One-loop corrections to gaugino (co-)annihilation into quarks in the MSSM

We present the full $\mathcal{O}(\alpha_s)$ supersymmetric QCD corrections for gaugino annihilation and co-annihilation into light and heavy quarks in the Minimal Supersymmetric Standard Model (MSSM). We demonstrate that these channels are phenomenologically relevant within the so-called phenomenological MSSM. We discuss selected technical details such as the dipole subtraction method in the case of light quarks and the treatment of the bottom quark mass and Yukawa coupling. Numerical results for the (co-)annihilation cross sections and the predicted neutralino relic density are presented. We show that the impact of including the radiative corrections on the cosmologically preferred region of the parameter space is larger than the current experimental uncertainty from Planck data.Comment: 19 pages, 9 figures. Matches version published in Phys.Rev.

Precision predictions for supersymmetric dark matter

The dark matter relic density has been measured by Planck and its predecessors with an accuracy of about 2%. We present theoretical calculations with the numerical program DM@NLO in next-to-leading order SUSY QCD and beyond, which allow to reach this precision for gaugino and squark (co-)annihilations, and use them to scan the phenomenological MSSM for viable regions, applying also low-energy, electroweak and hadron collider constraints.Comment: 6 pages, 1 table, 8 figures, proceedings of ICHEP 201

The effect of steroids on GPR54 and GnRH neurons in the postpubertal male mouse [abstract]

Abstract only availableA novel neuropeptide, kisspeptin, binds to the receptor GPR54, to influence the initiation and regulation of puberty in mammals. It appears that the activation of GPR54 stimulates the release of gonadotropin releasing hormone (GnRH) from specialized neurons, resulting in the activation of the reproductive system. To further understand the role of the kisspeptin system in GnRH secretion, levels of GPR54 and GnRH mRNA were compared in hypothalamic tissue before, during, and after puberty in male mice. In addition, the expression of GPR54 and GnRH mRNA was examined after castration with or without steroid replacement in postpubertal males. Transgenic male mice that express green fluorescent protein (GFP) were used at 20, 30, and 60 days postnatal (PND). Some postnatal mice were gonadectomized (GDX), and half received testosterone (T) replacement. RNA was isolated from the septum and the basal hypothalamus (areas known to contain GnRH neurons), reverse transcribed, and subjected to real-time, quantitative PCR. Levels of mRNA were compared between GDX and GDX+T, as well as at each of the three ages. Relative amounts of mRNA from GPR54 and GnRH were compared with a housekeeping gene, RPII, using standard curves. Preliminary data suggests that the amount of GPR54 mRNA in hypothalamic tissue is unchanged at the ages studied (p<0.892), although we need to increase the number of mice studied at each age. However, the levels of GnRH mRNA in hypothalamic tissue do increase, although not significantly, with age and the pubertal transition (p<0.112). In postpubertal mice, the relative amount of GnRH mRNA is greater than GPR54 mRNA. Thus, data indicate that there is a decrease in GPR54 mRNA when compared to GnRH mRNA (p<0.05) during the pubertal transition. Studies that examine the effect of steroids on GPR54 and GnRH mRNA expression are currently in progress.Life Sciences Undergraduate Research Opportunity Progra

Kisspeptin, GPR54, and GnRH neurons: Interactions in the male mouse [abstract]

Abstract only availableFaculty Mentor: Dr. M. Cathleen Kovarik, Veterinary Biomedical SciencesA novel neuropeptide, kisspeptin, binds to the receptor GPR54, to influence the initiation and regulation of puberty in mammals. It appears that the activation of GPR54 stimulates the release of gonadotropin releasing hormone (GnRH) from specialized neurons, resulting in the activation of the reproductive system. To further understand the role of the kisspeptin system in GnRH secretion, levels of GPR54 and GnRH mRNA were compared in hypothalamic tissue before, during, and after puberty in male mice. Transgenic male mice that express green fluorescent protein (GFP) in their GnRH neurons were used at 20 (prepubertal), 30 (pubertal) and 60 (postpubertal) days postnatal. RNA was isolated from brain areas known to contain GnRH neurons. Isolated RNA was reverse transcribed and will be subjected to real-time, quantitative PCR. Relative amounts of mRNA from GPR54 and GnRH will be compared with a housekeeping gene, RPII using standard curves at each of the three ages. Currently, we have used real-time PCR to detect amplicons, of approximately 60 base pairs, for each group down to the attogram (10-18) level. We have also determined that the ABI 7000 machine and SYBR- green as a detector are optimal for our purposes. We are currently performing PCRs for each of the three genes of interest. Amounts of GPR54 and GnRH in older animals will be expressed relative to amounts from the 20 day postnatal animals. Similar techniques will be used to study the expression of GPR54 and GnRH mRNA at the level of the single GnRH neuron, as well as the effect of steroids on the system

Next generation sequencing analysis reveals a relationship between rDNA unit diversity and locus number in Nicotiana diploids

© 2012 Matyášek et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited

Usefulness of Ultrahigh Resolution Microstructural Studies for Understanding Localized Corrosion Behavior of Al Alloys

The corrosion behavior of different tempers of two aluminum alloys, AA7050 and an experimental Al–Mg–Cu–Si alloy, was studied in NaCl solution by anodic polarization and scanning electron microscopy and was correlated with differences in the microstructure. Potentiodynamic polarization experiments were performed on samples from the exact sheets used by others to study the microstructure evolution during the early stages of the precipitation sequence by high-resolution characterization tools [i.e., high-resolution transmission electron microscopy and atom probe tomography (APT)]. The usefulness of information from these state-of-the-art tools to lead to a better understanding about the effects of nanoscale segregation on localized corrosion of aluminum alloys is discussed. APT was able to provide information about the composition of the solid solution matrix region between the fine-scale hardening particles, which is not possible by any other technique. Some of the changes in corrosion behavior, e.g., the breakdown potentials, with temper could be rationalized based on changes in the matrix composition. The formation of corrosion-susceptible surface layers on as-polished AA7050 depended on the predominant type of hardening particle. The lack of detailed knowledge of the grain boundary region limited the applicability of the microstructural information generated by previous studies for understanding intergranular corrosion

ν(νˉ)\nu(\bar\nu)-208^{208}Pb deep inelastic scattering

Nuclear-medium effects in the weak structure functions $F_2(x,Q^2)$ and $F_3(x,Q^2)$ in the charged current neutrino and antineutrino induced deep inelastic reactions in $^{208}$Pb have been studied. The calculations have been performed in a theoretical model using relativistic nuclear spectral functions which incorporate Fermi motion, binding and nucleon correlations. We also consider the pion and rho meson cloud contributions calculated from a microscopic model for meson-nucleus self-energies. Using these structure functions, the results for the differential cross section have been obtained and compared with the CERN Hybrid Oscillation Research apparatUS (CHORUS) data. The results for the ratios $\frac{2F_{i}^{Pb}}{208F_i^D}$, $\frac{4F_{i}^{Pb}}{208F_i^{He}}$, $\frac{12F_{i}^{Pb}}{208F_i^C}$, $\frac{16F_{i}^{Pb}}{208F_i^O}$, and $\frac{56F_{i}^{Pb}}{208F_i^{Fe}}$ (i=2,3) have also been obtained and a few have been compared with some of the phenomenological fits.Comment: 19Pages, 12 Fig