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2. Prochlorococcus marinus responses to light and oxygen.

Author

Savoie, Mireille, Mattison, Aurora, Genge, Laurel, Nadeau, Julie, Śliwińska-Wilczewska, Sylwia, Berthold, Maximilian, Omar, Naaman M., Prášil, Ondřej, Cockshutt, Amanda M., and Campbell, Douglas A.

Subjects
PROCHLOROCOCCUS, RED light, REACTIVE oxygen species, ATTENUATION of light, DNA repair, OXYGEN, SOLAR spectra
Abstract

Prochlorococcus marinus, the smallest picocyanobacterium, comprises multiple clades occupying distinct niches, currently across tropical and sub-tropical oligotrophic ocean regions, including Oxygen Minimum Zones. Ocean warming may open growth-permissive temperatures in new, poleward photic regimes, along with expanded Oxygen Minimum Zones. We used ocean metaproteomic data on current Prochlorococcus marinus niches, to guide testing of Prochlorococcus marinus growth across a matrix of peak irradiances, photoperiods, spectral bands and dissolved oxygen. MED4 from Clade HLI requires greater than 4 h photoperiod, grows at 25 μmol O2 L-1 and above, and exploits high cumulative diel photon doses. MED4, however, relies upon an alternative oxidase to balance electron transport, which may exclude it from growth under our lowest, 2.5 μmol O2 L-1, condition. SS120 from clade LLII/III is restricted to low light under full 250 μmol O2 L-1, shows expanded light exploitation under 25 μmol O2 L-1, but is excluded from growth under 2.5 μmol O2 L-1. Intermediate oxygen suppresses the cost of PSII photoinactivation, and possibly the enzymatic production of H2O2 in SS120, which has limitations on genomic capacity for PSII and DNA repair. MIT9313 from Clade LLIV is restricted to low blue irradiance under 250 μmol O2 L-1, but exploits much higher irradiance under red light, or under lower O2 concentrations, conditions which slow photoinactivation of PSII and production of reactive oxygen species. In warming oceans, range expansions and competition among clades will be governed not only by light levels. Short photoperiods governed by latitude, temperate winters, and depth attenuation of light, will exclude clade HLI (including MED4) from some habitats. In contrast, clade LLII/III (including SS120), and particularly clade LLIV (including MIT9313), may exploit higher light niches nearer the surface, under expanding OMZ conditions, where low O2 relieves the stresses of oxidation stress and PSII photoinhibition. [ABSTRACT FROM AUTHOR]

Published
2024
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4. CyanoCyc cyanobacterial web portal

Author

Moore, Lisa R., primary, Caspi, Ron, additional, Campbell, Douglas A., additional, Casey, John R., additional, Crevecoeur, Sophie, additional, Lea-Smith, David J., additional, Long, Bin, additional, Omar, Naaman M., additional, Paley, Suzanne M., additional, Schmelling, Nicolas M., additional, Torrado, Alejandro, additional, Zehr, Jonathan P., additional, and Karp, Peter D., additional

Published
2024
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7. License plate detection and recognition: A study of review.

Author

Omar, Naaman, Zeebaree, Subhi R. M., Sadeeq, Mohammed A. M., Zebari, Rizgar R., Shukur, Hanan M., Alkhayyat, Ahmed, Haji, Lailan M., and Kak, Shakir Fattah

Subjects
*AUTOMOBILE license plates, *CONVOLUTIONAL neural networks, *DEEP learning, *TRAFFIC monitoring, *ADAPTIVE filters, *IMAGE processing
Abstract

The detection and recognition of automatic license plates (ALPs) is an important task for traffic surveillance and parking management systems, as well as for sustaining the flow of modern civic life. It's been suggested that there are a variety of ways to detect and recognize ALPs thus far Image processing and machine learning techniques are typically used in these approaches. For object detection and license plate identification, this article reviews most of the approaches. In order to improve the suitability of the input pictures for subsequent processing, many pre-processing approaches including Gaussian filtering and adaptive image contrast augmentation were examined. Deep semantic segmentation networks and deep learning techniques are also utilized to find the license plate areas in the input picture... For example, deep encoder-decoder network architecture and convolutional neural network (CNN) models used to recognize license plate. [ABSTRACT FROM AUTHOR]

Published
2023
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17. State of Art Survey for Fault Tolerance Feasibility in Distributed Systems

Author

Hussein, Arshad A., primary, AL-zebari, Adel, primary, Omar, Naaman, primary, Merceedi, Karwan Jameel, primary, Ahmed, Abdulraheem Jamil, primary, Salim, Nareen O. M., primary, Hasan, Sheren Sadiq, primary, Kak, Shakir Fattah, primary, Ibrahim, Ibrahim Mahmood, primary, Yasin, Hajar Maseeh, primary, and Salih, Azar Abid, primary

Published
2021
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19. A Survey of Data Mining Activities in Distributed Systems

Author

Mohammad, Waleed A., primary, Yasin, Hajar Maseeh, primary, Salih, Azar Abid, primary, AL-Zebari, Adel, primary, Omar, Naaman, primary, Merceedi, Karwan Jameel, primary, Ahmed, Abdulraheem Jamil, primary, Salim, Nareen O. M., primary, Hasan, Sheren Sadiq, primary, Kak, Shakir Fattah, primary, and Ibrahim, Ibrahim Mahmood, primary

Published
2021
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22. SQL Injection Attacks Prevention System Technology: Review

Author

Kareem, Fairoz Q., primary, Ameen, Siddeeq Y., primary, Salih, Azar Abid, primary, Ahmed, Dindar Mikaeel, primary, Kak, Shakir Fattah, primary, Yasin, Hajar Maseeh, primary, Ibrahim, Ibrahim Mahmood, primary, Ahmed, Awder Mohammed, primary, Rashid, Zryan Najat, primary, and Omar, Naaman, primary

Published
2021
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23. Secure Data Transfer over Internet Using Image Steganography: Review

Author

Abdullah, Dakhaz Mustafa, primary, Ameen, Siddeeq Y., primary, Omar, Naaman, primary, Salih, Azar Abid, primary, Ahmed, Dindar Mikaeel, primary, Kak, Shakir Fattah, primary, Yasin, Hajar Maseeh, primary, Ibrahim, Ibrahim Mahmood, primary, Ahmed, Awder Mohammed, primary, and Rashid, Zryan Najat, primary

Published
2021
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24. Reliable Communications for Vehicular Networks

Author

Ismael, Halbast Rasheed, primary, Ameen, Siddeeq Y., primary, Kak, Shakir Fattah, primary, Yasin, Hajar Maseeh, primary, Ibrahim, Ibrahim Mahmood, primary, Ahmed, Awder Mohammed, primary, Rashid, Zryan Najat, primary, Omar, Naaman, primary, Salih, Azar Abid, primary, and Ahmed, Dindar Mikaeel, primary

Published
2021
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25. Paralinguistic Speech Processing: An Overview

Author

Abdullah, Rozin Majeed, primary, Ameen, Siddeeq Y., primary, Ahmed, Dindar Mikaeel, primary, Kak, Shakir Fattah, primary, Yasin, Hajar Maseeh, primary, Ibrahim, Ibrahim Mahmood, primary, Ahmed, Awder Mohammed, primary, Rashid, Zryan Najat, primary, Omar, Naaman, primary, and Salih, Azar Abid, primary

Published
2021
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27. Review on Natural Language Processing Based on Different Techniques

Author

Maulud, Dastan Hussen, primary, Ameen, Siddeeq Y., primary, Omar, Naaman, primary, Kak, Shakir Fattah, primary, Rashid, Zryan Najat, primary, Yasin, Hajar Maseeh, primary, Ibrahim, Ibrahim Mahmood, primary, Salih, Azar Abid, primary, Salim, Nareen O. M., primary, and Ahmed, Dindar Mikaeel, primary

Published
2021
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29. Deep Learning Approaches for Intrusion Detection

Author

Salih, Azar Abid, primary, Ameen, Siddeeq Y., primary, Zeebaree, Subhi R. M., primary, Sadeeq, Mohammed A. M., primary, Kak, Shakir Fattah, primary, Omar, Naaman, primary, Ibrahim, Ibrahim Mahmood, primary, Yasin, Hajar Maseeh, primary, Rashid, Zryan Najat, primary, and Ageed, Zainab Salih, primary

Published
2021
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32. Diffusional Interactions among Marine Phytoplankton and Bacterioplankton: Modelling H 2 O 2 as a Case Study.

Author

Omar, Naaman M., Prášil, Ondřej, McCain, J. Scott P., and Campbell, Douglas A.

Subjects
MARINE phytoplankton, BACTERIOPLANKTON, CELL suspensions, CELL membranes, REACTIVE oxygen species, HYDROGEN peroxide, HEMODILUTION
Abstract

Marine phytoplankton vary widely in size across taxa, and in cell suspension densities across habitats and growth states. Cell suspension density and total biovolume determine the bulk influence of a phytoplankton community upon its environment. Cell suspension density also determines the intercellular spacings separating phytoplankton cells from each other, or from co-occurring bacterioplankton. Intercellular spacing then determines the mean diffusion paths for exchanges of solutes among co-occurring cells. Marine phytoplankton and bacterioplankton both produce and scavenge reactive oxygen species (ROS), to maintain intracellular ROS homeostasis to support their cellular processes, while limiting damaging reactions. Among ROS, hydrogen peroxide (H2O2) has relatively low reactivity, long intracellular and extracellular lifetimes, and readily crosses cell membranes. Our objective was to quantify how cells can influence other cells via diffusional interactions, using H2O2 as a case study. To visualize and constrain potentials for cell-to-cell exchanges of H2O2, we simulated the decrease of [H2O2] outwards from representative phytoplankton taxa maintaining internal [H2O2] above representative seawater [H2O2]. [H2O2] gradients outwards from static cell surfaces were dominated by volumetric dilution, with only a negligible influence from decay. The simulated [H2O2] fell to background [H2O2] within ~3.1 µm from a Prochlorococcus cell surface, but extended outwards 90 µm from a diatom cell surface. More rapid decays of other, less stable ROS, would lower these threshold distances. Bacterioplankton lowered simulated local [H2O2] below background only out to 1.2 µm from the surface of a static cell, even though bacterioplankton collectively act to influence seawater ROS. These small diffusional spheres around cells mean that direct cell-to-cell exchange of H2O2 is unlikely in oligotrophic habits with widely spaced, small cells; moderate in eutrophic habits with shorter cell-to-cell spacing; but extensive within phytoplankton colonies. [ABSTRACT FROM AUTHOR]

Published
2022
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