scholarly journals Can the mechanoreceptional setae of a feeding‐current feeding copepod detect hydrodynamic disturbance induced by entrained free‐floating prey?

2021 ◽  
Author(s):  
Xinhui Shen ◽  
Xin Yao ◽  
Marcos ◽  
Henry C. Fu
Keyword(s):  
Hydrodynamic Disturbance

Effects of interactions between macroalgae and seagrass on the distribution of macrobenthic invertebrate communities at the Yellow River Estuary, China

2021 ◽  
Author(s):  
Xinyan Wang ◽  
Jiaguo Yan ◽  
Junhong Bai ◽  
Dongdong Shao ◽  
Baoshan Cui
Keyword(s):  
Yellow River ◽  
River Estuary ◽  
Yellow River Estuary ◽  
The Yellow River ◽  
Negative Effects ◽  
Primary Producers ◽  
Biomass Density ◽  
Invertebrate Communities ◽  
Seagrass Ecosystem ◽  
Hydrodynamic Disturbance

<p>Algae-dominance in seagrass beds has been well recognized, however, the competitive relationship between seagrass and macroalgae along land-sea gradients and their ecological effects has received little attention. In this study, a field survey was conducted at the Yellow River Estuary to investigate the effects of macroalgal proliferation on seagrass and macrobenthic invertebrate communities. Our results suggested that strong competitive interaction existed between the two primary producers, and the positive or negative effects of macroalgae on seagrass growth varied along land-sea gradient. Furthermore, the dominant controlling factors on the biomass, density and diversity of macrobenthic invertebrate communities were found to vary accordingly, i.e., from features of the primary producers in the nearshore where macroalgae suppressed seagrass growth to hydrodynamic disturbance in the offshore where macroalgae facilitated seagrass growth. Our study emphasizes the importance to integrate interspecific competition into ecosystem-based management of seagrass ecosystem, and provides references for additional ecological indicators.</p>

Impact of hydrodynamic disturbance on the generation times of four species of marine naked amoebae

2006 ◽  
Vol 86 (1) ◽  
pp. 39-42 ◽  
Author(s):  
Phillip R. Cowie ◽  
Fiona Hannah
Keyword(s):  
Sandy Shore ◽  
Generation Times ◽  
Hydrodynamic Disturbance ◽  
Naked Amoebae

Four species of gymnamoebae isolated from a sandy shore were subjected to hydrodynamic disturbance within microcosms. Increasing the level of disturbance increased the generation times of all four isolates. Generation times of a small Platyamoeba sp. and a limax amoeba were least affected by increasing disturbance. The greatest increase in generation times was observed in populations of two large (>15 μm) Mayorella sp. and Vannella sp. This study shows that hydrodynamic disturbance may be an important community structuring force within natural marine amoebae communities.

Hydrocephalus and craniosynostosis

1998 ◽  
Vol 88 (2) ◽  
pp. 209-214 ◽  
Author(s):  
Giuseppe Cinalli ◽  
Christian Sainte-Rose ◽  
Eve Marie Kollar ◽  
Michel Zerah ◽  
Francis Brunelle ◽  
...  
Keyword(s):  
Ventricular Dilation ◽  
Content Type ◽  
Syndromic Craniosynostosis ◽  
Review Period ◽  
Hydrodynamic Disturbance ◽  
Csf Hydrodynamics ◽  
Constant Feature ◽  
Apert's Syndrome ◽  
Fine Print

Object. A retrospective study of 1727 cases of craniosynostosis was undertaken to determine the interrelationship between abnormal cerebrospinal fluid (CSF) hydrodynamics and craniosynostosis. Methods. The patients were divided into two groups: nonsyndromic craniosynostosis and syndromic craniosynostosis. Cases of occipital plagiocephaly without suture synostosis and cases of shunt-induced craniosynostosis were excluded from the study. The majority of patients (1297) were treated surgically for their cranial deformity; 95% of these patients had a postoperative follow-up review period lasting 5 years. Clinical and radiographic charts covering the time from presentation through the follow-up period were reviewed. Conclusions. Abnormal intracranial CSF hydrodynamics was found in 8.1% of the patients (3.4% of whom had received shunts and 4.5% of whom had not). Three types of CSF hydrodynamic disturbance were observed: progressive hydrocephalus with ventricular dilation, nonprogressive ventriculomegaly, and dilation of the subarachnoid spaces. Hydrocephalus occurred much more frequently in patients with syndromic craniosynostosis (12.1%) than in those with isolated craniosynostosis (0.3%). In fact, patients with kleeblattschädel exhibited hydrocephalus as a constant feature and patients with Crouzon's syndrome were far more likely to have hydrocephalus than those with other syndromes. In Apert's syndrome, ventricular dilation occurred very frequently, but it was almost always nonprogressive in nature. In most cases of syndromic craniosynostosis, venous sinus obstruction and/or chronic tonsillar herniation were found. Their role in the pathophysiology of hydrocephalus in craniosynostosis is discussed.

scholarly journals Hydrodynamic disturbance controls microbial community assembly and biogeochemical processes in coastal sediments

2021 ◽  
Author(s):  
Ya-Jou Chen ◽  
Pok Man Leung ◽  
Perran L. M. Cook ◽  
Wei Wen Wong ◽  
Tess Hutchinson ◽  
...  
Keyword(s):  
Microbial Community ◽  
Community Assembly ◽  
Microbial Community Composition ◽  
Coastal Sediments ◽  
Sediment Geochemistry ◽  
Biogeochemical Processes ◽  
Microbial Abundance ◽  
Microbial Composition ◽  
Hydrodynamic Disturbance ◽  
Microbial Community Assembly

AbstractThe microbial community composition and biogeochemical dynamics of coastal permeable (sand) sediments differs from cohesive (mud) sediments. Tide- and wave-driven hydrodynamic disturbance causes spatiotemporal variations in oxygen levels, which select for microbial generalists and disrupt redox cascades. In this work, we profiled microbial communities and biogeochemical dynamics in sediment profiles from three sites varying in their exposure to hydrodynamic disturbance. Strong variations in sediment geochemistry, biogeochemical activities, and microbial abundance, composition, and capabilities were observed between the sites. Most of these variations, except for microbial abundance and diversity, significantly correlated with the relative disturbance level of each sample. In line with previous findings, metabolically flexible habitat generalists (e.g., Flavobacteriaceae, Woeseaiceae, Rhodobacteraceae) dominated in all samples. However, we present evidence that aerobic specialists such as ammonia-oxidizing archaea (Nitrosopumilaceae) were more abundant and active in more disturbed samples, whereas bacteria capable of sulfate reduction (e.g., uncultured Desulfobacterales), dissimilatory nitrate reduction to ammonium (DNRA; e.g., Ignavibacteriaceae), and sulfide-dependent chemolithoautotrophy (e.g., Sulfurovaceae) were enriched and active in less disturbed samples. These findings are supported by insights from nine deeply sequenced metagenomes and 169 derived metagenome-assembled genomes. Altogether, these findings suggest that hydrodynamic disturbance is a critical factor controlling microbial community assembly and biogeochemical processes in coastal sediments. Moreover, they strengthen our understanding of the relationships between microbial composition and biogeochemical processes in these unique environments.

scholarly journals Clustering Groundwater Level Time Series of the Exploited Almonte-Marismas Aquifer in Southwest Spain

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1063
Author(s):  
Nuria Naranjo-Fernández ◽  
Carolina Guardiola-Albert ◽  
Héctor Aguilera ◽  
Carmen Serrano-Hidalgo ◽  
Esperanza Montero-González
Keyword(s):  
Time Series ◽  
Groundwater Resources ◽  
Management Strategies ◽  
Groundwater Levels ◽  
Management Plans ◽  
Distribution Parameters ◽  
Hydrodynamic Disturbance ◽  
Over Exploitation ◽  
Hydrodynamic Behaviors ◽  
Guadalquivir River

Groundwater resources are regularly the principal water supply in semiarid and arid climate areas. However, groundwater levels (GWL) in semiarid aquifers are suffering a general decrease because of anthropic exploitation of aquifers and the repercussions of climate change. Effective groundwater management strategies require a deep characterization of GWL fluctuations, in order to identify individual behaviors and triggering factors. In September 2019, the Guadalquivir River Basin Authority (CHG) declared that there was over-exploitation in three of the five groundwater bodies of the Almonte-Marismas aquifer, Southwest Spain. For that reason, it is critical to understand GWL dynamics in this aquifer before the new Spanish Water Resources Management Plans (2021–2027) are developed. The application of GWL series clustering in hydrogeology has grown over the past few years, as it is an extraordinary tool that promptly provides a GWL classification; each group can be related to different responses of a complex aquifer under any external change. In this work, GWL time series from 160 piezometers were analyzed for the period 1975 to 2016 and, after data pre-processing, 24 piezometers were selected for clustering with k-means (static) and time series (dynamic) clustering techniques. Six and seven groups (k) were chosen to apply k-means. Six characterized types of hydrodynamic behaviors were obtained with time series clustering (TSC). Number of clusters were related to diverse affections of water exploitation depending on soil uses and hydrogeological spatial distribution parameters. TSC enabled us to distinguish local areas with high hydrodynamic disturbance and to highlight a quantitative drop of GWL during the studied period.

Risks of the Vision System Lesion during a Long Space Flight

2021 ◽  
pp. 34-41
Author(s):  
Olga M. Man’ko ◽  
◽  
Alexander E. Smoleyevsky ◽  
Keyword(s):  
Space Flight ◽  
Simulated Microgravity ◽  
Potential Role ◽  
Vision System ◽  
Ocular Pathology ◽  
Term Space Flight ◽  
Hydrodynamic Disturbance

The article describes the factors of a long-term space flight associated with the risk of ocular pathology, including the established risk of space neuroocular syndrome (SANS). The mechanisms of intraocular hydrodynamic disturbance and their potential role in the development of SANS are considered. The results of the studies concerning the hydrodynamics of the eye in the conditions of simulated microgravity are presented.

Impacts of hydrodynamic disturbance on sediment resuspension, phosphorus and phosphatase release, and cyanobacterial growth in Lake Tai

2015 ◽  
Vol 74 (5) ◽  
pp. 3945-3954 ◽  
Author(s):  
Jian Huang ◽  
Qiujin Xu ◽  
Beidou Xi ◽  
Xixi Wang ◽  
Weiping Li ◽  
...  
Keyword(s):  
Sediment Resuspension ◽  
Hydrodynamic Disturbance
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