Showing papers by "Jagiellonian University published in 2010"

Observation of a centrality-dependent dijet asymmetry in lead-lead collisions at √sNN=2.76 Tev with the ATLAS detector at the LHC

Abstract: By using the ATLAS detector, observations have been made of a centrality-dependent dijet asymmetry in the collisions of lead ions at the Large Hadron Collider. In a sample of lead-lead events with a per-nucleon center of mass energy of 2.76 TeV, selected with a minimum bias trigger, jets are reconstructed in fine-grained, longitudinally segmented electromagnetic and hadronic calorimeters. The transverse energies of dijets in opposite hemispheres are observed to become systematically more unbalanced with increasing event centrality leading to a large number of events which contain highly asymmetric dijets. This is the first observation of an enhancement of events with such large dijet asymmetries, not observed in proton-proton collisions, which may point to an interpretation in terms of strong jet energy loss in a hot, dense medium.

Combined Measurement and QCD Analysis of the Inclusive e± p Scattering Cross Sections at HERA

Abstract: A combination is presented of the inclusive deep inelastic cross sections measured by the H1 and ZEUS Collaborations in neutral and charged current unpolarised e(+/-)p scattering at HERA during the period 1994-2000. The data span six orders of magnitude in negative four-momentum-transfer squared, Q(2), and in Bjorken x. The combination method used takes the correlations of systematic uncertainties into account, resulting in an improved accuracy. The combined data are the sole input in a NLO QCD analysis which determines a new set of parton distributions, HERAPDF1.0, with small experimental uncertainties. This set includes an estimate of the model and parametrisation uncertainties of the fit result.

Peptidylarginine deiminase from Porphyromonas gingivalis citrullinates human fibrinogen and α-enolase: Implications for autoimmunity in rheumatoid arthritis

Abstract: Objectives To investigate protein citrullination by the periodontal pathogen Porphyromonas gingivalis (P. gingivalis) as a potential mechanism for breaking tolerance to citrullinated proteins in rheumatoid arthritis (RA).

Critical role for the chemokine receptor CXCR6 in NK cell-mediated antigen-specific memory of haptens and viruses

Abstract: Hepatic natural killer (NK) cells mediate antigen-specific contact hypersensitivity (CHS) in mice deficient in T cells and B cells. We report here that hepatic NK cells, but not splenic or naive NK cells, also developed specific memory of vaccines containing antigens from influenza, vesicular stomatitis virus (VSV) or human immunodeficiency virus type 1 (HIV-1). Adoptive transfer of virus-sensitized NK cells into naive recipient mice enhanced the survival of the mice after lethal challenge with the sensitizing virus but not after lethal challenge with a different virus. NK cell memory of haptens and viruses depended on CXCR6, a chemokine receptor on hepatic NK cells that was required for the persistence of memory NK cells but not for antigen recognition. Thus, hepatic NK cells can develop adaptive immunity to structurally diverse antigens, an activity that requires NK cell-expressed CXCR6.

The First Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope

Abstract: We present the first catalog of active galactic nuclei (AGN) detected by the LAT, corresponding to 11 months of data collected in scientific operation mode. The First LAT AGN Catalog (1LAC) includes 671 gamma-ray sources located at high Galactic latitudes (|b| > 10 deg) that are detected with a test statistic (TS) greater than 25 and associated statistically with AGNs. Some LAT sources are associated with multiple AGNs, and consequently, the catalog includes 709 AGNs, comprising 300 BL Lacertae objects (BL Lacs), 296 flat-spectrum radio quasars (FSRQs), 41 AGNs of other types, and 72 AGNs of unknown type. We also classify the blazars based on their spectral energy distributions (SEDs) as archival radio, optical, and X-ray data permit. In addition to the format 1LAC sample, we provide AGN associations for 51 low-latitude LAT sources and AGN "affiliations" (unquantified counterpart candidates) for 104 high-latitude LAT sources without AGN associations. The overlap of the 1LAC with existing gamma-ray AGN catalogs (LBAS, EGRET, AGILE, Swift, INTEGRAL, TeVCat) is briefly discussed. Various properties--such as gamma-ray fluxes and photon power law spectral indices, redshifts, gamma-ray luminosities, variability, and archival radio luminosities--and their correlations are presented and discussed for the different blazar classes. We compare the 1LAC results with predictions regarding the gamma-ray AGN populations, and we comment on the power of the sample to address the question of the blazar sequence.

Dynamics of a quantum phase transition and relaxation to a steady state

Abstract: We review recent theoretical work on two closely related issues: excitation of an isolated quantum condensed matter system driven adiabatically across a continuous quantum phase transition or a gapless phase, and apparent relaxation of an excited system after a sudden quench of a parameter in its Hamiltonian. Accordingly, the review is divided into two parts. The first part revolves around a quantum version of the Kibble–Zurek mechanism including also phenomena that go beyond this simple paradigm. What they have in common is that excitation of a gapless many-body system scales with a power of the driving rate. The second part attempts a systematic presentation of recent results and conjectures on apparent relaxation of a pure state of an isolated quantum many-body system after its excitation by a sudden quench. This research is motivated in part by recent experimental developments in the physics of ultracold atoms with potential applications in the adiabatic quantum state preparation and quantum computation.

Emotion-regulation ability, burnout, and job satisfaction among British secondary-school teachers.

Abstract: The topic of emotion regulation and its relationship with teacher effectiveness is beginning to garner attention by researchers. This study examined the relationship between emotion-regulation ability (ERA), as assessed by the Mayer – Salovey – Caruso Emotional Intelligence Test (MSCEIT), and both job satisfaction and burnout among secondary-school teachers (N = 123). It also examined the mediating effects of affect and principal support on these outcomes. ERA was associated positively with positive affect, principal support, job satisfaction, and one component of burnout, personal accomplishment. Two path models demonstrated that both positive affect and principal support mediated independently the associations between ERA and both personal accomplishment and job satisfaction. C � 2010 Wiley Periodicals, Inc.

Prognostic Value of Reading-to-Reading Blood Pressure Variability Over 24 Hours in 8938 Subjects From 11 Populations

Abstract: In previous studies, of which several were underpowered, the relation between cardiovascular outcome and blood pressure (BP) variability was inconsistent. We followed health outcomes in 8938 subjects (mean age: 53.0 years; 46.8% women) randomly recruited from 11 populations. At baseline, we assessed BP variability from the SD and average real variability in 24-hour ambulatory BP recordings. We computed standardized hazard ratios (HRs) while stratifying by cohort and adjusting for 24-hour BP and other risk factors. Over 11.3 years (median), 1242 deaths (487 cardiovascular) occurred, and 1049, 577, 421, and 457 participants experienced a fatal or nonfatal cardiovascular, cardiac, or coronary event or a stroke. Higher diastolic average real variability in 24-hour ambulatory BP recordings predicted (P0.03) total (HR: 1.14) and cardiovascular (HR: 1.21) mortality and all types of fatal combined with nonfatal end points (HR: 1.07) with the exception of cardiac and coronary events (HR: 1.02; P0.58). Higher systolic average real variability in 24-hour ambulatory BP recordings predicted (P0.05) total (HR: 1.11) and cardiovascular (HR: 1.16) mortality and all fatal combined with nonfatal end points (HR: 1.07), with the exception of cardiac and coronary events (HR: 1.03; P0.54). SD predicted only total and cardiovascular mortality. While accounting for the 24-hour BP level, average real variability in 24-hour ambulatory BP recordings added 1% to the prediction of a cardiovascular event. Sensitivity analyses considering ethnicity, sex, age, previous cardiovascular disease, antihypertensive treatment, number of BP readings per recording, or the night:day BP ratio were confirmatory. In conclusion, in a large population cohort, which provided sufficient statistical power, BP variability assessed from 24-hour ambulatory recordings did not contribute much to risk stratification over and beyond 24-hour BP. (Hypertension. 2010;55:1049-1057.)

A change in the optical polarization associated with a γ-ray flare in the blazar 3C 279

Abstract: It is widely accepted that strong and variable radiation detected over all accessible energy bands in a number of active galaxies arises from a relativistic, Doppler-boosted jet pointing close to our line of sight1. The size of the emitting zone and the location of this region relative to the central supermassive black hole are, however, poorly known, with estimates ranging from light-hours to a light-year or more. Here we report the coincidence of a gamma (γ)-ray flare with a dramatic change of optical polarization angle. This provides evidence for co-spatiality of optical and γ-ray emission regions and indicates a highly ordered jet magnetic field. The results also require a non-axisymmetric structure of the emission zone, implying a curved trajectory for the emitting material within the jet, with the dissipation region located at a considerable distance from the black hole, at about 105 gravitational radii.

HIF-1 and HIF-2 transcription factors — Similar but not identical

Abstract: Hypoxia inducible factor (HIF)-1 and HIF-2 are heterodimeric transcription factors mediating the cellular response to hypoxia. Recent data indicate that not only ubiquitous HIF-1α, but also more cell-specific HIF-2α, is an important regulator of the hypoxia response. Although both α subunits are highly conservative at protein level, share similar domain structure, heterodimerize with HIF-1β, and bind to the same DNA sequence called hypoxia responsive element (HRE), their effect on the expression of some genes may vary. In this review we stressed the differences between the isoforms, their structure and expression pattern. Moreover, we described diversity of coactivators and proteins which interact with HIFs, and which are responsible for the specificity of their action. Finally, recent data showing link between HIFs and specific microRNA have been presented.

Fermi LAT observations of cosmic-ray electrons from 7 GeV to 1 TeV

Abstract: We present the results of our analysis of cosmic-ray electrons using about 8 x 10(6) electron candidates detected in the first 12 months on-orbit by the Fermi Large Area Telescope. This work extend ...

Review of AdS/CFT Integrability: An Overview

Abstract: This is the introductory chapter of a review collection on integrability in the context of the AdS/CFT correspondence. In the collection we present an overview of the achievements and the status of this subject as of the year 2010.

Prognostic value of isolated nocturnal hypertension on ambulatory measurement in 8711 individuals from 10 populations

Abstract: BACKGROUND: We and other investigators previously reported that isolated nocturnal hypertension on ambulatory measurement (INH) clustered with cardiovascular risk factors and was associated with intermediate target organ damage. We investigated whether INH might also predict hard cardiovascular endpoints. METHODS AND RESULTS: We monitored blood pressure (BP) throughout the day and followed health outcomes in 8711 individuals randomly recruited from 10 populations (mean age 54.8 years, 47.0% women). Of these, 577 untreated individuals had INH (daytime BP <135/85 mmHg and night-time BP ≥120/70 mmHg) and 994 untreated individuals had isolated daytime hypertension on ambulatory measurement (IDH; daytime BP ≥135/85 mmHg and night-time BP <120/70 mmHg). During follow-up (median 10.7 years), 1284 deaths (501 cardiovascular) occurred and 1109 participants experienced a fatal or nonfatal cardiovascular event. In multivariable-adjusted analyses, compared with normotension (n = 3837), INH was associated with a higher risk of total mortality (hazard ratio 1.29, P = 0.045) and all cardiovascular events (hazard ratio 1.38, P = 0.037). IDH was associated with increases in all cardiovascular events (hazard ratio 1.46, P = 0.0019) and cardiac endpoints (hazard ratio 1.53, P = 0.0061). Of 577 patients with INH, 457 were normotensive (<140/90 mmHg) on office BP measurement. Hazard ratios associated with INH with additional adjustment for office BP were 1.31 (P = 0.039) and 1.38 (P = 0.044) for total mortality and all cardiovascular events, respectively. After exclusion of patients with office hypertension, these hazard ratios were 1.17 (P = 0.31) and 1.48 (P = 0.034). CONCLUSION: INH predicts cardiovascular outcome in patients who are normotensive on office or on ambulatory daytime BP measurement.

Measurement of the solar 8B neutrino rate with a liquid scintillator target and 3 MeV energy threshold in the Borexino detector

Abstract: We report the measurement of {nu}-e elastic scattering from {sup 8}B solar neutrinos with 3 MeV energy threshold by the Borexino detector in Gran Sasso (Italy). The rate of solar neutrino-induced electron scattering events above this energy in Borexino is 0.22{+-}0.04(stat){+-}0.01(syst) cpd/100 t, which corresponds to {Phi}{sub {sup 8}B}{sup ES}=2.4{+-}0.4{+-}0.1x10{sup 6} cm{sup -2} s{sup -1}, in good agreement with measurements from SNO and SuperKamiokaNDE. Assuming the {sup 8}B neutrino flux predicted by the high metallicity standard solar model, the average {sup 8}B {nu}{sub e} survival probability above 3 MeV is measured to be 0.29{+-}0.10. The survival probabilities for {sup 7}Be and {sup 8}B neutrinos as measured by Borexino differ by 1.9{sigma}. These results are consistent with the prediction of the MSW-LMA solution of a transition in the solar {nu}{sub e} survival probability P{sub ee} between the low-energy vacuum-driven and the high-energy matter-enhanced solar neutrino oscillation regimes.

Prenatal exposure to airborne polycyclic aromatic hydrocarbons and children's intelligence at 5 years of age in a prospective cohort study in Poland

Abstract: BackgroundIn this prospective cohort study of Caucasian mothers and children in Krakow, Poland, we evaluated the role of prenatal exposure to urban air pollutants in the pathogenesis of neurobehavi...

Hypochlorous Acid: A Natural Adjuvant That Facilitates Antigen Processing, Cross-Priming, and the Induction of Adaptive Immunity

Abstract: The production of hypochlorous acid (HOCl) is a characteristic of granulocyte activation, a hallmark of the early phase of innate immune responses. In this study, we show that, in addition to its well-established role as a microbicide, HOCl can act as a natural adjuvant of adaptive immunity. HOCl enhances the T cell responses to the model Ag OVA, facilitating the processing and presentation of this protein via the class II MHC pathway. HOCl modification also enhances cross-presentation of the tumor Ag tyrosinase-related protein 2 via class I MHC. The adjuvant effects of HOCl are independent of TLR signaling. The enhanced presentation of HOCl-modified OVA is mediated via modification of the N-linked carbohydrate side chain rather than formation of protein aldehydes or chloramines. HOCl-modified OVA is taken up more efficiently by APCs and is degraded more efficiently by proteinases. Atomic force microscopy demonstrated that enhanced uptake is mediated via specific receptor binding, one candidate for which is the scavenger receptor lectin-like oxidized low-density lipoprotein receptor, which shows enhanced binding to chlorinated OVA. A function of HOCl is therefore to target glycoprotein Ags to scavenger receptors on the APC surface. This additional mechanism linking innate and adaptive immunity suggests novel strategies to enhance immunity to vaccines.

Fermi Gamma-Ray Imaging of a Radio Galaxy

Abstract: The Fermi Gamma-ray Space Telescope has detected the gamma-ray glow emanating from the giant radio lobes of the radio galaxy Centaurus A. The resolved gamma-ray image shows the lobes clearly separated from the central active source. In contrast to all other active galaxies detected so far in high-energy gamma-rays, the lobe flux constitutes a considerable portion (greater than one-half) of the total source emission. The gamma-ray emission from the lobes is interpreted as inverse Compton-scattered relic radiation from the cosmic microwave background, with additional contribution at higher energies from the infrared-to-optical extragalactic background light. These measurements provide gamma-ray constraints on the magnetic field and particle energy content in radio galaxy lobes, as well as a promising method to probe the cosmic relic photon fields.

Critical role of the disintegrin metalloprotease ADAM17 for intestinal inflammation and regeneration in mice

Abstract: The protease a disintegrin and metalloprotease (ADAM) 17 cleaves tumor necrosis factor (TNF), L-selectin, and epidermal growth factor receptor (EGF-R) ligands from the plasma membrane. ADAM17 is expressed in most tissues and is up-regulated during inflammation and cancer. ADAM17-deficient mice are not viable. Conditional ADAM17 knockout models demonstrated proinflammatory activities of ADAM17 in septic shock via shedding of TNF. We used a novel gene targeting strategy to generate mice with dramatically reduced ADAM17 levels in all tissues. The resulting mice called ADAM17ex/ex were viable, showed compromised shedding of ADAM17 substrates from the cell surface, and developed eye, heart, and skin defects as a consequence of impaired EGF-R signaling caused by failure of shedding of EGF-R ligands. Unexpectedly, although the intestine of unchallenged homozygous ADAM17ex/ex mice was normal, ADAM17ex/ex mice showed substantially increased susceptibility to inflammation in dextran sulfate sodium colitis. This was a result of impaired shedding of EGF-R ligands resulting in failure to phosphorylate STAT3 via the EGF-R and, consequently, in defective regeneration of epithelial cells and breakdown of the intestinal barrier. Besides regulating the systemic availability of the proinflammatory cytokine TNF, our results demonstrate that ADAM17 is needed for vital regenerative activities during the immune response. Thus, our mouse model will help investigate ADAM17 as a potential drug target.

Physics with the KLOE-2 experiment at the upgraded DA Phi NE

Abstract: Investigation at a f-factory can shed light on several debated issues in particle physics. We discuss: (i) recent theoretical development and experimental progress in kaon physics relevant for the Standard Model tests in the flavor sector, (ii) the sensitivity we can reach in probing CPT and Quantum Mechanics from time evolution of entangled-kaon states, (iii) the interest for improving on the present measurements of non-leptonic and radiative decays of kaons and eta/eta' mesons, (iv) the contribution to understand the nature of light scalar mesons, and (v) the opportunity to search for narrow di-lepton resonances suggested by recent models proposing a hidden dark-matter sector. We also report on the e(+)e(-) physics in the continuum with the measurements of (multi) hadronic cross sections and the study of gamma gamma processes.

Circulating tumour-derived microvesicles in plasma of gastric cancer patients

Abstract: Cell membrane microfragments called microvesicles (MV) originating from different cells are circulating in the blood of healthy subjects and their elevated numbers are found in different diseases, including cancer. This study was designed to characterise MV present in plasma of gastric cancer patients. Since majority of MV in blood are platelets-derived (PMV), plasma samples deprived of PMV were used. In comparison to control, the number of MV in patients was significantly elevated in all stages, higher in more advanced disease. Patients' MV showed an increased membrane expression of CCR6 and HER-2/neu. The proportion of MV carrying some leucocyte determinants was low and similar in patients and control. Transmission electron microscopy showed their substantial heterogeneity in size and shape. The size determined by dynamic light scattering analysis confirmed this heterogeneity. The MV size distribution in patients was broader within the range of 10-800 nm, while in control MV showed 3-mode distribution within the range of 10-400 nm. Atomic force microscopy confirmed MV size heterogeneity with implication that larger objects represented aggregates of smaller microparticles. Patients' MV exhibited increased absolute values of zeta potential, indicating a higher surface charge. Tumour markers HER-2/neu, MAGE-1, c-MET and EMMPRIN were detected both in control and patients' samples with stronger expression in the latter. Significantly higher expression of MAGE-1 and HER-2/neu mRNA was observed in individual patients. All together, it suggests that at least some MV in plasma of gastric cancer patients are tumour-derived. However, their role in cancer requires further studies.

Quest for precision in hadronic cross sections at low energy: Monte Carlo tools vs. experimental data

Abstract: We present the achievements of the last years of the experimental and theoretical groups working on hadronic cross section measurements at the low energy e+e- colliders in Beijing, Frascati, Ithaca, Novosibirsk, Stanford and Tsukuba and on tau decays. We sketch the prospects in these fields for the years to come. We emphasise the status and the precision of the Monte Carlo generators used to analyse the hadronic cross section measurements obtained as well with energy scans as with radiative return, to determine luminosities and tau decays. The radiative corrections fully or approximately implemented in the various codes and the contribution of the vacuum polarisation are discussed.

Comprehensive analysis of coronal mass ejection mass and energy properties over a full solar cycle

Abstract: The LASCO coronagraphs, in continuous operation since 1995, have observed the evolution of the solar corona and coronal mass ejections (CMEs) over a full solar cycle with high-quality images and regular cadence. This is the first time that such a data set becomes available and constitutes a unique resource for the study of CMEs. In this paper, we present a comprehensive investigation of the solar cycle dependence on the CME mass and energy over a full solar cycle (1996-2009) including the first in-depth discussion of the mass and energy analysis methods and their associated errors. Our analysis provides several results worthy of further studies. It demonstrates the possible existence of two event classes: normal CMEs reaching constant mass for >10 R ☉ and pseudo-CMEs which disappear in the C3 field of view. It shows that the mass and energy properties of CME reach constant levels and therefore should be measured only above ~10 R ☉. The mass density (g/R 2 ☉) of CMEs varies relatively little (< order of magnitude) suggesting that the majority of the mass originates from a small range in coronal heights. We find a sudden reduction in the CME mass in mid-2003 which may be related to a change in the electron content of the large-scale corona and we uncover the presence of a 6 month periodicity in the ejected mass from 2003 onward.

Heme oxygenase-1 in tumor biology and therapy.

Abstract: Heme oxygenase-1 (HO-1) degrades heme to carbon monoxide (CO), biliverdin, and ferrous iron. As HO-1 expression is highly increased by stressful conditions, the major role of the enzyme is the protection against oxidative injury. Additionally, it regulates cell proliferation, modulates inflammatory response and facilitates angiogenesis. Beneficial activities of HO-1 have been recognized in many pathological states e.g. atherosclerosis, diabetes, ischemia/reperfusion injury or organ transplantation. Interestingly HO-1 expression is very often boosted in tumor tissues and could be further elevated in response to radio-, chemo-, or photodynamic therapy. A growing body of evidence suggests that HO-1 may play a role in tumor induction and can potently improve the growth and spread of tumors. This review discusses the implications of HO-1 properties for tumor proliferation and cell death, differentiation, angiogenesis and metastasis, and tumor-related inflammation. Finally, it suggests that pharmacological agents that regulate HO activity or HO-1 gene silencing may become powerful tools for preventing the onset or progression of various cancers and sensitize them to anticancer therapies.