Reproducir y transformar la didáctica de las ciencias en un ambiente colaborativo

La adopción de nuevas perspectivas teóricas arroja nueva luz sobre las formas en que las personas experimentan la vida social y cómo le dan sentido a la participación en sus vidas cotidianas. Reflexiono sobre las diferentes posibilidades de una nueva y estimulante era de investigación y estudios en didáctica de las ciencias, especialmente en lo referente a la intersección entre investigación, políticas y prácticas profesionales. Durante casi 40 años he seguido dos líneas de investigación paralelas: ciencia del aprendizaje y la enseñanza y aprender a enseñar ciencias. Continuamente he desarrollado los marcos teóricos para mejorar la calidad de mi investigación, cambiando los focos de interés y los métodos de investigación, y favoreciendo cambios simultáneos en temas identificados como significativos. Por ejemplo, la enseñanza y el aprendizaje fueron teorizados como asociados a cultura y la dialéctica, modelos que previamente enfatizaban la agencia humana incluyeron la pasividad, y las emociones se enmarcaron como partes permanentemente presentes en la didáctica de las ciencias. Presento la revisión de una investigación en diálogo cogenerativo como ejemplo de un enfoque colaborativo a la didáctica de las ciencias, lo cual promete resolver muchos de los problemas que persisten. Los participantes en el diálogo cogenerativo ampliaron su agencia y aprendieron a colaborar con otros que eran social y culturalmente diferentes a ellos. La investigación en diálogo cogenerativo destaca el potencial de construir la educación en torno a la colaboración, rechazando así la máxima hegemónica de que la efectividad en la didáctica de las ciencias necesita someterse a metáforas tales como la competición, el individualismo y el control sobre los demás.The adoption of new theoretical perspectives sheds fresh light on the ways in which people experience social life and make sense of participation in their everyday life. I consider possibilities that this new era of research and science teaching has -especially in regards to the interfaces between research, policy and professional practice. For almost 40 years I pursued two parallel lines of research: science learning and teaching, and learning to teach science. I continuously developed theoretical frameworks to improve the quality of my research, changing foci and research methods, and affording simultanious changes in issues identified as salient. For example, teaching and learning were theorized as culture and associated to dialectical theory, models that previously emphasized human agency included passivity, and emotions were framed as ever-present parts of science education. I present a review of research in cogenerative dialogue (cogen) as an example of a collaborative approach to science education that holds the promise of overcoming many persistent problems. Participants in cogen expanded their agency and learned how to collaborate with others who differed from them socially and culturally. Research in cogen highlights the potential of building schooling around collaboration, rejecting the hegemonic axiom that effective science education needs to submit itself to metaphors such as competition, individualism, and control over others

Internet como instrumento de formación de los maestros de ciencias : ¿agente transformador o catalizador de la reproducción cultural?

This article describes a postgraduate programme in mathematics and sciences education for teachers of primary and secondary schools in areas with ethnic groups that are marginated in the educational system. A central aspect of the programme was the participation in learning communities and the interaction with other geographically distant participants, through an Internet network. Although most teachers have changed their professional perception, the fact that a minority have not moved to a reflection about the difficulty to break the cycle of cultural production that leads to cultural reproduction

Una visión alternativa de la evaluación por pares : perspectivas dialógicas

Presento un enfoque alternativo a la evaluación por pares y la participación para publicar en una revista internacional. Los coeditores deciden si los artículos son adecuados para ser publicados, los evaluadores son seleccionados por su área de especialización y su posición en dicha área, además se busca que estos evaluadores aporten diferentes perspectivas, mientras que los foros públicos permiten que la evaluación por pares sea visible para los lectores de la revista. El proceso de evaluación toma el papel central en un proceso dialógico donde los puntos de acuerdo y desacuerdo son identificados y entendidos como progreso en el campo de la educación científica y matemática.I am presenting an alternative focus to peer assessment and participation for publishing in an international journal. Co-editors decide whether articles are suitable for publication, assessors are selected because of their field of specialisation and their position in this field, and it is also sought for these assessors to contribute different perspectives, while the public forums allow peer assessment to be visible to the journal's readers. The assessment process takes the central role in a process of dialogue in which the points of agreement and disagreement are identified and understood as progress in the field of science and mathematics education

Connecting Science Education to a World in Crisis

Even though humanity faces grand challenges, including climate change, sustainability of the planet and its resources, and well-being of humans and other species, for the past 60 years science educators have been preoccupied with much the same priorities. Adherence to the tenets of crypto-positivism creates problems for research in the social sciences (e.g., over reliance on statistical analyses leads to oversimplified models that strip away context and are reductive). Hypotheses and associated statistical tests support causal models that rarely predict social conduct or blaze pathways for meaningful transformation. In contrast to the mainstream of research in science education, I advocate a multilogical methodology that embraces incommensurability, polysemia, subjectivity, and polyphonia as a means of preserving the integrity and potential of knowledge systems to generate and maintain disparate perspectives, outcomes, and implications for practice. In such a multilogical model, power discourses such as Western medicine carry no greater weight than complementary knowledge systems that may have been marginalized in a social world in which monosemia is dominant. I describe research methodologies that have the potential to transform science education and our ongoing research in urban science education. I show how our research evolved to include studies of science for literate citizenry – expanding foci to address birth through death and all settings in which learning occurs – not just schools. Our research aims to be transformative since it includes interventions developed to use what we learned from research to ameliorate intense emotions, improve learning, and enhance the well-being of participants. I explain how we incorporated Jin Shin Jyutsu, a complementary medical knowledge system, to ameliorate intense emotions, become mindful, and improve well-being of participants. I also address research on meditation and mindfulness and their potential to improve learning, emotional styles, and wellness. In a final section I address three of the most important questions raised by colleagues, including scholars from Asia, as I exhort science educators to address grand challenges that threaten the Earth and its social institutions – the alternatives are catastrophi

Towards a Praxeology of Teaching

Both preservice and seasoned teachers experience a considerable gap between theory and prescriptions for teaching and their day-to-day practice. We concep- tualize this gap in terms of the difference between descriptions of practice and practice itself. Descriptions cannot include the tacit understanding against which specific acts of teaching become meaningful; thus, they are inherently out of syn- chrony with practice. We illustrate how Bourdieu’s notion of habitus (a set of dispositions) accounts for appropriate actions in situations where there is no “time out” for deliberation and how coteaching can support preservice teachers’ development of this habitus. Les étudiants-maîtres comme les enseignants chevronnés ressentent l’écart considérable entre la théorie et les règles de l’enseignement et leur pratique quotidienne. Les auteurs conceptualisent cet écart en termes de différence entre les descriptions de la pratique et la pratique elle-même. Les descriptions ne peuvent inclure la compréhension tacite par rapport à laquelle des activités pré- cises d’enseignement prennent un sens; aussi ces descriptions en elles-mêmes ne concordent pas avec la pratique. Les auteurs illustrent comment la notion d’habitus de Bourdieu (un ensemble de dispositions) explique la pertinence des actions effectuées dans des situations où il n’y a pas de temps pour délibérer et comment le coenseignement peut favoriser de développement de cet habitus chez les stagiaires.

Towards a Praxeology of Teaching

Both preservice and seasoned teachers experience a considerable gap between theory and prescriptions for teaching and their day-to-day practice. We concep- tualize this gap in terms of the difference between descriptions of practice and practice itself. Descriptions cannot include the tacit understanding against which specific acts of teaching become meaningful; thus, they are inherently out of syn- chrony with practice. We illustrate how Bourdieu’s notion of habitus (a set of dispositions) accounts for appropriate actions in situations where there is no “time out” for deliberation and how coteaching can support preservice teachers’ development of this habitus. Les étudiants-maîtres comme les enseignants chevronnés ressentent l’écart considérable entre la théorie et les règles de l’enseignement et leur pratique quotidienne. Les auteurs conceptualisent cet écart en termes de différence entre les descriptions de la pratique et la pratique elle-même. Les descriptions ne peuvent inclure la compréhension tacite par rapport à laquelle des activités pré- cises d’enseignement prennent un sens; aussi ces descriptions en elles-mêmes ne concordent pas avec la pratique. Les auteurs illustrent comment la notion d’habitus de Bourdieu (un ensemble de dispositions) explique la pertinence des actions effectuées dans des situations où il n’y a pas de temps pour délibérer et comment le coenseignement peut favoriser de développement de cet habitus chez les stagiaires.

Quality Assessment of Retinal Fundus Images using Elliptical Local Vessel Density

Diabetic retinopathy is the leading cause of blindness in the Western world. The World Health Organisation estimates that 135 million people have diabetes mellitus worldwide and that the number of people with diabetes will increase to 300 million by the year 2025 (Amos et al., 1997). Timely detection and treatment for DR prevents severe visual loss in more than 50% of the patients (ETDRS, 1991). Through computer simulations is possible to demonstrate that prevention and treatment are relatively inexpensive if compared to the health care and rehabilitation costs incurred by visual loss or blindness (Javitt et al., 1994). The shortage of ophthalmologists and the continuous increase of the diabetic population limits the screening capability for effective timing of sight-saving treatment of typical manual methods. Therefore, an automatic or semi-automatic system able to detect various type of retinopathy is a vital necessity to save many sight-years in the population. According to Luzio et al. (2004) the preferred way to detect diseases such as diabetic retinopathy is digital fundus camera imaging. This allows the image to be enhanced, stored and retrieved more easily than film. In addition, images may be transferred electronically to other sites where a retinal specialist or an automated system can detect or diagnose disease while the patient remains at a remote location. Various systems for automatic or semi-automatic detection of retinopathy with fundus images have been developed. The results obtained are promising but the initial image quality is a limiting factor (Patton et al., 2006); this is especially true if the machine operator is not a trained photographer. Algorithms to correct the illumination or increase the vessel contrast exist (Chen & Tian, 2008; Foracchia et al., 2005; Grisan et al., 2006;Wang et al., 2001), however they cannot restore an image beyond a certain level of quality degradation. On the other hand, an accurate quality assessment algorithm can allow operators to avoid poor images by simply re-taking the fundus image, eliminating the need for correction algorithms. In addition, a quality metric would permit the automatic submission of only the best images if many are available. The measurement of a precise image quality index is not a straightforward task, mainly because quality is a subjective concept which varies even between experts, especially for images that are in the middle of the quality scale. In addition, image quality is dependent upon the type of diagnosis being made. For example, an image with dark regions might be considered of good quality for detecting glaucoma but of bad quality for detecting diabetic retinopathy. For this reason, we decided to define quality as the 'characteristics of an image that allow the retinopathy diagnosis by a human or software expert'. Fig. 1 shows some examples of macula centred fundus images whose quality is very likely to be judged as poor by many ophthalmologists. The reasons for this vary. They can be related to the camera settings like exposure or focal plane error (Fig. 1.(a,e,f)), the camera condition like a dirty or shuttered lens (Fig. 1.(d,h)), the movements of the patient which might blur the image (Fig. 1.(c)) or if the patient is not in the field of view of the camera (Fig. 1.(g)). We define an outlier as any image that is not a retina image which could be submitted to the screening system by mistake. Existing algorithms to estimate the image quality are based on the length of visible vessels in the macula region (Fleming et al., 2006), or edges and luminosity with respect to a reference image (Lalonde et al., 2001; Lee & Wang, 1999). Another method uses an unsupervised classifier that employs multi-scale filterbanks responses (Niemeijer et al., 2006). The shortcomings of these methods are either the fact that they do not take into account the natural variance encountered in retinal images or that they require a considerable time to produce a result. Additionally, none of the algorithms in the literature that we surveyed generate a 'quality measure'. Authors tend to split the quality levels into distinct classes and to classify images in particular ones. This approach is not really flexible and is error prone. In fact human experts are likely to disagree if many categories of image quality are used. Therefore, we think that a normalized 'quality measure' from 0 to 1 is the ideal way to approach the classification problem. Processing speed is another aspect to be taken into consideration. While algorithms to assess the disease state of the retina do not need to be particularly fast (within reason), the time response of the quality evaluation method is key towards the development of an automatic retinopathy screening system

N-methyl-D-aspartate receptors mediate the phosphorylation and desensitization of muscarinic receptors in cerebellar granule neurons.

Changes in synaptic strength mediated by ionotropic glutamate N-methyl-D-asparate (NMDA) receptors is generally considered to be the molecular mechanism underlying memory and learning. NMDA receptors themselves are subject to regulation through signaling pathways that are activated by G-protein-coupled receptors (GPCRs). In this study we investigate the ability of NMDA receptors to regulate the signaling of GPCRs by focusing on the G(q/11)-coupled M(3)-muscarinic receptor expressed endogenously in mouse cerebellar granule neurons. We show that NMDA receptor activation results in the phosphorylation and desensitization of M(3)-muscarinic receptors through a mechanism dependent on NMDA-mediated calcium influx and the activity of calcium-calmodulin-dependent protein kinase II. Our study reveals a complex pattern of regulation where GPCRs (M(3)-muscarinic) and NMDA receptors can feedback on each other in a process that is likely to influence the threshold value of signaling networks involved in synaptic plasticity

Respiratory and sleep disorders in mucopolysaccharidosis

MPS encompasses a group of rare lysosomal storage disorders that are associated with the accumulation of glycosaminoglycans (GAG) in organs and tissues. This accumulation can lead to the progressive development of a variety of clinical manifestations. Ear, nose, throat (ENT) and respiratory problems are very common in patients with MPS and are often among the first symptoms to appear. Typical features of MPS include upper and lower airway obstruction and restrictive pulmonary disease, which can lead to chronic rhinosinusitis or chronic ear infections, recurrent upper and lower respiratory tract infections, obstructive sleep apnoea, impaired exercise tolerance, and respiratory failure. This review provides a detailed overview of the ENT and respiratory manifestations that can occur in patients with MPS and discusses the issues related to their evaluation and management. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10545-012-9555-1) contains supplementary material, which is available to authorized users