bluuebunny/crossref_metadata_2025 huggingface dataset:
Silicon‐mediated resistance of sugarcane to Eldana saccharina Walker (Lepidoptera: Pyralidae): effects of silicon source and cultivar
Authors: Keeping M. G. , Meyer J. H.
Published: August 2006

Abstract:  The effects of four silicon sources – a USA calcium silicate, a local (South African) calcium silicate, Slagment® and fly ash – on the resistance of sugarcane cultivars (two resistant and two susceptible) to Eldana saccharina Walker (Lepidoptera: Pyralidae) were studied in a potted sugarcane trial. Silicon sources were applied at 5000 or 10 000 kg/ha for the calcium silicates and Slagment; fly ash was applied at 15 000 or 30 000 kg/ha. The greatest increase in plant silicon content (particularly in stalks) was recorded for plants treated with local calcium silicate. Silicon uptake did not vary significantly between the susceptible and resistant cultivars, although the resistant cultivars had inherently higher silicon content than the susceptible ones. Treatment with silicon significantly reduced borer damage and borer performance at the higher treatment level. In general, borer damage and performance decreased with increasing rates of applied silicon and both variables were inversely related with per cent stalk silicon. On average, the higher silicon rate reduced damage by 34% in the susceptible cultivars and by 26% in the resistant cultivars, supporting the argument that susceptible cultivars benefit more from silicon treatments than resistant ones. We propose that calcium silicate amendments could be employed in the integrated, area‐wide management of E. saccharina and in the management of soil acidity, both of which are widespread problems in the South African sugar industry.
Interspecific hybridization between introduced and indigenous green lacewings (Neurop., Chrysopidae: Chrysoperla) at different adult densities
Authors: Naka H. , Haruyama N. , Ito K. , Mitsunaga T. , Nomura M. , Mochizuki A.
Published: August 2006

Abstract  We investigated laboratory hybridization in different‐capacity cages between the indigenous Chrysoperla nipponensis and its close relative, Chrysoperla carnea, which has been recently introduced from Germany to Japan. Fertility varied depending on the combination of cross and cage capacity, and was decreased by reduced adult density in all crosses. Conspecific crosses showed significantly higher fertility than interspecific crosses. Interspecific crosses, especially C. nipponensis females × C. carnea males, showed low fertility at all adult densities. There will be few losses of identity of the indigenous C. nipponensis via interspecific hybridization with the introduced C. carnea, even if C. carnea were to become established in the wild.
Importance of long‐term research in classical biological control: an analytical review of a release against the cabbage seedpod weevil in North America
Authors: Gillespie D. R. , Mason P. G. , Dosdall L. M. , Bouchard P. , Gibson G. A. P.
Published: August 2006

Abstract: Cabbage seedpod weevil,Ceutorhynchus obstrictus(Marsham) (Col., Curculionidae), is an invasive alien pest that is spreading in North America. To aid with planning for introductions of European parasitoids in North America, we examined the status of the only classical biological control release against this pest in North America, which in 1949 introducedMesopolobus morys,Stenomalina gracilisandTrichomalus perfectus(Hym., Pteromalidae). Weevils and parasitoids were reared in 2005 from mass collections of seedpods ofBrassica napus,Brassica rapaandRaphanus raphanistrum(Brassicaceae) from 18 sites in the Fraser Valley, near Vancouver, British Columbia, Canada. Of the three European parasitoid species that were originally released, onlyS. graciliswas found. The predominant hymenopterous parasitoid species wereTrichomalus lucidus,S. gracilis,Mesopolobus moryoides(Pteromalidae),Necremnus tidius(Eulophidae) andEupelmus vesicularis(Eupelmidae). These constituted over 97% of the parasitoids reared, although overall parasitism was low. OnlyM. moryoidesis clearly North American in distribution; other thanS. gracilis, the remaining species were either accidentally introduced or are Holarctic in distribution. Based on these results, re‐releases ofM. morysandT. perfectusin North America should be considered as part of a classical biological control programme. However, redistribution ofS. gracilisis not recommended at present because of potential conflicts with biological control programmes against weeds. Ongoing re‐examination of classical biological control programmes can further our understanding of failure of release programmes, particularly when re‐examination can be made in the light of improved taxonomy and systematics of the target and agent species.
Diamondback moth resistance to Bacillus thuringiensis transgenic canola: evaluation of refugia size with non‐recessive resistant insects
Authors: Cerda H. , Sayyed A. H. , Wright D. J.
Published: August 2006

Abstract:  Current recommendations to delay the evolution of resistance to Bacillus thuringiensis crops are that a minimum of 5–50% of a crop‐growing region should include non‐B. thuringiensis varieties as refuges. These recommendations are based in part on the assumption that resistance will be inherited as a recessive trait. Laboratory microcosm experiments are described with transgenic canola expressing Cry1Ac and a non‐recessive Cry1Ac resistant population of the diamondback moth Plutella xylostella, in which the effect of different sizes of refugia (0%, 20% and 50%) on resistance was compared over five generations. The LC50 values for Cry1Ac increased markedly in the P. xylostella sub‐populations with 0% (>100‐fold) and 20% refugia (>35‐fold) but showed little change (less than fivefold increase) with 50% refugia. The results support the idea that relatively high levels of refugia (non‐B. thuringiensis varieties) may be required where resistance is not functionally recessive at the level of toxin expressed in the B. thuringiensis crop.
Leaf litter nitrogen concentration as related to climatic factors in Eurasian forests
Authors: Liu Chunjiang , Berg Björn , Kutsch Werner , Westman Carl J. , Ilvesniemi Hannu , Shen Xiaohui , Shen Guangrong , Chen Xiaobin
Published: August 2006

Aim  The aim of this study is to determine the patterns of nitrogen (N) concentrations in leaf litter of forest trees as functions of climatic factors, annual average temperature (Temp, °C) and annual precipitation (Precip, dm) and of forest type (coniferous vs. broadleaf, deciduous vs. evergreen, Pinus, etc.).

Location  The review was conducted using data from studies across the Eurasian continent.

Methods  Leaf litter N concentration was compiled from 204 sets of published data (81 sets from coniferous and 123 from broadleaf forests in Eurasia). We explored the relationships between leaf litter N concentration and Temp and Precip by means of regression analysis. Leaf litter data from N2‐fixing species were excluded from the analysis.

Results  Over the Eurasian continent, leaf litter N concentration increased with increasing Temp and Precip within functional groups such as conifers, broadleaf, deciduous, evergreen and the genus Pinus. There were highly significant linear relationships between ln(N) and Temp and Precip (P < 0.001) for all available data combined, as well as for coniferous trees, broadleaf trees, deciduous trees, evergreen trees and Pinus separately. With both Temp and Precip as independent variables in multiple regression equations, the adjusted coefficient of determination () was evidently higher than in simple regressions with either Temp or Precip as independent variable. Standardized regression coefficients showed that Temp had a larger impact than Precip on litter N concentration for all groups except evergreens. The impact of temperature was particularly strong for Pinus.

Conclusions  The relationship between leaf litter N concentration and temperature and precipitation can be well described with simple or multiple linear regression equations for forests over Eurasia. In the context of global warming, these regression equations are useful for a better understanding and modelling of the effects of geographical and climatic factors on leaf litter N at a regional and continental scale.
COPYRIGHT AND ARTISTS: A VIEW FROM CULTURAL ECONOMICS
Authors: Towse Ruth
Published: August 2006

Abstract Most of the standard economic literature on copyright ignores a number of aspects that have considerable significance for cultural production and for artists, the primary creators of copyright works, the supply of which copyright is supposed to stimulate. Specifically, there is little mention in that literature of moral rights, no distinction is made between copyright for authors and neighbouring rights for performers, the distributional effects of copyright are barely referred to, and the question of how much artists earn from copyright is ignored. In this article, I survey work that relates copyright and cultural economics showing that cultural economics offers another view to the ‘standard’ economics of copyright. Moreover, the case for government intervention in the arts and heritage made by cultural economists has resonance for the economic rationale of copyright.
HOW TO BEST ENSURE REMUNERATION FOR CREATORS IN THE MARKET FOR MUSIC? COPYRIGHT AND ITS ALTERNATIVES
Authors: Liebowitz Stan J. , Watt Richard
Published: August 2006

Abstract The focus of this essay is to examine the market for copyrighted works with a particular emphasis on the sound recording market. This market is currently in a state of flux, some would say disarray, due to the ability of the Internet to lower transmission costs for both authorized and unauthorized copies, with the latter being, at this time, far more prevalent. In this essay we discuss the intent of copyright, the role of copying and file‐sharing, and some alternative production/consumption schemes meant to strengthen or to replace copyright.
BEYOND THE HYPE: INTELLECTUAL PROPERTY AND THE KNOWLEDGE SOCIETY/KNOWLEDGE ECONOMY
Authors: Carlaw Kenneth , Oxley Les , Walker Paul , Thorns David , Nuth Michael
Published: August 2006

AbstractThis paper explores the debates surrounding whether or not we have now moved into a new knowledge economy and/or knowledge society and if so whether this shift is as significant and as far reaching as the industrial revolution. In this possible transformation the place of information communications technologies has been crucial. Debate has occurred across both economics and sociology with differing emphases as is shown in the ranges of definitions that we review in the paper. One consistent factor is the lack of clarity and consistency between them both within and across the disciplines. In order to explore the issues that the debates raises in a more grounded way, the paper explores them in relation to intellectual property (IP) and the intellectual commons in the process of innovation, growth and economic development. The paper is developed through an analysis first of the industrial revolution and the role within this of uncertainty, technologies, complementarities and elective affinities and the way IP was protected and controlled through patents, secrecy, being first to the market and copyright. The second part of the paper examines definitions of the knowledge economy and society and the role within these of information communication technologies in order to explore whether the ways that IP is protected and controlled have changed. In the debate about the ‘knowledge economy and society’ the role of innovation via human capital with a greater reliance on intellectual capabilities has been emphasized. The role of IP thus remains central but is now challenged by the rise of new forms of communication, which make its protection harder and move much of the concern with respect to regulation to a global rather than national and local level.
HOW DOES COUNTRY RISK AFFECT INNOVATION? AN APPLICATION TO FOREIGN PATENTS REGISTERED IN THE USA
Authors: Hoti Suhejla , McAleer Michael
Published: August 2006

Abstract Innovation can occur at the national level under a wide range of settings. However, the leading innovative countries internationally have several common traits, including economic, financial and political stability, which are reflected in various measures of country risk. The purpose of the paper is to examine, for the first time, the relationship between the economic, financial and political country risk ratings, on the one hand, and innovation, as measured by a country's registered patents, on the other. The relationships between various monthly country risk ratings and registered patents are analyzed for the leading 12 foreign patenting countries in the USA from 1975 to 1997. The empirical results show that economic, financial and political risk ratings have a considerable impact on the innovative activities of the 12 countries. Total US patent applications are also influential in inducing innovation in the 12 countries. Such issues have not previously been addressed in the literature on country risk and innovation.
INTELLECTUAL PROPERTY LITIGATION ACTIVITY IN THE USA
Authors: Hoti Suhejla , McAleer Michael , Slottje Daniel
Published: August 2006

Abstract Brand names or trademarks carry incredible economic power and prestige. There is increasing recognition by world bodies that intellectual property (IP), whether manifested in patents, trademarks, copyrights or trade secrets, is highly valuable and must be protected through robust IP enforcement. The USA is an interesting natural laboratory as patent, trademark and copyright litigation battles have been raging domestically for some time. The paper discusses the four main forms of IP assets, the legal remedies that are available to enforce the property rights inherent in each type of IP asset, the basic damages theory relating to each form of IP, and how damages may be calculated when each type of asset is presumed to be infringed. The increased recognition of the value of IP has led to stronger enforcement of IP protection, an increase in IP litigation, and growing policy actions that are focused on how that protection should be manifested. An empirical analysis of how the IP litigation activity in the USA has changed over time is also presented.
Combination of vinblastine and bleomycin as first line therapy in advanced classic Kaposi's sarcoma
Authors: Brambilla L , Miedico A , Ferrucci S , Romanelli A , Brambati M , Vinci M , Tedeschi L , Boneschi V
Published: August 2006

Background  Classic KS (CKS) mainly affects elderly people, has an irregular course, and is relatively benign for years. However, sometimes the disease may progress rapidly and spread to internal organs, thus necessitating systemic chemotherapy. We therefore decided to carry out a prospective trial using vinblastine and bleomycin, which are active, easy to administer and control, and low cost.

Methods  We treated 29 patients affected by CKS with vinblastine i.v., up to 10 mg in combination with bleomycin i.m., 15 IU every 3 weeks. We administered a median of seven cycles of therapy.

Results  All the 29 enrolled patients were evaluated: 21% reached a complete response and 76% had an intermediate response. Toxicity was limited. The maximal response was attained in a median of 5 months, with a mean duration of 4 months.

Conclusion  The combination of vinblastine and bleomycin achieved a high rate of objective responses in a subgroup of elderly and symptomatic patients, without considerable toxicity. We recommend the combination as first line chemotherapy for advanced CKS.
Treatment of inflammatory dermatoses by tumour necrosis factor antagonists
Authors: Jacobi A , Mahler V , Schuler G , Hertl M
Published: August 2006

Background The treatment of inflammatory skin diseases is at present often empirical as causal therapeutic approaches, based on an incomplete knowledge of the immune pathogenesis, are mostly unavailable. The currently applied treatments can in fact lead to remission of the disease; however, under certain circumstances undesirable side‐effects must be expected. On the basis of experience gained in cytokine modulation therapy of chronic inflammatory diseases such as rheumatoid arthritis and psoriasis, the application of TNF‐α inhibitors represents a novel, more specific, and effective therapeutic option for distinct chronic inflammatory diseases.

Patients and methods The current status of the therapeutic effect of TNF‐α blockers is discussed based on our own observations and a review of the current literature. Also discussed are potential undesirable side‐effects and possible contraindications of this therapy.

Results and conclusions Based on recent findings, the use of TNF‐α blockers seems to be promising in the treatment of therapy‐resistant inflammatory dermatoses. At present, guidelines for indications and contraindications of anti‐TNF‐α treatment of inflammatory skin disorders are rare. Such guidelines are necessary to improve the efficacy of anticytokine treatment and the reduction of side‐effects.
Extracorporeal photochemotherapy in patients with cutaneous T‐cell lymphoma: is clinical response predictable?
Authors: Rao V , Ryggen K , Aarhaug M , Dai HY , Jørstad S , Moen T
Published: August 2006

Background  Extracorporeal photochemotherapy (ECP) has been accepted as a standard therapy in cutaneous T‐cell lymphomas (CTCL), a category of lymphomas mainly resistant to conventional therapies. Approximately one half of patients demonstrate a reduction in skin affliction by at least 50% within 12 months of therapy and are categorized as responders to ECP. Predictive criteria for selecting patients who will respond to ECP are lacking. Such criteria would however, be of great benefit.

Objectives  This study compared T‐cell clonality and serum levels of soluble interleukin‐2 receptor (sIL‐2R), lactate dehydrogenase (LD), neopterin, beta2‐microglobulin (β2‐M) and granzyme B in CTCL patients in order to evaluate their potential usefulness as predictive markers.

Patients/methods  Serum and T lymphocytes obtained from 16 patients with CTCL receiving ECP treatment were evaluated in an open retrospective study.

Results  We found no evident correlation between detected T‐cell clonality and response to ECP. The non‐responding group had on average a higher level of serum sIL‐2R. This difference was significant after 6 and 12 months of therapy, but not pretreatment. An individual reduction in serum sIL‐2R, neopterin and β2‐M during a 6‐month course of ECP was well correlated to clinical remission.

Conclusions  Seven out of 16 patients were classified as responders. Neither T‐cell clonality nor any of the serum markers assessed pretreatment could reliably predict the response to ECP treatment. However, the individual relative changes in sIL‐2R, neopterin and β2‐M during 6 months of ECP treatment coherently displayed correlation to the clinical response, as assessed after 12 months of ECP treatment.
Algorithmic reproduction of asymmetry and border cut‐off parameters according to the ABCD rule for dermoscopy
Authors: Pellacani G , Grana C , Seidenari S
Published: August 2006

Backgroud  Semiquantitative algorithms were applied to dermoscopic images to improve the clinical diagnosis for melanoma.

Objective  The aim of the study was to develop a computerized method for automated quantification of the ‘A’ (asymmetry) and ‘B’ (border cut‐off) parameters, according to the ABCD rule for dermoscopy, thus reproducing human evaluation.

Methods  Three hundred and thirty‐one melanocytic lesion images, referring to 113 melanomas and 218 melanocytic nevi, acquired by means of a digital videodermatoscope, were considered. Images were evaluated by two experienced observers and by using computer algorithms developed by us. Clinical evaluation of asymmetry was performed by attributing scores to shape asymmetry and asymmetry of pigment distribution and structures, whereas computer evaluation of shape and pigment distribution asymmetries were based on the assessment of differences in area and lightness in the two halves of the image, respectively. Borders were evaluated both by clinicians and by the computer, by attributing a score to each border segment ending abruptly. Differences between nevus and melanoma values were evaluated using the chi‐square test, while Cohen's Kappa index for agreement was employed for the evaluation of the concordance between human and computer.

Results  Pigment distribution asymmetry appears the most striking parameter for melanoma diagnosis both for human and for automated diagnosis. A good concordance between clinicians and computer evaluation was achieved for all asymmetry parameters, and was excellent for border cut‐off evaluation.

Conclusions  These algorithms enable a good reproduction of the ‘A’ and ‘B’ parameters of the ABCD rule for dermoscopy, and appear useful for diagnostic and learning purposes.
How much fruit do fruit‐eating frogs eat? An investigation on the diet of Xenohyla truncata (Lissamphibia: Anura: Hylidae)
Authors: Da Silva H. R. , De Britto‐Pereira M. C.
Published: August 2006

This paper presents the results of a 22‐month survey and the examination of the intestinal content of 356 specimens of Xenohyla truncata (Anura: Hylidae) from Restinga de Maricá, Rio de Janeiro, Brazil. Our results confirm prior observations that fruits are intrinsic to the diet of these frogs. In addition, these new data increase our understanding of the relationship between frogs and the plants they feed upon. Plant consumption follows availability of fruits in the area, indicating that the diversity of fruits consumed by the frogs does not represent choice, but rather plant phenology and fruit availability.
Screening for Meares–Irlen sensitivity in adults: can assessment methods predict changes in reading speed?
Authors: Hollis Jarrod , Allen Peter M.
Published: August 2006

Two methods of assessing candidates for coloured overlays were compared with the aim of determining which method had the most practical utility. A total of 58 adults were assessed as potential candidates for coloured overlays, using two methods; a questionnaire, which identified self‐reported previous symptoms, and a measure of perceptual distortions immediately prior to testing. Participants were classified as normal, Meares–Irlen sensitive, and borderline sensitive. Reading speed was measured with and without coloured overlays, using the Wilkins Rate of Reading Test and the change in speed was calculated. Participants classified as normal did not show any significant benefit from reading with an overlay. In contrast, a significant reading advantage was found for the borderline and Meares–Irlen participants. Current symptom rating was found to be a significant predictor of the change in reading speed, however the previous symptom rating was not found to be a reliable predictor. These data indicate that the assessment of perceptual distortions immediately prior to measuring colour preference and reading speed is the most meaningful method of assessing pattern glare and determining the utility of coloured overlays.
Comparison of logMAR ETDRS chart and a new computerised staircased procedure for assessment of the visual acuity of children
Authors: Stewart Catherine E. , Hussey Alex , Davies Nigel , Moseley Merrick J.
Published: August 2006

The validity and repeatability of visual acuity measures are particularly important in the detection and monitoring of childhood visual anomalies such as amblyopia. The repeatability and sensitivity of a new computerised visual acuity test, ‘Staircased Procedure’ is compared with the now gold standard visual acuity test, the early treatment of diabetic retinopathy study (ETDRS). Twenty‐seven visually normal children (mean age: 6.7 ± 1.1 years) and 27 children with amblyopia (mean age: 6.1 ± 0.7 years) were tested with the ETDRS and Staircased Procedure. A retest was administered 4–5 weeks later and 30 min later for the visually normal and the amblyopic children, respectively. The staircased procedure produced significantly better visual acuity than the ETDRS for visually normal and amblyopic children. Repeatability was similar for both tests (ETDRS: 0.11 log units; staircased procedure: 0.13 log units). In conclusion, the Staircased Procedure was an acceptable test with high repeatability and validity.
The effect of font and line width on reading speed in people with mild to moderate vision loss
Authors: Rubin Gary S. , Feely Mary , Perera Sylvie , Ekstrom Katherin , Williamson Elizabeth
Published: August 2006

Purpose:  The aim of this study was to evaluate the effects of print size, typeface, and line width on reading speed in readers with mild to moderate sight problems.

Methods:  A total of 43 patients, most of whom had mild cataract or glaucoma with acuity 6/30 or better (median age = 72; range = 24–88 years), read aloud a selection of texts presented randomly in four sizes (10, 12, 14 and 16 point), for each of four typefaces [Foundry Form Sans (FFS), Helvetica (HV), Tiresias PCfont (TPC), Times New Roman (TNR)] at a standard line width of 70 characters and a viewing distance of 40 cm. A subset of letter sizes and typefaces were tested at two additional line widths (35, 90).

Results:  As expected, reading speed increased with print size from a median of 144 words min−1 for 10‐point text to 163 words min−1 for 16‐point text (repeated measures anova, p < 0.0001). There was also a significant effect of typeface with TPC being read about 8 words min−1 faster, on average, than the other fonts (159 words min−1 for TPC vs 151 words min−1 for the other fonts, p < 0.0001). However fonts of the same nominal point size were not equivalent in actual size. When adjusted for the actual horizontal and vertical space occupied, the advantage of TPC was eliminated. There was no effect of line width (p > 0.3). Data from the present study were extrapolated to the general population over age 65. This extrapolation indicated that increasing minimum print size from 10 points to 16 points would increase the proportion of the population able to read fluently (>85 words min−1) from 88.0% to 94.4%.

Conclusion:  This study shows that line width and typeface have little influence on reading speed in people with mild to moderate sight problems. Increasing the minimum recommended print size from 10 points to 14 or 16 points would significantly increase the proportion of the population able to read fluently.
End‐box scoring artefact evaluation of the Farnsworth‐Munsell 100‐Hue colour vision test
Authors: Viliūnas V. , Lukauskienė R. , Švegžda A. , Žukauskas A.
Published: August 2006

The scoring artefact in the Farnsworth‐Munsell 100‐Hue test, arising from the grouping of the caps into four boxes, was investigated. The traditional method of scoring performed with the numbers of the anchor caps disregarded and the alternative scoring performed with the numbers of the anchor caps employed, were compared. For the traditional method of scoring, we revealed an increase of the error score of the outside (end‐box) caps when the total error score was above 240. On the contrary for scoring performed with the numbers of the anchor caps employed, the difference between the error score of the outside caps and the average error per cap is not significant. To mitigate the end‐box artefact and to improve the reliability of the Farnsworth‐Munsell 100‐Hue test, corrections to the traditional method of scoring are proposed.
Is colposcopy needed following laser ablation for dysplasia?
Authors: JIN Li , TAN Jeffrey , THOMPSON Derrick , NEESHAM Deborah , QUINN Michael
Published: August 2006

Aims:  To evaluate the effectiveness of cytology and colposcopy in the follow up of women treated by laser CO2 ablation for cervical intraepithelial neoplasia (CIN).

Methods:  A retrospective analysis of 1784 patients with CIN treated with laser CO2 ablation from 1998 to 2003 at the Royal Women's Hospital, Melbourne. Data were collected prospectively in a computerised colposcopy database utilised in the Dysplasia Unit.

Results:  There was equal distribution in the study population treated for low‐grade intraepithelial neoplasia (LSIL) and high‐grade intraepithelial neoplasia (HSIL), with no significant age difference in both groups (mean 27.6 years). The success rate of treatment of LSIL (94%) was similar to that of HSIL (92%). Fifty‐seven per cent of all failures occurred within the first year of treatment. Colposcopy was more sensitive in detecting intraepithelial neoplasia (SIL) than cytology, whereas cytology was more specific. No case of cancer was diagnosed on follow up.

Conclusions:  CO2 laser ablation was equally effective in treating different grades of CIN. There is a continuing incidence of recurrent CIN, even up to five years after initial treatment, which suggests that it is necessary for patients to adhere to long‐term follow up. The combination of cytology and colposcopic assessment is essential for surveillance of SIL in the initial two years after treatment.
What do obstetricians think about media influences on their patients?
Authors: HANDFIELD Bronny , TURNBULL Sue , BELL Robin J.
Published: August 2006

Background:  Patients are playing an increasingly active role in decision‐making about their care and are becoming increasingly informed about their health. Traditionally, sources of information about pregnancy and birth were family and friends and, in more recent times, antenatal classes. Evidence suggests that the media, particularly the Internet, is an increasingly influential source of information about illness and health.

Aims:  The aim of this study was to survey Australian Fellows of the Royal Australian and New Zealand College of Obstetricians and Gynaecologists (RANZCOG) about their perceptions of sources of patient information about pregnancy and birth, particularly the media and the Internet.

Methods:  A two‐page survey with a reply paid envelope was sent to all Australian Fellows of RANZCOG. Most questions only allowed a selection of prespecified categorical options. Some questions allowed open‐ended replies that were assessed using thematic analysis.

Results:  RANZCOG fellows thought that family and friends were the most important source of information for patients about pregnancy and birth followed by formal antenatal education, although they ranked the influence of the Internet above that of free‐to‐air television. Responses suggested that women in both the public and the private sectors were accessing the Internet.

Conclusions:  Fellows felt that their patients are actively involved in decisions about their care during pregnancy and birth and that the media influences their knowledge and attitudes. The Internet appears to have an increasingly important role in providing women with information. Obstetricians need to be aware of what their patients are accessing on the Internet.
Extremely skewed X‐chromosome inactivation patterns in women with recurrent spontaneous abortion
Authors: BAGISLAR Sevgi , USTUNER Isik , CENGIZ Bora , SOYLEMEZ Feride , AKYERLI Cemaliye Boylu , CEYLANER Serdar , CEYLANER Gulay , ACAR Aynur , OZCELIK Tayfun
Published: August 2006

Background:  The role of extremely skewed X‐chromosome inactivation (XCI) has been questioned in the pathogenesis of recurrent spontaneous abortion (RSA) but the results obtained were conflicting.

Aims:  We therefore investigated the XCI patterns in peripheral blood DNA obtained from 80 patients who had RSA and 160 age‐matched controls.

Methods:  Pregnancy history, age, karyotype, and disease information was collected from all subjects. The methylation status of a highly polymorphic cytosine‐adenine‐guanine repeat in the androgen‐receptor (AR) gene was determined by use of methylation‐sensitive restriction enzyme HpaII and polymerase chain reaction.

Results:  Skewed XCI (> 85% skewing) was observed in 13 of the 62 patients informative for the AR polymorphism (20.9%), and eight of the 124 informative controls (6.4%) (P = 0.0069; χ2 test). More importantly, extremely skewed XCI, defined as > 90% inactivation of one allele, was present in 11 (17.7%) patients, and in only two controls (P = 0.0002; χ2 test).

Conclusions:  These results support the interpretation that disturbances in XCI mosaicism may be involved in the pathogenesis of RSA.
Customised birthweight: Coefficients for an Australian population and validation of the model
Authors: PAIN Scott , CHANG Allan M. Z. , FLENADY Vicki , CHAN Fung Y.
Published: August 2006

Background:  Published birthweight references in Australia do not fully take into account constitutional factors that influence birthweight and therefore may not provide an accurate reference to identify the infant with abnormal growth. Furthermore, studies in other regions that have derived adjusted (customised) birthweight references have applied untested assumptions in the statistical modelling.

Aims:  To validate the customised birthweight model and to produce a reference set of coefficients for estimating a customised birthweight that may be useful for maternity care in Australia and for future research.

Methods:  De‐identified data were extracted from the clinical database for all births at the Mater Mother's Hospital, Brisbane, Australia, between January 1997 and June 2005. Births with missing data for the variables under study were excluded. In addition the following were excluded: multiple pregnancies, births less than 37 completed week's gestation, stillbirths, and major congenital abnormalities. Multivariate analysis was undertaken. A double cross‐validation procedure was used to validate the model.

Results:  The study of 42 206 births demonstrated that, for statistical purposes, birthweight is normally distributed. Coefficients for the derivation of customised birthweight in an Australian population were developed and the statistical model is demonstrably robust.

Conclusions:  This study provides empirical data as to the robustness of the model to determine customised birthweight. Further research is required to define where normal physiology ends and pathology begins, and which segments of the population should be included in the construction of a customised birthweight standard.
Intrapartum analgesia and its association with post‐partum back pain and headache in nulliparous women
Authors: ORLIKOWSKI Christopher E. P. , DICKINSON Jan E. , PAECH Michael J. , McDONALD Susan J. , NATHAN Elizabeth
Published: August 2006

Background:  The effect of intrapartum analgesia on post‐partum maternal back and neck pain, headache and migraine, is uncertain.

Aims:  To determine if nulliparous women having epidural analgesia during labour have a similar incidence of the above‐mentioned post‐partum symptoms compared with women managed using other forms of pain relief.

Methods:  Secondary analysis of cohort data from a randomised trial in which nulliparous women intending to deliver vaginally were randomised to either epidural analgesia (EPI) or continuous midwifery support (CMS) at admission for delivery. Because of high cross‐over rates, groups were initially defined by the randomised treatment allocation and the actual treatment received (CMS–CMS n = 185, EPI–CMS n = 117, EPI–EPI n = 376 and CMS–EPI n = 314). Univariate analysis showed no difference between groups, so final analysis was based on the actual treatment received.

Results:  Six hundred and ninety women received epidural analgesia (EPIDURAL) and 302 received other methods of pain relief including CMS. Back pain was common before, during and after pregnancy, and risk factors for post‐partum back pain at six months were back pain prior to pregnancy or at two months post‐partum. Epidural analgesia, mode of delivery, spontaneous or induced labour, birthweight and back pain during pregnancy had no significant relationship with post‐partum back pain at six months. Headache was significantly more common in the EPIDURAL group during pregnancy and at two months post‐partum, but not at six months. Migraine was not associated with intrapartum analgesia.

Conclusions:  This analysis supports previous research suggesting that epidural analgesia is not a significant risk factor for persisting post‐partum back pain, headache or migraine.
The association between intratwin birthweight discordance and preterm birth in twin pregnancy
Authors: WEN Shi Wu , TAN Hongzhuan , WALKER Mark
Published: August 2006

Background:  Previous studies found that increased birthweight discordance among twins was associated with increased risk of perinatal mortality and morbidity, but there is disagreement regarding the relationship between birthweight discordance and the risk of preterm birth.

Aims:  To examine the relationship between intratwin birthweight discordance and preterm birth, and the influence of total birthweight as a confounding factor.

Methods:  We conducted a historical cohort study to assess the relationship between intratwin birthweight discordance and preterm birth, using the 1995–1997 twin registry data of the USA. Parallel analyses with and without adjustment for total birthweight were performed.

Results:  A total of 147 262 eligible twin sets were included in the analysis. In the non‐stratified analysis, preterm birth (< 37 weeks) rates were 64.3 and 51.8%, respectively, in subjects with a birthweight discordance > 25% and in those ≤ 25%. In the analysis stratified by total birthweight, the rates of preterm birth were higher in subjects with a birthweight discordance > 25% than in those ≤ 25% at every total birthweight stratum. Changing the thresholds to define preterm birth or treating gestational age as a continuously distributed variable yielded similar results. Using other methods to adjust for total birthweight also reversed the direction of this relationship.

Conclusions:  Increased intratwin birthweight discordance is associated with increased risk of preterm birth, and adjustment for total birthweight biases the relationship to the wrong direction. Clinicians should be aware of the possibility of a preterm birth when there are signs of discordance in birthweight between the two twins.
Pregnancy outcome in women presenting with pre‐eclampsia at less than 25 weeks gestation
Authors: BUDDEN Astrid , WILKINSON Lucille , BUKSH Mariam Jan , McCOWAN Lesley
Published: August 2006

Objective:  We aimed to (i) assess maternal and perinatal outcomes in pre‐eclampsia at < 250 weeks; and (ii) determine if any antenatal factors were associated with adverse maternal and perinatal outcomes.

Design:  A retrospective study.

Setting:  Tertiary referral hospital, Auckland, New Zealand.

Methods:  Data were extracted from the clinical record and hospital database. The study population involved women admitted with pre‐eclampsia at < 250 weeks, with a live singleton pregnancy, from 1997 to 2004 and managed expectantly.

Outcome measures:  Maternal morbidity, perinatal death, neurodevelopmental outcome at 18 months, small for gestational age assessed by population and customised birthweight centiles.

Results:  Gestation at admission was the only antenatal variable associated with adverse perinatal outcome. Of 14 women admitted < 23 weeks, no babies survived, but eight (62%) babies of women admitted in the 24th week (240−246) survived. Neurodevelopmental outcome was assessed in eight of nine survivors; two (25%) had moderate and two (25%) had minor disability. All babies in this cohort had birthweights < 5th customised centile. Only one baby (10%) weighing < 500 g survived.

Conclusion:  Maternal morbidity was high in this expectantly managed cohort. As no babies survived when pre‐eclampsia occurred before 23 weeks, induction of labour should be considered. In the 24th week two‐thirds of babies survived and 25% had moderate handicap. This information may help clinicians and women in the future to make informed choices about management.
The quality and size of yolk sac in early pregnancy loss
Authors: CHO Fu‐Nan , CHEN San‐Nung , TAI Ming‐Hong , YANG Tsung‐Lung
Published: August 2006

Background:  Accurate differentiation between normal pregnancy and pregnancy loss in early gestation remains a clinical challenge.

Aims:  To determine whether ultrasound findings of yolk sac size and morphology are valuable in relation to pregnancy loss at six to ten weeks gestation.

Methods:  Transvaginal ultrasonography was performed in 111 normal singleton pregnancies, 25 anembryonic gestations, and 18 missed abortions. Mean diameters of gestational sac and yolk sac were measured. The relationship between yolk sacs and gestational sacs in normal pregnancies was depicted. The yolk sacs ultrasound findings in cases of pregnancy loss were recorded.

Results:  In normal pregnancies with embryonic heartbeats, a deformed or an absent yolk sac was never detected. Sequential appearance of yolk sac, embryonic heartbeats and amniotic membrane was essential for normal pregnancy. The largest yolk sac in viable pregnancies was 8.1 mm. Findings in anembryonic gestations included an absent yolk sac, an irregular‐shaped yolk sac and a relatively large yolk sac (> 95% upper confidence limits, in 11 cases). In cases of missed abortion with prior existing embryonic heartbeats, abnormal findings included a relatively large, a progressively regressing, a relatively small, and a deformed yolk sac (an irregular‐shaped yolk sac, an echogenic spot, or a band).

Conclusion:  A very large yolk sac may exist in normal pregnancy. When embryonic heartbeats exist, the poor quality and early regression of a yolk sac are more specific than the large size of a yolk sac in predicting pregnancy loss. When an embryo is undetectable, a relatively large yolk sac, even of normal shape, may be an indicator of miscarriage.
Postnatal home visiting for illicit drug‐using mothers and their infants: A randomised controlled trial
Authors: BARTU Anne , SHARP Jennifer , LUDLOW Joanne , DOHERTY Dorota A.
Published: August 2006

Background:  Postnatal home‐visiting programs for illicit drug‐using mothers have reported some success in reducing harms in some areas but there is a lack of data on their impact on breastfeeding and immunisation rates.

Aims:  To investigate the effect on breastfeeding, immunisation and parental drug use. The hypothesis was that the outcomes of the home‐visiting group (HVG) would be superior to the control group (CG).

Method:  One hundred and fifty‐two illicit drug‐using women were recruited at 35–40 weeks gestation from King Edward Memorial Hospital, Perth, Western Australia and randomised after delivery to the HVG or the CG. The HVG had eight home visits; the CG had telephone contact at two months and a home visit at six months. The HVG received education and support for parenting, breastfeeding and child development. This was not provided by the research midwives for the CG.

Results:  The main drugs were heroin, amphetamines, cannabis and benzodiazepines. Immunisation rates were similar for each group. Median duration of breastfeeding for the HVG was eight weeks (95% CI, 3.8–12.2); for the CG ten weeks (95% CI, 7.3–12.7). Drug use was reduced during pregnancy but increased by six months post‐partum in both groups. The retention rates were: HVG 93%; CG 86%.

Conclusion:  The hypothesis for this study was not supported. Long‐term studies are urgently required to assess the effects of parental drug use on infant and child development.
Regional variations in prenatal screening across Australia: Stepping towards a national policy framework
Authors: O’LEARY Peter , BREHENY Nikki , REID Gabrielle , CHARLES Taryn , EMERY Jon
Published: August 2006

Background:  A relatively few centres across Australia provide screening tests for maternal serum markers or ultrasound measurement of fetal nuchal translucency to assess risk of fetal anomalies such as Down syndrome. While providers engage in external accreditation and quality assurance programs, state and federal governments have been slow to formulate relevant policies and standards.

Aim:  In this paper we review the current practices across Australian states and territories and propose recommendations for developing a national policy framework.

Methods:  Data on the number and types of screening tests provided as well as state policies, where they are available, were obtained from government reports and supplemented by a mail survey to selected stakeholders in each state or territory.

Results:  At a jurisdictional level, our results highlight the need to integrate the collection and monitoring of antenatal population‐screening programs to assess clinical effectiveness and program performance (detection and screen‐positive rates, uptake of diagnostic tests as a result of screening). Women's expectations and satisfaction with the information they are provided should be evaluated and used to adjust education resources. At a local level, collaboration between providers of the separate tests, both public and private, would enable the ascertainment of outcomes of integrated screening programs. To complete the cycle, these data should inform decisions to improve antenatal screening programs at a national level.

Conclusions:  A primary goal at a national level would be to develop a consensus on key performance indicators for programs that clarify best practice guidelines and establish optimal performance and accreditation standards.
The impact of fetal fibronectin testing for women with symptoms of preterm labour in routine clinical practice within a New Zealand population
Authors: GROOM Katie. M. , LIU Emily. , ALLENBY Keith.
Published: August 2006

Aims:  To perform a comparative analysis of antenatal management received according to the results of cervico‐vaginal fetal fibronectin (fFN) testing, and to review preterm delivery rates and fFN predictive values within a New Zealand population of women presenting with threatened preterm labour.

Methods:  Case note review of all fFN tests performed at Middlemore Hospital, South Auckland from August 2003 to March 2005 (n = 199). Data collected included risk factors for preterm delivery, signs and symptoms at presentation, antenatal management received after fFN test and outcome and delivery details. Positive and negative fFN results were compared.

Results:  Women with a positive fFN were more likely to receive antenatal corticosteroids (96.4 vs 4.7% RR 8.74 (95% CI 5.40–14.17)) and tocolysis (71.4 vs 2.4% RR 8.10 (95% CI 4.49–14.59)) and to be admitted antenatally (96.4 vs 54.4% RR 1.77 (95% CI 1.50–2.10)) with a higher mean cost of treatment ($NZ967.47 vs $NZ335.27 P < 0.05). Rates of delivery < 34 weeks were higher in those with a positive fFN (41.9 vs 0.7% RR 62.06 (95% CI 8.43–457.14)).

Conclusion:  Women with a positive fFN result received different treatment to those with a negative fFN. Use of fFN test in routine clinical practice allows management and resources to be targeted more appropriately and may limit unnecessary interventions.
Readmission risk and metabolic, biochemical, haematological and clinical indicators of severity in hyperemesis gravidarum
Authors: TAN Peng Chiong , JACOB Reena , QUEK Kia Fatt , OMAR Siti Zawiah
Published: August 2006

In a retrospective analysis of 192 cases of presumed hyperemesis gravidarum, there were no biochemical markers that predicted hospital readmission. There was, however, statistically significant negative predictive value in abnormal liver function tests. This could represent acute self‐limited illness with a component of hepatitis as the cause for the clinical presentation, rather than hyperemesis.
Tuberculosis in pregnancy – Case studies and a review of Australia's screening process
Authors: MCCARTHY Fergus P. , ROWLANDS Shelley , GILES Michelle
Published: August 2006

Few changes have occurred in the management of tuberculosis over the past two decades and many of the recent developments are in the area of diagnostics. The application of these to the pregnant population is not yet established. Two cases recently managed at the Royal Women's Hospital, Melbourne highlight the need for clinicians managing pregnant women to rethink this condition and, with changes in migration and epidemiology, reconsider our screening practice.