1,721,150 research outputs found
Bioprocess feeding optimization through in silico dynamic experiments and hybrid digital models—a proof of concept
Full text linkThe development of cell cultures to produce monoclonal antibodies is a multi-step, time-consuming, and labor-intensive procedure which usually lasts several years and requires heavy investment by biopharmaceutical companies. One key aspect of process optimization is improving the feeding strategy. This step is typically performed though design of experiments (DoE) during process development, in such a way as to identify the optimal combinations of factors which maximize the productivity of the cell cultures. However, DoE is not suitable for time-varying factor profiles because it requires a large number of experimental runs which can last several weeks and cost tens of thousands of dollars. We here suggest a methodology to optimize the feeding schedule of mammalian cell cultures by virtualizing part of the experimental campaign on a hybrid digital model of the process to accelerate experimentation and reduce experimental burden. The proposed methodology couples design of dynamic experiments (DoDE) with a hybrid semi-parametric digital model. In particular, DoDE is used to design optimal experiments with time-varying factor profiles, whose experimental data are then utilized to train the hybrid model. This will identify the optimal time profiles of glucose and glutamine for maximizing the antibody titer in the culture despite the limited number of experiments performed on the process. As a proof-of-concept, the proposed methodology is applied on a simulated process to produce monoclonal antibodies at a 1-L shake flask scale, and the results are compared with an experimental campaign based on DoDE and response surface modeling. The hybrid digital model requires an extremely limited number of experiments (nine) to be accurately trained, resulting in a promising solution for performing in silico experimental campaigns. The proposed optimization strategy provides a 34.9% increase in the antibody titer with respect to the training data and a 2.8% higher antibody titer than the optimal results of two DoDE-based experimental campaigns comprising different numbers of experiments (i.e., 9 and 31), achieving a high antibody titer (3,222.8 mg/L) -very close to the real process optimum (3,228.8 mg/L)
Flexural coupling of hip prosthesis stem and femur: a simple method of theoretical analysis
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Urticaria and bacterial infections
No full textThe association between urticaria and infectious diseases has been discussed for >100 years. However, a causal relationship with underlying or precipitating infection is difficult to establish. The purpose of this work was to perform a systematic analysis of the published cases of urticaria associated with bacterial infections. We give an umbrella breakdown of up-to-date systematic reviews and other important publications on the complex association of urticaria and bacterial infections. we did a Medline search, for English language articles published until January 2014, using the key words "urticaria" and "bacteria/bacterial disease"; a second analysis was performed in groups of bacteria and using each germ name as a key word. Many bacterial infections have been associated with urticaria manifestation, such as Helicobacter pylon, Streptococcus, Staphylococcus, Mycoplasma pneumonia, Salmonella, Brucella, Mycobacterium leprae, Borrelia, Chlamydia pneumonia, and Yersinia enterocolitica. In some cases the skin manifestations, described as urticaria, could caused by the presence of the microorganism in the skin, or for the action of their toxins, or to the complement activation mediated by circulating immune complexes. Although only a weak association with urticaria of unclear pathogenesis exists, clinicians should consider these bacterial agents in the workup of the patients with urticaria. The eradication of the infection could, in fact, lead to the resolution of urticaria. Prospective studies and well structured research are obviously needed to better clarify the real role of bacteria in the pathogenesis of urticaria and their relative prevalence
Sismicità all’Etna tra Luglio 2005 e Gennaio 2006: evidenze di intrusione magmatica e di dinamica di fianco
No full textNel presente lavoro sono presentati i risultati di uno studio della sismicità dell’Etna registrata tra Luglio 2005 e Gennaio 2006. Durante tale periodo l’integrazione dei dati provenienti da un esperimento condotto attraverso l’impiego di 20 stazioni temporanee a larga banda in aggiunta alla rete permanente, costituita da 40 stazioni, ha permesso di ottenere migliori localizzazioni ipocentrali (maggior numero di letture P ed S, riduzione degli errori ipocentrali e del gap azimutale). Ciò ha consentito analisi di maggior dettaglio anche degli eventi a più bassa magnitudo (M<2.0) che costituiscono il 75 % del campione. In particolare, si è proceduto alla rilocalizzazione degli eventi (Fig. 1) utilizzando il modello di velocità 3D di Patanè et al. (2006) e al calcolo dei meccanismi focali. La maggior parte della sismicità è localizzata sul fianco orientale del vulcano permettendo una più accurata interpretazione della dinamica di questo settore. Inoltre, la localizzazione 3D dei terremoti ha meglio evidenziato l’attività sismica lungo il Rift meridionale del vulcano relativa ad uno sciame profondo (tra 10 e 15 km) registrato nell’agosto del 2005, probabilmente correlata ad una intrusione magmatica. Infatti, tale sismicità è stata seguita nei mesi successivi da un forte incremento del tremore che, tuttavia, non ha portato nel breve termine ad alcuna eruzione. Ciò nonostante, è stato osservato che in altri periodi la sismicità lungo questo trend strutturale ha preceduto di alcuni mesi l’attività eruttiva (2001, 2002-2003 e 2008).PublishedRome3.6. Fisica del vulcanismoope
Sismicità all’Etna tra Luglio 2005 e Gennaio 2006: evidenze di intrusione magmatica e di dinamica di fianco
No full textNel presente lavoro sono presentati i risultati di uno studio della sismicità dell’Etna registrata tra Luglio 2005 e Gennaio 2006. Durante tale periodo l’integrazione dei dati provenienti da un esperimento condotto attraverso l’impiego di 20 stazioni temporanee a larga banda in aggiunta alla rete permanente, costituita da 40 stazioni, ha permesso di ottenere migliori localizzazioni ipocentrali (maggior numero di letture P ed S, riduzione degli errori ipocentrali e del gap azimutale). Ciò ha consentito analisi di maggior dettaglio anche degli eventi a più bassa magnitudo (M<2.0) che costituiscono il 75 % del campione. In particolare, si è proceduto alla rilocalizzazione degli eventi (Fig. 1) utilizzando il modello di velocità 3D di Patanè et al. (2006) e al calcolo dei meccanismi focali. La maggior parte della sismicità è localizzata sul fianco orientale del vulcano permettendo una più accurata interpretazione della dinamica di questo settore. Inoltre, la localizzazione 3D dei terremoti ha meglio evidenziato l’attività sismica lungo il Rift meridionale del vulcano relativa ad uno sciame profondo (tra 10 e 15 km) registrato nell’agosto del 2005, probabilmente correlata ad una intrusione magmatica. Infatti, tale sismicità è stata seguita nei mesi successivi da un forte incremento del tremore che, tuttavia, non ha portato nel breve termine ad alcuna eruzione. Ciò nonostante, è stato osservato che in altri periodi la sismicità lungo questo trend strutturale ha preceduto di alcuni mesi l’attività eruttiva (2001, 2002-2003 e 2008).PublishedRome3.6. Fisica del vulcanismoope
- …
