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18 pages, 5 figures, 3 tables, supplementary information https://doi.org/10.1007/s11160-023-09787-2, N. norvegicus supports one of the most commercially-important fisheries in the Mediterranean, and there is considerable interest in developing non-invasive sampling stock assessment methods. Currently, stock assessments are conducted via trawling or by UnderWater TeleVision (UWTV) surveys with limited capacity to provide direct population data due to the burrowing behavior of the species. Here, we used acoustic telemetry to characterize the burrow emergence and movement patterns of N. norvegicus in relation to internal tides and inertial currents in deep-sea habitats of the northwestern Mediterranean. We deployed acoustic tags on 25 adults between May and June 2019, and collected up to 4 months of detection data from each tag. Tagged lobsters spent approximately 12% of their time in door-keeping (i.e., detections at burrow entrance with no displacements) but differences existed among the different behavioral rhythms identified. We observed that mixed day-night, tidal and inertial rhythms in field settings were similar to those observed in laboratory tests. The presence of mixed day-night and tidal periodicity poses the question of why N. norvegicus exhibits flexible responses to environmental cues other than photoperiod. It is possible that tidal regulation of locomotor activity could reduce energy expenditure in relation to hydrodynamic drag. Inertial periodicity occurs in animals with no clear burrowing-oriented activity (always present on the seabed). Possibly, inertial-related movements are the result of a disruption of the biological clock. Our results are discussed in the context of how burrow emergence rhythms may bias UWTV surveys and how novel in situ monitoring approaches address these biases, Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. Ministerio de Ciencia e Innovación, RESNEP (CTM2017-82991-C2-1-R), RESBIO (TEC2017-87861-R), PLOME (PLEC2021-007525/AEI/10.13039/501100011033), PhD-fellowship5642. (ref. PRE2021-099558) under the BITER project (PID2020-114732RBC-31),Antoni Sánchez-Márquez,Severo Ochoa Centre of Excellence (CEX2019-000928-S), LIFE programme, LIFE20 NAT/ES/001270 LIFE ECOREST, DAMIANOS CHATZIEVANGELOU, H2020 Marie Skłodowska-Curie Actions,893089, Ivan Masmitja

One-dimensional modeling of the hydrodynamic river networks of plain urban rivers has been employed to optimize operating regulations in these river networks. However, pilot-scale experiments are still lacking for the validation of hydrodynamics obtained by modeling to improve water quality. In this study, a pilot-scale experiment combined with theoretical calculation was conducted to determine both the hydrodynamics and water quality in the Hutang area of Changzhou, China. The simulation results showed that using high-performance pumps on the border to drain the river beyond it could increase the frequency of water replenishment. The results of the pilot-scale experiment are consistent with the simulation. Moreover, only in condition (c) does the water of the Wuyi canal flow into the Wunan river. With the exception of turbidity, the highest number of rivers with improved water quality tables occurred in this condition. Based on the response mechanism between the flow rate and the water quality, a flow rate within the range of 0.12 m/s to 0.28 m/s can help reduce comprehensive pollution. This study successfully enhanced the hydrodynamic regulation and water quality of the rivers in the Hutang region using technologies combined with simulation and pilot-scale experiments.

Hydrodynamic regulation is widely used to improve the water quality of urban rivers. However, it is yet to explore substantially whether hydrodynamics could regulate the metabolic activity of biofilm in such aquatic systems. Herein, the pilot experiment of hydrodynamics in the rotation tanks was designed, including two experiment phases, namely constant flow and adjusting flow for 21 days and 14 days, respectively. In constant flow phase, biofilms grew in five shear stress gradients (R1–R5, 0.0044– 0.12 Pa). The carbon metabolic rate (k) of mature biofilms evaluated by BIOLOG ECO microplates showed a hump-shaped relationship with increasing shear stress, with R3 (0.049 Pa) the highest, while R5 (0.12 Pa) the lowest. To verify whether the metabolic activity of biofilm cultured at constant flow phase can be regulated by shear stress, we initiated the adjusting flow phase, and shear stress in reactors was reset uniformly at 0.049 Pa (with the highest k). Results showed the carbon metabolic activity of biofilm in reactor R4 and R5 increased rapidly by day 3, and there was no significant difference between the carbon metabolic rates among the five treatments by day 14. Meanwhile, the utilization levels of polymers and carbohydrates by biofilms were significantly different among the five treatments after hydrodynamic regulations. These results suggested that the total carbon metabolic activity of biofilm can be regulated by hydrodynamics, while the divergent changes of the specific carbon source category might affect the biofilm-mediated carbon biogeochemical processes, which should be considered for the application of hydrodynamic regulation in river ecological restoration projects. Refereed/Peer-reviewed

Розглянуто модель артеріальної судинної мережі як єдиної в’язкопружної камери з біологічно активного (біоактивного) матеріалу. Біоактивність розглядається як властивість матеріалу стінок камери реагувати на будь-яке збільшення гідродинамічного тиску всередині камери та напруги зсуву стінки на внутрішній поверхні стінок. Така поведінка відповідає активній реакції артеріальної стінки на зміну артеріального тиску та умов кровотоку. Для в’язкопружного тіла Кельвіна–Фойгта та наявності локальних гідродинамічних, механічних та хімічних регуляцій математична постановка задачі зводиться до системи двох звичайних диференціальних рівнянь для тиску та об’єму камери. Коли механізм активного регулювання є чисто гідродинамічним, розв’язок проблеми можна знайти як розширення потужності за малим параметром. Отримано розв’язок задачі та порівняно з випадком пасивної в’язкопружної камери без регулювання. Розроблена модель може бути використана в медичній діагностиці для аналізу пульсової хвилі та кількісної оцінки в’язкопружних параметрів артеріальної стінки. The model of arterial vasculature as a single viscoelastic chamber from a biological active (bioactive) material is considered. The bioactivity is considered as a property of the material of the chamber walls respond to any increase in hydrodynamic pressure inside the chamber and in wall shear stress at the inner surface of the walls. That behavior corresponds to the active reaction of the arterial wall for variations of the arterial blood pressure and blood flow conditions. For the Kelvin–Voigt viscoelastic body and presence of local hydrodynamical, mechanical and chemical regulations, the mathematical problem formulation is reduced to the system of two ordinary differential equations for pressure and volume f the chamber. When the mechanism of active regulation is purely hydrodynamic, a solution of the problem may be found as the power expansion over a small parameter. The solution of the problem is obtained and compared to the case of passive viscoelastic chamber without regulation. The developed model can be used in medical diagnostics for a pulse wave analysis and a quantitative estimation of the viscoelastic parameters of the arterial wall.