Tests of General Relativity with GW150914

The LIGO detection of GW150914 provides an unprecedented opportunity to study the two-body motion of a compact-object binary in the large-velocity, highly nonlinear regime, and to witness the final merger of the binary and the excitation of uniquely relativistic modes of the gravitational field. We carry out several investigations to determine whether GW150914 is consistent with a binary black-hole merger in general relativity. We find that the final remnant's mass and spin, as determined from the low-frequency (inspiral) and high-frequency (postinspiral) phases of the signal, are mutually consistent with the binary black-hole solution in general relativity. Furthermore, the data following the peak of GW150914 are consistent with the least-damped quasinormal mode inferred from the mass and spin of the remnant black hole. By using waveform models that allow for parametrized general-relativity violations during the inspiral and merger phases, we perform quantitative tests on the gravitational-wave phase in the dynamical regime and we determine the first empirical bounds on several high-order post-Newtonian coefficients. We constrain the graviton Compton wavelength, assuming that gravitons are dispersed in vacuum in the same way as particles with mass, obtaining a 90%-confidence lower bound of 10^{13}  km. In conclusion, within our statistical uncertainties, we find no evidence for violations of general relativity in the genuinely strong-field regime of gravity.

Measurement of the Transverse Single-Spin Asymmetry in p^{↑}+p→W^{±}/Z^{0} at RHIC

We present the measurement of the transverse single-spin asymmetry of weak boson production in transversely polarized proton-proton collisions at sqrt[s]=500  GeV by the STAR experiment at RHIC. The measured observable is sensitive to the Sivers function, one of the transverse-momentum-dependent parton distribution functions, which is predicted to have the opposite sign in proton-proton collisions from that observed in deep inelastic lepton-proton scattering. These data provide the first experimental investigation of the nonuniversality of the Sivers function, fundamental to our understanding of QCD.

GW150914: Implications for the Stochastic Gravitational-Wave Background from Binary Black Holes

The LIGO detection of the gravitational wave transient GW150914, from the inspiral and merger of two black holes with masses ≳30M_{⊙}, suggests a population of binary black holes with relatively high mass. This observation implies that the stochastic gravitational-wave background from binary black holes, created from the incoherent superposition of all the merging binaries in the Universe, could be higher than previously expected. Using the properties of GW150914, we estimate the energy density of such a background from binary black holes. In the most sensitive part of the Advanced LIGO and Advanced Virgo band for stochastic backgrounds (near 25 Hz), we predict Ω_{GW}(f=25  Hz)=1.1_{-0.9}^{+2.7}×10^{-9} with 90% confidence. This prediction is robustly demonstrated for a variety of formation scenarios with different parameters. The differences between models are small compared to the statistical uncertainty arising from the currently poorly constrained local coalescence rate. We conclude that this background is potentially measurable by the Advanced LIGO and Advanced Virgo detectors operating at their projected final sensitivity.

GW150914: The Advanced LIGO Detectors in the Era of First Discoveries

Following a major upgrade, the two advanced detectors of the Laser Interferometer Gravitational-wave Observatory (LIGO) held their first observation run between September 2015 and January 2016. With a strain sensitivity of 10^{-23}/sqrt[Hz] at 100 Hz, the product of observable volume and measurement time exceeded that of all previous runs within the first 16 days of coincident observation. On September 14, 2015, the Advanced LIGO detectors observed a transient gravitational-wave signal determined to be the coalescence of two black holes [B. P. Abbott et al., Phys. Rev. Lett. 116, 061102 (2016)], launching the era of gravitational-wave astronomy. The event, GW150914, was observed with a combined signal-to-noise ratio of 24 in coincidence by the two detectors. Here, we present the main features of the detectors that enabled this observation. At full sensitivity, the Advanced LIGO detectors are designed to deliver another factor of 3 improvement in the signal-to-noise ratio for binary black hole systems similar in mass to GW150914.

Beam Energy Dependence of the Third Harmonic of Azimuthal Correlations in Au+Au Collisions at RHIC

We present results from a harmonic decomposition of two-particle azimuthal correlations measured with the STAR detector in Au+Au collisions for energies ranging from sqrt[s_{NN}]=7.7 to 200 GeV. The third harmonic v_{3}^{2}{2}=⟨cos3(ϕ_{1}-ϕ_{2})⟩, where ϕ_{1}-ϕ_{2} is the angular difference in azimuth, is studied as a function of the pseudorapidity difference between particle pairs Δη=η_{1}-η_{2}. Nonzero v_{3}^{2}{2} is directly related to the previously observed large-Δη narrow-Δϕ ridge correlations and has been shown in models to be sensitive to the existence of a low viscosity quark gluon plasma phase. For sufficiently central collisions, v_{3}^{2}{2} persist down to an energy of 7.7 GeV, suggesting that quark gluon plasma may be created even in these low energy collisions. In peripheral collisions at these low energies, however, v_{3}^{2}{2} is consistent with zero. When scaled by the pseudorapidity density of charged-particle multiplicity per participating nucleon pair, v_{3}^{2}{2} for central collisions shows a minimum near sqrt[s_{NN}]=20  GeV.

Centrality and Transverse Momentum Dependence of Elliptic Flow of Multistrange Hadrons and ϕ Meson in Au+Au Collisions at √[sNN]=200 GeV

We present high precision measurements of elliptic flow near midrapidity (|y|<1.0) for multistrange hadrons and ϕ meson as a function of centrality and transverse momentum in Au+Au collisions at center of mass energy √[sNN]=200  GeV. We observe that the transverse momentum dependence of ϕ and Ω v2 is similar to that of π and p, respectively, which may indicate that the heavier strange quark flows as strongly as the lighter up and down quarks. This observation constitutes a clear piece of evidence for the development of partonic collectivity in heavy-ion collisions at the top RHIC energy. Number of constituent quark scaling is found to hold within statistical uncertainty for both 0%-30% and 30%-80% collision centrality. There is an indication of the breakdown of previously observed mass ordering between ϕ and proton v2 at low transverse momentum in the 0%-30% centrality range, possibly indicating late hadronic interactions affecting the proton v2.

Observation of Gravitational Waves from a Binary Black Hole Merger

On September 14, 2015 at 09:50:45 UTC the two detectors of the Laser Interferometer Gravitational-Wave Observatory simultaneously observed a transient gravitational-wave signal. The signal sweeps upwards in frequency from 35 to 250 Hz with a peak gravitational-wave strain of 1.0×10(-21). It matches the waveform predicted by general relativity for the inspiral and merger of a pair of black holes and the ringdown of the resulting single black hole. The signal was observed with a matched-filter signal-to-noise ratio of 24 and a false alarm rate estimated to be less than 1 event per 203,000 years, equivalent to a significance greater than 5.1σ. The source lies at a luminosity distance of 410(-180)(+160)  Mpc corresponding to a redshift z=0.09(-0.04)(+0.03). In the source frame, the initial black hole masses are 36(-4)(+5)M⊙ and 29(-4)(+4)M⊙, and the final black hole mass is 62(-4)(+4)M⊙, with 3.0(-0.5)(+0.5)M⊙c(2) radiated in gravitational waves. All uncertainties define 90% credible intervals. These observations demonstrate the existence of binary stellar-mass black hole systems. This is the first direct detection of gravitational waves and the first observation of a binary black hole merger.

Prospects for Observing and Localizing Gravitational-Wave Transients with Advanced LIGO and Advanced Virgo

We present a possible observing scenario for the Advanced LIGO and Advanced Virgo gravitational-wave detectors over the next decade, with the intention of providing information to the astronomy community to facilitate planning for multi-messenger astronomy with gravitational waves. We determine the expected sensitivity of the network to transient gravitational-wave signals, and study the capability of the network to determine the sky location of the source. We report our findings for gravitational-wave transients, with particular focus on gravitational-wave signals from the inspiral of binary neutron-star systems, which are considered the most promising for multi-messenger astronomy. The ability to localize the sources of the detected signals depends on the geographical distribution of the detectors and their relative sensitivity, and 90% credible regions can be as large as thousands of square degrees when only two sensitive detectors are operational. Determining the sky position of a significant fraction of detected signals to areas of 5 deg2 to 20 deg2 will require at least three detectors of sensitivity within a factor of ∼ 2 of each other and with a broad frequency bandwidth. Should the third LIGO detector be relocated to India as expected, a significant fraction of gravitational-wave signals will be localized to a few square degrees by gravitational-wave observations alone.

Observation of Transverse Spin-Dependent Azimuthal Correlations of Charged Pion Pairs in p^{↑}+p at sqrt[s]=200 GeV

We report the observation of transverse polarization-dependent azimuthal correlations in charged pion pair production with the STAR experiment in p^{↑}+p collisions at RHIC. These correlations directly probe quark transversity distributions. We measure signals in excess of 5 standard deviations at high transverse momenta, at high pseudorapidities η>0.5, and for pair masses around the mass of the ρ meson. This is the first direct transversity measurement in p+p collisions.

Azimuthal Anisotropy in U+U and Au+Au Collisions at RHIC

Collisions between prolate uranium nuclei are used to study how particle production and azimuthal anisotropies depend on initial geometry in heavy-ion collisions. We report the two- and four-particle cumulants, v_{2}{2} and v_{2}{4}, for charged hadrons from U+U collisions at sqrt[s_{NN}]=193  GeV and Au+Au collisions at sqrt[s_{NN}]=200  GeV. Nearly fully overlapping collisions are selected based on the energy deposited by spectators in zero degree calorimeters (ZDCs). Within this sample, the observed dependence of v_{2}{2} on multiplicity demonstrates that ZDC information combined with multiplicity can preferentially select different overlap configurations in U+U collisions. We also show that v_{2} vs multiplicity can be better described by models, such as gluon saturation or quark participant models, that eliminate the dependence of the multiplicity on the number of binary nucleon-nucleon collisions.

Three-dimensional charge density wave order in YBa2Cu3O6.67 at high magnetic fields

Charge density wave (CDW) correlations have been shown to universally exist in cuprate superconductors. However, their nature at high fields inferred from nuclear magnetic resonance is distinct from that measured with x-ray scattering at zero and low fields. We combined a pulsed magnet with an x-ray free-electron laser to characterize the CDW in YBa2Cu3O6.67 via x-ray scattering in fields of up to 28 tesla. While the zero-field CDW order, which develops at temperatures below ~150 kelvin, is essentially two dimensional, at lower temperature and beyond 15 tesla, another three-dimensionally ordered CDW emerges. The field-induced CDW appears around the zero-field superconducting transition temperature; in contrast, the incommensurate in-plane ordering vector is field-independent. This implies that the two forms of CDW and high-temperature superconductivity are intimately linked.

Dosimetric planning study for the prevention of anal complications after post-operative whole pelvic radiotherapy in cervical cancer patients with hemorrhoids

OBJECTIVE

Radiation-induced anal toxicity can be induced by low radiation doses in patients with haemorrhoids. The object of this study was to determine the dosimetric benefits of different whole pelvic radiotherapy (WPRT) techniques in terms of dose delivered to the anal canal in post-operative patients with cervical cancer.

METHODS

The planning CT images of 10 patients with cervical cancer undergoing postoperative radiotherapy were used for comparison of three different plans. All patients had been treated using the conventional box technique WPRT (CV-WPRT), and we tried low-margin-modified WPRT (LM-WPRT), three-dimensional conformal techniques WPRT (CF-WPRT) and intensity-modulated WPRT (IM-WPRT) planning for dosimetric comparison of the anal canal, retrospectively.

RESULTS

Mean anal canal doses of the IM-WPRT were significantly lower (p < 0.05) than those of CV-WPRT, LM-WPRT and CF-WPRT, and V10, V20, V30 and V40 to the anal canal were also significantly lower for IM-WPRT (p < 0.05). The proportion of planning target volumes (PTVs) that received ≥98% of the prescribed dose for all plans was >99%, and the proportion that received ≥108% of the prescribed dose for IM-WPRT was <2%. Volumes of bladders and rectums that received ≥30 or ≥40 Gy were significantly lower for IM-WPRT than for three of the four-field WPRT plans (p = 0.000).

CONCLUSION

IM-WPRT can significantly reduce radiation dose delivered to the anal canal and does not compromise PTV coverage. In patients with haemorrhoids, IM-WPRT may be of value for the prevention of anal complications.

ADVANCES IN KNOWLEDGE

Although tolerance of the anal canal tends to be ignored in patients undergoing post-operative WPRT, patients with haemorrhoids may suffer complications at low radiation doses. The present study shows IM-WPRT can be meaningful in these patients.

Precision Measurement of the Longitudinal Double-Spin Asymmetry for Inclusive Jet Production in Polarized Proton Collisions at sqrt[s]=200 GeV

We report a new measurement of the midrapidity inclusive jet longitudinal double-spin asymmetry, A_{LL}, in polarized pp collisions at center-of-mass energy sqrt[s]=200  GeV. The STAR data place stringent constraints on polarized parton distribution functions extracted at next-to-leading order from global analyses of inclusive deep-inelastic scattering (DIS), semi-inclusive DIS, and RHIC pp data. The measured asymmetries provide evidence at the 3σ level for positive gluon polarization in the Bjorken-x region x>0.05.

Impact of smoking on neurodegeneration and cerebrovascular disease markers in cognitively normal men

BACKGROUND AND PURPOSE

Smoking is a major risk factor for cognitive decline and dementia. However, the exact pathobiology of smoking remains unknown. The effects of smoking on cortical thickness as a biomarker of neurodegeneration or white matter hyperintensities and lacunes as biomarkers of cerebrovascular burden were concurrently evaluated.

METHODS

Our study included 977 cognitively normal men who visited a health promotion centre and underwent medical check-ups, including 3.0 T magnetic resonance imaging. Participants were categorized into never smoker, past smoker or current smoker groups and pack-years and the years of smoking cessation were used as continuous variables.

RESULTS

The current smoker group exhibited cortical thinning in frontal and temporo-parietal regions compared with the never smoker group. These effects were particularly prominent in smokers with a high cumulative exposure to smoking in the current smoker group. However, there was no association between smoking and the severity of white matter hyperintensity or number of lacunes.

CONCLUSION

Our findings indicate that smoking might impact on neurodegeneration rather than cerebrovascular burdens in cognitively normal men, suggesting that smoking might be an important modifiable risk factor for the development of Alzheimer's disease.

Acute anal toxicity after whole pelvic radiotherapy in patients with asymptomatic haemorrhoids: identification of dosimetric and patient factors

OBJECTIVE

Patients with asymptomatic haemorrhoids are known to be less tolerant of radiation doses lower than known tolerance doses. In the present study, the authors sought to identify the risk factors of acute haemorrhoid aggravation after whole pelvic radiotherapy (WPRT).

METHODS

The records of 33 patients with cervical, rectal or prostate cancer with asymptomatic haemorrhoids, which were confirmed by colonoscopy before the start of radiotherapy (RT), were reviewed. Acute anal symptoms, such as anal pain and bleeding, were observed up to 1 month after RT completion. Dosimetric and patient factors were analysed, and subgroup analyses were performed.

RESULTS

The median induction dose for acute anal symptoms was 34.1 Gy (range, 28.8-50.4 Gy). Post-operative treatment intent showed more acute anal toxicity of patient factors (p = 0.04). In subgroup analysis, post-operative treatment intent and concurrent chemoradiotherapy were found to be related to acute anal symptoms (p < 0.01). Of the dosimetric factors, V10 tended to be related to acute anal symptoms (p = 0.08).

CONCLUSION

This study indicates that asymptomatic haemorrhoid may deteriorate after low-dose radiation and that patient factors, such as treatment intent and concurrent chemotherapy, probably influence anal toxicity. In patients with asymptomatic haemorrhoids, WPRT requires careful dosimetry and clinical attention.

ADVANCES IN KNOWLEDGE

The tolerance of anal canal tends to be ignored in patients with pelvic cancer who are undergoing WPRT. However, patients with asymptomatic haemorrhoids may be troubled by low radiation doses, and further studies are required.

ΛΛ Correlation function in Au+Au collisions at √[S(NN)]=200 GeV

We present ΛΛ correlation measurements in heavy-ion collisions for Au+Au collisions at sqrt[s_{NN}]=200  GeV using the STAR experiment at the Relativistic Heavy-Ion Collider. The Lednický-Lyuboshitz analytical model has been used to fit the data to obtain a source size, a scattering length and an effective range. Implications of the measurement of the ΛΛ correlation function and interaction parameters for dihyperon searches are discussed.

Improved upper limits on the stochastic gravitational-wave background from 2009-2010 LIGO and Virgo data

Gravitational waves from a variety of sources are predicted to superpose to create a stochastic background. This background is expected to contain unique information from throughout the history of the Universe that is unavailable through standard electromagnetic observations, making its study of fundamental importance to understanding the evolution of the Universe. We carry out a search for the stochastic background with the latest data from the LIGO and Virgo detectors. Consistent with predictions from most stochastic gravitational-wave background models, the data display no evidence of a stochastic gravitational-wave signal. Assuming a gravitational-wave spectrum of Ω_{GW}(f)=Ω_{α}(f/f_{ref})^{α}, we place 95% confidence level upper limits on the energy density of the background in each of four frequency bands spanning 41.5-1726 Hz. In the frequency band of 41.5-169.25 Hz for a spectral index of α=0, we constrain the energy density of the stochastic background to be Ω_{GW}(f)<5.6×10^{-6}. For the 600-1000 Hz band, Ω_{GW}(f)<0.14(f/900  Hz)^{3}, a factor of 2.5 lower than the best previously reported upper limits. We find Ω_{GW}(f)<1.8×10^{-4} using a spectral index of zero for 170-600 Hz and Ω_{GW}(f)<1.0(f/1300  Hz)^{3} for 1000-1726 Hz, bands in which no previous direct limits have been placed. The limits in these four bands are the lowest direct measurements to date on the stochastic background. We discuss the implications of these results in light of the recent claim by the BICEP2 experiment of the possible evidence for inflationary gravitational waves.

Comparison of serum neutralization and enzyme-linked immunosorbent assay on sera from porcine epidemic diarrhea virus vaccinated pigs

BACKGROUND

Porcine epidemic diarrhea virus (PEDV) is an economically important pathogen of swine.

OBJECTIVE

Serum neutralization (SN) and enzyme-linked immunosorbent assay (ELISA) test results as well as the utility of spike proteins S1, S2, and S3 and entire nucleocapsid protein were compared.

ANIMALS AND METHODS

Serum samples from 400 pigs vaccinated against PEDV strain SM98P were collected from 78 farms in Korea. SN test and ELISA were performed to confirm the presence of antibodies. For prokaryotic expression of partial fragments of spike protein the size and location of S1, S2, and S3, and full nucleocapsid protein, polymerase chain reaction was performed using specific primers.

RESULTS

Comparison of these results demonstrated that there was a correlation between the SN and ELISA results. Sera with higher neutralizing activity also had higher IgG titer. The antibody profiling data presented the correlation of neutralizing activity with the level of spike protein antibody. In particular, the S3 region may have an important role in neutralizing activity.

CONCLUSIONS

We confirmed that the carboxy-terminal region that includes the endodomain of the S protein induced stronger neutralizing activity than the region that includes the ectodomain.

CLINICAL RELEVANCE

The region of the S protein may have a stronger neutralizing KPEDV-9 epitope and could be useful for the evaluation of future PEDV vaccine efficacy.

Evaluation of antibody response of killed and live vaccines against porcine epidemic diarrhea virus in a field study

BACKGROUND

Porcine epidemic diarrhea virus (PEDV) is an infectious, highly contagious virus, and is an etiological agent of acute entero-pathogenic diarrhea in swine.

OBJECTIVES

Evaluation of the antibody response of two types of PEDV vaccines is to be carried out.

ANIMALS AND METHODS

Sows were vaccinated with either live or killed commercial PEDV SM98 (GenBank: GU937797.1) vaccines. Four different groups of sows with five sows in each group were used in this study: the unvaccinated negative control group, the killed virus vaccination group with killed virus boosting (K/K), the live virus vaccinated group with live virus boosting (L/L), and the combination group vaccinated with live virus and subsequently boosted with killed vaccine (L/K). Sows were vaccinated intramuscularly twice at four and two weeks prior to farrowing with 2ml/head vaccine dose. Antibody titers in sow and piglet serum one week after farrowing and that in colostrum were compared by enzyme-linked immunosorbent assay (ELISA) and serum neutralization test.

RESULTS

Vaccination with K/K vaccine induced the highest level of IgG and IgA in sow serum, colostrum, and especially in piglet serum, with the lowest levels found in the L/L group. The major neutralizing activity was also found in the K/K group, particularly in colostrum, with piglets bearing higher neutralizing activity compared to sow sera. Among recombinant spike S1, S2, S3, and nucleocapsid N protein of PEDV, S3 protein presented the highest antibody level in the K/K group.

CONCLUSION

Killed PEDV SM98 vaccine induced higher antibody levels.

CLINICAL IMPORTANCE

This study clearly confirms that killed vaccine has induced higher antibody levels and may contribute to the design of future research and vaccine programs.

Observation of D0 meson nuclear modifications in Au+Au collisions at sqrt[s(NN)] = 200 GeV

We report the first measurement of charmed-hadron (D(0)) production via the hadronic decay channel (D(0) → K(-) + π(+)) in Au+Au collisions at sqrt[s(NN)] = 200 GeV with the STAR experiment. The charm production cross section per nucleon-nucleon collision at midrapidity scales with the number of binary collisions, N(bin), from p+p to central Au+Au collisions. The D(0) meson yields in central Au + Au collisions are strongly suppressed compared to those in p+p scaled by N(bin), for transverse momenta p(T) > 3 GeV/c, demonstrating significant energy loss of charm quarks in the hot and dense medium. An enhancement at intermediate p(T) is also observed. Model calculations including strong charm-medium interactions and coalescence hadronization describe our measurements.

Beam energy dependence of moments of the net-charge multiplicity distributions in Au+Au collisions at RHIC

We report the first measurements of the moments--mean (M), variance (σ(2)), skewness (S), and kurtosis (κ)--of the net-charge multiplicity distributions at midrapidity in Au+Au collisions at seven energies, ranging from sqrt[sNN]=7.7 to 200 GeV, as a part of the Beam Energy Scan program at RHIC. The moments are related to the thermodynamic susceptibilities of net charge, and are sensitive to the location of the QCD critical point. We compare the products of the moments, σ(2)/M, Sσ, and κσ(2), with the expectations from Poisson and negative binomial distributions (NBDs). The Sσ values deviate from the Poisson baseline and are close to the NBD baseline, while the κσ(2) values tend to lie between the two. Within the present uncertainties, our data do not show nonmonotonic behavior as a function of collision energy. These measurements provide a valuable tool to extract the freeze-out parameters in heavy-ion collisions by comparing with theoretical models.

Measurement of longitudinal spin asymmetries for weak boson production in polarized proton-proton collisions at RHIC

We report measurements of single- and double-spin asymmetries for W^{±} and Z/γ^{*} boson production in longitudinally polarized p+p collisions at sqrt[s]=510  GeV by the STAR experiment at RHIC. The asymmetries for W^{±} were measured as a function of the decay lepton pseudorapidity, which provides a theoretically clean probe of the proton's polarized quark distributions at the scale of the W mass. The results are compared to theoretical predictions, constrained by polarized deep inelastic scattering measurements, and show a preference for a sizable, positive up antiquark polarization in the range 0.05<x<0.2.

Beam-energy dependence of charge separation along the magnetic field in Au+Au collisions at RHIC

Local parity-odd domains are theorized to form inside a quark-gluon plasma which has been produced in high-energy heavy-ion collisions. The local parity-odd domains manifest themselves as charge separation along the magnetic field axis via the chiral magnetic effect. The experimental observation of charge separation has previously been reported for heavy-ion collisions at the top RHIC energies. In this Letter, we present the results of the beam-energy dependence of the charge correlations in Au+Au collisions at midrapidity for center-of-mass energies of 7.7, 11.5, 19.6, 27, 39, and 62.4 GeV from the STAR experiment. After background subtraction, the signal gradually reduces with decreased beam energy and tends to vanish by 7.7 GeV. This implies the dominance of hadronic interactions over partonic ones at lower collision energies.

Dielectron mass spectra from Au+Au collisions at √[s(NN)]=200 GeV

We report the STAR measurements of dielectron (e(+)e(-)) production at midrapidity (|y(ee)|<1) in Au+Au collisions at √[s(NN)]=200  GeV. The measurements are evaluated in different invariant mass regions with a focus on 0.30-0.76 (ρ-like), 0.76-0.80 (ω-like), and 0.98-1.05 (ϕ-like)   GeV/c(2). The spectrum in the ω-like and ϕ-like regions can be well described by the hadronic cocktail simulation. In the ρ-like region, however, the vacuum ρ spectral function cannot describe the shape of the dielectron excess. In this range, an enhancement of 1.77±0.11(stat)±0.24(syst)±0.33(cocktail) is determined with respect to the hadronic cocktail simulation that excludes the ρ meson. The excess yield in the ρ-like region increases with the number of collision participants faster than the ω and ϕ yields. Theoretical models with broadened ρ contributions through interactions with constituents in the hot QCD medium provide a consistent description of the dilepton mass spectra for the measurement presented here and the earlier data at the Super Proton Synchrotron energies.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Search for gravitational waves associated with γ-ray bursts detected by the interplanetary network

We present the results of a search for gravitational waves associated with 223 γ-ray bursts (GRBs) detected by the InterPlanetary Network (IPN) in 2005-2010 during LIGO's fifth and sixth science runs and Virgo's first, second, and third science runs. The IPN satellites provide accurate times of the bursts and sky localizations that vary significantly from degree scale to hundreds of square degrees. We search for both a well-modeled binary coalescence signal, the favored progenitor model for short GRBs, and for generic, unmodeled gravitational wave bursts. Both searches use the event time and sky localization to improve the gravitational wave search sensitivity as compared to corresponding all-time, all-sky searches. We find no evidence of a gravitational wave signal associated with any of the IPN GRBs in the sample, nor do we find evidence for a population of weak gravitational wave signals associated with the GRBs. For all IPN-detected GRBs, for which a sufficient duration of quality gravitational wave data are available, we place lower bounds on the distance to the source in accordance with an optimistic assumption of gravitational wave emission energy of 10(-2)M⊙c(2) at 150 Hz, and find a median of 13 Mpc. For the 27 short-hard GRBs we place 90% confidence exclusion distances to two source models: a binary neutron star coalescence, with a median distance of 12 Mpc, or the coalescence of a neutron star and black hole, with a median distance of 22 Mpc. Finally, we combine this search with previously published results to provide a population statement for GRB searches in first-generation LIGO and Virgo gravitational wave detectors and a resulting examination of prospects for the advanced gravitational wave detectors.

Beam-energy dependence of the directed flow of protons, antiprotons, and pions in Au+Au collisions

Rapidity-odd directed flow (v1) measurements for charged pions, protons, and antiprotons near midrapidity (y=0) are reported in sNN=7.7, 11.5, 19.6, 27, 39, 62.4, and 200 GeV Au+Au collisions as recorded by the STAR detector at the Relativistic Heavy Ion Collider. At intermediate impact parameters, the proton and net-proton slope parameter dv1/dy|y=0 shows a minimum between 11.5 and 19.6 GeV. In addition, the net-proton dv1/dy|y=0 changes sign twice between 7.7 and 39 GeV. The proton and net-proton results qualitatively resemble predictions of a hydrodynamic model with a first-order phase transition from hadronic matter to deconfined matter, and differ from hadronic transport calculations.

Constraints on cosmic strings from the LIGO-Virgo gravitational-wave detectors

Cosmic strings can give rise to a large variety of interesting astrophysical phenomena. Among them, powerful bursts of gravitational waves (GWs) produced by cusps are a promising observational signature. In this Letter we present a search for GWs from cosmic string cusps in data collected by the LIGO and Virgo gravitational wave detectors between 2005 and 2010, with over 625 days of live time. We find no evidence of GW signals from cosmic strings. From this result, we derive new constraints on cosmic string parameters, which complement and improve existing limits from previous searches for a stochastic background of GWs from cosmic microwave background measurements and pulsar timing data. In particular, if the size of loops is given by the gravitational backreaction scale, we place upper limits on the string tension Gμ below 10(-8) in some regions of the cosmic string parameter space.

Jet-hadron correlations in √[s(NN)]=200 GeV p+p and central Au+Au collisions

Azimuthal angular correlations of charged hadrons with respect to the axis of a reconstructed (trigger) jet in Au+Au and p+p collisions at √[s(NN)]=200  GeV in STAR are presented. The trigger jet population in Au+Au collisions is biased toward jets that have not interacted with the medium, allowing easier matching of jet energies between Au+Au and p+p collisions while enhancing medium effects on the recoil jet. The associated hadron yield of the recoil jet is significantly suppressed at high transverse momentum (pTassoc) and enhanced at low pTassoc in 0%-20% central Au+Au collisions compared to p+p collisions, which is indicative of medium-induced parton energy loss in ultrarelativistic heavy-ion collisions.

Energy dependence of moments of net-proton multiplicity distributions at RHIC

We report the beam energy (sqrt[sNN]=7.7-200  GeV) and collision centrality dependence of the mean (M), standard deviation (σ), skewness (S), and kurtosis (κ) of the net-proton multiplicity distributions in Au+Au collisions. The measurements are carried out by the STAR experiment at midrapidity (|y|<0.5) and within the transverse momentum range 0.4<pT<0.8  GeV/c in the first phase of the Beam Energy Scan program at the Relativistic Heavy Ion Collider. These measurements are important for understanding the quantum chromodynamic phase diagram. The products of the moments, Sσ and κσ2, are sensitive to the correlation length of the hot and dense medium created in the collisions and are related to the ratios of baryon number susceptibilities of corresponding orders. The products of moments are found to have values significantly below the Skellam expectation and close to expectations based on independent proton and antiproton production. The measurements are compared to a transport model calculation to understand the effect of acceptance and baryon number conservation and also to a hadron resonance gas model.

High-quality Si3N4 circuits as a platform for graphene-based nanophotonic devices

Hybrid circuits combining traditional nanophotonic components with carbon-based materials are emerging as a promising platform for optoelectronic devices. We demonstrate such circuits by integrating single-layer graphene films with silicon nitride waveguides as a new architecture for broadband optical operation. Using high-quality microring resonators and Mach-Zehnder interferometers with extinction ratios beyond 40 dB we realize flexible circuits for phase-sensitive detection on chip. Hybrid graphene-photonic devices are fabricated via mechanical transfer and lithographic structuring, allowing for prolonged light-matter interactions. Our approach holds promise for studying optical processes in low-dimensional physical systems and for realizing electrically tunable photonic circuits.

Mid-long term effect of non-ablative high radiofrequency therapy on the rabbit dermal extracellular matrix

This study quantitatively investigated the postoperative effects of radiofrequency (RF) application on the normal dermal extracellular matrix (ECM) of in vivo rabbits. Postoperative effects were evaluated by histology and atomic force microscopy analysis of dermal tissues treated using three RF energy levels (10 ~ 30 W) and either a single- or multiple-pass procedure. Progressive changes in the morphology of rabbit dermal ECMs were investigated over a 30-day postoperartive period. All RF-treated groups, except for the low energy group (10 W), displayed more prominent inflammatory responses compared to the control. This inflammatory reaction was more prominent a day after application. Dermal tissues 30 days after RF application exhibited prominent myofibroblast activity associated with ECM contractile activity during wound healing in addition to chronic inflammation. A decrease in the morphology of dermal ECMs after RF application continued until seven days postoperatively. The ECM diameter increased to near baseline at 30 days postoperatively. Low energy and multi-pass applications resulted in greater collagen fibril contraction and recovery at the ultra-structural level at 30 days postoperatively than did a single high energy application.

Cell patterning with mucin biopolymers

The precise spatial control of cell adhesion to surfaces is an endeavor that has enabled discoveries in cell biology and new possibilities in tissue engineering. The generation of cell-repellent surfaces currently requires advanced chemistry techniques and could be simplified. Here we show that mucins, glycoproteins of high structural and chemical complexity, spontaneously adsorb on hydrophobic substrates to form coatings that prevent the surface adhesion of mammalian epithelial cells, fibroblasts, and myoblasts. These mucin coatings can be patterned with micrometer precision using a microfluidic device, and are stable enough to support myoblast differentiation over seven days. Moreover, our data indicate that the cell-repellent effect is dependent on mucin-associated glycans because their removal results in a loss of effective cell-repulsion. Last, we show that a critical surface density of mucins, which is required to achieve cell-repulsion, is efficiently obtained on hydrophobic surfaces, but not on hydrophilic glass surfaces. However, this limitation can be overcome by coating glass with hydrophobic fluorosilane. We conclude that mucin biopolymers are attractive candidates to control cell adhesion on surfaces.

Antifungal effects of palmitic acid salt and ultrapure soft water on Scedosporium apiospermum

AIMS

Scedosporium apiospermum sometimes causes serious infectious diseases on the skin of immunodeficient subjects. Antifungal effects of fatty acid salts in soap against S. apiospermum were investigated under different water conditions.

METHODS AND RESULTS

Ultrapure soft water (UPSW) was generated by the water softener with cation-exchange resin. The calcium and magnesium ions were replaced with sodium ions in UPSW. Scedosporium apiospermum was incubated with different fatty acid salts that constituted soap in distilled water (DW), tap water (TW) and UPSW. After incubation, the number of fungi was counted. Among the fatty acids, palmitic acid salt (C16) reduced the number of S. apiospermum. UPSW enhanced the antifungal effect of C16 on S. apiospermum. The absence of both calcium and magnesium ions and the existence of sodium chloride in UPSW were responsible for its antifungal effect. In addition, repeated short-term treatment with UPSW and C16 decreased the number of S. apiospermum.

CONCLUSIONS

Antifungal effects of C16 on S. apiospermum were demonstrated. Moreover, the use of UPSW promoted the antifungal effect of C16.

SIGNIFICANCE AND IMPACT OF STUDY

This study provides the preventive method for diseases associated with S. apiospermum infection using novel palmitic acid soap in UPSW.