Article
Geography, Physical
Majed N. Turkistani, Eduard G. Reinhardt, David A. Kynaston, Janok P. Bhattacharya
Summary: This study investigates the associations between ancient deltaic environments and foram-iniferal and testate amoebae assemblages and finds clear relationships between test morphology and depositional environment.
PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY
(2022)
Article
Environmental Sciences
Jean Claude Ndayishimiye, Tian Lin, Pascaline Nyirabuhoro, Gan Zhang, Wenjing Zhang, Yuri Mazei, Hossein Ganjidoust, Jun Yang
Summary: This study focused on examining the impact of human activities on chemical pollutants influx and environmental transformations in a large subtropical reservoir in south China. The research used a multi-proxy approach based on sediment core analysis and found that the development of the reservoir experienced two distinct stages, influenced by both anthropogenic sources and climatic factors. The study highlighted the significant relationship between testate amoebae community dynamics and environmental conditions, indicating a stronger impact of human disturbance on the ecosystem compared to natural environmental changes.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Biochemistry & Molecular Biology
Ruben Gonzalez-Miguens, Milcho Todorov, Quentin Blandenier, Clement Duckert, Alfredo L. Porfirio-Sousa, Giulia M. Ribeiro, Diana Ramos, Daniel J. G. Lahr, David Buckley, Enrique Lara
Summary: In this study, the authors used Arcellinida testate amoebae as a model to test the paradigm of morphological stasis in protists. The results showed a lack of conservatism in shell outlines and widespread morphological convergences between far-related taxa. In addition, the authors revised the systematics and established a new infraorder and two new genera.
MOLECULAR PHYLOGENETICS AND EVOLUTION
(2022)
Article
Environmental Sciences
M. A. Davies, J. W. McLaughlin, M. S. Packalen, S. A. Finkelstein
Summary: Wetlands are the largest natural source of methane, yet the roles of source region and paleoclimate in explaining the variability in Holocene atmospheric methane concentrations remain poorly constrained. The study on Hudson Bay Lowlands (HBL) shows that total methane flux is closely related to the increasing area of land emerging from below sea level in the Middle Holocene, and due to lower evapotranspiration in a wetter and cooler climate in the Late Holocene, methane fluxes remained high.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2021)
Article
Biodiversity Conservation
Thomas G. Sim, Graeme T. Swindles, Paul J. Morris, Andy J. Baird, Dan J. Charman, Matthew J. Amesbury, Dave Beilman, Alex Channon, Angela V. Gallego-Sala
Summary: This study utilized new transfer functions to reconstruct water-table depth (WTD) and pH in Svalbard peatlands, enabling a greater understanding of the long-term impact of climate change on these ecosystems.
ECOLOGICAL INDICATORS
(2021)
Article
Paleontology
Nawaf A. Nasser, Braden R. B. Gregory, David Singer, R. Timothy Patterson, Helen M. Roe
Summary: Testate lobose amoebae of the order Arcellinida are a diverse group of shelled protists found in various environments. The family Difflugidae includes many species and subspecies, with molecular evidence suggesting that test morphology is more important in categorizing distinct taxa than test composition. The reclassification of Difflugia bidens as the type species of genus Erugomicula highlights the importance of test morphology in taxonomy.
PALAEONTOLOGIA ELECTRONICA
(2021)
Article
Biodiversity Conservation
Rafael Carballeira, Xabier Pontevedra-Pombal
Summary: Testate amoebae are important bioindicators of Sphagnum peatland ecosystems, which are threatened wetland types with a delicate biogeochemical balance. A study on chemical parameters and testate amoebae diversity in the western Iberian Peninsula revealed an inverse relationship between diversity and conservation status, influenced by anthropogenic activities and geographical patterns of disturbance.
Article
Zoology
Veronika Horsakova, Eva Llznarova, Oihana Razkin, Jeffrey C. Nekola, Michal Horsak
Summary: Many molecular phylogenetic studies report the discovery of new cryptic species, but often these discoveries are not verified outside of DNA evidence or are only superficially analyzed. In this study, the researchers challenge the conclusions of a previous study on land snails, showing that the species can be visually distinguished through the use of mtDNA, nDNA, morphometric analyses, and shell features. The researchers propose an evolutionary explanation based on climate and thermal flux optimization. This study highlights the importance of microscopic shell features and provides a protocol for identifying visual identification criteria in taxonomic groups.
CONTRIBUTIONS TO ZOOLOGY
(2022)
Article
Engineering, Geological
Sparsha Nagula, Michael Nguyen, Jurgen Grabe, Jens Kardel, Thorsten Bahl
Summary: Vibroflotation is an established ground improvement technique that densifies loose sands using horizontal vibrations. Numerical simulations and empirical relations have been used to study and analyze the method. This research aimed to validate the numerical results and evaluate the effects of various factors on the compaction process.
Article
Engineering, Civil
Giovanni Spagnoli, Stefano Collico
Summary: Grouting is a well-known ground improvement technique that can increase the strength and stiffness of soils. Permeation grouting, a type of grouting, fills soil voids with grout without altering the stress state in the soils. This study presents laboratory results of the hydro-mechanical properties of fine-grained sand grouted with colloidal silica at different solid content, including unconfined compressive strength, hydraulic conductivity, effective cohesion, and friction angles. The uncertainties associated with geotechnical parameters are quantified using a probabilistic approach, and a Bayesian Information Criterion is applied for selecting the best dependence structure for reliability design.
TRANSPORTATION GEOTECHNICS
(2023)
Article
Engineering, Marine
He Wang, Rui Wang, Jian-Min Zhang
Summary: This study investigates the changes in suction pressure and seepage field during the process of suction caisson installation in sand using ALE large deformation solid-fluid coupled FEM. Results show that the difference in penetration resistance for jacked and suction installation is caused by seepage and excess pore pressure generated during the suction caisson installation, highlighting the importance of considering seepage in the evaluation of suction caisson penetration.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2021)
Article
Microbiology
Angela L. Creevy, David M. Wilkinson, Roxane Andersen, Richard J. Payne
Summary: The extensive drainage of peatlands in north-west Europe for afforestation has led to changes in carbon balance and biodiversity value. Large-scale restoration projects aim to restore the hydrological conditions and promote active peat growth. This study investigated the response of testate amoebae assemblages and vegetation composition after tree removal on a drained raised bog. The results show that microbial recovery is a slow process, with vegetation composition responding faster than the microbial assemblages.
EUROPEAN JOURNAL OF PROTISTOLOGY
(2023)
Article
Engineering, Chemical
Noor Ilyana Ismail, Shibo Kuang, Mengmeng Zhou, Aibing Yu
Summary: This study explores non-uniform sand retention behavior on wire wrapped screens through numerical analysis, identifying five distinct sand retention modes and proposing a phase diagram to predict their transitions. Additionally, a new screen design with a converging slot configuration is introduced to improve particle accumulation and achieve uniform sand retention on the screen.
Article
Engineering, Marine
Y. Wang, M. J. Cassidy, B. Bienen
Summary: A site-specific assessment is essential for the safe operation of a mobile jack-up unit in extreme weather conditions, with the evaluation of structural response relying heavily on accurate interaction assessment between spudcan foundations and supporting soils. The use of macro-element models, especially in layered soils, can improve the understanding of system response and pushover capacity, particularly when dealing with external loading from wind, waves, and current.
Article
Engineering, Civil
Qi Wu, Xuanming Ding, Yanling Zhang, Yanli Zhang
Summary: This study simulated the dynamic characteristics of coral sand using a finite difference program and established numerical models to investigate the seismic response of underground structures in coral sand. The results indicate that the density and permeability coefficient of the coral sand foundation play a significant role in the seismic response.
