2,425 research outputs found
Imamate and Leadership: The Case of the Shi'a Fundamentalists in Modern Iran
The theory of Imamate (absolute religious, spiritual and political leadership of the Muslim community) is one of the most important pillars in Twelver Shi'ism (the second largest branch of Islam). While there was a relative agreement on the nature and boundaries of the theory of Imamate and leadership during the presence of the twelve Shi'i Imams, there is no such consensus among the Shi'a in this regard after the Occultation of the last Imam, the Mahdi, in 874. Generally speaking, with respect to the latter period, there are two broad schools of thought. For Traditionalists, during the absence of the Imam, Imamate is no longer conceivable as the absolute religious and political leadership of the community of believers. On the other hand, Fundamentalists believe in full implementation of the theory of Imamate in the society by jurists, as the general deputies of Imam Mahdi in his absence. This study intends to examine the views of the Shi'a fundamentalists, particularly in the modern Iran. Keywords: Shi'ism; Imamate; infallible Imams; fundamentalism; Islamic government; guardianship of the jurist; democracyRÊsumÊ: La thÊorie de l'imamat (le leadership absolu, religieux, spirituel et politique de la communautÊ musulmane) est l'un des piliers les plus importants dans le chiisme duodÊcimain (la deuxième plus grande branche l'islam). Bien qu'il y ait un accord relatif sur la nature et les limites de la thÊorie de l'imamat et du leadership au cours de la prÊsence des douze imams chiites, il n'y a pas ce genre de consensus parmi les chiites à cet Êgard après l'occultation du dernier Imam, le Mahdi, en 874. De manière gÊnÊrale, à l'Êgard de cette dernière pÊriode, il y a deux grandes Êcoles de pensÊe. Pour les traditionalistes, l'imamat n'est plus concevable en tant que le leadership absolu religieux et politique de la communautÊ des croyants. Par contre, les fondamentalistes croient en la pleine application de la thÊorie de l'imamat dans la sociÊtÊ par les juristes, en absence des reprÊsentants gÊnÊraux de l'Imam Mahdi. Cette Êtude vise à examiner les vues des fondamentalistes chiites, en particulier en Iran moderne.Mots-clÊs: Chiisme; imamat; imamsinfaillibles; fondamentalisme; gouvernement islamique; tutelle du juriste; dÊmocrati
Experimental design approach to the optimization of PAHs bioremediation from artificially contaminated soil: Application of variables screening development
Background: The effectiveness of bioremediation systems for PAH-contaminated soil may be constrained by physicochemical properties of contaminants and environmental factors. Information on what is the most effective factor in bioremediation process is essential in the decision of what stimulations can be taken to assist the biodegradation efficacy. Methods: In this study, four factors of surfactant (Tween 80), humic acid (HA), salinity and nutrients in a 24 full factorial design were screened in bioremediation of phenanthrene contaminated soil by using a consortium of bacteria. Results: Between the employed levels of the factors only salinity had not significant effect. Optimal concentrations of surfactant, HA and nutrient were obtained by a response surface design. For phenanthrene biodegradation, a central composite face centred design (CCFD) showed that nutrient, surfactant and HA concentrations had highly significant, significant and insignificant effects, respectively. The best conditions with 87.1 phenanthrene biodegradation were 150 mg HA/Kg soil, 12.68 ĂÂźg/L surfactant, and nutrients as K2HPO4, 0.8; KH2PO4, 0.2 and KNO3, 1 g/L. A high similarity was between the model prediction and experimental results. Conclusions: This study showed that nutrient with 81.27 efficiency could be considered as the most effective factor for practical implications of bioremediation process for PAHs contaminated soil cleanup strategies. ĂŠ 2015 Ravanipour et al.; licensee BioMed Central
Debonding Time and Dental Pulp Temperature With the Er, Cr: YSGG Laser for Debonding Feldespathic and Lithium Disilicate Veneers
Introduction: The removal of ceramic veneers is a time-consuming procedure in a dentaloffice. Little research has been done in alternative removal techniques for ceramic veneers.The objective of this study was to evaluate the removal of feldspathic and lithium disilicatereinforced glass ceramic veneers by Er, Cr: YSGG and to measure debonding time and pulpaltemperature increase during veneer removal.Methods: Fifty-seven bovine incisor teeth were prepared and divided into 3 groups. Ceramicspecimens with a thickness of 0.7mm, a width of 4mm and a length of 8 mm were fabricatedfrom feldspathic ceramic, lithium disilicate reinforced glass ceramic HT (high translucency) andlithium disilicate reinforced glass ceramic MO (medium opacity) (19 for each group). Specimenswere cemented on the labial surface of incisors using resin cement. The Er, Cr: YSGG laserwas applied to each specimen at 2.5 W and 25 Hz. Debonding time was measured for eachspecimen, and the intrapulpal temperature was detected in 3 specimens for each group. Datawere analyzed via one-way analysis of variance (ANOVA) at significance level of 0.05 (ι = 0.05).Results: Mean debonding time was 103.68 (26.76), 106.58 (47.22) and 103.84 (32.90) secondsfor feldspathic, lithium disilicate MO, and lithium disilicate HT respectively. There was nosignificant statistical difference among the groups (P value = 0.96). The intrapulpal temperatureincrease was less than 1°C in all groups.Conclusion: Er, Cr: YSGG can successfully be used to efficiently debond feldspathic and lithiumdisilicate reinforced glass ceramic veneers. There was no significant difference for debondingtime among these ceramic materials. During ceramic laminate veneer removal by laserirradiation, no irritating temperature rise was detected
Experimental design approach to the optimization of PAHs bioremediation from artificially contaminated soil: Application of variables screening development
Background: The effectiveness of bioremediation systems for PAH-contaminated soil may be constrained by physicochemical properties of contaminants and environmental factors. Information on what is the most effective factor in bioremediation process is essential in the decision of what stimulations can be taken to assist the biodegradation efficacy. Methods: In this study, four factors of surfactant (Tween 80), humic acid (HA), salinity and nutrients in a 24 full factorial design were screened in bioremediation of phenanthrene contaminated soil by using a consortium of bacteria. Results: Between the employed levels of the factors only salinity had not significant effect. Optimal concentrations of surfactant, HA and nutrient were obtained by a response surface design. For phenanthrene biodegradation, a central composite face centred design (CCFD) showed that nutrient, surfactant and HA concentrations had highly significant, significant and insignificant effects, respectively. The best conditions with 87.1 phenanthrene biodegradation were 150 mg HA/Kg soil, 12.68 ĂÂźg/L surfactant, and nutrients as K2HPO4, 0.8; KH2PO4, 0.2 and KNO3, 1 g/L. A high similarity was between the model prediction and experimental results. Conclusions: This study showed that nutrient with 81.27 efficiency could be considered as the most effective factor for practical implications of bioremediation process for PAHs contaminated soil cleanup strategies. ĂŠ 2015 Ravanipour et al.; licensee BioMed Central
Measurements of branching fraction ratios and CP-asymmetries in suppressed B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^- decays
We report the first reconstruction in hadron collisions of the suppressed
decays B^- -> D(-> K^+ pi^-)K^- and B^- -> D(-> K^+ pi^-)pi^-, sensitive to the
CKM phase gamma, using data from 7 fb^-1 of integrated luminosity collected by
the CDF II detector at the Tevatron collider. We reconstruct a signal for the
B^- -> D(-> K^+ pi^-)K^- suppressed mode with a significance of 3.2 standard
deviations, and measure the ratios of the suppressed to favored branching
fractions R(K) = [22.0 \pm 8.6(stat)\pm 2.6(syst)]\times 10^-3, R^+(K) =
[42.6\pm 13.7(stat)\pm 2.8(syst)]\times 10^-3, R^-(K)= [3.8\pm 10.3(stat)\pm
2.7(syst]\times 10^-3, as well as the direct CP-violating asymmetry A(K) =
-0.82\pm 0.44(stat)\pm 0.09(syst) of this mode. Corresponding quantities for
B^- -> D(-> K^+ pi^-)pi^- decay are also reported.Comment: 8 pages, 1 figure, accepted by Phys.Rev.D Rapid Communications for
Publicatio
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV
The performance of muon reconstruction, identification, and triggering in CMS
has been studied using 40 inverse picobarns of data collected in pp collisions
at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection
criteria covering a wide range of physics analysis needs have been examined.
For all considered selections, the efficiency to reconstruct and identify a
muon with a transverse momentum pT larger than a few GeV is above 95% over the
whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4,
while the probability to misidentify a hadron as a muon is well below 1%. The
efficiency to trigger on single muons with pT above a few GeV is higher than
90% over the full eta range, and typically substantially better. The overall
momentum scale is measured to a precision of 0.2% with muons from Z decays. The
transverse momentum resolution varies from 1% to 6% depending on pseudorapidity
for muons with pT below 100 GeV and, using cosmic rays, it is shown to be
better than 10% in the central region up to pT = 1 TeV. Observed distributions
of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO
X-ray emission from the Sombrero galaxy: discrete sources
We present a study of discrete X-ray sources in and around the
bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival
Chandra observations with a total exposure of ~200 ks. With a detection limit
of L_X = 1E37 erg/s and a field of view covering a galactocentric radius of ~30
kpc (11.5 arcminute), 383 sources are detected. Cross-correlation with Spitler
et al.'s catalogue of Sombrero globular clusters (GCs) identified from HST/ACS
observations reveals 41 X-rays sources in GCs, presumably low-mass X-ray
binaries (LMXBs). We quantify the differential luminosity functions (LFs) for
both the detected GC and field LMXBs, whose power-low indices (~1.1 for the
GC-LF and ~1.6 for field-LF) are consistent with previous studies for
elliptical galaxies. With precise sky positions of the GCs without a detected
X-ray source, we further quantify, through a fluctuation analysis, the GC LF at
fainter luminosities down to 1E35 erg/s. The derived index rules out a
faint-end slope flatter than 1.1 at a 2 sigma significance, contrary to recent
findings in several elliptical galaxies and the bulge of M31. On the other
hand, the 2-6 keV unresolved emission places a tight constraint on the field
LF, implying a flattened index of ~1.0 below 1E37 erg/s. We also detect 101
sources in the halo of Sombrero. The presence of these sources cannot be
interpreted as galactic LMXBs whose spatial distribution empirically follows
the starlight. Their number is also higher than the expected number of cosmic
AGNs (52+/-11 [1 sigma]) whose surface density is constrained by deep X-ray
surveys. We suggest that either the cosmic X-ray background is unusually high
in the direction of Sombrero, or a distinct population of X-ray sources is
present in the halo of Sombrero.Comment: 11 figures, 5 tables, ApJ in pres
Azimuthal anisotropy of charged particles at high transverse momenta in PbPb collisions at sqrt(s[NN]) = 2.76 TeV
The azimuthal anisotropy of charged particles in PbPb collisions at
nucleon-nucleon center-of-mass energy of 2.76 TeV is measured with the CMS
detector at the LHC over an extended transverse momentum (pt) range up to
approximately 60 GeV. The data cover both the low-pt region associated with
hydrodynamic flow phenomena and the high-pt region where the anisotropies may
reflect the path-length dependence of parton energy loss in the created medium.
The anisotropy parameter (v2) of the particles is extracted by correlating
charged tracks with respect to the event-plane reconstructed by using the
energy deposited in forward-angle calorimeters. For the six bins of collision
centrality studied, spanning the range of 0-60% most-central events, the
observed v2 values are found to first increase with pt, reaching a maximum
around pt = 3 GeV, and then to gradually decrease to almost zero, with the
decline persisting up to at least pt = 40 GeV over the full centrality range
measured.Comment: Replaced with published version. Added journal reference and DO
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
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