Regulation of Ovarian Function by the Germ Cell Specific DAZL Gene

The RNA binding protein DAZL (Deleted in Azoospermia) is essential for germ cell survival and subsequent fertility. The transgenic mouse DAZL model has confirmed that knockout (KO) females are infertile as a direct consequence of complete postnatal oocyte ablation. Interestingly, the heterozygous (Het) DAZL females have increased fertility giving rise to significantly more viable offspring, accompanied by significantly reduced plasma FSH and increased inhibin B compared to levels observed in the wildtype (Wt) females. Recent studies to identify putative DAZL mRNA targets suggest that DAZL may have multiple functions and mRNA targets throughout germ cell development. However, how this protein functions within the oocyte and how functional copy number gives rise to increased fertility remains to be fully elucidated.The studies in this thesis sought to identify putative DAZL mRNA targets in addition to molecular mechanisms which may be either affected direct or indirectly as a result of the functional copy number of DAZL (Wt or Het) within the oocyte or follicular unit. Oocytes from Wt and Het were evaluated for their expression of selected oocyte genes and comparative analysis suggests that oocyte gene expression is significantly altered between the genotypes. Genes of interest include Oospl and Hlfoo, both of which are down-regulated in mRNA expression in Het d21 oocytes and dlO ovaries compared to the Wt. Furthermore, an in silico bioinformatics approach was utilised to identify putative DAZL mRNA targets using a consensus DAZL binding sequence. One candidate target, PDCD4, previously identified as a tumour suppressor gene was selected for further investigation. Despite PDCD4 mRNA and protein being highly expressed within the ovary, no difference in mRNA levels between Het and Wt was observed. However, although not ruling out the possibility of being a DAZL target we now have evidence that PDCD4 can function within the steroidogenic cells of the corpus luteum in relation to functional luteolysis. Abstract Indirect actions of DAZL upon local regulation and response of follicle growth in culture were evaluated to investigate follicles at the gonadotrophin dependent stage of growth. Individual follicles from Wt and Het d21 mice were cultured in the presence of FSH at liu, 0.5iu, O.liu and O.Oliu for a six day period. Final follicle size/morphology did not differ between genotypes at liu, 0.5iu and O.liu of FSH, but by d3 at O.Oliu FSH growth o f Wt follicles was significantly (PO.OOl) perturbed compared to the Het. Despite no difference in final size between liu, 0.5iu, O.liu FSH treatments, mRNA analysis of individual follicles demonstrated a significant up-regulation of FSH receptor (P<0.05), aromatase (P<0.05) and inhibin PA (P<0.01) and a significant down-regulation in inhibin PB (P<0.01) expression in the Het follicles compared to the Wt, suggesting an increase in follicle maturity, sensitivity and hence suitability for selection as viable pre-ovulatory follicles. Furthermore, atresia rates from cultured follicles were significantly lower (P<0.05 (liu, O.liu FSH); P<0.01(0,01iu FSH)) in the Het compared to the Wt.These studies provide strong evidence that multiple mechanisms within the oocyte/follicle are directly and indirectly affected as a result of functional copy number of DAZL. Although direct in vivo targets remain to be identified it is clear that DAZL protein potentially targets multiple mRNAs at different stages of development, pre-programming the oocyte to increase the sensitivity of follicle and/or the functioning within a transcription complex regulating development. In conclusion, the beneficial consequences of increased fertility in the Het females is accompanied by a possible acceleration in oocyte and follicle maturation, an increased sensitivity to FSH in vitro with evidence of advanced stages of growth and, a reduction in follicle atresia. These differences support the suggestion that DAZL is having systemic effects on the paracrine communication within the follicle unit between the oocyte and somatic cells altering regulation and subsequent selection, and affecting final ovulation rate and litter size

Annual Report Readership: A Study of an Agricultural Supply Cooperative

Recent corporate collapses have focussed attention on the (un)reliability of financial information. However, although the agricultural sector, which is significant globally, is run primarily using the cooperative form, there is scant research on these users' perception of financial information. Therefore this paper examines members' readership and understanding of the annual reports of a large, fertiliser cooperative. The findings show that there is a lack of readership of the annual report, due to a lack of understanding and a lack of time. A minority of non-readers trust directors to "do a good job". Preparers of information should focus on making reports more user-friendly and evidence suggests that financial information could be released more strategically using other sources of communication, namely other print media and the internet.cooperatives, annual reports, readership, understanding, Agribusiness,

Non-contact free-form shape measurement for coordinate measuring machines

Precision measurement of manufactured parts commonly uses contact measurement methods. A Coordinate Measuring Machine (CMM) mounted probe touches the surface of the part, recording the probe’s tip position at each contact. Recently, devices have been developed that continuously scan the probe tip across the surface, allowing points to be measured more quickly. Contact measurement is accurate and fast for shapes that are easily parameterized such as a sphere or a plane, but is slow and requires considerable user input for more general objects such as those with free-form surfaces. Phase stepping fringe projection and photogrammetry are common non-contact shape measurement methods. Photogrammetry builds a 3D model of feature points from images of an object taken from multiple perspectives. In phase stepping fringe projection a series of sinusoidal patterns, with a phase shift between each, is projected towards an object. A camera records a corresponding series of images. The phase of the pattern at each imaged point is calculated and converted to a 3D representation of the object’s surface. Techniques combining phase stepping fringe projection and photogrammetry were developed and are described here. The eventual aim is to develop an optical probe for a CMM to enable non-contact measurement of objects in an industrial setting. For the CMM to accurately report its position the probe must be small, light, and robust. The methods currently used to provide a phase shift require either an accurately calibrated translation stage to move an internal component, or a programmable projector. Neither of these implementations can be practically mounted on a CMM due to size and weight limits or the delicate parts required. A CMM probe consisting of a single camera and a fringe projector was developed. The fringe projector projects a fixed fringe pattern. Phase steps are created by moving the CMM mounted probe, taking advantage of the geometry of the fringe projection system. New techniques to calculate phase from phase stepped images created by relative motion of probe and object are proposed, mathematically modelled, and tested experimentally. Novel techniques for absolute measurement of surfaces by viewing an object from different perspectives are developed. A prototype probe is used to demonstrate measurements of a variety of objects.Engineering and Physical Sciences Research Council (EPSRC) Grant No. GR/T11289/0

Integrating reading and literature into content area curriculum through thematic units

The goals of this project include developing a way to efficiently teach the many required subjects in the overloaded elementary school day and incorporating litrature into content area curriculum

MS

thesisMean arterial blood pressures were measured peripherally in the upper and lower positions of the right leg, right arm, and left arm by a neonate oscillometric blood pressure machine. They also were compared to the mean arterial pressures measured centrally by an umbilical artery catheter or radial arterial line. The study consisted of 10 infants (3 males, 7 females) 1,200 grams or less. Measurements were obtained in each infant for 3 consecutive days. The data collected were analyzed by computer statistical analysis. The analysis revealed that day and day by location were significant. However, the standard deviations were so great that further analysis was not continued. The physiological significance of these findings was discussed. In order to obtain a correct clinical evaluation, the importance of knowing these physiological variances of blood pressure in infants was stressed

‘My Body Feels Old’: Seniors’ Discursive Constructions of Aging-as-Disabling

Social gerontology and disability studies have made similar but separate arguments for ways to study aging and disability, respectively. This study of interviews with seniors finds that seniors characterize aging as disabling and position both identity constructions as negative. The article argues for the use of disability theory and discourse to examine seniors’ lived experiences

Understanding the Perceptions of High School Dropouts with Disabilities in the Commonwealth of the Northern Mariana Islands

Over the last 5 years, high school students with disabilities in the Commonwealth of the Northern Mariana Islands (CNMI) have experienced a higher rate of dropout compared to their peers, adding to an ever-widening gap in learning and graduation rates. The rationale for this study was the growing numbers of dropouts among students with disabilities that contribute to high rates of poor performing schools and create a burden on the local and federal government as the CNMI employment rates decline and reliance on the U.S. government for support increases. The purpose of this study was to understand the experiences of students with disabilities who drop out of high school, their perceptions of the learning environment, and the factors that contributed to their decisions to drop out. The conceptual framework was the constructivist theory. To answer what influenced high school students with disabilities to drop out of school and to what extent their perceptions of the constructivist element of belonging, engagement, or advocacy contributed to their decision to drop out, a qualitative case study design was used. Interviews were conducted with 10 former students who dropped out between 2013 and 2016 school years from high schools in the CNMI. Thematic analysis was used for emergent themes. Findings included that students do not receive their high school diploma because school policies prevented them due to age and lack of credits. Poor learning environments hindered students\u27 engagement. Poor teachers\u27 advocacy also hindered students\u27 graduation. The findings can be used by school district leaders and staff in the implementation of effective interventions for improving graduation outcomes for students with disabilities in order for these students to become contributing members of society through gainful employment and enhanced quality of life

Forebrain Origins of Glutamatergic Innervation to the Rat Paraventricular Nucleus of the Hypothalamus: Differential Inputs to the Anterior Versus Posterior Subregions

The hypothalamic paraventricular nucleus (PVN) regulates numerous homeostatic systems and functions largely under the influence of forebrain inputs. Glutamate is a major neurotransmitter in forebrain, and glutamate neurosignaling in the PVN is known to mediate many of its functions. Previous work showed that vesicular glutamate transporters (VGluTs; specific markers for glutamatergic neurons) are expressed in forebrain sites that project to the PVN; however, the extent of this presumed glutamatergic innervation to the PVN is not clear. In the present study retrograde FluoroGold (FG) labeling of PVN-projecting neurons was combined with in situ hybridization for VGluT1 and VGluT2 mRNAs to identify forebrain regions that provide glutamatergic innervation to the PVN and its immediate surround in rats, with special consideration for the sources to the anterior versus posterior PVN. VGluT1 mRNA colocalization with retrogradely labeled FG neurons was sparse. VGluT2 mRNA colocalization with FG neurons was most abundant in the ventromedial hypothalamus after anterior PVN FG injections, and in the lateral, posterior, dorsomedial, and ventromedial hypothalamic nuclei after posterior PVN injections. Anterograde tract tracing combined with VGluT2 immunolabeling showed that 1) ventromedial nucleus-derived glutamatergic inputs occur in both the anterior and posterior PVN; 2) posterior nucleus-derived glutamatergic inputs occur predominantly in the posterior PVN; and 3) medial preoptic nucleus-derived inputs to the PVN are not glutamatergic, thereby corroborating the innervation pattern seen with retrograde tracing. The results suggest that PVN subregions are influenced by varying amounts and sources of forebrain glutamatergic regulation, consistent with functional differentiation of glutamate projections. J. Comp. Neurol. 519:1301–1319, 2011. © 2010 Wiley-Liss, Inc

Changing the νmax⁡\nu_{\max} Scaling Relation: The Need For a Mean Molecular Weight Term

The scaling relations that relate the average asteroseismic parameters $\Delta \nu$ and $\nu_{\max}$ to the global properties of stars are used quite extensively to determine stellar properties. While the $\Delta \nu$ scaling relation has been examined carefully and the deviations from the relation have been well documented, the $\nu_{\max}$ scaling relation has not been examined as extensively. In this paper we examine the $\nu_{\max}$ scaling relation using a set of stellar models constructed to have a wide range of mass, metallicity, and age. We find that as with $\Delta \nu$, $\nu_{\max}$ does not follow the simple scaling relation. The most visible deviation is because of a mean molecular weight term and a $\Gamma_1$ term that are commonly ignored. The remaining deviation is more difficult to address. We find that the influence of the scaling relation errors on asteroseismically derived values of $\log g$ are well within uncertainties. The influence of the errors on mass and radius estimates is small for main sequence and subgiants, but can be quite large for red giants.Comment: 15 pages, 14 figures, accepted for publication in Ap