7,140 research outputs found
Non-ischaemic cardiomyopathy, sudden death and implantable defibrillators: a review and meta-analysis
Objective: The recent Danish Study to Assess the Efficacy of ICDs in Patients with Non-ischemic Systolic Heart Failure on Mortality (DANISH) trial suggested that implantable cardioverter defibrillators (ICDs) do not reduce overall mortality in patients with non-ischaemic cardiomyopathy (NICM), despite reducing sudden cardiac death. We performed an updated meta-analysis to examine the impact of ICD therapy on mortality in NICM patients.
Methods: A systematic search for studies that examined the effect of ICDs on outcomes in NICM was performed. Our analysis compared patients randomised to an ICD with those randomised to no ICD, and examined the endpoint of overall mortality.
Results: Six primary prevention trials and two secondary prevention trials were identified that met the pre-specified search criteria. Using a fixed-effects model, analysis of primary prevention trials revealed a reduction in overall mortality with ICD therapy (RR 0.76, 95%âCI 0.65 to 0.91).
Conclusions: Although our updated meta-analysis demonstrates a survival benefit of ICD therapy, the effect is substantively weakened by the inclusion of the DANISH trialâwhich is both the largest and most recent of the analysed trialsâindicating that the residual pooled benefit of ICDs may reflect the risk of sudden death in older trials which included patients treated sub-optimally by contemporary standards. As such, these data must be interpreted cautiously. The results of the DANISH trial emphasise that there is no âone size fits allâ indication for primary prevention ICDs in NICM patients, and clinicians must consider age and comorbidity on an individual basis when determining whether a defibrillator is appropriate
An Introduction to the Standards for Preparation and Professional Development for Teachers of Engineering
The past 30 years have yielded a mature body of research regarding effective professional development for teachers of science and mathematics, leading to a robust selection of professional development programs for these teachers. The current emphasis on connections among science, technology, engineering, and mathematics underscores the need for similar research into the nature of effective professional development for teachers of engineering. With this in mind, this paper completes a review of the literature concerning effective professional development for teachers of engineering, both as a unique discipline and as a context for teaching and learning in other subjects. The results of this review serve as the foundation for five research-based design standards for professional development initiatives in the field of engineering education, which have been published on the American Society for Engineering Education (ASEE) website along with a matrix that will enable providers and consumers of engineering professional development to determine the extent to which a given program focuses on each of those standards
Rapid ascent and emplacement of basaltic lava during the 2005â06 eruption of the East Pacific Rise at ca. 9°51âČN as inferred from CO2 contents
© The Author(s), 2016. This is the author's version of the work and is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Earth and Planetary Science Letters 453 (2016): 152-160, doi:10.1016/j.epsl.2016.08.007.Eruption rates at the midâocean ridges (MORs) are believed to strongly
control the morphology and length of lava flows emplaced along the ridge axis, and thus
the structure and porosity of the upper oceanic crust. Eruption rate also represents one of
the few tools to gain insight into the driving pressures within sub-ridge magmatic
systems. As eruption rate is inferred to vary systematically along the global mid-ocean
ridge, understanding of how to assess eruption rate in submarine systems and how it
maps to observable features of the ridge axis would provide a powerful tool to understand
Earth's largest magmatic system. Eruption rates at MORs are poorly constrained,
however, because of a lack of direct observations, preventing the duration of an eruption
to be quantified. This study uses decompression experiments of MORB samples and
numerical modeling of CO2 degassing to reconstruct the timescales for magma ascent and
lava emplacement during the 2005â06 eruption of the East Pacific Rise at ca. 9°51âN.
Samples collected from the lava flow are all supersaturated in dissolved CO2 contents,
but CO2 decreases with distance from the vent, presumably as a consequence of
progressive CO2 diffusion into growing bubbles. Samples collected at the vent contain
~105 vesicles per cm3. Pieces of these samples were experimentally heated to 1225°C at
high pressure and then decompressed at controlled rates. Results, plus those from
numerical modeling of diffusive bubble growth, indicate that magma rose from the axial
magma chamber to the seafloor in â€1 hour and at a rate of â„2â3 km hr-1. Our modeling,
as validated by experimental decompression of MORB samples with ~106 vesicles cm-3,
also suggests that CO2 degassed from the melt within ~10â100 minutes as the vesicular
lava traveled ~ 1.7 km along the seafloor, implying a volumetric flow rate on order of
103â4 m3 s-1. Given an ascent rate of â„0.2 m s-1, the width of a rectangular dike feeding
the lava would have been ~1â2 meters wide. MORB samples from the Pacific ridge are
generally more supersaturated in dissolved CO2 than those from slower spreading
Atlantic and Indian ridges. Our results suggest that Pacific MORBs ascend to the
seafloor faster than Atlantic or Indian MORBsThis project was partially
funded by a grant to J.E.G. from the U.S. National Science Foundation (OCE-1333882).2017-08-2
Report for the NGFA-5 project.
The objective of this project is to provide DHS a comprehensive evaluation of the current genomic technologies including genotyping, TaqMan PCR, multiple locus variable tandem repeat analysis (MLVA), microarray and high-throughput DNA sequencing in the analysis of biothreat agents from complex environmental samples. To effectively compare the sensitivity and specificity of the different genomic technologies, we used SNP TaqMan PCR, MLVA, microarray and high-throughput illumine and 454 sequencing to test various strains from B. anthracis, B. thuringiensis, BioWatch aerosol filter extracts or soil samples that were spiked with B. anthracis, and samples that were previously collected during DHS and EPA environmental release exercises that were known to contain B. thuringiensis spores. The results of all the samples against the various assays are discussed in this report
A solenoidal electron spectrometer for a precision measurement of the neutron -asymmetry with ultracold neutrons
We describe an electron spectrometer designed for a precision measurement of
the neutron -asymmetry with spin-polarized ultracold neutrons. The
spectrometer consists of a 1.0-Tesla solenoidal field with two identical
multiwire proportional chamber and plastic scintillator electron detector
packages situated within 0.6-Tesla field-expansion regions. Select results from
performance studies of the spectrometer with calibration sources are reported.Comment: 30 pages, 19 figures, 1 table, submitted to NIM
Xenopus Cdc14α/ÎČ are localized to the nucleolus and centrosome and are required for embryonic cell division
BACKGROUND: The dual specificity phosphatase Cdc14 has been shown to be a critical regulator of late mitotic events in several eukaryotes, including S. cerevisiae, S. pombe. C. elegans and H. sapiens. However, Cdc14 homologs have clearly evolved to regulate distinct cellular processes and to respond to regulatory signals important for these processes. The human paralogs hCdc14A and B are the only vertebrate Cdc14 homologues studied to date, but their functions are not well understood. Therefore, it is of great interest to examine the function Cdc14 homologs in other vertebrate species. RESULTS: We identified two open reading frames from Xenopus laevis closely related to human Cdc14A, called XCdc14α and XCdc14ÎČ, although no obvious paralog of the hCdc14B was found. To begin a functional characterization of Xcdc14α and XCdc14ÎČ, we raised polyclonal antibodies against a conserved region. These antibodies stained both the nucleolus and centrosome in interphase Xenopus tissue culture cells, and the mitotic centrosomes. GFP-tagged version of XCdc14α localized to the nucleulus and GFP-XCdc14ÎČ localized to the centrosome, although not exclusively. XCdc14α was also both meiotically and mitotically phosphorylated. Injection of antibodies raised against a conserved region of XCdc14/ÎČ into Xenopus embryos at the two-cell stage blocked division of the injected blastomeres, suggesting that activities of XCdc14α/ÎČ are required for normal cell division. CONCLUSION: These results provide evidence that XCdc14α/ÎČ are required for normal cellular division and are regulated by at least two mechanisms, subcellular localization and possibly phosphorylation. Due to the high sequence conservation between Xcdc14α and hCdc14A, it seems likely that both mechanisms will contribute to regulation of Cdc14 homologs in vertebrates
Social Dimensions of Urban Flood Experience, Exposure, and Concern
With growing urban populations and climate change, urban flooding is an important global issue, even in dryland regions. Flood risk assessments are usually used to identify vulnerable locations and populations, flooding experience patterns, or levels of concern about flooding, but rarely are all of these approaches combined. Furthermore, the social dynamics of flood concerns, exposure, and experience are underexplored. We combined geographic and survey data on householdâlevel measures of flood experience, concern, and exposure in Utah\u27s urbanizing Wasatch Front. We asked: (1) Are socially vulnerable groups more likely to be exposed to flood risk? (2) How common are flooding experiences among urban residents, and how are these experiences related to sociodemographic characteristics and exposure? and (3) How concerned are urban residents about flooding, and does concern vary by exposure, flood experience, and sociodemographic characteristics? Although floodplain residents were more likely to be White and have higher incomes, respondents who were of a racial/ethnic minority, were older, had less education, and were living in floodplains were more likely to report flood experiences and concern about flooding. Flood risk management approaches need to address social as well as physical sources of vulnerability to floods and recognize social sources of variation in flood experiences and concern
Palliative care needs in patients hospitalized with heart failure (PCHF) study: rationale and design
Abstract Aims The primary aim of this study is to provide data to inform the design of a randomized controlled clinical trial (RCT) of a palliative care (PC) intervention in heart failure (HF). We will identify an appropriate study population with a high prevalence of PC needs defined using quantifiable measures. We will also identify which components a specific and targeted PC intervention in HF should include and attempt to define the most relevant trial outcomes. Methods An unselected, prospective, near-consecutive, cohort of patients admitted to hospital with acute decompensated HF will be enrolled over a 2-year period. All potential participants will be screened using B-type natriuretic peptide and echocardiography, and all those enrolled will be extensively characterized in terms of their HF status, comorbidity, and PC needs. Quantitative assessment of PC needs will include evaluation of general and disease-specific quality of life, mood, symptom burden, caregiver burden, and end of life care. Inpatient assessments will be performed and after discharge outpatient assessments will be carried out every 4âmonths for up to 2.5âyears. Participants will be followed up for a minimum of 1âyear for hospital admissions, and place and cause of death. Methods for identifying patients with HF with PC needs will be evaluated, and estimates of healthcare utilisation performed. Conclusion By assessing the prevalence of these needs, describing how these needs change over time, and evaluating how best PC needs can be identified, we will provide the foundation for designing an RCT of a PC intervention in HF
Body Size Estimation from Early to Middle Childhood: Stability of Underestimation, BMI, and Gender Effects
Individuals who are overweight are more likely to underestimate their body size than those who are normal weight, and overweight underestimators are less likely to engage in weight loss efforts. Underestimation of body size might represent a barrier to prevention and treatment of overweight; thus insight in how underestimation of body size develops and tracks through the childhood years is needed. The aim of the present study was therefore to examine stability in childrenâs underestimation of body size, exploring predictors of underestimation over time. The prospective path from underestimation to BMI was also tested. In a Norwegian cohort of 6 year olds, followed up at ages 8 and 10 (analysis sample: n = 793) body size estimation was captured by the Childrenâs Body Image Scale, height and weight were measured and BMI calculated. Overall, children were more likely to underestimate than overestimate their body size. Individual stability in underestimation was modest, but significant. Higher BMI predicted future underestimation, even when previous underestimation was adjusted for, but there was no evidence for the opposite direction of influence. Boys were more likely than girls to underestimate their body size at ages 8 and 10 (age 8: 38.0% vs. 24.1%; Age 10: 57.9% vs. 30.8%) and showed a steeper increase in underestimation with age compared to girls. In conclusion, the majority of 6, 8, and 10-year olds correctly estimate their body size (prevalence ranging from 40 to 70% depending on age and gender), although a substantial portion perceived themselves to be thinner than they actually were. Higher BMI forecasted future underestimation, but underestimation did not increase the risk for excessive weight gain in middle childhood
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