Comparison of seed and seedling functional traits in native Helianthus species and the crop H. annuus (sunflower).

Seed functional traits of native Helianthus species contribute towards ecosystem services but limitations to their use in managed programmes exist. Many perennial Helianthus possess seed dormancy. The ability for germination to occur under different temperature and drought conditions, as well as the capacity of germinated seeds to convert into normal seedlings is rarely considered. Our aim was to identify and quantify these constraints through functional trait analyses. In five seed lots of native Helianthus (four perennial and one annual) and five genotypes of sunflower (H. annuus) for comparison, dormancy, thermal and hydro thresholds and times, morphology, mass, oil content and conversion into normal seedlings were quantified. The influence of the seed collection site environment on these traits was also explored. Seed dormancy of the perennial species was overcome by scarification followed by germination in 5 mm GA3 . Thermal and hydro-time analyses revealed slower germination for the native seed lots (>1350 °Ch) in comparison to the sunflower genotypes (<829.9 °Ch). However, native seed lots had a higher capacity to convert into normal seedlings at high temperatures and low water potentials than sunflower genotypes. For the native seed lots, the average monthly temperature of the collection site was negatively correlated with thermal time. Variability in seed functional traits of native Helianthus and greater capacity for germinated seeds to convert into normal seedlings suggests they are better equipped to cope with high temperature and drought scenarios than sunflower. Effective dormancy alleviation is required to facilitate the use of native Helianthus species.

The impact of global warming on germination and seedling emergence in Alliaria petiolata, a woodland species with dormancy loss dependent on low temperature.

The impact of global warming on seed dormancy loss and germination was investigated in Alliaria petiolata (garlic mustard), a common woodland/hedgerow plant in Eurasia, considered invasive in North America. Increased temperature may have serious implications, since seeds of this species germinate and emerge at low temperatures early in spring to establish and grow before canopy development of competing species. Dormancy was evaluated in seeds buried in field soils. Seedling emergence was also investigated in the field, and in a thermogradient tunnel under global warming scenarios representing predicted UK air temperatures through to 2080. Dormancy was simple, and its relief required the accumulation of low temperature chilling time. Under a global warming scenario, dormancy relief and seedling emergence declined and seed mortality increased as soil temperature increased along a thermal gradient. Seedling emergence advanced with soil temperature, peaking 8 days earlier under 2080 conditions. The results indicate that as mean temperature increases due to global warming, the chilling requirement for dormancy relief may not be fully satisfied, but seedling emergence will continue from low dormancy seeds in the population. Adaptation resulting from selection of this low dormancy proportion is likely to reduce the overall population chilling requirement. Seedling emergence is also likely to keep pace with the advancement of biological spring, enabling A. petiolata to maintain its strategy of establishment before the woodland canopy closes. However, this potential for adaptation may be countered by increased seed mortality in the seed bank as soils warm.

Predicted global warming scenarios impact on the mother plant to alter seed dormancy and germination behaviour in Arabidopsis.

Seed characteristics are key components of plant fitness that are influenced by temperature in their maternal environment, and temperature will change with global warming. To study the effect of such temperature changes, Arabidopsis thaliana plants were grown to produce seeds along a uniquely designed polyethylene tunnel having a thermal gradient reflecting local global warming predictions. Plants therefore experienced the same variations in temperature and light conditions but different mean temperatures. A range of seed-related plant fitness estimates were measured. There were dramatic non-linear temperature effects on the germination behaviour in two contrasting ecotypes. Maternal temperatures lower than 15-16 °C resulted in significantly greater primary dormancy. In addition, the impact of nitrate in the growing media on dormancy was shown only by seeds produced below 15-16 °C. However, there were no consistent effects on seed yield, number, or size. Effects on germination behaviour were shown to be a species characteristic responding to temperature and not time of year. Elevating temperature above this critical value during seed development has the potential to dramatically alter the timing of subsequent seed germination and the proportion entering the soil seed bank. This has potential consequences for the whole plant life cycle and species fitness.

Seed vigour and crop establishment: extending performance beyond adaptation.

Seeds are central to crop production, human nutrition, and food security. A key component of the performance of crop seeds is the complex trait of seed vigour. Crop yield and resource use efficiency depend on successful plant establishment in the field, and it is the vigour of seeds that defines their ability to germinate and establish seedlings rapidly, uniformly, and robustly across diverse environmental conditions. Improving vigour to enhance the critical and yield-defining stage of crop establishment remains a primary objective of the agricultural industry and the seed/breeding companies that support it. Our knowledge of the regulation of seed germination has developed greatly in recent times, yet understanding of the basis of variation in vigour and therefore seed performance during the establishment of crops remains limited. Here we consider seed vigour at an ecophysiological, molecular, and biomechanical level. We discuss how some seed characteristics that serve as adaptive responses to the natural environment are not suitable for agriculture. Past domestication has provided incremental improvements, but further actively directed change is required to produce seeds with the characteristics required both now and in the future. We discuss ways in which basic plant science could be applied to enhance seed performance in crop production.

Longitudinal changes in liver fibrosis in children with sickle cell disease undergoing chronic transfusion therapy.

BACKGROUND AND STUDY AIMS: The progression of liver injury from transfusional iron overload in sickle cell disease (SCD) is poorly understood. We sought to identify predictors liver fibrosis development over time. PATIENTS AND METHODS: We performed a retrospective cohort study of chronically transfused SCD patients who had > or = 2 serial liver biopsies. Core biopsies were scored for fibrosis in a blinded fashion. Primary analyses evaluated longitudinal changes in liver fibrosis and changes in surrogate markers. Secondary analyses determined the relationship between liver iron concentration (LIC) and serum biomarkers. RESULTS: 26 people had > or = 2 serial biopsies for evaluation (n = 70 biopsies total). Fibrosis was Ishak grade 0 or 1 in all biopsies. Evaluation of the first 2 biopsies showed fibrosis regression (n = 6), development (n = 2), persistence (n = 1), and absence (n = 17). There was no consistent association of fibrosis with LIC over time, or between changes in fibrosis status and surrogate markers. For predicting fibrosis on a cross-sectional basis, ALT and ferritin performed moderately (AUCs 0.80 and 0.63, respectively) but LIC performed poorly (AUC 0.30). The highest positive likelihood ratios for fibrosis were for ferritin cutoff of 5000 ng/mL (LR + 5.7) and ALT cutoff of 65 U/L (LR + 5.2). CONCLUSIONS: Liver fibrosis progression is minimal in chronically transfused SCD. LIC does not correlate well with fibrosis development. We propose routine liver biopsies are not necessary components in the standard monitoring of chronically transfused SCD patients.

British gynaecologists' attitudes in 2008 to the provision of legal abortion.

In 2008, we investigated the attitudes and practice of British consultant gynaecologists towards induced abortion, and made comparisons with our similar survey in 1989. A random sample of one in six (217) was selected from the register of the Royal College of Obstetricians and Gynaecologists (RCOG). The response to the postal questionnaire was 70% (152). Satisfaction with the way the 1967 Abortion Act is operating was expressed by 59% (76% in 1989) and an upper limit of 24 weeks was supported by 50% (77% in 1989). Abortion after 20 weeks was approved to protect health by 92%; after rape by 60% and for serious fetal handicap by 87%. A change in the regulations to require the signature of only one doctor (rather than two) to certify the need for abortion was supported by 65%. Only a minority (41%) provided 2nd trimester abortion in person; 61% would separate abortion provision from general gynaecology; 57% suggested there should be separate abortion units for gestations over 13 weeks and 56% felt that fertility control should become be a sub-specialty. Satisfaction with the Abortion Act 1967 has decreased during the last 20 years. Gynaecologists' attitudes to the indications for 2nd trimester abortion remain wide, with clear implications for women seeking abortion. The service to women would be improved if abortion on request was permitted in the 1st trimester and after only one medical signature in the 2nd trimester. Our view is that the decision to end a pregnancy should be made by the woman and that abortion should be decriminalised.

Development of a hydrothermal time model that accurately characterises how thermoinhibition regulates seed germination.

Thermoinhibition is the decline in germinability within a seed population as soil temperatures increase above the optimum for germination. Hydrothermal time (HTT) models have been developed that describe the thermoinhibition response as a function of increases in the threshold water potential for seed germination [seed base water potential, Ψ(b) (G)]. Although these models assume a normal distribution of Ψ(b) (G) and a linear upward shift in Ψ(b) (G) with increasing temperature, little research has tested these assumptions. Using germination data obtained from four unrelated plant species, we fitted HTT models that use the Weibull and normal distribution to describe Ψ(b) (G) and compared the accuracy and bias of these two HTT models. For all four species, Ψ(b) (G) and germination were more accurately described by the Weibull than the normal distribution HTT model. At supra-optimal temperatures, Ψ(b) (G) of the earliest germinating seeds showed little thermoinhibition effect so that the seeds germinated very rapidly under moist conditions. However, for the rest of the population, Ψ(b) (G) increased progressively in response to supra-optimal temperatures so that the slower germinating seeds were thermoinhibited. The fitted HTT models reveal aspects of seed thermoinhibition that appear to have adaptational value under variable conditions of soil temperature and moisture.

Attitudes and practice of gynaecologists towards abortion in Northern Ireland.

Women from Northern Ireland (NI) have to travel to Britain and pay for their terminations as the Abortion Act (1967) does not apply in that part of the UK. This paper analyses the attitudes of gynaecologists. A questionnaire was posted in 2009 to all NHS gynaecologists in NI (43). One had retired. After three mailings, 37 replied; a response rate of 88% (37.42). We found that of these, 21 (57%) favoured a liberalisation of the law in NI. If all the non-responders were against liberalisation, then still half (21/42) would be in favour. A total of 35% (13/37) wanted unrestricted access in the 1st trimester, a more liberal position than allowed by the current law in Great Britain. A total of 29 (78%) were in favour of free abortions for women from NI, as is largely the case in England and Wales. A total of 19 (51%) were in favour of the abortion charities being licensed to carry out legal abortions in Northern Ireland but 38% were opposed to this proposal.

The practice of caesarean birth in the UK.

A survey of 231 clinical directors in obstetrics and gynaecology in the British isles in 2005 asking about attitudes and practice relating to Caesarean Section (CS) had a 68.3% response rate. This paper reports on consultants' practice. Since our previous survey done in 1990 relating to births in 1989 the use of epidural anaesthesia had increased and the vast majority of caesarean sections were done under epidural or spinal aneasthesia and the majority of consultants allowed the partner to be present at the birth compared with 55% in 1989. Practice varied considerably between consultants in regard to the risks of surgery routinely mentioned, the proportion who would allow a trial of scar after two previous CS and those who would perform a CS at 24 weeks for fetal distress. A third accepted the NICE guidleines about CS fully and only 5% did not accept these with 61% accepting partially despite the lack of evidence for some of their recommendations. The proportion of women monitored routinely in labour had dropped from 45% to 11% although half still had an admission strip performed despite the 2001 guidelines. Few had read, the FIGO Ethics committee recommendations about non-medically indicated CS and it is suggested that the RCOG should bring such information to the attention of members through O&G news. A leaflet explaining the possible risks of CS and the long term implications should be produced by the RCOG alone or in conjunction with the Dept of Health so that women are better informed about these.

British consultants' attitudes to caesareans.

The caesarean rate more than doubled between 1990 and 2004. In this paper, 151 clinical directors give their views about this development. The three main reasons they gave for the rise were: fear of litigation, maternal request and reduced skill of newly appointed consultants and non-consultant staff. However, they provided about 90 reasons overall. Three in five of the consultants thought the local rate was too high; two in five thought it about right; and only one in 74 said it was too low. The major suggestions they gave for reducing the rate were that there should be more consultant input, an increased amount of VBAC, better education of women and discussion at weekly meetings. In addition, three-quarters agreed with 'no fault compensation' in the case of brain damage.

Development of combined imbibition and hydrothermal threshold models to simulate maize (Zea mays) and chickpea (Cicer arietinum) seed germination in variable environments.

* The ability of hydrothermal time (HTT) and virtual osmotic potential (VOP) models to describe the kinetics of maize (Zea mays) and chickpea (Cicer arietinum) seed germination under variable conditions of water potential was investigated with a view to gaining an improved understanding of the impact of on-farm seed priming on seedling establishment through simulation. * Germination and/or imbibition time courses were recorded over a wide range of constant temperatures and water potentials and simple stepwise changes in water potential. * Both models adequately described germination under constant environmental conditions, but not conditions of water potential that varied. To test the hypothesis that this inaccuracy resulted from the use of ambient water potential, a parsimonious model of seed imbibition was developed to calibrate the HTT and VOP models (IHTT and IVOP) and drive them with estimates of seed water potential. * The IHTT and IVOP models described germination during stepwise changes in water potential more accurately than the conventional models, and should contribute to improved predictions of germination time in the field.

Seed reserve-dependent growth responses to temperature and water potential in carrot (Daucus carota L.).

Both temperature and soil moisture vary greatly in the surface layers of the soil through which seedlings grow following germination. The work presented studied the impact of these environmental variables on post-germination carrot growth to nominal seedling emergence. The rapid pre-crook downward growth of both the hypocotyl and root was consistent with their requirement for establishment in soil drying from the surface. At all temperatures, both hypocotyl and root growth rates decreased as water stress increased and there was a very distinct temperature optimum that tended to occur at lower temperatures as water stress increased. A model based on the thermodynamics of reversible protein denaturation was adapted to include the effects of water potential in order to describe these growth rate responses. In general, the percentage of seedlings that reached the crook stage (start of upward hypocotyl growth) decreased at the extremes of the temperature range used and was progressively reduced by increasing water stress. A model was developed to describe this response based on the idea that each seedling within a population has lower and upper temperature thresholds and a water potential threshold which define the conditions within which it is able to grow. This threshold modelling approach which applies growth rates within a distribution of temperature and water potential thresholds could be used to simulate seedling growth by dividing time into suitable units.

Lymphocyte reconstitution following non-myeloablative hematopoietic stem cell transplantation follows two patterns depending on age and donor/recipient chimerism.

The effect of mixed chimerism on the pace of post-transplant immune reconstitution is unknown. Using flow cytometry, recall and neo-antigen vaccine responses, and T cell receptor recombination excision circle (TREC) quantification, we evaluated phenotypic and functional characteristics of T and B cells in nine patients following non-myeloablative, HLA-identical peripheral blood stem cell transplantation for chronic granulomatous disease. Engraftment of T cell, B cell, and myeloid lineages proceeded at similar paces within each patient, but engraftment kinetics segregated patients into two groups: adults, who became full donor T cell chimeras before 6 months (rapid engrafters) and children, who became full donor T cell chimeras after 6 months or not at all (slow engrafters). Quantitative B cell recovery was achieved by 6 weeks after transplantation in children, but was delayed until 1 year in adults. Early quantitative B cell recovery was not accompanied by an early humoral immune response to tetanus toxoid (TT). Emergence of TT-specific T cell responses coincided with naive T cell reconstitution, as measured by CD4/CD45RA T cell recovery and TREC quantification. These data suggest that immune reconstitution occurs faster in pediatric patients who have prolonged mixed hematopoietic chimerism compared to adults, who have rapid donor stem cell engraftment.

Water stress can induce quiescence in newly-germinated onion (Allium cepa L.) seedlings.

The effect of water stress on the early seedling growth of onions was studied by placing newly-germinated seedlings in vermiculite equilibrated at different water potentials. Roots and shoots elongated more at -0.29 than at -0.64 MPa, but did not elongate at -1.66 MPa. However, roots and shoots of seedlings that had been incubated in vermiculite at -1.66 MPa for up to 35 d resumed elongation when subsequently placed on wet filter boards. This suggests that water stress can induce quiescence in newly-germinated seedlings.

Designing a community-based fourth-year obstetrics and gynaecology module: an example of innovative curriculum development.

INTRODUCTION: This paper describes the design and evaluation of the community-based obstetrics and gynaecology module at St Bartholomew's and the Royal London School of Medicine and Dentistry. This module sets out to comply with the General Medical Council's recommendations of encouraging students to consider the community perspective, and places less emphasis on a disease-orientated approach. OBJECTIVES: The development of the module, issues of improving student acceptance of the course, staff development and the benefits of community teaching in obstetrics and gynaecology are discussed. MODULE ORGANIZATION: The 2-week module precedes the 8-week hospital obstetrics and gynaecology firms that occur in the fourth undergraduate year. The course is organized into three components: general practice, departmental teaching, and self-directed learning. Students are allocated to general practices for their clinical teaching, for eight sessions. Seven departmental sessions are run by the Academic Department of General Practice and Primary Care. These include a review of the students' self-directed learning. EVALUATION AND CONCLUSION: Evaluation data are reported for the three components of the course. Overall the majority of students rated the module as useful, GP attachments being most favourably received. The majority of students have grasped the basic obstetric and gynaecological history and examination skills and found this useful before starting their hospital firms. Aspects of a specialist subject, such as, obstetrics and gynaecology, can be taught successfully in the community and GP tutors are, as yet, an untapped source of excellent obstetric and gynaecology teaching.