22 research outputs found

    Qualitative and quantitative assessment of magnetic vestibular stimulation in humans

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    The sensation of phantom motion or exhibition of bodily sway is often reported in the proximity of an MR scanner. It is proposed that the magnetic field stimulates the vestibular system. There are a number of possible mechanisms responsible, and the relative contributions of susceptibility on the otolithic receptors and the Lorentz force on the cupulae have not yet been explored. This exploratory study aims to investigate the impact of being in the proximity of a 7.0 T MR scanner. The modified clinical test of sensory interaction on balance (mCTSIB) was used to qualitatively ascertain whether or not healthy control subjects who passed the mCTSIB in normal conditions 1) experienced subjective sensations of dizziness, vertigo or of leaning or shifting in gravity when in the magnetic field and 2) exhibited visibly increased bodily sway whilst in the magnetic field compared to outside the magnetic field. Condition IV of the mCTSIB was video recorded outside and inside the magnetic field, providing a semi-quantitative measure of sway. For condition IV of the mCTSIB (visual and proprioceptive cues compromised), all seven locations/orientations around the scanner yielded significantly more sway than at baseline (

    Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus

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    Idiopathic congenital nystagmus (ICN) is characterised by involuntary, periodic, predominantly horizontal, oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 ICN singleton cases (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina suggesting a specific role in the control of eye movement and gaze stability

    Communicating Information on Eruptions and Their Impacts from the Earliest Times Until the Late Twentieth Century

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    Volcanoes hold a fascination for human beings and, before they were recorded by literate observers, eruptions were portrayed in art, were recalled in legends and became incorporated into religious practices: being viewed as agents of punishment, bounty or intimidation depending upon their state of activity and the culture involved. In the Middle East the earliest depiction of an eruption is a wall painting dating from the Neolithic at Çatal Hüyük and the earliest record dates from the third millennium BCE. Knowledge of volcanoes increased over time. In some parts of the world knowledge of eruptions was passed down by oral transmission, but as far as written records were concerned, in the first century CE only 9 volcanoes in the Mediterranean region were recognised, together with Mount Cameroon in West Africa. In the next 1000 years the list grew by 17, some 14 of these volcanoes being in Japan. The first recorded eruptions in Indonesia occurred in 1000 and 1006, and volcanoes in newly settled Iceland increased the number to just 48 in 1380 CE. After this the list continued to increase, with important regions such as New Zealand and Hawaii only being added in the past 200 years. Only from 1900 did the rate of growth decline significantly (Simkin et al. 1981: 23; Simkin, 1993 Siebert et al. 2011; Simkin, 1993), but it is sobering to recall that in the twentieth century major eruptions have occurred from volcanoes that were considered inactive or extinct examples including: Mount Lamington - Papua New Guinea, 1951; Mount Arenal - Costa Rica, 1968 and Nyos - Cameroon, 1986. Although there are instances where the human impact of historical eruptions have been compiled - with examples including the 1883 eruption of Krakatau (Simkin and Fiske (1983) and 1943 -1952 eruption of Parícutin (Luhr and Simkin, 1993) - these are exceptions and there remains a significant gap in knowledge about both the short and long-term effects on societies of major eruptions which occurred before the 1980s. Following a broad review the chapter provides a discussion of the ways in which information has been collected, compiled and disseminated from the earliest times until the 1980s in two case study areas: the Azores Islands (Portugal) and southern Italy. In Italy information on eruptions stretches back to prehistoric times and has become progressively better known over more than 2,000 years of written history, yet even here there remain significant gaps in the record even for events that took place between 1900 and 1990. In contrast, located in the middle of the Atlantic, the Azores have been isolated for much of their history and illustrate the difficulties involved in using indigenous sources to compile, not only assessments of impact, but also at a more basic level a complete list of historical events with accurate dates

    Earthquakes, Volcanoes and God: Comparative Perspectives from Christianity and Islam

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    This paper asserts that both Christian and Islamic traditions of faith affect the ways in which people both try to make sense of, and respond to, disasters. This contention is supported by the results of empirical research, which demonstrates that differing Islamic and Christian perspectives on human suffering caused by disasters are neither as diverse, nor are they so intractable, as is commonly supposed. Today pastoral convergence between the two traditions may also be discerned, together with a general acceptance of the policies of both State agencies and Non-Governmental Organisations (NGOs) which are concerned with hazard relief and the propagation of policies of disaster risk reduction (DRR). Indeed some important disaster relief NGOs have emerged from Islamic and Christian faith communities and are supported by charitable donations

    Geological Hazards: their assessment, avoidance and mitigation

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    Best practice guidelines on first-line laboratory testing for porphyria

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    The porphyrias are disorders of haem biosynthesis which present with acute neurovisceral attacks or disorders of sun-exposed skin. Acute attacks occur mainly in adults and comprise severe abdominal pain, nausea, vomiting, autonomic disturbance, central nervous system involvement and peripheral motor neuropathy. Cutaneous porphyrias can be acute or chronic presenting at various ages. Timely diagnosis depends on clinical suspicion leading to referral of appropriate samples for screening by reliable biochemical methods. All samples should be protected from light. Investigation for an acute attack: • Porphobilinogen (PBG) quantitation in a random urine sample collected during symptoms. Urine concentration must be assessed by measuring creatinine, and a repeat requested if urine creatinine &lt;2 mmol/L. • Urgent porphobilinogen testing should be available within 24 h of sample receipt at the local laboratory. Urine porphyrin excretion (TUP) should subsequently be measured on this urine. • Urine porphobilinogen should be measured using a validated quantitative ion-exchange resin-based method or LC-MS. • Increased urine porphobilinogen excretion requires confirmatory testing and clinical advice from the National Acute Porphyria Service. • Identification of individual acute porphyrias requires analysis of urine, plasma and faecal porphyrins. Investigation for cutaneous porphyria: • An EDTA blood sample for plasma porphyrin fluorescence emission spectroscopy and random urine sample for TUP. • Whole blood for porphyrin analysis is essential to identify protoporphyria. • Faeces need only be collected, if first-line tests are positive or if clinical symptoms persist. Investigation for latent porphyria or family history: • Contact a specialist porphyria laboratory for advice. Clinical, family details are usually required. </jats:p

    The gendered nature of natural disasters: the impact of catastrophic events on the gender gap in life expectancy, 1981–2002

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    Natural disasters do not affect people equally. In fact, a vulnerability approach to disasters would suggest that inequalities in exposure and sensitivity to risk as well as inequalities in access to resources, capabilities and opportunities systematically disadvantage certain groups of people, rendering them more vulnerable to the impact of natural disasters. In this article we address the specific vulnerability of girls and women with respect to mortality from natural disasters and their aftermath. Biological and physiological differences between the sexes are unlikely to explain large-scale gender differences in mortality rates. Social norms and role behavior provide some further explanation, but what is likely to matter most is the everyday socio-economic status of women. We analyze the effect of disaster strength and its interaction with the socio-economic status of women on the change in the gender gap in life expectancy in a sample of up to 141 countries over the period 1981 to 2002. We find, first, that natural disasters lower the life expectancy of women more than that of men. In other words, natural disasters (and their subsequent impact) on average kill more women than men or kill women at an earlier age than men. Since female life expectancy is generally higher than that of males, for most countries natural disasters narrow the gender gap in life expectancy. Second, the stronger the disaster (as approximated by the number of people killed relative to population size), the stronger this effect on the gender gap in life expectancy. That is, major calamities lead to more severe impacts on female life expectancy (relative to that of males) than smaller disasters. Third, the higher women’s socio-economic status, the weaker this effect on the gender gap in life expectancy. In other words, taken together our results show that it is the socially constructed gender-specific vulnerability of females built into everyday socio-economic patterns that lead to the relatively higher female disaster mortality rates compared to men
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