1,245 research outputs found
Steps toward a Universal Influenza Vaccine: Research Models and Comparison of Current Approaches
The ability of influenza virus to adapt to various species and evade natural immunity makes the ubiquitous pathogen particularly difficult to eradicate. Annual reformulation of influenza vaccines is costly and time-consuming and has varying efficacy against influenza virus strains. Therefore, worldwide efforts aim to develop a universal influenza vaccine to prevent potential healthcare emergencies such as pandemic influenza threats, such as the 1918 Spanish Flu and pandemic Swine Flu of 2009. Efficacy of a universal influenza vaccine must overcome current challenges with subtype diversity, antigenic drift, and adequately protect against emerging reassortants from both environmental and agricultural sources. Furthermore, the manufacturing and production of vaccines largely influence the effectiveness of a vaccine and technological advancements may soon rival current vaccine strategies. This review discusses the evolution and diversity of influenza viruses, how viral glycoprotein hemagglutinin plays a dominant role in influenza surveillance and assessment of protection and compares the methodologies of current and upcoming vaccine options. While the obstacles remain daunting, growing knowledge of influenza evolution and immunity may lead to more viable candidates that protect against broader varieties of influenza viruses and help prevent future international health crises
Troponin T Gene Switching Is Developmentally Regulated by Plasma-Borne Factors in Parabiotic Chicks
AbstractMyogenesis involves a conserved program of muscle gene isoform switching requiring the synchronized induction and repression of numerous muscle-specific gene family members. Central to understanding the regulation of this process are questions related to the origin and transmission of regulatory signals to the myofiber. We show here that troponin T gene switching can be precociously initiated by extrinsic blood-borne components but also requires other mechanisms that are regulated locally, intrinsically, or posttranscriptionally. We established a chimeric blood circulation by parabiosis between fetal chicks and quails to determine whether signals inducing earlier troponin T mRNA isoform switching in quails could be transduced to chick partners through the serum. While quail fetuses were unaffected by parabiosis, quail serum caused premature troponin T iso-mRNA switching in chick muscle, although initiation remained later than in quails. The onset of repression of a known innervation-dependent acetylcholine receptor mRNA did not coincide with the initiation of troponin T iso-mRNA switching and was not affected by parabiosis. These results support serum-borne factor regulation of isoform switching as an important and distinct mechanism relevant to understanding how extrinsic and intrinsic cues are integrated during muscle differentiation and development
Atomic ionization by sterile-to-active neutrino conversion and constraints on dark matter sterile neutrinos with germanium detectors
The transition magnetic moment of a sterile-to-active neutrino conversion
gives rise to not only radiative decay of a sterile neutrino, but also its
non-standard interaction (NSI) with matter. For sterile neutrinos of keV-mass
as dark matter candidates, their decay signals are actively searched for in
cosmic X-ray spectra. In this work, we consider the NSI that leads to atomic
ionization, which can be detected by direct dark matter experiments. It is
found that this inelastic scattering process for a nonrelativistic sterile
neutrino has a pronounced enhancement in the differential cross section at
energy transfer about half of its mass, manifesting experimentally as peaks in
the measurable energy spectra. The enhancement effects gradually smear out as
the sterile neutrino becomes relativistic. Using data taken with germanium
detectors that have fine energy resolution in keV and sub-keV regimes,
constraints on sterile neutrino mass and its transition magnetic moment are
derived and compared with those from astrophysical observations
Derivations of Atomic Ionization Effects Induced by Neutrino Magnetic Moments
A recent paper [M.B. Voloshin, Phys. Rev. Lett. 105, 201801 (2010)] pointed
out that our earlier derivations of atomic ionization cross-section due to
neutrino magnetic moments (arXiv:1001.2074v2) involved unjustified assumptions.
We confirm and elaborate on this comment with these notes. We caution that the
results of the sum-rule approach in this paper contradict the expected
behaviour in atomic transitions.Comment: V3 3 pages ; confirm and elaborate on unjustified assumptions in V1 &
V
Spherically Symmetric Noncommutative Spacetime via Exotic Atomic Transitions
In discussing non-commutative spacetime, the generally studied
-Poincare model is inconsistent with bound states. In this Letter, we
develop the formalism and study the phenomenology of another model
by the twisted permutation algebra and extend the
Pauli Exclusion Principle(PEP) into non-commutative spacetime. The model also
implies time quantization and can avoid UV/IR mixing. Applying it to atomic
systems, we show that the model with newly induced phase factors can cause
exotic transitions consisting of three electrons in the 1S orbit of atoms. The
transition rate is derived, and the upper bound of non-commutative parameter
is thus set by utilizing data from the low-energy and low-background
experiments, where strongest constraint eV
at 90\% C.L. is given by XENONnT, with the time quanta , equivalent to twenty times smaller than the Planck time.Comment: 6 pages, 4 figure
- …