347 research outputs found

    Bank And Non-Bank Financial Institutions And The Development Of The Nigerian Economy

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    The focus of this study was on the impact of bank and non-bank financial institutions on the growth and development of the Nigerian economy. In an attempt to achieve the objectives of the research, data for the period 1992 to 2012 were collected from the CBN publications. Hypotheses were also formulated. The data collected were analysed using the E-views econometric software under the ordinary least square (OLS) regression analysis. The study as confirmed by the result of the joint test revealed that the financial institutions play prominent role on the growth and development of the Nigerian economy. However, it was further revealed that individual contributions of the explanatory variables varied. For example, the Deposit Money Banks were revealed to have impacted very insignificantly to the growth and development of the Nigerian economy. This may not be unconnected with the unwholesome practices in the banking sector such as granting of loans/advances to “ghost” applicants, diversion of loans and advances granted, high incidence of moral hazards. In view of the above, it is recommended among others that government should come up with lending policies that will not only reduce diversions of bank loans/advances but will deter persons involved in such sharp practices. Such loans and advances which must be on long-term basis should be extended to needy investors in the real sector. Consumer loans and also loans and advances for commerce do not play prominent role in the growth and development of the economy and thus should be discouraged. The current and on-going reforms in the financial sector should be encouraged and maintained

    Internalization of rabies virus glycoprotein differs between pathogenic and attenuated virus strains

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    The zoonotic rabies virus (RABV) is a non-segmented negative-sense RNA virus classified within the family Rhabdoviridae, and is the most common aetiological agent responsible for fatal rabies disease. The RABV glycoprotein (G) forms trimeric spikes that protrude from RABV virions and mediate virus attachment, entry and spread, and is a major determinant of RABV pathogenesis. A range of RABV strains exist that are highly pathogenic in part due to their ability to evade host immune detection. However, some strains are disease-attenuated and can be cleared by host defences. A detailed molecular understanding of how strain variation relates to pathogenesis is currently lacking. Here, we reveal key differences in the trafficking profiles of RABV-G proteins from the challenge virus standard strain (CVS-11) and a highly attenuated vaccine strain SAD-B19 (SAD). We show that CVS-G traffics to the cell surface and undergoes rapid internalization through both clathrin- and cholesterol-dependent endocytic pathways. In contrast, SAD-G remains resident at the plasma membrane and internalizes at a significantly slower rate. Through engineering hybrids of CVS-G and SAD-G, we show that the cytoplasmic tail of CVS-G is the key determinant of these different internalization profiles. Alanine scanning further revealed that mutation of Y497 in CVS-G (H497 in SAD-G) could reduce the rate of internalization to SAD-G levels. Together, these data reveal new phenotypic differences between CVS-G and SAD-G proteins that may contribute to altered in vivo pathogenicity

    The Oscillation Probability of GeV Solar Neutrinos of All Active Species

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    In this paper, I address the oscillation probability of O(GeV) neutrinos of all active flavours produced inside the Sun and detected at the Earth. Flavours other than electron-type neutrinos may be produced, for example, by the annihilation of WIMPs which may be trapped inside the Sun. In the GeV energy regime, matter effects are important both for the ``1-3'' system and the ``1-2'' system, and for different neutrino mass hierarchies. A numerical scan of the multidimensional three-flavour parameter space is performed, ``inspired'' by the current experimental situation. One important result is that, in the three-flavour oscillation case, P{alpha,beta} is different from P{beta,alpha} for a significant portion of the parameter space, even if there is no CP-violating phase in the MNS matrix. Furthermore, P{mu,mu} has a significantly different behaviour from P{tau,tau}, which may affect expectations for the number of events detected at large neutrino telescopes.Comment: 38 pages, 10 figure

    Approximate Treatment of Lepton Distortion in Charged-Current Neutrino Scattering from Nuclei

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    The partial-wave expansion used to treat the distortion of scattered electrons by the nuclear Coulomb field is simpler and considerably less time-consuming when applied to the production of muons and electrons by low and intermediate-energy neutrinos. For angle-integrated cross sections, however, a modification of the "effective-momentum-transfer" approximation seems to work so well that for muons the full distorted-wave treatment is usually unnecessary, even at kinetic energies as low as an MeV and in nuclei as heavy as lead. The method does not work as well for electron production at low energies, but there a Fermi function usually proves adequate. Scattering of electron-neutrinos from muon decay on iodine and of atmospheric neutrinos on iron are discussed in light of these results.Comment: 11 pages, LaTeX, submitted to Phys. Rev.

    Constraining neutrino oscillation parameters with current solar and atmospheric data

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    We analyze the impact of recent solar, atmospheric and reactor data in the determination of the neutrino oscillation parameters, taking into account that both the solar nu_e and the atmospheric nu_mu may convert to a mixture of active and sterile neutrinos. We use the most recent global solar neutrino data, including the 1496-day Super-K neutrino data sample, and we investigate in detail the impact of the SNO neutral current, spectral and day/night data by performing also an analysis using only the charged current rate from SNO. The implications of the first 145.1 days of KamLAND data on the determination of the solar neutrino parameters are also discussed in detail. We confirm the clear preference of solar+reactor data for the pure active LMA-MSW solution of the solar neutrino problem, and obtain that the LOW, VAC, SMA and Just-So^2 solutions are disfavored with a Delta_chi^2 = 22, 22, 36, 44, respectively. Furthermore, we find that the global solar data constrains the admixture of a sterile neutrino to be less than 43% at 99% CL. By performing an improved fit of the atmospheric data, we also update the corresponding regions of oscillation parameters. We find that the recent atmospheric Super-K (1489-day) and MACRO data have a strong impact on constraining a sterile component in atmospheric oscillations: if the nu_mu is restricted to the atmospheric mass states only a sterile admixture of 16% is allowed at 99% CL, while a bound of 35% is obtained in the unconstrained case. Pure sterile oscillations are disfavored with a Delta_chi^2 = 34.6 compared to the pure active case.Comment: 28 pages, LaTeX file using RevTEX4, 12 figures and 3 tables included. Improved version including the new KamLAND dat

    Lepton Flavor Violation in the SUSY-GUT Models with Lopsided Mass Matrix

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    The tiny neutrino masses measured in the neutrino oscillation experiments can be naturally explained by the supersymmetric see-saw mechanism. If the supersymmetry breaking is mediated by gravity, the see-saw models may predict observable lepton flavor violating effects. In this work, we investigate the lepton flavor violating process Ό→eÎł\mu\to e\gamma in the kind of neutrino mass models based on the idea of the ``lopsided'' form of the charged lepton mass matrix. The constraints set by the muon anomalous magnetic moment are taken into account. We find the present models generally predict a much larger branching ratio of Ό→eÎł\mu\to e\gamma than the experimental limit. Conversely, this process may give strong constraint on the lepton flavor structure. Following this constraint we then find a new kind of the charged lepton mass matrix. The feature of the structure is that both the elements between the 2-3 and 1-3 generations are ``lopsided''. This structure produces a very small 1-3 mixing and a large 1-2 mixing in the charged lepton sector, which naturally leads to small Br(Ό→eÎł)Br(\mu\to e\gamma) and the LMA solution for the solar neutrino problem.Comment: 24 pages, 8 figure

    Leptogenesis and low energy observables in left-right symmetric models

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    In the context of left-right symmetric models we study the connection of leptogenesis and low energy parameters such as neutrinoless double beta decay and leptonic CP violation. Upon imposition of a unitarity constraint, the neutrino parameters are significantly restricted and the Majorana phases are determined within a narrow range, depending on the kind of solar solution. One of the Majorana phases gets determined to a good accuracy and thereby the second phase can be probed from the results of neutrinoless double beta decay experiments. We examine the contributions of the solar and atmospheric mass squared differences to the asymmetry and find that in general the solar scale dominates. In order to let the atmospheric scale dominate, some finetuning between one of the Majorana phases and the Dirac CP phase is required. In this case, one of the Majorana phases is determined by the amount of CP violation in oscillation experiments.Comment: 18 pages, 6 figures. Matches version to appear in PR

    Lymphocytic choriomeningitis arenavirus requires cellular COPI and AP-4 complexes for efficient virion production

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    Lymphocytic choriomeningitis virus (LCMV) is a bisegmented negative-sense RNA virus classified within the Arenaviridae family of the Bunyavirales order. LCMV is associated with fatal disease in immunocompromized populations, and as the prototypical arenavirus, acts as a model for the many serious human pathogens within this group. Here, we examined the dependence of LCMV multiplication on cellular trafficking components using a recombinant LCMV expressing enhanced green fluorescent protein in conjunction with a curated siRNA library. The screen revealed a requirement for subunits of both the coat protein 1 (COPI) coatomer and adapter protein 4 (AP-4) complexes. By rescuing a recombinant LCMV harboring a FLAG-tagged glycoprotein (GP-1) envelope spike (rLCMV-GP1-FLAG), we showed infection resulted in marked co-localization of individual COPI and AP-4 components with both LCMV nucleoprotein (NP) and GP-1, consistent with their involvement in viral processes. To further investigate the role of both COPI and AP-4 complexes during LCMV infection, we utilized the ARF-I inhibitor brefeldin A (BFA) that prevents complex formation. Within a single 12-h cycle of virus multiplication, BFA pre-treatment caused no significant change in LCMV-specific RNA synthesis, alongside no significant change in LCMV NP expression, as measured by BFA time-of-addition experiments. In contrast, BFA addition resulted in a significant drop in released virus titers, approaching 50-fold over the same 12-h period, rising to over 600-fold over 24 h. Taken together, these findings suggest COPI and AP-4 complexes are important host cell factors required for the formation and release of infectious LCMV

    (S)fermion Masses in Fat Brane Scenario

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    We discuss the fermion mass hierarchy and the flavor mixings in the fat brane scenario of a five dimensional SUSY theory. Assuming that the matter fields lives in the bulk, their zero mode wave functions are Gaussians, and Higgs fields are localized on the brane, we find simple various types of the matter configurations generating the mass matrices consistent with experimental data. Sfermion mass spectrum is also discussed using the matter configurations found above. Which type of squark mass spectra (the degeneracy, the decoupling and the alignment) is realized depends on the relative locations of SUSY breaking brane and the brane where Higgs fields are localized.Comment: 18 pages, LaTe

    Possible Flavor Mixing Structures of Lepton Mass Matrices

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    To search for possible textures of lepton mass matrices, we systematically examine flavor mixing structures which can lead to large lepton mixing angles. We find out 37 mixing patterns are consistent with experimental data, taking into account phase factors in the mixing matrices. Only six of the patterns can explain the observed data without any tuning of parameters, while the others need particular choices for the phase values. It is found that these six mixing patterns are those predicted by the models which have been proposed to account for fermion mass hierarchies. On the other hand, the others may give new flavor mixing structures of lepton mass matrices and therefore new possibilities of model construction.Comment: 21 page
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