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.

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.

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.

Vascular smooth muscle cell apoptosis promotes transplant arteriosclerosis through inducing the production of SDF-1α

Transplant arteriosclerosis is a leading cause of late allograft loss. Medial smooth muscle cell (SMC) apoptosis is considered to be an important event in transplant arteriosclerosis. However, the precise contribution of medial SMC apoptosis to transplant arteriosclerosis and the underlying mechanisms remain unclear. We transferred wild-type p53 to induce apoptosis of cultured SMCs. We found that apoptosis induces the production of SDF-1α from apoptotic and neighboring viable cells, resulting in increased SDF-1α in the culture media. Conditioned media from Ltv-p53-transferred SMCs activated PI3K/Akt/mTOR and MAPK/Erk signaling in a SDF-1α-dependent manner and thereby promoted mesenchymal stem cell (MSC) migration and proliferation. In a rat aorta transplantation model, lentivirus-mediated BclxL transfer selectively inhibits medial SMC apoptosis in aortic allografts, resulting in a remarkable decrease of SDF-1α both in allograft media and in blood plasma, associated with diminished recruitment of CD90(+)CD105(+) double-positive cells and impaired neointimal formation. Systemic administration of rapamycin or PD98059 also attenuated MSC recruitment and neointimal formation in the aortic allografts. These results suggest that medial SMC apoptosis is critical for the development of transplant arteriosclerosis through inducing SDF-1α production and that MSC recruitment represents a major component of vascular remodeling, constituting a relevant target and mechanism for therapeutic interventions.

Genetically engineered Escherichia coli FBR5: part II. Ethanol production from xylose and simultaneous product recovery

In these studies, concentrated xylose solution was fermented to ethanol using Escherichia coli FBR5 which can ferment both lignocellulosic sugars (hexoses and pentoses). E. coli FBR5 can produce 40-50 g L(-1) ethanol from 100 g L(-1) xylose in batch reactors. Increasing sugar concentration beyond this level results in the loss of sugar with the reactor effluent thus affecting the process yield adversely. In a nonintegrated system without simultaneous product removal more than 120 g L(-1) xylose was left unused of the 220 g L(-1) that was fed into the reactor. In contrast to this, application of simultaneous product removal by gas stripping was able to relieve product inhibition and the culture was able to use 216.6 g L(-1) xylose thus producing 140 g L(-1) (based on reactor volume) ethanol resulting in a product yield of 0.48. The product stream achieved an ethanol concentration up to 148.41 g L(-1). This process has potential for greatly improving the performance of E. coli FBR5 where the strain can ferment all the lignocellulosic sugars to ethanol and gas stripping can be applied to recover product.

Impact of vitamin D supplementation on markers of inflammation in adults with cystic fibrosis hospitalized for a pulmonary exacerbation

Patients with cystic fibrosis (CF) suffer from chronic lung infection and inflammation leading to respiratory failure. Vitamin D deficiency is common in patients with CF, and correction of vitamin D deficiency may improve innate immunity and reduce inflammation in patients with CF. We conducted a double-blinded, placebo-controlled, randomized clinical trial of high-dose vitamin D to assess the impact of vitamin D therapy on antimicrobial peptide concentrations and markers of inflammation. We randomized 30 adults with CF hospitalized with a pulmonary exacerbation to 250,000 IU of cholecalciferol or placebo, and evaluated changes in plasma concentrations of inflammatory markers and the antimicrobial peptide LL-37 at baseline and 12 weeks post intervention. In the vitamin D group, there was a 50.4% reduction in tumor necrosis factor-α (TNF-α) at 12 weeks (P<0.01), and there was a trend for a 64.5% reduction in interleukin-6 (IL-6) (P=0.09). There were no significant changes in IL-1β, IL-8, IL-10, IL-18BP and NGAL (neutrophil gelatinase-associated lipocalin). We conclude that a large bolus dose of vitamin D is associated with reductions in two inflammatory cytokines, IL-6 and TNF-α. This study supports the concept that vitamin D may help regulate inflammation in CF, and that further research is needed to elucidate the potential mechanisms involved and the impact on clinical outcomes.

Enhanced stimulus sequence-dependent repeated learning in male offspring after prenatal stress alone or in conjunction with lead exposure

Both lead (Pb) exposure and prenatal stress (PS) can produce cognitive deficits, and in a prior study we demonstrated enhanced cognitive deficits in repeated learning of female rats exposed to both of these developmental insults (Cory-Slechta et al., 2010). However, PS can also lead to improved cognitive outcomes that are both gender- and context-dependent. Thus, the current study examined whether Pb ± PS likewise produced repeated learning deficits in males, either after maternal or lifetime Pb exposure. Repeated learning was evaluated using a multiple schedule of repeated learning and performance that required learning 3-response sequences in male offspring that had been subjected to either maternal Pb (0 or 150 ppm) or lifetime Pb exposure (0 or 50 ppm) beginning two months prior to dam breeding, to prenatal immobilization restraint stress (gestational days 16-17), or to both Pb and PS. Blood Pb, corticosterone, hippocampal glucocorticoid receptor density and brain monoamines were also measured. In contrast to outcomes in females, sequence-specific enhancements of repeated learning accuracy were produced by PS, particularly when combined with Pb, results that appeared to be more robust in combination with lifetime than maternal Pb exposure. A common behavioral mechanism of these improvements appears to be an increased reinforcement density associated with increased response rates and shorter session times seen with PS ± Pb that could shorten time to reinforcement. Trends toward lower levels of nucleus accumbens dopamine activity seen after both maternal Pb and lifetime Pb combined with PS suggest a possible role for this region/neurotransmitter in enhanced accuracy, whereas PS ± Pb-induced corticosterone changes did not exhibit an obvious systematic relationship to accuracy enhancements. While PS ± Pb-based increases in accuracy appear to be an improved outcome, the benefits of increased response rate are by no means universal, but highly context-dependent and can lead to adverse behavioral effects in other conditions.

Azimuthal anisotropy of charged particles at high transverse momenta in Pb-Pb collisions at sqrt[s(NN)] = 2.76 TeV

The azimuthal anisotropy of charged particles in Pb-Pb collisions at sqrt[s(NN)]=2.76  TeV is measured with the CMS detector at the LHC over an extended transverse momentum (p(T)) range up to approximately 60  GeV/c. The data cover both the low-p(T) region associated with hydrodynamic flow phenomena and the high-p(T) region where the anisotropies may reflect the path-length dependence of parton energy loss in the created medium. The anisotropy parameter (v2) of the particles is extracted by correlating charged tracks with respect to the event-plane reconstructed by using the energy deposited in forward-angle calorimeters. For the six bins of collision centrality studied, spanning the range of 0-60% most-central events, the observed v2 values are found to first increase with p(T), reaching a maximum around p(T)=3  GeV/c, and then to gradually decrease to almost zero, with the decline persisting up to at least pp(T)=40  GeV/c over the full centrality range measured.

Genomic sequencing of key genes in mouse pancreatic cancer cells

Pancreatic cancer is a multiple genetic disorder with many mutations identified during the progression. Two mouse pancreatic cancer cell lines were established which showed different phenotype in vivo: a non-metastatic cell line, Panc02, and a highly metastatic cell line, Panc02-H7, a derivative of Panc02. In order to investigate whether the genetic mutations of key genes in pancreatic cancer such as KRAS, TP53 (p53), CDKN2A (p16), SMAD4, ZIP4, and PDX-1 contribute to the phenotypic difference of these two mouse pancreatic cancer cells, we sequenced the exonic regions of these key genes in both cell lines and in the normal syngeneic mouse pancreas and compared them with the reference mouse genome sequence. The exons of KRAS, SMAD4, CDKN2A (p16), TP53 (p53), ZIP4, and PDX-1 genes were amplified and the genotype of these genes was determined by Sanger sequencing. The sequences were analyzed with Sequencher software. A mutation in SMAD4 was identified in both cell lines. This homozygote G to T mutation in the first position of codon 174 (GAA) generated a stop codon resulting in the translation of a truncated protein. Further functional analysis indicates that different TGF-β/SMAD signaling pathways were involved in those two mouse cell lines, which may explain the phonotypic difference between the two cells. A single nucleotide polymorphism (SNP) in KRAS gene (TAT to TAC at codon 32) was also identified in the normal pancreas DNA of the syngenic mouse and in both derived tumoral Panc02 and Panc02-H7 cells. No mutation or SNP was found in CDKN2A (p16), TP53 (p53), ZIP4, and PDX-1 genes in these two cell lines. The absence of mutations in genes such as KRAS, TP53, and CDKN2A, which are considered as key genes in the development of human pancreatic cancer suggests that SMAD4 might play a central and decisive role in mouse pancreatic cancer. These results also suggest that other mechanisms are involved in the substantial phenotypic difference between these two mouse pancreatic cancer cell lines. Further studies are warranted to elucidate the molecular pathways that lead to the aggressive metastatic potential of Panc02-H7.

Endothelin-1 stimulates human trophoblast cell migration through Cdc42 activation

PURPOSE

This study investigated the role and mechanism of Cdc42 in Endothelin-1 (ET-1)-induced trophoblast cell migration.

METHODS

We examined ET-1-mediated stimulation of trophoblast migration with HTR-8/SVneo cells. Cdc42 activation was measured after ET-1 treatment of HTR-8/SVneo cells. To determine the ET receptor subtype involved in ET-1-mediated Cdc42 activation, experiments were performed in the presence of ET(A) and ET(B) receptor antagonists. Finally, using siRNA we knocked down the expression of Cdc42 to examine the involvement of Cdc42 in the regulation of ET-1-stimulated trophoblast cell migration.

RESULTS

ET-1 was shown to have a dose-dependent effect on trophoblast migration. At low concentrations of ET-1 (0.1 nmol/L) ET-1 had a stimulatory effect on cell migration. ET-1 (10 nmol/L) increased HTR-8/svneo cell migration index by 2.5 fold. ET-1 (10 nmol/L) elevated protein level and activity of Cdc42. ET-1 induced activation of Cdc42 GTPase was mediated by both ET(A) and ET(B). ET-1-induced cell migration was shown to be inhibited by Cdc42 siRNA.The inhibition was not mitigated by the addition of ET-1, suggesting that Cdc42 plays an important role in trophoblast migration and is obligatory for ET-1 action.

CONCLUSIONS

ET-1 stimulates EVT migration through Cdc42 activation.

Expression patterns of human DAB2IP protein in fetal tissues

Human DOC-2/DAB2-interacting protein (DAB2IP) is encoded by a tumor suppressor gene and a newly recognized member of the Ras-GTPase-activating family. DAB2IP is a critical component of many signal transduction pathways mediated by Ras and tumor necrosis factors including apoptosis pathways, and it is involved in the formation of many types of tumors. DAB2IP participates in regulation of gene expression and pluripotency of cells. It has been reported that DAB2IP was expressed in different tumor tissues. Little information is available concerning the expression levels of DAB2IP in normal tissues and cells, however, and no studies of its expression patterns during the development of human embryos have been reported. We examined the expression of DAB2IP during human embryonic development to understand better DAB2IP functions. Human fetuses, weeks 9 to 38, and a newborn were obtained from miscarriages or stillbirths. Tissues were embedded in paraffin to construct arrays that were stained immunohistochemically. The DAB2IP-positive cells were identified and scored based on both the percentage of stained cells and their staining intensities. DAB2IP was expressed in most fetal tissues examined. DAB2IP was expressed primarily in cell cytoplasm throughout the fetal development. The expression levels varied among tissues and different gestational ages. Virtually no expression was observed in the cerebrum, parotid gland, thymus, thyroid gland and spleen. Expression was much greater in the adrenal gland and pancreas; weakly to moderately strong in the endocardium, stomach, kidney, testis and small intestine; and lower in liver, trachea, skin, ovary and endometrium. Its expression in the lung, esophagus and bladder were much weaker to absent.

Search for dark matter and large extra dimensions in pp collisions yielding a photon and missing transverse energy

Results are presented from a search for new physics in the final state containing a photon (γ) and missing transverse energy (E[combininb /](T)). The data correspond to an integrated luminosity of 5.0 fb(-1) collected in pp collisions at √[s]=7 TeV by the CMS experiment. The observed event yield agrees with standard-model expectations for the γ+E[combininb /](T) events. Using models for the production of dark-matter particles (χ), we set 90% confidence level (C.L.) upper limits of 13.6-15.4 fb on χ production in the γ+E[combininb /](T) state. These provide the most sensitive upper limits for spin-dependent χ-nucleon scattering for χ masses (M(χ)) between 1 and 100 GeV. For spin-independent contributions, the present limits are extended to M(χ)<3.5 GeV. For models with 3-6 large extra dimensions, our data exclude extra-dimensional Planck scales between 1.64 and 1.73 TeV at 95% C.L.

Improving susceptibility mapping using a threshold-based K-space/image domain iterative reconstruction approach

To improve susceptibility quantification, a threshold-based k-space/image domain iterative approach that uses geometric information from the susceptibility map itself as a constraint to overcome the ill-posed nature of the inverse filter is introduced. Simulations were used to study the accuracy of the method and its robustness in the presence of noise. In vivo data were processed and analyzed using this method. Both simulations and in vivo results show that most streaking artifacts inside the susceptibility map caused by the ill-defined inverse filter were suppressed by the iterative approach. In simulated data, the bias toward lower mean susceptibility values inside vessels has been shown to decrease from around 10% to 2% when choosing an appropriate threshold value for the proposed iterative method. Typically, three iterations are sufficient for this approach to converge and this process takes less than 30 s to process a 512×512×256 dataset. This iterative method improves quantification of susceptibility inside vessels and reduces streaking artifacts throughout the brain for data collected from a single-orientation acquisition. This approach has been applied to vessels alone as well as to vessels and other structures with lower susceptibility to generate whole brain susceptibility maps with significantly reduced streaking artifacts.