Profiles of Serial Changes in Cardiac Troponin T Concentrations and Outcome in Ambulatory Patients With Chronic Heart Failure

ObjectivesThe purpose of this study was to determine whether different profiles of cardiac troponin T (cTnT) values assessed over time would yield incremental prognostic information on clinically stable outpatients with heart failure (HF).BackgroundcTnT levels were used to estimate prognosis in HF; however, most studies evaluated hospitalized patients using single measurements.MethodsA cohort of 172 New York Heart Association functional class III to IV outpatients was prospectively studied with serial cTnT measurements collected every 3 months over a 2-year period. The primary end point was death or cardiac transplantation, and secondary end points included HF hospitalization.ResultsOf the 172 patients, 22 (13%) died or underwent transplantation during the first year. Therefore, 150 patients were included in the second-year analysis of 3 pre-determined groups: 1) no serial cTnT elevations (defined as <0.01 ng/ml); 2) 1 or more, but not all cTnT values elevated ≥0.01 ng/ml; and 3) all cTnT values elevated during the first year. During the second year, 30 events occurred: 53 patients had persistently normal cTnT levels (<0.01 ng/ml) with 6 primary events (11%); 57 patients had 1 or more but not all cTnT levels elevated with 11 events (19%); 40 patients demonstrated persistently elevated cTnT levels with 13 (33%) primary events (odds ratio: 3.77; 95% confidence interval: 1.28 to 11.07, p = 0.02).ConclusionsElevations in cTnT, even using a low threshold of 0.01 ng/ml, detected during routine clinical follow-up of ambulatory patients with HF, are highly associated with an increased risk of events, particularly with frequent or persistent cTnT elevations of ≥0.01 ng/ml. Therefore, the ability to monitor clinical change through serial cTnT measurements may add to risk assessment in the ambulatory HF population

Phonons of Metallic Vicinal Surfaces

We present an analysis of the vibrational dynamics of metal vicinal surfaces using the embedded atom method to describe the interaction potential and both a real space Green's function method and a slab method to calculate the phonons. We report two main general characteristics : a global shift of the surface vibrational density of states resulting from a softening of the force field. The latter is a direct result of the reduction of coordination for the different type of surface atoms; and an appearance of high frequency modes above the bulk band, resulting from a stiffening of the force field near the step atom. The latter is due to a rearrangement of the atomic positions during the relaxation of the surface atoms yielding a large shortening of the nearest neighbor distances near the step atoms.Comment: 6 figures, to appear in Sur. Sci. proceedings of VAS1

Asthma in Inner-City Children at 5–11 Years of Age and Prenatal Exposure to Phthalates: The Columbia Center for Children’s Environmental Health Cohort

Background: Studies suggest that phthalate exposures may adversely affect child respiratory health. Objectives: We evaluated associations between asthma diagnosed in children between 5 and 11 years of age and prenatal exposures to butylbenzyl phthalate (BBzP), di-n-butyl phthalate (DnBP), di(2-ethylhexyl) phthalate (DEHP), and diethyl phthalate (DEP). Methods: Phthalate metabolites were measured in spot urine collected from 300 pregnant inner-city women. Children were examined by an allergist or pulmonologist based on the first parental report of wheeze, other respiratory symptoms, and/or use of asthma rescue/controller medication in the preceding 12 months on repeat follow-up questionnaires. Standardized diagnostic criteria were used to classify these children as either having or not having current asthma at the time of the physician examination. Children without any report of wheeze or the other asthma-like symptoms were classified as nonasthmatics at the time of the last negative questionnaire. Modified Poisson regression analyses were used to estimate relative risks (RR) controlling for specific gravity and potential confounders. Results: Of 300 children, 154 (51%) were examined by a physician because of reports of wheeze, other asthma-like symptoms, and/or medication use; 94 were diagnosed with current asthma and 60 without current asthma. The remaining 146 children were classified as nonasthmatic. Compared with levels in nonasthmatics, prenatal metabolites of BBzP and DnBP were associated with a history of asthma-like symptoms (p 70% higher among children with maternal prenatal BBzP and DnBP metabolite concentrations in the third versus the first tertile. Conclusion: Prenatal exposure to BBzP and DnBP may increase the risk of asthma among inner-city children. However, because this is the first such finding, results require replication. Citation: Whyatt RM, Perzanowski MS, Just AC, Rundle AG, Donohue KM, Calafat AM, Hoepner LA, Perera FP, Miller RL. 2014. Asthma in inner-city children at 5–11 years of age and prenatal exposure to phthalates: the Columbia Center for Children’s Environmental Health Cohort. Environ Health Perspect 122:1141–1146; http://dx.doi.org/10.1289/ehp.130767

Prenatal phthalate and early childhood bisphenol A exposures increase asthma risk in inner-city children

To the Editor: We previously reported that inner-city childhood asthma was independently associated with measures of early childhood exposure to bisphenol A (BPA)1 and prenatal, but not childhood, exposures to di-n-butyl phthalate and butylbenzyl phthalate (BBzP). 2 Here, we evaluate whether these 2 classes of endocrine-disrupting chemicals interact to increase the risk of asthma. We evaluated 292 inner-city women and their children aged 5 to 11 years from the Columbia Center for Children's Environmental Health birth cohort of pregnant women who delivered between 1998 and 2006. Enrollment, exclusion criteria, and a description of the cohort have been reported previously.3 Subjects were selected for the present study on the basis of the availability of (1) measurements of phthalates in spot urine collected from the mother during pregnancy (33.9 ± 3.1 weeks' gestation) and BPA in child urine at ages 3 (n = 237), 5 (259), and/or 7 (n = 161) years; (2) data on child asthma and wheeze-related outcomes; and (3) availability of model covariates. Demographic characteristics of Columbia Center for Children's Environmental Health subjects are provided in Table E1 in this article's Online Repository at www.jacionline.org. All participants gave written informed consent

New Zealand Guideline for the Connection of PV Solar Power and Determining Hosting Capacity for PV Solar Power

Small-scale distributed generation (DG) in New Zealand, particularly photovoltaic (PV) generation, has been growing steadily over the past few years. In the last year alone to 31 March 2016, installed PV generation of all capacities has grown by a factor of about 1.6 to reach 37 MW. Approximately 90% (33 MW) of this installed PV capacity is made up of small-scale, single phase residential grid-tied systems with ratings below 10 kW. This corresponds, on average, to approximately 300-400 new PV systems being installed each month within low voltage (LV) distribution networks. Traditionally, the flow of power in electricity distribution networks has been largely unidirectional. However, distributed generation introduces reverse power flows into the LV network when the power produced by DG systems is greater than what can be consumed locally. This introduction of reverse power flows and the dynamic behavior of DG system inverters can negatively impact the electricity network, causing issues such as over-voltage, phase imbalance, overloading of conductors and transformers, and create unique safety challenges. As such, each DG connection application received by electricity distribution businesses (EDBs) presently needs to be carefully considered for its impact on the electricity network. The resourcing demand imposed by larger numbers of connection applications, and the difficulty of technical assessment including congestion evaluation, are likely to increase substantially as DG uptake intensifies. This has prompted the Electric Power Engineering Centre (EPECentre) via its GREEN Grid programme, with the assistance of the electricity industry based Network Analysis Group (NAG), to develop a small-scale inverter based DG connection guideline for New Zealand EDBs. This has been developed on behalf of the Electricity Engineers’ Association (EEA) specifically for the connection of inverter energy systems (IES) of 10 kW or less. This paper summarizes key aspects of this guideline. This includes a streamlined connection application evaluation process that enables EDBs to efficiently categorize DG applications into three groups. These groups vary from those with minimal or moderate network impact that can be autoassessed, to those most likely to cause network congestion that require manual assessment. These categories are determined by looking at the DG hosting capacity specific to the LV network that the DG is connecting to. For two of these categories, mitigation measures for connection, are prescribed. It is also shown how DG hosting capacity can be used to simply evaluate LV network congestion in order to satisfy Electricity Industry Participation Code (EIPC) Part 6 requirements. Key technical requirements for all IES, appropriate for New Zealand conditions, are also summarized

Prenatal and postnatal bisphenol A exposure and asthma development among inner-city children

Background Bisphenol A (BPA) is used widely to manufacture food container linings. Mouse models suggest exposure to BPA might increase allergic inflammation. Objectives We hypothesized that BPA exposure, as assessed based on urinary BPA concentrations, would be associated with increased odds of wheeze and asthma and increased fraction of exhaled nitric oxide (Feno) values in children. Methods The Columbia Center for Children's Environmental Health recruited pregnant women for a prospective birth cohort study (n = 568). Mothers during the third trimester and children at ages 3, 5, and 7 years provided spot urine samples. Total urinary BPA concentrations were measured by using online solid-phase extraction, high-performance liquid chromatography, isotope-dilution tandem mass spectrometry. Wheeze in the last 12 months was measured by using questionnaires at ages 5, 6, and 7 years. Asthma was determined by a physician once between ages 5 and 12 years. Feno values were measured at ages 7 to 11 years. Results Prenatal urinary BPA concentrations were associated inversely with wheeze at age 5 years (odds ratio [OR], 0.7; 95% CI, 0.5-0.9; P = .02). Urinary BPA concentrations at age 3 years were associated positively with wheeze at ages 5 years (OR, 1.4; 95% CI, 1.1-1.8; P = .02) and 6 years (OR, 1.4; 95% CI, 1.0-1.9; P = .03). BPA concentrations at age 7 years were associated with wheeze at age 7 years (OR, 1.4; 95% CI, 1.0-1.9; P = .04) and Feno values (β = 0.1; 95% CI, 0.02-0.2; P = .02). BPA concentrations at ages 3, 5, and 7 years were associated with asthma (OR, 1.5 [95% CI, 1.1-2.0], P = .005; OR, 1.4 [95% CI, 1.0-1.9], P = .03; and OR, 1.5 [95% CI, 1.0-2.1], P = .04, respectively). Conclusions This is the first report of an association between postnatal urinary BPA concentrations and asthma in children

INTEGRAL/SPI Limits on Electron-Positron Annihilation Radiation from the Galactic Plane

The center of our Galaxy is a known strong source of electron-positron 511-keV annihilation radiation. Thus far, however, there have been no reliable detections of annihilation radiation outside of the central radian of our Galaxy. One of the primary objectives of the INTEGRAL (INTErnational Gamma-RAy Astrophysics Laboratory) mission, launched in Oct. 2002, is the detailed study of this radiation. The Spectrometer on INTEGRAL (SPI) is a high resolution coded-aperture gamma-ray telescope with an unprecedented combination of sensitivity, angular resolution and energy resolution. We report results from the first 10 months of observation. During this period a significant fraction of the observing time was spent in or near the Galactic Plane. No positive annihilation flux was detected outside of the central region (|l| > 40 deg) of our Galaxy. In this paper we describe the observations and data analysis methods and give limits on the 511-keV flux.Comment: Accepted for publication in the Astrophysical Journal. 13 pages, 3 figure

Optimizing Maintenance Activities Second Report: Snow and Ice Control Operations

FH-11-8250This report presents the major results of an in-depth study of Snow and Ice Control Operations conducted in four States during the winter of 1975-76. The states involved were California, Colorado, Pennsylvania, and Utah. To the extent possible, within the time frame of the study, all aspects of snow and ice control activities (material, equipment and labor) were analyzed. Initial estimates indicate potential savings on the order of $5 million among the four states upon implementation of the changes recommended as a result of this project. The recommendation with the greatest potential for immediate cost reduction are the control of application rates and the adoption of ground control spreaders