Matter in Toy Dynamical Geometries

One of the objectives of theories describing quantum dynamical geometry is to compute expectation values of geometrical observables. The results of such computations can be affected by whether or not matter is taken into account. It is thus important to understand to what extent and to what effect matter can affect dynamical geometries. Using a simple model, it is shown that matter can effectively mold a geometry into an isotropic configuration. Implications for "atomistic" models of quantum geometry are briefly discussed.Comment: 8 pages, 1 figure, paper presented at DICE 200

The Free Particle in Deformed Special Relativity

The phase space of a classical particle in DSR contains de Sitter space as the space of momenta. We start from the standard relativistic particle in five dimensions with an extra constraint and reduce it to four dimensional DSR by imposing appropriate gauge fixing. We analyze some physical properties of the resulting theories like the equations of motion, the form of Lorentz transformations and the issue of velocity. We also address the problem of the origin and interpretation of different bases in DSR.Comment: 15 page

Experimental Simulation of Helium Discharge into the LHC Tunnel

The LHC cryogenic system contains about 100 tons of liquid helium. The highest amount of helium is located in the magnet cold mass (about 58 tons @ 1.9 K, 0.13 MPa), in the QRL supply header C (about 26 tons @ 4.6 K, 0.36 MPa) and in the ring line (about 0.7 tons 290 K, 2 MPa). The rupture of header C is one of the failures leading to the worst scenario of helium discharge into the tunnel. To investigate the consequences of this failure an experiment has been performed. This paper presents the layout of the test set-up and compares the experimental results with calculated data

Modeling the functional genomics of autism using human neurons.

Human neural progenitors from a variety of sources present new opportunities to model aspects of human neuropsychiatric disease in vitro. Such in vitro models provide the advantages of a human genetic background combined with rapid and easy manipulation, making them highly useful adjuncts to animal models. Here, we examined whether a human neuronal culture system could be utilized to assess the transcriptional program involved in human neural differentiation and to model some of the molecular features of a neurodevelopmental disorder, such as autism. Primary normal human neuronal progenitors (NHNPs) were differentiated into a post-mitotic neuronal state through addition of specific growth factors and whole-genome gene expression was examined throughout a time course of neuronal differentiation. After 4 weeks of differentiation, a significant number of genes associated with autism spectrum disorders (ASDs) are either induced or repressed. This includes the ASD susceptibility gene neurexin 1, which showed a distinct pattern from neurexin 3 in vitro, and which we validated in vivo in fetal human brain. Using weighted gene co-expression network analysis, we visualized the network structure of transcriptional regulation, demonstrating via this unbiased analysis that a significant number of ASD candidate genes are coordinately regulated during the differentiation process. As NHNPs are genetically tractable and manipulable, they can be used to study both the effects of mutations in multiple ASD candidate genes on neuronal differentiation and gene expression in combination with the effects of potential therapeutic molecules. These data also provide a step towards better understanding of the signaling pathways disrupted in ASD

Accurate quantification of selenoproteins in human plasma/serum by isotope dilution ICP-MS : focus on selenoprotein P

Acknowledgements The research leading to these results was funded by the EMRP Joint Research Project “Metrology for metalloproteins” (HLT-05 2012). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.Peer reviewedPostprin

Endplate calcification and cervical intervertebral disc degeneration: the role of endplate marrow contact channel occlusion

Background: The aim of this study was to determine the fundamental relationships between cervical intervertebral disc (IVD) degeneration, endplate calcification, and the patency of endplate marrow contact channels (MCC). Materials and methods: Sixty cervical IVDs were excised from 30 human cadavers. After sectioning the specimens underwent micro computed tomography (microCT) — from all images the number, calibre, diameter and distribution of endplate openings were measured using ImageJ. Next, the specimens were scored for macroscopic degeneration (Thompson’s classification), and subsequently underwent histological analysis for both IVD and endplate degeneration (Boos’s classification) and calcification. Results: The study group comprised 30 female and 30 male IVDs (mean age ± SD: 51.4 ± 19.5). Specimen’s age, macroscopic and microscopic degeneration correlated negatively with the number of MCCs (r = –0.33–(–0.95); p < 0.0001), apart from the MCCs > 300 μm in diameter (r = 0.66–0.79; p < 0.0001). The negative relationship was strongest for the MCCs 10–50 μm in diameter. Conclusions: There is a strong negative correlation between the number of endplate MCCs, and both macroscopic and microscopic cervical IVD and endplate degeneration. This could further support the thesis that endplate calcification, through the occlusion of MCCs, leads to a fall in nutrient transport to the IVD, and subsequently causes its degeneration

ELEVATED LEVELS OF PLATELETS AND MDM2 EXPRESSION ARE CONTRIB-UTING FACTORS TO FACILITATING THE METASTASIS OF OSTEOSARCOMA

poster abstractOsteosarcoma (OS) is the most common form of primary bone cancer and the 6th leading cause of cancer in pediatric patients. A chart review of OS patients treated at this institution suggests that a high platelet count at di-agnosis is significantly (p=0.023) and inversely associated with the first year of survival. As the effects of platelet interaction with OS have been exten-sively researched and suggest that platelets may facilitate tumor metastasis, and the most important prognostic factor for OS patient survival is metasta-sis to the lungs, we hypothesized that platelets increase metastasis to the lungs and reduce survival. Therefore, we sought to determine whether in-creasing platelet numbers in a well characterized OS mouse model would de-crease survival and/or increase metastasis to the lungs. We found that thrombopoietin (TPO) treated mice, had increased platelet numbers, died earlier than placebo treated controls, and that lungs from TPO treated mice contained a small number of large tumor cells (most metastatic lesions were 2-4 cells), whereas lungs from placebo treated controls showed no signs of metastases. Next, an OS tissue microarray (TMA) was built from OS patients seen at our institution over the past 10 years. Mdm2, p53, TPO, and c-mpl expression were evaluated by immunohistochemical (IHC) staining followed by quantitation using the Aperio Imaging system and analysis software. C-mpl (TPO receptor) expression was higher in the metastatic than the primary tumors, suggesting that platelets may contribute to the metastasis of OS. Elevated levels of Mdm2 correlated with metastasis and lower levels of p53, as detected by IHC. In conclusion, both the mouse model and the human OS data were similar, suggesting that both platelets and Mdm2 promote metas-tases in OS

Threshold configurations in the presence of Lorentz violating dispersion relations

A general characterization of lower and upper threshold configurations for two particle reactions is determined under the assumptions that the single particle dispersion relations E(p) are rotationally invariant and monotonic in p, and that energy and momentum are conserved and additive for multiple particles. It is found that at a threshold the final particle momenta are always parallel and the initial momenta are always anti-parallel. The occurrence of new phenomena not occurring in a Lorentz invariant setting, such as upper thresholds and asymmetric pair production thresholds, is explained, and an illustrative example is given.Comment: 5 pages, 3 figure