2,541 research outputs found
Searching for dark matter via mono- boson production at the ILC
High energy colliders provide a new unique way to determine the microscopic
properties of the dark matter (DM). Weakly interacting massive particles
(WIMPs) are widely considered as one of the best DM candidates. It is usually
assumed that the WIMP couples to the SM sector through its interactions with
quarks and leptons. In this paper, we investigate the DM pair production
associated with a boson in an effective field theory framework at the
International Linear Collider (ILC), which can be used to study the
interactions between the DM and leptons. For illustrative purposes, we present
the integrated and differential cross sections for the process, where the boson is radiated from the initial
state electron or positron. Meanwhile, we analyze the neutrino pair production
in association with a boson as the SM background.Comment: 12 pages, 5 figure
Diethyl 2,2-bis(3,5-di-tert-butyl-4-hydroxybenzyl)malonate
The title molecule, C37H56O6, possesses twofold symmetry, with the twofold axis passing through the quaternary C atom. In the crystal, neighbouring molecules are linked via O—H⋯O hydrogen bonds involving the phenol OH group and the carbonyl O atom, forming chains propagating in [101]. Within these chains, rings are formed with an R
2
2(20) motif. There are also C—H⋯O interactions present within the rings
Quantification of viable bioaerosol emanation from an ACMV system and its impact on indoor bioaerosol pollution
Viable bioaerosol can deposit and multiply in air-conditioning and mechanical ventilation (ACMV) systems, eventually entering indoor environments after these systems are operated and contributing to indoor pollution. We propose a method for identifying and quantifying the emanation of viable bioaerosol from an ACMV system and its impact on indoor pollution through surface and air sampling followed by analysis using a material-balance model. Adopting this method, we investigated the contribution of viable bioaerosol from an ACMV system to the indoor pollution in an air-conditioned room located in Singapore. The system, which emanated viable bacteria and viable fungi at the rates of 2.4 CFU s–1 and 3.9 CFU s–1, respectively, was the largest source of indoor viable bacteria and the second largest source of indoor viable fungi (exceeded only by the outdoor fungi introduced through mechanical ventilation) in the air. Potentially pathogenic bioaerosol species in the genera of Staphylococcus, Moraxella and Aspergillus were also identified in the ACMV system. In particular, Moraxella osloensis, the most likely genus to originate from occupants, was found to accumulate in the ACMV system, indicating the potential effect of this system’s cleanliness on indoor pollution. Our method can be used as a tool for analysing the potential sources of indoor bioaerosol and supporting the development of effective control measures for bioaerosol emanation from ACMV systems
Gene Expression Divergence and Evolutionary Analysis of the Drosomycin Gene Family in Drosophila melanogaster
Drosomycin (Drs) encoding an inducible 44-residue antifungal peptide is clustered
with six additional genes, Dro1, Dro2, Dro3, Dro4, Dro5, and Dro6, forming a
multigene family on the 3L chromosome arm in Drosophila melanogaster. To get
further insight into the regulation of each member of the drosomycin gene family,
here we investigated gene expression patterns of this family by either microbe-free
injury or microbial challenges using real time RT-PCR. The results indicated that
among the seven drosomycin genes, Drs, Dro2, Dro3, Dro4, and Dro5 showed
constitutive expressions. Three out of five, Dro2, Dro3, and Dro5, were able to be
upregulated by simple injury. Interestingly, Drs is an only gene strongly upregulated
when Drosophila was infected with microbes. In contrast to these five genes, Dro1
and Dro6 were not transcribed at all in either noninfected or infected flies.
Furthermore, by 5′ rapid amplification of cDNA ends, two transcription start sites
were identified in Drs and Dro2, and one in Dro3, Dro4, and Dro5. In addition, NF-κB
binding sites were found in promoter regions of Drs, Dro2, Dro3, and Dro5, indicating
the importance of NF-κB binding sites for the inducibility of drosomycin genes. Based
on the analyses of flanking sequences of each gene in D. melanogaster and
phylogenetic relationship of drosomycins in D. melanogaster species-group, we
concluded that gene duplications were involved in the formation of the drosomycin
gene family. The possible evolutionary fates of drosomycin genes were discussed
according to the combining analysis of gene expression pattern, gene structure, and
functional divergence of these genes
Competitions of magnetism and superconductivity in FeAs-based materials
Using the numerical unrestricted Hartree-Fock approach, we study the ground
state of a two-orbital model describing newly discovered FeAs-based
superconductors. We observe the competition of a mode spin-density
wave and the superconductivity as the doping concentration changes. There might
be a small region in the electron-doping side where the magnetism and
superconductivity coexist. The superconducting pairing is found to be spin
singlet, orbital even, and mixed s + d wave (even
parity).Comment: 5 pages, 3 figure
Supersymmetric Electroweak Corrections to the Higgs Boson Decays into Chargino or Neutralino Pair
We investigate the supersymmetric electroweak corrections to the decay widths
of the CP-odd and the heavy CP-even Higgs bosons into chargino or neutralino
pair in the framework of the Minimal Supersymmetric Standard Model. The
corrections involve the contributions of the order , and . The detailed calculations of the electroweak corrections to the
following decay processes: and
are presented in this paper. We
find that these relative corrections maybe rather large quantitatively, and can
exceed 10% in some regions of parameter space. The corrections to the decay
can be obtained analogously,
but our results show that they are very small and can be neglected.Comment: 25 pages, 9 figures,accepted by Physical Review
- …