bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the tolerability and efficacy of unit‐dose, preservative‐free topical ocular anaesthetics
Authors: Lawrenson J. G. , Edgar D. F. , Tanna G.K. , Gudgeon A.C. 
Published: September 2002

SummarySeveral topical ocular local anaesthetics are available in preservative‐free unit‐dose applicators. There is little comparative data as to the efficacy and tolerability of these drugs. The purpose of this study was to compare the tolerability, and the depth and duration of corneal anaesthesia following instillation of one drop of 0.4% oxybuprocaine (benoxinate), 0.5% amethocaine, or 0.5% proxymetacaine. The tolerability of each anaesthetic was assessed using a linear ten point arbitrary comfort scale. A group of 14 healthy male subjects, with a wide variation in iris pigment levels, participated in the study (mean age 26.6 years, range 18–40 years). Corneal sensitivity was measured using a slit‐lamp mounted Cochet–Bonnet aesthesiometer prior to instillation, and at 1, 2, 5, 10, 15, 20 and 30 min after instillation, and continued if necessary until corneal sensitivity had returned to pre‐instillation levels. For each anaesthetic, complete anaesthesia occurred within 1 min of instillation and a return to baseline sensitivity levels occurred by 45 min. No significant difference in anaesthesia was found between the drugs at each time point. Tolerability profiles indicated that proxymetacaine was significantly better tolerated than either amethocaine (p<0.01) or oxybuprocaine (benoxinate) (p<0.001). There was considerable inter‐subject variability in the duration of anaesthesia, and practitioners should be alert to this when allowing patients to leave the practice following the production of corneal anaesthesia. There seems little to choose clinically between the three active agents as regards clinical effectiveness. Proxymetacaine was significantly better tolerated than either amethocaine or oxybuprocaine.
Assessment of a new through‐the‐eyelid technique for ‘A’ scan ultrasound ocular axial length measurement
Authors: Laws Fiona , Laws David , Wood Ivan , Clark David 
Published: September 2002

SummaryThis study evaluated the repeatability both within one session and between two sessions of a new technique of axial length measurement using ‘A’ scan ultrasound through the eyelids. The validity of the technique was assessed by comparing the results to those taken through the cornea. The new technique was very reliable, the mean difference between two readings at the first visit being 0.01 mm and between the two visits being 0.01 mm with 95% of differences between two readings in both cases being less than two standard deviations. The axial length measurements through the lid were a mean of 0.05 mm longer than the corneal measurements. The standard deviation of the difference between the two forms of measurement was 0.16 mm and 95% of axial length readings through the eyelid were within two standard deviations (±=0.32 mm) of the corneal measurement. Providing strict criteria are applied to the quality of the ‘A’ scan images we believe that satisfactory axial length values may be obtained using this technique.
An optical explanation of the entoptic phenomenon of ‘clouds’ in posterior vitreous detachment
Authors: Serpetopoulos Christos N. , Korakitis Romylos A. 
Published: September 2002

SummaryThe purpose of this work is to investigate in detail the optics of the shadow cast by vitreous opacities and its effects in the perception of related entoptic phenomena. The optics of the eclipse has been used as a model. The various parameters affecting the shadow, i.e. the diameter of the opacity, its distance from the retina and the overall distance between the pupillary plane and the retina, have been taken into account in the calculations. A mathematical function has been derived and curves defining the density of the penumbra have been plotted for various distances of an opacity from the retina. An area of uniform partial illumination of the retina behind the opacity has been defined, outside of which the density of the penumbra falls rapidly. It is concluded that the sensation of ‘cloud’ or ‘smoke’ reported by the patient stems from this uniform area of penumbra behind the opacity, whose extent depends on the above mentioned parameters. Thus, the optics of the eclipse explains this entoptic phenomenon. Of course, ‘clouds’ can also be due to semi‐transparent vitreous floaters.
Kinematics of eye movement
Authors: Bolina Oscar , Monteiro L.H.A. 
Published: September 2002

SummaryIn a simplified fashion, the motion of the eyeball in its orbit consists of rotations around a fixed point. Therefore, this motion can be described in terms of Euler's angles of rigid body dynamics. However, there is a physiological constraint in the motion of the eye which reduces to two its degrees of freedom, so that one of Euler's angles is not an independent variable. This paper reviews the basic features of the kinematics of the eye and the laws governing its motion.
The ageing effect on the central posterior corneal radius
Authors: Lam Andrew K. C. , Douthwaite William A. 
Published: September 2002

SummaryThe posterior corneal radii along the vertical and horizontal meridians were measured using the Purkinje image technique. Two‐hundred and forty subjects were recruited and divided into four different age groups (mean age of 20, 33, 41 and 50 years, respectively). Male and female subjects were nearly equally distributed in each group. A significant correlation was found between the anterior and posterior corneas, along both the vertical (r=0.83, P<0.01) and horizontal (r=0.89, P<0.01) meridians. Ageing has a significant effect on the horizontal meridian but not on the vertical meridian. The radii reduced with age and this phenomenon applied to both the anterior and posterior corneas, gives rise to a more spherical cornea in advancing age. The posterior cornea has a surface power around 13% of the anterior corneal surface, which indicates that the use of keratometer index 1.3375 is valid in estimating the total corneal power from the anterior corneal radius. More information about the anterior and posterior corneas could be useful in the proposal of a four‐surface schematic eye.
Improving the reliability of visual acuity measures in young children
Authors: McGraw Paul V. , Winn Barry , Gray Lyle S. , Elliott David B. 
Published: September 2002

SummaryWhilst the methodology of adult letter acuity measurement has been substantially refined over the last two decades, relatively little development has occurred in methods for quantifying letter acuity in young children. This study compares a recently developed visual acuity test (Glasgow Acuity Cards), which incorporates several key design features used in adult test charts to improve the sensitivity and reliability of visual acuity measurements. The equivalence of acuity measurements made with Glasgow Acuity Cards were compared with the Bailey–Lovie logMAR chart and Snellen chart in adults, and with traditional Single Letter Acuity and a modified Single Letter Acuity test in children. The test–retest reliability of acuity measurements made with Glasgow Acuity Cards and the Single Letter Acuity tests were also assessed in a large group of visually normal children. In addition, the ability of the pre‐school letter acuity tests to detect differences in acuity between the two eyes, and to detect amblyopia were examined. Ninety‐five percent of vision measurements made with the Bailey–Lovie chart and Glasgow Acuity Cards differ by less than 0.07 log unit. Furthermore, the sensitivity of Glasgow Acuity Cards to detecting changes in acuity longitudinally and inter‐ocular differences in acuity is considerably greater as compared with traditional Single Letter Acuity tests. Improvements in paediatric acuity chart design are important for the effective detection and management of children with amblyopia.
An introduction to analysis of variance (ANOVA) with special reference to data from clinical experiments in optometry
Authors: Armstrong R. A. , Slade S. V. , Eperjesi F. 
Published: September 2002

SummaryThis article is aimed primarily at eye care practitioners who are undertaking advanced clinical research, and who wish to apply analysis of variance (ANOVA) to their data. ANOVA is a data analysis method of great utility and flexibility. This article describes why and how ANOVA was developed, the basic logic which underlies the method and the assumptions that the method makes for it to be validly applied to data from clinical experiments in optometry. The application of the method to the analysis of a simple data set is then described. In addition, the methods available for making planned comparisons between treatment means and for making post hoc tests are evaluated. The problem of determining the number of replicates or patients required in a given experimental situation is also discussed.
The three point vernier alignment or acuity test (3Pt VA test): an analysis of variance
Authors: Fang Michelle Shih‐Ming , Enoch Jay M. , Lakshminarayanan Vasudevan , Kim Eunice , Kono Momoyo , Strada Elisabetta , Srinivasan Ranjani 
Published: September 2002

SummaryA very useful clinical vernier acuity or vernier alignment test has been developed in this and associated laboratories over a span of two decades. We seek to refine further this test, to seek internal inconsistencies and to optimize parameters used in a variety of devices and environments. Vernier testing, and many aspects of this work have been considered by numerous able scientists over a long time period (not reviewed here), but none have encountered conditions faced by this group, particularly in the developing world.The three point vernier alignment (acuity) threshold test (3Pt VeA test) employed here has broad applications; it can be used as a clinical test of vision status, for triage, and as a reference standard for vision testing (in general). As one example, if sufficient luminance is employed, the test is applicable in the presence of truly dense media disorders, even advanced leucomas, mature cataracts, intraocular bleeds, as well as combinations of these disorders, with or without a window to the retina. Only retinal and centrally‐based neural disorders, eccentricity from fixation, and about 50% of hypermature cataracts affect outcomes. With minor alterations, this test can be employed to assess the visual field. An analysis of variance (ANOVA) was performed on a defined set of parameters, to enable us to understand better the special properties and requirements associated with this test. Results are not significantly altered between ages 10–94 years (not assessed here). Employing settings well above threshold for test spot detection and well separated individual test spots, changes in test spot luminance, or background luminance (or adaptation level), contrast, veiling glare, test spot size, clear and variously degraded images, seem not to affect meaningfully measured outcomes. If an observer can define well a center of gravity for each test spot viewed, he can align the three points with remarkable precision.
The effect of prism adaptation on the response AC/A ratio
Authors: Rainey Bill B. 
Published: September 2002

SummaryVergence adaptation, also known as prism adaptation, is a phenomenon in which a patient's heterophoria changes after prolonged viewing through prism. The effect of prism adaptation on the accommodation–convergence relationship, quantified by the AC/A ratio, is not known. Previous studies of AC/A ratio stability and alterability have used only stimulus AC/A ratio calculations, or have measured accommodative responses to only one or two stimuli. The ideal study of AC/A ratio stability and alterability would measure accommodative responses to several accommodative stimuli, and use these along with vergence responses to calculate response AC/A ratios, rather than stimulus AC/A ratios. In addition, the gradient method should be used to avoid any effect of proximal vergence resulting from changes in target distance. This paper describes a project which investigated the effect of vergence (prism) adaptation on the gradient response AC/A ratio, using accommodative responses measured for five different accommodative stimuli. The response AC/A ratio did not significantly change following a period of adaptation to base‐in prism for six of the eight subjects in this study. In addition, the response AC/A ratio did not significantly change following a period of adaptation to base‐out prism for six of the eight subjects.
Aging, perception, and visual short‐term memory for luminance‐defined form
Authors: Sara Mona , Faubert Jocelyn 
Published: September 2002

SummaryThe sensory, perceptual, and visual short‐term memory (VSTM) capacity of young and older observers for processing luminance‐defined shape information was assessed in a series of experiments. The following were assessed: each individual's threshold necessary to detect a square from its background as measured by luminance thresholds; the capacity for making simultaneous size discriminations when compensating for individual differences in sensory input; the capacity for making sequential size discriminations; and the capacity for remembering size differences over time. The results show a selective deficit for simultaneous perceptual processing for older subjects, which cannot be attributed to differences in sensory input, task difficulty, interhemispheric transfer, or VSTM.
Light-Intensity-Dependent Expression of Lhc Gene Family Encoding Light-Harvesting Chlorophyll-a/b Proteins of Photosystem II in Chlamydomonas reinhardtii
Authors: Teramoto Haruhiko , Nakamori Akira , Minagawa Jun , Ono Taka-aki 
Published: September 2002

Abstract
Excessive light conditions repressed the levels of mRNAs accumulation of multiple Lhc genes encoding light-harvesting chlorophyll-a/b (LHC) proteins of photosystem (PS)II in the unicellular green alga, Chlamydomonas reinhardtii. The light intensity required for the repression tended to decrease with lowering temperature or CO2concentration. The responses of six LhcII genes encoding the major LHC (LHCII) proteins and two genes (Lhcb4 andLhcb5) encoding the minor LHC proteins of PSII (CP29 and CP26) were similar. The results indicate that the expression of theseLhc genes is coordinately repressed when the energy input through the antenna systems exceeds the requirement for CO2 assimilation. The Lhc mRNA level repressed under high-light conditions was partially recovered by adding the electron transport inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea, suggesting that redox signaling via photosynthetic electron carriers is involved in the gene regulation. However, the mRNA level was still considerably lower under high-light than under low-light conditions even in the presence of 3-(3,4-dichlorophenyl)-1,1-dimethylurea. Repression of theLhc genes by high light was prominent even in the mutants deficient in the reaction center(s) of PSII or both PSI and PSII. The results indicate that two alternative processes are involved in the repression of Lhc genes under high-light conditions, one of which is independent of the photosynthetic reaction centers and electron transport events.
FEMALE RESISTANCE AND MATING OUTCOMES IN A STREAM-DWELLING ISOPOD: EFFECTS OF MALE ENERGY RESERVES AND MATING HISTORY
Authors: Sparkes Timothy , Keogh Daniel , Orsburn Tyler 
Published: September 2002

Abstract
In the stream-dwelling isopod, Lirceus fontinalis, conspicuous mating contests occur between males and females prior to pair formation. Our previous work has shown that female resistance during contests determines contest outcomes. Here we examined whether female resistance could act as a mechanism of choice in which females discriminate against males with low energy (glycogen) reserves. We manipulated male glycogen levels by chasing males around a race-track then exposed females to males that differed in glycogen levels. We found that high-glycogen males were more successful than low-glycogen males and that this effect appeared to be due to increased female resistance towards low-glycogen males. We then examined one potential benefit to females of energy-based mate discrimination. In L. fontinalis, male mating history and levels of glycogen reserves are correlated, i.e. recently mated males are glycogen-depleted due to energy costs associated with mating. We examined whether recently mated males were also costly mates, and thus should be avoided by females. We quantified the relationship between male mating history and female fertilization success and found that females suffered an 18% reduction in fertilization success by mating with a male that had recently inseminated another female. We propose that female resistance could act as a mechanism of choice in which males with low energy reserves are avoided and that one benefit of this discrimination is that females increase fertilization success be avoiding males that have recently mated.
Photodissociation of Small Molecules in the Gas Phase
Authors: Kawasaki Masahiro , Bersohn Richard 
Published: September 2002

Abstract
Our knowledge of the process of photodissociation is built on a foundation of molecular spectroscopy developed since the 1920’s. However, modern photodissociation dynamics has been mainly created by the introduction of laser light sources around 1970. This review of molecular photodissociation emphasizes findings based on techniques developed in the past ten–fifteen years. These include measurement of the energy dependence of the branching ratios of the yields of different photodissociation channels and the distribution of velocity and internal states of the fragments. The time scale of the separation of the fragments is shown to vary from the microsecond to the femtosecond regime depending on whether the dissociation is indirect or direct. Multiphoton dissociation can be incoherent or coherent. In the latter case, if two different optical paths can accomplish dissociation, changing the relative phase of the transition matrix elements of the two paths can control the branching ratio of different channels. The branching ratio can also be controlled by aligning the parent molecule in an electric field or by using successive ultraviolet and infrared transitions. The review concludes with some applications of photodissociation to the terrestrial atmosphere and to the generation of reactive radical sources.
Counter Ion Release of Ionic Surfactant Micelles Induced by Solubilized Amphiphiles: Size Effect of a Polar Head Group
Authors: Manabe Masahiro , Kaneko Miharu , Miura Takako , Akiyama Chinami , Kawamura Hideo , Katsuura Hajime , Shiomi Masaki 
Published: September 2002

Abstract
The acceleration rate (dα/dXam) of the dissociation degree (α) of ionic SDS micelles to the mole fraction (Xam) of solubilized additives has been determined at infinite dilution by a differential conductivity method. The additives used were a homologous series of amphiphiles with different types of polar groups: alkylglucosides, MEGAs, diols, and cyclooctanol. The method allows us to determine the partition coefficient between the bulk water and the micelles (Kx) and the rate of depression (Csf/Caf) of the monomer surfactant concentration (Csf) to the monomer additive (Caf), in addition to dα/dXam. The results are as follows: (1) dα/dXam in each homologous series is independent of the alkyl chain length, indicating a characteristic value of each polar group. (2) dα/dXam increases with increasing molecular weight of the groups, representing the size effect on the counter ion dissociation. (3) For diols, dα/dXam is higher than twice that of 1-alkanols, due to a large effective size. (4) Kx is dependent on the alkychain length, but independent of the polar group types, indicating that the net charge on the surface of the micelles remains unaltered by solubilization. (5) (Csf/Caf) determined above cmc is identical with the cmc decreasing rate, Δcmc/ΔCa, at cmc.
Detection of Ligand-Substitution Intermediates in the Photoreactions of Bis(2,2′-bipyridine)butanediamineruthenium(II) Complex Using Electrospray Ionization Mass Spectrometry
Authors: Arakawa Ryuichi , Abe Kazuyuki , Abura Tsutomu , Nakabayashi Yasuo 
Published: September 2002

Abstract
The photolysis of [Ru(bpy)2(bn)]2+ (bpy = 2,2′-bipyridine, bn = 1,4-butanediamine) in acetonitrile and acetone by light of wavelength longer than 420 nm was studied by electrospray ionization mass spectrometry (ESI-MS). The results were different from those of two other amine complexes, [Ru(bpy)2(en)]2+ and [Ru(bpy)2(tn)]2+ (en = ethylenediamine and tn = 1,3-propanediamine). An analysis of the irradiation time course revealed that one end of the bn ligand is quickly dissociated to form a solvent-coordinated complex, [Ru(bpy)2(bn)(AN)]2+ (AN = acetonitrile), and its protonated complex, [Ru(bpy)2(bn + H)(AN)]3+. These solvent-coordinated complexes were not observed in the photochemical reactions of the en or tn complex. The difference in photolysis is due to the fact that the coordination of the bn ligand in [Ru(bpy)2(bn)]2+ is less stable than the en or tn ligand. Both the en and tn complexes formed oxygenated complexes, while the bn complex did not form such a complex. This can be explained by the incorporation of singlet oxygen during the photochemical reaction.
Mechanism for Photocleavage of N-(Anthroyloxy)-9-fluorenylideneamines and Dynamic Behavior of Anthroyloxyl Radicals
Authors: Saitoh Yasuo , Kaneko Makoto , Segawa Katsunori , Itoh Hiroki , Sakuragi Hirochika 
Published: September 2002

Abstract
Photocleavage of the N–O bond of N-(9-anthroyloxy)-9-fluorenylideneamine and its 1-and 2-anthroyloxy derivatives takes place efficiently in acetonitrile in the excited singlet state attributed to the fluorenylidene moiety. This made it possible for the first time to directly observe anthroyloxyl radicals by the transient absorption method. The quantum efficiency for photocleavage decreases remarkably in benzene, in which the lowest excited singlet state is attributed to the anthroate moiety. All the three kinds of anthroyloxyl radicals are much less reactive in decarboxylation, addition to olefins, and hydrogen-atom abstraction than benzoyloxyl and 1- and 2-naphthoyloxyl radicals; 9-anthroyloxyl radicals supposedly undergo intramolecular addition–elimination in the ipso-position in equilibrium with α-lactonic spirodihydroanthryl radicals, as indicated by one-color and two-color laser photolyses.
Triethylborane Induced Radical Reaction of Gallium Enolates with α -Halo Esters
Authors: Usugi Shin-ichi , Yorimitsu Hideki , Shinokubo Hiroshi , Oshima Koichiro 
Published: September 2002

Abstract
Treatment of silyl enolates with methyllithium followed by an addition of gallium trichloride afforded the corresponding gallium enolates. The reaction of the resulting gallium enolates with α-halo carbonyl compounds in the presence of triethylborane as a radical initiator provided 1,4-dicarbonyl compounds in good yields.
Electronic Characterization of Dimethyl 1,2-Dihydropyrrolo[1,2-a] quinoxaline-2,3-dicarboxylate in Solution and in the Solid State
Authors: Hirano Keisuke , Yamaoka Seiji , Minakata Satoshi , Komatsu Mitsuo 
Published: September 2002

Abstract
Dimethyl 1,2-dihydropyrrolo[1,2-a]quinoxaline-2,3-dicarboxylate is red colored in the solid state, while it is a small molecule and has no hydrogen-bonding interaction. This unusual color property was investigated by means of electronic characterization in solution and in the solid state. The push-pull system from electron-donating pyrrole nitrogen to the electron-withdrawing 3-methoxycarbonyl moiety causes a spectral shift to an orange color in the visible region. An X-ray structure analysis indicated that these polar molecules (μ = 7.6 D) are arranged in a zig-zag fashion so as to minimize the electrostatic energy. As a consequence, the absorption band is presumably shifted toward longer wavelengths by about 60 nm (about 2508 cm−1) in going from a solution to the solid state. These results lead to a large bathochromic shift in the absorption spectrum, resulting in the red color of this compound in the solid state.