Exotic fermion multiplets as a solution to baryon asymmetry, dark matter and neutrino masses

We propose an extension to the standard model where three exotic fermion 5-plets and one scalar 6-plet are added to the particle content. By demanding that all interactions are renormalizable and standard model gauge invariant, we show that the lightest exotic particle in this model can be a dark matter candidate as long as the new 6-plet scalar does not develop a nonzero vacuum expectation value. Furthermore, light neutrino masses are generated radiatively at one-loop while the baryon asymmetry is produced by the CP-violating decays of the second lightest exotic particle. We have demonstrated using concrete examples that there is a parameter space where a consistent solution to the problems of baryon asymmetry, dark matter and neutrino masses can be obtained.Comment: 17 pages, 2 figures (REVTeX4.1), v2: some refs added, v3: typos corrected, Sec.VI.B, C modified, this version to appear in PR

Rare B decays and Tevatron top-pair asymmetry

The recent Tevatron result on the top quark forward-backward asymmetry, which deviates from its standard model prediction by 3.4$\sigma$, has prompted many authors to build new models to account for this anomaly. Among the various proposals, we find that those mechanisms which produce $t\bar t$ via $t$- or $u$-channel can have a strong correlation to the rare B decays. We demonstrate this link by studying a model with a new charged gauge boson, $W'$. In terms of the current measurements on $B\to \pi K$ decays, we conclude that the branching ratio for $B^-\to \pi^- \bar K^0$ is affected most by the new effects. Furthermore, using the world average branching ratio for the exclusive B decays at $2\sigma$ level, we discuss the allowed values for the new parameters. Finally, we point out that the influence of the new physics effects on the direct CP asymmetry in B decays is insignificant.Comment: 15 page, 6 figures, typos corrected and references added, final version to appear journa

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Decreased inhibin B responses following recombinant human chorionic gonadotropin administration in normal women and women with polycystic ovary syndrome.

ObjectiveTo determine whether granulosa cells contribute to excess androgen production, by assessing inhibin B (Inh B) responses to hCG in women with polycystic ovary syndrome (PCOS) and in normal women.DesignProspective study.SettingAcademic medical center.Patient(s)Twenty women with PCOS and 16 normal women.Intervention(s)Blood samples obtained before and 24 hours after injection of 25 μg recombinant hCG (r-hCG).Main outcome measure(s)Basal and stimulated Inh B, E2, androstenedione (A), and T responses after r-hCG administration.Result(s)In normal and PCOS women, r-hCG induced a significant reduction of Inh B levels. Lowered Inh B responses were not related to body mass index, PCOS status, or age by multivariate regression. Recombinant hCG significantly increased serum A and E2 in both normal and PCOS women.Conclusion(s)In normal and PCOS women, Inh B production was decreased following r-hCG administration. These findings strongly suggest that in PCOS women androgen excess is not enhanced by LH-stimulated Inh B production.Clinical trial registration numberNCT00747617

Decreased inhibin B responses following recombinant human chorionic gonadotropin administration in normal women and women with polycystic ovary syndrome.

ObjectiveTo determine whether granulosa cells contribute to excess androgen production, by assessing inhibin B (Inh B) responses to hCG in women with polycystic ovary syndrome (PCOS) and in normal women.DesignProspective study.SettingAcademic medical center.Patient(s)Twenty women with PCOS and 16 normal women.Intervention(s)Blood samples obtained before and 24 hours after injection of 25 μg recombinant hCG (r-hCG).Main outcome measure(s)Basal and stimulated Inh B, E2, androstenedione (A), and T responses after r-hCG administration.Result(s)In normal and PCOS women, r-hCG induced a significant reduction of Inh B levels. Lowered Inh B responses were not related to body mass index, PCOS status, or age by multivariate regression. Recombinant hCG significantly increased serum A and E2 in both normal and PCOS women.Conclusion(s)In normal and PCOS women, Inh B production was decreased following r-hCG administration. These findings strongly suggest that in PCOS women androgen excess is not enhanced by LH-stimulated Inh B production.Clinical trial registration numberNCT00747617

Serum Anti-Müllerian Hormone Concentrations Are Elevated in Oligomenorrheic Girls without Evidence of Hyperandrogenism

Context: Serum anti-Müllerian hormone (AMH) levels are significantly elevated in adolescents with polycystic ovary syndrome (PCOS) compared to normal controls. Whether adolescents with oligomenorrhea have elevated AMH levels is unknown