Stochastic Segmentation Models for Array-Based Comparative Genomic Hybridization Data Analysis

Array-based comparative genomic hybridization (array-CGH) is a high throughput, high resolution technique for studying the genetics of cancer. Analysis of array-CGH data typically involves estimation of the underlying chromosome copy numbers from the log fluorescence ratios and segmenting the chromosome into regions with the same copy number at each location. We propose for the analysis of array-CGH data, a new stochastic segmentation model and an associated estimation procedure that has attractive statistical and computational properties. An important benefit of this Bayesian segmentation model is that it yields explicit formulas for posterior means, which can be used to estimate the signal directly without performing segmentation. Other quantities relating to the posterior distribution that are useful for providing confidence assessments of any given segmentation can also be estimated by using our method. We propose an approximation method whose computation time is linear in sequence length which makes our method practically applicable to the new higher density arrays. Simulation studies and applications to real array-CGH data illustrate the advantages of the proposed approach

4,4′-Bipyridinium bis­(oxalato-κ2 O 1,O 2)cuprate(II): an ion-pair complex

The title compound, (C10H10N2)[Cu(C2O4)2] or (4,4′-H2bpy)[Cu(ox)2] (bpy is 4,4′-bipyridine and ox is oxalate), is an ion-pair complex comprising a protonated 4,4′-bipyridinium dication and a square-planar dioxalatocopper(II) dianion. In the centrosymmetric dianion, the CuII centre is coordinated by four O atoms from the two dicrete oxalate ligands [Cu—O = 1.9245 (19) and 1.9252 (17) Å], while the planar dications are also centrosymmetric. Inter-species N—H⋯O hydrogen bonds link the cations and anions into one-dimensional chains and, together with weak intra-ion C—H⋯O inter­actions, give a two-dimensional sheet structure

A further study of \mu-\tau symmetry breaking at neutrino telescopes after the Daya Bay and RENO measurements of \theta_{13}

Current neutrino oscillation data indicate that \theta_{13} is not strongly suppressed and \theta_{23} might have an appreciable deviation from \pi/4, implying that the 3 \times 3 neutrino mixing matrix V does not have an exact \mu-\tau permutation symmetry. We make a further study of the effect of \mu-\tau symmetry breaking on the democratic flavor distribution of ultrahigh-energy (UHE) cosmic neutrinos at a neutrino telescope, and find that it is characterized by |V_{\mu i}|^2 - |V_{\tau i}|^2 which would vanish if either \theta_{23} = \pi/4 and \theta_{13} = 0 or \theta_{23} = \pi/4 and \delta = \pm \pi/2 held. We observe that the second-order \mu-\tau symmetry breaking term \bar{\Delta} may be numerically comparable with or even larger than the first-order term \Delta in the flux ratios \phi^{T}_e : \phi^{T}_\mu : \phi^{T}_\tau \simeq (1- 2\Delta) : (1 + \Delta + \bar{\Delta}) : (1 + \Delta - \bar{\Delta}), if \sin (\theta_{23} - \pi/4) and \cos\delta have the same sign. The detection of the UHE \bar{\nu}_e flux via the Glashow-resonance channel \bar{\nu}_e e \to W^- \to anything is also discussed by taking account of the first- and second-order \mu-\tau symmetry breaking effects.Comment: RevTeX 12 pages, 1 Table, More discussions added, accepted for publication in Phys. Lett.

Understanding Delayed T-Cell Priming, Lung Recruitment, and Airway Luminal T-Cell Responses in Host Defense against Pulmonary Tuberculosis

Mycobacterium tuberculosis (M.tb), the causative bacterium of pulmonary tuberculosis (TB), is a serious global health concern. Central to M.tb effective immune avoidance is its ability to modulate the early innate inflammatory response and prevent the establishment of adaptive T-cell immunity for nearly three weeks. When compared with other intracellular bacterial lung pathogens, such as Legionella pneumophila, or even closely related mycobacterial species such as M. smegmatis, this delay is astonishing. Customarily, the alveolar macrophage (AM) acts as a sentinel, detecting and alerting surrounding cells to the presence of an invader. However, in the case of M.tb, this may be impaired, thus delaying the recruitment of antigen-presenting cells (APCs) to the lung. Upon uptake by APC populations, M.tb is able to subvert and delay the processing of antigen, MHC class II loading, and the priming of effector T cell populations. This delay ultimately results in the deferred recruitment of effector T cells to not only the lung interstitium but also the airway lumen. Therefore, it is of upmost importance to dissect the mechanisms that contribute to the delayed onset of immune responses following M.tb infection. Such knowledge will help design the most effective vaccination strategies against pulmonary TB

Augmented Reality 3D Design Space

Ph.DDOCTOR OF PHILOSOPH