Effect of tricyclazole on morphology, virulence and gene expression of Aspergillus aculeatus for management of soft rot disease in peach

AIMS

Aspergillus aculeatus, a pathogen of peaches, can cause soft rot and lead to economic losses in agricultural production. However, studies on the prevention of soft rot caused by A. aculeatus have rarely been reported. Tricyclazole (TCZ) is a fungicide that has been widely used in disease prevention of various crops but the inhibitory mechanism of TCZ on A. aculeatus is unknown. Our aim was to determine the effects of TCZ on A. aculeatus.

METHODS AND RESULTS

In our study, TCZ inhibited the growth of fungal colonies when applied at 0·5-6 mmol l-1 and inhibited the production of melanin at 3 mmol l-1 . Conidia exposed to TCZ were less effective at causing the disease in inoculated samples, and electrical conductivity, divulgation of nucleic acids and proteins rose with increasing concentrations of TCZ. Microscopic results suggest that TCZ damages not only the cell wall but also the cell membrane. Results of qRT-PCR showed that TCZ had no significant effect on the regulation of genes coding for laccase, apoptosis and hypothetical protein; however, it significantly down-regulated genes coding for cellulase, chitinase and sterol.

CONCLUSIONS

Tricyclazole can influence the pathogenic ability of A. aculeatus by damaging the cell structure of hyphae and conidia, reducing the melanin production, and altering the expression of pathogenic-related gene.

SIGNIFICANCE AND IMPACT OF THE STUDY

The results explained the potential cause and mechanism TCZ produced in A. aculeatus. Our research offers scientific insights into future research interest relative to using TCZ in the treatment of soft rot caused by A. aculeatus.

D-Meson Azimuthal Anisotropy in Midcentral Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

The azimuthal anisotropy coefficient v_{2} of prompt D^{0}, D^{+}, D^{*+}, and D_{s}^{+} mesons was measured in midcentral (30%-50% centrality class) Pb-Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, with the ALICE detector at the LHC. The D mesons were reconstructed via their hadronic decays at midrapidity, |y|<0.8, in the transverse momentum interval 1<p_{T}<24  GeV/c. The measured D-meson v_{2} has similar values as that of charged pions. The D_{s}^{+} v_{2}, measured for the first time, is found to be compatible with that of nonstrange D mesons. The measurements are compared with theoretical calculations of charm-quark transport in a hydrodynamically expanding medium and have the potential to constrain medium parameters.

Genetic and phylogenetic analysis of reemerged novel Seneca Valley virus strains in Guangdong province, 2017

From June to July 2017, six Seneca Valley virus (SVV) strains were isolated from swine herds exhibiting SVV-associated porcine idiopathic vesicular disease (PIVD) in Guangdong province, China. Complete genomic sequences of these six newly identified strains were genetically and phylogenetically analysed. The results revealed that these six SVV strains were genetically closely related to USA/GBI29/2015 and notably distinct from all previous Chinese strains, indicating the reemergence of new SVV strains in Guangdong province.

Exogenous niacin treatment increases NADPH oxidase in kiwifruit

Kiwifruit are a popular fruit worldwide; however, plant growth is threatened by abiotic stresses such as drought and high temperatures. Niacin treatment in plants has been shown to increase NADPH levels, thus enhancing abiotic stresses tolerance. Here, we evaluate the effect of niacin solution spray treatment on NADPH levels in the kiwifruit cultivars Hayward and Xuxiang. We found that spray treatment with niacin solution promoted NADPH and NADP+ levels and decreased both O2·- production and H2O2 contents in leaves during a short period. In fruit, NADPH contents increased during early development, but decreased later. However, no effect on NADP+ levels has been observed throughout fruit development. In summary, this report suggests that niacin may be used to increase NADPH oxidases, thus increasing stress-tolerance in kiwifruit during encounter of short-term stressful conditions.

[Outcomes of adult patients with de novo acute myeloid leukemia received idarubicin plus cytarabine regimen as induction chemotherapy]

Objective: To explore outcomes in adult with de novo acute myeloid leukemia (AML) received IA10 (10 mg/m(2) d1-3 idarubicin plus cytarabine 100 mg/m(2) d1-7) regimen as induction chemotherapy. Methods: From January 2008 to February 2016, data of consecutive newly-diagnosed AML (non-M(3)) adults treated with IA10 who achieved morphologic leukemia-free state (MLFS) but not accepted allogeneic hematopoietic stem cell transplantation (allo-HSCT) were assessed retrospectively. Results: A total of 198 patients were included in this study with 96 (48.5%) male and a median age of 42 years old (range, 18-62 years old). Using the SWOG cytogenetic classification, 45 (22.7%), 104 (52.5%), 24 (12.1%) and 25 (12.6%) patients belonged to favorable, intermediate, unfavorable and unknown categories, respectively. 6 (3.0%) patients had monosomal karyotype, and 28 (14.1%) positive FLT3-ITD mutation. A complete remission (CR, defined as MLFS with ANC ≥ 1×10(9)/L and PLT ≥ 100×10(9)/L) achieved in 168 (84.8%) patients, a CRp (defined as MLFS with incomplete PLT recovery) in 16 (8.1%) and a CRi (defined as MLFS with incomplete ANC and PLT recovery) in 14 (7.1%). With a median follow-up period of 15 months (range, 1 to 70 months) in survivors, the probabilities of cumulative incident of relapse (CIR), disease free survival (DFS) and overall survival (OS) rates at 2-year were 45.2%, 46.9% and 62.9%, respectively; the median durations of relapse, DFS and OS were 34, 20 and 37 months respectively. At the time of achieving first MLFS, multivariate analyses showed that positive FLT3-ITD mutation and CRi were common adverse factors affecting CIR, DFS and OS; unfavorable-risk of SWOG criteria was an adverse factor affecting CIR and DFS; monosomal karyotype was associated with shorter OS. After first consolidation therapy, FLT3-ITD mutation positive and unfavorable-risk of SWOG criteria had negatively impact on CIR, DFS and OS; peripheral blasts ≥ 0.50 and positive MRD (defined as RQ-PCR WT1 mRNA ≥ 0.6% or any level of abnormal blast population detected by flow cytometry) after first consolidation therapy were common adverse factors affecting CIR and DFS; CRi was an adverse factor affecting DFS and OS. Conclusions: In adult with de novo AML received IA10 regimen as induction regimen, unfavorable molecular markers or cytogenetics at diagnosis and CRi independently predicted poor outcome. In addition, a higher percentage of peripheral blasts, monosomal karyotype and positive MRD after first consolidation therapy had negatively impact on outcomes.

J/ψ Elliptic Flow in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

We report a precise measurement of the J/ψ elliptic flow in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The J/ψ mesons are reconstructed at midrapidity (|y|<0.9) in the dielectron decay channel and at forward rapidity (2.5<y<4.0) in the dimuon channel, both down to zero transverse momentum. At forward rapidity, the elliptic flow v_{2} of the J/ψ is studied as a function of the transverse momentum and centrality. A positive v_{2} is observed in the transverse momentum range 2<p_{T}<8  GeV/c in the three centrality classes studied and confirms with higher statistics our earlier results at sqrt[s_{NN}]=2.76  TeV in semicentral collisions. At midrapidity, the J/ψ  v_{2} is investigated as a function of the transverse momentum in semicentral collisions and found to be in agreement with the measurements at forward rapidity. These results are compared to transport model calculations. The comparison supports the idea that at low p_{T} the elliptic flow of the J/ψ originates from the thermalization of charm quarks in the deconfined medium but suggests that additional mechanisms might be missing in the models.

CO2 and Redox Dual Responsive Pickering Emulsion

Herein, we described for the first time a CO₂ and redox dual responsive paraffin oil-in-water Pickering emulsion stabilized by the modified silica nanoparticles with Se-containing tertiary amine, SeTA, in which the tertiary amine serves as a CO₂-sensitive group, and the Se atom serves as a redox-sensitive center. The Pickering emulsion can be reversibly switched between stable and unstable states by bubbling CO₂ and N₂ in the reduced state, or with the addition of H₂O₂ and Na₂SO₃ in the absence of CO₂, because of the adsorption and desorption of SeTA on the silica surface. The former is mainly attributed to a CO₂-controllable electrostatic attraction, resulting from the transition of molecules between cationic and nonionic states; whereas, the latter is ascribed to a redox-tunable hydrogen bonding, originating from the transition of molecules between selenide and selenoxide. However, in the presence of CO₂, redox can only induce a change in the droplet size, not demulsification. These interesting and unique multiresponsive behaviors endow the Pickering emulsion with a capacity for intelligent control of emulsification and demulsification, as well as the droplet size, which may be an asset for a myriad of technological applications in biomedicine, microfluidics, drug delivery, and cosmetics.

Rifampicin-induced injury in HepG2 cells is alleviated by TUDCA via increasing bile acid transporters expression and enhancing the Nrf2-mediated adaptive response

Bile acid transporters and the nuclear factor erythroid 2-related factor (Nrf-2)-mediated adaptive response play important roles in the development of drug-induced liver injury (DILI). However, little is known about the contribution of the adaptive response to rifampicin (RFP)-induced cell injury. In this study, we found RFP decreased the survival rate of HepG2 cells and increased the levels of lactate dehydrogenase (LDH), alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AKP), γ-glutamyl-transferase (γ-GT), total bilirubin (TBIL), direct bilirubin (DBIL), indirect bilirubin (IBIL), total bile acid (TBA) and adenosine triphosphate (ATP) in the cell culture supernatants in both a concentration- and a time-dependent manner. RFP increased the expression levels of bile acid transporter proteins and mRNAs, such as bile salt export pump (BSEP), multidrug resistance protein 1 (MDR1), multidrug resistance-associated protein 2 (MRP2), Na+/taurocholate cotransporter (NTCP), organic anion transporting protein 2 (OATP2), organic solute transporter β (OSTβ) and Nrf2. Following the transient knockdown of Nrf2 and treatment with RFP, the expression levels of the BSEP, MDR1, MRP2, NTCP, OATP2 and OSTβ proteins and mRNAs were decreased to different degrees. Moreover, the cell survival was decreased, whereas the LDH level in the cell culture supernatant was increased. Overexpression of the Nrf2 gene produced the opposite effects. Treatment with tauroursodeoxycholic acid (TUDCA) increased the expression levels of the bile acid transporters and Nrf2, decreased the expression levels of glucose-regulated protein 78 (GRP78), PKR-like ER kinase (PERK), activating transcription factor 4 (ATF4), and C/EBP-homologous protein (CHOP), and inhibited RFP-induced oxidative stress. Moreover, TUDCA reduced cell apoptosis, increased cell survival and decreased the levels of LDH, ALT, AST, AKP, γ-GT, TBIL, DBIL, IBIL, TBA and ATP in the cell culture supernatant. Therefore, TUDCA alleviates RFP-induced injury in HepG2 cells by enhancing bile acid transporters expression and the Nrf2-mediated adaptive response.

Epidemiology and molecular characterization of Porcine teschovirus in Hunan, China

Porcine teschoviruses (PTVs) have been shown to be widely distributed in pig populations. In this study, 261 faecal and 91 intestinal content samples collected from pigs at 29 farms in Hunan, China, were tested for the presence of PTV by reverse transcription-polymerase chain reaction (RT-PCR). An overall PTV-positivity rate of 19.03% was detected by RT-PCR, and a high PTV infection rate was circulating in asymptomatic fattening and nursery pigs. In total, 40 PTV isolates (PTV-HuNs) were obtained. Alignment of their coding sequences with those of other known PTVs revealed that the genomic sequence of the polyprotein contains 6,606-6,621 nucleotides, encoding a 2,202-2,207-amino acid sequence. Phylogenetic analyses based on the VP1 gene and capsid protein gene exhibited 13 main lineages corresponding to PTV serotypes 1-13, and seven PTV serotypes (PTV 2-6, 9, and 11) were identified in the isolates obtained in our study; this is the first report of PTV 5, 9 and 11 in China. Recombination analysis among the PTV-HuNs indicated that nine recombination events have occurred, including both inter- and intraserotype events. In addition, results demonstrated that only limited positive selection is acting on the global population of PTV isolates, and purifying selection is predominant. In conclusion, this study revealed a high infection rate of PTVs circulating in asymptomatic fattening and nursery pigs. The 40 PTV-HuNs showed high genetic diversity, and genetic analysis of all available PTV sequences revealed that strong purifying selection and recombination play important roles in the genetic diversity and evolution of the virus.

[Factors associated with early treatment response in adults with acute myeloid leukemia]

Objective: To explore the factors influencing early treatment responses in adult with de novo acute myeloid leukemia (AML) . Methods: Data of consecutive newly-diagnosed AML (non-acute promyelocytic leukemia) adults were analyzed retrospectively. To assess the impact of clinical characteristics at diagnosis and induction regimen on achieving morphologic leukemia-free state (MLFS) , blood counts and minimal residual leukemia (MRD, positive MRD defined as RQ-PCR WT1 mRNA ≥0.6% and/or any level of abnormal blast population detected by flow cytometry) at the time of achieving MLFS. Results: 739 patients were included in this study. 406 (54.9%) patients were male, with a median age of 42 years (range, 18-65 years) . In the 721 evaluable patients, MLFS was achieved in 477 (66.2%) patients after the first induction regimen and 592 (82.1%) within two cycles. A total of 634 patients (87.9%) achieved MLFS, including 534 (84.2%) achieving a complete remission (CR, defined as MLFS with ANC ≥ 1×10(9)/L and PLT ≥ 100×10(9)/L) , 100 (15.8%) achieving a CRi (defined as MLFS with incomplete ANC or PLT recovery) , respectively. 260 (45.9%) patients of 566 (89.3%) who detected MRD at the time of achieving MLFS had positive MRD. Multivariate analyses showed that female gender, favorable-risk of SWOG criteria, IA10 and HAA/HAD as induction regimen were factors associated with achieving early MLFS. In addition, low bone marrow blasts, HGB ≥ 80 g/L, PLT counts<30×10(9)/L and mutated NPM1 without FLT3-ITD were factors associated with achieving MLFS after the first induction regimen; Negative FLT3-ITD mutation was factor associated with achieving MLFS within two cycles. PLT counts ≥30×10(9)/L and IA10, IA8 or HAA/HAD as induction chemotherapy were factors associated with achieving CR. Female gender, favorable-risk of SWOG criteria, FLT3-ITD mutation negative, mutated NPM1 without FLT3-ITD were factors associated with negative MRD. Conclusions: Female gender, favorable molecular markers or cytogenetics, and standard-dose induction regimen were key factors associated with higher probability of early and deep responses in adults with AML.

Anomalous Evolution of the Near-Side Jet Peak Shape in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV

The measurement of two-particle angular correlations is a powerful tool to study jet quenching in a p_{T} region inaccessible by direct jet identification. In these measurements pseudorapidity (Δη) and azimuthal (Δφ) differences are used to extract the shape of the near-side peak formed by particles associated with a higher p_{T} trigger particle (1<p_{T,trig}<8  GeV/c). A combined fit of the near-side peak and long-range correlations is applied to the data allowing the extraction of the centrality evolution of the peak shape in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV. A significant broadening of the peak in the Δη direction at low p_{T} is found from peripheral to central collisions, which vanishes above 4  GeV/c, while in the Δφ direction the peak is almost independent of centrality. For the 10% most central collisions and 1<p_{T,assoc}<2  GeV/c, 1<p_{T,trig}<3  GeV/c a novel feature is observed: a depletion develops around the center of the peak. The results are compared to pp collisions at the same center of mass energy and ampt model simulations. The comparison to the investigated models suggests that the broadening and the development of the depletion is connected to the strength of radial and longitudinal flow.

[Minimal residual disease level predicts outcomes in the non-favorable risk patients with acute myeloid leukemia]

Objective: To explore impact of minimal residual leukemia (MRD) on outcomes in the non-favorable risk adults with de novo acute myeloid leukemia (AML) . Methods: From January 2008 to February 2016, data of consecutive newly-diagnosed non-favorable risk adults with AML (non-APL) according to SWOG criteria who achieved morphologic leukemia-free state (MLFS) and received continuous chemotherapy were assessed retrospectively. Results: 292 AML patients were enrolled, 150 (51.4%) were male. Median age was 46 years (range, 18-65 years) . Using the SWOG cytogenetic classification, 186 (63.7%) , 49 (16.8%) and 57 (19.5%) patients belonged to intermediate, unfavorable and unknown categories, respectively. With a median follow-up period of 15 months (range, 1 to 94 months) in survivors, the probabilities of cumulative rates of relapse (CIR) , disease free survival (DFS) and overall survival (OS) at 2-years were 51.6%, 42.6% and 60.0%, respectively. Multivariate analyses showed that MRD positive (defined as Q-PCR WT1 mRNA ≥0.6% or any level of abnormal blast population detected by flow cytometry) after achieving MLFS and PLT<100×10(9)/L were common adverse factors affecting CIR and DFS. In addition, positive FLT3-ITD mutation and CRp/CRi had negatively impact on CIR, DFS and OS. Monosomal karyotype was adverse factors affecting CIR and OS. Age ≥44 years and unfavorable-risk of SWOG criteria were associated with shorter DFS. Conclusions: MRD level after achieving MLFS had prognostic significance on outcomes in non-favorable adults with AML who received continuous chemotherapy after achieving MLFS.

Comparison of irinotecan/platinum versus etoposide/platinum chemotherapy for extensive-stage small cell lung cancer: A meta-analysis

This meta-analysis was performed to compare the effects and toxicities between irinotecan/platinum (IP) and etoposide/platinum (EP) regimens as the fist-line treatment of patients with extensive-stage small cell lung cancer (E-SCLC). A systematic search was made of MEDLINE, Cochrane, ISI Web of Science and SCOPUS databases. Randomised clinical trials on treatment of E-SCLC with the IP regimens, compared with EP regimens, were reviewed. Studies were pooled to hazard ratio (HR), relative risk (RR) and odds ratio (OR), with 95% confidence interval (CI). Eight trials (enrolling 2089 participants) met the inclusion criteria. Overall survival (OS) and 1-year survival rate were superior in the IP group (HR 0.83; 95% CI 0.75 to 0.91 and RR 1.19; 95% CI 1.06 to 1.34). Grades 3 and 4 anaemia, leukopenia, neutropenia, thrombocytopenia and febrile neutropenia were less frequent in the IP regimens than that in the EP regimens. And grades 3 and 4 nausea/vomiting, diarrheal, anorexia and fatigue were less frequent in the EP regimens. IP combination chemotherapy achieved a superior OS and 1-year survival rate, compared with EP doublets, in patients with E-SCLC.

A genome-wide association study reveals candidate genes for the supernumerary nipple phenotype in sheep (Ovis aries)

Genome-wide association studies (GWASs) have been widely applied in livestock to identify genes associated with traits of economic interest. Here, we conducted the first GWAS of the supernumerary nipple phenotype in Wadi sheep, a native Chinese sheep breed, based on Ovine Infinium HD SNP BeadChip genotypes in a total of 144 ewes (75 cases with four teats, including two normal and two supernumerary teats, and 69 control cases with two teats). We detected 63 significant SNPs at the chromosome-wise threshold. Additionally, one candidate region (chr1: 170.723-170.734 Mb) was identified by haplotype-based association tests, with one SNP (rs413490006) surrounding functional genes BBX and CD47 on chromosome 1 being commonly identified as significant by the two mentioned analyses. Moreover, Gene Ontology enrichment for the significant SNPs identified by the GWAS analysis was functionally clustered into the categories of receptor activity and synaptic membrane. In addition, pathway mapping revealed four promising pathways (Wnt, oxytocin, MAPK and axon guidance) involved in the development of the supernumerary nipple phenotype. Our results provide novel and important insights into the genetic mechanisms underlying the phenotype of supernumerary nipples in mammals, including humans. These findings may be useful for future breeding and genetics in sheep and other livestock.

Genome-wide association analysis identifies the genetic basis of fat deposition in the tails of sheep (Ovis aries)

Fat-tailed sheep (Ovis aries) can survive in harsh environments and satisfy human's intake of dietary fat. However, the animals require more feed, which increases the cost of farming. Thus, most farmers currently prefer thin-tailed, short-tailed or docked sheep. To date, the molecular mechanism of the formation of fat tails in sheep has not been completely elucidated. Here, we conducted a genome-wide association study using phenotypes and genotypes (the Ovine Infinium HD SNP BeadChip genotype data) of two breeds of contrasting tail types (78 Small-tailed and 78 Large-tailed Han sheep breeds) to identify functional genes and variants associated with fat deposition. We identified four significantly (rs416433540, rs409848439, rs408118325 and rs402128848) and three approximately associated autosomal SNPs (rs401248376, rs402445895 and rs416201901). Gene annotation indicated that the surrounding genes (CREB1, STEAP4, CTBP1 and RIP140, also known as NRIP1) function in lipid storage or fat cell regulation. Furthermore, through an X-chromosome-wide association analysis, we detected significantly associated SNPs in the OARX: 88-89 Mb region, which could be a strong candidate genomic region for fat deposition in tails of sheep. Our results represent a new genomic resource for sheep genetics and breeding. In addition, the findings provide novel insights into genetic mechanisms of fat deposition in the tail of sheep and other mammals.

Energy dependence of forward-rapidity [Formula: see text] and [Formula: see text] production in pp collisions at the LHC

We present results on transverse momentum ([Formula: see text]) and rapidity ([Formula: see text]) differential production cross sections, mean transverse momentum and mean transverse momentum square of inclusive [Formula: see text] and [Formula: see text] at forward rapidity ([Formula: see text]) as well as [Formula: see text]-to-[Formula: see text] cross section ratios. These quantities are measured in pp collisions at center of mass energies [Formula: see text] and 13 TeV with the ALICE detector. Both charmonium states are reconstructed in the dimuon decay channel, using the muon spectrometer. A comprehensive comparison to inclusive charmonium cross sections measured at [Formula: see text], 7 and 8 TeV is performed. A comparison to non-relativistic quantum chromodynamics and fixed-order next-to-leading logarithm calculations, which describe prompt and non-prompt charmonium production respectively, is also presented. A good description of the data is obtained over the full [Formula: see text] range, provided that both contributions are summed. In particular, it is found that for [Formula: see text] GeV/c the non-prompt contribution reaches up to 50% of the total charmonium yield.

Production of Σ(1385)± and Ξ(1530)0 in p-Pb collisions at sNN=5.02 TeV

The transverse momentum distributions of the strange and double-strange hyperon resonances (Σ ( 1385 ) ± , Ξ ( 1530 ) 0 ) produced in p-Pb collisions at s NN = 5.02 TeV were measured in the rapidity range - 0.5 < y CMS < 0 for event classes corresponding to different charged-particle multiplicity densities, ⟨ dN ch /dη lab ⟩ . The mean transverse momentum values are presented as a function of ⟨ dN ch /dη lab ⟩ , as well as a function of the particle masses and compared with previous results on hyperon production. The integrated yield ratios of excited to ground-state hyperons are constant as a function of ⟨ dN ch /dη lab ⟩ . The equivalent ratios to pions exhibit an increase with ⟨ dN ch /dη lab ⟩ , depending on their strangeness content.

Production of [Formula: see text] and [Formula: see text] mesons up to high transverse momentum in pp collisions at 2.76 TeV

The invariant differential cross sections for inclusive [Formula: see text] and [Formula: see text] mesons at midrapidity were measured in pp collisions at [Formula: see text] TeV for transverse momenta [Formula: see text] GeV/c and [Formula: see text] GeV/c, respectively, using the ALICE detector. This large range in [Formula: see text] was achieved by combining various analysis techniques and different triggers involving the electromagnetic calorimeter (EMCal). In particular, a new single-cluster, shower-shape based method was developed for the identification of high-[Formula: see text] neutral pions, which exploits that the showers originating from their decay photons overlap in the EMCal. Above 4 GeV/[Formula: see text], the measured cross sections are found to exhibit a similar power-law behavior with an exponent of about 6.3. Next-to-leading-order perturbative QCD calculations differ from the measured cross sections by about 30% for the [Formula: see text], and between 30-50% for the [Formula: see text] meson, while generator-level simulations with PYTHIA 8.2 describe the data to better than 10-30%, except at [Formula: see text] GeV/[Formula: see text]. The new data can therefore be used to further improve the theoretical description of [Formula: see text] and [Formula: see text] meson production.

Flow Dominance and Factorization of Transverse Momentum Correlations in Pb-Pb Collisions at the LHC

We present the first measurement of the two-particle transverse momentum differential correlation function, P_{2}≡⟨Δp_{T}Δp_{T}⟩/⟨p_{T}⟩^{2}, in Pb-Pb collisions at sqrt[s_{NN}]=2.76  TeV. Results for P_{2} are reported as a function of the relative pseudorapidity (Δη) and azimuthal angle (Δφ) between two particles for different collision centralities. The Δϕ dependence is found to be largely independent of Δη for |Δη|≥0.9. In the 5% most central Pb-Pb collisions, the two-particle transverse momentum correlation function exhibits a clear double-hump structure around Δφ=π (i.e., on the away side), which is not observed in number correlations in the same centrality range, and thus provides an indication of the dominance of triangular flow in this collision centrality. Fourier decompositions of P_{2}, studied as a function of the collision centrality, show that correlations at |Δη|≥0.9 can be well reproduced by a flow ansatz based on the notion that measured transverse momentum correlations are strictly determined by the collective motion of the system.