2,631 research outputs found
Microarray evidence for off target effects in tick RNA interference experiments, and the lack of strong correlation between DSRNA and antibody phenotypes in tick In vitro treatments for vaccine candidate screening
No abstract availabl
Model for a Light Z' Boson
A model of a light boson is constructed and phenomenological bounds are
derived. This boson arises from a very simple extension to the Standard
Model, and it is constrained to be light because the vacuum expectation values
which generate its mass also break the electroweak gauge group. It is difficult
to detect experimentally because it couples exclusively or primarily (depending
on symmetry breaking details) to second and third generation leptons. However,
if the boson is sufficiently light, then there exists the possibility of
the two-body decay occuring. This will provide a
striking signature to test the model.Comment: 20 pages + 5 pages of figures (appended as postscipt files), LaTeX,
OITS-53
Spatial mapping of band bending in semiconductor devices using in-situ quantum sensors
Band bending is a central concept in solid-state physics that arises from
local variations in charge distribution especially near semiconductor
interfaces and surfaces. Its precision measurement is vital in a variety of
contexts from the optimisation of field effect transistors to the engineering
of qubit devices with enhanced stability and coherence. Existing methods are
surface sensitive and are unable to probe band bending at depth from surface or
bulk charges related to crystal defects. Here we propose an in-situ method for
probing band bending in a semiconductor device by imaging an array of
atomic-sized quantum sensing defects to report on the local electric field. We
implement the concept using the nitrogen-vacancy centre in diamond, and map the
electric field at different depths under various surface terminations. We then
fabricate a two-terminal device based on the conductive two-dimensional hole
gas formed at a hydrogen-terminated diamond surface, and observe an unexpected
spatial modulation of the electric field attributed to a complex interplay
between charge injection and photo-ionisation effects. Our method opens the way
to three-dimensional mapping of band bending in diamond and other
semiconductors hosting suitable quantum sensors, combined with simultaneous
imaging of charge transport in complex operating devices.Comment: This is a pre-print of an article published in Nature Electronics.
The final authenticated version is available online at
https://dx.doi.org/10.1038/s41928-018-0130-
Evaluation and histological examination of a Campylobacter fetus subsp. venerealis small animal infection model
Bovine genital campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is associated with production losses in cattle worldwide. This study aimed to develop a reliable BGC guinea pig model to facilitate future studies of pathogenicity, abortion mechanisms and vaccine efficacy. Seven groups of five pregnant guinea pigs (1 control per group) were inoculated with one of three strains via intraperitoneal (IP) or intra-vaginal routes. Samples were examined using culture, PCR and histology. Abortions ranged from 0% to 100% and re-isolation of causative bacteria from sampled sites varied with strain, dose of bacteria and time to abortion. Histology indicated metritis and placentitis, suggesting that the bacteria induce inflammation, placental detachment and subsequent abortion. Variation of virulence between strains was observed and determined by culture and abortion rates. IP administration of C fetus subsp. venerealis to pregnant guinea pigs is a promising small animal model for the investigation of BGC abortion. (C) 2014 Elsevier Ltd. All rights reserved
Cloud Atlas: High-Contrast Time-Resolved Observations of Planetary-Mass Companions
Directly-imaged planetary-mass companions offer unique opportunities in
atmospheric studies of exoplanets. They share characteristics of both brown
dwarfs and transiting exoplanets, therefore, are critical for connecting
atmospheric characterizations for these objects. Rotational phase mapping is a
powerful technique to constrain the condensate cloud properties in ultra-cool
atmospheres. Applying this technique to directly-imaged planetary-mass
companions will be extremely valuable for constraining cloud models in low mass
and surface gravity atmospheres and for determining the rotation rate and
angular momentum of substellar companions. Here, we present Hubble Space
Telescope Wide Field Camera 3 near-infrared time-resolved photometry for three
planetary-mass companions, AB Pic B, 2M0122B, and 2M1207b. Using two-roll
differential imaging and hybrid point spread function modeling, we achieve
sub-percent photometric precision for all three observations. We find tentative
modulations () for AB Pic B and 2M0122B but cannot reach
conclusive results on 2M1207b due to strong systematics. The relatively low
significance of the modulation measurements cannot rule out the hypothesis that
these planetary-mass companions have the same vertical cloud structures as
brown dwarfs. Our rotation rate measurements, combined with archival period
measurements of planetary-mass companions and brown dwarfs do not support a
universal mass-rotation relation. The high precision of our observations and
the high occurrence rates of variable low-surface gravity objects encourage
high-contrast time-resolved observations with the James Webb Space Telescope.Comment: Accepted for publication in AAS Journa
PCV139 EVALUATION OF A HEALTH CARE PROVIDER INTERVENTION TO INITIATE ACEI OR ARB THERAPY AMONG PATIENTS WITH DIABETES PLUS HYPERTENSION AND/OR NEPHROPATHY
Amplitude Zeros in Radiative Decays of Scalar Particles
We study amplitude zeros in radiative decay processes with a photon or a
gluon emission of all possible scalar particles(e.g. scalar leptoquarks) which
may interact with the usual fermions in models beyond the standard model. For
the decays with a photon emission, the amplitudes clearly exhibit the
factorization property and the differential decay rates vanish at specific
values of a certain variable which are determined only by the electric charges
of the particles involved and independent of the particle masses and the
various couplings. For the decays with a gluon emission, even though the zeros
are washed away, the differential decay rates still have distinct minima. The
branching ratios as a function of leptoquark masses are presented for the
scalar leptoquark decays. We also comment on the decays of vector particles
into two fermions and a photon.Comment: Revtex, 17 pages + 6 figures (available upon request), Preprint,
OITS559. Several typos with tex file were correcte
Evaluation and histological examination of a Campylobacter fetus subsp. venerealis small animal infection model
Bovine genital campylobacteriosis (BGC), caused by Campylobacter fetus subsp. venerealis, is associated with production losses in cattle worldwide. This study aimed to develop a reliable BGC guinea pig model to facilitate future studies of pathogenicity, abortion mechanisms and vaccine efficacy. Seven groups of five pregnant guinea pigs (1 control per group) were inoculated with one of three strains via intra-peritoneal (IP) or intra-vaginal routes. Samples were examined using culture, PCR and histology. Abortions ranged from 0% to 100% and re-isolation of causative bacteria from sampled sites varied with strain, dose of bacteria and time to abortion. Histology indicated metritis and placentitis, suggesting that the bacteria induce inflammation, placental detachment and subsequent abortion. Variation of virulence between strains was observed and determined by culture and abortion rates. IP administration of C. fetus subsp. venerealis to pregnant guinea pigs is a promising small animal model for the investigation of BGC abortion
Evaluation of a Phenotypic MicroArray (BIOLOG) for characterisation of bovine reproductive Campylobacter fetus subspecies and other Campylobacter-like isolates by comparison with standard phenotypic, PCR and 16S rDNA sequencing
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