Very Light Axigluons and the Top Asymmetry

We show that very light (50 - 90 GeV) axigluons with flavor-universal couplings of order g_{s}/3 may explain the anomalous top forward-backward asymmetry reported by both CDF and D0 collaborations. The model is naturally consistent with the observed t \bar t invariant mass distribution and evades bounds from light Higgs searches, LEP event shapes, and hadronic observables at the Z pole. Very light axigluons can appear as resonances in multijet events, but searches require sensitivity to masses below current limits.Comment: 10 pages, 5 figures, references added, discussion of constraints expanded, general conclusions unchange

Weak-triplet, color-octet scalars and the CDF dijet excess

We extend the standard model to include a weak-triplet and color-octet scalar. This `octo-triplet' field consists of three particles, two charged and one neutral, whose masses and renormalizable interactions depend only on two new parameters. The charged octo-triplet decay into a W boson and a gluon is suppressed by a loop factor and an accidental cancellation. Thus, the main decays of the charged octo-triplet may occur through higher-dimensional operators, mediated by a heavy vectorlike fermion, into quark pairs. For an octo-triplet mass below the t\bar{b} threshold, the decay into Wb\bar{b} or Wb\bar{s} through an off-shell top quark has a width comparable to that into c\bar{s} or c\bar{b}. Pair production with one octo-triplet decaying into two jets and the other decaying into a W and two soft b jets may explain the dijet-plus-W excess reported by the CDF Collaboration. Using a few kinematic distributions, we compare two mechanisms of octo-triplet pair production: through an s-channel coloron and through the coupling to gluons. The higher-dimensional operators that allow dijet decays also lead to CP violation in B_s - \bar B_s mixing.Comment: 18 pages. New CDF kinematic distributions using 7.3 fb^{-1} compared to both resonant and gluon-induced pair production of octets. Corrections in Section 3.1. Comment on the D0 Wjj result included in Section 3.3. Implications for LHC expanded in Section 3.

Selected methods for buildup factor calculation in gamma and X radiation protection

U ovom radu je dat pregled izabranih metoda proračuna buildup faktora na osnovu empirijskih aproksimacija Bergera, Tejlora i aproksimacije Geometrijske Progresije, sa kojima mogu da se rešavaju praktični problemi u zaštiti od zračenja u zavisnosti od stepena njihove složenosti. Razmatran je bazičan slučaj za određivanje buildup faktora u zavisnosti od karakteristika homogene materijalne sredine kroz koju se obavlja transport fotona X i gama zračenja, zatim od energije fotona iz izvora zračenja, kao od rastojanja između izvora fotona i tačke u materijalnoj sredini u kojoj se određuje dozimetrijska veličina. Posle sprovedene diskusije rezultata proračuna buildup faktora za olovo, gvožđe, običan beton i vodu, u radu su izvedeni odgovarajući zaključci u vezi efikasnosti primene pojedinih metoda proračuna u homogenoj materijalnoj sredini, uzimajući u obzir da svaka od prikazanih metoda ima svoje prednosti, kao i ograničenja, u zavisnosti od fokusa njene primene.This paper provides an overview of selected calculation method buildup factors based on empirical approximation that can not be solved practical problems in radiation protection, depending on their level of complexity. A basic case was considered for the determination of the buildup factor depending on the characteristics of the homogeneous material environment through which the transport of photons X and gamma radiation is carried out, then from the energy of photons from the radiation source, from the distance between the photon source and the point in the material environment in which the dosimetric size. After the discussion of the results of the calculation of the buildup factors for lead, iron, ordinary concrete and water, the conclusions about the efficiency of the application of individual calculation methods in a homogeneous material environment were carried out, taking into account that each of the methods presented has its advantages, as well as the limitations, depending on the focus of its application.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Selected methods for buildup factor calculation in gamma and X radiation protection

U ovom radu je dat pregled izabranih metoda proračuna buildup faktora na osnovu empirijskih aproksimacija Bergera, Tejlora i aproksimacije Geometrijske Progresije, sa kojima mogu da se rešavaju praktični problemi u zaštiti od zračenja u zavisnosti od stepena njihove složenosti. Razmatran je bazičan slučaj za određivanje buildup faktora u zavisnosti od karakteristika homogene materijalne sredine kroz koju se obavlja transport fotona X i gama zračenja, zatim od energije fotona iz izvora zračenja, kao od rastojanja između izvora fotona i tačke u materijalnoj sredini u kojoj se određuje dozimetrijska veličina. Posle sprovedene diskusije rezultata proračuna buildup faktora za olovo, gvožđe, običan beton i vodu, u radu su izvedeni odgovarajući zaključci u vezi efikasnosti primene pojedinih metoda proračuna u homogenoj materijalnoj sredini, uzimajući u obzir da svaka od prikazanih metoda ima svoje prednosti, kao i ograničenja, u zavisnosti od fokusa njene primene.This paper provides an overview of selected calculation method buildup factors based on empirical approximation that can not be solved practical problems in radiation protection, depending on their level of complexity. A basic case was considered for the determination of the buildup factor depending on the characteristics of the homogeneous material environment through which the transport of photons X and gamma radiation is carried out, then from the energy of photons from the radiation source, from the distance between the photon source and the point in the material environment in which the dosimetric size. After the discussion of the results of the calculation of the buildup factors for lead, iron, ordinary concrete and water, the conclusions about the efficiency of the application of individual calculation methods in a homogeneous material environment were carried out, taking into account that each of the methods presented has its advantages, as well as the limitations, depending on the focus of its application.Proceedings: [http://vinar.vin.bg.ac.rs/handle/123456789/8681]XXX симпозијум ДЗЗСЦГ (Друштва за заштиту од зрачења Србије и Црне Горе), 2- 4. октобар 2019. године, Дивчибаре, Србиј

Atomic Dark Matter

We propose that dark matter is dominantly comprised of atomic bound states. We build a simple model and map the parameter space that results in the early universe formation of hydrogen-like dark atoms. We find that atomic dark matter has interesting implications for cosmology as well as direct detection: Protohalo formation can be suppressed below $M_{proto} \sim 10^3 - 10^6 M_{\odot}$ for weak scale dark matter due to Ion-Radiation interactions in the dark sector. Moreover, weak-scale dark atoms can accommodate hyperfine splittings of order 100 \kev, consistent with the inelastic dark matter interpretation of the DAMA data while naturally evading direct detection bounds.Comment: 17 pages, 3 figure

The association between subclass-specific IgG Fc N-glycosylation profiles and hypertension in the Uygur, Kazak, Kirgiz, and Tajik populations

Hypertension results from the interaction of genetic and acquired factors. IgG occurs in the form of different subclasses, of which the effector functions show significant variation. The detailed differences between the glycosylation profiles of the individual IgG subclasses may be lost in a profiling method for total IgG N-glycosylation. In this study, subclass-specific IgG Fc glycosylation profile was investigated in the four northwestern Chinese minority populations, namely, Uygur (UIG), Kazak (KZK), Kirgiz (KGZ), and Tajik (TJK), composed of 274 hypertensive patients and 356 healthy controls. The results showed that ten directly measured IgG N-glycan traits (i.e., IgG1G0F, IgG2G0F, IgG2G1FN, IgG2G1FS, IgG2G2S, IgG4G0F, IgG4G1FS, IgG4G1S, IgG4G2FS, and IgG4G2N) representing galactosylation and sialylation are significantly associated with hypertension, with IgG4 consistently showing weaker associations of its sialylation, across the four ethnic groups. We observed a modest improvement on the AUC of ROC curve when the IgG Fc N-glycan traits are added into the glycan-based model (difference between AUCs, 0.044, 95% CI: 0.016-0.072, P = 0.002). The AUC of the diagnostic model indicated that the subclass-specific IgG Fc N-glycan profiles provide more information reinforcing current models utilizing age, gender, BMI, and ethnicity, and demonstrate the potential of subclass-specific IgG Fc N-glycosylation profiles to serve as a biomarker for hypertension. Further research is however required to determine the additive value of subclass-specific IgG Fc N-glycosylation on top of biomarkers, which are currently used

Hypoxia-inducible factor-1 alpha, in association with inflammation, angiogenesis and MYC, is a critical prognostic factor in patients with HCC after surgery

<p>Abstract</p> <p>Background</p> <p>Despite well-studied tumor hypoxia in laboratory, little is known about the association with other pathophysiological events in the clinical view. We investigated the prognostic value of hypoxia-inducible factor-1 alpha (HIF-1alpha) in hepatocellular carcinoma (HCC), and its correlations with inflammation, angiogenesis and MYC oncogene.</p> <p>Methods</p> <p>In a random series of 110 HCC patients, the mRNA of HIF-1alpha, inflammation related factors (COX-2, MMP7 and MMP9), angiogenesis related factors (VEGF and PDGFRA) and MYC in tumor tissue were detected by real-time RT-PCR and HIF-1alpha protein was assessed by immunohistochemistry. The correlations between HIF-1alpha mRNA and the factors mentioned previously, the relationship between HIF-1alpha and clinicopathologic features, and the prognostic value were analyzed.</p> <p>Results</p> <p>The expression of both HIF-1alpha mRNA and protein in HCC were independent prognostic factors for overall survival (OS) (<it>P </it>= 0.012 and <it>P </it>= 0.021, respectively) and disease-free survival (DFS) (<it>P </it>= 0.004 and <it>P </it>= 0.007, respectively) as well. Besides, the high expression of HIF-1alpha mRNA and protein proposed an advanced BCLC stage and more incidence of vascular invasion. The mRNA of HIF-1alpha had significantly positive correlations to that of COX-2, PDGFRA, MMP7, MMP9, MYC, except VEGF. In addition to HIF-1alpha, COX-2 and PDGFRA were also independent prognosticators for OS (<it>P </it>= 0.004 and <it>P </it>= 0.010, respectively) and DFS (<it>P </it>= 0.010 and <it>P </it>= 0.038, respectively).</p> <p>Conclusion</p> <p>HIF-1alpha in HCC plays an important role in predicting patient outcome. It may influence HCC biological behaviors and affect the tumor inflammation, angiogenesis and act in concert with the oncogene MYC. Attaching importance to HIF-1alpha in HCC may improve the prognostic and therapeutic technique.</p