bluuebunny/crossref_metadata_2025 huggingface dataset:
The Mitochondrial Genome in Embryo Technologies
Authors: Hiendleder S , Wolf E
Published: July 2003

Contents

The mammalian mitochondrial genome encodes for 37 genes which are involved in a broad range of cellular functions. The mitochondrial DNA (mtDNA) molecule is commonly assumed to be inherited through oocyte cytoplasm in a clonal manner, and apparently species‐specific mechanisms have evolved to eliminate the contribution of sperm mitochondria after natural fertilization. However, recent evidence for paternal mtDNA inheritance in embryos and offspring questions the general validity of this model, particularly in the context of assisted reproduction and embryo biotechnology. In addition to normal mt DNA haplotype variation, oocytes and spermatozoa show remarkable differences in mtDNA content and may be affected by inherited or acquired mtDNA aberrations. All these parameters have been correlated with gamete quality and reproductive success rates. Nuclear transfer (NT) technology provides experimental models for studying interactions between nuclear and mitochondrial genomes. Recent studies demonstrated (i) a significant effect of mtDNA haplotype or other maternal cytoplasmic factors on the efficiency of NT; (ii) phenotypic differences between transmitochondrial clones pointing to functionally relevant nuclear–cytoplasmic interactions; and (iii) neutral or non‐neutral selection of mtDNA haplotypes in heteroplasmic conditions. Mitochondria form a dynamic reticulum, enabling complementation of mitochondrial components and possibly mixing of different mtDNA populations in heteroplasmic individuals. Future directions of research on mtDNA in the context of reproductive biotechnology range from the elimination of adverse effects of artificial heteroplasmy, e.g. created by ooplasm transfer, to engineering of optimized constellations of nuclear and cytoplasmic genes for the production of superior livestock.
The Predictive Value of Semen Analysis in the Evaluation of Stallion Fertility
Authors: Colenbrander B , Gadella BM , Stout TAE
Published: July 2003

Contents

Pregnancy rates in managed horse populations depend on the innate fertility of the mares and stallions involved and on the quality of breeding management. Of course, because a single stallion usually mates many mares, stallion fertility is a critical factor in the overall success of a breeding program. Unfortunately, accurate evaluation of stallion fertilityper serequires a large number of normal mares to be mated and is necessarily retrospective. Rather, the ideal is to predict fertility in advance of the stallion's breeding career, and this is currently attempted by way of a thorough physical examination and a routine analysis of semen quality. However, while such a ‘breeding soundness examination’ identifies stallions that clearly lack the capacity for adequate fertility, it is of limited use for predicting the level of fertility and fails to identify some seriously sub‐fertile animals. Similarly, while various sperm function tests (e.g., sperm head morphometry, the hypoosmotic swelling test, glass wool‐sephadex filtration, progesterone receptor exposure) have been shown to correlate fairly well with fertility in the field, most examine only a single or a narrow range of the attributes that a sperm must possess if it is to fertilize an oocytein vivo, and are thus more useful for identifying specific causes of sub‐fertility than for predicting the level of fertility. On the other hand, combining the results of the various sperm function tests does improve the reliability of fertility estimation and current research is therefore concentrated on identifying a range of tests that covers as many important sperm attributes as possible but that can be performed rapidly and cheaply. In this respect, flow‐cytometry has proven to be an ideal tool because it allows the objective, rapid and simultaneous analysis of a number of properties in a large number of sperm. Moreover, stains are available for an increasing range of sperm characteristics including viability, capacitation and acrosome status, mitochondrial activity and chromatin integrity. Flow‐cytometric analysis of sperm with appropriate probes thus offers considerable promise for the prediction of stallion fertility.
Invasive meningococcal infection in Western Australia
Authors: Olesch CA , Knight GJ
Published: July 2003

Objectives: To review signs and symptoms in children diagnosed with meningococcal infection; to assess age, sex and race distribution of meningococcal infection; and to assess associations of the presenting features with morbidity and mortality.

Design: Retrospective case notes review for a 5‐year period.

Subjects: 105 patients aged between 19 days and 13 years.

Main data reviewed: Temperature, blood pressure, heart rate, respiratory rate, type of rash, age, sex, race and outcome.

Results: Of the 105 patients, 67.6% were Caucasian, 27.6% Aboriginal and 4.8% of other origin. There were 14.3% patients under 3 months of age (2.9% neonates), 48.6% between 3 months and 2 years, 21% between 2 and 4 years and 16.2% older than 4 years. The male:female ratio was 1.4. Features at presentation in decreasing order of frequency were: fever (89.5%), tachypnoea (73.3%), rash (59% [maculopapular 17.1%, petechial 27.6% and purpuric 14.3%]), vomiting (52.4%), irritability (44.8%), tachycardia (37.5%), lethargy (36.2%), neck stiffness (32.4%) and non‐specific immediately preceding illness (15.2%). Purpura and a reduced systolic blood pressure were significantly associated with an increased risk of mortality, purpura and reduced diastolic blood pressure with an increased risk of morbidity. Initial misdiagnosis occurred in 17.1% of cases, with the majority of those misdiagnosed (83.3%) aged less than 2 years. Predominant serotyping was Group B followed by Group C. Major findings were a marked male preponderance in patients under 3 months of age. The incidence of meningococcal infection in the Aboriginal population was approximately six times that in the non‐Aboriginal population. The yearly incidence of meningococcal disease during the study period ranged from 5.2 to 10.5 per 100.000. Long‐term morbidity occurred in 8.6% of cases and mortality was 8.6%. Higher morbidity and mortality figures were found in those with septicaemia alone. Children referred from peripheral hospitals had a higher mortality but a comparable morbidity.
Meeting the needs of medical students training in paediatrics and child health
Authors: Forsyth K , Rotem A
Published: July 2003

Abstract: The way education is delivered is changing, and the type of clinical experience in paediatrics available to medical students is changing. Accordingly, the academic departments of Paediatrics and Child Health in Australia and New Zealand are revising both the content and methods of delivery of training in Paediatrics and Child Health. The educational change paradigm and the nature of the changes in training proposed are summarized.
Should we now hold back from initially prescribing antibiotics for acute otitis media?
Authors: Mar CB DEL , Glasziou PP
Published: July 2003

Abstract: The research literature provides surprisingly little evidence of benefit for initially treating acute otitis media in children with antibiotics. We show how to calculate the amount of benefit and harm from the evidence, and how this might be applied to change management practice.
Haemophagocytic lymphohistiocytosis in children
Authors: Hallahan AR , Carpenter PA , O’Gorman‐Hughes DW , Vowels MR , Marshall GM
Published: July 2003

Objective: To evaluate the clinical and diagnostic features of children presenting with haemophagocytic lymphohistiocytosis (HLH), evolution of the disease and outcomes in response to treatment.

Methodology: The medical records of 12 children, aged 5 weeks to 13 years at diagnosis, with HLH managed at a single institution were reviewed.

Results: Presenting features were fever, hepatosplenomegaly, pancytopenia and hypertriglyceridemia or hypofibrinogenemia. Nine patients (75%) developed central nervous system (CNS) disease. Only one child with CNS disease survived. Five children had complete responses to therapy (42%), but all relapsed at a median of 1.5 months after starting treatment (range 2 weeks to 5 months). Two of the children treated are long‐term survivors (17%), both after allogeneic bone marrow transplantation. All deaths occurred in the context of active disease.

Conclusions: Haemophagocytic lymphohistiocytosis is a disease with a poor prognosis. Central nervous system complications are common and response to treatment usually is transient. This study provides support for the use of immuno‐ modulatory therapy for remission introduction followed by consideration of allogeneic bone marrow transplantation.
Five‐year incidence of age‐related maculopathyin relation to iris, skin or hair colour, and skin sun sensitivity:the Blue Mountains Eye Study
Authors: Wang JieJin , Jakobsen Kirsten , Smith Wayne , Mitchell Paul
Published: July 2003

This study aimed to assess longitudinal associations between iris, hair and skin colour, plus skin sensitivity to sun and the 5‐year incidence of age‐related maculopathy (ARM). Of 3654 baseline Blue Mountains Eye Study participants (aged 49+ years), 2335 survivors (75.1%) were re‐examined after 5 years. Retinal photographs were graded using the Wisconsin ARM Grading System and incident ARM lesions confirmed using side‐by‐side grading. Iris/skin/hair colour was assessed and skin sensitivity questions were asked at baseline. After adjusting for age, sex and smoking, no significant associations were found between iris or hair colour and incident late or early ARM. Compared to persons with fair skin, those with very fair skin had an increased risk of developing geographical atrophy (odds ratio [OR] 3.5,95% confidence interval [CI] 1.2−10.4). However, persons with sun‐related skin damage were less likely than those without to develop indistinct soft drusen (OR 0.6, 95% CI0.4−0.9). Longitudinal data provide no support for the previously reported cross‐sectional association between iris colour and ARM.
Patterns of glaucomatous visual field defects in an older population: the Blue Mountains Eye Study
Authors: Lee Anne J , Wang Jie Jin , Rochtchina Elena , Healey Paul , Chia Ee‐Munn , Mitchell Paul
Published: July 2003

This report aims to describe the frequency of different patterns of visual field loss in open‐angle glaucoma (OAG). The Blue Mountains Eye Study examined 3654 persons (aged 49+) during 1992−1994. Humphrey supra‐threshold visual fields were performed in 88.9%. Those classified as glaucoma suspects had 30−2 full‐threshold fields (9.2%). Of OAG cases (n = 108) with field tests in both eyes (n = 97), unilateral defects were present in 49 (50.5%) and bilateral in 48 (49.5%). Advanced field loss was found in 16 (15.4%) subjects and in 22 (10.9%) eyes, with bilateral loss present in 6 (6.2%) cases. Of all eyes of OAG cases (n = 201), 49 (24.4%) had no defects, 52 (25.9%) upper, 61 (30.3%) lower, and 17 (8.5%) had combined upper and lower loss. Of the upper and lower cases (n = 113), the types of defects included nasal step (36), arcuate (26), nasal plus arcuate (26), and hemispherical defects (25). Of subjects with fields in at least one eye (n = 104), there was a similar proportion in the worse eye of upper defects (28.8%), lower (31.7%), and combined upper and lower (24.0%). Undiagnosed OAG was more frequent in unilateral (65.3%) than bilateral (34.7%) cases (P = 0.003). This study reports the pattern of typical glaucomatous field loss in an older Australian population.
Computer‐assisted retinal vessel measurement in an older population: correlation between right and left eyes
Authors: Leung Harry , Wang Jie Jin , Rochtchina Elena , Tan Ava G , Wong Tien Y , Hubbard Larry D , Klein Ronald , Mitchell Paul
Published: July 2003

This study assessed the correlation between computer‐assisted retinal vessel measurements of right and left eyes, from subjects in a defined, community‐based older population. Retinal photographs from participants in the Blue Mountains Eye Study were digitized. All retinal arterioles and venules located 0.5−1.0 disc diameters from the optic disc margin were identified and a computer program measured their diameters. Pearson correlation (R2) statistic was used to assess the correlation in a random subsample of 1546 images. Substantial correlation between right and left eye measurements was found for summary indices of retinal arterioles (R2 = 0.70) and venules (R2 = 0.77). Higher correlation was found for intragrader (R2 0.75−079) than for intergrader assessment (R2 0.67−0.72). Moderate correlation was found in arteriole‐to‐venule ratio assessed by the same (R2 = 0.57) or different (R2 = 0.52) graders. Measurements from one eye can thus adequately represent the retinal vessel diameters of a person.
Correlation between generalized and focal retinal arteriolar narrowing in an older population
Authors: Tan AvaG , Wang JieJin , Rochtchina Elena , Klein Ronald , Wong Tien Y , Hubbard LarryD , Mitchell Paul
Published: July 2003

This study aimed to assess the associations between generalized and focal retinal arteriolar narrowing in the Blue Mountains Eye Study population (n = 3654 personsaged 49+ years). Summarized estimates of the average retinal arteriolar diameter, the central retinal arteriolar equivalent (CRAE) and arteriole‐to‐venule ratio were obtained from right eye photographs of each participant using a computer‐assisted method. Focal retinal arteriolar narrowing was graded from retinal photographs of both eyes using a ‘light‐box’ method. The proportion of subjects with focal arteriolar narrowing increased as CRAE decreased from the widest (2.2%) to the narrowest (7.8%) quintile (P for trend = 0.001). A receiver operating characteristic curve was constructed using CRAE to detect focal arteriolar narrowing. With the diagnostic cut point set at the 4th decile of CRAE, the sensitivity and specificity in detecting focal arteriolar narrowing were 64% and 61%,respectively. These data suggest a moderate correlation between generalized (CRAE) and focal arteriolar narrowing. However, no significant association was found between arteriole‐to‐venule ratio and focal arteriolar narrowing.
Research contributions in ophthalmology: Australia's productivity
Authors: Davis Mari , Wilson Concepción S
Published: July 2003

Background: In 2000, the Australian and New Zealand Journal of Ophthalmology (ANZJO) changed title to Clinical and Experimental Ophthalmology. At this time, a review of Australia's contributions to the literature over the previous 21 years appears timely. Bibliometric indicators are used extensively to assess research performance as they offer views of a field that might not otherwise be apparent. The aim of this study was to explore publication output data to construct a picture of ophthalmology that may be of benefit to researchers and ophthalmologists.

Methods: Science Citation Index and Social Sciences Citation Index databases were used to collate data on ophthal­mology research literature from 1980 to 2000. Subsequent analysis particularly focused on Australia's contribution to this literature, including publication frequency vis‐à‐vis the world, collaboration, and the journals in which Australian researchers frequently publish. These data were also compared with other countries of similar scientific stature or language.

Results: Since 1980, Australia has ranked in the top 10 nations contributing to world ophthalmology research. Its contribution was close to world average in the 1980s, but increasing numbers of researchers and papers show Australia exceeding the world average during the 1990s. Most ophthalmology research collaboration by Australians is within Australia. Although fewer in number, collaborative papers with overseas researchers include 28 other countries. Data on the journals in which Australians publish show that Australian researchers continue to exhibit a preference for publication in their own regional journals.

Conclusions: This paper, one of a series on the literature of the vision sciences, provides some initial benchmarks on Australia's standing and contribution to the field of ophthalmology research.
Age‐dependent variations in the drusen fluorescence on indocyanine green angiography
Authors: Chang Andrew A , Guyer David R , Orlock Dennis R , Yannuzzi Lawrence A
Published: July 2003

Purpose: To examine the fluorescence patterns of macular drusen using indocyanine green (ICG) angiography in human subjects of different ages.

Methods: A total of 180 eyes in 100 consecutive patients aged 34−90 years with macula drusen were evaluated with ICG angiography using the Topcon 1024 ImageNet system. Eyes were divided into two groups depending on age. The older group (subjects over the age of 55 years) comprised 170 eyes. The younger group (subjects 55 years or younger) comprised 10 eyes. The fluorescence patterns of the drusen were graded as hyper­fluorescent (brighter than the background fluorescence), hypofluorescent (darker than the background fluorescence) or isofluorescent (unable to be distinguished from the background fluorescence). The ICG angiogram appearances were correlated with the clinical types of drusen in differing age groups.

Results: An age‐dependent difference in the fluorescence pattern of drusen was observed. Drusen in the older group were hypofluorescent or isofluorescent (169/170 eyes). In contrast, drusen in the younger group (55 years or younger) were hyperfluorescent (10/10 eyes).

Conclusions: This study defines the distinct age‐dependent differences in the ICG fluorescence pattern of drusen. This heterogeneity might be due to differential binding of extravasated ICG to the constituents and histological site of the drusen deposits. Furthermore, ICG angiography is able to differentiate drusen types not possible by clinical and fluorescein angiographic evaluation.
Clinical outcomes following laser photocoagulation treatment for diabetic retinopathy at a large Australian ophthalmic hospital
Authors: Yi Qing , Bamroongsuk Parapun , McCarty Daniel J , Mukesh Bickol N , Harper C Alex
Published: July 2003

Objective: To evaluate clinical outcomes of diabetic retinopathy laser treatment at a large Australian ophthalmic hospital.

Methods: A retrospective medical record review of all patients who had initial laser treatment for diabetic retinopathy at the Royal Victorian Eye and Ear Hospital from January 1997 to December 1998.

Results: The study included 322 eyes from 203 patients. The mean age was 65.8 years (range 18−89) and the mean follow up was 18 months (range 2−33). Focal photocoagulation treatment alone was performed in 238 eyes. Clinically significant macular oedema (CSME) resolved in 218 (91.6%) eyes. Vision was improved or maintained in 137 (57.6%) eyes. Moderate visual loss occurred in 49 (20.6%) eyes. Panretinal photocoagulation (PRP) was performed in 84 eyes, including 37 eyes with PRP alone and 47 eyes with PRP and focal together. Neovascularization regressed in 55 (65.5%) eyes. Vision was improved or maintained in 52 (61.9%) eyes. Moderate visual loss was observed in 20 (23.8%) eyes and severe visual loss was observed in 4 (4.8%) eyes.

Conclusions: The clinical outcomes reported here are similar to those reported in other studies.
Visual loss in sarcoid‐related uveitis
Authors: Lobo Aires , Barton Keith , Minassian Darwin , Du Bois Roland M , Lightman Susan
Published: July 2003

Purpose: To assess the visual acuity outcome after treatment, in patients with differing types of uveitis associated with sarcoidosis, and to determine the types of sight‐threatening complications.

Methods: This was an retrospective, non‐comparative, interventional study of patients who had uveitis with a confirmed diagnosis of sarcoidosis and a minimum follow‐up duration of 6 months from presentation. The worst affected eye at presentation was selected for the study. Complications causing impaired vision were documented, changes in visual acuity after completion of treatment were measured, and the risk of ‘poor outcome’ (visual acuity 6/12 and less) was compared in the various types of uveitis, using ‘exact’ multiple logistic regression to control confounding by other prognostic factors.

Results: Seventy‐five patients were studied. The spectrum of ocular inflammation in sarcoidosis is wide. Presentation may be acute and non‐granulomatous or chronic and granulomatous with posterior segment involvement being varied. Poor visual outcome was significantly more frequent in multifocal choroiditis (5/7, 71.4%), and in panuveitis without multifocal choroiditis (13/28, 46.4%), compared to only 3/24 (12.5%) patients with anterior uveitis. The excess risks remained significant after adjustment for confounding effects of other prognostic factors including age, sex and manifest systemic sarcoidosis. Causes of visual loss were cataract, glaucoma, macular oedema, vitreous haemorrhage and retinal detachment.

Conclusion: Multifocal choroiditis is a less common manifestation of uveitis associated with sarcoidosis but appears to be associated with a worse visual prognosis despite immunosuppressive therapy.
Measurement of indirect costs for people with vision impairment
Authors: Chou Shiao‐Lan , Misajon RoseAnne , Gallo Jayne , Keeffe Jill E
Published: July 2003

From a societal perspective, chronic eye diseases can affect not only the person who has vision impairment but also the economics of that society. To obtain comprehensive medical and non‐medical expenditures for people with impaired vision, direct and indirect costs should be collected. Indirect costs are usually not included in cost evaluation in health economics due to the difficulty of the data collection and analysis. Questionnaires and cost diaries have been developed in this study to estimate total resource use, expenses, and lost production from the participants or their caregivers due to the participants’ vision loss. Pilot testing was conducted to verify the format, clarity of instructions, relevance of content and completeness of the questionnaires and diary. Modifications were then made to the format from feedback from the participants. Diaries using large print, audio and Braille facilitate data collection for people with impaired vision.
Comparison of the Retinomax autorefractor with hand‐held retinoscopy in 1‐year‐old infants
Authors: Gole Glen A , Schluter Philip J , Hall Julie , Colville Deborah
Published: July 2003

This study aimed to determine the accuracy (and usability) of the Retinomax, a hand‐held autorefractor, compared to measurements taken from hand‐held retinoscopy (HHR) in a sample of normal 1‐year‐old children. The study was a method comparison set at four Community Child Health Clinics. Infants (n = 2079) of approximately 1 year of age were identified from birth/immunization records and their caregivers were contacted by mail. A total of 327 infants ranging in age from 46 weeks to 81 weeks (mean 61 weeks) participated in the study. The children underwent a full ophthalmic examination. Under cycloplegia, refraction was measured in each eye by streak retinoscopy (HHR) and then re‐measured using the Retinomax autorefractor. Sphere, cylinder, axis of cylinder and spherical equivalent measurements were recorded for HHR and Retinomax instruments, and compared. Across the range of refractive errors measured, there was generally close agreement between the two examination methods, although the Retinomax consistently read around 0.3 D less hyperopic than HHR. Significantly more girls (72 infants, 47.7%), struggled during examination with the Retinomax than boys (52 infants, 29.5%) (P < 0.001). Agreement deteriorated between the two instruments if the patient struggled during the examination (P < 0.001). In general, the Retinomax would appear to be a useful screening instrument in early childhood. However, patient cooperation affects the accuracy of results and is an important con­sideration in determining whether this screening instrument should be adopted for measuring refractive errors in early infancy.
Effect of pupil size on multifocal pattern visual evoked potentials
Authors: Martins Alessandra , Balachandran Chandra , Klistorner Alexander I , Graham Stuart L , Billson Francis A
Published: July 2003

The purpose of this study was to investigate the influence of pupil diameter on the amplitude and latency of multifocal visual evoked potentials (mfVEP). The multifocal objective perimeter (Accumap; Objectivision) was used to stimulate the visual field at 56 sites extending to 32° using a pseudo­random pattern stimulus. The mfVEP were recorded using bipolar occipital electrodes, 7 min/eye. Ten normal subjects were recruited from the community and one eye was randomly selected for testing. The mfVEP were recorded at four different pupil diameters (2 mm, 4 mm, 6 mm, 8 mm), obtained by applying tropicamide (0.5%) or pilocarpine (2%) in different dilutions. Appropriate refractive correction was provided to overcome cycloplegia and achieve a visual acuity of 6/7.5 or better. Analysis revealed that at most pupil diameters the normalized full field amplitude did not show significant variation, except at the most miotic pupil diameter (2 mm), where the amplitude became reduced, based on 2‐way anova and Tukey's T method. There was, however, significant correlation between latency and pupil area (correlation coefficient: upper field −0.63, lower field −0.76). The results suggest that even in the presence of mydriatics or miotics, the mfVEP test can be used to assess diseases that affect amplitude, provided near correction is used. The interpretation of latency, however, must be made with caution, as a borderline conduction defect with a dilated pupil may appear normal.
Transendothelial electrical resistanceof bovine retinal capillary endothelial cells is influenced by cell growth patterns: an ultrastructural study
Authors: Tretiach Marina , Van Driel Diana , Gillies Mark C
Published: July 2003

The purpose of this study was to describe the ultrastructural features of an in vitro capillary endothelial cell model of blood−retinal barrier permeability and to relate morphological features with transendothelial electrical resistance. The electrical resistance of endothelial cell monocultures on small and large pore size polycarbonate Transwell filters was measured and compared with cocultures of endothelial cells and Müller cells. There was a wide variation in electrical resistance measurements with many preparations not achieving a functional barrier. The ultrastructural features associated with barrier function in vitro were studied by comparing cultures that exhibited a ‘tight’ or ‘leaky’ barrier when measured immediately prior to processing for electron microscopy. Preparations with low transendothelial electrical resistance were associated with irregular cell growth when studied morphologically. It was concluded that parallel light and electron microscopic studies are important for validation of in vitro models of vascular endothelial permeability.
Assessing binocular cooperation with patchwork stimuli
Authors: Freeman Alan W , Wong Elaine MY
Published: July 2003

This study investigated binocular cooperation with patchwork stimuli,which were constructed by cutting a picture into patches, presenting some patches to one eye and presenting the remaining patches to the fellow eye. Reconstruction of the original picture requires subjects to combine information from the two eyes, and therefore tests the quality of their binocular cooperation. The strength of cooperation was measured by presenting closed contours in patchwork form, and asking adult human subjects to discriminate between distorted and undistorted contours. Both normal and strabismic subjects were tested. The strabismic subjects required a distortion amplitude fivefold that of the normal subjects to achieve the same level of discrimination. Further, the binocular performance of the strabismic subjects was largely determined by their performance when using only the non‐strabismic eye. These results suggest that patchwork stimuli may be useful in clinical tests for binocular cooperation.
Attitudes to research and research training among ophthalmologists and ophthalmology trainees in New Zealand
Authors: Jayasundera Thiran , Fisk Michael , McGhee Charles NJ
Published: July 2003

Purpose: To determine the attitudes to research and research training among ophthalmologists and ophthalmology trainees in New Zealand.

Methods: A structured, self‐administered questionnaire was devised and after preliminary validation a postal survey was sent to all ophthalmologists and ophthalmology registrars and fellows in New Zealand.

Results: A total of 82 replies were received from 115 questionnaires sent out; a response rate of 71.3%. An overwhelming majority found research to have benefited their education, clinical practice and career; 67.1% of the respondents intended to do research in the future. Although a majority (56.4%) felt research to be beneficial to ophthalmology training, 42.3% felt research would be of limited or no benefit when selecting candidates for vocational training. However, 97.5% of respondents felt that ophthalmology trainees should undertake some form of research during training, with most supporting small studies or case reports (44.4%) or a short structured training course in research (42.0%). Interestingly, 86.6% felt that research methodology and data analysis should be taught in a structured fashion with most supporting courses or seminars of a few weeks duration during the vocational training period. Many ophthalmologists felt inadequately equipped or trained to mentor and supervise trainees undertaking research and 41.5% of consultant ophthalmologists felt further training to fulfil this role would be beneficial.

Conclusions: This survey suggests that New Zealand ophthalmologists generally approve of and support a place for research, possibly of a more structured design, during ophthalmology training.
Effect of species richness and relative abundance on the shape of the species accumulation curve
Authors: Thompson Graham G. , Withers Philip C.
Published: July 2003

Abstract  We explain how species accumulation curves are influenced by species richness (total number of species), relative abundance and diversity using computer‐generated simulations. Species richness defines the boundary of the horizontal asymptote value for a species accumulation curve, and the shape of the curve is influenced by both relative abundance and diversity. Simulations with a high proportion of rare species and a few abundant species have a species accumulation curve with a low ‘shoulder’ (inflection point on the ordinate axis) and a long upward slope to the asymptote. Simulations with a high proportion of relatively abundant species have a steeply rising initial slope to the species accumulation curve and plateau early. Diversity (as measured by Simpson's and Shannon–Weaver indices) for simulations is positively correlated with the initial slope of the species accumulation curve. Species accumulation curves cross when one simulation has a high proportion of both rare and abundant species compared with another that has a more even distribution of abundance among species.
Assessing biodiversity with species accumulation curves; inventories of small reptiles by pit‐trapping in Western Australia
Authors: Thompson Graham G. , Withers Philip C. , Pianka Eric R. , Thompson Scott A.
Published: July 2003

Abstract  We examined 11 non‐linear regression models to determine which of them best fitted curvilinear species accumulation curves based on pit‐trapping data for reptiles in a range of heterogeneous and homogenous sites in mesic, semi‐arid and arid regions of Western Australia. A well‐defined plateau in a species accumulation curve is required for any of the models accurately to estimate species richness. Two different measures of effort (pit‐trapping days and number of individuals caught) were used to determine if the measure of effort influenced the choice of the best model(s). We used species accumulation curves to predict species richness, determined the trapping effort required to catch a nominated percentage (e.g. 95%) of the predicted number of species in an area, and examined the relationship between species accumulation curves with diversity and rarity. Species richness, diversity and the proportion of rare species in a community influenced the shape of species accumulation curves. The Beta‐P model provided the best overall fit (highest r2) for heterogeneous and homogeneous sites. For heterogeneous sites, Hill, Rational, Clench, Exponential and Weibull models were the next best. For homogeneous habitats, Hill, Weibull and Chapman–Richards were the next best models. There was very little difference between Beta‐P and Hill models in fitting the data to accumulation curves, although the Hill model generally over‐estimated species richness. Most models worked equally well for both measures of trapping effort. Because the number of individuals caught was influenced by both pit‐trapping effort and the abundance of individuals, both measures of effort must be considered if species accumulation curves are to be used as a planning tool. Trapping effort to catch a nominated percentage of the total predicted species in homogeneous and heterogeneous habitats varied among sites, but even for only 75% of the predicted number of species it was generally much higher than the typical effort currently being used for terrestrial vertebrate fauna surveys in Australia. It was not possible to provide a general indication of the effort required to predict species richness for a site, or to capture a nominated proportion of species at a site, because species accumulation curves are heavily influenced by the characteristics of particular sites.
Burning issues for conservation: A critique of faunal fire research in Southern Africa
Authors: Parr Catherine L. , Chown Steven L.
Published: July 2003

Abstract  Fire is a key ecological process in several biomes worldwide. Although many conservation agencies have the protection of biodiversity as at least one of their major goals, information on the effects of fire on fauna in these biomes is fragmentary. Here we provide an overview of the published research undertaken to date on the effects of fire on fauna using examples from Southern Africa. We found that few studies have examined the effects of fire on amphibians or reptiles, and work on invertebrates is likewise sparse. The majority of studies that have been published are observational reports, and few experimental studies have been undertaken using an experimental fire regime, or over appropriately long time intervals. Replication was often not reported and where this was done, it was generally inadequate. The majority of the studies failed to report the area over which the studies were undertaken and sampling unit size was often not reported. Despite the importance of fire duration, ignition method, season and time of day of fire, few studies investigated these variables. We conclude that at present the information on the effects of fire on fauna in Southern Africa is fragmentary and, consequently, informed management decisions regarding the consequences of burning policies on the conservation of biodiversity both within and outside protected areas are problematic. We recommend that future studies, both in Southern Africa and elsewhere, be based on a suite of large‐scale and experimental approaches (the latter firmly grounded in the principles of sound experimental design), use non‐classical statistics to explore the effects of large‐scale or unreplicated fires, and where possible include baseline information such as that gathered in fragmentation experiments.
Habitat and sex specific differences in the dioecious weed Acetosella vulgaris (Polygonaceae)
Authors: Pickering Catherine Marina , Kirkwood Andrew , Arthur J. Michael
Published: July 2003

Abstract  Patterns of resource allocation, numbers of reproductive structures and sex ratios of flowering populations of the dioecious weed Acetosella vulgaris (Fourr.) were examined in the Kosciuszko alpine region of Australia. Specifically, the sex‐specific response of ramets was compared between a disturbed alpine habitat, in which weeds such as A. vulgaris are common (disturbed roadside/path‐edge), and a native alpine habitat in which weeds appear to have a limited capacity to germinate, grow and reproduce (undisturbed tall alpine herbfield). The disturbed habitat was generally more favourable for growth of A. vulgaris. Ramets of both sexes had greater total and vegetative biomass than ramets in native habitats. Although reproductive biomass was also greater in disturbed habitats, females had less reproductive biomass than males, which was not as predicted. Reproductive effort was not affected by habitat or gender. The disturbed habitat also favoured increased numbers of inflorescences per ramet and flowers per ramet, as expected. Whereas the gender of the ramet also influenced numbers of reproductive structures, again, this was not as predicted. Females had more flowers per ramet and more flowers per inflorescence than males. This may be because of factors associated with wind pollination. Females were taller in native habitats but there was no difference between the sexes in disturbed habitats. Sex ratios varied from all male populations to nearly all female populations among the 25 sites sampled irrespective of habitat. Factors such as time since last disturbance may have contributed to variation in the sex ratios of alpine populations of A. vulgaris in Australia.
Species richness–environment relationships within coastal sclerophyll and mesophyll vegetation in Ku‐ring‐gai Chase National Park, New South Wales, Australia
Authors: Le Brocque Andrew F. , Buckney Rodney T.
Published: July 2003

Abstract  Patterns in species richness from a wide range of plant communities in Ku‐ring‐gai Chase National Park, New South Wales, Australia, were examined in relation to a number of environmental variables, including soil physical and chemical characteristics. Total species richness and richness of three growth‐form types (trees, shrubs and ground cover) were determined in duplicate 500‐m2 quadrats from 50 sites on two geological substrata: Hawkesbury Sandstone and Narrabeen shales and sandstones. Generalized linear models (GLM) were used to determine the amount of variation in species richness that could be significantly explained by the measured environmental variables. Seventy‐three per cent of the variation in total species richness was explained by a combination of soil physical and chemical variables and site attributes. The environmental variables explained 24% of the variation in tree species richness, 67% of the variation in shrub species richness and 62% of the variation in ground cover species richness. These results generally support the hypothesis of an environmental influence on patterns in total species richness and richness of shrubs and ground cover species. However, tree species richness was not adequately predicted by any of the measured environmental variables; the present environment exerts little influence on the richness of this growth‐form type. Historical factors, such as fire or climatic/environmental conditions at time of germination or seedling establishment, may be important in determining patterns in tree species richness at the local scale.
Dynamics of North Patagonian rainforests from fine‐resolution pollen, charcoal and tree‐ring analysis, Chonos Archipelago, Southern Chile
Authors: Szeicz Julian M. , Haberle Simon G. , Bennett Keith D.
Published: July 2003

Abstract  Fine‐resolution palaeoecological and dendrochronological methods were used to investigate the impacts of climate change, and natural and anthropogenic disturbances on vegetation in the North Patagonian rainforest of southern Chile at decadal to century timescales during the late Holocene. A lake sediment mud–water interface core was collected from the northern Chonos Archipelago and analysed for pollen and charcoal. Dendrochronological analysis of tree cores collected from stands of Pilgerodendron uviferum close to the lake site was incorporated into the study. The combined analysis showed that the present mosaic of vegetation types in this region is a function of environmental changes across a range of timescales: millennial climate change, more recent natural and anthropogenic disturbances, and possibly short‐term climatic variations. Of particular interest is the spatiotemporal distribution of Pilgerodendron uviferum dieback/burning in the Chonos Archipelago region.
Responses of ants to disturbance in Australia, with particular reference to functional groups
Authors: Hoffmann Benjamin D. , Andersen Alan N.
Published: July 2003

Abstract  Ants are widely used as bioindicators in environmental assessment in Australia, partly because the responses of ant communities to disturbance are relatively well understood. In particular, the use of functional groups has provided a predictive framework for analysing ant community responses to disturbance in the absence of reliable information on the responses of individual species. Here we review 45 studies of the responses of Australian ant communities to disturbance, in order to: (i) identify individual species or species‐groups that respond consistently to disturbance; and (ii) examine the usefulness of the functional group scheme as a framework for predicting ant community responses under different disturbance regimes in different biogeographical regions. The most common forms of disturbance in our studies were fire (17 studies), mining (12; mostly studies of minesite restoration) and grazing (7), with other disturbances including clearing, logging, flooding, recreation, urbanization and farming. Responses of individual species were inevitably variable because of differences in vegetation type, severity of disturbance and time since disturbance. However, we identified a range of widespread species that showed predictable responses, including species of the metallica group of Rhytidoponera in temperate Australia (‘increasers’ in relation to disturbance), species of the terebrans and denticulatus groups of Camponotus (increasers), the aeneovirens group of Melophorus (increasers) from the arid zone, and Iridomyrmex pallidus (increaser) from the monsoonal region. The functional group scheme assessed here was not designed specifically in the context of disturbance, but nevertheless in some situations provides a useful framework for analysing ant community responses. Three distinct syndromes of functional group responses can be recognized. First, Dominant Dolichoderinae and Hot Climate Specialists are groups that prefer open environments, and tend to be favoured by low levels of disturbance in well‐forested habitats. Second, Opportunists and often also Generalized Myrmicinae are broadly adapted taxa with wide habitat tolerances, but are particularly sensitive to competitive interactions such that their responses oppose those of Dominant Dolichoderinae. Finally, Cryptic Species and Specialist Predators have highly specialized requirements that make them especially sensitive to disturbance. Functional groups are of most use in situations where disturbance causes substantial change in habitat structure, particularly in the ground‐layer. Functional groups are of least use in very open habitats, where disturbance merely increases what is already extensive bare ground, and has relatively little impact on microclimate. The ant functional group scheme can play an important role in assessing disturbance in mesic Australia, but may be of more limited use for this in the arid zone.
Two stage growth of microdiamond in UHP dolomite marble from Kokchetav Massif, Kazakhstan
Authors: Ishida H. , Ogasawara Y. , Ohsumi K. , Saito A.
Published: July 2003

The abundance and morphology of microdiamond in dolomite marble from Kumdy‐kol in the Kokchetav Massif, are unusual; a previous study estimated the maximum content of diamonds in dolomite marble to be about 2700 carat ton−1. Microdiamond is included primarily in garnet, and occasionally in diopside and phlogopite pseudomorphs after garnet. They are classified into three types on the basis of their morphology: (1) S‐type: star‐shaped diamond consisting of translucent cores and transparent subhedral to euhedral very fine‐grained outer parts; (2) R‐type: translucent crystals with rugged surfaces; and (3) T‐type: transparent, very fine‐grained crystals. The S‐type is the most abundant.

Micro‐Laue diffraction using a 1.6‐µm X‐ray beam‐size demonstrated that the cores of the star‐shaped microdiamond represent single crystals. In contrast, the most fine‐grained outer parts usually have different orientations compared to the core. Laser–Raman studies indicate that the FWHM (Full Width at Half Maximum) of the Raman band of the core of the S‐type diamond is slightly larger than that for the outer parts. Differences in morphology, crystal orientations, and in the FWHM of the Raman band between the core and the fine‐grained outer‐parts of S‐type microdiamond suggest that the star‐shaped microdiamond was formed discontinuously in two distinct stages.
‘Forbidden zone’ subduction of sediments to 150 km depth— the reaction of dolomite to magnesite + aragonite in the UHPM metapelites from western Tianshan, China
Authors: Zhang L. , Ellis D. J. , Arculus R. J. , Jiang W. , Wei C.
Published: July 2003

The solid‐state reaction magnesite (MgCO3) + calcite (aragonite) (CaCO3) = dolomite (CaMg(CO3)2) has been identified in metapelites from western Tianshan, China. Petrological studies show that two metamorphic stages are recorded in the metapelites: (1) the peak mineral assemblage of magnesite and calcite pseudomorphs after aragonite which is only preserved as inclusions within dolomite; and (2) the retrograde glaucophane‐chloritoid facies mineral assemblage of glaucophane, chloritoid, dolomite, garnet, paragonite, chlorite and quartz. The peak metamorphic temperatures and pressures are calculated to be 560–600 °C, 4.95–5.07 GPa based on the calcite–dolomite geothermometer and the equilibrium calculation of the reaction dolomite = magnesite + aragonite, respectively. These give direct evidence in UHP metamorphic rocks from Tianshan, China, that carbonate sediments were subducted to greater than 150 km depth. This UHP metamorphism represents a geotherm lower than any previously estimated for subduction metamorphism (< 3.7 °C km−1) and is within what was previously considered a ‘forbidden’ condition within Earth. In terms of the carbon cycle, this demonstrates that carbonate sediments can be subducted to at least 150 km depth without releasing significant CO2 to the overlying mantle wedge.
Basement‐Cover Sequences within the UHP unit of the Dabie Shan
Authors: Schmid R. , Romer R. L. , Franz L. , Oberhänsli R. , Martinotti G.
Published: July 2003

Field data define two lithologically distinct basement‐cover sequences within the ultrahigh‐pressure metamorphic (UHPM) unit of the Dabie Shan, eastern China. One of the cover units, the Changpu unit, comprises calc‐arenitic metasediments in stratigraphic contact with a basement consisting of gneisses of the Yangtze craton. The second cover unit, the Ganghe unit, consists of felsic‐intermediate metavolcanics and clastic metasediments. Basement exposure of the Ganghe unit is not known. Fold axes in the Ganghe unit are oblique to those of the Changpu unit, which are parallel to those of the Yangtze gneisses. Preservation of primary textures in some volcanic rocks, and tectonic separation from the Yangtze gneisses by a greenschist facies mylonite, support an interpretation of the Ganghe unit as a low‐strain domain. Protolith associations in the Ganghe and Changpu units are compatible with deposition in a rift setting and along a passive continental margin, respectively. A U–Pb single zircon age of 761 ± 33 Ma for volcanoclastic rocks of the Ganghe unit demonstrates a Neoproterozoic deposition age, concordant with inferred rifting at that time. Eclogite facies parageneses in the gneisses and both cover units, along with P–T data demonstrate regional UHPM in the Dabie Shan.