Frecuencia y tipo de actividades de laboratorio que realizan profesores/as primarios en el area de las ciencias, en Santiago de Chile

El presente estudio tuvo como objetivos principal indagar sobre las percepciones que tienen los profesores primarios que realizan clases de ciencias en dos comunas de Santiago de Chile, sobre las actividades de laboratorio. Para ello se desarrolló un cuestionario con 13 preguntas cerradas y 32 afirmaciones de escala likert. La encuesta fue respondida por un total de 70 profesores de quinto y sexto nivel de educación primaria durante el periodo final de clases en el año 2008. Los resultados más importantes de la investigación señalan que: la actividad de laboratorio mas realizada son los experimentos y las menos la resolución de problemas; más del 50% de los profesores señala realizar dos o menos actividades de laboratorio en el año escolar y aquellos que realizan más actividades son los que están más de acuerdo con que estas fomentan la motivación de los niños por la ciencia

3D extracellular matrix microenvironment in bioengineered tissue models of primary pediatric and adult brain tumors.

Dynamic alterations in the unique brain extracellular matrix (ECM) are involved in malignant brain tumors. Yet studies of brain ECM roles in tumor cell behavior have been difficult due to lack of access to the human brain. We present a tunable 3D bioengineered brain tissue platform by integrating microenvironmental cues of native brain-derived ECMs and live imaging to systematically evaluate patient-derived brain tumor responses. Using pediatric ependymoma and adult glioblastoma as examples, the 3D brain ECM-containing microenvironment with a balance of cell-cell and cell-matrix interactions supports distinctive phenotypes associated with tumor type-specific and ECM-dependent patterns in the tumor cells\u27 transcriptomic and release profiles. Label-free metabolic imaging of the composite model structure identifies metabolically distinct sub-populations within a tumor type and captures extracellular lipid-containing droplets with potential implications in drug response. The versatile bioengineered 3D tumor tissue system sets the stage for mechanistic studies deciphering microenvironmental role in brain tumor progression

Developing a toolkit for the assessment and monitoring of musculoskeletal ageing

The complexities and heterogeneity of the ageing process have slowed the development of consensus on appropriate biomarkers of healthy ageing. The Medical Research Council–Arthritis Research UK Centre for Integrated research into Musculoskeletal Ageing (CIMA) is a collaboration between researchers and clinicians at the Universities of Liverpool, Sheffield and Newcastle. One of CIMA’s objectives is to ‘Identify and share optimal techniques and approaches to monitor age-related changes in all musculoskeletal tissues, and to provide an integrated assessment of musculoskeletal function’—in other words to develop a toolkit for assessing musculoskeletal ageing. This toolkit is envisaged as an instrument that can be used to characterise and quantify musculoskeletal function during ‘normal’ ageing, lend itself to use in large-scale, internationally important cohorts, and provide a set of biomarker outcome measures for epidemiological and intervention studies designed to enhance healthy musculoskeletal ageing. Such potential biomarkers include: biochemical measurements in biofluids or tissue samples, in vivo measurements of body composition, imaging of structural and physical properties, and functional tests. This review assesses candidate biomarkers of musculoskeletal ageing under these four headings, details their biological bases, strengths and limitations, and makes practical recommendations for their use. In addition, we identify gaps in the evidence base and priorities for further research on biomarkers of musculoskeletal ageing

Assessing age-related balance deterioration: Visual or mechanical tasks?

BACKGROUND: Mediolateral balance assessment (MELBA) comprises tracking of predictable and unpredictable targets moving at increasing frequencies, using centre-of-mass feedback. The mediolateral-balance-assessment was shown to be sensitive to subtle age-related balance deterioration. However, it has been suggested that performance during ground-level tasks can be more sensitive to balance deterioration. METHODS: we developed a modified mediolateral-balance-assessment using tracking of surface translations with comparable waveforms (mechanical mediolateral-balance-assessment) to compare age sensitivity of the visual and mechanical mediolateral-balance-assessment, 15 older adults (68 SD 5 yr) and 12 young adults (30 SD 4 yr) performed both tasks. Phase-shift and gain between the CoM and either the visual target or the surface displacement for the visual and the mechanical mediolateral-balance-assessment, respectively, were calculated. To identify differences in tracking strategies between the visual and mechanical mediolateral-balance-assessment, phase-shift between trunk and leg angles was calculated. FINDINGS: Overall, older adults performed worse than young across the predictable and unpredictable tracking and visual and mechanical tasks. Of all mediolateral-balance-assessment performance descriptors, a significant interaction between age and task (visual or mechanical) was only found for the mean phase-shift. Post-hoc comparisons revealed significant age differences in the visual but not in the mechanical mediolateral-balance-assessment. Significant differences in tracking strategies were found between visual and mechanical mediolateral-balance-assessment with a greater decoupling of trunk and legs during the mechanical than the visual mediolateral-balance-assessment. INTERPRETATION: the visual mediolateral-balance-assessment was more sensitive to age-related balance deterioration than the mechanical mediolateral-balance-assessment, possibly because visual tracking elicits motor strategies that are more affected by ageing.status: publishe

Can explicit visual feedback of postural sway efface the effects of sensory manipulations on mediolateral balance performance?

Explicit visual feedback on postural sway is often used in balance assessment and training. However, up-weighting of visual information may mask impairments of other sensory systems. We therefore aimed to determine whether the effects of somatosensory, vestibular and proprioceptive manipulations on mediolateral balance are reduced by explicit visual feedback on mediolateral sway of the body center of mass and by the presence of visual information. We manipulated sensory inputs of the somatosensory system by transcutaneous electric nerve stimulation on the feet soles (TENS), of the vestibular system by galvanic vestibular stimulation (GVS) and of the proprioceptive system by muscle-tendon vibration (VMS) of hip abductors. The effects of these manipulations on mediolateral sway were compared to a control condition without manipulation under three visual conditions: explicit feedback of sway of the body center of mass (FB), eyes open (EO) and eyes closed (EC). Mediolateral sway was quantified as the sum of energies in the power spectrum and as the energy at the dominant frequencies in each of the manipulation signals. Repeated measures ANOVA were used to test effects of each of the sensory manipulations, of visual conditions and their interaction. Overall, sensory manipulations increased body sway when compared to the control conditions. Absence of normal visual information had no effect on sway, while explicit feedback reduced sway. Furthermore, interactions of visual information and sensory manipulation were found at specific dominant frequencies for GVS and VMS, with explicit feedback reducing the effects of the manipulations but not effacing these.status: publishe

Frecuencia y tipo de actividades de laboratorio que realizan profesores/as primarios en el area de las ciencias, en Santiago de Chile

El presente estudio tuvo como objetivos principal indagar sobre las percepciones que tienen los profesores primarios que realizan clases de ciencias en dos comunas de Santiago de Chile, sobre las actividades de laboratorio. Para ello se desarrolló un cuestionario con 13 preguntas cerradas y 32 afirmaciones de escala likert. La encuesta fue respondida por un total de 70 profesores de quinto y sexto nivel de educación primaria durante el periodo final de clases en el año 2008. Los resultados más importantes de la investigación señalan que: la actividad de laboratorio mas realizada son los experimentos y las menos la resolución de problemas; más del 50% de los profesores señala realizar dos o menos actividades de laboratorio en el año escolar y aquellos que realizan más actividades son los que están más de acuerdo con que estas fomentan la motivación de los niños por la ciencia