Probing Transverse Momentum Broadening via Dihadron and Hadron-jet Angular Correlations in Relativistic Heavy-ion Collisions

Dijet, dihadron, hadron-jet angular correlations have been reckoned as important probes of the transverse momentum broadening effects in relativistic nuclear collisions. When a pair of high-energy jets created in hard collisions traverse the quark-gluon plasma produced in heavy-ion collisions, they become de-correlated due to the vacuum soft gluon radiation associated with the Sudakov logarithms and the medium-induced transverse momentum broadening. For the first time, we employ the systematical resummation formalism and establish a baseline calculation to describe the dihadron and hadron-jet angular correlation data in $pp$ and peripheral $AA$ collisions where the medium effect is negligible. We demonstrate that the medium-induced broadening $\langle p_\perp^2\rangle$ and the so-called jet quenching parameter $\hat q$ can be extracted from the angular de-correlations observed in $AA$ collisions. A global $\chi^2$ analysis of dihadron and hadron-jet angular correlation data renders the best fit $\langle p_\perp^2 \rangle \sim 13~\textrm{GeV}^2$ for a quark jet at RHIC top energy. Further experimental and theoretical efforts along the direction of this work shall significantly advance the quantitative understanding of transverse momentum broadening and help us acquire unprecedented knowledge of jet quenching parameter in relativistic heavy-ion collisions.Comment: 6 pages, 3 figure

CYP1A1 MspI and exon7 gene polymorphisms and lung cancer risk: An updated meta-analysis and review

<p>Abstract</p> <p>Background</p> <p>Many studies have examined the association between the CYP1A1 MspI and exon 7 gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent.</p> <p>Methods</p> <p>To assess this relationship more precisely, a meta-analysis and review were performed. The PubMed, Embase, Web of Science, and CNKI database was searched for case-control studies published up to June 2010. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated.</p> <p>Results</p> <p>Ultimately, 64 studies, comprising 18,397 subjects from 49 case-control studies of the MspI genotype and 18,518 patients from 40 case-control studies of the exon 7 genotype, were included. A significantly elevated lung cancer risk was associated with 2 MspI genotype variants (for type C vs Type A: OR = 1.26, 95% CI = 1.12-1.42; for types B and C combined vs Type A: OR = 1.20, 95% CI = 1.13-1.28) in overall population. In the stratified analysis, a significant association was found in Asians, Caucasians, lung SCC, lung AC and Male population, not in mixed population, lung SCLC and Female population. However, inconsistent results were observed for CYP1A1 exon7 in our meta-analysis, two variants of the exon 7 polymorphism were associated with a significantly higher risk for lung cancer (for Val/Val vs Ile/Ile: OR = 1.24, 95% CI = 1.09-1.42; for (Ile/Val +Val/Val) vs Ile/Ile: OR = 1.15, 95% CI = 1.07-1.24) in overall population. In the stratified analysis, a significant assocation was found in Asians, Caucasians, lung SCC and Female population, not in mixed population, lung AD, lung SCLC and Male population. Additionally, a significant association was found in smoker population and not found in non-smoker populations for CYP1A1 MspI and exon7 gene.</p> <p>Conclusions</p> <p>This meta-analysis suggests that the MspI and exon 7 polymorphisms of CYP1A1 correlate with increased lung cancer susceptibility and there is an interaction between two genotypes of CYP1A1 polymorphism and smoking, but these associations vary in different ethnic populations, histological types of lung caner and gender of case and control population.</p

Properties of the FCC Catalyst Additive Prepared from Guizhou Kaoline

The properties of a FCC catalyst additive prepared from Guizhou kaoline were extensively investigated. The samples were characterized by N<sub>2 adsorption, X-ray diffraction, IR spectrometry, and scanning electron microscope (SEM). The results showed that the crystallinity of NaY zeolite synthesized from this kaoline was 25% and the silica alumina ratio was _{rk/s ˇ m}= 5.05. The catalyst additive prepared from above crystallization product exhibited excellent performance of nickel and vanadium passivation, offered 21% lower coke versus base catalyst, while maintaining high bottoms upgrading selectivity

Svojstva aditiva FCC katalizatora pripravljenih iz Guizhou kaolina

The properties of a FCC catalyst additive prepared from Guizhou kaoline were extensively investigated. The samples were characterized by N2 adsorption, X-ray diffraction, IR spectrometry, and scanning electron microscope (SEM). The results showed that the crystallinity of NaY zeolite synthesized from this kaoline was 25% and the silica alumina ratio was rk/s ˇ m = 5.05. The catalyst additive prepared from above crystallization product exhibited excellent performance of nickel and vanadium passivation, offered 21% lower coke versus base catalyst, while maintaining high bottoms upgrading selectivity.U radu su opisana istraživanja svojstava aditiva FCC-katalizatora pripravljenih iz Guizhou kaolina. Aditivi su karakterizirani adsorpcijom N2, rengenskom difrakcijom praškastih uzoraka, IR-spektroskopijom i pretražnom elektronskom mikroskopijom. Rezultati ukazuju da kristaliničnost zeolita NaY pripravljenog iz Guizhou kaolina iznosi 25% te da je omjer silicijevog oksida (SiO2) i aluminijevog oksida (Al2O3) 5,05 (mol/mol). Aditiv iskazuje prestižna svojstva FCC-katalizatora prvenstveno pasivizacije nikla i vanadija, proizvodi 21% manje koksa, i održava visoku selektivnost destilacijskih ostataka

EFFECTS OF LONG-TERM TAI CHI EXERCISE ON BALANCE CONTROL IN OLDER ADULTS

This study assessed the static and dynamic balance control of older adults who have 10 years of Tai Chi exercise experience and compared their characteristics with their sedentary counterparts. The abilities were measured using methods: single-leg stance times with eyes open and closed; sway of center of pressure (COP) during static standing with eyes open/closed, and leaning the body in three specific directions. Compared with control group, 1) Tai Chi Group showed longer single-leg stance times with eyes open and closed, 2) slower sway velocity of COP in mediolateral and anterioposterior directions and shorter sway distance in both directions, and 3) shorter total, anterioposterior, and mediolateral routes and shorter time spent during the dynamic balance test. Long-term Tai Chi exercise improves the balance ability, especially the dynamic balance, of older adults

VPRSM Based Decision Tree Classifier

A new approach for inducing decision trees is proposed based on the Variable Precision Rough Set Model. From the rough set theory point of view, in the process of inducing decision trees with evaluations of candidate attributes, some methods based on purity measurements, such as information entropy based methods, emphasize the effect of class distribution. The more unbalanced the class distribution is, the more favorable it is. The rough set based approaches emphasize the effect of certainty. The more certain it is, the better. The criterion for node selection in the new method is based on the measurement of the variable precision explicit regions corresponding to candidate attributes. We compared the presented approach with C4.5 on some data sets from the UCI machine learning repository, which instantiates the feasibility of the proposed method

The Hydrodynamic Characteristics Induced by Multiple Layouts of Typical Artificial M-Type Reefs with Sea Currents Typical of Liaodong Bay, Bohai Sea

Artificial reefs are effective measures to improve the marine ecological environment and increase fishery production. However, there are several geometries being investigated nowadays and their setup, including the spacing between groups of them, can provide dissimilar effects on hydrodynamics. To enhance the understanding of this topic, in this paper, the focus is mainly on M-Type artificial reefs that will be adopted in Juehua Island, Liaodong Bay, China. An experimental campaign was carried out in order to simulate the influence that M-Type unit reef groups may have on the local flow field and the Particle Image Velocimetry (PIV) technique has been implemented to provide velocity maps. The results showed that with the increase of velocity’s current approaching the artificial reef, the height, length and area of the upwelling and the back vortex rise with the increase of spacing between the artificial reefs. Furthermore, when comparing different geometrical configurations with similar currents approaching the artificial reef, the maximum values of both upwelling and back vortex were obtained when the spacing between unit reefs was 1.25 L. Finally, the entropy method was used to evaluate the effects on the flow field under four kinds of spacing based on the hydrodynamic characteristics and the economic cost. The comprehensive score obtained for all the configurations followed the order 1.25 L > 1.50 L > 0.75 L > 1.00 L. Therefore, it is suggested that the original design spacing should be increased by 25% when the M-type unit reef is put into practice. Additionally, after having completed a comparative analysis, it is recommended to further change the reef group into four reef monocases. By executing this adjustment, the unit reef cost was reduced by 10%, and the influence range on the flow field increased by 10%, and this result can consequently achieve greater ecological benefits with less economic input. The results of this study provide a preliminary reference for the construction of artificial reefs M-Type from the perspective of theory and practice

Characterization of Chemical Composition of Pericarpium Citri Reticulatae Volatile Oil by Comprehensive Two-Dimensional Gas Chromatography with High-Resolution Time-of-Flight Mass Spectrometry

Pericarpium Citri Reticulatae (Chenpi in Chinese) has been widely used as an herbal medicine in Korea, China, and Japan. Chenpi extracts are used to treat indigestion and inflammatory syndromes of the respiratory tract such as bronchitis and asthma. This thesis will analyze chemical compositions of Chenpi volatile oil, which was performed by comprehensive two-dimensional gas chromatography with high-resolution time-of-flight mass spectrometry (GC × GC-HR-TOFMS). One hundred and sixty-seven components were tentatively identified, and terpene compounds are the main components of Chenpi volatile oil, a significant larger number than in previous studies. The majority of the eluted compounds, which were identified, were well separated as a result of high-resolution capability of the GC × GC method, which significantly reduces, the coelution. β-Elemene is tentatively qualified by means of GC × GC in tandem with high-resolution TOFMS detection, which plays an important role in enhancing the effects of many anticancer drugs and in reducing the side effects of chemotherapy. This study suggests that GC × GC-HR-TOFMS is suitable for routine characterization of chemical composition of volatile oil in herbal medicines