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Tang, Yajiao, Junkai Ji, Yulin Zhu, Shangce Gao, Zheng Tang, and Yuki Todo. "A Differential Evolution-Oriented Pruning Neural Network Model for Bankruptcy Prediction." Complexity 2019 (August 4, 2019): 1–21. http://dx.doi.org/10.1155/2019/8682124.
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Financial bankruptcy prediction is crucial for financial institutions in assessing the financial health of companies and individuals. Such work is necessary for financial institutions to establish effective prediction models to make appropriate lending decisions. In recent decades, various bankruptcy prediction models have been developed for academics and practitioners to predict the likelihood that a loan customer will go bankrupt. Among them, Artificial Neural Networks (ANNs) have been widely and effectively applied in bankruptcy prediction. Inspired by the mechanism of biological neurons, we propose an evolutionary pruning neural network (EPNN) model to conduct financial bankruptcy analysis. The EPNN possesses a dynamic dendritic structure that is trained by a global optimization learning algorithm: the Adaptive Differential Evolution algorithm with Optional External Archive (JADE). The EPNN can reduce the computational complexity by removing the superfluous and ineffective synapses and dendrites in the structure and is simultaneously able to achieve a competitive classification accuracy. After simplifying the structure, the EPNN can be entirely replaced by a logic circuit containing the comparators and the logic NOT, AND, and OR gates. This mechanism makes it feasible to apply the EPNN to bankruptcy analysis in hardware implementations. To verify the effectiveness of the EPNN, we adopt two benchmark datasets in our experiments. The experimental results reveal that the EPNN outperforms the Multilayer Perceptron (MLP) model and our previously developed preliminary pruning neural network (PNN) model in terms of accuracy, convergence speed, and Area Under the Receiver Operating Characteristics (ROC) curve (AUC). In addition, the EPNN also provides competitive and satisfactory classification performances in contrast with other commonly used classification methods.
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Sailaja, Rayi, Chiramdasu Rupa, and Ardhani Chakravarthy. "EPNN Based High Secure Intensive Hidden Digital Watermark Application in Telemedicine." Advances in Modelling and Analysis A 56, no. 1 (2019): 21–25. http://dx.doi.org/10.18280/ama_a.560104.
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Wang, Ying, Christopher E. Pedigo, Kazunori Inoue, et al. "Murine Epsins Play an Integral Role in Podocyte Function." Journal of the American Society of Nephrology 31, no. 12 (2020): 2870–86. http://dx.doi.org/10.1681/asn.2020050691.
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BackgroundEpsins, a family of evolutionarily conserved membrane proteins, play an essential role in endocytosis and signaling in podocytes.MethodsPodocyte-specific Epn1, Epn2, Epn3 triple-knockout mice were generated to examine downstream regulation of serum response factor (SRF) by cell division control protein 42 homolog (Cdc42).ResultsPodocyte-specific loss of epsins resulted in increased albuminuria and foot process effacement. Primary podocytes isolated from these knockout mice exhibited abnormalities in cell adhesion and spreading, which may be attributed to reduced activation of cell division control protein Cdc42 and SRF, resulting in diminished β1 integrin expression. In addition, podocyte-specific loss of Srf resulted in severe albuminuria and foot process effacement, and defects in cell adhesion and spreading, along with decreased β1 integrin expression.ConclusionsEpsins play an indispensable role in maintaining properly functioning podocytes through the regulation of Cdc42 and SRF-dependent β1 integrin expression.
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Haji Allahverdipour, Hana, and Javad Karimi. "Nematodes Versus White Grubs: Long But Challenging Association." Annals of the Entomological Society of America 114, no. 4 (2021): 448–58. http://dx.doi.org/10.1093/aesa/saab016.
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Abstract Soil as a shared habitat of white grubs and entomopathogenic nematodes (EPNs) is a double-edged sword from the biological control point of view. Soil encompasses a diverse array of EPNs that could be exploited in grub microbial control; on the other hand, soil promotes the natural resistance of grubs to EPNs via the battle between both sides within the soil matrix. White grubs and EPNs have been armed in this battle by a multifaceted range of mechanisms, namely grub structural and physiological barriers, antagonism of grub gut microbiota toward the nematode bacterial symbionts, EPN excreted/secreted proteins, surface coat proteins, ascaroside pheromones produced by EPNs, and evolution of EPN resistance to herbivore self-defense. From the evolutionary point of view, EPN–grub interactions, the most advanced (sophisticated) association among others, could have evolved from other types of associations. Entomophilic nematode (e.g., Pristionchus spp.), the cognate bacterium and scarab associations along with the formation of dauer juveniles, are proof of preadaptation to entomopathogeny in a continual evolution. Here, we delve into the salient features of each component of EPN-white grub–host plant tripartite interactions as well as hints to improved exploitation of EPNs for grub management. Also, evolutionary associations between nematodes and scarabs will be reviewed, in short.
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Treviño-Cueto, Diego, Sergei A. Subbotin, and Sergio R. Sanchez-Peña. "Larvicidal Activity of Entomopathogenic Nematodes Isolated from Mexico against Aedes aegypti (Diptera: Culicidae)." Journal of Entomological Science 56, no. 1 (2021): 12–23. http://dx.doi.org/10.18474/0749-8004-56.1.12.
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Abstract Entomopathogenic nematodes (EPNs) are widely used agents of biological control, mainly targeting soil-inhabiting insect pests. Reports indicate that these terrestrial EPNs are also able to infect the aquatic larvae of mosquitoes. We isolated EPN strains (Heterorhabditis bacteriophora Poinar and Steinernema carpocapsae [Weiser]) from local soils at Saltillo, Coahuila state, Mexico. EPNs from these strains were produced in the laboratory in yellow mealworm (Tenebrio molitor L.) larvae, and their pathogenicity as infective juveniles (IJs) was tested against larvae of the yellow fever mosquito Aedes aegypti (L.) Third- and fourth-instar mosquito larvae were exposed to four concentrations of IJs (25, 50, 100, and 200 IJ/larva) of five strains of local EPNs in laboratory assays. All strains of EPN caused lethal infections in larvae (3–100%); in particular, strain M5 of S. carpocapsae caused 100% mortality at the 200 IJ/larva concentration, with a median lethal concentration (LC50) of 42 IJ/larva (LC90 = 91 IJ/larva). Strain M18 of H. bacteriophora caused 73% mortality at 200 IJ/larva, with an LC50 = 72 and LC90 = 319 IJ/larva. IJs were produced by all strains in mosquito larvae, with a range of 66–239 IJ/mosquito larva (inoculated at 100 IJ/larva) across strains, suggesting that horizontal transmission might occur in the field. This represents the first report of native EPN strains from Mexico exhibiting pathogenicity against mosquito larvae. Native EPN strains should be further evaluated as potential biological control agents in mosquito management.
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Leal, Luís Carlos de Souza Rodrigues, Caio Márcio de Oliveira Monteiro, Alessandra Ésther de Mendonça, Vânia Rita Elias Pinheiro Bittencourt, and Avelino José Bittencourt. "Potential of entomopathogenic nematodes of the genus Heterorhabditis for the control of Stomoxys calcitrans (Diptera: Muscidae)." Revista Brasileira de Parasitologia Veterinária 26, no. 4 (2017): 451–56. http://dx.doi.org/10.1590/s1984-29612017065.
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Abstract The present study verified the pathogenic potential of entomopathogenic nematodes (EPNs) of the genus Heterorhabditis (Heterorhabditis bacteriophora, isolate HP88 and Heterorhabditis baujardi isolate LPP7) to immature stages of Stomoxys calcitrans in the laboratory. All EPN concentrations of the H. bacteriophora HP88 strain caused mean larval mortality greater than 90% after four days. Higher concentrations of the H. baujardi LPP7 isolate (≥50 EPNs/larva) eliminated more than 70% of larvae after six days with the concentration 200 EPNs/larva reaching mortality levels of 93.3%. The larval mortality at all concentrations of EPNs (25, 50, 100, 150, and 200 EPNs/larva) for both strains was significant (p<0.05) when compared to the respective control groups. Concentrations of H. bacteriophora HP88 yielded an LC50 of 0.36 EPN/larva and LC90 of 29.1; while H. baujardi LPP7 yielded an LC50 of 39.85 and LC90 of 239.18. H. bacteriophora HP88 provided greater inhibition of the emergence of adults when compared to the response obtained with H. baujardi LPP7. EPNs did not cause considerable mortality when applied directly to pupae. The set of observed results suggests that the EPNs of the genus Heterorhabditis, isolates HP88 and LPP7, are a promising alternative in the control of the stable fly.
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Abd-Elgawad, Mahfouz M. M. "Optimizing Sampling and Extraction Methods for Plant-Parasitic and Entomopathogenic Nematodes." Plants 10, no. 4 (2021): 629. http://dx.doi.org/10.3390/plants10040629.
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Plant-parasitic and entomopathogenic nematodes (PPNs and EPNs) are key groups in crop production systems. This study aims at optimizing nematode sampling and extraction methods to benefit integrated pest management (IPM) through (a) management of PPNs and (b) use of EPNs. The impacts of these methods on PPNs and EPNs to achieve cost-effective and efficient IPM programs are presented. The common misuses of sampling and extraction methods are discussed. Professionals engaged in IPM should consider sampling the reliability level in the light of the intended goal, location, crop value, susceptibility, nematode species, and available funds. Logical sampling methodology should be expanded to integrate various factors that can recover extra EPN isolates with differential pathogenicity. It should seek for the best EPN-host matching. Merits of repeated baiting for EPN extraction from soil and sieving for PPN recovery from suspensions are presented. Their extraction values may be modelled to quantify the efficiency of nematode separation. The use of proper indices of dispersion to enhance the biocontrol potential of EPNs or save costs in nematicidal applications is ideally compatible with IPM programs. Selecting an extraction method may sometimes require further tests to find the best extraction method of the existing fauna and/or flora. Cons and pros of modern sampling and extraction techniques are highlighted.
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Kin, Kassandra, Tiffany Baiocchi, and Adler R. Dillman. "Dispersal and Repulsion of Entomopathogenic Nematodes to Prenol." Biology 8, no. 3 (2019): 58. http://dx.doi.org/10.3390/biology8030058.
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Chemosensory cues are crucial for entomopathogenic nematodes (EPNs)—a guild of insect-killing parasitic nematodes that are used as biological control agents against a variety of agricultural pests. Dispersal is an essential element of the EPN life cycle in which newly developed infective juveniles (IJs) emerge and migrate away from a resource-depleted insect cadaver in order to search for new hosts. Emergence and dispersal are complex processes that involve biotic and abiotic factors, however, the elements that result in EPN dispersal behaviors have not been well-studied. Prenol is a simple isoprenoid and a natural alcohol found in association with EPN-infected, resource-depleted insect cadavers, and this odorant has been speculated to play a role in dispersal behavior in EPNs. This hypothesis was tested by evaluating the behavioral responses of five different species of EPNs to prenol both as a distal-chemotactic cue and as a dispersal cue. The results indicate that prenol acted as a repulsive agent for all five species tested, while only two species responded to prenol as a dispersal cue.
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Maass, Kendra K., Mieke Roosen, Julia Benzel, et al. "EPEN-44. EXTRACELLULAR VESICLES OF SUPRATENTORIAL EPENDYMOMA RELA MEDIATE INTERACTIONS WITH CELLS OF THE TUMOR MICROENVIRONMENT." Neuro-Oncology 22, Supplement_3 (2020): iii316—iii317. http://dx.doi.org/10.1093/neuonc/noaa222.178.
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Abstract Ependymal tumors (EPNs) account for ~10% of all pediatric brain tumors. Supratentorial EPN characterized by RELA fusions (ST-EPN-RELA) and posterior fossa EPN group A (PF-EPN-A) form the two most frequent molecular groups, both of which are associated with poor prognosis and for which only limited therapeutic options are available. Since pediatric EPNs have a relatively low mutational burden, identification and characterization of tumor-associated pathways and molecular processes is of critical importance to inform potential therapeutic targets. Previous transcriptional studies implicated aberrant vesicular pathways in ST-EPN-RELA, prompting further investigation into their putative role in EPN pathogenesis. To this aim, we isolated extracellular vesicles (EVs) of ST-EPN-RELA patient derived cell lines and performed protein mass spectrometry. The specific ST-EPN-RELA EV protein content resembles the parental cells as well as primary tumors. Promising candidates to be transferred by ST-EPN-RELA EVs but not control EVs were associated with unfolded protein response and endoplasmic reticulum stress. When uptaken by recipient cells of the tumor microenvironment, brain endothelial cells or microglia, ST-EPN-RELA EVs induced proliferation and had a chemoattractant effect towards the tumor. ST-EPN-RELA EVs stimulated angiogenesis of brain endothelial cells potentially by the transfer of ER stress proteins. Uptake of ST-EPN-RELA EVs by microglia changed their activation status indicating a tumor promoting function through EV transfer. Therefore, we hypothesize that vesicular pathways play an important role in the pathogenesis of pediatric ST-EPN-RELAs and that an improved understanding may promote new therapeutic opportunities.
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Peña, Jennifer M., Mayra A. Carrillo, and Elissa A. Hallem. "Variation in the Susceptibility of Drosophila to Different Entomopathogenic Nematodes." Infection and Immunity 83, no. 3 (2015): 1130–38. http://dx.doi.org/10.1128/iai.02740-14.
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Entomopathogenic nematodes (EPNs) in the generaHeterorhabditisandSteinernemaare lethal parasites of insects that are of interest as models for understanding parasite-host interactions and as biocontrol agents for insect pests. EPNs harbor a bacterial endosymbiont in their gut that assists in insect killing. EPNs are capable of infecting and killing a wide range of insects, yet how the nematodes and their bacterial endosymbionts interact with the insect immune system is poorly understood. Here, we develop a versatile model system for understanding the insect immune response to parasitic nematode infection that consists of seven species of EPNs as model parasites and five species ofDrosophilafruit flies as model hosts. We show that the EPNSteinernema carpocapsae, which is widely used for insect control, is capable of infecting and killingD. melanogasterlarvae.S. carpocapsaeis associated with the bacteriumXenorhabdus nematophila, and we show thatX. nematophilainduces expression of a subset of antimicrobial peptide genes and suppresses the melanization response to the nematode. We further show that EPNs vary in their virulence towardD. melanogasterand thatDrosophilaspecies vary in their susceptibilities to EPN infection. Differences in virulence among different EPN-host combinations result from differences in both rates of infection and rates of postinfection survival. Our results establish a powerful model system for understanding mechanisms of host-parasite interactions and the insect immune response to parasitic nematode infection.
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Heriberto, Cruz-Martínez, Ruiz-Vega Jaime, Matadamas-Ortíz Pastor T, Cortés-Martínez Carlos I, and Rosas-Diaz Jesusita. "Formulation of entomopathogenic nematodes for crop pest control – a review." Plant Protection Science 53, No. 1 (2017): 15–24. http://dx.doi.org/10.17221/35/2016-pps.
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The different materials and methods used to develop biopesticides with entomopathogenic nematodes (EPNs) still limit the quality of the final product, reducing field efficacy and complicating application strategies. Therefore, the objective of this review is to identify priority areas to improve the EPN formulation process based on the scientific and technological research developed so far. The results show great progress in the EPN survival time, from 7 days to 180 days, through two types of formulations: water dispersible granules and calcium alginate capsules. Also, EPNs formulated and applied as insect cadavers showed higher efficacy for the pest control than the EPNs applied in an aqueous solution. We consider that the priority areas of research are: automated massive formulation and exploration of new additives with better properties that may lead to increase the infectivity in the field. It is concluded that the study of these aspects requires a systemic approach with greater involvement of the invertebrate physiology and systems modelling disciplines.
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Theopold, Ulrich, Alexis Dziedziech, and Pavel Hyrsl. "Special Issue: Insects, Nematodes, and Their Symbiotic Bacteria." Insects 11, no. 9 (2020): 577. http://dx.doi.org/10.3390/insects11090577.
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This special issue contains articles that add to the ever-expanding toolbox of insect pathogenic nematodes (entomopathogenic nematodes; EPNs) as well articles that provide new insights into the mutualistic interaction between EPNs and their hosts. The study of natural infection models such as EPNs allows detailed insight into micro- and macro-evolutionary dynamics of innate immune reactions, including known but also emerging branches of innate immunity. Additional new insights into the kinetics of EPN infections are gained by increased spatiotemporal resolution of advanced transcriptome studies and live imaging.
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Valadas, V., P. Vieira, S. Oliveira, and M. Mota. "First report of the genus Heterorhabditis (Nematoda: Heterorhabditidae) from continental Portugal." Helminthologia 46, no. 1 (2009): 45–48. http://dx.doi.org/10.2478/s11687-009-0009-8.
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AbstractUntil recently, the only entomopathogenic nematode (EPN) species reported from continental Portugal, was of the genus Steinernema. Following a national survey of EPNs in continental Portugal, several natural and managed habitats have been surveyed in the southern part of the country. From 57 soil samples collected using the Galleria mellonella trapping method, three samples yielded EPN. Morphological characterization and sequence analysis of the ITS regions of ribosomal DNA allowed the identification of EPN isolates as Heterorhabditis bacteriophora, representing the first report of this genus for continental Portugal.
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Zheng, Tuyu, David R. Ghasemi, Konstantin Okonechnikov, et al. "EPEN-18. CROSS-SPECIES GENOMICS IDENTIFIES GLI2 AS AN ONCOGENE OF C11orf95 FUSION-POSITIVE SUPRATENTORIAL EPENDYMOMA." Neuro-Oncology 22, Supplement_3 (2020): iii311. http://dx.doi.org/10.1093/neuonc/noaa222.156.
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Abstract The majority of supratentorial ependymomas (ST-EPN) are driven by fusions between RELA and a zinc finger containing gene, C11orf95. Apart from fusions to the Hippo effector YAP1, which affects a small group of infant patients, the oncogenic mechanism of remaining ST-EPNs is unclear. Aiming at refining the molecular classification of ST-EPNs, we analyzed methylation profiles, RNA and DNA sequencing results as well as clinical data in a cohort of 617 ST-EPNs. Unsupervised clustering analysis of DNA methylation data revealed four distinct clusters that formed in addition to the known molecular groups ST-EPN-RELA and –YAP1. Tumors within these additional clusters were characterized by fusions of C11orf95 to numerous fusion partners different from RELA, e.g. MAML2, MAML3, NCOA2 and SS18, suggesting a general role of C11orf95 in tumorigenesis of ST-EPN. Transforming capacity of newly identified fusion genes was validated using an electroporation-based in vivo gene transfer technology. All fusion genes were sufficient to drive malignant transformation in the cerebral cortex of mice and resulting tumors faithfully recapitulated molecular characteristics of their human counterparts. We found that both, the partner gene and the zinc finger DNA binding domain of C11orf95, were essential to exert tumorigenesis. When exploring genes commonly upregulated in C11orf95 fusion-expressing tumors of human and murine origin, the Sonic Hedgehog effector gene Gli2 was identified as a promising downstream target. Subsequent co-expression of C11orf95:RELA and a dominant negative form of Gli2 indeed hampered tumorigenesis. We thus propose GLI2 as a potential therapeutic downstream target of C11orf95 fusion-dependent oncogenic signaling in ST-EPN.
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Alonso, Valentina, Shyon Nasrolahi, and Adler Dillman. "Host-Specific Activation of Entomopathogenic Nematode Infective Juveniles." Insects 9, no. 2 (2018): 59. http://dx.doi.org/10.3390/insects9020059.
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Entomopathogenic nematodes (EPNs) are potent insect parasites and have been used for pest control in agriculture. Despite the complexity of the EPN infection process, hosts are typically killed within 5 days of initial infection. When free-living infective juveniles (IJs) infect a host, they release their bacterial symbiont, secrete toxic products, and undergo notable morphological changes. Collectively, this process is referred to as “activation” and represents the point in a nematode’s life cycle when it becomes actively parasitic. The effect of different host tissues and IJ age on activation, and how activation itself is related to virulence, are not well understood. Here, we employed a recently developed bioassay, which quantifies IJ activation, as a tool to address these matters. Appreciating that activation is a key part of the EPN infection process, we hypothesized that activation would positively correlate to virulence. Using the EPNs Steinernema carpocapsae and S. feltiae we found that EPN activation is host-specific and influenced by infective juvenile age. Additionally, our data suggest that activation has a context-dependent influence on virulence and could be predictive of virulence in some cases such as when IJ activation is especially low.
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Al-Zaidawi, Jawad B., Javad Karimi, and Esmat Mahdikhani Moghadam. "Entomopathogenic Nematodes as Potential Biological Control Agents of Subterranean Termite, Microcerotermes diversus (Blattodea: Termitidae) in Iraq." Environmental Entomology 49, no. 2 (2020): 412–21. http://dx.doi.org/10.1093/ee/nvaa014.
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Abstract The infectivity of three species of entomopathogenic nematodes (EPNs) such as Steinernema carpocapsae Weiser (Rhabditida: Steinernematidae), Heterorhabditis bacteriophora Poinar (Rhabditida: Heterorhabditidae), and H. bacteriophora Poinar (IRQ.1 strain) were examined against subterranean termite Microcerotermes diversus (Silvestri) (Blattodea: Termitidae) that is the most economically destructive termite in Iraq. Laboratory and field efficacy of these strains were evaluated to test the feasibility of indigenous EPNs to be used in a biological control program. The biological traits examined included pathogenicity, penetration, and reproduction of EPN species. Filter paper and wood bioassays were conducted using six concentrations: 25, 50, 100, 200, 400, and 600 IJs/termite. In both tests, all strains were virulent against M. diversus workers. The LC50 of S. carpocapsae in both petri dishes and in containers with sawdust was (57.9 and 15.7 IJs/termite) less than both indigenous (274.2 and 60.8 IJs/termite) and commercial (139.6 and 52.6 IJs/termite) Heterorhabditis bacteriophora, respectively. In the field, the percent mortality of the tested workers ranged from 22.5–80 ± 8.3%, 37.5–96.2 ± 8.9%, and 28.7–67.5 ± 6.8% for commercial H. bacteriophora and S. carpocapsae and native H. bacteriophora, respectively. All EPN strains successfully penetrated the M. diversus workers under field conditions, while the results showed that there was a significant difference between the three EPN strains. The percent mortality caused by native H. bacteriophora against termites was higher (43.6 ± 2.7%) than both commercial strains of S. carpocapsae (36.9 ± 1.6%) and H. bacteriophora (29.9 ± 1.4 %). These results highlight the efficiency of EPNs for the control of M. diversus workers.
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Petrikovszki, Renáta, Pratik Doshi, György Turóczi, Ferenc Tóth, and Péter Nagy. "Investigating the Side-Effects of Neem-Derived Pesticides on Commercial Entomopathogenic and Slug-Parasitic Nematode Products Under Laboratory Conditions." Plants 8, no. 8 (2019): 281. http://dx.doi.org/10.3390/plants8080281.
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Lethal effects of neem derived pesticides (neem leaf extract (NLE) and NeemAzal-T/S (NA)) were examined on different entomopathogenic (EPN) and slug-parasitic (SPN) nematodes. In our recent study, neem derived pesticides were tested against Phasmarhabditis hermaphrodita for the first time under in vitro conditions. Laboratory experiments were set up in 96-well microplates with different concentrations of NLE (0.1%, 0.3%, 0.6%, and 1%) and NA (0.001%, 0.003%, 0.006%, and 0.01%) and Milli-Q water as the control. After 24-h exposure time, mortality of individual nematodes was observed and recorded. Considering LC10 values, 0.1% of NLE could be used safely in combination with all the EPNs and SPNs tested in recent study. A concentration of NA three times higher than the recommended dosage did not harm either EPN or SPN species. In conclusion, NeemAzal-T/S might be applied with EPNs and the SPN Ph. hermaphrodita simultaneously, while the compatibility of neem leaf extract and beneficial nematode products needs further evaluation.
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Stephen, James H., Angela J. Sievert, Peter J. Madsen, et al. "Spinal cord ependymomas and myxopapillary ependymomas in the first 2 decades of life: a clinicopathological and immunohistochemical characterization of 19 cases." Journal of Neurosurgery: Pediatrics 9, no. 6 (2012): 646–53. http://dx.doi.org/10.3171/2012.2.peds11285.
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Object Primary spinal cord ependymomas (EPNs) are rare in children, comprising classical WHO Grade II and III tumors and Grade I myxopapillary ependymomas (MEPNs). Despite their benign histology, recurrences and neural-axis dissemination have been reported in up to 33% MEPNs in the pediatric population. Treatment options beyond resection are limited, and little is known about their tumorigenesis. The purpose of this study was to explore the tumor biology and outcomes in a consecutive series of pediatric patients treated at a single institution. Methods The authors performed a retrospective clinicopathological review of 19 patients at a tertiary referral children's hospital for resection of a spinal cord ependymoma. The population included 8 patients with a pathological diagnosis of MEPN and 11 patients with a pathological diagnosis of spinal EPN (10 cases were Grade II and 1 case was Grade III). The upregulation of the following genes HOXB13, NEFL, PDGFRα, EGFR, EPHB3, AQP1, and JAGGED 1 was studied by immunohistochemistry from archived paraffin-embedded tumor samples of the entire cohort to compare the expression in MEPN versus EPN. Results Gross-total resection was achieved in 75% of patients presenting with MEPNs and in 100% of those with EPNs. The average follow-up period was 79 months for the MEPN subset and 53 months for Grade II/III EPNs. Overall survival for both subsets was 100%. However, event-free survival was only 50% for patients with MEPNs. Of note, in all cases involving MEPNs that recurred, the patients had undergone gross-total resection on initial surgery. In contrast, there were no tumor recurrences in patients with EPNs. Immunohistochemistry revealed no significant differences in protein expression between the two tumor types with the exception of EPHB3, which demonstrates a tendency to be positive in MEPNs (6 reactive tumors of 9) rather than in EPN (2 reactive tumors of 10). Conclusions The authors' experience shows that, following a gross-total resection, MEPNs are more likely to recur than their higher-grade counterpart, EPNs. This supports the recommendation for close long-term radiological follow-up of pediatric patients with MEPNs to monitor for recurrence, despite the tumor's low-grade histological feature. No significant difference in the protein expression of HOXB13, NEFL, PDGFRα, EGFR, EPHB3, AQP1, and JAGGED 1 was present in this selected cohort of pediatric patients.
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Dziedziech, Alexis, Sai Shivankar, and Ulrich Theopold. "Drosophila melanogaster Responses against Entomopathogenic Nematodes: Focus on Hemolymph Clots." Insects 11, no. 1 (2020): 62. http://dx.doi.org/10.3390/insects11010062.
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Several insect innate immune mechanisms are activated in response to infection by entomopathogenic nematodes (EPNs). In this review, we focus on the coagulation of hemolymph, which acts to stop bleeding after injury and prevent access of pathogens to the body cavity. After providing a general overview of invertebrate coagulation systems, we discuss recent findings in Drosophila melanogaster which demonstrate that clots protect against EPN infections. Detailed analysis at the cellular level provided insight into the kinetics of the secretion of Drosophila coagulation factors, including non-classical modes of secretion. Roughly, clot formation can be divided into a primary phase in which crosslinking of clot components depends on the activity of Drosophila transglutaminase and a secondary, phenoloxidase (PO)-dependent phase, characterized by further hardening and melanization of the clot matrix. These two phases appear to play distinct roles in two commonly used EPN infection models, namely Heterorhabditis bacteriophora and Steinernema carpocapsae. Finally, we discuss the implications of the coevolution between parasites such as EPNs and their hosts for the dynamics of coagulation factor evolution.
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Dziedziech, Alexis, Sai Shivankar, and Ulrich Theopold. "High-Resolution Infection Kinetics of Entomopathogenic Nematodes Entering Drosophila melanogaster." Insects 11, no. 1 (2020): 60. http://dx.doi.org/10.3390/insects11010060.
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Entomopathogenic nematodes (EPNs) have been a useful model for studying wound healing in insects due to their natural mechanism of entering an insect host either through the cuticle or an orifice. While many experiments have shed light on nematode and host behavior, as well as the host immune response, details regarding early nematode entry and proliferative events have been limited. Using high-resolution microscopy, we provide data on the early infection kinetics of Heterorhabditis bacteriophora and its symbiotic bacteria, Photorhabdus luminescens. EPNs appendage themselves to the host and enter through the host cuticle with a drill-like mechanism while leaving their outer sheath behind. EPNs immediately release their symbiotic bacteria in the host which leads to changes in host behavior and septicemia within 6 h while EPNs travel through the host in a predictable manner, congregating in the anterior end of the host. This paper sheds light on the entry and proliferative events of EPN infection, which will further aid in our understanding of wound healing and host immune activation at a high spatiotemporal resolution.
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Keshari, Arvind Kumar, B. K. C. Hari, Aashaq Hussain Bhat, and M. M. Shah. "Prospects and Present Status and of Entomopathogenic Nematodes (Steinernematidae and Heterorhabditidae) in Nepal." Journal of Applied and Advanced Research 4, no. 1 (2019): 31. http://dx.doi.org/10.21839/jaar.2019.v4i1.261.
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Naturally occurring entomopathogenic nematodes(EPN) and their symbiotic bacteria are important biotic factor in suppression of insect pest populations in soil and cryptic habitats. These nematodes can control pests due to their mutualistic association with bacteria that kill the hosts by septicemia and make the environment favorable for EPN development and reproduction.The virulent species of EPN can commercially be mass produced as biological control agents all over the world. Nepal has a great potential to exploit these beneficial nematodes for the control of insect pests. Exploration of indigenous EPN is receiving attention around th eworld. Numerous surveys conducted worldwide have detected many indigenous isolates. Altogether 115 species of EPN (97 of Steinernema and 18 of Heterorhabdits species) have been reported so far worldwide. However, very limited research on EPN in Nepal has been done with 29 species only with some new species. Hence,the isolation and description of the native efficacious species and populationsof EPN is the need of the hour,not only from a biodiversity view point but also from an environmental and biological control perspective.Thei dentification of EPNs, adapted to environmental and climatic conditions of cultivated areas, is important for sustainable pest suppression in integrated management programs in agricultural areas of Nepal. This article provides an overview of recent development on EPN research and evaluates their potential for use and exploitation in Nepal.
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Torrini, Giulia, Francesco Paoli, Giuseppe Mazza, et al. "Evaluation of Indigenous Entomopathogenic Nematodes as Potential Biocontrol Agents against Popillia japonica (Coleoptera: Scarabaeidae) in Northern Italy." Insects 11, no. 11 (2020): 804. http://dx.doi.org/10.3390/insects11110804.
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The natural presence of entomopathogenic nematodes (EPNs) has been investigated in the Piedmont region (Northern Italy) in areas infested by the Japanese beetle Popillia japonica. Thirty-nine out of 155 soil samples (25.2%) were positive for EPNs. Most of the samples contained only steinermatids (92.3%), 5.1% contained heterorhabditids, and one sample (2.6%) contained both genera. All the recovered isolates were identified at species level both morphologically and molecularly. Steinernema carpocapsae was the most abundant and it was mainly distributed in open habitats, such as perennial meadows, uncultivated soils, and cropland, characterized by sandy loam soil texture and acidic pH. Steinernema feltiae has been found associated mainly with closed habitats such as coniferous and deciduous woodland, characterized by sandy loam-texture and extremely acidic soil. The three isolates of Heterorhabditis bacteriophora were collected only in open habitats (perennial meadows and uncultivated fields) characterized by strongly acidic soils with sandy loam texture. The virulence of all EPN natural strains was evaluated by laboratory assays against P. japonica third-instar larvae collected during two different periods of the year (spring, autumn). The results showed that larval mortality was higher for pre-wintering larvae than post-wintering ones. The five more promising EPN isolates were tested in the semi-field assay in which H. bacteriophora natural strains have been shown to be more efficient in controlling P. japonica grubs. All of these results are finally discussed considering the use of these natural EPNs as biological control agents against P. japonica, within an eco-friendly perspective of management.
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Sandhi, Ramandeep Kaur, David Shapiro-Ilan, Michael Ivie, and Gadi V. P. Reddy. "Biocontrol of Wireworms (Coleoptera: Elateridae) Using Entomopathogenic Nematodes: The Impact of Infected Host Cadaver Application and Soil Characteristics." Environmental Entomology 50, no. 4 (2021): 868–77. http://dx.doi.org/10.1093/ee/nvab042.
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Abstract Wireworms have become a significant menace to cereals in the Northern Great Plains. Therefore, research toward developing effective control methods such as biological control with entomopathogenic nematodes (EPNs) is warranted. Two strains, each of two EPN species, Steinernema carpocapsae (Weiser) and Steinernema riobrave Cabanillas, Poinar, and Raulston in the form of infected Galleria mellonella (L.) cadavers were evaluated against wireworms in field and greenhouse. In field experiments, none of the four EPN strains were found effective against wireworms. However, in the greenhouse test, three of the strains, S. carpocapsae (All and Cxrd) or S. riobrave (355) applied in cadavers killed 50–68% of the sugarbeet wireworm, Limonius californicus (Mannerheim) was associated with 8–24% plant damage at 35 d after treatment (DAT), when seeds were treated with imidacloprid. The mortality range was 40–56% with 57–75% plant damage observed at 35 DAT, when seeds were planted without imidacloprid treatment. Synergistic effect among imidacloprid and S. carpocapsae (Cxrd) or S. riobrave (355) was observed in regard to L. californicus mortality. Additionally, effects of soil texture, moisture, and temperature on the infection rate of EPNs against L. californicus were examined in the laboratory. Limonius californicus mortality was not significantly affected by either soil moisture or soil types maintained at field capacity moisture levels. However, soil temperature showed a significant effect on L. californicus mortality. Overall, imidacloprid enhanced the infection and killing ability of EPNs against L. californicus and S. carpocapsae (All and Cxrd) strains were the virulent strains in different soil experiments.
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du Preez, Francois, Antoinette Paula Malan, and Pia Addison. "Potential of in vivo- and in vitro-cultured entomopathogenic nematodes to infect Lobesia vanillana (Lepidoptera: Tortricidae) under laboratory conditions." PLOS ONE 16, no. 8 (2021): e0242645. http://dx.doi.org/10.1371/journal.pone.0242645.
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Entomopathogenic nematodes (EPNs) have been successfully applied as biological control agents against above ground and soil stages of insect pests. However, for commercial application, it is crucial to mass culture these nematodes using in vitro liquid culture technology, as it is not attainable when using susceptible insects as hosts. Lobesia vanillana (Lepidoptera: Tortricidae) is regarded a sporadic pest of wine grapes in South Africa. The in vivo- and in vitro-cultured South African EPNs, Steinernema yirgalemense and Steinernema jeffreyense (Rhabditida: Steinernematidae), were evaluated against larvae and pupae of L. vanillana in laboratory bioassays. For larvae, high mortality was observed for all treatments: In vitro-cultured S. yirgalemense (98%) performed better than S. jeffreyense (73%), while within in vivo cultures, there was no difference between nematode species (both 83%). No significant difference was detected between in vivo- and in vitro cultures of the same nematode species. The LD50 of the in vitro-cultured S. yirgalemense, was 7.33 nematodes per larva. Mortality by infection was established by dissecting L. vanillana cadavers and confirming the presence of nematodes, which was > 90% for all treatments. Within in vitro cultures, both S. yirgalemense and S. jeffreyense were able to produce a new cohort of infective juveniles from L. vanillana larvae. Pupae, however, were found to be considerably less susceptible to EPN infection. This is the first study on the use of EPNs to control L. vanillana. The relative success of in vitro-cultured EPN species in laboratory assays, without any loss in pathogenicity, is encouraging for further research and development of this technology.
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Sharma, A. "P12.06 Clinicopathological evaluation of PD-L1 expression and cytotoxic T-lymphocyte infiltrates across intracranial molecular subgroups of ependymomas." Neuro-Oncology 21, Supplement_3 (2019): iii60. http://dx.doi.org/10.1093/neuonc/noz126.217.
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Abstract BACKGROUND Immune check-point blockade targeting programmed cell death ligand-1 (PD-L1)/programmed death-1 (PD-1) axis has created paradigm shift in the treatment of advanced cancer. The prognosis of the ‘ST-RELA’ and ‘PF-A’ molecular subgroups of ependymomas (EPN) remains poor. This study aims to understand the potential candidature of EPNs for ICB. MATERIAL AND METHODS All supratentorial (ST) Grade II/III EPNs were classified into ST-RELA, ST-YAP and ST-not otherwise specified (NOS), based on L1CAM protein expression and/or presence of RELA/YAP1 fusion transcripts by RT-PCR. All posterior fossa (PF) BEPNs were classified into PF-A and PF-B based on H3K27me3 protein expression and chromosome 1q gain. Immunohistochemistry for PD-L1 (SP263, Ventana) and CD8 was performed. RelA protein enrichment at PDL1 promoter site was analysed by chromatin immunoprecipitation-qPCR (ChIP-qPCR) in three ST-RELA samples. RESULTS A total of 83 intracranial EPNs were included as follows: ST-RELA (n=32), ST-YAP (n=1), ST-NOS (n=11), ST-subependymoma (n=1), PF-A (n=25) and PF-B (n=13). Median tumor infiltrating CD8+ cytotoxic T-lymphocyte (CTL) density was 6/mm2, and was higher in ST EPNs (median 10/mm2) as compared to PF EPNs (median 3/mm2). PD-L1 protein expression in ≥1% tumor cells was noted in 17/83 (20%) of all EPNs, including 12/32 (37%) of ST-RELA and rare ST-NOS (2/11), PF-A (2/25) and PF-B (1/13) tumors. Twelve intracranial EPNs (14%, 12/83) showed high CTL density and concurrent PD-L1 positivity, of which majority (83%, 10/12) were ST-RELA EPNs. Enrichment of RelA protein was seen at PD-L1 promoter. CONCLUSION Increased CTL densities and upregulation of PD-L1 in ST-RELA ependymomas suggests potential candidature for immunotherapy.
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Vicente-Díez, Ignacio, Rubén Blanco-Pérez, María del Mar González-Trujillo, Alicia Pou, and Raquel Campos-Herrera. "Insecticidal Effect of Entomopathogenic Nematodes and the Cell-Free Supernatant from Their Symbiotic Bacteria against Philaenus spumarius (Hemiptera: Aphrophoridae) Nymphs." Insects 12, no. 5 (2021): 448. http://dx.doi.org/10.3390/insects12050448.
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The meadow spittlebug Philaenus spumarius (Hemiptera: Aphrophoridae) is the primary vector of Xylella fastidiosa (Proteobacteria: Xanthomonadaceae) in Europe, a pest–disease complex of economically relevant crops such as olives, almonds, and grapevine, managed mainly through the use of broad-spectrum pesticides. Providing environmentally sound alternatives to reduce the reliance on chemical control is a primary challenge in the control of P. spumarius and, hence, in the protection of crops against the expansion of its associated bacterial pathogen. Entomopathogenic nematodes (EPNs) are well-known biocontrol agents of soil-dwelling arthropods. Recent technological advances in field applications, including improvements in obtaining cell-free supernatant from their symbiotic bacteria, allow their successful implementation against aerial pests. Thus, this study aimed to evaluate, for the first time, the efficacy of EPN applications against nymphal instars of P. spumarius. We tested four EPN species and the cell-free supernatant of their corresponding symbiotic bacteria: Steinernema feltiae–Xenorhabdus bovienii, S. carpocapsae–X. nematophila, S. riojaense–X. kozodoii, and Heterorhabditis bacteriophora–Photorhabdus laumondii subsp. laumondii. First, we showed that 24 and 72 h exposure to the foam produced by P. spumarius nymphs did not affect S. feltiae virulence. The direct application of steinernematid EPNs provided promising results, reaching 90, 78, and 53% nymphal mortality rates after five days of exposure for S. carpocapsae, S. feltiae, and S. riojaense, respectively. Conversely, the application of the cell-free supernatant from P. laumondii resulted in nymphal mortalities of 64%, significantly higher than observed for Xenorhabdus species after five days of exposure. Overall, we demonstrated the great potential of the application of specific EPNs and cell-free supernatant of their symbiont bacteria against P. spumarius nymphs, introducing new opportunities to develop them as biopesticides for integrated management practices or organic vineyard production.
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Zheng, Tuyu, David R. Ghasemi, Konstantin Okonechnikov, et al. "EPEN-03. ZFTA/C11ORF95 FUSIONS DRIVE SUPRATENTORIAL EPENDYMOMA VIA SHARED ONCOGENIC MECHANISMS." Neuro-Oncology 23, Supplement_1 (2021): i13—i14. http://dx.doi.org/10.1093/neuonc/noab090.053.
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Abstract The majority of supratentorial ependymomas (ST-EPN) are driven by fusion genes between RELA and zinc finger translocation associated, ZFTA, previously named C11orf95. Apart from fusions with a portion of the Hippo effector YAP1, which affects a small group of infant patients, the oncogenic mechanism of remaining ST-EPNs remains unclear. Aiming at refining the molecular classification of ST-EPNs, we have analyzed methylation profiles, RNA and DNA sequencing results as well as clinical data in a cohort of 613 ST-EPNs. An unbiased approach revealed distinct methylation clusters composed of tumors with ependymal but also various other histological features containing alternative translocations that shared ZFTA as a partner gene. Tumors within these additional clusters were characterized by fusions of ZFTA to numerous fusion partners different from RELA, e.g. MAML2, MAML3, NCOA2 and SS18, implying a general role of ZFTA in tumorigenesis of ST-EPN. Indeed, the transforming capacity of newly identified fusion genes was validated using an electroporation-based in vivo gene transfer technology in mice. All fusion genes themselves were sufficient to drive malignant transformation in the developing cerebral cortex and resulting tumors faithfully recapitulated molecular characteristics of their human counterparts. We found that both, the partner gene and the zinc finger DNA binding domain of ZFTA, were essential to exert tumorigenesis. Together with two additional studies, we performed a comprehensive analysis across datasets to derive a 93 gene signature of ZFTA-RELA-driven tumors, in which the Sonic Hedgehog effector gene GLI2 was identified as a promising downstream target. Subsequent co-expression of ZFTA:RELA and a dominant negative form of Gli2 indeed hampered tumorigenesis. Targeting GLI2 with arsenic trioxide caused extended survival of tumor-bearing animals, indicating GLI2 as a critical regulator of ZFTA fusion-positive tumorigenesis as well as a potential therapeutic vulnerability in these tumors.
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Donson, Andrew, Austin Gillen, Riemondy Kent, et al. "EPEN-31. SINGLE-CELL RNAseq OF CHILDHOOD EPENDYMOMA REVEALS DISTINCT NEOPLASTIC CELL SUBPOPULATIONS THAT IMPACT ETIOLOGY, MOLECULAR CLASSIFICATION AND OUTCOME." Neuro-Oncology 22, Supplement_3 (2020): iii314. http://dx.doi.org/10.1093/neuonc/noaa222.167.
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Abstract Ependymoma (EPN) is a brain tumor commonly presenting in childhood that remains fatal in the majority of children. Intra-tumoral cellular heterogeneity in bulk-tumor samples significantly confounds our understanding of EPN biology, impeding development of effective therapy. We therefore used single-cell RNA sequencing to catalog cellular heterogeneity of 26 childhood EPN, predominantly from ST-RELA, PFA1 and PFA2 subgroups. ST-RELA and PFA subgroups clustered separately, with ST-RELA clustering largely according to individual sample-of-origin. PFA1 and PFA2 subgroup EPNs cells were intermixed and revealed 4 major subpopulations – 2 with characteristics of ependymal differentiation (transporter and ciliated phenotype subpopulations), an undifferentiated subpopulation and a mesenchymal phenotype. Pseudotime analysis showed the undifferentiated progenitor subpopulation either differentiating into ependymal differentiation subpopulations or transitioning into the mesenchymal subpopulation. Histological analysis revealed that undifferentiated and mesenchymal subpopulations cells colocalized to perinecrotic/perivascular zones, the putative ependymoma stem cell niche. Deconvolution of PFA bulk transcriptome data showed that undifferentiated and mesenchymal subpopulations were associated with a poor prognosis; whereas the ciliated ependymal cell-differentiated subpopulation was associated with a good prognosis. In conflict with current distinct classification paradigms, the ratio of mesenchymal and ciliated subpopulations determined bulk-tumor subgroups assignment to PFA1 and PFA2 respectively. This atlas of EPN cellular heterogeneity provides an important advance in our understanding of EPN biology, identifying high-risk associated subpopulations for therapeutic targeting.
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Acharya, Rajendra, Hwal-Su Hwang, Md Munir Mostafiz, Yeon-Su Yu, and Kyeong-Yeoll Lee. "Susceptibility of Various Developmental Stages of the Fall Armyworm, Spodoptera frugiperda, to Entomopathogenic Nematodes." Insects 11, no. 12 (2020): 868. http://dx.doi.org/10.3390/insects11120868.
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The fall armyworm, Spodoptera frugiperda, which is native to Central and South America, has recently invaded Africa and Asia, causing serious damage to various crops. Although management to date has been largely unsuccessful, entomopathogenic nematodes (EPNs) are a potential biological control agent that could be used to control the late larval and pupal stages of S. frugiperda that dwell under the ground. Here, we compared the virulence of seven EPNs against larval and pupal stages of S. frugiperda. In a Petri dish assay, both Heterorhabditis indica and Steinernema carpocapsae were highly virulent against younger larvae, whereas S. arenarium and S. longicaudum were highly virulent against older larvae. In contrast, H. bacteriophora, Heterorhabditis sp., and S. kushidai showed low virulence against all larval stages. In soil column and pot assays, H. indica, S. carpocapsae, and S. longicaudum were highly virulent against late larval and pupal stages compared with the other EPN species. Thus, H. indica, S. carpocapsae, and S. longicaudum are recommended for the biological control of S. frugiperda. Our study provides important information of EPNs for the practical application of biological control of fall armyworm.
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Brivio, Maurizio, and Maristella Mastore. "Nematobacterial Complexes and Insect Hosts: Different Weapons for the Same War." Insects 9, no. 3 (2018): 117. http://dx.doi.org/10.3390/insects9030117.
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Entomopathogenic nematodes (EPNs) are widely used as biological control agents against insect pests, the efficacy of these organisms strongly depends on the balance between the parasitic strategies and the immune response of the host. This review summarizes roles and relationships between insect hosts and two well-known EPN species, Steinernema feltiae and Steinernema carpocapsae and outlines the main mechanisms of immune recognition and defense of insects. Analyzing information and findings about these EPNs, it is clear that these two species use shared immunosuppression strategies, mainly mediated by their symbiotic bacteria, but there are differences in both the mechanism of evasion and interference of the two nematodes with the insect host immune pathways. Based on published data, S. feltiae takes advantage of the cross reaction between its body surface and some host functional proteins, to inhibit defensive processes; otherwise, secretion/excretion products from S. carpocapsae seem to be the main nematode components responsible for the host immunosuppression.
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Nambirajan, Aruna, Madhu Rajeshwari, Meher Boorgula, et al. "EPEN-38. EZH2 INHIBITORY PROTEIN (EZHIP/Cxorf67) EXPRESSION IS HIGHLY CONCORDANT WITH H3K27me3 LOSS AND IS A PROMISING SURROGATE MARKER FOR POSTERIOR FOSSA TYPE A EPENDYMOMAS." Neuro-Oncology 22, Supplement_3 (2020): iii315. http://dx.doi.org/10.1093/neuonc/noaa222.173.
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Abstract BACKGROUND Gene expression and DNA methylation have identified 2 distinct clinicopathological subgroups among the WHO Grade II/III posterior fossa (PF) ependymomas (EPN), of which the PF-A molecular subgroup associates with poor outcome. OBJECTIVE To analyse the utility of immunohistochemistry for H3K27me3, Tenascin C, EZHIP (Cxorf67), EZH2 and fluorescence-in-situ-hybridisation for chromosome 1q21 locus gain in the prognostic stratification of PF-EPNs. METHODS All PF Grade II/III tumors were retrieved (2009–2019). Immunohistochemistry for H3K27me3, H3K27M-mutation-specific antibody, EZH2, EZHIP, Tenascin-C and fluorescence in-situ hybridisation for 1q21 locus was performed and compared with outcome. RESULTS 71 PF-EPNs were included. H3K27me3 loss (PF-A) was seen in 65% (46/71) of cases, of which majority were positive for EZHIP (73%, 24/33) and Tenascin C (65%, 28/43). Minority showed chromosome 1q gain (19%, 8/42). An EZHIP negative PF-A tumor was immunopositive for H3K27M-mutant staining, while all others were negative. PF-A EPNs occurred at a median age of 4.5 years (range 1–53), were predominantly grade III (Grade III:II – 1.6:1), and 50% (10/20) of patients on follow-up experienced tumor progression. EPNs with retained H3K27me3 (PF-B) did not show EZHIP expression (0/20) or 1q gain; however, tenascin C expression was seen in 47% (8/25) of them. They occurred predominantly in adults, showed Grade II preponderance and only 2/11 patients on follow-up experienced progression. EZH2 expression did not correlate with H3K27me3 loss but positively correlated with EZHIP expression (p=0.015). CONCLUSION H3K27me3 is a reliable surrogate for prognostic classification of PF-EPNs. EZHIP expression is highly concordant with H3K27me3 loss and is a valuable adjunct.
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Ngugi, C. N., P. M. Wachira, J. N. Mbaka, S. Okoth, S. Haukeland, and E. G. Thuranira. "Biocontrol Potential of Four Indigenous Entomopathogenic Nematodes From Kenya." Journal of Agricultural Science 13, no. 10 (2021): 107. http://dx.doi.org/10.5539/jas.v13n10p107.
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Globally, vegetable production including tomato is constrained by pests and diseases. The tomato leafminer, Tuta absoluta (Meyrick.), is a major pest of tomato, mainly managed using chemical pesticides. There is a need for integrated pest management (IPM), approaches that are human and environmentally friendly. The study aimed at molecular identification and virulence evaluation of four entomopathogenic nematodes (EPNs) against T. absoluta larvae. The DNA was extracted, sequenced, and phylogeny analyzed. The EPNs virulence was evaluated using the insect baiting technique at different nematode concentrations (0-Control, 100, 150, 200, and 250 infective juveniles/ml of distilled water). Larval mortality data were collected for five days. Molecular identification resulted in nucleotide sequence lengths of 877-895 base pairs (bp). All the isolates were found to be Steinernema species of EPNs. The % similarity of the isolates and their close relatives ranged between 82-100%. The isolates closely matched Steinernema spp. AY230184 (Sri Lanka); AY230186 (Kenya), JN651414 (Ethiopia), and MW151701 (Kenya). The sequences were deposited to Genbank as Steinernema sp. Isolate Kalro 75 (MW150871), Steinernema sp. Isolate Kalro S86 (MW150872), Steinernema sp. isolate Kalro97 (MW150873) and Steinernema sp. Isolate KalroR52 (MW150874). All the EPN isolates were virulent against T. absoluta. Isolate Kalro R52 and Kalro S86 recorded the highest mortality of 76&plusmn;7.5%; 72&plusmn;15.0% respectively in the 48 h. There was a significant difference (P &lt; 0.001), between all the isolates and the Control. The four EPNs were virulent and have bio-control potential against, T. absoluta. Research on their virulence against T. absoluta in the field is recommended.
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Henning, P. H., D. G. Steyn, and H. H. Meissner. "The effect of energy and nitrogen supply pattern on rumen bacterial growthin vitro." Animal Science 53, no. 2 (1991): 165–75. http://dx.doi.org/10.1017/s0003356100020080.
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AbstractThe effect of energy and nitrogen (N) supply pattern on rumen bacterial growth was investigated in vitro. In experiment 1, glucose was was fed to batch cultures of mixed rumen bacteria according to three patterns namely a pulse dose at time zero (P); even increments at 0·5-h intervals (G) or an intermediate pattern (I), whilst N was supplied in excess. In experiment 2, glucose and N (not in excess) were fed to batch cultures according to four patterns namely glucose and N as pulse doses at time zero, (EPNP); glucose as a pulse dose at time zero and N in 24 even increments at 0·5-h intervals (EPNG); glucose in 24 even increments at 0·5-h intervals and N as a pulse dose at time zero (EGNP) or both glucose and N in 24 even increments at 0·5-h intervals (EGNG). Fermentaton was studied over a 12-h period for both experiments.In experiment 1, bacterial growth efficiency and specific growth rate (39·8,35·5 and 29·9 (g bacterial dry matter (DM) per mol glucose utilized) and 0·33, 0·27 and 0·20 (fraction per h) for treatments P, I, and G respectively) differed significantly between glucose supply patterns. In experiment 2, bacterial growth efficiency and specific growth rate (33·8, 34·7, 25·9 and 22·5 (g baterial DM per mol glucose) and 0·21, 0·18, 0·14 and 0·13 (fraction per h) for treatments EPNP, EPNG, EGNP and EGNG respectively) differed significantly only between glucose supply patterns.It is concluded that the pattern according to which a given amount of energy becomes available affects bacterial growth efficiency, with the fastest supply rate giving the highest efficiency and that, within accepted levels of N supply, synchronization between energy and N availability may be of less importance to bacterial growth efficiency than the energy supply pattern.
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Tumialis, D., M. Łopieńska, A. Mazurkiewicz, E. Pezowicz, and I. Skrzecz. "Identification and intraspecific variability of Steinernema feltiae (Filipjev, 1934) isolates from different localities in Poland." Helminthologia 53, no. 3 (2016): 304–8. http://dx.doi.org/10.1515/helmin-2016-0030.
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Summary Presented study is part of a project aimed at identifying entomopathogenic nematode (EPN) species and analysing their distribution in various habitats of Poland. Here, an attempt was undertaken to determine intraspecific variability of nematodes of the species Steinernema feltiae isolated from seven different localities in central and southern Poland. Molecular characteristic and phylogenetic analysis was performed based on nucleotide sequences in the ITS region. Research on the occurrence of EPNs in Poland have been conducted since the 1990s but there is still no data verified genetically, as well as data on the intraspecific variability of isolates Steinernema feltiae. This paper reports initial results of intraspecific variability Steinernema feltiae in Poland.
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Henriques, David. "Cards on the Table: Efficiency and Welfare Effects of the No-Surcharge Rule." Review of Network Economics 17, no. 1 (2018): 25–50. http://dx.doi.org/10.1515/rne-2017-0036.
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Abstract In Electronic Payment Networks (EPNs), the No-Surcharge Rule (NSR) requires that merchants charge at most the same amount for a payment card transaction as for cash. In this paper, I use a three-party model (consumers, local monopolistic merchants, and a proprietary EPN) with endogenous transaction volumes, heterogeneous card use benefits for merchants and network externalities of card-accepting merchants on cardholders to assess the efficiency and welfare effects of the NSR. I show that the NSR: (i) promotes retail price efficiency for cardholders, and (ii) inefficiently reduces card acceptance among merchants. The NSR can enhance social welfare and improve payment efficiency by shifting output from cash payers to cardholders. However, if network externalities are sufficiently strong, the reduction of card payment acceptance affects cardholders negatively and, with the exception of the EPN, all agents will be worse off under the NSR. This paper also suggests that the NSR may be an instrument to decrease cash usage, but the social optimal policy on the NSR may depend on the competitive conditions in each market.
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Donson, Andrew, Austin Gillen, Kent Riemondy, et al. "EPEN-21. SINGLE CELL RNASEQ IDENTIFIES A PUTATIVE CANCER STEM CELL POPULATION IN POSTERIOR FOSSA EPN." Neuro-Oncology 20, suppl_2 (2018): i77. http://dx.doi.org/10.1093/neuonc/noy059.222.
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Torrini, Giulia, Giuseppe Mazza, Claudia Benvenuti, and Pio Federico Roversi. "Susceptibility of olive fruit fly, Bactrocera oleae (Diptera: Tephritidae) pupae to entomopathogenic nematodes." Journal of Plant Protection Research 57, no. 3 (2017): 318–20. http://dx.doi.org/10.1515/jppr-2017-0030.
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Abstract The olive fruit fly Bactrocera oleae is one of the most serious and economically damaging insects worldwide, affecting the quality and quantity of both olive oil and table olives. Laboratory bioassays were conducted for the first time to evaluate the susceptibility of B. oleae pupae to two entomopathogenic nematodes (EPN) species, Steinernema carpocapsae and Heterorhabditis bacteriophora. The nematodes tested caused pupal mortality of 62.5% and 40.6%, respectively. The most noteworthy result was obtained with S. carpocapsae which was able to infect 21.9% of the emerged adults. Since this tephritid fly spent several months in the soil as pupa, the use of EPNs could be a promising method to control this pest.
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Sandhi, Ramandeep Kaur, David Shapiro-Ilan, and Gadi V. P. Reddy. "Montana Native Entomopathogenic Nematode Species Against Limonius californicus (Coleoptera: Elateridae)." Journal of Economic Entomology 113, no. 5 (2020): 2104–11. http://dx.doi.org/10.1093/jee/toaa164.
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Abstract Wireworms are destructive soil inhabiting polyphagous pests in the Pacific Northwest and Intermountain region of the United States. Continuously increasing wireworm populations and damage in small grain crops such as spring wheat in Northern Great Plains has become a challenge for growers. Due to unavailability of effective control measures, alternative methods, including biological control agents such as entomopathogenic nematodes (EPNs) are needed. Native/indigenous EPN species are expected to have better potential than exotic species to control the local insect pests. Two Montana native EPN species (Steinernema feltiae and Heterorhabditis bacteriophora) were tested against, Limonius californicus (Coleoptera: Elateridae) in laboratory and shade house studies. In the laboratory bioassay, two isolates of S. feltiae at the rate of 28,000 IJs/five larvae killed 48–50% of the insects within 4 wk. Heterorhabditis bacteriophora was not able to cause &gt;30% L. californicus larval mortality. None of the two isolates of S. feltiae performed well against L. californicus when tested in different soil types. Similarly, two isolates of S. feltiae that were tested killed only 20–25% wireworms in a shade house trial that did not differ significantly from the control treatment. Four weeks after EPN treatment in the shade house trial, the percentage of wheat plant damage from L. californicus ranged from 30 to 40% in the presence of S. felitae, not differing statistically from control. These results suggest that S. felitae have limited potential in managing wireworm populations.
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Baiocchi, Tiffany, Chunjie Li, and Adler R. Dillman. "EPNs Exhibit Repulsion to Prenol in Pluronic Gel Assays." Insects 11, no. 8 (2020): 457. http://dx.doi.org/10.3390/insects11080457.
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Entomopathogenic nematodes (EPNs) are lethal parasites of insects that have become valuable in biological control and as a model system for studying host–parasite interactions, behavioral ecology, neurobiology, and genomics, among other fields. Their ability to locate hosts is paramount to successful infection and host seeking has been extensively studied in many species in the lab. Here, we explored the usefulness of pluronic gel as a medium to assess EPN host seeking in the lab by characterizing the response of Steinernema carpocapsae, S. feltiae, S. glaseri, S. riobrave, Heterorhabditis bacteriophora, and H. indica to the odor prenol. We found that the infective juveniles (IJs) of these species were repelled by prenol in pluronic gel. We then evaluated how storing the IJs of S. carpocapsae, S. feltiae, and S. glaseri for different amounts of time affected their behavioral responses to prenol. The response of S. carpocapsae was significantly affected by the storage time, while the responses of S. feltiae and S. glaseri were unaffected. Our data support the notion that pluronic gel is a useful medium for studying EPN behavior and that the response of S. carpocapsae to informative odors is significantly affected by long-term storage.
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Baiocchi, Tiffany, Kyle Anesko, Nathan Mercado, et al. "Signaling by AWC Olfactory Neurons Is Necessary for Caenorhabditis elegans’ Response to Prenol, an Odor Associated with Nematode-Infected Insects." Genetics 216, no. 1 (2020): 145–57. http://dx.doi.org/10.1534/genetics.120.303280.
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Chemosensation plays a role in the behaviors and life cycles of numerous organisms, including nematodes. Many guilds of nematodes exist, ranging from the free-living Caenorhabditis elegans to various parasitic species such as entomopathogenic nematodes (EPNs), which are parasites of insects. Despite ecological differences, previous research has shown that both EPNs and C. elegans respond to prenol (3-methyl-2-buten-1-ol), an odor associated with EPN infections. However, it is unclear how C. elegans responds to prenol. By utilizing natural variation and genetic neuron ablation to investigate the response of C. elegans to prenol, we found that the AWC neurons are involved in the detection of prenol and that several genes (including dcap-1, dcap-2, and clec-39) influence response to this odorant. Furthermore, we identified that the response to prenol is mediated by the canonically proposed pathway required for other AWC-sensed attractants. However, upon testing genetically diverse isolates, we found that the response of some strains to prenol differed from their response to isoamyl alcohol, suggesting that the pathways mediating response to these two odorants may be genetically distinct. Further, evaluations leveraging natural variation and genome wide association revealed specific genes that influence nematode behavior and provide a foundation for future studies to better understand the role of prenol in nematode behavioral ecology.
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Damascena, Alixelhe Pacheco, Vanessa Rafaela de Carvalho, Murilo Fonseca Ribeiro, et al. "Steinernema diaprepesi (Rhabditida: Steinernematidae) parasitizing Gonipterus platensis (Coleoptera: Curculionidae)." Royal Society Open Science 7, no. 8 (2020): 200282. http://dx.doi.org/10.1098/rsos.200282.
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Entomopathogenic nematodes (EPNs) can control pests due to mutualistic association with bacteria that reproduce and kill the host from septicemia, making the environment favourable for nematode development and reproduction. The objective of this study was to identify an EPN isolate collected in eucalyptus cultivation and to determine its pathogenicity with regard to Gonipterus platensis Marelli (Coleoptera: Curculionidae). Four steel-mesh traps with two seventh-instar Galleria mellonella larvae were buried 5 cm deep in the soil in a commercial Eucalyptus plantation. After 7 days, the traps were packed in plastic bags and transported to laboratory to isolate the EPNs using White traps. The obtained nematodes were multiplied in G. mellonella larvae and identified by sequencing their D2/D3 expansion of the 28S rDNA region by polymerase chain reaction (PCR) and specific primers for ITS regions. Steinernema diaprepesi was identified and inoculated into G. platensis pupae at doses of 500, 1000 and 5000 infective juveniles (IJs) to determine its pathogenicity to this pest. At 8 days after inoculation, the mortality rate of the G. platensis pupae was 80% with the lowest concentration and 100% with the others. The emergence of nematodes and the rapid degradation of G. platensis pupae were observed in those inoculated with IJs. The pathogenicity to the G. platensis pupae indicates potential for using this nematode in the integrated management of this insect.
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Eliáš, Sara, Jana Hurychová, Duarte Toubarro, et al. "Bioactive Excreted/Secreted Products of Entomopathogenic Nematode Heterorhabditis bacteriophora Inhibit the Phenoloxidase Activity during the Infection." Insects 11, no. 6 (2020): 353. http://dx.doi.org/10.3390/insects11060353.
Full textAbstract:
Entomopathogenic nematodes (EPNs) are efficient insect parasites, that are known for their mutualistic relationship with entomopathogenic bacteria and their use in biocontrol. EPNs produce bioactive molecules referred to as excreted/secreted products (ESPs), which have come to the forefront in recent years because of their role in the process of host invasion and the modulation of its immune response. In the present study, we confirmed the production of ESPs in the EPN Heterorhabditis bacteriophora, and investigated their role in the modulation of the phenoloxidase cascade, one of the key components of the insect immune system. ESPs were isolated from 14- and 21-day-old infective juveniles of H. bacteriophora, which were found to be more virulent than newly emerged nematodes, as was confirmed by mortality assays using Galleria mellonella larvae. The isolated ESPs were further purified and screened for the phenoloxidase-inhibiting activity. In these products, a 38 kDa fraction of peptides was identified as the main candidate source of phenoloxidase-inhibiting compounds. This fraction was further analyzed by mass spectrometry and the de novo sequencing approach. Six peptide sequences were identified in this active ESP fraction, including proteins involved in ubiquitination and the regulation of a Toll pathway, for which a role in the regulation of insect immune response has been proposed in previous studies.
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Ngugi, C. N., P. M. Wachira, J. N. Mbaka, et al. "Characterization and Pathogenicity Test of Entomopathogenic Nematode Steinernema Species-Kalro." Journal of Agricultural Science 13, no. 3 (2021): 93. http://dx.doi.org/10.5539/jas.v13n3p93.
Full textAbstract:
Entomopathogenic nematodes (EPNs) are worldwide soil-dwelling insect parasitic nematodes. They are potential pest bio-control agents a key component of Integrated Pest Management (IPM) programs. This study aimed to characterize and evaluate the pathogenicity of an EPN isolate from Kenya. The nematode was isolated from soils using insect bait technique and both morphological and molecular identification was performed. Efficacy of the isolate was evaluated against Tomato leafminer larvae (Tuta absoluta Meyrick.) using dose-based treatments of 0-control, 100, 150, 200, and 250 infective juveniles (IJs/ml). Morphological analysis revealed body length (L) of 835(659-987) &micro;m and 1781 (1297-2097) &micro;m from fresh IJs and males respectively. Males lacked a mucron. The isolate was characterized by the partial sequence length of 877 bp of the ITS region. Blastn results indicated the EPN isolate had a similarity match of 81-92% with Afro-tropical Steinernema species. It matched with Steinernema sp. (AY230186.1) from Kenya at 92% and Sri Lanka (AY230184.1). Phylogenetic analysis placed the isolate together with Steinernema sp. (AY230186.1) and (AY230184.1) with a bootstrap value of 100%. Maximum mean larval mortality (80%; 96%) was achieved 24 and 48 h post-treatment at concentration 150 IJs/ml. All nematode concentrations achieved over 50% mean mortality after 24 h period. There was a significant difference (P = 0.001) between doses 150 and 200 IJs/ml. From the study, it was concluded that the nematode isolate was Steinernema sp now referred to as Steinernema sp. Kalro (Genebank Accession MW151701). The EPN has the potential for development as a biological control agent against T. absoluta.
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Plecko, Barbara. "Newsletter EPNS." European Journal of Paediatric Neurology 16, no. 5 (2012): vi—viii. http://dx.doi.org/10.1016/s1090-3798(12)00181-x.
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Begeer, JH. "EPNS Newsletter." European Journal of Paediatric Neurology 5, no. 4 (2001): 183–87. http://dx.doi.org/10.1053/ejpn.2001.0507.
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de Meirleir, Linda. "EPNS Newsletter." European Journal of Paediatric Neurology 5, no. 4 (2001): 189–90. http://dx.doi.org/10.1053/ejpn.2001.0509.
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De Meirleir, Linda. "EPNS Newsletter." European Journal of Paediatric Neurology 6, no. 1 (2002): 87–89. http://dx.doi.org/10.1053/ejpn.2002.0552.
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De Meirleir, Linda. "EPNS Newsletter." European Journal of Paediatric Neurology 6, no. 2 (2002): 137–38. http://dx.doi.org/10.1053/ejpn.2002.0565.
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de Meirleir, Linda. "EPNS Newsletter." European Journal of Paediatric Neurology 5, no. 4 (2001): 188. http://dx.doi.org/10.1053/ejpn.2001.0508.
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De Meirleir, Linda. "EPNS Newsletter." European Journal of Paediatric Neurology 13, no. 4 (2009): 382–83. http://dx.doi.org/10.1016/j.ejpn.2009.04.008.
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