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Perlucin is a shell matrix protein that plays a significant role in regulating shell biomineralization. This study aimed to isolate and characterize the perlucin gene and analyze its expression to explore its role in shell formation, regeneration, and responses to thermal stress and starvation in Pacific abalone. The isolated full-length cDNA sequence of Hdh-Perlucin is 1002 bp long, encoding a 163-amino-acid polypeptide with a signal peptide. The mature peptide of Hdh-Perlucin contains a C-type lectin domain with signature motif and six conserved cysteine residues. Gene Ontology analysis suggests that Hdh-Perlucin exhibits carbohydrate-binding activity. Significantly higher expression of Hdh-Perlucin was observed during the juvenile, veliger, and trochophore stages, compared with cell division stage during early development. Upregulated expression was recorded from slow to rapid growth phases and during shell biomineralization, while downregulated expression was noted during starvation. Under thermal stress, expression peaked at 30 °C and 25 °C for 6 and 12 h, respectively, while consistently higher levels were observed at 15 °C throughout the experiment. This study provides the first comprehensive structural and expression analysis of Hdh-Perlucin, highlighting its roles in metamorphosis, shell formation and regeneration, and responses to heat stress and starvation in abalone.

Abstract SPARC is an extracellular Ca2+-binding, secreted glycoprotein that plays a dynamic role in the growth and development of organisms. This study aimed to describe the isolation, characterization, and expression analysis of HdhSPARC in Pacific abalone (Haliotis discus hannai) to infer its potential functional role. The isolated HdhSPARC was 1633 bp long, encoding a polypeptide of 284 amino acid residues. Structurally, the SPARC protein in abalone is comprised of three biological domains. However, the structure of this protein varied between vertebrates and invertebrates, as suggested by their distinct clustering patterns in phylogenetic analysis. In early development, HdhSPARC was variably expressed, and higher expression was found in veliger larvae. Moreover, HdhSPARC was highly expressed in juvenile abalone with rapid growth compared to their slower-growing counterparts. Among the testicular development stages, the growth stage exhibited higher HdhSPARC expression. HdhSPARC was also upregulated during muscle remodeling and shell biomineralization, as well as in response to different stressors such as heat shock, LPS, and H2O2 exposure. However, this gene was downregulated in Cd-exposed abalone. The present study first comprehensively characterized the HdhSPARC gene, and its spatio-temporal expressions were analyzed along with its responses to various stressors.

The development of a shell is a complex calcium metabolic process involving shell matrix proteins (SMPs). In this study, we describe the isolation, characterization, and expression of SMP5 and investigate its potential regulatory role in the shell biomineralization of Pacific abalone Haliotis discus hannai. The full-length Hdh-SMP5 cDNA contains 685 bp and encodes a polypeptide of 134 amino acids. Structurally, the Hdh-SMP5 protein belongs to the EF-hand-binding superfamily, which possesses three EF-hand Ca2+-binding regions and is rich in aspartic acid. The distinct clustering patterns in the phylogenetic tree indicate that the amino acid composition and structure of this protein may vary among different SMPs. During early development, significantly higher expression was observed in the trochophore and veliger stages. Hdh-SMP5 was also upregulated during shell biomineralization in Pacific abalone. Long periods of starvation cause Hdh-SMP5 expression to decrease. Furthermore, Hdh-SMP5 expression was observed to be significantly higher under thermal stress at temperatures of 15, 30, and 25 °C for durations of 6 h, 12 h, and 48 h, respectively. Our study is the first to characterize Hdh-SMP5 comprehensively and analyze its expression to elucidate its dynamic roles in ontogenetic development, shell biomineralization, and the response to starvation and thermal stress.

Abstract In this paper, a nonlinear decentralized double‐integral sliding mode controller (DI‐SMC) is designed along with an energy management system (EMS) for the DC microgrid (DCMG). This DCMG includes having a hybrid energy storage system (HESS) that incorporates a battery energy storage system (BESS) and supercapacitor energy storage system (SCESS) while the load demand is met through the power generated from solar photovoltaic (SPV) units. First, dynamical models of each subsystem of DCMGs such as the SPV system, BESS, and SCESS are developed to capture highly nonlinear behaviors of DCMGs under various operating conditions. The proposed nonlinear DI‐SMC is then designed for each power unit in DCMGs to ensure the desired voltage level at the common DC‐bus and appropriate power dispatch of different components to fulfill the load requirement of the DCMG. On the other hand, an energy management system (EMS) is designed to determine the set point for the controller with an aim of ensuring the power balance within DCMGs under various operating conditions where the overall stability is assessed using the Lyapunov theory. Simulation studies along with the processor‐in‐loop validation, including a comparative study with a proportional‐integral (PI) controller, verify the applicability and effectiveness of the EMS‐based DI‐SMC under different operating conditions of the DCMG.

Valorising waste from the processing of fishery and aquaculture products into functional additives, and subsequent use in aquafeed as supplements could be a novel approach to promoting sustainability in the aquaculture industry. The present study supplemented 10% of various fish protein hydrolysates (FPHs), obtained from the hydrolysis of kingfish (KH), carp (CH) and tuna (TH) waste, with 90% of poultry by-product meal (PBM) protein to replace fishmeal (FM) completely from the barramundi diet. At the end of the trial, intestinal mucosal barriers damage, quantified by villus area (VA), lamina propria area (LPA), LPA ratio, villus length (VL), villus width (VW), and neutral mucin (NM) in barramundi fed a PBM-based diet was repaired when PBM was supplemented with various FPHs (p

Purpose – The purpose of this paper is to find a doubly nonlinear parabolic equation of fast diffusion in a bounded domain. Design/methodology/approach – For positive and bounded initial data, the authors study the initial zero-boundary value problem. Findings – The findings of this study showed the complete extinction of a continuous weak solution at a finite time. Originality/value – The extinction time is studied earlier but for the Laplacian case. The authors presented the finite extinction time for the case of p-Laplacian.

Mechanized farming is an indispensable part of modern agriculture. Bangladesh has managed to achieve significant progress in some components of farm mechanization i.e., irrigation and tillage. The majority of the agricultural operations are still being carried out with manual labor. This paper reports the status of agricultural machineries in the country while analyzing the historical policy changes towards intensive farm mechanization. The potential sectors requiring urgent attention for mechanization was also identified in this study. The manuscript discusses how mechanization could help ensure the food security of the country by maintaining timeliness of agricultural operation. Urgent introduction of mini-combined harvesters during COVID-19 pandemic was discussed as a commendable decision taken by the Government of Bangladesh. It also shows how the use of machine power is increasing in the country through custom hiring based ownership models of the machineries. Local manufacturing of agricultural machineries and spare parts was championed by the fact that small scale industries have developed in this sector. In line with this, we argued that the local companies should focus on precision manufacturing in the coming days. The manuscript also urged the need to include rural youth for sustainable farm mechanization process.

Abstract Background Sardine Amblygaster clupeoides is a reef-associated oceanic species having long-standing socioeconomic and ecological importance along the coast of Bay of Bengal, Bangladesh, but less is known about the morphometric variability of the species. To uncover this, morphometric variability of A. clupeoides based on truss network technique was employed Results A total number of 160 specimens from four coastal regions (Sundarbans, Kuakata, Bhola, and Cox’s Bazar) of the Bay of Bengal coast were used to determine whether separate populations could be distinguished. To test the hypothesis of differentiation, each sample was subjected to morphometric measurements consisting of twenty-eight landmarks. In one way ANOVA analysis, twenty-six out of 28 morphometric measurements showed significant differences among the four populations. The principal component analysis indicated shape variation and explained 70.11% of the total variance. About 68.39% of individuals into their original group were correctly classified in discriminating space, as determined by discriminant function (DF) analysis. Conclusion Morphometric traits like body length, body depth, body diagonal, body height, head length, head depth, mouth length, anal fin length, dorsal fin length, and caudal length diagonal were mainly responsible for variation and discrimination of populations. The present investigation demonstrates that the population of the east coast (Cox’s Bazar) is morphometrically different from other populations. Future stock assessment of A. clupeoides should be considered especially on the east coast (Cox’s Bazar) while formulating management action plans.

Growth factors are mostly secreted proteins that play key roles in an organism’s biophysical processes through binding to specific receptors on the cell surface. The mollusk-like growth factor (MLGF) is a novel cell signaling protein in the adenosine deaminase-related growth factor (ADGF) subfamily. In this study, the MLGF gene was cloned and characterized from the digestive gland tissue of Pacific abalone and designated as Hdh-MLGF. The transcribed full-length sequence of Hdh-MLGF was 1829 bp long with a 1566 bp open reading frame (ORF) encoding 521 amino acids. The deduced amino acid sequence contained a putative signal peptide and two conserved adenosine deaminase domains responsible for regulating molecular function. Fluorescence in situ hybridization localized Hdh-MLGF in the submucosa layer of digestive tubules in the digestive gland. The mRNA expression analysis indicated that Hdh-MLGF expression was restricted to the digestive gland in the adult Pacific abalone. However, Hdh-MLGF mRNA expressions were observed in all stages of embryonic and larval development, suggesting Hdh-MLGF might be involved in the Pacific abalone embryonic and larval development. This is the first study describing Hdh-MLGF and its involvement in the Pacific abalone embryonic and larval development.

In this work, a control strategy is developed for different components in DC microgrids where set points for all controllers are determined from an energy management system (EMS). The proposed EMS-based control scheme is developed for DC microgrids with solar photovoltaic (PV) systems as the primary generation units along with energy storage systems. In this work, the concept of dual energy storage systems (DESSs) is used, which includes a battery energy storage system (BESS) and supercapacitor (SC). The main feature of this DESS is to improve the dynamic performance of DC microgrids during severe transients appearing from changes in load demands as well as in the output power from solar PV units. Furthermore, the proposed EMS-based control scheme aims to enhance the lifetime of the BESS in DC microgrids with DESSs and voltage stability as compared to the same without SCs. The proposed EMS-based control strategy uses proportional-integral (PI) controllers to regulate the switching control actions for different converters within the DC microgrid based on the decision obtained from the EMS in order to achieve the desired control objectives. The performance of the proposed scheme was analyzed through simulation results in terms of improving the voltage stability, maintaining the power balance, and enhancing the lifetime of BESSs within a DC microgrid framework incorporated with the DESS. The simulations are carried out in the MATLAB/SIMULINK simulation platform and compared with a similar approach having only a single energy storage system, i.e., the BESS.

The aim of the present study was to establish the baseline data on fishery biology of Sillaginopsis panijus which is very endemic in the southern coastal waters of Bangladesh. Altogether 300 individuals of S. panijus were sampled from five catchment areas within the Ganges delta in which males represent 46% and females 54% of the total sampled population. The overall sex ratio in the populations agrees with the expected value of 1:1 in normal population. The values of allometric coefficient (b) of the LWRs indicated positive allometric growth (b > 3) in female and combined sexes, while male showed a negative allometric growth (b 0.900. The mean values of CFs for males were higher than those of females in all different length classes. The study would expedite future studies on population assessment and sustainable conservation of the fish species along the southern coastal region of Bangladesh.