1,058 research outputs found
Search for long lived charged massive particles in pp collisions at s-hat = 1.8TeV
We report a search for the production of long-lived charged massive particles in a data sample of 90âââpb-1 of âs=1.8âââTeV ppÌ
collisions recorded by the Collider Detector at Fermilab. The search uses the muonlike penetration and anomalously high ionization energy loss signature expected for such a particle to discriminate it from backgrounds. The data are found to agree with background expectations, and cross section limits of O(1) pb are derived using two reference models, a stable quark and a stable scalar lepton
miR-122 Stimulates Hepatitis C Virus RNA Synthesis by Altering the Balance of Viral RNAs Engaged in Replication versus Translation
SummaryThe liver-specific microRNA, miR-122, stabilizes hepatitis C virus (HCV) RNA genomes by recruiting host argonaute 2 (AGO2) to the 5âČ end and preventing decay mediated by exonuclease Xrn1. However, HCV replication requires miR-122 in Xrn1-depleted cells, indicating additional functions. We show that miR-122 enhances HCV RNA levels by altering the fraction of HCV genomes available for RNA synthesis. Exogenous miR-122 increases viral RNA and protein levels in Xrn1-depleted cells, with enhanced RNA synthesis occurring before heightened protein synthesis. Inhibiting protein translation with puromycin blocks miR-122-mediated increases in RNA synthesis, but independently enhances RNA synthesis by releasing ribosomes from viral genomes. Additionally, miR-122 reduces the fraction of viral genomes engaged in protein translation. Depleting AGO2 or PCBP2, which binds HCV RNA in competition with miR-122 and promotes translation, eliminates miR-122 stimulation of RNA synthesis. Thus, by displacing PCBP2, miR-122 reduces HCV genomes engaged in translation while increasing the fraction available for RNA synthesis
Search for the supersymmetric partner of the top quark in dileption events from pp colisions at ûs = 1.8TeV
We have searched for pair production of the supersymmetric partner of the top quark (stop) in 107âââpb-1 of ppÌ
collisions at âs=1.8âââTeV collected by the Collider Detector at Fermilab (CDF). Each stop is assumed to decay into a lepton, bottom quark, and supersymmetric neutrino. Such a scenario would give rise to events with two leptons, two hadronic jets, and a substantial imbalance of transverse energy. No evidence of such a stop signal has been found. We exclude stop masses in the region (80â€mtËâ€135âââGeV/c2) in the mass plane of stop versus sneutrino
Exploring rationales for branding a university: Should we be seeking to measure branding in UK universities?
Although branding is now widespread among UK universities, the application of branding principles in the higher education sector is comparatively recent and may be controversial for internal audiences who question its suitability and efficiency.
This paper seeks to investigate how and whether the effectiveness of branding activity in the higher education sector should be evaluated and measured, through exploratory interviews with those who often drive it; UK University marketing professionals.
Conclusions suggest that university branding is inherently complex and therefore application of commercial approaches may be over simplistic. Whilst marketing professionals discuss challenges they do not necessarily have a consistent view of the objectives of branding activity although all were able to clearly articulate branding objectives for their university, including both qualitative and, to some extent, quantitative metrics. Some measures of the real value of branding activity are therefore suggested but a key debate is perhaps whether the objectives and role of branding in higher education needs to be clarified, and a more consistent view of appropriate metrics reached? Various challenges in implementing branding approaches are also highlighted
Modulating Iron for Metabolic Support of TB Host Defense
Tuberculosis (TB) is the world's biggest infectious disease killer. The increasing prevalence of multidrug-resistant and extensively drug-resistant TB demonstrates that current treatments are inadequate and there is an urgent need for novel therapies. Research is now focused on the development of host-directed therapies (HDTs) which can be used in combination with existing antimicrobials, with a special focus on promoting host defense. Immunometabolic reprogramming is integral to TB host defense, therefore, understanding and supporting the immunometabolic pathways that are altered after infection will be important for the development of new HDTs. Moreover, TB pathophysiology is interconnected with iron metabolism. Iron is essential for the survival of Mycobacterium tuberculosis (Mtb), the bacteria that causes TB disease. Mtb struggles to replicate and persist in low iron environments. Iron chelation has therefore been suggested as a HDT. In addition to its direct effects on iron availability, iron chelators modulate immunometabolism through the stabilization of HIF1α. This review examines immunometabolism in the context of Mtb and its links to iron metabolism. We suggest that iron chelation, and subsequent stabilization of HIF1α, will have multifaceted effects on immunometabolic function and holds potential to be utilized as a HDT to boost the host immune response to Mtb infection
First evidence of coherent meson production in neutrino-nucleus scattering
Neutrino-induced charged-current coherent kaon production,
, is a rare, inelastic electroweak process
that brings a on shell and leaves the target nucleus intact in its ground
state. This process is significantly lower in rate than neutrino-induced
charged-current coherent pion production, because of Cabibbo suppression and a
kinematic suppression due to the larger kaon mass. We search for such events in
the scintillator tracker of MINERvA by observing the final state ,
and no other detector activity, and by using the kinematics of the final state
particles to reconstruct the small momentum transfer to the nucleus, which is a
model-independent characteristic of coherent scattering. We find the first
experimental evidence for the process at significance.Comment: added ancillary file with information about the six kaon candidate
MINERvA neutrino detector response measured with test beam data
The MINERvA collaboration operated a scaled-down replica of the solid
scintillator tracking and sampling calorimeter regions of the MINERvA detector
in a hadron test beam at the Fermilab Test Beam Facility. This article reports
measurements with samples of protons, pions, and electrons from 0.35 to 2.0
GeV/c momentum. The calorimetric response to protons, pions, and electrons are
obtained from these data. A measurement of the parameter in Birks' law and an
estimate of the tracking efficiency are extracted from the proton sample.
Overall the data are well described by a Geant4-based Monte Carlo simulation of
the detector and particle interactions with agreements better than 4%, though
some features of the data are not precisely modeled. These measurements are
used to tune the MINERvA detector simulation and evaluate systematic
uncertainties in support of the MINERvA neutrino cross section measurement
program.Comment: as accepted by NIM
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