653 research outputs found
A Widespread Distribution for Arostrilepis Tenuicirrosa (Eucestoda: Hymenolepididae) Among Arvicoline Rodent Hosts (Cricetidae) from the Palearctic Based on Molecular and Morphological Criteria: Historical and Biogeographic Implications
Separation of isomeric glycans by ion mobility spectrometry–the impact of fluorescent labelling
The analysis of complex oligosaccharides is traditionally based on multidimensional workflows where liquid chromatography is coupled to tandem mass spectrometry (LC-MS/MS). Due to the presence of multiple isomers, which cannot be distinguished easily using tandem MS, a detailed structural elucidation is still challenging in many cases. Recently, ion mobility spectrometry (IMS) showed great potential as an additional structural parameter in glycan analysis. While the time-scale of the IMS separation is fully compatible to that of LC-MS-based workflows, there are very few reports in which both techniques have been directly coupled for glycan analysis. As a result, there is little knowledge on how the derivatization with fluorescent labels as common in glycan LC-MS affects the mobility and, as a result, the selectivity of IMS separations. Here, we address this problem by systematically analyzing six isomeric glycans derivatized with the most common fluorescent tags using ion mobility spectrometry. We report >150 collision cross-sections (CCS) acquired in positive and negative ion mode and compare the quality of the separation for each derivatization strategy. Our results show that isomer separation strongly depends on the chosen label, as well as on the type of adduct ion. In some cases, fluorescent labels significantly enhance peak-to-peak resolution which can help to distinguish isomeric specie
A precision study of the fine tuning in the DiracNMSSM
Recently the DiracNMSSM has been proposed as a possible solution to reduce
the fine tuning in supersymmetry. We determine the degree of fine tuning needed
in the DiracNMSSM with and without non-universal gaugino masses and compare it
with the fine tuning in the GNMSSM. To apply reasonable cuts on the allowed
parameter regions we perform a precise calculation of the Higgs mass. In
addition, we include the limits from direct SUSY searches and dark matter
abundance. We find that both models are comparable in terms of fine tuning,
with the minimal fine tuning in the GNMSSM slightly smaller.Comment: 20 pages + appendices, 10 figure
Gastrointestinal parasites in an isolated Norwegian population of wild red deer (Cervus elaphus)
In the Eye of the Cyclops: The Classic Case of Cospeciation and Why Paradigms are Important
Dark Matter Direct Detection with Non-Maxwellian Velocity Structure
The velocity distribution function of dark matter particles is expected to
show significant departures from a Maxwell-Boltzmann distribution. This can
have profound effects on the predicted dark matter - nucleon scattering rates
in direct detection experiments, especially for dark matter models in which the
scattering is sensitive to the high velocity tail of the distribution, such as
inelastic dark matter (iDM) or light (few GeV) dark matter (LDM), and for
experiments that require high energy recoil events, such as many directionally
sensitive experiments. Here we determine the velocity distribution functions
from two of the highest resolution numerical simulations of Galactic dark
matter structure (Via Lactea II and GHALO), and study the effects for these
scenarios. For directional detection, we find that the observed departures from
Maxwell-Boltzmann increase the contrast of the signal and change the typical
direction of incoming DM particles. For iDM, the expected signals at direct
detection experiments are changed dramatically: the annual modulation can be
enhanced by more than a factor two, and the relative rates of DAMA compared to
CDMS can change by an order of magnitude, while those compared to CRESST can
change by a factor of two. The spectrum of the signal can also change
dramatically, with many features arising due to substructure. For LDM the
spectral effects are smaller, but changes do arise that improve the
compatibility with existing experiments. We find that the phase of the
modulation can depend upon energy, which would help discriminate against
background should it be found.Comment: 34 pages, 16 figures, submitted to JCAP. Tables of g(v_min), the
integral of f(v)/v from v_min to infinity, derived from our simulations, are
available for download at http://astro.berkeley.edu/~mqk/dmdd
Towards constraints on the SUSY seesaw from flavour-dependent leptogenesis
We systematically investigate constraints on the parameters of the
supersymmetric type-I seesaw mechanism from the requirement of successful
thermal leptogenesis in the presence of upper bounds on the reheat temperature
of the early Universe. To this end, we solve the
flavour-dependent Boltzmann equations in the MSSM, extended to include
reheating. With conservative bounds on , leading to mildly
constrained scenarios for thermal leptogenesis, compatibility with observation
can be obtained for extensive new regions of the parameter space, due to
flavour-dependent effects. On the other hand, focusing on (normal) hierarchical
light and heavy neutrinos, the hypothesis that there is no CP violation
associated with the right-handed neutrino sector, and that leptogenesis
exclusively arises from the CP-violating phases of the matrix,
is only marginally consistent. Taking into account stricter bounds on
further suggests that (additional) sources of CP violation must
arise from the right-handed neutrino sector, further implying stronger
constraints for the right-handed neutrino parameters.Comment: 42 pages, 12 figures; final version published in JCAP; numerical
results for the efficiency factor can be downloaded from
http://www.newphysics.eu/leptogenesis
The generalised NMSSM at one loop: fine tuning and phenomenology
We determine the degree of fine tuning needed in a generalised version of the
NMSSM that follows from an underlying Z4 or Z8 R symmetry. We find that it is
significantly less than is found in the MSSM or NMSSM and extends the range of
Higgs mass that have acceptable fine tuning up to Higgs masses of mh ~ 130 GeV.
For universal boundary conditions analogous to the CMSSM the phenomenology is
rather MSSM like with the singlet states typically rather heavy. For more
general boundary conditions the singlet states can be light, leading to
interesting signatures at the LHC and direct detection experiments.Comment: 20 pages, 9 figures, matches published versio
Resurrection and redescription of Varestrongylus alces (Nematoda; Protostrongylidae), a lungworm of the Eurasian moose (Alces alces), with report on associated pathology
Varestrongylus alces, a lungworm in Eurasian moose from Europe has been considered a
junior synonym of Varestrongylus capreoli, in European roe deer, due to a poorly detailed
morphological description and the absence of a type-series.
Methods
Specimens used in the redescription were collected from lesions in the lungs of Eurasian
moose, from Vestby, Norway. Specimens were described based on comparative morphology
and integrated approaches. Molecular identification was based on PCR, cloning and
sequencing of the ITS-2 region of the nuclear ribosomal DNA. Phylogenetic analysis
compared V. alces ITS-2 sequences to these of other Varestrongylus species and other
protostrongylids.
Results
Varestrongylus alces is resurrected for protostrongylid nematodes of Eurasian moose from
Europe. Varestrongylus alces causes firm nodular lesions that are clearly differentiated from
the adjacent lung tissue. Histologically, lesions are restricted to the parenchyma with adult,
egg and larval parasites surrounded by multinucleated giant cells, macrophages, eosinophilic
granulocytes, lymphocytes. The species is valid and distinct from others referred to
Varestrongylus, and should be separated from V. capreoli. Morphologically, V. alces can be
distinguished from other species by characters in the males that include a distally bifurcated
gubernaculum, arched denticulate crura, spicules that are equal in length and relatively short,
and a dorsal ray that is elongate and bifurcated. Females have a well-developed provagina,
and are very similar to those of V. capreoli. Morphometrics of first-stage larvae largely
overlap with those of other Varestrongylus. Sequences of the ITS-2 region strongly support
mutual independence of V. alces, V. cf. capreoli, and the yet undescribed species of
Varestrongylus from North American ungulates. These three taxa form a well-supported
crown-clade as the putative sister of V. alpenae. The association of V. alces and Alces or its
ancestors is discussed in light of host and parasite phylogeny and host historical
biogeography.
Varestrongylus alces is a valid species, and should be considered distinct from V. capreoli.
Phylogenetic relationships among Varestrongylus spp. from Eurasia and North America are
complex and consistent with faunal assembly involving recurrent events of geographic
expansion, host switching and subsequent speciation.
Cervidae, Cryptic species, Historical biogeography, ITS-2, Metastrongyloidea, Parasite
biodiversity, Varestrongylinae, Varestrongylus capreoli, Verminous pneumoniapublishedVersio
Interplay between Fermi gamma-ray lines and collider searches
We explore the interplay between lines in the gamma-ray spectrum and LHC searches involving missing energy and photons. As an example, we consider a singlet Dirac
fermion dark matter with the mediator for Fermi gamma-ray line at 130 GeV. A new chiral or local U(1) symmetry makes weak-scale dark matter natural and provides the axion or
Z 0 gauge boson as the mediator connecting between dark matter and electroweak gauge bosons. In these models, the mediator particle can be produced in association with a
monophoton at colliders and it produces large missing energy through the decays into a DM pair or ZZ; Z with at least one Z decaying into a neutrino pair. We adopt the monophoton searches with large missing energy at the LHC and impose the bounds on the coupling and mass of the mediator field in the models. We show that the parameter space of the Z 0 mediation model is already strongly constrained by the LHC 8TeV data, whereas a certain region of the parameter space away from the resonance in axion-like mediator models are bounded. We foresee the monophoton bounds on the Z 0 and axion mediation models at the LHC 14 TeV
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