Social and demographic characteristics of young and mature aged nursing students in Australian universities.

This national study compares the social and demographic characteristics of direct and delay entry students in a control group of 1551 students in higher education programmes in 1987 and 1990 with the national study group of 2295 students sampled in 1995. Using a specially constructed socioeconomic variable for comparison the analyses demonstrated a significant difference in the socioeconomic level of the household for the younger aged group but not for the mature aged group. There was also a significant difference between males and females in their age of entry patterns. Furthermore, there was a significant difference in the location of school attended for most of their secondary education for the younger aged group but not for the mature aged group. For both groups there was a significant difference in the number of siblings, the level of education attained by the mother and the income received by the mother in the households of the control and study groups. Logit analysis revealed that there was a significant interaction between the household variables: socioeconomic status, number of siblings, and income received by the mother of the respondents in the control and study groups for the younger age group but not for the mature age group. This interaction for the younger age group, plus the finding that nursing students were more likely to delay their Higher Education Contribution Scheme (HECS) payment than other university students suggests that politicians need to take great care in any changes to current HECS payments as such changes could upset the delicate social balance that has been achieved in nursing recruitment in Australia.

The social and gender composition of nursing students in Australia: a comparison between 1987-1990 and 1995 recruits.

This national study compares the social and gender characteristics of an earlier group of 1551 students in higher-education programs in 1987 and 1990 with the national study group of 2295 students sampled in 1995. Using a specially constructed socio-economic variable for comparison, the analyses demonstrated a significant difference in the socio-economic level of the household for the female but not the male group. There was a significant difference in the proportion of males entering nursing between the earlier and latter groups. Further, in the latter group, these males were more likely to enter nursing programs directly from school. Members of the female group in the latter sample were more likely to have attended a school in a less populated area, come from households with a reduced family size, have mothers who were earning an income and have mothers who had achieved a higher level of education than was found in the earlier group. Logic analysis revealed that there was a significant interaction between the household variables, socio-economic status, number of siblings and income received by the mother of the respondents in the early and latter groups for females but not for males. This interaction for the female group, plus the finding that members of the latter group were more likely than other university students to defer their Higher Education Contribution Scheme (HECS) payments, suggests that if politicians were to make changes to the HECS it may affect the delicate social balance currently achieved in nursing recruitment in Australia.

Linkage mapping of quantitative trait loci controlling seed weight in pea (Pisum sativum L.).

Quantitative trait loci (QTLs) affecting seed weight in pea (Pisum sativum L.) were mapped using two populations, a field-grown F2 progeny of a cross between two cultivated types ('Primo' and 'OSU442-15') and glasshouse-grown single-seed-descent recombinant inbred lines (RILs) from a wide cross between a P. sativum ssp. sativum line ('Slow') and a P. sativum ssp. humile accession ('JI1794'). Linkage maps for these crosses consisted of 199 and 235 markers, respectively. QTLs for seed weight in the 'Primo' x 'OSU442-15' cross were identified by interval mapping, bulked segregant analysis, and selective genotyping. Four QTLs were identified in this cross, demonstrating linkage to four intervals on three linkage groups. QTLs for seed weight in the 'JI1794' x 'Slow' cross were identified by single-marker analyses. Linkage were demonstrated to four intervals on three linkage groups plus three unlinked loci. In the two crosses, only one common genomic region was identified as containing seed-weight QTLs. Seed-weight QTLs mapped to the same region of linkage group III in both crosses. Conserved linkage relationships were demonstrated for pea, mungbean (Vigna radiata L.), and cowpea (V. unguiculata L.) genomic regions containing seed-weight QTLs by mapping RFLP loci from the Vigna maps in the 'Primo' x 'OSU442-15' and 'JI1794' x 'Slow' crosses.

Inhibitors of phospholipid intracellular signaling as antiproliferative agents.

The improved understanding of oncogenesis and the involvement of oncogenes and tumor suppressor genes, has led to a rational approach of specific target-directed anti-cancer drug development. Cancer genes have been found to be important not only in the control of cell proliferation but also in the mediation of processes such as drug resistance, metastasis, neo-vascularization (angiogenesis), and apoptosis. These are all important targets in their own right and the development of drugs against specific "upstream" targets in oncogenic or growth factor signal transduction cascades it may be possible to inhibit multiple "downstream" targets. Ultimately, to test the hypothesis that signaling pathways offer good targets for anticancer drug development will take several years of careful clinical study and we cannot say at this time whether the approach will work. There are a small number of compounds in the early stages of clinical development as anticancer agents that may act by inhibiting growth factor signaling pathways. In all cases the activity of the compounds on intracellular signaling pathways was discovered after their identification as antiproliferative agents. There are also compounds in preclinical development that have been specifically developed as inhibitors of growth factor signaling, although their selectivity for tumor cells compared to normal tissue remains to be investigated fully in appropriate animal tumor models. It is possible that a single antisignaling drug by itself may not have the power to completely inhibit tumor growth and a combination of drugs may be needed. It may also take a combination of drugs to prevent the emergence of resistance. Clearly there are several challenges to developing this new class of anticancer drugs, and there will undoubtedly be others that must be faced.

Transformation of peas (Pisum sativum L.) using immature cotyledons.

A reliable Agrobacterium tumefaciens-mediated transformation method has been developed for peas (Pisum sativum) using immature cotyledons as the explant source. Transgenic plants were recovered from the four cultivars tested: Bolero, Trounce, Bohatyr and Huka. The method takes approximately 7 months from explant to seed-bearing primary regenerant. The binary vector used carried genes for kanamycin and phosphinothricin resistance. Transformed pea plants were selected on 10 mg/l phosphinothricin. The nptII and bar genes were shown to be stably inherited through the first sexual generation of transformed plants. Expression of the phosphinothricin-resistance gene in the transformed plants was demonstrated using the 'Buster' (='Basta') leaf-paint test and the phosphinothricin acetyl transferase enzyme assay.

Linkage analysis of er-1, a recessive Pisum sativum gene for resistance to powdery mildew fungus (Erysiphe pisi D.C.).

Linkage analysis was used to determine the genetic map location of er-1, a recessive gene conditioning resistance to powdery mildew, on the Pisum sativum genome. Genetic linkage was demonstrated between er-1 and linkage group 6 markers after analyzing the progeny of two crosses, an F2 population and a set of recombinant inbred lines. The classes of genetic markers surrounding er-1 include RFLP, RAPD and allozyme markers as well as the morphological marker Gty. A RAPD marker tightly linked to er-1 was identified by bulked segregant analysis. After DNA sequence characterization, specific PCR primers were designed to convert this RAPD marker into a sequence characterized amplified region (SCAR).

Linkage mapping of sbm-1, a gene conferring resistance to pea seed-borne mosaic virus, using molecular markers in Pisum sativum.

The location of sbm-1 on the Pisum sativum genetic map was determined by linkage analysis with eight syntenic molecular markers. Analysis of the progeny of two crosses confirmed that sbm-1 is on chromosome 6 and permitted a more detailed map of this chromosome to be constructed. The inclusion of Fed-1 and Prx-3 among the markers facilitated the comparison of our map with the classical genetic map of pea. The sbm-1 gene is most closely linked to RFLP marker GS185, being separated by a distance of about 8 cM. To determine the practical value of GS185 as a marker for sbm-1 in plant breeding programs, the GS185 hybridization pattern and virus-resistance phenotype were compared in of a collection of breeding lines and cultivars. Three GS185 hybridization patterns were discerned among the lines. A strong association was found between one of these patterns and resistance to PSbMV.

Expression of virally-transduced mouse tyrosinase in cultured chick embryo cells.

A cDNA encoding mouse tyrosinase was inserted into a plasmid containing the provirus of a replication competent Avian Leukosis Virus (ALV). A viral stock produced from the plasmid was used to infect cultured tyrosinase-negative (ca/ca) unpigmented chick embryo pigment cells. Five days after infection many cells were producing very dark discrete pigment granules. Cultures of tyrosinase positive, sex linked albino (sal) pigment cells produced no additional pigmentation. White Leghorn pigment cells responded to viral infection like the sal pigment cells.

Expression of virally transduced mouse tyrosinase in tyrosinase-negative chick embryo melanocytes in culture.

A cDNA encoding mouse tyrosinase was inserted into a plasmid containing the provirus of a replication competent avian leukosis virus (ALV). A viral stock produced from the plasmid was used to infect cultured tyrosinase-negative (ca/ca) unpigmented chick embryo melanocytes. Five days after infection many cells were producing very dark discrete melanosomes.