432 research outputs found

    Process simulation based decisional tool to evaluate strategies for continuous downstream bioprocess implementation - A CDMO perspective

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    To maintain a competitive space in the rapidly expanding and highly competitive market, many biopharmaceutical companies are outsourcing to contract development and manufacturing organizations (CDMOs) to accelerate research and development, shorten the time to market, alleviate internal capacity and technical constraints, and reduce risks associated with production [1]. To acquire new and maintain current clients, CDMOs must have strong, diverse technical offerings for development, manufacture, and testing of products with competitive pricing and timelines [2]. Adopting innovative technologies like continuous downstream processing can help debottleneck the process and reduce processing time, which is the most appealing to CDMOs as it translates to an increased number of batches per year. The majority of continuous processing assessments to date have focused on cost of goods and not on the time reduction potential [3-7]. End-to-end continuous downstream processing is not always practical as CDMOs must accommodate a wide range of molecules and processes. Hence, it is imperative to evaluate and customize continuous production based on client needs. Application of process simulation as a decisional tool to select an appropriate downstream processing strategy was evaluated. Two modelling programs were evaluated: BioSolve Process and SuperPro Designer®. Fully continuous and hybrid (continuous Protein A operation only) downstream processing were assessed for a 2000 L fed-batch bioreactor producing 1, 5, and 10 g/L of monoclonal antibody at 40 and 200 kg production demands. Hybrid and continuous processing decreased batch duration by 20% and 60%, respectively. Continuous processing was more favorable for higher titer processes (≥ 5 g/L). The largest cost reductions were observed for 5 and 10 g/L titer processes during 40 kg production. The results highlight the business case for continuous downstream bioprocessing especially at a CDMO. Selection of a processing method will be influenced by a range of factors and the impact can easily be assessed using process simulation. Therefore, it is recommended that CDMOs use process simulation to ensure the most favorable processing strategy is selected. [1] O. Gassmann, A. Schuhmacher, M. von Zedtwitz, G. Reepmeyer, The Make-or-Buy Challenge: How to In-and Outsource Innovation, Leading Pharmaceutical Innovation, Springer2018, pp. 79-110. [2] R. Hernandez, Contract Biomanufacturing Firms Become More Specialized, BioPharm International, 28 (2015) 22-27. [3] D. Pollard, M. Brower, Y. Abe, A.G. Lopes, Standardized Economic Cost Modeling for Next-Generation MAb Production, BioProcess Int, (2016). [4] A. Xenopoulos, A new, integrated, continuous purification process template for monoclonal antibodies: process modeling and cost of goods studies, Journal of biotechnology, 213 (2015) 42-53. [5] J. Hummel, M. Pagkaliwangan, X. Gjoka, T. Davidovits, R. Stock, T. Ransohoff, R. Gantier, M. Schofield, Modeling the Downstream Processing of Monoclonal Antibodies Reveals Cost Advantages for Continuous Methods for a Broad Range of Manufacturing Scales, Biotechnology journal, (2018) 1700665. [6] J. Pollock, J. Coffman, S.V. Ho, S.S. Farid, Integrated continuous bioprocessing: Economic, operational, and environmental feasibility for clinical and commercial antibody manufacture, Biotechnology progress, 33 (2017) 854-866. [7] S. Klutz, L. Holtmann, M. Lobedann, G. Schembecker, Cost evaluation of antibody production processes in different operation modes, Chemical Engineering Science, 141 (2016) 63-74

    Adaptive Boolean Networks and Minority Games with Time--Dependent Capacities

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    In this paper we consider a network of boolean agents that compete for a limited resource. The agents play the so called Generalized Minority Game where the capacity level is allowed to vary externally. We study the properties of such a system for different values of the mean connectivity KK of the network, and show that the system with K=2 shows a high degree of coordination for relatively large variations of the capacity level.Comment: 4 pages, 4 figure

    Enhancing Emotional Safety in a Graduate School Setting

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    In the United States, racial disparities in education can be seen in rates of graduation from high school through doctoral programs, with People of Color reporting rates that are significantly lower than their White peers. Academic success has been significantly predicted in prior research by the support of teaching staff. Our Safety in the Classroom (SITC) program was developed to close the support gap for several different, often-marginalized groups within graduate school classes at a university in southern California. Students within racial, religious, and sexual orientation groups reported stronger perceptions of prejudice when compared to their peers. The SITC program provided all students an additional tool for resolving questions and concerns about any aspect of a particular course, including behaviors or statements of the instructor, and resulted in greater effect sizes on enhanced feelings of safety in the classroom for students of color. These results were achieved without undermining the students’ belief in their own ability to negotiate over or confront problems in the classroom. Expanded use and evaluation of the SITC program could contribute to the growing literature on academic success and achievement among underrepresented groups, providing one possible tool for helping to close the support gap

    Stakeholders’ knowledge, attitude and perceptions on the control of Taenia solium in Kamuli and Hoima districts, Uganda

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    Objective: Taenia (T.) solium is a zoonotic parasite causing three diseases: - Taeniasis and cysticercosis in humans and porcine cysticercosis in pigs. Although biomedically, the transmission of the parasite can be easily interrupted at six points along the life cycle, the contextual factors that may influence the adoption of these control strategies in Uganda remain unclear. This study assessed the stakeholders’ knowledge, attitudes and perceptions relating to the six control strategies for T. solium infections in Kamuli and Hoima districts, Uganda. Materials and Methods: A total of 22 focus group discussions (FGD) were conducted with pig farmers, community leaders, pig/pork traders, animal health assistants and human health assistants. In addition, nine key informant interviews were held with senior officials in the ministries of agriculture and health, and other relevant agencies at the district level. Results: The results showed differential, limited and fragmented knowledge on T. solium infections among stakeholders. Pig farmers, community leaders and pig/pork traders had almost no knowledge and were often confused regarding the differences existing between T. solium and other gastro-intestinal infections in pigs and humans. Pig confinement, pit latrine construction, coverage, maintenance and sustained use are influenced by cultural, socio-economic, and physical/ environmental factors of study population and area. Conclusion: Proper sensitization programmes and health education interventions should target all, but with material appropriately focused to suit the different stakeholder’s categories. Reminders or nudges may be needed to ensure that increase in knowledge translates to changes in practice. Intervention programmes should also aim to overcome challenges created by the various contextual factors operating in the specific endemic areas

    Ecological consequences of early Late Pleistocene megadroughts in tropical Africa

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    Extremely arid conditions in tropical Africa occurred in several discrete episodes between 135 and 90 ka, as demonstrated by lake core and seismic records from multiple basins [Scholz CA, Johnson TC, Cohen AS, King JW, Peck J, Overpeck JT, Talbot MR, Brown ET, Kalindekafe L, Amoako PYO, et al. (2007) Proc Natl Acad Sci USA 104:16416–16421]. This resulted in extraordinarily low lake levels, even in Africa\u27s deepest lakes. On the basis of well dated paleoecological records from Lake Malawi, which reflect both local and regional conditions, we show that this aridity had severe consequences for terrestrial and aquatic ecosystems. During the most arid phase, there was extremely low pollen production and limited charred-particle deposition, indicating insufficient vegetation to maintain substantial fires, and the Lake Malawi watershed experienced cool, semidesert conditions (\u3c400 mm/yr precipitation). Fossil and sedimentological data show that Lake Malawi itself, currently 706 m deep, was reduced to an ≈125 m deep saline, alkaline, well mixed lake. This episode of aridity was far more extreme than any experienced in the Afrotropics during the Last Glacial Maximum (≈35–15 ka). Aridity diminished after 95 ka, lake levels rose erratically, and salinity/alkalinity declined, reaching near-modern conditions after 60 ka. This record of lake levels and changing limnological conditions provides a framework for interpreting the evolution of the Lake Malawi fish and invertebrate species flocks. Moreover, this record, coupled with other regional records of early Late Pleistocene aridity, places new constraints on models of Afrotropical biogeographic refugia and early modern human population expansion into and out of tropical Africa

    Implementing GitHub Actions Continuous Integration to Reduce Error Rates in Ecological Data Collection

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    Accurate field data are essential to understanding ecological systems and forecasting their responses to global change. Yet, data collection errors are common, and data analysis often lags far enough behind its collection that many errors can no longer be corrected, nor can anomalous observations be revisited. Needed is a system in which data quality assurance and control (QA/QC), along with the production of basic data summaries, can be automated immediately following data collection. Here, we implement and test a system to satisfy these needs. For two annual tree mortality censuses and a dendrometer band survey at two forest research sites, we used GitHub Actions continuous integration (CI) to automate data QA/QC and run routine data wrangling scripts to produce cleaned datasets ready for analysis. This system automation had numerous benefits, including (1) the production of near real-time information on data collection status and errors requiring correction, resulting in final datasets free of detectable errors, (2) an apparent learning effect among field technicians, wherein original error rates in field data collection declined significantly following implementation of the system, and (3) an assurance of computational reproducibility—that is, robustness of the system to changes in code, data and software. By implementing CI, researchers can ensure that datasets are free of any errors for which a test can be coded. The result is dramatically improved data quality, increased skill among field technicians, and reduced need for expert oversight. Furthermore, we view CI implementation as a first step towards a data collection and analysis pipeline that is also more responsive to rapidly changing ecological dynamics, making it better suited to study ecological systems in the current era of rapid environmental change

    Ultra-Stable Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (5STAR)

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    The Spectrometer for Sky-Scanning, Sun-Tracking Atmospheric Research (4STAR) combines airborne sun tracking and sky scanning with diffraction spectroscopy to improve knowledge of atmospheric constituents and their links to airpollution and climate. Direct beam hyperspectral measurement of optical depth improves retrievals of gas constituentsand determination of aerosol properties. Sky scanning enhances retrievals of aerosol type and size distribution.Hyperspectral cloud-transmitted radiance measurements enable the retrieval of cloud properties from below clouds.These measurements tighten the closure between satellite and ground-based measurements. 4STAR incorporates amodular sun-tracking sky-scanning optical head with optical fiber signal transmission to rack mounted spectrometers,permitting miniaturization of the external optical tracking head, and future detector evolution.4STAR has supported a broad range of flight experiments since it was first flown in 2010. This experience provides thebasis for a series of improvements directed toward reducing measurement uncertainty and calibration complexity, andexpanding future measurement capabilities, to be incorporated into a new 5STAR instrument. A 9-channel photodioderadiometer with AERONET-matched bandpass filters will be incorporated to improve calibration stability. A wide dynamic range tracking camera will provide a high precision solar position tracking signal as well as an image of sky conditions around the solar axis. An ultrasonic window cleaning system design will be tested. A UV spectrometer tailored for formaldehyde and SO2 gas retrievals will be added to the spectrometer enclosure. Finally, expansion capability for a 4 channel polarized radiometer to measure the Stokes polarization vector of sky light will be incorporated. This paper presents initial progress on this next-generation 5STAR instrument

    Structured inquiry-based learning: Drosophila GAL4 enhancer trap characterization in an undergraduate laboratory course.

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    We have developed and tested two linked but separable structured inquiry exercises using a set of Drosophila melanogaster GAL4 enhancer trap strains for an upper-level undergraduate laboratory methods course at Bucknell University. In the first, students learn to perform inverse PCR to identify the genomic location of the GAL4 insertion, using FlyBase to identify flanking sequences and the primary literature to synthesize current knowledge regarding the nearest gene. In the second, we cross each GAL4 strain to a UAS-CD8-GFP reporter strain, and students perform whole mount CNS dissection, immunohistochemistry, confocal imaging, and analysis of developmental expression patterns. We have found these exercises to be very effective in teaching the uses and limitations of PCR and antibody-based techniques as well as critical reading of the primary literature and scientific writing. Students appreciate the opportunity to apply what they learn by generating novel data of use to the wider research community

    A strategy for the conservation of biodiversity on mid-ocean ridges from deep-sea mining

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    Mineral exploitation has spread from land to shallow coastal waters and is now planned for the offshore, deep seabed. Large seafloor areas are being approved for exploration for seafloor mineral deposits, creating an urgent need for regional environmental management plans. Networks of areas where mining and mining impacts are prohibited are key elements of these plans. We adapt marine reserve design principles to the distinctive biophysical environment of mid-ocean ridges, offer a framework for design and evaluation of these networks to support conservation of benthic ecosystems on mid-ocean ridges, and introduce projected climate-induced changes in the deep sea to the evaluation of reserve design. We enumerate a suite of metrics to measure network performance against conservation targets and network design criteria promulgated by the Convention on Biological Diversity. We apply these metrics to network scenarios on the northern and equatorial Mid-Atlantic Ridge, where contractors are exploring for seafloor massive sulfide (SMS) deposits. A latitudinally distributed network of areas performs well at (i) capturing ecologically important areas and 30 to 50% of the spreading ridge areas, (ii) replicating representative areas, (iii) maintaining along-ridge population connectivity, and (iv) protecting areas potentially less affected by climate-related changes. Critically, the network design is adaptive, allowing for refinement based on new knowledge and the location of mining sites, provided that design principles and conservation targets are maintained. This framework can be applied along the global mid-ocean ridge system as a precautionary measure to protect biodiversity and ecosystem function from impacts of SMS mining
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