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The technology of operating lighting has developed. The performances are concerning both the quality of the light provided and mechanical performances of the lighting. In order to judge the qualities of a lighting, the following keypoints have to be understood: the light itself; optics and geometry of light beams; mechanical and ergonomic performances; available options.
The basic concepts of citation analysis and journal impact factors are discussed in the light of quality assessment of scientific publications, individual scientists and research units. The major controversies concerning this topic are addressed: technical limitations, database selectivity, time and discipline-related biases, language and publication type biases, multiple authorship merits and citing motivations. Both positive and negative aspects are put into perspective. The authors conclude that citation analysis, even when based on journal impact factors, can be a worthwhile criterion for evaluating publication records of individual scientists or research units, as long as some of the problems discussed are sufficiently taken into account. However, this conclusion in no way implies that citation analysis may be considered as the one and only evaluation criterion.
The axial (longitudinal) red light gradient (632 nanometers) of 4 day old dark-grown maize seedlings is increased by staining the peripheral cells of the coleoptile. The magnitude of increase in the light gradient is dependent solely on the light-absorbing qualities of the stain used. Metanil yellow has no effect on the axial red-light gradient, while methylene blue causes a large increase in this light gradient. These stains did not affect growth in darkness or the sensitivity of mesocotyl elongation to red light. However, mesocotyl elongation was altered for the dark-grown seedlings stained with methylene blue when these seedlings were transplanted, covered with soil, and permitted to emerge under natural lighting conditions. These observations are consistent with the idea that there is a single perceptive site below the coleoptilar node, and suggest that this perceptive site gives the actinic light which has traveled downward through the length of the shoot from an entry point in the plant tip region.
Physiological studies over a long period have shown that light acts to regulate flowering through the three main variables of quality, quantity, and duration. Intensive molecular genetic and genomic studies with the model plant Arabidopsis have given considerable insight into the mechanisms involved, particularly with regard to quality and photoperiod. For photoperiodism light, acting through phytochromes and cryptochromes, the main photomorphogenetic photoreceptors, acts to entrain and interact with a circadian rhythm of CONSTANS (CO) expression leading to transcription of the mobile floral integrator, FLOWERING LOCUS T (FT). The action of phytochromes and cryptochromes in photoperiodism is augmented by ZEITLUPE (ZTL) and FLAVIN-BINDING, KELCH REPEAT, F-BOX (FKF1) acting as accessory photoreceptors on entrainment and interaction, respectively. Light quality acts independently of the circadian system through Phytochromes B, D, and E to regulate FT. Light quantity effects, on the other hand, are still incompletely understood but are likely to be linked either directly or indirectly to patterns of assimilate partitioning and resource utilization within the plant.
Differentiation of the filamentous cyanobacteria Calothrix sp strains PCC 7601 and PCC 7504 is regulated by light spectral quality. Vegetative filaments differentiate motile, gas-vacuolated hormogonia after transfer to fresh medium and incubation under red light. Hormogonia are transient and give rise to vegetative filaments, or to heterocystous filaments if fixed nitrogen is lacking. If incubated under green light after transfer to fresh medium, vegetative filaments do not differentiate hormogonia but may produce heterocysts directly, even in the presence of combined nitrogen. We used inhibitors of thylakoid electron transport (3-[3,4-dichlorophenyl]-1,1-dimethylurea and 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone) to show that the opposing effects of red and green light on cell differentiation arise through differential excitations of photosystems I and II. Red light excitation of photosystem I oxidizes the plastoquinone pool, stimulating differentiation of hormogonia and inhibiting heterocyst differentiation. Conversely, net reduction of plastoquinone by green light excitation of photosystem II inhibits differentiation of hormogonia and stimulates heterocyst differentiation. This photoperception mechanism is distinct from the light regulation of complementary chromatic adaptation of phycobilisome constituents. Although complementary chromatic adaptation operates independently of the photocontrol of cellular differentiation, these two regulatory processes are linked, because the general expression of phycobiliprotein genes is transiently repressed during hormogonium differentiation. In addition, absorbance by phycobilisomes largely determines the light wavelengths that excite photosystem II, and thus the wavelengths that can imbalance electron transport.
Quality is key to being able to read radiographs. If it is lacking or poor, it is impossible to make a proper diagnosis. This article describes simple techniques and provides answers to problems encountered in the production of quality radiographs, such as, darkroom management, correct safelights, fresh chemistry and clean equipment. It includes a problem-solving guide to causes and solutions for film marks, density and drying, as well as a simple method for evaluating when to change chemical solutions. Using these techniques should greatly improve quality without a large expenditure of time or money.
HYPOTHESIS: Asynchronous remote telementoring and teleproctoring with anatomical subject matter relevant to surgical procedures is an effective instructional tool for surgical trainees. DESIGN: A validation model was established to assess the capabilities of current technologies to conduct effective instruction of surgical procedures in a remote location relative to the actual surgical procedure. A total of 23 unilateral thyroid dissections in 13 patients using a laparoscope affixed to a stationary robotic arm were videotaped. Anatomical confirmation was sought for the superior flap, middle thyroid vein, carotid sheath, 2 parathyroids, inferior thyroidal artery, recurrent laryngeal nerve, and superior thyroid pole. MAIN OUTCOME MEASURES: Ten surgical trainees reviewed video segments of these 8 anatomical landmarks at a later time after surgery. During observation of the video segments, these physicians were asked to validate the anatomical landmarks on a survey by choosing concur, do not concur, or uncertain. The review panel was also asked to score the images for quality of light, focus (clarity), field range, and contrast. CONCLUSION: This study validates the use of asynchronous education with high-quality optical capture for distance education and collaboration in open surgery.
PURPOSE: The objective of this study is to shed some light on quality improvement practices of for-profit and not-for-profit hospitals DESIGN/METHODOLOGY/APPROACH: The scope and effectiveness of several quality improvement efforts are studied for a sample of 110 hospitals. Factor analysis was utilized to analyze the data collected. FINDINGS: The results of this study tended to suggest that for-profit and not-for-profit hospitals were more similar than different with the regard to the effective utilization of quality improvement initiatives, thus underscoring the utility of quality improvement efforts despite differences in operating characteristics, strategies and operating constraints. RESEARCH LIMITATIONS/IMPLICATIONS: The sample used in this study is limited. Thus, the results should be interpreted accordingly. PRACTICAL IMPLICATIONS: This study offers decision-makers in healthcare operational settings empirical evidence of the operational and strategic effectiveness of different quality improvement efforts, thus justifying investments related to the initiation and implementation of such quality improvement efforts. ORIGINALITY/VALUE: This study represents an important step toward understanding the effective implementation of quality improvement initiatives in different operational settings.
Phototropins are blue-light photoreceptor molecules mediating the capacity for phototropism or bending toward or away from directional light. Like the red-light sensing phytochromes that control shade avoidance, phototropins modulate developmental plasticity in plant architecture. Yet, unlike phytochromes, the adaptive significance of phototropins has been largely a topic of conjecture. In Arabidopsis thaliana, phototropism of seedling and plant stems is under the control of two paralogous genes, PHOT1 and PHOT2, that encode different phototropins with partially redundant light response qualities. The PHOT1 gene product interacts with the NPH3 gene product to cause phototropic bending over a broad range of light intensity, from very weak light in the soil to stronger light in the aerial environment. The PHOT2 gene product modulates shoot bending in response to light of higher intensity only. We compared the fitness of wild-type, phot1, phot2, and nph3 genotypes over a range of light conditions in the field. Seeds were sown in the field on the soil surface and left bare or covered with either gravel or bark mulch chips. Plantings were made under full sun and dense canopy cover. Rates of seedling emergence, survival to flowering, and total seed set were measured. All mutant genotypes had significantly reduced lifetime fitness compared to wild-type. Consistent with their different fluence rate sensitivities, phot1 and phot2 signaling pathways affected fitness at discrete life-cycle stages. Fitness costs of phot1 and nph3 were expressed mainly during seedling emergence from the soil whereas that of phot2 was expressed solely after emergence. Surprisingly, the only significant genotype-by-environment interaction for fitness occurred during emergence: genotypes blind to dim blue light (phot1 and nph3) had poor emergence in the open, but not in the shade. Possibly, the loss of negative phototropism in seedling roots of mutant genotypes reduced establishment success in open (dry soil) conditions. Results show that phototropin-modulated pathways are adaptive and that their evolution has involved functional specialization. However, mechanism(s) of selection on these pathways remain a mystery.
In this paper, field experiment was conducted to analysis the canonical correlations of light and temperature with the yield and quality characters of F1 ecological populations of 54 hybrid rice breeds. The results showed that the yield and quality characters of the populations were significantly correlated with the accumulated temperature, effective accumulated temperature, extreme temperature difference, and sunshine length through the growth period of hybrid rice. The first canonical correlation coefficient (lambda1) between the light and temperature during vegetative growth stage and the yield characters was 0.9975, with the canonical information accounted for 99.96% of the total canonical information, leading to 99.50% of yield variation. Light and temperature affected the yield of hybrid rice mainly through their effects on the total and effective numbers of grains' spikelet and its fertility. In this aspect, accumulated and effective accumulated temperature played a determinative role during vegetative growth stage, while extreme temperature difference and sunshine length were the key factors during reproductive growth stage. As for the quality characters of hybrid rice, light and temperature mainly affected the percentage of polished to head rice, and in this aspect, accumulated and effective accumulated temperature played a determinative role before filling stage, while extreme temperature difference and sunshine length were the key factors after this
Previous research indicates that the specific emotions expressed by stimuli may be closely associated with their pleasing and arousing qualities, and this parallels psychomusicological research on the relationship between these two stimulus qualities. In light of this, the present research contends that the emotions expressed by musical stimuli are associated with their pleasing and arousing qualities. Sixty subjects rated 32 musical excerpts on 11-point scales representing the expression of eight specific emotions. Statistical analyses showed that these emotion ratings were predictable on the basis of 60 additional subjects' ratings of each excerpt in terms of 'liking' and 'arousal potential'. This indicates that ratings of liking and arousal potential are essentially similar to ratings of the specific emotions expressed by musical stimuli. These results are discussed in terms of the relationship between liking and arousal potential, and the implications that this may have for research on affective processes.
The reversible red and far-red light-induced transitions of cyanobacterial phytochrome Cph1 from Synechocystis PCC 6803 were investigated by Fourier transform infrared (FTIR) difference spectroscopy. High-quality light-induced Pfr-Pr difference FTIR spectra were recorded for the 58 kDa N-terminal domain of Cph1 by repetitive photochemical cycling and signal averaging. The Pfr-Pr difference spectra in H(2)O and D(2)O were very similar to those previously reported for full-length 85 kDa Cph1.(1) Published assignments were extended by analysis of the effects of (13)C and (15)N isotope substitutions at selected sites in the phycocyanobilin chromophore and by (15)N global labeling of the protein. The Pfr-Pr difference spectra were dominated by an amide I peak/trough at 1653 cm(-1)(+)/1631 cm(-1)(-) and a smaller amide II band at 1554 cm(-1). Labeling effects allowed specific chromophore assignments for the C(1)=O (1736 cm(-1)(-)/1724 cm(-1)(+)) and C(19)=O (1704 cm(-1)(-)) carbonyl vibrations, C=C vibrations at 1589 cm(-1)(+), and bands at 1537(-), 1512(+), 1491(-), 1163(+), 1151(-), 1134(+), 1109(-), and 1072(-) cm(-1) that must involve chromophore C-N bonds. A variety of additional changes were insensitive to isotope labeling of the chromophore. Effects of (15)N labeling of the protein were used to tentatively assign some of these to specific amino acid changes. Those insensitive to (15)N labeling included a protonated aspartic or glutamic acid at 1734 cm(-1)(-)/1722 cm(-1)(+) and a cysteine at 2575 cm(-1)(+)/2557 cm(-1)(-). Bands sensitive to (15)N protein labeling at 1487 cm(-1)(+)/1502 cm(-1)(-) might arise from trytophan and bands at 1261 cm(-1)(+)/1244 cm(-1)(-) and 1107 cm(-1)(-)/1095 cm(-1)(+) might arise from a histidine environment or protonation change. These assignments are discussed in light of the 15Z-E photoisomerization model of phototransformation and the associated protein conformational changes.
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Previous research has demonstrated that autoclaving of conventional curing tips results in the build-up of an opaque scale on the curing tips ends, greatly reducing light intensity output. Cold sterilization of conventional light-curing tips in most glutaraldehyde-based solutions did not damage the tip or decrease light-transmission quality. However, the specific brand of cold sterilant was found to be of importance, as one specific product was shown to decrease light-tip intensity values irreversibly, even after subsequent tip polishing. A decrease in light intensity output from the curing source significantly affects polymer cure and the biological properties of the restorative material.
High-resolution film dosimetry has been used for several decades to check and to measure two-dimensional dose distributions. However, in recent years, the automatic processor has been replaced by the spread of computed radiography, or has been little used hospitals. In this study, we measured the off-center ratio (OCR) of the open field, after an irradiating radiation beam was delivered to the imaging plate (IP) under conditions in which the IP was exposed to a fixed amount of light with fading, and compared these data with the OCR measured by an ionization-chamber dosimeter, which is the standard method used for measuring radiation dose. Profile measurement using IP could be achieved by performing light fading, even at a range of more than 100 MU. Further, by using a metallic filter, we succeeded in demonstrating that the profile measurement of IP in an open irradiation field could approximate the values of those obtained by an ionization chamber dosimeter. This method can serve as a simple, easy-to-use method for evaluating the QA of dose distribution in radiation therapy.
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A new kind of instrument and method for simultaneous and real-time collection of multi-object spectra by using multi-fiber coupling and Optical Multi-channel Analysis (OMA) was reported. The spectral signals of one object, three objects and five objects were collected successfully in experiments. The spatial resolution of 0.5 mm and detected spectral range of 200-1100 nm were reached, and at most twenty objects could be collected on the image plane of 1 cm2 area with OMA 4 system. The design of the coupling lens's light path was discussed to guarantee enough light energy to enter the instrument and little effect on the resolution of spectral instrument. The instrument can be applied widely to the areas of supervising and controlling the quality of light beam in transmission and in the time-resolved and spatial-resolved spectral measurement.
Light is used by plants as a signal for many physiological and developmental processes. Phytochrome is the most extensively studied family of photoreceptors that plants use to perceive the presence and quality of light in their environment. While the initial action of the phytochrome molecule is not yet known, one important kind of response, changes in the expression of specific nuclear genes, has been intensively investigated. Although phytochrome-regulated promoters are complex and can also respond to other signals, specific DNA elements that are involved in conferring phytochrome responsiveness have been identified. Potential signal transduction pathway components include G proteins, cyclic GMP and Ca2+/calmodulin. In addition, the study of transcription factors involved in phytochrome-regulated gene expression has yielded insights into some of the final steps of transcriptional regulation by phytochrome.