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

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

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

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

Oligomeric cocoa procyanidins possess enhanced bioactivity compared to monomeric and polymeric cocoa procyanidins for preventing the development of obesity, insulin resistance, and impaired glucose tolerance during high-fat feeding

There is interest in the potential of cocoa flavanols, including monomers and procyanidins, to prevent obesity and type-2 diabetes. Fermentation and processing of cocoa beans influence the qualitative and quantitative profiles of individual cocoa constituents. Little is known regarding how different cocoa flavanols contribute to inhibition of obesity and type-2 diabetes. The objective of this study was to compare the impacts of long-term dietary exposure to cocoa flavanol monomers, oligomers, and polymers on the effects of high-fat feeding. Mice were fed a high-fat diet supplemented with either a cocoa flavanol extract or a flavanol fraction enriched with monomeric, oligomeric, or polymeric procyanidins for 12 weeks. The oligomer-rich fraction proved to be most effective in preventing weight gain, fat mass, impaired glucose tolerance, and insulin resistance in this model. This is the first long-term feeding study to examine the relative activities of cocoa constituents on diet-induced obesity and insulin resistance.

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

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

Measurement of J/ψ azimuthal anisotropy in Au+Au collisions at sqrt[s(NN)]=200 GeV

The measurement of J/ψ azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at sqrt[s(NN)]=200 GeV. The measured J/ψ elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/ψ particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

Observation of an energy-dependent difference in elliptic flow between particles and antiparticles in relativistic heavy ion collisions

Elliptic flow (v(2)) values for identified particles at midrapidity in Au + Au collisions, measured by the STAR experiment in the beam energy scan at RHIC at sqrt[s(NN)] = 7.7-62.4 GeV, are presented. A beam-energy-dependent difference of the values of v(2) between particles and corresponding antiparticles was observed. The difference increases with decreasing beam energy and is larger for baryons compared to mesons. This implies that, at lower energies, particles and antiparticles are not consistent with the universal number-of-constituent-quark scaling of v(2) that was observed at sqrt[s(NN)] = 200 GeV.

Deletion of Rab GAP AS160 modifies glucose uptake and GLUT4 translocation in primary skeletal muscles and adipocytes and impairs glucose homeostasis

Tight control of glucose uptake in skeletal muscles and adipocytes is crucial to glucose homeostasis and is mediated by regulating glucose transporter GLUT4 subcellular distribution. In cultured cells, Rab GAP AS160 controls GLUT4 intracellular retention and release to the cell surface and consequently regulates glucose uptake into cells. To determine AS160 function in GLUT4 trafficking in primary skeletal muscles and adipocytes and investigate its role in glucose homeostasis, we characterized AS160 knockout (AS160(-/-)) mice. We observed increased and normal basal glucose uptake in isolated AS160(-/-) adipocytes and soleus, respectively, while insulin-stimulated glucose uptake was impaired and GLUT4 expression decreased in both. No such abnormalities were found in isolated AS160(-/-) extensor digitorum longus muscles. In plasma membranes isolated from AS160(-/-) adipose tissue and gastrocnemius/quadriceps, relative GLUT4 levels were increased under basal conditions and remained the same after insulin treatment. Concomitantly, relative levels of cell surface-exposed GLUT4, determined with a glucose transporter photoaffinity label, were increased in AS160(-/-) adipocytes and normal in AS160(-/-) soleus under basal conditions. Insulin augmented cell surface-exposed GLUT4 in both. These observations suggest that AS160 is essential for GLUT4 intracellular retention and regulation of glucose uptake in adipocytes and skeletal muscles in which it is normally expressed. In vivo studies revealed impaired insulin tolerance in the presence of normal (male) and impaired (female) glucose tolerance. Concurrently, insulin-elicited increases in glucose disposal were abolished in all AS160(-/-) skeletal muscles and liver but not in AS160(-/-) adipose tissues. This suggests AS160 as a target for differential manipulation of glucose homeostasis.

Directed flow of identified particles in Au+Au collisions at √[SNN]=200 GeV at RHIC

STAR's measurements of directed flow (v1) around midrapidity for π±, K±, KS0, p, and p[over ¯] in Au+Au collisions at √[sNN]=200  GeV are presented. A negative v1(y) slope is observed for most of produced particles (π±, K±, KS0, and p[over ¯]). In 5%-30% central collisions, a sizable difference is present between the v1(y) slope of protons and antiprotons, with the former being consistent with zero within errors. The v1 excitation function is presented. Comparisons to model calculations (RQMD, UrQMD, AMPT, QGSM with parton recombination, and a hydrodynamics model with a tilted source) are made. For those models which have calculations of v1 for both pions and protons, none of them can describe v1(y) for pions and protons simultaneously. The hydrodynamics model with a tilted source as currently implemented cannot explain the centrality dependence of the difference between the v1(y) slopes of protons and antiprotons.

Identified hadron compositions in p+p and Au+Au collisions at high transverse momenta at √S(NN)=200 GeV

We report transverse momentum (p(T)≤15  GeV/c) spectra of π(±), K(±), p, p[over ¯], K(S)(0), and ρ(0) at midrapidity in p+p and Au+Au collisions at √S(NN)=200  GeV. Perturbative QCD calculations are consistent with π(±) spectra in p+p collisions but do not reproduce K and p(p[over ¯]) spectra. The observed decreasing antiparticle-to-particle ratios with increasing p(T) provide experimental evidence for varying quark and gluon jet contributions to high-p(T) hadron yields. The relative hadron abundances in Au+Au at p(T)≳8  GeV/c are measured to be similar to the p+p results, despite the expected Casimir effect for parton energy loss.

Strangeness enhancement in Cu-Cu and Au-Au collisions at √S(NN)=200 GeV

We report new STAR measurements of midrapidity yields for the Λ, Λ[over ¯], K(S)(0), Ξ(-), Ξ[over ¯](+), Ω(-), Ω[over ¯](+) particles in Cu+Cu collisions at √S(NN)==200  GeV, and midrapidity yields for the Λ, Λ[over ¯], K(S)(0) particles in Au+Au at √S(NN)==200  GeV. We show that, at a given number of participating nucleons, the production of strange hadrons is higher in Cu+Cu collisions than in Au+Au collisions at the same center-of-mass energy. We find that aspects of the enhancement factors for all particles can be described by a parametrization based on the fraction of participants that undergo multiple collisions.

Measurement of the parity-violating longitudinal single-spin asymmetry for W± boson production in polarized proton-proton collisions at sqrt[s] = 500 GeV

We report the first measurement of the parity-violating single-spin asymmetries for midrapidity decay positrons and electrons from W+ and W- boson production in longitudinally polarized proton-proton collisions at sqrt[s] = 500 GeV by the STAR experiment at RHIC. The measured asymmetries, A(L)(W+) = -0.27 ± 0.10(stat.) ± 0.02(syst.) ± 0.03(norm.) and A(L)(W-) = 0.14 ± 0.19(stat.) ± 0.02(syst.) ± 0.01(norm.), are consistent with theory predictions, which are large and of opposite sign. These predictions are based on polarized quark and antiquark distribution functions constrained by polarized deep-inelastic scattering measurements.

Measurement of the bottom quark contribution to nonphotonic electron production in p + p collisions at √s=200 GeV

The contribution of B meson decays to nonphotonic electrons, which are mainly produced by the semileptonic decays of heavy-flavor mesons, in p + p collisions at √s=200  GeV has been measured using azimuthal correlations between nonphotonic electrons and hadrons. The extracted B decay contribution is approximately 50% at a transverse momentum of pT≥5  GeV/c. These measurements constrain the nuclear modification factor for electrons from B and D meson decays. The result indicates that B meson production in heavy ion collisions is also suppressed at high pT.

Higher moments of net proton multiplicity distributions at RHIC

We report the first measurements of the kurtosis (κ), skewness (S), and variance (σ2) of net-proton multiplicity (Np-Np) distributions at midrapidity for Au+Au collisions at square root of s(NN)=19.6, 62.4, and 200 GeV corresponding to baryon chemical potentials (μB) between 200 and 20 MeV. Our measurements of the products κσ2 and Sσ, which can be related to theoretical calculations sensitive to baryon number susceptibilities and long-range correlations, are constant as functions of collision centrality. We compare these products with results from lattice QCD and various models without a critical point and study the square root of s(NN) dependence of κσ2. From the measurements at the three beam energies, we find no evidence for a critical point in the QCD phase diagram for μB below 200 MeV.

Three-particle coincidence of the long range pseudorapidity correlation in high energy nucleus-nucleus collisions

We report the first three-particle coincidence measurement in pseudorapidity (Δη) between a high transverse momentum (p⊥) trigger particle and two lower p⊥ associated particles within azimuth |Δϕ|<0.7 in square root of s(NN)=200 GeV d+Au and Au+Au collisions. Charge ordering properties are exploited to separate the jetlike component and the ridge (long range Δη correlation). The results indicate that the correlation of ridge particles are uniform not only with respect to the trigger particle but also between themselves event by event in our measured Δη. In addition, the production of the ridge appears to be uncorrelated to the presence of the narrow jetlike component.

Phylogenetic analysis of New World screwworm fly, Cochliomyia hominivorax, suggests genetic isolation of some Caribbean island populations following colonization from South America

Larval infestations of the New World screwworm (NWS) fly, Cochliomyia hominivorax, cause considerable economic losses through the direct mortality and reduced production of livestock. Since the 1950s, NWS populations in North and Central America have been the target of virtually continuous eradication attempts by sterile insect technique (SIT). Nevertheless, in some areas, such as Jamaica, SIT-based control programmes have failed. Reasons for the failure of SIT-based programmes in some locations are unknown, but it is hypothesized that failure may be related to the mating incompatibility between sterile and wild flies or to the existence of sexually incompatible cryptic species. Accordingly, the current research investigates intraspecific phylogenetic relationships and associated biogeographic patterns between NWS populations from the Caribbean and South America, which represent those populations involved in, or earmarked for, forthcoming SIT programmes. Uniquely, this study also includes analyses of two North American samples, collected in Texas in 1933 and 1953 prior to initiation of the SIT-based eradication programme. The study utilizes three nucleotide datasets: elongation factor-1alpha (nuclear); cytochrome oxidase subunit 1 (mitochondrial), and 12S rRNA (mitochondrial). Phylogenetic analysis of these data, representing populations from across the Caribbean, South America and Texas, indicates sub-structuring of fly populations on several of the larger Caribbean islands, suggesting a period of isolation and/or founder effects following colonization from South America; significantly, our findings do not support a North American origin for Cuban flies. The importance of these findings in the light of proposed SIT programmes in the region is discussed.

Characterization and utilization of microsatellite loci in the New World screwworm fly, Cochliomyia hominivorax

New World screwworm populations in North and Central America have been the targets of virtually continuous eradication attempts by sterile insect technique (SIT) since the 1950s. Nevertheless, in some areas, such as Jamaica, SIT control programmes have failed. Reasons for the failure of SIT-based control programmes in some locations are unknown, but it has been hypothesized that failure may be related to mating incompatibility between sterile and wild fly populations or to the existence of sexually incompatible cryptic species. This paper outlines the development of a suite of four new microsatellite loci which can be used to study intra-specific relationships between populations of Cochliomyia hominivorax from the Caribbean and South America, which represent those populations involved in, or earmarked for, forthcoming SIT control. Cross-amplification with the secondary screwworm, Cochliomyia macellaria, was also successful with three of the new loci. We present results which suggest that populations from Trinidad and Jamaica form distinct groupings of flies and that C. hominivorax from Trinidad appears particularly distinct.

Complete mitochondrial control region sequences indicate a distinct variety of brown trout Salmo trutta in the Aral Sea

Complete sequencing of the mtDNA control region (CR) from five specimens of brown trout Salmo trutta from the Amu Darya River identified two novel haplotypes belonging to the Danubian lineage. This finding supports the long-standing hypothesis that brown trout in the Aral Sea represent a distinct genetic stock and also illustrates the benefits that complete sequencing of the CR can provide for elucidating phylogeographic relationships.

Molecular characterization and phylogenesis of Steganinae (Diptera, Drosophilidae) inferred by the mitochondrial cytochrome c oxidase subunit 1

The subfamily Steganinae (Diptera, Drosophilidae) includes flies which display zoophilic feeding behaviour in the larval and/or adult stages, some of which act as vectors of Spirurida eyeworms, which infect both carnivores and humans. To date, the taxonomy and phylogeny of the subfamily Steganinae has been studied only superficially and many aspects of their systematics remain unresolved. Thus, the present study aimed to provide a molecular dataset to facilitate the identification and phylogenetic analysis of Steganinae species based on partial ( approximately 700 basepairs) mitochondrial cytochrome c oxidase subunit 1 (cox1) sequences. A total of 134 flies belonging to 13 species and eight genera of Steganinae were subjected to molecular and phylogenetic analyses. The mean nucleotide variation within the Steganinae subfamily was 8.1%, with a variation within genera for which more than one species was examined ranging from 1.6% (in Phortica spp.) to 21.8% (in Amiota spp.). Interspecific pairwise divergence ranged from 1.6% (Phortica variegata vs. Phortica semivirgo) to 24.8% (Cacoxenus indagator vs. Amiota alboguttata) and intraspecific variation ranged from 0% to 1%. Seventy of the 233 amino acids were variable, including 26 parsimony informative sites and 44 singleton sites, with some highly conserved residues identified within the genera Stegana and Amiota. Parsimony and maximum likelihood-based phylogenetic analyses provided strong support for the genus Phortica, phylogenetically distinct from the genus Amiota. Gitona distigma was placed in an unresolved position adjacent to the outgroup taxa, Drosophila yakuba and Drosophila melanogaster. The molecular data reported here represent the first molecular dataset based on cox1 of Steganinae flies and provide a base for further investigations into the evolutionary relationships among this little-studied subfamily.

Mitochondrial genomes of the sheep blowfly, Lucilia sericata, and the secondary blowfly, Chrysomya megacephala

This paper presents complete mitochondrial genomes for the sheep blowfly, Lucilia sericata (Meigen), and the secondary blowfly, Chrysomya megacephala (Fabricius). Both L. sericata and C. megacephala had standard dipteran-type mitochondrial genome architectures and lengths of 15 945 bp and 15 831 bp, respectively. Additionally, C. megacephala possessed a tRNA duplication either side of the D-loop, as previously reported in another Chrysomya species, C. putoria; this duplication appears to be synapomorphic for the genus Chrysomya. As in other insect mitochondrial genomes, base compositions had a high AT content, with both genomes more than 76% AT-rich.

Comprehensive DNA methylation profiling in a human cancer genome identifies novel epigenetic targets

Using a unique microarray platform for cytosine methylation profiling, the DNA methylation landscape of the human genome was monitored at more than 21,000 sites, including 79% of the annotated transcriptional start sites (TSS). Analysis of an oligodendroglioma derived cell line LN-18 revealed more than 4000 methylated TSS. The gene-centric analysis indicated a complex pattern of DNA methylation exists along each autosome, with a trend of increasing density approaching the telomeres. Remarkably, 2% of CpG islands (CGI) were densely methylated, and 17% had significant levels of 5 mC, whether or not they corresponded to a TSS. Substantial independent verification, obtained from 95 loci, suggested that this approach is capable of large scale detection of cytosine methylation with an accuracy approaching 90%. In addition, we detected large genomic domains that are also susceptible to DNA methylation reinforced inactivation, such as the HOX cluster on chromosome 7 (CH7). Extrapolation from the data suggests that more than 2000 genomic loci may be susceptible to methylation and associated inactivation, and most have yet to be identified. Finally, we report six new targets of epigenetic inactivation (IRX3, WNT10A, WNT6, RARalpha, BMP7 and ZGPAT). These targets displayed cell line and tumor specific differential methylation when compared with normal brain samples, suggesting they may have utility as biomarkers. Uniquely, hypermethylation of the CGI within an IRX3 exon was correlated with over-expression of IRX3 in tumor tissues and cell lines relative to normal brain samples.

Amplification of DNA from preserved specimens shows blowflies were preadapted for the rapid evolution of insecticide resistance

Mutations of esterase 3 confer two forms of organophosphate resistance on contemporary Australasian Lucilia cuprina. One form, called diazinon resistance, is slightly more effective against commonly used insecticides and is now more prevalent than the other form, called malathion resistance. We report here that the single amino acid replacement associated with diazinon resistance and two replacements associated with malathion resistance also occur in esterase 3 in the sibling species Lucilia sericata, suggesting convergent evolution around a finite set of resistance options. We also find parallels between the species in the geographic distributions of the polymorphisms: In both cases, the diazinon-resistance change is absent or rare outside Australasia where insecticide pressure is lower, whereas the changes associated with malathion resistance are widespread. Furthermore, PCR analysis of pinned specimens of Australasian L. cuprina collected before the release of organophosphate insecticides reveals no cases of the diazinon-resistance change but several cases of those associated with malathion resistance. Thus, the early outbreak of resistance in this species can be explained by the preexistence of mutant alleles encoding malathion resistance. The pinned specimen analysis also shows much higher genetic diversity at the locus before organophosphate use, suggesting that the subsequent sweep of diazinon resistance in Australasia has compromised the scope for the locus to respond further to the ongoing challenge of the insecticides.

Morphological and molecular comparison of host-derived populations of parasitic Psoroptes mites

Infestation by parasitic Psoroptes mites (Acari: Psoroptidae) is an important cause of economic loss and welfare problems in livestock in many areas of the world. At least five species within this genus have been recognized, based on the host infested, the infestation site and differences in length of the opisthosomal setae of adult male mites. Here the integrity of these species is considered by subjecting populations of mites from a range of host species and geographical locations to simultaneous morphological and molecular genetic analyses. Morphological analysis showed that there were significant differences in shape and size between mite populations from different hosts, and that length of the outer opisthosomal setae in males and the homologous seta in females were the most important distinguishing character in adults. However, considerable variation in outer opisthosomal seta length was evident within and between populations of mites, and differences were not clearly related to host-species or geographical origin and did not support the accepted species differences. Molecular characterization using sequence data from the mitochondrial second internal transcribed spacer (ITS-2) region and microsatellite markers found little or no consistent host-related variation between the mite population samples. The results suggest that there is no case for considering the Psoroptes mites from the different hosts examined as separate species and that the morphological variation observed therefore may represent phenotypic adaptation to the local microenvironment on particular species of host.

Phylogeny of Trypanosoma ( Megatrypanum ) theileri and related trypanosomes reveals lineages of isolates associated with artiodactyl hosts diverging on SSU and ITS ribosomal sequences

SSU ribosomal sequences of trypanosomes from Brazilian cattle and water buffalo were used to infer phylogenetic relationships between non-pathogenic T. theileri and allied species parasitic in artiodactyls. T. theileri trypanosomes from distinct geographical regions in Brazil and from other countries were tightly clustered into the 'clade T. theileri' distant from the 'T. brucei clade' of pathogenic parasites of artiodactyls, and also distinct from trypanosomes of other mammals. The existence of this monophyletic assemblage (T. theileri clade) composed only by isolates from artiodactyl species justifies the continued recognition of the subgenus T. (Megatrypanum) with T. theileri as its type species. Phylogenies based on SSU and ITS1 ribosomal sequences produced the same branching pattern with isolates from different mammalian hosts clustered in 5 lineages: A, related to water buffalo; B, C and D, to cattle; E, to fallow deer. The pattern of host specificity allied to some congruence between host and parasite phylogenies suggested association of these trypanosomes with their respective hosts. Segregation of cattle isolates into three lineages revealed an overall geographical structure. Moreover, positioning of trypanosomes infecting tabanids in the T. theileri clade is consistent with the role of these flies as important vectors of these trypanosomes.

Antibacterial properties of larval secretions of the blowfly, Lucilia sericata

The antibacterial properties of secretions aseptically collected from larvae of the greenbottle fly Lucilia sericata (Meigen) (Diptera: Calliphoridae) were examined. These investigations revealed the presence of small (<1 kDa) antibacterial factor(s) within the larval secretions, active against a range of bacteria. These include the Gram-positive Staphylococcus aureus, both methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-sensitive Staphylococcus aureus (MSSA), Streptococcus pyogenes and to a lesser extent the Gram-negative Pseudomonas aeruginosa. These secretions were shown to be highly stable as a freeze-dried preparation and, considering the activity against organisms typically associated with clinical infection, may be a source of novel antibiotic-like compounds that may be used for infection control and in the fight against MRSA.

The inadvertent introduction into Australia of Trypanosoma nabiasi, the trypanosome of the European rabbit (Oryctolagus cuniculus), and its potential for biocontrol

Wild rabbits (Oryctolagus cuniculus) in Australia are the descendents of 24 animals from England released in 1859. We surveyed rabbits and rabbit fleas (Spilopsyllus cuniculi) in Australia for the presence of trypanosomes using parasitological and PCR-based methods. Trypanosomes were detected in blood from the European rabbits by microscopy, and PCR using trypanosome-specific small subunit ribosomal RNA (SSU rRNA) gene primers and those in rabbit fleas by PCR. This is the first record of trypanosomes from rabbits in Australia. We identified these Australian rabbit trypanosomes as Trypanosoma nabiasi, the trypanosome of the European rabbit, by comparison of morphology and SSU rRNA gene sequences of Australian and European rabbit trypanosomes. Phylogenetic analysis places T. nabiasi in a clade with rodent trypanosomes in the subgenus Herpetosoma and their common link appears to be transmission by fleas. Despite the strict host specificity of trypanosomes in this clade, phylogenies presented here suggest that they have not strictly cospeciated with their vertebrate hosts. We suggest that T. nabiasi was inadvertently introduced into Australia in the 1960s in its flea vector Spilopsyllus cuniculi, which was deliberately introduced as a potential vector of the myxoma virus. In view of the environmental and economic damage caused by rabbits in Australia and other islands, the development of a virulent or genetically modified T. nabiasi should be considered to control rabbits.