Journal articles: 'Isolating mechanism'

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Peicheng, Shi, Shi Peilei, Nie Gaofa, Tang Ye, and Pan Daoyuan. "Research on Displacement Transfer Characteristics of a New Vibration-Isolating Platform Based on Parallel Mechanism." Mathematical Problems in Engineering 2017 (2017): 1–8. http://dx.doi.org/10.1155/2017/8743868.

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Based on the parallel mechanism theory, a new vibration-isolating platform is designed and its kinetic equation is deduced. Taylor expansion is used to approximately replace the elastic restoring force expression of vibration-isolating platform, and the error analysis is carried out. The dynamic-displacement equation of the vibration-isolating platform is studied by using the Duffing equation with only the nonlinear term. The dynamic characteristics of the vibration-isolating platform are studied, including amplitude-frequency response, jumping-up and jumping-down frequency, and displacement transfer rate under base excitation. The results show that the lower the excitation amplitude, the lower the initial vibration isolation frequency of the system. The influence of the platform damping ratio ζ on displacement transfer rate is directly related to the jumping-down frequency Ωd and the external excitation frequency. The vibration-isolating platform is ideally suited for high-frequency and small-amplitude vibrations.

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Mazur, Karolina. "Isolating mechanisms as sustainability factors of resource-based competitive advantage." Management 17, no. 2 (December 1, 2013): 31–46. http://dx.doi.org/10.2478/manment-2013-0053.

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Summary Isolating mechanisms as sustainability factors of resource-based competitive advantage Strategic resources which fulfill conditions of VRIN generate extraordinary profits for organizations. The possibility of these long-term profits (rents) to achieve can be protected by isolating mechanisms. These mechanisms can be different but the most important are causal ambiguity, lead time, path dependency, the role of history, socially complex links and the time compression diseconomies. These mechanism can be WIM and AIM type (based on willingness or ability). They can be also analyzed on individual, organizational or social levels. The article presents the case study which supports available systems of mechanism categorization.

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ITAGAKI, T., M. ICHINOMIYA, K. FUKUDA, S. FUSYUKU, and C. CARMONA. "Hybridization experiments indicate incomplete reproductive isolating mechanism between Fasciola hepatica and Fasciola gigantica." Parasitology 138, no. 10 (July 18, 2011): 1278–84. http://dx.doi.org/10.1017/s0031182011000965.

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SUMMARYExperiments on hybridization between Fasciola hepatica and Fasciola gigantica were carried out to clarify whether a reproductive isolating mechanism appears between the two Fasciola species. Molecular evidence for hybridization was based on the DNA sequence of the internal transcribed spacer 1 (ITS1) region in nuclear ribosomal DNA, which differs between the species. The results suggested that there were not pre-mating but post-mating isolating mechanisms between the two species. However, viable adults of the hybrids F1 and F2 were produced from both parental F. hepatica and F. gigantica. The hybrids inherited phenotypic characteristics such as ratio of body length and width and infectivity to rats from parental Fasciola hepatica and F. gigantica. These findings suggest that reproductive isolation is incomplete between Fasciola hepatica and F. gigantica. Adults of the hybrids F1 and F2 were completely different in mode of reproduction from aspermic Fasciola forms that occur in Asia and seem to be offspring originated from hybridization between F. hepatica and F. gigantica and to reproduce parthenogenetically.

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ISHIDA, Sachiko. "Vibration-isolating Mechanism using Origami-based Deployable Structures." Journal of the Society of Mechanical Engineers 119, no. 1175 (2016): 554–55. http://dx.doi.org/10.1299/jsmemag.119.1175_554.

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Watson, J. A. L. "Genital structure as an isolating mechanism in Odonata." Proceedings of the Royal Entomological Society of London. Series A, General Entomology 41, no. 10-12 (April 2, 2009): 171–74. http://dx.doi.org/10.1111/j.1365-3032.1966.tb00338.x.

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Lou, Yu, and Peng Zhou. "Design and evaluation of a quasi-zero-stiffness isolator using flexibly supported negative stiffness mechanism." E3S Web of Conferences 233 (2021): 03052. http://dx.doi.org/10.1051/e3sconf/202123303052.

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In traditional quasi-zero-stiffness (QZS) isolation system, the negative stiffness part is usually fixed rigidly, lacking of effective amplifying mechanism. For reaching a quasi-zero state, the value of negative stiffness need to be very large to offset the positive stiffness of the structure. This paper proposes a novel isolator incorporating a flexible support to magnify negative stiffness part for effective realization of quasi-zero state. First, the concept and formulation of the innovative quasi-zero isolator are presented. Equivalent model for the flexibly supported negative stiffness part is established, followed by a parametric analysis to reveal the amplification effect. Thereafter, a design method is developed and numerical simulation is performed to verify the isolating performance. The results show that a flexible support enlarges the negative stiffness remarkably, thereby resulting in a cost-effective design. The optimized QZS isolator is capable of isolating external disturbance significantly.

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Mizuguti, Aki, and Aya Nishiwaki. "Reproductive isolating mechanism between two types of Imperata cylindrica." Journal of Weed Science and Technology 50, Supplement (2005): 18–19. http://dx.doi.org/10.3719/weed.50.supplement_18.

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Beamish, Richard J., and Chrys-Ellen M. Neville. "The Importance of Size as an Isolating Mechanism in Lampreys." Copeia 1992, no. 1 (February 3, 1992): 191. http://dx.doi.org/10.2307/1446551.

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Hasyim, Sahyar, and Mahmud. "Isolating Mechanism as a Mean to Improve Performance of SMEs." EUROPEAN RESEARCH STUDIES JOURNAL XX, Issue 3A (November 1, 2017): 594–612. http://dx.doi.org/10.35808/ersj/731.

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Ney, Gideon, and Johannes Schul. "Epigenetic and genetic variation between two behaviorally isolated species of Neoconocephalus (Orthoptera: Tettigonioidea)." Journal of Orthoptera Research 28, no. 2 (May 17, 2019): 11–19. http://dx.doi.org/10.3897/jor.28.28888.

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Epigenetic variation allows for rapid changes in phenotypes without alterations to nucleotide sequences. These epigenetic signatures may diverge over time among isolated populations. Epigenetic incompatibility following secondary contact between these populations could result in the evolution of reproductive isolating mechanisms. If epigenetic incompatibility drove the evolution of species isolating mechanisms, we expect to see significant epigenetic differentiation between these species. Alternatively, epigenetic variation could be the result of predominantly environmental variables and not align along species boundaries. A methylation sensitive amplified fragment length polymorphism analysis was performed on individuals of the closely related katydid species Neoconocephalusrobustus and N.bivocatus. We observed significant variation in total methylation levels between species. However, genetic differentiation remained larger than epigenetic differentiation between species groups. We measured a significant correlation between the epigenetic and genetic distance between individuals. Epigenetic differentiation is therefore likely the result of an interaction between genetic and epigenetic loci and not a mechanism for species differentiation. We therefore did not find evidence to support our hypothesis of an epigenetically mediated mechanism for speciation between N.robustus and N.bivocatus.

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Xu, Mengxue, Qingwei Du, Caihuan Tian, Ying Wang, and Yuling Jiao. "Stochastic gene expression drives mesophyll protoplast regeneration." Science Advances 7, no. 33 (August 2021): eabg8466. http://dx.doi.org/10.1126/sciadv.abg8466.

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Cell pluripotency is fundamental to biology. It has long been known that differentiated somatic plant cells may reacquire pluripotency, but the underlying mechanism remains elusive. In many plant species, a single isolated mesophyll protoplast may regenerate into an entire plant, which is widely used in gene transformation. Here, we identified two transcription factors whose ectopic activation promotes protoplast regeneration. Furthermore, we found that their expression was induced by protoplast isolation but at a very low frequency. Using live imaging and single-cell transcriptomics, we show that isolating protoplasts induces enhanced expression variation at the genome level. Isolating protoplasts also leads to genome-wide increases in chromatin accessibility, which promotes stochastic activation of gene expression and enhances protoplast regeneration. We propose that transcriptome chaos with increased expression variability among cells creates a cellular-level evolutionary driver selecting for regenerating cells.

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Schmidt, E. M., and K. S. Pfennig. "Hybrid female mate choice as a species isolating mechanism: environment matters." Journal of Evolutionary Biology 29, no. 4 (January 20, 2016): 865–69. http://dx.doi.org/10.1111/jeb.12818.

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Wei-LaPierre, Lan, and Robert T. Dirksen. "Isolating a reverse-mode ATP synthase–dependent mechanism of mitoflash activation." Journal of General Physiology 151, no. 6 (April 22, 2019): 708–13. http://dx.doi.org/10.1085/jgp.201912358.

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Jiang, Xin, Yongguo Fu, Linyu Li, Hanyan Gu, and Yanjun Qiu. "Design Optimisation Analysis of Isolating Wall for Separated Widening Embankment on Soft Ground." Baltic Journal of Road and Bridge Engineering 16, no. 2 (June 21, 2021): 127–50. http://dx.doi.org/10.7250/bjrbe.2021-16.527.

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In this paper, the typical cases of subgrade separated widening project in China are summarised. The research progress of subgrade separated widening and isolating wall applications are reviewed in highway reconstruction and extension. A numerical model is established based on the PLAXIS finite element software, considering both material nonlinearity and geometric nonlinearity. The effect mechanism of the isolating wall is discussed on the settlement control of the new and existing embankment on soft ground. The effect rule of the core design parameters of the isolating wall is revealed on the settlement disturbance of the existing embankment, such as location, depth, thickness and elastic modulus, and the weight rank of the influence is analysed. The results indicate that the isolating wall effectively reduces the lateral displacement and vertical settlement of the existing embankment, and there is an optimal design location for the isolating wall. In addition, with the increase of design parameters of the isolating wall, including depth, thickness and elastic modulus, the overall settlement of the existing embankment tends to be uniform, and there are optimal values. Furthermore, the depth of isolating wall is given priority, compared to location, thickness and elastic modulus during the isolating wall design process. The research results lay a theoretical foundation for the design optimisation of the isolating wall in the separated widening project of soft ground.

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Jamaludin, Nur Mas Ayu, Muhammad Khairulanwar Abdul Rahim, Azrul Azlan Hamzah, Nadiah Abu, and Muhamad Ramdzan Buyong. "Rapid Manipulation of Extracellular Vesicles using Dielectrophoretic Mechanism." Sains Malaysiana 49, no. 12 (December 31, 2020): 2901–12. http://dx.doi.org/10.17576/jsm-2020-4912-03.

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Extracellular vesicles (EVs) are small entities that are released by most cell types. EVs are important form of intercellular communication and a rich source of biomarkers for a wide variety of diseases. Many methods for EVs isolation have been utilized, however, most of them have significant drawbacks including lengthy processing time, high cost, shortfalls in selectivity and surface marker dependency. In consideration of these issues, this paper discussed on the dielectrophoresis (DEP) microelectrode method designed to rapidly isolate EVs from its medium. The advantage of this DEP microelectrode is the capability of isolating EVs using a droplet of 1 µL placed onto the microelectrode within 30 s and 20 V peak-to-peak (Vp-p) of alternating current (AC). The method used in the characterization of sample are dynamic light scattering (DLS) and transmission electron microscopy (TEM); both prove the heterogeneity of EVs’ population and the EVs appear to be spherical with size ranging from 40 to 200 nm. The experimental results from this preliminary experiment show that the DEP microelectrode was able to manipulate EVs as evidenced by the negative dielectrophoresis (NDEP) fluorescent images. Further investigation of grid analysis conducted shows the consistency of the theory and the results presented. Corrected Total Cell Fluorescence (CTCF) values from the grid analysis concluded that the EVs were manipulated to the center of region of interest (ROI). Therefore, this DEP technique suggests a rapid strategy for EVs isolation from its medium in small quantity while maintaining accuracy and cost-effectivity.

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Coyne, Jerry A. "The Genetics of an Isolating Mechanism between Two Sibling Species of Drosophila." Evolution 47, no. 3 (June 1993): 778. http://dx.doi.org/10.2307/2410183.

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Coyne, Jerry A. "THE GENETICS OF AN ISOLATING MECHANISM BETWEEN TWO SIBLING SPECIES OF DROSOPHILA." Evolution 47, no. 3 (June 1993): 778–88. http://dx.doi.org/10.1111/j.1558-5646.1993.tb01233.x.

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Sengathir, J., and R. Manoharan. "Exponential Reliability Coefficient based Reputation Mechanism for isolating selfish nodes in MANETs." Egyptian Informatics Journal 16, no. 2 (July 2015): 231–41. http://dx.doi.org/10.1016/j.eij.2015.05.003.

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Ichikawa, Mie, and Yoshitaka Ichikawa. "A mechanism-based affinity-labeling agent for possible use in isolating N-acetylglucosaminidase." Bioorganic & Medicinal Chemistry Letters 11, no. 13 (July 2001): 1769–73. http://dx.doi.org/10.1016/s0960-894x(01)00300-6.

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Klips, Robert A. "Pollen competition as a reproductive isolating mechanism between two sympatric Hibiscus species (Malvaceae)." American Journal of Botany 86, no. 2 (February 1999): 269–72. http://dx.doi.org/10.2307/2656942.

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Al-Rushdan, Huthifh, Mohammad Shurman, and Sharhabeel Alnabelsi. "On Detection and Prevention of Zero-Day Attack Using Cuckoo Sandbox in Software-Defined Networks." International Arab Journal of Information Technology 17, no. 4A (July 31, 2020): 662–70. http://dx.doi.org/10.34028/iajit/17/4a/11.

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Networks attacker may identify the network vulnerability within less than one day; this kind of attack is known as zero-day attack. This undiscovered vulnerability by vendors empowers the attacker to affect or damage the network operation, because vendors have less than one day to fix this new exposed vulnerability. The existing defense mechanisms against the zero-day attacks focus on the prevention effort, in which unknown or new vulnerabilities typically cannot be detected. To the best of our knowledge the protection mechanism against zero-day attack is not widely investigated for Software-Defined Networks (SDNs). Thus, in this work we are motivated to develop a new zero-day attack detection and prevention mechanism for SDNs by modifying Cuckoo sandbox tool. The mechanism is implemented and tested under UNIX system. The experiments results show that our proposed mechanism successfully stops the zero-day malwares by isolating the infected clients, in order to prevent the malwares from spreading to other clients. Moreover, results show the effectiveness of our mechanism in terms of detection accuracy and response time

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TROUVÉ, S., F. RENAUD, P. DURAND, and J. JOURDANE. "Experimental evidence of hybrid breakdown between genetically distinct populations of Echinostoma caproni." Parasitology 117, no. 2 (August 1998): 133–35. http://dx.doi.org/10.1017/s0031182098002947.

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In this paper we investigate whether the assortative mating between individuals of the same genetic entity (i.e. coming from the same geographical area) of Echinostoma caproni, reported in a previous paper, may be explained by a post-zygotic isolating mechanism. The fecundity of the adults of 2 parental genetic entities and of their hybrids (i.e. F1, F2, F3) was quantified through 3 successive generations. Whereas the number of eggs released by F1 hybrids is similar to that of the mid-parent, that of recombinant hybrids (F2–3 hybrids) is significantly lower than that of F1 and that of the mid-parent. Since these results seem to demonstrate hybrid breakdown, 2 important factors maintaining reproductive isolation, i.e. pre-mating reproductive isolation and low hybrid fecundity, may influence the evolution of E. caproni.

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Liao, Wen Jun, Yu Xin Wang, Le Cai Zeng, and Biao Yan. "Study on Preparation and Application of High-Performance Cu-Al Composite Row." Advanced Materials Research 217-218 (March 2011): 1716–20. http://dx.doi.org/10.4028/www.scientific.net/amr.217-218.1716.

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Cu-Al composite row was produced by continuous cast-rolling technique and metallurgical bonding interface was achieved. The microstructure of interface and the composite mechanism was investigated. Isolating switch was fabricated by using copper-aluminum composite row as current-carrying conductor. Main performance index and technical parameters were evaluated. The composite row shows excellent mechanical property and conductivity: overall tensile strength of 102MPa, elastic modulus of 1.5GPa, resistance rate of 0.0216Ωmm2/m and carrier density of 750A. The results present that the temperature rise, circuit resistance, mechanical life and other properties of the copper-aluminum composite row can meet the requirements of being the current-carrying conductor of isolating switch.

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Disselhoff, B. C. V. M., A. I. Rem, R. M. Verdaasdonk, D. J. der Kinderen, and F. L. Moll. "Endovenous laser ablation: an experimental study on the mechanism of action." Phlebology: The Journal of Venous Disease 23, no. 2 (April 2008): 69–76. http://dx.doi.org/10.1258/phleb.2007.007038.

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Objectives The aim of this experimental study was to investigate the mechanism of action of endovenous laser ablation (EVLA) using an 810-nm diode laser. Methods We compared intermittent and continuous delivery of laser energy and studied the absorption of laser light by blood, intravascular temperatures in ex vivo human vein segments using an intravascular thermography catheter and heat dissipation in a model tissue using the Schlieren technique. Results Laser light is absorbed by blood and converted to heat leading to coagulation, vaporization and carbonization, and forming an isolating layer at the fibre tip. Laser energy is then absorbed into the isolating layer forming black patches that burned on the laser fibre. Intravascular temperature increased rapidly above carbonization temperatures (300°C) after the fibre tip reached the thermocouple, stayed at this temperature for a few seconds and decreased gradually to around 30°C, 10 s after the fibre tip passed the thermocouple. Schlieren techniques revealed that heat spread from the laser was locally distributed and closely around the laser fibre tip while heat dissipation is minimal and comparable for both exposures. Compared with intermittent exposure, continuous exposure results in more carbonization, higher mean maximum intravascular temperature (128 ± 7 vs. 75 ± 4°C), and long-lasting temperature of 100°C (1.2 ± 0.4 vs. 0.1 ± 0.1 s). Conclusion In this experimental study, application of endovenous laser shows to be dominated by carbonization at the fibre tip. Although intraluminal laser-induced heat was heterogeneously distributed, with laser tip temperatures up to 1200°C, heat dissipation was minimal. Continuous exposure of laser light appears to be better suited in EVLA than intermittent.

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Bay, Rachael A., and Kristen Ruegg. "Genomic islands of divergence or opportunities for introgression?" Proceedings of the Royal Society B: Biological Sciences 284, no. 1850 (March 8, 2017): 20162414. http://dx.doi.org/10.1098/rspb.2016.2414.

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In animals, introgression between species is often perceived as the breakdown of reproductive isolating mechanisms, but gene flow between incipient species can also represent a source for potentially beneficial alleles. Recently, genome-wide datasets have revealed clusters of differentiated loci (‘genomic islands of divergence’) that are thought to play a role in reproductive isolation and therefore have reduced gene flow. We use simulations to further examine the evolutionary forces that shape and maintain genomic islands of divergence between two subspecies of the migratory songbird, Swainson's thrush ( Catharus ustulatus ), which have come into secondary contact since the last glacial maximum. We find that, contrary to expectation, gene flow is high within islands and is highly asymmetric. In addition, patterns of nucleotide diversity at highly differentiated loci suggest selection was more frequent in a single ecotype. We propose a mechanism whereby beneficial alleles spread via selective sweeps following a post-glacial demographic expansion in one subspecies and move preferentially across the hybrid zone. We find no evidence that genomic islands are the result of divergent selection or reproductive isolation, rather our results suggest that differentiated loci both within and outside islands could provide opportunities for adaptive introgression across porous species boundaries.

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Whiteley, A. R., K. N. Persaud, N. Derome, R. Montgomerie, and L. Bernatchez. "Reduced sperm performance in backcross hybrids between species pairs of whitefish (Coregonus clupeaformis)." Canadian Journal of Zoology 87, no. 7 (July 2009): 566–72. http://dx.doi.org/10.1139/z09-042.

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Previous work has demonstrated that genomic incompatibilities work together with ecologically divergent selection to promote and maintain reproductive isolation between incipient species (dwarf and normal) of lake whitefish ( Coregonus clupeaformis (Mitchill, 1818)). Whitefish spawn in groups with external fertilization, which creates conditions for strong sperm competition. In this study, we asked whether reduced sperm performance in hybrids from whitefish species-pair matings might contribute to postzygotic isolating mechanisms between these taxa. We examined two sperm traits, sperm swimming speed and flagellum length, in pure dwarf and normal whitefish and in their F1 and backcross hybrids. We observed significantly reduced sperm swimming speed in backcross but not in F1 hybrids. Sperm flagellum length was not significantly correlated with sperm swimming speed. These results demonstrate that F1 hybrids formed in nature should be capable of the same fertilization success as the parental species during sperm competition, everything else being equal. However, reduced sperm performance in the backcross generation is consistent with other evidence suggesting that genomic incompatibilities create a range of negative fitness effects in post-F1 whitefish hybrids and provides evidence for an additional postzygotic isolation mechanism involved in the incipient speciation of sympatric dwarf and normal whitefish.

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Lau, Pui Yan Flora, and Iulia Gheorghiu. "Vanishing Selves under Hong Kong’s Unified Screening Mechanism." Cultural Diversity in China 3, no. 1 (June 26, 2018): 21–35. http://dx.doi.org/10.1515/cdc-2018-0003.

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Abstract Drawing on Erving Goffman’s analysis of total institutions and his concept of mortification of the self, the present article deals with the process of identity construction and identity loss among refugees and asylum seekers in Hong Kong. We argue that the slow pace of processing of political asylum applications as well as the harsh restrictions imposed on rights to work and the minimal welfare provisions for refugees and asylum seekers in Hong Kong operate as means of isolating them from the broader society. Another consequence of these restrictive conditions becomes manifest in the loss of identity experienced by those who have been stuck in Hong Kong for many years waiting for their applications to be processed. Being unable to preserve the sense of identity they had in their countries of origin, they find themselves deprived of the social and institutional resorts necessary to forge a new one.

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Spirito, Franco. "The reduction of gene exchange due to a prezygotic isolating mechanism with monogenic inheritance." Theoretical Population Biology 32, no. 2 (October 1987): 216–39. http://dx.doi.org/10.1016/0040-5809(87)90048-7.

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Stearns, Frank W., Kelley J. Tilmon, and Thomas K. Wood. "Felsenstein’s “one-allele model” of speciation: The role of philopatry in the initial stages of host plant mediated reproductive isolation in Enchenopa binotata." Current Zoology 59, no. 5 (October 1, 2013): 658–66. http://dx.doi.org/10.1093/czoolo/59.5.658.

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Abstract The study of speciation genetics is primarily concerned with identifying the genetic traits that allow divergent selection to overcome the homogenizing effects of gene flow. Felsenstein reviewed this race between gene flow and selection, concluding that speciation with gene flow was unlikely under a “two-allele model” (where two traits were necessary for reproductive isolation) but that divergence could occur quite easily under a “one-allele model.” Despite this finding, much of the sympatric speciation research involving phytophagous insects has relied on a two-trait model, where insects evolve both preferences for and increased performance on novel host plants. Philopatry (a tendency to remain where one was born) is known to occur in phytophagous insects and is a single trait isolation mechanism. However, it is traditionally invoked as simply augmenting reproductive isolation. Species in the Enchenopa binotata complex are believed to have speciated in sympatry. They exhibit host plant preferences, host specific performance advantages and strong philopatry. We experimentally shifted E. binotata to evolutionarily novel host plants. Previous research has demonstrated that the experimental population of insects possesses genetic variation in preference and performance to the novel host. The degree of philopatry at mating and egg-laying was assayed for the first four years under full choice conditions. Host plant preference and performance was assayed after eight years. Philopatry was an immediate and strong isolating mechanism, while preference for and performance on the novel host lagged. We therefore suggest that philopatry may be a more important mechanism in the early stages of a host shift than previously believed.

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Ding, Ming, and Kathryn M. Rexrode. "A Review of Lipidomics of Cardiovascular Disease Highlights the Importance of Isolating Lipoproteins." Metabolites 10, no. 4 (April 23, 2020): 163. http://dx.doi.org/10.3390/metabo10040163.

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Cutting-edge lipidomic profiling measures hundreds or even thousands of lipids in plasma and is increasingly used to investigate mechanisms of cardiovascular disease (CVD). In this review, we introduce lipidomic techniques, describe distributions of lipids across lipoproteins, and summarize findings on the association of lipids with CVD based on lipidomics. The main findings of 16 cohort studies were that, independent of total and high-density lipoprotein cholesterol (HDL-c), ceramides (d18:1/16:0, d18:1/18:0, and d18:1/24:1) and phosphatidylcholines (PCs) containing saturated and monounsaturated fatty acyl chains are positively associated with risks of CVD outcomes, while PCs containing polyunsaturated fatty acyl chains (PUFA) are inversely associated with risks of CVD outcomes. Lysophosphatidylcholines (LPCs) may be positively associated with risks of CVD outcomes. Interestingly, the distributions of the identified lipids vary across lipoproteins: LPCs are primarily contained in HDLs, ceramides are mainly contained in low-density lipoproteins (LDLs), and PCs are distributed in both HDLs and LDLs. Thus, the potential mechanism behind previous findings may be related to the effect of the identified lipids on the biological functions of HDLs and LDLs. Only eight studies on the lipidomics of HDL and non-HDL particles and CVD outcomes have been conducted, which showed that higher triglycerides (TAGs), lower PUFA, lower phospholipids, and lower sphingomyelin content in HDLs might be associated with a higher risk of coronary heart disease (CHD). However, the generalizability of these studies is a major concern, given that they used case–control or cross-sectional designs in hospital settings, included a very small number of participants, and did not correct for multiple testing or adjust for blood lipids such as HDL-c, low-density lipoprotein cholesterol (LDL-c), or TAGs. Overall, findings from the literature highlight the importance of research on lipidomics of lipoproteins to enhance our understanding of the mechanism of the association between the identified lipids and the risk of CVD and allow the identification of novel lipid biomarkers in HDLs and LDLs, independent of HDL-c and LDL-c. Lipidomic techniques show the feasibility of this exciting research direction, and the lack of high-quality epidemiological studies warrants well-designed prospective cohort studies.

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Gál, Miroslav F., Miriam Gálová, and Andrea Turoňová. "Transfer of Charge in a Particulate Iron-Electrolyte System." Collection of Czechoslovak Chemical Communications 65, no. 9 (2000): 1515–26. http://dx.doi.org/10.1135/cccc20001515.

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Mechanism of the charge transfer through a heterogeneous system consisting of Fe powder particles suspended in nickel-plating electrolyte was studied in the regime of electrolysis. Conductivity and impedance spectra were used to elucidate the contribution of solid particles to the charge transfer through the cell. Combined short-circuit and collision mechanism takes place in low-density suspensions. A complete elucidation of the mechanism is complicated by the presence of powder particles of three groups: particles carrying the charge, uncharged particles representing just a barrier to the charge transfer and particles passivated during the electrolysis by adsorption of an isolating layer of Fe and Ni hydroxocomplexes. The formation of powder aggregates in high-density suspensions was indirectly evidenced.

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Fu, Aaron. "Sense and Motion: The Barrier Preventing Us from Understanding Motion." JOURNAL OF ADVANCES IN PHYSICS 16, no. 1 (October 30, 2019): 372–76. http://dx.doi.org/10.24297/jap.v16i1.8468.

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Currently, scientific study and advancements are at odds with the natural motion systems that surround us. This paper explores how it is our sensory form and the cognition developed upon this sensory form that creates a barrier preventing us from truly understanding the laws of motion. It begins by isolating and defining two distinct forms of information and information processing mechanisms: motion information and integrated information. From this new perspective, it then explains how our sensory system is necessarily based on an integrated information mechanism to support basic survival needs, but is essentially blind to the true features of motion. The far-reaching effects of this discovery include the limitations within our cognitive mode and the current methods of scientific study and development.

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Adekenov, S. M. "Natural Sesquiterpene Lactones as Renewable Chemical Materials for New Medicinal Products." Eurasian Chemico-Technological Journal 15, no. 3 (May 13, 2013): 163. http://dx.doi.org/10.18321/ectj220.

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Literature data and own research results on the technology for isolating natural sesquiterpene lactones such as arglabin, alantolactone, artemisinin, grosheimin, isoalantolactone, parthenolide, santonin and potential possibilities of their use as renewable material for obtaining new compounds as well as biologically active derivatives are generalized in this review. Sesquiterpene lactones from plants are promising sources for the development and practical application of new original medical products possessing antitumor, anti-inflammatory, antimalarial, antiulcer, antiviral and immune-stimulating action. The technology for isolating sesquiterpene lactones is based on the extraction of raw plant material by different organic solvents with the subsequent chromatographic purification. The effective and environmentally safe technology for isolation and purification of sesquiterpene lactone arglabin from Artemisia glabella Kar. et Kir. by the СО2-extraction method is developed. Thereat, it was experimentally determined that the method for isolating arglabin from CO2 extract of Artemisia glabella Kar. et Kir. using centrifugal partition chromatography is effective for preparative isolation of the active substance and its manufacturing application. It is practically important to obtain water-soluble derivatives of biologically active sesquiterpene lactones and also to use the nanotechnology achievements for directed transportation of a molecule of the medicine in the human body thereby reducing toxicity of an active component. Promising direction is chemical modification of molecules in sesquiterpene lactones which are renewable material for obtaining new derivatives, thanks to which it becomes possible to solve two problems at the same time. Firstly, these researches help to obtain derivatives with higher biological activity or improved physical and chemical properties. Secondly, these researches enable us to disclose the mechanism of action of different medicines within the framework of “structure-activity” correlation. The article presents the literature data and own results on chemical modification of sesquiterpene lactones of alantolactone, arglabin, artemisinin, grosheimin, isoalantolactone, parthenolide and santonin. Various reactions on functional groups of these molecules were used to obtain a number of new derivatives of sesquiterpene lactones containing haloid-, pyrazole-, triazole-, amino-, dialkylamino-, hydroxy-, dialkyl phosphonate- and cyclopropane groups, which have shown high physiological activity.

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ALICHI, MAHMOOD. "A bio-syringe mechanism and the pattern of genital correspondence in the weevil genus Sitona (Coleoptera: Curculionidae): an approach to the great interest of Sharp and Muir." Zootaxa 4933, no. 4 (February 23, 2021): 514–26. http://dx.doi.org/10.11646/zootaxa.4933.4.3.

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The remarkable diversity in male and female genital morphology among the species of Sitona Germar might contribute to the understanding of the structural “lock-and-key” isolating mechanism. Recently, it has been found that in spite of the phallic sizes in male weevils of the genus Sitona, their internal sacs should precisely match with the vaginal infoldings of conspecific females. The present research also deals with the male transfer apparatus, which is a special organ for insemination procedure inside the female bursa copulatrix. A wedge-shaped structure with a fused ejaculatory pump was distinguished as the bio-syringe part of the transfer apparatus in the examined species. Two paired sclerites of the transfer apparatus support the bio-syringe, so that it would slide freely between them and lock precisely over the opening of the spermathecal duct inside the bursa copulatrix of the female. In this phenomenon, several new structures were also found, including a bursal sclerite (“bursal disc”) and a pair of miniature pouches (“bursal plugs”) which are embedded in the thickened wall of the female bursal lumen. These findings explain how the shapes of male and female copulatory organs are normally species-specific and provide an opportunity for understanding the role of the structural lock-and-key isolating mechanism.

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C, Daniel Nesa Kumar, and Saravanan V. "Improved Exponential Reliability Coefficient Based Reputation Mechanism for Isolating Selfish Nodes in Mobile Ad hoc Network." International Journal of Computer Sciences and Engineering 6, no. 6 (June 30, 2018): 206–12. http://dx.doi.org/10.26438/ijcse/v6i6.206212.

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Szijj, Laszlo J. "Hybridization and the Nature of the Isolating Mechanism in Sympatric Populations of Meadowlarks (Sturnella) in Ontario." Zeitschrift für Tierpsychologie 23, no. 6 (April 26, 2010): 677–90. http://dx.doi.org/10.1111/j.1439-0310.1966.tb01705.x.

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Tchuente, Louis-Albert Tchuem, Daniéle Imbert-Establet, Bernard Delay, and Joseph Jourdane. "Choice of mate, a reproductive isolating mechanism between Schistosoma intercalatum and S. mansoni in mixed infections." International Journal for Parasitology 23, no. 2 (April 1993): 179–85. http://dx.doi.org/10.1016/0020-7519(93)90139-p.

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Xu, Changyu, Lijun Han, Maolin Tian, Yajie Wang, and Yuhao Jin. "Study on Foamed Concrete Used as Gas Isolation Material in the Coal Mine Goaf." Energies 13, no. 17 (August 25, 2020): 4377. http://dx.doi.org/10.3390/en13174377.

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In view of the serious threat of gas accumulation in the coal mine goaf and the limitations of the existing gas sealing materials, the orthogonal experiment was developed to study a new type of foamed concrete for mine gas sealing. Dry density, gas permeability, and compressive strength were studied as the material indicators according to the demands of the gas isolation material in the coal mine goaf, and the experimental results showed that foam content was the most important factor. Meanwhile, the optimum mix was selected according to the influence of foam content as well as the engineering requirement. Then two application modes of this foamed concrete for goaf gas isolation were put forward, after which the convection-diffusion model of gas was built by COMSOL Multiphysics (COMSOL Inc., Stockholm, Sweden) to reveal the mechanism of different application modes using the parameters of the new foamed concrete. Simulation results showed that this foamed concrete used as isolating material for goaf gas could significantly decrease the gas concentration in workface, which can provide a reference for similar engineering.

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Wang, Li, Mingshan Xia, and Fazhi Qi. "Security Mechanism for user access to Single SSID WLAN." EPJ Web of Conferences 245 (2020): 07009. http://dx.doi.org/10.1051/epjconf/202024507009.

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Wireless local area network (WLAN) technology is widely used in various enterprises and institutions. In order to facilitate the use of users, they often provide a single SSID access point, resulting in different identities of users authenticated and authorized can connect to the wireless network anytime, anywhere as needed and obtain the same accessible network resources such as bandwidth, access control (ACL) and so on. Multiple SSID can solve the problem but it will be confused to users who don’t know which SSID can be connected. Although we could prevent visitors from accessing intranet resources by isolating the wireless network from the internal network, this would make it impossible for users to use the wireless network for internal office work. In this paper, we propose an access control system that grouping users according to the different identities and users authenticated and authorized can access different network resources because a wireless access point dynamically maps an SSID provided by a mobile station to a BSSID based on a VLAN assignment. The deployment experiment of the solution proves that users of different identities accessing the same wireless network can set different access policies, which effectively improves the security of the wireless network and simplifies the management of the wireless network.

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Drosopoulos, S. "Acoustic Communication and Mating Behaviour in the Muellerianella Complex (Homoptera - Delphacidae)." Behaviour 94, no. 1-2 (1985): 183–201. http://dx.doi.org/10.1163/156853985x00334.

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AbstractSome data on acoustic communication and mating behavior of two biparentally reproducing species and the clonally reproducing pseudogamous "species" of the genus Muellerianella are reported. Although bioacoustic differences were found in the calling songs between the species, these did not prevent pairforming. Also, differences in mating behavior, such as pre-copulation behavior, courtship activities, frequency and duration of copulation were not sufficient to prevent successful hybridization between both the two biparentally reproducing species and between each of these two species and the pseudogamous "species". The data reported here are related to other biological differences reported previously. According to these data there is some evidence that differences in acoustic communication and mating behavior between the two species are established by ecological influences which in turn have established analogous physiological requirements. These differences are rather weak isolating mechanisms. Regarding the behavioral relation of the pseudogamous species with males of the two parental species it was found that these females behave exactly as the females of M. fairmairei with which they coexist in the field. In interspecific crosses mechanical barriers to copulation are more efficient than courtship differences. Finally it is assumed that pseudogamy is a strong isolation mechanism between the not yet fully genetically differentiated bisexual species of Muellerianella.

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Shukla, Mahendra K., Akimasa Watanabe, Sam Wilson, Vasco Giovagnetti, Ece Imam Moustafa, Jun Minagawa, and Alexander V. Ruban. "A novel method produces native light-harvesting complex II aggregates from the photosynthetic membrane revealing their role in nonphotochemical quenching." Journal of Biological Chemistry 295, no. 51 (October 20, 2020): 17816–26. http://dx.doi.org/10.1074/jbc.ra120.016181.

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Nonphotochemical quenching (NPQ) is a mechanism of regulating light harvesting that protects the photosynthetic apparatus from photodamage by dissipating excess absorbed excitation energy as heat. In higher plants, the major light-harvesting antenna complex (LHCII) of photosystem (PS) II is directly involved in NPQ. The aggregation of LHCII is proposed to be involved in quenching. However, the lack of success in isolating native LHCII aggregates has limited the direct interrogation of this process. The isolation of LHCII in its native state from thylakoid membranes has been problematic because of the use of detergent, which tends to dissociate loosely bound proteins, and the abundance of pigment–protein complexes (e.g. PSI and PSII) embedded in the photosynthetic membrane, which hinders the preparation of aggregated LHCII. Here, we used a novel purification method employing detergent and amphipols to entrap LHCII in its natural states. To enrich the photosynthetic membrane with the major LHCII, we used Arabidopsis thaliana plants lacking the PSII minor antenna complexes (NoM), treated with lincomycin to inhibit the synthesis of PSI and PSII core proteins. Using sucrose density gradients, we succeeded in isolating the trimeric and aggregated forms of LHCII antenna. Violaxanthin- and zeaxanthin-enriched complexes were investigated in dark-adapted, NPQ, and dark recovery states. Zeaxanthin-enriched antenna complexes showed the greatest amount of aggregated LHCII. Notably, the amount of aggregated LHCII decreased upon relaxation of NPQ. Employing this novel preparative method, we obtained a direct evidence for the role of in vivo LHCII aggregation in NPQ.

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Si, Chao Wei, Guo Wei Han, Jin Ning, Wei Wei Zhong, and F. H. Yang. "Quality Factor Optimization Techniques for MEMS Gyroscopes of Frame Structures." Advanced Materials Research 590 (November 2012): 173–78. http://dx.doi.org/10.4028/www.scientific.net/amr.590.173.

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MEMS gyroscopes of frame structures are capable of isolating the quadrature error between the drive motion and the sense motion, which is often utilized in current gyroscope design. But quality factors of previous reported gyroscopes of frame structure are hardly over 1000, which are far more less than that of gyroscopes manufactured before with only one mass block for sensing and driving. Although the effectiveness of isolating quadrature errors is proved, the sensitivity is decreased as well as the power consumption is increased for higher drive voltage. Reasons why MEMS gyroscopes of frame structure has low quality factors is pointed out here with a method of anchor loss mechanism, and the energy dissipation is modeled with a 2 degree of vibration system, which tells the relationship between the mass ratio of the inner mass and the outer frame and the spring factor ratio for supporting masses, and the quality factor assess techniques is proposed here. Therefore the admissible parameters of the mass ratio and the spring factor ratio are given, which makes MEMS gyroscopes of frame structures have advantages of quadrature error isolation as well as high sensitivity. In the end, gyroscopes with optimized parameters and reported parameters are manufactured on SOI wafer, and variations of the quality factors as expected proves the rationality of the proposed energy dissipation model in this paper. For Process limitations, quality factors of gyroscopes of frame structures are improved lower than expected, but far more improved than previous reported gyroscopes, and better results should be realized in more mature and stabilized process.

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Albert, Arianne Y. K. "MATE CHOICE, SEXUAL IMPRINTING, AND SPECIATION: A TEST OF A ONE-ALLELE ISOLATING MECHANISM IN SYMPATRIC STICKLEBACKS." Evolution 59, no. 4 (2005): 927. http://dx.doi.org/10.1554/04-609.

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Albert, Arianne Y. K. "MATE CHOICE, SEXUAL IMPRINTING, AND SPECIATION: A TEST OF A ONE-ALLELE ISOLATING MECHANISM IN SYMPATRIC STICKLEBACKS." Evolution 59, no. 4 (April 2005): 927–31. http://dx.doi.org/10.1111/j.0014-3820.2005.tb01767.x.

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Um, Dugan. "Massive Sensor Array Fault Tolerance: Tolerance Mechanism and Fault Injection for Validation." Journal of Robotics 2010 (2010): 1–8. http://dx.doi.org/10.1155/2010/745834.

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As today's machines become increasingly complex in order to handle intricate tasks, the number of sensors must increase for intelligent operations. Given the large number of sensors, detecting, isolating, and then tolerating faulty sensors is especially important. In this paper, we propose fault tolerance architecture suitable for a massive sensor array often found in highly advanced systems such as autonomous robots. One example is the sensitive skin, a type of massive sensor array. The objective of the sensitive skin is autonomous guidance of machines in unknown environments, requiring elongated operations in a remote site. The entirety of such a system needs to be able to work remotely without human attendance for an extended period of time. To that end, we propose a fault-tolerant architecture whereby component and analytical redundancies are integrated cohesively for effective failure tolerance of a massive array type sensor or sensor system. In addition, we discuss the evaluation results of the proposed tolerance scheme by means of fault injection and validation analysis as a measure of system reliability and performance.

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Pengo, V., P. Thiagarajan, SS Shapiro, and MJ Heine. "Immunological specificity and mechanism of action of IgG lupus anticoagulants." Blood 70, no. 1 (July 1, 1987): 69–76. http://dx.doi.org/10.1182/blood.v70.1.69.69.

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Abstract Although observations have implied that lupus anticoagulants have immunologic specificity toward anionic phospholipids, this assumption has been directly demonstrated in only one patient with a monoclonal IgM paraprotein. We tested the generality of this hypothesis directly by isolating five IgG lupus anticoagulants from patients with lupuslike syndromes and/or thrombosis. IgG lupus anticoagulant fractions were isolated free of other plasma proteins and free of contaminating phospholipid by adsorption to and elution from cardiolipin-cholesterol- dicetyl phosphate liposomes, followed by chromatography on protein A- Sepharose. Cardiolipin liposomes, but not phosphatidylcholine liposomes, were capable of removing all, or nearly all, lupus anticoagulant activity from patient plasma. The affinity-purified IgG preparations reacted with cardiolipin, phosphatidylserine, phosphatidylinositol, and phosphatidic acid, but not with phosphatidylcholine or phosphatidylethanolamine, and inhibited calcium- dependent binding of prothrombin and of factor X to phosphatidylserine- coated and to cardiolipin-coated surfaces. F(ab')2 fragments retained lupus anticoagulant activity and bound to cardiolipin in an enzyme- linked immunosorbent assay (ELISA). Anticardiolipin and lupus anticoagulant activity were both present in acidic fractions on isoelectric focusing. These data strongly suggest that most, if not all, lupus anticoagulants are antibodies that have immunologic specificity towards anionic phospholipids, thereby blocking the calcium- mediated binding of vitamin K-dependent coagulation factors to coagulation-active phospholipid surfaces.

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Pengo, V., P. Thiagarajan, SS Shapiro, and MJ Heine. "Immunological specificity and mechanism of action of IgG lupus anticoagulants." Blood 70, no. 1 (July 1, 1987): 69–76. http://dx.doi.org/10.1182/blood.v70.1.69.bloodjournal70169.

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Although observations have implied that lupus anticoagulants have immunologic specificity toward anionic phospholipids, this assumption has been directly demonstrated in only one patient with a monoclonal IgM paraprotein. We tested the generality of this hypothesis directly by isolating five IgG lupus anticoagulants from patients with lupuslike syndromes and/or thrombosis. IgG lupus anticoagulant fractions were isolated free of other plasma proteins and free of contaminating phospholipid by adsorption to and elution from cardiolipin-cholesterol- dicetyl phosphate liposomes, followed by chromatography on protein A- Sepharose. Cardiolipin liposomes, but not phosphatidylcholine liposomes, were capable of removing all, or nearly all, lupus anticoagulant activity from patient plasma. The affinity-purified IgG preparations reacted with cardiolipin, phosphatidylserine, phosphatidylinositol, and phosphatidic acid, but not with phosphatidylcholine or phosphatidylethanolamine, and inhibited calcium- dependent binding of prothrombin and of factor X to phosphatidylserine- coated and to cardiolipin-coated surfaces. F(ab')2 fragments retained lupus anticoagulant activity and bound to cardiolipin in an enzyme- linked immunosorbent assay (ELISA). Anticardiolipin and lupus anticoagulant activity were both present in acidic fractions on isoelectric focusing. These data strongly suggest that most, if not all, lupus anticoagulants are antibodies that have immunologic specificity towards anionic phospholipids, thereby blocking the calcium- mediated binding of vitamin K-dependent coagulation factors to coagulation-active phospholipid surfaces.

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Fair, C. Christine, Rebecca Littman, Neil Malhotra, and Jacob N. Shapiro. "Relative Poverty, Perceived Violence, and Support for Militant Politics: Evidence from Pakistan." Political Science Research and Methods 6, no. 1 (February 16, 2016): 57–81. http://dx.doi.org/10.1017/psrm.2016.6.

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Challenging conventional wisdom, previous research in South Asia and the Middle East has shown that poverty and exposure to violence are negatively correlated with support for militant organizations. Existing studies, however, provide evidence consistent with two potential mechanisms underlying these relationships: (1) the direct effects of poverty and violence on attitudes toward militant groups and (2) the psychological effects of perceptions of poverty and violence on attitudes. Isolating whether the psychological mechanism is an important one is critical for building theories of mass responses to political violence. We conducted a series of original, large-scale survey experiments in Pakistan (n=16,279) in which we randomly manipulated perceptions of both poverty and violence before measuring support for militant organizations. We find evidence that psychological perceptions do in part explain why the poor seem to be less supportive of militant political groups.

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Złotko, Katarzyna, Adam Waśko, Daniel M. Kamiński, Iwona Budziak-Wieczorek, Piotr Bulak, and Andrzej Bieganowski. "Isolation of Chitin from Black Soldier Fly (Hermetia illucens) and Its Usage to Metal Sorption." Polymers 13, no. 5 (March 7, 2021): 818. http://dx.doi.org/10.3390/polym13050818.

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Chitin has become a desirable raw material used in various areas of life. The black soldier fly (Hermetia illucens) can be a source of this substance. In the literature, there are many methods of obtaining chitin but there is no one universal method of isolating it. In this publication, we present various procedures for the isolation of chitin from H. illucens pupal exuviae. The obtained chitin variants were characterized using different techniques (optical and confocal microscopy, FTIR, XRD, EDX, thermogravimetric analysis). The tested chitin isolated with an efficiency of 5.69–7.95% was the α form with a crystallinity degree of 60% and maximum degradation temperature of 392 °C. Furthermore, we characterized the nickel ion biosorption process on chitin and proposed the mechanism of this process to be ion exchange and complexation. There have been no such studies thus far on the isolation of chitin from H. illucens exuviae or on the biosorption of nickel ions on this type of biosorbent. The conducted research can be used to develop the application of chitin as a metal biosorbent that can be obtained with relatively high efficiency and good sorption properties.

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Timakov, Benjamin, Xiaoru Liu, Ismail Turgut, and Ping Zhang. "Timing and Targeting of P-Element Local Transposition in the Male Germline Cells of Drosophila melanogaster." Genetics 160, no. 3 (March 1, 2002): 1011–22. http://dx.doi.org/10.1093/genetics/160.3.1011.

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Abstract The P element in Drosophila melanogaster preferentially transposes into nearby sites. The local insertions display a preferential orientation toward the starting element. We investigated the mechanism of the P-element local transposition by isolating and characterizing local insertions in the male germline. We designed a genetic screen employing a marker gene that is carried in the P element and is dose sensitive. This dose effect allows isolation of flies containing newly transposed P elements in the presence of the starting element. A rapid molecular screen with PCR was used to identify 45 local insertions located within an ~40-kb genomic region on both sides of the starting element. Our system permits the isolation of the cluster progeny derived from a single insertion event, but none was isolated. The data suggest that local transposition occurs in the meiotic cell cycle. Nearly all of the local insertions were located within the promoter regions of the genes that were active in the male germline cells, suggesting that local insertions target predominantly active promoters. Our analysis shows that local transposition of the P element is highly regulated, displaying a cell-type specificity and a target specificity.

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Journal articles on the topic 'Isolating mechanism'

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