3,107 research outputs found
Is the ‘Visual Fields Easy’ Application a Useful Tool to Identify Visual Field Defects in Patients Who Have Suffered a Stroke?
Aims: To determine the level of agreement between the visual Fields easy application (VFE) for
iPad and a standard clinical test for assessing peripheral vision in stroke survivors.
Study Design: This was a prospective cross-sectional study comparing the VFE application to the
Humphrey Field Analyser (HFA) SITA Fast c30-2 program in identifying and diagnosing visual field
defects post-stroke.
Place and Duration of Study: The ophthalmic department at Imperial College Healthcare NHS
Trust. Data collection was undertaken between January 2016 and August 2016.
Methodology: A total of 50 participants with a diagnosis of stroke and a suspected visual problem
were recruited to the study. Normative data was collected from 50 participants with no history of
stroke or visual loss. Analysis comprised of comparing the extent of the visual field loss detected by
both the VFE and HFA, and clinically assessing the results for normality.
Results: Bland-Altman analysis demonstrated that with more severe visual field loss, the agreement
between both modalities was found to decrease. There was a higher proportion of false negatives with the VFE compared to the HVF. The bias towards detecting more missed test locations with the
VFE application compared to the HFA was 6% for the normal participants and 2% for the stroke
participants. The limits of agreement between the two modalities were large; 20% and 40% for the
normal and stroke participants respectively. The sensitivity of the VFE application to determine an
abnormal visual field in comparison to HFA was 88% and specificity was 76% in the stroke cohort
based upon a clinical impression of its findings. The majority of stroke participants (88%) found the
VFE test more comfortable to perform.
Conclusion: As a screening tool, the VFE application is quick and easy to administer, preferred by
patients and has good sensitivity and specificity for detecting the presence of an abnormal visual
field when compared to HFA. In patients with extensive visual field loss, the VFE may overestimate
visual field reduction
Un ejemplo de uso del análisis secuencial en la investigación en resolución de problemas en Educación Matemática
En este trabajo presentamos las posibilidades del análisis secuencial y la técnica de coordenadas polares para describir y analizar el proceso de resolución, por parejas, de un problema de optimización mediado por una i-actividad. Iniciamos el trabajo con algunos antecedentes teóricos y la descripción de las técnicas del análisis secuencial y de coordenadas polares. Finalmente ejemplificamos y describimos el potencial de estas técnicas
Diseño de una e-actividad orientada a la resolución de problemas de matemáticas
Proponemos una metodologÃa para el diseño de e-actividades, la cual incluye un diseño inicial, puesta en práctica y revisión de la e-actividad hasta el logro de los objetivos propuestos. En este trabajo utilizamos un problema de optimización para diseñar una e-actividad que pretende trabajar diferentes fases en la resolución de problemas
Un sistema de categorÃas para el análisis de la interactividad en una i-actividad de resolución de problemas
Presentamos una propuesta de un sistema de categorÃas diseñado para describir y analizar el proceso de resolución de una i-actividad por parejas de estudiantes, y la influencia de la interactividad en este proceso. Utilizamos una i-actividad basada en un problema de optimización
Sensory evaluation of environmental impact : wine and oil industries
El objetivo de este trabajo fue probar y
poner a punto un método para la valoración
del impacto sobre el ambiente, generado por
las industrias vitivinÃcolas y aceiteras. Sus
efluentes lÃquidos se evaluaron sensorialmente
durante dos años, en momentos y
horarios clave de producción. Se practicaron
pruebas de valoración de intensidad -mediante
escalas de intervalo- y de ordenamiento,
tanto para atributos: olor, color, turbidez y sedimento
de efluentes lÃquidos, como para impactos:
visual, olfativo y auditivo.
Se caracterizaron las variables en cada
tipo de establecimiento y por etapa considerada.
Se elaboró una cartilla de color de
efluentes lÃquidos mediante comparación con
la escala Munsell. Se obtuvieron perfiles sensoriales
de cada punto de muestreo. Las
pruebas de ordenamiento (nivel de
significancia = 0,05) arrojaron diferencias significativas
para las variables y puntos de
muestreo en estudio. Las pruebas de comparación
múltiple indicaron los puntos de
muestreo que debÃan mantenerse.This work was done in order to prove
and to complete a methodology of valuation
of the impact produced by wine and oil
industries. Sensorial evaluations of liquid
effluents and working environment were
made at key moments and schedules of
production, during two years. It was practiced
intensity valuation test by means of interval
scales and ordering test for smell, color,
turbidity and liquid effuents sediment and visual,
olfactory and auditory impacts of
environment.
The variables were characterized on
each type of establishment and by
considered stage. A liquid effluents color
scale was made by means of comparison
with Munsell scale. Sensory profiles of each
point of sampling were obtained. Ordering
test, for a level of significance of 0,05, giving
significant differences for the variables and
points of sampling. Multiple comparison test
indicated the sampling points that should be
maintained.Fil: Cánovas, Laura.
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Biomatemática y FisicoquÃmicaFil: Herrera, MarÃa C..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Biomatemática y FisicoquÃmicaFil: Codina, Ramón A..
Universidad Nacional de Cuyo. Facultad de Ciencias Agrarias. Departamento de Producción Agropecuari
Insights into the stability of a therapeutic antibody Fab fragment by molecular dynamics and its stabilization by computational design
Successful development of protein therapeutics depends critically on achieving stability under a range of conditions, while retaining their specific mode of action. Gaining a deeper understanding of the drivers of instability across different stress conditions, will potentially enable the engineering of protein scaffolds that are inherently manufacturable and stable. Here, we compared the structural robustness of a humanized antibody fragment (Fab) A33 using atomistic molecular dynamics simulations under two different stresses of low pH and high temperature. RMSD calculations, structural alignments and contact analysis revealed that low pH unfolding was initiated through loss of contacts at the constant domain interface (CL-CH1), prior to CL domain unfolding. By contrast, thermal unfolding began with loss of contacts in both the CL-CH1 and variable domain interface (VL-VH), followed by domain unfolding of CL and also of VH, thus revealing divergent unfolding pathways. FoldX and Rosetta both agreed that mutations at the CL-CH1 interface have the greatest potential for increasing the stability of Fab A33. Additionally, packing density calculations found these residues to be under-packed relative to other inter-domain residues. Two salt bridges were identified that possibly drive the conformational change at low pH, while at high temperature, salt bridges were lost and reformed quickly, and not always with the same partner, thus contributing to an overall destabilization. Sequence entropy analysis of existing Fab sequences revealed considerable scope for further engineering, where certain natural mutations agreed with FoldX and Rosetta predictions. Lastly, the unfolding events at the two stress conditions exposed different predicted aggregation-prone regions (APR), which would potentially lead to different aggregation mechanisms. Overall, our results identified the early stages of unfolding and stability-limiting regions of Fab A33, which provide interesting targets for future protein engineering work aimed at stabilizing to both thermal and pH-stresses simultaneously
FIC/FEM formulation with matrix stabilizing terms for incompressible flows at low and high Reynolds numbers
The final publication is available at Springer via http://dx.doi.org/10.1007/s00466-006-0060-yWe present a general formulation for incompressible fluid flow analysis using the finite element method. The necessary stabilization for dealing with convective effects and the incompressibility condition are introduced via the Finite Calculus method using a matrix form of the stabilization parameters. This allows to model a wide range of fluid flow problems for low and high Reynolds numbers flows without introducing a turbulence model. Examples of application to the analysis of incompressible flows with moderate and large Reynolds numbers are presented.Peer ReviewedPostprint (author's final draft
A continuous flow-batch hybrid reactor for commodity chemical synthesis enabled by inline NMR and temperature monitoring
Inline, real time NMR and temperature measurements have been used to optimise the continuous flow synthesis of difluoromethyltrimethylsilane (TMSCF2H) by the reduction of the Ruppert-Prakash reagent (TMSCF3). These measurements were used to maximise the space-time-yield, while ensuring this exothermic process remains safe. In this way, a three-fold increase in space-time-yield was achieved compared to the reported batch procedure, isolating 25 g of pure TMSCF2H after 105 min
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