563 research outputs found
Burns from e-cigarettes and other electronic nicotine delivery systems
With increasing use of electronic cigarettes (e-cigarettes) and other electronic nicotine delivery systems (ENDS) globally, the debate surrounding the potential harms or benefits may shift to ensuring that the devices are manufactured, marketed, and sold according to standards that reduce harm and promote health
Detecting the neutral top-pion at colliders
We investigate some processes of the associated production of a neutral
top-pion with a pair of fermions() in the context of top-color-assisted technicolor(TC2)
theory at future colliders.
The studies show that the largest cross sections of the processes
could only reach the
level of 0.01fb, we can hardly detect a neutral top-pion through these
processes. For the processes ,
and ,
the cross sections of these processes are at the level of a few fb for the
favorable parameters and a few tens, even hundreds, of neutral top-pion events
can be produced at future colliders each year through these
processes. With the clean background of the flavor-changing channel,
the top-pion events can possibly be detected at the planned high luminosity
colliders. Therefore, such neutral top-pion production processes
provide a useful way to detect a neutral top-pion and test the TC2 model
directly.Comment: 13 pages, 4 figure
Top quark associated production of the neutral top-pion at high energy colliders
In the context of topcolor-assisted technicolor (TC2) models, we calculate
the associated production of the neutral top-pion with a pair of
top quarks via the process . We
find that the production cross section is larger than that of the process both in the standard model (SM) and in the
minimal supersymmetric SM. With reasonable values of the parameters in TC2
models, the cross section can reach . The neutral top-pion
may be direct observed via this process.Comment: Latex files, 10 pages and 3 figure
Astrophysical structures from primordial quantum black holes
The characteristic sizes of astrophysical structures, up to the whole
observed Universe, can be recovered, in principle, assuming that gravity is the
overall interaction assembling systems starting from microscopic scales, whose
order of magnitude is ruled by the Planck length and the related Compton
wavelength. This result agrees with the absence of screening mechanisms for the
gravitational interaction and could be connected to the presence of Yukawa
corrections in the Newtonian potential which introduce typical interaction
lengths. This result directly comes out from quantization of primordial black
holes and then characteristic interaction lengths directly emerge from quantum
field theory.Comment: 11 page
The role of evidence-based guidelines in the diagnosis and treatment of functional neurological disorder
Evidence-based clinical practice guidelines, based on systematic reviews of existing evidence, play an important role in improving and standardizing the quality of patient care in many medical and psychiatric disorders, and could play an important role in the diagnosis and treatment of functional seizures and other functional neurological disorder (FND) subtypes. There are several reasons to think that evidence-based guidelines might be especially beneficial for the management of FND. In particular, the interdisciplinary and multidisciplinary teamwork necessary for the care of people with FND, the current lack of formal clinical training in FND, and the rapidly expanding body of evidence relating to FND all make guidelines based on systematic literature reviews especially valuable. In this perspective piece, we review clinical practice guidelines, their advantages and limitations, the reasons why evidence-based guidelines might be especially beneficial in the diagnosis and treatment of FND, and the steps that must be taken to create such guidelines for FND. We propose that professional organizations such as the American Academy of Neurology and the American Psychiatric Association undertake guideline development, ideally to create a co-authored or jointly endorsed set of guidelines that can set standards for interdisciplinary care for neurologists and mental health clinicians alike
Cetacean <i>Morbillivirus</i>: Current knowledge and future directions
We review the molecular and epidemiological characteristics of cetacean morbillivirus (CeMV) and the diagnosis and pathogenesis of associated disease, with six different strains detected in cetaceans worldwide. CeMV has caused epidemics with high mortality in odontocetes in Europe, the USA and Australia. It represents a distinct species within the Morbillivirus genus. Although most CeMV strains are phylogenetically closely related, recent data indicate that morbilliviruses recovered from Indo-Pacific bottlenose dolphins (Tursiops aduncus), from Western Australia, and a Guiana dolphin (Sotalia guianensis), from Brazil, are divergent. The signaling lymphocyte activation molecule (SLAM) cell receptor for CeMV has been characterized in cetaceans. It shares higher amino acid identity with the ruminant SLAM than with the receptors of carnivores or humans, reflecting the evolutionary history of these mammalian taxa. In Delphinidae, three amino acid substitutions may result in a higher affinity for the virus. Infection is diagnosed by histology, immunohistochemistry, virus isolation, RT-PCR, and serology. Classical CeMV-associated lesions include bronchointerstitial pneumonia, encephalitis, syncytia, and lymphoid depletion associated with immunosuppression. Cetaceans that survive the acute disease may develop fatal secondary infections and chronic encephalitis. Endemically infected, gregarious odontocetes probably serve as reservoirs and vectors. Transmission likely occurs through the inhalation of aerosolized virus but mother to fetus transmission was also reported
Origins of the Ambient Solar Wind: Implications for Space Weather
The Sun's outer atmosphere is heated to temperatures of millions of degrees,
and solar plasma flows out into interplanetary space at supersonic speeds. This
paper reviews our current understanding of these interrelated problems: coronal
heating and the acceleration of the ambient solar wind. We also discuss where
the community stands in its ability to forecast how variations in the solar
wind (i.e., fast and slow wind streams) impact the Earth. Although the last few
decades have seen significant progress in observations and modeling, we still
do not have a complete understanding of the relevant physical processes, nor do
we have a quantitatively precise census of which coronal structures contribute
to specific types of solar wind. Fast streams are known to be connected to the
central regions of large coronal holes. Slow streams, however, appear to come
from a wide range of sources, including streamers, pseudostreamers, coronal
loops, active regions, and coronal hole boundaries. Complicating our
understanding even more is the fact that processes such as turbulence,
stream-stream interactions, and Coulomb collisions can make it difficult to
unambiguously map a parcel measured at 1 AU back down to its coronal source. We
also review recent progress -- in theoretical modeling, observational data
analysis, and forecasting techniques that sit at the interface between data and
theory -- that gives us hope that the above problems are indeed solvable.Comment: Accepted for publication in Space Science Reviews. Special issue
connected with a 2016 ISSI workshop on "The Scientific Foundations of Space
Weather." 44 pages, 9 figure
Ex vivo culture of intact human patient derived pancreatic tumour tissue
The poor prognosis of pancreatic ductal adenocarcinoma (PDAC) is attributed to the highly fibrotic stroma and complex multi-cellular microenvironment that is difficult to fully recapitulate in pre-clinical models. To fast-track translation of therapies and to inform personalised medicine, we aimed to develop a whole-tissue ex vivo explant model that maintains viability, 3D multicellular architecture, and microenvironmental cues of human pancreatic tumours. Patient-derived surgically-resected PDAC tissue was cut into 1-2Â mm explants and cultured on gelatin sponges for 12Â days. Immunohistochemistry revealed that human PDAC explants were viable for 12Â days and maintained their original tumour, stromal and extracellular matrix architecture. As proof-of-principle, human PDAC explants were treated with Abraxane and we observed different levels of response between patients. PDAC explants were also transfected with polymeric nanoparticlesâ+âCy5-siRNA and we observed abundant cytoplasmic distribution of Cy5-siRNA throughout the PDAC explants. Overall, our novel model retains the 3D architecture of human PDAC and has advantages over standard organoids: presence of functional multi-cellular stroma and fibrosis, and no tissue manipulation, digestion, or artificial propagation of organoids. This provides unprecedented opportunity to study PDAC biology including tumour-stromal interactions and rapidly assess therapeutic response to drive personalised treatment.John Kokkinos, George Sharbeen, Koroush S. Haghighi, Rosa Mistica C. Ignacio, Chantal Kopecky, Estrella Gonzales-Aloy ... et al
Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV
Results are presented from a search for a W' boson using a dataset
corresponding to 5.0 inverse femtobarns of integrated luminosity collected
during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV.
The W' boson is modeled as a heavy W boson, but different scenarios for the
couplings to fermions are considered, involving both left-handed and
right-handed chiral projections of the fermions, as well as an arbitrary
mixture of the two. The search is performed in the decay channel W' to t b,
leading to a final state signature with a single lepton (e, mu), missing
transverse energy, and jets, at least one of which is tagged as a b-jet. A W'
boson that couples to fermions with the same coupling constant as the W, but to
the right-handed rather than left-handed chiral projections, is excluded for
masses below 1.85 TeV at the 95% confidence level. For the first time using LHC
data, constraints on the W' gauge coupling for a set of left- and right-handed
coupling combinations have been placed. These results represent a significant
improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe
Search for the standard model Higgs boson decaying into two photons in pp collisions at sqrt(s)=7 TeV
A search for a Higgs boson decaying into two photons is described. The
analysis is performed using a dataset recorded by the CMS experiment at the LHC
from pp collisions at a centre-of-mass energy of 7 TeV, which corresponds to an
integrated luminosity of 4.8 inverse femtobarns. Limits are set on the cross
section of the standard model Higgs boson decaying to two photons. The expected
exclusion limit at 95% confidence level is between 1.4 and 2.4 times the
standard model cross section in the mass range between 110 and 150 GeV. The
analysis of the data excludes, at 95% confidence level, the standard model
Higgs boson decaying into two photons in the mass range 128 to 132 GeV. The
largest excess of events above the expected standard model background is
observed for a Higgs boson mass hypothesis of 124 GeV with a local significance
of 3.1 sigma. The global significance of observing an excess with a local
significance greater than 3.1 sigma anywhere in the search range 110-150 GeV is
estimated to be 1.8 sigma. More data are required to ascertain the origin of
this excess.Comment: Submitted to Physics Letters
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