A senior manufacturing laboratory for determining injection molding process capability

The following is a laboratory experiment designed to further understanding of materials science. This subject material is directed at an upper level undergraduate/graduate student in an Engineering or Engineering Technology program. It is assumed that the student has a thorough understanding of the process and quality control. The format of this laboratory does not follow that which is normally recommended because of the nature of process capability and that of the injection molding equipment and tooling. This laboratory is instead developed to be used as a point of departure for determining process capability for any process in either a quality control laboratory or a manufacturing environment where control charts, process capability, and experimental or product design are considered important topics

Managing contactability in telephone surveys

The Australian market research industry relies on telephone interviewing as one of its major data collection methods. Through Its LIST initiative, the industry has committed to best practice In research methods in order to address various concerns, especially the decline in response rates for telephone interviews. Response rates are determined by the co-operation of eligible respondents and their degree of contactabllity. The reported study is concerned with the way the industry attempts to manage contactabiIity. A study of fieldwork managers responSible for over 75% of all phone interviews in Australia revealed a limited use of contact enhancing strategies such as longer fieldwork periods and more callbacks. Commercial imperatives for timely surveys and a lack of end-user concern for response rate issues, along with cost issues, were believed to be responsible.<br /

Response rates in telephone surveys: managing contactability

Telephone interviewing is the major data collection method for the market research industry. Although social trends such as mobile phones and call screening make it harder to contact people, better technology and contact regimes can assist companies to ameliorate the situation. A study of fieldwork managers responsible for over 75% of all phone interviews in Australia revealed limited use of contact enhancing strategies such as longer survey periods and more callbacks. Commercial imperatives for timely surveys and a lack of end-user concern for response rate issues, along with costs concerns, were believed to be responsible.<br /

Managing respondent co-operation in Australian telephone research

Non-response to telephone surveys threatens the accuracy of the collected data and leads to increased research costs. This study examines ways in which Australian telephone research providers are combating non-response by managing the issue of respondent co-operation, including the management of the interviewers and of the survey process. The research found that many of these response-rate boosting practices proposed in the literature are not available to Australian telephone researchers, mainly for cost and regulatory reasons.<br /

Molecular basis for DNA strand displacement by NHEJ repair polymerases

The non-homologous end-joining (NHEJ) pathway repairs DNA double-strand breaks (DSBs) in all domains of life. Archaea and bacteria utilize a conserved set of multifunctional proteins in a pathway termed Archaeo-Prokaryotic (AP) NHEJ that facilitates DSB repair. Archaeal NHEJ polymerases (Pol) are capable of strand displacement synthesis, whilst filling DNA gaps or partially annealed DNA ends, which can give rise to unligatable intermediates. However, an associated NHEJ phosphoesterase (PE) resects these products to ensure that efficient ligation occurs. Here, we describe the crystal structures of these archaeal (Methanocella paludicola) NHEJ nuclease and polymerase enzymes, demonstrating their strict structural conservation with their bacterial NHEJ counterparts. Structural analysis, in conjunction with biochemical studies, has uncovered the molecular basis for DNA strand displacement synthesis in AP-NHEJ, revealing the mechanisms that enable Pol and PE to displace annealed bases to facilitate their respective roles in DSB repair

Mycobacterium tuberculosis ClpX Interacts with FtsZ and Interferes with FtsZ Assembly

FtsZ assembly at the midcell division site in the form of a Z-ring is crucial for initiation of the cell division process in eubacteria. It is largely unknown how this process is regulated in the human pathogen Mycobacterium tuberculosis. Here we show that the expression of clpX was upregulated upon macrophage infection and exposure to cephalexin antibiotic, the conditions where FtsZ-ring assembly is delayed. Independently, we show using pull-down, solid-phase binding, bacterial two-hybrid and mycobacterial protein fragment complementation assays, that M. tuberculosis FtsZ interacts with ClpX, the substrate recognition domain of the ClpXP protease. Incubation of FtsZ with ClpX increased the critical concentration of GTP-dependent polymerization of FtsZ. Immunoblotting revealed that the intracellular ratio of ClpX to FtsZ in wild type M. tuberculosis is approximately 1∶2. Overproduction of ClpX increased cell length and modulated the localization of FtsZ at midcell sites; however, intracellular FtsZ levels were unaffected. A ClpX-CFP fusion protein localized to the cell poles and midcell sites and colocalized with the FtsZ-YFP protein. ClpX also interacted with FtsZ mutant proteins defective for binding to and hydrolyzing GTP and possibly for interactions with other proteins. Taken together, our results suggest that M. tuberculosis ClpX interacts stoichiometrically with FtsZ protomers, independent of its nucleotide-bound state and negatively regulates FtsZ activities, hence cell division