Flexure of the oceanic lithosphere in the vicinity of the Marquesas Islands

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1992.Includes bibliographical references (p. 225-234).by Paul Edward Filmer.Ph.D

Improved multitasking following prefrontal tDCS

We have a limited capacity for mapping sensory information onto motor responses. This processing bottleneck is thought to be a key factor in determining our ability to make two decisions simultaneously - i.e., to multitask ( Pashler, 1984, 1994; Welford, 1952). Previous functional imaging research ( Dux, Ivanoff, Asplund, & Marois, 2006; Dux etal., 2009) has localised this bottleneck to the posterior lateral prefrontal cortex (pLPFC) of the left hemisphere. Currently, however, it is unknown whether this region is causally involved in multitasking performance. We investigated the role of the left pLPFC in multitasking using transcranial direct current stimulation (tDCS). The behavioural paradigm included single- and dual-task trials, each requiring a speeded discrimination of visual stimuli alone, auditory stimuli alone, or both visual and auditory stimuli. Reaction times for single- and dual-task trials were compared before, immediately after, and 20min after anodal stimulation (excitatory), cathodal stimulation (inhibitory), or sham stimulation. The cost of responding to the two tasks (i.e., the reduction in performance for dual- vs single-task trials) was significantly reduced by cathodal stimulation, but not by anodal or sham stimulation. Overall, the results provide direct evidence that the left pLPFC is a key neural locus of the central bottleneck that limits an individual's ability to make two simple decisions simultaneously

Applications of transcranial direct current stimulation for understanding brain function

In recent years there has been an exponential rise in the number of studies employing transcranial direct current stimulation (tDCS) as a means of gaining a systems-level understanding of the cortical substrates underlying behaviour. These advances have allowed inferences to be made regarding the neural operations that shape perception, cognition, and action. Here we summarise how tDCS works, and show how research using this technique is expanding our understanding of the neural basis of cognitive and motor training. We also explain how oscillatory tDCS can elucidate the role of fluctuations in neural activity, in both frequency and phase, in perception, learning, and memory. Finally, we highlight some key methodological issues for tDCS and suggest how these can be addressed

Disrupting prefrontal cortex prevents performance gains from sensory-motor training

Humans show large and reliable performance impairments when required to make more than one simple decision simultaneously. Such multitasking costs are thought to largely reflect capacity limits in response selection (Welford, 1952; Pashler, 1984, 1994), the information processing stage at which sensory input is mapped to a motor response. Neuroimaging has implicated the left posterior lateral prefrontal cortex (pLPFC) as a key neural substrate of response selection (Dux et al., 2006, 2009; Ivanoff et al., 2009). For example, activity in left pLPFC tracks improvements in response selection efficiency typically observed following training (Dux et al., 2009). To date, however, there has been no causal evidence that pLPFC contributes directly to sensory-motor training effects, or the operations through which training occurs. Moreover, the left hemisphere lateralization of this operation remains controversial (Jiang and Kanwisher, 2003; Sigman and Dehaene, 2008; Verbruggen et al., 2010). We used anodal (excitatory), cathodal (inhibitory), and sham transcranial direct current stimulation (tDCS) to left and right pLPFC and measured participants' performance on high and low response selection load tasks after different amounts of training. Both anodal and cathodal stimulation of the left pLPFC disrupted training effects for the high load condition relative to sham. No disruption was found for the low load and right pLPFC stimulation conditions. The findings implicate the left pLPFC in both response selection and training effects. They also suggest that training improves response selection efficiency by fine-tuning activity in pLPFC relating to sensory-motor translations

A estrutura do sentimento e das formas sócio-culturais: o sentido de literatura e de experiência para a sociologia da cultura de Raymond Williams

Williams elaborates the concept of structures of feeling in different ways at important points in his writings. This gives it a particular methodological signifi cance in relating the extraordinariness of imaginative literature to the ordinariness of cultural process. It is employed particularly to show the signifi cance of literature for the articulation of alternatives to dominant world views, and thus to the politics of social change. Williams’s different formulations of the concept are discussed in terms of their ways of relating refl exive experience to institutional structures and in relation to the genetic structuralism of Goldmann and Bourdieu’s concepts of habitus and cultural fi eld. Three types of criticisms are considered, which have in common the contention that the concept is unclear. Operationalized in analysing literature and its symbols, it can contribute towards clarifi cation of the complexity of the processes of refl exive communication of experience which are at the root of social order and change.Williams elabora o conceito de estrutura de sentimento de diversas maneiras em vários trechos importantes de sua obra. Este conceito adquire uma signifi cância metodológica especial ao relacionar o extraordinário da literatura imaginativa ao ordinário do processo cultural. Ele é empregado particularmente para mostrar o sentido de literatura na articulação de alternativas para as visões dominantes de mundo, e, consequentemente, para a política da mudança social. As diferentes formulações do conceito apresentadas por Williams são discutidas através da maneira como a experiência refl exiva se relaciona com as estruturas institucionais, com o estruturalismo genérico de Goldmann e com os conceitos de “habitus” e campo cultural de Bourdieu. Três tipos de críticas são levados em conta e têm em comum a ideia de que o conceito não é claro. Ao ser usado na análise da literatura e seus símbolos, este conceito pode contribuir para o esclarecimento da complexidade dos processos de comunicação refl exiva da experiência, que estão enraizados na ordem e na mudança social

Towards a Critical Understanding of Music, Emotion and Self-Identity

The article begins by outlining a dominant conception of these relations in sociologically informed analysis of music, which sees music primarily as a positive resource for active self-making. My argument is that this conception rests on a problematic notion of the self and also on an overly optimistic understanding of music, which implicitly sees music as highly independent of negative social and historical processes. I then attempt to construct a) a more adequately critical conception of personal identity in modern societies; and b) a more balanced appraisal of music-society relations. I suggest two ways in which relations between self, music and society may not always be quite so positive or as healthy as the dominant conception suggests: 1) Music is now bound up with the incorporation of authenticity and creativity into capitalism, and with intensified consumption habits. 2) Emotional self-realisation through music is now linked to status competition. Interviews are analysed

Effects on mortality of a nutritional intervention for malnourished HIV-infected adults referred for antiretroviral therapy: a randomised controlled trial.

Malnourished HIV-infected African adults are at high risk of early mortality after starting antiretroviral therapy (ART). We hypothesized that short-course, high-dose vitamin and mineral supplementation in lipid nutritional supplements would decrease mortality

Predictors for neonatal death in the rural areas of Shaanxi Province of Northwestern China: a cross-sectional study

Background Almost all (99%) neonatal deaths arise in low-income and middle-income countries. Approximately 450 new-born children die every hour, which is mainly from preventable causes. There has been increased recognition of the need for these countries to implement public health interventions that specifically target neonatal deaths. The purpose of this paper is to identify the predictors of neonatal death in Type 4 rural (poorest) counties in Shaanxi Province of northwestern China. Methods A cross-sectional study was conducted in Shaanxi Province, China. A single-stage survey design was identified to estimate standard errors. Because of concern about the complex sample design, the data were analysed using multivariate logistic regression analysis. Socioeconomic and maternal health service utilization factors were added into the model. Results During the study period, a total of 4750 women who delivered in the past three years were randomly selected for interview in the five counties. There were 4880 live births and 54 neonatal deaths identified. In the multiple logistic regression, the odds of neonatal death was significantly higher for multiparous women (OR = 2.77; 95% CI: 1.34, 5.70) and women who did not receive antennal health care in the first trimester of pregnancy (OR = 2.49; 95% CI: 1.41, 4.40). Women who gave birth in a county-level hospital (OR = 0.18; 95% CI: 0.04, 0.86) and had junior high school or higher education level (OR = 0.20; 95% CI: 0.05, 0.84) were significantly protected from neonatal death. Conclusions Public health interventions directed at reducing neonatal death should address the socioeconomic factors and maternal health service utilization, which significantly influence neonatal mortality in rural China. Multipara, low educational level of the women, availability of prenatal visits in the first trimester of pregnancy and hospital delivery should be considered when planning the interventions to reduce the neonatal mortality in rural areas

Child Mortality in Rural Malawi: HIV Closes the Survival Gap between the Socio-Economic Strata

BACKGROUND: As HIV-related deaths increase in a population the usual association between low socioeconomic status and child mortality may change, particularly as death rates from other causes decline. METHODS/PRINCIPAL FINDINGS: As part of a demographic surveillance system in northern Malawi in 2002-6, covering a population of 32,000, information was collected on socio-economic status of the households. Deaths were classified as HIV/AIDS-related or not by verbal autopsy. Poisson regression models were used to assess the association of socio-economic indicators with all-cause mortality, AIDS-mortality and non-AIDS mortality among children. There were 195 deaths in infants, 109 in children aged 1-4 years, and 38 in children aged 5-15. All-cause child mortality in infants and 1-4 year olds was similar in households with higher and lower socio-economic status. In infants 13% of deaths were attributed to AIDS, and there were no clear trends with socio-economic status for AIDS or non-AIDS causes. For 1-4 year olds 27% of deaths were attributed to AIDS. AIDS mortality was higher among those with better built houses, and lowest in those with income from farming and fishing, whereas non-AIDS mortality was higher in those with worse built houses, lowest in those with income from employment, and decreased with increasing household assets. CONCLUSIONS/SIGNIFICANCE: In this population, since HIV infection among adults was initially more common among the less poor, childhood mortality patterns have changed. The usual gap in survival between the poor and the less poor has been lost, but because the less poor have been disproportionately affected by HIV, rather than because of relative improvement in the survival of the poorest