bluuebunny/crossref_metadata_2025_split huggingface dataset:
Life on a limb: ecology of the tree agama (Acanthocercus a. atricollis) in southern Africa
Authors: Reaney Leeann T. , Whiting Martin J. 
Published: September 2002

AbstractOne hundred and sixty‐four museum specimens of the tree agama Acanthocercus a. atricollis were measured and dissected to examine sexual size dimorphism, reproduction and diet. Foraging mode and behaviour were also quantified in a wild population to obtain a broader picture of their foraging ecology and to test the hypothesis that tree agamas are ambush foragers. Males and females did not differ significantly in snout–vent length (SVL) or tail length; however, mature males had larger heads than females of the same body size. The smallest female showing sexual maturity was 96 mm SVL and the smallest male was 82 mm SVL. Mean clutch size was 11.3 and was positively correlated with female body size. Reproduction was seasonal and male and female reproductive cycles were synchronous. Testicular volume was greatest during August–September and females contained enlarged follicles during August–December and showed no evidence of multiple clutching. Tree agamas fed on a broad spectrum of arthropods (10 orders), including millipedes, which other lizard taxa have been reported to avoid. Gut contents were dominated numerically by ants (92%), followed by beetles (4%). Volumetrically, orthopterans (26.8%) were most important, followed by beetles (26.3%) and ants (17.9%). Compared to adults, juvenile diet by volume was dominated by ants and consisted of fewer large prey items (e.g. beetles and orthopterans). Seasonal effects in both prey diversity and volume were evident. Tree agamas are classic ambush foragers. They spent only 4% of their time moving and made few movements per minute (mean = 0.4). When stationary, adult tree agamas positioned themselves on tree trunks (34.7%), on lateral branches (41.8%) and occasionally, on the ground (23.4%). No evidence of trophic partitioning (intraspecific niche divergence hypothesis) was found and field observations revealed that males defend territories and engage in combat. This supports the idea that selection may be favouring larger head size in males, as an outcome of male contest competition.
Modeling of Mixing in 96‐Well Microplates Observed with Fluorescence Indicators
Authors: Weiss Svenja , John Gernot T. , Klimant Ingo , Heinzle Elmar 
Published: September 2002

AbstractMixing in 96‐well microplates was studied using soluble pH indicators and a fluorescence pH sensor. Small amounts of alkali were added with the aid of a multichannel pipet, a piston pump, and a piezoelectric actuator. Mixing patterns were observed visually using a video camera. Addition of drops each of about 1 nL with the piezoelectric actuator resulted in umbrella and double‐disklike shapes. Convective mixing was mainly observed in the upper part of the well, whereas the lower part was only mixed quickly when using the multichannel pipet and the piston pump with an addition volume of 5 μL or larger. Estimated mixing times were between a few seconds and several minutes. Mixing by liquid dispensing was much more effective than by shaking. A mixing model consisting of 21 elements could describe mixing dynamics observed by the dissolved fluorescence dye and by the optical immobilized pH sensor. This model can be applied for designing pH control in microplates or for design of kinetic experiments with liquid addition.
Images may show start of European‐African plate collision
Authors: Mascle J. , Huguen C. , Benkhelil J. , Chamot‐Rooke N. , Chaumillon E. , Foucher J. P. , Griboulard R. , Kopf A. , Lamarche G. , Volkonskaia A. , Woodside J. , Zitter T. 
Published: September 2002

Aspects of the initial stages of a collision between European and African plates may have been documented in a geophysical survey of the central Mediterranean Ridge (MR) conducted last year. The idea of an incipient collision was first suggested by Finetti [1976],and details of the seafloor and tectonic deformation along the MR, revealed for the first time in the survey, seem to point in that direction.A unique opportunity may therefore exist for studying the beginnings of such a collision—between the passive margin of a major plate (Africa) acting as a continental indenter against the active margin of another plate (Europe). More wide angle data, deep penetrating multichannel seismic data, and drilling data are crucial to better assess the nature and the architecture of the underlying lithosphere, the styles of sedimentary deformation, and the consequences on fluid releases. Such data will make it possible to establish, or reject, a geodynamic collision model.
Pharmacology and potential therapeutic applications of nitric oxide‐releasing non‐steroidal anti‐inflammatory and related nitric oxide‐donating drugs
Authors: Keeble J E , Moore P K 
Published: September 2002

This review examines the biological significance, therapeutic potential and mechanism(s) of action of a range of nitric oxide‐releasing non‐steroidal anti‐inflammatory drugs (NO‐NSAID) and related nitric oxide‐releasing donating drugs (NODD). The slow release of nitric oxide (NO) from these compounds leads to subtle changes in the profile of pharmacological activity of the parent, non‐steroidal anti‐inflammatory drugs (NSAID). For example, compared with NSAID, NO‐NSAID cause markedly diminished gastrointestinal toxicity and improved anti‐inflammatory and anti‐nociceptive efficacy. In addition, nitroparacetamol exhibits hepatoprotection as opposed to the hepatotoxic activity of paracetamol. The possibility that NO‐NSAID or NODD may be of therapeutic benefit in a wide variety of disease states including pain and inflammation, thrombosis and restenosis, neurodegenerative diseases of the central nervous system, colitis, cancer, urinary incontinence, liver disease, impotence, bronchial asthma and osteoporosis is discussed.British Journal of Pharmacology (2002) 137, 295–310. doi:10.1038/sj.bjp.0704876
Eye problems and visual display terminals—the facts and the fallacies
Authors: Thomson W. David 
Published: September 2002

SummaryEstimates of the prevalence of eye problems associated with using visual display terminals (VDTs) vary enormously depending on the sample tested and the research methods employed. However, most authors agree that eye problems are common among VDT users. In this paper, the relative contributions of the nature of VDT displays, workstation design, work‐practices and optometric factors are discussed, drawing from the substantial body of literature which now exists on this subject.
Early ocular and non‐ocular indications of diabetes mellitus
Authors: North Rachel V. 
Published: September 2002

SummaryThis article aims to review the early indications of diabetes, both ocular and non‐ocular. Epidemiological data is showing an increase in both non‐insulin dependent and insulin dependent diabetes mellitus. It is therefore important that diabetes mellitus is detected early so that regular screening and good metabolic control can be encouraged. Strict glycaemic control is important in order to delay the onset or slow the progression of diabetic complications.
The aging eye and vision appliances
Authors: Rumney Nicholas J. 
Published: September 2002

SummaryThis paper describes some of the potential impact the aging population may have on routine optometric practice from the perspective of the aging normal patient as opposed to the low vision patient. The significance of social aspects, criteria for change and the importance of effective communication are emphasised. The implications of the major aging diseases (stroke, Parkinson's disease and Alzheimer's disease) on the optometric examination is included.
Current trends in modern orthokeratology
Authors: Dave Trusit , Ruston David 
Published: September 2002

SummaryThe present article describes the basic concepts and principles of modern orthokeratology. Early investigators postulated a variety of theories. However, controlled clinical studies have shown these methods to be both unpredictable and also modest in their ability to correct myopia. These traditional techniques involved fitting lenses according to a `rule‐of‐thumb' and clinicians had no means of accurately evaluating corneal topography. More recently, with the significant advances in corneal topography systems and the application of reverse geometry lenses (lenses where the secondary curve steepens) certain investigators have concluded that the technique can rapidly reduce greater levels of myopia with greater predictability. The procedure involves a more scientific sagitta based fitting philosophy and predictability is defined according to corneal asphericity.
Accommodation to perceived depth in stereotests
Authors: Koh L‐H. , Charman W. N. 
Published: September 2002

SummaryThe question of whether the eye may accommodate to the stimulus provided by apparent depth in stereograms is considered theoretically in relation to the magnitudes of the disparities and viewing distances found in typical clinical stereotests. It is concluded that, for the relevant range of disparities (≤2000 arc sec), any shift in accommodation is likely to be small (≤0.15 D). An experimental study with two different clinical stereotests (Lang, TNO) confirms this prediction.
Repeatability and comparability of automated keratometry: the Nikon NRK‐8000, the Nidek KM‐800 and the Bausch and Lomb keratometer
Authors: Elliott Michelle , Simpson Trefford , Richter Doris , Fonn Desmond 
Published: September 2002

SummaryThis study assessed the repeatability of the Nikon NRK‐8000, the Nidek KM‐800 and the Bausch and Lomb keratometer. In addition, the comparability of the Nikon NRK‐8000 and the Nidek KM‐800 are evaluated relative to the Bausch and Lomb keratometer. Measurements were taken with all three techniques on two separate occasions with a test–retest separation of at least 24 hr. The right eyes of 30 normal subjects were used. Repeatability and comparability statistics and plots were generated using matrix representations of dioptric power. The Nidek KM‐800 coefficient of repeatability values were found to be 0.345, 0.187, and 0.321 in the vertical, torsional, and horizontal meridians while the Nikon NRK‐8000 values were 0.346, 0.232, and 0.276 respectively.
Variability in glaucomatous visual fields: implications for shared care schemes
Authors: Henson David B. , Spry Paul G. , Spencer Ian C. , Sparrow John M. 
Published: September 2002

SummaryThe purpose of this study was to establish the extent of variability in the visual fields of patients with glaucoma using a suprathreshold perimetric test strategy. The visual fields of 104 patients (126 eyes) were measured twice, on separate days, with a Henson CFA3000 central visual field analyser. All eyes had a diagnosis of glaucoma and had a minimum of three stimuli missed at 12 dB above their threshold estimate derived at the beginning of the first suprathreshold examination. The perimeter tested 132 locations within the central 25 degrees with a multiple stimulus suprathreshold strategy. Data were analysed on the basis of the difference in the number of recorded missed stimuli between the two visits. Large amounts of variability were found in the visual field results. Variability was largest when all levels of defect were included (>=5 dB) and was found to be independent of the overall extent of loss. Results from the superior hemifield were found to be more variable than those from the inferior hemifield. The results highlight the problem of differentiating real change in visual field status from the enhanced variability seen in patients with glaucomatous visual field loss. The results from this study can be used to establish return‐referral criteria for shared care schemes. The advantages of duplicate measures of the visual field are highlighted.
The effect of different forms of monocular occlusion on measures of central visual function
Authors: Wildsoet Christine , Wood Joanne , Maag Helene , Sabdia Safira 
Published: September 2002

SummaryThe purpose of this study was to determine whether clinically used measures of central visual function were influenced by the method of monocular occlusion used. Twenty young visually normal subjects were tested both monocularly and binocularly using an Australian Vision Chart No. 5 (which includes high and low contrast letters) and the Pelli–Robson letter chart. During monocular assessments, the non‐tested eye was occluded with either a translucent (frosted) diffuser, a +1.50 D (fogging) lens, or a white opaque occluder. A significant difference in monocular sensitivity between the three occluder types was found for Pelli–Robson contrast sensitivity, and the high and low contrast letter acuities, with poorest performance being recorded with the opaque occluder in all cases. The same trend was evident in the derived binocular summation ratios which were found to vary with the type of occluder used before the non‐tested eye, as well as with the visual function measured. The data imply that binocular interactions occur during ‘monocular’ testing of central visual function and that these interactions vary with the method of occlusion used. The clinical ramifications of these results are discussed.
Transverse chromatic aberration and colour‐defined motion
Authors: Faubert Jocelyn , Bilodeau Lynda , Simonet Pierre 
Published: September 2002

SummaryA number of recent studies have explored the role of the chromatic system in motion processes using the isoluminance paradigm. A major concern when using such methodological procedures is potential artefacts produced by chromatic aberrations. In the present study we address the problem of optically induced luminance artefacts produced by transverse chromatic aberrations (TCA), which may contaminate the results obtained in chromatic motion‐nulling experiments. Results show that different TCA levels artificially increase chromatic motion sensitivity values to varying degrees above 0.5 cpd for red/green gratings. The data also suggest the notion that naturally occurring TCA can decrease motion‐nulling thresholds for chromatic gratings at high spatial frequencies. Furthermore, our data show that the motion‐nulling paradigm for chromatic gratings may in fact be an efficient functional method for assessing the amount of TCA produced by optical factors.
Iris color and age‐related changes in lens optical density⋆
Authors: Hammond Billy R. , Nanez Jose E. , Fair Christine , Snodderly D. Max 
Published: September 2002

Summary Purpose: Epidemiologic evidence indicates that dark iris color increases risk of age‐related cataract. No information is currently available, however, on the effects of iris color on the lens prior to cataract development. In this study, we relate iris color to lens optical density (OD) in individuals without frank cataract. Methods: 90 subjects with blue or green irises (light color) were compared with 87 subjects having hazel, brown, or black irises (dark color). Lens OD was measured psychophysically by comparing scotopic thresholds obtained at 410 (measuring) and 550 nm (reference). Stimuli were presented in Maxwellian view. Results: The groups with light and with dark iris color did not differ significantly in smoking habits, dietary patterns, or age. Despite other similarities between the groups, lens OD was significantly(p<0.024) higher in the group with dark irises. The higher OD of the dark iris group was due to differences in the older subjects (>45 years,p<0.005), rather than the younger subjects (20–45 years) who showed no differences in lens OD. Conclusion: Our data indicate that iris pigmentation may be directly related to age‐associated increases in lens OD.
ASYMMETRIC CONTESTS FOR BREEDING SITES BETWEEN MONOGAMOUS PAIRS OF CONVICT CICHLIDS (ARCHOCENTRUS NIGROFASCIATUM, CICHLIDAE): PAIR EXPERIENCE PAYS
Authors: Draud Matthew , Lynch Pamela 
Published: September 2002

AbstractResearch on fighting has emphasized contests between individuals, typically males, but pairs also compete. Monogamous pairs of convict cichlids (Archocentrus nigrofasciatum) compete with other pairs for breeding sites in nature. We simulated such contests with competing pairs who differed in one or two of three possible asymmetries: body size, residency, and pair experience. In single-asymmetry experiments, larger pairs defeated smaller pairs, resident pairs defeated intruder pairs, and experienced pairs (those that had been together for 96 hours) defeated novice pairs (those that had been together for 48 hours). Thus, each of the three asymmetries was important in determining the outcome of contests. In further experiments, pairs had two contrasting asymmetries simultaneously. Larger pairs always defeated smaller pairs (15-25% difference in male standard length) even though the larger pair was inferior in one of the other asymmetries. When the two pairs were similar in size (standard length of males differed less than 6%), experienced intruder pairs defeated novice resident pairs nearly half the time. This is the first study to investigate the effects of pair experience on fighting ability. Although we predicted that experience might benefit pairs through improved coordination of their behaviour, behavioral measures such as time spent at the spawning site and pair digging behaviour showed no significant differences among groups. We posit that more experienced pairs fought harder for the breeding site because they were closer to spawning and the expected payoff for winning the breeding site was therefore higher. Finally, when both pairs were of similar size but differed in residence status and experience, there was more escalated fighting than in contests between size-disparate pairs; two possible interpretations of this result are discussed.
TOOLS AND BRAINS IN BIRDS
Authors: Lefebvre Louis , Nicolakakis Nektaria , Boire Denis 
Published: September 2002

Abstract
Tools are traditionally defined as objects that are used as an extension of the body and held directly in the hand or mouth. By these standards, a vulture breaking an egg by hitting it with a stone uses a tool, but a gull dropping an egg on a rock does not. This distinction between true and borderline (or proto-tool) cases has been criticized for its arbitrariness and anthropocentrism. We show here that relative size of the neostriatum and whole brain distinguish the true and borderline categories in birds using tools to obtain food or water. From two sources, the specialized literature on tools and an innovation data base gathered in the short note sections of 68 journals in 7 areas of the world, we collected 39 true (e.g. use of probes, hammers, sponges, scoops) and 86 borderline (e.g. bait fishing, battering and dropping on anvils, holding with wedges and skewers) cases of tool use in 104 species from 15 parvorders. True tool users have a larger mean residual brain size (regressed against body weight) than do users of borderline tools, confirming the distinction in the literature. In multiple regressions, residual brain size and residual size of the neostriatum (one of the areas in the avian telencephalon thought to be equivalent to the mammalian neocortex) are the best predictors of true tool use reports per taxon. Innovation rate is the best predictor of borderline tool use distribution. Despite the strong concentration of true tool use cases in Corvida and Passerida, independent constrasts suggest that common ancestry is not responsible for the association between tool use and size of the neostriatum and whole brain. Our results demonstrate that birds are more frequent tool users than usually thought and that the complex cognitive processes involved in tool use may have repeatedly co-evolved with large brains in several orders of birds.
Sphericity beyond Topicity in Characterizing Stereochemical Phenomena. Novel Concepts Based on Coset Representations and Their Subductions
Authors: Fujita Shinsaku 
Published: September 2002

Abstract
Fundamental concepts proposed for comprehending stereochemical phenomena are described in order to bring out a more systematized format to conventional concepts and terminologies. The concept of coset representation (CR), the symbol of which is G(/Gi), is intuitively introduced by considering the global symmetry G and the local symmetry Gi for an orbit of stereochemically equivalent objects (e.g. atoms in a molecule). The SCR (set-of-coset-representations) notation for classifying molecular symmetries is proposed to remedy the usual insufficient classification based on point groups. According to the chirality/achirality of G and Gi, the sphericity concept (homospheric, enantiospheric, and hemispheric) and the relevant concept of chirality fittingness are proposed to specify the stereochemical phenomena of the G(/Gi)-orbit. The sphericity terms are shown to be superior to the well-known topicity terms (homotopic, enantiotopic, and heterotopic; chirotopic and achirotopic) especially in comprehending complicated stereochemical phenomena. In fact, the topicity terms as well as the terms “stereogenicity and prostereogenicity” and “prochirality” can be derived subsidiarily from the sphericity terms. The concept of subduction of CRs, for which the symbol G(/Gi) ↓ Gi has been coined, is proposed to characterize the desymmetrization of molecules. Thereby, the design of high-symmetry molecules is discussed in term of desymmetrization by atom replacement and by bond replacement. In order to characterize the stereochemistry of non-rigid molecules with rotatable ligands, the concept of proligand/promolecule is proposed; here biphenyl derivatives, methane derivatives, ethane derivatives, and ferrocene derivatives are examined in terms of matched and mismatched molecules. Applications to combinatorial enumeration, symmetry adapted functions, flexible six-membered cyclic compounds, and symmetry numbers are also described.
Synthesis of Mono-Dispersed Mesoporous Silica Spheres with Hexagonal Symmetry
Authors: Yano Kazuhisa , Suzuki Noritomo , Akimoto Yuusuke , Fukushima Yoshiaki 
Published: September 2002

Abstract
Mono-dispersed mesoporous silica spheres with ordered hexagonal regularity were synthesized from tetramethoxysilane and dodecyltrimethylammonium bromide as a surfactant under very specific conditions. By adjusting the optimum concentrations of the reactants, silica particles with diverse morphology were obtained at higher initial concentrations. Dilution of the reactants led to the formation of silica spheres with various sizes and relatively less mesoporous regularity. Mono-dispersed silica spheres could not be obtained when hexadecyltrimethylammonium bromide and tetradecyltrimethylammonium bromide were used as surfactants.
Anodic Oxidation of Benzil Hydrazones in the Presence of Halide Ions
Authors: Okimoto Mitsuhiro , Takahashi Yukio 
Published: September 2002

Abstract
Benzil hydrazones were subjected to electrolytic oxidation in MeOH containing a halide ion source, such as KI and KBr. The results show that the reaction products were dependent on both the electrolytes and the substituents. In the presence of KI, benzoylphenyldiazomethanes were obtained, whereas in the presence of KBr, benzil dimethyl acetals were obtained.