1,625 research outputs found
Influence of production process design on inclusion bodies protein: the case of an Antarctic flavohemoglobin
<p>Abstract</p> <p>Background</p> <p>Protein over-production in <it>Escherichia coli </it>often results in formation of inclusion bodies (IBs). Some recent reports have shown that the aggregation into IBs does not necessarily mean that the target protein is inactivated and that IBs may contain a high proportion of correctly folded protein. This proportion is variable depending on the protein itself, the genetic background of the producing cells and the expression temperature. In this paper we have evaluated the influence of other production process parameters on the quality of an inclusion bodies protein.</p> <p>Results</p> <p>The present paper describes the recombinant production in <it>Escherichia coli </it>of the flavohemoglobin from the Antarctic bacterium <it>Pseudoalteromonas haloplanktis </it>TAC125. Flavohemoglobins are multidomain proteins requiring FAD and heme cofactors. The production was carried out in several different experimental setups differing in bioreactor geometry, oxygen supply and the presence of a nitrosating compound. In all production processes, the recombinant protein accumulates in IBs, from which it was solubilized in non-denaturing conditions. Comparing structural properties of the solubilized flavohemoglobins, i.e. deriving from the different process designs, our data demonstrated that the protein preparations differ significantly in the presence of cofactors (heme and FAD) and as far as their secondary and tertiary structure content is concerned.</p> <p>Conclusions</p> <p>Data reported in this paper demonstrate that other production process parameters, besides growth temperature, can influence the structure of a recombinant product that accumulates in IBs. To the best of our knowledge, this is the first reported example in which the structural properties of a protein solubilized from inclusion bodies have been correlated to the production process design.</p
Conceptions from a constructivist and phenomenological perspective of a group of students at the beginning of their science teacher training.
Las investigaciones sobre formación del profesorado han mostrado que las concepciones sobre el aprendizaje próximas a modelos tradicionales de enseñanza son uno de los mayores obstáculos para desarrollar prácticas inspiradas en los principios de las teorías constructivistas, que gozan hoy de plena legitimidad como marcos para la promoción de los aprendizajes profundos. En esta investigación se realizaron dos estudios para interpretar las concepciones desde una perspectiva constructivista y fenomenográfica de un grupo de estudiantes al inicio de su formación de profesorado de ciencias. En primer lugar se exploraron y categorizaron las concepciones sobre el aprendizaje de los estudiantes de los profesorados de Física, Química, Biología y Matemática de la Universidad Nacional de Mar del Plata. En segundo lugar, se seleccionó el caso cuya concepción se identificó como más sofisticada y constructivista. Se realizó un estudio en profundidad incluyendo la biografía escolar. Los resultados indican que las representaciones gráficas presentan puntos en común con el modelo tradicional del aprendizaje. Por su parte, las proposiciones analizadas presentaron un modelo afín al tradicional, pero combinado también con elementos más innovadores. En el estudio de caso se visibilizó la importancia de los diversos modos de aprender, de las experiencias emocionalmente positivas durante el aprendizaje y de los vínculos positivos entre docentes y alumnos, siendo factores reconocidos y valorados para la construcción de la identidad de docente de cienciasResearch on teacher education has shown that conceptions of learning close to traditional teaching models are one of the biggest obstacles to developing practices inspired by the principles of constructivist theories, which today enjoy full legitimacy as frameworks for the promotion of the deep learning. In this research, two studies were carried out to interpret the conceptions from a constructivist and phenomenological perspective of a group of students at the beginning of their science teacher training. In the first place, the conceptions about the learning of the students of the Physics, Chemistry, Biology and Mathematics professors of the National University of Mar del Plata were explored and categorized. Secondly, the case whose conception was identified as more sophisticated and constructivist was selected. An in- depth study including school biography was conducted. The results indicate that the graphic representations have points in common with the traditional model of learning. For its part, the proposals analyzed presented a model similar to the traditional one, but also combined with more innovative elements. In the case study, the importance of different ways of learning, of emotionally positive experiences during learning and of positive links between teachers and students was highlighted, being recognized and valued factors for the construction of the identity of science teacher.Fil: Giuliani, María Florencia. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Educación Cientifica; ArgentinaFil: Vilanova, Silvia Lucia. Universidad Nacional de Mar del Plata. Facultad de Cs.exactas y Naturales. Departamento de Educación Cientifica; ArgentinaFil: Yedaide, Maria Marta. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Centro de Investigaciones Multidisciplinarias en Educación; Argentin
A FOSS Based Web Geo- Service Architecture For Data Management In Complex Water Resources Contexts
Advances in environmental monitoring systems from remote sensing to pervasive real and virtual sensor networks are enlarging the amount and types of data available at local and global scale at increasingly higher temporal and spatial resolution. However, accessing and integrating these data for modeling and operational purposes can be challenging and highly time consuming, particularly in complex physical and institutional contexts, where data are from different sources. This research focuses on the design of a web geo- service architecture, based on Free and Open Source Software (FOSS), to enable collection and sharing of data coming from complex water resources domains and managed by multiple institutions. The heterogeneous nature of these data requires the combination of different geospatial data servers (Catalog Service for the Web, Web Map Service, Web Feature service, Web Coverage Service, Sensor Observations Service,) and interface technologies that enable interoperability of all complex resources data types. This is a key feature of web geo- service tools in multidata and multiowners environment. Besides the storage of the available hydrological data according to the Open Geospatial Consortium standards, the architecture provides a platform for comparatively analyzing alternative water supply and demand management strategies. The architecture is developed for the Lake Como system (Italy), a regulated lake serving multiple and often competing water uses (irrigation, hydropower, flood control) in northern Italy. . This research gives important insights on currently operating GEOSS (Global Earth Observation System of Systems) architectures, demonstrating that Spatial Data Infrastructures using FOSS are a feasible and effective alternative to data and metadata collection, storage, sharing and visualization in complex water resources management contexts, using open international standards
Do Non-Aromatic Labiatae Produce Essential Oil? The Case Study of Prasium Majus L
Prasium majus L. (Labiatae, Lamioideae) is considered a typical non-aromatic plant. In this work we examined the glandular trichomes present on leaves and inflorescences and the essential oils of plants growing along the Tuscan coast of Italy. The micromorphological study evidenced different types of trichomes responsible for the essential oil production. The essential oil compositions of leaves and flowers were analyzed by GC/MS and are here reported
Heart failure: Tools for nursing and medical treatment
Background: To validate a structured interview designed to evaluate the healthcare and
information needs of patients with heart failure (HF), who were also characterized by means of
the Kansas City Cardiomyopathy Questionnaire (KCCQ) and the 36-item Short-Form Health
Survey (SF-36).
Methods: Forty-five in- and outpatients with HF were administered a structured interview
concerning their information and healthcare needs (together with the KCCQ and SF-36) with
the aim of investigating the effects of healthcare models on their quality of life (QoL). Twenty-
-one patients were also involved in a one-week test-retest validity study carried out in order to
verify reproducibility and stability by means of concordance and K statistics.
Results: The reproducibility of the structured interview was good or very good for all items,
with a mean Kw of 0.59; the clarity and acceptability of most of the questions were good.
Positive judgements of hospital care inversely related to the patients’ New York Heart Association
class. The subjects about which the patients sought greater information were diet, sleep,
therapies and physical exercise, with cardiologists and general practitioners (GPs) being more
involved than nurses. The most frequently discussed subject was diagnostic examinations. The
questionnaire scores of our patients were generally lower than those reported in the literature,
possibly because of their advanced age. However, it is difficult to believe that the quality of care
was extraneous to their generally worse health-related QoL.
Conclusions: Our HF patients experienced a ‘basic’ healthcare model (hospitals, GPs, cardiologists)
and judged them acceptable. Their ability to think critically about care was increasingly
compromised as HF progressed and their health-related QoL decreased. (Cardiol J 2011; 18,
4: 411–420
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