Cage Area Research Articles

Remote sensing and computer vision for marine aquaculture.

Aquaculture, the cultivation of aquatic plants and animals, has grown rapidly since the 1990s, but sparse, self-reported, and aggregated production data limit the effective understanding and monitoring of the industry's trends and potential risks. Building on a manual survey of aquaculture production from remote sensing imagery, we train a computer vision model to identify marine aquaculture cages from aerial and satellite imagery and generate a spatially explicit dataset of finfish production locations in the French Mediterranean from 2000 to 2021 including 4010 cages (average cage area, 69 square meters). We demonstrate the value of our method as an easily adaptable, cost-effective approach that can improve the speed and reliability of aquaculture surveys and enables downstream analyses relevant to researchers and regulators. We illustrate its use to compute independent estimates of production and develop a flexible framework to quantify uncertainty in these estimates. Overall, our study presents an efficient, scalable, and adaptable method for monitoring aquaculture production from remote sensing imagery.

Design and Building of a Breeding House for IoT-based Goat Farming

Abstract — Goat farming is an industry that supplies goat meat for food purposes. This makes goats have a high potential to boost the economy of the community as their meat products are needed by everyone. These conditions motivate farmers to improve the quality of livestock maintenance so that the livestocks produced are of the highest quality. The development of information technology has facilitated a wide range of human activities, including monitoring activities in goat cages. The use of Information Technology helps farmers to improve the quality of livestock maintenance. The large cage area and the distance between cages and communal settlements are the main reasons for the planned IoT-based cage. This research has developed an IoT-based goat cage design that can be used to monitor livestock maintenance in real time via a website or Android. The methods used in this study were cattle identity information, cattle health through body temperature, cage.

Effects of Intermittent Harem Mating on Parturition-induced Stress and Success Rate of Weaning in C57BL/6JNarl Mice.

Improving the effectiveness of mating schemes for large-scale production of mice is an ongoing challenge in animal facilities. Continuous mating, which requires fewer breeding cages than intermittent mating, has traditionally been used to take advantage of postpartum estrus for efficient production. However, the continuous mating scheme lacks flexibility because it cannot immediately accommodate the reduced needs of mice when production levels are high. In this study, we compared reproductive performance, fecal corticosterone metabolite (FCM) level as a stress indicator, and mouse mortality between the continuous trio (CT) and intermittent quad (IQ) mating schemes. The weaning rates in the IQ scheme were higher than those in the CT scheme (98.8% compared with 85.3%). The FCM levels in IQ female breeders were lower during the first 5 d after parturition than those in CT female breeders. The FCM levels in postpartum females housed with 2 adult mice were significantly higher on days 1, 3, and 5 after giving birth than those of females housed alone. This suggests that the presence of cage mates may induce stress responses in postpartum females. Increasing the individual cage area did not reduce the FCM levels of female breeders when accompanied by cage mates after parturition. In addition, the incidence of dystocia and mortality was lower in IQ breeders than in CT breeders. In summary, this breeding trial suggests that compared with the continuous mating scheme, the intermittent mating scheme improves the welfare of postpartum females with normal breeding performance in the C57BL/6JNarl production colony.

Influence of facetectomy, cross-link augmentation, and interbody procedure on progression of bone fusion in single-level posterior lumbar interbody fusion using the long cortical bone trajectory technique.

When using the cortical bone trajectory (CBT) technique, two technical countermeasures are recommended to promote bone fusion: taking a long CBT screw path directed more anteriorly and improving the stability of the spinal construct by facet joint preservation, cross-link augmentation, and rigid anterior interbody reconstruction. However, there has been no report on how these surgical procedures, which are heavily dependent on the surgeon's preference, contribute to successful bone fusion. The aim of the present study was to investigate the progression of lumbar spinal fusion using the long CBT technique and identify factors contributing to the time taken to achieve bone fusion, with a particular focus on the involvement of surgical procedures. A total of 167 consecutive patients with L4 degenerative spondylolisthesis who underwent single-level posterior lumbar interbody fusion at L4-5 using the long CBT technique were included (mean follow-up 42.8 months). Bone fusion was assessed to identify factors contributing to the time to achieve bone fusion. Investigated factors were 1) age, 2) sex, 3) BMI, 4) bone mineral density, 5) intervertebral mobility, 6) screw depth in the vertebra, 7) extent of facetectomy, 8) cross-link augmentation, 9) cage material, 10) cage design, 11) number of cages, and 12) contact area of cages with the vertebral endplate. The bone fusion rate was 89.2% at 2 years postoperatively and 95.8% at the last follow-up, with a mean period to bone fusion of 16.6 ± 9.6 months. Multivariate regression analysis revealed that age (standardized regression coefficient [β] = 0.25, p = 0.002), female sex (β = -0.22, p = 0.004), and BMI (β = 0.15, p = 0.045) were significant independent factors affecting the time to achieve bone fusion. There was no significant effect of surgical procedures (p ≥ 0.364). This is the first study to investigate the progression of lumbar spinal fusion using the long CBT technique and identify factors contributing to the time taken to achieve bone fusion. Patient factors such as age, sex, and BMI affected the progression of bone fusion, and surgical factors had only weak effects.

Analysis of The Effect of Floating Net Cages on Reservoir Water Quality

The use of Darma Waduk is as a source of clean water and a place of fish cultivation in the form of net cages. The number of floating net cages that currently exist is 6521, and the number continues to increase quite significantly from the previous year. The existence of floating net cages affects water quality, while water quality is an aspect to be considered in water utilization. The study aims to analyze the impact of floating net cages on water quality and efforts to control the floating net cage population in Darma Waduk. The research uses a quantitative and qualitative approach, starting with surveys and interviews with floating net cage farmers and related services. Subsequently, water samples were taken, and the results of laboratory tests were analyzed using the Pollution Index (IP) method. The results of the calculation using the pollution index (IP) method at the first point (PDAM Intake Area) obtained a result of 4.14, at the second point (around the floating net cage area of the village of Cipasung) a value of 3.76, and at the third point (in the floating net cage village of Jagara) a score of 4.12. The results of the research showed that the water quality taken from the three points of the sample included light pollution when referring to the class I water quality standard according to PP No. 22 for 2021. However, the presence of household and agricultural waste also contributes to the pollution burden in the Darma Valley.

Analysis of the Abundance and Diversity of Microplastic Contamination in Ekas Bay Cultivation Areas

Ekas Bay is a semi-enclosed bay and estuary in the southern part of Lombok Island. Ekas Bay has an area of 5,312.68 hectares, although it is not very wide, this bay has its own uniqueness and is relatively protected from waves because it is located inland. In Ekas Bay itself, two river estuaries are found, namely the Awang River Estuary and the Kelongkong River Estuary. The existence of these two river estuaries has a negative impact on the condition of the waters of Ekas Bay because residue from household activities is carried away by the river current, one of which is plastic waste. The presence of microplastics on ocean coasts has a negative impact on sea water quality and the life of marine biota, microplastics cannot evaporate or degrade by themselves, microplastics will accumulate in sea water and the body parts of marine biota. This research aims to identify the type and abundance of microplastics in the Ekas Bay floating net cage area and the results obtained in water samples were that the abundance of microplastics at point A was 49.44 par/L, point B was 55.76 par/L and point C was 40.40 par /L. The abundance of microplastics in sediment samples at point A was 12.25 par/L, point B was 10.8 par/L and point C was 11.01 par/L.

Haematological, biochemical and oxidative stress parameters of New Zealand rabbits housed at different stocking densities

The aim of this study was to investigate the effects of different stocking densities on oxidative stress, some hematological and biochemical blood parameters in New Zealand rabbits, and to determine the ideal cage area where rabbits can live without being stressed. A total of 36 1–month–old mixed sex New Zealand weaned rabbits were selected for the study. The rabbits were placed in cages at different densities of stocking. Experimental groups were 1 rabbit per cage (C1), 2 rabbits per cage (C2) and 3 rabbits per cage (C3). There was no significant differences between groups in terms of RBC, HGB, HCT, MCV, MCH, WBC, neutrophils, lymphocytes, monocytes, eosinophlis, basophlis, AST, ALT, trigliseride, cholesterol, HDL and LDL parameters (P>0.05). C2 group had lower count of PLT comparing C1 and C3 groups. C1 group had the highest value for MCHC (P<0.05). As oxidative stress parameters, there was no significant differences between IMA and TAS parameters (P>0.05). C2 group had the lowest value in terms of SOD (P<0.05). In conclusion C2 group was determined more advantageous in terms of breeding and welfare, since C1 group does not support social needs of the animals and C3 group leads to increased stress levels due to reduced individual space and restricted movement.

Trajectory of Particulate Waste Transported by Artificial Upwelling

The feeding activities of fish in marine aquaculture have raised concerns about severe benthic pollution within the cage area. This paper suggests removing particulate waste from the cage area through the implementation of artificial upwelling (AU), a method likely to alleviate the organic burden within the cultivation area. A numerical model was developed to simulate AU-induced particulate matter transport under different operating conditions, with the majority of simulation results validated through flume experiments. The influence of particle characteristics, environmental conditions, and engineering parameters of AU on organic matter transport are discussed. In particular, our study offers a detailed analysis of the minimum initial upwelling velocity required to transport particulate waste to a designated distance. It also recommends situating the bottom of the cage above the maximum height of the waste plume to effectively segregate fish from the waste carried by the upwelling.

Automatic Identification of Pangolin Behavior Using Deep Learning Based on Temporal Relative Attention Mechanism.

With declining populations in the wild, captive rescue and breeding have become one of the most important ways to protect pangolins from extinction. At present, the success rate of artificial breeding is low, due to the insufficient understanding of the breeding behavior characteristics of pangolins. The automatic recognition method based on machine vision not only monitors for 24 h but also reduces the stress response of pangolins. This paper aimed to establish a temporal relation and attention mechanism network (Pangolin breeding attention and transfer network, PBATn) to monitor and recognize pangolin behaviors, including breeding and daily behavior. There were 11,476 videos including breeding behavior and daily behavior that were divided into training, validation, and test sets. For the training set and validation set, the PBATn network model had an accuracy of 98.95% and 96.11%, and a loss function value of 0.1531 and 0.1852. The model is suitable for a 2.40 m × 2.20 m (length × width) pangolin cage area, with a nest box measuring 40 cm × 30 cm × 30 cm (length × width × height) positioned either on the left or right side inside the cage. A spherical night-vision monitoring camera was installed on the cage wall at a height of 2.50 m above the ground. For the test set, the mean Average Precision (mAP), average accuracy, average recall, average specificity, and average F1 score were found to be higher than SlowFast, X3D, TANet, TSN, etc., with values of 97.50%, 99.17%, 97.55%, 99.53%, and 97.48%, respectively. The recognition accuracies of PBATn were 94.00% and 98.50% for the chasing and mounting breeding behaviors, respectively. The results showed that PBATn outperformed the baseline methods in all aspects. This study shows that the deep learning system can accurately observe pangolin breeding behavior and it will be useful for analyzing the behavior of these animals.

Finite element biomechanical analysis of 3D printed intervertebral fusion cage in osteoporotic population

ObjectiveTo study the biomechanical characteristics of each tissue structure when using different 3D printing Cage in osteoporotic patients undergoing interbody fusion.MethodsA finite element model of the lumbar spine was reconstructed and validated with regarding a range of motion and intervertebral disc pressure from previous in vitro studies. Cage and pedicle screws were implanted and part of the lamina, spinous process, and facet joints were removed in the L4/5 segment of the validated mode to simulate interbody fusion. A 280 N follower load and 7.5 N·m moment were applied to different postoperative models and intact osteoporotic model to simulate lumbar motion. The biomechanical characteristics of different models were evaluated by calculating and analyzing the range of motion of the fixed and cephalic adjacent segment, the stress of the screw-rod system, the stress at the interface between cage and L5 endplate, and intervertebral disc pressure of the adjacent segment.ResultsAfter rigid fixation, the range of motion of the fixed segment of model A-C decreased significantly, which was much smaller than that of the osteoporotic model. And with the increase of the axial area of the interbody fusion cages, the fixed segment of model A-C tended to be more stable. The range of motion and intradiscal pressure of the spinal models with different interbody fusion cages were higher than those of the complete osteoporosis model, but there was no significant difference between the postoperative models. On the other hand, the L5 upper endplate stress and screw-rod system stress of model A-C show a decreasing trend in different directions of motion. The stress of the endplate is the highest during flexion, which can reach 40.5 MPa (model A). The difference in endplate stress between models A-C was the largest during lateral bending. The endplate stress of models A and B was 150.5% and 140.9% of that of model C, respectively. The stress of the screw-rod system was the highest during lateral bending (model A, 102.0 MPa), which was 108.4%, 102.4%, 110.4%, 114.2% of model B and 158.5%, 110.1%, 115.8%, 125.4% of model C in flexion, extension, lateral bending, and rotation, respectively.ConclusionsFor people with osteoporosis, no matter what type of cage is used, good immediate stability can be achieved after surgery. Larger cage sizes provide better fixation without significantly increasing ROM and IDP in adjacent segments, which may contribute to the development of ASD. In addition, larger cage sizes can disperse endplate stress and reduce stress concentration, which is of positive significance in preventing cage subsidence after operation. The cage and screw rod system establish a stress conduction pathway on the spine, and a larger cage greatly enhances the stress-bearing capacity of the front column, which can better distribute the stress of the posterior spine structure and the stress borne by the posterior screw rod system, reduce the stress concentration phenomenon of the nail rod system, and avoid exceeding the yield strength of the material, resulting in the risk of future instrument failure.

Perancangan Pembangkit Listrik Tenaga Surya Dengan Sudut Panel Optimal Sebagai Sumber Energi Listrik Pada Area Keramba Jaring Apung Padang Cermin

Indonesia's seas hold abundant natural resources and are a highly desirable location for marine fish farming, especially among fishermen. One of the most common methods used in this activity is the use of floating net cages. However, an obstacle faced by fishermen is limited access to electrical energy at the cage sites which are generally far from settlements. This research aims to design a Solar Power Plant (PLTS) in order to meet the electrical energy needs of fishermen in the floating net cage area. The focus of the research is on the design and assembly of the PLTS system with an emphasis on setting the optimal panel angle. The panel angle is calculated based on the amount of radiation received by the inclined plane surface, utilizing geographic location data obtained from NASA SSE. The results show that the proposed solar power plant design can meet the electrical energy demand in the floating net cage area. In practical implementation, the daily energy requirement of 481 Wh for lighting and automatic feeding devices can be met by using a 100 Wp solar PV system, with a battery storage capacity of 46 Ah. Furthermore, the determination of the optimal tilt angle, based on radiation and geographical factors at the location of floating net cages, is about 6 degrees, with a radiation value of 57.38848 kWh per year at the location of Padang Cermin, Durian District.

Factors and Strategies for The Development of Buffalo Production in Aceh Barat District

This study analyzes what factors affect buffalo production in Aceh Barat District. Analyze what factors are more dominant in influencing buffalo production in Aceh Barat District. Determining the strategy for buffalo development in Aceh Barat District This research was conducted in Aceh Barat District from April to August 2023 with a sample of 90 farmers spread across three districts in Aceh Barat. The data analysis used was to use liner regression coo Douglas analysis to see the factors affecting. The results of multiple regression analysis can be seen that the factors of seeds, labor, cage area, total feed have a real effect on buffalo livestock production in Aceh Barat.

A Diversity of Copepods in Gajah Mungkur in Wonogiri Regency, Central Java, Indonesia

GajahMungkur Reservoir is a freshwater ecosystem thatis located6kmsouthofWonogiri Regency,CentralJavaProvince. Zooplankton is the primary consumer in the food chain of aquatic ecosystems. One of the common zooplankton found in freshwater ecosystem is copepod. Copepod is sensitive organism and play an important role as bioindicatator of water quality. The aimed of this study was to investigate the copepods diversity in Gajah Mungkur Reservoir. The method applied to this study is exploration and application of purposive sampling techniques in sampling. Copepods were collected from three different station, namely Station 1 (fishing area), Station 2 (tourism area), and Station 3 (fish cage area or keramba). The abiotic parameters were found to be varied on each station. Results showed that Gajah Mungkur Reservoir has moderately diverse copepods species with the average of diversity index 1.21. There were 7 species of copepods found in Gajah Mungkur Reservoir which mostly dominated by Mesocyclops sp., especially in Station 1 (fishing area). Meanwhile Microcyclops sp. was only found in Station 3 (fish cage area or keramba), suggesting that this species has a potential as bioindicator in Gajah Mungkur Reservoir. This study suggest that changes in physicochemical parameters might influence the diversity and abundance of copepod in Gajah Mungkur Reservoir.

Spatial distribution and proximity effect-dependent multi-enzyme cascades catalysis operating in dendritic mesoporous silica nanoparticles

Enzymatic cascades catalysis engenders complex and selective intracellular transformations due to the organization of the enzymes in confined cellular environments. In this work, a biomimetic strategy is employed to develop a synthetic cell analogue for operating multi-enzymatic cascade catalysis in vitro. The glucose peroxidase (GOx) and chloroperoxidase (CPO) are co-encapsulated in the channel of dendritic mesoporous silica nanoparticles (DMSP) modified by phase-transitioned lysozyme (PTL@GOx&CPO@DMSP). The cascade efficiency is substantially enhanced compared with the diffusion mixtures of the free enzymes in bulk solution due to some nanoscale construction, such as confinement effect, proximity effect and special distribution mode of the enzymes. The high specific surface area and high concentration of mesoporous cages in DMSP is beneficial for encapsulation of enzyme. The cross-linked cavities ensure directional transfer of the intermediate from GOx to CPO, known as “substrate channel”. PTL plays multiple functions including inhibiting leaking of enzyme from DMSP, concentrating intermediate H2O2 at DMSP domains and keeping this biocomposite stable in aqueous environment by improving its dispersibility. The prepared biocomposite PTL@GOx & CPO@DMSP is very stable at harsh conditions. It can retain 42% of original catalytic activity at 90°C with incubation for 3 h while the retained activity of free enzymes is only 5% under the same conditions. Meanwhile, it can keep 92.4% of its original catalytic activity after 10 reuses. These characteristics ensure practical application of this biocatalytic material. The active HClO generated by GOx-CPO cascade has an efficient anti-tumor effect and is effectively applied to preserve fruit.

Cage subsidence-Amultifactorial matter!

Retrospective cohort study OBJECTIVE: Wider cages are associated with improved decompression and reduced subsidence, but variation in cage physical properties limits consistent outcome analysis after thoracolumbar interbody fusion. This study investigated cage subsidence and its relationship to lateral and posterior approaches with afocus on the hypothesis that the larger surface area of lateral cages results in lower subsidence rates. This study retrospectively reviewed 194patients who underwent interbody fusion between 2016 and 2019 with aprimary outcome of cage subsidence. Secondary outcomes were cage distribution (patients, approaches, expandability), cage dimensions, t‑scores, length of hospital stay, blood loss, surgical time, and pelvic incidence-lumbar lordosis (PI-LL) mismatch. Medical records were reviewed for 194patients receiving 387 cages at 379 disc levels. Subsidence was identified in 35.1% of lateral cages, 40.9% of posterior cages, and 36.3% of all cages. Lower surface area (p = 0.008) and cage expandability were associated with subsidence risk. Lower anteroposterior cage length proved to be asignificant factor in the subsidence of posteriorly placed cages (p = 0.007). Osteopenic and osteoporotic patients experienced cage subsidence 36.8% of the time compared to 3.5% of patients with normal t‑scores (p = 0.001). Cage subsidence correlated with postoperative deterioration of the PI-LL mismatch (p = 0.03). Patients receiving fusion augmentation with bone morphogenic protein experienced higher fusion rates (p < 0.01). Cage subsidence is acommon complication that can significantly impact operative outcomes following thoracolumbar interbody fusion. Low t‑scores, smaller surface area, cage expandability, and lower cage length in posterior approaches contribute significantly to cage subsidence.

THE PRODUCTIVITY OF EGG-CROSS CHICKENS DEPENDS ON THEM NUMBERS IN CAGES OF 12-TIER BATTERIES

The group size of hens is one of the key stimuli that affects the welfare of the bird. This is especially important for hens, which evolutionarily live in much smaller groups in the natural environment than in the conditions of enterprises producing edible eggs. But the specific parameters of hеns group size for keeping them in cages of multi-tiered batteries of traditional structures, known as "conventional cages" or "battery cages" according to the international classification, are not regulated by either domestic or foreign standards. There are only restrictions on the minimum number of chickens in one cage of batteries of "improved" designs ("modified enriched cages", or "furnished cages"). It should be at least 7 birds. Therefore, the purpose of the work was to study the productivity and efficiency of the production of edible eggs by increasing group size of hеns in cages of 12-tier batteries of traditional structures from 9 to 93 birds at the standard stocking density (area provision). For this, in the conditions of a modern complex for the production of edible eggs, 4 groups of hens were formed, each of which was kept in a separate poultry house-similar in area (2915 m2), equipped with 12-tier "Big Dutchman" cage batteries, the size and area of which cages differed. The group size of hens on 1st group was 9 birds/cage, 2 groups – 17 birds/cage, 3 groups – 52 birds/cage, 4 groups – 93 birds/cage, density of keeping hens of all groups – 22.6-23.1 birds/m2 with regulatory requirements no more than 25 birds/m2. It was established that an increase the group size of hens in cages from 9 to 93 birds contributes to an increase in the level of preservation (by 5.7%), laying per initial laying hen (by 9.1%), the volume of egg production (by 71.4%), in including based on the calculation per 1 m2 of the poultry house area, the level of profitability of their production from 34.7% to 40.1% and the reduction of the cost price from 1.70 to 1.56 UAH/egg.

Technical efficiency analysis of pearl lobster (Panulirus ornatus) farming in East Lombok Regency using a Stochastic Frontier Approach

Pearl lobster is a fishery and marine commodity that has a high export value and the world demand for pearl lobster is still high. This is an opportunity for cultivators to increase pearl lobster production and productivity. The purpose of this study was to analyze the factors that affect the production of pearl lobster farming, analyze the level of technical efficiency and analyze the factors that affect the technical inefficiency of pearl lobster farming in East Lombok Regency. This research was conducted in Jerowaru and Pare Mas Villages, Jerowaru District, East Lombok Regency, which was determined by multi stages and purposive sampling method. This research includes descriptive research with a quantitative analysis approach. Respondents in this study were 45 pearl lobster cultivators who were determined by proportionally random sampling metod. Analysis of the data used in this study using the analysis of the Cobb Douglas production function stochastic frontier analysis (SFA). The results showed that the production of pearl lobster farming in East Lombok Regency was influenced by factors of cage area, feed, labor and pearl lobster seeds. The level of technical efficiency of pearl lobster farming cultivation is efficient, which a value is 87.86 percent. Then the factors that affect the technical inefficiency of pearl lobster farming in East Lombok Regency are age and education level, which have a negative effect.

Water Quality Of Lake Toba By Space And Time Based On Environmental Physics, Chemical Factors And Community Phytoplankton

The purpose of this study was to analyze the water quality of Toba Lake based on the physics-chemical properties of the waters, the phytoplankton community, and the relationship between the physico-chemical factors of the water and the phytoplankton community according to space and time. This research was conducted during two seasons, Dry season (April, May, July) and Rainy season (October, November and December), and was conducted at four stations, namely around the floating net cage area, around the pier, around the agricultural area, and the control area near the waterfall. Data analysis was performed using the SAS 913 program and the Duncan Multiple Range Test (DMRT). The results of the analysis of water physics-chemical factors by space and time showed the quality of the waters in each station is still relatively good, except for floating net cages that have lower oxygen solubility.Data on chemical physics factors that affect phytoplankton in the waters of Lake Toba based on space, namely the temperature factor is in the range of 26.41 °C - 26.70 °C, light penetration in the range of 3.44 m - 5.10 m, degree of acidity (pH) in the range of 7.89 – 8.27, oxygen solubility (DO) in the range of 4 mg/L- 6.79 mg/L, biochemical oxygen requirements (BOD5) in the range of 0.69 mg/L - 0.95 mg/L, conductivity is in the range of 97.39 μS/cm - 164.59 μS/cm, total dissolved solids (TDS) are in the range of 91.48 mg/L - 98.1 1 mg/L, total nitrate is in the range of 2.14 mg/L - 3.95 mg/L, phosphate content (PO4) is in the range of 0.009 mg/L - 0.013 mg/L.

Modeling impact of culture facilities on hydrodynamics and solute transport in marine aquaculture waters of North Yellow Sea

An increasing number of marine aquaculture facilities have been placed in shallow bays and open sea, which might significantly affect hydrodynamic and solute transport processes in marine aquaculture waters. In this study, a coupled hydrodynamic and solute transport model was developed with high-resolution schemes in marine aquaculture waters based on depth-averaged shallow water equations. A new expression of drag force was incorporated into the momentum equations to express the resistance of suspended culture cages. The coupled model was used to simulate the effect of suspended structures on tidal currents and the movement of a contaminant cloud in the marine aquaculture of the North Yellow Sea, China. The simulation results showed a low-velocity area appearing inside the aquaculture cage area, with a maximum reduction rate of velocity close to 45% under high-density culture. The results also showed that tidal currents were sensitive to the density of suspended cages, the length of cages, and the drag coefficients of cages. The transport processes of pollutants inside aquaculture facilities were inhibited away from the vicinity of the culture cage area because of the diminished tidal currents. Therefore, the suspended cages significantly affected the transport processes of pollutants in the coastal aquaculture waters. Furthermore, the reduced horizontal velocity significantly decreased the food supply for the aquaculture areas from the surrounding sea.

Small Preoperative Dural Sac Cross-Sectional Area and Anteriorly Placed Fusion Cages Are Risk Factors for Indirect Decompression Failure after Oblique Lateral Interbody Fusion

1) To investigate if implant-related factors such as cage size and cage position are associated with radiologic improvement after indirect decompression with oblique lateral interbody fusion (OLIF). 2) To investigate the risk factors associated with indirect decompression failure (IDF) at the surgical levels after OLIF. From February 2015 to December 2019, 92 consecutive patients (188 levels) with lumbar spinal stenosis who underwent indirect decompression via OLIF with or without posterior instrumentation were studied retrospectively. Radiographic variables were measured preoperatively and postoperatively. The radiographic results were compared for cages with different heights and positions. IDF was defined as revision surgery within 6 months or persistent compressive symptoms 6 months after surgery. Postoperative improvements were observed in all measured radiographic parameters except for segmental lordosis. Taller cages were associated with more shrinkage of the bulging disc and greater increase in dural sac diameter. Cages placed posteriorly showed larger postoperative subarticular diameters. Twelve patients (16 levels) had IDF. Multivariate logistic regression showed that after adjusting for age, sex, and body mass index, smaller preoperative dural sac cross-sectional area and anterior positioning of cages were both independent risk factors for IDF. OLIF is an effective procedure for indirectdecompression. To avoid reoperation for lumbar spinal stenosis, surgeons should aim to place the center of the cage at the posterior half of the lower endplate. Surgical levels with a preoperative dural sac cross-sectional area <44 mm2 may not be suitable for indirect decompression.