In the Zapotitan Valley near San Andres, El Salvador, Central America, an experiment was conducted to determine the availability of residual soil N to corn grown during the rainy season. This was an extension of an experiment conducted during the preceding dry season. The variables of the dry season experiment were irrigation method, crop, and rate of fertilizer N application. Soil N03-N and NH4-N were determined by soil sample analysis to a soil depth of 120 em by 30 em depth increments. The samples were taken at the end of the dry season experiment and again at harvest time of the wet season experiment. Yield of corn grown during the rainy season was measured. The results indicate the following: (1) soil N03-N alone was an efficient indicator of residual soil N; (2) there was a linear increase of soil N03-N with N applied four months previously at the beginning of the dry season crops; (3) soil sampled to the 30 cm depth was sufficient to estimate availability of the residual N; (4) corn yields increased linearly with the increase of soil N03-N; (5) the measurement of residual soil N03-N can be used as a soil text index in connection with N prediction equations for estimating fertilizer N requirements. The measurements of soil N03-N can, therefore, increase the efficiency of fertilizer use in a wet-dry tropical climate.

Growth chamber studies showed that a relationship exists between transpiration and dry matter production of spring wheat (Tritiaum Aestivum L. var . Thatcher). A temperature of 27 C for a 16-hour day,and 21 C at night were used throughout the experiment. Relative humidities (RH) of 12, 25, 71, and 83 percent and matric suctions of 1, 3, and 9 bars were used a l ong with six fertility levels and a 20-day growing period. An equation was developed from previous equations by De Wit and Arkley to describe the transpiration ratio (Tr = mass of water transpired/mass of dry matter produced) as it relates to evaporative demand conditions measured by humidity and pan evaporation. Time and fertility effects were not included because of insufficient data. As humidity both increases and decreases from 25 percent, the transpiration ratio decreases. Increasing levels of matric suction had an effect on Tr only at 25 percent RH. As fertility increased, Tr decreased toward some minimum level. Tr seems to reach a stable maximum as plants mature under steady state conditions.

We study the aggregate gap between intended and actual fertility in 19 European countries and the US based on a cohort approach. This complements prior research that had mainly used a period approach. We compare the mean intended number of children among young women aged 20 to 24 (born in the early 1970s), meas ured during the 1990s in the Fertility and Family Surveys, with data on completed fertility in the same cohorts around age 40. In a similar manner, we compare the share who state that they do not want a child with actual cohort childlessness. Our exploration is informed by the cognitive-social model of fertility intentions devel- oped by Bachrach and Morgan (Popul Dev Rev 39(3):459-485, 2013). In all coun- tries, women eventually had, on average, fewer children than the earlier expectations in their birth cohort, and more often than intended, they remained childless. The results reveal distinct regional patterns, which are most apparent for childlessness. The gap between intended and actual childlessness is widest in the Southern Euro- pean and the German-speaking countries and smallest in the Central and Eastern European countries. Additionally, we analyze the aggregate intentions-fertility gap among women with different levels of education. The gap is largest among highly educated women in most countries studied and the educational gradient varies by region, most distinctively for childlessness. Differences between countries suggest that contextual factors-norms about parenthood, work-family policies, unemployment-shape women's fertility goals, total family size, and the gap between them.

Abstract not available

Bovine reproductive performance is one of the most important factors influencing dairy farm profitability. Present-day techniques for oestrus- and pregnancy-detection are unreliable and labour-intensive. Although measuring milk-progesterone at regular intervals allows the fertility status of a cow to be determined reliably, the labour cost of collecting and analysing samples is prohibitive. This project aimed to develop a progesterone sensing system that could be automated and integrated with the milking unit, thus minimising labour costs. The proposed system involved mixing the milk sample with an enzyme-antibody conjugate and then passing the sample through a column containing immobilised progesterone. Any progesterone in the milk would inhibit conjugate binding to the column. An enzyme substrate would then flow through the column and bound conjugate would be detected as a colour change at the column's outlet. Periodate-coupling was used to attach horseradish peroxidase enzyme to anti-progesterone antibody, and progesterone-3-carboxymethyloxime was immobilised on the polystyrene bead surface using amine-coupling. Both techniques are widely used. Initial experiments attempted to verify the success of these two reactions simultaneously, whereas later experiments focused on the bead-coating. Beads were suspended in a specially-constructed syringe and the antibody activity of the eluted solution was measured by SPR. However, a combination of non-specific binding and antibody stability and activity issues meant neither reaction was conclusively verified. Many trials were done to investigate how to overcome the problems encountered but a suitable, workable procedure was not developed. Despite poor progress, the problems encountered did not undermine the project's potential. There remains optimism of developing an on-line method if research were to continue.

Bibliography: leaves [124-153]

How fast and how far China’s fertility declined in the 1990s has long been a matter of considerable debate, despite very low fertility consistently being reported in a number of statistical investigations over time. Most demographers interpreted this as a result of serious underreporting of births in population statistics, due to the family planning program, especially the program strengthening after 1991. Consequently, they suggested that fertility fell only moderately below-replacement level, around 1.8 children per woman from the early 1990s. But some demographers argued that surveys and census may have reflected a real decline of fertility even allowing for some underreporting of births, given the consistency between data sources and over time. They believed that fertility declined substantially in the 1990s, very likely in the range between 1.5 and 1.6 by the year 2000.¶ The controversy over fertility is primarily related to the problem of underreporting of births, in particular the different estimations of the extent of underreporting. However, a correct interpretation of fertility data goes far beyond the pure numbers, which calls for a thorough understanding of different data sources, the programmatic and societal changes that occurred in the 1990s, and their effects on both fertility changes and data collection efforts. This thesis aims to address the question whether the reported far-below-replacement level fertility was a reality of substantial fertility decline or just an illusion arising from underreporting of births. Given the nature of the controversy, it devotes most efforts in assessing data quality, through examining the patterns, causes and extent of underreporting of births in each data source; reconstructing the decline of fertility in the 1990s; and searching corroborating evidence for the decline.¶ After reviewing programmatic changes in the 1990s, this thesis suggests that the program efforts were greatly strengthened, which would help to bring fertility down, but the birth control policy and program target were not tightened as generally believed. The program does affect individual reporting of births, but the completeness of births in each data source is greatly dependent on who collects fertility data and how the data are collected. The thesis then carefully examines the data collection operations and underreporting of births in five sets of fertility data: the hukou statistics, the family planning statistics, population census, annual survey and retrospective survey. The analysis does not find convincing evidence that fertility data deteriorated more seriously in the 1990s than the preceding decade. Rather, it finds that surveys and censuses have a far more complete reporting of births than the registration-based statistics, because they directly obtain information from respondents, largely avoiding intermediate interference from local program workers. In addition, the detailed examination suggests that less than 10 percent births may have been unreported in surveys and censuses. The annual surveys, which included many higher-order our-of-plan births being misreported as first-order births, have more complete reporting of births than censuses, which were affected by the increasing population mobility and field enumeration difficulties, and retrospective surveys, which suffered from underreporting of higher-order births.¶ Using the unadjusted data of annual surveys from 1991 to 1999, 1995 sample census and 2000 census, this research shows that fertility first dropped from 2.3 to 1.7 in the first half of the 1990s, and further declined to a lower level around 1.5-1.6 in the second half of the decade. The comparison with other independent sources corroborates the reliability of this estimation. Putting China’s fertility decline in international perspective, comparison with the experiences of Thailand and Korea also supports such a rapid decline. Subsequently, the thesis reveals an increasingly narrow gap between state demands and popular fertility preferences, and great contributions from delayed marriage and nearly universal contraception. It is concluded that the fertility declined substantially over the course of the 1990s and dropped to a very low level by the end of last century. It is very likely that the combination of a government-enforced birth control program and rapid societal changes quickly moved China into the group of very low-fertility countries earlier than that might have been anticipated, as almost all the others are developed countries.

Human granulosa cells play an important role in the follicle, providing the oocyte with nutrients and growth factors to ensure successful ovulation. Normal granulosa cell functioning is thus crucial to human fertility. By studying their transcriptome, the mechanisms underpinning follicle development and infertility will be better understood. In this study, granulosa cells were retrieved at the time of oocyte removal for in vitro fertilization (IVF). Cells were purified through a combination of a Percoll gradient to remove red blood cells and positive selection of granulosa cell aggregations. On average, contamination by white blood cells was 2% as measured by FACS analysis using specific white blood cell markers. Histological and electron microscopy of granulosa cell aggregations did not detect evidence of resident ovarian white blood cells. This technique provided a good source of pure, healthy granulosa cells for RNA extraction and subsequent gene expression studies. The construction of a human granulosa cell SAGE library derived 1689 SAGEtags and 1289 discrete mRNA transcripts. SAGEtags for a number of well recognized granulosa cell genes (FSH receptor, follistatin, connexin 43) were found in addition to hormone receptors, multiple kinases, structural genes, apoptosis related genes and secreted proteins. A variety of other SAGE libraries were downloaded from SAGEmap (two ovary epithelium, ovary, white blood cell, brain, cerebellum, heart, liver, lung, kidney, pancreas and universal human reference) and compared to the human granulosa cell library. This was based on two measures: a gene specificity score (GSS) and a tissue specificity score (TSS). Three SAGEtags were identified with high levels of expression in granulosa cells, but no or low expression in the other libraries. These were retinol binding protein 1 (RBP 1), scavenger receptor class B member 1 (SCARB 1) and hydroxysteroid (11-beta) dehydrogenase 1 (11-β-HSD). Library comparisons were validated by real time RT-PCR. The TSS score revealed granulosa cells were most similar to the universal reference library and least similar to liver. Granulosa cell samples were collected from woman undergoing IVF for a range of infertility disorders. These included polycystic ovary syndrome (PCOS), tubal disease, endometriosis and idiopathic (unknown). Gene expression was compared between these groups using real time RT-PCR. Candidate genes included RBP 1, 11-β-HSD, SCARB 1, FSH receptor, follistatin, decidual protein induced by progesterone, and progesterone membrane receptor component 1 and 2. Granulosa cell gene expression was significantly different (p<0.05) from human white blood cells. No differences were found in gene expression levels between the infertility disorders. Analysis of each patient, however, revealed individuals with marked over-expression of selected genes. The technique of Generation of Longer cDNA fragments for Gene Identification (GLGI) was used to investigate seven SAGEtags that did match known genes or ESTs. Although no novel genes were characterized, a further 14 granulosa cell transcripts were identified by this technique. This thesis used an integrated approach to the study of human granulosa cell gene expression. This has involved development of a purification method, the use of a high-throughput technique (SAGE), bioinformatics tools to identify candidates genes, real time RT-PCR to investigate gene expression of particular genes in infertility disorders and finally a technique with the potential to characterize unknown SAGEtags (GLGI). This systematic approach has advanced the understanding of gene expression in human granulosa cells and identified avenues for future research into folliculogenesis and human infertility.

Bibliography: leaves [124-153] / x, 123 leaves : ill. (chiefly col.) ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Obstetrics and Gynaecology, 2001

Typescript (photocopy) Includes bibliographical references (leaves 198-259) The role of gonadal steroids in the mating behaviour of rams was investigated in both entire rams and castrated rams (wethers) treated with different steroids.