Lower Water Layers Research Articles

Sensitivity Simulations of Wind-driven Water Circulation in İzmit Bay

İzmit Bay, a 50 km long inlet at the eastern end of the Marmara Sea, is crucial for the region’s economy, culture, and marine ecosystem. The bay’s water circulation regulates nutrient distribution, stratification, sedimentation, oxygen levels, heat, and pollution levels. It is also influenced by meteorological events, such as short-term moderate to strong wind conditions. This study investigated the sensitivity of İzmit Bay Water Circulation to wind speed, direction, and duration using the MITgcm model with Orlanski boundary conditions and process-oriented modeling. The simulations showed that under weak forcing conditions, seawater temperature, salinity, and stratification do not significantly vary. However, strong forcing and wind speeds (statistically defined by percentiles of observation data) of 4.9 m/s (75%), 6.7 m/s (90%), and 10.1 m/s (99%) generate significant mesoscale and sub-mesoscale processes, depending on the direction. Westerly component winds cause downwelling at the eastern coastline, while easterly component winds bring sub-surface water to the surface. Strong winds from N, NE, and E sectors lead to the rise in lower-layer waters in the western basin, forcing them to overflow through the Hersek Delta sill into the central basin. Overall, severe wind events greater than 4.9 m/s (75%) significantly affect the bay’s hydrography by transforming the upper layer, with a decrease in temperature up to 5 °C and an increase in salinity up to 10 ppt.

Simulation and Control Strategies for Longitudinal Propagation of Acid Fracture in a Low-Permeability Reservoir Containing Bottom Water

The reservoir in the Anyue gas field, located in the Sichuan basin of China, belongs to the second member of the Dengying formation and has distinctive geological features. It is characterized by strong heterogeneity, low porosity, low permeability, and locally developed natural fractures. The reservoir space consists primarily of corrosion holes, natural fractures, and similar voids. Moreover, the lower reservoir exhibits high water saturation and a homogeneous bottom-water interface. Since it is a carbonate-based hydrocarbon reservoir with low porosity and permeability, deep acid fracturing has proven to be an efficient method for enhancing individual well production. However, the reconstruction of the second member of the Dengying formation reservoir poses significant challenges. The reservoir contains high-angle natural fractures, small vertical stress differences, and is located in close proximity to the gas–water interface. As a result, it becomes difficult to control the height of the acid break. Improper acid break treatment may easily result in water production affecting gas well production. To explore ways to control the longitudinal extension of acid fractures, 3D numerical models focusing on the initiation and expansion of acid fractures have been developed. This model takes into account geological and engineering factors such as stress differences, acid fracture displacements and scales, and their effects on the longitudinal extension of acid fractures. It was revealed that the pressure difference is the main controlling factor for the acid fracture height, followed by the reservoir thickness, the interlayer thickness, and the viscosity of the working fluid. Technical countermeasures for controlled fracture and high-acid fracturing tailored to different reservoir characteristics have been proposed, and design parameters for controlled fracture and high-acid fracturing can be optimized. By effectively controlling the vertical extension of the acid fracture, it is possible to maximize production from a single well while avoiding interference from the lower water layer. This study provides theoretical guidance for the application of deep-acid-fracturing techniques in low-permeability bottom-water gas reservoirs.

Exploring the Sensitivity of Water Temperature Models for High Dams and Large Reservoirs: A Case Study of the Nuozhadu Reservoir in China

The parameters governing a water temperature model play a pivotal role in determining the uncertainties associated with the model’s outcome. In this study, a two-dimensional (2D) hydrodynamic and water temperature coupling model is constructed, focusing on the Nuozhadu Reservoir situated along the Lancang River. Employing a single-factor analysis approach, the sensitivity of the thermal balance parameters and hydrodynamic parameters in the model is assessed. This study overcomes the shortcomings of previous sensitivity analyses of hydrodynamic parameters in reservoir water temperature models. The findings reveal that the attenuation parameters of light and Beer’s law parameter exhibit minimal sensitivity to the vertical temperature structure. Conversely, radiation parameter A and radiation parameter B exert tenfold disparate influences on the surface and bottom temperatures of the reservoir. Among the hydrodynamic parameters considered, the horizontal viscosity factor shows no sensitivity to the vertical temperature structure, whereas the vertical viscosity factor serves as a crucial determinant, directly influencing the intensity of vertical temperature stratification. An increased vertical viscosity factor promotes heat exchange between the upper and lower water layers, thereby reducing the vertical temperature gradient and weakening stratification. Conversely, diminishing this factor intensifies stratification. Thus, when conducting water temperature simulations in high dams and large reservoirs, careful attention should be given to calibrating vertical viscosity factor.

Agent-Based Model of Diatom Population Dynamics in Marginal Arctic Seas in Summer

A hypothesis is proposed for the functioning of the diatom population under conditions of water column stratification. It is assumed that cells in the upper illuminated water layer accumulate biomass due to photosynthesis. In the lower layer, rich in minerals, the cells replenish their intracellular reserves. Moving from one layer to another allows to cells to compensate for the lack of resources. Sinking occurs as a result of sedimentation, and lifting occurs due to the release of carbon dioxide microbubbles in the process of respiration. On the basis of this hypothesis, an agent model of the population is constructed. The calculations have shown that vertical movements ensure the existence of the population. Various surface illumination make it possible to obtain various distributions of cell numbers in the upper and lower water layers, which is consistent with the data of expeditionary observations.

A multispectral method for retrieving overlapping cloud top heights from passive radiometers

Cloud top height (CTH) is an important factor influencing its radiative effects, weather and climate change, and spaceborne passive radiometers widely used to retrieve CTH mostly use an oversimplified single-layer cloud assumption. Nevertheless, natural clouds exhibit complex vertical inhomogeneity, such as overlapping clouds. This study investigates the potential of multispectral observations for characterizing overlapping cloud properties and introduces a new CTH retrieval algorithm for overlapping CTHs. Synthetic radiative transfer simulations and an information content analysis are applied to demonstrate the theoretical basis of using passive radiometers for overlapping cloud property retrievals. Specifically, this method leverages the merits of four shortwave infrared (0.87, 1.6, 2.13 and 2.25 μm) channels in distinguishing cloud optical and microphysical properties in different phases and the capabilities of longwave infrared (8.6, 11 and 12 μm) channels for the corresponding CTHs. The method performs effectively for overlapping clouds with an optically thin but detectable ice layer (optical thickness less than ∼7) above a liquid water layer. We consider collocated Advanced Himawari Imager (AHI)/Visible Infrared Imaging Radiometer Suite (VIIRS) and Moderate Resolution Imaging Spectroradiometer (MODIS) measurements to provide sufficient spectral information. Compared with conventional single-layer-assumed CTH retrievals, our CTHs for both upper-layer ice and lower-layer water clouds show closer agreement with those indicated by active instruments. Statistically, the average bias of the upper ice CTH results is constrained from −2.89 km to −1.36 km and we obtain lower water CTHs with an average bias of −1.21 km. The cloud properties based on our retrievals also make the simulated multichannel radiances more consistent with the observed ones. The new method will greatly improve our understanding of the vertical structures of overlapping clouds and their parameterization in general circulation models; thus, we suggest that including increased numbers of cloud-sensitive channels is necessary to better determine cloud properties.

Quantitative assessment of decadal water temperature changes in Lake Kasumigaura, a shallow turbid lake, using a one-dimensional model

To assess the decadal water temperature (WT) changes observed at the center of Lake Kasumigaura, a shallow turbid lake in Japan, we constructed a prediction model for WT. The thermal interactions among air, water, and sediment were simulated by a one-dimensional differential equation using hourly observations of meteorological and limnological parameters. The validated model showed good performance (i.e., <1 °C RMSE for the daily averaged WT) for 2012, 2013, and 2015, respectively, in both upper and lower water layers, which were attained by incorporating a physical sub-model regarding the surface water temperature (surface WT). The good description of seasonal, daily, and hourly changes in surface WT obtained with the sub-model was confirmed by the observed and simulated time series. We then quantified and evaluated the trends of the meteorological and limnological parameters influencing WT changes from 1979 to 2015 based on their effects on WT by using the prediction model with the increases in air temperature (AT), solar radiation (SR), wind velocity (WV), and turbidity during that period; then, WT in the former period (1979) was predicted according to the trends and compared with the measured WT. The observed WT changes during the period were quantitatively explained by the compound effects of the parameters' changes, i.e., the AT and SR raising the WT, and the WV and turbidity lowering the WT.

Assessing Overlapping Cloud Top Heights: An Extrapolation Method and Its Performance

Under the assumption that clouds are homogeneous and single-layered (SL), most current operational cloud top height (CTH) products derived from passive radiometers may largely underestimate the CTH of overlapping clouds. This article proposes a statistics-based extrapolation algorithm for retrieving the CTHs of overlapping clouds using only existing cloud property products available for most operational radiometers, and the method is successfully employed for the advanced himawari imager (AHI) observations. Because regional clouds within the same “system” have relatively continuous geometric properties, especially CTH, due to similar atmospheric conditions, upper-layer ice cloud CTHs (ITHs) and lower-layer water cloud CTHs (WTHs) are inferred using the CTH retrievals of well-chosen neighboring SL ice and water clouds, respectively. The proposed algorithm uses the latest machine-learning-based model to reasonably distinguish overlapping clouds from SL clouds, and optimizes the extrapolation by considering three physical constraints on neighboring, cloud phase, and cloud optical thickness (COT). Validated using active observations from CloudSat and cloud-aerosol Lidar and infrared pathfinder satellite observation (CALIPSO), our algorithm improves the AHI CTH mean bias for overlapping clouds from −5.1 to −2.6 km. More importantly, the algorithm provides CTH information of underlying water clouds that are unavailable from existing radiometer-based products. With the simultaneous retrieval of ITH and WTH, this algorithm increases our capability to detect the vertical structures of overlapping clouds and better evaluate the cloud radiative effects (CREs).

Polydopamine-stabilized ZIF-8: Improved water stability and lubrication performance

ZIF-8, a novel lubricant additive, is considered to have great potential in reducing friction and wear due to large specific surface area, thermal stability and mechanical flexibility. However, ZIF-8 nanoparticles readily hydrolyze in aqueous solutions, transforming into large-sized lamellar and rod-like materials, which is a major bottleneck as a water-based lubricant additive. Herein, a strategy is proposed to functionalize ZIF-8 via mussel-inspired polydopamine (PDA) polymerization process to improve its lubrication stability in the water phase. The modified ZIF-8 (PDA@ZIF-8) can firmly “locked” water molecules on the surface of PDA to protect internal structure of ZIF-8, and improve its dispersion and stability of ZIF-8 in water. Moreover, ZIF-8@PDA tribofilm and iron oxide chemical protection film are formed during the friction process, and the low shear strength water layer between the contact surfaces contribute to achieving powerful synergistic lubricating effects, resulting in friction coefficient and wear track width reduce by 65% and 66%, respectively. Therefore, this work provides a promising alternative for expanding the practical application of ZIF-8 in aqueous environment and tribology.

A Novel Model for Oil–Water Stratified Flow in Horizontal Wells With a Curved Interface Based on Dynamic Contact Angle

Abstract During the process of oil production and transportation, oil–water two-phase flow is a common occurrence. Well completion optimization and production design are greatly affected by the prediction accuracy of two-phase flow characteristics. In this paper, a novel model is proposed to predict the influence of interface shape on stratified flow. Dynamic contact angle theory and minimum energy method are introduced to solve the momentum equations with a curved interface and dispersed phase holdup in the lower water layer or the upper oil layer, respectively. When the Eotvos number is lower than ten, the interface shape changes from a flat surface to a curved surface, and the flow area of the upper water layer and the lower oil layer will increase and decrease, respectively. Results show that the dynamic contact angle and pressure gradient are greatly affected by oil superficial velocity, oil viscosity, and pipe diameter. By comparing the prediction with available experiment results, the validity of the model is evaluated. Results show that the novel model has an overall good prediction performance for the pressure gradient, with an average percentage error of 13.12%. While the average percentage error of Liu's model and two-fluid model are 22.89% and 34.98%, respectively. The novel model is a unified model that could be used to solve the problem with a curved/flat interface. It will also promote the oil well production design and horizontal well completion optimization.

Into the deep – Dispersal models for deep-water decapod shrimp larvae: The case of Parapenaeus longirostris

Deep-water shrimps remain some of the less understood decapod crustacean taxa, despite the high commercial and ecological importance. The lack of knowledge on adults and larval stages of many species results in an incomplete view of the biology, distribution, dispersal and connectivity, essential knowledge for conservation and stock management. In zooplankton samples, larvae of deep-water shrimps are usually found in low abundances. Here, we address the insufficiently studied topics of distribution and transport of deep-water shrimp larvae, providing information on potential pathways and mechanisms of dispersal. The work focuses on southern Portuguese waters, giving important indications for deep-water shrimp species worldwide. Physical-ecological modelling was used to examine the dispersal of larvae of the deep-water rose shrimp, Parapenaeus longirostris, that were found distributed over shelf waters in the study region. In situ spatial abundances were examined, and ontogenetic vertical distributions and sites of larval release were included in the models. The circulation in the vicinity of submarine canyons and deep moats promoted relatively shallower positions of simulated particles. Passive drifts were insufficient for larvae to reach the uppermost water layers, while the vertical distribution adopted, in the upper or lower water layers, was highly important, dictating the direction of the transport and the retention over shelf waters. Slope or shelf larval releases influenced the dispersal patterns and the concentration of particles over productive waters, suggesting that the onshore movement of females during spawning may benefit the larval retention over shelf waters.

Source Versus Recycling Influences on the Isotopic Composition of Nitrate and Nitrite in the East China Sea

AbstractNitrogen transfer processes and NO3− sources in the East China Sea (ECS) were analyzed using dual isotopes of NO3− and NO2−, the concentration and isotopes of dissolved O2 and N2 gases, nutrient concentrations, and the hydrological conditions. It was clear that the δ15N and δ18O values of NO3− in the Changjiang freshwater were 5.6–6.6‰ and 0.6–1.0‰, respectively, affected by human activities (fertilizer, sewage, and manure) and nitrification. Off the Changjiang Estuary to the ECS continental slope, the NO3− concentration was lower or exhausted in the upper water layers, where both available δ15N and δ18O values for NO3− were high related to phytoplankton assimilation. In the lower water layers, organic matter remineralization, nitrification, and coupled sedimentary nitrification and denitrification resulted in low NO3− isotope values. Moreover, in the upper water layers of the ECS continental slope, NO3− showed high δ15N and δ18O values and low Δ(15, 18) values affected by assimilation, nitrification, and N2 fixation. NO2− in the ECS was dominated by NH4+ oxidation, and NO2− oxidation plays an important role in depleting NO2− in δ15N values. An overall NO3− budget is built for the ECS shelf, indicating that open boundary exchanges of NO3− flux and isotopes through Kuroshio invasion and Taiwan Warm Current Water are comparable to outflow off the ECS shelf, and nitrogen transformation processes (such as NO3− assimilation and nitrification) play an important role in nitrogen cycle, and NO3− is modified on the ECS shelf.

Seasonal Estuarine Turbidity Maximum under Strong Tidal Dynamics: Three-Year Observations in the Changjiang River Estuary

The estuarine turbidity maximum (ETM) under strong tidal dynamics (during spring tides) was investigated along the Deepwater Navigation Channel (DNC) in the North Passage (NP) of the Changjiang River Estuary (CRE) in wet and dry seasons of 2016, 2017 and 2018. The observed water current, salinity, stratification and suspended sediment concentration (SSC) were illustrated and analyzed. Results show that the SSC was lower in wet seasons than dry seasons in 2016 and 2017 because of the weak influence of typhoons before observations in wet seasons. On the contrary, the SSC was higher in the wet season than the dry season in 2018 because of the strong influence of typhoons in the wet season. Our observations challenged the common perspective that SSC in the NP is higher in wet seasons than dry seasons, because the magnitudes of SSC were found to be easily influenced by strong winds before observations. The along-channel distribution of high SSC was determined by the location of salt wedge, and consequently, the ETM was further upstream in dry seasons than wet seasons. The observed SSC was more concentrated in lower water layers in wet seasons (“exponential” profile) than dry seasons (“linear” profile). This seasonal difference of vertical SSC was related to the flocculation setting velocity influenced by temperature rather than the weak stratification during spring tides. Moreover, on the basis of the net water/sediment transport and flux splitting, large river discharge and a low-SSC condition could reduce siltation in the middle DNC. The former vanished the convergence of water transport, and the latter reduced landward tidal pumping sediment transport. Sediment trapping and siltation in the dry seasons occurred in the seaward segment of the upper reach because of the decrease in the river discharge.

Water resources potential in Co To island and exploitation orientation to use

Co To is an island of the Co To district in Quang Ninh province with an area of about 18 km2. Average rainfall on the island is 1,738.8 mm/yr, evaporation is 925 mm/yr. On the island, there are some small streams but they are temporary flow in the rainy season, there is not any natural lakes. There are 2 aquifers. The Quaternary aquifer (q) is distributed in a low terrain with area of about 9 km2, thin thickness and saline water is in about half of the area, so it does not make sense for water supply. The fissured aquifer of the ocdovic-silua (o-s) formation is distributed in the high terrain with an area of about 9 km2, this is low potential water layer. The flow rate in the boreholes in the fractured zone due to tectonic activity can be 1–1.5 l/s, it can satisfy small-scale water supply. Potential groundwater reserve of Co To island is 6,472 m3/day, exploitable reserve is 1941 m3/day, exploited reserve level at C1 range is 1,144 m3/day. This can satisfy the water demand for the living of people on the island today. Small-scale groundwater exploitation in the island has just been beginning, but it has the prospect of replication and at the same time there must be reasonable measures to protect and develop water resources to ensure sustainable development and meet the larger water requirements in the future.

Effect of Wave, Current, and Lutocline on Sediment Resuspension in Yellow River Delta-Front

Historically, the Yellow River in China discharges &gt; 1 × 109 ton/yr sediment to the sea, and has formed a large delta in the western Bohai Sea. Its river mouth is characterized by an extremely high suspended sediment concentration (SSC), up to 50 g/L. However, the hydrodynamic factors controlling the high suspended sediments in the Yellow River estuary are not well understood. Here, we conducted two hydrodynamic observations and SSC measurements in the winter and spring low-flow seasons of 2014–2015 and 2016–2017 under five sea conditions, including calm-rippled, smooth-wavelet, slight, moderate, and rough, in the Yellow River Delta-front during the observation period. Under calm-rippled conditions, the contribution of currents to the total resuspended sediment concentration (RSC) was 77.7%–100.0%. During the smooth-wavelet and slight periods, the currents’ contribution decreased as low as 30% and 3.0% of the total RSC, respectively. Under moderate and rough-sea conditions, waves accounted for at least 70% and 85% of the total RSC, respectively. The results indicate that 20 cm-thick lutoclines were created after a significant increase in the wave height to a peak value followed by a decrease. When the SSC is over 3 g/L and hydrodynamic conditions could not break the lutoclines, the flocculent settling of suspended sediment changes to hindered settling in the Yellow River Delta. Under hindered settling, the settling velocity decreases, and the resuspended sediments remains in the lutoclines and their lower water layers. This study reveals different controlling factors for the high SSC near a river-influenced delta, and helps us get a better understanding of a delta’s resuspension and settling mechanisms.

Zooplankton Community Responses to Oxygen Stress

Recent changes in climate and eutrophication have caused increases in oxygen depletion in both freshwater and marine ecosystems. However, the impact of oxygen stress on zooplankton, which is the major trophic link between primary producers and fish, remains largely unknown in lakes. Therefore, we studied 41 lakes with different trophic and oxygen conditions to assess the role of oxygen stress on zooplankton communities and carbon transfer between phytoplankton and zooplankton. Samples were collected from each lake at the peak of summer stratification from three depth layers (the epilimnion, metalimnion, and hypolimnion). Our results revealed that freshwater zooplankton were relatively tolerant to anoxic conditions and the greatest changes in community structure were found in lakes with the highest oxygen deficits. This caused a switch in dominance from large to small species and reduced the zooplankton biomass in lower, anoxic layers of water, but not in the upper layers of water where the oxygen deficits began. This upper anoxic layer could thus be a very important refuge for zooplankton to avoid predation during the day. However, the reduction of zooplankton in the lower water layers was the main factor that reduced the effectiveness of carbon transfer between the phytoplankton and zooplankton.

Characterization of longshore currents in southern East China Sea during summer and autumn

Current characteristics and vertical variations during summer and autumn in the southern East China Sea were investigated by measuring current profile, tide, wind, and wave data for 90 d from July 28 to October 25, 2015. Our results are: (1) The current was mainly a (clockwise) rotating flow, displaying reciprocating flow characteristics, and vertically the current directions were the same throughout the vertical profile. (2) The horizontal current speed was strongest during August (summer) with an average speed of 51.8 cm/s. The average current speeds during spring tides were highest in August and weakest in September, with speeds of 59.9 and 42.8 cm/s, respectively. (3) Considerable differences exist in average current speeds in different layers and seasons. The highest average current speeds were found in the middle–upper layers in August and in the middle–lower layers in September and October. (4) The residual current speed was highest in August, when the speed was 12.5–47.1 cm/s, whereas the vertical average current speed was 34.3 cm/s. The depth-averaged residual current speeds in September and October were only 50% of that in August, and the residual current direction gradually rotated in a counter-clockwise direction from the lower to surface layers. (5) Typhoon waves had a significant influence on the currents, and even affected the middle and lower water layers at depths of >70.0 m. Our results showed that the currents are controlled by the dynamic interplay of the Taiwan Warm Current, incursion of the Kuroshio Current onto the continental shelf, and monsoonal changes.

A rapid hydroclimate change and its influence on the Songliao Basin during the Santonian-Campanian transition as recorded by compound-specific isotopes

Reconstruction of the paleoclimate and paleoenvironment of the Songliao Basin has important theoretical and practical significance to reveal the regional continental climate characteristics and continental organic matter accumulation under the Cretaceous greenhouse climate conditions. Here, we report the composition of biomarkers and the stable carbon and hydrogen isotope compositions of n-alkanes from Nenjiang Formation sediments in the Songliao Basin, which provide information on the source of organisms, paleoenvironmental conditions, and paleoclimate changes during the Late Cretaceous. Our hydrogen isotope records of n-alkanes displayed a significantly negative shift, indicating that a dramatically wet climate occurred during the Santonian-Campanian transition. A wet climate, such as that during a prolonged rainfall event, had a significant impact on the lake and resulted in the lake level increasing and the salinity decreasing in the surface water during this period. However, the freshwater input increased the salinity difference between the upper and lower water layers, which caused stable water stratification to occur in the lake. In addition, the high total organic carbon (TOC) content indicates high primary productivity because of increased precipitation carrying more terrigenous nutrients into the lake, which resulted in eutrophication during this period. Notably, the increased aryl isoprenoid ratios and the occurrence of isorenieratane indicates that photic zone euxinia (PZE) was enhanced during the Santonian-Campanian transition, which was possibly due to the dramatic change in the hydroclimate. We speculate that the large freshwater input promoted the formation of PZE in the lake. Then, PZE restricted the habitat available for aerobic organisms, which had fatal effects on the lake ecosystem.

Downwelling Events in a Coastal Mussel Farming Area, NW Thessaloniki’s Gulf (NW Aegean Sea)

The coastal area of Chalastra (NW Thessaloniki’s Gulf, Northern Greece) features prominent mussel farming activity as well as fishing activity. These activities are closely related to the hydrodynamics of the basin’s seawaters. The prevailing hydrodynamic force for the circulation of coastal waters of Chalastra is wind stresses. The hydrodynamics of this coastal region may be further influenced by three rivers outflowing to the southwestern part of the basin; however, this runoff has dramatically decreased during the last few decades. Concerning the wind forcing regime, this is distinguished by two characteristic regimes. The first one is realized in winter and the other mainly in summer. Systematic field studies were conducted during one year for current and density measurements. Seawater samples were collected and chemically analyzed for dissolved oxygen, chlorophyll α and nutrients. Data revealed some cases of flow currents of opposite direction between the upper and the lower water layer, and a characteristic captured downwelling which seemed to evolve periodically on a diurnal time scale, especially in summer. Furthermore, a two layer mathematical model was developed and applied for the study of the water circulation and the investigation of downwelling processes under specific conditions; the tracing as well as the temporal and spatial evolution of these hydrodynamic processes in the mussels’ culture study area constituted the main aim of the present work. The formation of such events, which were observed mainly during summer periods, may affect the mussels’ development and has to be considered when designing farming practices in the area.

单独隔离孵化对镇海林蛙蝌蚪生长发育、社交行为和运动表现的影响

PDF HTML阅读 XML下载 导出引用 引用提醒 单独隔离孵化对镇海林蛙蝌蚪生长发育、社交行为和运动表现的影响 DOI: 10.5846/stxb201802120365 作者: 作者单位: 南京师范大学生命科学学院,南京师范大学生命科学学院,丽水学院生态学院,丽水学院生态学院,丽水学院生态学院,丽水学院生态学院,丽水学院生态学院 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31270443）；丽水市科技局重点研发计划项目（20150406，SH2017001） Effects of isolated-incubation embryos on the growth, development, social behavior, and locomotor performance of Rana zhenhaiensis tadpoles Author: Affiliation: College of Life Sciences,Nanjing Normal University,College of Life Sciences,Nanjing Normal University,College of Ecology,Lishui University,College of Ecology,Lishui University,College of Ecology,Lishui University,College of Ecology,Lishui University,College of Ecology,Lishui University Fund Project: The National Natural Science Foundation of China (General Program) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:两栖类胚胎呈卵群一起孵化在反捕食、维持胚胎间的温度平衡和促进胚胎的同步发育等方面具有重要作用。在实验条件下探究孵化条件（单独隔离孵化和卵群一起孵化）对镇海林蛙（Rana zhenhaiensis）蝌蚪的生长发育、社交行为及其运动表现能力的影响。结果表明，孵出2天后，单独隔离孵化组蝌蚪的体长和发育历期均显著大于卵群一起孵化组。以体长为协变量的协方差分析表明，特定体长的单独隔离孵化组蝌蚪的体宽和体重均显著大于卵群一起孵化组的个体。在蝌蚪的活动行为中，单独隔离孵化组蝌蚪在水体上层和中层出现的频次显著小于卵群一起孵化组，而在水体底层的出现频次显著大于卵群一起孵化组。单独隔离孵化组蝌蚪个体的分布面积率、最近邻个体的距离、个体间的距离均显著大于卵群一起孵化组，但个体间的接触频次显著小于卵群一起孵化组。在运动表现方面，单独隔离孵化组胚胎的摆尾搏动频次显著小于卵群一起孵化组。单独隔离孵化组蝌蚪的运动时长和运动频次均显著小于卵群一起孵化组。本研究结果将为无尾两栖类幼期的生长发育规律提供参考数据。 Abstract:Embryo-clustering incubation plays an important role in anti-predation, maintaining temperature balance between embryos, and promoting hatching synchrony for anurans. In this study, we investigated the effects of two hatching conditions (isolated-incubation and clustered-incubation) on the growth, development, social behavior, and locomotor performance of Rana zhenhaiensis tadpoles under laboratory conditions. Our results showed that both body length and the Gosner development stage of two-day-old hatchlings in a single-embryo treatment were significantly larger than those of the group-embryo treatment. The results of the ANCOVA (with body length as the covariate) analysis showed that both body width and body mass in the group-embryo treatment were significantly lower than those of the single-embryo treatment. For tadpole activity behavior, the occurrence frequency in the upper and middle water layers in the single-embryo treatments were significantly lower than those of the group-embryo treatment, whereas it was significantly greater in the single-embryo treatments than that of the group-embryo treatment in the lower water layers. The proportion of area occupied by tadpoles, the nearest neighbor distance, and the distance among individuals in the single-embryo treatment were both significantly greater than those of the group-embryo treatment, but the contact frequency between pairwise tadpoles was significantly lower than those of the group-embryo treatment. Regarding locomotor performance, we found that activity duration and activity frequency in the single-embryo treatment were significantly lower than those of the group-embryo treatment. These findings should provide valuable reference data on the growth and development of Rana zhenhaiensis, as well as other anuran species. 参考文献 相似文献 引证文献

Clinical effect of facial contour remodeling by using transplantation of the autologous granular fat grafting combined with botulinum toxin A injection

Objective To discuss the clinical effect of facial contour remodeling using transplantation of the autologous granular fat grafting combined with botulinum toxin A injection. Methods Negative-pressure liposuction was carried out in the inner thigh or abdomen using liposuction needle connected with an injector, to let stand for layered, discharge lower layer water, rinse, extract the fat particles into a 2 ml syringe, inject into facial depression area with multipoint, multiple-tunnel, and multilayer manner, over injection of about 20%-30% every time. 89 patients received the injection; some accepted two injections; 13 cases were injected in temple (14.6%), and 16 in forehead (17.98%). 30 of them received subcutaneous injection of botulinum toxin A, each side dose was less than 20 U. Results Patients had been followed up for 3-36 months, and obvious improvements were observed in facial contour in the frontal and temporal region as well as the skin texture; the survival rate of fat granule reached to 60%-80%. No hematoma, nodes and infection been observed. Patients combined with botulinum toxin A injection had more ideal facial contour and more satisfaction. Conclusions Autologous fat granules transplantation in the face has stable clinical effect, and combining with botulinum toxin A injection can improve facial contour. It is a safe, ideal treatment in facial rejuvenation and facial contour remodeling and it therefore can be widely recommended in clinical treatment. Key words: Autologous fat grafting; Fat granule; Botulinum toxin A; Contour remodeling