3,871 research outputs found
Structural and functional interaction between polyamine related molecules and biological membranes
La comunicación describe el conocimiento actual sobre las interacciones de biomoléculas relacionadas con el metabolismo de poliaminas con las estructuras y funciones de las membranas biológicasChanges induced by PA on nucleic acid (NA) conformation and synthesis is proven to be a major reason for PA essentiality (1-3). However, PA interactions with other polyanions, for instance polyanionic membrane lipid bilayers and glyosaminoglycans have received less attention (3-4). The functional importance of these interactions still is an obscure but interesting area of cell and molecular biology, especially in mammalian cells for which specific PA transport systems are not fully characterized (5). In mammals, activity and turnover of the polyamine (PA) synthesis key enzyme is controlled by a set of proteins: Antizymes (OAZ1-3) and antizyme inhibitors (AZIN1 and 2). It is demonstrated that AOZ modulate polyamine uptake (6), and that PA transport to mitochondria is linked to the respiratory chain state and modulates mitochondrial permeability transition (7). Antizyme expression variants have been located in mitochondria, being proposed as a proapoptotic factor (7-8). AZIN 2 is only expressed in a reduced set of tissues that includes mast cells, where it is associated to mast cell granules membrane (9). This fact, together to the abnormalities observed in bone marrow derived mast cell granules when they are differentiated under restricted PA synthesis conditions (10 and unpublished results), point out to important roles of PA and their related proteins in structure and function of mast cell granules. We will also present novel biophysical results on tripartite interactions of PA that remark the interest of the characterization of PA interactions with lipid bilayers for biomedicine and biotechnology.
Thus, the information reported in this paper integrates previously reported information with our still unpublished results, all indicating that PA and their related proteins also are important factors for structure and dynamics of biological membranes and their associated functions essential in human physiology; for instance, solute interchange with the environment (uptake and secretion), oxidative metabolism and apoptosis. The importance of these involved processes for human homeostasis claim for further research efforts.
1. Ruiz-Chica J, Medina MA, Sánchez-Jiménez F and Ramírez FJ (2001) Fourier Transform Raman study of the structural specificities on the interaction between DNA and biogenic polyamines. Biophysical J. 80:443-454.
2. Lightfoot HL, Hall J (2014) Endogenous polyamine function--the RNA perspective. Nucleic Acids Res. 42:11275-11290.
3. Igarashi K, Kashiwagi K (2010) Modulation of cellular function by polyamines. Int J Biochem Cell Biol. 42:39-51.
4. Finger S, Schwieger C, Arouri A, Kerth A, Blume A (2014) Interaction of linear polyamines with negatively charged phospholipids: the effect of polyamine charge distance. Biol Chem. 395:769-778.
5. Poulin R, Casero RA, Soulet D. (2012) Recent advances in the molecular biology of metazoan polyamine transport. Amino Acids. 42:711-723.
6. Kahana C (2009) Regulation of cellular polyamine levels and cellular proliferation by antizyme and antizyme inhibitor. Essays Biochem. 4:47-61.
7. Agostinelli E, Marques MP, Calheiros R, Gil FP, Tempera G, Viceconte N, Battaglia V, Grancara S, Toninello A (2010) Polyamines: fundamental characters in chemistry and biology. Amino Acids 38:393-403.
8. Liu GY, Liao YF, Hsu PC, Chang WH, Hsieh MC, Lin CY, Hour TC, Kao MC, Tsay GJ, Hung HC (2006) Antizyme, a natural ornithine decarboxylase inhibitor, induces apoptosis of haematopoietic cells through mitochondrial membrane depolarization and caspases' cascade. Apoptosis 11:1773-1788.
9. Kanerva K, Lappalainen J, Mäkitie LT, Virolainen S, Kovanen PT, Andersson LC (2009). Expression of antizyme inhibitor 2 in mast cells and role of polyamines as selective regulators of serotonin secretion. PLoS One 31:e6858.
10. García-Faroldi G, Rodríguez CE, Urdiales JL, Pérez-Pomares JM, Dávila JC, Pejler G, Sánchez-Jiménez F, Fajardo I (2010) Polyamines are present in mast cell secretory granules and are important for granule homeostasis. PLoS One 30:e15071.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech
Building and implementing policies in autonomous and autonomic systems using MaCMAS
Autonomic Computing, self-management based on
high level guidance from humans, is increasingly being accepted
as a means forward in designing reliable systems that
both hide complexity from the user and control IT management
costs. Effectively, AC may be viewed as Policy-Based
Self-Management.We look at ways of achieving this, and in
particular focus on Agent-Oriented Software Engineering.
We propose utilizing MaCMAS, an AOSE methodology, for
specifying autonomic and autonomous properties of the system
independently, and later, by means of composition of
these specifications, guided by a policy specification, construct
a specification for the policy and its subsequent deployment.
We illustrate this by means of a case study based
on a NASA concept mission, and describe future work on a
support toolkit
Modelo B-learning para el desarrollo del pensamiento crítico y creativo en estudiantes de una institución pública del Perú
This descriptive-propositive research is aimed at designing a model to promote the development of critical and creative thinking (CCP) through face-to-face and virtual teaching in students of the VII cycle of a public institution. In this quantitative approach research, two questionnaires were administered, the first one developed by the students, which helped to identify the level at which they are with respect to the development of CCP, and the second one applied to teachers in relation to the use of technological tools and their influence on the development of the thoughts in question. It was identified that most of the students participating in the research were at the process level in both types of thinking, as well as in the B-learning variable. As a result of these results, a proposal was developed to encourage students to analyze, reflect and issue opinions, turning TICs into valuable allies that strengthen teaching by promoting self-learning in them. The proposal was disseminated through the institution's fan page and Facebook, as well as in the local radio media so that the educational community is informed about the work to be done.La presente investigación descriptiva-propositiva, está orientada a diseñar un modelo para fomentar el desarrollo del pensamiento crítico y creativo (PCC) a través de la enseñanza presencial y virtual en los estudiantes del VII ciclo de una institución pública. En esta investigación de enfoque cuantitativo se administraron dos cuestionarios, el primero desarrollado por los estudiantes, los cuales ayudaron a identificar el nivel en el que se encuentran con respecto al desarrollo del PCC, y el segundo aplicado a los docentes en relación al uso de las herramientas tecnológicas y su influencia en el desarrollo de los pensamientos en cuestión. Se identificó que la mayoría de los estudiantes participantes en la investigación se ubicaron en el nivel de proceso en ambos tipos de pensamiento, así como también en la variable B-learning. A raíz de estos resultados se elaboró la propuesta que fomentará en los estudiantes analizar, reflexionar y emitir opiniones, convirtiendo a las TIC en valiosos aliados que fortalezcan la enseñanza promoviendo el autoaprendizaje en ellos. Se difundió la propuesta planteada a través del fan page y Facebook de la institución, así como en el medio radial local para que la comunidad educativa se encuentre informada sobre el trabajo a realizar
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GRB 180620A: Evidence for Late-time Energy Injection
The early optical emission of gamma-ray bursts (GRBs) gives an opportunity to understand the central engine and first stages of these events. About 30% of GRBs present flares whose origin is still a subject of discussion. We present optical photometry of GRB 180620A with the COATLI telescope and RATIR instrument. COATLI started to observe from the end of prompt emission at T + 39.3 s and RATIR from T + 121.4 s. We supplement the optical data with the X-ray light curve from Swift/XRT. We observe an optical flare from T + 110 s to T + 550 s, with a temporal index decay α O,decay = 1.32 ± 0.01, and Δt/t = 1.63, which we interpret as the signature of a reverse shock component. After the initial normal decay the light curves show a long plateau from T + 500 s to T + 7800 s in both X-rays and the optical before decaying again after an achromatic jet break at T + 7800 s. Fluctuations are seen during the plateau phase in the optical. Adding to the complexity of GRB afterglows, the plateau phase (typically associated with the coasting phase of the jet) is seen in this object after the "normal" decay phase (associated with the deceleration phase of the jet), and the jet break phase occurs directly after the plateau. We suggest that this sequence of events can be explained by a rapid deceleration of the jet with t d ≲ 40 s due to the high density of the environment (≈100 cm-3) followed by reactivation of the central engine, which causes the flare and powers the plateau phase
Tato Pavlovsky y Elvira Onetto
En Octubre de 2014 se realizaron en la Facultad de Arte las primeras Jornadas de Dirección en Artes escénicas1. En este marco se presentó la obra Asuntos Pendientes de Tato Pavlovsky; con dirección de Elvira Onetto y las actuaciones de Susy Evans, Eduardo Misch, Paula Marrón y Eduardo Pavlovsky. A casi un año de la muerte de Tato recordamos su profundo compromiso con la cultura y el teatro, publicando estos fragmentos de la charla que él y Elvira Onetto mantuvieron con el público de las jornadas el día previo a la función. La misma fue moderada por Paula Fernández.1Estas Jornadas fueron organizadas por los docentes- investigadores: Paula Fernández, Jerónimo Ruiz, Gabriela González y Agustina Fittipaldi.
Desarrollo del pensamiento crítico y creativo con estrategias motivacionales virtuales en una institución primaria en Perú
The research work aimed to create a model of virtual motivational strategies for strengthening the development of critical and creative thinking of girls in the V cycle, of primary education of a public institution, was guided by the basic type, non-experimental design, descriptive-propositional, with a quantitative approach. The use of virtual learning tools or environments was considered as motivation. The data was obtained through a survey administered by a questionnaire with 30 items, applied to identify the level of development of critical and creative thinking in which the students were located. The electronic means Google and WhatsApp form allowed the girls to take the sample, valued with a Likert scale. The results indicated that most of the students who participated are at the beginning and process level of achievement; with this information, the proposal of the strategy model was elaborated, validated by expert judgment, with the aim of solving the problem encountered as well as allowing students to achieve characteristics of skillful, sophisticated thinkers with improvements in their decisions, actions, and qualifications.El trabajo de investigación tuvo como objetivo crear un modelo de estrategias motivacionales virtuales para el fortalecimiento del desarrollo del pensamiento crítico y creativo (PCC) de las niñas del V ciclo, de educación primaria de una institución pública, se orientó por el tipo básica, diseño no experimental, de carácter descriptiva propositiva, con enfoque cuantitativo. Se consideró el uso de herramientas o entornos virtuales de aprendizaje como motivación. Los datos fueron obtenidos por medio de una encuesta administrada por un cuestionario con 30 ítems, aplicada con la finalidad de identificar el nivel de desarrollo del PCC en el cual se ubicaron las estudiantes. Los medios electrónicos formulario Google y WhatsApp permitieron tomar la muestra a las niñas, valorados con escala Likert. Los resultados señalaron que la mayoría de las estudiantes que participaron se encuentran en el nivel de logro inicio y proceso; con esta información se elaboró la propuesta del modelo de estrategias, validado por juicio de expertos, con la pretensión de dar solución a la problemática encontrada además de permitir lograr estudiantes con características de pensadoras hábiles, sofisticadas con mejoras en sus decisiones, actuaciones y calificaciones
Causes of Microcephaly in the Zika Era in Argentina: A Retrospective Study
There are gaps in understanding the causes and consequences of microcephaly. This paper describes the epidemiological characteristics, clinical presentations, and etiologies of children presenting microcephaly during the Zika outbreak in Argentina. This observational retrospective study conducted in the pediatric hospital of Juan P. Garrahan reviewed the medical records of 40 children presenting microcephaly between March 2017 and November 2019. The majority (60%) were males and born full-term. At first evaluation, microcephaly was defined as congenital (31/40, 77%) and associated with other features (68%) such as seizures, developmental delay, non-progressive chronic encephalopathy, and West Syndrome. It was found manifestations restricted to central nervous system (55%), ocular (8/40, 20%), and acoustic (9/40, 23%) defects, and abnormal neuroimaging findings (31/39, 79%). Non-infectious diseases were the primary cause of isolated microcephaly (21/37, 57%), largely related to genetic diseases (13/21, 62%). Only 3 were children were diagnosed with Congenital Zika infection (3/16, 7.5%)
Development of efficient recirculation system for Tilapia (Oreochromis niloticus) culture using low cost materials
In the current experiment, a recirculation system was built using low cost materials that are available locally and its performance was tested. The performance evaluation procedure was carried out in an aquaculture system in greenhouse with sex-reversed male Nile tilapia (Oreochromis niloticus) production in Querétaro State, Mexico. The recirculation system had four sections (sediment collector, gravel and sand filters, biofilter and clarification) in order to eliminate the organic matter produced by the fish excretion material and uneaten food, as well as, the nitrogenous compounds undesirable in the water tanks, such as, total ammonia nitrogen (TAN). The monitored variables include: temperature, dissolved oxygen, pH, visibility, TAN, nitrites and nitrates. The obtained data were compared with previous studies to evaluate the achieved state of the system. This research clearly demonstrated that it is feasible to use the proposed configuration in aquaculture systems in areas where water source is limited. Consequently, the obtained results represent an environmental standpoint for the conservation of water use in the aquaculture industry and also constitute an important contribution to the aquaculture and farmers who receive minimal economic support.Key words: Water recirculation, aquaculture, sustainability, low cost, water use efficiency
Technological tools for a virtuality in education
El objetivo del presente artículo es conocer las diferentes herramientas tecnológicas que permiten una virtualidad en la educación, ya que debido al contexto que nos tocó enfrentar por la COVID-19, originó que los estudiantes busquen nuevas formas de aprender y los maestros nuevos desafíos que afrontar, por ello es necesario tener un soporte tecnológico para poder interactuar y aplicar las herramientas digitales haciendo de las aulas convencionales espacios virtuales, que permitan continuar con el aprendizaje, esto conlleva a los maestros a estar en constante aprendizaje y ver las mejores estrategias para sus estudiantes ya que esta modalidad también puede ser un elemento distractor para el estudiantes, por eso es necesario mantener la atención y motivación del estudiantes en todo momento, para lograr que sus aprendizajes sean similares o mejores a los obtenidos cuando la educación era de manera presencial. La metodología utilizada fue la revisión de variados artículos de investigaciones de las bases de datos de Google Académico, Scopus, EBSCO y ProQuest, obteniéndose 20 artículos publicados en revistas indexadas, realizadas en dos momentos específicos de búsqueda de acuerdo con las variables estudiadas entre los periodos de enero 2015 a diciembre 2020. Teniendo como resultado que son de vital importancia las herramientas tecnológicas en la virtualidad educativa, ya que genera espacios de aprendizajes colaborativos y fortalecen las capacidades cognitivas de los estudiantes.The objective of this article is to know the different technological tools that allow virtuality in education, since due to the context that we had to face due to COVID-19, it caused students to seek new ways of learning and teachers new challenges to face. Therefore, it is necessary to have technological support to be able to interact and apply digital tools, making conventional classrooms virtual spaces that allow learning to continue, this leads teachers to be constantly learning and see the best strategies for their students. since this modality can also be a distracting element for the students, that is why it is necessary to maintain the attention and motivation of the students at all times, to ensure that their learning is similar or better than that obtained when the education was face-to-face. The methodology used was the review of various research articles from the Google Scholar, Scopus, EBSCO and ProQuest databases, obtaining 20 articles published in indexed journals, carried out at two specific search times according to the variables studied between the periods. from January 2015 to December 2020.
Having as a result that technological tools in educational virtuality are of vital importance, since it generates collaborative learning spaces and strengthens the cognitive abilities of students
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