bluuebunny/crossref_metadata_2025 huggingface dataset:
Hysteresis-free pentacene field-effect transistors and inverters containing poly(4-vinyl phenol-co-methyl methacrylate) gate dielectrics
Authors: Kim Se Hyun , Jang Jaeyoung , Jeon Hayoung , Yun Won Min , Nam Sooji , Park Chan Eon
Published: May 2008

The influence of hydroxyl groups on the hysteresis of pentacene field-effect transistors (FETs) and metal-insulator-semiconductor diodes containing poly(4-vinyl phenol) and poly(4-vinyl phenol-co-methyl methacrylate) (PVP-PMMA) gate dielectrics was investigated. The electrical characteristics and Fourier transform infrared spectroscopy measurements show that hysteresis is intimately related to the presence of free OH groups in the polymer gate dielectrics. The methyl methacryl moieties in PVP-PMMA minimize residual water in the polymer and form hydrogen bonds with the hydroxyl groups, thus reducing the number of free OH species. Therefore, pentacene FETs and inverters using PVP-PMMA gate dielectrics exhibit high, hysteresis-free performances.
Crop and environmental attributes underpinning genotype by environment interaction in synthetic-derived bread wheat evaluated in Mexico and Australia
Authors: Dreccer M. Fernanda , Chapman Scott C. , Ogbonnaya Francis C. , Borgognone M. Gabriela , Trethowan R. M.
Published: May 2008

Synthetic backcrossed-derived bread wheats (SBWs) from CIMMYT were grown in the north-west of Mexico (CIANO) and sites across Australia during 3 seasons. A different set of lines was evaluated each season, as new materials became available from the CIMMYT crop enhancement program. Previously, we have evaluated both the performance of genotypes across environments and the genotype × environment interaction (G × E). The objective of this study was to interpret the G × E for yield in terms of crop attributes measured at individual sites and to identify the potential environmental drivers of this interaction. Groups of SBWs with consistent yield performance were identified, often comprising closely related lines. However, contrasting performance was also relatively common among sister lines or between a recurrent parent and its SBWs. Early flowering was a common feature among lines with broad adaptation and/or high yield in the northern Australian wheatbelt, while yields in the southern region did not show any association with the maturity type. Lines with high yields in the southern and northern regions had cooler canopies during flowering and early grain filling. Among the SBWs with Australian genetic backgrounds, lines best adapted to CIANO were tall (>100 cm), with a slightly higher ground cover. These lines also displayed a higher concentration of water-soluble carbohydrates in the stem at flowering, which was negatively correlated with stem number per unit area when evaluated in southern Australia (Horsham). Possible reasons for these patterns are discussed. Selection for yield at CIANO did not specifically identify the lines best adapted to northern Australia, although they were not the most poorly adapted either. In addition, groups of lines with specific adaptation to the south would not have been selected by choosing the highest yielding lines at CIANO. These findings suggest that selection at CIMMYT for Australian environments may be improved by either trait based selection or yield data combined with trait information. Flowering date, canopy temperature around flowering, tiller density, and water-soluble carbohydrate concentration in the stem at flowering seem likely candidates.
CIMMYT's use of synthetic hexaploid wheat in breeding for adaptation to rainfed environments globally.
Authors: Lage J. , Trethowan R. M.
Published: May 2008

The International Maize and Wheat Improvement Center (CIMMYT) has had significant impact on wheat production in rainfed regions of the developing world. During the last decade, yield potential has increased in drought-prone areas partly due to the use of synthetic hexaploid wheat (SHW), produced through interspecific hybridisation of Triticum turgidum spp. and Aegilops tauschii, followed by chromosome doubling. The objectives of this study were to document the use of SHW in wheat breeding at CIMMYT and quantify its potential effect on global wheat adaptation. The first SHW-derived lines targetted at rainfed conditions appeared in the 5th Semi-Arid Wheat Yield Trial (SAWYT) representing 8% of the lines, increasing to 46% by the 15th SAWYT. During the same period the average coefficient of parentage of SHW in all synthetically derived crosses decreased from 75 to 19%. Average yield rank of genotypes across locations and years was used as a performance indicator of the SHW-derived lines in SAWYT 5–12. In the 5th SAWYT the average rank of the SHW-derived lines was 30 (out of 50) increasing to 25 by the 12th SAWYT. SAWYT 11 was the first trial to include SHW-derived lines bred exclusively for rainfed environments, using directed selection for drought tolerance. International trial data from SAWYT 11 and 12 showed that the SHW-derived line Vorobey was a top-performing line. Vorobey performed well across all environments compared with the best locally adapted check cultivar at each location; trial means ranged from 1 to 8 t/ha. To further exploit genetic diversity for adaptation to drought, SHW has been produced using emmer wheat (T. turgidum L. subsp. dicoccon) as the tetraploid parent. Yield trial data from Mexico show that SHW derivatives based on emmer wheat improved yield performance under drought compared with their drought-tolerant recurrent parents. The use of SHW in wheat breeding for rainfed environments at CIMMYT has increased significantly over the past 10–15 years and the performance and effect of the derived lines have improved with time.
Genetic variation for quality traits in synthetic wheat germplasm
Authors: Mares Daryl , Mrva Kolumbina
Published: May 2008

Synthetic hexaploid wheats offer breeders ready access to potentially novel genetic variation associated with the D genome of Aegilops tauschii. In order to assess the application of this germplasm to wheat quality improvement, collections of primary and derived synthetic hexaploid wheat lines were surveyed for traits that determine colour and colour stability in Asian noodles and the frequency of a genetic defect know as late maturity α-amylase (LMA). The range of variation was then compared with bread wheat and durum wheat cultivar collections. Primary synthetics contained substantial genetic variation for quality traits associated with colour and colour stability of Asian noodles including near-zero extremes for polyphenol oxidase and lipoxygenase. These extremes represent a significant advantage compared with current bread wheat cultivars and are similar to the best durum wheats. While alternative strategies for reducing polyphenol oxidase and lipoxygenase are available, the synthetics nevertheless provide a useful resource for wheat breeders attempting to develop improved wheat cultivars for the Asian noodle market. Unfortunately, however, most primary synthetics were prone to late maturity α-amylase and mature grain contained unacceptably high levels of α-amylase. Elimination of this genetic defect, or selection within breeding populations for low or non-LMA, is both time consuming and labour intensive and presents a significant obstacle to exploitation of variation for other traits. As proof of concept, near-zero polyphenol oxidase (PPO) lines, free from LMA, were recovered from backcross populations involving a high LMA primary synthetic.
Use of synthetic hexaploid wheat to increase diversity for CIMMYT bread wheat improvement
Authors: Dreisigacker S. , Kishii M. , Lage J. , Warburton M.
Published: May 2008

To date, the International Maize and Wheat Improvement Center (CIMMYT) has produced more than 1000 synthetic hexaploid wheats (SHWs), using diverse accessions of the D genome donor species (Aegilops tauschii). Many of these SHWs produced from many different Ae. tauschii have shown resistance or tolerance to various biotic and abiotic stresses, indicating the potential importance of the Ae. tauschii gene pool for breeding purposes. SHWs were backcrossed to CIMMYT improved germplasm to produce synthetic backcross-derived lines (SBLs), which are agronomically similar to the improved parents, but retain the introgressed traits of interest under selection and thereby new diversity. Molecular studies show that SHWs and SBLs are genetically diverse at the DNA level when compared with traditional bread wheat cultivars and preferential transmission of some alleles from the SHW parent has been seen in all genomes, indicating positive selection. Marker analyses of wheat cultivars released over time indicate that SBLs are ideal materials to simultaneously increase yield and diversity for other traits. Following successful diversification of the wheat D genome, CIMMYT has shifted to target improvement of hexaploid wheat via the A and B genomes, focusing on specific traits. Screening the CIMMYT germplasm collection of T. turgidum subsp. dicoccum for Russian wheat aphid resistance and drought tolerance revealed varying levels of phenotypic expression. Promising accessions will be used for the production of new SHWs for future introgressions into elite bread wheat backgrounds.
Mining synthetic hexaploids for multiple disease resistance to improve bread wheat
Authors: Ogbonnaya F. C. , Imtiaz M. , Bariana H. S. , McLean M. , Shankar M. M. , Hollaway G. J. , Trethowan R. M. , Lagudah E. S. , van Ginkel M.
Published: May 2008

A collection of 253 synthetic hexaploid wheats (SHWs) produced from 192 Aegilops tauschii accessions and 39 elite durum varieties were studied to identify, characterise, and evaluate potentially untapped diversity of disease resistance in wheat. The diseases for which resistance was sought included cereal cyst nematode (CCN), root lesion nematode (RLN), Stagonospora nodorum blotch (SNB), Septoria tritici blotch (STB), and the 3 rusts, leaf rust, stem rust, and stripe rust, all important diseases of bread wheat worldwide, which can severely reduce wheat yield and quality. The SHWs exhibited a wide spectrum of resistance to the 8 pathogens. The frequency of disease-resistant SHWs ranged from 1% for one species of RLN (Pratylenchus neglectus), 3% and 10% for Septoria nodorum leaf and glume blotch, 10% for seedling resistance to yellow leaf spot, 16% for CCN, 21% for the second species of RLN (Pratylenchus thornei), 73% for Septoria tritici blotch, and 15%, 40%, and 24% for leaf rust, stem rust, and stripe rust, respectively. Five SHWs, Aus26860, Aus30258, Aus30294, Aus30301, and Aus30304, exhibited high levels of resistance to CCN, YLP, STB, LR, and SR, while 56 SHWs showed resistance to either 3 or 4 diseases. The genetics of resistance to CCN in some of the SHWs revealed that some of the accessions carry the same CCN gene(s) against pathotype Ha13, while others may carry different resistance gene(s). Additional studies were carried out to understand the relationship between the resistances identified in SHWs and the ones already present in common wheat, in particular the resistance genes Cre1 and Cre3 against CCN. The use of perfect markers associated with Cre1 and Cre3 suggested that some SHWs may carry a new CCN resistance gene(s), which could be deployed in breeding programs to increase the diversity of available resistance. The identification of SHWs with resistance to a range of diseases provides an opportunity to generate genetic knowledge and resistant germplasm to be used in future variety development.
Rising from Down Under: developments in subterranean biodiversity in Australia from a groundwater fauna perspective
Authors: Humphreys William F.
Published: May 2008

Over the last two decades, Australia has undergone a renaissance in studies of subterranean biology. This paper sets these recent developments into context from the perspective of groundwater fauna. Owing to its obligate subterranean life, typical local endemicity and the geological persistence of subterranean habitats, stygofauna is an excellent subject for biogeographic study. Groundwater containing diverse faunas range from freshwater to marine salinities in both coastal and continental locations. They occur in typical karst, alluvial, and fractured rock aquifers, but also in novel matrices formed during the hydrogeochemical evolution of groundwater (goethite pisolites and groundwater calcretes) in the Tertiary. This range of habitats, water quality and the diverse origins of the fauna (Gondwanan, Pangaean and Tethys) support a phylogenetically highly diverse fauna. Several taxa, notably among the Podocopida, Bathynellacea, Amphipoda, and Dytiscidae show remarkable species diversity. Typically there is fine spatial scale endemicity of species associated with local aquifers, but there are inexplicable regional differences, such as the change of fauna between the Yilgarn and Pilbara, contiguous areas on the long emergent Western Shield. The anchialine taxa representing higher taxa are highly disjunct from their congeners in the North Atlantic. The emerging species richness, the fine scale patchwork of endemicity, and the distinct regional differences, respectively, contribute to a substantial increase in α, β and γ diversity of the aquatic fauna, especially in arid Australia. This diversity is posing challenging issues for proponents and regulators of mineral development because much of this diversity has emerged in the two most mineraliferous provinces of Australia. The scientific capacity to respond is challenged by the sheer scale of the emerging issues.
Stygofauna biodiversity and endemism in four alluvial aquifers in eastern Australia
Authors: Hancock P. J. , Boulton A. J.
Published: May 2008

Short-range endemism is common in groundwater fauna (stygofauna), placing many species at risk from anthropogenic impacts such as water abstraction and pollution. Few of the alluvial aquifers in eastern Australia have been sampled for stygofauna. Fauna from two aquifers in Queensland and two in New South Wales was sampled to improve ecological knowledge of stygofauna and the potential threats posed to it by development. Our surveys found stygofauna in all four aquifers, with most taxa collected from bores with low electrical conductivity (<1500 µS cm–1). Taxon richness decreased with distance below the water table. The most taxon-rich bores in each region occurred where the water table depth was <10 m, were associated with the alluvium of tributaries of large regulated river systems, and were near phreatophytic trees. It is possible that tree roots constitute a habitat and source of organic matter in alluvial aquifers as they do in cave streams. It is important to document the biodiversity of particular regions and aquifers so that species can be conserved in the face of increasing groundwater use. For effective resource management, future research should strive to understand the tolerances and ecological requirements of groundwater communities and the ecosystem services they provide.
Short-range endemism in hypogean environments: the pseudoscorpion genera Tyrannochthonius and Lagynochthonius (Pseudoscorpiones: Chthoniidae) in the semiarid zone of Western Australia
Authors: Edward Karen L. , Harvey Mark S.
Published: May 2008

We studied a variety of chthoniid pseudoscorpions collected from the semiarid zone of Western Australia. Five new species of Tyrannochthonius Chamberlin, 1929 and three new species of Lagynochthonius Beier, 1951 are named and described from the Pilbara and Gasgoyne regions, and surrounding areas such as Barrow Island. Tyrannochthonius basme, sp. nov. and Lagynochthonius asema, sp. nov. from pisolitic mesas near Pannawonica, T. garthhumphreysi, sp. nov. from limestone karst on Barrow Island, T. souchomalus, sp. nov. from calcrete deposits near Cue, T. billhumphreysi, sp. nov. and L. polydentatus, sp. nov. from a calcrete deposit on Sturt Meadows Station and L. leemouldi, sp. nov. from calcrete near Marble Bar are all considered to represent hypogean species as all exhibit typical troglomorphic adaptations including total loss of eyes and attenuated appendages. New records are provided for T. brooksi Harvey and T. butleri Harvey from Cape Range peninsula. A new epigean species, T. aridus, sp. nov., was found on Barrow Island and the Pilbara mainland. Two further putative new species based upon nymphal specimens from subterranean environments are described but not named owing to the lack of adult specimens. Although the epigean species T. aridus, sp. nov. is relatively widespread, all of the subterranean species are thought to represent short-range endemic species as they have been found at very few locations, all of which occur in localised habitats such as limestone or within mesa formations. Tyrannochthonius chamorro Chamberlin, 1947 from Guam is transferred to the genus Lagynochthonius, creating the new combination Lagynochthonius chamorro (Chamberlin 1947).
The first indigenous palpigrade from Australia: a new species of Eukoenenia (Palpigradi:Eukoeneniidae)
Authors: Barranco Pablo , Harvey Mark S.
Published: May 2008

We present a description of the first indigenous member of the arachnid order Palpigradi from Australia. Eukoenenia guzikae, sp. nov. was collected from subterranean environments in the Yilgarn region of Western Australia. The sole male specimen differs from all other members of the genus in several small but significant ways, including by the combined presence of six blades in the prosomal lateral organs, nine pairs of setae on the propeltidium, the presence of a spur on coxa IV, the chaetotaxy of sternites IV–VIII, and the shape of the male genital lobes. It shows some similarities in the male genital region to a group of species found in Madagascar.
Subterranean archipelago: mitochondrial DNA phylogeography of stygobitic isopods (Oniscidea:Haloniscus) from the Yilgarn region of Western Australia
Authors: Cooper Steven J. B. , Saint Kathleen M. , Taiti Stefano , Austin Andrew D. , Humphreys William F.
Published: May 2008

The arid Yilgarn region of Western Australia contains numerous isolated calcrete aquifers, within which a diverse subterranean fauna has been discovered. Genetic and morphological studies of subterranean dytiscid beetles and amphipods have suggested that individual calcretes are equivalent to closed island habitats, which have been isolated for millions of years. Here we test this ‘subterranean island’ hypothesis further by phylogeographic analyses of subterranean oniscidean isopods (Haloniscus), using mitochondrial DNA (mtDNA) sequence data derived from the cytochrome c oxidase subunit I gene. Phylogenetic and population genetic analyses provided evidence for significant phylogeographic structuring of isopod populations, with evidence for at least 24 divergent mtDNA lineages, each restricted in their distribution to a single calcrete aquifer. The high level of divergence among calcrete populations (generally >25%) and several mtDNA lineages within calcretes (>16%) suggests that each lineage is likely to represent a distinct species. These analyses, together with comparative phylogeographic data from dytiscid beetles and amphipods, provide strong support for the ‘subterranean island’ hypothesis, applying to both air-breathing and fully aquatic arthropod groups. The finding of several epigean lineages that grouped with stygobitic Haloniscus populations, and the overall phylogeographic structure of populations, suggests that the majority of stygobitic species evolved within individual calcretes following independent colonisation by epigean ancestors.
The fundamental importance of taxonomy in conservation biology: the case of the eyeless Cicurina bandida (Araneae:Dictynidae) of central Texas, including new synonyms and the description of the male of the species
Authors: Paquin Pierre , Dupérré Nadine , Cokendolpher James C. , White Kemble , Hedin Marshal
Published: May 2008

Three eyeless species belonging to the spider genus Cicurina Menge are known from five caves located south of Austin, Travis County (Texas, United States). Because adult female cave-dwelling Cicurina are not common, and adult males rarely collected, these species were described from a very small sample of individuals (nine females). Recent collections have allowed the examination of a larger series of specimens, providing an opportunity to assess intraspecific variability. This has resulted in the synonymy of C. cueva Gertsch and C. reyesi Gertsch with Cicurina bandida Gertsch. The synonymy is supported by both female and male morphology; the male of the species is described for the first time. Cicurina bandida is now known from ~20 caves, restricted to a 10 km × 30 km area. Cicurina cueva was proposed to be listed as an endangered species. Because of the special conservation status of troglobitic Cicurina, modifications of the original species hypothesis are fertile grounds for confrontation between conservationists and proponents of development. Taxonomy is a dynamic science that progresses by proposing new scientific hypotheses and this conflicts with conservation principles that are embedded in a static framework. The criteria used to assign species a particular conservation status should be based on the best available evidence, and not limited by political considerations. Long-term conservation goals can only be achieved when based on a robust taxonomy, which is still largely unavailable for most Texas cave arthropods.
Diversity and distribution of groundwater fauna in a calcrete aquifer: does sampling method influence the story?
Authors: Allford Adam , Cooper Steven J. B. , Humphreys William F. , Austin Andrew D.
Published: May 2008

There has been an increase in the number of studies examining the spatial and temporal patterns in species richness, community structure and population dynamics of groundwater organisms. These studies have raised the issue of uncertainty about the comparability of different sampling methods, and questions of whether sampling bias may exist. Recently, a diverse subterranean fauna was discovered in calcrete (carbonate) aquifers of the Yilgarn Region of central Western Australia. Little is known about the community structure and population dynamics in these aquifers. One important issue is whether current sampling methods adequately sample the species richness and abundance of the fauna to allow for comparative studies. Here we investigate the effectiveness of three sampling methods: haul net sampling, pumping with a 12-V impeller pump, and a discrete interval sampler. The methods were trialled over 16 months with >250 samples taken from 55 uncased bore holes. No significant taxonomic bias was detected across the sampling methods. However, sampling using a haul net was found to be the most efficient method for capturing the available taxa per unit time when sampling bores are less than 10 m deep, with pumping being the least efficient. These results are discussed in relation to the problems of studying stygofauna in Western Australian calcrete aquifers, and of groundwater faunas more generally.
Chlamydia trachomatis infection in patients attending an Early Pregnancy Unit: Prevalence, symptoms, pregnancy location and viability
Authors: KIRK EMMA , BORA SHABANA , VAN CALSTER BEN , CONDOUS GEORGE , VAN HUFFEL SABINE , TIMMERMAN DIRK , BOURNE TOM
Published: May 2008

Objective. To assess the prevalence of Chlamydia trachomatis and its relationship to age, ethnicity, symptomatology, pregnancy location and viability in women attending an Early Pregnancy Unit. Method. Women were offered screening for Chlamydia over a 4‐month period. Presenting complaints, maternal age, ethnic origin, gestational age, pregnancy location, pregnancy viability and swab results were recorded. Results. One thousand, one hundred and one women were offered screening. Nine hundred and sixteen (83.2%) agreed to participate. Eight hundred and six (88.0%) had readable swabs. The prevalence of Chlamydia was 2.2% (95% CI: 1.4–3.5) (18/806). The prevalence in those <25 years of age was 8.7% (95% CI: 5.1–14.3). Prevalence was higher in black women compared to Asian or Caucasian women. The prevalence of Chlamydia in symptomatic and asymptomatic women was 2.3% (12/521) and 2.1% (6/285), respectively, p>0.166. There was no significant difference in the final early pregnancy outcome in women with or without Chlamydia. Conclusion. Currently Chlamydia screening is not advised in Early Pregnancy Units as the women are thought to be of low risk; however, there are subgroups that are at relatively high risk. Screening this population is therefore important. There is, however, no difference in pregnancy location and viability in women with or without Chlamydia.
Placenta weight in pre‐eclampsia
Authors: DAHLSTRØM BERIT , ROMUNDSTAD PÅL , ØIAN PÅL , VATTEN LARS J. , ESKILD ANNE
Published: May 2008

Objective. Preterm and term pre‐eclampsia may differ in etiology. This could be reflected in differences in placenta weight. Therefore, we compared placenta weight in pregnancies with preterm or term pre‐eclampsia to placenta weight in pregnancies without pre‐eclampsia. Design. Population study. Setting. Medical Birth Registry of Norway. Population. All singleton pregnancies in Norway from 1999 through 2004 delivered at or after 21 weeks’ gestation (n = 317,688). Methods. Placenta weight in pregnancies without pre‐eclampsia (n = 304,875) was compared to placenta weight in pregnancies with preterm pre‐eclampsia (delivery before week 37 of pregnancy, n = 3,070) and term pre‐eclampsia (delivery on or after week 37 of pregnancy, n = 9,743). Placenta weight z‐scores were calculated to adjust for offspring sex and length of gestation, and grouped in tenths. Placenta weight according to pre‐eclampsia status is presented as proportions within each tenth. Main outcome measures. Pre‐eclampsia status. Results. In preterm pre‐eclampsia, placentas were over‐represented in the two lowest (33.8%; 95% CI 32.1–35.5) and under‐represented in the two highest (13.1%; 95% CI 11.9–14.3) tenths of placenta weight compared to pregnancies without pre‐eclampsia (20%). In term pre‐eclampsia, placentas were over‐represented in the two lowest (22.0%; 95% CI 21.2–22.8) and the two highest (22.7%; 95% CI 21.9–23.6) placenta weight groups. Mean placenta weight z‐score was higher in term pre‐eclampsia compared to pregnancies without pre‐eclampsia. Conclusions. Small placentas were associated with pre‐eclampsia, and more strongly with preterm than term pre‐eclampsia. In term pre‐eclampsia, the association with placenta weight was u‐shaped, yielding higher proportions of both low and high placenta weight compared to pregnancies without pre‐eclampsia.
Dietary and lifestyle interventions to limit weight gain during pregnancy for obese or overweight women: A systematic review
Authors: DODD JODIE M. , CROWTHER CAROLINE A. , ROBINSON JEFFREY S.
Published: May 2008

Background. To assess the benefits and harm of dietary and lifestyle interventions during pregnancy to improve maternal and infant outcomes for pregnant women who are overweight or obese. Methods. Randomized controlled trials comparing any form of dietary or lifestyle intervention during pregnancy for women who are overweight or obese with no treatment to improve maternal and infant health were considered. The Cochrane Controlled Trials Register (CENTRAL), PUBMED and the Australian and International Clinical Trials Registry were searched (date of last search November 2007). Results. Two published trials were identified with no statistically significant differences identified between the intervention and standard care groups for maternal or infant health outcomes. Conclusion. There is limited information available assessing the benefits and harm associated with dietary and lifestyle interventions for overweight and obese pregnant women. Further evaluation through randomized trials with adequate power is required.
Placenta previa: Its relationship with race and the country of origin among Asian women
Authors: YANG QIUYING , WEN SHI WU , CAUGHEY SHARON , KREWSKI DANIEL , SUN LUMING , WALKER MARK C.
Published: May 2008

Objectives. To examine the association between placenta previa with maternal race and its variations by country of origin among Asian women. Study design. Retrospective cohort study. Methods. We analyzed data from a population‐based retrospective cohort study of 16,751,627 pregnancies in the US. The data were derived from the national linked birth/infant mortality database for the period 1995–2000. Multiple logistic regressions were used to describe the relationship between placenta previa and race as well as country of origin among Asian women. Results. About 3.3 per 1,000 pregnancies were complicated with placenta previa among white women, while the corresponding figures for black women and women of other races were 3.0 and 4.5 per 1,000 pregnancies, respectively. The excess risk remained substantial and significant after adjustment for confounders for women of other races compared to white women. The frequencies of placenta previa among Chinese, Japanese, Filipino, Asian Indian, Korean, Vietnamese and other Asian or Pacific Islander were 5.6, 5.1, 7.6, 4.5, 5.9, 4.4 and 4.4 per 1,000 pregnancies, respectively. The adjusted odds ratios ranged from 1.39 to 2.15 among Asian women by country of origin, with the lowest for Japanese and Vietnamese and the highest for Filipino women in our study. Conclusion. Asian women have excess risk of placenta previa compared with white women. Major variation exists in placenta previa risk among Asian women, with the lowest risk in Japanese and Vietnamese women and the highest risk in Filipino women.
Risk factors and interventions associated with major primary postpartum hemorrhage unresponsive to first‐line conventional therapy
Authors: MOUSA HATEM A. , CORDING VICKY , ALFIREVIC ZARKO
Published: May 2008

Background. To examine risk factors and interventions associated with major primary postpartum hemorrhage (PPH) unresponsive to first‐line conventional therapy. Methods. From computerized maternity database, we identified women with major primary PPH defined as blood loss ≥1,000 ml and/or the need for a blood transfusion within 24 h of delivery beyond 24 weeks’ gestation. Cases were assigned according to the mode of delivery and response to the first‐line therapy (responders and non‐responders). Results. Between 1998 and 2002, 20,610 women delivered after 24 weeks’ gestation. A total of 306 women developed primary PPH (14.8/1,000 deliveries) including 103 vaginal and 203 caesarean (CS) births. Out of 103 women with PPH following vaginal birth, 22 (21%) failed to respond to first‐line therapy. Following CS, 20 of 203 (10%) failed first line treatment and required examination under anesthesia (EUA) and other interventions to control bleeding. Irrespective of the mode of delivery, antepartum risk factors did not differ between responders and non‐responders to first‐line therapy. In the vaginal group, non‐responders were treated with required bimanual compression and intra‐myometrial PGF2α (49%), repair of cervical tear (14%), vaginal packing (9%), and uterine packing (5%). In the CS group, hysterectomy was the most common surgical intervention (54%) after other methods including uterine packing, B‐Lynch procedure, uterine tamponade, and intra‐myometrial prostaglandin were ineffective. Conclusions. The currently known risk factors for primary PPH are not useful in the identification of patients who continue to bleed after first‐line therapy. Emergency hysterectomy was the most common surgical intervention used to control major PPH unresponsive to conventional therapy following CS birth.
Three‐dimensional endoanal ultrasound assessment of the anal sphincters during rest and squeeze
Authors: OLSEN INGRID P. , AUGENSEN KÅRE , WILSGAARD TOM , KISERUD TORVID
Published: May 2008

Background. Current ultrasound assessment of the anal sphincter is based on measurements during rest. However, active constriction plays a role in maintaining continence. Here we assess female anal dimensions during rest and squeeze. Methods. Thirty women were recruited for a cross‐sectional endoanal ultrasound study after written consent according to an ethically approved protocol: nine 0‐gravida, 10 with normal vaginal delivery, and 11 with complicated vaginal delivery (babies >4,500 g, operative vaginal delivery or perineal rupture). Endoanal three‐dimensional (3D)‐ultrasound volume was obtained during rest and squeeze. Length of anal canal and volume of the external and internal sphincters were determined. Results. In the 0‐gravida group, the mean anal canal at rest was 3.28 cm (SD: ±0.63) compared with 2.30 (±0.77) in those who had given birth (p =0.002). Correspondingly, the volume of the external sphincter was 7.61 cm3 (±2.63) versus 4.80 (±2.02) (p =0.004), and for the internal sphincter 2.63 (±1.18) versus 2.68 (±1.30) (p =0.98). There were no differences between rest and squeeze within the 0‐gravida, but after a traumatic vaginal delivery the internal sphincter was smaller during squeeze (p =0.01), and the overlap between external and internal sphincter was 0.76 cm (±0.41), insignificantly shorter (p =0.09) than in the 0‐gravida group at 1.21 (±0.62). Conclusions. Women with vaginal delivery had a shorter anal canal and smaller external sphincter than 0‐gravida. Active squeeze had no effect on the dimensions of the sphincter apart from a reduction of the internal sphincter in those who had undergone a complicated delivery, possibly due to a dislodging upwards during squeeze.
Severe maternal morbidity and the mode of delivery
Authors: PALLASMAA NANNELI , EKBLAD ULLA , GISSLER MIKA
Published: May 2008

Objective. To define the rate of severe maternal morbidity in different modes of delivery and to find out if the rate of severe morbidity has changed over a 5‐year time span. Design. Retrospective register‐based study. Setting. Finnish Medical Birth Registry and Hospital Discharge Registry. Population. All singleton deliveries in Finland in 1997 and 2002 (n = 110,717). Methods. Diagnoses and operative interventions recorded in the Hospital Discharge Registry indicating a severe maternal complication were linked with Birth Register data and compared by mode of delivery: spontaneous vaginal delivery (VD), instrumental VD, elective cesarean section and non‐elective cesarean section. Main outcome measures were severe maternal morbidity: deep venous thromboembolism and amniotic fluid embolism, major puerperal infection, severe hemorrhage, events requiring operative intervention after delivery, uterine rupture and inversion, and intestinal obstruction. Results. Severe maternal morbidity was more frequent in cesarean than vaginal deliveries (p<0.001), and more frequent in non‐elective than in elective operations (p<0.001). The rate of severe maternal morbidity increased considerably from 1997 to 2002; from 5.9 to 7.6 per 1,000 in all deliveries (p<0.001), from 4.0 per 1,000 to 5.2 per 1,000 in spontaneous vaginal deliveries (p = 0.005), from 9.9 per 1,000 to 12.1 per 1,000 in elective cesarean sections (CSs) (p = 0.164), and from 19.6 per 1,000 to 27.2 per 1,000 in non‐elective CSs (p = 0.090), respectively. Conclusions. Severe maternal morbidity has increased both in cesarean and vaginal deliveries from 1997 to 2002. Cesarean delivery, even an elective one, carries a significantly higher risk of life‐threatening maternal complications than VD.
Psychotherapy and neuroscience: Towards closer integration
Authors: Peres Julio , Nasello Antonia Gladys
Published: May 2008

The original aim of psychology was to study and understand the spirit—from the Latin spiritus, literally “breath.” The limitations of scientific methods in the past favoured psychology's aloofness in terms of studying the “intangible,” while medicine developed methods of examining the body (Latin corpus: essential part). Until 20 years ago, knowledge of the localization of brain functions was limited to inferences from clinical observation of brain‐lesioned patients or parallel studies of primate brains. Current neuroscience, with its integrative approach, is bringing together research from molecular through cognitive levels, and psychotherapy has benefited from these findings. Functional neuroimaging studies may make specific and more far‐reaching contributions in this respect, since cerebral dynamics may be observed in vivo and in controlled situations. Methods such as single photon emission tomography, positron emission tomography, and functional magnetic resonance imaging have been able to evaluate the neural correlates involved in psychotherapy for individuals with obsessive‐compulsive disorder, major depression, social phobia, specific phobia, and post‐traumatic disorder. Researchers have found that psychotherapy has the potential to modify dysfunctional neural circuits associated with these disorders. However, precautions are required in constructing feasible designs for neurofunctional investigations. This article reviews the 21 studies that have been published on the subject, and sets out the main advantages and limitations of the technologies used most frequently in protocols involving psychotherapies, and prerequisites for experimental designs. We also pose ways in which the findings from neuroimaging may produce knowledge to guide psychotherapeutic interventions by specifying what should be stimulated in these individuals in order to normalize deficient neural activities.
Confidence judgments in real classroom settings: Monitoring performance in different types of tests
Authors: de Carvalho Filho Moisés Kirk
Published: May 2008

During testing, students have a valuable opportunity to exercise and improve their self‐regulatory skills. However, the extent to which they profit from those experiences may vary according to some personal, test‐related, and environmental factors. This study investigated the effects of metacognitive skills and test types on students' test performances, confidence judgments, and on the accuracy of those judgments. A sample of 129 psychology undergraduate students (50 men and 79 women, mean age = 18.9 years) were categorized according to their metacognitive skills (high vs average vs low) and had their test performances and monitoring processes in two different types of tests (i.e., multiple‐choice and short‐answer tests) compared throughout one academic term. Their test preparation practices, along with their attributional and regulatory processes during test‐taking, were also compared by using open‐ended questions. The results showed that: (1) high‐metacognitive students presented more effective test preparation practices, better test performances, and superior attributional, regulatory, and monitoring processes than their counterparts; (2) differences in performance and judgment accuracy were significantly larger in the short‐answer tests than in the multiple‐choice tests; and (3) over time, students' performances and confidence levels varied in specific patterns according to the type of test being taken. The results are discussed, focusing on the educational implications of the interactions observed and on how they may determine what students can learn from test‐taking experiences. In addition, based on the results obtained, specific suggestions on how to increase the metacognitive awareness of university students through instruction and on how to improve their academic assessment are provided.
Cultural differences in family, marital, and gender‐role values among immigrants and majority members in the Netherlands
Authors: Arends‐Tóth Judit , Van de Vijver Fons J. R.
Published: May 2008

This study examined the size of differences in self‐reported family, marital, and gender‐role values in five cultural groups in the Netherlands (6338 Dutch mainstreamers and 422 Turkish, 369 Moroccan, 429 Surinamese, and 394 Antillean first‐ and second‐generation immigrants). It was found that the three value scales were neither completely independent, nor could they be merged into a single value scale. The factor structures of all scales were identical for the five cultural groups, implying that the concepts can be compared. Age, sex, and notably education accounted for a substantial part of the cultural differences in all values. Cultural differences were larger for marital and family values than for gender‐role values. Family and marital values yielded the same rank order of mean scores in the five cultural groups: Turks and Moroccans scored the lowest (having the most traditional values), followed by Surinamers, Antilleans, and Dutch mainstreamers. This rank order corresponds with the ethnic hierarchy of cultural groups that is based on the evaluation of ethnic groups by mainstreamers according to their liking of and likeness to ethnic groups. Generational differences were not found for family and gender‐role values but first‐generation immigrants in all groups had more traditional marital values than had second‐generation immigrants. It was concluded that the theoretical framework based on a combination of three Hofstede dimensions (individualism–collectivism, power‐distance, and femininity–masculinity), a model of the hierarchy of the ethnic groups in the Dutch society, and acculturation theory provided an adequate way to address family, marital, and gender‐role value differences in the five cultural groups.
Effects of received and mobilized support on recipients' and providers' self‐efficacy beliefs: A 1‐year follow‐up study with patients receiving radical prostatectomy and their spouses
Authors: Knoll Nina , Scholz Urte , Burkert Silke , Roigas Jan , Gralla Oliver
Published: May 2008

From a proactive agentic perspective, social support is not just seen as a protective cushion against environmental demands. Rather, support may facilitate an individual's self‐regulation by enhancing perceived self‐efficacy (i.e., enabling hypothesis). In the present study, patient‐reported indicators of mobilized and received spousal support as predictors of their own and their spouses' self‐efficacy beliefs were investigated within 1 year following radical prostatectomy. During this time frame, postoperative sequelae such as urinary incontinence and erectile dysfunctions are still likely to interfere with couples' everyday activities. Seventy‐two patients receiving radical prostatectomy and their spouses participated. Patients' and spouses' self‐efficacy beliefs and patients' received and mobilized spousal support were assessed prior to and 12 months following surgery. Additional patient‐reported covariates at 1 year post‐surgery were degree of bother by urinary incontinence, overall sexual satisfaction, and relationship satisfaction. Results indicated that patients' received spousal support was associated with higher levels of patients' self‐efficacy only cross‐sectionally, but not longitudinally. Support mobilized by the patient prior to and 1 year after surgery, however, positively predicted spouses' levels and changes in self‐efficacy. Results, thus, did not fully confirm predictions by the enabling hypothesis of social support; rather, associated aspects, such as the degree of being mobilized as a provider of support or being needed, seem to enhance agency beliefs in spouses.
The relationship between three types of aggression and peer relations in elementary school children
Authors: Yamasaki Katsuyuki , Nishida Noriko
Published: May 2008

Previous studies have repeatedly found that aggression causes various internalizing and externalizing problems. Despite the robust relationship, exactly how aggression causes these problems remains unclear, although it is plausible to postulate that this occurs both directly and indirectly (via other behavioural factors). One possible indirect factor might be the aggravation of peer relations. The poor peer relations of aggressive children could make them isolated psychologically or physically from peers, which in turn might result in depressive or disruptive problems. This study examined the relationships between three types of aggression and peer relations in Japanese elementary school children. The three aggression types comprised reactive‐expressive (i.e., verbal and physical aggression), reactive‐inexpressive (e.g., hostility), and proactive‐relational aggression (i.e., aggression that can break human relationships, for instance, by circulating malicious rumours). Participants were 1581 children in grades 4 to 6 (752 boys and 829 girls), all of whom completed the Proactive‐Reactive Aggression Questionnaire for Children to measure three types of aggression and the Peer Relation Questionnaire to measure peer relations (mutual understanding, self‐disclosure, and similarity of taste) and number of friends. Hierarchical regression analyses of the data showed that higher scores of relational aggression were significantly associated with higher scores of all of the peer relations and the number of friends, and that higher scores of inexpressive aggression were significantly associated with lower scores of all except for self‐disclosure in the peer relations. These findings suggest that among the three types of aggression, relational aggression leads to the best friendship in both dyadic relations and the number of friends, whereas inexpressive aggression to the poorest friendship. The implications of these findings with respect to internalizing and externalizing problem behaviours for aggressive children are discussed.
The impact of role stress on workers' behaviour through job satisfaction and organizational commitment
Authors: Antón Concha
Published: May 2008

Dysfunctions in role performance have been associated with a large number of consequences, almost always negative, which affect the well‐being of workers and the functioning of organizations. An individual's experience of receiving incompatible or conflicting requests (role conflict) and/or the lack of enough information to carry out his/her job (role ambiguity) are causes of role stress. According to previous theory, role ambiguity and conflict decrease workers' performance and are positively related to the probability of workers leaving the organization. Job satisfaction refers to a positive evaluation of a job, while organizational commitment refers to an employee's attachment to the organization. The affective dimensions of organizational commitment and job satisfaction are considered to be important predictors of turnover intention, absenteeism, and job performance. In the literature, role conflict and ambiguity have been proposed as determining factors of workers' job satisfaction and their commitment towards the organization. The role of job satisfaction and organizational commitment were analysed as variables that should mediate between role ambiguity and conflict and employees' behaviour. The hypotheses were confirmed by means of path analysis carried out with data obtained from a sample of Spanish blue‐collar workers employed by a bus company and a water supply company. Role stressors were negatively related to affective commitment mediated through job satisfaction. Affective commitment to the organization exerted a positive influence on performance and reduces the withdrawal behaviour analysed— intention to leave and absenteeism—although the strongest predictor of intention to leave was, in this study, job satisfaction.