206 research outputs found

    Darwin y el mar

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    Además de sus conocidos aportes a la geología, la paleontología y la biogeografía de ecosistemas terrestres de la región pampeana y la Patagonia (Argentina), Darwin realizó notables y poco difundidas contribuciones al conocimiento de los ambientes marinos costeros del actual territorio argentino y de los organismos que habitan en ellos. La intimidad de Darwin con el mar se advierte en toda su obra: en el Viaje y en el Origen igual que en numerosos trabajos de investigación realizados y publicados a su regreso a Inglaterra. Entre 1846 y 1854 dio a conocer una extensa obra sobre cirrípedos o cirripedios, que sentó las bases del estudio de esos crustáceos y, aún hoy, es bibliografía obligada de los taxónomos. Su trabajo sobre la estructura y distribución de los arrecifes coralinos de 1842, es considerado un documento fundacional del conocimiento sobre el origen de los atolones. Los moluscos fueron igualmente objeto de publicaciones y cartas entre 1848 y 1871. La difundida imagen de Darwin sentado ante un escritorio escribiendo sus libros lleva a olvidar que pasaba también mucho tiempo con el microscopio. En el Viaje del Beagle incluyó párrafos sobre aves marinas, lo mismo que sobre briozoos o briozoarios, y en El origen, explicó sus pensamientos acerca de la migración de los ojos en los lenguados. Dedicó especial atención a las algas gigantes o sargazos marinos de Tierra del Fuego (donde se los conoce por cachiyuyos). Se incluyen los siguientes trabajos de divulgación científica -Darwin y los briozoos; -Darwin y el desarrollo larval de crustáceos; -Sobre Cirripedios; De Darwin a los acelerómetros; -Los peces de cara torcida; -La incursión en la costa sur de Buenos Aires

    Severe Paediatric Asthma Collaborative in Europe (SPACE):protocol for a European registry

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    The development of new asthma biologics and receptor blockers for the treatment of paediatric severe asthma raises challenges. It is unclear whether there are sufficient children in Europe to recruit into randomised placebo-controlled trials to establish efficacy and safety in this age group. In February 2016, the European Respiratory Society funded a clinical research collaboration entitled “Severe Paediatric Asthma Collaborative in Europe” (SPACE). We now report the SPACE protocol for a prospective pan-European observational study of paediatric severe asthma. Inclusion criteria are: 1) age 6–17 years, 2) severe asthma managed at a specialised centre for ≥6 months, 3)clinical and spirometry evidence of asthma, and 4) reaching a pre-defined treatment threshold. The exclusion criterion is the presence of conditions which mimic asthma symptoms. Eligible children will be prospectively recruited into a registry, recording demographics, comorbidities, quality of life, family history, neonatal history, smoking history, asthma background, investigations, and treatment. Follow-up will provide longitudinal data on asthma control and treatment changes. The SPACE registry, by identifying well-phenotyped children eligible for clinical trials, and the amount of overlap in eligibility criteria, will inform the design of European trials in paediatric severe asthma, and facilitate observational research where data from single centres are limited

    Development of lung function in very low birth weight infants with or without bronchopulmonary dysplasia: Longitudinal assessment during the first 15 months of corrected age

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    <p>Abstract</p> <p>Background</p> <p>Very low birth weight (VLBW) infants (< 1,500 g) with bronchopulmonary dysplasia (BPD) develop lung damage caused by mechanical ventilation and maturational arrest. We compared functional lung development after discharge from hospital between VLBW infants with and without BPD.</p> <p>Methods</p> <p>Comprehensive lung function assessment was performed at about 50, 70, and 100 weeks of postmenstrual age in 55 sedated VLBW infants (29 with former BPD [O<sub>2 </sub>supplementation was given at 36 weeks of gestational age] and 26 VLBW infants without BPD [controls]). Mean gestational age (26 vs. 29 weeks), birth weight (815 g vs. 1,125 g), and the proportion of infants requiring mechanical ventilation for ≥7 d (55% vs. 8%), differed significantly between BPD infants and controls.</p> <p>Results</p> <p>Both body weight and length, determined over time, were persistently lower in former BPD infants compared to controls, but no significant between-group differences were noted in respiratory rate, respiratory or airway resistance, functional residual capacity as determined by body plethysmography (FRC<sub>pleth</sub>), maximal expiratory flow at the FRC (V'max <sub>FRC</sub>), or blood gas (pO<sub>2</sub>, pCO<sub>2</sub>) levels. Tidal volume, minute ventilation, respiratory compliance, and FRC determined by SF6 multiple breath washout (representing the lung volume in actual communication with the airways) were significantly lower in former BPD infants compared to controls. However, these differences became non-significant after normalization to body weight.</p> <p>Conclusions</p> <p>Although somatic growth and the development of some lung functional parameters lag in former BPD infants, the lung function of such infants appears to develop in line with that of non-BPD infants when a body weight correction is applied. Longitudinal lung function testing of preterm infants after discharge from hospital may help to identify former BPD infants at risk of incomplete recovery of respiratory function; such infants are at risk of later respiratory problems.</p

    Lung Volume, Breathing Pattern and Ventilation Inhomogeneity in Preterm and Term Infants

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    BACKGROUND: Morphological changes in preterm infants with bronchopulmonary dysplasia (BPD) have functional consequences on lung volume, ventilation inhomogeneity and respiratory mechanics. Although some studies have shown lower lung volumes and increased ventilation inhomogeneity in BPD infants, conflicting results exist possibly due to differences in sedation and measurement techniques. METHODOLOGY/PRINCIPAL FINDINGS: We studied 127 infants with BPD, 58 preterm infants without BPD and 239 healthy term-born infants, at a matched post-conceptional age of 44 weeks during quiet natural sleep according to ATS/ERS standards. Lung function parameters measured were functional residual capacity (FRC) and ventilation inhomogeneity by multiple breath washout as well as tidal breathing parameters. Preterm infants with BPD had only marginally lower FRC (21.4 mL/kg) than preterm infants without BPD (23.4 mL/kg) and term-born infants (22.6 mL/kg), though there was no trend with disease severity. They also showed higher respiratory rates and lower ratios of time to peak expiratory flow and expiratory time (t(PTEF)/t(E)) than healthy preterm and term controls. These changes were related to disease severity. No differences were found for ventilation inhomogeneity. CONCLUSIONS: Our results suggest that preterm infants with BPD have a high capacity to maintain functional lung volume during natural sleep. The alterations in breathing pattern with disease severity may reflect presence of adaptive mechanisms to cope with the disease process

    Professional development in teaching and learning for early career academic geographers: Contexts, practices and tensions

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Geography in Higher Education on 16th May 2011, available online: doi: 10.1080/03098265.2011.563380This paper provides a review of the practices and tensions informing approaches to professional development for early career academic geographers who are teaching in higher education. We offer examples from Britain, Canada, Nigeria and the USA. The tensions include: institutional and departmental cultures; models that offer generic and discipline-specific approaches; the credibility of alternative settings for professional development in teaching and learning; the valuing of professional development and of teaching in academic systems of reward and recognition; and the challenges of balancing professional and personal life. We summarize concepts of good practice and suggest opportunities for future research

    Comparing introductory course planning among full-time and part-time faculty

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    Using data from a nationally representative survey of faculty teaching introductory college courses, this exploratory study compares course planning procedures of full-time and part-time faculty teaching courses in eight academic fields. The choice of variables examined was guided by a general model of course design developed from earlier studies of course planning. To control for discipline-related differences in faculty planning assumptions, separate analyses were conducted for the eight fields. No key differences were found between full-time and part-time faculty on the primary factors under investigation: substantive content-related influences on courses, strength of influence within the instructional environment, and planning steps and content arrangements faculty preferred.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43604/1/11162_2004_Article_BF00992618.pd
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