814 resultados para Parental alienation
Resumo:
The memoir The Other Country and the essay Inspiration is Power examine i) contemporary experiences of autism and ii) the representation of autism disorder in scientific and autobiographical writing. The Other Country is a memoir of four years in the life of its author Michael Whelan, and his family, in the care of his son, Charlie. In February 1998, Charlie was diagnosed with autism, and in that moment Michael and his family's lives changed. The memoir describes in four parts a four-year journey through a father?s experiences: - Part 1, Welcome to Holland, the family's feelings of fear, grief and dislocation following diagnosis; - Part 2, Look at Me, the chaotic process of research and treatment, and intense early intervention programs; - Part 3, The Enchanted Cottage, the slow process of recovery that the family went through, and; - Part 4, The Long Way Home, the transformation of Charlie, Michael and his family and notions of home and normalcy. The title, The Other Country, in this context refers to the largely invisible parallel society inhabited by anyone who lives outside the mainstream. The accompanying critical essay, Inspiration is Power, examines the influence of the discourses of biomedical science and parental pathology on the representation and understanding of autism. Specifically, among autism narratives, the medical voice has an overwhelming authority and power in characterizing autistic disorder and experience for the lay reader. This discourse contests the moral authority of parental autobiographical writing, which, by contrast, characterizes autism as a personalized invading other and thief of their child. Through a critique of specific aspects of identity, narrative, evidence and authority, the essay suggests a register of rhetorical moves that may be employed to influence, and consequently empower, the reader of autism narratives.
Resumo:
Telomere length (TL) has been associated with aging and mortality, but individual differences are also influenced by genetic factors, with previous studies reporting heritability estimates ranging from 34 to 82%. Here we investigate the heritability, mode of inheritance and the influence of parental age at birth on TL in six large, independent cohort studies with a total of 19 713 participants. The meta-analysis estimate of TL heritability was 0.70 (95% CI 0.64–0.76) and is based on a pattern of results that is highly similar for twins and other family members. We observed a stronger mother–offspring (r=0.42; P-value=3.60 × 10−61) than father–offspring correlation (r=0.33; P-value=7.01 × 10−5), and a significant positive association with paternal age at offspring birth (β=0.005; P-value=7.01 × 10−5). Interestingly, a significant and quite substantial correlation in TL between spouses (r=0.25; P-value=2.82 × 10−30) was seen, which appeared stronger in older spouse pairs (mean age ≥55 years; r=0.31; P-value=4.27 × 10−23) than in younger pairs (mean age<55 years; r=0.20; P-value=3.24 × 10−10). In summary, we find a high and very consistent heritability estimate for TL, evidence for a maternal inheritance component and a positive association with paternal age.
Resumo:
The immune system has to recognize and destroy abnormal or infected cells to maintain homeostasis. Natural killer (NK) cells directly recognize and kill transformed or virus-infected cells without prior sensitization. We have studied both virus-infected and tumor cells in order to identify the target structures involved in triggering NK activity. Mouse/human cell hybrids containing various human chromosomes were used as targets. The human chromosome responsible for activating NK cell killing was identified to chromosome number 6. The results suggest that activated NK cells recognize ligands that are encoded on human chromosome 6. We showed that the ligand on the target cell side was intercellular adhesion molecule 2 (ICAM-2). There was no difference in the level of expression of ICAM-2, however, but a drastic difference was seen in the distribution of the molecule: ICAM-2 was evenly distributed on the surface of the NK-resistant cells, but almost totally redistributed to the tip of uropods, bud-like extensions, which were absent from the parental cells. Interestingly, the gene coding for cytoskeletal linker protein ezrin has been localized to human chromosome 6, and there was a colocalization of ezrin and ICAM-2 in the uropods. Furthermore, the transfected human ezrin into NK cell-resistant cells induced uropod formation, ICAM-2 and ezrin redistribution to newly formed uropods, and sensitized target cells to NK cell killing. These data reveal a novel form of NK cell recognition: target structures are already present on normal cells; they become detectable only after abnormal redistribution into hot spots on the target cell membrane. NK cells are central players in the defence against virus infections. They inhibit the spread of infection, allowing time for specific immune responses to develop. The virus-proteins that directly activate human NK cell killing are largely unknown. We studied the sensitivity of virus-specific early proteins of Semliki Forest virus (SFV) to NK killing. The viral non-structural proteins (nsP1-4) translated early in the virus cycle were transfected in NK-resistant cells. Viral early gene nsP1 alone efficiently sensitized target cells to NK activity, and the tight membrane association of nsP1 seems to be critical in the triggering of NK killing. NsP1 protein colocalized with (redistributed) ezrin in filopodia-like structures to which the NK cells were bound. The results suggest that also in viral infections NK cells react to rapid changes in membrane topography. Based on the results of this thesis, a new model of target cell recognition of NK cells can be suggested: reorganization of the cytoskeleton induces alterations in cell surface topography, and this new pattern of surface molecules is recognized as "altered-self".
Resumo:
The reproductive biology of two invasive tilapia species, Oreochromis mossambicus and Tilapia mariae, resident in freshwater habitats in north-eastern Australia was investigated. Oreochromis mossambicus exhibited plasticity in some of its life-history characteristics that enhanced its ability to occupy a range of habitats. These included a shallow, weed-choked, freshwater coastal drain that was subject to temperature and dissolved oxygen extremes and water-level fluctuations to cooler, relatively high-altitude impoundments. Adaptations to harsher conditions included a decreased total length (LT) and age ( A) at 50% maturity (m50), short somatic growth intervals, early maturation and higher relative fecundities. Potential fecundity in both species was relatively low, but parental care ensured high survival rates of both eggs and larvae. No significant difference in the relative fecundity of T. mariae populations in a large impoundment and a coastal river was found, but there were significant differences in relative fecundities between several of the O. mossambicus populations sampled. Total length ( LT) and age at 50% maturity of O. mossambicus populations varied considerably depending on habitat. The LTm50 and Am50 values for male and female O. mossambicus in a large impoundment were considerably greater than for those resident in a small coastal drain. Monthly gonad developmental stages and gonado-somatic indices suggested that in coastal areas, spawning of O. mossambicus and T. mariae occurred throughout most of the year while in cooler, high-altitude impoundments, spawning peaked in the warmer, summer months. The contribution these reproductive characteristics make to the success of both species as colonizers is discussed in the context of future control and management options for tilapia incursions in Australia.