baena et al., 2007; Fowler, 2011). Such information has become increasingly important in recent years as a result of studies that document the usefulness of measuring the disequilibrium between the 210Po/210Pb pair in sinking particulate matter in order to estimate the export flux of particulate organic carbon in the upper water column (Stewart et al., 2007, 2010; Rutgers van der Loeff and Geibert, 2008; Tang et al., 2018a, 2018b).
Macro and Micro Algal Impact on Marine Ecosystem
Published in Gokare A. Ravishankar, Ranga Rao Ambati, Handbook of Algal Technologies and Phytochemicals, 2019
Among the biogeochemical cycles operating in nature, the carbon (C) cycle has attracted a particularly great deal of attention from scientists. The global carbon cycle encompasses five distinct pools—the Atmospheric, Biotic, Pedologic, Geologic and the Oceanic pools. The pools are interconnected, and the C flux between these pools is extremely prone to human disturbances (Lal 2008). Anthropogenic activities like conversion of forest to agricultural land and combustion of fossil fuels have created dire imbalances in the biogeochemical cycling of carbon by selectively enriching the atmospheric pool with carbon dioxide (CO2). This selective enrichment of the atmospheric C pool has caused the atmospheric level of CO2 to rise from the pre-industrial level of 280 ppm to 399 ppm in 2015. Currently, it is rising at a rate of 2.2 ppm/year (Sengupta et al. 2017), causing global warming and associated climate change. Of the five interconnected pools, it is the Oceanic pool that is responsible for the absorption of the greatest amount of the emitted CO2.
Biology of microbes
Published in Philip A. Geis, Cosmetic Microbiology, 2006
The bacteria play a major role in the world’s ecosystems. They are so ubiquitous and important that they are considered by some to be the lifeblood of the planet. According to the Gaia hypothesis, they are involved in biogeochemical cycling to maintain Earth’s homeostasis.7 They occupy every conceivable niche and some that we may not have even dreamed possible. Their ubiquity means they are found throughout cosmetic and drug manufacturing plants. An area the size of a single pinhead may contain well over a billion bacterial cells. A single handful of soil represents an entire universe of bacterial possibilities, all capable of adapting to even the harshest environments. Well-preserved products and scrupulously clean manufacturing environments help prevent these organisms from establishing niches within consumer products, but their genetic adaptability and remarkable evolutionary capability present moving targets that are difficult to control without constant surveillance. This chapter presents an introduction to microbiology intended to enable even non-microbiologists to understand at least the basics of the very complex and ever-changing world of microorganisms.
Neglecting the ecosystemic dimension of life hinders efficient environmental protection from radiation and other hazards
Published in International Journal of Radiation Biology, 2022
During the past decades, and notably after the Chernobyl accident, radioecology lost the vision and skills of its founders who were much inspired and involved in ecology and ecosystem science (Rhodes et al. 2020). In Russia, V. I. Vernadsky started off his carreer by studying radionuclides environmental behavior and their impact on biocenoses, and this led him to conceive the most advanced planetary concepts in ecology. Later, a similar development happened in USA with the Odum brothers who emerged as prominent ecologists by demonstrating the vast potential of using radionuclides as tracers of biogeochemical cycling in ecosystems (Odum 1953, 1962). Similar historical trends can be traced in other nuclearized countries. However, after a while within the radioecology community, consideration of the ecosystem concept, which was central at the very beginning, started to vanish out under the pressure for pragmatic human radioprotection needs arising from the industrial growth of civil nuclear energy (Bréchignac et al. 2008; Rhodes et al. 2020). This is why the recent efforts undertaken by the radioecology community to protect the environment against radiation have largely ignored the ecosystem concept. Instead, it has simply transferred to non human biota the concepts and methods developped for human radioprotection. This oversimplification, rooted within a narrow anthropocentric view dominating radiation protection, urgently needs to be corrected.
In vitro and in silico study of mixtures cytotoxicity of metal oxide nanoparticles to Escherichia coli: a mechanistic approach
Published in Nanotoxicology, 2022
Supratik Kar, Kavitha Pathakoti, Danuta Leszczynska, Paul B. Tchounwou, Jerzy Leszczynski
Computational toxicity models are essential in association with the present announcement from the United States Environmental Protection Agency (USEPA) about the reduction of animal testing (including mammals) by diminishing funding to 30% by 2025 and eliminating it by 2035 (Administrator Memo Prioritizing Efforts to Reduce Animal Testing 2019). Additionally, the in silico methodologies are proven substitutes for evaluating the toxicity of chemical mixtures. Therefore, toxicity modeling of MONPs mixtures to predict the effects of new and untested mixtures of MONPs is also helpful in providing a mechanistic interpretation of toxicity data. Although many predictive models for toxicity of chemical mixtures exist, very limited literature (Mikolajczyk et al. 2018; Roy, Ojha, and Roy 2019) is presently available for modeling toxicity nanomaterials mixtures. In the present study, E. coli was used as a test model to assess the in vitro cytotoxicity of 6 single MONPs, and 15 binary and 20 tertiary mixtures with an equitoxic ratio, following standard bioassay protocols. The bacterial model can act as surrogates in assessing potential nanotoxicity to organisms of higher order, due to their vital role in the biogeochemical cycling of elements, pollutant degradation and ecological balance maintenance (Heinlaan et al. 2008; Osler and Sommerkorn 2007). In addition, bacteria serve as a good model organism for assessing the ecotoxicity of nanoparticles (Erdem et al. 2015).
Function is what counts: how microbial community complexity affects species, proteome and pathway coverage in metaproteomics
Published in Expert Review of Proteomics, 2020
Patrick Lohmann, Stephanie Serena Schäpe, Sven-Bastiaan Haange, Kaitlyn Oliphant, Emma Allen-Vercoe, Nico Jehmlich, Martin Von Bergen
In nature, bacteria rarely occur axenically but are rather found in microbial communities that exhibit complex interactions and niche formations [1]. Microbial communities not only play a primary role in global biogeochemical cycling to make our planet habitable [2] but also form complex interactions with other organisms that are crucial for the development and maintenance of health in animals [3] and humans [4]. To characterize microbial communities and identify how they can potentially affect the host or the environment, it is common to profile the taxonomy and functionality of such communities [5].