180 resultados para Early-Bronze pontic cultures
em University of Queensland eSpace - Australia
Resumo:
The causes of schizophrenia are unknown, but there is evidence linking subtle deviations in neural development with schizophrenia. Embryonic brain development cannot be studied in an adult with schizophrenia, but neurogenesis and early events in neuronal differentiation can be investigated throughout adult life in the human olfactory epithelium. Our past research has demonstrated that neuronal cultures can be derived from biopsy of the human adult olfactory epithelium. In the present study, we examined mechanisms related to neurogenesis and neuronal differentiation in adults with schizophrenia versus well controls. Forty biopsies were collected under local anaesthesia from ten individuals with DSM III-R schizophrenia and ten age- and sex-matched well controls. All patients, except one, were receiving antipsychotic medication at the time of the biopsy, Immunostaining for neuronal markers indicated that neurogenesis occurred in the biopsies from both patients and controls since all contained cells expressing tubulin and/or olfactory marker protein. The major findings of this study are: 1. biopsies from patients with schizophrenia showed a significantly reduced ability to attach to the culture slide: 29.9% of patient biopsies attached compared to 73.5% of control biopsies; 2. biopsies from patients with schizophrenia had a significantly greater proportion of cells undergoing mitosis: 0.69% in the patients compared to 0.29% in the controls; and 3. dopamine (10 mu M) significantly increased the proportion of apoptotic cells in the control cultures but significantly decreased the proportion in patients' cultures. (C) 1999 Elsevier Science B.V. All rights reserved.
Resumo:
Early pregnancy factor (EPF) is a secreted protein with growth regulatory and immunomodulatory properties. It is an extracellular form of the mitochondrial matrix protein chaperonin 10 (Cpn10), a molecular chaperone. An understanding of the mechanism of action of EPF and an exploration of therapeutic potential has been limited by availability of purified material. The present study was undertaken to develop a simple high-yielding procedure for preparation of material for structure/function studies, which could be scaled up for therapeutic application. Human EPF was expressed in Sf9 insect cells by baculovirus infection and in Escherichia coli using a heat inducible vector. A modified molecule with an additional N-terminal alanine was also expressed in E coli. The soluble protein was purified from cell lysates via anion exchange (negative-binding mode), cation exchange, and hydrophobic interaction chromatography, yielding similar to42 and 36 mg EPF from 300 ml bacterial and I L Sf9 cultures, respectively. The preparations were highly purified ( greater than or equal to99% purity on SDS-PAGE for the bacterial products and greater than or equal to97% for that of insect cells) and had the expected mass and heptameric structure under native conditions, as determined by mass spectrometry and gel permeation chromatography, respectively. All recombinant preparations exhibited activity in the EPF bioassay, the rosette inhibition test, with similar potency both to each other and to the native molecule. In two in vivo assays of immuno suppressive activity, the delayed-type hypersensitivity reaction and experimental autoimmune encephalomyelitis, the insect cell and modified bacterial products, both with N-terminal additions (acetylation or amino acid), exhibited similar levels of suppressive activity, but the bacterial product with no N-terminal modification had no effect in either assay. Studies by others have shown that N-terminal addition is not necessary for Cpn10 activity. By defining techniques for facile production of molecules with and without immunosuppressive properties, the present studies make it possible to explore mechanisms underlying the distinction between EPF and Cpn10 activity. (C) 2003 Elsevier Inc. All rights reserved.
Resumo:
Passive avoidance learning is with advantage studied in day-old chicks trained to distinguish between beads of two different colors, of which one at training was associated with aversive taste. During the first 30-min post-training, two periods of glutamate release occur in the forebrain. One period is immediately after the aversive experience, when glutamate release is confined to the left hemisphere. A second release, 30 min later, may be bilateral, perhaps with preponderance of the right hemisphere. The present study showed increased pool sizes of glutamate and glutamine, specifically in the left hemisphere, at the time when the first glutamate release occurs, indicating de novo synthesis of glutamate/glutamine from glucose or glycogen, which are the only possible substrates. Behavioral evidence that memory is extinguished by intracranial administration at this time of iodoacetate, an inhibitor of glycolysis and glycogenolysis, and that the extinction of memory is counteracted by injection of glutamine, supports this concept. A decrease in forebrain glycogen of similar magnitude and coinciding with the increase in glutamate and glutamine suggests that glycogen rather than glucose is the main source of newly synthesized glutamate/glutamine. The second activation of glutamatergic activity 30 min after training, when memory is consolidated into stable, long-term memory, is associated with a bilateral increase in pool size of glutamate/glutamine. No glycogenolysis was observed at this time, but again there is a temporal correlation with sensitivity to inhibition by iodoacetate and rescue by glutamine, indicating the importance of de novo synthesis of glutamate/glutamine from glucose or glycogen. (C) 2003 Elsevier B.V All rights reserved.
Resumo:
Patterns of first sexual activity among Australians born between the 1940s and 1980s were analysed using data from a national telephone survey of 1784 adults (876 males; 908 females). Sixty-one percent of those randomly selected from the Australian electoral roll and contactable by telephone responded. Many trends, including earlier first intercourse - from 20 to 18 years (females) and 18.8 to 17.8 years (males) - were established with the 40-49 year cohort, whose sexual debut was in the late 1960s-70s. Significant age-cohort effects saw women in the contemporary (18-29 year) cohort draw level with males for age at first intercourse and first sex before age 16 and before leaving school. First intercourse contraceptive use climbed from 30% to 80'%. Condom use quadrupled to 70%. Australian age-cohort effects are remarkably consistent with those in similar western cultures: gender convergence in sexual experience and increasing avoidance of sexually transmitted disease and pregnancy. If such trends continue, positive long-term outcomes for health and social wellbeing should result.
Resumo:
Most studies on kidney development have considered the interaction of the metanephric mesenchyme and the ureteric bud to be the major inductive event that maintains tubular differentiation and branching morphogenesis. The mesenchyme produces Gdnf, which stimulates branching, and the ureteric bud stimulates continued growth of the mesenchyme and differentiation of nephrons from the induced mesenchyme. Null mutation of the Wt1 gene eliminates outgrowth of the ureteric bud, but Gdnf has been identified as a target of Pax2, but not of Wt1. Using a novel system for microinjecting and electroporating plasmid expression constructs into murine organ cultures, it has been demonstrated that Vegfa expression in the mesenchyme is regulated by Wt1. Previous studies had identified a population of Flk1-expressing cells in the periphery of the induced mesenchyme, and adjacent to the stalk of the ureteric bud, and that Vegfa was able to stimulate growth of kidneys in organ culture. Here it is demonstrated that signaling through Flk1 is required to maintain expression of Pax2 in the mesenchyme of the early kidney, and for Pax2 to stimulate expression of Gdnf. However, once Gdnf stimulates branching of the ureteric bud, the Flk1-dependent angioblast signal is no longer required to maintain branching morphogenesis and induction of nephrons. Thus, this work demonstrates the presence of a second set of inductive events, involving the mesenchymal and angioblast populations, whereby Wt1-stimulated expression of Vegfa elicits an as-yet-unidentified signal from the angioblasts, which is required to stimulate the expression of Pax2 and Gdnf, which in turn elicits an inductive signal from the ureteric bud.
Resumo:
Age-related changes in the adult language addressed to children aged 2;0-4;0 years in polyadic conditions were investigated in Australian childcare centres. The language that 21 staff members addressed to these children was coded for multiple variables in the broad social categories of prosody, context, speech act and gesture. The linguistic components were coded within the categories of phonology, lexicon, morphology, syntax and referential deixis. Minimal age-related differences were found. Explanations for the similarity of the adult language input across the age groups within the early childhood educational environment, will be discussed
Resumo:
There is a morpheme 'li' in Mauritian Creole (MC), which is homophonous with the 3sg pronoun, and which, in the early creole, occurs frequently between the subject and the predicate in affirmative, present tense clauses. I propose that that 'li' may have originated as a resumptive pronoun, co-referential with the subject, but following the grammaticalization of new determiner elements to mark the semantic contrasts of [±definite] and singular vs. plural, 'li' has now grammaticalized into a predicate marker. Its presence is sensitive to both the nature of the predicate, and to the definiteness and specificity features of the subject NP. My analysis is within the framework of Truth Conditional Semantics, where indefinite NPs are analyzed as variables that get introduced into the discourse, and must be bound by an operator to yield a closed proposition, with a truth value. Drawing on a comparison with a cognative morpheme 'i' in Seychellois Creole, I claim that its path to grammaticalization is linked to that of the specificity marking 'la'.
Letters of the Great Kings of the Ancient Near East: The Royal Correspondence of the Late Bronze Age
Resumo:
This is a highly original study of possession by demons and their exorcism, which was rife in early modern times, focussing on the place where they were most prevalent, France. Catholics at the time believed that the devil was present everywhere, in the rise of the heretics, in the activities of witches, and even in the bodies of the pious young women. The rite of exorcism was intended to heal the possessed and show the power of the church - but it generated as many problems as it resolved. Possessed nuns endured frequently violent exorcisms, exorcists were suspected of conjuring devils, and possession itself came to be seen as a form of holiness, elevating several women to the status of living saints. Sarah Ferber offers a challenging study of one of the most intriguing phenomena of early modern Europe; looking also at the present day, it argues that early modern conflicts over the devil still carry an unexpected force and significance for western Christianity (from publisher).
Resumo:
The project was commissioned to investigate and analyse the issue of effective support for distance education students in the early years of school to maximise literacy and numeracy outcomes. The scope of this project was limited to students living in rural and remote areas who are undertaking education at home and who are in their early years of schooling. For the purpose of this project, the early years are conceptualised as the first three years of formal compulsory schooling in each of the States and Territories. There were a number of key tasks for the project which included: 1. Examining of the role of home tutors/supervisors This included interviewing personnel from the State and Territory distance education providers as well as the principals, teachers, home tutors and children. 2. Describing literacy and numeracy teaching and learning, and the use of information and communication technologies (ICT) in distance education This aspect of the project involved a critical review and analysis of relevant literature and reports in the last five years, and a consideration of the new initiatives that had been implemented in the States and Territories in the last two years. 3. The development of resources Through examination of the role of home tutors/supervisors, and an examination of literacy and numeracy and the use of technology in distance education, three resources were developed: ● A guide for home tutors/supervisors and schools of distance education about effective intervention and assessment strategies to support students’ learning and to assist the home tutors/supervisors in implementing ICT to support the development of literacy and numeracy in the early years. ● A calendar of activities for literacy and numeracy that would act as a stimulus for integrated and authentic activity for young children. ● An embryonic website of resources for the stakeholders in rural and distance education that might act as a catalyst for future resource building and sharing. In this way the final key task of the project, which was to create a context for a strategic dissemination plan, was realised when a strategy to address effective dissemination of the findings of the project so as to maximise their usefulness for the relevant groups was achieved.
Resumo:
Previous studies have shown that multiple ; birth children (MBC) are prone to early phonological ;difficulties and later literacy problems. However, to date, ;there has been no systematic long-term follow-up of MBC with phonological difficulties in the preschool years to determine whether these difficulties predict later literacy problems. In this study, 20 MBC whose early speech and language skills had been previously documented were compared to normative data and 20 singleton controls on tasks assessing phonological ; processing and literacy. The major findings indicated that MBC performed significantly more poorly on some tasks :df phonological processing than singleton controls did. Further, the early phonological skills of MBC (i.e., the number of inappropriate phonological processes used) correlated with poor performance on visual rhyme recognition, word repetition, and phoneme detection tasks 5 years later. There was no significant relationship between early biological factors (birth weight and gestation period) and performance on the phonological processing and literacy-related subtests. These results cl-support the hypothesis that MBC's early speech and language difficulties are not merely a transient phase;of; development, but a real disorder, with consequences for later academic achievement.
Resumo:
Background & Aims: An elevated transferrin saturation is the earliest phenotypic abnormality in hereditary hemochromatosis. Determination of transferrin saturation remains the most useful noninvasive screening test for affected individuals, but there is debate as to the appropriate screening level. The aims of this study were to estimate the mean transferrin saturation in hemochromatosis heterozygotes and normal individuals and to evaluate potential transferrin saturation screening levels. Methods: Statistical mixture modeling was applied to data from a survey of asymptomatic Australians to estimate the mean transferrin saturation in hemochromatosis heterozygotes and normal individuals. To evaluate potential transferrin saturation screening levels, modeling results were compared with data from identified hemochromatosis heterozygotes and homozygotes. Results: After removal of hemochromatosis homozygotes, two populations of transferrin saturation were identified in asymptomatic Australians (P < 0.01). In men, 88.2% of the truncated sample had a lower mean transferrin saturation of 24.1%, whereas 11.8% had an increased mean transferrin saturation of 37.3%. Similar results were found in women, A transferrin saturation threshold of 45% identified 98% of homozygotes without misidentifying any normal individuals. Conclusions: The results confirm that hemochromatosis heterozygotes form a distinct transferrin saturation subpopulation and support the use of transferrin saturation as an inexpensive screening test for hemochromatosis. In practice, a fasting transferrin saturation of greater than or equal to 45% identifies virtually all affected homozygous subjects without necessitating further investigation of unaffected normal individuals.