BackgroundHorizontal gene transfer (HGT) is relatively common in plant mitochondrial genomes but the mechanisms, extent and consequences of transfer remain largely unknown. Previous results indicate that parasitic plants are often involved as either transfer donors or recipients, suggesting that direct contact between parasite and host facilitates genetic transfer among plants.ResultsIn order to uncover the mechanistic details of plant-to-plant HGT, the extent and evolutionary fate of transfer was investigated between two groups: the parasitic genus Cuscuta and a small clade of Plantago species. A broad polymerase chain reaction (PCR) survey of mitochondrial genes revealed that at least three genes (atp1, atp6 and matR) were recently transferred from Cuscuta to Plantago. Quantitative PCR assays show that these three genes have a mitochondrial location in the one species line of Plantago examined. Patterns of sequence evolution suggest that these foreign genes degraded into pseudogenes shortly after transfer and reverse transcription (RT)-PCR analyses demonstrate that none are detectably transcribed. Three cases of gene conversion were detected between native and foreign copies of the atp1 gene. The identical phylogenetic distribution of the three foreign genes within Plantago and the retention of cytidines at ancestral positions of RNA editing indicate that these genes were probably acquired via a single, DNA-mediated transfer event. However, samplings of multiple individuals from two of the three species in the recipient Plantago clade revealed complex and perplexing phylogenetic discrepancies and patterns of sequence divergence for all three of the foreign genes.ConclusionsThis study reports the best evidence to date that multiple mitochondrial genes can be transferred via a single HGT event and that transfer occurred via a strictly DNA-level intermediate. The discovery of gene conversion between co-resident foreign and native mitochondrial copies suggests that transferred genes may be evolutionarily important in generating mitochondrial genetic diversity. Finally, the complex relationships within each lineage of transferred genes imply a surprisingly complicated history of these genes in Plantago subsequent to their acquisition via HGT and this history probably involves some combination of additional transfers (including intracellular transfer), gene duplication, differential loss and mutation-rate variation. Unravelling this history will probably require sequencing multiple mitochondrial and nuclear genomes from Plantago.See Commentary: http://www.biomedcentral.com/1741-7007/8/147.
A firewall is one of the key components in securing an organization's network and computational assets against different network and application-based attacks. Most firewall solutions only consider one or two layers of TCP/IP networking architecture to protect against attacks, especially spoofing-based attacks.In contrast, there are some proposed solutions to protect against such attacks. However, these solutions work in areas such as clouds or Software Defined Networks (SDN), and legacy networks cannot utilize such techniques. Therefore, establishing a type of firewall that can be scalable, strong, and easy to implement is a challenge necessary for a new firewall technique to prevail. This paper presents a novel strategy to implement a multi-layered firewall to overcome the current state-of-art firewalls. Our firewall combines a packet-filtering approach (i.e., Internet and Transport layer) with an application layer firewall under the umbrella of Stateful-Packet-Inspection. The experiments were performed in a controlled environment with 1% legitimate packets, and 99% spoofed traffic on average. The Stateful-Packet-Inspection discards any packets based on their traffic flow given to them by the firewall while informing the network administrator about the system breach passively. The results of the experiments are benchmarked with previous works and showed improvement in accuracy by 13.5% and sensitivity by 13.75% while decreasing the false negative rate by 86.5% with minimal computational and network overhead.
Introduction The study of composite materials, i.e., mixtures consisting of at least two phases of different chemical compositions, has been of great interest fro m both fundamental and practical standpoints. The macroscopic physical p roperties of such materials can be co mbined so as to produce materials with a desired average response. [1]. The properties of poly me r-mineral reinforced composites are determined by the co mponent properties (particle shape, surface area, surface chemistry, poly mer microstructure) and by the preparation method and processing conditions as well. A mong of preparation methods, injection mo lding has strong influence on the internal microstructure of polymers and in a consequence on mechanical response of the material [2]. Doping of poly mers attracted the scientific and technological researchers , because of their wide applications. The dopants in polymer can change the molecular structure and hence the microstructure as well as the macroscopic properties of the polymer [3]. Po lyvinyl alcohol (PVA), which is essentially made fro m polyvinyl acetate through hydrolysis, is easily degradable by bio logical organis ms and in water is a solubilized crystalline structure polymer [4]. PVA is formed by the polymerizat ion of vinyl acetate, which is then hydrolyzed into PVA. Fig. 1 shows the chemical structure of PVA. The excellent chemical resistance and physical p roperties of PVA resins have led to broad industrial use [5]. PVA is a low cost hydrophilic poly mer and therefore swells in the presence of water or bio logical flu ids to form hydrogels. This property is particularly useful because it can allow for the release of drugs incorporated into these hydrogels. Since PVA has a high selectivity of water to alcohols, it exhibits low methanol permeab ility and has been used in some alkaline fuel cell [6-7]. PVA is an artificial polymer that has been used during the first half of the century worldwide. It has been applied in the industrial, co mmercial, med ical, and food sectors and has been used to produce many end products, such as lacquers, resins, surgical threads, and food packaging materials that are often in contact with food [8]
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.