Institutional Work and Artifact Evolution

How artifacts come to persist is a neglected area in organizational theory. In IS, Lucas et al. (2007) stress implementation research that takes the long view, but little is known about maintenance practices. Using Lawrence et al. (2009) institutional work framework, we analyze stakeholder efforts to stabilize and now maintain the Urban-net, a broadband network. We track it from inception through design stabilization to post-stabilization. Empirically, we add to research on the neglected area of maintenance work. Re: theory, our contributions are two-fold. First, we distinguish artifact stabilization from maintenance, a distinction Lawrence et al. (2009) ignore. Bijker’s (1997) idea of stabilization offers a way to think about the two. The temporal and relational scope of the effort involved, we show, can be different. Second, we adapt the term gardening from Olsen (2003) to characterize the multi-stranded nature of maintenance, involving efforts to preserve while also amending the Urban-net

Friction Stir Welding of Aluminium Alloys

This chapter investigates on the characterization of friction stir welded dissimilar aluminium alloys AA2024 with AA5052, AA2024 with AA6061 and AA 5052 with AA6061. Five tool designs were employed with first two dissimilar combinations to analyze the influence of rotation and traverse speed over microstructural and mechanical properties. H13 tool steel was used as tool material with various pin profiles which includes cylindrical, cylindrical-threaded, squared, tapered and stepped types. In the dissimilar welding of AA 2024 with AA 5052, sound welds were produced with stepped pin tool. In the dissimilar welding of AA 2024 with AA 6061, ratio between tool shoulder to diameter of tool pin was the most influential factor. Welded joints failed in the Heat affected zone (HAZ) of 6061 where the hardness values were comparatively less. In dissimilar welding of AA 5052 with AA6061, cylindrical pin tool was used at a constant speed of 710 rpm and at different feed rates of 28 and 40 mm/min. Micro structural examination showed variation of grain size in every zone and their influence on mechanical properties. Correlating mechanical and metallurgical properties, the optimized process parameters of speed and feed were identified to be 710 rpm and 28 mm/min respectively for all attempted dissimilar combinations

Continuous downstream process or connected batch process: Which one makes most sense for Biogen?

As biologics-based products move into therapeutic areas with large patient populations and high doses, batch processing may not be able to keep pace with product demands. At Biogen, we have been exploring a number of options that can enable higher productivity of our downstream processes. In addition to a fully “end to end” continuous process, a batch process comprised of several steps connected in series has been evaluated. In this presentation, technologies Biogen has evaluated to enable either continuous or connected processing will be shown. Multi-Column-Chromatography (MCC) for the Protein A capture chromatography step was evaluated in order to maximize resin utilization and increase productivity. Connecting subsequent polishing steps was explored to eliminate the need for large intermediate hold tanks. Various options for continuous diafiltration were assessed to enable a fully continuous UF/DF step. The results of these evaluations will be presented as well a comparison of the expected productivity and COGs for both process options

Comparison of World Health Organization body mass index for age Z scores and revised Indian Academy of Pediatrics growth standards for the diagnosis of thinness, overweight, and obesity among adolescent girls

Background: In spite of the rapid economic growth of India in recent years, the health of our children is being challenged by thetroublesome duo of over nutrition and undernutrition. Determination of the magnitude of this problem needs uniform and representativegrowth standards across the country. Aim: To compare the prevalence of thinness, overweight, and obesity among girls aged 10-15 yearsbelonging to urban Pondicherry using the World Health Organization (WHO) body mass index (BMI) for age Z scores and revisedIndian Academy of Pediatrics (IAP) growth standards. Materials and Methods: A total of 287 girls were included in the study. Weightand height were measured for all of them as per standard guidelines and BMI were calculated. Thin, overweight and obese girls wereidentified based on the WHO Z scores for BMI-for-age as well as revised IAP growth standards 2015. Results: The prevalence ofthinness as per WHO BMI for age Z scores was 22.6%. The prevalence of overweight and obesity were 6.6% and 2.1%, respectively.In comparison, the prevalence of thinness according to revised IAP growth standards was 10% and that of overweight and obesitywere 6.3% and 1.4% respectively. The prevalence of thinness as per recent IAP growth standards is significantly less compared to theprevalence obtained using WHO Z scores. Conclusion: Using the WHO BMI for age Z scores is likely to overestimate the prevalenceof thinness significantly when compared to revised IAP growth standards for Indian children. BMI for age Z scores for Indian childrenis needed to address this issue in large prospective multicenter studies

Quality-of-Service Routing Using Path and Power Aware Techniques in Mobile Ad Hoc Networks

Mobile ad hoc network (MANET) is a collection of wireless mobile hosts dynamically forming a temporary network without the aid of any existing established infrastructure. Quality of service (QoS) is a set of service requirements that needs to be met by the network while transporting a packet stream from a source to its destination. QoS support MANETs is a challenging task due to the dynamic topology and limited resources. The main objective of this paper is to enhance the QoS routing for MANET using temporally ordered routing algorithm (TORA) with self-healing and optimized routing techniques (SHORT). SHORT improves routing optimality by monitoring routing paths continuously and redirecting the path whenever a shortcut path is available. In this paper, the performance comparison of TORA and TORA with SHORT has been analyzed using network simulator for various parameters. TORA with SHORT enhances performance of TORA in terms of throughput, packet loss, end-to-end delay, and energy

Moving Beyond CHO: Alternative host systems may be the future of biotherapeutics

CHO cells are the primary expression system for recombinant proteins with significant investment over the last three decades resulting in robust cell lines and processes. The flexible nature of CHO has lent itself to multiple process formats, such as fed batch, perfusion and continuous cultures, and advances in omics technology has enabled customization of media formulations and targeted engineering of CHO cells. This knowledge has led to large gains in protein productivity that can be captured with culture duration and/or scale. Despite this, constant pressure exists to reduce cost of manufacturing and improve per batch productivity to meet the needs of increased patient populations and increase accessibility of these therapeutics. Biogen has partnered with MIT to take a holistic view of the potential future of biomanufacturing to identify technologies that can make step changes in productivity and cost reduction. This effort has identified the host system as the most important factor to enabling this vision. Specifically, a non-mammalian host could be the key to realizing the most significant gains in productivity and reduction in cost of manufacturing. Through this initiative, we sought to take a more comprehensive approach to investigate alternative hosts for recombinant antibody production. Eight non-mammalian hosts were selected based on several properties, including proven secretion of recombinant protein products, ability to glycosylate proteins, established genome or molecular biology toolkit, amongst others. The final panel of organisms included yeast, filamentous fungi, a diatom, and a trypanosome. In collaboration with Amyris, we evaluated these eight non-mammalian host cell lines to compare their suitability as a potential primary host for the biotechnology industry. Only non-engineered, wild-type strains were used as a starting point for this evaluation, which assessed the ability of each host to express the same IgG1 model antibody. The outcome of this comparative analysis demonstrated that several of the alternative hosts could express full length antibody with acceptable glycoforms. Additionally, the ease of culture, ability to engineer the genome, and flexibility of carbon source were assessed. As an output of this work, the most productive strains will be made available for use without restrictions to allow others in the community to freely work with these hosts. Based on this initial assessment, a strategy to further investigate the potential of the most promising hosts will be shared

Beyond CHO – Non-mammalian hosts could be the future expression systems of choice for recombinant biotherapeutics

Over the last 30 years there have been tremendous advances in CHO cell culture process engineering. Novel process concepts, such as fed batch, perfusion and continuous cultures, evolved from a deep understand of CHO metabolic needs and extensive media/feed formulation development. This knowledge has led to large gains in protein productivity that can be captured with culture duration and/or scale. The biotechnology industry is consistently pressured to reduce cost of manufacturing and improve per batch productivity. Independent, but related to this burden, is the ability to support an ever growing patient population with high doses of therapeutic protein. As such, Biogen partnered with MIT to take a holistic view of the potential future of biomanufacturing to identify technologies that can make step changes in productivity and cost reduction. These efforts have cast doubt that CHO would be the optimal host in the future, whereas a non-mammalian host could be a key to realizing the most significant gains in productivity and reduction in cost of manufacturing. Recombinant antibody production from non-mammalian hosts has been reported in the past, for example from the yeast pichia and filamentous fungi Trichoderma, and antibody material produced from pichia has been used in clinical trials. In the next phase of this initiative, we sought to take a more comprehensive approach to investigate alternative hosts in recombinant antibody production. Eight non-mammalian hosts were selected based on a number of properties, including proven secretion of recombinant protein products, ability to glycosylate proteins, established genome or molecular biology toolkit, amongst other characteristics. We designed an experimental plan that would enable more straightforward comparative analysis between hosts and included two main criteria to maintain a level playing field. First, only non-engineered, wild-type strains would be used as a starting point for all eight hosts of interest. Second, a single IgG1 model antibody was selected to be expressed by all hosts. In this presentation, the outcome of this comparative analysis will be discussed, including productivity values and details of the model antibody product quality. Based on this data the most productive strains will be made available for use without restrictions to allow others in the community to freely work with these hosts

Antibody production in micro-organisms

Global demand for monoclonal antibody-based therapeutics (Mab’s) far exceeds current production capacity, and is expected to continue to grow based on current development pipelines. Despite their proven efficacy in a large number of indications, equitable use of these drugs is limited by the high cost of CHO-cell based production and purification. Micro-organisms such as yeasts and filamentous fungi present an attractive alternative for antibody production, but will require extensive genetic modification to achieve both high titers and mammalian-like glycosylation patterns in a secreted product that is easily purified. Towards this end, we developed state-of-the-art genetic engineering tools for eight micro-organisms to enable the highly efficient, targeted multiplexed integrations necessary for antibody production in these hosts. We demonstrated successful antibody production in several of these micro-organisms, paving the way to low-cost microbial fermentation to replace CHO fermentation

Cancer-associated mesothelial cells promote ovarian cancer chemoresistance through paracrine osteopontin signaling

Ovarian cancer is the leading cause of gynecological malignancy-related deaths, due to its widespread intraperitoneal metastases and acquired chemoresistance. Mesothelial cells are an important cellular component of the ovarian cancer microenvironment that promote metastasis. However, their role in chemoresistance is unclear. Here, we investigated whether cancer-associated mesothelial cells promote ovarian cancer chemoresistance and stemness in vitro and in vivo. We found that osteopontin is a key secreted factor that drives mesothelial-mediated ovarian cancer chemoresistance and stemness. Osteopontin is a secreted glycoprotein that is clinically associated with poor prognosis and chemoresistance in ovarian cancer. Mechanistically, ovarian cancer cells induced osteopontin expression and secretion by mesothelial cells through TGF-β signaling. Osteopontin facilitated ovarian cancer cell chemoresistance via the activation of the CD44 receptor, PI3K/AKT signaling, and ABC drug efflux transporter activity. Importantly, therapeutic inhibition of osteopontin markedly improved the efficacy of cisplatin in both human and mouse ovarian tumor xenografts. Collectively, our results highlight mesothelial cells as a key driver of ovarian cancer chemoresistance and suggest that therapeutic targeting of osteopontin may be an effective strategy for enhancing platinum sensitivity in ovarian cancer

Depletion of Deoxyribonucleotide Pools is an Endogenous Source of DNA Damage in Cells Undergoing Oncogene-Induced Senescence

In normal human cells, oncogene-induced senescence (OIS) depends on induction of DNA damage response (DDR). Oxidative stress and hyper-replication of genomic DNA have been proposed as major causes of DNA damage in OIS cells. Here we report that down-regulation of deoxyribonucleoside pools is another endogenous source of DNA damage in normal human fibroblasts (NHF) undergoing HRAS[superscript G12V]-induced senescence. NHF-HRAS[superscript G12V] cells under-expressed thymidylate synthase (TS) and ribonucleotide reductase (RR), two enzymes required for the entire de novo deoxyribonucleotide biosynthesis, and possessed low dNTP levels. Chromatin at the promoters of the genes encoding TS and RR was enriched with RB tumor suppressor protein and histone H3 tri-methylated at lysine 9. Importantly, ectopic co-expression of TS and RR or addition of deoxyribonucleosides substantially suppressed DNA damage, senescence-associated phenotypes and proliferation arrest in two types of NHF expressing HRAS[superscript G12V]. Reciprocally, shRNA-mediated suppression of TS and RR caused DNA damage and senescence in NHF although less efficiently than HRAS[superscript G12V]. However, overexpression of TS and RR in quiescent NHF did not overcome proliferation arrest, suggesting that unlike quiescence, OIS requires depletion of dNTP pools and activated DNA replication. Our data identify a previously unknown role of deoxyribonucleotides in regulation of oncogene-induced senescence.This is the author's peer-reviewed final manuscript, as accepted by the publisher. The published article is copyrighted by Elsevier and can be found at: http://www.journals.elsevier.com/the-american-journal-of-pathology/