Alternative Control Strategies Research Articles

Investigating novel Streptomyces bacteriophage endolysins as potential antimicrobial agents.

As antibiotic resistance has become a major global threat, the World Health Organization (WHO) has urgently called for alternative strategies for control of bacterial infections. Endolysin, a phage-encoded protein, can degrade bacterial peptidoglycan in the bacterial cell wall and disrupt bacterial growth. According to the WHO, there are only three endolysin products currently in clinical phase development. In this study we explored novel endolysins from Streptomyces phages as only a few of them have been experimentally characterized. Using several bioinformatics tools, we identified nine different combinations of functional enzymatic domain types from 250 Streptomyces bacteriophages possible endolysins. From these, three potential endolysins were selected for experimental characterization. All three showed positive results in degrading cell wall material and disrupting bacterial growth, indicating their potential as possible antimicrobial agents.

Convergence rate sliding mode control of permanent magnet synchronous motor based on expanded sliding mode observer

The aim is to address the limitations of conventional sliding mode control for PMSM, namely the problems of sliding mode oscillation, load disturbance, and poor control accuracy. An improved sliding mode control strategy for PMSM is proposed based on the novel convergence rate and extended state observer. Firstly, an integral sliding mode velocity loop controller is designed based on the novel convergence rate to solve the sliding mode vibration problem. The stability of the proposed control strategy is derived by the Lyapunov criterion. Secondly, an extended state observer capable of estimating the disturbance torque is designed for the purpose of disturbance compensation. The disturbance torque estimate is then used as a feed-forward signal for the sliding mode velocity loop controller. A fast second-order sliding mode controller is used for the current loop to avoid the potential introduction of noise and disturbances. The simulation results show that compared to alternative control strategies, the proposed control strategy enables the PMSM to respond effectively to start-up and load disturbances, significantly reduces the sliding mode jitter, and improves both the torque estimation accuracy and the system control accuracy.

Can Benzimidazole Resistance Undermine the Philippines’ Success in Controlling and Eliminating Soil-Transmitted Helminth Infections? A Mini-Review

Abstract Soil-transmitted helminth (STH) infections remain a significant global health burden, affecting over 1.5 billion people worldwide. In the Philippines, STH infections continue to be prevalent, despite ongoing control efforts. The Integrated Helminth Control Program (IHCP), whose cornerstone is mass drug administration (MDA) with benzimidazole drugs, has shown some success in reducing STH prevalence in the country. However, the persistence of infection prevalence being above the national and global targets and the potential for benzimidazole resistance have raised concerns about the long-term sustainability of current control strategies. This review examines the development of benzimidazole resistance in STH, focusing on the role of single nucleotide polymorphisms (SNPs) in the β-tubulin isotype that alter the protein’s amino acid constitution, thereby negatively affecting benzimidazole drug binding efficiency. This review discusses the epidemiology of STH infections in the Philippines, the implementation of IHCP and the potential challenges posed by benzimidazole resistance. This review highlights the need for further research to assess the occurrence of benzimidazole resistance in Philippine STH populations and to explore alternative control strategies. Understanding the mechanisms of benzimidazole resistance and developing effective countermeasures is crucial for achieving sustainable STH control and elimination in the Philippines.

Potential of Small Molecules Piperidine and Pyrrolidine Against Copper-Resistant Xanthomonas perforans, Causal Agent of Bacterial Spot of Tomato.

Bacterial spot of tomato (BST), caused by Xanthomonas perforans, is an economically important disease of tomatoes in Florida. Due to the heavy reliance on copper-based bactericides for control of BST, copper-resistant strains of X. perforans are widely distributed in Florida, leading to reduced efficacy of copper-based bactericides for disease control. There is a need for alternative chemical control strategies to effectively manage this disease in tomato production. In this study, two small molecules, piperidine and pyrrolidine, were evaluated for their efficacy against the copper-resistant X. perforans strain GEV 485 in laboratory, greenhouse, and field experiments. In in vitro experiments, piperidine and pyrrolidine at concentrations as low as 2 mg/L and 16 mg/L, respectively, significantly (P<0.001) reduced bacterial populations within 4 h of incubation compared to the untreated control, while Kocide 3000, the grower copper-based bactericide standard, at 0.9 g/L and 2.1 g/L (full label rate) did not significantly reduce bacterial populations. When tested as foliar sprays in the greenhouse, pyrrolidine at 128 mg/L significantly (P <0.001) reduced disease severity compared to the untreated control, with an equivalent efficacy to Kocide 3000 (copper hydroxide at 2.1 g/L). Kocide 3000 at 1.0 g/L, in combination with piperidine at 64 mg/L and pyrrolidine at 64 and 128 mg/L significantly improved the efficacy in disease control compared to untreated controls and Kocide 3000 at 1.0 g/L alone. In field trials, both small molecules demonstrated equivalent or superior efficacy to ManKocide (copper hydroxide + mancozeb) against X. perforans compared to the untreated control. This study demonstrated for the first time the potential of piperidine and pyrrolidine for controlling bacterial spot of tomato.

Future semiochemical control of codling moth, Cydia pomonella

Codling moth (CM), Cydia pomonella, is a significant pest of apple (Malus domestica) and other orchard crops worldwide, posing challenges due to the decrease in registered insecticides, rising resistance, and a changing climate. The pest exhibits a strong resistance capacity to both synthetic and natural insecticides, while shifting seasonal temperatures disrupt the reliability of phenology-temperature models for predicting targeted control strategies. Alternative control strategies are necessary to future-proof control of this pest. Current control methods primarily rely on chemical insecticide sprays or granulosis virus applications during egg hatching. This review focuses explicitly on semiochemical-based manipulation of CM adults and larvae for control in orchards. Topics covered include the role of semiochemicals in integrated pest management, area-wide control, mating disruption, female attractants, larval kairomones, and incorporation into monitoring and control strategies. The potential of CM repellents in a push–pull strategy is also discussed. Primary sources for identifying relevant literature included GoogleScholar and ResearchGate, with a focus on papers published since 2013 but also include relevant papers from 2003. Nine review papers and 119 papers were reviewed. The review emphasizes that effective control necessitates an area-wide approach targeting all life stages (eggs, larvae, pupae, and adults). Comprehensive monitoring is crucial for identifying CM “hot-spots” and enhancing targeted interventions. Growers must consider landscape context when designing control programs. Lastly, recommendations are provided for future research and CM management strategies. There are opportunities to explore and exploit female kairomone attractants and repellents in control strategies and modify monitoring traps to be more attractive and autonomous.

Bioefficacy of Methanolic Leaf Extracts from Coleus amboinicus and Mentha spicata against Aedes aegypti Mosquitoes

Mosquito-borne diseases (MBDs) pose significant public health challenges globally, with India and Sub-Saharan Africa accounting for the majority of cases. Aedes aegypti, a primary vector of dengue fever, thrives in an environment with inadequate water supply and poor waste management. The increasing resistance of mosquito population to chemical insecticides necessitates the exploration of alternative control strategies, such as botanical extracts. This study evaluates the adulticidal efficacy of methanolic leaf extracts of Coleus amboinicus and Mentha spicata against the adults of Ae. aegypti. Fresh leaves of both plants were collected, dried, and extracted with methanol. Phytochemical screening revealed a moderate presence of alkaloids, flavonoids, saponins, terpenoids, and glycosides in C. amboinicus, while phenols are highly prevalent, indicating significant biological activity. In contrast, M. spicata displayed a high concentration of alkaloids, flavonoids, and terpenoids, though saponins, phenols, and glycosides were less abundant. Adulticidal bioassays demonstrated that C. amboinicus achieved higher mortality rates across all concentrations compared to M. spicata. The LC50 value for C. amboinicus was 202.00 ppm, while M. spicata exhibited an LC50 of 230.00 ppm. Similarly, the LC90 values were 428.51 ppm and 457.40 ppm for C. amboinicus and M. spicata, respectively. These findings suggest that C. amboinicus has a more balanced and diverse phytochemical profile, which likely contributes to its superior adulticidal activity against Ae. aegypti. This study highlights the potential of C. amboinicus as a natural alternative for mosquito control, warranting further exploration and development for effective vector management.

Products of allelopathic plants for organic weed management: Environmentally approach

Allelopathic substances from different crops may have synergistic effects and can be applied in the mixture. In the previous research, several crop plants have been identified as phytotoxic against various weeds like sorghum, brassica, and sunflower. However, the effect of their tank mixture with each other was never studied in cotton before. Furthermore, it was not sure before this study whether the allele chemicals present in these crops viz. sorghum, sunflower and brassica can have synergistic or additive effects when applied in combination. Herbicides account for 42% of global pesticides’ use. Therefore, recent emphases have been on biological weed control measures so as to reduce dependence on synthetic herbicides and finding alternative strategies for weed control in agro ecosystems. Allelopathy is one of such strategies that can be explored for biological weed control of cropping systems. The mimosine that occurs in Leucaena has the potential to be used as a bio-herbicide in weed management. Mimosine is the main allelochemicals in Leucaena and is responsible for the strong allelopathic activity of the plant. The allelopathic effects of L. leucocephala towards several agricultural crops and forest trees have been reported. Plant seedlings of various crops possess allelopathic potential or weed-suppressing activity, including cucumber (Cucumber sativa L.), oat (Avena spp.) and rice (Oryza sativa L.). The main barley allelochemicals are the alkaloids gramine and hordenine which play a significant role in barley allelopathic potential and its defense against weeds, insects, or pathogens. In particular, barley allelopathic extracts have the ability to reduce emergence and growth of serious weeds like winter wild oat (Avena sterilis L.), hood canary grass (Phalaris paradoxa L.), black grass (Alopecurus myosuroides Huds.), great brome (Bromus diandrus Roth.), and wild mustard (Sinapis arvensis L.). This growth reduction has been mainly attributed to lipid peroxidation. Tamarindus contains allelochemicals on roots, leaves, seeds and bark , however, its allelopathic potential has not yet been compared to that of other allelopathic species such as Parthenium. Citharexylum (Citharexylum spinosum L) is equally a tree, a tropical plant with numerous usages but also know to have some allelopathic potential. Flower extracts have proved to be extremely potent to lettuce seed germination and seedlings growth and are very little known regarding its leaves phytotoxity. Consequently, the current experiment will provide additional information regarding Citharexylum leave allelopathic potential. Sunflower (Helianthus annuus L.). In Asteraceae members including sunflower, the main allelochemicals are sesquiterpenes, especially heliannuoles, sesquiterpene lactones and bisnorse squiterpenes, in addition to triterpenes and flavonoids Its allelopathic effects have been tested on both other crops and weeds, in field conditions and in vitro bioassays. In recent years, the allelopathic potential of Cynara cardunculus L., an herbaceous perennial species belonging to the Mediterranean basin, was assessed on seed germination and seedling growth of some weeds and target crops. Allelochemicals responsible for C. cardunculus allelopathy are the sesquiterpene lactones cynaropicrin, deacylcynaropicrin, 11, 13-dihydro-deacylcynaropicrin, aguerin B, grosheimin, 11,13-dihydroxy-8-deoxygrosheimin and cy-naratriol, as well as polyphenols such as caffeoylquinic and dicaffeoylquinic acids, luteolin and apigenin derivatives. Around 800 species of plants produce biologically active substances, but only a few of them are used in agricultural practice. However, in recent years, there has been an increase in interest in allelopathy due to the effective use of allelochemicals in plant protection, such as bioherbicides, bio insecticides, biofungicides and growth regulators.

Induced resistance to control postharvest stem-end rot by methyl jasmonate in mango fruit

Induced resistance is an alternative disease control strategy for postharvest fruits and vegetables. Methyl jasmonate (MeJA) is a crucial phytohormone in the defense response to biotic and abiotic stresses. The effect and relevant mechanism of MeJA on the control of postharvest disease in mango fruit remain unclear. This study investigated the effect and possible mechanism of MeJA against stem-end rot caused by Lasiodiplodia theobromae in mango fruit. The results showed that MeJA significantly inhibited the lesion expansion on mango fruit inoculated with L. theobromae. 10 μM MeJA treatment effectively induced disease resistance against L. theobromae during postharvest storage. MeJA enhanced the activities of defense-related enzymes, including phenylalanine ammonia lyase (PAL), peroxidase (POD), β-1,3-glucanase (GLU), and chitinase (CHT), increased the accumulation of endogenous jasmonic acid (JA) and salicylic acid (SA) contents, up-regulated the expressions of the related genes on JA pathway (AOS, JAR1, MYC2, and COI1) and SA pathway (ICS, and PR1), stimulated the contents of total phenolics and flavonoids, and inhibited the accumulation of malondialdehyde (MDA). Furthermore, MeJA delayed the ripening and senescence of the fruit by inhibiting the peel yellowing, flesh softening and change in soluble solids content (SSC) of mango fruit. The results indicated that the enhanced resistance of MeJA-treated mango to stem-end rot was potentially due to the activation of defense responses induced by synergistic interaction between JA and SA pathways, as well as delayed postharvest ripening. The MeJA treatment is a promising strategy to control stem-end rot of mango fruit.

Wolbachia infection in Aedes aegypti does not affect its vectorial capacity for Dirofilaria immitis.

Mosquito-borne diseases such as dengue and filariasis are a growing public health concern in endemic countries. Biological approaches, such as the trans-infection of Wolbachia pipientis in mosquitoes, are an alternative vector control strategy, especially for arthropod-borne viruses such as dengue. In the present study, the effect of Wolbachia (wMel strain) on the vectorial capacity of Aedes aegypti for Dirofilaria immitis was studied. Our results showed that Wolbachia does not affect the phenotype of mosquito survival or the prevalence, number, and molting rate of third-stage larvae in both susceptible and resistant strains of Ae. aegypti. RNA-seq analysis of Malpighian tubules at 2days post-infection with D. immitis showed the differentially expressed genes (DEGs) with and without wMel infection. No characteristic immune-related gene expression patterns were observed among the DEGs. No significant change in the amount of Wolbachia was observed in the Ae. aegypti after D. immitis infection. Our results suggest that infection of D. immitis in Ae. aegypti populations will not interfere with Wolbachia-based vector control strategies in dengue-endemic areas where cases of D. immitis are present. This study demonstrated the veterinary medical validity of a dengue control program using Wolbachia.

Intraguild Predation or Spatial Separation? The efficacy and Interactions of Two Natural Enemy Species for the Biological Control of Pear Psyllid (Cacopsylla pyri)

Pear psyllid (Cacopsylla pyri) is a persistent pest to the pear industry; with an estimated cost of £5 million per annum in the UK alone. This phloem feeding insect is resistant to a large proportion of approved pesticides, necessitating the use of alternative control strategies. Many pear growers practice integrated pest management (IPM) of pear psyllid, focusing on maximizing natural enemy populations, whilst minimizing the use of agrochemical sprays. The anthocorid Anthocoris nemoralis and the European earwig Forficula auricularia are particularly effective at controlling pear psyllid populations during the summer months. Despite the effectiveness of both natural enemies, there is a lack of understanding on whether both species should be promoted together or separately, due to the risk of intraguild predation (IGP) or interference competition. Furthermore, abiotic factors including temperature may influence both behaviors, altering activity level and niche overlap. Although IGP and interference competition have been documented between multiple species of natural enemies neither have been studied between these two specific predators. Using microcosm experiments, olfactometer assays and survival analyses this study demonstrated whether A. nemoralis and F. auricularia can be used in synchrony to control pear psyllid. Results indicated that IGP is present; F. auricularia will consume A. nemoralis when predators are not spatially separate and in absence of psyllid prey. There was no evidence for interference competition, although both predators consumed more prey at higher temperatures. This confirms that pear growers can encourage both predators for the control of pear psyllid without losing predation efficacy.

Phytocytokine StPep1-Secreting Bacteria Suppress Potato Powdery Scab Disease.

Powdery scab is an important potato disease caused by the soilborne pathogen Spongospora subterranea f. sp. subterranea. Currently, reliable chemical control and resistant cultivars for powdery scab are unavailable. As an alternative control strategy, we propose a novel approach involving the effective delivery of a phytocytokine to plant roots by the rhizobacterium Bacillus subtilis. The modified strain is designed to secrete the plant elicitor peptide StPep1. In our experiments employing a hairy root system, we observed a significant reduction in powdery scab pathogen infection when we directly applied the StPep1 peptide. Furthermore, our pot assay, which involved pretreating potato roots with StPep1-secreting B. subtilis, demonstrated a substantial decrease in disease symptoms, including reduced root galling and fewer tuber lesions. These findings underscore the potential of engineered bacteria as a promising strategy for safeguarding plants against powdery scab.

Intelligent integration of ANN and H‐infinity control for optimal enhanced performance of a wind generation unit linked to a power system

AbstractThis article focuses on utilizing intelligent H‐∞ synthesis to create a controller for a wind generation system linked to a power system via a static VAR compensator. The purpose of the control approach is twofold: firstly, to enhance the system's dynamic reactions to turbulent wind variations, and secondly, to elevate the quality of power generation. To achieve optimal control of the system, an Artificial Neural Network (ANN) is combined with the H‐∞ control method. This integration leverages the strengths of both ANN, which excels in modeling and optimization, and H‐∞, which prioritizes robustness to enhance dynamic performance. The resultant control strategy, connecting ANN and H‐∞, demonstrates the capability to deliver superior performance, precise tracking, and minimal overshooting. This approach is adaptive to changing control signals and exhibits robust characteristics, effectively managing uncertainties and disturbances. Through a simulation study, the effectiveness of this presented technique is showcased in enhancing the dynamic response of the system when compared to alternative control strategies.

Interventions based on alternative and sustainable strategies for postharvest control of anthracnose and maintain quality in tropical fruits.

Colletotrichum spp. is a phytopathogen causing anthracnose in a variety of tropical fruits. Strategies used to control postharvest diseases in tropical fruits typically rely on the use of synthetic fungicides, which have stimulated the emergence of resistant pathogens. Safer alternative strategies to control anthracnose in tropical fruits have been described in the literature. This review presents and discusses the main innovative interventions concerning the application of sustainable alternative strategies in the postharvest control of pathogenic Colletotrichum species in tropical fruits, with a particular emphasis on the studies published in the last 5 years. The available studies have shown the use of various methods, including physical barriers, natural antimicrobials, and biological control with antagonistic microorganisms, to reduce anthracnose lesion severity and incidence in tropical fruits. The available literature showed high inhibitory activity in vitro, reduced anthracnose incidence and lesion diameter, and total disease inhibition in tropical fruits. Most studies focused on the inhibition of Colletotrichum gloeosporioides on avocado, papaya, and mango, as well as of Colletotrichum musae on banana; however, the inhibition of other Colletotrichum species was also demonstrated. The application of emerging sustainable alternative methods, including natural antimicrobial substances, also stimulated the induction of defense systems in tropical fruits, including enzymatic activity, such as polyphenol oxidase, peroxidase, and phenylalanine ammonia-lyase. The retrieved data helped to understand the current state of the research field and reveal new perspectives on developing efficient and sustainable intervention strategies to control pathogenic Colletotrichum species and anthracnose development in tropical fruits.

An approach to Molten Salt Reactor operation and control and its application to the ARAMIS actinide burner

Molten salt reactors (MSRs) are Generation IV nuclear reactor concepts gaining significant research interest worldwide. The present work proposes a methodology for the definition and optimization of the MSR operating conditions and control strategy. The proposed methodology employs a novel 0D steady-state model, the multi-physics system-scale MOSAICS (MOlten SAlt Incompressible Calculation System) model and a Global Sensitivity Analysis (GSA) method based on Hilbert-Schmidt Independence Criterion indices. The methodology was then applied to the ARAMIS (Advanced Reactor for Actinides Management in Salt) fast-spectrum chloride-salt burner reactor. Two alternative control strategies are proposed in order to achieve target margins to the salt freezing and structure material limit temperatures during normal operation, plus a 20 % power variation per minute load-following objective. The performance of the control strategies was assessed through comparison with the natural behavior during a load-increasing transient, as well as during Unprotected Transient Over-Power (UTOP) and Station Blackout (SBO) accidents. Controlled load variation transients are observed to reduce overall temperature variation rates throughout the salt circuits, while the inclusion of a variable fuel flow from the reactor commands can further limit these fluctuations. However, the selected operating conditions exhibited insufficient margins to freezing or the materials limit temperature under unprotected accident conditions. GSA enabled the derivation of correlations to characterize the dynamic response of MSRs to the accidents. Based on the observed reactor response to the various transients, potential modifications to the ARAMIS design and control strategies are proposed.

Microbiome and Microbial Pure Culture Study Reveal Commensal Microorganisms Alleviate Salmonella enterica Serovar Pullorum Infection in Chickens.

Pullorum disease, an intestinal disease in chickens caused by Salmonella enterica serovar pullorum (S. Pullorum), is a significant threat to the poultry industry and results in substantial economic losses. The bacteria's transmission, both vertical and horizontal, makes it difficult to completely eliminate it. Control strategies for pullorum disease primarily involve stringent eradication programs that cull infected birds and employ antibiotics for treatment. However, eradication programs are costly, and antibiotic use is restricted. Therefore, developing alternative control strategies is essential. Increasingly, studies are focusing on modulating the gut microbiota to control intestinal diseases. Modulating the chicken gut microbiota may offer a novel strategy for preventing and controlling pullorum disease in poultry. However, the impact of S. Pullorum on the chicken gut microbiota has not been well established, prompting our exploration of the relationship between S. Pullorum and the chicken gut microbiota in this study. In this study, we initially analyzed the dynamic distribution of the gut microbiota in chickens infected with S. Pullorum. Alpha diversity analysis revealed a decrease in observed OTUs and the Shannon diversity index in the infected group, suggesting a reduction in the richness of the chicken gut microbiota due to S. Pullorum infection. Principal coordinate analysis (PCoA) showed distinct clusters between the gut microbiota of infected and uninfected groups, indicating S. Pullorum infection changed the chicken gut microbiota structure. Specifically, S. Pullorum infection enriched the relative abundance of the genera Escherichia-Shigella (65% in infected vs. 40.6% in uninfected groups) and Enterococcus (10.8% vs. 3.7%) while reducing the abundance of Lactobacillus (9.9% vs. 32%) in the chicken microbiota. Additionally, based on the observed changes in the chicken gut microbiota, we isolated microorganisms, including Bifidobacterium pseudolongum, Streptococcus equi and Lacticaseibacillus paracasei (L. paracasei), which were decreased by S. Pullorum infection. Notably, the L. paracasei Lp02 strain was found to effectively inhibit S. Pullorum proliferation in vitro and alleviate its infection in vivo. We found that S. Pullorum infection reduced the richness of the chicken gut microbiota and enriched the relative abundance of the genera Escherichia-Shigella and Enterococcus while decreasing the abundance of the anaerobic genus Lactobacillus. Furthermore, microbiota analysis enabled the isolation of several antimicrobial microorganisms from healthy chicken feces, with a L. paracasei strain notably inhibiting S. Pullorum proliferation in vitro and alleviating its infection in vivo. Overall, this research enhances our understanding of the interaction between gut microbiota and pathogen infection, as well as offers new perspectives and strategies for modulating the chicken gut microbiota to control pullorum disease.

RNAi targeting Nav and CPR via leaf delivery reduces adult emergence and increases the susceptibility to λ-cyholthin in Tuta absoluta (Meyrick)

The tomato leafminer, Tuta absoluta (Meyrick), one of the most economically destructive pests of tomato, causes severe yields losses of tomato production globally. Rapid evolution of insecticide resistance requires the development of alternative control strategy for this pest. RNA interference (RNAi) represents a promising, innovative control strategy against key agricultural insect pests, which has recently been licensed for Colorado Potato Beetle control. Here two essential genes, voltage-gated sodium channel (Nav) and NADPH-cytochrome P450 reductase (CPR) were evaluated as targets for RNAi using an ex vivo tomato leaf delivery system. Developmental stage-dependent expression profiles showed TaNav was most abundant in adult stages, whereas TaCPR was highly expressed in larval and adult stages. T. absoluta larvae feeding on tomato leaflets treated with dsRNA targeting TaNav and TaCPR showed significant knockdown of gene expression, leading to reduction in adult emergence. Additionally, tomato leaves treated with dsRNA targeting these two genes were significantly less damaged by larval feeding and mining. Furthermore, bioassay with LC30 doses of λ-cyholthin showed that silencing TaNav and TaCPR increased T. absoluta mortality about 32.2 and 17.4%, respectively, thus indicating that RNAi targeting TaNav and TaCPR could increase the susceptibility to λ-cyholthin in T. absoluta. This study demonstrates the potential of using RNAi targeting key genes, like TaNav and TaCPR, as an alternative technology for the control of this most destructive tomato pests in the future.

The alleviative effect of Bacillus subtilis-supplemented diet against Vibrio cholerae infection in Nile tilapia (Oreochromis niloticus).

Bacterial illness causes detrimental impacts on fish health and survival and finally economic losses for the aquaculture industry. Antibiotic medication causes microbial resistance, so alternative control strategies should be applied. In this work, we investigated the probiotic-medicated diet as an alternative control approach for antibiotics in treating Vibrio cholerae infection in Nile tilapia (Oreochromis niloticus). One hundred eighty fish (50 ± 2.5g Mean ± SD) were allocated into six groups in glass aquariums (96L) in triplicate for 10 days. Groups 1 (G1), G2, and G 3 were intraperitoneally (IP) injected with 0.5 mL sterilized tryptic soy broth and fed on a basal diet, basal diet contained B. subtilis (BS) (1 × 10 5 CFU/ kg-1 diet), and basal diet contained trimethoprim-sulfamethoxazole (TMP-SMX) (1.5g/kg-1 diet), respectively. Additionally, G4, G5, and G6 were IP challenged with 0.5 mL of V. cholerae (1.5 × 107 CFU) and received the same feeding regime as G 1 to 3, respectively. The results exhibited that the V. cholera-infected fish exhibited skin hemorrhage, fin rot, and the lowest survival (63.33%). Additionally, lowered immune-antioxidant biomarkers (white blood cells count, serum bactericidal activity, phagocytic activity, phagocytic index, and lysozymes) with higher lipid peroxidation marker (malondialdehyde) were consequences of V. cholerae infection. Noteworthy, fish-fed therapeutic diets fortified with BS and TMP-SMX showed a substantial amelioration in the clinical signs and survival. The BS diet significantly improved (P < 0.05) the immune-antioxidant indices of the infected fish compared to the TMP-SMX diet. The current findings supported the use of a BS-enriched diet as an eco-friendly approach for the control of V. cholerae in O. niloticus.

Optimized sliding mode control for improved frequency response in an Islanded microgrid system

ABSTRACT This paper presents an enhanced Sliding Mode Control (SMC) approach in an Islanded Microgrid (IMG) system for regulating its frequency. The system encounters unpredictable disturbances arising from internal and external factors such as fluctuations in generation and demand, parameter variations, time delay, and many more. These factors challenge the frequency control during load fluctuations. To overcome these challenges, an Integral Sliding Mode-Load Frequency Control (ISM-LFC) as a robust control strategy employing integral sliding surface is proposed to regulate the system frequency. Particle Swarm Optimization (PSO) technique is used for optimal performance of ISM-LFC by meticulously determining the control variable parameters. A Simulink model of the IMG system in MATLAB is developed for conducting a comprehensive simulation analysis under diverse operational scenarios. The result outcomes affirm the effectiveness of the proposed controller using Integral sliding surface and modified saturation function-based control law for improved frequency response. Furthermore, comparative analysis with other alternative control strategies validates the improved performance of optimised ISM-LFC for frequency stabilisation.

Study on the alleviative effect of Lactobacillus plantarum on Eimeria falciformis infection.

Coccidia of the genus Eimeria are specialized intracellular parasitic protozoa that cause severe coccidiosis when they infect their hosts. Animals infected with Eimeria develop clinical symptoms, such as anorexia, diarrhea, and hematochezia, which can even cause death. Although the current preferred regimen for the treatment of coccidiosis is antibiotics, this treatment strategy is limited by the ban on antibiotics and the growing problem of drug resistance. Therefore, the exploration of alternative methods for controlling coccidiosis has attracted much attention. Lactobacillus plantarum has been shown to have many beneficial effects. In this study, L. plantarum M2 was used as a research object to investigate the effect of L. plantarum on intestinal inflammation induced by infection with Eimeria falciformis in mice by detecting indicators, such as oocyst output, serum cytokines, and the intestinal microbiota. Compared with that in the infection group, the percent weight loss of the mice that were administered with L. plantarum M2 was significantly reduced (P < 0.05). Supplemented L. plantarum M2 and probiotics combined with diclazuril can reduce the total oocyst output significantly (P < 0.05, P < 0.001). L. plantarum M2 had outstanding performance in maintaining intestinal barrier function, and the levels of the mucin MUC1 and the tight junction protein E-cadherin were significantly elevated (P < 0.01, P < 0.05). Studies have shown that probiotic supplementation can alleviate adverse reactions after infection and significantly improve intestinal barrier function. In addition, probiotics combined with diclazuril could optimize the partial efficacy of diclazuril, which not only enhanced the effect of antibiotics but also alleviated their adverse effects. This study expands the application of probiotics, provides new ideas for alternative strategies for coccidia control, and suggests a basis for related research on lactobacilli antagonizing intracellular pathogen infection.IMPORTANCECoccidia of the genus Eimeria are specialized intracellular parasitic protozoa, and the current preferred regimen for the treatment of coccidiosis is antibiotics. However, due to antibiotic bans and drug resistance, the exploration of alternative methods for controlling coccidiosis has attracted much attention. In this work, we focused on Lactobacillus plantarum M2 and found that probiotic supplementation can alleviate adverse reactions after infection and improve intestinal barrier function. This study proposes the possibility of using lactic acid bacteria to control coccidiosis, and its potential mechanism needs further exploration.

Current profile of phenotypic pyrethroid resistance in Rhipicephalus microplus (Acari: Ixodidae) populations sampled from Marathwada region of Maharashtra state, India.

This study examined the pattern of resistance to widely applied synthetic pyrethroids, i.e., cypermethrin and deltamethrin, against larvae of Rhipicephalus microplus ticks sampled from Marathwada region in Maharashtra, India. The study also examined the role of α- and β-esterases and glutathione-S-transferase (GST) in resistance development. All eight R. microplus isolates tested were resistant to deltamethrin (RL IV), having RR50 values from 6.88 to 131.26. LPT analysis exhibited the resistance level II deltamethrin resistance in Beed and Hingoli, III in Dharashiv, and IV in Sambhajinagar, Parbhani, Latur, Jalna, and Nanded isolates. The LIT analysis showed that Dharashiv field isolates had the lowest LC50 value of 229.09ppm against cypermethrin, while Sambhajinagar field isolates had the highest at 489.78ppm. The RR50 ranged from 1145.45 to 2448.9. Seven isolates were level I resistant to cypermethrin while the Jalna isolate was level II resistant. In larvae treated with deltamethrin and cypermethrin, the activity of α- and β-esterase enzymes increased significantly compared to control groups. The enzyme ratios in treated larvae ranged from 0.7533 to 1.7023 for α-esterase and 0.7434 to 3.2054 for β-esterase. The Hingoli isolate treated with cypermethrin exhibited the highest α-esterase activity (903.261), whereas Sambhajinagar isolate had the highest GST enzyme ratio (2.8224) after deltamethrin exposure. When exposed to cypermethrin, the Hingoli isolate showed the highest GST enzyme ratio, 2.0832. The present study provides the current resistance status in tick populations from Marathwada region indicating deltamethrin and cypermethrin to be ineffective for tick control. The results also suggest that SP compounds should be regulated in this region and alternative control strategies should be introduced.