The stability constants of praseodymium acetate and oxydiacetate complexes were measured by laser-induced photoacoustic spectroscopy, conventional UV-visible absorption spectroscopy, and pH ...titration. For the spectroscopic studies, changes in the free Pr absorption peaks at 468 and 481 nm were monitored at varying ligand concentrations. The total Pr concentration was 1 x 10 exp --4 M in solutions used for the photoacoustic studies and 0.02 M for conventional spectroscopy. For the pH titrations, solutions were used whose Pr concentrations varied from 5 x 10 exp --3 -5 x 10 exp --2 M, with total ligand-to-metal ratios ranging from 1-10. A comparison of the results obtained by the three techniques demonstrates that photoacoustic spectroscopy can give the same information about metal-ligand speciation as more conventional methods. It is particularly suited to those situations where the other techniques are insensitive because of limited metal concentrations. Spectra. 17 ref.--AA
Undisputed molecular evidence for apomixis in cassava is presented. Based on genome sampling with 130 RAPD markers we confirmed apomixis for one offspring of a cassava clone derived from an ...interspecific hybrid. The probability that complete uniformity in RAPD fingerprints between mother and offspring occurred by chance was < 10
−5
. Key words: Apomixis, cassava, Manihot esculenta, random amplified polymorphic DNA
This study evaluated the anatomical relationship between posterior teeth root apices and maxillary sinus floor (MSF) on 202 cone beam computed tomography (CBCT) exams. The distance between the root ...apices and the MSF, as well as the MSF thickness of the cortical bone closest to root apices and furcation regions were measured. The vertical and horizontal relationships of the MSF with the molar roots were classified into categories adapted from the criteria proposed by Kwak et al. (14). The shortest distances between MSF and the root apices were observed in the mesiobuccal root of the second molar (0.36±1.17 mm) and the palatal root of the first molar (0.45±1.10 mm) and the widest in buccal roots of the first premolars (5.47±4.43 mm). Significant differences were observed between the distance of MSF to the root apices of single-rooted first and second premolars. The cortical thickness ranged from 0.65±0.41 mm over the mesiobuccal root of the second molar to 1.28±0.42 mm over the buccal root of the first premolar. The most observed vertical and horizontal relationships were type II and 2H, respectively. The maxillary molar roots showed greater proximity to the MSF. The thickness of the MSF cortical bone closest to the apices and furcation regions was found to be similar only for premolars.
La neumonía asociada a ventilación mecánica (NAVM) en Chile, es una de las infecciones intrahospitalarias (IIH) más frecuentes y de mayor impacto en morbimortalidad. A pesar de las medidas habituales ...de prevención de IIH aplicadas en nuestro hospital, se presentó en el año 2002 un aumento en la tasa de NAVM, junto al aislamiento de un mayor porcentaje de Acinetobacter baumannii, cepa endémica en nuestro hospital. Con el fin de identificar posibles nichos de microorganismos nosocomiales, se realizó un plan de estudio, que involucró al paciente (secreción traqueal) y los sistemas de ventilación, humidificadores, tubo endotraqueal, tubo en Y, mangueras del sistema de ventilación. Se estudió por microscopia de barrido las mangueras de ventilación para precisar características del material. Se observó, al cabo de 7 días, tiempo de recambio establecido por el Comité Nacional de IIH, colonización por A. baumannii, Pseudomonas aeruginosa y Klebsiella pneumoniae, agentes asociados a NAVH en 2 pacientes. Se estudió el circuito de ventilación mecánica perteneciente a un paciente con NAVM tanto preesterilización como postesterilización, aislándose en ambos cultivos microorganismos multiresistentes. Al analizar porciones del circuito por microscopia de barrido se observó un desgaste de las mangueras con múltiples grietas con formas cocoides y bacilares incluidas en la trama. Al estudiar diferentes circuitos pre y posesterilización, se observó en 2 circuitos cultivos positivos con posterioridad a la esterilización en oxido de etileno. Nuestros datos dan énfasis a la necesidad de incorporar en forma rutinaria dentro de las normas de control de IIH las relacionadas a material reutilizable.
Describes the Algebra Project, which teaches algebra to middle school students and prepares them for college preparatory mathematics. The project includes some of the following elements: (1) a ...curriculum addressing the conceptual leap from arithmetic to algebra; (2) an experientially based curricular process; (3) high achievement expectations; and (4) ongoing teacher training and support. (AF)
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The presentation summarizes current and proposed activities for the GEOS-5 aerosol modeling system. Activities discussed include (i) forecasting and event simulation, (ii) observation simulation, ...(iii) aerosol-chemistry-climate applications, and (iv) future activities. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocenter website, after the meeting.
L’objectif spécifique de cette recherche est de rapporter et d’analyser les pratiques déclarées des formateurs (N= 25) au regard du recours aux TIC dans le développement de la compétence scripturale ...en FLE/S en contexte universitaire. La collecte de données a eu lieu dans cinq institutions dans le cadre d’un projet international. Pour recueillir les données en lien avec les pratiques déclarées, nous avons mené des entrevues de groupe semidirigées auprès des formateurs de FLE/S. L’analyse préliminaire de ces entrevues montre que l’enseignement-apprentissage de l’écriture et l’évaluation de celle-ci ont évolué avec le développement des TIC. Pour ce qui est du processus d’écriture (la planification, la mise en texte et la révision) dans ce contexte, les enseignants déclarent que pour les opérations de la mise en texte et de la révision, les TIC sont les plus utiles dans l’apprentissage de l’écrit en FLE/S pour les apprenants universitaires. De plus, les TIC auraient des effets à la fois positifs et négatifs sur les étudiants universitaires utilisant les technologies dans un cours d’écriture en langue seconde (L2).
1. The aims of the present study were to investigate the contribution of intracellular calcium and to evaluate the effect of the antagonists of the intracellular calcium stores, thapsigargin and ...8-(Diethylamino)-octyl-3,4,5-trimethoxybenzoate, HC1 TMB-8, on phenylephrine-stimulated contractions of rat anococcygeus smooth muscle, using functional studies. 2. Phenylephrine induced concentration-related contractions in both 2.5 mM Ca2(+)-free EGTA media. 3. In Ca2(+)-free media phenylephrine stimulated successive contractions, and the contractile response was abolished only after approximately 26 stimulations. 4. In Ca2(+)-free media, after incubation with 10 microM TMB-8 for 30 min, phenylephrine induced concentration-response curves that shifted to the right. The EC50 values were not changed, and the maximum contractile response was reduced by 39.2 +/- 7.6% in relation to phenylephrine-stimulated responses in absence of TMB-8. 5. Thapsigargin (1 microM) did not alter phenylephrine-stimulated contractions in Ca2(+)-free media. 6. These results indicate that intracellular Ca2+ plays an important role on phenylephrine-stimulated contractions on rat anococcygeus muscle and that the phenylephrine-sensitive intracellular Ca2+ store is not sensitive to thapsigargin.
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A notable strength of the volume is the use of multiple disciplines rather than merely political science or civil-military relations to study the transformation of Latin America. With great emphasis ...on the "national security states" of Brazil (1964-85), Uruguay (1972-85), Chile (1973-90), and Argentina (1976-83), the authors have the luxury of teasing out historical, societal, and political reasons why these states have suffered through periods of such severe and enduring upheaval.
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