OPERA tau neutrino charged current interactions.

The OPERA experiment was designed to discover the vτ appearance in a vµ beam, due to neutrino oscillations. The detector, located in the underground Gran Sasso Laboratory, consisted of a nuclear photographic emulsion/lead target with a mass of about 1.25 kt, complemented by electronic detectors. It was exposed from 2008 to 2012 to the CNGS beam: an almost pure vµ beam with a baseline of 730 km, collecting a total of 1.8·1020 protons on target. The OPERA Collaboration eventually assessed the discovery of vµâ†’vτ oscillations with a statistical significance of 6.1 σ by observing ten vτ CC interaction candidates. These events have been published on the Open Data Portal at CERN. This paper provides a detailed description of the vτ data sample to make it usable by the whole community.

Final Results of the OPERA Experiment on ν_{τ} Appearance in the CNGS Neutrino Beam.

The OPERA experiment was designed to study ν_{µ}→ν_{τ} oscillations in the appearance mode in the CERN to Gran Sasso Neutrino beam (CNGS). In this Letter, we report the final analysis of the full data sample collected between 2008 and 2012, corresponding to 17.97×10^{19} protons on target. Selection criteria looser than in previous analyses have produced ten ν_{τ} candidate events, thus reducing the statistical uncertainty in the measurement of the oscillation parameters and of ν_{τ} properties. A multivariate approach for event identification has been applied to the candidate events and the discovery of ν_{τ} appearance is confirmed with an improved significance level of 6.1σ. |Δm_{32}^{2}| has been measured, in appearance mode, with an accuracy of 20%. The measurement of the ν_{τ} charged-current cross section, for the first time with a negligible contamination from ν[over ¯]_{τ}, and the first direct evidence for the ν_{τ} lepton number are also reported.

Discovery of τ Neutrino Appearance in the CNGS Neutrino Beam with the OPERA Experiment.

The OPERA experiment was designed to search for ν_{µ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{µ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{µ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.

Degradation of oligosaccharides in nonenzymatic browning by formation of alpha-dicarbonyl compounds via a "peeling off" mechanism.

The formation of alpha-dicarbonyl-containing substances and Amadori rearrangement products was studied in the glycine-catalyzed (Maillard reaction) and uncatalyzed thermal degradation of glucose, maltose, and maltotriose using o-phenylenediamine as trapping agent. Various degradation products, especially alpha-dicarbonyl compounds, are formed from carbohydrates with differing degrees of polymerization during nonenzymatic browning. The different Amadori rearrangement products, isomerization products, and alpha-dicarbonyls produced by the used carbohydrates were quantified throughout the observed reaction time, and the relevance of the different degradation pathways is discussed. In the Maillard reaction (MR) the amino-catalyzed rearrangement with subsequent elimination of water predominated, giving rise to hexosuloses with alpha-dicarbonyl structure, whereas under caramelization conditions more sugar fragments with an alpha-dicarbonyl moiety were formed. For the MR of oligosaccharides a mechanism is proposed in which 1,4-dideoxyosone is formed as the predominating alpha-dicarbonyl in the quasi-water-free thermolysis of di- and trisaccharides in the presence of glycine.

Id genes are direct targets of bone morphogenetic protein induction in embryonic stem cells.

Bone morphogenetic proteins (BMPs) are morphogenetic signaling molecules essential for embryonic patterning. To obtain molecular insight into the influence of BMPs on morphogenesis, we searched for new genes directly activated by BMP signaling. In vitro cultured mouse embryonic stem (ES) cells were used, cultivated in chemically defined growth medium (CDM). CDM-cultured ES cells responded very selectively to stimulation by various mesoderm inducers (BMP2/4, activin A, and basic fibroblast growth factor). BMP2/4 rapidly induced transcript levels of the homeobox genes Msx-1 and Msx-2 and the proto-oncogene JunB, whereas c-jun transcripts displayed delayed albeit prolonged increase. Using differential display cDNA cloning, six direct BMP target genes were identified. These include Id3, which showed strong mRNA induction, and the moderately induced Cyr61, DEK, and eIF4AII genes, as well as a gene encoding a GC-binding protein. Besides Id3, also the Id1 and Id2 genes were activated by BMP4 in both ES cells and a range of different cell lines. Id genes encode negative regulators of basic helix-loop-helix transcription factors. In vivo we observed local ectopic expression of Id3 and Msx-2 mRNAs in Ft/+ embryos at overlapping regions of ectopic Bmp4 misexpression. We therefore propose that the Msx and Id genes are direct target genes of embryonic BMP4 signaling in vivo.

Parathyroid hormone enhances early and suppresses late stages of osteogenic and chondrogenic development in a BMP-dependent mesenchymal differentiation system (C3H10T1/2).

The role of parathyroid hormone (PTH) upon osteo-/chondrogenic development was investigated in a bone morphogenetic protein (BMP)-dependent differentiation system involving the recombinant expression of BMPs in mesenchymal progenitor cells (C3H10T1/2). The constitutive expression of the PTH/PTH related protein receptor in this system led to a marked stimulation of chondrogenic and osteogenic development, while the permanent application of the ligand PTH(1-34) resulted in opposite responses by stimulating the early and suppressing the late stages of osteo-/chondrogenic development. These contrasting effects of PTH(1-34) on osteogenic and chondrocytic development seem, therefore, to depend on the cellular state of differentiation. The osteogenic and chondrocytic differentiation potential was substantiated histologically and by genetic analyses of marker genes like c-fos, alkaline phosphatase, osteocalcin, collagen alpha1(I), and collagen alpha1(II). The capacity to regulate osteogenic and chondrogenic development is located in the amino-terminal (1-34) region of the PTH molecule and seems to be mediated by the cyclic adenosine monophosphate signaling cascade. The application of other PTH domains like PTH(28-48) and PTH(53-84) did not exhibit significant responses. PTH acts as an essential factor in mesenchymal development controlling rates of differentiation into the osteogenic or chondrogenic lineage. The analysis of PTH effects in this system demonstrates the value of recombinant mesenchymal progenitor cells in the in vitro analysis of osteo-/chondrogenic development.

Domain-specific gene activation by parathyroid hormone in osteoblastic ROS17/2.8 cells.

Parathyroid hormone (PTH)-mediated gene activation was assessed in the osteoblast-like rat cell line ROS17/2.8 with two PTH fragments harboring distinct activating domains: PTH-(1-34) and PTH-(28-48). The PTH response of genes expressed immediate early in the cell cycle or in the osteoblast developmental sequence was investigated. In addition, subtractive cloning was used to identify genes in ROS17/2.8 cells that are activated by the two PTH domains. PTH-(1-34) immediately increased the transcript levels of c-fos and c-jun at a considerably higher rate than PTH-(28-48). A significant immediate PTH effect on osteoblastic marker genes could not be detected, with the exception of elevated ornithine decarboxylase transcript levels. However, continuous application of PTH-(1-34) increased transcript levels of the osteoblast-specific osteocalcin gene and reduced those of other osteoblastic marker genes including alkaline phosphatase and the PTH/PTH-related peptide receptor. By subtractive cloning, nine cDNAs were isolated corresponding to mRNAs directly up-regulated by PTH-(1-34) or PTH-(28-48). Among these were a cyclic phosphodiesterase, a (cytosine 5)-methyltransferase, an 80-kDa protein kinase C substrate, junB, and a novel GC-binding protein. Three cDNAs are unknown at present. Interestingly, in all cases, the efficiency of gene activation by PTH-(28-48) was substantially lower in comparison with PTH-(1-34). PTH-mediated protein kinase C signaling in ROS17/2.8 cells may therefore constitute a minor pathway in comparison with the dominant cAMP/protein kinase A cascade.

Expression of human bone morphogenetic proteins-2 or -4 in murine mesenchymal progenitor C3H10T1/2 cells induces differentiation into distinct mesenchymal cell lineages.

The cDNAs encoding the human bone morphogenetic proteins BMP-2 and BMP-4 in an eukaryotic expression vector were permanently transferred into the murine mesenchymal progenitor cell line C3H10T1/2. Originally, these cells are known to differentiate into myotubes, adipocytes, and chondrocytes upon the addition of azacytidine. Permanent transfection of genes encoding human BMP-2 and BMP-4 induces differentiation into the osteogenic lineage. The osteogenic differentiation potential of C3H10T1/2 cells is substantiated by histochemical and genetic analyses of marker genes typical or specific for osteogenesis, including the parathyroid hormone receptor, alkaline phosphatase, osteopontin, osteonectin, and osteocalcin. In addition to osteoblast formation, development into adipocytes and chondrocytes is also observed, suggesting that BMP-2 and BMP-4 induce differentiation into three mesenchymal lineages.