992 resultados para ISO 846-1978
Resumo:
To evaluate if depth of cure D(ISO) determined by the ISO 4049 method is accurately reflected with bulk fill materials when compared to depth of cure D(new) determined by Vickers microhardness profiles.
Resumo:
The growth of ISO 14001 certificates worldwide has led to much research on the role of voluntary standards in improving the environmental impacts of industry. Most of this research, however, has focused on industrialized countries, with very little research examining the effects of ISO 14001 and other voluntary initiatives in the developing world. This is especially unfortunate because it is in these very countries that proponents of ISO 14001 claim the largest benefits of the standard will occur, by helping polluting industries improve performance and by assisting environmental regulators in enforcing laws more effectively. Indian industries have begun adopting ISO 14001 at an accelerating pace, but there is little available information on what this means for the environmental performance of Indian firms. The research described here closes this gap by exploring the reasons for the increasing popularity of ISO 14001 in India, the ways in which firms use the standard and the benefits they obtain from it. Findings suggest that while the processoriented approach of ISO 14001 does offer important benefits, changing market demands towards cheaper certification and away from rigorous EMS implementation have devalued the standard for those interested in using it as an indicator of a firm’s environmental performance.
Resumo:
This digital object was funded in part through a grant from the Andrew W. Mellon Foundation. The digitalization of this object was part of a collaborative effort with the Washington Research Library Consortium and George Washington University.
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For more than two-thirds of the life of the International Association of Schools of Social Work (IASSW), Katherine Kendall has been among its leaders. She began her involvement in 1950, served as the first paid Secretary General of the Association in the 1970's and, now in her late 90's, continues to share her wisdom as Honorary President. Beginning in 1950, she attended all the IASSW congresses except 2 (1990 and 1998) until 2004, when health issues prevented long international trips. She personally knew and worked with every President except the first. Thus, although the IASSW began with sustained involvement and contributions of two remarkable founders, Alice Salomon and René Sand, Kendall has surpassed all in terms of her enduring commitment to international social work education and its professional organization. Kendall's remarkable professional career spans 7 decades. Her international involvements began even earlier.
Resumo:
For more than two-thirds of the life of the International Association of Schools of Social Work (IASSW), Katherine Kendall has been among its leaders. She began her involvement in 1950, served as the first paid Secretary General of the Association in the 1970's and, now in her late 90's, continues to share her wisdom as Honorary President. Beginning in 1950, she attended all the IASSW congresses except 2 (1990 and 1998) until 2004, when health issues prevented long international trips. She personally knew and worked with every President except the first. Thus, although the IASSW began with sustained involvement and contributions of two remarkable founders, Alice Salomon and René Sand, Kendall has surpassed all in terms of her enduring commitment to international social work education and its professional organization. Kendall's remarkable professional career spans 7 decades. Her international involvements began even earlier. This article will focus on highlights of her international career, especially her IASSW service. It will also discuss her formative years and mention other aspects of contributions. Materials for the article are drawn from published and unpublished interviews conducted by other scholars, Kendall's own writings, and a personal interview conducted by the author in 2007.
Resumo:
Partially functional forms of iso-1-cytochrome c from Saccharomyces cerevisiae were obtained by replacements of the evolutionarily conserved proline 71 with valine, isoleucine and threonine (Ernst et.al.,1985). Pro-71 lies at the juncture of two short helical regions and is believed to be important for proper local polypeptide chain folding within the iso-1-cytochrome c structure.^ To study folding in the absence of intermolecular disulfide dimer formation the free sulfhydryl group of Cys-102 was modified in both wild type and mutant proteins with an alkylating reagent, methyl methanethiosulfonate. Spectral analysis of the wild type and mutant proteins shows that the native-like functional (or partially functional) folded structure of cytochrome c is retained in the chemically modified derivatives. The replacement of Pro-71 with valine, isoleucine or threonine reduces the intensity of the 696 nm absorbance band which is an indicator of the Met-80 ligation to the heme. Thermal stability and guanidine hydrochloride unfolding studies of the mutant proteins shows a destabilization of the protein as a result of mutation. The degree of destabilization depends on the chemical nature of the substituent amino acid in the mutant protiens.^ Kinetics of folding/unfolding reactions of the proteins were monitored by fluorescence changes using stopped flow mixing to obtain guanidine hydrochloride concentration jumps ending below, within, and above the transition zone. The replacement of Pro-71 alters the rate on one of the fastest phases, $\tau\sb3$, while the two other phases, $\tau\sb1$ & $\tau\sb2$, remain the same.^ Slow refolding kinetic studies indicate that replacement of Pro-71 does not completely eliminate the absorbance or fluorescence detected slow phases leading to the conclusion that Pro-71 is not involved in the generation of the slow phases in the folding kinetics of iso-1-cytochrome c.^ The alkaline conformational change involving the disappearance of the 696 nm absorbance band occurs with increasing pH in the alkaline pH region (Davis et al., 1974). The apparent pK of this conformational change in mutant proteins is shifted as much as two pH units compared to wild type. The equilibrium and kinetic data of alkaline transition for the wild type follows a simple mechanism proposed by Davis et al., (1974) for horse heart cytochrome c. A more complex mechanism is proposed for the behavior of the mutant proteins. ^
Resumo:
We present the synthesis of the two novel nucleosides iso-tc-T and bcen-T, belonging to the bicyclo-/tricyclo-DNA molecular platform. In both modifications the torsion around C6’–C7’ within the carbocyclic ring is planarized by either the presence of a C6’–C7’ double bond or a cyclopropane ring. Structural analysis of these two nucleosides by X-ray analysis reveals a clear preference of torsion angle γ for the gauche orientation with the furanose ring in a near perfect 2’-endo conformation. Both modifications were incorporated into oligodeoxynucleotides and their thermal melting behavior with DNA and RNA as complements was assessed. We found that the iso-tc-T modification was significantly more destabilizing in duplex formation compared to the bcen-T modification. In addition, duplexes with complementary RNA were less stable as compared to duplexes with DNA as complement. A structure/affinity analysis, including the already known bc-T and tc-T modifications, does not lead to a clear correlation of the orientation of torsion angle γ with DNA or RNA affinity. There is, however, some correlation between furanose conformation (N- or S-type) and affinity in the sense that a preference for a 3’-endo like conformation is associated with a preference for RNA as complement. As a general rule it appears that Tm data of single modifications with nucleosides of the bicyclo-/tricyclo-DNA platform within deoxyoligonucleotides are not predictive for the stability of fully modified oligonucleotides.
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Welche politischen Voraussetzungen müssen gegeben sein, damit Regierungen den Staatshaushalt konsolidieren? In diesem Beitrag konzentrieren wir uns auf zwei Erklärungsgrößen: Die parteipolitische Zusammensetzung einer Regierung und die Breite der Regierungskoalition. Wir zeigen einerseits, dass die Wahrscheinlichkeit der Initiierung eines Konsolidierungsprogramms unter Parteien der politischen Rechten sowie unter kleinen Reformkoalitionen (Einparteienregierungen und minimal winning Koalitionen) am höchsten ist. Andererseits finden wir ein nahezu entgegengesetztes Muster bezüglich des Umfangs der verabschiedeten Sparmaßnahmen. Hier zeigt sich, dass die Breite der Regierungskoalition grundsätzlich einen positiven Einfluss auf die Größe des Konsolidierungsprogramms ausübt. Zudem fallen die Sparpakete rechter Parteien generell bescheidener aus als jene ihrer Konkurrenten der politischen Mitte und Linken. Wir erklären diese Ergebnisse mit den strategischen und wahlpolitischen Optionen der Akteure, auf Basis eines Vergleichs von 17 OECD-Ländern zwischen 1978 und 2009.
Resumo:
We report 2 cases of Iso Kikuchi syndrome: A new born female patient with a 21 days history and a 62 year-old male. We present two cases of this unusual congenital abnormality of the nails at the extremes of life.