Comparative study of five commonly used gravity type fish cages under pure current conditions

Gravity type fish cages have been commonly used in marine aquaculture for years. However, only limited research efforts have been made to assess the influences of different design parameters on the structural responses of gravity type fish cages. The present study first develops and validates an open-source numerical library under the toolbox Code_Aster for the structural analyses of fish cages. Then, the newly developed library is employed to conduct time-domain simulations to investigate the effects of the main design parameters on the cultivation volumes and drag forces. In this paper, five circumferences of the floating collar, five depths of the net bag, five weights and nine current velocities are considered in the parametric study of five commonly used fish cages. Moreover, regression functions are proposed based on the large number of numerical results to provide accurate predictions for the most concerning aspects in the design process for fish cages. Based on the parametric study, recommendations for selecting fish cage types and practical guides for cage construction are given. This study should be of value to structural designers as well as researchers wishing to optimise cage design.publishedVersio

Development of a coupling algorithm for fluid-structure interaction analysis of submerged aquaculture nets

A coupling algorithm between two open-source numerical toolboxes, i.e., OpenFOAM and Code_Aster, is implemented for fluid-structure interaction analysis of submerged nets. This algorithm is developed to handle the wake effects of thin, flexible and highly permeable structures with complex geometries. Compared to previous approaches, the present algorithm simplifies the procedures of the model preparation by removing additional data-fitting processes for porous coefficients, and improves the accuracy of structural responses by employing a fluid solver to calculate the flow field and a superior Screen model to calculate the hydrodynamic forces. The coupling algorithm is comprehensively described and validated with published experiments for both fixed and flexible nets. Different solidities, inflow angles, incoming velocities and dimensions of nets are also considered. The comparisons of flow velocity in the wake, deformation of flexible nets and drag force on the full-scale fish cage show that the numerical results obtained from the present coupling algorithm are in good agreement with published experimental data.publishedVersio

Effects of mooring line breakage on dynamic responses of grid moored fish farms under pure current conditions

Due to the lack of sheltered area, Norwegian fish farms are expanding to more exposed and remote sites. The severe environmental conditions in exposed sites can increase the risk of structural failure during aquaculture operations. In the present study, the program FhSim is employed to conduct time-domain simulations to investigate structural responses of a single-cage and 1 × 4 multi-cage fish farm due to breakages in mooring lines. The influences on the tension distribution in the mooring system and the displacement of the buoys due to breakage at different mooring lines are analysed in detail. Based on the analysis, a method to identify the broken mooring line and to predict the maximum tension increment in the remaining mooring lines is proposed. The results indicate that the breakage at one mooring line is unlikely to cause a progressive collapse of the fish farm immediately when the current velocity is less than 0.5 m/s. However, these breakages may cause structural collapses and fish escapes when the current and waves increase. In order to prevent fish escapes, suggestions to improve the mooring system design and recommendations for monitoring during operations are given.publishedVersio

Graphene oxide incorporated polysulfone substrate for flat sheet thin film nanocomposite pressure retarded osmosis membrane

This study focuses on the development of flat sheet thin film nanocomposite (TFN) pressure retarded osmosis (PRO) membranes for the enhancement of osmotic power generation by the incorporation of laboratory-synthesised graphene oxide (GO) into the polysulfone (PSf) polymer matrix. A series of membranes containing different weight percent of GO (0, 0.1, 0.25, 0.5 and 1.0 wt%) were fabricated via a phase inversion method with polyethylene glycol (PEG) as the pore forming agent. The results show that the TFN-0.25GO membrane has excellent water flux, salt reverse flux, high porosity and an enhanced microvoids morphology compared to the control membrane. The highest power density was achieved when TFN-0.25GO was used is 8.36 Wm−2 at pressure >15 bar. It was found that the incorporation of GO into the polymer matrix has significantly improved the intrinsic and mechanical properties of the membrane

Effects of Stearic Acid on Tensile, Morphological and Thermal Analysis of Polypropylene (PP)/Dolomite (Dol) Composites

The effects of stearic acid treated dolomite (Sa-Dol) on the mechanical, morphological and thermal properties of polypropylene (PP) composite were studied. Prior treatment, raw dolomite was ground in planetary mill using different grinding time to obtain the submicron size (under 10µm). Particle size and specific surface area of dolomite was analyzed and validated using particle size analyzer (Malvern Mastersizer) and BrunauerEmmett-Teller (BET) method respectively. Dolomite with five filler loadings (5, 10, 15, 20 & 25%) were mixed with PP thermoplastic and were compounded using hot melt blending method. Fourier Transform Infrared (FTIR) spectroscopy confirms the successful of filler treatment using stearic acid according to the new peak at 2917 cm --1 attributed to the alkyl group that represented the addition of C-H bond. Tensile properties indicated that tensile strength of PP/Dol decreased with the increasing of filler loading for both systems. The elongation at break decreased with filler loading and showed better and improved result after treatment with stearic acid. The incorporation of stearic acid coated filler into PP matrix enhanced the break elongation of the composites that makes the composites more ductile. Morphological analysis using Scanning Electron Microscopy (SEM) proved better interfacial adhesion and less agglomeration of dolomite filler after treatment with stearic acid at low filler loading (5 wt.%)

Heterochromatin protein 1α mediates development and aggressiveness of neuroendocrine prostate cancer

Neuroendocrine prostate cancer (NEPC) is a lethal subtype of prostate cancer (PCa) arising mostly from adenocarcinoma via NE transdifferentiation following androgen deprivation therapy. Mechanisms contributing to both NEPC development and its aggressiveness remain elusive. In light of the fact that hyperchromatic nuclei are a distinguishing histopathological feature of NEPC, we utilized transcriptomic analyses of our patient-derived xenograft (PDX) models, multiple clinical cohorts, and genetically engineered mouse models to identify 36 heterochromatin-related genes that are significantly enriched in NEPC. Longitudinal analysis using our unique, first-in-field PDX model of adenocarcinoma-to-NEPC transdifferentiation revealed that, among those 36 heterochromatin-related genes, heterochromatin protein 1α (HP1α) expression increased early and steadily during NEPC development and remained elevated in the developed NEPC tumor. Its elevated expression was further confirmed in multiple PDX and clinical NEPC samples. HP1α knockdown in the NCI-H660 NEPC cell line inhibited proliferation, ablated colony formation, and induced apoptotic cell death, ultimately leading to tumor growth arrest. Its ectopic expression significantly promoted NE transdifferentiation in adenocarcinoma cells subjected to androgen deprivation treatment. Mechanistically, HP1α reduced expression of androgen receptor (AR) and RE1 silencing transcription factor (REST) and enriched the repressive trimethylated histone H3 at Lys9 (H3K9me3) mark on their respective gene promoters. These observations indicate a novel mechanism underlying NEPC development mediated by abnormally expressed heterochromatin genes, with HP1α as an early functional mediator and a potential therapeutic target for NEPC prevention and management

DESIGN, ENGINEERING, AND ASSESSMENT OF MOBILE MINEFIELDS

Naval mine warfare typically supports a sea denial strategy through the denial and/or delay of the enemy’s use of the water space or by controlling sea traffic in a designated area. Sea mines have been effective for decades. However, with technological progress, mine countermeasure (MCM) efforts have reduced the risks of a minefield by detecting and/or neutralizing mines to establish and maintain a Q-route for safe passage. The concept of a mobile minefield is proposed to increase the difficulty of the enemy’s MCM and improve the survivability of the minefield by adding mobility. This research explores both the physical design concepts and the operational effectiveness of mobile mines based on simulations and models. The simulation results show that, compared to static mines, mobile mines improved the number of enemy ships destroyed by at least 200% and increased the time it took the enemy to transition through the minefield by 50%. The results suggest that the mobile minefield would be operationally useful for the Department of the Navy and this technology is worth pursing and exploring.Distribution Statement A. Approved for public release: Distribution is unlimited.Captain, Singapore ArmyCaptain, Singapore ArmyMajor, Singapore ArmyLieutenant, Taiwan NavyMajor, United States ArmyCivilian, Department of the NavyLieutenant, United States NavyCivilian, Singapore Technologies Engineering, SingaporeMajor, Singapore ArmyMajor, Singapore ArmyMajor, Singapore ArmyCommander, United States NavyCivilian, Defense Science and Technology Agency (DSTA), SingaporeMajor, Singapore ArmyMajor, Republic of Singapore Air ForceTenente-Coronel, Brazilian Air ForceLieutenant, United States NavyCivilian, Department of the ArmyMajor, Singapore ArmyMajor, Israel Defense ForcesCivilian, Defense Science Organisation, SingaporeCaptain, Singapore Arm

An essential role for the Id1/PI3K/Akt/NFkB/survivin signalling pathway in promoting the proliferation of endothelial progenitor cells in vitro

The enhancement of re-endothelialisation is a critical therapeutic option for repairing injured blood vessels. Endothelial progenitor cells (EPCs) are the major source of cells that participate in endothelium repair and contribute to re-endothelialisation by reducing neointima formation after vascular injury. The over-expression of the inhibitor of differentiation or DNA binding 1 (Id1) significantly improved EPC proliferation. This study aimed to investigate the effects of Id1 on the phosphatidylinositol-3-kinase (PI3K)/Akt/nuclear factor kappa B (NFκB)/survivin signalling pathway and its significance in promoting EPC proliferation in vitro. Spleen-derived EPCs were cultured as previously described. Id1 was presented at low levels in EPCs, and was rapidly up-regulated by stimulation with vascular endothelial growth factor. We demonstrated that transient transfection of Id1 into EPCs activated the PI3K/Akt/NFκB/survivin signalling pathway and promoted EPC proliferation. The proliferation of EPCs was extensively inhibited by silencing of endogenous Id1, and knockdown of Id1 expression led to suppression of PI3K/Akt/NFκB/survivin signalling pathway in EPCs. In addition, blockade by the PI3K-specific inhibitor LY294002, Akt inhibitor, the NFκB inhibitor BAY 11-7082, the survivin inhibitor Curcumin, or the survivin inhibitor YM155 reduced the effects of Id1 transfection. These results suggest that the Id1/PI3K/Akt/NFκB/survivin signalling pathway plays a critical role in EPC proliferation. The Id1/PI3K/Akt/NFκB/survivin signalling pathway may represent a novel therapeutic target in the prevention of restenosis after vascular injury

Emodin Suppresses Migration and Invasion through the Modulation of CXCR4 Expression in an Orthotopic Model of Human Hepatocellular Carcinoma

10.1371/journal.pone.0057015PLoS ONE83

CIDO: The Community-Based Coronavirus Infectious Disease Ontology

Current COVID-19 pandemic and previous SARS/MERS outbreaks have caused a series of major crises to global public health. We must integrate the large and exponentially growing amount of heterogeneous coronavirus data to better understand coronaviruses and associated disease mechanisms, in the interest of developing effective and safe vaccines and drugs. Ontologies have emerged to play an important role in standard knowledge and data representation, integration, sharing, and analysis. We have initiated the development of the community-based Coronavirus Infectious Disease Ontology (CIDO). As an Open Biomedical Ontology (OBO) library ontology, CIDO is an open source and interoperable with other existing OBO ontologies. In this article, the general architecture and the design patterns of the CIDO are introduced, CIDO representation of coronaviruses, phenotypes, anti-coronavirus drugs and medical devices (e.g. ventilators) are illustrated, and an application of CIDO implemented to identify repurposable drug candidates for effective and safe COVID-19 treatment is presented