707 research outputs found
Dataset for: Establishing an invertebrate Galleria mellonella Greater wax moth larval model of Neisseria gonorrhoeae infection
No full textThis dataset supports the publication:
Aiste Dijokaite, Maria Victoria Humbert, Emma Borkowski, Roberto M La Ragione, Myron Christodoulides (2021) 'Establishing an invertebrate Galleria mellonella Greater wax moth larval model of Neisseria gonorrhoeae infection' published in Virulence, DOI: 10.1080/21505594.2021.1950269</span
Dataset supporting the publication "An in silico reverse vaccinology study of Brachyspira pilosicoli, the causative organism of intestinal spirochaetosis, to identify putative vaccine candidates"
No full textDataset supporting the publication by M Christodoulides, D de Oliveira, D W. Cleary, M V Humbert, R A. Machado-de-Ávila, R M. La Ragione,
"An in silico reverse vaccinology study of Brachyspira pilosicoli, the causative organism of intestinal spirochaetosis, to identify putative vaccine candidates", Process Biochemistry, Volume 122, Part 1,
2022, Pages 128-148, ISSN 1359-5113,
https://doi.org/10.1016/j.procbio.2022.08.014
This dataset contains raw data from in silico analyses for reverse vaccinology. IT has supplemental material for Figure 1 including datasets 1 to 21. The data is presented in word document, PDF and excel files.
This study was funded by Houghton Trust, UK
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Frame synchronisation of differentially encoded binary and quaternary PSK digital communications systems
No full textIn this thesis a frame synchronisation system is proposed and studied for binary and quaternary differential PSK modulation schemes. A frame synchronisation algorithm has been proposed as well as optimum Frame Alignment Words (FAWs) for use by the algorithm.The Rural Telecommunication Network, that is being developed jointly by the Universities of Southampton, Warwick and Dar-Es-Salaam, aims to provide low cost tele-communications to sparsely populated areas. It is based on intelligent nodes that use packet radio to establish synchronous conversation channels with neighbouring nodes. Frame synchronisation for the conversation channel is studied in this thesis.The RTN poses the constraints of fast and robust frame synchronisation using a FAW of 4 bits in π/4-QPSK. The above constraints pose severe demands on conventional frame synchronisation systems that use one FAW. The author proposes a frame synchronisation system that uses two FAWs that provide the required performance with the required reduced overhead. This system uses an initial long FAW for the acquisition of frame synchronisation at call set-up, and then, uses a short 4 bit FAW for maintaining synchronisation. The long FAW is also transmitted during silence frames for acquiring synchronisation in case of loss during a call, the effect of which has been studied.Apart from the algorithm frame synchronisation also requires optimum FAWs for the modulation scheme. This thesis describes a method for deriving optimum FAWs for use in systems with differentially encoded PSK modulation schemes. In particular optimum FAWs have been found for DEBPSK, DBPSK and π/4-QPSK for use in frame synchronisation systems.</p
Basic methods for examining <i>Neisseria gonorrhoeae</i> interactions with host cells in vitro
No full textThe obligate human pathogen Neisseria gonorrhoeae colonizes primarily the mucosal columnar epithelium of the male urethra and the female endocervix. In addition, gonococci can infect the anorectal, pharyngeal, and gingival mucosae and epithelial cells of the conjunctiva. More rarely, the organism can disseminate through the bloodstream, which can involve interactions with other host cell types, including blood vessel endothelial cells and innate immune cells such as dendritic cells, macrophages, and neutrophils. “Disseminated gonococcal infection” is a serious condition with various manifestations resulting from the seeding of organs and tissues with the pathogen. The host response to gonococcal infection is inflammatory. Knowledge of the biology of gonococcal interactions has been served well through the use of a wide variety of ex vivo models using host tissues and eukaryotic cell monocultures. These models have helped identify bacterial surface adhesins and invasins and the corresponding cell surface receptors that play roles in gonococcal pathogenesis. Furthermore, they have been useful for understanding virulence mechanisms as well as innate and adaptive immune responses. In this chapter, readers are provided with protocols for examining the basic interactions between gonococci and a representative human cell line.</p
Anomalously Large Chiral Sensitivity in the Dissociative Electron Attachment of 10-Iodocamphor
No full textWe have studied dissociative electron attachment (DEA) between low energy (≤ 0.6 eV) longitudinally polarized electrons and gas-phase chiral targets of 3-bromocamphor (C10H15BrO), 3-iodocamphor (C10H15IO), and 10-iodocamphor. The DEA rate depends on the sign of the incident electron helicity for a given target handedness, and it varies with both the atomic number (Z) and location of the heaviest atom in the molecule. While simple dynamic mechanisms can account for the asymmetry dependence on Z, they fail to explain the large asymmetry variation with the heavy atom location
Establishing an invertebrate Galleria mellonella greater wax moth larval model of Neisseria gonorrhoeae infection
No full textNeisseria gonorrhoeae (gonococcus) causes the human sexually transmitted disease gonorrhea. Studying gonococcal pathogenesis and developing new vaccines and therapies to combat the increasing prevalence of multi-antibiotic resistant bacteria has made use of many ex vivo models based on human cells and tissues, and in vivo vertebrate models, for example, rodent, pig and human. The focus of the current study was to examine the utility of the invertebrate greater wax moth Galleria mellonella as an in vivo model of gonococcal infection. We observed that a threshold of ~106 – 107 gonococci/larva was required to kill >50% of larvae (P 0.05) than Pseudomonas aeruginosa. Larvae primed with nontoxic doses of gonococci were more susceptible to subsequent challenge with homologous and heterologous bacteria, and larval survival was significantly reduced (P 0.05)
Effective plasmid DNA and small interfering RNA delivery to diseased human brain microvascular endothelial cells
No full textExpression of exogenous DNA or small interfering RNA (siRNA) in vitro is significantly affected by the particular delivery system utilized. In this study, we evaluated the transfection efficiency of plasmid DNA and siRNA into human brain microvascular endothelial cells (HBMEC) and meningioma cells, which constitute the blood-cerebrospinal fluid barrier, a target of meningitis-causing pathogens. Chemical transfection methods and various lipofection reagents including Lipofectamin™, FuGene™, or jetPRIME®, as well as physical transfection methods and electroporation techniques were applied. To monitor the transfection efficiencies, HBMEC and meningioma cells were transfected with the reporter plasmid pTagGFP2-actin vector, and efficiency of transfection was estimated by fluorescence microscopy and flow cytometry. We established protocols based on electroporation using Cell Line Nucleofector® Kit V with the Amaxa® Nucleofector® II system from Lonza and the Neon® Transfection system from Invitrogen resulting in up to 41 and 82% green fluorescent protein-positive HBMEC, respectively. Optimal transfection solutions, pulse programs and length were evaluated. We furthermore demonstrated that lipofection is an efficient method to transfect meningioma cells with a transfection efficiency of about 81%. Finally, we applied the successful electroporation protocols to deliver synthetic siRNA to HBMEC and analyzed the role of the actin-binding protein cortactin in Neisseria meningitidis pathogenesis
Calorimetry of photon gases in nonlinear multimode optical fibers
No full textRecent studies have shown that light propagating in a nonlinear, highly multimode system can thermalize in a manner totally analogous to that encountered in traditional statistical mechanics. At thermal equilibrium, the system’s entropy is at a maximum, in full accord with the second law of thermodynamics. In such arrangements, the entropy is extremized once the statistical power allocation among modes associated with this photon gas attains a Rayleigh-Jeans distribution that is fully characterized by an optical temperature
T
and a chemical potential
μ
. However, it has been theoretically argued that the variables
T
and
μ
represent actual thermodynamic forces that control the exchange of the respective conjugate quantities between two subsystems. In this work, we report, for the first time, optical calorimetric measurements in nonlinear multimode fibers, which unambiguously demonstrate that both the temperature
T
and the chemical potential
μ
dictate the flow of their associated extensive quantities, i.e., the energy and the optical power. Specifically, we study the process of light thermalization associated with two orthogonally polarized laser beams. Our observations are enabled by recently developed techniques that allow one to judiciously multiplex/demultiplex the optical power within various mode groups. Our results indicate that because of photon-photon collisions, “heat” only flows from a hot to a cold photon gas subsystem—thus providing an unequivocal demonstration of the second law in such all-optical thermodynamic arrangements. In addition to being fundamental, our findings provide a new approach to manipulate laser beams using thermodynamic principles
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