Measurement of Direct-Photon Cross Section and Double-Helicity Asymmetry at sqrt[s]=510 GeV in p[over →]+p[over →] Collisions.

We present measurements of the cross section and double-helicity asymmetry A_{LL} of direct-photon production in p[over →]+p[over →] collisions at sqrt[s]=510 GeV. The measurements have been performed at midrapidity (|η|<0.25) with the PHENIX detector at the Relativistic Heavy Ion Collider. At relativistic energies, direct photons are dominantly produced from the initial quark-gluon hard scattering and do not interact via the strong force at leading order. Therefore, at sqrt[s]=510 GeV, where leading-order-effects dominate, these measurements provide clean and direct access to the gluon helicity in the polarized proton in the gluon-momentum-fraction range 0.02

Erratum: Evolution of π

This corrects the article DOI: 10.1103/PhysRevLett.109.152301.

Beam Energy and Centrality Dependence of Direct-Photon Emission from Ultrarelativistic Heavy-Ion Collisions.

The PHENIX collaboration presents first measurements of low-momentum (0.41 GeV/c) direct-photon yield dN_{γ}^{dir}/dη is a smooth function of dN_{ch}/dη and can be well described as proportional to (dN_{ch}/dη)^{α} with α≈1.25. This scaling behavior holds for a wide range of beam energies at the Relativistic Heavy Ion Collider and the Large Hadron Collider, for centrality selected samples, as well as for different A+A collision systems. At a given beam energy, the scaling also holds for high p_{T} (>5 GeV/c), but when results from different collision energies are compared, an additional sqrt[s_{NN}]-dependent multiplicative factor is needed to describe the integrated-direct-photon yield.

Measurements of Elliptic and Triangular Flow in High-Multiplicity 3He+Au Collisions at √(s(NN))=200 GeV.

We present the first measurement of elliptic (v(2)) and triangular (v(3)) flow in high-multiplicity (3)He+Au collisions at √(s(NN))=200 GeV. Two-particle correlations, where the particles have a large separation in pseudorapidity, are compared in (3)He+Au and in p+p collisions and indicate that collective effects dominate the second and third Fourier components for the correlations observed in the (3)He+Au system. The collective behavior is quantified in terms of elliptic v(2) and triangular v(3) anisotropy coefficients measured with respect to their corresponding event planes. The v(2) values are comparable to those previously measured in d+Au collisions at the same nucleon-nucleon center-of-mass energy. Comparisons with various theoretical predictions are made, including to models where the hot spots created by the impact of the three (3)He nucleons on the Au nucleus expand hydrodynamically to generate the triangular flow. The agreement of these models with data may indicate the formation of low-viscosity quark-gluon plasma even in these small collision systems.

Measurement of Long-Range Angular Correlation and Quadrupole Anisotropy of Pions and (Anti)Protons in Central d+Au Collisions at sqrt[s_{NN}]=200 GeV.

We present azimuthal angular correlations between charged hadrons and energy deposited in calorimeter towers in central d+Au and minimum bias p+p collisions at sqrt[s_{NN}]=200 GeV. The charged hadron is measured at midrapidity |η|<0.35, and the energy is measured at large rapidity (-3.7<η<-3.1, Au-going direction). An enhanced near-side angular correlation across |Δη|>2.75 is observed in d+Au collisions. Using the event plane method applied to the Au-going energy distribution, we extract the anisotropy strength v_{2} for inclusive charged hadrons at midrapidity up to p_{T}=4.5 GeV/c. We also present the measurement of v_{2} for identified π^{±} and (anti)protons in central d+Au collisions, and observe a mass-ordering pattern similar to that seen in heavy-ion collisions. These results are compared with viscous hydrodynamic calculations and measurements from p+Pb at sqrt[s_{NN}]=5.02 TeV. The magnitude of the mass ordering in d+Au is found to be smaller than that in p+Pb collisions, which may indicate smaller radial flow in lower energy d+Au collisions.

Adaptive array technique for differential-phase reflectometry in QUEST.

A Phased Array Antenna (PAA) was considered as launching and receiving antennae in reflectometry to attain good directivity in its applied microwave range. A well-focused beam was obtained in a launching antenna application, and differential-phase evolution was properly measured by using a metal reflector plate in the proof-of-principle experiment at low power test facilities. Differential-phase evolution was also evaluated by using the PAA in the Q-shu University Experiment with Steady State Spherical Tokamak (QUEST). A beam-forming technique was applied in receiving phased-array antenna measurements. In the QUEST device that should be considered as a large oversized cavity, standing wave effect was significantly observed with perturbed phase evolution. A new approach using derivative of measured field on propagating wavenumber was proposed to eliminate the standing wave effect.

Thermal imaging of plasma with a phased array antenna in QUEST.

A thermal imaging system to measure plasma Electron Bernstein Emission (EBE) emanating from the mode conversion region in overdense plasma is discussed. Unlike conventional ECE/EBE imaging, this diagnostics does not employ any active mechanical scanning mirrors or focusing optics to scan for the emission cones in plasma. Instead, a standard 3 × 3 waveguide array antenna is used as a passive receiver to collect emission from plasma and imaging reconstruction is done by accurate measurements of phase and intensity of these signals by heterodyne detection technique. A broadband noise source simulating the EBE, is installed near the expected mode conversion region and its position is successfully reconstructed using phase array technique which is done in post processing.

Cold-nuclear-matter effects on heavy-quark production at forward and backward rapidity in d + Au collisions at √sNN = 200 GeV.

The PHENIX experiment has measured open heavy-flavor production via semileptonic decay over the transverse momentum range 1 < p(T) < 6 GeV/c at forward and backward rapidity (1.4 < |y| < 2.0) in d+Au and p + p collisions at √sNN = 200 GeV. In central d+Au collisions, relative to the yield in p + p collisions scaled by the number of binary nucleon-nucleon collisions, a suppression is observed at forward rapidity (in the d-going direction) and an enhancement at backward rapidity (in the Au-going direction). Predictions using nuclear-modified-parton-distribution functions, even with additional nuclear-p(T) broadening, cannot simultaneously reproduce the data at both rapidity ranges, which implies that these models are incomplete and suggests the possible importance of final-state interactions in the asymmetric d + Au collision system. These results can be used to probe cold-nuclear-matter effects, which may significantly affect heavy-quark production, in addition to helping constrain the magnitude of charmonia-breakup effects in nuclear matter.

Medium modification of jet fragmentation in Au+Au collisions at √[s(NN)]=200 GeV measured in direct photon-hadron correlations.

The jet fragmentation function is measured with direct photon-hadron correlations in p+p and Au+Au collisions at √[s(NN)]=200 GeV. The p(T) of the photon is an excellent approximation to the initial p(T) of the jet and the ratio z(T)=p(T)(h)/p(T)(γ) is used as a proxy for the jet fragmentation function. A statistical subtraction is used to extract the direct photon-hadron yields in Au+Au collisions while a photon isolation cut is applied in p+p. I(AA), the ratio of hadron yield opposite the photon in Au+Au to that in p+p, indicates modification of the jet fragmentation function. Suppression, most likely due to energy loss in the medium, is seen at high z(T). The associated hadron yield at low z(T) is enhanced at large angles. Such a trend is expected from redistribution of the lost energy into increased production of low-momentum particles.

Evolution of π(0) suppression in Au+Au collisions from √(s(NN))=39 to 200 GeV.

Neutral-pion π(0) spectra were measured at midrapidity (|y|<0.35) in Au+Au collisions at √(s(NN))=39 and 62.4 GeV and compared with earlier measurements at 200 GeV in a transverse-momentum range of 1

Observation of interface carrier states in no-common-atom heterostructures ZnSe/BeTe.

The existence of intrinsic carrier interface states in heterostructures with no common atom at the interface (such as ZnSe/BeTe) is shown experimentally by ellipsometry and photoluminescence spectroscopy. These states are located on interfaces and lie inside the effective bandgap of the structure; they are characterized by a high density and a long lifetime. A tight binding model confirms theoretically the existence of these states in ZnSe/BeTe heterostructures for a ZnTe-type interface, in contrast to the case of the BeSe-type interface for which they do not exist.

Cross section and parity-violating spin asymmetries of W± boson production in polarized p + p collisions at sqrt[s] = 500 GeV.

Large parity-violating longitudinal single-spin asymmetries A(L)(e+) = -0.86(-0.14) (+0.30) and A(L)(e-) = 0.88(-0.71) (+0.12) are observed for inclusive high transverse momentum electrons and positrons in polarized p+p collisions at a center-of-mass energy of sqrt[s] = 500 GeV with the PHENIX detector at RHIC. These e± come mainly from the decay of W± and Z0 bosons, and their asymmetries directly demonstrate parity violation in the couplings of the W± to the light quarks. The observed electron and positron yields were used to estimate W± boson production cross sections for the e± channels of σ(pp → W+ X) × BR(W+ → e+ ν(e)) = 144.1 ± 21.2(stat)(-10.3) (+3.4) (syst) ± 21.6(norm) pb, and σ(pp → W- X) × BR(W- → e- ν[over ¯](e)) = 31.7 ± 12.1(stat)(-8.2) (+10.1) (syst) ± 4.8(norm) pb.

Midrapidity antiproton-to-proton ratio in pp collisons at sqrt[s]=0.9 and 7 TeV measured by the ALICE experiment.

The ratio of the yields of antiprotons to protons in pp collisions has been measured by the ALICE experiment at sqrt[s]=0.9 and 7 TeV during the initial running periods of the Large Hadron Collider. The measurement covers the transverse momentum interval 0.45

Low-saturation-energy-driven ultrafast all-optical switching operation in (CdS/ZnSe)/BeTe intersubband transition.

The authors report their latest results on II-VI intersubband all-optical switches in which the 10 dB absorption saturation energy is lowered to ~2.0-2.2 pJ for 1.55-1.58 mum by decreasing the thickness of the active layer and increasing the refractive index difference between the core layer and the cladding layers in waveguides. Such low saturation energies greatly improve the switching performance. <7 pJ pump energy at 1520 nm is sufficient for realizing 10 dB switching operation at 1566 nm (switching energy: ~0.7 pJ/dB). To the best of our knowledge, these switching energy and saturation energy values are the lowest reported ones for such ultrafast intersubband all-optical switches at telecommunication wavelengths.

Acquired and congenital cholesteatoma: determination of tumor necrosis factor-alpha, intercellular adhesion molecule-1, interleukin-1-alpha and lymphocyte functional antigen-1 in the inflammatory process.

The molecular and cellular factors resulting in the pathologic features of acquired and congenital cholesteatomas are not completely known. Recently, proinflammatory cytokines like interleukin-1 alpha (IL-1 alpha) and tumor necrosis factor-alpha (TNF-alpha) have been shown to induce bone resorption, in vitro. To elucidate the key molecules involved in bone resorption and cell infiltration associated with cholesteatoma, we examined the in vivo levels of IL-1 alpha and TNF-alpha, intercellular adhesion molecule-1 (ICAM-1) and lymphocyte functional antigen-1 (LFA-1) in acquired and congenital cholesteatomas, by reverse transcriptase-polymerase chain reaction, immunohistochemistry, and ELISA. Increased levels of IL-1 and TNF-alpha were detected in both types of cholesteatomas as compared to normal skin. Increased ICAM-1 expression and LFA-1+ cells were detected in acquired but not congenital cholesteatoma. Strong correlation was detected between TNF-alpha and bone resorption in both types of cholesteatoma, and between TNF-alpha and ICAM, TNF-alpha and severity of infection, or cell infiltration in acquired cholesteatoma. No correlation existed between various parameters and IL-1 alpha. These results suggest that TNF-alpha may play a crucial role in the pathogenesis of both acquired and congenital cholesteatomas by regulating bone resorption and cell infiltration.

Anomalous union of the pancreaticobiliary ductal system without dilation of the common bile duct or tumor: case reports and literature review.

Among 698 patients subjected to endoscopic retrograde cholangiopancreatography, an anomalous union of the pancreaticobiliary ductal system (AUPBD) was found in 6 patients (0.9%). One of these 6 patients had an associated congenital choledochal cyst, and 4 did not. Two of these 4 patients, however, had advanced gallbladder cancer. The remaining 2 patients had no associated carcinoma of the biliary tract. A clinicopathological study was performed on these 2 patients and 26 such cases have been reported in the literature. The diagnosis of AUPBD was made by direct cholangiography. Regarding the type of union, the Pancreatic-Biliary type was present in 15 of 18 (83.3%) of these patients. Fifteen of 28 patients (53.6%) had right upper abdominal pain. Thickness of the gallbladder wall was visualized in 26 of the 28 (92.9%) patients. Gallstones were present in 4 (14.3%). AUPBD should always be kept in mind when a patient with abdominal pain is diagnosed as having gallbladder wall thickness without gallstones. ERCP should be performed in these patients in order to detect AUPBD without dilation of the bile duct. This may allow early detection of carcinoma of the biliary tract.

Systemic and local toxicity in the rat of methyl tert-butyl ether: a gallstone dissolution agent.

Methyl tert-butyl ether (MTBE) is an organic solvent that has been used to dissolve gallstones via a percutaneous transhepatic catheter into the gallbladder. To test whether MTBE might cause serious tissue injury if accidentally infused outside the gallbladder, the effect of MTBE (0.2 ml/kg) injected into the hepatic parenchyma, or administered intravenously or intraperitoneally, was examined in the rat. The toxicity of isopropyl acetate (IPA), an organic solvent with a similar chemical structure, was examined similarly. Intracaval injection of MTBE caused the highest mortality (100%). Mortality was less (59%) after intrahepatic injection and still less (17%) after peripheral vein injection. Most animals died instantaneously from cardiorespiratory arrest. Almost all animals that were injected with MTBE intrahepatically or intravenously showed localized areas of congestion, hemorrhage, and interstitial edema in the lungs. These changes were more severe in rats which survived for 24 hr than in those which died sooner. In those rats receiving intrahepatic injections, most rats which survived for 24 hr had liver necrosis at the site of injection. Intraperitoneal injection of MTBE produced 100% survival with only 1/5 rats showing a mild pulmonary injury at autopsy. IPA had toxic effects similar to those evoked by MTBE. To test whether tumor necrosis factor was involved in organ injury, serum levels were measured; they remained unchanged. These experiments indicate that two organic solvents, MTBE and IPA, are cytotoxic to local tissues and cause severe, and often fatal, lung damage when infused into a central vein. Less toxicity occurred if solvents were given into a peripheral or portal vein or intraperitoneally.(ABSTRACT TRUNCATED AT 250 WORDS)

Recovery and hypersecretion of insulin and reversal of insulin resistance after withdrawal of short-term cyclosporine treatment.

We have previously demonstrated decreased insulin release and insulin resistance in dogs treated with cyclosporine (20 mg/kg/day). In this study we examine the changes caused by a lower CsA dose and evaluate the reversal of these changes. Six animals were treated for 2 weeks with oral CsA (15 mg/kg/day), after which CsA was discontinued. Glucagon stimulation tests (GST) and euglycemic clamp studies (ECS) were used to evaluate changes in insulin release and insulin resistance. GST were performed before CsA, after 2 weeks of CsA, and 3, 9, and 15 days after discontinuing CsA. ECS were performed before CsA, after 2 weeks of CsA, and 2, 4, 8, and 14 days after discontinuing CsA. The mean serum CsA level after 2 weeks of treatment was 188 +/- 28 ng/ml. GST demonstrated decreased insulin release during CsA with recovery and hypersecretion after CsA withdrawal. ECS showed peripheral insulin resistance during CsA with a rapid recovery and a temporary increase in insulin sensitivity after CsA withdrawal. Comparisons were made with our previous study group given 20 mg/kg/day of CsA. In summary, CsA induces a dose-dependent impairment of glucose homeostasis due to inhibition of insulin release and development of peripheral insulin resistance. Withdrawal of short-term CsA at commonly used therapeutic doses results in reversal of and temporary overcompensation for these changes. CsA withdrawal after long-term treatment results in a slower normalization of the insulin response as compared with after short-term treatment. The hypersecretory reaction of the beta cell may be of help in further investigations of mechanisms of CsA- and FK506-induced inhibition of insulin release.

Annual changes in levels of plasma LH and size of cloacal protrusion in Japanese quail (Coturnix coturnix japonica) housed in outdoor cages under natural conditions.

Japanese quail of the strain used in our laboratory do not show a complete decrease in levels of circulating luteinizing hormone (LH) concentrations and show no collapse of the testes following their transfer from long to short days under laboratory conditions. Thus, merely manipulating photoperiods in the laboratory does not simulate an annual breeding cycle. To see whether an annual breeding cycle does exist in "our" quail under natural conditions, mature male birds were housed in individual cages and placed on the roof of a building at 35 degrees 45'N, 139 degrees 53'E; day length and ambient temperature were not controlled at all though food and water were continuously supplied. For 16 months blood was collected every week and the area of the cloacal protrusion measured at the time of each blood collection. The results showed that levels of plasma LH and the area of the cloacal protrusion had a clear annual cycle under the natural conditions. To detect more precisely the changes in circulating LH concentrations during spring and autumn, samples were collected every other day. The first significant increase in levels of plasma LH was found when the day length exceeded 12-12.5 hr, though the increase was sporadic and not synchronized among individuals. The results also showed that circulating levels of LH declined significantly in early September starting when the day length was still about 14 hr; this downward trend continued rather steadily to nonbreeding levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Inhibition of insulin release by cyclosporine and production of peripheral insulin resistance in the dog.

Cyclosporine has been shown to cause glucose intolerance in both humans and animals. This can result from alterations in insulin release, insulin metabolism, the sensitivity of peripheral or hepatic tissues to insulin, or a combination of these factors. The present study was designed to simultaneously evaluate the effect of CsA on these variables. A group of chronically catheterized dogs were administered oral CsA (20 mg/kg/day) for a period of 10 weeks. The glucagon stimulation test (GST) and the euglycemic glucose clamp technique, using a primed continuous infusion of 3H-3-glucose and a continuous insulin infusion (0.8 mU/kg/min), were employed to evaluate pancreatic insulin release, peripheral glucose disposal rate (Rd), hepatic glucose output (HGO), and metabolic clearance rate (MCR) of insulin. The dogs were tested before and after 2, 6, and 10 weeks of CsA administration. Serum CsA levels were 358 +/- 85, 244 +/- 48, and 355 +/- 81 ng/ml at 2, 6, and 10 weeks, respectively (P = NS). Elevated fasting glucose and an abnormal glucose response to an i.v. bolus of glucagon (0.25 U) were noted after 2, 6, and 10 weeks of CsA administration. The areas under the glucose curve (AUCG) for 0-60 min were 9605 +/- 773, 11634 +/- 1226, 12380 +/- 719, and 12626 +/- 1560 mg/min/dl at 0, 2, 6, and 10 weeks, P(F3, 15 = 5.1) = 0.012, demonstrating a CsA-induced disturbance of glucose homeostasis. The areas under the insulin curve (AUCI) for 0-20 min of the insulin response curve were 2033 +/- 203, 1089 +/- 187, 1038 +/- 179, and 972 +/- 161 uU/min/dl at 0, 2, 6, and 10 weeks, P(F3, 15 = 13.1) less than 0.001, indicating a 50% reduction during CsA treatment. CsA did not affect basal Rd, but peripheral insulin resistance was noted in the insulin-stimulated state. Rd during the third hour of the insulin infusion decreased from 6.72 +/- 0.69 to 4.42 +/- 0.44, 5.02 +/- 0.64, 4.47 +/- 0.52 mg/kg/min at 0, 2, 6, and 10 weeks, respectively, P(F3, 15 = 6.94) less than 0.004. HGO suppression by insulin and MCR of insulin were not altered by CsA. Similarly, glucagon secretion did not appear to be influenced by CsA. In conclusion, this study has simultaneously evaluated the effect of CsA on several aspects of glucose and insulin metabolism in the dog. CsA administration produces abnormal glucose homeostasis by reducing pancreatic insulin release, in addition to inducing peripheral insulin resistance.(ABSTRACT TRUNCATED AT 400 WORDS)