Genetic variation in baculoviruses is recognized as a key factor, not only due to the influence of such variation on pathogen transmission and virulence traits, but also because genetic variants can form the basis for novel biological insecticides. In this study, we examined the genetic variability of Chrysodeixis includens nucleopolyhedrovirus (ChinNPV) present in field isolates obtained from virus-killed larvae. Different ChinNPV strains were identified by restriction endonuclease analysis, from which genetic variants were isolated by plaque assay. Biological characterization studies were based on pathogenicity, median time to death (MTD), and viral occlusion body (OB) production (OBs/larva). Nine different isolates were obtained from eleven virus-killed larvae collected from fields of soybean in Mexico. An equimolar mixture of these isolates, named ChinNPV-Mex1, showed good insecticidal properties and yielded 23 genetic variants by plaque assay, one of which (ChinNPV-R) caused the highest mortality in second instars of C. includens. Five of these variants were selected: ChinNPV-F, ChinNPV-J, ChinNPV-K, ChinNPV-R, and ChinNPV-V. No differences in median time to death were found between them, while ChinNPV-F, ChinNPV-K, ChinNPV-R and ChinNPV-V were more productive than ChinNPV-J and the original mixture of field isolates ChinNPV-Mex1. These results demonstrate the high variability present in natural populations of this virus and support the use of these new genetic variants as promising active substances for baculovirus-based bioinsecticides.
The joint use of baculoviruses and synthetic insecticides for integrated pest management requires the study of the additive, synergistic or antagonistic effects among them on pest mortality. Droplet bioassays were conducted with Autographa californica multiple nucleopolyhedrovirus (AcMNPV), Spodoptera littoralis nucleopolyhedrovirus (SpliNPV) and seven insecticides (azadirachtin, Bacillus thuringiensis, cyantraniliprole, emamectin, metaflumizone, methoxyfenozide and spinetoram) on Spodoptera exigua and Spodoptera littoralis. The lethal concentrations LC50 and LC95 were calculated through probit regressions. Then, the sequential feeding of insecticides and nucleopolyhedroviruses was studied. Larvae were provided with the LC50 of one insecticide, followed by the LC50 of one nucleopolyhedrovirus 24 h later. The inverse order was also conducted. The insecticide LC50 and LC95 were higher for S. littoralis than for S. exigua. AcMNPV showed greater toxicity on S. exigua than SpliNPV on S. littoralis. Emamectin showed synergy with AcMNPV when the chemical was applied first, and metaflumizone and AcMNPV were synergistic regardless of the order of application, both from the first day of evaluation. SpliNPV was synergistic with azadirachtin and emamectin when it was applied first, but synergy was reached after 12–13 days. Excellent control is possible with the LC50 of azadirachtin, emamectin and metaflumizone in combination with nucleopolyhedroviruses, and merits further study as a means of controlling lepidopteran pests.
The mechanisms generating variability in viruses are diverse. Variability allows baculoviruses to evolve with their host and with changes in their environment. We examined the role of one genetic variant of Chrysodeixis includens nucleopolyhedrovirus (ChinNPV) and its contribution to the variability of the virus under laboratory conditions. A mixture of natural isolates (ChinNPV‑Mex1) contained two genetic variants that dominated over other variants in individual larvae that consumed high (ChinNPV-K) and low (ChinNPV-E) concentrations of inoculum. Studies on the ChinNPV‑K variant indicated that it was capable of generating novel variation in a concentration-dependent manner. In cell culture, cells inoculated with high concentrations of ChinNPV-K produced OBs with the ChinNPV-K REN profile, whereas a high diversity of ChinNPV variants was recovered following plaque purification of low concentrations of ChinNPV-K virion inoculum. Interestingly, the ChinNPV-K variant could not be recovered from plaques derived from low concentration inocula originating from budded virions or occlusion-derived virions of ChinNPV-K. Genome sequencing revealed marked differences between ChinNPV-K and ChinNPV-E, with high variation in the ChinNPV-K genome, mostly due to single nucleotide polymorphisms. We conclude that ChinNPV‑K is an unstable genetic variant that is responsible for generating much of the detected variability in the natural ChinNPV isolates used in this study.
The Queensland Curtis Liquefied Natural Gas (QCLNG) project is the world's first project to convert coal seam gas (CSG) into liquefied natural gas 1 . The project involves drilling thousands of wells in the Surat basin, installing an underground 540 km long pipeline to Gladstone and the building of a plant on Curtis Island to liquefy the natural gas. The project, which has been under construction since 2010, is on schedule to provide LNG for export from the end of 2014.The multi-billion-dollar investment by QGC, the Australian business of BG Group, is one of Australia's largest current capital infrastructure projects. Schlumberger has been contracted to deliver on the drilling and completion phase of this critical project.The "Factory Drilling*" project operates nine rigs using a multidisciplinary team consisting of project management staff utilising/coordinating logistics, warehousing, wellsite management, cementing, wireline, bits, solids control and directional services/personnel. The project has overcome significant challenges in the business development and start-up phases. Through the application of the "excellence in execution" philosophy, records have been broken and new performance benchmarks set in this unconventional CSG market.Since the start of the project in early 2012, using the team's project management abilities and incorporating LEAN (the identification and steady elimination of waste from operations) initiatives, the project has drilled and completed more than 1000 wells, some in as little as 2.15 days (drilling time) and 1.04 days (completion time).The optimisation initiatives have contributed towards reaching a state where the project is currently performing very close to the technical limit, yet challenges are still ahead to maintain and mature the safety culture and improve the operational efficiency even further.
We report on the phase transition of finding a complete subgraph, of specified dimensions, in a bipartite graph. Finding a complete subgraph in a bipartite graph is a problem that has growing attention in several domains, including bioinformatics, social network analysis and domain clustering. A key step for a successful phase transition study is identifying a suitable order parameter, when none is known. To this purpose, we have applied a decision tree classifier to real-world instances of this problem, in order to understand what problem features separate an instance that is hard to solve from those that is not. We have successfully identified one such order parameter and with it the phase transition of finding a complete bipartite subgraph of specified dimensions. Our phase transition study shows an easy-to-hard-to-easy-to-hard-toeasy pattern. Further, our results indicate that the hardest instances are in a region where it is more likely that the corresponding bipartite graph will have a complete subgraph of specified dimensions, a positive answer. By contrast, instances with a negative answer are more likely to appear in a region where the computational cost is negligible. This behaviour is remarkably similar for problems of a number of different sizes.
Este trabajo es un estudio socio-analítico de la novela Mano de obra (Eltit, 2002) la cual refiere a las vicisitudes laborales que se viven en un supermercado en el Chile contemporáneo. El estudio se enfoca en el entendimiento de las prácticas de Management Flexible en el supermercado y de la toxicidad emocional que tales prácticas ocasionan en los trabajadores. La narrativa destaca por la elocuencia fenomenológica con que se retratan las experiencias vividas por hombres y mujeres en las relaciones con supervisores, clientes, compañeros y con la organización como totalidad. El enfoque socio-analítico pone énfasis en el entendimiento de dinámicas colectivas inconscientes en el supermercado. Diferentes conceptos socio-analíticos iluminan esas dinámicas, la organización psicótica; toxicidad emocional y cambios organizacionales; estado mental de guerra en los negocios; e impedimentos para el duelo en organizaciones. La interpretación de la novela considera la aplicación del método hermenéutico. Abstract: This paper is a socio-analytic study of the novel Mano de obra (Eltit, 2002) which refers to the labour vicissitudes in a supermarket in Chilean contemporary society. The study focuses on understanding the practices of Flexible Management in the supermarket and the emotional toxicity that such practices cause on people at the workplace, family and society. The narrative stands out for the phenomenological eloquence with which it shows the experiences lived by men and women in their work relationship with supervisors, clients and co-workers in the context of the supermarket. The socio-analytical approach puts emphasis on the understanding of unconscious collective dynamics. Different socio-analytic contributions are applied to shed light on those dynamics, the psychotic organization; emotional toxicity and organizational changes; war mentality in business; and impediments to mourn in organizations. The interpretation of the novel considers the use of the hermeneutic method.
This article is concerned with the recovery and discovery of conscious and unconscious meanings in the construction of the identity of the Human Resource Management (HRM) discipline at the Faculty of Economics and Business Administration, Universidad de Chile. The article is based on a research exploring the role of collective memory in the construction of that identity, from its inception in 1958 until 2017. A socio-analytical approach was applied to understand the dynamics implied in the construction of the identity of HRM. The results of the research show the existence of silenced meanings about that construction as a consequence of an unconscious political memory operating at the faculty that restricted the access and understanding of unexamined institutional knowledge. Such censorship is thought to be associated with the transformations that occurred in Chilean society and the faculty before and after the coup d’état that took place in 1973.
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