Comparison of vertical condensation of warm gutta percha and diffusion of gutta percha techniques

Thesis (M.Sc.D.)--Boston University, School of Graduate Dentistry, 1974 (Endodontics)Includes bibliography

Resistance to DDT of a Freshwater Alga

Author Institution: Department of Biology, Oberlin College, Oberlin, Ohio 44074The amount of chlorophyll, the oxygen evolution in the light, and the oxygen uptake in the dark by Chlamydomonas reinhardtii Dangeard are unaffected by exposure to 100-1,000 ppb DDT for 16-96 hours at 18°-22°C in inorganic basal medium with and without acetate in the medium. The growth rate and final cell density of Chlamydomonas reinhardtii Dangeard were identical in control and experimental cultures exposed to 1000 ppb DDT in the growth medium for nine days at 22°C

Emergency medicine in Dubai, UAE

Dubai has rapidly risen to prominence in the Persian Gulf region as a center of global commerce and tourism and as a cultural crossroad between East and West. The health-care infrastructure has undergone rapid development. Collaborations with academic medical centers now exist to advance clinical care, teaching and research. Emergency medicine has also advanced and is undergoing dynamic change. Dubai may soon emerge as a regional leader in emergency medicine training and practice

Study and Simulation of Enhancements for TCP (Transmission Control Protocol) Performance Over Noisy, High-Latency Links

The designers of the TCP/IP protocol suite explicitly included support of satellites in their design goals. The goal of the Internet Project was to design a protocol which could be layered over different networking technologies to allow them to be concatenated into an internet. The results of this project included two protocols, IP and TCP. IP is the protocol used by all elements in the network and it defines the standard packet format for IP datagrams. TCP is the end-to-end transport protocol commonly used between end systems on the Internet to derive a reliable bi-directional byte-pipe service from the underlying unreliable IP datagram service. Satellite links are explicitly mentioned in Vint Cerf's 2-page article which appeared in 1980 in CCR [2] to introduce the specifications for IP and TCP. In the past fifteen years, TCP has been demonstrated to work over many differing networking technologies, including over paths including satellites links. So if satellite links were in the minds of the designers from the beginning, what is the problem? The problem is that the performance of TCP has in some cases been disappointing. A goal of the authors of the original specification of TCP was to specify only enough behavior to ensure interoperability. The specification left a number of important decisions, in particular how much data is to be sent when, to the implementor. This was deliberately' done. By leaving performance-related decisions to the implementor, this would allow the protocol TCP to be tuned and adapted to different networks and situations in the future without the need to revise the specification of the protocol, or break interoperability. Interoperability would continue while future implementations would be allowed flexibility to adapt to needs which could not be anticipated at the time of the original protocol design

Biophysical and structural characterization of components from the nuclear pore complex and the ubiquitin pathway

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 136-151).Formation of an endomembrane system in the eukaryotic cell is a hallmark of biological evolution. One such system is the nuclear envelope (NE), composed of an inner and outer membrane, used to form a nucleus and enclose the cell's genome. Access to the nucleus from the cytoplasm is mediated by a massive macromolecular machine called the nuclear pore complex (NPC). The NPC resides as a circular opening embedded in the NE and is composed of only -30 proteins that assemble with octagonal symmetry as biochemically defined subcomplexes to form the NPC. One such subcomplex is the Nspl / Nup62 complex, composed of three proteins and stabilized by coiled-coil interactions. Here we reconstitute a tetrameric assembly between the Nspl-complex and a fourth nucleoporin (Nup) Nic96. Nic96 harbors a 20 kDa coiled-coil domain at the N-terminus followed by a 65 kDa stacked helical domain. The coiled-coil domain of the Nspl -complex and the N-terminus of Nic96 combine to form a tetrameric assembly, integrated into the NPC lattice scaffold via the stacked helical domain of Nic96. We characterized the coiled-coil assembly with size exclusion chromatography and analytical ultracentrifugation. Deletion experiments and point mutations, directed by hydrophobic cluster analysis, were used to map connecting helices between members of the protein assembly. Although the core of the NPC is a rigid scaffold built for structural integrity, the NPC as a whole is a dynamic macromolecular machine. Protein transport is regulated by the small G protein Ran. Ran interacts with the NPC of metazoa via two asymmetrically localized components, Nupl53 at the nuclear face and Nup358 at the cytoplasmic face. Both Nups contain distinct RANBP2 type zinc finger (ZnF) domains. We present crystallographic data detailing the interaction between Nup1 53-ZnFs and RanGDP. A crystal-engineering approach led to well-diffracting crystals so that all ZnF-Ran complex structures are refined to high resolution. Each of the four zinc finger modules of Nup1 53 binds one Ran molecule in largely independent fashion. Nupl53-ZnFs bind RanGDP with higher affinity than RanGTP, however the modest difference suggests that this may not be physiologically meaningful. ZnFs may be used to concentrate Ran at the NPC to facilitate nucleocytoplasmic transport. In a separate study we present a structural analysis of the HECT domain from the E3 ubiquitin ligase HUWE1 and with biophysical data we show that an N-terminal helix stabilizes the HECT domain. This element modulates activity, as measured by self-ubiquitination induced in the absence of this helix, distinct from its effects on Ub conjugation of substrate Mcl-1. Such subtle structural elements in this domain potentially regulate the variable substrate specificity displayed by all HECT domain type, E3 ubiquitin ligases.by James R. Partridge.Ph.D

Un peu moins de vingt mille incipit inédits de Georges Perec

Un peu moins de vingt mille incipit inédits de Georges Pere

10th Annual Collage Concert

An exciting highlight each season, the School of Music is proud to present the 10th Annual Collage Concert. Collage, a major fundraising event for supporting scholarships for music students, is the signature production of the School of Music featuring soloists, chamber groups, and ensembles totaling over 250 student and faculty performers. This special production features a rapid-fire program of diverse works presented as flowing vignette performances with unique lighting and stage design that combine to create a truly memorable and unique experience. The Collage Concert features a matinee at 5 p.m. and evening performance at 8 p.m.https://digitalcommons.kennesaw.edu/musicprograms/1001/thumbnail.jp

Insulin Signaling Is Necessary for Vitellogenesis in Drosophila melanogaster Independent of the Roles of Juvenile Hormone and Ecdysteroids: Female Sterility of the chico1 Insulin Signaling Mutation Is Autonomous to the Ovary

It has been suggested that insulin signaling mutations of Drosophila melanogaster are sterile and long-lived because of juvenile hormone (JH) and ecdysteroid deficiency. However, female sterility of an insulin/IGF-like signaling mutant (chico1) of D. melanogaster is not mediated by downstream systemic signaling in terms of major alterations in JH or ecdysteroid levels. chico1 is a null mutation in the insulin substrate protein (CHICO) gene of D. melanogaster. Homozygous chico1 females are sterile and their oocytes do not mature beyond the last previtellogenic stage. Homozygous chico1 females exhibit approximately wild-type rates of JH biosynthesis, ovarian release of ecdysteroids and haemolymph ecdysteroid levels, suggesting that these two major hormone systems play no role in producing the sterility. Previtellogenic wild-type ovaries transplanted into homozygous chico1 females underwent vitellogenesis, showing that systemic factors present in mutant females are sufficient to support nor-mal vitellogenesis. chico1 ovaries transplanted into wild-type females did not undergo vitellogenesis indicating that CHICO is necessary in the ovary for vitellogenic maturation. The ovary transplant experiments corroborate the endocrine results and demonstrate that insulin/insulin-like signaling (IIS) is necessary for vitellogenesis even when sufficient levels of JH, ecdysteroids or other factors are present

Insulin Signaling Is Necessary for Vitellogenesis in Drosophila melanogaster Independent of the Roles of Juvenile Hormone and Ecdysteroids: Female Sterility of the chico1 Insulin Signaling Mutation Is Autonomous to the Ovary

It has been suggested that insulin signaling mutations of Drosophila melanogaster are sterile and long-lived because of juvenile hormone (JH) and ecdysteroid deficiency. However, female sterility of an insulin/IGF-like signaling mutant (chico1) of D. melanogaster is not mediated by downstream systemic signaling in terms of major alterations in JH or ecdysteroid levels. chico1 is a null mutation in the insulin substrate protein (CHICO) gene of D. melanogaster. Homozygous chico1 females are sterile and their oocytes do not mature beyond the last previtellogenic stage. Homozygous chico1 females exhibit approximately wild-type rates of JH biosynthesis, ovarian release of ecdysteroids and haemolymph ecdysteroid levels, suggesting that these two major hormone systems play no role in producing the sterility. Previtellogenic wild-type ovaries transplanted into homozygous chico1 females underwent vitellogenesis, showing that systemic factors present in mutant females are sufficient to support nor-mal vitellogenesis. chico1 ovaries transplanted into wild-type females did not undergo vitellogenesis indicating that CHICO is necessary in the ovary for vitellogenic maturation. The ovary transplant experiments corroborate the endocrine results and demonstrate that insulin/insulin-like signaling (IIS) is necessary for vitellogenesis even when sufficient levels of JH, ecdysteroids or other factors are present