Loss of enteric neurons accompanied by decreased expression of GDNF and PI3K/Akt pathway in diabetic rats

To investigate the enteric neuropathy in diabetic rats and the role of glia cell line-derived neurotrophic factor (GDNF) and its signalling pathway PI3K/Akt in regulating enteric neurons survival. Male Sprague-Dawley (SD) rats were randomly divided into normal control group, diabetic groups (rats with diabetes for 4, 8 and 12 weeks respectively). Proximal and distal colon specimens were obtained from each rat. Phosphoinositol-3-kinase signalling pathway was analysed by Akt phosphorylation. Protein gene product 9.5 (PGP9.5) used as a pan-neuronal marker. The expressions of GDNF, phospho-Akt (p-Akt), neuronal nitric oxide synthase (nNOS) neurons, cholinergic [choline acetyltransferase (CHAT) stained] neurons and total neurons were measured by immunohistochemical streptavidin-biotin complex (SABC) methods, Western blot and real-time polymerase chain reaction methods for each specimen. (i) Expression of GDNF was significantly decreased in diabetes 8 and 12 weeks group compared with the control group in both proximal (P < 0.01) and distal (P < 0.01) colon. The change of GDNF expression was greater in the 12 weeks group than that in the 8 weeks group (P < 0.05). There were no significant differences between the 4 weeks group and the control group in expression of GDNF (P > 0.05). (ii) The change trend of Akt phosphorylation was the same with GDNF. (iii) The numbers of nNOS, CHAT neurons and total neurons in proximal and distal colon were decreased significantly during the course of diabetes (P < 0.05). Diabetes can significantly induce enteric neuropathy. This change may be mediated, in partly, via a reduction of GDNF and its main downstream signalling pathway PI3K/Akt, which is a survival signal for enteric neurons.

Growth of long range forward-backward multiplicity correlations with centrality in Au + Au collisions at square root of sNN = 200 GeV

Forward-backward multiplicity correlation strengths have been measured with the STAR detector for Au + Au and p + p collisions at square root of s(NN) = 200 GeV. Strong short- and long-range correlations (LRC) are seen in central Au + Au collisions. The magnitude of these correlations decrease with decreasing centrality until only short-range correlations are observed in peripheral Au + Au collisions. Both the dual parton model (DPM) and the color glass condensate (CGC) predict the existence of the long-range correlations. In the DPM, the fluctuation in the number of elementary (parton) inelastic collisions produces the LRC. In the CGC, longitudinal color flux tubes generate the LRC. The data are in qualitative agreement with the predictions of the DPM and indicate the presence of multiple parton interactions.

Observation of two-source interference in the photoproduction reaction AuAu --> AuAurho0

In ultraperipheral relativistic heavy-ion collisions, a photon from the electromagnetic field of one nucleus can fluctuate to a quark-antiquark pair and scatter from the other nucleus, emerging as a rho{0}. The rho{0} production occurs in two well-separated (median impact parameters of 20 and 40 F for the cases considered here) nuclei, so the system forms a two-source interferometer. At low transverse momenta, the two amplitudes interfere destructively, suppressing rho{0} production. Since the rho{0} decays before the production amplitudes from the two sources can overlap, the two-pion system can only be described with an entangled nonlocal wave function, and is thus an example of the Einstein-Podolsky-Rosen paradox. We observe this suppression in 200 GeV per nucleon-pair gold-gold collisions. The interference is 87%+/-5%(stat.)+/-8%(syst.) of the expected level. This translates into a limit on decoherence due to wave function collapse or other factors of 23% at the 90% confidence level.

Indications of conical emission of charged hadrons at the BNL relativistic heavy ion collider

Three-particle azimuthal correlation measurements with a high transverse momentum trigger particle are reported for pp, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV by the STAR experiment. Dijet structures are observed in pp, d+Au and peripheral Au+Au collisions. An additional structure is observed in central Au+Au data, signaling conical emission of correlated charged hadrons. The conical emission angle is found to be theta=1.37+/-0.02(stat)-0.07+0.06(syst), independent of p_{ perpendicular}.

220 SYNERGISTIC EFFECT ON EMBRYO DEVELOPMENT BY INCLUSION OF SUPPLEMENTAL EMBRYOS IN AGAR CHIPS

The main scope of this study was to evaluate the likelihood of a helper effect of agar-embedded cleaved embryos on a low number of free embryos at a similar stage of development within the same culture droplet. Such an improved system could be beneficial within ovum pickup/in vitro embryo production (OPU/IVEP) combined protocols whenever a low number of OPU-derived cleaved embryos are produced per donor. Oocytes were recovered from abattoir ovaries, and after in vitro maturation (IVM) and in vitro fertilization (IVF), presumptive zygotes were deprived of cumulus investment and allocated into culture droplets for 24 h. At 48 h from IVF, 4- to 8-cell cleaved embryos were randomly allocated into a control and a treatment group. Control groups consisted of 1, 3, 5, and 10 embryos, respectively, in 50-μL droplets. Treatment groups consisted of 1, 3, and 5 free embryos with the addition of 9, 7, and 5 embryos, respectively, at a similar stage of development embedded in agar chips, so as to reach a total number of 10 cleaved embryos in each culture droplet. Culture was performed for both the control and treatment groups in SOF medium droplets covered with mineral oil, with the supplementation of essential and nonessential amino acids in a controlled gas atmosphere consisting of 5% CO2, 7% O2, and 88% N2 at 39°C. Final embryo output was checked at Day 7 from IVF. When considering only free embryos, the difference in progression to blastocyst development was highly significant between the control and treatment groups: 1) group 1 v. 1 + 9: 6.6 v. 84.3% (P = 0.00000); 2) group 3 v. 3 + 7: 11.1 v. 41.3% (P = 0.00001); 3) group 5 v. 5 + 5: 24.4 v. 42.2% (P = 0.00001). Rate of blastocyst development in the control group containing 10 cleaved embryos was not significantly different from free cleaved embryos in the 3 + 7 (39.2 v. 41.3%, P = 0.71) and 5 + 5 treatment groups (39.2 v. 42.2%, P = 0.54), but was significantly lower when compared with the 1 + 9 treatment group (39.2 v. 84.3%, P = 0.000). For 1, 3, 5, and 10 control group embryos, the numbers of replicates and total cleaved embryos used (n) were 30 (n = 30), 27, (n = 81), 27 (n = 135), and 39 (n = 390), respectively. For the 1 + 9, 3 + 7, and 5 + 5 treatment group embryos, the numbers of replicates and total cleaved embryos used were 32 (n = 32), 29 (n = 87), and 27 (n = 135), respectively. In conclusion, a beneficial effect of agar-embedded embryos on the development of free embryos within the same culture droplet was shown. A striking improvement in late-stage embryo development was particularly evident when considering the 1 v. 1 + 9 control and treatment groups. These results may foster a different strategic approach in in vitro culture to enhance embryo development from highly valuable donors.

203 EFFECT OF FRUCTOSE ON THE DEVELOPMENT OF BOVINE SEXED EMBRYOS IN VITRO

It is important to optimize the condition of culture to promote the development of embryos fertilized by sex-sorted sperm. Fructose is a monosaccharide hexose that can be used as a substrate for glycolysis. Recently, there has been interest in exploring the embryotrophic properties of fructose during bovine embryo culture. The present study was undertaken to ascertain the effect of supplementation of fructose in culture on the development of sexed embryos in vitro. A total of 2310 slaughterhouse dairy oocytes, spread over 3 experimental replicates, were subjected to routine in vitro maturation (IVM) for 22 h. The maturation medium was M-199 with Earl’s salts, L-glutamine, 26.19 mm sodium bicarbonate, and 25 mm HEPES plus 10% fetal bovine serum. Fertilization of IVM oocytes was performed in Brackett and Oliphant’s medium by using frozen and sorted X-sperm from a single bull. Groups of 50 matured oocytes were added to a final volume of 100 μL of fertilization medium, with a final concentration of 0.3 × 106 spermatozoa mL–1. The oocytes were incubated with X-sperm for 6 h in 5% CO2 humidified air at 39°C. Presumptive zygotes were randomly allocated to culture either in a control medium (6 mg mL–1 of BSA CR1aa medium) or with 4.5 mm fructose added to CR1aa culture medium for 7 days in an atmosphere of 5% O2, 5% CO2, and 90% N2 at 39°C. Embryo cleavage, and development to the morulae and blastocyst stages were evaluated on Days 2, 5, and 7 of culture, respectively. Embryos were graded according to International Embryo Transfer Society standards. The total number of blastocysts recorded was the sum of grade C1 and C2 embryos. Data were analyzed by using the General Linear Model (SPSS 11.0, SPSS Inc., Chicago, IL, USA). As shown in Table 1, addition of fructose to the culture medium affected neither the rate of cleavage nor subsequent development to the morula stage or total blastocyst development. However, the proportion of C1-grade embryos of the total blastocysts was significantly (P < 0.05) improved. This study suggests that addition of fructose to the culture medium can promote embryo quality and yields that are suitable for embryo transfer. Table 1.Effect of addition of fructose on in vitro development of bovine sexed embryos

System-size independence of directed flow measured at the BNL relativistic heavy-ion collider

We measure directed flow (v_{1}) for charged particles in Au+Au and Cu+Cu collisions at sqrt[s_{NN}]=200 and 62.4 GeV, as a function of pseudorapidity (eta), transverse momentum (p_{t}), and collision centrality, based on data from the STAR experiment. We find that the directed flow depends on the incident energy but, contrary to all available model implementations, not on the size of the colliding system at a given centrality. We extend the validity of the limiting fragmentation concept to v_{1} in different collision systems, and investigate possible explanations for the observed sign change in v_{1}(p_{t}).

Forward neutral-pion transverse single-spin asymmetries in p + p collisions at sqrt[s] = 200 GeV

We report precision measurements of the Feynman x (xF) dependence, and first measurements of the transverse momentum (pT) dependence, of transverse single-spin asymmetries for the production of pi0 mesons from polarized proton collisions at sqrt[s] = 200 GeV. The xF dependence of the results is in fair agreement with perturbative QCD model calculations that identify orbital motion of quarks and gluons within the proton as the origin of the spin effects. Results for the pT dependence at fixed xF are not consistent with these same perturbative QCD-based calculations.

Longitudinal double-spin asymmetry for inclusive jet production in p[over -->] + p[over -->] collisions at sqrt[s]=200 GeV

We report a new STAR measurement of the longitudinal double-spin asymmetry A(LL) for inclusive jet production at midrapidity in polarized p + p collisions at a center-of-mass energy of sqrt[s]=200 GeV. The data, which cover jet transverse momenta 5<p(T)<30 GeV/c, are substantially more precise than previous measurements. They provide significant new constraints on the gluon spin contribution to the nucleon spin through the comparison to predictions derived from one global fit to polarized deep-inelastic scattering measurements.

98 VITRIFICATION OF ZYGOTES SUPPORTS FULL-TERM DEVELOPMENT IN RABBITS

Rabbit can serve as an excellent model for human reproduction and relevant disease study. The objective of the study was to develop an effective procedure to preserve the rabbit genome by vitrifying zygotes. Sexually matured New Zealand White rabbits maintained under a 16 h light:8 h dark cycle were superovulated with a regime of two 0.3-mg, two 0.4-mg, and two 0.7-mg injections of FSH with an interval of 12 h between, followed by an injection of 200 IU hCG and mating. Presumptive zygotes were flushed from the oviducts and collected by midventral lapartomy 18 h after hCG injection. One-cell-stage embryos were assigned to pre-equilibration at 38.5�C in HEPES-buffered TCM199 supplemented with 20% FBS + 7.5% ethylene glycol (EG) (v/v) + 7.5% dimethylsulphoxide (DMSO) (v/v) (dehydration medium) for 3 min, and subsequently to 1.0 ml of vitrification medium (TCM199 supplemented with 20% FBS + 20% EG and 20% DMSO), as described by Vajta et al. (1998 Mol. Reprod. Dev. 51, 53–58), at room temperature for 3 min. Five to six embryos per group were then vitrified in a micro-droplet (approximately 1–2 µL) by directly dropping them into a thin layer of liquid nitrogen on the solid surface that generated a super cold surface for vitrification. Vitrified embryos were sequentially warmed, rehydrated in 20% FBS M199 with different concentrations of sucrose, and washed in 20% FBS M199 for 5 min. Warmed embryos were assigned either for further in vitro culture or for embryo transfer to test corresponding developmental potentials. Dutch rabbits were used as recipients in the procedure of asynchronous ovulation induction (22-h delay to zygote donors) by an intramuscular injection of 15 µg of GnRH per doe. Three or four warmed zygotes were surgically transferred into the recipients on the same day of thawing. Pregnancy was monitored by palpation and/or ultrasound on Days 14–16 post-embryo transfer (ET); C-sections were performed on Day 31 to retrieve full-term developed newborns. Preliminary results showed that a 96% (n = 35) post-warming survival rate was achieved with vitrified rabbit zygotes; subsequent cleavage and blastocyst development were 41.6 and 33.3%, respectively. Transfer of a total of 23 warmed embryos into 6 recipients resulted in 5 pregnancies (83.3%, 5/6). Five live kits (21.7%, 5/23) were delivered. Our study suggests that vitrification of rabbit zygotes is a feasible approach for preserving rabbit genetic material. The establishment of suitable conditions for the vitrification of rabbit zygotes could be useful as a model for vitrification of human 1-celled embryos. The authors thank the staff of the animal facility at the University of Connecticut for animal care and maintenance. This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261-01.

199 EFFECT OF HEPARIN CONCENTRATION ON BOVINE PREIMPLANTATIONAL DEVELOPMENT IN VITRO USING SEX-SORTED SPERM

The objective of this study was to examine the effect of heparin on bovine IVF and to improve the efficiency of IVF production by using sex-sorted sperm. The fertility performance of sex-sorted and unsorted semen from 4 bulls was compared to determine the optimal heparin concentration during preimplantational embryo development. A total of 7615 matured bovine oocytes were randomly allocated among different heparin concentrations (0, 2.5, 5, 10, 20, 40, 60, 80, and 100 μg mL–1) in Brackett-Oliphant medium and coincubated with either sex-sorted or unsorted sperm for 6 h. Presumptive zygotes were cultured in CR1aa+ 6 mg mL–1 of BSA in 5% O2 , 5% CO2 and 90% N2 at 39°C until Day 8 (Day 0, culture post-IVF). Cleavage rates at Day 2 and embryo development to blastocyst (BL) at Day 8 were recorded. Data (4 replicates) were analyzed by a general linear model (SPSS 11.0, SPSS Inc., Chicago, IL). The optimal heparin concentration for each treatment was determined as the lowest value from those groups that resulted in the highest BL rates. The results (Table 1) demonstrated that a differential requirement of heparin concentration was important for the highest preimplantational BL development between sexed sperm and unsorted control within each bull. By optimizing heparin concentration, in 3 out of 4 (75%) bulls, the in vitro BL development with sex-sorted sperm could be increased to a level that was comparable to the highest BL rate from unsorted sperm (bulls A, B, and C, P > 0.05). A higher heparin concentration was required for optimal BL development in bulls A and C; however, a lower concentration was desirable for bulls B and D, indicating that a partial capacitation to the sperm may have taken place in bulls B and D during the sorting process, as reported by Lu and Seidel (2004 Theriogenology 62, 819–830). The fertility of sorted sperm from bull D (1 out of 4, 25%) was adversely affected, even after heparin optimization for BL development (P < 0.05). This result suggests that sperm sorting could affect the IVF fertility of sorted sperm in a bull-specific manner, but it was not significant for all bulls. Table 1. Blastocyst (BL) development in bovine IVF after heparin optimization using sorted and unsorted sperm This project was supported by the SBIR program under a USDA Cooperative State Research, Education, and Extension Service (CSREES) grant to F. Du (USDA #2006-03069).

Nuclear reprogramming by somatic cell nuclear transfer--the cattle story

Somatic cell nuclear transfer (cloning) returns a differentiated cell to a totipotent status; a process termed nuclear reprogramming. Nuclear transfer has potential applications in agriculture and biomedicine, but is limited by low efficiency. To understand the deficiencies of nuclear reprogramming, our research has focused on both candidate genes (imprinted and X-linked genes) and global gene expression patterns in cloned bovine embryos/offspring as compared to those generated by conventional reproduction. We found aberrant expression patterns of H19 and Igf2r as well as X-linked genes in term cloned calves. The expression profiles of cloned blastocysts, however, closely resembled those of the naturally fertilized embryos but were considerably different from those of their nuclear donor cells. Our findings suggest that cloned embryos have undergone significant nuclear reprogramming by the blastocyst stage. However, it is possible that during re-differentiation in later development gene expression aberrancies occur. Additionally, small initial nuclear reprogramming errors may be manifested during subsequent development.

Pregnancy and fetal characteristics after transfer of vitrified in vivo and cloned bovine embryos

This study was conducted to examine pregnancy progression and fetal characteristics following transfer of vitrified bovine nuclear transfer versus in vivo-derived embryos. Nuclear transfer (NT) was conducted using cumulus cells collected from an elite Holstein-Friesian dairy cow. Expanding and hatching blastocysts on Day 7 were vitrified using liquid nitrogen surface vitrification. Day 7 in vivo embryos, produced using standard superovulation procedures applied to Holstein-Friesian heifers (n=6), were vitrified in the same way. Following warming, embryos were transferred to synchronized recipients (NT: n=65 recipients; Vivo: n=20 recipients). Pregnancies were monitored by ultrasound scanning on Days 25, 45 and 75 and a sample of animals were slaughtered at each time point to recover the fetus/placenta for further analyses. Significantly more animals remained pregnant after transfer of in vivo-derived embryos than NT embryos at all time points: Day 25 (95.0 versus 67.7%, P<0.05), Day 45 (92.8 versus 49.1%, P<0.01) and Day 75 (70.0 versus 20.8%, P<0.0). There was no significant difference (P=0.10) in the weight of the conceptus on Day 25 from NT transfers (1.14+/-0.23 g, n=8) versus in vivo transfers (0.75+/-0.19 g, n=8). On Day 45, there was no significant difference in the weight of either fetus (P=0.393) or membranes (P=0.167) between NT embryos (fetus: 2.76+/-0.40, n=12; membranes: 59.0+/-10.0, n=11) or in vivo-derived embryos (fetus: 2.60+/-0.15, n=6; membranes: 41.8+/-5.2, n=4). However, on Day 75 the weight of the fetus and several of the major organs were heavier from NT embryos. These data suggest that morphological abnormalities involving the fetus and the placenta of cloned pregnancies are manifested after Day 45.

Measurement of transverse single-spin asymmetries for Dijet production in proton-proton collisions at sqrt[s]=200 GeV

We report the first measurement of the opening angle distribution between pairs of jets produced in high-energy collisions of transversely polarized protons. The measurement probes (Sivers) correlations between the transverse spin orientation of a proton and the transverse momentum directions of its partons. With both beams polarized, the wide pseudorapidity (-1< or = eta < or = +2) coverage for jets permits separation of Sivers functions for the valence and sea regions. The resulting asymmetries are all consistent with zero and considerably smaller than Sivers effects observed in semi-inclusive deep inelastic scattering. We discuss theoretical attempts to reconcile the new results with the sizable transverse spin effects seen in semi-inclusive deep inelastic scattering and forward hadron production in pp collisions.

Partonic Flow and phi-Meson production in Au+Au collisions at sqrt radical sNN = 200 GeV

We present first measurements of the phi-meson elliptic flow (v2(pT)) and high-statistics pT distributions for different centralities from radical sNN=200 GeV Au+Au collisions at RHIC. In minimum bias collisions the v2 of the phi meson is consistent with the trend observed for mesons. The ratio of the yields of the Omega to those of the phi as a function of transverse momentum is consistent with a model based on the recombination of thermal s quarks up to pT approximately 4 GeV/c, but disagrees at higher momenta. The nuclear modification factor (R CP) of phi follows the trend observed in the K S 0 mesons rather than in Lambda baryons, supporting baryon-meson scaling. These data are consistent with phi mesons in central Au+Au collisions being created via coalescence of thermalized s quarks and the formation of a hot and dense matter with partonic collectivity at RHIC.

Transverse momentum and centrality dependence of high-pT nonphotonic electron suppression in Au+Au collisions at sqrt[s NN]=200 GeV

The STAR collaboration at the BNL Relativistic Heavy-Ion Collider (RHIC) reports measurements of the inclusive yield of nonphotonic electrons, which arise dominantly from semileptonic decays of heavy flavor mesons, over a broad range of transverse momenta (1.2<p(T)<10 GeV/c) in p+p, d+Au, and Au+Au collisions at sqrt[s_{NN}]=200 GeV. The nonphotonic electron yield exhibits an unexpectedly large suppression in central Au+Au collisions at high p(T), suggesting substantial heavy-quark energy loss at RHIC. The centrality and p(T) dependences of the suppression provide constraints on theoretical models of suppression.

Determination of triadimenol based on the quenching effect on resonance light scattering from the triadimenol–deoxyribonucleic acid–hydrochloric acid system

Analysis of triadimenol was carried out using deoxyribonucleic acids (DNA) via the resonance light scattering (RLS) technique. After adding triadimenol into aqueous medium of pH 1.72, the RLS of DNA was remarkably quenched. A resonance light scattering peak at 310 nm was found, and the quenched intensity of RLS at this wavelength was proportional to the concentration of triadimenol. The linear range of the calibration curve was approximately 0-3 microg mL-1 with a detection limit (S/N=3) of 0.07 microg mL-1. The triadimenol in samples of water, cucumber and human serum was determined. The results were satisfactory, and the recovery rates were in the range of 96.3-106.0%, 94.8-105.9% and 92.3-100.5%, respectively. The interaction mechanism was also studied.

Scaling properties of hyperon production in Au+Au collisions at square root [sNN]=200 GeV

We present the scaling properties of Lambda, Xi, and Omega in midrapidity Au+Au collisions at the Brookhaven National Laboratory Relativistic Heavy Ion Collider at sqrt[s_{NN}]=200 GeV. The yield of multistrange baryons per participant nucleon increases from peripheral to central collisions more rapidly than that of Lambda, indicating an increase of the strange-quark density of the matter produced. The strange phase-space occupancy factor gamma_{s} approaches unity for the most central collisions. Moreover, the nuclear modification factors of p, Lambda, and Xi are consistent with each other for 2<p_{T}<5 GeV/c in agreement with a scenario of hadron formation from constituent quark degrees of freedom.

96 TRICHOSTATIN A IMPROVED THE QUALITY OF RABBIT NUCLEAR TRANSFER EMBRYOS

Nuclear reprogramming is dependent upon a number of factors, including chromatin organization and modification. Trychostatin A (TSA), a histone deacetylase inhibitor, was used to increase histone acetylation and to improve reprogrammability in both cattle and mice. The objective of the study was to determine whether TSA could improve the pre-implantational development potential of rabbit nuclear transplant (NT) embryos. Rabbit oocytes were flushed from the oviducts of superovulated donors treated with the regime of FSH and hCG. Cumulus cells were then denuded from the oocytes by incubation in 0.5% hyaluronidase and pipetting. Oocyte enucleation was conducted in 10% FBS M199 and confirmed under fluorescence microscopy. Cumulus cells were prepared as nuclear donors for NT; a donor cell with the diameter approximately 15–19 µm was transferred into the perivitelline space of an enucleated oocyte, and subsequently fused with the oocyte recipient by application of 3 direct current pulses at 3.2 kV cm−1 for a duration of 20 µs/pulse. Fused embryos were activated by the same electrical stimulation regime described above, and subsequently cultured in M199 + 10% FBS containing 2.0 mM 6-dimethylaminopurine (DMAP) and 5 µg mL−1 cycloheximide for 1 h. Rabbit NT embryos were cultured in 5 nM TSA-2.5% FBS-B2 medium for 10 h before being transferred into regular medium (FBS-B2). The TSA-treated embryos (5 nM vs. 0 nM) were cultured in 400 µL FBS-B2 medium for 5 days in 5% CO2 in a humidified atmosphere at 38.5°C (initiation of activation = Day 0). NT embryo development to cleaved (2 to 4 cell), morula, and blastocyst stages was evaluated on Day 2, Day 3, and Day 5, respectively. The selected NT blastocysts were counted for cell numbers following Hoechst 33342 epifluorescenin staining. The results (Table 1) showed that there was no difference on pre-implantational development of cloned embryos between TSA-added and control groups (P &gt; 0.05). However, a significantly higher cell number per NT blastocyst was found in the TSA-added group (357 vs. 113; P &lt; 0.05). This indicated that the blastocyst quality in NT embryos was improved with the addition of TSA by increasing histone acetylation activity. The developmental potential of TSA-treated NT embryos to term is under investigation. Table 1.Effects of TSA on the pre-implantational development of cloned rabbit embryos This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261-01.

307 ADDITION OF HIGH CONCENTRATIONS OF HEPARIN DURING IN VITRO FERTILIZATION IMPROVES PERCENTAGES OF CLEAVAGE AND BLASTOCYST FORMATION WHEN BOVINE OOCYTES ARE INSEMINATED IN VITRO WITH SEX-SORTED SPERM

The developmental potential of oocytes fertilized in vitro by sexed–sorted frozen–thawed sperm remains low. The aim of this study was to find an optimal concentration of heparin during IVF using frozen–thawed sex-sorted sperm to improve the percentages of fertilization and blastocyst formation. A total of 1708 matured bovine oocytes were randomly allocated among different concentrations of heparin (0, 2.5, 5, 10, 20, and 40 µg mL−1) in Bracket-Olifant medium and co-incubated with non-sexed or sex-sorted sperm for 6 h (Day 0). The sperm (sorted or not) used for IVF was from one bull of proven fertility. Presumptive zygotes then were cultured in CR1aa + 6 mg mL−1 of BSA in 5% O2, 5% CO2, and 90% N2 at 39°C until Day 8. Percentages of cleavage were recorded on Day 2. Data (3 replicates) were analyzed by ANOVA. The results (Table 1) demonstrated that addition of different concentrations of heparin in IVF medium for non-sexed sperm groups did not alter cleavage and blastocyst formation. However, the lowest percentages of cleavage were observed with 0, 2.5, and 5 µg mL−1 of heparin in sexed sperm groups, demonstrating that high concentrations of heparin (20 and 40 µg mL−1) positively affected the percentages of cleavage and blastocyst formation. A greater proportion of zygotes in 20 and 40 µg mL−1 sexed sperm groups developed into grade 1 blastocysts on Day 7, and subsequently formed more blastocysts on Day 8 compared with 0, 2.5, and 5 µg mL−1 of heparin in sexed sperm groups. In conclusion, addition of heparin was not necessary when frozen–thawed non-sexed sperm were used for IVF with this particlar bull. However, addition of higher concentrations of heparin during IVF improved fertilization and blastocyst formation in vitro (40 µg mL−1 of heparin could be used as an alternative concentration for frozen–thawed sex-sorted sperm with this particular bull). The incidence of polyspermy as well as polyploidy in blastocysts is currently being studied. Table 1.Effect of heparin concentrations during IVF on cleavage and blastocyst formation

Longitudinal double-spin asymmetry and cross section for inclusive jet production in polarized proton collisions at square root of s = 200 GeV

We report a measurement of the longitudinal double-spin asymmetry A(LL) and the differential cross section for inclusive midrapidity jet production in polarized proton collisions at square root of s = 200 GeV. The cross section data cover transverse momenta 5 < pT < 50 GeV/c and agree with next-to-leading order perturbative QCD evaluations. The A(LL) data cover 5 < pT < 17 GeV/c and disfavor at 98% C.L. maximal positive gluon polarization in the polarized nucleon.

Direct observation of dijets in central Au+Au collisions at sqrt[sNN]=200 GeV

The STAR Collaboration at the Relativistic Heavy Ion Collider reports measurements of azimuthal correlations of high transverse momentum (pT) charged hadrons in Au+Au collisions at higher pT than reported previously. As (pT) is increased, a narrow, back-to-back peak emerges above the decreasing background, providing a clear dijet signal for all collision centralities studied. Using these correlations, we perform a systematic study of dijet production and suppression in nuclear collisions, providing new constraints on the mechanisms underlying partonic energy loss in dense matter.

Identified baryon and meson distributions at large transverse momenta from Au + Au collisions at square root sNN=200 GeV

Transverse momentum spectra of pi+/-, p, and p up to 12 GeV/c at midrapidity in centrality selected Au + Au collisions at square root sNN=200 GeV are presented. In central Au + Au collisions, both pi +/- and p(p) show significant suppression with respect to binary scaling at pT approximately >4 GeV/c. Protons and antiprotons are less suppressed than pi+/-, in the range 1.5 approximately < pT approximately < 6 GeV/c. The pi-/pi+ and p/p ratios show at most a weak pT dependence and no significant centrality dependence. The p/pi ratios in central Au + Au collisions approach the values in p + p and d + Au collisions at pT approximately >5 GeV/c. The results at high pT indicate that the partonic sources of pi+/-, p, and p have similar energy loss when traversing the nuclear medium.

Forward neutral pion production in p + p and d + Au collisions at square root sNN=200 GeV

Measurements of the production of forward pi0 mesons from p + p and d + Au collisions at square root sNN=200 GeV are reported. The p + p yield generally agrees with next-to-leading order perturbative QCD calculations. The d + Au yield per binary collision is suppressed as eta increases, decreasing to approximately 30% of the p + p yield at eta =4.00, well below shadowing expectations. Exploratory measurements of azimuthal correlations of the forward pi0 with charged hadrons at eta approximately 0 show a recoil peak in p + p that is suppressed in d + Au at low pion energy. These observations are qualitatively consistent with a saturation picture of the low-x gluon structure of heavy nuclei.

Strange baryon resonance production in sqrt s NN=200 GeV p+p and Au+Au collisions

We report the measurements of Sigma(1385) and Lambda(1520) production in p+p and Au+Au collisions at sqrt[s{NN}]=200 GeV from the STAR Collaboration. The yields and the p(T) spectra are presented and discussed in terms of chemical and thermal freeze-out conditions and compared to model predictions. Thermal and microscopic models do not adequately describe the yields of all the resonances produced in central Au+Au collisions. Our results indicate that there may be a time span between chemical and thermal freeze-out during which elastic hadronic interactions occur.

Developmental potential of vitrified holstein cattle embryos fertilized in vitro with sex-sorted sperm

In vitro fertilization (IVF) is a feasible way to utilize sex-sorted sperm to produce offspring of a predetermined sex in the livestock industry. The objective of the present study was to examine the effects of various factors on bovine IVF and to systematically improve the efficiency of IVF production using sex-sorted sperm. Both bulls and sorting contributed to the variability among differential development rates of embryos fertilized by sexed sperm. Increased sorting pressures (275.8 to 344.75 kPa) did not have a significant effect on the in vitro fertility of the sorted sperm; neither did an extended period of 9 to 14 h from semen collection to sorting. As few as 600 sorted sperm were used to fertilize an oocyte, resulting in blastocyst development of 33.2%. Postwarming of vitrified sexed IVF embryos resulted in high morphological survival (96.3%) and hatching (84.4%) rates, similar to those fertilized by nonsexed sperm (93.1 and 80.6%, respectively). A 40.9% pregnancy rate was established following the transfer of 3,627 vitrified, sexed embryos into synchronized recipients. This was not different from the rates with nonsexed IVF (41.9%, n = 481), or in vivo-produced (53.1%, n = 192) embryos. Of 458 calves born, 442 (96.5%) were female and 99.6% appeared normal. These technologies (sperm sexing-IVF-vitrification-embryo transfer) provide farmers, as well as the livestock industry, with a valuable option for herd expansion and heifer replacement programs. In summary, calves were produced using embryos fertilized by sex-sorted sperm in vitro and cryopreserved by rapid cooling vitrification.

Prolonging bovine sperm-oocyte incubation in modified medium 199 improves embryo development rate and the viability of vitrified blastocysts

This study was conducted to compare the efficacy of four in vitro fertilization (IVF) media: Bracket and Oliphant's medium (BO), modified medium 199 (IVF-M199), modified Tyrode's medium (MTM), and modified KSOM (m-KSOM) on fertilization efficiency and blastocyst formation rate. In addition, we wanted to investigate the benefit of prolonging the IVF period (from 6 to 18 h) using the two most effective IVF media determined in our initial experiment; subsequently, blastocyst viability was assessed following vitrification. A higher incidence of polyspermic fertilization was observed in the MTM (6%) and in BO, in both the 6 and 18 h (7% and 11%, respectively) groups, than in the m-KSOM (1%) or in the IVF-M199 6 or 18 h (1 and 3%, respectively) groups. Cleavage rates were similar in BO, IVF-M199, and MTM 48 h post-fertilization; however, the lowest cleavage rate was observed for m-KSOM. A greater proportion of zygotes developed into 8-cell embryos in IVF-M199 than in other IVF media. Subsequently, a greater proportion of blastocyst formation and hatching was achieved in IVF-M199 (40% and 79%, respectively) or BO (35% and 74%, respectively) than in m-KSOM (18% and 58%, respectively) or MTM (22% and 66%, respectively). Prolonging IVF to 18 h did not alter cleavage rates; however, the highest rate of overall blastocyst formation was achieved in the IVF-M199 18 h (49%), rather than in the BO 18 h (20%) group. Vitrified/thawed blastocysts from IVF-M199 groups re-expanded and developed better, as compared to the BO 18 h group, and hatching rate and total cell number in IVF-M199 18 h group was comparable to the control groups (non-vitrified). Vitrification reduced survival compared to controls. In conclusion, IVF-M199 was successfully used for IVF, compared favorably to BO medium, and offered the advantage of an extended IVF period for up to 18 h that requires only one-half a dose of semen, and resulted in better quality blastocysts that endured vitrification with a hatching rate comparable to that of control groups.

Mefloquine induces dose-related neurological effects in a rat model

Mefloquine is one of the drugs approved by the FDA for malaria chemoprophylaxis. Mefloquine is also approved for the treatment of malaria and is widely used for this purpose in combination with artesunate. However, the clinical utility of the compound has been compromised by reports of adverse neurological effects in some patients. In the present study, the potential neurological effects of mefloquine were investigated with six 7-week-old female rats given a single oral dose of the compound. Potential mefloquine-induced neurological effects were monitored using a standard functional observational battery, automated open field tests, automated spontaneous activity monitoring, a beam traverse task, and histopathology. Plasma mefloquine concentrations were determined 72 h after dosing by using liquid chromatography-mass spectrometry. Mefloquine induced dose-related changes in endpoints associated with spontaneous activity and impairment of motor function and caused degeneration of specific brain stem nuclei (nucleus gracilis). Increased spontaneous motor activity was observed only during the rats' normal sleeping phase, suggesting a correlate to mefloquine-induced sleep disorders. The threshold dose for many of these effects was 187 mg/kg of body weight. This dose yielded plasma mefloquine concentrations after 72 h that are similar to those observed in humans after the treatment dose. Collectively, these data suggest that there may be a biological basis for some of the clinical neurological effects associated with mefloquine.

31 FULL-TERM AND LIVE RABBIT CLONES PRODUCED BY SOMATIC CELL NUCLEAR TRANSFER

Transgenic/knockout (KO) rabbits can serve as an excellent animal model for human cardiovascular diseases (CVD) and other diseases. However, the production of transgenic/KO rabbits is hindered by low efficiency of traditional DNA microinjection and the unavailability of embryonic stem cell lines. An alternative approach is to produce transgenic/KO rabbits by somatic cell nuclear transfer (SCNT) using genetically modified somatic cells as nuclear donors. Our initial objective of the study was to prove the feasibility of cloning rabbits by SCNT because rabbit is a difficult species to be cloned. Rabbit oocytes were flushed from the oviducts of superovulated donors treated with the regime of follicle-stimulating hormone (FSH) and human choriani gonadotropin (hCG). Cumulus cells were then denuded from the oocytes by incubation in 0.5% hyaluronidase and pipetting. Oocyte enucleation was conducted in M199 + 10% fetal bovine serum (FBS) and confirmed by fluorescence microscopy. Cumulus cells used for nuclear donors were prepared from fresh cumulus-oocytes complexes. The donor nucleus was transferred into a recipient oocyte by either cell fusion or direct nuclear injection method. In the cell fusion method, a small donor cell with the diameter approximately 15–19 µm was transferred into the perivitelline space of an enucleated oocyte; subsequently the somatic cell-cytoplast pair was fused by applying three direct current pulses at 3.2 kV/cm for a duration of 20 µs/pulse. In the direct nuclear injection method, a mechanically lysed donor cell was injected into oocyte cytoplasm with the aid of a piezo-drill system. Fused embryos or injected oocytes were activated by the same electrical stimulation regime described above, and subsequently cultured in M199 + 10% FBS containing 2.0 mM 6-dimethylaminopurine (DMAP) and 5 µg/mL cycloheximide for 2 h. For the in vitro study, cloned embryos were cultured in B2 medium plus 2.5% FBS for 5 days (initiation of activation = day 0) at 38.5°C in 5% CO2 humidified air. For the in vivo study, cloned embryos were cultured for 20–22 h in vitro before transfer into pseudopregnant rabbit recipients. Pregnancy was monitored by palpation and/or ultrasound on Days 14–16 post embryo transfer (ET). The results (Table 1) show that the donor nuclei-introducing rate was higher with nuclear direct injection than with the cell fusion method (P < 0.05). There were no significant differences among subsequent cleavage and development to morula and blastocysts between both methods, although the development rates of cloned embryos via electrically mediated fusion were higher than those derived from the injection group. One recipient in the injection group (1/6, 17%) and six recipients in the fusion group (6/16, 38%) were diagnosed as pregnant. From the fusion group, one full-term but stillborn and one live and healthy clone rabbit were delivered on Days 33 and 31 post-ET, respectively. To our knowledge, this is the second report of full term development of cloned rabbit by somatic nuclear transfer cloning. Our further study is to clone live rabbit offspring with modified transgenic/KO somatic cell lines. Table 1. In vitro development of rabbit cloned embryos with cumulus cells as nuclear donors This work was supported by NIH/NCRR-SBIR grant: 1R43RR020261–11.

6 EXPRESSION PROFILING OF SINGLE BOVINE EMBRYOS REVEALS SIGNIFICANT EFFECTS OF IN VITRO MATURATION, FERTILIZATION AND CULTURE

Cattle and sheep embryos transferred after in vitro production are often afflicted by large offspring syndrome (LOS), which has been correlated with the presence of serum and/or cell co-culture. Previous research indicates that post-fertilization culture affects blastocyst quality and gene expression, and in vitro oocyte maturation and fertilization impact developmental competence. To dissect the effects of in vitro maturation, fertilization, and culture, we compared the expression profiles of single bovine blastocysts generated by: (1) in vitro maturation, fertilization and culture (IVF, n = 15); (2) in vivo maturation, in vivo fertilization, and in vitro culture (IVD, n = 14); and (3) in vivo maturation, fertilization, and development (AI, n = 14). For in vitro culture, the embryos were cultured for 2 days in CR1aa medium with bovine serum albumin (BSA) and then transferred to CR1aa with 10% fetal bovine serum (FBS) with cumulus cells until Day 7, at which time the embryos were vitrified. IVD zygotes were surgically collected from two superovulated Holstein donor cows 24 h post-insemination and cultured in the same system. To conduct expression profiling, total RNA was isolated from individual thawed embryos. The RNA was subjected to three rounds of amplification utilizing a previously adapted and validated T7 linear amplification protocol. Amplified RNA from each embryo and from a standard reference was indirectly labeled with Cy3 or Cy5 by dye swap and hybridized to a custom bovine cDNA microarray containing ~6300 unique genes. After Loess normalization, an ANOVA model (GeneSpring 6.1 and SAS 9.0) was used to identify differentially expressed genes. The P-values were adjusted for multiple comparisons using the false discovery rate approach, and a e2-fold differential criterion was applied. A subset of the differentially expressed genes was verified by real-time RT-PCR. The blastocyst rates for IVF and IVD embryos were 37% and 75%, respectively. There were 305, 365, and 200 genes differentially expressed between the AI and IVD, the IVF and IVD, and the AI and IVF comparisons, respectively. Interestingly, 44 differentially expressed genes were identified between the AI embryos and both the IVF and the IVD embryos, making these potential candidates for LOS. There were 61 genes differentially expressed between the IVF embryos and the AI and IVD embryos. The Gene Ontology categories 'RNA processing' and 'RNA binding' were over-represented among the genes that were down-regulated in the IVF embryos, indicating an effect of in vitro oocyte maturation/fertilization on embryonic gene expression. This work was supported by USDA grants to X.Y., H.A.L., and X.C.T.

Distributions of charged hadrons associated with high transverse momentum particles in pp and Au+Au collisions at sqrt[sNN]=200 GeV

Charged hadrons in [EQUATION: SEE TEXT] associated with particles of [EQUATION: SEE TEXT] are reconstructed in pp and Au+Au collisions at sqrt[sNN]=200 GeV. The associated multiplicity and p magnitude sum are found to increase from pp to central Au+Au collisions. The associated p distributions, while similar in shape on the nearside, are significantly softened on the awayside in central Au+Au relative to pp and not much harder than that of inclusive hadrons. The results, consistent with jet quenching, suggest that the awayside fragments approach equilibration with the medium traversed.

Multistrange Baryon elliptic flow in Au+Au collisions at square root of sNN=200 GeV

We report on the first measurement of elliptic flow v2(pT) of multistrange baryons Xi- +Xi+ and Omega- + Omega+ in heavy-ion collisions. In minimum-bias Au+Au collisions at square root of s(NN)=200 GeV, a significant amount of elliptic flow, comparable to other nonstrange baryons, is observed for multistrange baryons which are expected to be particularly sensitive to the dynamics of the partonic stage of heavy-ion collisions. The pT dependence of v2 of the multistrange baryons confirms the number of constituent quark scaling previously observed for lighter hadrons. These results support the idea that a substantial fraction of the observed collective motion is developed at the early partonic stage in ultrarelativistic nuclear collisions at the Relativistic Heavy Ion Collider.

Multiplicity and pseudorapidity distributions of photons in Au+Au collisions at square root of (S(NN)) = 62.4 GeV

We present the first measurement of pseudorapidity distribution of photons in the region 2.3 < or = eta < or = 3.7 for different centralities in Au+Au collisions at square root of (S(NN)) = 62.4 GeV. We find that the photon yield scales with the number of participating nucleons at all collision centralities studied. The pseudorapidity distribution of photons, dominated by pi0 decays, has been compared to those of charged pions, photons, and inclusive charged particles from heavy-ion and nucleon-nucleon collisions at various energies. The photon production has been shown to be consistent with the energy and centrality independent limiting fragmentation scenario.

Open charm yields in d+Au collisions at squareroot[sNN]=200 GeV

Midrapidity open charm spectra from direct reconstruction of D0(D0)-->K-/+pi+/- in d+Au collisions and indirect electron-positron measurements via charm semileptonic decays in p+p and d+Au collisions at squareroot[sNN]=200 GeV are reported. The D0(D0) spectrum covers a transverse momentum (pT) range of 0.1<pT<3 GeV/c, whereas the electron spectra cover a range of 1<pT<4 GeV/c. The electron spectra show approximate binary collision scaling between p+p and d+Au collisions. From these two independent analyses, the differential cross section per nucleon-nucleon binary interaction at midrapidity for open charm production from d+Au collisions at BNL RHIC is dsigma(NN)cc/dy=0.30+/-0.04(stat)+/-0.09(syst) mb. The results are compared to theoretical calculations. Implications for charmonium results in A+A collisions are discussed.

The determination of deoxyribonucleic acids with triadimenol based on the enhancement of resonance light scattering

For the first time, triadimenol was used to determine nucleic acid (DNA) using the resonance light scattering (RLS) technique. The RLS of triadimenol was greatly enhanced by DNA in the range of pH 1.6 to approximately 1.9. A resonance light-scattering peak at 310 nm was found, and the enhanced intensity of RLS at this wavelength was proportional to the concentration of DNA. The linear range of the calibration curve was 0 to approximately 9 microg/ml with the detection limit of 24 ng ml(-1). The mechanism studies of the system indicated that the enhanced RLS is due to the aggregation of triadimenol on DNA. The nucleic acids in synthetic samples and in rice seedling extraction were analyzed with satisfactory results. Compared with other methods, this method is convenient, rapid, inexpensive and simple.

48 PREGNANCY AND FETAL CHARACTERISTICS AFTER TRANSFER OF VITRIFIED IN VIVO AND CLONED BOVINE EMBRYOS

This study was conducted to examine pregnancy progression and fetal characteristics following transfer of vitrified bovine nuclear transfer (NT) vs. in vivo-derived (Vivo) embryos. Nuclear transfer was conducted using skin fibroblast cells derived from cultured ear explants taken from an elite Holstein-Friesian dairy cow. Expanding and hatching blastocysts on Day 7 were vitrified using liquid nitrogen surface vitrification (Shen et al. 2004 Reprod. Fertil. Dev. 16, 158). Day 7 in vivo embryos, produced using standard superovulation procedures applied to Holstein-Friesian heifers (n = 6), were vitrified in the same way. Following warming, embryos were transferred to synchronized recipients (2 per recipient; NT: n = 81 recipients; Vivo: n = 20 recipients). Pregnancies were monitored by ultrasound scanning on Days 25, 45, and 75, and a sample of animals was slaughtered at each time point to recover the fetus/placenta for further analyses. On Day 25, the entire conceptus was weighed together; on Day 45, the fetus and placenta were weighed separately; on Day 75, the fetus was dissected and the major organs were weighed. Significantly more animals remained pregnant after transfer of in vivo-derived embryos than NT embryos at all time points: Day 25 (95.0 vs. 61.7%, P < 0.01), Day 45 (93.3 vs. 39.7%, P < 0.001), and Day 75 (90.9 vs. 19.8%, P < 0.001). There was no significant difference (P = 0.10) in the weight of the conceptus on Day 25 from NT transfers (1.14 ± 0.23 g, n = 8) vs. Vivo transfers (0.75 ± 0.19 g, n = 8). On Day 45, there was no significant difference in the weight of either fetus (P = 0.393) or membranes (P = 0.167) between NT embryos (fetus: 2.76 ± 0.40 g, n = 12; membranes 59.0 ± 10.0 g, n = 11) or in vivo-derived embryos (fetus: 2.60 ± 0.15 g, n = 6; membranes 41.8 ± 5.2 g, n = 4). However, on Day 75, the weights of the fetus and several of the major organs were heavier from NT embryos (Table 1). These data suggest that the large calf syndrome is manifested after Day 45. Table 1. Fetal characteristics on Day 75 of gestation following transfer of vitrified in vivo-derived vs. NT blastocysts This work was supported by the U.S. Department of Agriculture.

67 PREMATURE CHROMOSOME CONDENSATION IS NOT ESSENTIAL FOR BOVINE SOMATIC NUCLEAR REPROGRAMMING

The objective of this study was to determine the effect of donor nuclear exposure in MII oocyte cytoplasm on nuclear reprogramming events and subsequent development of cloned embryos in cattle. Somatic nuclear transfer (NT) was performed by electrofusion of the enucleated MII oocytes with cultured cumulus cells by ovum pickup. Donor cell-cytoplast pairs were fused by applying two direct current pulses at 2 kV/cm for 10 μs. Fused NT embryos were randomly divided in to Treatment A (immediate activation) and Treatment B (delayed activation, 4-h exposure in MII cytoplast before activation). In both treatment groups, the activation protocol was identical and consisted of incubation in cycloheximide (10 μg/mL) plus cytochalasin D (2.5 μg/mL) in M199 + 7.5% FBS for 1 h, followed by culture in cycloheximide (10 μg/mL) for an additional 4 h. Reconstructed embryos in both groups were subsequently cultured in CR1aa in 5% CO2, 5% O2, and 90% N2 at 39°C. Samples from both treatments were fixed at 0, 1, 2, 4, 6, 12, 18, 24, 30, 36, and 44 h after fusion. All fixed samples were double stained for tubulin and DNA, and observed with a laser-scanning confocal microscope for changes in nuclei and microtubules. The experiment was replicated three times. Cleavage rate and blastocyst rate were recorded and analyzed by Studen's t-test (SPSS 11.0, Chicago, IL). The staining revealed an absence of premature chromosome condensation (PCC) in all embryos in Treatment A. However, delayed activation (Treatment B) resulted in a high incidence of PCC, probably due to high levels of MPF in the MII cytoplasts. Chromosome condensation was observed in Treatment B at 4 h (82%, n = 17), 6 h (80%, n = 10), 12 h (36%, n = 25), 18 h (71%, n = 24), 24 h (50%, n = 16) and 30 h (6%, n = 18) after fusion. Subsequent culture results of these cloned embryos (Table 1) indicated that there were significantly higher cleavage rates and blastocyst development in Treatment A than in Treatment B. This study clearly demonstrated that PCC is not essential to support bovine cloned blastocyst development. Direct exposure of donor nuclei in a MII cytoplast enviroment for a very short time was sufficient for nuclear reprogramming. Table 1. Effect of donor nuclear exposure duration in MII cytoplasm on the development potential of cloned bovine embryos

Azimuthal anisotropy and correlations at large transverse momenta in p + p and Au + Au collisions at square root sNN=200 GeV

Results on high transverse momentum charged particle emission with respect to the reaction plane are presented for Au + Au collisions at square root s(NN)=200 GeV. Two- and four-particle correlations results are presented as well as a comparison of azimuthal correlations in Au + Au collisions to those in p + p at the same energy. The elliptic anisotropy v(2) is found to reach its maximum at p(t) approximately 3 GeV/c, then decrease slowly and remain significant up to p(t) approximately 7-10 GeV/c. Stronger suppression is found in the back-to-back high-p(t) particle correlations for particles emitted out of plane compared to those emitted in plane. The centrality dependence of v(2) at intermediate p(t) is compared to simple models based on jet quenching.

Study on the interaction between nucleic acids and acetamiprid

The interaction between deoxyribonucleic acid (DNA) and acetamiprid was studied. It was found that the fluorescence of acetamiprid could be enhanced in the presence of DNA in sulfuric acid solution. The excitation and emission wavelength of acetamiprid was 291 nm and 587 nm, respectively. Under optimal conditions, the calibration graph is over the range of 0.1-10 micromL(-1). The calibration limit is 0.06 microg mL(-1) (S/N = 3). The determination results of DNA in yeast cell and golden staphylococcus samples by this method were satisfactory. The mechanism of the reaction is discussed.

Multistrange baryon production in Au-Au collisions at sqrt[s(NN)]=130 GeV

The transverse mass spectra and midrapidity yields for Xis and Omegas are presented. For the 10% most central collisions, the (-)Xi(+)/h(-) ratio increases from the Super Proton Synchrotron to the Relativistic Heavy Ion Collider energies while the Xi(-)/h(-) stays approximately constant. A hydrodynamically inspired model fit to the Xi spectra, which assumes a thermalized source, seems to indicate that these multistrange particles experience a significant transverse flow effect, but are emitted when the system is hotter and the flow is smaller than values obtained from a combined fit to pi, K, p, and Lambdas.

Cross sections and transverse single-spin asymmetries in forward neutral-pion production from proton collisions at sqrt[s]=200 GeV

Measurements of the production of forward high-energy pi(0) mesons from transversely polarized proton collisions at sqrt[s]=200 GeV are reported. The cross section is generally consistent with next-to-leading order perturbative QCD calculations. The analyzing power is small at x(F) below about 0.3, and becomes positive and large at higher x(F), similar to the trend in data at sqrt[s]< or =20 GeV. The analyzing power is in qualitative agreement with perturbative QCD model expectations. This is the first significant spin result seen for particles produced with p(T)>1 GeV/c at a polarized proton collider.