Seed factors involved in early seedling establishment of Festuca arundinacea (tall fescue) : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Plant Biology and Biotechnology at Massey University, New Zealand

New Zealand pastures are commonly based on vigorously growing Lolium (ryegrass) species. In many situations, however, it is often advantageous to combine the vigorous qualities of Lolium species with the versatility of other species such as Festuca arundinacea (tall fescue) to result in a pasture which is high in quality all year. F. arundinacea, however, has poor seedling vigour which places it at a competitive disadvantage when sown with Lolium. During seedling establishment, the seedling is dependent upon the food reserves present in the seed. The nature and amount of these reserves and the ability of the seed to mobilise them are therefore likely to have an affect on seedling perfonnance. While much knowledge exists about the processes involved in seed reserve mobilisation in some cereals, little information is available for pasture grasses. An in depth investigation of the behaviour of one seed lot of F. arundinacea was undertaken in order to gain a more detailed understanding of germination, reserve mobilisation and establishment processes in pasture grasses and how they relate to the processes of seedling growth. Comparisons between this species and Lolium multiflorum (Italian ryegrass) were undertaken throughout the study. Germination and seedling growth of the F. arundinacea seed lot was found to be heterogenous and slower than in L. multiflorum due to later radicle emergence. Mobilisation of reserves and the onset of α-amylase activity correlated well with the utilisation of reserves in L. multiflorum. In both prechilled and non prechilled F. arundinacea seeds, however, anomalies were identified in the process which indicated that reserve mobilisation was less tightly coupled to seedling growth in F. arundinacea. Reciprocal plot analyses indicated that the beneficial effects of prechilling in most seeds of the F. arundinacea seed lot were not related to residual dormancy but were a thermal time benefit. It appears prechilling was allowing rate limiting steps in embryo growth to be advanced before visible germination. Apart from this, no real differences were detected in the way the two species mobilised reserves. Differences in the appearance of α-amylase isoenzymes of F. arundinacea at different times during germination indicated that gene expression may be under some complex differential control mechanisms during germination and reserve mobilisation. Prechilling was not found to change the spectrum of isoenzymes, but merely to advance the time-course in which different isoenzymes appeared. There were also distinct differences in α-amylase isoenzyme patterns between F. arundinacea and L. multiflorum, and also wheat. Preliminary studies indicated that exogenous gibberellic acid was more effective in promoting α-amylase production in L. multiflorum than in F. arundinacea. However, α-amylase production in F. arundinacea was more susceptible to promotion by prechilling. This study has identified a wide range of variables impacting on germination and seedling establishment in F. arundinacea. This, together with the lack of previous detailed studies on grass seed germination and seedling growth and the lack of literature on F. arundinacea germination in particular, highlights the enormity of the task ahead of extending key areas of this study to different seed lots and species

In Vitro small intestinal motility in horses with and without equine grass sickness

This thesis describes investigations of small intestinal motility in horses with and without equine grass sickness using an in vitro technique. Equine grass sickness is a disease of horses of unknown aetiology, characterised by dysfunction of the autonomic nervous system, primarily affecting the alimentary tract. Examination of autonomic ganglia taken from horses affected with grass sickness shows evidence of neuronal degeneration and ultimately depletion of cell numbers.The in vitro technique implemented used strips of intestinal smooth muscle cut parallel to the longitudinal muscle layer from the duodenum and ileum. Tissue was taken from control horses and those affected with the three clinical forms of grass sickness (acute [AGS], subacute [SAGS] and chronic grass sickness [CGS]). Motility patterns were measured isometrically using strain gauge transducers and recorded onto a Washington ink writing oscillograph. Contraction rate and amplitude, alterations in tone (baseline) and the latency before a response to pharmacological agents were recorded.The characteristics of the background contractions were established. In the control group the duodenal preparations had a significantly higher contractile rate than ileal preparations (P<0.05). There was no significant difference in contractile amplitude between the two regions. The contractile rate was reduced in grass sickness cases, although not always significantly. The effect of storage for 24 hours at 4"C was investigated to determine whether stored control tissue would subsequently behave like fresh grass sickness tissue: it was concluded that this was not the case.Physostigmine was used to establish the viability of enteric cholinergic neurones and to test their capacity to release endogenous acetylcholine. All muscle strips from both control horses and those affected with grass sickness showed significant increases in the rate of contractions following physostigmine addition (P<0.05 or less). The latency before a response to physostigmine in the AGS and SAGS groups was significantly larger than for the control groups in both regions of the gut (PcO.OOl for duodenal tissue, P<0.05 for ileal tissue). The effect of storage on responses to physostigmine confirmed that neuronal cell death takes place during this iii storage period. Grass sickness tissue could no longer produce a significant increase in contractile rate following physostigmine. Dose response curves to bethanecol were constructed for control, AGS and CGS tissue. For the AGS group there was a leftward shift of the dose response curve and a reduced ED50 value, which suggested that the tissue has become supersensitive (denervation hypersensitivity). However, there were no significant differences between the tissue sensitivity of the CGS and the control groups.Cisapride is a prokinetic drug which has been used with some clinical success in the treatment of selected chronic grass sickness cases. Experiments using cisapride indicated there was an increase in the contractile rate in control and CGS duodenal muscle strips (P<0.06) and in control, AGS and CGS groups in ileal regions (P<0.06). Cisapride also caused an increase in the amplitude of contractions in ileal muscle strips taken from control horses (P<0.06).In agreement with other workers, it was found that in vitro equine small intestine contracts oa addition of noradrenaline or adrenaline. This contractile response was found to be due to excitatory a2 receptors on the smooth muscle membrane. Grass sickness affected tissue responded similarly to control tissue in the duodenal region, however, in certain AGS and SAGS cases no contractile response to noradrenaline could be achieved until tissue was pretreated with the (3 antagonist propranolol. As cold storage had no significant effect on the contractile response to noradrenaline it would suggest the response was independent of nervous elementsA subjective histological scoring method was applied on sections of small intestine adjacent to those used in pharmacological experiments, to investigate neuronal cell number, size and the proportion of abnormal cells in the myenteric and submucous plexuses. There was a significantly lower score for neuronal cell number for the AGS and CGS groups compared with control values (P<0.05). The evidence suggested that in CGS cases the largest enteric neurones were preferentially affected by grass sickness (P<0.05). In the ileal AGS group, the proportion of abnormal cells was significantly greater than both the control and CGS ileal groups (P<0.05). In the duodenum there was no significant difference between the proportion of abnormal cells between the AGS and CGS groups, although they were both awarded significantly higher scores than the control group (P<0.05)

Intergenerational Transmission of Healthy Eating Behaviour and the Role of Household Income

This paper investigates the possibility of intergenerational transmission of unhealthy eating habits from parents to adult children. It uses the 2003 Scottish Health Survey and estimates the association between the present healthy eating behaviour of adult children and the past parental death from cardiovascular disease (CVD). It uses parental CVD death as an adverse health signal which may cause a healthy eating compensatory response in adult children. This response is due to increased chances and perception of genetic predisposition of adult children as well as an indicator for parental past unhealthy eating habits which may have been passed onto the adult children. Regression analysis suggests that paternal history has no impact on either sons or daughters, and maternal history influences negatively the eating behaviour of daughters only. Unhealthy eating intergenerational transmission appears to be more intense amongst lower household income individuals.intergenerational transmission, healthy eating, household income, cardiovascular disease, public health, gender

A Study of Problems in Family Functioning in Long Term Male Hospital Patients

The topic for this exploratory study arose out of the question “What happens to long term male hospital patients when they return home?” The assumption is that men who have been absent from their homes and families for long term hospital treatment have some difficulty fitting in to the pattern of family life on their return. They may have difficulty in re-establishing a mutually satisfactory relationship with their wives and children. They may find it stress producing to reassume their role in decision making, in exercising authority and in providing economic security and a satisfactory style of living. The results of this study will indicate to medical social workers when and in what areas treatment around discharge to home situations should begin. This would be preventative social work, following the identification of a potential problem-solving situation. There might be a use for family therapy here in fostering some husband/father role retention and in preparing all members of the family to deal with the necessary adjustment in accommodating the long absent family member. Treatment of patient groups might be a method of helping the men foresee their problems and motivate their resources to deal with them as effectively as possible

The effect of gonadotrophins on follicular development and subsequent oocyte competence

The growth and development of the ovarian follicle is a long and complex process. Throughout this process the oocyte maintains close contact with the surrounding somatic cells and through bi-directional communication acquires the developmental programs necessary for fertilisation and embryonic development. During the latter phase of follicular development the signals between oocyte and the somatic cells are dependent on stimulation by the gonadotrophin hormones, FSH and LH. The precise and individual role that FSH and LH play in this tightly co-ordinated process has yet to be determined. Despite this, exogenous administration of gonadotrophin preparations is used extensively in clinical and agricultural settings as a means of obtaining a large number of oocytes for use in ART. However, the basic question as to what affects gonadotrophins have on oocyte development within the follicle prior to ovulation remains to be answered. The main aim of this thesis was to use an animal model, the mouse, to begin to address this question.In an attempt to distinguish between intra follicular and inter follicular/extra ovarian effects, experiments were performed using both in vitro and in vivo models. The results obtained using the hypogonadal mouse as an in vivo model were limited. However they did show that stimulation by both gonadotrophins might be necessary to induce sufficient ovarian oestrogen production to prime the reproductive tract prior to pregnancy. After optimising the in vitro system, which gave interesting insights into the nutritional aspects of follicular development, the results obtained indicated that elevation of LH during the follicular growth phase affected the ability of the oocyte to complete pre-implantation development.Manipulation of gonadotrophins resulted in alterations in the production of the sex steroids. Both androgens and oestrogens are potential mediators of gonadotrophin action. Using a different experimental paradigm this was investigated directly by elevating androgens, oestrogens or both steroids in vitro. It was found that the fertilisation rates of the oocytes was adversely affected by elevating oestrogens but positively correlated in the presence of elevated androgens.Whether oestrogen plays an obligatory role within the ovary is controversial. The finding that two receptors exist for this steroid has complicated the issue. Investigations using the ERKO transgenic mouse and in vitro techniques have gone some way towards clarifying this situation. Lack of the ERa receptor does not impair follicular development or developmental competence of the oocyte. Observations made during these experiments and those using the hypogonadal mouse suggest that oestrogen may facilitate the ovulatory process.In conclusion the findings presented in this thesis have demonstrated that androgens, independently of oestrogens, are a necessary component of the signalling system in follicular development and subsequent oocyte maturation. Additionally, alterations in the pattern of intra-follicular steroid production either directly, or as a result of manipulating gonadotrophin levels such as occurs during ovulation induction, can influence the viability and developmental potential of the oocyte

A Study of Problems in Family Functioning in Long Term Male Hospital Patients

The topic for this exploratory study arose out of the question “What happens to long term male hospital patients when they return home?” The assumption is that men who have been absent from their homes and families for long term hospital treatment have some difficulty fitting in to the pattern of family life on their return. They may have difficulty in re-establishing a mutually satisfactory relationship with their wives and children. They may find it stress producing to reassume their role in decision making, in exercising authority and in providing economic security and a satisfactory style of living. The results of this study will indicate to medical social workers when and in what areas treatment around discharge to home situations should begin. This would be preventative social work, following the identification of a potential problem-solving situation. There might be a use for family therapy here in fostering some husband/father role retention and in preparing all members of the family to deal with the necessary adjustment in accommodating the long absent family member. Treatment of patient groups might be a method of helping the men foresee their problems and motivate their resources to deal with them as effectively as possible

Neural indicators of fatigue in chronic diseases : A systematic review of MRI studies

The authors would like to thank the Sir Jules Thorn Charitable Trust for their financial support.Peer reviewedPublisher PD

How can universities ‘ASSIST’ student midwives with additional needs to achieve?

Previous articles have discussed how pre-registration midwifery education should prepare student midwives ‘to cope with the complex emotional and physical demands of their chosen profession’ (Power, 2016a:66); acknowledged the importance of a partnership approach to education through the ‘Clinicians in the Classroom’ series (Power, 2016b; Power and Rea, 2016; Power and Rooth, 2016; Power and Gupta, 2016; Power and Briody, 2016) and considered how best to support student midwives with appropriate learning and teaching strategies (Power and Farmer, 2017). What is yet to be considered is what extra support is available to students who have additional needs, disabilities or medical conditions that might impact on their studies. This article will take the University of Northampton as a case study and review the support services it has in place to support such students to meet their full potential. This service is called The Additional Student Support and Inclusion Services Team (ASSIST)