Culture Cycle Research Articles

Physico-Chemical Dynamics of Vanname Shrimp (Litopenaeus vannamei) Cultivation Pond Water Quality with A Recirculation System

In 2021 Indonesia was experiencing an increase in shrimp exports. Litopenaeus vannamei shrimp is one of the shrimp with a good increase in exports and a type of shrimp with high resistance to environmental disturbances. Indonesia has land potential of about 2,964,331.24 hectares which can be used to increase shrimp production. The cultivation technique that can maximize this potential is a superintensive technique that uses closed aquaculture system. Recirculating Aquaculture system (RAS) is a closed aquaculture system that is suitable for shrimp farming because the water treatment is separated so that there is no significant change in environmental conditions. In this study, the RAS system was equipped with the use of an ultrafiltration membrane as a tool for the inflow water treatment. This study observe the physico-chemical water dynamics that occur during one cultivation cycle. It was observed that the DO of the pond decreased as the shrimp grew, the salinity increased during the cultivation process if there was no water replacement, the brightness decreased every day until it reached a specified point. Temperatures tended to be low due to weather factors, ammonia levels tended to decrease but nitrite and nitrate levels tended to increase due to the slower transformation rate of nitrite and nitrate. The operating system for this process was carried out by adding CaO and sugar. The addition of CaO ranges from 100-600 g/day. The effective addition of sugar if there was a spike in ammonia levels was 1.25 kg/day.

Crescimento e acúmulo de nutrientes na cultura do capim-elefante

ABSTRACT Elephant grass fertilization is performed more efficiently by analyzing growth curves and nutrient accumulation. This study evaluated elephant grass's growth, dry matter production, and nutrient accumulation. A sampling design was used, with plant collections over time. Elephant grass was cultivated in four plots of 27 m2 during two cultivation cycles. Destructive sampling of four plants was carried out per collection to evaluate dry matter production and nutrient accumulations. In the first cycle, plants were collected at 21, 35, 49, 63, 77, 91, 105 and 119 days after planting. After the last collection of the first cycle, a standardization cut was made, eliminating the remaining plants in the experimental plots. The second cycle of collections was carried out at 21, 35, 49, 63, 77, 91, and 105 days after the uniformity cut. In all collections, the number of tillers per linear meter was counted, and the height of the plants was evaluated. The data were subjected to nonlinear regression analysis. The accumulation of nutrients by elephant grass accompanied the production of dry matter. The highest rates of dry matter production occurred around 70 days. The greatest height growth occurred from 18 to 102 days in the 1st cycle and 8 to 61 days in the 2nd cycle. Nutrient accumulation showed the following decreasing order: K>N>Mg>Ca>P>S>Fe>Mn>Zn>Cu (1st cycle); and K>N>Mg>Ca>P>S>Fe>Zn>Mn>Cu (2nd cycle).

Impact of carbon source for the synthesis of α-amylase in rice callus culture

Various carbon sources such as fructose, glucose, sucrose and maltose were tested at different concentrations to control enzyme synthesis in callus culture. Among them, 3% maltose was found to be the best carbon source for effective synthesis and secretion in the callus induction medium. The effect of various carbon sources on the synthesis of α-amylase in rice callus culture was studied. The features of the production of α-amylase in rice callus culture were studied on media containing as a carbon source a natural polysaccharide – starch and the end products of its enzymatic hydrolysis – maltose and glucose. A study of the dynamics of growth of callus culture of rice embryos on media with various carbon sources showed that the greatest growth of calli during the cultivation cycle was observed in the variant with glucose and corresponded to an almost 7-fold increase in cell mass. Using different concentrations of sucrose, it was found that the onset of induction of synthesis and secretion of cathodic isoforms of AMY1 α-amylase in rice suspension cells coincided exactly with the moment of depletion of the carbon source in the nutrient medium. The synthesis of the anodic forms of the AMY2 enzyme was constitutive.

Modeling future carbon stock in melon cultivation agroecosystems under different climate scenarios

Intensive melon cultivation is based on conventional monoculture models that can inefficiently use natural resources, which, combined with inadequate management, contribute to climate change. The main objective of this study was to model the future carbon stock in melon cultivation agroecosystems under different climate scenarios. The study was conducted at the Bebedouro Experimental Field of Embrapa Semi-arid, Petrolina/PE, Brazil, in an area cultivated with yellow melon cv. Gladial, and eight cultivation cycles were considered. The experimental design was composed of two types of soil management (with and without tillage), two treatments using green manures consisting of 14 species with different proportions of legumes, grasses and oilseeds, and spontaneous vegetation, containing four replications divided into randomized blocks. After 70 days of development, the plants were cut and placed in the soil. Temperature and precipitation data were acquired from the BCC-CSM, MIROC5, CESM1-BGC, IPSL-CM5B-LR, and HadGEM2-AO climate models, following the RCP 4.5 and 8.5 climate scenarios. The carbon (C) stock was estimated until the year 2071 using the RothC model.

Otimização da tecnologia de micropropagação clonal de variedades ornamentais de rosas ‘Dream Come True’ e ‘Full Sail’

Abstract The rose is the most important ornamental and floral crop, as well as a valuable aromatic and medicinal plant. For accelerated production of planting material, clonal micropropagation is used. There are problems in obtaining an aseptic culture and the peculiarities of plant cultivation at different stages, depending on the variety. It is necessary to develop and optimize the technological cycle of cultivation in in vitro culture. The results showed that the highest viability of rose explants obtained from lateral buds was noted by sterilization with 0.2% silver nitrate solution of and 5% Lysoformin 3000 with an exposure of 15 minutes (82%-95%); the highest viability of explants obtained from etiolated shoots was observed when sterilized with 0.2% silver nitrate solution with an exposure of 10 minutes and 5% Lysoformin 3000 with an exposure of 15 min (82%-100%). The maximum length of the micro-shoots was noted in the ‘Dream Come True’ variety on a QL (Quoirin and Lepoivre) nutrient medium (on average 21.2 cm), in the ‘Full Sail’ variety - on a ½ QL medium (on average 24.9 cm). An increase in the concentration of 6-BAP from 0.5 to 1.0 mg L-1 in the nutrient medium contributed to an increase in the number of micro-shoots (by 1.7-1.9 times). The maximum root length was noted on the nutrient medium ½ QL (on average 88.7-95.3 cm). An increase in the concentration of IAA from 0.5 to 1.0 mg L-1 in the nutrient medium contributed to an increase in root length by 1.4-1.8 times. The protocol developed in this study allows to propagate these two varieties in vitro and produce a large number of plants.

Assessing the influence of diverse phosphorus sources on bacterial communities and the abundance of phosphorus cycle genes in acidic paddy soils.

The impact of chemical fertilizers on soil microbial communities is well acknowledged. This study assesses the influence of various phosphorus sources on soil bacterial composition, abundance, and Phosphorus Cycle Gene Abundance. Three phosphorus sources (natural phosphate rock, triple super phosphate (TSP), and chemical fertilizer NPK) were field tested following two rice cultivation cycles. Soil samples were subsequently collected and analyzed for bacterial groups and phosphorus cycle genes. Results indicated that the bacterial community composition remained consistent, comprising five main phyla: Firmicutes, Actinobacteria, Proteobacteria, Halobacterota, and Chloroflexia, regardless of fertilizer type. NPK fertilizer significantly reduced the relative abundance of Chloroflexia by 19% and Firmicutes by 16.4%, while increasing Actinobacteria and Proteobacteria by 27.5 and 58.8%, respectively. TSP fertilizer increased Actinobacteria by 27.1% and Halobacterota by 24.8%, but reduced Chloroflexia by 8.6%, Firmicutes by 12.6%, and Proteobacteria by 0.6%. Phosphate rock application resulted in reductions of Chloroflexia by 27.1%, Halobacterota by 22.9%, and Firmicutes by 6.2%, alongside increases in Actinobacteria by 46.6% and Proteobacteria by 23.8%. Combined application of TSP, NPK, and phosphate rock led to increases in Proteobacteria (24-40%) and Actinobacteria (13-39%), and decreases in Chloroflexia (5.2-22%) and Firmicutes (6-12.3%) compared to the control (T0). While the different phosphorus sources did not alter the composition of phosphorus cycle genes, they did modulate their abundance. NPK fertilizer did not significantly affect ppK genes (57-59%) but reduced gcd (100 to 69%), 3-phytase (74 to 34%), appA (91 to 63%), and phoD (83 to 67%). Phosphate rock reduced appA and gcd by 27 and 15%, respectively, while increasing 3-phytase by 19%. TSP decreased ppK and phoD by 42 and 40%, respectively, and gcd and appA by 34 and 56%, respectively. Combined fertilizers reduced appA (49 to 34%), 3-phytase (10 to 0%), and gcd (27 to 6%), while increasing ppK (72 to 100%). Among tested phosphorus sources, natural phosphate rock was best, causing moderate changes in bacterial composition and phosphorus genes, supporting balanced soil microbial activity. These findings highlight the complex interactions between fertilizers and soil microbial communities, underscoring the need for tailored fertilization strategies to maintain soil health and optimize agricultural productivity.

Effect of natural increase of pH and microalgae cyclical re-cultivation on biomass production and polishing of municipal secondary effluent

A constant source of nutrient pollution that causes eutrophication is municipal wastewater treatment plant (WWTP) secondary effluent. This paper investigates the natural increase of pH, nutrient removal and biomass production from a cyclical re-cultivation system designed to favor the adaptation of microalgae consortia to WWTP secondary effluent. An outdoor experiment was performed with the microalgae consortia MC-10 under 3 sequential batch cycles. The natural pH increase (range 9–10) in the WWTP secondary effluent was established as an operation parameter because it certainly influenced microalgae biomass production (by maintenance and bioavailability of C and P), water treatment and pathogen removal. The increase of pH (9.7, 9.8 and 9.9) during the culture cycles of MC-10 probably generated conditions for fecal bacterial removal below detectable values (i.e., < 2 MPN/100 mL). The treatment of WWTP secondary effluent after batch cycles (cycles 1 to 3) using MC-10 indicated improvements in biomass productivity (66 to 167%) and a great potential for the reduction of total alkalinity (13.1 to 50.3%), NO3–-N (30.9 to 53.6%), PO43–- P (90.4 to 93.0%) and electrical conductivity (EC) (8.5 to 18.1%). Additionally, the harvested biomass showed a high mineral concentration (46.5%) suggesting its potential use as a bio-fertilizer.

An estimation of dissolved oxygen production model by paddle aerator in whiteleg shrimp (Litopenaeus vannamei) culture

Dissolved oxygen is an important parameter in L. vannamei culture. The aim of this research is to determine of the oxygen levels produced by the paddle aerator in L. vannamei ponds. The research method used is a descriptive method by collecting research data using the causal expose-facto design which is analyzed by a dynamic modeling system. The results showed that water quality parameters were relatively stable during the shrimp culture periods. Based on dynamic modeling studies, the effectiveness of using the paddle aerator will decrease in the third week. According to modeling estimates of 1 HP paddle aerators produce dissolved oxygen levels was 0.5-8.0 mg/L. The oxygen solubility level from using the paddle aerator was lowest when the shrimp culture period reached 50 days and the highest solubility was 7.5 mg/L. The oxygen solubility rate in shrimp pond waters is also influenced by the temperature stability and other abiotic factors. Finally, the oxygen production rate in the paddle aerator oscillates dynamically throughout the shrimp culture cycle with estimated oxygen production rates ranging from 0.5-8 mg/L.

Agronomic characteristics of carrot cultivars under water stress

The objective of the study was to evaluate the agronomic performance of carrot cultivars subjected to different levels of water supply. The experiment was conducted in a randomized block design, in a split-plot scheme with four replicates. Five irrigation depths were used in the plot, one to replace 100% of the crop’s evapotranspiration (ETc), two in deficit (50% and 75% of ETc) and two in excess (125% and 150% of ETc). Four carrot cultivars were used in the subplots: Brasília, Alvorada, Esplanada, and Nantes. Two carrot cultivation cycles were carried out, the first lasting 121 d and the second lasting 103 d after sowing. The following variables were evaluated: total fresh mass of the plant, fresh carrot mass, carrot length, length of the aerial part, average carrot diameter, carrot volume, green shoulder, crop productivity, water productivity, and water potential of the plants. The Brasília carrot cultivar had better development and the Esplanada cultivar was less adapted to the studied environment. All carrot cultivars were affected by stress caused by excess and lack of water. Carrot irrigation must be carried out with a depth equal to 100% of the crop’s evapotranspiration for the region and conditions similar to those of the present study.

THE EFFECTIVENESS OF THE SUPER MEAT DUCK FARMING MODEL COMPARED TO VARIOUS OTHER FARMING METHODS IN PHU THO PROVINCE

The 6550 meat ducklings were monitored and raised using three different methods in two cultivation cycles to evaluate several criteria regarding the efficiency of livestock farming, aiming at selecting a model for expanding meat duck farming and providing high economic efficiency in Phu Tho province. 550 ducklings were raised in the traditional household style combined with pond/field release; 1000 were raised in open-floor pens; 5000 were raised in enclosed industrial-style pens. The study results showed that the survival rate ranged from 91.5% to 96.5%, with the traditional style having the lowest survival rate (91.5% to 92.3%), and the enclosed pens having the highest (95% to 96.5%). The weight of the ducks for sale ranged from 3.2-3.5 kg/duck at 7-8 weeks of age, with the enclosed pens showing the most even growth, the best growth rate, and stability, and unaffected by seasonal changes in farming, especially in the first two weeks. The feed conversion ratio (FCR) of ducks raised in enclosed pens showed a better feed conversion rate in the spring-summer season, with FCR higher than open-floor pens and traditional farming, ranging from 7.7-14.5%. The economic efficiency per duck raised was highest in the 1000-bird scale and open-floor pen with 35,291 VND, followed by enclosed pens at 28,551 VND, and traditional farming at 19,275 VND.

MAC Family Transcription Factors Enhance the Tolerance of Mycelia to Heat Stress and Promote the Primordial Formation Rate of Pleurotus ostreatus.

Pleurotus ostreatus is a typical tetrapolar heterologous edible mushroom, and its growth and development regulatory mechanism has become a research hotspot in recent years. The MAC1 protein is a transcription factor that perceives copper and can regulate the expression of multiple genes, thereby affecting the growth and development of organisms. However, its function in edible mushrooms is still unknown. In this study, two transcription factor genes, PoMCA1a and PoMAC1b, were identified. Afterwards, PoMAC1 overexpression (OE) and RNA interference (RNAi) strains were constructed to further explore gene function. The results showed that the PoMAC1 mutation had no significant effect on the growth rate of mycelia. Further research has shown that OE-PoMAC1a strains and RNAi-PoMAC1b strains exhibit strong tolerance under 32 °C heat stress. However, under 40 °C heat stress, the OE of PoMAC1a and PoMAC1b promoted the recovery of mycelial growth after heat stress. Second, the OE of PoMAC1a can promote the rapid formation of primordia and shorten the cultivation cycle. In summary, this study indicated that there are functional differences between PoMAC1a and PoMAC1b under different heat stresses during the vegetative growth stage, and PoMAC1a has a positive regulatory effect on the formation of primordia during the reproductive growth stage.

Identification of odor-causing compounds in six species of odor-producing microalgae separated from drinking water source with distinct fishy odor: Insight into microalgae growth and odor characteristics

Fishy odor, as an offensive and unpleasant odor, could occur in drinking water source with poor nutrition, it is usually considered to be associated with odor-producing microalgae. However, the specific relations among fishy odor, fishy odorants and responsible microalgae were not elucidated comprehensively. In this paper, the odor-causing compounds generated from six microalgae with fishy odor characteristic, isolated in drinking water source Tongyu River, were identified simultaneously. The sensory evaluation result indicated that Tongyu River was principally related to fishy odor (odor intensity 6.5–7.6). Correspondingly, seven, nine, seven, six, seven and seven olfactory detection peaks (ODP) were screened by combining data of GC/O/MS and GC/GC/TOFMS in Cyclotella, Cryptomonas ovate, Melosira, Dinobryon sp., Synedra and Ochromonas sp., which were isolated in Tongyu River and cultured in laboratory. Totally twenty odor-causing compounds, including hexanal, 2-hexenal, 3-hexen-1-ol, heptanal, 1-octen-3-one, 2,4-heptadienal, 2-tetradecanone, 3,5-octadien-2-one, octanal, 1-octen-3-ol, 2-octenal, nonanal, 2,4-octadienal, 2-nonenal, decanal, 2,6-nonadienal, 2-decenal, undecanal, 2,4-decadienal and dodecanal, were screened and identified in all isolated microalgae. Additionally, fishy odor intensity for all identified microalgae increased obviously as microalgae cell number increased and microalgae cell ruptured in cultivation cycles through pearson and spearman correlation analysis. For the first time, twenty odor-causing compounds associating with fishy odor were recognized from six isolated microalgae, which would provide more scientific basis and theoretical support for preventing and treating fishy odor episode of drinking water source.

Biochemical composition of the Atlantic pearl oyster Pinctada imbricata (Bivalvia: Pteriidae) in suspended culture: Influence of environmental factors

Atlantic pearl oyster Pinctada imbricata is a bivalve with high potential for cultivation in tropical and subtropical environments. In this study, P. imbricata energetic metabolism was analyzed throughout a culture cycle at Gulf of Cariaco, Venezuela. Juvenile individuals (shell length 27.40 ± 2.70 mm) were cultured in a long line at 3 m depth between May-2012 and January-2013. Monthly data of biometric measurements, Fulton index (K) and protein, carbohydrate, and lipid content of the adductor muscle, digestive gland, and mantle were estimated, and were related with environmental variables: temperature, chlorophyll a (Ch a), total particulate matter (TPM), particulate inorganic matter (PIM), particulate organic matter (POM) and upwelling index (UI). Shell length increased steadily reaching 46.23 ± 3.79 mm on the 8th month of culture, while average soft tissue weight increased associated to food availability. Biometric data and biochemical substrates from the muscle, digestive gland and mantle presented significant differences among months. Principal Component Analysis (PCA) showed positive relationships between carbohydrate content with temperature; mantle and digestive gland protein content with TPM, PIM, POM, UI; lipid and protein in muscle with K. Energy allocation was associated with environmental factors, mainly through high food availability given the seasonal upwelling pulses in the area.

Participant-oriented evaluation through participatory action research: a case study of a community engagement approach

PurposeThis article explores the applicability of participatory action research (PAR) on two levels: on the one hand, as a participatory evaluation method for community engagement and community development; on the other hand, as a tool to link ex ante and ex-post evaluation that situated at various stages of the policy cycle.Design/methodology/approachThrough a practice-based case study of the community engagement process of Valletta Design Cluster, this paper aims to illustrate how PAR can offer collaborative and continuous evaluation by facilitating social action through a practical, situative, context-bounded, responsive and transformative framework.FindingsThe study explores how PAR can contribute to cultural sustainability by linking community development with participatory evaluation, and it offers new perspectives on the applicability of PAR as a tool to link ex ante and ex-post evaluation, situated at various stages of the policy cycle.Research limitations/implicationsAlthough based on a single case, the paper demonstrates that the method has the potential to be applied in various contexts, as it helps to foster local ownership and to develop future cultural strategies, thus providing a base for cultural sustainability.Originality/valueThe novelty of this study is to link evaluation – a majorly top-down and ex ante approach – with participatory planning. PAR-E offers a continuous participatory framework for the whole European Capitals of Culture (ECoC) cycle, as well as serving as a tool for empowerment and community development.

Producing and Testing Prototype Tissue-Engineered 3D Tri-Leaflet Valved Stents on Biodegradable Poly-ε-Caprolactone Scaffolds.

Transcatheter pulmonary valve replacement is a minimally-invasive alternative treatment for right ventricular outflow tract dysfunction and has been rapidly evolving over the past years. Heart valve prostheses currently available still have major limitations. Therefore, one of the significant challenges for the future is the roll out of transcatheter tissue engineered pulmonary valve replacement to more patients. In the present study, biodegradable poly-ε-caprolactone (PCL) nanofiber scaffolds in the form of a 3D leaflet matrix were successfully seeded with human endothelial colony-forming cells (ECFCs), human induced pluripotent stem cell-derived MSCs (hMSCs), and porcine MSCs (pMSCs) for three weeks for the generation of 3D tissue-engineered tri-leaflet valved stent grafts. The cell adhesion, proliferation, and distribution of these 3D heart leaflets was analyzed using fluorescence microscopy and scanning electron microscopy (SEM). All cell lineages were able to increase the overgrown leaflet area within the three-week timeframe. While hMSCs showed a consistent growth rate over the course of three weeks, ECFSs showed almost no increase between days 7 and 14 until a growth spurt appeared between days 14 and 21. More than 90% of heart valve leaflets were covered with cells after the full three-week culturing cycle in nearly all leaflet areas, regardless of which cell type was used. This study shows that seeded biodegradable PCL nanofiber scaffolds incorporated in nitinol or biodegradable stents will offer a new therapeutic option in the future.

The efficient capture of polysaccharides in Tetradesmus obliquus of indole-3-acetic acid coupling sludge extraction

Polysaccharide is an important biomass of algae. The sludge extract is rich in organic substances, which can be used by algae for biomass growth and high-value biomass synthesis, but its organic toxicity has an inhibitory effect on algae. To overcome inhibition and improve polysaccharide enrichment, Tetradesmus obliquus was cultured with sludge extract with different indole-3-acetic acid (IAA) concentrations. Within 30 days of the culture cycle, T. obliquus showed in good condition at the IAA dosage content of 10−6 M, the maximum cell density and dry weight were respectively (106.78 ± 2.20) × 106 cell/mL and 2.941 ± 0.067 g/L while the contents of chlorophyll-a, chlorophyll-b, and carotenoid were 1.79, 1.91 and 2.80 times that of the blank group, respectively. The highest polysaccharide accumulation was obtained under this culture condition, reaching 533.15 ± 21.11 mg/L on the 30th day, which was 2.49 times that in the blank group. By FT-IR and NMR analysis, it was found that the polysaccharides of T. obliquus were sulfated polysaccharide with glucose and rhamnose as the main monosaccharides. Proteomic showed that the up-regulation of A0A383WL26 and A0A383WLM8 enhanced the light trapping ability, and A0A383WMJ2 enhanced the accumulation of NADPH. The up-regulation of A0A383WHD5 and A0A383WAY6 indicated that IAA culture could repair the damage caused by sludge toxicity, thus promoting the accumulation of biomass. The above findings provided new insights into the mechanism of sludge toxicity removal of T. obliquus and the enhancement of the polysaccharide accumulation effect under different concentrations of IAA.

Improvement of N and P ratio for enhanced biomass productivity and sustainable cultivation of Chlorella vulgaris microalgae

Microalgae cultivation could contribute to the achievement of several sustainable development goals (SDGs). However, cultivating Chlorella vulgaris, like any other microalgae, is challenging due to various biotic, abiotic and process related factors that can affect its growth and biomass productivity. Nutrient availability, particularly N and P, and their ratio play a crucial role in building cellular structures and maintaining metabolic processes, determining basically the maximum achievable biomass productivity under given circumstances. The present article aims to improve the N and P ratio to enhance the biomass productivity of Chlorella vulgaris microalgae as well as to characterize the biomass growth kinetics that can be used for prediction purposes. The results showed that the nutrient solutions prepared with increased nitrate concentration (T1 – N:P = 55:1 and T3 – N:P = 28:1) promoted chlorophyll formation and significantly outperformed the control sample (BG-11 – N:P = 35:1) with 192% and 183%, leading to higher biomass productivity with 1160 μg L−1 and 1103 μg L−1, respectively. Moreover, a strong positive correlation was revealed (0.81) between phosphate concentration and microalgae activity rate, indicating the role of phosphorous in energy transfer, resulted in stimulated microalgae activity rates with 71.2% and 70.66% in the phosphate-increased nutrient solutions (T2 – N:P = 14:1 and T3 – N:P = 28:1). In addition, an exponential equation was introduced to characterize the biomass growth kinetics, of which the theoretically achievable maximum chlorophyll concentration (CTAM) and the theoretical cultivation time (tcultivation) were determined for the tested nutrient solutions with variable N:P ratio. It was concluded, that the higher the N:P ratio, the higher the CTAM is, nevertheless the absolute concentration of these nutrients need to be considered as well. The introduced two key parameters could provide valuable information for decision makers regarding the optimization of growth conditions, nutrient supplementation, and harvesting, additionally decreasing the production costs and making the cultivation cycles more effective and sustainable.

Numerical Studies on Effects of Blade Number Variations on Performance of Sludge Pumps

The sedimentation of sludge in pangasius catfish ponds constitutes a notable challenge for the economic advancement of Vietnamese farmers. Sludge formation is the result of a composite process involving residual food, waste material, and algae, which undergo decomposition, thereby releasing hazardous gases such as hydrogen sulfide (H2S), ammonia (NH3), and nitrogen dioxide (NO2). These emissions subsequently diminish oxygen levels within the ponds, adversely affecting the growth of catfish. Removal of the accumulated sludge is deemed necessary every two months throughout the catfish cultivation cycle. A proficient sludge pump, designed to function effectively within the Vietnamese environmental context, becomes imperative to address this predicament. The primary objective of this research paper is to explore the influence of blade count on the performance metrics of a sludge pump. Given that pangasius ponds typically exhibit depths ranging from 2 to 4 meters, this study is predominantly centered on assessing pump performance within the specified head range of 2 to 4 meters. Employing the computational fluid dynamics (CFD) methodology, the research delves into the fluid dynamics of sludge pumps featuring impeller blades numbering 7, 8, 9, and 10. These pumps are modeled as semi-open impeller centrifugal pumps operating at a speed of 2200 revolutions per minute (rpm), with the k-e turbulence model and the time-averaged Navier-Stokes equation serving as the fundamental analytical framework.

Identification, prevalence and intensity of ectoparasite in sand lobster (Panulirus homarus) cultivated in floating cages (floating net cage) and bottom cage (bottom cage)

Lobster (Panulirus homarus) is one of the marine fishery commodities that is gaining popularity and has been widely cultivated in Indonesia. This is because lobster has great business prospects and is one of the important commodities and has high economic value. Lobster cultivation can now be done in various systems including floating net cages, bottom cages and ponds. The problem that is often faced by cultivators is the emergence of diseases in the lobster cultivation cycle caused by an unbalanced interaction between lobster conditions, the environment, and pathogens. This is one of the main problems in lobster cultivation that can interfere with the survival of lobsters and can also cause death. Research on ectoparasite infection in Sand Lobster (Panulirus homarus) cultured in floating net cages and bottom cages aims to identify the types of ectoparasites and calculate the prevalence and intensity of ectoparasites infecting sand lobster (Panulirus homarus). The method used in this study is a survey method. The sampling method was carried out by random sampling method and the method of analysis and presentation of data using descriptive methods. The main parameters observed in this study were the type of ectoparasites, prevalence and intensity values of sand lobster (Panulirus homarus) infected with ectoparasites, while the supporting parameter was lobster size. The ectoparasite found to infest the sand lobster (Panulirus homarus) was Octolamis angulata. The highest prevalence value was obtained in cultivation using floating net cages of 53,3% which belonged to the Frequently category (commonly) and the highest intensity value was obtained in cultivation using floating net cages of 30,1 which belonged to the Medium category (currently). It is necessary to conduct further studies on Octolasmis species based on the DNA chain arrangement and description of tissue damage due to Octolasmis infestation

Ebf1 Is Involved in Primitive Myelopoiesis and Contributes in Leukemia Pathogenesis

Acute myeloid leukemia (AML) is caused by the abnormal proliferation and differentiation of a clonal population of myeloid progenitors. EBF1 is a key transcriptional factor in regulating hematopoiesis and has been linked to acute lymphoblastic leukemia (ALL). However, the relationship between AML and EBF1 mutation has not yet been studied. Recent research has shown that deleting EBF1 results in myeloid-biased progenitors and decreased HSC quiescence and repopulation capacity. This suggests that EBF1 is involved in earlier hematopoiesis and has additional functions beyond B-cell committed development. Our clinical center conducted whole-exome sequencing on 231 cases of acute myeloid leukemia and identified four patients with an Ebf1 mutation. This corresponds to a mutation frequency of 1.73% and the mutations were identified as p.Q477H (c.1434G&amp;gt;T), p.S513P (c.1537T&amp;gt;C), p.C534F (c.1601GT), and p.P570A (c.1708C&amp;gt;G). Data from the cBioPortal database showed that AML patients with Ebf1 deep deleted mutation had shortened survival. To better understand the role of Ebf1 in AML pathogenesis, we generated an ebf1a-deficient zebrafish mutant. Further research showed that the ebf1a deficiency caused neutrophilia during primitive hematopoiesis. BrdU staining in Tg(coronin1a: GFP) labeled myeloid progenitors was significantly higher in ebf1a-deficient larvae than in wild-type larvae, indicating that ebf1a deficiency led to increased proliferating myeloid progenitors which would take responsibility for the neutrophilia in early-developing larvae. We conducted experiments using four RNA variants (p.Q477H, p.S513P, p.C534F, and p.P570A) injected into ebf1a deficiency zebrafish larvae to verify their pathogenicity. Our findings showed that while EBF1 p.Q477H and p.S513P caused a decrease in neutrophils, p.C534F resulted in neutrophilia, indicating that it might be a loss-of-function mutation. To further understand the mechanism, we introduced EBF1 p.C534F to AML cell culture, and CCk8 and cell cycle analysis showed increased proliferation rates and disturbed cell cycle balance, leading to increased proliferation of AML cells of EBF1-C534F mutation. The cells bearing this mutation showed a higher rate of proliferation, likely due to a disturbance in the balance of the cell cycle. These findings provide valuable insight into the potential pathogenetic mechanism of EBF1 p.C534F. Our investigation into the cause of ebf1 deficiency disrupting normal hematopoiesis led us to perform bulk RNA-sequencing with sorted myeloid-progenitors labeled by Tg:(coronin1a-GFP) in 30hpf zebrafish larvae. We found that leukocyte differentiation and myeloid cell cycle-related genes such as lyz, lygl1, coro1a, lcp1, cebpa, spi1b, mpx, irf8, il6, il34, etc were upregulated in ebf1a deficiency zebrafish. Additionally, anxa1c, anxa1b, Cish, and nlrc3l, which have been reported to suppress lymphoid proliferation but increase myeloid expansion, were down-regulated. Go enrichment analysis showed that the significant genes were associated with hematopoietic disorders including AML and MDS. To address the issue of disturbed cell cycle balance caused by EBF1 deficiency and loss-of-function mutation, we sought to suppress the G1-S transition via CDK inhibitor. We treated EBF1-C534F, EBF1-WT, and control AML cell culture with CDK4 inhibitor: AMG925. We were surprised to find that the CDK4 inhibitor sufficiently suppressed the proliferation and reversed the prolonged S phase caused by EBF1 mutation. We investigated the myeloid-bias function of Ebf1 deficiency and the potential pathogenesis of EBF1 mutations of AML from the development view and were surprised to find CDK inhibitors as a potential drug for EBF1-deficient AML patients.