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PubMed1999

Facilitating critical reflection in mothers of chronically ill children.

The hybrid model, developed by Schwartz-Barcott & Kim guided the conduct of a study of empowerment in mothers of chronically ill children. Integral to the model of empowerment that emerged from the study was an ongoing process of critical reflection. Through this process, mothers became aware of their strengths, abilities and resources. This paper is an in-depth analysis of the process of critical reflection, which corroborates recent theory on women's development. The process of critical reflection is illuminated by women's ways of knowing, as exemplified in the story of one mother, and by elements of maternal thinking. Implications for nursing practice in working with mothers of chronically ill children are highlighted.

Adaptation, Psychological↗

PubMedDate not supplied

Reflection mode scanning near-field optical microscopy analyses of integrated devices.

Ultra-large-scale integrated devices have been investigated by a reflection mode scanning near-field optical microscope designed for semiconductor analyses. Although it could be found that imaging the reflectivity of metal structures buried underneath thin, optically transparent passivation layers is practicable, shading of the reflected light by the SNOM probe complicated the interpretability of the achieved results. This issue has been overcome by using the SNOM probe as both illumination source and detector, simultaneously. The application of focused ion beam milling to the probes has allowed the increase of the transmittivity of the probes to such an extent that coated fibres could be utilized and the interpretability of the results could be enhanced. Furthermore, the investigated structures are of great interest for an investigation of z-motion artefacts, as the presence of the polished passivation layers allows topographical influences to be distinguished from pure optical contrast.

Journal Article↗

PubMed2001

Non-optically probing near-field microscopy with illumination of total internal reflection.

We have developed a non-optically probing near-field microscope with illumination of total internal reflection. Because the illumination light does not pass through the specimens, it is possible to observe thick specimens or highly absorptive materials. It reduces the background noise because the decay length of the evanescent wave is a few hundred nanometres. We found that although in the total internal reflection illumination system the light passed through the photosensitive film and illuminated the specimen, it did not affect the photosensitive film severely and did not limit the resolution. The imaging properties of reflection illumination and transmission illumination are analysed using a finite-differential time domain method.

Journal Article↗

PubMed2001

Shaping the reflection near-field optical probe: finite domain time difference modelling and fabrication using a focused ion beam.

An optical fibre ending in a trihedral tip is proposed as a convenient probe for reflection near-field optical microscopy in emission/collection mode. Its shape is obtained by ion milling. A first example of manufacturing and numerical models using the bi-dimensional FDTD method is presented. It confirms the strong influence of the facet angle on the intensity reflected by the probe, which is predicted by a rough analysis. This method can help us to optimize the 'reflection probe' by reducing this offset signal.

Journal Article↗

PubMed2003

Tracking of secretory vesicles of PC12 cells by total internal reflection fluorescence microscopy.

Total internal reflection fluorescence microscopy is used to detect cellular events near the plasma membrane. Behaviours of secretory vesicles near the cell surface of living PC12 cells, a neuroendocrine cell line, are studied. The secretory vesicles are labelled by over-expression of enhanced green fluorescent protein-tagged Rab3A, one of the small G proteins involved in the fusion of secretory vesicles to plasma membrane in PC12 cells. Images acquired by a fast cooled charge-coupled device camera using conventional fluorescence microscopy and total internal reflection fluorescence microscopy are compared and analysed. Within the small evanescent range (< 200 nm), the movements of the secretory vesicles of PC12 cells before and after stimulation by high K+ are examined. The movements of one vesicle relative to another already docked on the membrane are detected. Total internal reflection fluorescence microscopy provides a novel optical method to trace and analyse the exocytotic events and vesicle specifically near a cell membrane without interference of signals from other parts of the cell.

Animals↗

PubMed2003

Reflecting together: developing a new strategy for continuous user involvement in mental health nurse education.

This paper explores the first issues encountered when establishing a method of service user involvement in the preparation of a cohort of mental health nursing students during their branch programme. The method involved the creation of a group of service users and students whose purpose was to jointly reflect upon mental health issues. To do this students are expected to use their experience from practice placements and the service users to use their experiences as recipients of mental health services. This approach is being investigated through research utilizing an evaluative case study with features of action research incorporated into the design. The findings to date, which concern the process of negotiation, pre-study attitudinal survey and the first group process, will be presented. This will offer mental health professionals the opportunity to gain insight into one approach of actively involving service users in programmes of higher education over a sustained period of time. Reflection on practice themes will include: collaborative strategy, evaluative case study, education, mental health nursing, reflection on practice, and service-user involvement.

Education, Nursing↗

PubMed1997

Medical students' professional identity: self-reflection during the preclinical years.

Critical thinking, readiness for self-reflection and professional development have recently been emphasized as important goals of medical education. However, little is known about the developmental processes through which a medical student elaborates his or her personal experiences during the training, and about the way he or she gradually develops a professional identity. How does the student identify the opportunities and alternatives offered by the profession and finally commit to the professional values and goals he or she finds personally important? In order to grasp the essential characteristics of the personal development process in depth, qualitative, process-oriented and individually tailored methods are warranted. In this paper, the quality of professional self-reflection and identity formation during the preclinical training are described on the basis of two qualitative materials--learning logs and identity status interviews. Four types of learning log reports on the early patient contact course could be identified: 'committed reflection', 'emotional exploration', 'objective reporting' and 'diffuse reporting'. At the end of the preclinical training, the identity status of several students could still be characterized as diffuse or giving rise to only very tentative professional considerations.

Adult↗

PubMed2002

Total internal reflection: an essay on paradigms.

INTRODUCTION: This paper presents a personal view of the relationship between science and the humanities within medical education, arguing for a more even balance between the two. This view stems from the author's recent experience of exploring the literature of learning theory and the social sciences. BACKGROUND: For historical reasons, medical education is dominated by a positivistic paradigm which assumes the existence of a single objective external reality. This can seduce us into believing that positivism is not a paradigm at all, but simply how the universe really is. Clinical practice, however, takes place in a much less certain world, where reconciling different interpretations of truth is an everyday necessity. This paper outlines the perils of uncritical adherence to a traditionally 'scientific' mode of thinking. TOTAL INTERNAL REFLECTION: In physics, total internal reflection is a phenomenon whereby light is reflected from the surface of a liquid without penetrating it, thereby making it impossible for anyone within a pool of water to see outside it. The author uses this concept as a metaphor to describe a limitation of perspective which characterises orthodox medical training, cutting students off from valuable sources of insight and understanding. CONCLUSIONS: Medical education often fails to provide learners with the tools they need to interpret the literature of other disciplines. In particular, it ignores the importance of recognising different perspectives. The paper ends by pleading for a more inclusive approach to alternative paradigms within our educational system.

Cultural Diversity↗

PubMed2002

An electronic learning portfolio for reflective continuing professional development.

OBJECTIVES: These were to measure the uptake and use of an electronic learning portfolio to support reflective continuing professional development, and to characterize attitudes towards its use and obstacles to its adoption. DESIGN: Uncontrolled, longitudinal intervention study with quantitative and qualitative evaluation. PARTICIPANTS: Physicians with a specialty interest in endocrinology and diabetes mellitus, registered for continuing professional development with the Royal College of Physicians, London. INTERVENTION: All registered consultants were offered a 1-year free trial of PC Diary. Those who accepted were offered a training workshop. MAIN OUTCOME MEASURES: Quantitative and qualitative responses to a simple questionnaire. Two researchers independently used a template approach to analyse free-text responses and jointly agreed a final system of coding. RESULTS: 22% of registered consultants applied to participate; 14% attended training workshops. Of registered participants, 94% returned the questionnaire. PC Diary was used by 34%, but only 10% used it regularly. Among the registrants, 54% asked to continue their subscription for a second year, and 40% asked for further training. There were emotive expressions of both like and dislike, often coupled with statements about the individual's learning style. Time pressures and lack of computer access, literacy and support were dominant obstacles to adoption. CONCLUSIONS: There was considerable support for reflective learning using an electronic portfolio. Acceptability and use were influenced by individual learning style, resources, training and technical support, and these were often inadequate. The balance for consultants between workload demands and support provided did not favour a reflective type of learning.

Attitude to Computers↗

PubMed2002

Becoming a reflective nurse or midwife: using complementary therapies while practising holistically.

Complementary therapies augment nursing and midwidfery practice, but they do not necessarily make it holistic, nor is that practice guaranteed of being based on systematic reflection. This article argues the need for holistic nursing and midwifery to be based on reflective processes, enabling continual development and renewal of the person and practitioner. Practical hints are suggested to assist nurses and midwives in becoming reflective, thereby increasing the likelihood of incorporating complementary therapies while practising holistically.

Complementary Therapies↗

PubMed1993

Comparison of infrared electronic endoscopy using reflection and transmission.

Twelve subjects were examined using both the reflecting type of infrared electronic endoscopy and the transmission method to visualize submucosal gastric architecture. Under transmission infrared illumination, submucosal structures were more clearly observed than by using the reflecting type. Using the transmission method, only the anterior wall of the antrum could be fully visualized, although the anterior wall of the lower corpus was recognized in only 33% of the cases. Furthermore, the upper or middle corpus and the entire posterior wall were not properly recognized using transmission illumination. The entire gastric circumference was visualized with the reflecting type illumination. Both types of infrared illumination of the gastric wall can be used complementarily for visualizing submucosal gastric architecture.

Aged↗

PubMed2006

Smectic order induced at homeotropically aligned nematic surfaces: a neutron reflection study.

Neutron reflection was used to measure the buildup of layers at a solid surface as the smectic phase is approached from higher temperatures in a nematic liquid crystal. The liquid crystal was 4-octyl-4'-cyanobiphenyl (8CB), and the solid was silicon with one of five different surface treatments that induce homeotropic alignment: (i) silicon oxide; (ii) a cetyltrimethylammonium bromide coating; (iii) an octadecyltrichlorosilane monolayer; (iv) an n-n-dimethyl-n-octadecyl-3- aminopropyltrimethyloxysilyl chloride monolayer; and (v) a lecithin coating. The development of surface smectic layers in the nematic phase of 8CB was followed by measuring specular reflectivity and monitoring the pseudo-Bragg peak from the layers. The scattering data were processed to remove the scattering from short-ranged smecticlike fluctuations in the bulk nematic phase from the specular reflection. The pseudo-Bragg peak at scattering vector Q approximately 0.2 A(-1) therefore corresponded to the formation of long-range smectic layers at the surface. The amplitude of the smectic density wave decayed with increasing distance from the surface, and the characteristic thickness of this smectic region diverged as the transition temperature was approached. It was found that the characteristic thickness for some of the surface treatments was greater than the correlation length in the bulk nematic. The different surfaces gave different values of the smectic order parameter at the surface. This suggests that the interaction with the surface is significantly different from a "hard wall" which would give the same values of the smectic order parameter and penetration depths similar to the bulk correlation length. Comparison of the different surfaces also suggested that the strength and range of the surface smectic ordering may be varied independently.

Journal Article↗

PubMed2000

Sublingual nitroglycerin delays arterial wave reflections despite increased aortic "stiffness" in patients with hypertension: a Doppler echocardiography study.

Venodilatation with consequent reduction in left ventricular filling and end-diastolic wall stress is an important mechanism for the beneficial effects of nitroglycerin in ischemic heart disease and in left ventricular failure. The effects of sublingual nitroglycerin on arterial pulsatile hemodynamics are less well defined. Doppler echocardiography and the calibrated subclavian artery pulse tracing were used to assess hemodynamics in subjects with sustained arterial hypertension (n = 25) before and 5 to 10 minutes after sublingual deposition of 0.5 mg glyceryl trinitrate. Aortic characteristic impedance was calculated by averaging the modulus of the input impedance (ratio of pressure to flow) at high frequencies and by calculating the ratio of pressure and flow increments during upstroke. The pressure wave was split into forward and backward components, and the reflection coefficient (the ratio of backward to forward pressures) was calculated. Parameters of the arterial bed were estimated by using 2- and 3-element Windkessel models. Nitroglycerin delayed the return of arterial wave reflections by 17% (P =.02) and increased aortic characteristic impedance by 20% (P =. 01), but it did not influence total arterial compliance. Mean arterial pressure decreased 7% (P =.0001), but pulse pressure did not change. Stroke volume and the acceleration time of aortic root flow decreased by 13% (P =.0001) and 8% (P =.01), respectively. Cardiac output decreased 7% (P =.01), despite an increase in heart rate of 10% (P =.0001). Peripheral resistance tended to decrease (4%, P =.06). Thus, in subjects with sustained hypertension, sublingual nitroglycerin dilates peripheral, predominantly muscular arteries with a subsequent delayed return of reflected pressure waves. Reflex activation of the sympathetic nervous system with consequent increased acceleration of left ventricular ejection seems to counteract the effect of reduced mean arterial pressure (distending pressure) with respect to the "stiffness" of the aorta.

Adult↗

PubMed1984

Perception of lightness and illumination in a world of one reflectance.

Observers looked into a miniature room in which everything was painted matte white, or--in another room--matte black. They made both reflectance and illumination judgments for eight test spots. The test spots (which varied in luminance) were perceived as approximately equal in reflectance--not different, as conventional contrast theories would seem to require. The illumination matches made to the same points, however, closely paralleled the pattern of actual illumination levels, and this result is discussed as evidence that edges are classified as changes in either reflectance or illumination. The white room was correctly perceived as white, and the black room was perceived as middle gray; similar results were obtained even when the luminances in the black room were higher (owing to higher illumination) than the corresponding luminances in the white room. An explanation in terms of differences in gradient patterns is presented and supported with luminance profiles.

Discrimination, Psychological↗

PubMed1989

Effects of room reflectance and background noise on perceived auditory distance.

Perceptions of egocentric auditory distance were investigated within an environment for which the reverberation time could be systematically varied without changes in the size or shape of the room. Two levels of wide-band background noise, differing by 20 dB, were used as a masking stimulus. Target sounds were presented from distances between 0.75 and 6.0 m and verbal reports of distance were collected from 288 listeners in two separate experiments. Changes in physical distance produced variation in reported distance in each configuration. Reported distance was generally proportional to real distance, but considerably underestimated when room reflectance was low. When room reflectance was high (T60 approximately 1.7 s for the range of frequencies used), initial reports of distance were often overestimates; upon repeated presentation, judgments in the high reflectance room became more nearly veridical. The effect of increasing the background noise level was to decrease the perceived distance. These findings are in accord with expectations based upon the importance of reverberation cue(s) to distance and upon previous analyses from this laboratory.

Acoustics↗

PubMed2002

A model for the simultaneous analysis of reflectance spectra and basis factors of Munsell color samples under D65 illumination in three-dimensional Euclidean space.

In this paper we present the results of an analysis of the physically measured surface reflectance spectra of 360 matte Munsell chromatic color chips plus 10 flat achromatic vectors corresponding to Munsell value levels 10 (white) to 1 (near black) for a total sample size of 370. Each of the 370 spectra was multiplied by the spectral radiant power distribution of D65 light so that the final results represent the spectra of reflected light from Munsell color chips under D65 illumination. We simultaneously model the structure of the color chips and the spectra in a common three-dimensional Euclidean space, oriented to yield the most interpretable structure with respect of the Munsell color structure. In this orientation, axis 1 roughly corresponds to the mean power of the spectral reflectance (approximate Munsell value), axis 2 goes from Munsell red to blue-green, and axis 3 goes from Munsell green-yellow to purple. Basis factors for the spectra are also plotted against wavelength and Munsell hue. These plots have implications for theories of opponent processes. By plotting the chips and spectra in the same space we obtain virtually exact correspondences between the various Munsell hues and spectral values in nanometers for comparison to those obtained by previous researchers. Mathematical derivations are provided to validate the common Euclidean model.

Color Perception↗

PubMed1986

Hepatocellular influx of [14C]oleate reflects membrane transport rather than intracellular metabolism or binding.

When [14C]oleate bound to bovine serum albumin was incubated at 37 degrees C for 7 min with isolated rat hepatocytes in the absence of glucose, the cumulative oleate uptake curve had two components: a rapid, linear segment over the first 30 sec, followed by a slower, curvilinear component. At 173 microM [14C]oleate/albumin (1:1, mol/mol), the initial component had a slope (Vo) of 118 +/- 18 pmol per min per 5 X 10(4) hepatocytes (mean +/- SD). During this initial 30 sec, virtually no oleate was oxidized, and less than 11% was esterified. By 5 min, 79% was esterified; oxidation never exceeded 4%. Addition of 2 mM glucose significantly increased oleate esterification and thereby available oleate binding sites on cytosolic fatty acid binding protein but had no influence on Vo. Pretreatment with trypsin reduced Vo by 49 +/- 15%. These data indicate that the initial component of the oleate uptake curve reflects predominantly influx, whereas the subsequent component reflects a balance between influx, efflux, and intracellular metabolism. Influx is independent of intracellular binding, oxidation, and esterification and may reflect a membrane-associated carrier-mediated process.

Animals↗

PubMed2005

Optimized UVB treatment of atopic dermatitis using skin reflectance measurements. A controlled, left-right comparison trial.

In a randomized, open, left-right comparison study, 20 patients with atopic dermatitis were treated with UVB. One side of the body received UVB in a conventional regimen with fixed dosage increments, the other side was given UVB dosages according to skin reflectance measurements of skin pigmentation and erythema. Clinical outcome was assessed by SCORAD. The initial, final and cumulative UVB dosages, time to 50% reduction in SCORAD, and side effects were compared. The initial UVB dosage was somewhat higher in the skin reflectance-guided treatment than in the conventional UVB regimen, although not significantly. There was no difference in the reduction of SCORAD comparing the two treatment options; however, the final UVB dosage and the cumulative UVB dosages were significantly lower in the optimized regimen. This new technique offers the same therapeutic advantage and security as a dose regimen guided by minimal erythema dose testing. However, measurement of skin pigmentation by skin reflectance is a rapid method, which can easily be operated by nurses.

Adolescent↗