2,001 research outputs found

    Understanding the lived experiences of Mexican informal caregivers with Ambient Assisted Living Technologies

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    Ambient Assisted Living (AAL) Technologies, have the potential to support the people with dementia living in their homes for longer. Dementia is a major public health concern. It currently affects approximately 46.8 million people worldwide and by 2050 this figure will increase to 131.5 million. Low-and-middle income countries (LMIC) will be particularly affected by this situation as their poor health infrastructures and governmental support will mean that they have to rely on the informal caregiver (IC) sector. ICs are people who care for a dependent or disabled family member, commonly spouses or daughters. Mexico was the first Spanish speaking country in the world to recognise dementia as a public health priority. In-home technologies, such as AAL Technologies, are used in dementia care in order to improve patients’ and caregivers’ quality of life. This paper explores the way in which Mexican ICs of people with dementia (PWD) make sense of their lived experiences with AAL technologies

    Effects of mode degeneracy in the LIGO Livingston Observatory recycling cavity

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    We analyze the electromagnetic fields in a Pound-Drever-Hall locked, marginally unstable, Fabry-Perot cavity as a function of small changes in the cavity length during resonance. More specifically, we compare the results of a detailed numerical model with the behavior of the recycling cavity of the Laser Interferometer Gravitational-wave Observatory (LIGO) detector that is located in Livingston, Louisiana. In the interferometer's normal mode of operation, the recycling cavity is stabilized by inducing a thermal lens in the cavity mirrors with an external CO2 laser. During the study described here, this thermal compensation system was not operating, causing the cavity to be marginally optically unstable and cavity modes to become degenerate. In contrast to stable optical cavities, the modal content of the resonating beam in the uncompensated recycling cavity is significantly altered by very small cavity length changes. This modifies the error signals used to control the cavity length in such a way that the zero crossing point is no longer the point of maximum power in the cavity nor is it the point where the input beam mode in the cavity is maximized.Comment: Eight pages in two-column format. Six color figures. To be published JOSA

    Global tephra studies: role and importance of the international tephra research group “Commission on Tephrochronology” in its first 60 years

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    Tephrochronology is a correlational and age-equivalent dating method whereby practitioners characterize, map, and date tephra (or volcanic ash) layers and use them stratigraphically as connecting and dating tools in the geosciences (including volcanology) and in studies of past environments and archaeology. Modern tephra studies per se began around 100 years ago (in the 1920s), but the first collective of tephrochronologists with a common purpose and nascent global outlook was not formed until 7 September 1961 in Warsaw, Poland. On that date, the inaugural “Commission on Tephrochronology” (COT) was ratified under the aegis of the International Union for Quaternary Research (INQUA). The formation of COT is attributable largely to the leadership of Kunio Kobayashi of Japan, the commission's president for its first 12 years. We were motivated to record and evaluate the function and importance of COT because tephrochronology continues to grow globally and its heritage needs to be understood, appreciated, and preserved. In addition, studies on cryptotephras, which are fine-grained glass-shard and/or crystal concentrations preserved in sediments or soils but insufficiently numerous to be visible as a layer to the naked eye, have also expanded dramatically in recent times. Therefore, in this article, we review the role and impacts of COT under the umbrella of INQUA for 53 of the last 60 years or under IAVCEI (International Association of Volcanology and Chemistry of the Earth's Interior) for 7 of the last 60 years, including since 2019. The commission also functioned under other names (abbreviated as COTS, CEV, ICCT, COTAV, SCOTAV, and INTAV; see Table 2 for definitions). As well as identifying key persons of influence, we describe the development of the commission, its leaders, and its activities, which include organizing nine specialist tephra field meetings in seven different countries. Members of the commission have participated in numerous other conferences (including specialist tephra sessions) or workshops of regional to international scale, and they have played leading roles in international projects such as INTIMATE (INTegrating Ice-core, MArine and TErrestrial records) and SMART (Synchronising Marine And ice-core Records using Tephrochronology). As well as strongly supporting early-career researchers including graduate students, the commission has generated 10 tephra-themed journal volumes and two books. It has published numerous other articles including field guidebooks, reports, and specialist internet documents/sites. Although its fortunes have ebbed as well as flowed, the commission began to prosper after 1987 when key changes in leadership occurred. COT has blossomed further, especially in the past decade or so, as an entire new cohort of specialists, including many engaged in cryptotephra studies, has emerged alongside new geoanalytical and dating techniques or protocols to become a vibrant global group today. We name 29 elected officers who have been involved with COT since 1961 as well as 15 honorary life members. After reviewing the aims of the commission, we conclude by evaluating its legacies and by documenting current and future work

    Independent tephrochronological evidence for rapid and synchronous oceanic and atmospheric temperature rises over the Greenland stadial-interstadial transitions between ca. 32 and 40 ka b2k

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    Understanding the dynamics that drove past abrupt climate changes, such as the Dansgaard-Oeschger (DO) events, depends on combined proxy evidence from disparate archives. To identify leads, lags and synchronicity between different climate system components, independent and robust chronologies are required. Cryptotephrochronology is a key geochronological tool as cryptotephra horizons can act as isochrons linking disparate and/or distant records. Here, we investigated marine sediment core MD99-2284 from the Norwegian Sea to look for previously identified Greenland ice core cryptotephra horizons and define time-parallel markers between the archives. We explored potential secondary transport and depositional mechanisms that could hamper the isochronous integrity of such horizons. We identified six cryptotephra layers of which four correlate to previously known Greenland ice core horizons. None of those were identified in other marine cores and thus, this study contributes greatly to the North Atlantic tephra framework tripling the original amount of existing isochrons between ca. 25 and 60 ka b2k. The latter allow a synchronization between MD99-2284 and the Greenland ice cores between ca. 32 e40 ka b2k, which is, in the North Atlantic, the shortest time-interval during the Last Glacial Period to be constrained by four independent tephra isochrons. These findings provide essential tephra-based evidence for synchronous and rapid oceanic and atmospheric temperature rises during the Greenland Stadial-Interstadial transitions. Furthermore, it enables us to estimate the average peak-duration of interstadial temperature overshoots at approximately 136 years. As such, this well-targeted high-resolution investigation successfully demonstrates the use of cryptotephra for geochronological purposes in the marine realm.publishedVersio

    Widespread tephra dispersal and ignimbrite emplacement from a subglacial volcano (Torfajökull, Iceland)

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    The tephra dispersal mechanisms of rhyolitic glaciovolcanic eruptions are little known, but can be investigated through the correlation of eruptive products across multiple depositional settings. Using geochemistry and geochronology, we correlate a regionally important Pleistocene tephra horizon—the rhyolitic component of North Atlantic Ash Zone II (II-RHY-1)—and the ThĂłrsmörk Ignimbrite with rhyolitic tuyas at Torfajökull volcano, Iceland. The eruption breached an ice mass >400 m thick, leading to the widespread dispersal of II-RHY-1 across the North Atlantic and the Greenland ice sheet. Locally, pyroclastic density currents traveled across the ice surface, depositing the variably welded ThĂłrsmörk Ignimbrite beyond the ice margin and ~30 km from source. The widely dispersed products of this eruption represent a valuable isochronous tie line between terrestrial, marine, and ice-core paleoenvironmental records. Using the tephra horizon, estimates of ice thickness and extent derived from the eruption deposits can be directly linked to the regional climate archive, which records the eruption at the onset of Greenland Stadial 15.2

    Profiles of family-focused adverse experiences through childhood and early adolescence: the ROOTS project a community investigation of adolescent mental health.

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    BACKGROUND: Adverse family experiences in early life are associated with subsequent psychopathology. This study adds to the growing body of work exploring the nature and associations between adverse experiences over the childhood years. METHODS: Primary carers of 1143 randomly recruited 14-year olds in Cambridgeshire and Suffolk, UK were interviewed using the Cambridge Early Experiences Interview (CAMEEI) to assess family-focused adversities. Adversities were recorded retrospectively in three time periods (early and later childhood and early adolescence). Latent Class Analysis (LCA) grouped individuals into adversity classes for each time period and longitudinally. Adolescents were interviewed to generate lifetime DSM-IV diagnoses using the K-SADS-PL. The associations between adversity class and diagnoses were explored. RESULTS: LCA generated a 4-class model for each time period and longitudinally. In early childhood 69% were allocated to a low adversity class; a moderate adversity class (19%) showed elevated rates of family loss, mild or moderate family discord, financial difficulties, maternal psychiatric illness and higher risk for paternal atypical parenting; a severe class (6%) experienced higher rates on all indicators and almost exclusively accounted for incidents of child abuse; a fourth class, characterised by atypical parenting from both parents, accounted for the remaining 7%. Class membership was fairly stable (~ 55%) over time with escape from any adversity by 14 years being uncommon. Compared to those in the low class, the odds ratio for reported psychopathology in adolescents in the severe class ranged from 8 for disruptive behaviour disorders through to 4.8 for depressions and 2.0 for anxiety disorders. Only in the low adversity class did significantly more females than males report psychopathology. CONCLUSIONS: Family adversities in the early years occur as multiple rather than single experiences. Although some children escape adversity, for many this negative family environment persists over the first 15 years of life. Different profiles of family risk may be associated with specific mental disorders in young people. Sex differences in psychopathologies may be most pronounced in those exposed to low levels of family adversities.This is the published version of the article. It was published in BMC Psychiatry by BioMed Central. The online version can be found here: http://www.biomedcentral.com/1471-244X/11/109

    Mid-to Late Holocene East Antarctic ice-core tephrochronology : implications for reconstructing volcanic eruptions and assessing their climatic impacts over the last 5,500 years

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    PA and MS received funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant agreement no. 820047). WH is funded by a UKRI Future Leaders Fellowship (MR/S033505/1). Continuous analysis of the B53 and B54 cores for sulphur and insoluble particles was supported by internal funding from the Desert Research Institute, with partial support for interpretation provided by National Science Foundation grant 1925417 to JRM.Ice cores are powerful archives for reconstructing volcanism as they contain both soluble (i.e. aerosols) and insoluble (i.e. tephra) products of volcanic eruptions and for more recent periods have high-precision annually resolved chronologies. The identification and geochemical analysis of cryptotephra in these cores can provide their volcanic source and latitude of injection, complementing records of sulphur injections from volcanic eruptions developed using continuous flow ice-core analysis. Here, we aim to improve the volcanic record for the Southern Hemisphere using a sampling strategy for cryptotephra identification based on coeval deposition of sulphate and microparticles in ice cores from the interior of East Antarctica covering the Mid-to Late Holocene. In total, 15 cryptotephras and one visible horizon were identified and geochemically characterised. Through comparisons to proximal deposits a range of possible sources were isolated for these horizons including the South Sandwich Islands, South Shetland Islands, Victoria Land (Antarctica) and South America. This new tephra framework contributes to the volcanic history of the region by extending the known geographical range of tephra deposition for previously identified events and providing a potential indication of phases of eruptive activity from key sources. Using the tephra-based source attributions and comparison of the timing of the events to a database of sulphur injections from Holocene volcanic eruptions it is possible to refine injection latitudes for some events, which can lead to improved estimates of their radiative forcing potential. The relatively low magnitude of the volcanic stratospheric sulphur injections related to the events in the tephra framework indicates they would have had a limited impact on Southern Hemisphere climate. Further work is required to improve source attributions for some events and/or to determine the magnitude of sulphur injections for individual events during years when coeval eruptions occurred. One limitation of the framework is the dominance of cryptotephra from regional volcanic sources and a lack of tephra from tropical sources, which hampers the refinement of eruption parameters for these large magnitude and often climate-impacting eruptions. This issue could be explored further through increased sampling of these events and/or development of additional analytical techniques for the identification and robust geochemical analysis of glass tephra shards less than 5 Όm in diameter. Such investigations could be coupled with model experiments to determine the likelihood that past tropical eruptions deposited glass tephra shards over Antarctica and the potential size range and geographical spread of deposition.Peer reviewe

    LOOC UP: Locating and observing optical counterparts to gravitational wave bursts

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    Gravitational wave (GW) bursts (short duration signals) are expected to be associated with highly energetic astrophysical processes. With such high energies present, it is likely these astrophysical events will have signatures in the EM spectrum as well as in gravitational radiation. We have initiated a program, "Locating and Observing Optical Counterparts to Unmodeled Pulses in Gravitational Waves" (LOOC UP) to promptly search for counterparts to GW burst candidates. The proposed method analyzes near real-time data from the LIGO-Virgo network, and then uses a telescope network to seek optical-transient counterparts to candidate GW signals. We carried out a pilot study using S5/VSR1 data from the LIGO-Virgo network to develop methods and software tools for such a search. We will present the method, with an emphasis on the potential for such a search to be carried out during the next science run of LIGO and Virgo, expected to begin in 2009.Comment: 11 pages, 2 figures; v2) added acknowledgments, additional references, and minor text changes v3) added 1 figure, additional references, and minor text changes. v4) Updated references and acknowledgments. To be published in the GWDAW 12 Conf. Proc. by Classical and Quantum Gravit
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