Predictions of the emergence of vaccine-resistant hepatitis B in The Gambia using a mathematical model

Vaccine escape variants of hepatitis B virus (HBV) have been identified world-wide. A mathematical model of HBV transmission is used to investigate the potential pattern of emergence of such variants. Attention is focused on The Gambia as a country with high quality epidemiological data, universal infant immunization and in which escape mutants after childhood infections have been observed. We predict that a variant cannot become dominant for at least 20 years from the start of vaccination, even when using a vaccine which affords no cross protection. The dominant factor responsible for this long time scale is the low rate of infectious contacts between infected and susceptible individuals (we estimate the basic reproduction number of hepatitis B in The Gambia to be 1·7). A variant strain that achieves high prevalence will also take many years to control, and it is questionable whether emergence will be identifiable by sero-surveillance until of high prevalence. The sensitivity of the model predictions to epidemiological and demographic factors is explored

Predictions of the emergence of vaccine-resistant hepatitis B in The Gambia using a mathematical model

Vaccine escape variants of hepatitis B virus (HBV) have been identified world-wide. A mathematical model of HBV transmission is used to investigate the potential pattern of emergence of such variants. Attention is focused on The Gambia as a country with high quality epidemiological data, universal infant immunization and in which escape mutants after childhood infections have been observed. We predict that a variant cannot become dominant for at least 20 years from the start of vaccination, even when using a vaccine which affords no cross protection. The dominant factor responsible for this long time scale is the low rate of infectious contacts between infected and susceptible individuals (we estimate the basic reproduction number of hepatitis B in The Gambia to be 1·7). A variant strain that achieves high prevalence will also take many years to control, and it is questionable whether emergence will be identifiable by sero-surveillance until of high prevalence. The sensitivity of the model predictions to epidemiological and demographic factors is explored

Probing the origin of 750 GeV diphoton excess with the precision measurements at the ILC

The recently reported diphoton excess at the LHC may imply the existence of a new resonance with a mass of about 750 GeV which couples to photons via loops of new charged particles. In this letter, we study the possibility to test such models at the ILC, paying attention to the new charged particles responsible for the diphoton decay of the resonance. We show that they affect the scattering processes $e^+e^- \to f\bar{f}$ (with $f$ denoting Standard Model fermions) at the ILC, which makes it possible to indirectly probe the new charged particles even if they are out of the kinematical reach. We also show that the discriminations of the diphoton models may be possible based on a study of the angular distributions of $f\bar{f}$.Comment: 14 pages, 5 figure

The masses, and the mass discrepancy of O-type stars

Context. The "mass discrepancy" in massive O stars represents a long-standing problem in stellar astrophysics with far-reaching implications for the chemical and dynamical feedback in galaxies. Aims. Our goal is to investigate this mass discrepancy by comparing state-of-the-art model masses with model-independent masses determined from eclipsing binaries. Methods. Using stellar evolution models and a recent calibration of stellar parameters for O-star spectral sub-classes, we present a convenient way to convert observed solar metallicity O star spectral types into model masses, which we subsequently compare to our dynamical mass compilation. We also derive similar conversions for LMC and SMC metallcities. Results. We obtain good agreement between model and dynamical masses, suggesting the long-standing problem of a systematic mass discrepancy problem might have been solved. We also provide error ranges for the model masses, as well as minimal and maximal age estimates for when the model stars are in a given spectral type box.Comment: 21 pages, 7 figures, 9 tables; accepted for publication by A&

LHC Accessible Second Higgs Boson in the Left-Right Model

A second Higgs doublet arises naturally as a parity partner of the standard model (SM) Higgs, once SM is extended to its left-right symmetric version (LRSM) to understand the origin of parity violation in weak interactions as well as to accommodate small neutrino masses via the seesaw mechanism. The flavor changing neutral Higgs (FCNH) effects in the minimal version of this model (LRSM), however, push the second Higgs mass to more than 15 TeV making it inaccessible at the LHC. Furthermore since the second Higgs mass is directly linked to the $W_R$ mass, discovery of a "low" mass $W_R$ ($M_{W_R}\leq 5-6$ TeV) at the LHC would require values for some Higgs self couplings larger than one. In this paper we present an extension of LRSM by adding a vector-like $SU(2)_R$ quark doublet which weakens the FCNH constraints allowing the second Higgs mass to be near or below TeV and a third neutral Higgs below 3 TeV for a $W_R$ mass below 5 TeV. It is then possible to search for these heavier Higgs bosons at the LHC, without conflicting with FCNH constraints. A right handed $W_R$ mass in the few TeV range is quite natural in this class of models without having to resort to large scalar coupling parameters. The CKM mixings are intimately linked to the vector-like quark mixings with the known quarks, which is the main reason why the constraints on the second Higgs mass is relaxed. We present a detailed theoretical and phenomenological analysis of this extended LR model and point out some tests as well as its potential for discovery of a second Higgs at the LHC. Two additional features of the model are: (i) a 5/3 charged quark and (ii) a fermionic top partner with masses in the TeV range.Comment: 22 pages, 4 figures, lots of stuff moved to the appendices, errors and typos corrected, version to appear in PR

Small Sample Bias in Synthetic Cohort Models of Labor Supply

In synthetic cohort models (cross-sectional data grouped at the cohort and year level), researchers often ignore potential biases induced by sampling error because they have 100 or 200 observations per group. I investigate small sample biases in the context of two synthetic cohort labor supply applications ? a model of intertemporal labor supply of men (similar to that of Browning, Deaton, and Irish, 1985) and a female labor supply model (similar to that of Blundell, Duncan, and Meghir, 1998). My approach is to use the Current Population Survey to compare the estimates when group sizes are extremely large to those that arise from randomly drawing subsamples of observations from the large groups. This provides a natural framework for examining the extent of small sample biases and the group sizes required so that small sample biases are negligible. I augment this approach with Monte Carlo analysis so as to precisely quantify biases and coverage rates. I find that, in these two applications, thousands of observations per group are required before small sample issues can be ignored in estimation. In these applications, sampling error leads one to underestimate intertemporal labor supply elasticities for men, and conclude that the income response of female labor supply is zero or tiny when in fact it is quite large.

PENYULUHAN HUKUM KEUANGAN DESA (POTENSI TINDAK PIDANA KORUPSI DAN PENCEGAHANNYA) DI DESA GALALA KOTA AMBON

Pengabdian Masyarakat (PPKM) ditujukan kepada aparatur pemerintah desa dan masyarakat agar memiliki pemahaman tentang tindak pidana korupsi. Undang-undang Tipikor di Indonesia masih menjadi musuh terbesar meskipun berbagai upaya telah dilakukan untuk menekan angka korupsi di Indonesia. Adanya korupsi dana desa dan alokasi dana desa berdampak pada tidak optimalnya pelayanan publik di desa. Oleh karena itu, perlu dilakukan pencegahan korupsi dana desa dan pengalokasian dana desa dengan cara meningkatkan partisipasi masyarakat khususnya perangkat desa untuk meningkatkan kualitas pelayanan publik di desa, melalui kegiatan sosialisasi pencegahan tindak pidana korupsi dana desa dan alokasi dana desa

Fast Integrated Spectra Analyzer: A New Computational Tool For Age and Reddening Determination of Small Angular Diameter Open Clusters

We present a new algorithm called 'Fast Integrated Spectra Analyzer" (FISA) that permits fast and reasonably accurate age and reddening determinations for small angular diameter open clusters by using their integrated spectra in the (3600-7400) \AA \ range and currently available template spectrum libraries. This algorithm and its implementation help to achieve astrophysical results in shorter times than from other methods. A brief review is given of the integrated spectroscopic technique applied to the study of open clusters as well as the basic assumptions that justify its use. We describe the numerical algorithm employed in detail, show examples of its application, and provide a link to the code. Our method has successfully been applied to integrated spectroscopy of open clusters, both in the Galaxy and in the Magellanic Clouds, to determine ages and reddenings.Comment: 27 Pages, 7 Figures, 1 table. Accepted to PAS