Horizontal Migration Research Articles

Field-scale impacts of long-term wettability alteration in geological [formula omitted] storage

Constitutive functions that govern macroscale capillary pressure and relative permeability are central in constraining both storage efficiency and sealing properties of CO2 storage systems. Constitutive functions for porous systems are in part determined by wettability, which is a pore-scale phenomenon that influences macroscale displacement. While wettability of saline aquifers and caprocks are assumed to remain water-wet when CO2 is injected, there is recent evidence of contact angle change due to long-term CO2 exposure. Weakening of capillary forces alters the saturation functions dynamically over time. Recently, new dynamic models were developed for saturation functions that capture the impact of wettability alteration (WA) due to long-term CO2 exposure. In this paper, these functions are implemented into a two-phase two-component simulator to study long-term WA dynamics for field-scale CO2 storage. We simulate WA effects on horizontal migration patterns under injection and buoyancy-driven migration in the caprock. We characterize the behavior of each scenario for different flow regimes. Our results show the impact on storage efficiency can be described by the capillary number, while vertical leakage can be scaled by caprock sealing parameters. Scaling models for CO2 migration into the caprock show that long-term WA poses little risk to CO2 containment over relevant timescales.

Force and Control Measures of Pulverized Coal Migration in Coalbe-d Methane Horizontal Wells

Pulverized coal production is a common problem in the process of coalbed methane drainage and production, which is one of the key factors restricting the continuous stability drainage and production of coalbed methane. The reasons and characteristics of pulverized coal output are summarized. Through a detailed analysis of the migration and stress of pulverized coal in the borehole, the migration of pulverized coal is controlled by the stress conditions of pulverized coal, which causes the migration position of pulverized coal to change. Under the action of total pressure difference ΔF, pulverized coal particles can be divided into three situations: downward inclination, upward inclination and near horizontal migration. Finally, a solution to the control of pulverized coal is put forward from two aspects: the control of drainage and mining system and the selection of drainage and mining equipment. The research shows that continuous stability drainage and mining is the key of drainage and mining system, and controlling the hydrodynamic difference ΔF is the means to control the migration of pulverized coal. Choosing a pump with strong adaptability to pulverized coal is beneficial to coalbed methane drainage and production and increase productivity. Two horizontal wells in Shizhuang South Area 2 were replaced by membrane pumps, and the diaphragm pump system guide cover scheme was adopted. The coalbed methane production increased by about 1000m3/d, and the number of well repair was significantly reduced.

Satellite tags describe movement and diving behaviour of blue sharks Prionace glauca in the southwest Pacific

The blue shark Prionace glauca is the most abundant, widely distributed and exploited pelagic shark species. Its population is declining in almost all major oceanic basins. Population management and conservation efforts have traditionally depended on fishery bycatch and observer data. Recent studies correlating animal distribution derived from satellite tags, with commercial fishery impacts, across multi-jurisdictional regions, have provided an improved data platform for population management. Here we present the first fishery-independent data of blue shark distribution in the southwest Pacific Ocean. Fifteen blue sharks were satellite tagged, adding to the global dataset of approximately 179 individuals successfully tracked using bolt-on satellite tags. Smart Position and Temperature (SPOT) tags transmitted between 66 and 505 d, and SPLASH tags between 200 and 343 d. Individual track lengths ranged from 3000 to 14559 km, spanning 10 exclusive economic zones, from latitudes 0.1° to 43.1°S, and longitudes 160.1°E to 150.8°W. Horizontal movements revealed age/sex segregation and large-scale horizontal migration patterns. Dive data collected with SPLASH tags showed fine-scale vertical habitat use at depths between 0 and 1364 m and temperatures of 5 to >30°C. Behavioural events, such as foraging, searching and travelling, were inferred from commonly repeated patterns in the retrieved dive profiles. This study provides a characterisation of critical habitat use in a region never before sampled, adding to the global understanding of blue sharks, and the fishery-independent database necessary to inform blue shark population management.

Effect of growing forage legumes on the migration and survival in the pasture of gastrointestinal nematodes of sheep.

In order to identify types of forage that inhibit pasture contamination, an evaluation was performed of the effect of the forage legumes Trifolium repens (white clover), Trifolium pratense (red clover) and Lotus corniculatus (bird's-foot-trefoil) on the survival and migration of infective larvae (L3) of gastrointestinal nematodes (GIN) of sheep. An experimental area of 441 m2 was divided into four blocks, subdivided into areas of 1.20 × 1.20 in which the three forage legumes were separately overseeded. After growth of the forage in each subdivision, experimental units were established that were later artificially contaminated with sheep faeces containing GIN eggs. Between October and December 2018, pasture, faecal and soil samples were collected on four occasions during weeks 1, 2, 4 and 8 after the deposition of faeces. In week 6, the forage legumes in all the experimental units were mown to simulate grazing. The number of L3 was quantified to determine their survival in the pasture, faeces and soil. In addition, the horizontal migration of L3 was measured at two distances from the faecal pellets (10 and 30 cm), as well as their vertical migration at two heights of the plant stems, that is, lower half and upper half. Larvae vertical migration was affected by the forage species (P < 0.001), in that bird's-foot-trefoil contained fewer larvae in the upper stratum. Bird's-foot-trefoil restricted the migration of L3 to the upper stratum of the plant, which could potentially decrease the risk of infection by intestinal nematodes in grazing sheep.

Dual‐domain model of advective‐diffusion transport with variable mass transfer rate for long-term contaminant transport simulation at radwaste injection site

Since 1963, liquid radioactive waste has been injected into deep artesian aquifer waste disposal sites at the Siberian Chemical Combine. The injection and overlaying zones are sandy clay formations with complex internal architectures. Therefore, obtaining relevant forecasts of long-term waste migration largely depends on accounting for the heterogeneity of water-bearing sediments. At present, it is impossible to create regional models that consider detailed hydraulic heterogeneity (due to the insufficient provision parameters and limitations of computing capacities). Therefore, for long-term forecasts of the migration of contaminants in groundwater, the solution is to use a dual-domain model.To use a dual-domain model, one must set the mass transfer parameter. To estimate this parameter, the article proposes an approach using an auxiliary three-dimensional (3D) high-resolution model of hydraulic heterogeneity. This model was constructed using the transition probability/Markov chain geostatistical approach (TP/MC method) and detailed lithological analysis data of the sections of 295 boreholes in the Siberian Chemical Combine region, which were obtained by core studies and using geophysical methods for studying boreholes. An important feature of this model was that the thicknesses of the low-permeability hydrofacies have an exponential-like distribution with an average thickness of about 6 m. This thickness heterogeneity, as it appeared from the simulation results, essentially affects the overall subsurface contaminant spreading during long time. The effective mass transfer rate coefficient was obtained by processing the breakthrough curves of the flux concentrations by modeling horizontal migration on the auxiliary model, providing setting the highest weight coefficients in the “tail” part of the breakthrough curve. As a result of the selection, the effective mass transfer rate coefficient for the assessment of long-term subsurface waste migration for the conditions of the Siberian Chemical Combine was 6.4 × 10−8 day−1.

Seasonal epidemiology of gastrointestinal nematodes of cattle in the northern continental climate zone of western Canada as revealed by internal transcribed spacer-2 ribosomal DNA nemabiome barcoding

Background Gastrointestinal nematode (GIN) epidemiology is changing in many regions of the world due to factors such as global warming and emerging anthelmintic resistance. However, the dynamics of these changes in northern continental climate zones are poorly understood due to a lack of empirical data.Methods We studied the accumulation on pasture of free-living infective third-stage larvae (L3) of different GIN species from fecal pats deposited by naturally infected grazing cattle. The field study was conducted on three organic farms in Alberta, western Canada. Grass samples adjacent to 24 fecal pats were collected from each of three different pastures on each farm. Internal transcribed spacer-2 nemabiome metabarcoding was used to determine the GIN species composition of the harvested larvae. The rotational grazing patterns of the cattle ensured that each pasture was contaminated only once by fecal pat deposition. This design allowed us to monitor the accumulation of L3 of specific GIN species on pastures under natural climatic conditions without the confounding effects of pasture recontamination or anthelmintic treatments.ResultsIn seven out of the nine pastures, grass L3 counts peaked approximately 9 weeks after fecal deposition and then gradually declined. However, a relatively large number of L3 remained in the fecal pats at the end of the grazing season. Nemabiome metabarcoding revealed that Cooperia oncophora and Ostertagia ostertagi were the two most abundant species on all of the pastures and that the dynamics of larval accumulation on grass were similar for both species. Daily precipitation and temperature across the whole sampling period were similar for most of the pastures, and multiple linear regression showed that accumulated rainfall 1 week prior to sample collection had a significant impact on the pasture L3 population, but accumulated rainfall 3 weeks prior to sample collection did not.Conclusions The results suggest that the pasture L3 population was altered by short-term microclimatic conditions conducive for horizontal migration onto grass. Overall, the results show the importance of the fecal pat as a refuge and reservoir for L3 of cattle GIN on western Canadian pastures, and provide an evidence base for the risk assessment of rotational grazing management in the region.Graphical

Breakthrough pressure anisotropy and intra-source migration model of crude oil in shale

With shale oil becoming an increasingly important resource in global oil and gas exploration and development, the breakthrough pressure of crude oil in shale series source rocks has become an important topic for research on hydrocarbon migration. Shale has long been recognized as an effective source and cap rock, with, up to now, the most common method used for breakthrough pressure testing in shale being the gas method. However, this paper sets out a new system for testing the breakthrough pressure of crude oil in siltstone, mudstone, and shale based on differences in electrical resistance between crude oil and formation water. The breakthrough pressure of crude oil with different lithology was tested in different directions using this method. The results show that breakthrough pressure anisotropy can be observed in mudstone, shale, and siltstone, and that the breakthrough pressure parallel to the bedding direction is one fourth or one seventh of the breakthrough pressure perpendicular to the bedding direction. The horizontal breakthrough pressure of shale is one twentieth to one third of that of mudstone and siltstone, and the vertical breakthrough pressure of siltstone is one seventh of that of mudstone and shale. The breakthrough pressure anisotropy of crude oil reveals that the main migration direction in shale series source rocks is in the direction of bedding unless faults or fractures are encountered. The main migration channels in shale series source rocks are in the horizontal direction, and hydrocarbon migration occurs more easily in laminar shale than in mudstone. Horizontal migration is also the principal mode of hydrocarbon expulsion in thick mudstone and shale. The breakthrough pressure experiments on crude oil in this study also reveal the migration directions and modes in intra-source rocks. This improves on the existing oil migration model and has great significance for understanding the migration of oil in shale source rocks.

Sensitivity Analysis of Geomechanical Constraints in CO2 Storage to Screen Potential Sites in Deep Saline Aquifers

In order to tackle the exponential rise in global CO2 emissions, the Intergovernmental Panel on Climate Change (IPCC) proposed a carbon budget of 2,900 Gt to limit the rise in global temperature levels to 2°C above the pre-industrial level. Apart from curbing our emissions, carbon sequestration can play a significant role in meeting these ambitious goals. More than 500 Gt of CO2 will need to be stored underground by the end of this century to make a meaningful impact. Global capacity for CO2 storage far exceeds this requirement, the majority of which resides in unexplored deep aquifers. To identify potential storage sites and quantify their storage capacities, prospective aquifers or reservoirs need to be screened based on properties that affect the retention of CO2 in porous rocks. Apart from the total volume of a reservoir, the storage potential is largely constrained by an increase in pore pressure during the early years of injection and by migration of the CO2 plume in the long term. The reservoir properties affect both the pressure buildup and the plume front below the caprock. However, not many studies have quantified these effects. The current analysis computes the effect of rock properties (porosity, permeability, permeability anisotropy, pore compressibility, and formation water salinity) and injection rate on both these parameters by simulating CO2 injection at the bottom of a 2D mesh grid with hydrostatic boundary conditions. The study found that the most significant property in the sensitivity analysis was permeability. Porosity too affected the CO2 plume migration substantially, with higher porosities considerably delaying horizontal and vertical migration. Injection rate impacted both the pressure rise and plume migration consistently. Thus, in screening potential storage sites, we can infer that permeability is the dominant criterion when the pore pressure is closer to the minimum principal stress in the rocks, due to which injection rate needs to be managed with greater caution. Porosity is more significant when the lateral extents of the reservoir limit the storage potential.

High-frequency monitoring of neonicotinoids dynamics in soil-water systems during hydrological processes

Neonicotinoids pollution poses a serious threat to aquatic ecosystems. However, there is currently little knowledge about how neonicotinoids are transferred from the agricultural environment to the aquatic environment. Here, we conducted in situ high-frequency monitoring of neonicotinoids in soil-water systems along the hydrological flow path during rainfall to explore the horizontal and vertical transport mechanisms of neonicotinoids. The collected samples included 240 surface runoff, 128 subsurface runoff, 60 eroded sediment, 120 soil and 144 soil solution, which were used to analyse neonicotinoids concentrations. Surface runoff, subsurface runoff and eroded sediment were the three main paths for the horizontal migration of neonicotinoids. In the CK (citrus orchards without grass cover) and grass-covered citrus orchards, there are 15.89% and 2.29% of the applied neonicotinoids were transported with surface runoff, respectively. While in the CK and grass-covered citrus orchards, there are only 1.23% and 0.19% of the applied neonicotinoids were transported with eroded sediment and subsurface runoff. Although the amount of neonicotinoids lost along with eroded sediment was small, the concentration of neonicotinoids in eroded sediment was two orders of magnitude higher than the concentration of neonicotinoids in sediments of the surface water. Meanwhile, neonicotinoids migrated vertically in soil due to water infiltration. In the CK and grass-covered citrus orchards, there are 57.64% and 24.36% of the applied neonicotinoids were retained in soil and soil solution, respectively, and their concentration decreased as soil depth increased. Another noteworthy phenomenon is that more neonicotinoids migrated to deeper soil layers under grass cover compared with no grass cover because grass roots promoted the formation of cracks and vertical preferential flow. Our results are expected to improve the accuracy of neonicotinoids pollution prediction by considering migration paths, including surface and subsurface runoff and eroded sediment.

Microbial characteristics of the leachate contaminated soil of an informal landfill site

Because informal landfills are not constructed in a regulated manner, they will inevitably become a source of leachate pollution to the surrounding environment over time. Microbes are an important part of the soil system, playing a vital role in maintaining the normal functionality of soil. This study investigated the microbial composition and co-occurrence pattern in the leachate contaminated soil of an informal landfill site. The landfill leachate underwent horizontal and vertical migration through the contaminated soil, resulting in significant differences in the microbial compositions of horizontal surface soil (CS) and vertical subsurface soil (DS and ES) compared to uncontaminated soil (S). The microbial diversity of CS, DS, and ES was lower than that of S. Due to the migration of landfill leachate, the microbial composition of the surface soil was substantially changed. The dominant phyla in S included Proteobacteria (26.88%), Chloroflexi (23.68%), Actinobacteroita (17.36%), and Acidobacteroita (16.86%), but in contaminated soils, Firmicutes (35.27–86.68%) were the dominant bacteria. A network analysis indicated that Bacilli, Clostridia, and Thermacetogeniazai of the Firmicutes were the keystone taxa and played a vital role in maintaining the stability of the soil ecosystem. A functional annotation of prokaryotic taxa (FAPROTAX) analysis showed that the microbes involved in the C-, N-, and S-cycles in contaminated soil were significantly different to those in uncontaminated soil. The proportion of (aerobic)-chemoheterotrophy and cellulolysis functional communities in contaminated soils was significantly reduced, while there was an increase in functional communities, such as anammox and denitrification, which are not conducive to soil nitrogen fixation. This negatively affected the maintenance of normal soil ecological functions. This study identified the microbial characteristics in leachate contaminated soil and the results will be beneficial for the remediation of contaminated soil in informal landfill sites.

Differential horizontal migration patterns of two male salmon sharks (Lamna ditropis) tagged in the Bering Sea

BackgroundThe salmon shark (Lamna ditropis) is a widely distributed apex predator in the North Pacific Ocean. Many salmon sharks from the eastern North Pacific, specifically Prince William Sound, Alaska, have been satellite tagged and tracked, but due to the sexual segregation present in salmon sharks, most of these tagged sharks were female. Consequently, little information exists regarding the migration patterns of male salmon sharks. To better understand the migration and distribution of this species, information on the male component of the population as well as from sharks outside of Prince William Sound, Alaska, is needed. In this study, we deployed satellite transmitters on two mature male salmon sharks caught in the Bering Sea.ResultsThe two mature male salmon sharks tagged in the Bering Sea exhibited distinct migration patterns. The first male, tagged in August 2017, traveled to southern California where it remained from January to April after which it traveled north along the United States’ coast and returned to the Bering Sea in August 2018. The second male, tagged in September 2019, remained in the North Pacific between 38° N and 50° N before returning to the Bering Sea in July of year one and as of its last known location in year two. The straight-line distance traveled by the 2017 and 2019 sharks during their 12 and 22 months at liberty was 18,775 km and 27,100 km, respectively.ConclusionsBefore this study, our understanding of salmon shark migration was limited to female salmon sharks satellite tagged in the eastern North Pacific. The 2017 male salmon shark undertook a similar, but longer, north–south migration as tagged female sharks whereas the 2019 shark showed little overlap with previously tagged females. The different migration patterns between the two male sharks suggest distinct areas exist for foraging across the North Pacific. The return of both sharks to the Bering Sea suggests some fidelity to the region. Continued tagging efforts are necessary to understand the population structure of salmon sharks in the North Pacific. This tagging study highlights the importance of opportunistic efforts for obtaining information on species and sex with limited distribution data.

Intensity of Soil Pollution by Toxic Substances Depending on the Degree of Its Washout

A significant degree of ploughness of agricultural lands of Ukraine has led to increased erosion and the creation of soils of varying degrees of washout, which leads to dehumification and contamination of soils with toxic substances. Therefore, the purpose of the study was to establish the features of horizontal migration and accumulation of heavy metals of lead, cadmium, copper, and zinc, trace elements of boron and manganese, radionuclides of caesium and strontium on podzolic heavy loamy chernozems with varying degrees of washout: non-eroded, weak and medium washout, conditioned by the development of erosion processes. During the study, spectrophotometric, colorimetric, gamma-spectrometric, and radiochemical methods were used to determine the content of toxic substances in the soil. The study results showed that on slightly washed soils, the content of humus is 12.9% less, easily hydrolysed nitrogen – 13.3%, mobile forms of phosphorus – 51.1%, mobile potassium – 34.9% less than on slightly washed soils. The humus content on medium-washed soil was 8.8% less than on lightly washed soil, easily hydrolysed nitrogen – 14.3% less, mobile phosphorus – 15.3% more, mobile potassium – 42.9% more. A strong horizontal migration of mobile lead forms in washed podzolic heavy loamy chernozem was established, which increases with increasing degree of soil washout with the content of mobile lead forms on medium-washed soil by 24% more than on non-eroded soil. The same dependence was established on the content of mobile forms of zinc in the soil, with their predominance on medium-washed soil by 17 %, compared to non-washed. The content of mobile forms of copper is lower on slightly washed soil, compared to non – washed soil by 5%, boron – 18.8% less on non-washed soil, compared to medium-washed, and the content of mobile forms of manganese increases by 3.3% from slightly to medium-washed soil. It was also found that the concentration of caesium decreased by 25.6% on medium-washed soils, compared to non-washed ones

Economics and Energy Consumption of Brackish Water Reverse Osmosis Desalination: Innovations and Impacts of Feedwater Quality.

Brackish water desalination, using the reverse osmosis (BWRO) process, has become common in global regions, where vast reserves of brackish groundwater are found (e.g., the United States, North Africa). A literature survey and detailed analyses of several BWRO facilities in Florida have revealed some interesting and valuable information on the costs and energy use. Depending on the capacity, water quality, and additional scope items, the capital cost (CAPEX) ranges from USD 500 to USD 2947/m3 of the capacity (USD 690–USD 4067/m3 corrected for inflation to 2020). The highest number was associated with the City of Cape Coral North Plant, Florida, which had an expanded project scope. The general range of the operating cost (OPEX) is USD 0.39 to USD 0.66/m3 (cannot be corrected for inflation), for a range of capacities from 10,000 to 70,000 m3/d. The feed-water quality, in the range of 2000 to 6000 mg/L of the total dissolved solids, does not significantly impact the OPEX. There is a significant scaling trend, with OPEX cost reducing as plant capacity increases, but there is considerable scatter based on the pre- and post-treatment complexity. Many BWRO facilities operate with long-term increases in the salinity of the feedwater (groundwater), caused by pumping-induced vertical and horizontal migration of the higher salinity water. Any cost and energy increase that is caused by the higher feed water salinity, can be significantly mitigated by using energy recovery, which is not commonly used in BWRO operations. OPEX in BWRO systems is likely to remain relatively constant, based on the limitation on the plant capacity, caused by the brackish water availability at a given site. Seawater reverse osmosis facilities, with a very large capacity, have a lower OPEX compared to the upper range of BWRO, because of capacity scaling, special electrical energy deals, and process design certainty.

Effects of initial soil moisture content on soil water and nitrogen transport under muddy water film hole infiltration

Film hole irrigation has been widely adopted as an effective water-saving irrigation technology in the arid and semiarid areas of China. To investigate the effects of initial soil moisture content (θ0) on soil water and nitrogen transport characteristics under muddy water film hole infiltration, the laboratory experiments were conducted with muddy water film hole infiltration, using five initial soil moisture content treatments. The models for describing the relationships between the cumulative infiltration (I(t)) and infiltration duration (t); the relationship among the horizontal and vertical migration distances of the wetting front (Fx, Fz), θ0 and t, were established. The results showed that the initial soil moisture content had a significant effect on I(t), Fx, Fz and moisture content distribution in the wetted body. The change of I(t) over t conformed to Kostiakov model. With the increase of θ0, the infiltration coefficient (K) gradually decreased. NO–3-N was mainly distributed in the range of the wetting radius of 15 cm, while NH +4-N was mainly distributed in the range of the wetting radius of 8 cm. This study can provide a theoretical basis and technical support for film hole irrigation. Keywords: film hole irrigation, muddy water, initial soil moisture content, water and nitrogen transport, water redistribution DOI: 10.25165/j.ijabe.20211404.6024 Citation: Liu L H, Fei L J, Chen L, Hao K, Zhang Q J. Effects of initial soil moisture content on soil water and nitrogen transport under muddy water film hole infiltration. Int J Agric & Biol Eng, 2021; 14(4): 182–189.

Tracing the horizontal transport of microplastics on rough surfaces

Occurrence and distribution of microplastics in different ecosystems have recently become subjects of numerous studies. However, to date the research has focused mainly on marine and freshwater ecosystems and widely neglected terrestrial environments. Only recently, first studies investigated the microplastics contamination of soils. Therefore, we know little about the transport mechanisms of microplastics in soils and sediments and virtually nothing about their surface transport. In this study we investigate surface transport mechanisms by tracking fluorescent, irregularly shaped polymethyl methacrylate (PMMA) particles in real time in a laboratory setup. In 108 experimental runs, we vary the irrigation rates, inclinations and surface roughnesses. Additionally, we simulate the small-scale flow patterns to resolve the role of the roughness-induced microrelief. Our results suggest that microplastics are transported along preferential pathways resulting from the micro- and macrorelief, which can be correlated to the flow pattern observed in the computer simulation. Our model study facilitates a deeper insight into microplastic transport on different soil surfaces and serves as a pilot for investigating mechanisms of horizontal microplastic transport. However, microplastics are a diverse group of contaminants with varying shapes, densities and sizes. Therefore, for a full understanding of transport of microplastics in terrestrial environments, it is important to address these properties as well as more variable surfaces for horizontal migration and to include vertical transport mechanisms in future research.

Horizontal and vertical migration behavior of silver-phase Japanese eels in coastal, pelagic and spawning areas observed by pop-up satellite archival tags

Pop-up satellite archival tags (PSAT) have been used to study the mysterious open ocean spawning migrations of several anguillid eel species including the Japanese eel, Anguilla japonica. To compare migration behaviors of Japanese eels in each general geographic region of their spawning migration, 7 silver eels (852–992 cm, 1095–1809 g) were tracked with PSATs and their swimming behaviors in regions of east of Japan, south of the Ogasawara Islands, and in their spawning area was analyzed. Three eels released from coastal Japan migrated east or southeastward, likely including some transport by the Kuroshio in the initial phase of the spawning migration. An eel released from the coast of Japan changed swimming depths as it crossed meanders and different water masses on different sides of the eastward flow of the Kuroshio Extension. An eel released west of the Ogasawara Islands moved mostly southward from the release site toward the spawning area where an eel released in the spawning area showed very stable diel vertical migrations (DVM). Five eels showed stable DVM for 9–47 days (60.0–72.1%) of the tracking periods (14–69 days), and 2 other eels showed abnormal behaviors. The daily rhythms of DVM behavior transitioned between shallower/warmer water at night (12.0–535.2 m/12.5–24.5 °C) and deeper/colder water during daytime (593.0–941.0 m/4.5–9.5 °C). The swimming depths of 5 eels had positive correlations with lunar age, moon altitude and sun altitude. Eels experienced almost the same daytime minimum water temperature (5.7 ± 0.98 °C) in the 3 areas regardless of depth, suggesting that they stop descending when they reach a temperature of approximately 5 °C. The ascending and descending occurred between around sunset and dusk, and dawn and sunrise, respectively. Three eels were ingested by predators near dawn (5:05–6:35) at depths of 119.5, 59, and 423.5 m when the eels start the decent phase of their DVM. Potential predators were estimated to be fish that have heat conservation ability such as tuna and swordfish based on rapid increases in recorded temperature. This study suggests that Japanese eels probably use similar DVM behaviors regardless of the location or environmental conditions during their spawning migration and that the swimming depths are determined by light and thermal environments. These behaviors are likely essential for predation avoidance.

Response of transient rock uplift and base level knickpoints to erosional efficiency contrasts in bedrock streams

AbstractKnickpoints in bedrock streams are often interpreted as transient features generated by a change in boundary conditions. It is typically assumed that knickpoints propagate upstream with constant vertical velocities, though this relies on a stream being in erosional steady state (erosion rate equals rock uplift rate) prior to the knickpoint's formation. Recent modeling and field studies suggest that along‐stream contrasts in rock erodibility perturb streams from erosional steady state. To evaluate how contrasts in rock erodibility might impact knickpoint interpretations, we test parameter space (rock erodibility, rock contact dip angle, change in rock uplift rate) in a one‐dimensional (1D) bedrock stream model that has variable rock erodibility and produces a knickpoint with a sudden change in rock uplift rate. Upstream of a rock contact, the vertical velocity of a knickpoint generated by a change in rock uplift rate is strongly correlated with how the rock contact has previously perturbed erosion rates. These knickpoints increase vertical velocity upon propagating upstream of a hard over soft contact and decrease vertical velocity upon propagating upstream of a soft over hard contact. However, interactions with other transient perturbations produced by rock contacts make for nuances in knickpoint behavior. Rock contacts also influence the geometry of knickpoints, which can become particularly difficult to identify upstream of soft over hard rock contacts. Using our simulations, we demonstrate how a contact's along‐stream horizontal migration rate and cross‐contact change in rock strength control how much an upstream reach is perturbed from erosional steady state. When simulations include multiple contacts, the knickpoint is particularly prone to colliding with other transient perturbations and can even disappear altogether if rock contact dips are sufficiently shallow. Caution should be taken when analyzing stream profiles in areas with significant changes in rock strength, especially when rock contact dip angles are near the stream's slope.

HS6: An Efficient H-Code RAID-6 Scaling by Optimizing Data Migrating and Parity Updating

Caused by massive data, large-scale data centers suffer from insufficient storage capacity. This increases the risk of component damage and disk failure. To enhance storage capacity of data centers, scaling has turned out to be one of the most popular choices. RAID-6 is deployed extensively that has superior reliability, availability, and scalability compared to other RAID levels. However, higher reliability also means expensive parity data update cost. To address this issue, this paper proposes an efficient RAID-6 scaling scheme, HS6, for H-Code. The basic idea of HS6 is reducing the total parity data update cost and saving the total scaling time by optimizing data migration and parity data update. The properties of HS6 can be summarized as follows: (1) it utilizes horizontal data migration to eliminate the horizontal parity data update, and (2) it makes full use of original parity data to cut down the total parity data update cost. Numerical results and experimental data analysis indicate that: (1) HS6 decreases the data migration rate by 76.92% $$\sim$$ 95.31%, 55.56% $$\sim$$ 84.46%, and 14.29% $$\sim$$ 16.67% compared to Round-Robin, Semi-RR, and HCS, (2) HS6 saves the total scaling time by 62.05% $$\sim$$ 76.75%, 53.24% $$\sim$$ 73.94%, and 3.68% $$\sim$$ 6.79% against Round-Robin, Semi-RR, and HCS, respectively, under offline and outperforms Round-Robin by 59.99% $$\sim$$ 79.02%, Semi-RR by 53.04% $$\sim$$ 76.41%, and HCS by 0.56% $$\sim$$ 23.78% in total scaling time under four workloads, and (3) HS6 maintains almost the same user average response time with Round-Robin, Semi-RR, and HCS during scaling and after scaling.

Substance P, a Neuropeptide, Promotes Wound Healing via Neurokinin-1 Receptor.

Substance P (SP), an endogenous neuropeptide, mediates intracellular signaling, mainly through a tachykinin receptor. The tachykinin receptors family consists of neurokinin-1 (NK-1), neurokinin-2 (NK-2), and neurokinin-3 receptors. Our previous studies on SP have shown its wound healing potentials. But the exact mechanism of wound healing by SP is not exactly known. In view of this, the present study was aimed at evaluating the in vitro wound healing effect of SP alone and in the presence of NK-1, NK-2, and both receptor antagonists. Scratch assay, transwell assay, and tumor growth factor-beta 1 (TGF-β1) assay were performed on buffalo fetal fibroblast culture. The cotreatment of fibroblast cultures with SP alone during the 24 h caused the significant proliferation and migrations of cells in both horizontal and vertical directions. The SP in the presence of spantide II (NK-1 antagonist) failed to stimulate this migration. The treatment of cells with SP in the presence of NK-2 antagonist treatment also showed a significant reduction of migration of cells with respect to SP treatment alone. The SP in the presence of both NK-1 and NK-2 antagonists failed to stimulate the horizontal migration of cells and most of the ineffectiveness of SP was observed in this combination. The TGF-β1 levels were significantly higher in the supernatants of cells that were exposed to SP alone. All other treatments have significantly lower TGF-β1 levels than SP alone treatment. It is concluded that different actions on fibroblast cells by SP were mainly mediated through the NK-1 receptor.

Study on the Influence of Fertilizer Solution Concentration on Soil Water and Nitrogen Transport Characteristics Under Film Hole Irrigation

Film hole irrigation is a new technique in agricultural production, which can improve water conservation and increase soil temperature. The purpose of this study was to disclose the effects of fertilizer solution concentration (c) on soil water and nitrogen transport characteristics under muddy water film hole infiltration. The laboratory experiments were conducted with muddy water film hole infiltration, using five fertilizer solution concentration treatments (c = 0, 300, 600, 900, and 1200 mg L−1). The cumulative infiltration, migration distance of the wetting front, soil moisture content, and $$ \mathrm{N}{\mathrm{O}}_3^{-}-\mathrm{N} $$ and $$ {\mathrm{NH}}_4^{+}-\mathrm{N} $$ contents in the wetted body were observed. The models about (i) the relationship between the cumulative infiltration volume per unit film hole area (I(t)) and infiltration duration (t) and (ii) the relationship among the horizontal and vertical migration distances of the wetting front (Fx, Fz), c, and t were established. The results showed that fertilizer solution concentration (c) had a significant effect on I(t), Fx, Fz, and moisture distribution in the wetted body. Cumulative infiltration volume per unit film hole area and infiltration duration conformed to the Kostiakov infiltration model (R2 > 0.98, P < 0.05). $$ \mathrm{N}{\mathrm{O}}_3^{-}-\mathrm{N} $$ is mainly distributed in the range of the wetting radius 12 cm, while $$ {\mathrm{NH}}_4^{+}-\mathrm{N} $$ is mainly distributed in the range of the wetting radius 6 cm. This study could provide a theoretical basis and technical support for fertilizer solution infiltration under muddy water film hole irrigation.