To what extent is Gluon Confinement an empirical fact?

Experimental verifications of Confinement in hadron physics have established the absence of charges with a fraction of the electron's charge by studying the energy deposited in ionization tracks at high energies, and performing Millikan experiments with charged droplets at rest. These experiments test only the absence of particles with fractional charge in the asymptotic spectrum, and thus "Quark" Confinement. However what theory suggests is that Color is confined, that is, all asymptotic particles are color singlets. Since QCD is a non-Abelian theory, the gluon force carriers (indirectly revealed in hadron jets) are colored. We empirically examine what can be said about Gluon Confinement based on the lack of detection of appropriate events, aiming at an upper bound for high-energy free-gluon production.Comment: 14 pages, 12 figures, version accepted at Few Body Physic

Reactive oxygen species induce virus-independent MAVS-oligomerization in systemic lupus erythematosus

The increased expression of genes induced by type I interferon (IFN) is characteristic of viral infections and systemic lupus erythematosus (SLE). We showed that mitochondrial antiviral signaling (MAVS) protein, which normally forms a complex with retinoic acid gene I (RIG-I)–like helicases during viral infection, was activated by oxidative stress independently of RIG-I helicases. We found that chemically generated oxidative stress stimulated the formation of MAVS oligomers, which led to mitochondrial hyperpolarization and decreased adenosine triphosphate production and spare respiratory capacity, responses that were not observed in similarly treated cells lacking MAVS. Peripheral blood lymphocytes of SLE patients also showed spontaneous MAVS oligomerization that correlated with the increased secretion of type I IFN and mitochondrial oxidative stress. Furthermore, inhibition of mitochondrial reactive oxygen species (ROS) by the mitochondria-targeted antioxidant MitoQ prevented MAVS oligomerization and type I IFN production. ROS-dependent MAVS oligomerization and type I IFN production were reduced in cells expressing the MAVS-C79F variant, which occurs in 30% of sub-Saharan Africans and is linked with reduced type I IFN secretion and milder disease in SLE patients. Patients expressing the MAVS-C79F variant also had reduced amounts of oligomerized MAVS in their plasma compared to healthy controls. Together, our findings suggest that oxidative stress–induced MAVS oligomerization in SLE patients may contribute to the type I IFN signature that is characteristic of this syndrome

Enhancing the effectiveness of nucleoside analogs with mTORC1 blockers to treat acute myeloid leukemia patients

Powerpoint and speaker's note

Narrowing the window for millicharged particles by CMB anisotropy

We calculate the cosmic microwave background (CMB) anisotropy spectrum in models with millicharged particles of electric charge q\sim 10^{-6}-10^{-1} in units of electron charge. We find that a large region of the parameter space for the millicharged particles exists where their effect on the CMB spectrum is similar to the effect of baryons. Using WMAP data on the CMB anisotropy and assuming Big Bang nucleosynthesis value for the baryon abundance we find that only a small fraction of cold dark matter, Omega_{mcp}h_0^2 < 0.007 (at 95% CL), may consists of millicharged particles with the parameters (charge and mass) from this region. This bound significantly narrows the allowed range of the parameters of millicharged particles. In models without paraphoton millicharged particles are now excluded as a dark matter candidate. We also speculate that recent observation of 511 keV gamma-rays from the Galactic bulge may be an indication that a (small) fraction of CDM is comprised of the millicharged particles.Comment: 10 pages, 3 figures; v2: journal version, references adde

Bounds on the Tau Magnetic Moments: Standard Model and Beyond

We obtain new bounds for the magnetic dipole moments of the tau lepton. These limits on the magnetic couplings of the tau to the electroweak gauge bosons (gamma, W, Z) are set in a model independent way using the most general effective Lagrangian with the SU(2)_L x U(1)_Y symmetry. Comparison with data from the most precise experiments at high energies shows that the present limits are more stringent than the previous published ones. For the anomalous magnetic moment the bounds are, for the first time, within one order of magnitude of the standard model prediction.Comment: 8 pages, 1 figure; to appear in the proceedings of the 6th International Workshop on Tau Lepton Physics, 18-21 September (2000), Victoria (Canada

Weak Gravity Conjecture and Holographic Dark Energy Model with Interaction and Spatial Curvature

In the paper, we apply the weak gravity conjecture to the holographic quintessence model of dark energy. Three different holographic dark energy models are considered: without the interaction in the non-flat universe; with interaction in the flat universe; with interaction in the non-flat universe. We find that only in the models with the spatial curvature and interaction term proportional to the energy density of matter, it is possible for the weak gravity conjecture to be satisfied.Comment: 14 pages, 7 figures, typographical errors are corrected; conclusin is unchange

Distinct subsets of unmyelinated primary sensory fibers mediate behavioral responses to noxious thermal and mechanical stimuli

Behavioral responses to painful stimuli require peripheral sensory neurons called nociceptors. Electrophysiological studies show that most C-fiber nociceptors are polymodal (i.e., respond to multiple noxious stimulus modalities, such as mechanical and thermal); nevertheless, these stimuli are perceived as distinct. Therefore, it is believed that discrimination among these modalities only occurs at spinal or supraspinal levels of processing. Here, we provide evidence to the contrary. Genetic ablation in adulthood of unmyelinated sensory neurons expressing the G protein-coupled receptor Mrgprd reduces behavioral sensitivity to noxious mechanical stimuli but not to heat or cold stimuli. Conversely, pharmacological ablation of the central branches of TRPV1+ nociceptors, which constitute a nonoverlapping population, selectively abolishes noxious heat pain sensitivity. Combined elimination of both populations yielded an additive phenotype with no additional behavioral deficits, ruling out a redundant contribution of these populations to heat and mechanical pain sensitivity. This double-dissociation suggests that the brain can distinguish different noxious stimulus modalities from the earliest stages of sensory processing

The first NINDS/NIBIB consensus meeting to define neuropathological criteria for the diagnosis of chronic traumatic encephalopathy.

Chronic traumatic encephalopathy (CTE) is a neurodegeneration characterized by the abnormal accumulation of hyperphosphorylated tau protein within the brain. Like many other neurodegenerative conditions, at present, CTE can only be definitively diagnosed by post-mortem examination of brain tissue. As the first part of a series of consensus panels funded by the NINDS/NIBIB to define the neuropathological criteria for CTE, preliminary neuropathological criteria were used by 7 neuropathologists to blindly evaluate 25 cases of various tauopathies, including CTE, Alzheimer's disease, progressive supranuclear palsy, argyrophilic grain disease, corticobasal degeneration, primary age-related tauopathy, and parkinsonism dementia complex of Guam. The results demonstrated that there was good agreement among the neuropathologists who reviewed the cases (Cohen's kappa, 0.67) and even better agreement between reviewers and the diagnosis of CTE (Cohen's kappa, 0.78). Based on these results, the panel defined the pathognomonic lesion of CTE as an accumulation of abnormal hyperphosphorylated tau (p-tau) in neurons and astroglia distributed around small blood vessels at the depths of cortical sulci and in an irregular pattern. The group also defined supportive but non-specific p-tau-immunoreactive features of CTE as: pretangles and NFTs affecting superficial layers (layers II-III) of cerebral cortex; pretangles, NFTs or extracellular tangles in CA2 and pretangles and proximal dendritic swellings in CA4 of the hippocampus; neuronal and astrocytic aggregates in subcortical nuclei; thorn-shaped astrocytes at the glial limitans of the subpial and periventricular regions; and large grain-like and dot-like structures. Supportive non-p-tau pathologies include TDP-43 immunoreactive neuronal cytoplasmic inclusions and dot-like structures in the hippocampus, anteromedial temporal cortex and amygdala. The panel also recommended a minimum blocking and staining scheme for pathological evaluation and made recommendations for future study. This study provides the first step towards the development of validated neuropathological criteria for CTE and will pave the way towards future clinical and mechanistic studies