J/psi production in sqrt s_NN=200 GeV Cu+Cu collisions

Yields for J/psi production in Cu+Cu collisions at sqrt s_NN=200 GeV have been measured over the rapidity range |y|<2.2 and compared with results in p+p and Au+Au collisions at the same energy. The Cu+Cu data offer greatly improved precision over existing Au+Au data for J/psi production in collisions with small to intermediate numbers of participants, in the range where the quark-gluon plasma transition threshold is predicted to lie. Cold nuclear matter estimates based on ad hoc fits to d+Au data describe the Cu+Cu data up to N_part approximately 50, corresponding to a Bjorken energy density of at least 1.5 GeV/fm(3).

Particle-species dependent modification of jet-induced correlations in Au+Au collisions at sqrt[s_{NN}]=200 GeV

Measurements in Au+Au collisions at sqrt[s_{NN}]=200 GeV of jet correlations for a trigger hadron at intermediate transverse momentum (p_{T,trig}) with associated mesons or baryons at lower p_{T,assoc} indicate strong modification of the away-side jet. The ratio of jet-associated baryons to mesons increases with centrality and p_{T,assoc}. For the most central collisions, the ratio is similar to that for inclusive measurements. This trend is incompatible with in-vacuum fragmentation but could be due to jetlike contributions from correlated soft partons, which recombine upon hadronization.

Comparative ability of various plasmid-based cytokines and chemokines to adjuvant the activity of HIV plasmid DNA vaccines

The effectiveness of plasmid DNA (pDNA) vaccines can be improved by the co-delivery of plasmid-encoded molecular adjuvants. We evaluated pDNAs encoding GM-CSF, Flt-3L, IL-12 alone, or in combination, for their relative ability to serve as adjuvants to augment humoral and cell-mediated immune responses elicited by prototype pDNA vaccines. In Balb/c mice we found that co-administration of plasmid-based murine GM-CSF (pmGM-CSF), murine Flt-3L (pmFlt-3L) or murine IL-12 (pmIL-12) could markedly enhance the cell-mediated immune response elicited by an HIV-1 env pDNA vaccine. Plasmid mGM-CSF also augmented the immune response elicited by DNA vaccines expressing HIV-1 Gag and Nef-Tat-Vif. In addition, the use of pmGM-CSF as a vaccine adjuvant appeared to markedly increase antigen-specific proliferative responses and improved the quality of the resulting T-cell response by increasing the percentage of polyfunctional memory CD8(+) T cells. Co-delivery of pmFlt-3L with pmGM-CSF did not result in a further increase in adjuvant activity. However, the co-administration of pmGM-CSF with pmIL-12 did significantly enhance env-specific proliferative responses and vaccine efficacy in the murine vaccinia virus challenge model relative to mice immunized with the env pDNA vaccine adjuvanted with either pmGM-CSF or pmIL-12 alone. These data support the testing of pmGM-CSF and pmIL-12, used alone or in combination, as plasmid DNA vaccine adjuvants in future macaque challenge studies.

Source breakup dynamics in Au + Au collisions at sqrt[s(NN)]=200 GeV via three-dimensional two-pion source imaging

A three-dimensional correlation function obtained from midrapidity, low p(T), pion pairs in central Au+Au collisions at sqrt[s(NN)]=200 GeV is studied. The extracted model-independent source function indicates a long range tail in the directions of the pion pair transverse momentum (out) and the beam (long). A proper breakup time tau(0) ~ 9 fm/c and a mean proper emission duration Delta tau ~ 2 fm/c, leading to sizable emission time differences ({|Delta t(LCM)|} approximately 12 fm/c), are required to allow models to be successfully matched to these tails. The model comparisons also suggest an outside-in "burning" of the emission source reminiscent of many hydrodynamical models.

Increased immune responses in rhesus macaques by DNA vaccination combined with electroporation

We used optimized DNA expression vectors to compare two gene delivery methodologies in rhesus macaques, namely direct DNA injection and in vivo adaptive constant-current electroporation via the intramuscular route. The use of in vivo electroporation increased levels of gene expression and immune responses. We used an optimized HIV gag expression plasmid to show the development of new cellular immune responses in SIV-infected animals controlling viremia. Furthermore, after vaccination with SIV expression plasmids the recall responses to the SIV antigens were very high, indicating that DNA is a strong boost in the presence of antiretroviral treatment in SIV-infected animals. There was substantial animal-to-animal variability in DNA expression, revealed by plasma measurements of IL-15 produced by co-injected IL-15 DNA. IL-15 expression levels correlated with peak immune responses. Electroporation led to an expansion of antigen-specific CD4+ and CD8+ T cells of both central and effector memory phenotype. These results indicate that improved gene delivery and expression by electroporation dramatically increases immunogenicity of DNA vaccines. Electroporation is thus an important method to improve the effectiveness of DNA vaccination.

Efficient systemic expression of bioactive IL-15 in mice upon delivery of optimized DNA expression plasmids

Efficient expression vectors for interleukin 15 (IL-15) were developed combining RNA/codon optimization and modification of the IL-15 native long signal peptide. These changes resulted in elevated cytoplasmic levels of the optimized mRNA and more than 100-fold improved production of secreted human IL-15 protein. Similar modifications have also led to greatly increased rhesus macaque and murine IL-15 production. Comparison of different heterologous secretory signals showed that the tissue plasminogen activator signal is most efficient for the production of extracellular IL-15. Upon intramuscular injection of the fully optimized expression vectors in mice, IL-15 was readily detected in the serum. Serum levels represented <1% of intramuscular IL-15 and were sufficient in causing some systemic effects, such as increasing the frequency of natural killer (NK) cells in the liver. Upon hydrodynamic DNA delivery in mice, very high levels of IL-15 were produced, which increased the frequency of NK cells in liver as well as in spleen and lung. These optimized expression vectors have potential applications in vaccine and immunotherapy approaches against AIDS and cancer.

Elliptic flow for phi mesons and (anti)deuterons in Au+Au collisions at square root of sNN=200 GeV

Differential elliptic flow (v(2)) for phi mesons and (anti)deuterons (d)d is measured for Au+Au collisions at square root of sNN=200 GeV. The v(2) for phi mesons follows the trend of lighter pi+/- and K+/- mesons, suggesting that ordinary hadrons interacting with standard hadronic cross sections are not the primary driver for elliptic flow development. The v(2) values for (d)d suggest that elliptic flow is additive for composite particles. This further validation of the universal scaling of v(2) per constituent quark for baryons and mesons suggests that partonic collectivity dominates the transverse expansion dynamics.

Response to primary chemotherapy (CHT) in advanced epithelial ovarian cancer (EOC) patients (pts) and molecular characterization of CHT-resistant tumor cell populations: Findings from the Arianna 02 Project

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Background: Despite a high response rate to CHT the prognosis of pts with advanced EOC remains poor. The molecular analysis of pre- and post-CHT tumor specimen may enable the identification of CHT resistant tumor cell populations and thereby lead to adapted treatment options. Methods: Stage III-IV EOC pts diagnosed by laparoscopy and biopsy and not suitable for optimal debulking surgery were eligible. Gene-expression profiles generated from total RNA using the Affymetrix U133A oligonucleotide microarray containing over 22,000 probe sets were obtained at diagnosis and on surgical specimens after 6 courses of primary carboplatin/paclitaxel CHT. Initial comparative analysis focused on proliferative and invasive tumor activity, and on growth factor- and hormone receptors expression. Results: 30 pts were enrolled and data were analyzed according to response to CHT and to time to relapse after surgery. Initial expression analysis results reveal that the quantitative determination of growth factor- and hormone receptors in pre- and post-treatment samples can be used to discriminate responders from non-responders and relates to clinical outcome. Moreover, multiple CHT-resistant tumor cell populations displayed pronounced estrogen receptor expression suggesting a role of hormone receptors in the development of CHT resistance. Conclusions: While hormonal therapies are used in the treatment of other endocrine related tumors, they are not approved for the treatment of EOC. Treatment of EOC cell lines with estrogens down-regulates GnRH activity and promotes cell growth, while tamoxifen has an opposite effect. However, further biological data are lacking in this setting and only few clinical trials have addressed this possibility so far. We have found that the expression of hormone receptors in vivo persists in CHT-resistant tumor cell populations after CHT for EOC. We suggest that hormone receptor activity contributes to the initial development of CHT resistance; hence endocrine therapies particularly in an early setting may be advantageous to a subset of pts and are worth studying.

No significant financial relationships to disclose.

Relevance of circulating tumor cells (CTC) in the progression of metastatic breast cancer

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Background: metastatic breast cancer is an incurable disease. Molecular tumor staging methods are required for a better therapeutic approach. Patients and Methods: eight mL blood samples were drawn from 20 patients (pts) (mean age 61.9±9) with metastatic breast cancer at the time of the beginning of a new chemo- or hormonal treatment line. Median follow-up was 7±4.5 months. Twenty- five female healthy blood donor volunteers were used as controls. Blood samples were screened for the presence of circulating tumor cells (CTC) with a quantitative PCR method using molecular probes for human mammaglobin (hMAM) and cytokeratin 19 (CK19). Relative quantification of hMAM and CK19 RNA was obtained using a blood sample infected with known concentrations of MDA-MB453 cells as calibrator. Results: none of the healthy controls was hMAM positive while the cut-off for CK19 was calculated as the mean value of the controls plus two standard deviations. Nine of 20 (45%) pts were hMAM positive, 15/20 (75%) CK19 positive, while 18/20 (90%) pts were positive for at least one marker (CTC positive). Among the 14 (70%) pts who had a disease progression 7 died. Seven of 9 hMAM positive (78%) and 11/15 (73%) CK19 positive pts had disease progression. All the 14 pts who had disease progression were CTC positive while the only 2 CTC negative pts were free from progression at the time of last follow-up. Conclusions: (1) Multiple (hMAM, CK19) rather than single marker detection should be preferred for CTC blood screening in breast cancer. (2) Combined hMAM and CK19 evaluation might identify pts at higher risk of tumor progression and might be useful for stratification and decision making in metastatic breast cancer pts.

No significant financial relationships to disclose.

Hypoxia-induced p21waf and p27 regulation in c-myc immortalized cells

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Background: Hypoxia is an adaptative response to tissue damage whose mechanisms have not been yet characterized. From a clinical viewpoint, tumours with more necrosis, an indicator of severe hypoxic stress, are often resistant to conventional treatment. Moreover, numerous tumours overexpressed c-myc which strongly enforces proliferation in oxygen deprived conditions. Evidences showed that c-myc blocked cyclin-dependent kinase inhibitors (CDKI) through a complex network of interactions inducing proliferation and G0-S transition. We examined whether Rat-1 immortalized fibroblasts underwent cell cycle arrest p21waf- and p27- mediated in response to O2-deprivation. Materials and Methods: c-myc null cells (-/-) were derived by gene targeting from an immortalized but otherwise non- transformed Rat-1 fibroblast cell line. Oxygen deprivation conditions (0.2% and 1% O2) were achieved in a humidified anaerobic workstation at 37 °C for 6 or 24 hours. Protein concentration was determined by the Lawry assay method. Immunoblots for c-myc and p21waf and p27 were performed. Results: c-myc (+/+) samples collected after 6 hours of hypoxia, which were supposed to be slowly proliferating, showed lower p21waf and p27 levels than c-myc (-/-). Over 24 hours of hypoxia, cell cultures were supposed to be oxygen-dependent and we found higher CDKI levels in c-myc (+/+) cells. Discussion: Our data could explain same resistance mechanisms of tumours cells. In fact, 6 hours O2-deprived-cells, which are unable to supply autonomous O2 support (neo-angiogenesis, in vivo), downregulated p21waf and p27 expression to overcome CDKI cell-cycle arrest. When the cells acquired O2-dependent growth mechanism, low O2 level induced c-myc mediated p21waf and p27 up-regulation to induce cell cycle arrest. Despite the up-regulation of CDKI, PS 341 (a proteasome inhibitors) has been demonstrated to induce apoptosis. Our data kindly encouraging trials on the use of p21waf and p27 stabilizers (like PS 341) in those tumours which overexpressed c-myc.

No significant financial relationships to disclose.

System size and energy dependence of jet-induced hadron pair correlation shapes in Cu+Cu and Au+Au collisions at square root sNN=200 and 62.4 GeV

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at square root sNN=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.

J/psi production versus transverse momentum and rapidity in p+p collisions at square root s=200 GeV

J/psi production in p+p collisions at square root s=200 GeV has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over a rapidity range of -2.2<y<2.2 and a transverse momentum range of 0<pT<9 GeV/c. The size of the present data set allows a detailed measurement of both the pT and the rapidity distributions and is sufficient to constrain production models. The total cross section times the branching ratio is Bll sigma pp J/psi=178+/-3stat+/-53sys+/-18norm nb.

J/psi production versus centrality, transverse momentum, and rapidity in Au+Au collisions at square root sNN=200 GeV

The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured J/psi production for rapidities -2.2<y<2.2 in Au+Au collisions at square root sNN=200 GeV. The J/psi invariant yield and nuclear modification factor RAA as a function of centrality, transverse momentum, and rapidity are reported. A suppression of J/psi relative to binary collision scaling of proton-proton reaction yields is observed. Models which describe the lower energy J/psi data at the CERN Super Proton Synchrotron invoking only J/psi destruction based on the local medium density predict a significantly larger suppression at RHIC and more suppression at midrapidity than at forward rapidity. Both trends are contradicted by our data.

Effect of plasmid DNA vaccine design and in vivo electroporation on the resulting vaccine-specific immune responses in rhesus macaques

Since human immunodeficiency virus (HIV)-specific cell-mediated immune (CMI) responses are critical in the early control and resolution of HIV infection and correlate with postchallenge outcomes in rhesus macaque challenge experiments, we sought to identify a plasmid DNA (pDNA) vaccine design capable of eliciting robust and balanced CMI responses to multiple HIV type 1 (HIV-1)-derived antigens for further development. Previously, a number of two-, three-, and four-vector pDNA vaccine designs were identified as capable of eliciting HIV-1 antigen-specific CMI responses in mice (M. A. Egan et al., Vaccine 24:4510-4523, 2006). We then sought to further characterize the relative immunogenicities of these two-, three-, and four-vector pDNA vaccine designs in nonhuman primates and to determine the extent to which in vivo electroporation (EP) could improve the resulting immune responses. The results indicated that a two-vector pDNA vaccine design elicited the most robust and balanced CMI response. In addition, vaccination in combination with in vivo EP led to a more rapid onset and enhanced vaccine-specific immune responses. In macaques immunized in combination with in vivo EP, we observed a 10- to 40-fold increase in HIV-specific enzyme-linked immunospot assay responses compared to those for macaques receiving a 5-fold higher dose of vaccine without in vivo EP. This increase in CMI responses translates to an apparent 50- to 200-fold increase in pDNA vaccine potency. Importantly, in vivo EP enhanced the immune response against the less immunogenic antigens, resulting in a more balanced immune response. In addition, in vivo EP resulted in an approximate 2.5-log(10) increase in antibody responses. The results further indicated that in vivo EP was associated with a significant reduction in pDNA persistence and did not result in an increase in pDNA associated with high-molecular-weight DNA relative to macaques receiving the pDNA without EP. Collectively, these results have important implications for the design and development of an efficacious vaccine for the prevention of HIV-1 infection.

Scaling properties of azimuthal anisotropy in Au+Au and Cu+Cu Collisions at sqrt[s NN]=200 GeV

Differential measurements of elliptic flow (v2) for Au+Au and Cu+Cu collisions at sqrt[sNN]=200 GeV are used to test and validate predictions from perfect fluid hydrodynamics for scaling of v2 with eccentricity, system size, and transverse kinetic energy (KE T). For KE T identical with mT-m up to approximately 1 GeV the scaling is compatible with hydrodynamic expansion of a thermalized fluid. For large values of KE T mesons and baryons scale separately. Quark number scaling reveals a universal scaling of v2 for both mesons and baryons over the full KE T range for Au+Au. For Au+Au and Cu+Cu the scaling is more pronounced in terms of KE T, rather than transverse momentum.

Evidence for a long-range component in the pion emission source in Au+Au collisions at sqrt sNN=200 GeV

Emission source functions are extracted from correlation functions constructed from charged pions produced at midrapidity in Au+Au collisions at sqrt[s(NN)]=200 GeV. The source parameters extracted from these functions at low k(T) give first indications of a long tail for the pion emission source. The source extension cannot be explained solely by simple kinematic considerations. The possible role of a halo of secondary pions from resonance emissions is explored.

Comparative ability of plasmid IL-12 and IL-15 to enhance cellular and humoral immune responses elicited by a SIVgag plasmid DNA vaccine and alter disease progression following SHIV(89.6P) challenge in rhesus macaques

Plasmid-based IL-12 has been demonstrated to successfully enhance the immunogenicity of DNA vaccines, thus enabling a reduction of the amount of DNA required for immunization. IL-15 is thought to affect the maintenance and enhance effector function of CD8(+) memory T cells. Since the ability to elicit a long-term memory response is a desirable attribute of a prophylactic vaccine, we sought to evaluate the ability of these plasmid-based cytokines to serve as vaccine adjuvants in rhesus macaques. Macaques were immunized with plasmid DNA encoding SIVgag in combination with plasmid IL-12, IL-15, or a combination of IL-12 and IL-15. The plasmid-based cytokines were monitored for their ability to augment SIVgag-specific cellular and humoral immune responses and to alter the clinical outcome following pathogenic SHIV(89.6P) challenge. Macaques receiving SIVgag pDNA in combination with plasmid IL-12 alone, or in combination with plasmid IL-12 and IL-15, demonstrated significantly elevated cell-mediated and humoral immune responses resulting in an improved clinical outcome following virus challenge compared to macaques receiving SIVgag pDNA alone. Macaques receiving SIVgag pDNA in combination with plasmid IL-15 alone demonstrated minor increases in cell-mediated and humoral immune responses, however, the clinical outcome following virus challenge was not improved. These results have important implications for the continued development of plasmid DNA vaccines for the prevention of HIV-1 infection.

Measurement of direct photon production in p+p collisions at sqrt[s] = 200 GeV

Cross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported for transverse momenta of 3 < pT < 16 GeV/c. Next-to-leading order perturbative QCD (pQCD) describes the data well for pT >5 GeV/c, where the uncertainties of the measurement and theory are comparable. We also report on the effect of requiring the photons to be isolated from parton jet energy. The observed fraction of isolated photons is well described by pQCD for pT >7 GeV/c.

Measurement of high-pT single electrons from heavy-flavor decays in p + p collisions at square root of s = 200 GeV

The momentum distribution of electrons from decays of heavy flavor (charm and bottom) for midrapidity absolute value of y < 0.35 in p + p collisions at square root of s = 200 GeV has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.3 < pT < 9 GeV/c. Two independent methods have been used to determine the heavy-flavor yields, and the results are in good agreement with each other. A fixed-order-plus-next-to-leading-log perturbative QCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of 1.71+/-0.02stat+/-0.18sys for 0.3 < pT < 9 GeV/c. The total charm production cross section at this energy has also been deduced to be sigma cc = 567+/-57stat+/-193sys microb.

Long-lasting decrease in viremia in macaques chronically infected with simian immunodeficiency virus SIVmac251 after therapeutic DNA immunization

Rhesus macaques chronically infected with highly pathogenic simian immunodeficiency virus (SIV) SIVmac251 were treated with antiretroviral drugs and vaccinated with combinations of DNA vectors expressing SIV antigens. Vaccination during therapy increased cellular immune responses. After the animals were released from therapy, the virus levels of 12 immunized animals were significantly lower (P = 0.001) compared to those of 11 animals treated with only antiretroviral drugs. Vaccinated animals showed a persistent increase in immune responses, thus indicating both a virological and an immunological benefit following DNA therapeutic vaccination. Several animals show a long-lasting decrease in viremia, suggesting that therapeutic vaccination may provide an additional benefit to antiretroviral therapy.

Ability of herpes simplex virus vectors to boost immune responses to DNA vectors and to protect against challenge by simian immunodeficiency virus

The immunogenicity and protective capacity of replication-defective herpes simplex virus (HSV) vector-based vaccines were examined in rhesus macaques. Three macaques were inoculated with recombinant HSV vectors expressing Gag, Env, and a Tat-Rev-Nef fusion protein of simian immunodeficiency virus (SIV). Three other macaques were primed with recombinant DNA vectors expressing Gag, Env, and a Pol-Tat-Nef-Vif fusion protein prior to boosting with the HSV vectors. Robust anti-Gag and anti-Env cellular responses were detected in all six macaques. Following intravenous challenge with wild-type, cloned SIV239, peak and 12-week plasma viremia levels were significantly lower in vaccinated compared to control macaques. Plasma SIV RNA in vaccinated macaques was inversely correlated with anti-Rev ELISPOT responses on the day of challenge (P value<0.05), anti-Tat ELISPOT responses at 2 weeks post challenge (P value <0.05) and peak neutralizing antibody titers pre-challenge (P value 0.06). These findings support continued study of recombinant herpesviruses as a vaccine approach for AIDS.

Dense-medium modifications to jet-induced hadron pair distributions in Au+Au collisions at sqrt s NN=200 GeV

Azimuthal correlations of jet-induced high-p(T) charged hadron pairs are studied at midrapidity in Au+Au collisions at sqrt[s(NN)]=200 GeV. The distribution of jet-associated partner hadrons (1.0<p(T)<2.5 GeV/c) per trigger hadron (2.5<p(T)<4.0 GeV/c) is found to vary with collision centrality, in both shape and yield, indicating a significant effect of the nuclear collision medium on the jet fragmentation process.

Early evaluation of response to neoadjuvant chemotherapy in stage IIIC-IV epithelial ovarian cancer patients by 18FDG-PET and CA 125: Preliminary findings from the Arianna Project 02

15039

Background: Early evaluation of response to primary chemotherapy (PSC) in epithelial ovarian cancer (EOC) pts could allow to administer a proper number of cycles in order to obtain optimal results. Arianna Project 02 is aimed to investigate early tumor response to PSC correlating a set of routine and experimental hystological, biological and gene-expression profile data with clinical data before, during and after PSC. Methods: Stage III-IV EOC received 6 cycles of carboplatin AUC 5 and paclitaxel 175 mg/m2 and are evaluated at baseline and before each cycle by 18FDG-PET, CA 125, circulating tumor cells and experimental circulating bio-markers. Ultrasounds, CT scan and pelvic MRI are done at baseline and every other cycle. This preliminary report is focused on the correlation between changes of PET and CA 125 serum levels and pathological response. Results: Up to now 6 out of 11 pts completed PSC and surgery. Baseline tumoral 18FDG uptake expressed as Standardized Uptake Value (SUV) and CA125 were abnormal in all pts (SUVmax range: 12.1–20; CA 125 range: 416–2026 U/ml, upper normal limit 35 U/ml). One complete and 4 partial pathological remissions > 90% and one no change were observed. Mean (with range) SUVmax and CA125 decrease (Δ SUV and Δ CA125) measured after the 1st, 2nd, 3rd and last cycle of PSC in the 5 responders are similar (table). In the non-responder SUV decreased by 63% after the 1st cycle of PSC, but increased to baseline value after the 2nd cycle and remained unchanged until surgery, while CA 125 progressively decreased from 416 U/ml to 47 U/ml. Conclusions: These preliminary findings indicate that the behaviour of PET and CA 125 in responders are similar. More data are necessary to define the role of PET in the early evaluation of response to PSC in EOC pts. The study is still ongoing and the relationship between evaluation performed by PET and CA125 and by CT scan, ultrasound and pelvic MRI will be presented at ASCO meeting.

[Table: see text]

No significant financial relationships to disclose.

Azimuthal angle correlations for rapidity separated Hadron pairs in d+Au collisions at square root of sNN=200 GeV

Deuteron-gold (d+Au) collisions at the Relativistic Heavy Ion Collider provide ideal platforms for testing QCD theories in dense nuclear matter at high energy. In particular, models suggesting strong saturation effects for partons carrying small nucleon momentum fraction (x) predict modifications to jet production at forward rapidity (deuteron-going direction) in d+Au collisions. We report on two-particle azimuthal angle correlations between charged hadrons at forward/backward (deuteron/gold going direction) rapidity and charged hadrons at midrapidity in d+Au and p+p collisions at square root of sNN=200 GeV. Jet structures observed in the correlations are quantified in terms of the conditional yield and angular width of away-side partners. The kinematic region studied here samples partons in the gold nucleus with x~0.1 to ~0.01. Within this range, we find no x dependence of the jet structure in d+Au collisions.

Common suppression pattern of eta and pi0 mesons at high transverse momentum in Au + Au collisions at square root S(NN) = 200 GeV

Inclusive transverse momentum spectra of eta mesons have been measured within p(T) = 2-10 GeV/c at midrapidity by the PHENIX experiment in Au + Au collisions at square root S(NN) = 200 GeV. In central Au+Au the eta yields are significantly suppressed compared to peripheral Au + Au, d + Au, and p + p yields scaled by the corresponding number of nucleon-nucleon collisions. The magnitude, centrality, and p(T) dependence of the suppression is common, within errors, for eta and pi0. The ratio of eta to pi0 spectra at high p(T) amounts to 0.40 < R(eta/pi)0 < 0.48 for the three systems, in agreement with the world average measured in hadronic and nuclear reactions and, at large scaled momentum, in e+e- collisions.

Rational design of a plasmid DNA vaccine capable of eliciting cell-mediated immune responses to multiple HIV antigens in mice

Given the importance of the HIV-specific cell-mediated immune response in the early control and resolution of HIV infection and the observed correlation between pre-challenge vaccine elicited CTL responses and post challenge outcome in SHIV/rhesus macaque experiments, we sought to identify several candidate plasmid DNA (pDNA) vaccine designs capable of eliciting robust and balanced cell-mediated immune responses to multiple HIV-1 derived antigens in mice for further vaccine development. To rationally construct candidate vaccines for immunogenicity testing, we determined the relative immunogenicity of the individual HIV-derived vaccine antigens (env, gag, pol, nef, tat and vif) and the relative strength of various transcriptional control elements (HCMV, SCMV, HSV Lap1) in Balb/c mice. Next, a number of 1-, 2-, 3- and 4-vector pDNA vaccine designs were tested for their ability to elicit HIV-1 antigen-specific CMI responses. For these studies, Balb/c mice were immunized with a fixed total pDNA vaccine dose of 100 mcg in combination with 25 mcg plasmid-based murine IL-12 and tested for the induction of HIV-1 antigen-specific CMI responses by IFN-gamma ELISpot analysis. The results of this study indicate that all pDNA vaccine designs were capable of eliciting CMI responses to multiple HIV-1 antigens. As a result of this iterative comparative analysis, we have identified a number of pDNA vaccine candidates capable of eliciting potent, balanced CMI responses to multiple HIV-1 derived antigens. These results have important implications for the design and development of an efficacious vaccine for the prevention of HIV-1 infection.

Single electrons from heavy-flavor decays in collisions at

The invariant differential cross section for inclusive electron production in p+p collisions at [FORMULA: SEE TEXT] has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.4<or=pT<OR=5.0 GeV/c in the central rapidity region ([FORMULA: SEE TEXT]). The contribution to the inclusive electron spectrum from semileptonic decays of hadrons carrying heavy flavor, i.e., charm quarks or, at high , bottom quarks, is determined via three independent methods. The resulting electron spectrum from heavy-flavor decays is compared to recent leading and next-to-leading order perturbative QCD calculations. The total cross section of charm quark-antiquark pair production is determined to be [FORMULA: SEE TEXT].

Measurement of identified and inclusive photon second-harmonic parameter and implications for direct photon production in [FORMULA: SEE TEXT] Au+Au

The azimuthal distribution of identified pi0 and inclusive photons has been measured in [FORMULA: SEE TEXT] Au+Au collisions with the PHENIX experiment at the Relativistic Heavy-Ion Collider (RHIC). The second-harmonic parameter (nu2) was measured to describe the observed anisotropy of the azimuthal distribution. The measured inclusive photon is consistent with the value expected for the photons from hadron decay and is also consistent with the lack of direct photon signal over the measured pT range 1-6 GeV/c. An attempt is made to extract nu2 of direct photons.

Nuclear modification of electron spectra and implications for heavy quark energy loss in Au+Au collisions at [FORMULA: SEE TEXT]

The PHENIX experiment has measured midrapidity ([FORMULA: SEE TEXT]) transverse momentum spectra ([FORMULA: SEE TEXT]) of electrons as a function of centrality in Au+Au collisions at [FORMULA: SEE TEXT]. Contributions from photon conversions and from light hadron decays, mainly Dalitz decays of pi0 and eta mesons, were removed. The resulting nonphotonic electron spectra are primarily due to the semileptonic decays of hadrons carrying heavy quarks. Nuclear modification factors were determined by comparison to nonphotonic electrons in p+p collisions. A significant suppression of electrons at high pT is observed in central Au+Au collisions, indicating substantial energy loss of heavy quarks.

J/psi production and nuclear effects for d + Au and p + p collisions at square root of S(NN) = 200 GeV

J/psi production in d + Au and p + p collisions at square root of S(NN) = 200 GeV has been measured by the PHENIX experiment at rapidities -2.2 < y < +2.4. The cross sections and nuclear dependence of J/psi production versus rapidity, transverse momentum, and centrality are obtained and compared to lower energy p + A results and to theoretical models. The observed nuclear dependence in d + Au collisions is found to be modest, suggesting that the absorption in the final state is weak and the shadowing of the gluon distributions is small and consistent with Dokshitzer-Gribov-Lipatov-Altarelli-Parisi-based parametrizations that fit deep-inelastic scattering and Drell-Yan data at lower energies.

RTE and CTE mRNA export elements synergistically increase expression of unstable, Rev-dependent HIV and SIV mRNAs

Studies of retroviral mRNA export identified two distinct RNA export elements utilizing conserved eukaryotic mRNA export mechanism(s), namely the Constitutive Transport Element (CTE) and the RNA Transport Element (RTE). Although RTE and CTE are potent in nucleocytoplasmic mRNA transport and expression, neither element is as powerful as the Rev-RRE posttranscriptional control. Here, we found that whereas CTE and the up-regulatory mutant RTEm26 alone increase expression from a subgenomic gag and env clones, the combination of these elements led to a several hundred-fold, synergistic increase. The use of the RTEm26-CTE combination is a simple way to increase expression of poorly expressed retroviral genes to levels otherwise only achieved via more cumbersome RNA optimization. The potent RTEm26-CTE element could be useful in lentiviral gene therapy vectors, DNA-based vaccine vectors, and gene transfer studies of other poorly expressed genes.

Measurement of transverse single-spin asymmetries for midrapidity production of neutral pions and charged hadrons in polarized p + p collisions at square root(s) = 200 GeV

Transverse single-spin asymmetries to probe the transverse-spin structure of the proton have been measured for neutral pions and nonidentified charged hadrons from polarized proton-proton collisions at midrapidity and square root(s) = 200 GeV. The data cover a transverse momentum (pT) range 1.0-5.0 GeV/c for neutral pions and 0.5-5.0 GeV/c for charged hadrons, at a Feynman-x value of approximately zero. The asymmetries seen in this previously unexplored kinematic region are consistent with zero within errors of a few percent. In addition, the inclusive charged hadron cross section at midrapidity from 0.5 < pT < 7.0 GeV/c is presented and compared to next-to-leading order perturbative QCD (pQCD) calculations. Successful description of the unpolarized cross section above approximately 2 GeV/c suggests that pQCD is applicable in the interpretation of the asymmetry results in the relevant kinematic range.

DNA vaccines expressing different forms of simian immunodeficiency virus antigens decrease viremia upon SIVmac251 challenge

We have tested the efficacy of DNA immunization as a single vaccination modality for rhesus macaques followed by highly pathogenic SIVmac251 challenge. To further improve immunogenicity of the native proteins, we generated expression vectors producing fusion of the proteins Gag and Env to the secreted chemokine MCP3, targeting the viral proteins to the secretory pathway and to a beta-catenin (CATE) peptide, targeting the viral proteins to the intracellular degradation pathway. Macaques immunized with vectors expressing the MCP3-tagged fusion proteins developed stronger antibody responses. Following mucosal challenge with pathogenic SIVmac251, the vaccinated animals showed a statistically significant decrease in viral load (P = 0.010). Interestingly, macaques immunized with a combination of vectors expressing three forms of antigens (native protein and MCP3 and CATE fusion proteins) showed the strongest decrease in viral load (P = 0.0059). Postchallenge enzyme-linked immunospot values for Gag and Env as well as gag-specific T-helper responses correlated with control of viremia. Our data show that the combinations of DNA vaccines producing native and modified forms of antigens elicit more balanced immune responses able to significantly reduce viremia for a long period (8 months) following pathogenic challenge with SIVmac251.

Priming with plasmid DNAs expressing interleukin-12 and simian immunodeficiency virus gag enhances the immunogenicity and efficacy of an experimental AIDS vaccine based on recombinant vesicular stomatitis virus

Of the various approaches being developed as prophylactic HIV vaccines, those based on a heterologous plasmid DNA prime, live vector boost vaccination regimen appear especially promising in the nonhuman primate/simian-human immunodeficiency virus (SHIV) challenge model. In this study, we sought to determine whether a series of intramuscular priming immunizations with a plasmid DNA vaccine expressing SIVgag p39, in combination with plasmid expressed rhesus IL-12, could effectively enhance the immunogenicity and postchallenge efficacy of two intranasal doses of recombinant vesicular stomatitis virus (rVSV)-based vectors expressing HIV-1 env 89.6P gp160 and SIVmac239 gag p55 in rhesus macaques. In macaques receiving the combination plasmid DNA prime, rVSV boost vaccination regimen we observed significantly increased SIVgag- specific cell-mediated and humoral immune responses and significantly lower viral loads postintravenous SHIV89.6P challenge relative to macaques receiving only the rVSV vectored immunizations. In addition, the plasmid DNA prime, rVSV boost vaccination regimen also tended to increase the preservation of peripheral blood CD4+ cells and reduce the morbidity and mortality associated with SHIV89.6P infection. An analysis of immune correlates of protection after SHIV89.6P challenge revealed that the prechallenge SHIV-specific IFN-gamma ELISpot response elicited by vaccination and the ability of the host to mount a virus-specific neutralizing antibody response postchallenge correlated with postchallenge clinical outcome. The correlation between vaccine-elicited cell-mediated immune responses and an improved clinical outcome after SHIV challenge provides strong justification for the continued development of a cytokine-enhanced plasmid DNA prime, rVSV vector boost immunization regimen for the prevention of HIV infection.

Saturation of azimuthal anisotropy in Au + Au collisions at (square root)s(NN) = 62-200 GeV

New measurements are presented for charged hadron azimuthal correlations at midrapidity in Au+Au collisions at (square root)s(NN) = 62.4 and 200 GeV. They are compared to earlier measurements obtained at (square root)s(NN) = 130 GeV and in Pb + Pb collisions at (square root)s(NN) = 17.2 GeV. Sizeable anisotropies are observed with centrality and transverse momentum (pT) dependence characteristic of elliptic flow (upsilon2). For a broad range of centralities, the observed magnitudes and trends of the differential anisotropy, upsilon2(pT), change very little over the collision energy range (square root)s(NN) = 62-200 GeV, indicating saturation of the excitation function for upsilon2 at these energies. Such a saturation may be indicative of the dominance of a very soft equation of state for (square root)s(NN) approximately 60-200 GeV.

Centrality dependence of direct photon production in (square root)S(NN) = 200 GeV Au + Au collisions

The first measurement of direct photons in Au + Au collisions at (square root)S(NN) = 200 GeV is presented. The direct photon signal is extracted as a function of the Au + Au collision centrality and compared to next-to-leading order perturbative quantum chromodynamics calculations. The direct photon yield is shown to scale with the number of nucleon-nucleon collisions for all centralities.

Deuteron and antideuteron production in Au+Au collisions at square root of s(NN)=200 GeV

The production of deuterons and antideuterons in the transverse momentum range 1.1<p(T)<4.3 GeV/c at midrapidity in Au+Au collisions at square root of s(NN)=200 GeV has been studied by the PHENIX experiment at RHIC. A coalescence analysis, comparing the deuteron and antideuteron spectra with that of proton and antiproton, has been performed. The coalescence probability is equal for both deuterons and antideuterons and it increases as a function of p(T), which is consistent with an expanding collision zone. Comparing (anti)proton yields, p /p=0.73+/-0.01, with (anti)deuteron yields, d /d=0.47+/-0.03, we estimate that n /n=0.64+/-0.04. The nucleon phase space density is estimated from the coalescence measurement.

Centrality dependence of charm production from a measurement of single electrons in Au+Au collisions at sqrt[s(NN)]=200 GeV

The PHENIX experiment has measured midrapidity transverse momentum spectra (0.4<p(T)<4.0 GeV/c) of single electrons as a function of centrality in Au+Au collisions at sqrt[s(NN)]=200 GeV. Contributions from photon conversions and Dalitz decays of light neutral mesons are measured by introducing a thin (1.7% X0) converter into the PHENIX acceptance and are statistically removed. The subtracted nonphotonic electron spectra are primarily due to the semileptonic decays of hadrons containing heavy quarks, mainly charm at lower p(T). For all centralities, the charm production cross section is found to scale with the nuclear overlap function, T(AA). For minimum-bias collisions the charm cross section per binary collision is N(cc )/T(AA)=622+/-57(stat)+/-160(syst) microb.

Nuclear modification factors for hadrons at forward and backward rapidities in deuteron-gold collisions at sqrt[s(NN)]=200 GeV

We report on charged hadron production in deuteron-gold reactions at sqrt[s(NN)]=200 GeV. Our measurements in the deuteron direction cover 1.4<eta<2.2, referred to as forward rapidity, and in the gold direction -2.0<eta<-1.4, referred to as backward rapidity, and a transverse momentum range p(T)=0.5-4.0 GeV/c. We compare the relative yields for different deuteron-gold collision centrality classes. We observe a suppression relative to binary collision scaling at forward rapidity, sensitive to low momentum fraction (x) partons in the gold nucleus, and an enhancement at backward rapidity, sensitive to high momentum fraction partons in the gold nucleus.

Double helicity asymmetry in inclusive midrapidity pi0 production for polarized p+p collisions at square root s = 200 GeV

We present a measurement of the double longitudinal spin asymmetry in inclusive pi(0) production in polarized proton-proton collisions at sqrt[s]=200 GeV. The data were taken at the Relativistic Heavy Ion Collider with average beam polarizations of 0.27. The measurements are the first in a program to study the longitudinal spin structure of the proton, using strongly interacting probes, at collider energies. The asymmetry is presented for transverse momenta 1-5 GeV/c at midrapidity, where next-to-leading-order perturbative quantum chromodynamic (NLO pQCD) calculations well describe the unpolarized cross section. The observed asymmetry is small and is compared to a NLO pQCD calculation with a range of polarized gluon distributions.

Bose-Einstein correlations of charged pion pairs in Au + Au collisions at square root sNN = 200 GeV

Bose-Einstein correlations of identically charged pion pairs were measured by the PHENIX experiment at midrapidity in Au + Au collisions at square root s(NN)=200 GeV. The Bertsch-Pratt radius parameters were determined as a function of the transverse momentum of the pair and as a function of the centrality of the collision. Using the standard core-halo partial Coulomb fits, and a new parametrization which constrains the Coulomb fraction as determined from the unlike-sign pion correlation, the ratio R(out)/R(side) is within 0.8-1.1 for 0.25< <k(T)> <1.2 GeV/c. The centrality dependence of all radii is well described by a linear scaling in N(1/3)(part), and R(out)/R(side) for <k(T)> approximately 0.45 GeV/c is approximately constant at unity as a function of centrality.

Measurement of nonrandom event-by-event fluctuations of average transverse momentum in square root of (sNN)=200 GeV Au+Au and p+p collisions

Event-by-event fluctuations of the average transverse momentum of produced particles near midrapidity have been measured by the PHENIX Collaboration in square root of (sNN)=200 GeV Au+Au, and p+p collisions at the Relativistic Heavy Ion Collider. The fluctuations are observed to be in excess of the expectation for statistically independent particle emission for all centralities. The excess fluctuations exhibit a dependence on both the centrality of the collision and on the pT range over which the average is calculated. Both the centrality and pT dependence can be well reproduced by a simulation of random particle production with the addition of contributions from hard-scattering processes.

J/psi production from proton-proton collisions at square root of s=200 GeV

J/psi production has been measured in proton-proton collisions at square root of s=200 GeV over a wide rapidity and transverse momentum range by the PHENIX experiment at the Relativistic Heavy Ion Collider. Distributions of the rapidity and transverse momentum, along with measurements of the mean transverse momentum and total production cross section are presented and compared to available theoretical calculations. The total J/psi cross section is 4.0+/-0.6(stat)+/-0.6(syst)+/-0.4(abs) mu b. The mean transverse momentum is 1.80+/-0.23(stat)+/-0.16(syst) GeV/c.

Midrapidity neutral-pion production in proton-proton collisions at square root s = 200 GeV

The invariant differential cross section for inclusive neutral-pion production in p+p collisions at sqrt[s]=200 GeV has been measured at midrapidity (|eta|<0.35) over the range 1<p(T) less, similar 14 GeV/c by the PHENIX experiment at the Relativistic Heavy Ion Collider. Predictions of next-to-leading order perturbative QCD calculations are consistent with these measurements. The precision of our result is sufficient to differentiate between prevailing gluon-to-pion fragmentation functions.

Elliptic flow of identified hadrons in Au+Au collisions at sqrt sNN =200 GeV

The anisotropy parameter (v(2)), the second harmonic of the azimuthal particle distribution, has been measured with the PHENIX detector in Au+Au collisions at sqrt[s(NN)]=200 GeV for identified and inclusive charged particle production at central rapidities (|eta|<0.35) with respect to the reaction plane defined at high rapidities (|eta|=3-4 ). We observe that the v(2) of mesons falls below that of (anti)baryons for p(T)>2 GeV/c, in marked contrast to the predictions of a hydrodynamical model. A quark-coalescence model is also investigated.