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Assessment of structural changes of human teeth by low-field nuclear magnetic resonance (NMR)
No full textA technique of low-field pulsed proton nuclear magnetic resonance (NMR) spin relaxation is described for assessment of age-related structural changes (dentin and pulp) of human teeth in vitro. The technique involves spin-spin relaxation measurement and inversion spin-spin spectral analysis methods. The spin-spin relaxation decay curve is converted into a T2 distribution spectrum by a sum of single exponential decays. The NMR spectra from the extracted dentin-portion-only and dental pulp-cells-only were compared with the whole extracted teeth spectra, for the dentin and pulp peak assignments. While dentin and pulp are highly significant parameters in determining tooth quality, variations in these parameters with age can be used as an effective tool for estimating tooth quality. Here we propose an NMR calibration method - the ratio of the amount of dentin to the amount of pulp obtained from NMR T2 distribution spectra can be used for measuring the age-related structural changes in teeth while eliminating any variations in size of teeth. Eight teeth (third molars) extracted from humans, aged among 17-67 years old, were tested in this study. It is found that the intensity ratio of dentin to pulp sensitively changes from 0.48 to 3.2 approaching a linear growth with age. This indicates that age-related structural changes in human teeth can be detected using the low-field NMR technique. © 2010 IOP Publishing Ltd
Poly(pyridinium salt)s with organic counterions derived from an aromatic diamine containing tetraoxyethylene units exhibiting amphotropic liquid-crystalline and photoluminescence properties
No full textSeveral poly(pyridinium salt)s containing various organic counterions and tetraoxyethylene units in their backbones were synthesized by either ring-transmutation polymerization reaction of 4, 4\u27-(1, 4-phenylene)- bis(2, 6-diphenylpyrylium tosylate) with bis(2-(2-(4-aminophenoxy)ethoxy)ethyl) ether on heating in dimethyl sulfoxide or metathesis reaction of the tosylate polymer with the corresponding lithium or sodium salts in acetonitrile. Their chemical structures were determined by 1H-NMR and 13C-NMR spectroscopy, and elemental analyses. Their number-average molecular weights and polydispersity indices were in the range of 34, 000-52, 000 and 1.14-1.38, respectively, as determined by gel permeation chromatography. They were characterized both for their thermotropic and lyotropic liquid-crystalline properties by using differential scanning calorimetry and polarizing optical microscopy. As these polymers exhibited liquid-crystalline phase both in the melt and in solutions, they are classified as an amphotropic class of ionic polymers. Their light-emitting properties in a large number of organic solvents that ranged from nonpolar to polar solvents and in films cast from methanol and acetonitrile were also studied by using spectrofluorometry. © 2009 Wiley Periodicals, Inc
Contingent claim valuation of express certificates
No full textIn this paper we introduce a new financial product named Express Certificates and we provide detailed descriptions of the product specifications. We show that the payoff of an Express Certificate can be duplicated by the combination of a zero coupon bond, a cash-or-nothing call option on the index and a put option on the index. We develop a pricing formula to price the certificates. Finally, we apply the pricing model for Express Certificates to a certificate issued by Bayerische Hypo- und Vereinsbank AG to examine how well the model fits empirical data. The results are in line with previous studies pricing other structured products. JEL classification: G13; G24. © 2010, Banking and Finance Review
Explorando nuevas formas de violencia de género: la mujer como objeto en los folletos de clínicas de estética
No full textEn la actualidad muchos textos escritos aparecen acompañados de imágenes de mujeres con fines diversos. En este artículo se exploran las principales estrategias empleadas para crear significado en varios folletos de la clínica de estética Dorsia de Alicante. El fin de esta investigación es poner de manifiesto que el modo en que las mujeres son representadas en dichos folletos es diferente al modo en que aparecen representados los hombres. Para ello se analizan las principales características lingüísticas y visuales empleadas en varios de estos textos y la influencia que estas elecciones pueden llegar a tener en la población. El análisis permite poner de manifiesto que en muchas ocasiones la mujer es tratada como un objeto y que la imagen de mujer que aparece en algunos folletos de clínicas de estética es tan agresiva que puede entenderse como una nueva forma de violencia de género. Palabras clave: violencia de género, clínicas de estética, texto multimodal, mujer objeto, gramática visual
Excess postexercise oxygen consumption after aerobic exercise training
No full textLiterature examining the effects of aerobic exercise training on excess postexercise oxygen consumption (EPOC) is sparse. In this study, 9 male participants (19-32 yr) trained (EX) for 12 wk, and 10 in a control group (CON) maintained normal activity. VO2max, rectal temperature (T re), epinephrine, norepinephrine, free fatty acids (FFA), insulin, glucose, blood lactate (BLA), and EPOC were measured before (PRE) and after (POST) the intervention. EPOC at PRE was measured for 120 min after 30 min of treadmill running at 70% VO2max. EX completed 2 EPOC trials at POST, i.e., at the same absolute (ABS) and relative (REL) intensity; 1 EPOC test for CON served as both the ABS and REL trial because no significant change in VO2max was noted. During the ABS trial, total EPOC decreased significantly (p \u3c .01) from PRE (39.4 ± 3.6 kcal) to POST (31.7 ± 2.2 kcal). Tre, epinephrine, insulin, glucose, and BLA at end-exercise or during recovery were significantly lower and FFA significantly higher after training. Training did not significantly affect EPOC during the REL trial; however, epinephrine was significantly lower, and norepinephrine and FFA, significantly higher, at end-exercise after training. Results indicate that EPOC varies as a function of relative rather than absolute metabolic stress and that training improves the efficiency of metabolic regulation during recovery from exercise. Mechanisms for the decreased magnitude of EPOC in the ABS trial include decreases in BLA, Tre, and perhaps epinephrine-mediated hepatic glucose production and insulin-mediated glucose uptake. © 2010 Human Kinetics, Inc
A study of the relative efficiency of Chinese ports: A financial ratio-based data envelopment analysis approach
No full textThis research examines the relative efficiency of 11 major Chinese ports by using an innovative adopted version of Data Envelopment Analysis (DEA). DEA is a non-parametric approach to weigh the inputs/outputs and measure the relative efficiency of decision-making units. This paper adopts an output-oriented version of DEA based on financial ratios in which no inputs are utilized. The new adopted DEA model provides a rounded judgement on port efficiency taking into consideration multiple financial ratios simultaneously and combining them into a single measure of efficiency. The mathematical model is solved for every port, and the relative efficiency of each port is determined. The results of DEA show that the higher a port\u27s efficiency ratio in relation to the corresponding ratio of another port, the higher the efficiency of this port. Finally, suggestions based on the data analysis are provided for managerial decision makers to improve the areas needed for port operating efficiency. © 2010 Blackwell Publishing Ltd
Estereotipos Mediáticos o sociales. Influencia del consumo de televisión en el prejuicio detectado hacia los indígenas mexicanos.
No full textDiversos estudios han observado el efecto que puede tener el consumo de televisión en los estereotipos o rasgos con que las personas identifican a los grupos minoritarios (Busselle y Crandall, 2002). En el caso mexicano, aunque el colectivo indígena de la población ha sido estudiado desde diversas disciplinas, sin embargo siguen siendo escasos los análisis sobre su representación mediática o sobre la percepción pública que se tiene de este colectivo. A tal efecto, se realizó una investigación mediante cuestionario, aplicado a 447 estudiantes de la Universidad Autónoma de Nuevo León, el Tecnológico de Monterrey y la Universidad Anáhuac, a los que se les preguntó por su consumo de televisión, los rasgos que consideraban que definían a los indígenas mexicanos y sus percepciones prejuiciosas respecto de este grupo social. Los resultados mostraron que el consumo de televisión no explicaba la generación de estereotipos negativos o positivos. Además, se detectó que el prejuicio aumentaba cuando era mayor el consumo televisivo y la presencia de estereotipos negativos, mientras que disminuía si los estereotipos positivos estaban presentes. En las conclusiones se debate acerca de si la formación del ideario sobre indígenas deriva del contacto y aprendizaje social más que del vicario generado por la televisión
El consumo de YouTube en España
No full textEn España utilizan Youtube 13,5 millones de personas al mes, lo que supone el 54.25% de la audiencia total de Internet en el país, es el cuarto sitio web más visitado y el primero entre los de entretenimiento. El objetivo de este estudio es analizar cuáles son los contenidos que consumen los usuarios de Youtube en España, según sexo y edad. De este modo, se pretende obtener las tendencias de los contenidos que circulan por este portal y saber el seguimiento por parte de la sociedad. Estos datos nos permitirán establecer modelos de negocio.Palabras clave: Youtube, audiencia, contenidos, usuarios, consum
Particulate matter air quality analysis and the possible effects of increasing airborne pollutants on the human respiratory system
No full textThis study focuses on the possible effects of airborne pollutants on the human respiratory system. In order to determine whether or not there was any distinct correlation between air quality and respiratory illness, local pollutant level data and hospital records spanning the past two years were obtained. PM10 and PM2.5 particulate measurements were juxtaposed and compared with hospital records of patients who suffered from asthma, pneumonia, bronchitis, cough or congestion, upper respiratory infection, wheezing or shortness of breath, or respiratory distress. Several studies have been conducted in the United States which show a correlation between air quality and respiratory health. However, the statistics collected from air samples and hospital records in Laredo do not seem to show any distinct correlation, positive or negative. This inconsistency with similar studies performed in other, more densely populated, urban environments may be due to Laredo\u27s relatively high air quality. The margin of error was also most likely increased by the fact that the sample size for the health data was relatively small. Although the data did not support similar studies in its health data, an association between north/northwest winds and high PM10 values was found. © Research India Publications