Determination of the bremsstrahlung spectra of a clinical linear accelerator using a Simpson iteration technique

X-ray spectral reconstruction from x-ray transmission data was investigated using graphite as an attenuating material which has a monotonic declining mass attenuation coefficient for energies up to 30 MeV, and by employing the numerical method for unfolding spectra. No experimental investigation of energies above 10 MeV using this technique has been performed prior to this research. Previous works utilizing this method have used material such as lead and aluminum which exhibit an increase in attenuation coefficients in the 8 to 10 MeV range and beyond. This increased attenuation leads the Simpson technique to produce a number of non-unique fractional fluencies representing dual energies. Photon energy spectra for 6 MV and 18 MV beams produced by Varian 6100 and Varian 2100C linear accelerators were determined to validate the consistency of the measured data and the modeling method. The resulting Simpson unfolded spectra were compared to the published 6 MV Mohan spectrum and an interpolated 18MV spectrum. Both spectra are Monte Carlo based and used in the ADAC Laboratories three dimensional Pinnacle treatment planning system (3DPRTP). Modal energies for the Simpson technique were determined and compared to the modal energies for the Mohan spectrum and the interpolated 18 MV spectrum. Our method\u27s modal energies for the 6MV beams were similar to the Mohan 6MV spectrum. The modal energies for this work are 0.73 MeV for 2100-6 MV beam and 0.84 MeV for the 6100. For the 2100-18 MV beam, the modal energy for the determined Simpson spectrum was approximately 4.2 MeV. The Pinnacle (ADAC 3DPRTP) interpolated 18 MV spectral model yield a modal energy of 1.0 MeV. All of the above spectra were also compared to a Huang modified Jones-fit Laplace transform generated energy fluence spectra. The Laplace technique produced modal energies of 1 MeV for the 2100-6 MV beam and .7 MeV for the 6100 photon beams. The 2100-18 MV modal energy for the Laplace technique was 2.5 MeV. The relatively large differences in the modal energies for the 18 MV spectra lead the author to compare the results with a fourth spectral model generated by Francois and Catala through a technique of direct resolution of a matrix system of transmission data. The Francois - Catala technique yields a number of modal energies for 15MV to 20 MV beam spectra ranging from 2.76 to 3.58 MeV. These modal energies agree with the Simpson model as opposed to the interpolated 18 MV model. The HVL data also suggests that the modal energy of the beam is substantially larger than 1 MeV. The disagreement of all the above models leads the author to conclude that further work and unification of methodology is needed to verify true photon energy spectra

SUPPRESSION OF ANTI-TUMOR IMMUNITY IN CHRONIC LYMPHOCYTIC LEUKEMIA VIA INTERLEUKIN-10 PRODUCTION

The most common human leukemia is B-cell chronic lymphocytic leukemia (B-CLL), which is characterized by a progressive accumulation of abnormal B-lymphocytes in blood, bone marrow and secondary lymphoid organs. Typically disease progression is slow, but as the number of leukemic cells increases, they interfere with the production of other important blood cells, causing the patients to be in an immunosuppressive state. To study the basis of this immunoregulation, we used cells from the transgenic Eμ-TCL1 mouse, which spontaneously develop B-CLL due to a B-cell specific expression of the oncogene, TCL1. Previously we showed that Eμ-TCL1 CLL cells constitutively produce an anti-inflammatory cytokine, IL-10. Here we studied the role of IL-10 in CLL cell survival in vitro and the development of CLL in vivo. We found that neutralization of IL-10 using anti-IL-10 antibodies or blocking the IL-10 receptor (IL-10R) using anti-IL-10R antibodies did not affect the survival of CLL cells in vitro. On the other hand, adoptively transferred Eμ-TCL1 cells grew at a slower rate in IL-10R KO mice vs. wild type (WT) mice. There was a significant reduction in CLL cell engraftment in the spleen, bone marrow, peritoneal cavity and liver of the IL-10R KO compared to WT mice. Further studies revealed that IL-10 could be playing a role in the tumor microenvironment possibly by affecting anti-tumor immunity. This was seen by a reduction in the activation of CD8+ T cells as well as a significantly lower production of IFN-γ by CD4+ T cells purified from CLL-injected WT mice compared to those purified from CLL-injected IL-10R KO mice. Also CLL-primed IL-10R null T cells were more effective than those from similarly CLL-primed wild type mice in controlling CLL growth in immunodeficient recipient mice. These studies demonstrate that CLL cells suppress host anti-tumor immunity via IL-10 production. This led us to investigate possible mechanisms by which IL-10 is produced. We found a novel role of B-cell receptor (BCR) signaling pathway in constitutive IL-10 secretion. Inhibition of Src or Syk family kinases reduces the constitutive IL-10 production by Eμ-TCL1 cells in a dose dependent manner. We identified the transcription factor Sp1 as a novel regulator of IL-10 production by CLL cells and that it is regulated by BCR signaling via the Syk/MAPK pathway

3D seismic attribute analysis and machine learning for reservoir characterization in Taranaki Basin, New Zealand

The Kapuni group within the Taranaki Basin in New Zealand is a potential petroleum reservoir. The objective of the study includes building a sequential approach to identify different geological features and facies sequences within the strata, through visualizing the targeted formations by interpreting and correlating the regional geological data, 3D seismic, and well data by following a sequential workflow. First, seismic interpretation is performed targeting the Kapuni group formations, mainly, the Mangahewa C-sand and Kaimiro D-sand. Synthetic seismograms and well ties are conducted for structural maps, horizon slices, isopach, and velocity maps. Well log and morphological analyses are performed for formation sequence and petrophysics identification. Attribute analyses including RMS, dip, azimuth, and eigenstructure coherence are implemented to identify discontinuities, unconformities, lithology, and bright spots. Algorithmic analyses are conducted using Python programming to generate and overlay the attributes which are displayed in 3D view. Integrating all of the attributes in a single 3D view significantly strengthens the summation of the outputs and enhances seismic interpretation. The attribute measurements are utilized to characterize the subsurface structure and depositional system such as fluvial dominated channels, point bars, and nearshore sandstone. The study follows a consecutive workflow that leads to several attribute maps for identifying potential prospects --Abstract, page iv

3D seismic data interpretation of Boonsville Field, Texas

The Boonsville field is one of the largest gas fields in the US located in the Fort Worth Basin, north central Texas. The highest potential reservoirs reside in the Bend Conglomerate deposited during the Pennsylvanian. The Boonsville data set is prepared by the Bureau of Economic Geology at the University of Texas, Austin, as part of the secondary gas recovery program. The Boonsville field seismic data set covers an area of 5.5 mi². It includes 38 wells data. The Bend Conglomerate is deposited in fluvio-deltaic transaction. It is subdivided into many genetic sequences which include depositions of sandy conglomerate representing the potential reserves in the Boonsville field. The geologic structure of the Boonsville field subsurface are visualized by constructing structure maps of Caddo, Davis, Runaway, Beans Cr, Vineyard, and Wade. The mapping includes time structure, depth structure, horizon slice, velocity maps, and isopach maps. Many anticlines and folds are illustrated. Karst collapse features are indicated specially in the lower Atoka. Dipping direction of the Bend Conglomerate horizons are changing from dipping toward north at the top to dipping toward east at the bottom. Stratigraphic interpretation of the Runaway Formation and the Vineyard Formation using well logs and seismic data integration showed presence of fluvial dominated channels, point bars, and a mouth bar. RMS amplitude maps are generated and used as direct hydrocarbon indicator for the targeted formations. As a result, bright spots are indicated and used to identify potential reservoirs. Petrophysical analysis is conducted to obtain gross, net pay, NGR, water saturation, shale volume, porosity, and gas formation factor. Volumetric calculations estimated 989.44 MMSCF as the recoverable original gas in-place for a prospect in the Runaway and 3.32 BSCF for a prospect in the Vineyard Formation --Abstract, page iii

Functional and Phenotypic Analysis of B- and T-Helper Cells in Rhesus Macaques and African Green Monkeys

Human immunodeficiency virus (HIV) is one of the most challenging infectious agents at the current time. To date, many vaccine trials have been conducted. However, there has not been a fully successful trial. This is due, in part, to the gap in knowledge of the protective immune response against HIV. African green monkeys (AGMs) serve as an interesting model to study immune protection in primate immunodeficiency virus infections due to their resistance to AIDS. Experimental SIV infection in rhesus macaques (RMs) resembles HIV infection in humans with chronic immune activation and progression to AIDS well characterized in both. Understanding the immune systems of AGMs and RMs and how they differ is likely to advance our knowledge of immune protection and immunopathogenesis in SIV/HIV disease. B cells are responsible for the humoral arm of acquired immunity, which results in the production of specific antibodies. In lentiviral infections, neutralizing antibodies block viral entry and are, therefore, essential for protective immunity. Other antibody-mediated functions, such as antibody-dependent cellular cytotoxicity, have gained increased interest after the recent demonstration of enhanced antibody-dependent cell-mediated cytotoxicity (ADCC) in vaccinees in a vaccine trial commonly known as the Thai trial. T helper cells provide co-stimulatory signals that are essential for B cell activation and antibody production. Blocking CD40/CD40L interactions impairs antiviral humoral response, which emphasizes the importance of B and T helper interaction for protective humoral response. The current study aims to identify key B-cell and T-cell-related differences that separate African green monkeys and rhesus macaques in term of constitutive function (i.e. in the absence of infection) and in vitro, SIV-induced dysfunction. In this study, multiparametric flow cytometry approaches were used to identify any differences in the distribution of B and T cell subsets. B cells were stimulated with anti-IgM/G and T cells with phorbol myristate acetate and ionomycin (PMA/I) to assess the expression of their activation markers. These are unspecific stimuli that give an idea about the potential responses of the cells following specific stimulus. Also, B cells were evaluated for the expression and phosphorylation of intracellular signaling proteins. In addition, T cells were evaluated for the production of IFNɣ, TNFα, IL-2, expression of CD107a, and their ability to have more than one function. The results showed that AGMs have lower frequencies and absolute numbers of B and CD4+ T cells than RMs. Moreover, B cells of AGMs showed higher expression levels of CD40 than RMs, a molecule that plays an essential role in antibody production and Ig class switching. Furthermore, the analyses of B cell signaling proteins showed that AGMs express higher levels of these proteins and they get phosphorylated in higher levels than RMs. This may indicate a more robust signaling activity of AGMs’ B cells as compared to RMs, which may play a role in an early antibody response that controls the infection. T cells data analyses revealed that CD4 T cells of AGMs produce less IFNɣ, TNFα, and IL-2 than RM, which may indicate another immediate response, anti-inflammatory, rather than pro-inflammatory response. Also, this may explain the lack of chronic immune activation in AGM. DN T cells of AGM showed higher expression levels of CD107a than the DN T cells of RM. This may indicate the cytotoxic function of these cells in addition to their helper functions. DN T cells are resistant to SIV infection, and their multifunctionality give insights into new cellular therapeutic approaches

Genital tuberculosis: A rare cause of vulvovaginal discharge and swelling

Herein, we report a patient with vulvovaginal tuberculosis (TB) presented with a vulvovaginal mass and vaginal discharge.The diagnosis was made by both histopathological examination of the excised specimen which was clinicallysuspected to be a malignant lesion and cervical smear culture positivity for Mycobacterium tuberculosis. The patientwas prescribed a full course of anti-tuberculous drugs. In this report, we discuss the genital TB and its gynecologicaleffects in the light of medical literature. J Microbiol Infect Dis 2013; 3(3): 140-142Key words: Genital tuberculosis, vulvovaginal swellin

Formal verification of secondary authentication protocol for 5G secondary authentication

The Fifth-Generation mobile network (5G) will enable interconnectivity between the Home Network (HN) and Data Network (DN) whereby mobile users with their User Equipment (UE) will be able to access services provided by external Service Providers (SP) seamlessly. The mobile user and SP will rely on security assurances provided by authentication protocols used. For 5G, primary authentication between the UE and the HN has been defined and specified by the Third Generation Partnership Project (3GPP) while the secondary authentication has also been defined but not specified. 3GPP recommends the Extensible Authentication Protocol (EAP) framework for secondary authentication between the UE and the SP. However, the secondary authentication methods have not been formally verified, so this paper proposes a Secondary Authentication Protocol (SAP) for service authentication and provides a comprehensive formal analysis using ProVerif a security protocol verifier. Finally, it conducts a security analysis on the protocol's security properties