52 resultados para audiovisual records
Resumo:
ABSTRACT High resolution records of mid-late Holocene hydro-climatic change are presented from Mer Bleue Bog, eastern Ontario. Past climatic changes in this region have previously been inferred from lake sediments, but rain-fed peatlands can offer additional insights into the spatial and temporal pattern of moisture availability. In this study, reconstructed water table depths are based on a testate amoeba-derived transfer function developed for the region and changes in bog surface wetness are compared with plant macrofossil and peat humification data.
RÉSUMÉ Nous présentons les enregistrements hautes résolutions des variations hydrologique durant la second moitié de l’Holocène pour les tourbières Mer Bleue á l’est de l'Ontario. Précédemment, les changements climatiques de cette région ont été dérivés à partir de prélèvement de sédiments de lac. Mais ils s’avèrent que les tourbières ombrotrophes offrir un éclairage supplémentaire sur les schémas de répartition spatiale et temporelle de la disponibilité de l'humidité. Dans cette étude, des profondeurs reconstruites de nappe phréatique sont basées sur un modèle de function de transfert d’amibes (Arcellinida) et des changements de l’humidité de surface de la tourbière sont comparés avec les macrofossils et au humification de tourbe dans une analyse multi-proxy.
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Proxy records derived from ombrotrophic peatlands provide important insights into climate change over decadal to millennial timescales. We present mid- to late- Holocene humification data and testate amoebae-derived water table records from two peatlands in Northern Ireland. We examine the repli- cation of periodicities in these proxy climate records, which have been precisely linked through teph- rochronology. Age-depth models are constructed using a Bayesian piece-wise linear accumulation model and chronological errors are calculated for each profile. A Lomb-Scargle Fourier transform-based spectral analysis is used to test for statistically significant periodicities in the data. Periodicities of c. 130, 180, 260, 540 and 1160 years are present in at least one proxy record at each site. The replication of these peri- odicities provides persuasive evidence that they are a product of allogenic climate controls, rather than internal peatland dynamics. A technique to estimate the possible level of red-noise in the data is applied and demonstrates that the observed periodicities cannot be explained by a first-order autoregressive model. We review the periodicities in the light of those reported previously from other marine and terrestrial climate proxy archives to consider climate forcing parameters. © 2012 Elsevier Ltd. All rights reserved.
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Three species of introduced marine macroalgae are reported for Wellington Harbour (North Island, New Zealand). One of these, Polysiphonia senticulosa (Ceramiales, Rhodophyta) is illustrated from New Zealand for the first time, and the known distributional ranges of two species, Striaria attenuata (Dictyosiphonales, Phaeophyta) and Antithamnionella ternifolia (Ceramiales, Rhodophyta), are extended to the North Island.
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Isolation basin records from the Seymour-Belize Inlet Complex, a remote area of central mainland British Columbia, Canada are used to constrain post-glacial sea-level changes and provide a preliminary basis for testing geophysical model predictions of relative sea-level (RSL) change. Sedimentological and diatom data from three low-lying (<4 m elevation) basins record falling RSLs in late-glacial times and isolation from the sea by ~11,800–11,200 14C BP. A subsequent RSL rise during the early Holocene (~8000 14C BP) breached the 2.13 m sill of the lowest basin (Woods Lake), but the two more elevated basins (sill elevations of ~3.6 m) remained isolated. At ~2400 14C BP, RSL stood at 1.49 ± 0.34 m above present MTL. Falling RSLs in the late Holocene led to the final emergence of the Woods Lake basin by 1604 ± 36 14C BP. Model predictions generated using the ICE-5G model partnered with a small number of different Earth viscosity models generally show poor agreement with the observational data, indicating that the ice model and/or Earth models considered can be improved upon. The best data-model fits were achieved with relatively low values of upper mantle viscosity (5 × 1019 Pa s), which is consistent with previous modelling results from the region. The RSL data align more closely with observational records from the southeast of the region (eastern Vancouver Island, central Strait of Georgia), than the immediate north (Bella Bella–Bella Coola and Prince Rupert-Kitimat) and areas to the north-west (Queen Charlotte Sound, Hecate Strait), underlining the complexity of the regional response to glacio-isostatic recovery.
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This 1 year prospective study involved nine general practitioners in an urban health centre who routinely record all patient contacts on computer. The study determines by comparison with a manual record how accurately doctors record laboratory investigations on computer and compares the effectiveness of three interventions in improving the completeness of computerized recording of presenting symptoms, problems/diagnoses and laboratory investigations. Recording was analysed for 1 month prior to and for two 1 month periods following each intervention. A control group was used. A total of 7983 patient contacts were analysed. Intervention led to an improvement in the recording of presenting symptoms and problems/diagnoses. Recording of investigations on the computer showed no improvement, remaining at one-third of the total in the treatment room book for both study and control doctors. The effectiveness of the different forms of intervention depended on both the aspect of the consultation considered and the familiarity of individual doctors with the method of data collection. Aspects considered less important required greater intervention to bring about a marked improvement, as did doctors relatively new to the practice. It may not be possible to get all aspects of the consultation recorded with the same degree of accuracy. This has implications for the accuracy of retrospective studies dependent on existing computerized data.
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Background: Information on patient symptoms can be obtained by patient self-report or medical records review. Both methods have limitations. Aims: To assess the agreement between self-report and documentation in the medical records of signs/symptoms of respiratory illness (fever, cough, runny nose, sore throat, headache, sinus problems, muscle aches, fatigue, earache, and chills). Methods: Respondents were 176 research participants in the Hutterite Influenza Prevention Study during the 2008-2009 influenza season with information about the presence or absence of signs/symptoms from both self-report and primary care medical records. Results: Compared with medical records, lower proportions of self-reported fever, sore throat, earache, cough, and sinus problems were found. Total agreements between self-report and medical report of symptoms ranged from 61% (for sore throat) to 88% (for muscle aches and earache), with kappa estimates varying from 0.05 (for chills) to 0.41 (for cough) and 0.51 (for earache). Negative agreement was considerably higher (from 68% for sore throat to 93% for muscle aches and earache) than positive agreement (from 13% for chills to 58% for earache) for each symptom except cough where positive agreement (77%) was higher than negative agreement (64%). Agreements varied by age group. We found better agreement for earache (kappa=0.62) and lower agreements for headache, sinus problems, muscle aches, fatigue, and chills in older children (aged =5 years) and adults. Conclusions: Agreements were variable depending on the specific symptom. Contrary to research in other patient populations which suggests that clinicians report fewer symptoms than patients, we found that the medical record captured more symptoms than selfreport. Symptom agreement and disagreement may be affected by the perspectives of the person experiencing them, the observer, the symptoms themselves, measurement error, the setting in which the symptoms were observed and recorded, and the broader community and cultural context of patients. © 2012 Primary Care Respiratory Society UK. All rights reserved.
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Introduction: Variation across research ethics boards (REBs) in conditions placed on access to medical records for research purposes raises concerns around negative impacts on research quality and on human subject protection, including privacy. Aim: To study variation in REB consent requirements for retrospective chart review and who may have access to the medical record for data abstraction. Methods: Thirty 90-min face-to-face interviews were conducted with REB chairs and administrators affiliated with faculties of medicine in Canadian universities, using structured questions around a case study with open-ended responses. Interviews were recorded, transcribed and coded manually. Results: Fourteen sites (47%) required individual patient consent for the study to proceed as proposed. Three (10%) indicated that their response would depend on how potentially identifying variables would be managed. Eleven sites (38%) did not require consent. Two (7%) suggested a notification and opt-out process. Most stated that consent would be required if identifiable information was being abstracted from the record. Among those not requiring consent, there was substantial variation in recognising that the abstracted information could potentially indirectly re-identify individuals. Concern over access to medical records by an outside individual was also associated with requirement for consent. Eighteen sites (60%) required full committee review. Sixteen (53%) allowed an external research assistant to abstract information from the health record. Conclusions: Large variation was found across sites in the requirement for consent for research involving access to medical records. REBs need training in best practices for protecting privacy and confidentiality in health research. A forum for REB chairs to confidentially share concerns and decisions about specific studies could also reduce variation in decisions.
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Magnetic properties of eight particle size ranges from nine locations in Iceland and 26 locations in southern Greenland reveal the importance of source variation for our understanding of paleomagnetic and environmental magnetic records in the marine environment. These terrestrial samples show varying degrees of particle size dependence with all samples showing that the silt fraction possesses greater concentrations of ferrimagnetic minerals than either clay or sand. Fine pseudo-single domain (PSD) size magnetic grains dominate the magnetic assemblage of all Icelandic fractions. In contrast, Greenlandic samples possess greater variation in magnetic grain size; only fine silt and clay are as magnetically fine as the Icelandic PSD grains, while Greenlandic silts and sands are dominated by coarser PSD and multi-domain grains. These observations from potential marine sediment sources suggest that the silt size fraction is a likely driver for much of the concentration-dependent parameters derived from bulk magnetic records and that the magnetic grain size of the silt fraction can be used to discriminate between Icelandic and Greenlandic sources. Using these results to examine magnetic grain size records from marine sediment cores collected across the northern North Atlantic suggests that source, not just transport-controlled physical grain-size, has a significant impact on determining the magnetic grain size at a particular location. Homogeneity of magnetic grain size in Icelandic sediments at least partially explains the consistent quality of paleomagnetic records derived from cores surrounding Iceland and their ability to buffer large environmental changes. © 2013 Elsevier B.V.
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The LIPARM schema links the parliamentary record together for the first time by creating a unified metadata scheme for all of its key elements. People, bills, acts, items of business, debates, divisions and sessions will all be described by the scheme and will be linked together across resources which are currently spread out and isolated. For the first time, it will be possible to trace a given MP’s entire voting record or to find every speech they made. It will be possible to follow the passage of every bill or act, and every contribution to the debates that accompany it. Both the historical and the contemporary record of parliamentary proceedings will become accessible in this way for the first time.
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We present pollen records from three sites in south Westland, New Zealand, that document past vegetation and inferred climate change between approximately 30,000 and 15,000 cal. yr BP. Detailed radiocarbon dating of the enclosing sediments at one of those sites, Galway tarn, provides a more robust chronology for the structure and timing of climate-induced vegetation change than has previously been possible in this region. The Kawakawa/Oruanui tephra, a key isochronous marker, affords a precise stratigraphic link across all three pollen records, while other tie points are provided by key pollen-stratigraphic changes which appear to be synchronous across all three sites. Collectively, the records show three episodes in which grassland, interpreted as indicating mostly cold subalpine to alpine conditions, was prevalent in lowland south Westland, separated by phases dominated by subalpine shrubs and montane-lowland trees, indicating milder interstadial conditions. Dating, expressed as a Bayesian-estimated single 'best' age followed in parentheses by younger/older bounds of the 95% confidence modelled age range, indicates that a cold stadial episode, whose onset was marked by replacement of woodland by grassland, occurred between 28,730 (29,390-28,500) and 25,470 (26,090-25,270) cal. yr BP (years before AD, 1950), prior to the deposition of the Kawakawa/Oruanui tephra. Milder interstadial conditions prevailed between 25,470 (26,090-25,270) and 24,400 (24,840-24,120) cal. yr BP and between 22,630 (22,930-22,340) and 21,980 (22,210-21,580) cal. yr BP, separated by a return to cold stadial conditions between 24,400 and 22,630 cal. yr BP. A final episode of grass-dominated vegetation, indicating cold stadial conditions, occurred from 21,980 (22,210-21,580) to 18,490 (18,670-17,950) cal. yr BP. The decline in grass pollen, indicating progressive climate amelioration, was well advanced by 17,370 (17,730-17,110) cal. yr BP, indicating that the onset of the termination in south Westland occurred sometime between ca 18,490 and ca 17,370 cal. yr BP. A similar general pattern of stadials and interstadials is seen, to varying degrees of resolution but generally with lesser chronological control, in many other paleoclimate proxy records from the New Zealand region. This highly resolved chronology of vegetation changes from southwestern New Zealand contributes to the examination of past climate variations in the southwest Pacific region. The stadial and interstadial episodes defined by south Westland pollen records represent notable climate variability during the latter part of the Last Glaciation. Similar climatic patterns recorded farther afield, for example from Antarctica and the Southern Ocean, imply that climate variations during the latter part of the Last Glaciation and the transition to the Holocene interglacial were inter-regionally extensive in the Southern Hemisphere and thus important to understand in detail and to place into a global context. © 2013 Elsevier Ltd. All rights reserved.