984 resultados para Rowan, Andrew Summers.


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This paper describes algorithms that can identify patterns of brain structure and function associated with Alzheimer's disease, schizophrenia, normal aging, and abnormal brain development based on imaging data collected in large human populations. Extraordinary information can be discovered with these techniques: dynamic brain maps reveal how the brain grows in childhood, how it changes in disease, and how it responds to medication. Genetic brain maps can reveal genetic influences on brain structure, shedding light on the nature-nurture debate, and the mechanisms underlying inherited neurobehavioral disorders. Recently, we created time-lapse movies of brain structure for a variety of diseases. These identify complex, shifting patterns of brain structural deficits, revealing where, and at what rate, the path of brain deterioration in illness deviates from normal. Statistical criteria can then identify situations in which these changes are abnormally accelerated, or when medication or other interventions slow them. In this paper, we focus on describing our approaches to map structural changes in the cortex. These methods have already been used to reveal the profile of brain anomalies in studies of dementia, epilepsy, depression, childhood and adult-onset schizophrenia, bipolar disorder, attention-deficit/ hyperactivity disorder, fetal alcohol syndrome, Tourette syndrome, Williams syndrome, and in methamphetamine abusers. Specifically, we describe an image analysis pipeline known as cortical pattern matching that helps compare and pool cortical data over time and across subjects. Statistics are then defined to identify brain structural differences between groups, including localized alterations in cortical thickness, gray matter density (GMD), and asymmetries in cortical organization. Subtle features, not seen in individual brain scans, often emerge when population-based brain data are averaged in this way. Illustrative examples are presented to show the profound effects of development and various diseases on the human cortex. Dynamically spreading waves of gray matter loss are tracked in dementia and schizophrenia, and these sequences are related to normally occurring changes in healthy subjects of various ages. (C) 2004 Published by Elsevier Inc.

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Although well recognized and studied in developed countries, canine parasitic zoonoses pose a lowly prioritized public health problem in developing countries such as India, where conditions are conducive for transmission. A study of the most recent parasite survey determining prevalence and epidemiology of canine parasitic zoonoses among tea-growing communities of northeast India demonstrated the endemicity of the problem. This particular study serves as a model using conventional, as well as molecular parasitological, tools to provide novel insights into the role of dogs as mechanical transmitters of human parasites such as Ascaris and Trichuris, and discusses the risks dogs pose with regards to zoonotic transmission of hookworms and Giardia.

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This work concerns the influence of industrialized agriculture in the tropics on precipitation chemistry. A total of 264 rain events were sampled using a wet-only collector in central Sao Paulo State, Brazil, between January 2003 and July 2007. Electroneutrality balance calculations (considering H(+), K(+), Na(+), NH(4)(+), Ca(2)(+), Mg(2)(+), Cl(-), NO(3)(-), SO(4)(2-), F(-), PO(4)(3-), H(3)CCOO(-), HCOO(-), C(2)O(4)(2-) and HCO(3)(-)) showed that there was an excess of cations (similar to 15%), which was attributed to the presence of unmeasured organic anion species originating from biomass burning and biogenic emissions. On average, the three ions NH(4)(+), NO(3)(-) and H(+) were responsible for >55% of the total ion concentrations in the rainwater samples. Concentrations (except of H(+)) were significantly higher (t-test; P = 0.05), by between two to six-fold depending on species, during the winter sugar cane harvest period, due to the practice of pre-harvest burning of the crop. Principal component analysis showed that three components could explain 88% of the variance for measurements made throughout the year: PC1 (52%, biomass burning and soil dust resuspension); PC2 (26%, secondary aerosols); PC3 (10%, road transport emissions). Differences between harvest and non-harvest periods appeared to be mainly due to an increased relative importance of road transport/industrial emissions during the summer (non-harvest) period. The volume-weighted mean (VWM) concentrations of ammonium (23.4 mu mol L(-1)) and nitrate (17.5 mu mol L(-1)) in rainwater samples collected during the harvest period were similar to those found in rainwater from Sao Paulo city, which emphasizes the importance of including rural agro-industrial emissions in regional-scale atmospheric chemistry and transport models. Since there was evidence of a biomass burning source throughout the year, it appears that rainwater composition will continue to be affected by vegetation fires, even after sugar cane burning is phased out as envisaged by recent Sao Paulo State legislation. (C) 2011 Elsevier Ltd. All rights reserved.

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The literature examining purported relationships between ownership of companion animals and health is extremely heterogeneous. While much of the descriptive literature tends to support benefits of animal companionship, large scale, controlled research yields inconsistent and even contradictory findings on several issues, including associations with cardiovascular disease, mood and wellbeing. In an analysis of a large longitudinal data-set from the Australian Longitudinal Study on Women's Health, a prospective study of a nationally representative sample of more than 12,000 older women, difficulties with disentangling the effects of powerful demographic variables and age-related factors from the specific effects of pet ownership became apparent. Both cross-sectional and longitudinal analyses demonstrated that associations between mental and physical health and pet ownership as well as changes in pet ownership over time were weak and inconsistent compared to the large effects of living arrangements and other demographic variables. As sociodemographic variables relate strongly to both health and opportunities for pet ownership, this high level of confounding means it is unlikely that the impact of the specific variable of pet ownership on health can be ascertained from such studies. Rather, well-designed experimental studies, wherein the majority of such confounding variables can be held constant or at least somewhat controlled, are needed.

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The pathways involved in the maintenance of human embryonic stem (hES) cells remain largely unknown, although some signaling pathways have been identified in mouse embryonic stem (mES) cells. Fibroblast feeder layers are used to maintain the undifferentiated growth of hES cells and an examination of the conditioned media (CM) of human neonatal fibroblasts (HNFs) could provide insights into the maintenance of hES cells. The neonatal foreskin fibroblast line (HNF02) used in this study was shown to have a normal 2n = 46, XY chromosomal complement and to support the undifferentiated growth of the Embryonic Stem Cell International Pte. Ltd.-hES3 cell line. The CM of HNF02 was examined using two-dimensional liquid chromatography-tandem mass spectrometry (2-D LCMS) and two-dimensional electrophoresis (2-DE) followed by matrix-assisted laser desorption/ionization-time of flight tandem mass spectrometry (2-DE/MALDI). A total of 102 proteins were identified, 19 by 2-DE/MALDI, 53 by 2-D LCMS and 30 by both techniques. These proteins were classified into 15 functional groups. Proteins identified in the extracellular matrix and differentiation and growth factor functional categories were considered most likely to be involved in the maintenance of hES cell growth, differentiation and pluripotency as these groups contained proteins involved in a variety of events including cell adhesion, cell proliferation and inhibition of cell proliferation, Writ signaling and inhibition of bone morphogenetic proteins.

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Selected Papers from the 5th International Symposium on Applied Isotope Geochemistry, Heron Island, Great Barrier Reef, Australia, 26–30 May 2003

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Drosophila Fallen, 1823 (Diptera, Drosophilidae) is for long a well-established model organism for genetics and evolutionary research. The ecology of these flies, however, has only recently been better studied. Recent papers show that Drosophila assemblies can be used as bioindicators of forested environment degradation. In this work the bioindicator potential of drosophilids was evaluated in a naturally opened environment, a coastal strand-forest (restinga). Data from nine consecutive seasonal collections revealed strong temporal fluctuation pattern of the majority of Drosophila species groups. Drosophila willistoni group was more abundant at autumns, whereas D. cardini and D. tripunctata groups were, respectively, expressive at winters and springs, and D. repleta group at both seasons. The exotic species D. simulans Sturtevant, 1919 (from D. melanogaster group) and Zaprionus indianus Gupta, 1970 were most abundant at summers. Overall, the assemblage structure did not show the same characteristics of forested or urban environments, but was similar to the forests at winters and to cities at summers. This raises the question that this locality may already been under urbanization impact. Also, this can be interpreted as an easily invaded site for exotic species, what might lead to biotic homogenization and therefore can put in check the usage of drosophilid assemblages as bioindicators at open environments.

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The purpose of this study was to investigate urban-rural differentials in Australian suicide rates, and to examine influences that previously have remained largely speculative. Suicide rates for males (all ages and young adults) were significantly higher in rural areas compared to urban areas. Urban-rural suicide rate differences in males were rendered nonsignificant after adjustment for migrant and area socioeconomic status. Adjusting for mental disorder prevalence, in addition to migrant status, reduced the excess suicide risk in rural areas; the excess was reduced further with addition of mental health service utilization. The implications of this study are that socioeconomic circumstances in rural populations contribute to higher male suicide rates compared to urban areas, but these conditions may be partly mediated by mental disorder prevalence and mental health service utilization.

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A history of agricultural production is proposed for Neolithic Catalhoyuk East, central Turkey, using archaeobotanical, environmental, population and settlement studies. In the aceramic early phase of site occupation, intensive strategies developed as changes in population and environment caused stress on food supplies produced within a limited territory. Food exchange may have been part of the social means by which Catalhoyuk and nearby contemporary settlements amalgamated into the single site of the main occupation phase. Population change, inherited territories and continuing environmental impact led to the development of an extensive system of agriculture using widely dispersed dry soils, with an intensive regime applied to nearby alluvial soils. Social tensions caused by the evolution of this system contributed to the fissioning of the site by the Chalcolithic.

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This paper investigates the relationship between suicide rates and prevalence of mental disorder and suicide attempts, across socio-economic status (SES) groups based on area of residence. Australian suicide data (1996-1998) were analysed in conjunction with area-based prevalences of mental disorder derived from the National Survey of Mental Health and Well-Being (1997). Poisson regression models of suicide risk included age, quintile of area-based SES, urban-rural residence, and country of birth (COB), with males and females analysed separately. Analysis focussed on the association between suicide and prevalences of (ICD-10) affective disorders, anxiety disorders, substance use disorders and suicide attempts by SES group. Prevalences of other psychiatric symptomatology, substance use problems, health service utilisation, stressful life-events and personality were also investigated. Significant increasing gradients were evident from high to low SES groups for prevalences of affective disorders, anxiety disorders (females only), and substance use disorders (males only); sub-threshold drug and alcohol problems and depression; and suicide attempts and suicide (males only). Prevalences of mental disorder, other sub-threshold mental health items and suicide attempts were significantly associated with suicide, but in most cases associations were reduced in magnitude and became statistically non-significant after adjustment for COB, urban-rural residence, and SES. For male suicide the relative risk (RR) in the lowest SES group compared to the highest was 1.40 (95% CI 1.29-1.52, p < 0.001) for all ages, and 1.46 (95% CI 1.27-1.67, p < 0.001) for male youth (20-34 years). This relationship was not substantially modified in males when regression models included prevalences of affective disorders, and other selected mental health variables and demographic factors. From a population perspective, SES remained significantly associated with suicide after controlling for the prevalence of mental disorders and other psychiatric symptomatology. Mental conditions and previous suicidal behaviour may play an intermediary role between SES and suicide, but this study suggests that an independent relationship between suicide and SES also exists. (c) 2005 Elsevier Ltd. All rights reserved.

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Objectives: To evaluate the effect of a radio and newspaper campaign encouraging Italian-speaking women aged 50-69 years to attend a population-based mammography screening program. Methods: A series of radio scripts and newspaper advertisements ran weekly in the Italian-language media over two, four-week periods. Monthly mammography screens were analysed to determine if numbers of Italian-speaking women in the program increased during the two campaign periods, using interrupted time series regression analysis. A survey of Italian-speaking women attending BreastScreen NSW during the campaign period (n=240) investigated whether individuals had heard or seen the advertisements. Results: There was no statistically significant difference in the number of initial or subsequent mammograms in Italian-speaking women between the campaign periods and the period prior to (or after) the campaign. Twenty per cent of respondents cited the Italian media campaign as a prompt to attend. Fifty per cent had heard the radio ad and 30% had seen the newspaper ad encouraging Italian-speaking women to attend BSNSW. The most common prompt to attend was the BSNSW invitation letter, followed by information or recommendation from a GP. Conclusion: Radio and newspaper advertisements developed for the Italian community did not significantly increase attendance to BSNSW. Implications: Measures of program effectiveness based on self-report may not correspond to aggregate screening behaviour. The development of the media campaign in conjunction with the Italian community, and the provision of appropriate levels of resourcing, did not ensure the media campaign's success.

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Direct accelerator mass spectrometry (AMS) dating of anaerobically preserved plant remains from the Dongan site in New Guinea, combined with assessment of preservation condition, confirms earlier doubts about the antiquity of betel-nut (Areca catechu L.) found at the site. A possible sago leaf fragment is also identified as a modem contaminant. The mid-Holocene age of other fruit and nut remains is verified using these methods. The utility of AMS dating in combination with detailed archaeobotanical assessment is demonstrated, thus improving chronometric hygiene and with it knowledge of past plant use in Oceania.