MAGIC observations of the February 2014 flare of 1ES 1011+496 and ensuing constraint of the EBL density

Context. In February-March 2014, the MAGIC telescopes observed the high-frequency peaked BL Lac 1ES 1011+496 (z=0.212) in flaring state at very-high energy (VHE, E>100GeV). The flux reached a level more than 10 times higher than any previously recorded flaring state of the source. Aims. Description of the characteristics of the flare presenting the light curve and the spectral parameters of the night-wise spectra and the average spectrum of the whole period. From these data we aim at detecting the imprint of the Extragalactic Background Light (EBL) in the VHE spectrum of the source, in order to constrain its intensity in the optical band. Methods. We analyzed the gamma-ray data from the MAGIC telescopes using the standard MAGIC software for the production of the light curve and the spectra. For the constraining of the EBL we implement the method developed by the H.E.S.S. collaboration in which the intrinsic energy spectrum of the source is modeled with a simple function (< 4 parameters), and the EBL-induced optical depth is calculated using a template EBL model. The likelihood of the observed spectrum is then maximized, including a normalization factor for the EBL opacity among the free parameters. Results. The collected data allowed us to describe the flux changes night by night and also to produce di_erential energy spectra for all nights of the observed period. The estimated intrinsic spectra of all the nights could be fitted by power-law functions. Evaluating the changes in the fit parameters we conclude that the spectral shape for most of the nights were compatible, regardless of the flux level, which enabled us to produce an average spectrum from which the EBL imprint could be constrained. The likelihood ratio test shows that the model with an EBL density 1:07 (-0.20,+0.24)stat+sys, relative to the one in the tested EBL template (Domínguez et al. 2011), is preferred at the 4:6 σ level to the no-EBL hypothesis, with the assumption that the intrinsic source spectrum can be modeled as a log-parabola. This would translate into a constraint of the EBL density in the wavelength range [0.24 μm,4.25 μm], with a peak value at 1.4 μm of λF_ = 12:27^(+2:75)_ (-2:29) nW m^(-2) sr^(-1), including systematics.

From Mill Gates to Magic City: U.S. Steel and Welfare Capitalism in Gary, Indiana, 1906-1930

Gary, Indiana is a city with indelible ties to industrial paternalism. Founded in 1906 by United States Steel Corporation to house workers of the trust’s showpiece mill, the emergence of this model company town was both the culmination of lessons learned from its predecessors’ mistakes and innovative corporate planning. U.S. Steel’s Progressive Era adaptation of welfare capitalism characterized the young city through a combination of direct community involvement and laissez-faire social control. This thesis examines the reactionary implementation of paternalist policies in Gary between 1906 and 1930 through the purviews of three elements under corporate influence: housing, education, and social welfare. Each category demonstrates how both the corporation and citizenry affected and adapted Gary’s physical and cultural landscape, public perceptions, and community identity. Parallel to the popular narrative throughout is that of Gary’s African-American community, and the controversial circumstances of this population’s segregated development.

A SURVEY OF DISTANCE MAGIC GRAPHS

In this report, we survey results on distance magic graphs and some closely related graphs. A distance magic labeling of a graph G with magic constant k is a bijection l from the vertex set to {1, 2, . . . , n}, such that for every vertex x Σ l(y) = k,y∈NG(x) where NG(x) is the set of vertices of G adjacent to x. If the graph G has a distance magic labeling we say that G is a distance magic graph. In Chapter 1, we explore the background of distance magic graphs by introducing examples of magic squares, magic graphs, and distance magic graphs. In Chapter 2, we begin by examining some basic results on distance magic graphs. We next look at results on different graph structures including regular graphs, multipartite graphs, graph products, join graphs, and splitting graphs. We conclude with other perspectives on distance magic graphs including embedding theorems, the matrix representation of distance magic graphs, lifted magic rectangles, and distance magic constants. In Chapter 3, we study graph labelings that retain the same labels as distance magic labelings, but alter the definition in some other way. These labelings include balanced distance magic labelings, closed distance magic labelings, D-distance magic labelings, and distance antimagic labelings. In Chapter 4, we examine results on neighborhood magic labelings, group distance magic labelings, and group distance antimagic labelings. These graph labelings change the label set, but are otherwise similar to distance magic graphs. In Chapter 5, we examine some applications of distance magic and distance antimagic labeling to the fair scheduling of tournaments. In Chapter 6, we conclude with some open problems.

Search for VHE gamma-ray emission from Geminga pulsar and nebula with the MAGIC telescopes

The Geminga pulsar, one of the brighest gamma-ray sources, is a promising candidate for emission of very-high-energy (VHE > 100 GeV) pulsed gamma rays. Also, detection of a large nebula have been claimed by water Cherenkov instruments. We performed deep observations of Geminga with the MAGIC telescopes, yielding 63 hours of good-quality data, and searched for emission from the pulsar and pulsar wind nebula. We did not find any significant detection, and derived 95% confidence level upper limits. The resulting upper limits of 5.3 × 10^(−13) TeV cm^(−2)s^(−1) for the Geminga pulsar and 3.5 × 10^(−12) TeV cm^(−2)s^(−1) for the surrounding nebula at 50 GeV are the most constraining ones obtained so far at VHE. To complement the VHE observations, we also analyzed 5 years of Fermi-LAT data from Geminga, finding that the sub-exponential cut-off is preferred over the exponential cut-off that has been typically used in the literature. We also find that, above 10 GeV, the gamma-ray spectra from Geminga can be described with a power law with index softer than 5. The extrapolation of the power-law Fermi-LAT pulsed spectra to VHE goes well below the MAGIC upper limits, indicating that the detection of pulsed emission from Geminga with the current generation of Cherenkov telescopes is very difficult.

Cadmium Telluride Magic-Sized Clusters and Superstructures

The aim of the present work is to gain new insights into the formation mechanism of CdTe magic-sized clusters (MSCs) at low temperatures, as well as on their evolution towards 1D and 2D nanostructures and assemblies thereof, under mild reaction conditions. The reaction system included toluene as solvent, octylamine as primary alkylamine, trioctylphosphine-Te as chalcogenide precursor and Cd(oleate)2 as metal precursor. UV-Vis absorption spectroscopy and transmission electron microscopy (TEM) were used to analyze samples containing concentrations of octylamine of 0.2, 0.8 and 2 M: well-defined, sharp absorption peaks were observed, with peaks maxima at 449, 417 and 373 nm respectively, and 1D structures with a string-like appearance were displayed in the TEM images. Investigating peaks growth, step-wise peaks shift to lower energies and reverse, step-wise peak shift to higher energies allowed to propose a model to describe the system, based on interconnected [CdTe]x cluster units originating an amine-capped, 1-dimensional, polymer-like structure, in which different degrees of electronic coupling between the clusters are held responsible for the different absorption transitions. The many parameters involved in the synthesis procedure were then investigated, starting from the Cd:Te ratio, the role of the amine, the use of different phosphine-Te and Cd precursors. The results allowed to gain important information of the reaction mechanism, as well as on the different behavior of the species featuring the sharp absorption peaks in each case. Using Cd(acetate)2 as metal precursor, 2D structures were found to evolve from the MSCs solutions over time, and their tendency to self-assemble was then analyzed employing two amines of different alkyl chain length, octylamine (C-8) and oleylamine (C-18). Their co-presence led to the formation of free-floating triangular nanosheets, which tend to readily aggregate if only octylamine is present in solution.

Shear bond strength of self-etch and total-etch bonding systems at different dentin depths

The purpose of this study was to evaluate the dentin shear bond strength of four adhesive systems (Adper Single Bond 2, Adper Prompt L-Pop, Magic Bond DE and Self Etch Bond) in regards to buccal and lingual surfaces and dentin depth. Forty extracted third molars had roots removed and crowns bisected in the mesiodistal direction. The buccal and lingual surfaces were fixed in a PVC/acrylic resin ring and were divided into buccal and lingual groups assigned to each selected adhesive. The same specimens prepared for the evaluation of superficial dentin shear resistance were used to evaluate the different depths of dentin. The specimens were identified and abraded at depths of 0.5, 1.0, 1.5 and 2.0 mm. Each depth was evaluated by ISO TR 11405 using an EMIC-2000 machine regulated at 0.5 mm/min with a 200 Kgf load cell. We performed statistical analyses on the results (ANOVA, Tukey and Scheffé tests). Data revealed statistical differences (p < 0.01) in the adhesive and depth variation as well as adhesive/depth interactions. The Adper Single Bond 2 demonstrated the highest mean values of shear bond strength. The Prompt L-Pop product, a self-etching adhesive, revealed higher mean values compared with Magic Bond DE and Self Etch Bond adhesives, a total and self-etching adhesive respectively. It may be concluded that the shear bond strength of dentin is dependent on material (adhesive system), substrate depth and adhesive/depth interaction.

Microhardness assessment of different commercial brands of resin composites with different degrees of translucence

Owing to improvements in its mechanical properties and to the availability of shade and translucence resources, resin composite has become one of the most widely used restorative materials in present day Dentistry. The aim of this study was to assess the relation between the surface hardness of seven different commercial brands of resin composites (Charisma, Fill Magic, Master Fill, Natural Look, Opallis, Tetric Ceram, and Z250) and the different degrees of translucence (translucid, enamel and dentin). Vickers microhardness testing revealed significant differences among the groups. Z250 was the commercial brand that showed the best performance in the hardness test. When comparing the three groups assessed within the same brand, only Master Fill and Fill Magic presented statistically significant differences among all of the different translucencies. Natural Look was the only one that showed no significant difference among any of the three groups. Charisma, Opallis, Tetric Ceram and Z250 showed significant differences among some of the tested groups. Based on the results found in this study, it was not possible to establish a relation between translucence and the microhardness of the resin composites assessed. Depending on the material assessed, however, translucence variation did affect the microhardness values of the resin composites.

Effect of different polishing systems on the surface roughness of microhybrid composites

The use of composite resins in dentistry is well accepted for restoring anterior and posterior teeth. Many polishing protocols have been evaluated for their effect on the surface roughness of restorative materials. This study compared the effect of different polishing systems on the surface roughness of microhybrid composites. Thirty-six specimens were prepared for each composite $#91;Charisma® (Heraeus Kulzer), Fill Magic® (Vigodent), TPH Spectrum® (Dentsply), Z100® (3M/ESPE) and Z250® (3M/ESPE)] and submitted to surface treatment with Enhance® and PoGo® (Dentsply) points, sequential Sof-Lex XT® aluminum oxide disks (3M/ESPE), and felt disks (TDV) combined with Excel® diamond polishing paste (TDV). Average surface roughness (Ra) was measured with a mechanical roughness tester. The data were analyzed by two-way ANOVA with repetition of the factorial design and the Tukey-Kramer test (p<0.01). The F-test result for treatments and resins was high (p<0.0001 for both), indicating that the effect of the treatment applied to the specimen surface and the effect of the type of resin on surface roughness was highly significant. Regarding the interaction between polishing system and type of resin used, a p value of 0.0002 was obtained, indicating a statistically significant difference. A Ra of 1.3663 was obtained for the Sof-Lex/TPH Spectrum interaction. In contrast, the Ra for the felt disk+paste/Z250 interactions was 0.1846. In conclusion, Sof-Lex polishing system produced a higher surface roughness on TPH Spectrum resin when compared to the other interactions.

Effect of insertion method on knoop hardness of high viscous glass ionomer cements

The aim of this study was to assess the Knoop hardness of three high viscous glass ionomer cements: G1 - Ketac Molar; G2 - Ketac Molar Easymix (3M ESPE) and G3 - Magic Glass ART (Vigodent). As a parallel goal, three different methods for insertion of Ketac Molar Easymix were tested: G4 - conventional spatula; G5 - commercial syringe (Centrix) and G6 - low-cost syringe. Ten specimens of each group were prepared and the Knoop hardness was determined 5 times on each specimen with a HM-124 hardness machine (25 g/30 s dwell time) after 24 h, 1 and 2 weeks. During the entire test period, the specimens were stored in liquid paraffin at 37ºC. Significant differences were found between G3 and G1/G2 (two-way ANOVA and Tukey's post hoc test; p<0.01). There was no significant difference in the results among the multiple ways of insertion. The glass ionomer cement Magic Glass ART showed the lowest hardness, while the insertion technique had no significant influence on hardness.

EPR and magnetic studies of a carboxylate-bridged dinuclear copper(II) compound: [cu2(flu)4(dmf)2]

We report magnetic and EPR (electron paramagnetic resonance) spectroscopy studies of [Cu2(flu)4(dmf)2] (flu = flufenamate and dmf = dimethylformamide), which has CuII ions in tetracarboxylate "paddle wheel" dinuclear units. Susceptibility measurements at 10 < T < 275 K allowed the evaluation of an antiferromagnetic intradinuclear exchange coupling J0 = -294 ± 5 cm-1 between CuII ions (Hex = "J0 S1·S2). EPR experiments at 300 K in powder and single-crystals at 9.5 and 34.4 GHz indicated g// = 2.373, g⊥ = 2.073 and zero field splitting parameters D = (-0.334 ± 0.001) cm"1 and E ca. 0. EPR signal intensity measurements at X-band in the range 4 < T < 295 K indicated that J0 = "283 ± 5 cm"1. A higher limit |J´| < 5×10-3 cm-1 for the interdinuclear exchange coupling between neighbor units at ca.14.24 Å was estimated from the angular variation of the single crystal spectra around the magic angles. The results are discussed in terms of the structure of the dinuclear unit and the bridges connecting CuII ions and compared with values reported for similar compounds.

Structural models for yttrium aluminium borate laser glasses: NMR and EPR studies of the system (Y(2)O(3))(0.2)-(Al(2)O(3))(x)-(B(2)O(3))(0.8-x)

The structure of laser glasses in the system (Y(2)O(3))(0.2){(Al(2)O(3))(x))(B(2)O(3))(0.8-x)} (0.15 <= x <= 0.40) has been investigated by means of (11)B, (27)Al, and (89)Y solid state NMR as well as electron spin echo envelope modulation (ESEEM) of Yb-doped samples. The latter technique has been applied for the first time to an aluminoborate glass system. (11)B magic-angle spinning (MAS)-NMR spectra reveal that, while the majority of the boron atoms are three-coordinated over the entire composition region, the fraction of three-coordinated boron atoms increases significantly with increasing x. Charge balance considerations as well as (11)B NMR lineshape analyses suggest that the dominant borate species are predominantly singly charged metaborate (BO(2/2)O(-)), doubly charged pyroborate (BO(1/2)(O(-))(2)), and (at x = 0.40) triply charged orthoborate groups. As x increases along this series, the average anionic charge per trigonal borate group increases from 1.38 to 2.91. (27)Al MAS-NMR spectra show that the alumina species are present in the coordination states four, five and six, and the fraction of four-coordinated Al increases markedly with increasing x. All of the Al coordination states are in intimate contact with both the three-and the four-coordinate boron species and vice versa, as indicated by (11)B/(27)Al rotational echo double resonance (REDOR) data. These results are consistent with the formation of a homogeneous, non-segregated glass structure. (89)Y solid state NMR spectra show a significant chemical shift trend, reflecting that the second coordination sphere becomes increasingly ""aluminate-like'' with increasing x. This conclusion is supported by electron spin echo envelope modulation (ESEEM) data of Yb-doped glasses, which indicate that both borate and aluminate species participate in the medium range structure of the rare-earth ions, consistent with a random spatial distribution of the glass components.

Aluminophosphate-based mesoporous molecular sieves: synthesis and characterization of TAPOs

Mesoporous Ti-substituted aluminophosphates (AlPOs) with a hexagonal, cubic and lamellar pore structure, characteristic of MCM-41, MCM-48. and MCM-50, respectively, were synthesized. The stability of these mesophases upon template removal was studied. The pore structures, surface properties, and local atom environments of Al, P, and Ti of the hexagonal and cubic Ti-containing mesoporous products were extensively characterized using X-ray diffraction, magic angle spinning nuclear magnetic resonance, AAS, XPS, ultraviolet-visible, and adsorption of nitrogen and water vapor techniques while the lamellar mesophase was not further characterized due to its very poor thermal stability. Ti-containing mesoporous AlPO materials show a reasonable thermal stability upon template removal, a hydrophilic surface property, and high porosity showing application potentials in catalytic oxidation of hydrocarbons. (C) 2001 Elsevier Science B,V. All rights reserved.

TOWARDS A BENJAMINIAN ANTHROPOLOGY: RETHINKING PARADIGMS OF DRAMATIC THEATRE

This essay is presented as a Benjaminian work site. The juxtaposition of apparently distant figures in brusque and surprising relations may well cause puzzlement. But the affinities are revealing. In the whirlpools of Michael Taussig`s studies, I search for a theoretical composition in counterpoint: on one side, Victor Turner and Clifford Geertz, whose writings possibly lead us to think of a kind of paradigm of the dramatic theatre in anthropology, and, on the other, two figures on the margins of anthropology and the dramatic theatre - Walter Benjamin and Bertolt Brecht. The essay`s gravitational force is located on these margins, especially the fragmented work of Benjamin. In short, this is an essay towards a Benjaminian anthropology, organized around three allegories: (1) magic mirror; (2) shattering; and (3) flashes of light. In some ways, the journey suggests the form of an unusual rite of passage: the passage towards a passing condition.

Copper-mediated amyloid-beta toxicity is associated with an intermolecular histidine bridge

Amyloid-beta peptide (A beta) is pivotal to the pathogenesis of Alzheimer disease. Here we report the formation of a toxic A beta-Cu2+ complex formed via a histidine-bridged dimer, as observed at Cu2+/ peptide ratios of > 0.6:1 by EPR spectroscopy. The toxicity of the A beta-Cu2+ complex to cultured primary cortical neurons was attenuated when either the pi- or tau-nitrogen of the imidazole side chains of His were methylated, thereby inhibiting formation of the His bridge. Toxicity did not correlate with the ability to form amyloid or perturb the acyl-chain region of a lipid membrane as measured by diphenyl- 1,3,5-hexatriene anisotropy, but did correlate with lipid peroxidation and dityrosine formation. P-31 magic angle spinning solid-state NMR showed that A beta and A beta-Cu2+ complexes interacted at the surface of a lipid membrane. These findings indicate that the generation of the A beta toxic species is modulated by the Cu2+ concentration and the ability to form an intermolecular His bridge.

Complex distal insertions of the tibialis posterior tendon: detailed anatomic and MR imaging investigation in cadavers

Purpose The purpose of this report was to demonstrate the normal complex insertional anatomy of the tibialis posterior tendon (TPT) in cadavers using magnetic resonance (MR) imaging with anatomic and histologic correlation. Material and methods Ten cadaveric ankles were used according to institutional guidelines. MR T1-weighted spin echo imaging was performed to demonstrate aspects of the complex anatomic distal insertions of the TPT in cadaveric specimens. Findings on MR imaging were correlated with those derived from anatomic and histologic study. Reults Generally, the TPT revealed a low signal in all MR images, except near the level of the medial malleolus, where the TPT suddenly changed direction and ""magic angle"" artifact could be observed. In five out of ten specimens (50%), a type I accessory navicular bone was found in the TPT. In all cases with a type I accessory navicular bone, the TPT had an altered signal in this area. Axial and coronal planes on MR imaging were the best in identifying the distal insertions of the TPT. A normal division of the TPT was observed just proximal to the insertion into the navicular bone in five specimens (100%) occurring at a maximum proximal distance from its attachment to the navicular bone of approximately 1.5 to 2 cm. In the other five specimens, in which a type I accessory navicular bone was present, the TPT directly inserted into the accessory bone and a slip less than 1.5 mm in thickness could be observed attaching to the medial aspect of the navicular bone (100%). Anatomic inspection confirmed the sites of the distal insertions of the components of the TPT. Conclusion MR imaging enabled detailed analysis of the complex distal insertions of the TPT as well as a better understanding of those features of its insertion that can simulate a lesion.