ABSTRACT
Osteoblasts, which orchestrate the deposition of small apatite crystals through the expression of nucleating proteins, have been shown to also express clock genes associated with the ...circadian signaling pathway. We hypothesized that protein‐mediated bone mineralization may be linked to circadian oscillator mechanisms functioning in peripheral bone tissue. In this study, Per1 expression in ex vivo neonatal murine calvaria organ cultures was monitored for 6 days using a Per1‐luciferase transgene as a bioluminescent indicator of clock function. Fluctuations in Per1 expression had a period of 25 ± 4 hours (n = 14) with early expression at CT09:59 ± 03:37 (CT = circadian time). We also established the kinetics of mineral deposition in developing bone by using noninvasive Raman microscopy to track mineral accumulation in calvarial tissue. The content and quality of newly deposited mineral was continually examined at the interparietal bone/fontanel boundary for a period of 6 days with 1‐hour temporal resolution. Using this approach, mineralization over time exhibited bursts of mineral deposition followed by little or no deposition, which was recurrent with a periodicity of 26.8 ± 9.6 hours. As many as six near‐daily mineralization events were observed in the calvaria before deposition ceased. Earliest mineralization events occurred at CT16:51 ± 03:45, which is 6 hours behind Per1 expression. These findings are consistent with the hypothesis that mineralization in developing bone tissue is regulated by a local circadian oscillator mechanism.
"This book is an important source for all anthropologists who seek to understand cultural variability from both an ethnographic and archaeological perspective.The author's attention to detail and ...in-depth coverage of many groups from South America's rich ethnographic record is rare in a book with such an extensive geographical scope.This book is certain to be widely used for many years by professional ethnographers and anthropologists, but it also has much to offer all readers who have an interest in small-scale societies."
—Lewis Binford
Southern Methodist University
"Wilson does not hesitate to critique the views of other scholars, but he always does so in a constructive fashion that informs the reader about the state of numerous important controversies.The work is a compelling blend of the theory and substance of South American ethnology and archaeology. I consider it to be the single most comprehensive general work on the anthropology of native South Americans to appear in forty years."
—Jeffrey R. Parsons
University of Michigan
"This book shows brilliance and contains a systematic explanation of archaeological, ethnological, ethnohistorical, and environmental information of indigenous groups in South America. It is an all-inclusive masterpiece."
—Joe Bastien
University of Texas at Arlington
•The flows of Helium and Xenon under pressures of 1.47 × 104 Pa for IG-11 were in the free molecular regime for IG-11.•The permeability constant for Helium in IG-11 was 6.259 × 10−6 m2 s−1.•The ...permeability constant for Xenon in IG-11 was 1.614 × 10−6 m2 s−1.•The ratio of the Helium and Xenon permeabilities in IG-11 did not follow fully the inverse square root of their molecular masses.
Understanding the flow and diffusion (transport) of gases through nuclear graphite is of interest in both the prismatic and pebble bed high-temperature gas reactors (HTGRs), for normal operation and under accident conditions, for example, as related to graphite oxidation. Both the laminar and turbulent gaseous transport are of interest. It has also been noted that nuclear graphite can have pore sizes that can possibly lead to non-continuum transport, as the pore size can be comparable to the gaseous mean free path. We report measurements and analyzes of experiments performed with IG-11 graphite in the pressure range of 10 Pa to 14,700 Pa, 293 K, using Helium, and research grade xenon (99.999%), respectively. These values are in fair agreement with those reported for different graphites and gases by other investigators, but are also higher by six orders of magnitude than those reported for Kr permeability in a developmental very low permeability graphite-HXT-90. Our measured ratio of the Helium and Xenon permeabilities is about 4, different from mXemHe≈5.72 that corresponds to diffuse reflection at the graphite surface for both gases. Simple analysis indicates that the two gases have slightly different accommodation coefficients (about 25%) with the graphite surface. However, there could also be other reasons, such as experimental uncertainties or the need for a more detailed analysis.
To evaluate Spot in detecting American Association for Pediatric Ophthalmology and Strabismus (AAPOS) Amblyopia risk factors (ARF) and for ARF myopia and hyperopia with variations in ocular pigments.
...Diagnostic screening test evaluation.
Study population: Children presented for a complete eye examination in pediatric clinic. The study population included 1040 participants, of whom 273 had darkly pigmented eyes, 303 were medium pigmented, and 464 were light pigmented.
Children were screened with the Spot vision screener before the complete eye examination. A pediatric ophthalmologist then completed an eye examination, including cycloplegic refraction. The pediatric ophthalmologist was blinded to the result of the Spot vision screener.
The association between Spot screening recommendation and meeting one or more ARF/ARF + Amblyopia criterion, Spot measured spherical equivalent, and ARF myopia and hyperopia detection.
The area under the receiver operative characteristic curve (AUC) for myopia was excellent for all. The AUC for hyperopia was good (darker-pigmented: 0.92, medium-pigmented: 0.81, and lighter-pigmented: 0.86 eyes). The Spot was most sensitive for ARF myopia (lighter-pigmented: 0.78, medium-pigmented: 0.52, darker-pigmented: 0.49). The reverse was found for hyperopia; however, sensitivity was relatively poor. The Spot was found most sensitive for hyperopia in the darker-pigment group (0.46), 0.27 for medium-pigment, and 0.23 for the lighter-pigment cohort.
While the Spot was confirmed as a sensitive screening test with good specificity in our large cohort, the sensitivity of the Spot in detecting AAPOS guidelines for myopia and hyperopia differed with variations in skin pigment. Our results support the consideration of ethnic and racial diversity in future advances in photorefractor technology.
A comprehensive assessment of the nature of the distribution of sub band-gap energy states in bulk GaAsBi is presented using power and temperature dependent photoluminescence spectroscopy. The ...observation of a characteristic red-blue-red shift in the peak luminescence energy indicates the presence of short-range alloy disorder in the material. A decrease in the carrier localisation energy demonstrates the strong excitation power dependence of localised state behaviour and is attributed to the filling of energy states furthest from the valence band edge. Analysis of the photoluminescence lineshape at low temperature presents strong evidence for a Gaussian distribution of localised states that extends from the valence band edge. Furthermore, a rate model is employed to understand the non-uniform thermal quenching of the photoluminescence and indicates the presence of two Gaussian-like distributions making up the density of localised states. These components are attributed to the presence of microscopic fluctuations in Bi content, due to short-range alloy disorder across the GaAsBi layer, and the formation of Bi related point defects, resulting from low temperature growth.
To examine the utility and reliability of obtaining early echocardiographic measurements of left ventricular (LV) remodeling as well as blood biomarkers of cardiac injury in asymptomatic childhood ...cancer survivors at risk for LV dysfunction and congestive heart failure due to past exposure to anthracycline chemotherapy.
Using a cross-sectional design, anthracycline-exposed childhood cancer survivors with preserved ejection fraction (EF; ≥50%) were evaluated using early echocardiographic indices and blood biomarkers of LV dysfunction. Survivors treated with ≥300 mg/m(2) anthracyclines high risk (HR): n = 100 were compared with those treated with <300 mg/m(2) anthracyclines low risk (LR): n = 50 and matched healthy controls (HC: n = 50). All echocardiograms were interpreted by an institutional cardiologist and a study cardiologist blinded to risk status.
Time from diagnosis was comparable for HR (12.0 years) and LR (13.2 years, P = 0.8) survivors. Echocardiograms: HR had lower LV thickness-dimension ratio (Z-score: HR: -0.62, LR: -0.03, HC: -0.02; P < 0.001), increased LV wall stress (HR: 66.7 g/cm(2), LR: 56.6 g/cm(2), HC: 54.2 g/cm(2); P < 0.01), and higher myocardial performance index (HR: 0.51, LR: 0.46, HC: 0.46; P < 0.01). Interobserver correlation (clinical/blinded reading) for all echocardiographic indices was excellent (range: R = 0.76-0.97, P < 0.001). Blood biomarkers: With the exception of NT-proBNP (r = 0.28, P < 0.01), there was no correlation between blood biomarkers (B-type natriuretic peptide, Troponin-T, ST-2, Galectin-3) and LV dysfunction.
Childhood cancer survivors with preserved EF 10+ years from anthracycline exposure had dose-dependent changes in echocardiographic markers of LV dysfunction.
Near-real time surveillance of excess mortality has been an essential tool during the COVID-19 pandemic. It remains critical for monitoring mortality as the pandemic wanes, to detect fluctuations in ...the death rate associated both with the longer-term impact of the pandemic (e.g. infection, containment measures and reduced service provision by the health and other systems) and the responses that followed (e.g. curtailment of containment measures, vaccination and the response of health and other systems to backlogs). Following the relaxing of social distancing regimes and reduction in the availability of testing, across many countries, it becomes critical to measure the impact of COVID-19 infection. However, prolonged periods of mortality in excess of the expected across entire populations has raised doubts over the validity of using unadjusted historic estimates of mortality to calculate the expected numbers of deaths that form the baseline for computing numbers of excess deaths because many individuals died earlier than they would otherwise have done: i.e. their mortality was displaced earlier in time to occur during the pandemic rather than when historic rates predicted. This is also often termed "harvesting" in the literature.
We present a novel Cox-regression-based methodology using time-dependent covariates to estimate the profile of the increased risk of death across time in individuals who contracted COVID-19 among a population of hip fracture patients in England (N = 98,365). We use these hazards to simulate a distribution of survival times, in the presence of a COVID-19 positive test, and then calculate survival times based on hazard rates without a positive test and use the difference between the medians of these distributions to estimate the number of days a death has been displaced. This methodology is applied at the individual level, rather than the population level to provide a better understanding of the impact of a positive COVID-19 test on the mortality of groups with different vulnerabilities conferred by sociodemographic and health characteristics. Finally, we apply the mortality displacement estimates to adjust estimates of excess mortality using a "ball and urn" model.
Among the exemplar population we present an end-to-end application of our methodology to estimate the extent of mortality displacement. A greater proportion of older, male and frailer individuals were subject to significant displacement while the magnitude of displacement was higher in younger females and in individuals with lower frailty: groups who, in the absence of COVID-19, should have had a substantial life expectancy.
Our results indicate that calculating the expected number of deaths following the first wave of the pandemic in England based solely on historical trends results in an overestimate, and excess mortality will therefore be underestimated. Our findings, using this exemplar dataset are conditional on having experienced a hip fracture, which is not generalisable to the general population. Fractures that impede mobility in the weeks that follow the accident/surgery considerably shorten life expectancy and are in themselves markers of significant frailty. It is therefore important to apply these novel methods to the general population, among whom we anticipate strong patterns in mortality displacement - both in its length and prevalence - by age, sex, frailty and types of comorbidities. This counterfactual method may also be used to investigate a wider range of disruptive population health events. This has important implications for public health monitoring and the interpretation of public health data in England and globally.
Preventability of severe acute maternal morbidity Lawton, Beverley, FRNZCGP; MacDonald, Evelyn Jane, FAChSHM; Brown, Selina Ann, RN ...
American journal of obstetrics and gynecology,
06/2014, Letnik:
210, Številka:
6
Journal Article
Recenzirano
Objective We sought to assess potential preventability of severe acute maternal morbidity (SAMM) cases admitted to intensive-care units (ICUs) or high-dependency units (HDUs). Study Design Inclusion ...criteria were admissions to ICUs or HDUs of women who were pregnant or within 42 days of delivery in 4 District Health Board areas (accounting for a third of annual births in New Zealand) during a 17-month period. Cases were reviewed by external multidisciplinary panels using a validated model for assessing preventability. Results In all, 98 SAMM cases were assessed; 38 (38.8%) cases were deemed potentially preventable, 36 (36.7%) not preventable but improvement in care was needed, and 24 (24.5%) not preventable. The most frequent preventable factors were clinician related: delay or failure in diagnosis or recognition of high-risk status (51%); and delay or inappropriate treatment (70%). The most common causes of preventable severe morbidity were blood loss and septicemia. Conclusion The majority of SAMM cases were potentially preventable or required improvement in care. Themes around substandard care related to delay in diagnosis and treatment for postpartum hemorrhage and septicemia. These findings can inform clinical educational programs and policies to improve maternal outcomes. This study has now been expanded to a national New Zealand audit of all SAMM cases admitted to an ICU/HDU.
Whilst the disruptive effects of anxiety on attention and performance have been well documented, the antecedents to anxiety in motivated performance scenarios are less well understood. We therefore ...sought to understand the cognitive appraisals that mediate the relationship between pressurised performance situations and the onset of anxiety.
We tested the effects of performance pressure and error feedback on appraisals of the probability and cost of failure, the experience of anxiety, and subsequent impacts on visual attention, movement kinematics, and task performance during a virtual reality interception task.
A series of linear mixed effects models indicated that failure feedback and situational pressure influenced appraisals of the probability and cost of failure, which subsequently predicted the onset of anxious states. We did not, however, observe downstream effects on performance and attention.
The findings support the predictions of Attentional Control Theory Sport, that (i) momentary errors lead to negative appraisals of the probability of future failure; and (ii) that appraisals of both the cost and probability of future failure are important predictors of anxiety. The results contribute to a better understanding of the precursors to anxiety and the feedback loops that may maintain anxious states.
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