Azimuthal anisotropy of π⁰ production in Au+Au collisions at sqrt((s)NN)=200 GeV: path-length dependence of jet quenching and the role of initial geometry

We have measured the azimuthal anisotropy of π⁰ production for 1<p(T)<18  GeV/c for Au+Au collisions at sqrt((s)NN)=200  GeV. The observed anisotropy shows a gradual decrease for 3≲p(T)≲7-10  GeV/c, but remains positive beyond 10  GeV/c. The magnitude of this anisotropy is underpredicted, up to at least ∼10  GeV/c, by current perturbative QCD (PQCD) energy-loss model calculations. An estimate of the increase in anisotropy expected from initial-geometry modification due to gluon saturation effects and fluctuations is insufficient to account for this discrepancy. Calculations that implement a path-length dependence steeper than what is implied by current PQCD energy-loss models show reasonable agreement with the data.

Elliptic and hexadecapole flow of charged hadrons in Au+Au collisions at sq.rt(s(NN))=200 GeV

Differential measurements of the elliptic (v(2)) and hexadecapole (v(4)) Fourier flow coefficients are reported for charged hadrons as a function of transverse momentum (p(T)) and collision centrality or number of participant nucleons (N(part)) for Au+Au collisions at sq.rt(s(NN))=200  GeV. The v(2,4) measurements at pseudorapidity |η|≤0.35, obtained with four separate reaction-plane detectors positioned in the range 1.0<|η|<3.9, show good agreement, indicating the absence of significant Δη-dependent nonflow correlations. Sizable values for v(4)(p(T)) are observed with a ratio v(4)(p(T),N(part))/v(2)(2)(p(T),N(part))≈0.8 for 50≲N(part)≲200, which is compatible with the combined effects of a finite viscosity and initial eccentricity fluctuations. For N(part)≳200 this ratio increases up to 1.7 in the most central collisions.

Transition in yield and azimuthal shape modification in dihadron correlations in relativistic heavy ion collisions

Hard-scattered parton probes produced in collisions of large nuclei indicate large partonic energy loss, possibly with collective produced-medium response to the lost energy. We present measurements of π^{0} trigger particles at transverse momenta p{T}{t}=4-12  GeV/c and associated charged hadrons (p{T}{a}=0.5-7  GeV/c) vs relative azimuthal angle Δϕ in Au+Au and p+p collisions at sqrt[s{NN}]=200  GeV. The Au+Au distribution at low p{T}{a}, whose shape has been interpreted as a medium effect, is modified for p{T}{t}<7  GeV/c. At higher p{T}{t}, the data are consistent with unmodified or very weakly modified shapes, even for the lowest measured p{T}{a}, which quantitatively challenges some medium response models. The associated yield of hadrons opposing the trigger particle in Au+Au relative to p+p (I{AA}) is suppressed at high p{T} (I{AA}≈0.35-0.5), but less than for inclusive suppression (R{AA}≈0.2).

Enhanced production of direct photons in Au + Au collisions at square root(S(NN)) = 200 GeV and implications for the initial temperature

The production of e+ e- pairs for m(e+ e-)<0.3 GeV/c2 and 1<p(T)<5 GeV/c is measured in p+p and Au+Au collisions at square root(S(NN))=200 GeV. An enhanced yield above hadronic sources is observed. Treating the excess as photon internal conversions, the invariant yield of direct photons is deduced. In central Au+Au collisions, the excess of the direct photon yield over p+p is exponential in transverse momentum, with an inverse slope T=221+/-19(stat)+/-19(syst) MeV. Hydrodynamical models with initial temperatures ranging from T(init) approximately 300-600 MeV at times of approximately 0.6-0.15 fm/c after the collision are in qualitative agreement with the data. Lattice QCD predicts a phase transition to quark gluon plasma at approximately 170 MeV.

Supraphysiological levels of IL-15 accelerate immune reconstitution in lymphopenic mice (134.16)

Loss of lymphocytes and T cells are a significant medical problem in AIDS and other immunodeficiencies, as well as after various treatments and cytoreductive therapies. T cell recovery after lymphopenia is delayed and incomplete and this can lead to prolonged immune dysfunctions. Lymphoablated patients have rapid and transient increases of circulating homeostatic cytokines IL-7 and IL-15, suggesting a role for these factors in immune reconstitution. Analysis of sera from lymphoablated patients revealed that the main form of circulating IL-15 is in a complex with soluble IL-15Rα (IL-15sRα). We have shown that injection of DNA expressing supraphysiological levels of IL-15/IL-15sRα in normal mice led to dose-dependent increases in the number and frequency of NK and T cells. The effect of IL-15/IL-15sRα on immune reconstitution was tested in mice lymphodepleted by cyclophosphamide (CTX) treatment. A single administration of IL-15/IL-15sRα DNA accelerates the full recovery of NK cells in spleen and lung. Two administrations of IL-15/IL-15sRα DNA promote the recovery of T cells in spleen within 14 days, faster than CTX-treated mice (p=0.017 Wilcoxon). T and NK cells from mice treated with supraphysiological levels of IL-15/IL-15sRα show greater degranulation and IFN-γ production after in vitro stimulation. These results suggest that IL-15 can contribute to rapid immune reconstitution, and suggest the use of IL-15/IL-15sRα to accelerate recovery from lymphopenia.

Hydrogeological studies for radiological monitoring of shallow groundwater in the Eurex plant of Saluggia (Vercelli, Italy)

In 2004, contaminated water was found inside the safety interspace around the spent fuel pool; therefore, an ample monitoring programme of the structure, soils and shallow groundwater was started in order to detect any radioactive leakage into the environment. A first group of piezometers was installed. In the one nearest to the pool, an anomalous activity of (90)Sr ( approximately 10(-2) Bq l(-1)) was found, calling for the following actions: gradual enlarging of the monitoring network, implementation of in situ permeability tests and groundwater tracer test and study of groundwater mobility of the main radionuclides contained in the pool water: (90)Sr, (137)Cs, (241)Am and (239/240)Pu. Because (90)Sr is the only artificial radionuclide detected in groundwater, this study mainly focused on this one. All the investigations demonstrated that (90)Sr coming from the pool is not detectable any longer just some tens of metres from the building and allow the correlation of (90)Sr concentration to flow and water-table fluctuations. Moreover, such a wide mass of hydrogeological and radiological data allows the estimation of an environmental value for environmental radiological significance.

Distribution, persistence, and efficacy of adoptively transferred central and effector memory-derived autologous simian immunodeficiency virus-specific CD8+ T cell clones in rhesus macaques during acute infection

Plasma viremia decreases coincident with the appearance of virus-specific CD8(+) T cells during acute HIV or SIV infection. This finding, along with demonstrations of viral mutational escape from CD8(+) T cell responses and transient increase in plasma viremia after depletion of CD8(+) T cells in SIV-infected monkeys strongly suggest a role for CD8(+) T cells in controlling HIV/SIV. However, direct quantitative or qualitative correlates between CD8(+) T cell activity and virus control have not been established. To directly assess the impact of large numbers of virus-specific CD8(+) T cells present at time of SIV infection, we transferred in vitro expanded autologous central and effector memory-derived Gag CM9-, Nef YY9-, and Vif WY8-specific CD8(+) T cell clones to acutely infected rhesus macaques. The cells persisted in PBMCs between 4 and 9 d, but were not detected in gut-associated lymphoid tissue or lymph nodes. Interestingly, a high frequency of the infused cells localized to the lungs, where they persisted at high frequency for >6 wk. Although persisting cells in the lungs were Ag reactive, there was no measurable effect on virus load. Sequencing of virus from the animal receiving Nef YY9-specific CD8(+) T cells demonstrated an escape mutation in this epitope <3 wk postinfection, consistent with immune selection pressure by the infused cells. These studies establish methods for adoptive transfer of autologous SIV-specific CD8(+) T cells for evaluating immune control during acute infection and demonstrate that infused cells retain function and persist for at least 2 mo in specific tissues.

Charged Kaon interferometric probes of space-time evolution in Au+Au collisions at sqrt[S(NN)]=200 GeV

Bose-Einstein correlations of charged kaons are used to probe Au+Au collisions at sqrt[S(NN)]=200 GeV and are compared to charged pion probes, which have a larger hadronic scattering cross section. Three-dimensional Gaussian source radii are extracted, along with a one-dimensional kaon emission source function. The centrality dependences of the three Gaussian radii are well described by a single linear function of N(part)1/3 with a zero intercept. Imaging analysis shows a deviation from a Gaussian tail at r greater than or approximately equal to 10 fm, although the bulk emission at lower radius is well described by a Gaussian. The presence of a non-Gaussian tail in the kaon source reaffirms that the particle emission region in a heavy-ion collision is extended, and that similar measurements with pions are not solely due to the decay of long-lived resonances.

Secretion and biological activity of short signal peptide IL-15 is chaperoned by IL-15 receptor alpha in vivo

The two known isoforms of IL-15 contain either a long signal peptide (LSP) or a short signal peptide (SSP), and are produced by alternatively spliced transcripts. It has been proposed that SSP IL-15 remains exclusively intracellular, and its function is unclear. In this study, we show that, similar to LSP IL-15, the SSP IL-15 is stabilized and secreted efficiently upon coexpression of IL-15Ralpha. Coinjection of SSP IL-15- and IL-15Ralpha-expressing plasmids into mice resulted in increased plasma levels of bioactive heterodimeric IL-15 and mobilization and expansion of NK and T cells. Therefore, SSP IL-15 is secreted and bioactive when produced as a heterodimer with IL-15Ralpha in the same cell. The apparent t(1/2) of this heterodimer is lower compared with LSP IL-15/IL-15Ralpha, due to different intracellular processing. Coexpression of both LSP IL-15 and SSP IL-15 in the presence of IL-15Ralpha results in lower levels of bioactive IL-15, indicating that LSP and SSP IL-15 compete for the binding to IL-15Ralpha when expressed in the same cell. Because the SSP IL-15 interaction to IL-15Ralpha leads to a complex with lower apparent stability, SSP IL-15 functions as competitive inhibitor of LSP IL-15. The data suggest that usage of alternative splicing is an additional level of control of IL-15 activity. Expression of both SSP and LSP forms of IL-15 appears to be conserved in many mammals, suggesting that SSP may be important for expressing a form of IL-15 with lower magnitude or duration of biological effects.

Measurement of bottom versus charm as a function of transverse momentum with electron-hadron correlations in p + p collisions at square root of s = 200 GeV

The momentum distribution of electrons from semileptonic decays of charm and bottom quarks for midrapidity |y|<0.35 in p+p collisions at square root of s=200 GeV is measured by the PHENIX experiment at the Relativistic Heavy Ion Collider over the transverse momentum range 2<pT<7 GeV/c. The ratio of the yield of electrons from bottom to that from charm is presented. The ratio is determined using partial D/D-->e(+/-)K(-/+)X (K unidentified) reconstruction. It is found that the yield of electrons from bottom becomes significant above 4 GeV/c in pT. A fixed-order-plus-next-to-leading-log perturbative quantum chromodynamics calculation agrees with the data within the theoretical and experimental uncertainties. The extracted total bottom production cross section at this energy is sigma(bb)=3.2(-1.1)(+1.2)(stat)(-1.3)(+1.4)(syst)mub.

Comparison of DNA vaccines producing HIV-1 Gag and LAMP/Gag chimera in rhesus macaques reveals antigen-specific T-cell responses with distinct phenotypes

Optimized DNA expression vectors encoding the native HIV-1 Gag or a fusion of Gag with the lysosomal membrane associated protein 1 (LAMP) were compared for immunogenicity upon intramuscular DNA delivery in rhesus macaques. Both vaccines elicited CD4(+) T-cell responses, but with significant differences in the phenotype of the Gag-specific cells: the native Gag induced CD4(+) responses with a phenotype of central memory-like T cells (CD28(+) CD45RA(-)), whereas the LAMP/Gag chimera induced CD4(+) responses with effector memory phenotype (CD28(-) CD45RA(-)). Antigen-specific T cells producing both IFN-gamma and TNFalpha were found in the animals receiving the native Gag, whereas the LAMP/Gag chimera induced humoral responses faster. These results demonstrate that modification of intracellular Gag trafficking results in the induction of distinct immune responses. Combinations of DNA vectors encoding both forms of antigen may be more potent in eliciting anti-HIV-1 immunity.

Gluon-spin contribution to the proton spin from the double-helicity asymmetry in inclusive pi0 production in polarized p+p collisions at [sqrt]s=200 GeV

The double helicity asymmetry in neutral pion production for pT=1 to 12 GeV/c was measured with the PHENIX experiment to access the gluon-spin contribution, DeltaG, to the proton spin. Measured asymmetries are consistent with zero, and at a theory scale of micro2=4 GeV2 a next to leading order QCD analysis gives DeltaG[0.02,0.3]=0.2, with a constraint of -0.7<DeltaG[0.02,0.3]<0.5 at Deltachi2=9 (approximately 3sigma) for the sampled gluon momentum fraction (x) range, 0.02 to 0.3. The results are obtained using predictions for the measured asymmetries generated from four representative fits to polarized deep inelastic scattering data. We also consider the dependence of the DeltaG constraint on the choice of the theoretical scale, a dominant uncertainty in these predictions.

Effect of six courses of neoadjuvant chemotherapy on pathological complete remission in advanced ovarian cancer

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Background: The role and the duration of NACT in ovarian cancer are debated. A randomized trial comparing upfront surgery versus 3 courses of NACT (Vergote 2008) demonstrated similar survival, but less morbidity in favor of NACT. However, pathological complete remissions (pCR) were rare and 68% of pts still had lesions greater than 2 cm after 3 courses of NACT. The rate of pCR correlates with a better survival in other tumors, such as breast cancer, and its rate is higher after 6–8 courses of NACT. We conducted this study to verify the incidence of optimal pathological remission after 6 courses of NACT. Methods: Eligible pts had stage IIIC-IV EOC unsuitable for optimal upfront surgery and were treated with 6 cycles of carboplatin AUC 5 and paclitaxel 175 mg/sm, every 3 weeks before surgery. We considered as optimal pathological responders: 1) the pts with absence of cancer cells in surgical specimens, and 2) the pts with no macroscopic residual after surgery and with only small clusters or individual cancer cells in surgical specimens. All the other cases were considered as pathological nonresponders, even if a relevant shrinkage of tumor burden and an optimal surgical debulking were obtained. Results: 35 stage IIIC/IV pts were enrolled; 33 (94%) completed 6 courses of NACT. We observed 18 (51%) pathological responders, and 17 pathological nonresponders (as defined above). Overall, in 20 (57%) pts the goal of no residual tumor after surgery was achieved. After a median follow-up of 21 mo.s, 21 pts progressed (median PFS 15 mo.s) and 10 pts died. As expected, pts with tumor residual after surgery less than 1 cm survived significantly longer than patients with a greater residual (p .0005). The median overall survival was longer in pathological responders (median not reached) vs nonresponders (19.8 mo.s) (p.03). Conclusions: In our study an optimal pathological response occurred in 51% of cases after 6 cycles of carboplatin-paclitaxel, doubling the results described in the literature with 3 courses of NACT. Given that an optimal pathological response correlates with a longer survival compared to a sub-optimal one, a randomized study of 6 vs 3 courses of NACT in order to verify if the increase in pathological response rate will translate into a survival benefit is warranted.

No significant financial relationships to disclose.

IL-15 Receptor alpha increases the stability and promotes secretion and bioactivity of the short signal peptide variant of IL-15 (38.3)

Two isoforms of interleukin-15 (IL-15) are known, containing a long signal peptide (LSP) or a short signal peptide (SSP), respectively. The two forms are produced by alternatively spliced mRNAs. It has been proposed that SSP IL-15 remains exclusively intracellular and its function is not known. We show that, similar to LSP IL-15, SSP IL-15 is stabilized and secreted efficiently upon coexpression of IL-15 Receptor alpha (IL-15Ra). Co-injection of mice with SSP IL-15 and IL-15Ra expressing plasmids showed increased plasma levels of bioactive IL-15 and mobilization and expansion of NK and T cells. Therefore, SSP IL-15 is secreted and bioactive when produced as a heterodimer with IL-15Ra in the same cell, though its apparent stability is lower compared to LSP IL-15, due to different intracellular processing. When both LSP IL-15 and SSP IL-15 are produced in the same cell they compete for the binding to IL-15Ra, and result in lower levels of bioactive IL-15. Therefore, co-expressed SSP IL-15 acts as competitive inhibitor of LSP IL-15. This suggests that usage of alternative splicing is an additional level of control of IL-15 activity. Expression of both SSP and LSP forms of IL-15 appears to be conserved in many mammals, suggesting that SSP may be important for expressing a form of IL-15 with lower magnitude and duration of biological effects.

These results support and expand our conclusions (Bergamaschi, J Biol Chem. 2008; 283:4189) that IL-15Ra needs to be co-expressed in the same cell with IL-15 for biological activity, and that IL-15Ra should be considered a part of the heterodimeric IL-15 cytokine, rather than part of the receptor.

Deep pelvic endometriosis (Adamyan IV stage): Multidisciplinary laparoscopic treatments

Background: Few small studies have confirmed the feasibility of laparoscopic colorectal resection for Deep Infiltrating Endometriosis (DIE), albeit with a wide range of complications. Aim: The aim of this study is to evaluate retrospectively the feasibility and clinical outcome of laparoscopic segmental bowel resection for DIE. Methods: We have retrospectively reviewed the data of patients undergoing laparoscopic rectosigmoidal resection for bowel endometriosis from January 2000 and June 2008. Data analysis included age, preoperative symptoms, operative procedure, operating room time, intraoperative and postoperative complication, length of stay and Quality of life. Results: 56 colorectal laparoscopic resection for DIE were performed. No conversion occurred. There were no intraoperative complication; 35 patients had a temporary ileostomy and 15 required reoperation for major complication. Conclusion: DIE should be managed in specialised centers with a multidisciplinary equipe; it represents a difficult surgery which require a high surgeon skill and it must be practiced considering both the risks and the benefits.

Suppression pattern of neutral pions at high transverse momentum in Au + Au collisions at sqrt[sNN]=200 GeV and constraints on medium transport coefficients

For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < pT < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e.g., q in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.

Onset of pi(0) suppression studied in Cu+Cu collisions at sqrt S NN=22.4, 62.4, and 200 GeV

Neutral pion transverse momentum (p(T)) spectra at midrapidity (|y| less than or approximately 0.35) were measured in Cu+Cu collisions at sqrt[s(NN)]=22.4, 62.4, and 200 GeV. Relative to pi_(0) yields in p+p collisions scaled by the number of inelastic nucleon-nucleon collisions (N(coll) the pi_(0) yields for p(T) more than or approximately 2 GeV/c in central Cu+Cu collisions are suppressed at 62.4 and 200 GeV whereas an enhancement is observed at 22.4 GeV. A comparison with a jet-quenching model suggests that final state parton energy loss dominates in central Cu+Cu collisions at 62.4 and 200 GeV, while the enhancement at 22.4 GeV is consistent with nuclear modifications in the initial state alone.