1,348 research outputs found
Methodological strengths and weakness of cohorts and administrative data for developing population estimates of dementia
Background: There are three main methods of obtaining population data on the incidence and/or prevalence of dementia: cross-sectional surveys (which may be repeated over time); cohort studies that follow people initially without dementia and count newly diagnosed cases over time; and administrative health records (including linkage of records from multiple sources). The major challenges for all these methods are: how well the study sample represents the target population, the accuracy of diagnoses, and the costs of maintaining the data collection over time. Method: In a project to improve Australia’s dementia statistics, we conducted a series of studies to compare population estimates of dementia obtained using different methods. Firstly, we used existing general health studies of community-based cohorts, supplemented by linkage to administrative records of hospital and emergency department admissions, assessments for aged care support, medication prescriptions, and death certificates to estimate the cumulative incidence of dementia. Secondly, we created cohorts based on administrative records for entire populations. Thirdly, we assessed the validity of the identification of people with dementia in the record linkage cohorts in various ways, including linkage with studies that had obtained clinical diagnosis through the standardised assessment of participants. Result: We will present empirical results illustrating the strengths and limitations of these different approaches. In summary, community-based cohort studies lack representativeness of national or regional populations due to recruitment biases and differential loss to follow-up. Cohort studies are also costly to maintain over the long time needed for participants to develop dementia. In contrast, the use of administrative records is relatively inexpensive, but is subject to policy changes that impact on the continuity of data coverage and quality. Population coverage may also be problematic for administrative data if important sources of care for people with dementia are not included; for example, in Australia linkable primary care data are not available. The validation studies showed that accuracy was highly dependent on data sources, and identification of dementia type was unreliable. Conclusion: Prevalence and trends data of dementia obtained from multiple sources are needed to provide accurate population estimates, together with detailed contextual knowledge and careful analysis
Revealing the former bed of Thwaites Glacier using sea-floor bathymetry: Implications for warm-water routing and bed controls on ice flow and buttressing
Abstract. The geometry of the sea floor immediately beyond
Antarctica's marine-terminating glaciers is a fundamental control on
warm-water routing, but it also describes former topographic pinning points
that have been important for ice-shelf buttressing. Unfortunately, this
information is often lacking due to the inaccessibility of these areas for
survey, leading to modelled or interpolated bathymetries being used as
boundary conditions in numerical modelling simulations. At Thwaites Glacier
(TG) this critical data gap was addressed in 2019 during the first cruise of
the International Thwaites Glacier Collaboration (ITGC) project. We present more than 2000 km2 of new multibeam
echo-sounder (MBES) data acquired in exceptional sea-ice conditions
immediately offshore TG, and we update existing bathymetric compilations.
The cross-sectional areas of sea-floor troughs are under-predicted by up to
40 % or are not resolved at all where MBES data are missing, suggesting that
calculations of trough capacity, and thus oceanic heat flux, may be
significantly underestimated. Spatial variations in the morphology of
topographic highs, known to be former pinning points for the floating ice
shelf of TG, indicate differences in bed composition that are supported by
landform evidence. We discuss links to ice dynamics for an overriding ice
mass including a potential positive feedback mechanism where erosion of
soft erodible highs may lead to ice-shelf ungrounding even with little
or no ice thinning. Analyses of bed roughnesses and basal drag contributions
show that the sea-floor bathymetry in front of TG is an analogue for extant
bed areas. Ice flow over the sea-floor troughs and ridges would have been
affected by similarly high basal drag to that acting at the grounding zone
today. We conclude that more can certainly be gleaned from these 3D
bathymetric datasets regarding the likely spatial variability of bed
roughness and bed composition types underneath TG. This work also addresses
the requirements of recent numerical ice-sheet and ocean modelling studies
that have recognised the need for accurate and high-resolution bathymetry to
determine warm-water routing to the grounding zone and, ultimately, for
predicting glacier retreat behaviour.
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Cancer chemotherapy in early life significantly alters the maturation of pain processing
Advances in paediatric cancer treatment have led to a ten year survival rate greater than 75%. Platinum-based chemotherapies (e.g.cisplatin) induce peripheral sensory neuropathy in adult and paedriatric cancer patients. The period from birth through to adulthood represents a period of maturation within nociceptive systems. Here we investigated how cisplatin impacts upon postnatal maturation of nociceptive systems. Neonatal Wistar rats (Postnatal day (P) 7) were injected (i.p.) daily with either vehicle (PBS) or cisplatin (1mg/kg) for five consecutive days. Neither group developed mechanical or thermal hypersensitivity immediately during or after treatment. At P22 the cisplatin group developed mechanical (P<0.05) and thermal (P<0.0001) hypersensitivity versus vehicle group. Total DRG or dorsal horn neuronal number did not differ at P45, however there was an increase in intraepidermal nerve fibre density in cisplatin treated animals at this age. The percentage of IB4+ve, CGRP+ve and NF200+ve DRG neurons was not different between groups at P45. There was an increase in TrkA+ve DRG neurons in the cisplatin group at P45, in addition to increased TrkA, NF200 and vGLUT2 immunoreactivity in the lumbar dorsal horn versus controls. These data highlight the impact paediatric cancer chemotherapy has upon the maturation of pain pathways and later life pain experience
Enhanced effects of cigarette smoke extract on inflammatory cytokine expression in IL-1β-activated human mast cells were inhibited by Baicalein via regulation of the NF-κB pathway
Background: Human mast cells are capable of a wide variety of inflammatory responses and play a vital role in the pathogenesis of inflammatory diseases such as allergy, asthma, and atherosclerosis. We have reported that cigarette smoke extract (CSE) significantly increased IL-6 and IL-8 production in IL-1β-activated human mast cell line (HMC-1). Baicalein (BAI) has anti-inflammatory properties and inhibits IL-1β- and TNF-α-induced inflammatory cytokine production from HMC-1. The goal of the present study was to examine the effect of BAI on IL-6 and IL-8 production from CSE-treated and IL-1β-activated HMC-1.Methods: Main-stream (Ms) and Side-stream (Ss) cigarette smoke were collected onto fiber filters and extracted in RPMI-1640 medium. Two ml of HMC-1 at 1 × 10 6 cells/mL were cultured with CSE in the presence or absence of IL-1β (10 ng/mL) for 24 hrs. A group of HMC-1 cells stimulated with both IL-1β (10 ng/ml) and CSE was also treated with BAI. The expression of IL-6 and IL-8 was assessed by ELISA and RT-PCR. NF-κB activation was measured by electrophoretic mobility shift assay (EMSA) and IκBα degradation by Western blot.Results: Both Ms and Ss CSE significantly increased IL-6 and IL-8 production (p \u3c 0.001) in IL-1β-activated HMC-1. CSE increased NF-κB activation and decreased cytoplasmic IκBα proteins in IL-1β-activated HMC-1. BAI (1.8 to 30 μM) significantly inhibited production of IL-6 and IL-8 in a dose-dependent manner in IL-1β-activated HMC-1 with the optimal inhibition concentration at 30 μM, which also significantly inhibited the enhancing effect of CSE on IL-6 and IL-8 production in IL-1β-activated HMC-1. BAI inhibited NF-κB activation and increased cytoplasmic IκBα proteins in CSE-treated and IL-1β-activated HMC-1.Conclusions: Our results showed that CSE significantly increased inflammatory cytokines IL-6 and IL-8 production in IL-1β-activated HMC-1. It may partially explain why cigarette smoke contributes to lung and cardiovascular diseases. BAI inhibited the production of inflammatory cytokines through inhibition of NF-κB activation and IκBα phosphorylation and degradation. This inhibitory effect of BAI on the expression of inflammatory cytokines induced by CSE suggests its usefulness in the development of novel anti-inflammatory therapies
Molecular and cellular mechanisms underlying the evolution of form and function in the amniote jaw.
The amniote jaw complex is a remarkable amalgamation of derivatives from distinct embryonic cell lineages. During development, the cells in these lineages experience concerted movements, migrations, and signaling interactions that take them from their initial origins to their final destinations and imbue their derivatives with aspects of form including their axial orientation, anatomical identity, size, and shape. Perturbations along the way can produce defects and disease, but also generate the variation necessary for jaw evolution and adaptation. We focus on molecular and cellular mechanisms that regulate form in the amniote jaw complex, and that enable structural and functional integration. Special emphasis is placed on the role of cranial neural crest mesenchyme (NCM) during the species-specific patterning of bone, cartilage, tendon, muscle, and other jaw tissues. We also address the effects of biomechanical forces during jaw development and discuss ways in which certain molecular and cellular responses add adaptive and evolutionary plasticity to jaw morphology. Overall, we highlight how variation in molecular and cellular programs can promote the phenomenal diversity and functional morphology achieved during amniote jaw evolution or lead to the range of jaw defects and disease that affect the human condition
Better governance, better access: practising responsible data sharing in the METADAC governance infrastructure.
BACKGROUND: Genomic and biosocial research data about individuals is rapidly proliferating, bringing the potential for novel opportunities for data integration and use. The scale, pace and novelty of these applications raise a number of urgent sociotechnical, ethical and legal questions, including optimal methods of data storage, management and access. Although the open science movement advocates unfettered access to research data, many of the UK's longitudinal cohort studies operate systems of managed data access, in which access is governed by legal and ethical agreements between stewards of research datasets and researchers wishing to make use of them. Amongst other things, these agreements aim to respect the reasonable expectations of the research participants who provided data and samples, as expressed in the consent process. Arguably, responsible data management and governance of data and sample use are foundational to the consent process in longitudinal studies and are an important source of trustworthiness in the eyes of those who contribute data to genomic and biosocial research. METHODS: This paper presents an ethnographic case study exploring the foundational principles of a governance infrastructure for Managing Ethico-social, Technical and Administrative issues in Data ACcess (METADAC), which are operationalised through a committee known as the METADAC Access Committee. METADAC governs access to phenotype, genotype and 'omic' data and samples from five UK longitudinal studies. FINDINGS: Using the example of METADAC, we argue that three key structural features are foundational for practising responsible data sharing: independence and transparency; interdisciplinarity; and participant-centric decision-making. We observe that the international research community is proactively working towards optimising the use of research data, integrating/linking these data with routine data generated by health and social care services and other administrative data services to improve the analysis, interpretation and utility of these data. The governance of these new complex data assemblages will require a range of expertise from across a number of domains and disciplines, including that of study participants. Human-mediated decision-making bodies will be central to ensuring achievable, reasoned and responsible decisions about the use of these data; the METADAC model described in this paper provides an example of how this could be realised
Circumstellar disks and planets. Science cases for next-generation optical/infrared long-baseline interferometers
We present a review of the interplay between the evolution of circumstellar
disks and the formation of planets, both from the perspective of theoretical
models and dedicated observations. Based on this, we identify and discuss
fundamental questions concerning the formation and evolution of circumstellar
disks and planets which can be addressed in the near future with optical and
infrared long-baseline interferometers. Furthermore, the importance of
complementary observations with long-baseline (sub)millimeter interferometers
and high-sensitivity infrared observatories is outlined.Comment: 83 pages; Accepted for publication in "Astronomy and Astrophysics
Review"; The final publication is available at http://www.springerlink.co
The ACTIVE cognitive training trial and predicted medical expenditures
<p>Abstract</p> <p>Background</p> <p>Health care expenditures for older adults are disproportionately high and increasing at both the individual and population levels. We evaluated the effects of the three cognitive training interventions (memory, reasoning, or speed of processing) in the ACTIVE study on changes in predicted medical care expenditures.</p> <p>Methods</p> <p>ACTIVE was a multisite randomized controlled trial of older adults (≥ 65). Five-year follow-up data were available for 1,804 of the 2,802 participants. Propensity score weighting was used to adjust for potential attrition bias. Changes in predicted annual<b/>medical expenditures were calculated at the first and fifth annual follow-up assessments using a new method for translating functional status scores. Multiple linear regression methods were used in this cost-offset analysis.</p> <p>Results</p> <p>At one and five years post-training, annual predicted expenditures declined<b/>by 128 (p = .309), respectively, in the speed of processing treatment group, but there were no statistically significant changes in the memory or reasoning treatment groups compared to the no-contact control group at either period. Statistical adjustment for age, race, education, MMSE scores, ADL and IADL performance scores, EPT scores, chronic condition counts, and the SF-36 PCS and MCS scores at baseline did not alter the one-year (143; p = .250) expenditure declines in the speed of processing treatment group.</p> <p>Conclusion</p> <p>The speed of processing intervention significantly reduced subsequent annual predicted medical care expenditures at the one-year post-baseline comparison, but annual savings were no longer statistically significant at the five-year post-baseline comparison.</p
Baropodometry on women suffering from chronic pelvic pain - a cross-sectional study
<p>Abstract</p> <p>Background</p> <p>Previous studies have associated chronic pelvic pain with a stereotyped pattern of movement and posture, lack of normal body sensations, a characteristic pain distribution. We aimed at evaluating if these postural changes are detectable in baropodometry results in patients with chronic pelvic pain.</p> <p>Methods</p> <p>We performed a prospective study in a university hospital. We selected 32 patients suffering from chronic pelvic pain (study group) and 30 women without this pathology (regular gynecological work out - control group). Pain scores and baropodometric analysis were performed.</p> <p>Results</p> <p>As expected, study group presented higher pain scores than control group. Study and control groups presented similar averages for the maximum pressures to the left and right soles as well as soles supports in the forefeet and hind feet. Women suffering from chronic pelvic pain did not present differences in baropodometric analysis when compared to healthy controls.</p> <p>Conclusions</p> <p>This data demonstrates that postural abnormalities resulting from CPP could not be demonstrated by baropodometric evaluation. Other postural measures should be addressed to evaluate pelvic pain patients.</p
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