Measurement of the relative prompt production rate of χc2 and χc1 in pp collisions at [Formula: see text]

A measurement is presented of the relative prompt production rate of χc2 and χc1 with 4.6 fb-1 of data collected by the CMS experiment at the LHC in pp collisions at [Formula: see text]. The two states are measured via their radiative decays χc→J/ψ+γ, with the photon converting into an e+e- pair for J/ψ rapidity |y(J/ψ)|<1.0 and photon transverse momentum pT(γ)>0.5 GeV/c. The measurement is given for six intervals of pT(J/ψ) between 7 and 25 GeV/c. The results are compared to theoretical predictions.

Observation of sequential Υ suppression in PbPb collisions

The suppression of the individual Υ(nS) states in PbPb collisions with respect to their yields in pp data has been measured. The PbPb and pp data sets used in the analysis correspond to integrated luminosities of 150 μb(-1) and 230 nb(-1), respectively, collected in 2011 by the CMS experiment at the LHC, at a center-of-mass energy per nucleon pair of 2.76 TeV. The Υ(nS) yields are measured from the dimuon invariant mass spectra. The suppression of the Υ(nS) yields in PbPb relative to the yields in pp, scaled by the number of nucleon-nucleon collisions, R(AA), is measured as a function of the collision centrality. Integrated over centrality, the R(AA) values are 0.56±0.08(stat)±0.07(syst), 0.12±0.04(stat)±0.02(syst), and lower than 0.10 (at 95% confidence level), for the Υ(1S), Υ(2S), and Υ(3S) states, respectively. The results demonstrate the sequential suppression of the Υ(nS) states in PbPb collisions at LHC energies.

Search for new physics in the multijet and missing transverse momentum final state in proton-proton collisions at √s = 7 TeV

A search for physics beyond the standard model is performed in events with at least three jets and large missing transverse momentum produced in proton-proton collisions at a center-of-mass energy of √s=7 TeV. No significant excess of events above the expected backgrounds is observed in 4.98 fb(-1) of data collected with the CMS detector at the Large Hadron Collider. The results are presented in the context of the constrained minimal supersymmetric extension of the standard model and more generically for simplified models. For the simplified models of gluino-gluino and squark-squark production, gluino masses below 1.0 TeV and squark masses below 0.76 TeV are excluded in case the lightest supersymmetric particle mass is below 200 GeV. These results significantly extend previous searches.

Measurement of the pseudorapidity and centrality dependence of the transverse energy density in Pb-Pb collisions at √(s(NN))=2.76 TeV

The transverse energy (E(T)) in Pb-Pb collisions at 2.76 TeV nucleon-nucleon center-of-mass energy (√(s(NN)) has been measured over a broad range of pseudorapidity (η) and collision centrality by using the CMS detector at the LHC. The transverse energy density per unit pseudorapidity (dE(T)/dη) increases faster with collision energy than the charged particle multiplicity. This implies that the mean energy per particle is increasing with collision energy. At all pseudorapidities, the transverse energy per participating nucleon increases with the centrality of the collision. The ratio of transverse energy per unit pseudorapidity in peripheral to central collisions varies significantly as the pseudorapidity increases from η=0 to |η|=5.0. For the 5% most central collisions, the energy density per unit volume is estimated to be about 14 GeV/fm(3) at a time of 1 fm/c after the collision. This is about 100 times larger than normal nuclear matter density and a factor of 2.6 times higher than the energy density reported at √(s(NN))=200 GeV at the Relativistic Heavy Ion Collider.

Search for a W' or techni-ρ decaying into WZ in pp Collisions at sqrt[s] = 7 TeV

A search is performed in pp collisions at sqrt[s]=7  TeV for exotic particles decaying via WZ to final states with electrons and muons. The data sample corresponds to an integrated luminosity of approximately 5  fb(-1). No significant excess is observed in the data above the expected standard model background. Upper bounds at 95% confidence level are set on the production cross section of the W' boson described by the sequential standard model and on the W' WZ coupling. W' bosons with masses below 1143 GeV are excluded. Limits are also set in the context of low-scale technicolor models, under a range of assumptions concerning the model parameters.

Bioengineering the hair follicle

The hair follicle develops from the primitive embryonic epidermis as a result of complex epithelial-mesenchymal interactions. The full follicle, consisting of epithelial cylinders under control of a proximal lying mesenchymal papilla, grows in cycles giving rise to a new hair shaft during each cycle. The ability to cycle endows the follicle with regenerative properties. The evolution of hair follicle engineering began with the recognition in the early 1960's that hair follicles could be transplanted clinically into a foreign site and still grow a shaft typical of the donor site. Since that time, it has been found that the follicular papilla has hair follicle inducing properties and that the hair follicle houses within it epithelial stem cells that can respond to hair inductive signals. These findings have laid the foundation for isolating hair-forming cells, for expanding the cells in culture, and for forming new follicles in vivo.

Identification of direct forkhead box O1 targets involved in palmitate-induced apoptosis in clonal insulin-secreting cells using chromatin immunoprecipitation coupled to DNA selection and ligation

AIMS/HYPOTHESIS

The transcription factor, forkhead box (FOX)O1, is involved in fatty acid-induced apoptosis in pancreatic beta cells, but the precise mechanism is poorly understood. We aimed to identify which direct downstream targets of FOXO1 are involved in palmitate-induced apoptosis in the pancreatic beta cell line MIN6.

METHODS

Chromatin immunoprecipitation (ChIP) coupled to a DNA selection and ligation technique (ChIP-DSL) was used to identify the direct targets of FOXO1. The mRNA level was examined by real-time PCR assay. The ChIP-DSL results were verified using ChIP-PCR and luciferase assay, respectively. The cell apoptosis rate was determined by TUNEL assay and by scoring cells with pycnotic nuclei.

RESULTS

We identified 189 target genes and selected 106 targets for expression analysis in MIN6 cells treated with palmitate. The results showed that six genes were significantly upregulated and four were downregulated. Binding of FOXO1 to the promoters was determined by ChIP-PCR and confirmed by luciferase assay. Among the ten up- and downregulated genes, mRNA expression of A930038C07Rik was significantly decreased and that of Ppa1 was increased in 8-week-old db/db mice. The apoptosis assay showed that overproduction of the protein 'RIKEN cDNA A930038C07' (A930038C07Rik) drastically enhanced palmitate-induced apoptosis, while pyrophosphatase (inorganic) 1 (PPA1) partially protected the cells from apoptosis. Knockdown of PPA1, moreover, significantly increased apoptosis.

CONCLUSIONS/INTERPRETATION

We identified for the first time FOXO1 targets in MIN6 cells treated with palmitate, thus revealing the important roles of A930038C07Rik and PPA1 in palmitate-induced cell apoptosis. These results shed light on the mechanisms of palmitate-induced apoptosis in pancreatic beta cells.

Protein tyrosine kinase 6 protects cells from anoikis by directly phosphorylating focal adhesion kinase and activating AKT

Protein tyrosine kinase 6 (PTK6) is a non-receptor tyrosine kinase expressed in epithelial cancers. Disruption of Ptk6 decreases AOM-induced colon tumorigenesis in mice by preventing STAT3 activation. Relocalization of PTK6 in prostate cancers contributes to increased growth. Although not expressed in normal breast or ovary, PTK6 promotes anchorage-independent survival of breast and ovarian tumor cells. We identified several potential PTK6 substrates in the human SW620 colon cancer cell line using mass spectrometry, including FAK (focal adhesion kinase). We show that FAK is a direct substrate of PTK6 in vitro and in vivo. Expression of membrane targeted active PTK6 (Palm-PTK6-YF) induces constitutive activation of FAK and cell morphology changes, which are independent of SRC family kinases in Src−/−, Yes−/−, Fyn−/− (SYF) mouse embryonic fibroblasts (MEFs). Palm-PTK6-YF expressing SYF cells are transformed and overcome contact inhibition, form colonies in transformation assays, proliferate in suspension, and form tumors in a xenograft model. Expression of FAK and Palm-PTK6-YF in Fak−/− MEFs synergistically activates AKT and protects cells against anoikis. However, expression of Palm-PTK6-YF in Akt1/2−/− MEFs fails to protect cells from anoikis, indicating AKT is critical in PTK6 and FAK mediated survival signaling. In a conditional Pten knockout murine prostate cancer model, we identify prostate epithelial cells with enhanced activation of endogenous PTK6 and FAK at the plasma membrane. Knockdown of PTK6 in the PC3 human prostate cancer cell line disrupts FAK and AKT activation and promotes anoikis, which can be rescued by exogenous expression of FAK. Our data reveal important roles for a PTK6-FAK-AKT signaling axis in promoting anchorage-independent cell survival.

PSGL-1/selectin and ICAM-1/CD18 interactions are involved in macrophage-induced drug resistance in myeloma

Chemoresistance is the major obstacle in multiple myeloma (MM) management. We previously showed that macrophages protect myeloma cells, on a cell contact basis, from melphalan or dexamethasone-induced apoptosis in vitro. In this study, we found that macrophage-mediated myeloma drug resistance was also seen with purified macrophages from myeloma patients' bone marrow (BM) in vitro and was confirmed in vivo using the human myeloma-SCID (severe combined immunodeficient) mouse model. By profiling differentially regulated and paired plasma membrane protein genes, we showed that PSGL-1 (P-selectin glycoprotein ligand-1)/selectins and ICAM-1/CD18 played an important role in macrophage-mediated myeloma cell drug resistance, as blocking antibodies against these molecules or genetic knockdown of PSGL-1 or ICAM-1 in myeloma cells repressed macrophages' ability to protect myeloma cells. Interaction of macrophages and myeloma cells via these molecules activated Src and Erk1/2 kinases and c-myc pathways and suppressed caspase activation induced by chemotherapy drugs. Thus, our study sheds new light on the mechanism of drug resistance in MM and provides novel targets for improving the efficacy of chemotherapy in patients.

Search for a light pseudoscalar Higgs boson in the dimuon decay channel in pp collisions at √s = 7 TeV

The dimuon invariant mass spectrum is searched in the range between 5.5 and 14 GeV for a light pseudoscalar Higgs boson a, predicted in a number of new physics models, including the next-to-minimal supersymmetric standard model. The data sample used in the search corresponds to an integrated luminosity of 1.3 fb(-1) collected in pp collisions at √s = 7 TeV with the CMS detector at the LHC. No excess is observed above the background predictions and upper limits are set on the cross section times branching fraction σ × B(pp→a→μ(+)μ(-)) in the range of 1.5-7.5 pb. These results improve on existing bounds on the abb coupling for m(a) < m(Υ(1S)) and are the first significant limits for m(a) > m(Υ(3S)). Constraints on the supersymmetric parameter space are presented in the context of the next-to-minimal model.

Measurement of the electron charge asymmetry in inclusive W production in pp collisions at sqrt[s]=7 TeV

A measurement of the electron charge asymmetry in inclusive pp→W+X→eν+X production at sqrt[s]=7  TeV is presented based on data recorded by the CMS detector at the LHC and corresponding to an integrated luminosity of 840  pb(-1). The electron charge asymmetry reflects the unequal production of W(+) and W(-) bosons in pp collisions. The electron charge asymmetry is measured in bins of the absolute value of electron pseudorapidity in the range of |η|<2.4. The asymmetry rises from about 0.1 to 0.2 as a function of the pseudorapidity and is measured with a relative precision better than 7%. This measurement provides new stringent constraints for parton distribution functions.

Mechanism of localization of the magnetization reversal in 3 nm wide Co nanowires

The mechanism of magnetization reversal has been studied in a model system of self-assembled cobalt nanowires with a 3 nm diameter. The structure, orientation and size of grains within the nanowires could be determined by high resolution transmission electron microscopy. The magnetic properties were probed using static and dynamic magnetization measurements. Micromagnetic modeling based on the structural analysis allows us to correlate the structure and the magnetic behavior of the wires, revealing competition between shape anisotropy, magnetocrystalline anisotropy and exchange in the localized reversal within Co hcp oriented grains. These results provide direct experimental evidence of the link between anisotropy fluctuations and reversal localization in nanowires.

Search for new physics with same-sign isolated dilepton events with jets and missing transverse energy

A search for new physics is performed in events with two same-sign isolated leptons, hadronic jets, and missing transverse energy in the final state. The analysis is based on a data sample corresponding to an integrated luminosity of 4.98 fb(-1) produced in pp collisions at a center-of-mass energy of 7 TeV collected by the CMS experiment at the LHC. This constitutes a factor of 140 increase in integrated luminosity over previously published results. The observed yields agree with the standard model predictions and thus no evidence for new physics is found. The observations are used to set upper limits on possible new physics contributions and to constrain supersymmetric models. To facilitate the interpretation of the data in a broader range of new physics scenarios, information on the event selection, detector response, and efficiencies is provided.