821 research outputs found

    Comparison of the Transmembrane Mucins MUC1 and MUC16 in Epithelial Barrier Function

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    Membrane-anchored mucins are present in the apical surface glycocalyx of mucosal epithelial cells, each mucosal epithelium having at least two of the mucins. The mucins have been ascribed barrier functions, but direct comparisons of their functions within the same epithelium have not been done. In an epithelial cell line that expresses the membrane-anchored mucins, MUC1 and MUC16, the mucins were independently and stably knocked down using shRNA. Barrier functions tested included dye penetrance, bacterial adherence and invasion, transepithelial resistance, tight junction formation, and apical surface size. Knockdown of MUC16 decreased all barrier functions tested, causing increased dye penetrance and bacterial invasion, decreased transepithelial resistance, surprisingly, disruption of tight junctions, and greater apical surface cell area. Knockdown of MUC1 did not decrease barrier function, in fact, barrier to dye penetrance and bacterial invasion increased significantly. These data suggest that barrier functions of membrane-anchored mucins vary in the context of other membrane mucins, and MUC16 provides a major barrier when present

    Implications of LEP Results for SO(10) Grandunification with Two Intermediate Stages

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    We consider the breaking of the grand unification group SO(10)SO(10) to the standard model gauge group through several chains containing two intermediate stages. Using the values of the gauge coupling constants at scale MZM_Z derived from recent LEP data, we determine the range of their intermediate and unification scales. In particular, we identify those chains that permit new gauge structure at relatively low energy (1TeV)(\sim 1\, {\rm TeV}).Comment: (LATEX, 9 pages + 3 pages of figures not included) OITS-48

    Collision-Induced Decay of Metastable Baby Skyrmions

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    Many extensions of the standard model predict heavy metastable particles which may be modeled as solitons (skyrmions of the Higgs field), relating their particle number to a winding number. Previous work has shown that the electroweak interactions admit processes in which these solitons decay, violating standard model baryon number. We motivate the hypothesis that baryon-number-violating decay is a generic outcome of collisions between these heavy particles. We do so by exploring a 2+1 dimensional theory which also possesses metastable skyrmions. We use relaxation techniques to determine the size, shape and energy of static solitons in their ground state. These solitons could decay by quantum mechanical tunneling. Classically, they are metastable: only a finite excitation energy is required to induce their decay. We attempt to induce soliton decay in a classical simulation by colliding pairs of solitons. We analyze the collision of solitons with varying inherent stabilities and varying incident velocities and orientations. Our results suggest that winding-number violating decay is a generic outcome of collisions. All that is required is sufficient (not necessarily very large) incident velocity; no fine-tuning of initial conditions is required.Comment: 24 pages, 7 figures, latex. Very small changes onl

    The effect of polar lipids on tear film dynamics

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    In this paper we present a mathematical model describing the effect of polar lipids on the evolution of a precorneal tear film, with the aim of explaining the interesting experimentally observed phenomenon that the tear film continues to move upwards even after the upper eyelid has become stationary. The polar lipid is an insoluble surface species that locally alters the surface tension of the tear film. In the lubrication limit, the model reduces to two coupled nonlinear partial differential equations for the film thickness and the concentration of lipid. We solve the system numerically and observe that the presence of the lipid causes an increase in flow of liquid up the eye. We further exploit the size of the parameters in the problem to explain the initial evolution of the system

    A mediation approach to understanding socio-economic inequalities in maternal health-seeking behaviours in Egypt.

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    BACKGROUND: The levels and origins of socio-economic inequalities in health-seeking behaviours in Egypt are poorly understood. This paper assesses the levels of health-seeking behaviours related to maternal care (antenatal care [ANC] and facility delivery) and their accumulation during pregnancy and childbirth. Secondly, it explores the mechanisms underlying the association between socio-economic position (SEP) and maternal health-seeking behaviours. Thirdly, it examines the effectiveness of targeting of free public ANC and delivery care. METHODS: Data from the 2008 Demographic and Health Survey were used to capture two latent constructs of SEP: individual socio-cultural capital and household-level economic capital. These variables were entered into an adjusted mediation model, predicting twelve dimensions of maternal health-seeking; including any ANC, private ANC, first ANC visit in first trimester, regular ANC (four or more visits during pregnancy), facility delivery, and private delivery. ANC and delivery care costs were examined separately by provider type (public or private). RESULTS: While 74.2% of women with a birth in the 5-year recall period obtained any ANC and 72.4% delivered in a facility, only 48.8% obtained the complete maternal care package (timely and regular facility-based ANC as well as facility delivery) for their most recent live birth. Both socio-cultural capital and economic capital were independently positively associated with receiving any ANC and delivering in a facility. The strongest direct effect of socio-cultural capital was seen in models predicting private provider use of both ANC and delivery. Despite substantial proportions of women using public providers reporting receipt of free care (ANC: 38%, delivery: 24%), this free-of-charge public care was not effectively targeted to women with lowest economic resources. CONCLUSIONS: Socio-cultural capital is the primary mechanism leading to inequalities in maternal health-seeking in Egypt. Future studies should therefore examine the objective and perceived quality of care from different types of providers. Improvements in the targeting of free public care could help reduce the existing SEP-based inequalities in maternal care coverage in the short term

    Static solitons with non-zero Hopf number

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    We investigate a generalized non-linear O(3) σ\sigma-model in three space dimensions where the fields are maps S3S2S^3 \mapsto S^2. Such maps are classified by a homotopy invariant called the Hopf number which takes integer values. The model exhibits soliton solutions of closed vortex type which have a lower topological bound on their energies. We explicitly compute the fields for topological charge 1 and 2 and discuss their shapes and binding energies. The effect of an additional potential term is considered and an approximation is given for the spectrum of slowly rotating solitons.Comment: 13 pages, RevTeX, 7 Postscript figures, minor changes have been made, a reference has been corrected and a figure replace

    How Mistimed and Unwanted Pregnancies Affect Timing of Antenatal Care Initiation in three Districts in Tanzania

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    Early antenatal care (ANC) initiation is a doorway to early detection and management of potential complications associated with pregnancy. Although the literature reports various factors associated with ANC initiation such as parity and age, pregnancy intentions is yet to be recognized as a possible predictor of timing of ANC initiation. Data originate from a cross-sectional household survey on health behaviour and service utilization patterns. The survey was conducted in 2011 in Rufiji, Kilombero and Ulanga districts in Tanzania on 910 women of reproductive age who had given birth in the past two years. ANC initiation was considered to be early only if it occurred in the first trimester of pregnancy gestation. A recently completed pregnancy was defined as mistimed if a woman wanted it later, and if she did not want it at all the pregnancy was termed as unwanted. Chisquare was used to test for associations and multinomial logistic regression was conducted to examine how mistimed and unwanted pregnancies affect timing of ANC initiation. Although 49.3% of the women intended to become pregnant, 50.7% (34.9% mistimed and 15.8% unwanted) became pregnant unintentionally. While ANC initiation in the 1st trimester was 18.5%, so was 71.7% and 9.9% in the 2nd and 3rd trimesters respectively. Multivariate analysis revealed that ANC initiation in the 2nd trimester was 1.68 (95% CI 1.10‒2.58) and 2.00 (95% CI 1.05‒3.82) times more likely for mistimed and unwanted pregnancies respectively compared to intended pregnancies. These estimates rose to 2.81 (95% CI 1.41‒5.59) and 4.10 (95% CI 1.68‒10.00) respectively in the 3rd trimester. We controlled for gravidity, age, education, household wealth, marital status, religion, district of residence and travel time to a health facility. Late ANC initiation is a significant maternal and child health consequence of mistimed and unwanted pregnancies in Tanzania. Women should be empowered to delay or avoid pregnancies whenever they need to do so. Appropriate counseling to women, especially those who happen to conceive unintentionally is needed to minimize the possibility of delaying ANC initiation.\u

    Predictive fermion mass matrix ansatzes in non-supersymmetric SO(10) grand unification

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    We investigate the status of predictive fermion mass ansatzes which make use of the grand unification scale conditions me=md/3m_e=m_d/3, mμ=3msm_\mu =3m_s, and Vcb=mc/mt\mid V_{cb}\mid =\sqrt{m_{c}/m_{t}} in non-supersymmetric SO(10) grand unification. The gauge symmetry below an intermediate symmetry breaking scale MIM_I is assumed to be that of the standard model with either one Higgs doublet or two Higgs doublets . We find in both cases that a maximum of 5 standard model parameters may be predicted within 1σ1\sigma experimental ranges. We find that the standard model scenario predicts the low energy Vcb\mid V_{cb}\mid to be in a range which includes its experimental mid-value 0.044 and which for a large top mass can extend to lower values than the range resulting in the supersymmetric case. In the two Higgs standard model case, we identify the regions of parameter space for which unification of the bottom quark and tau lepton Yukawa couplings is possible at grand unification scale. In fact, we find that unification of the top, bottom and tau Yukawa couplings is possible with the running b-quark mass within the 1σ1\sigma preferred range mb=4.25±0.1GeVm_b=4.25\pm 0.1\, GeV provided α3c(MZ)\alpha_{3c}(M_Z) is near the low end of its allowed range. In this case, one may make 6 predictions which include Vcb\mid V_{cb}\mid within its 90%90\% confidence limits. However unless the running mass mb>4.4GeVm_b>4.4\, GeV, third generation Yukawa coupling unification requires the top mass to be greater thanComment: 30 pages, 8 figures available on request from [email protected], Late

    1970: Abilene Christian College Bible Lectures - Full Text

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    THE APOSTLES’ DOCTRINE Being the Abilene Christian College Annual Bible Lectures 1970 Published by ABILENE CHRISTIAN COLLEGE BOOK STORE ACC Station Abilene, Texas 7960
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