Urine chromium as an estimator of air exposure to stainless steel welding fumes.

PubMed

Sjögren, B; Hedström, L; Ulfvarson, U

1983-01-01

Welding stainless steel with covered electrodes, also called manual metal arc welding, generates hexavalent airborne chromium. Chromium concentrations in air and post-shift urine samples, collected the same arbitrarily chosen working day, showed a linear relationship. Since post-shift urine samples reflect chromium concentrations of both current and previous stainless steel welding fume exposure, individual urine measurements are suggested as approximate although not exact estimators of current exposure. This study evaluates the practical importance of such measurements by means of confidence limits and tests of validity.

R package to estimate intracluster correlation coefficient with confidence interval for binary data.

PubMed

Chakraborty, Hrishikesh; Hossain, Akhtar

2018-03-01

The Intracluster Correlation Coefficient (ICC) is a major parameter of interest in cluster randomized trials that measures the degree to which responses within the same cluster are correlated. There are several types of ICC estimators and its confidence intervals (CI) suggested in the literature for binary data. Studies have compared relative weaknesses and advantages of ICC estimators as well as its CI for binary data and suggested situations where one is advantageous in practical research. The commonly used statistical computing systems currently facilitate estimation of only a very few variants of ICC and its CI. To address the limitations of current statistical packages, we developed an R package, ICCbin, to facilitate estimating ICC and its CI for binary responses using different methods. The ICCbin package is designed to provide estimates of ICC in 16 different ways including analysis of variance methods, moments based estimation, direct probabilistic methods, correlation based estimation, and resampling method. CI of ICC is estimated using 5 different methods. It also generates cluster binary data using exchangeable correlation structure. ICCbin package provides two functions for users. The function rcbin() generates cluster binary data and the function iccbin() estimates ICC and it's CI. The users can choose appropriate ICC and its CI estimate from the wide selection of estimates from the outputs. The R package ICCbin presents very flexible and easy to use ways to generate cluster binary data and to estimate ICC and it's CI for binary response using different methods. The package ICCbin is freely available for use with R from the CRAN repository (https://cran.r-project.org/package=ICCbin). We believe that this package can be a very useful tool for researchers to design cluster randomized trials with binary outcome. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-Term Geomagnetically Induced Current Observations From New Zealand: Peak Current Estimates for Extreme Geomagnetic Storms

NASA Astrophysics Data System (ADS)

Rodger, Craig J.; Mac Manus, Daniel H.; Dalzell, Michael; Thomson, Alan W. P.; Clarke, Ellen; Petersen, Tanja; Clilverd, Mark A.; Divett, Tim

2017-11-01

Geomagnetically induced current (GIC) observations made in New Zealand over 14 years show induction effects associated with a rapidly varying horizontal magnetic field (dBH/dt) during geomagnetic storms. This study analyzes the GIC observations in order to estimate the impact of extreme storms as a hazard to the power system in New Zealand. Analysis is undertaken of GIC in transformer number six in Islington, Christchurch (ISL M6), which had the highest observed currents during the 6 November 2001 storm. Using previously published values of 3,000 nT/min as a representation of an extreme storm with 100 year return period, induced currents of 455 A were estimated for Islington (with the 95% confidence interval range being 155-605 A). For 200 year return periods using 5,000 nT/min, current estimates reach 755 A (confidence interval range 155-910 A). GIC measurements from the much shorter data set collected at transformer number 4 in Halfway Bush, Dunedin, (HWB T4), found induced currents to be consistently a factor of 3 higher than at Islington, suggesting equivalent extreme storm effects of 460-1,815 A (100 year return) and 460-2,720 A (200 year return). An estimate was undertaken of likely failure levels for single-phase transformers, such as HWB T4 when it failed during the 6 November 2001 geomagnetic storm, identifying that induced currents of 100 A can put such transformer types at risk of damage. Detailed modeling of the New Zealand power system is therefore required to put this regional analysis into a global context.

Currents and Mixing in the San Lorenzo Overflow, Northern Gulf of California

NASA Astrophysics Data System (ADS)

Rosas-Villegas, Froylán.; López, Manuel; Candela, Julio

2018-02-01

The main properties of the San Lorenzo (SL) overflow are studied, using data from two nonsimultaneous ADCP moorings (located at the sill, and 5 km downstream), as well as CTD and LADCP profiles. Strong tidal currents at the sill modulate the overflow, which is not shut down during the neaps. At the downstream site, the largest flood currents are associated with colder water advected from the sill, flowing downslope, and creating an asymmetry in the semidiurnal tidal cycle. The overflow introduces a significant fortnightly harmonic at the downstream site, and delays the M2 tidal currents for more than an hour with respect to the currents at the sill. The overflow mixes with the overlying water by entrainment during its supercritical stage, reaching near-bottom velocities as high as 1.5 ms-1 and an estimated mean transport of 0.11 Sv; almost twice that estimated at the sill for the same period of the year. Estimated Froude numbers during spring tides suggest the development of an internal hydraulic jump. After relaxation of the maximum downstream currents, high-frequency temperature fluctuations, likely linked to upstream traveling waves, are consistently observed. Direct estimations of the turbulent dissipation rates were used to compute diapycnal diffusivity (Kρ) profiles. Mean estimates of Kρ, as high as 5.5 × 10-2 m2s-1, show that shear at the interface is the most significant source of cross-isopycnal mixing along the SL overflow during ebb tides.

Demographic and traditional knowledge perspectives on the current status of Canadian polar bear subpopulations.

PubMed

York, Jordan; Dowsley, Martha; Cornwell, Adam; Kuc, Miroslaw; Taylor, Mitchell

2016-05-01

Subpopulation growth rates and the probability of decline at current harvest levels were determined for 13 subpopulations of polar bears (Ursus maritimus) that are within or shared with Canada based on mark-recapture estimates of population numbers and vital rates, and harvest statistics using population viability analyses (PVA). Aboriginal traditional ecological knowledge (TEK) on subpopulation trend agreed with the seven stable/increasing results and one of the declining results, but disagreed with PVA status of five other declining subpopulations. The decline in the Baffin Bay subpopulation appeared to be due to over-reporting of harvested numbers from outside Canada. The remaining four disputed subpopulations (Southern Beaufort Sea, Northern Beaufort Sea, Southern Hudson Bay, and Western Hudson Bay) were all incompletely mark-recapture (M-R) sampled, which may have biased their survival and subpopulation estimates. Three of the four incompletely sampled subpopulations were PVA identified as nonviable (i.e., declining even with zero harvest mortality). TEK disagreement was nonrandom with respect to M-R sampling protocols. Cluster analysis also grouped subpopulations with ambiguous demographic and harvest rate estimates separately from those with apparently reliable demographic estimates based on PVA probability of decline and unharvested subpopulation growth rate criteria. We suggest that the correspondence between TEK and scientific results can be used to improve the reliability of information on natural systems and thus improve resource management. Considering both TEK and scientific information, we suggest that the current status of Canadian polar bear subpopulations in 2013 was 12 stable/increasing and one declining (Kane Basin). We do not find support for the perspective that polar bears within or shared with Canada are currently in any sort of climate crisis. We suggest that monitoring the impacts of climate change (including sea ice decline) on polar bear subpopulations should be continued and enhanced and that adaptive management practices are warranted.

Global Electric Circuit Implications of Total Current Measurements over Electrified Clouds

NASA Technical Reports Server (NTRS)

Mach, Douglas M.; Blakeslee, Richard J.; Bateman, Monte G.

2009-01-01

We determined total conduction (Wilson) currents and flash rates for 850 overflights of electrified clouds spanning regions including the Southeastern United States, the Western Atlantic Ocean, the Gulf of Mexico, Central America and adjacent oceans, Central Brazil, and the South Pacific. The overflights include storms over land and ocean, with and without lightning, and with positive and negative Wilson currents. We combined these individual storm overflight statistics with global diurnal lightning variation data from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) to estimate the thunderstorm and electrified shower cloud contributions to the diurnal variation in the global electric circuit. The contributions to the global electric circuit from lightning producing clouds are estimated by taking the mean current per flash derived from the overflight data for land and ocean overflights and combining it with the global lightning rates (for land and ocean) and their diurnal variation derived from the LIS/OTD data. We estimate the contribution of non-lightning producing electrified clouds by assuming several different diurnal variations and total non-electrified storm counts to produce estimates of the total storm currents (lightning and non-lightning producing storms). The storm counts and diurnal variations are constrained so that the resultant total current diurnal variation equals the diurnal variation in the fair weather electric field (+/-15%). These assumptions, combined with the airborne and satellite data, suggest that the total mean current in the global electric circuit ranges from 2.0 to 2.7 kA, which is greater than estimates made by others using other methods.

An expert system model for mapping tropical wetlands and peatlands reveals South America as the largest contributor.

PubMed

Gumbricht, Thomas; Roman-Cuesta, Rosa Maria; Verchot, Louis; Herold, Martin; Wittmann, Florian; Householder, Ethan; Herold, Nadine; Murdiyarso, Daniel

2017-09-01

Wetlands are important providers of ecosystem services and key regulators of climate change. They positively contribute to global warming through their greenhouse gas emissions, and negatively through the accumulation of organic material in histosols, particularly in peatlands. Our understanding of wetlands' services is currently constrained by limited knowledge on their distribution, extent, volume, interannual flood variability and disturbance levels. We present an expert system approach to estimate wetland and peatland areas, depths and volumes, which relies on three biophysical indices related to wetland and peat formation: (1) long-term water supply exceeding atmospheric water demand; (2) annually or seasonally water-logged soils; and (3) a geomorphological position where water is supplied and retained. Tropical and subtropical wetlands estimates reach 4.7 million km 2 (Mkm 2 ). In line with current understanding, the American continent is the major contributor (45%), and Brazil, with its Amazonian interfluvial region, contains the largest tropical wetland area (800,720 km 2 ). Our model suggests, however, unprecedented extents and volumes of peatland in the tropics (1.7 Mkm 2 and 7,268 (6,076-7,368) km 3 ), which more than threefold current estimates. Unlike current understanding, our estimates suggest that South America and not Asia contributes the most to tropical peatland area and volume (ca. 44% for both) partly related to some yet unaccounted extended deep deposits but mainly to extended but shallow peat in the Amazon Basin. Brazil leads the peatland area and volume contribution. Asia hosts 38% of both tropical peat area and volume with Indonesia as the main regional contributor and still the holder of the deepest and most extended peat areas in the tropics. Africa hosts more peat than previously reported but climatic and topographic contexts leave it as the least peat-forming continent. Our results suggest large biases in our current understanding of the distribution, area and volumes of tropical peat and their continental contributions. © 2017 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Poverty among Foster Children: Estimates Using the Supplemental Poverty Measure

PubMed Central

Pac, Jessica; Waldfogel, Jane; Wimer, Christopher

2017-01-01

We use data from the Current Population Survey and the new Supplemental Poverty Measure (SPM) to provide estimates for poverty among foster children over the period 1992 to 2013. These are the first large-scale national estimates for foster children who are not included in official poverty statistics. Holding child and family demographics constant, foster children have a lower risk of poverty than other children. Analyzing income in detail suggests that foster care payments likely play an important role in reducing the risk of poverty in this group. In contrast, we find that children living with grandparents have a higher risk of poverty than other children, even after taking demographics into account. Our estimates suggest that this excess risk is likely linked to their lower likelihood of receiving foster care or other income supports. PMID:28659651

Costing for the Future: Exploring Cost Estimation With Unmanned Autonomous Systems

DTIC Science & Technology

2016-04-30

account for how cost estimating for autonomy is different than current methodologies and to suggest ways it can be addressed through the integration and...The Development stage involves refining the system requirements, creating a solution description , and building a system. 3. The Operational Test...parameter describes the extent to which efficient fabrication methodologies and processes are used, and the automation of labor-intensive operations

Maximum current density and beam brightness achievable by laser-driven electron sources

NASA Astrophysics Data System (ADS)

Filippetto, D.; Musumeci, P.; Zolotorev, M.; Stupakov, G.

2014-02-01

This paper discusses the extension to different electron beam aspect ratio of the Child-Langmuir law for the maximum achievable current density in electron guns. Using a simple model, we derive quantitative formulas in good agreement with simulation codes. The new scaling laws for the peak current density of temporally long and transversely narrow initial beam distributions can be used to estimate the maximum beam brightness and suggest new paths for injector optimization.

Global access to safe water: accounting for water quality and the resulting impact on MDG progress.

PubMed

Onda, Kyle; LoBuglio, Joe; Bartram, Jamie

2012-03-01

Monitoring of progress towards the Millennium Development Goal (MDG) drinking water target relies on classification of water sources as "improved" or "unimproved" as an indicator for water safety. We adjust the current Joint Monitoring Programme (JMP) estimate by accounting for microbial water quality and sanitary risk using the only-nationally representative water quality data currently available, that from the WHO and UNICEF "Rapid Assessment of Drinking Water Quality". A principal components analysis (PCA) of national environmental and development indicators was used to create models that predicted, for most countries, the proportions of piped and of other-improved water supplies that are faecally contaminated; and of these sources, the proportions that lack basic sanitary protection against contamination. We estimate that 1.8 billion people (28% of the global population) used unsafe water in 2010. The 2010 JMP estimate is that 783 million people (11%) use unimproved sources. Our estimates revise the 1990 baseline from 23% to 37%, and the target from 12% to 18%, resulting in a shortfall of 10% of the global population towards the MDG target in 2010. In contrast, using the indicator "use of an improved source" suggests that the MDG target for drinking-water has already been achieved. We estimate that an additional 1.2 billion (18%) use water from sources or systems with significant sanitary risks. While our estimate is imprecise, the magnitude of the estimate and the health and development implications suggest that greater attention is needed to better understand and manage drinking water safety.

Global Access to Safe Water: Accounting for Water Quality and the Resulting Impact on MDG Progress

PubMed Central

Onda, Kyle; LoBuglio, Joe; Bartram, Jamie

2012-01-01

Monitoring of progress towards the Millennium Development Goal (MDG) drinking water target relies on classification of water sources as “improved” or “unimproved” as an indicator for water safety. We adjust the current Joint Monitoring Programme (JMP) estimate by accounting for microbial water quality and sanitary risk using the only-nationally representative water quality data currently available, that from the WHO and UNICEF “Rapid Assessment of Drinking Water Quality”. A principal components analysis (PCA) of national environmental and development indicators was used to create models that predicted, for most countries, the proportions of piped and of other-improved water supplies that are faecally contaminated; and of these sources, the proportions that lack basic sanitary protection against contamination. We estimate that 1.8 billion people (28% of the global population) used unsafe water in 2010. The 2010 JMP estimate is that 783 million people (11%) use unimproved sources. Our estimates revise the 1990 baseline from 23% to 37%, and the target from 12% to 18%, resulting in a shortfall of 10% of the global population towards the MDG target in 2010. In contrast, using the indicator “use of an improved source” suggests that the MDG target for drinking-water has already been achieved. We estimate that an additional 1.2 billion (18%) use water from sources or systems with significant sanitary risks. While our estimate is imprecise, the magnitude of the estimate and the health and development implications suggest that greater attention is needed to better understand and manage drinking water safety. PMID:22690170

Natural seepage of crude oil into the marine environment

USGS Publications Warehouse

Kvenvolden, K.A.; Cooper, C.K.

2003-01-01

Recent global estimates of crude-oil seepage rates suggest that about 47% of crude oil currently entering the marine environment is from natural seeps, whereas 53% results from leaks and spills during the extraction, transportation, refining, storage, and utilization of petroleum. The amount of natural crude-oil seepage is currently estimated to be 600,000 metric tons per year, with a range of uncertainty of 200,000 to 2,000,000 metric tons per year. Thus, natural oil seeps may be the single most important source of oil that enters the ocean, exceeding each of the various sources of crude oil that enters the ocean through its exploitation by humankind.

Estimating tuberculosis incidence from primary survey data: a mathematical modeling approach.

PubMed

Pandey, S; Chadha, V K; Laxminarayan, R; Arinaminpathy, N

2017-04-01

There is an urgent need for improved estimations of the burden of tuberculosis (TB). To develop a new quantitative method based on mathematical modelling, and to demonstrate its application to TB in India. We developed a simple model of TB transmission dynamics to estimate the annual incidence of TB disease from the annual risk of tuberculous infection and prevalence of smear-positive TB. We first compared model estimates for annual infections per smear-positive TB case using previous empirical estimates from China, Korea and the Philippines. We then applied the model to estimate TB incidence in India, stratified by urban and rural settings. Study model estimates show agreement with previous empirical estimates. Applied to India, the model suggests an annual incidence of smear-positive TB of 89.8 per 100 000 population (95%CI 56.8-156.3). Results show differences in urban and rural TB: while an urban TB case infects more individuals per year, a rural TB case remains infectious for appreciably longer, suggesting the need for interventions tailored to these different settings. Simple models of TB transmission, in conjunction with necessary data, can offer approaches to burden estimation that complement those currently being used.

Estimating dead wood during national forest inventories: a review of inventory methodologies and suggestions for harmonization.

PubMed

Woodall, Christopher W; Rondeux, Jacques; Verkerk, Pieter J; Ståhl, Göran

2009-10-01

Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) components around the world. Currently, information regarding the prevalence, status, and methods of DW inventories occurring in the world's forested landscapes is scattered. The goal of this study is to describe the status, DW components measured, sample methods employed, and DW component thresholds used by national forest inventories that currently inventory DW around the world. Study results indicate that most countries do not inventory forest DW. Globally, we estimate that about 13% of countries inventory DW using a diversity of sample methods and DW component definitions. A common feature among DW inventories was that most countries had only just begun DW inventories and employ very low sample intensities. There are major hurdles to harmonizing national forest inventories of DW: differences in population definitions, lack of clarity on sample protocols/estimation procedures, and sparse availability of inventory data/reports. Increasing database/estimation flexibility, developing common dimensional thresholds of DW components, publishing inventory procedures/protocols, releasing inventory data/reports to international peer review, and increasing communication (e.g., workshops) among countries inventorying DW are suggestions forwarded by this study to increase DW inventory harmonization.

Filling a void: abundance estimation of North American populations of arctic geese using hunter recoveries

USGS Publications Warehouse

Alisauskas, R.T.; Drake, K.L.; Nichols, J.D.; Thomson, David L.; Cooch, Evan G.; Conroy, Michael J.

2009-01-01

We consider use of recoveries of marked birds harvested by hunters, in conjunction with continental harvest estimates, for drawing inferences about continental abundance of a select number of goose species. We review assumptions of this method, a version of the Lincoln?Petersen approach, and consider its utility as a tool for making decisions about harvest management in comparison to current sources of information. Finally, we compare such estimates with existing count data, photographic estimates, or other abundance estimates. In most cases, Lincoln estimates are far higher than abundances assumed or perhaps accepted by many waterfowl biologists and managers. Nevertheless, depending on the geographic scope of inference, we suggest that this approach for abundance estimation of arctic geese may have usefulness for retrospective purposes or to assist with harvest management decisions for some species. Lincoln?s estimates may be as close or closer to truth than count, index, or photo data, and can be used with marking efforts currently in place for estimation of survival and harvest rates. Although there are bias issues associated with estimates of both harvest and harvest rate, some of the latter can be addressed with proper allocation of marks to spatially structured populations if subpopulations show heterogeneity in harvest rates.

Integrating environmental and self-report data to refine cannabis prevalence estimates in a major urban area of Switzerland.

PubMed

Been, Frederic; Schneider, Christian; Zobel, Frank; Delémont, Olivier; Esseiva, Pierre

2016-10-01

Cannabis consumption is a topical subject because of discussions about reviewing current regulations. In this context, having a more comprehensive approach to assess and monitor prevalence and consumption is highly relevant. The objective of this work was to refine current estimates about prevalence of cannabis use by combining self-report data and results derived from wastewater analysis. Self-report data was retrieved from surveys conducted in Switzerland and Europe. Wastewater samples were collected at the wastewater treatment plant of Lausanne, western Switzerland, over a 15 months period. The occurrence of 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH), a specific metabolite of delta-9-tetrahydrocannabinol (THC), was monitored. Bayesian hierarchical models were used to estimate consumption, prevalence and number of cannabis users in the investigated area. According to survey data, 12-months prevalence in western Switzerland was estimated to 6.2% of the population aged 15 or older, with an estimated daily cannabis consumption of 8.1gday(-1)·1000inhab(-1) (at 11.2% purity). The integrative model comprising self-report and wastewater data substantially reduced the uncertainty in the estimates and suggested a last-year prevalence of 9.4%, with a daily cannabis consumption of 14.0gday(-1)·1000inhab(-1). Although in the same order of magnitude, consumption and prevalence estimates obtained with the integrative model were 78% and 52% higher compared to self-report figures, respectively. Interestingly, these figures are similar to discrepancies observed when comparing self-reported alcohol consumption and sales or tax data. The suggested integrative model allowed to account for known sources of uncertainty and provided refined estimates of cannabis prevalence in a major urban area of Switzerland. Copyright © 2016 Elsevier B.V. All rights reserved.

78 FR 43274 - Submission for OMB Review; Comment Request

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-19

... burden estimate, or any other aspect of the information collection, including suggestions for reducing... change of a currently approved collection. Title: TD 7898--Employers Qualified Educational Assistance... employees. Information verifies that programs are qualified and that employees may exclude educational...

Evaluation of cost effective protective coatings for ODOT snow & ice equipment.

DOT National Transportation Integrated Search

2016-04-01

Current estimates suggest that the United States loses over $220 billion dollars due to corrosion each year. The research results from this project further ODOTs effort to implement a corrosion prevention strategy that will increase public safety ...

Airborne vs. Inventory Measurements of Methane Emissions in the Alberta Upstream Oil and Gas Sector

NASA Astrophysics Data System (ADS)

Johnson, M.; Tyner, D. R.; Conley, S.; Schwietzke, S.; Zavala Araiza, D.

2017-12-01

Airborne measurements of methane emission rates were directly compared with detailed, spatially-resolved inventory estimates for different oil and gas production regions in Alberta, Canada. For a 50 km × 50 km region near Red Deer, Alberta, containing 2700 older gas and oil wells, measured methane emissions were 16 times higher than reported venting and flaring volumes would suggest, but consistent with regional inventory estimates (which include estimates for additional emissions from pneumatic equipment, fugitive leaks, gas migration, etc.). This result highlights how 94% of methane emissions in this region are attributable to sources missing from current reporting requirements. The comparison was even more stark for a 60 km × 60 km region near Lloydminster, dominated by 2300 cold heavy oil with sand (CHOPS) production sites. Aircraft measured methane emissions in this region were 5 times larger than that expected from reported venting and flaring volumes, and more than 3 times greater than regional inventory estimates. This significant discrepancy is most likely attributable to underreported intentional venting of casing gas at CHOPS sites, which is generally estimated based on the product of the measured produced oil volume and an assumed gas to oil ratio (GOR). GOR values at CHOPS sites can be difficult to measure and can be notoriously variable in time. Considering the implications for other CHOPS sites across Alberta only, the present results suggest that total reported venting in Alberta is low by a factor of 2.4 (range of 2.0-2.7) and total methane emissions from the conventional oil and gas sector (excluding mined oil sands) are likely at least 25-41% greater than currently estimated. This work reveals critical gaps in current measurement and reporting, while strongly supporting the need for urgent mitigation efforts in the context of newly proposed federal methane regulations in Canada, and separate regulatory development efforts in the province of Alberta.

Worldwide variance in the potential utilization of Gamma Knife radiosurgery.

PubMed

Hamilton, Travis; Dade Lunsford, L

2016-12-01

OBJECTIVE The role of Gamma Knife radiosurgery (GKRS) has expanded worldwide during the past 3 decades. The authors sought to evaluate whether experienced users vary in their estimate of its potential use. METHODS Sixty-six current Gamma Knife users from 24 countries responded to an electronic survey. They estimated the potential role of GKRS for benign and malignant tumors, vascular malformations, and functional disorders. These estimates were compared with published disease epidemiological statistics and the 2014 use reports provided by the Leksell Gamma Knife Society (16,750 cases). RESULTS Respondents reported no significant variation in the estimated use in many conditions for which GKRS is performed: meningiomas, vestibular schwannomas, and arteriovenous malformations. Significant variance in the estimated use of GKRS was noted for pituitary tumors, craniopharyngiomas, and cavernous malformations. For many current indications, the authors found significant variance in GKRS users based in the Americas, Europe, and Asia. Experts estimated that GKRS was used in only 8.5% of the 196,000 eligible cases in 2014. CONCLUSIONS Although there was a general worldwide consensus regarding many major indications for GKRS, significant variability was noted for several more controversial roles. This expert opinion survey also suggested that GKRS is significantly underutilized for many current diagnoses, especially in the Americas. Future studies should be conducted to investigate health care barriers to GKRS for many patients.

Parameter estimation for a cohesive sediment transport model by assimilating satellite observations in the Hangzhou Bay: Temporal variations and spatial distributions

NASA Astrophysics Data System (ADS)

Wang, Daosheng; Zhang, Jicai; He, Xianqiang; Chu, Dongdong; Lv, Xianqing; Wang, Ya Ping; Yang, Yang; Fan, Daidu; Gao, Shu

2018-01-01

Model parameters in the suspended cohesive sediment transport models are critical for the accurate simulation of suspended sediment concentrations (SSCs). Difficulties in estimating the model parameters still prevent numerical modeling of the sediment transport from achieving a high level of predictability. Based on a three-dimensional cohesive sediment transport model and its adjoint model, the satellite remote sensing data of SSCs during both spring tide and neap tide, retrieved from Geostationary Ocean Color Imager (GOCI), are assimilated to synchronously estimate four spatially and temporally varying parameters in the Hangzhou Bay in China, including settling velocity, resuspension rate, inflow open boundary conditions and initial conditions. After data assimilation, the model performance is significantly improved. Through several sensitivity experiments, the spatial and temporal variation tendencies of the estimated model parameters are verified to be robust and not affected by model settings. The pattern for the variations of the estimated parameters is analyzed and summarized. The temporal variations and spatial distributions of the estimated settling velocity are negatively correlated with current speed, which can be explained using the combination of flocculation process and Stokes' law. The temporal variations and spatial distributions of the estimated resuspension rate are also negatively correlated with current speed, which are related to the grain size of the seabed sediments under different current velocities. Besides, the estimated inflow open boundary conditions reach the local maximum values near the low water slack conditions and the estimated initial conditions are negatively correlated with water depth, which is consistent with the general understanding. The relationships between the estimated parameters and the hydrodynamic fields can be suggestive for improving the parameterization in cohesive sediment transport models.

Valuing Reductions in Fatal Illness Risks: Implications of Recent Research.

PubMed

Robinson, Lisa A; Hammitt, James K

2016-08-01

The value of mortality risk reductions, conventionally expressed as the value per statistical life, is an important determinant of the net benefits of many government policies. US regulators currently rely primarily on studies of fatal injuries, raising questions about whether different values might be appropriate for risks associated with fatal illnesses. Our review suggests that, despite the substantial expansion of the research base in recent years, few US studies of illness-related risks meet criteria for quality, and those that do yield similar values to studies of injury-related risks. Given this result, combining the findings of these few studies with the findings of the more robust literature on injury-related risks appears to provide a reasonable range of estimates for application in regulatory analysis. Our review yields estimates ranging from about $4.2 million to $13.7 million with a mid-point of $9.0 million (2013 dollars). Although the studies we identify differ from those that underlie the values currently used by Federal agencies, the resulting estimates are remarkably similar, suggesting that there is substantial consensus emerging on the values applicable to the general US population. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

A limited universe of membrane protein families and folds

PubMed Central

Oberai, Amit; Ihm, Yungok; Kim, Sanguk; Bowie, James U.

2006-01-01

One of the goals of structural genomics is to obtain a structural representative of almost every fold in nature. A recent estimate suggests that 70%–80% of soluble protein domains identified in the first 1000 genome sequences should be covered by about 25,000 structures—a reasonably achievable goal. As no current estimates exist for the number of membrane protein families, however, it is not possible to know whether family coverage is a realistic goal for membrane proteins. Here we find that virtually all polytopic helical membrane protein families are present in the already known sequences so we can make an estimate of the total number of families. We find that only ∼700 polytopic membrane protein families account for 80% of structured residues and ∼1700 cover 90% of structured residues. While apparently a finite and reachable goal, we estimate that it will likely take more than three decades to obtain the structures needed for 90% residue coverage, if current trends continue. PMID:16815920

Non-linear effects of soda taxes on consumption and weight outcomes.

PubMed

Fletcher, Jason M; Frisvold, David E; Tefft, Nathan

2015-05-01

The potential health impacts of imposing large taxes on soda to improve population health have been of interest for over a decade. As estimates of the effects of existing soda taxes with low rates suggest little health improvements, recent proposals suggest that large taxes may be effective in reducing weight because of non-linear consumption responses or threshold effects. This paper tests this hypothesis in two ways. First, we estimate non-linear effects of taxes using the range of current rates. Second, we leverage the sudden, relatively large soda tax increase in two states during the early 1990s combined with new synthetic control methods useful for comparative case studies. Our findings suggest virtually no evidence of non-linear or threshold effects. Copyright © 2014 John Wiley & Sons, Ltd.

Finite element method modeling to assess Laplacian estimates via novel variable inter-ring distances concentric ring electrodes.

PubMed

Makeyev, Oleksandr; Besio, Walter G

2016-08-01

Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation has been demonstrated in a range of applications. In our recent work we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts using finite element method modeling. Obtained results suggest that increasing inter-ring distances electrode configurations may decrease the estimation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration the estimation error may be decreased more than two-fold while for the quadripolar configuration more than six-fold decrease is expected.

Estimating tuberculosis incidence from primary survey data: a mathematical modeling approach

PubMed Central

Chadha, V. K.; Laxminarayan, R.; Arinaminpathy, N.

2017-01-01

SUMMARY BACKGROUND: There is an urgent need for improved estimations of the burden of tuberculosis (TB). OBJECTIVE: To develop a new quantitative method based on mathematical modelling, and to demonstrate its application to TB in India. DESIGN: We developed a simple model of TB transmission dynamics to estimate the annual incidence of TB disease from the annual risk of tuberculous infection and prevalence of smear-positive TB. We first compared model estimates for annual infections per smear-positive TB case using previous empirical estimates from China, Korea and the Philippines. We then applied the model to estimate TB incidence in India, stratified by urban and rural settings. RESULTS: Study model estimates show agreement with previous empirical estimates. Applied to India, the model suggests an annual incidence of smear-positive TB of 89.8 per 100 000 population (95%CI 56.8–156.3). Results show differences in urban and rural TB: while an urban TB case infects more individuals per year, a rural TB case remains infectious for appreciably longer, suggesting the need for interventions tailored to these different settings. CONCLUSIONS: Simple models of TB transmission, in conjunction with necessary data, can offer approaches to burden estimation that complement those currently being used. PMID:28284250

Personal Distress and Sympathy Differentially Influence Health Care Professional and Parents' Estimation of Child Procedure-Related Pain.

PubMed

Caes, Line; Goubert, Liesbet; Devos, Patricia; Verlooy, Joris; Benoit, Yves; Vervoort, Tine

2017-02-01

Caregivers’ pain estimations may have important implications for pediatric pain management decisions. Affective responses elicited by facing the child in pain are considered key in understanding caregivers’ estimations of pediatric pain experiences. Theory suggests differential influences of sympathy versus personal distress on pain estimations; yet empirical evidence on the impact of caregivers’ feelings of sympathy versus distress upon estimations of pediatric pain experiences is lacking. The current study explored the role of caregiver distress versus sympathy in understanding caregivers’ pain estimates of the child’s pain experience. Using a prospective design in 31 children undergoing consecutive lumbar punctures and/or bone marrow aspirations at Ghent University Hospital, caregivers’ (i.e., parents, physicians, nurses, and child life specialists) distress and sympathy were assessed before each procedure; estimates of child pain were obtained immediately following each procedure. Results indicated that the child’s level of pain behavior in anticipation of the procedure had a strong influence on all caregivers’ pain estimations. Beyond the impact of child pain behavior, personal distress explained parental and physician’s estimates of child pain, but not pain estimates of nurses and child life specialists. Specifically, higher level of parental and physician’s distress was related to higher child pain estimates. Caregiver sympathy was not associated with pain estimations. The current findings highlight the important role of caregivers’ felt personal distress when faced with child pain, rather than sympathy, in influencing their pain estimates. Potential implications for pain management are discussed.

Widespread inhibition of day-time ecosystem respiration and implications for eddy-covariance flux partitioning

NASA Astrophysics Data System (ADS)

Keenan, T. F.

2017-12-01

Global terrestrial ecosystems absorb about a third of anthropogenic emissions each year, due to the difference between two key processes: photosynthesis and respiration. Despite the importance of these two processes at the global scale, no direct measurement exists of either. Eddy-covariance (EC) measurements have been widely used as the closest `quasi-direct' observation, and the resulting estimates have been used to produce global budgets of photosynthesis and respiration. Recent research, however, suggests that current estimates may be biased by up to 25%, as the methods used to partition observed net carbon fluxes to photosynthesis and respiration do not take into account any inhibition of leaf respiration in light. Yet the prevalence of light-inhibition of leaf respiration remains debated, and impacts on global estimates of photosynthesis and respiration unquantified. Here, we use novel approaches to estimate the extent of light-inhibition across the global FLUXNET EC network, and find strong evidence for an inhibition effect on ecosystem respiration, which varies by season and plant functional type. We develop partitioning methods that allow for inhibition, and find that that diurnal patterns of ecosystem respiration might be markedly different than previously thought. The results call for the reevaluation of global terrestrial carbon cycle models, and also suggest that current global budgets of photosynthesis and respiration may be biased on the order of magnitude of anthropogenic fossil fuel emissions.

Chicago's water market: Dynamics of demand, prices and scarcity rents

USGS Publications Warehouse

Ipe, V.C.; Bhagwat, S.B.

2002-01-01

Chicago and its suburbs are experiencing an increasing demand for water from a growing population and economy and may experience water scarcity in the near future. The Chicago metropolitan area has nearly depleted its groundwater resources to a point where interstate conflicts with Wisconsin could accompany an increased reliance on those sources. Further, the withdrawals from Lake Michigan is limited by the Supreme Court decree. The growing demand and indications of possible scarcity suggest a need to reexamine the pricing policies and the dynamics of demand. The study analyses the demand for water and develops estimates of scarcity rents for water in Chicago. The price and income elasticities computed at the means are -0.002 and 0.0002 respectively. The estimated scarcity rents ranges from $0.98 to $1.17 per thousand gallons. The results indicate that the current prices do not fully account for the scarcity rents and suggest a current rate with in the range $1.53 to $1.72 per thousand gallons.

Mental Disorder Symptoms among Public Safety Personnel in Canada.

PubMed

Carleton, R Nicholas; Afifi, Tracie O; Turner, Sarah; Taillieu, Tamara; Duranceau, Sophie; LeBouthillier, Daniel M; Sareen, Jitender; Ricciardelli, Rose; MacPhee, Renee S; Groll, Dianne; Hozempa, Kadie; Brunet, Alain; Weekes, John R; Griffiths, Curt T; Abrams, Kelly J; Jones, Nicholas A; Beshai, Shadi; Cramm, Heidi A; Dobson, Keith S; Hatcher, Simon; Keane, Terence M; Stewart, Sherry H; Asmundson, Gordon J G

2018-01-01

Canadian public safety personnel (PSP; e.g., correctional workers, dispatchers, firefighters, paramedics, police officers) are exposed to potentially traumatic events as a function of their work. Such exposures contribute to the risk of developing clinically significant symptoms related to mental disorders. The current study was designed to provide estimates of mental disorder symptom frequencies and severities for Canadian PSP. An online survey was made available in English or French from September 2016 to January 2017. The survey assessed current symptoms, and participation was solicited from national PSP agencies and advocacy groups. Estimates were derived using well-validated screening measures. There were 5813 participants (32.5% women) who were grouped into 6 categories (i.e., call center operators/dispatchers, correctional workers, firefighters, municipal/provincial police, paramedics, Royal Canadian Mounted Police). Substantial proportions of participants reported current symptoms consistent with 1 (i.e., 15.1%) or more (i.e., 26.7%) mental disorders based on the screening measures. There were significant differences across PSP categories with respect to proportions screening positive based on each measure. The estimated proportion of PSP reporting current symptom clusters consistent with 1 or more mental disorders appears higher than previously published estimates for the general population; however, direct comparisons are impossible because of methodological differences. The available data suggest that Canadian PSP experience substantial and heterogeneous difficulties with mental health and underscore the need for a rigorous epidemiologic study and category-specific solutions.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Valle, Massimo Della; International Center for Relativistic Astrophysics Network, Piazzale della Repubblica 10, I-65122, Pescara

I’ll review the status of the Supernova/Gamma-Ray Burst connection. Several pieces of evidence suggest that long duration Gamma-ray Bursts are associated with bright SNe-Ic. However recent works suggest that GRBs might be produced in tight binary systems composed of a massive carbon-oxygen cores and a neutron star companion. Current estimates of the SN and GRB rates yield a ratio GRB/SNe-Ibc in the range ∼ 0.4% − 3%.

Integrative Analysis of Desert Dust Size and Abundance Suggests Less Dust Climate Cooling

NASA Technical Reports Server (NTRS)

Kok, Jasper F.; Ridley, David A.; Zhou, Qing; Miller, Ron L.; Zhao, Chun; Heald, Colette L.; Ward, Daniel S.; Albani, Samuel; Haustein, Karsten

2017-01-01

Desert dust aerosols affect Earths global energy balance through interactions with radiation, clouds, and ecosystems. But the magnitudes of these effects are so uncertain that it remains unclear whether atmospheric dust has a net warming or cooling effect on global climate. Consequently, it is still uncertain whether large changes in atmospheric dust loading over the past century have slowed or accelerated anthropogenic climate change, and the climate impact of possible future alterations in dust loading is similarly disputed. Here we use an integrative analysis of dust aerosol sizes and abundance to constrain the climatic impact of dust through direct interactions with radiation. Using a combination of observational, experimental, and model data, we find that atmospheric dust is substantially coarser than represented in current climate models. Since coarse dust warms global climate, the dust direct radiative effect (DRE) is likely less cooling than the 0.4 W m superscript 2 estimated by models in a current ensemble. We constrain the dust DRE to -0.20 (-0.48 to +0.20) W m superscript 2, which suggests that the dust DRE produces only about half the cooling that current models estimate, and raises the possibility that dust DRE is actually net warming the planet.

Approaches to Refining Estimates of Global Burden and Economics of Dengue

PubMed Central

Shepard, Donald S.; Undurraga, Eduardo A.; Betancourt-Cravioto, Miguel; Guzmán, María G.; Halstead, Scott B.; Harris, Eva; Mudin, Rose Nani; Murray, Kristy O.; Tapia-Conyer, Roberto; Gubler, Duane J.

2014-01-01

Dengue presents a formidable and growing global economic and disease burden, with around half the world's population estimated to be at risk of infection. There is wide variation and substantial uncertainty in current estimates of dengue disease burden and, consequently, on economic burden estimates. Dengue disease varies across time, geography and persons affected. Variations in the transmission of four different viruses and interactions among vector density and host's immune status, age, pre-existing medical conditions, all contribute to the disease's complexity. This systematic review aims to identify and examine estimates of dengue disease burden and costs, discuss major sources of uncertainty, and suggest next steps to improve estimates. Economic analysis of dengue is mainly concerned with costs of illness, particularly in estimating total episodes of symptomatic dengue. However, national dengue disease reporting systems show a great diversity in design and implementation, hindering accurate global estimates of dengue episodes and country comparisons. A combination of immediate, short-, and long-term strategies could substantially improve estimates of disease and, consequently, of economic burden of dengue. Suggestions for immediate implementation include refining analysis of currently available data to adjust reported episodes and expanding data collection in empirical studies, such as documenting the number of ambulatory visits before and after hospitalization and including breakdowns by age. Short-term recommendations include merging multiple data sources, such as cohort and surveillance data to evaluate the accuracy of reporting rates (by health sector, treatment, severity, etc.), and using covariates to extrapolate dengue incidence to locations with no or limited reporting. Long-term efforts aim at strengthening capacity to document dengue transmission using serological methods to systematically analyze and relate to epidemiologic data. As promising tools for diagnosis, vaccination, vector control, and treatment are being developed, these recommended steps should improve objective, systematic measures of dengue burden to strengthen health policy decisions. PMID:25412506

Approaches to refining estimates of global burden and economics of dengue.

PubMed

Shepard, Donald S; Undurraga, Eduardo A; Betancourt-Cravioto, Miguel; Guzmán, María G; Halstead, Scott B; Harris, Eva; Mudin, Rose Nani; Murray, Kristy O; Tapia-Conyer, Roberto; Gubler, Duane J

2014-11-01

Dengue presents a formidable and growing global economic and disease burden, with around half the world's population estimated to be at risk of infection. There is wide variation and substantial uncertainty in current estimates of dengue disease burden and, consequently, on economic burden estimates. Dengue disease varies across time, geography and persons affected. Variations in the transmission of four different viruses and interactions among vector density and host's immune status, age, pre-existing medical conditions, all contribute to the disease's complexity. This systematic review aims to identify and examine estimates of dengue disease burden and costs, discuss major sources of uncertainty, and suggest next steps to improve estimates. Economic analysis of dengue is mainly concerned with costs of illness, particularly in estimating total episodes of symptomatic dengue. However, national dengue disease reporting systems show a great diversity in design and implementation, hindering accurate global estimates of dengue episodes and country comparisons. A combination of immediate, short-, and long-term strategies could substantially improve estimates of disease and, consequently, of economic burden of dengue. Suggestions for immediate implementation include refining analysis of currently available data to adjust reported episodes and expanding data collection in empirical studies, such as documenting the number of ambulatory visits before and after hospitalization and including breakdowns by age. Short-term recommendations include merging multiple data sources, such as cohort and surveillance data to evaluate the accuracy of reporting rates (by health sector, treatment, severity, etc.), and using covariates to extrapolate dengue incidence to locations with no or limited reporting. Long-term efforts aim at strengthening capacity to document dengue transmission using serological methods to systematically analyze and relate to epidemiologic data. As promising tools for diagnosis, vaccination, vector control, and treatment are being developed, these recommended steps should improve objective, systematic measures of dengue burden to strengthen health policy decisions.

Comment: Characterization of Two Historic Smallpox Specimens from a Czech Museum.

PubMed

Porter, Ashleigh F; Duggan, Ana T; Poinar, Hendrik N; Holmes, Edward C

2017-09-28

The complete genome sequences of two strains of variola virus (VARV) sampled from human smallpox specimens present in the Czech National Museum, Prague, were recently determined, with one of the sequences estimated to date to the mid-19th century. Using molecular clock methods, the authors of this study go on to infer that the currently available strains of VARV share an older common ancestor, at around 1350 AD, than some recent estimates based on other archival human samples. Herein, we show that the two Czech strains exhibit anomalous branch lengths given their proposed age, and by assuming a constant rate of evolutionary change across the rest of the VARV phylogeny estimate that their true age in fact lies between 1918 and 1937. We therefore suggest that the age of the common ancestor of currently available VARV genomes most likely dates to late 16th and early 17th centuries and not ~1350 AD.

Comment: Characterization of Two Historic Smallpox Specimens from a Czech Museum

PubMed Central

Porter, Ashleigh F.; Duggan, Ana T.

2017-01-01

The complete genome sequences of two strains of variola virus (VARV) sampled from human smallpox specimens present in the Czech National Museum, Prague, were recently determined, with one of the sequences estimated to date to the mid-19th century. Using molecular clock methods, the authors of this study go on to infer that the currently available strains of VARV share an older common ancestor, at around 1350 AD, than some recent estimates based on other archival human samples. Herein, we show that the two Czech strains exhibit anomalous branch lengths given their proposed age, and by assuming a constant rate of evolutionary change across the rest of the VARV phylogeny estimate that their true age in fact lies between 1918 and 1937. We therefore suggest that the age of the common ancestor of currently available VARV genomes most likely dates to late 16th and early 17th centuries and not ~1350 AD. PMID:28956829

Simulated wind-generated inertial oscillations compared to current measurements in the northern North Sea

NASA Astrophysics Data System (ADS)

Bruserud, Kjersti; Haver, Sverre; Myrhaug, Dag

2018-06-01

Measured current speed data show that episodes of wind-generated inertial oscillations dominate the current conditions in parts of the northern North Sea. In order to acquire current data of sufficient duration for robust estimation of joint metocean design conditions, such as wind, waves, and currents, a simple model for episodes of wind-generated inertial oscillations is adapted for the northern North Sea. The model is validated with and compared against measured current data at one location in the northern North Sea and found to reproduce the measured maximum current speed in each episode with considerable accuracy. The comparison is further improved when a small general background current is added to the simulated maximum current speeds. Extreme values of measured and simulated current speed are estimated and found to compare well. To assess the robustness of the model and the sensitivity of current conditions from location to location, the validated model is applied at three other locations in the northern North Sea. In general, the simulated maximum current speeds are smaller than the measured, suggesting that wind-generated inertial oscillations are not as prominent at these locations and that other current conditions may be governing. Further analysis of the simulated current speed and joint distribution of wind, waves, and currents for design of offshore structures will be presented in a separate paper.

Simulated wind-generated inertial oscillations compared to current measurements in the northern North Sea

NASA Astrophysics Data System (ADS)

Bruserud, Kjersti; Haver, Sverre; Myrhaug, Dag

2018-04-01

Measured current speed data show that episodes of wind-generated inertial oscillations dominate the current conditions in parts of the northern North Sea. In order to acquire current data of sufficient duration for robust estimation of joint metocean design conditions, such as wind, waves, and currents, a simple model for episodes of wind-generated inertial oscillations is adapted for the northern North Sea. The model is validated with and compared against measured current data at one location in the northern North Sea and found to reproduce the measured maximum current speed in each episode with considerable accuracy. The comparison is further improved when a small general background current is added to the simulated maximum current speeds. Extreme values of measured and simulated current speed are estimated and found to compare well. To assess the robustness of the model and the sensitivity of current conditions from location to location, the validated model is applied at three other locations in the northern North Sea. In general, the simulated maximum current speeds are smaller than the measured, suggesting that wind-generated inertial oscillations are not as prominent at these locations and that other current conditions may be governing. Further analysis of the simulated current speed and joint distribution of wind, waves, and currents for design of offshore structures will be presented in a separate paper.

An alternative method to measure the likelihood of a financial crisis in an emerging market

NASA Astrophysics Data System (ADS)

Özlale, Ümit; Metin-Özcan, Kıvılcım

2007-07-01

This paper utilizes an early warning system in order to measure the likelihood of a financial crisis in an emerging market economy. We introduce a methodology, where we can both obtain a likelihood series and analyze the time-varying effects of several macroeconomic variables on this likelihood. Since the issue is analyzed in a non-linear state space framework, the extended Kalman filter emerges as the optimal estimation algorithm. Taking the Turkish economy as our laboratory, the results indicate that both the derived likelihood measure and the estimated time-varying parameters are meaningful and can successfully explain the path that the Turkish economy had followed between 2000 and 2006. The estimated parameters also suggest that overvalued domestic currency, current account deficit and the increase in the default risk increase the likelihood of having an economic crisis in the economy. Overall, the findings in this paper suggest that the estimation methodology introduced in this paper can also be applied to other emerging market economies as well.

Americans misperceive racial economic equality

PubMed Central

Kraus, Michael W.; Rucker, Julian M.; Richeson, Jennifer A.

2017-01-01

The present research documents the widespread misperception of race-based economic equality in the United States. Across four studies (n = 1,377) sampling White and Black Americans from the top and bottom of the national income distribution, participants overestimated progress toward Black–White economic equality, largely driven by estimates of greater current equality than actually exists according to national statistics. Overestimates of current levels of racial economic equality, on average, outstripped reality by roughly 25% and were predicted by greater belief in a just world and social network racial diversity (among Black participants). Whereas high-income White respondents tended to overestimate racial economic equality in the past, Black respondents, on average, underestimated the degree of past racial economic equality. Two follow-up experiments further revealed that making societal racial discrimination salient increased the accuracy of Whites’ estimates of Black–White economic equality, whereas encouraging Whites to anchor their estimates on their own circumstances increased their tendency to overestimate current racial economic equality. Overall, these findings suggest a profound misperception of and unfounded optimism regarding societal race-based economic equality—a misperception that is likely to have any number of important policy implications. PMID:28923915

Americans misperceive racial economic equality.

PubMed

Kraus, Michael W; Rucker, Julian M; Richeson, Jennifer A

2017-09-26

The present research documents the widespread misperception of race-based economic equality in the United States. Across four studies ( n = 1,377) sampling White and Black Americans from the top and bottom of the national income distribution, participants overestimated progress toward Black-White economic equality, largely driven by estimates of greater current equality than actually exists according to national statistics. Overestimates of current levels of racial economic equality, on average, outstripped reality by roughly 25% and were predicted by greater belief in a just world and social network racial diversity (among Black participants). Whereas high-income White respondents tended to overestimate racial economic equality in the past, Black respondents, on average, underestimated the degree of past racial economic equality. Two follow-up experiments further revealed that making societal racial discrimination salient increased the accuracy of Whites' estimates of Black-White economic equality, whereas encouraging Whites to anchor their estimates on their own circumstances increased their tendency to overestimate current racial economic equality. Overall, these findings suggest a profound misperception of and unfounded optimism regarding societal race-based economic equality-a misperception that is likely to have any number of important policy implications.

Effect of previous and current vaccination against influenza A(H1N1)pdm09, A(H3N2), and B during the post-pandemic period 2010-2016 in Spain

PubMed Central

Castilla, Jesús; Pozo, Francisco

2017-01-01

Background Recent studies suggest that the protective effect of the current influenza vaccine could be influenced by vaccination in previous seasons. We estimated the combined effect of the previous and current influenza vaccines from the 2010–2011 season to the 2015–2016 season in Spain. Methods We performed a test-negative case-control study in patients ≥9 years old. We estimated the influenza vaccine effectiveness (IVE) against influenza A(H1N1)pdm09, A(H3N2), and B virus. Results We included 1206 influenza A(H1N1)pdm09 cases, 1358 A(H3N2) cases and 1079 B cases. IVE against A(H1N1)pdm09 virus in the pooled-season analysis was 53% (95% Confidence Interval (CI): 21% to 72%) for those vaccinated only in the current season and 50% (95%CI: 23% to 68%) for those vaccinated in the both current and previous seasons. Against the influenza A(H3N2) virus, IVE was 17% (95%CI: -43% to 52%) for those vaccinated only in the current season and 3% (95%CI: -33% to 28%) for those vaccinated in both seasons. Regarding influenza B, we obtained similar IVEs for those vaccinated only in the current and those vaccinated in both seasons: 57% (95%CI: 12% to 79%) and 56% (95%CI: 36% to 70%), respectively. Conclusion Our results suggested no interference between the previous and current influenza vaccines against A(H1N1)pdm09 and B viruses, but a possible negative interference against A(H3N2) virus. PMID:28614376

Effect of previous and current vaccination against influenza A(H1N1)pdm09, A(H3N2), and B during the post-pandemic period 2010-2016 in Spain.

PubMed

Gherasim, Alin; Martínez-Baz, Iván; Castilla, Jesús; Pozo, Francisco; Larrauri, Amparo

2017-01-01

Recent studies suggest that the protective effect of the current influenza vaccine could be influenced by vaccination in previous seasons. We estimated the combined effect of the previous and current influenza vaccines from the 2010-2011 season to the 2015-2016 season in Spain. We performed a test-negative case-control study in patients ≥9 years old. We estimated the influenza vaccine effectiveness (IVE) against influenza A(H1N1)pdm09, A(H3N2), and B virus. We included 1206 influenza A(H1N1)pdm09 cases, 1358 A(H3N2) cases and 1079 B cases. IVE against A(H1N1)pdm09 virus in the pooled-season analysis was 53% (95% Confidence Interval (CI): 21% to 72%) for those vaccinated only in the current season and 50% (95%CI: 23% to 68%) for those vaccinated in the both current and previous seasons. Against the influenza A(H3N2) virus, IVE was 17% (95%CI: -43% to 52%) for those vaccinated only in the current season and 3% (95%CI: -33% to 28%) for those vaccinated in both seasons. Regarding influenza B, we obtained similar IVEs for those vaccinated only in the current and those vaccinated in both seasons: 57% (95%CI: 12% to 79%) and 56% (95%CI: 36% to 70%), respectively. Our results suggested no interference between the previous and current influenza vaccines against A(H1N1)pdm09 and B viruses, but a possible negative interference against A(H3N2) virus.

Tidally-driven effluent detected by long-term temperature monitoring at the TAG hydrothermal mound, Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

Kinoshita, M.; Von Herzen, R. P.; Matsubayashi, O.; Fujioka, K.

1998-06-01

During Aug. 13-21, 1994, temperatures and current velocity were simultaneously monitored on the TAG hydrothermal mound. Three `Giant Kelps (GKs)', vertical thermistor arrays of 50 m height, were moored on the periphery of the central black smoker complex (CBC). A `Manatee', multi-monitoring system including current velocity, was deployed 50 m east of CBC. Four `Daibutsu' geothermal probes penetrated the sediment south to west of CBC. Compilation of all data revealed semi-diurnal variations in water temperatures and current velocity, and allowed us to discuss the source of these anomalies. Temperature anomalies of GKs correlate well with current velocity, and are interpreted to be caused by the main plume from CBC that was bent over by the tidal current. We identified two types of asymmetric, periodic temperature variations at Daibutsu Probes 2 and 8, located 20 m to the south of CBC. By comparing temperatures and current velocity, they are attributed to non-buoyant effluents laterally advected by the tidal current. The source of one variation is located east to ESE of the probes, and the source of the other is located to the north. On Aug. 31, a new periodic anomaly emerged on Probe 2 with its amplitude up to 0.8°C. The 6-h offset between the new anomaly and the previous one suggests that the source of the new anomaly lies to the west of Probe 2. The heat flux of these non-buoyant effluents is estimated to range from 30 to 100 kW/m 2, which is of the same order as direct estimates of diffuse flow at the TAG mound. It suggests that a significant amount of diffuse effluent is laterally advected by the prevailing current near the seafloor.

Analytic assessment of Laplacian estimates via novel variable interring distances concentric ring electrodes.

PubMed

Makeyev, Oleksandr; Besio, Walter G

2016-08-01

Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation has been demonstrated in a range of applications. In our recent work we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are analytically compared to their constant inter-ring distances counterparts using coefficients of the Taylor series truncation terms. Obtained results suggest that increasing inter-ring distances electrode configurations may decrease the truncation error of the Laplacian estimation resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration the truncation error may be decreased more than two-fold while for the quadripolar more than seven-fold decrease is expected.

Risk and Risk Assessment in Environmental Education.

ERIC Educational Resources Information Center

Chiras, Daniel D.

1982-01-01

Risk assessment (the identification of hazards, the determination of the probability of a hazardous event occurring, and an estimation of the severity of such an event's occurrence) is suggested as a technique to be used to analyze current issues in environmental education in an objective manner. (PEB)

Evaluation of methods for calculating maximum allowable standing height in amputees competing in Paralympic athletics.

PubMed

Connick, M J; Beckman, E; Ibusuki, T; Malone, L; Tweedy, S M

2016-11-01

The International Paralympic Committee has a maximum allowable standing height (MASH) rule that limits stature to a pre-trauma estimation. The MASH rule reduces the probability that bilateral lower limb amputees use disproportionately long prostheses in competition. Although there are several methods for estimating stature, the validity of these methods has not been compared. To identify the most appropriate method for the MASH rule, this study aimed to compare the criterion validity of estimations resulting from the current method, the Contini method, and four Canda methods (Canda-1, Canda-2, Canda-3, and Canda-4). Stature, ulna length, demispan, sitting height, thigh length, upper arm length, and forearm length measurements in 31 males and 30 females were used to calculate the respective estimation for each method. Results showed that Canda-1 (based on four anthropometric variables) produced the smallest error and best fitted the data in males and females. The current method was associated with the largest error of those tests because it increasingly overestimated height in people with smaller stature. The results suggest that the set of Canda equations provide a more valid MASH estimation in people with a range of upper limb and bilateral lower limb amputations compared with the current method. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

National physical activity surveillance: Users of wearable activity monitors as a potential data source.

PubMed

Omura, John D; Carlson, Susan A; Paul, Prabasaj; Watson, Kathleen B; Fulton, Janet E

2017-03-01

The objective of this study was to assess usage patterns of wearable activity monitors among US adults and how user characteristics might influence physical activity estimates from this type of sample. We analyzed data on 3367 respondents to the 2015 HealthStyles survey, an annual consumer mail panel survey conducted on a nationwide sample. Approximately 1 in 8 respondents (12.5%) reported currently using a wearable activity monitor. Current use varied by sex, age, and education level. Use increased with physical activity level from 4.3% for inactive adults to 17.4% for active adults. Overall, 49.9% of all adults met the aerobic physical activity guideline, while this prevalence was 69.5% among current activity monitor users. Our findings suggest that current users of wearable activity monitors are not representative of the overall US population. Estimates of physical activity levels using data from wearable activity monitors users may be an overestimate and therefore data from users alone may have a limited role in physical activity surveillance.

Current risk estimates based on the A-bomb survivors data - a discussion in terms of the ICRP recommendations on the neutron weighting factor.

PubMed

Rühm, W; Walsh, L

2007-01-01

Currently, most analyses of the A-bomb survivors' solid tumour and leukaemia data are based on a constant neutron relative biological effectiveness (RBE) value of 10 that is applied to all survivors, independent of their distance to the hypocentre at the time of bombing. The results of these analyses are then used as a major basis for current risk estimates suggested by the International Commission on Radiological Protection (ICRP) for use in international safety guidelines. It is shown here that (i) a constant value of 10 is not consistent with weighting factors recommended by the ICRP for neutrons and (ii) it does not account for the hardening of the neutron spectra in Hiroshima and Nagasaki, which takes place with increasing distance from the hypocentres. The purpose of this paper is to present new RBE values for the neutrons, calculated as a function of distance from the hypocentres for both cities that are consistent with the ICRP60 neutron weighting factor. If based on neutron spectra from the DS86 dosimetry system, these calculations suggest values of about 31 at 1000 m and 23 at 2000 m ground range in Hiroshima, while the corresponding values for Nagasaki are 24 and 22. If the neutron weighting factor that is consistent with ICRP92 is used, the corresponding values are about 23 and 21 for Hiroshima and 21 and 20 for Nagasaki, respectively. It is concluded that the current risk estimates will be subject to some changes in view of the changed RBE values. This conclusion does not change significantly if the new doses from the Dosimetry System DS02 are used.

Comparing fishers' and scientific estimates of size at maturity and maximum body size as indicators for overfishing.

PubMed

Mclean, Elizabeth L; Forrester, Graham E

2018-04-01

We tested whether fishers' local ecological knowledge (LEK) of two fish life-history parameters, size at maturity (SAM) at maximum body size (MS), was comparable to scientific estimates (SEK) of the same parameters, and whether LEK influenced fishers' perceptions of sustainability. Local ecological knowledge was documented for 82 fishers from a small-scale fishery in Samaná Bay, Dominican Republic, whereas SEK was compiled from the scientific literature. Size at maturity estimates derived from LEK and SEK overlapped for most of the 15 commonly harvested species (10 of 15). In contrast, fishers' maximum size estimates were usually lower than (eight species), or overlapped with (five species) scientific estimates. Fishers' size-based estimates of catch composition indicate greater potential for overfishing than estimates based on SEK. Fishers' estimates of size at capture relative to size at maturity suggest routine inclusion of juveniles in the catch (9 of 15 species), and fishers' estimates suggest that harvested fish are substantially smaller than maximum body size for most species (11 of 15 species). Scientific estimates also suggest that harvested fish are generally smaller than maximum body size (13 of 15), but suggest that the catch is dominated by adults for most species (9 of 15 species), and that juveniles are present in the catch for fewer species (6 of 15). Most Samaná fishers characterized the current state of their fishery as poor (73%) and as having changed for the worse over the past 20 yr (60%). Fishers stated that concern about overfishing, catching small fish, and catching immature fish contributed to these perceptions, indicating a possible influence of catch-size composition on their perceptions. Future work should test this link more explicitly because we found no evidence that the minority of fishers with more positive perceptions of their fishery reported systematically different estimates of catch-size composition than those with the more negative majority view. Although fishers' and scientific estimates of size at maturity and maximum size parameters sometimes differed, the fact that fishers make routine quantitative assessments of maturity and body size suggests potential for future collaborative monitoring efforts to generate estimates usable by scientists and meaningful to fishers. © 2017 by the Ecological Society of America.

Violence exposure among children with disabilities.

PubMed

Sullivan, Patricia M

2009-06-01

The focus of this paper is children with disabilities exposed to a broad range of violence types including child maltreatment, domestic violence, community violence, and war and terrorism. Because disability research must be interpreted on the basis of the definitional paradigm employed, definitions of disability status and current prevalence estimates as a function of a given paradigm are initially considered. These disability paradigms include those used in federal, education, juvenile justice, and health care arenas. Current prevalence estimates of childhood disability in the U.S. are presented within the frameworks of these varying definitions of disability status in childhood. Summaries of research from 2000 to 2008 on the four types of violence victimization addressed among children with disabilities are presented and directions for future research suggested.

How much would each researcher receive if competitive government research funding were distributed equally among researchers?

PubMed Central

Katzav, Joel

2017-01-01

Scientists are increasingly dissatisfied with funding systems that rely on peer assessment and, accordingly, have suggested several proposals for reform. One of these proposals is to distribute available funds equally among all qualified researchers, with no interference from peer review. Despite its numerous benefits, such egalitarian sharing faces the objection, among others, that it would lead to an unacceptable dilution of resources. The aim of the present paper is to assess this particular objection. We estimate (for the Netherlands, the U.S. and the U.K.) how much researchers would receive were they to get an equal share of the government budgets that are currently allocated through competitive peer assessment. For the Netherlands, we furthermore estimate what researchers would receive were we to differentiate between researchers working in low-cost, intermediate-cost and high-cost disciplines. Given these estimates, we then determine what researchers could afford in terms of PhD students, Postdocs, travel and equipment. According to our results, researchers could, on average, maintain current PhD student and Postdoc employment levels, and still have at their disposal a moderate (the U.K.) to considerable (the Netherlands, U.S.) budget for travel and equipment. This suggests that the worry that egalitarian sharing leads to unacceptable dilution of resources is unjustified. Indeed, our results strongly suggest that there is room for far more egalitarian distribution of funds than happens in the highly competitive funding schemes so prevalent today. PMID:28886054

How much would each researcher receive if competitive government research funding were distributed equally among researchers?

PubMed

Vaesen, Krist; Katzav, Joel

2017-01-01

Scientists are increasingly dissatisfied with funding systems that rely on peer assessment and, accordingly, have suggested several proposals for reform. One of these proposals is to distribute available funds equally among all qualified researchers, with no interference from peer review. Despite its numerous benefits, such egalitarian sharing faces the objection, among others, that it would lead to an unacceptable dilution of resources. The aim of the present paper is to assess this particular objection. We estimate (for the Netherlands, the U.S. and the U.K.) how much researchers would receive were they to get an equal share of the government budgets that are currently allocated through competitive peer assessment. For the Netherlands, we furthermore estimate what researchers would receive were we to differentiate between researchers working in low-cost, intermediate-cost and high-cost disciplines. Given these estimates, we then determine what researchers could afford in terms of PhD students, Postdocs, travel and equipment. According to our results, researchers could, on average, maintain current PhD student and Postdoc employment levels, and still have at their disposal a moderate (the U.K.) to considerable (the Netherlands, U.S.) budget for travel and equipment. This suggests that the worry that egalitarian sharing leads to unacceptable dilution of resources is unjustified. Indeed, our results strongly suggest that there is room for far more egalitarian distribution of funds than happens in the highly competitive funding schemes so prevalent today.

Model-based projections of Zika virus infections in childbearing women in the Americas.

PubMed

Perkins, T Alex; Siraj, Amir S; Ruktanonchai, Corrine W; Kraemer, Moritz U G; Tatem, Andrew J

2016-07-25

Zika virus is a mosquito-borne pathogen that is rapidly spreading across the Americas. Due to associations between Zika virus infection and a range of fetal maladies(1,2), the epidemic trajectory of this viral infection poses a significant concern for the nearly 15 million children born in the Americas each year. Ascertaining the portion of this population that is truly at risk is an important priority. One recent estimate(3) suggested that 5.42 million childbearing women live in areas of the Americas that are suitable for Zika occurrence. To improve on that estimate, which did not take into account the protective effects of herd immunity, we developed a new approach that combines classic results from epidemiological theory with seroprevalence data and highly spatially resolved data about drivers of transmission to make location-specific projections of epidemic attack rates. Our results suggest that 1.65 (1.45-2.06) million childbearing women and 93.4 (81.6-117.1) million people in total could become infected before the first wave of the epidemic concludes. Based on current estimates of rates of adverse fetal outcomes among infected women(2,4,5), these results suggest that tens of thousands of pregnancies could be negatively impacted by the first wave of the epidemic. These projections constitute a revised upper limit of populations at risk in the current Zika epidemic, and our approach offers a new way to make rapid assessments of the threat posed by emerging infectious diseases more generally.

The Armys Armored Multi Purpose Vehicle (AMPV): Background and Issues for Congress

DTIC Science & Technology

2016-02-24

vehicles and provide protection against the challenging threats that the ABCTs are designed to fight against (page 2).  Because the medical evacuation ...carriers, and medical treatment and evacuation vehicles. An estimated 3,000 of these M-113 variants are currently in service with the Army. The AMPV is...not vehicles that are specially designed and not currently in service). Some suggest that a non-developmental vehicle might make it easier for the

A Proposed Conceptual Model to Measure Unwarranted Practice Variation

DTIC Science & Technology

2007-05-03

its design. The AMEDD should be proud of its long history of clinical, educational, and technological innovation in the field of medicine. Its current...estimate or any other aspect of this collection ofinformation , including suggestions for reducing the burden, to Department of Defense. Washington...Strategy.................................................................. 11 Role of the Researcher

High voltage and high current density vertical GaN power diodes

DOE PAGES

Fischer, A. J.; Dickerson, J. R.; Armstrong, A. M.; ...

2016-01-01

We report on the realization of a GaN high voltage vertical p-n diode operating at > 3.9 kV breakdown with a specific on-resistance < 0.9 mΩ.cm 2. Diodes achieved a forward current of 1 A for on-wafer, DC measurements, corresponding to a current density > 1.4 kA/cm 2. An effective critical electric field of 3.9 MV/cm was estimated for the devices from analysis of the forward and reverse current-voltage characteristics. Furthermore this suggests that the fundamental limit to the GaN critical electric field is significantly greater than previously believed.

Self-reported concussion history: impact of providing a definition of concussion.

PubMed

Robbins, Clifford A; Daneshvar, Daniel H; Picano, John D; Gavett, Brandon E; Baugh, Christine M; Riley, David O; Nowinski, Christopher J; McKee, Ann C; Cantu, Robert C; Stern, Robert A

2014-01-01

In recent years, the understanding of concussion has evolved in the research and medical communities to include more subtle and transient symptoms. The accepted definition of concussion in these communities has reflected this change. However, it is unclear whether this shift is also reflected in the understanding of the athletic community. Self-reported concussion history is an inaccurate assessment of someone's lifetime exposure to concussive brain trauma. However, unfortunately, in many cases it is the only available tool. We hypothesize that athletes' self-reported concussion histories will be significantly greater after reading them the current definition of concussion, relative to the reporting when no definition was provided. An increase from baseline to post-definition response will suggest that athletes are unaware of the currently accepted medical definition. Cross-sectional study of 472 current and former athletes. Investigators conducted structured telephone interviews with current and former athletes between January 2010 and January 2013, asking participants to report how many concussions they had received in their lives. Interviewers then read participants a current definition of concussion, and asked them to re-estimate based on that definition. THE TWO ESTIMATES WERE SIGNIFICANTLY DIFFERENT (WILCOXON SIGNED RANK TEST: z=15.636, P<0.001). Comparison of the baseline and post-definition medians (7 and 15, respectively) indicated that the post-definition estimate was approximately twice the baseline. Follow-up analyses indicated that this effect was consistent across all levels of competition examined and across type of sport (contact versus non-contact). Our results indicate that athletes' current understandings of concussions are not consistent with a currently accepted medical definition. We strongly recommend that clinicians and researchers preface requests for self-reported concussion history with a definition. In addition, it is extremely important that researchers report the definition they used in published manuscripts of their work. Our study shows that unprompted reporting of concussion history produces results that are significantly different from those provided after a definition has been given, suggesting one possible mechanism to improve the reliability of self-reported concussion history across multiple individuals.

Modelling HIV/AIDS Epidemic among Men Who Have Sex with Men in China

PubMed Central

Sun, Xiaodan; Xiao, Yanni; Peng, Zhihang; Wang, Ning

2013-01-01

A compartmental model with antiviral therapy was proposed to identify the important factors that influence HIV infection among gay men in China and suggest some effective control strategies. We proved that the disease will be eradicated if the reproduction number is less than one. Based on the number of annual reported HIV/AIDS among MSM we used the Markov-Chain Monte-Carlo (MCMC) simulation to estimate the unknown parameters. We estimated a mean reproduction number of 3.88 (95% CI: 3.69–4.07). The estimation results showed that there were a higher transmission rate and a lower diagnose rate among MSM than those for another high-risk population. We compared the current treatment policy and immediate therapy once people are diagnosed with HIV, and numerical studies indicated that immediate antiviral therapy would lead to few HIV new infections conditional upon relatively low infectiousness; otherwise the current treatment policy would result in low HIV new infection. Further, increasing treatment coverage rate may lead to decline in HIV new infections and be beneficial to disease control, depending on the infectiousness of the infected individuals with antiviral therapy. The finding suggested that treatment efficacy (directly affecting infectiousness), behavior changes, and interventions greatly affect HIV new infection; strengthening intensity will contribute to the disease control. PMID:24195071

Assessing competition in hospital care markets: the importance of accounting for quality differentiation.

PubMed

Tay, Abigail

2003-01-01

Quality differentiation is especially important in the hospital industry, where the choices of Medicare patients are unaffected by prices. Unlike previous studies that use geographic market concentration to estimate hospital competitiveness, this article emphasizes the importance of quality differentiation in this spatially differentiated market. I estimate a random-coefficients discrete-choice model that predicts patient flow to different hospitals and find that demand responses to both distance and quality are substantial. The estimates suggest that patients do not substitute toward alternative hospitals in proportion to current market shares, implying that geographic market concentration is an inappropriate measure of hospital competitiveness.

Polar Motion Constraints on Models of the Fortnightly Tide

NASA Technical Reports Server (NTRS)

Ray, Richard D.; Egbert, G. D.; Smith, David E. (Technical Monitor)

2002-01-01

Estimates of the near-fortnightly Mf ocean tide from Topex/Poseidon satellite altimetry and from numerical solutions to the shallow water equations agree reasonably well, at least in their basin-scale features. For example, both show that the Pacific Ocean tide lags the Atlantic tide by roughly 30 degrees. There are hints of finer scale agreements in the elevation fields, but noise levels are high. In contrast, estimates of Mf currents are only weakly constrained by the TP data, because high-wavenumber Rossby waves (with intense currents) are associated with relatively small perturbations in surface elevation. As a result, a wide range of Mf current fields are consistent with both the TP data and the hydrodynamic equations within a priori plausible misfit bounds. We find that a useful constraint on the Mf currents is provided by independent estimates of the Earth's polar motion. At the Mf period polar motion shows a weak signal (both prograde and retrograde) which must be almost entirely caused by the ocean tide. We have estimated this signal from the SPACE2000 time series, after applying a broad-band correction for atmospheric angular momentum. Although the polar motion estimates have relatively large uncertainties, they are sufficiently precise to fix optimum data weights in a global ocean inverse model of Mf. These weights control the tradeoff between fitting a prior hydrodynamic model of Mf and fitting the relatively noisy T/P measurements of Mf. The predicted polar motion from the final inverse model agrees remarkably well with the Mf polar motion observations. The preferred model is also consistent with noise levels suggested by island gauges, and it is marginally consistent with differences observed by subsetting the altimetry (to the small extent that this is possible). In turn, this new model of the Mf ocean tide allows the ocean component to be removed from Mf estimates of length of day, thus yielding estimates of complex Love numbers less contaminated by oceanic effects than has hitherto been possible.

Field Monitoring Shows Smaller Sediment Deficit to the Louisiana Coast

NASA Astrophysics Data System (ADS)

Sanks, K. M.; Shaw, J.

2017-12-01

Current reports suggest that the Louisiana Coast will undergo significant drowning due to high subsidence rates and low sediment supply. One report suggests that sediment supply is just 30% of the amount necessary to sustain the current land area (Blum & Roberts, 2009). A novel dataset (CRMS) put together by the USGS and Louisiana's Coastal Protection and Restoration Authority provides direct measurements of sediment accumulation, subsidence rates, and sediment characteristics along the Louisiana Coast over the past 10 years (Jankowski et al., 2017). By interpolating bulk density, percent organic matter, and vertical accretion rates across the coast (274 sites), a more accurate estimate of sediment accumulation, both organic and inorganic, can be determined. Preliminary interpolation shows that an average of 53 MT organic and 132 MT inorganic sediment accumulates on coastal marshes each year. Assuming an average 9 mm/yr subsidence rate (Nienhuis et al., 2017) and 3 mm/yr sea-level rise (Blum & Roberts, 2009), this accumulation results in only a 12 MT/yr, or 6.5%, sediment deficit. Assuming a fluvial sediment discharge of 205 MT/yr, 64% of sediment is being trapped on the delta top. Although the sediment load estimates (MT/yr) may be slightly liberal due to interpolation over water, the fraction sediment deficit is unlikely to significantly change. These results suggest that even if current subsidence rates and sea level rise do not change, the gap between accommodation and accumulation may not be as dire as previously thought.

Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes

PubMed Central

Makeyev, Oleksandr; Besio, Walter G.

2016-01-01

Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected. PMID:27294933

Improving the Accuracy of Laplacian Estimation with Novel Variable Inter-Ring Distances Concentric Ring Electrodes.

PubMed

Makeyev, Oleksandr; Besio, Walter G

2016-06-10

Noninvasive concentric ring electrodes are a promising alternative to conventional disc electrodes. Currently, the superiority of tripolar concentric ring electrodes over disc electrodes, in particular, in accuracy of Laplacian estimation, has been demonstrated in a range of applications. In our recent work, we have shown that accuracy of Laplacian estimation can be improved with multipolar concentric ring electrodes using a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2. This paper takes the next step toward further improving the Laplacian estimate by proposing novel variable inter-ring distances concentric ring electrodes. Derived using a modified (4n + 1)-point method, linearly increasing and decreasing inter-ring distances tripolar (n = 2) and quadripolar (n = 3) electrode configurations are compared to their constant inter-ring distances counterparts. Finite element method modeling and analytic results are consistent and suggest that increasing inter-ring distances electrode configurations may decrease the truncation error resulting in more accurate Laplacian estimates compared to respective constant inter-ring distances configurations. For currently used tripolar electrode configuration, the truncation error may be decreased more than two-fold, while for the quadripolar configuration more than a six-fold decrease is expected.

A Method to Simultaneously Detect the Current Sensor Fault and Estimate the State of Energy for Batteries in Electric Vehicles

PubMed Central

Xu, Jun; Wang, Jing; Li, Shiying; Cao, Binggang

2016-01-01

Recently, State of energy (SOE) has become one of the most fundamental parameters for battery management systems in electric vehicles. However, current information is critical in SOE estimation and current sensor is usually utilized to obtain the latest current information. However, if the current sensor fails, the SOE estimation may be confronted with large error. Therefore, this paper attempts to make the following contributions: Current sensor fault detection and SOE estimation method is realized simultaneously. Through using the proportional integral observer (PIO) based method, the current sensor fault could be accurately estimated. By taking advantage of the accurate estimated current sensor fault, the influence caused by the current sensor fault can be eliminated and compensated. As a result, the results of the SOE estimation will be influenced little by the fault. In addition, the simulation and experimental workbench is established to verify the proposed method. The results indicate that the current sensor fault can be estimated accurately. Simultaneously, the SOE can also be estimated accurately and the estimation error is influenced little by the fault. The maximum SOE estimation error is less than 2%, even though the large current error caused by the current sensor fault still exists. PMID:27548183

A Method to Simultaneously Detect the Current Sensor Fault and Estimate the State of Energy for Batteries in Electric Vehicles.

PubMed

Xu, Jun; Wang, Jing; Li, Shiying; Cao, Binggang

2016-08-19

Recently, State of energy (SOE) has become one of the most fundamental parameters for battery management systems in electric vehicles. However, current information is critical in SOE estimation and current sensor is usually utilized to obtain the latest current information. However, if the current sensor fails, the SOE estimation may be confronted with large error. Therefore, this paper attempts to make the following contributions: Current sensor fault detection and SOE estimation method is realized simultaneously. Through using the proportional integral observer (PIO) based method, the current sensor fault could be accurately estimated. By taking advantage of the accurate estimated current sensor fault, the influence caused by the current sensor fault can be eliminated and compensated. As a result, the results of the SOE estimation will be influenced little by the fault. In addition, the simulation and experimental workbench is established to verify the proposed method. The results indicate that the current sensor fault can be estimated accurately. Simultaneously, the SOE can also be estimated accurately and the estimation error is influenced little by the fault. The maximum SOE estimation error is less than 2%, even though the large current error caused by the current sensor fault still exists.

Survey of air cargo forecasting techniques

NASA Technical Reports Server (NTRS)

Kuhlthan, A. R.; Vermuri, R. S.

1978-01-01

Forecasting techniques currently in use in estimating or predicting the demand for air cargo in various markets are discussed with emphasis on the fundamentals of the different forecasting approaches. References to specific studies are cited when appropriate. The effectiveness of current methods is evaluated and several prospects for future activities or approaches are suggested. Appendices contain summary type analyses of about 50 specific publications on forecasting, and selected bibliographies on air cargo forecasting, air passenger demand forecasting, and general demand and modalsplit modeling.

Decision-model estimation of the age-specific disability weight for schistosomiasis japonica: a systematic review of the literature.

PubMed

Finkelstein, Julia L; Schleinitz, Mark D; Carabin, Hélène; McGarvey, Stephen T

2008-03-05

Schistosomiasis is among the most prevalent parasitic infections worldwide. However, current Global Burden of Disease (GBD) disability-adjusted life year estimates indicate that its population-level impact is negligible. Recent studies suggest that GBD methodologies may significantly underestimate the burden of parasitic diseases, including schistosomiasis. Furthermore, strain-specific disability weights have not been established for schistosomiasis, and the magnitude of human disease burden due to Schistosoma japonicum remains controversial. We used a decision model to quantify an alternative disability weight estimate of the burden of human disease due to S. japonicum. We reviewed S. japonicum morbidity data, and constructed decision trees for all infected persons and two age-specific strata, <15 years (y) and > or =15 y. We conducted stochastic and probabilistic sensitivity analyses for each model. Infection with S. japonicum was associated with an average disability weight of 0.132, with age-specific disability weights of 0.098 (<15 y) and 0.186 (> or =15 y). Re-estimated disability weights were seven to 46 times greater than current GBD measures; no simulations produced disability weight estimates lower than 0.009. Nutritional morbidities had the greatest contribution to the S. japonicum disability weight in the <15 y model, whereas major organ pathologies were the most critical variables in the older age group. GBD disability weights for schistosomiasis urgently need to be revised, and species-specific disability weights should be established. Even a marginal increase in current estimates would result in a substantial rise in the estimated global burden of schistosomiasis, and have considerable implications for public health prioritization and resource allocation for schistosomiasis research, monitoring, and control.

Decision-Model Estimation of the Age-Specific Disability Weight for Schistosomiasis Japonica: A Systematic Review of the Literature

PubMed Central

Finkelstein, Julia L.; Schleinitz, Mark D.; Carabin, Hélène; McGarvey, Stephen T.

2008-01-01

Schistosomiasis is among the most prevalent parasitic infections worldwide. However, current Global Burden of Disease (GBD) disability-adjusted life year estimates indicate that its population-level impact is negligible. Recent studies suggest that GBD methodologies may significantly underestimate the burden of parasitic diseases, including schistosomiasis. Furthermore, strain-specific disability weights have not been established for schistosomiasis, and the magnitude of human disease burden due to Schistosoma japonicum remains controversial. We used a decision model to quantify an alternative disability weight estimate of the burden of human disease due to S. japonicum. We reviewed S. japonicum morbidity data, and constructed decision trees for all infected persons and two age-specific strata, <15 years (y) and ≥15 y. We conducted stochastic and probabilistic sensitivity analyses for each model. Infection with S. japonicum was associated with an average disability weight of 0.132, with age-specific disability weights of 0.098 (<15 y) and 0.186 (≥15 y). Re-estimated disability weights were seven to 46 times greater than current GBD measures; no simulations produced disability weight estimates lower than 0.009. Nutritional morbidities had the greatest contribution to the S. japonicum disability weight in the <15 y model, whereas major organ pathologies were the most critical variables in the older age group. GBD disability weights for schistosomiasis urgently need to be revised, and species-specific disability weights should be established. Even a marginal increase in current estimates would result in a substantial rise in the estimated global burden of schistosomiasis, and have considerable implications for public health prioritization and resource allocation for schistosomiasis research, monitoring, and control. PMID:18320018

Estimating the Contrail Impact on Climate Using the UK Met Office Model

NASA Astrophysics Data System (ADS)

Rap, A.; Forster, P. M.

2008-12-01

With air travel predicted to increase over the coming century, the emissions associated with air traffic are expected to have a significant warming effect on climate. According to current best estimates, an important contribution comes from contrails. However, as reported by the IPCC fourth assessment report, these current best estimates still have a high uncertainty. The development and validation of contrail parameterizations in global climate models is therefore very important. This current study develops a contrail parameterization within the UK Met Office Climate Model. Using this new parameterization, we estimate that for the 2002 traffic, the global mean annual contrail coverage is approximately 0.11%, a value which in good agreement with several other estimates. The corresponding contrail radiative forcing (RF) is calculated to be approximately 4 and 6 mWm-2 in all-sky and clear-sky conditions, respectively. These values lie within the lower end of the RF range reported by the latest IPCC assessment. The relatively high cloud masking effect on contrails observed by our parameterization compared with other studies is investigated, and a possible cause for this difference is suggested. The effect of the diurnal variations of air traffic on both contrail coverage and contrail RF is also investigated. The new parameterization is also employed in thirty-year slab-ocean model runs in order to give one of the first insights into contrail effects on daily temperature range and the climate impact of contrails.

The Incredible Shrinking Elasticities: Married Female Labor Supply, 1978-2002

ERIC Educational Resources Information Center

Heim, Bradley T.

2007-01-01

This paper demonstrates the extent to which married women's labor supply elasticities have changed over the past quarter century. Estimates from March Current Population Survey data suggest that these elasticities have decreased substantially, by 60 percent for the hours wage elasticity (from 0.36 to 0.14), 70 percent for the hours income…

A volume change index for forest growth and sustainability

Treesearch

Paul Van Deusen; Francis Roesch

2009-01-01

A volume change index is suggested that is derived from growth components that can be estimated from remeasured plots. The new index incorporates more information than the traditional growth over removals, ratio. The new index directly indicates whether the standing volume will be increasing or decreasing if current conditions persist, whereas the ratio of...

Subphotospheric current systems and flares

NASA Technical Reports Server (NTRS)

Hudson, Hugh S.

1987-01-01

Subphotospheric current systems inferred from recent vector magnetograph observations imply the existence of electric currents penetrating the photosphere and thus flowing deep in the solar convection zone. These currents presumably originate in an internal dynamo that supplies the observed photospheric magnetic fields through the buoyant motions of the initially deeply-buried flux tubes. The coronal fields resulting from this process therefore must carry slowly-varying currents driven by emfs remote from the surface. These currents may then drive solar-flare energy release. This paper discusses the consequences of such a deep origin of the coronal parallel currents. Simple estimates for a large active region suggest a mean current-closure depth of not less than 10,000 km, with a subphotospheric inductance of not less than 100 H and a subphotospheric stored energy of not less than 10 to the 33rd ergs.

Prevalence and Trends in Lifetime Obesity in the U.S., 1988-2014.

PubMed

Stokes, Andrew; Ni, Yu; Preston, Samuel H

2017-11-01

Estimates of obesity prevalence based on current BMI are an important but incomplete indicator of the total effects of obesity on a population. In this study, data on current BMI and maximum BMI were used to estimate prevalence and trends in lifetime obesity status, defined using the categories never (maximum BMI ≤30 kg/m 2 ), former (maximum BMI ≥30 kg/m 2 and current BMI ≤30 kg/m 2 ), and current obesity (current BMI ≥30 kg/m 2 ). Prevalence was estimated for the period 2013-2014 and trends for the period 1988-2014 using data from the National Health and Nutrition Examination Survey. Predictors of lifetime weight status and the association between lifetime weight categories and prevalent disease status were also investigated using multivariable regression. A total of 50.8% of American males and 51.6% of American females were ever obese in 2013-2014. The prevalence of lifetime obesity exceeded the prevalence of current obesity by amounts that were greater for males and for older persons. The gap between the two prevalence values has risen over time. By 2013-2014, a total of 22.0% of individuals who were not currently obese had formerly been obese. For each of eight diseases considered, prevalence was higher among the formerly obese than among the never obese. A larger fraction of the population is affected by obesity and its health consequences than is suggested in prior studies based on current BMI alone. Weight history should be incorporated into routine health surveillance of the obesity epidemic for a full accounting of the effects of obesity on the U.S. Copyright © 2017 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Unraveling the barriers to reconceptualization of the problem in chronic pain: the actual and perceived ability of patients and health professionals to understand the neurophysiology.

PubMed

Moseley, Lorimer

2003-05-01

To identify why reconceptualization of the problem is difficult in chronic pain, this study aimed to evaluate whether (1) health professionals and patients can understand currently accurate information about the neurophysiology of pain and (2) health professionals accurately estimate the ability of patients to understand the neurophysiology of pain. Knowledge tests were completed by 276 patients with chronic pain and 288 professionals either before (untrained) or after (trained) education about the neurophysiology of pain. Professionals estimated typical patient performance on the test. Untrained participants performed poorly (mean +/- standard deviation, 55% +/- 19% and 29% +/- 12% for professionals and patients, respectively), compared to their trained counterparts (78% +/- 21% and 61% +/- 19%, respectively). The estimated patient score (46% +/- 18%) was less than the actual patient score (P <.005). The results suggest that professionals and patients can understand the neurophysiology of pain but professionals underestimate patients' ability to understand. The implications are that (1) a poor knowledge of currently accurate information about pain and (2) the underestimation of patients' ability to understand currently accurate information about pain represent barriers to reconceptualization of the problem in chronic pain within the clinical and lay arenas.

Current-induced spin polarization on a Pt surface: A new approach using spin-polarized positron annihilation spectroscopy

NASA Astrophysics Data System (ADS)

Kawasuso, A.; Fukaya, Y.; Maekawa, M.; Zhang, H.; Seki, T.; Yoshino, T.; Saitoh, E.; Takanashi, K.

2013-09-01

Transversely spin-polarized positrons were injected near Pt and Au surfaces under an applied electric current. The three-photon annihilation of spin-triplet positronium, which was emitted from the surfaces into vacuum, was observed. When the positron spin polarization was perpendicular to the current direction, the maximum asymmetry of the three-photon annihilation intensity was observed upon current reversal for the Pt surfaces, whereas it was significantly reduced for the Au surface. The experimental results suggest that electrons near the Pt surfaces were in-plane and transversely spin-polarized with respect to the direction of the electric current. The maximum electron spin polarization was estimated to be more than 0.01 (1%).

A heuristic evaluation of long-term global sea level acceleration

NASA Astrophysics Data System (ADS)

Spada, Giorgio; Olivieri, Marco; Galassi, Gaia

2015-05-01

In view of the scientific and social implications, the global mean sea level rise (GMSLR) and its possible causes and future trend have been a challenge for so long. For the twentieth century, reconstructions generally indicate a rate of GMSLR in the range of 1.5 to 2.0 mm yr-1. However, the existence of nonlinear trends is still debated, and current estimates of the secular acceleration are subject to ample uncertainties. Here we use various GMSLR estimates published on scholarly journals since the 1940s for a heuristic assessment of global sea level acceleration. The approach, alternative to sea level reconstructions, is based on simple statistical methods and exploits the principles of meta-analysis. Our results point to a global sea level acceleration of 0.54 ± 0.27 mm/yr/century (1σ) between 1898 and 1975. This supports independent estimates and suggests that a sea level acceleration since the early 1900s is more likely than currently believed.

Estimating the Operating and Support Cost Difference between Royal Australian Air Force C-130E and C-130H Hercules Aircraft

DTIC Science & Technology

1992-09-01

AD-A2 5 9 679 AFIT/GLM/ILSQ/92S-40 DTIC S ELECT FD JAN 2 8 1993• C ESTIMATING THE OPERATING AND SUPPORT COST DIFFERENCE BETWEEN ROYAL AUSTRALIAN AIR...understanding of aircraft operating and support (O& S ) costing within the Royal Australian Air Force. At the beginning, my experience suggested that...current RAAF O& S costing was rudimentary and that suitable RAAF O& S data would be difficult to obtain. Accordingly, I anticipated that I would have to

Alzheimer disease amyloid beta protein forms calcium channels in bilayer membranes: blockade by tromethamine and aluminum.

PubMed Central

Arispe, N; Rojas, E; Pollard, H B

1993-01-01

Amyloid beta protein (A beta P) is the 40- to 42-residue polypeptide implicated in the pathogenesis of Alzheimer disease. We have incorporated this peptide into phosphatidylserine liposomes and then fused the liposomes with a planar bilayer. When incorporated into bilayers the A beta P forms channels, which generate linear current-voltage relationships in symmetrical solutions. A permeability ratio, PK/PCl, of 11 for the open A beta P channel was estimated from the reversal potential of the channel current in asymmetrical KCl solutions. The permeability sequence for different cations, estimated from the reversal potential of the A beta P-channel current for each system of asymmetrical solutions, is Pcs > PLi > PCa > or = PK > PNa. A beta P-channel current (either CS+ or Ca2+ as charge carriers) is blocked reversibly by tromethamine (millimolar range) and irreversibly by Al3+ (micromolar range). The inhibition of the A beta P-channel current by these two substances depends on transmembrane potential, suggesting that the mechanism of blockade involves direct interaction between tromethamine (or Al3+) and sites within the A beta P channel. Hitherto, A beta P has been presumed to be neurotoxic. On the basis of the present data we suggest that the channel activity of the polypeptide may be responsible for some or all of its neurotoxic effects. We further propose that a useful strategy for drug discovery for treatment of Alzheimer disease may include screening compounds for their ability to block or otherwise modify A beta P channels. PMID:8380642

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buckley, L; Lambert, C; Nyiri, B

Purpose: To standardize the tube calibration for Elekta XVI cone beam CT (CBCT) systems in order to provide a meaningful estimate of the daily imaging dose and reduce the variation between units in a large centre with multiple treatment units. Methods: Initial measurements of the output from the CBCT systems were made using a Farmer chamber and standard CTDI phantom. The correlation between the measured CTDI and the tube current was confirmed using an Unfors Xi detector which was then used to perform a tube current calibration on each unit. Results: Initial measurements showed measured tube current variations of upmore » to 25% between units for scans with the same image settings. In order to reasonably estimate the imaging dose, a systematic approach to x-ray generator calibration was adopted to ensure that the imaging dose was consistent across all units at the centre and was adopted as part of the routine quality assurance program. Subsequent measurements show that the variation in measured dose across nine units is on the order of 5%. Conclusion: Increasingly, patients receiving radiation therapy have extended life expectancies and therefore the cumulative dose from daily imaging should not be ignored. In theory, an estimate of imaging dose can be made from the imaging parameters. However, measurements have shown that there are large differences in the x-ray generator calibration as installed at the clinic. Current protocols recommend routine checks of dose to ensure constancy. The present study suggests that in addition to constancy checks on a single machine, a tube current calibration should be performed on every unit to ensure agreement across multiple machines. This is crucial at a large centre with multiple units in order to provide physicians with a meaningful estimate of the daily imaging dose.« less

Analysis of variance to assess statistical significance of Laplacian estimation accuracy improvement due to novel variable inter-ring distances concentric ring electrodes.

PubMed

Makeyev, Oleksandr; Joe, Cody; Lee, Colin; Besio, Walter G

2017-07-01

Concentric ring electrodes have shown promise in non-invasive electrophysiological measurement demonstrating their superiority to conventional disc electrodes, in particular, in accuracy of Laplacian estimation. Recently, we have proposed novel variable inter-ring distances concentric ring electrodes. Analytic and finite element method modeling results for linearly increasing distances electrode configurations suggested they may decrease the truncation error resulting in more accurate Laplacian estimates compared to currently used constant inter-ring distances configurations. This study assesses statistical significance of Laplacian estimation accuracy improvement due to novel variable inter-ring distances concentric ring electrodes. Full factorial design of analysis of variance was used with one categorical and two numerical factors: the inter-ring distances, the electrode diameter, and the number of concentric rings in the electrode. The response variables were the Relative Error and the Maximum Error of Laplacian estimation computed using a finite element method model for each of the combinations of levels of three factors. Effects of the main factors and their interactions on Relative Error and Maximum Error were assessed and the obtained results suggest that all three factors have statistically significant effects in the model confirming the potential of using inter-ring distances as a means of improving accuracy of Laplacian estimation.

Pre-anthropocene mercury residues in North American freshwater fish.

PubMed

Hope, Bruce K; Louch, Jeff

2014-04-01

Mercury (Hg) has been entering the environment from both natural and anthropogenic sources for millennia, and humans have been influencing its environmental transport and fate from well before the Industrial Revolution. Exposure to Hg (as neurotoxic monomethylmercury [MeHg]) occurs primarily through consumption of finfish, shellfish, and marine mammals, and regulatory limits for MeHg concentrations in fish tissue have steadily decreased as information on its health impacts has become available. These facts prompted us to consider 2 questions: 1) What might the MeHg levels in fish tissue have been in the pre-Anthropocene, before significant human impacts on the environment? and 2) How would these pre-Anthropocene levels have compared with current regulatory criteria for MeHg residues in fish tissue? We addressed the first question by estimating pre-Anthropocene concentrations of MeHg in the tissues of prey and predatory fish with an integrated Hg speciation, transport, fate, and food web model (SERAFM), using estimated Hg concentrations in soil, sediment, and atmospheric deposition before the onset of significant human activity (i.e., ≤2000 BCE). Model results show MeHg residues in fish varying depending on the characteristics of the modeled water body, which suggests that Hg in fish tissue is best considered at the scale of individual watersheds or water bodies. We addressed the second question by comparing these model estimates with current regulatory criteria and found that MeHg residues in predatory (but not prey) fish could have approached or exceeded these criteria in some water bodies during the pre-Anthropocene. This suggests that the possibility of naturally occurring levels of Hg in fish below which it is not possible to descend, regardless of where those levels stand with respect to current regulatory limits. Risk management decisions made under these circumstances have the potential to be ineffectual, frustrating, and costly for decision makers and stakeholders alike, suggesting the need for regulatory flexibility when addressing the issue of Hg in fish. © 2013 SETAC.

Relationship between field-aligned currents and inverted-V parallel potential drops observed at midaltitudes

NASA Astrophysics Data System (ADS)

Sakanoi, T.; Fukunishi, H.; Mukai, T.

1995-10-01

The inverted-V field-aligned acceleration region existing in the altitude range of several thousand kilometers plays an essential role for the magnetosphere-ionosphere coupling system. The adiabatic plasma theory predicts a linear relationship between field-aligned current density (J∥) and parallel potential drop (Φ∥), that is, J∥=KΦ∥, where K is the field-aligned conductance. We examined this relationship using the charged particle and magnetic field data obtained from the Akebono (Exos D) satellite. The potential drop above the satellite was derived from the peak energy of downward electrons, while the potential drop below the satellite was derived from two different methods: the peak energy of upward ions and the energy-dependent widening of electron loss cone. On the other hand, field-aligned current densities in the inverted-V region were estimated from the Akebono magnetometer data. Using these potential drops and field-aligned current densities, we estimated the linear field-aligned conductance KJΦ. Further, we obtained the corrected field-aligned conductance KCJΦ by applying the full Knight's formula to the current-voltage relationship. We also independently estimated the field-aligned conductance KTN from the number density and the thermal temperature of magnetospheric source electrons which were obtained by fitting accelerated Maxwellian functions for precipitating electrons. The results are summarized as follows: (1) The latitudinal dependence of parallel potential drops is characterized by a narrow V-shaped structure with a width of 0.4°-1.0°. (2) Although the inverted-V potential region exactly corresponds to the upward field aligned current region, the latitudinal dependence of upward current intensity is an inverted-U shape rather than an inverted-V shape. Thus it is suggested that the field-aligned conductance KCJΦ changes with a V-shaped latitudinal dependence. In many cases, KCJΦ values at the edge of the inverted-V region are about 5-10 times larger than those at the center. (3) By comparing KCJΦ with KTN, KCJΦ is found to be about 2-20 times larger than KTN. These results suggest that low-energy electrons such as trapped electrons, secondary and back-scattered electrons, and ionospheric electrons significantly contribute to upward field-aligned currents in the inverted-V region. It is therefore inferred that non adiabatic pitch angle scattering processes play an important role in the inverted-V region. .

Project Icarus: Nuclear Fusion Propulsion Concept Comparison

NASA Astrophysics Data System (ADS)

Stanic, M.

Project Icarus will use nuclear fusion as the primary propulsion, since achieving breakeven is imminent within the next decade. Therefore, fusion technology provides confidence in further development and fairly high technological maturity by the time the Icarus mission would be plausible. Currently there are numerous (over 2 dozen) different fusion approaches that are simultaneously being developed around the World and it is difficult to predict which of the concepts is going to be the most successful one. This study tried to estimate current technological maturity and possible technological extrapolation of fusion approaches for which appropriate data could be found. Figures of merit that were assessed include: current technological state, mass and volume estimates, possible gain values, main advantages and disadvantages of the concept and an attempt to extrapolate current technological state for the next decade or two. Analysis suggests that Magnetic Confinement Fusion (MCF) concepts are not likely to deliver sufficient performance due to size, mass, gain and large technological barriers of the concept. However, ICF and PJMIF did show potential for delivering necessary performance, assuming appropriate techno- logical advances. This paper is a submission of the Project Icarus Study Group.

Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation: A functional MRI study.

PubMed

Kwon, Yong Hyun; Jang, Sung Ho

2012-08-25

We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation.

Onsite-effects of dual-hemisphere versus conventional single-hemisphere transcranial direct current stimulation

PubMed Central

Kwon, Yong Hyun; Jang, Sung Ho

2012-01-01

We performed functional MRI examinations in six right-handed healthy subjects. During functional MRI scanning, transcranial direct current stimulation was delivered with the anode over the right primary sensorimotor cortex and the cathode over the left primary sensorimotor cortex using dual-hemispheric transcranial direct current stimulation. This was compared to a cathode over the left supraorbital area using conventional single-hemispheric transcranial direct current stimulation. Voxel counts and blood oxygenation level-dependent signal intensities in the right primary sensorimotor cortex regions were estimated and compared between the two transcranial direct current stimulation conditions. Our results showed that dual-hemispheric transcranial direct current stimulation induced greater cortical activities than single-hemispheric transcranial direct current stimulation. These findings suggest that dual-hemispheric transcranial direct current stimulation may provide more effective cortical stimulation than single-hemispheric transcranial direct current stimulation. PMID:25624815

Shipborne LF-VLF oceanic lightning observations and modeling

NASA Astrophysics Data System (ADS)

Zoghzoghy, F. G.; Cohen, M. B.; Said, R. K.; Lehtinen, N. G.; Inan, U. S.

2015-10-01

Approximately 90% of natural lightning occurs over land, but recent observations, using Global Lightning Detection (GLD360) geolocation peak current estimates and satellite optical data, suggested that cloud-to-ground flashes are on average stronger over the ocean. We present initial statistics from a novel experiment using a Low Frequency (LF) magnetic field receiver system installed aboard the National Oceanic Atmospheric Agency (NOAA) Ronald W. Brown research vessel that allowed the detection of impulsive radio emissions from deep-oceanic discharges at short distances. Thousands of LF waveforms were recorded, facilitating the comparison of oceanic waveforms to their land counterparts. A computationally efficient electromagnetic radiation model that accounts for propagation over lossy and curved ground is constructed and compared with previously published models. We include the effects of Earth curvature on LF ground wave propagation and quantify the effects of channel-base current risetime, channel-base current falltime, and return stroke speed on the radiated LF waveforms observed at a given distance. We compare simulation results to data and conclude that previously reported larger GLD360 peak current estimates over the ocean are unlikely to fully result from differences in channel-base current risetime, falltime, or return stroke speed between ocean and land flashes.

Per capita alcohol consumption and suicide mortality in a panel of US states from 1950 to 2002

PubMed Central

Kerr, William C.; Subbaraman, Meenakshi; Ye, Yu

2011-01-01

Introduction and Aims The relationship between per capita alcohol consumption and suicide rates has been found to vary in significance and magnitude across countries. This study utilizes a panel of time-series measures from the US states to estimate the effects of changes in current and lagged alcohol sales on suicide mortality risk. Design and Methods Generalized least squares estimation utilized 53 years of data from 48 US states or state groups to estimate relationships between total and beverage-specific alcohol consumption measures and age-standardized suicide mortality rates in first-differenced semi-logged models. Results An additional liter of ethanol from total alcohol sales was estimated to increase suicide rates by 2.3% in models utilizing a distributed lag specification while no effect was found in models including only current alcohol consumption. A similar result is found for men, while for women both current and distributed lag measures were found to be significantly related to suicide rates with an effect of about 3.2% per liter from current and 5.8% per liter from the lagged measure. Beverage-specific models indicate that spirits is most closely linked with suicide risk for women while beer and wine are for men. Unemployment rates are consistently positively related to suicide rates. Discussion and Conclusions Results suggest that chronic effects, potentially related to alcohol abuse and dependence, are the main source of alcohol’s impact on suicide rates in the US for men and are responsible for about half of the effect for women. PMID:21896069

Body Image in Anorexia Nervosa: Body Size Estimation Utilising a Biological Motion Task and Eyetracking.

PubMed

Phillipou, Andrea; Rossell, Susan Lee; Gurvich, Caroline; Castle, David Jonathan; Troje, Nikolaus Friedrich; Abel, Larry Allen

2016-03-01

Anorexia nervosa (AN) is a psychiatric condition characterised by a distortion of body image. However, whether individuals with AN can accurately perceive the size of other individuals' bodies is unclear. In the current study, 24 women with AN and 24 healthy control participants undertook two biological motion tasks while eyetracking was performed: to identify the gender and to indicate the walkers' body size. Anorexia nervosa participants tended to 'hyperscan' stimuli but did not demonstrate differences in how visual attention was directed to different body areas, relative to controls. Groups also did not differ in their estimation of body size. The hyperscanning behaviours suggest increased anxiety to disorder-relevant stimuli in AN. The lack of group difference in the estimation of body size suggests that the AN group was able to judge the body size of others accurately. The findings are discussed in terms of body image distortion specific to oneself in AN. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.

Health insurance tax credits, the earned income tax credit, and health insurance coverage of single mothers.

PubMed

Cebi, Merve; Woodbury, Stephen A

2014-05-01

The Omnibus Budget Reconciliation Act of 1990 enacted a refundable tax credit for low-income working families who purchased health insurance coverage for their children. This health insurance tax credit (HITC) existed during tax years 1991, 1992, and 1993, and was then rescinded. A difference-in-differences estimator applied to Current Population Survey data suggests that adoption of the HITC, along with accompanying increases in the Earned Income Tax Credit (EITC), was associated with a relative increase of about 4.7 percentage points in the private health insurance coverage of working single mothers with high school or less education. Also, a difference-in-difference-in-differences estimator, which attempts to net out the possible influence of the EITC increases but which requires strong assumptions, suggests that the HITC was responsible for about three-quarters (3.6 percentage points) of the total increase. The latter estimate implies a price elasticity of health insurance take-up of -0.42. Copyright © 2013 John Wiley & Sons, Ltd.

White dwarf stars and the age of the Galactic disk

NASA Technical Reports Server (NTRS)

Wood, M. A.

1990-01-01

The history of the Galaxy is written in its oldest stars, the white dwarf (WD) stars. Significant limits can be placed on both the Galactic age and star formation history. A wide range of input WD model sequences is used to derive the current limits to the age estimates suggested by fitting to the observed falloff in the WD luminosity function. The results suggest that the star formation rate over the history of the Galaxy has been relatively constant, and that the disk age lies in the range 6-12 billion years, depending upon the assumed structure of WD stars, and in particular on the core composition and surface helium layer mass. Using plausible mixed C/O core input models, the estimates for the disk age range from 8-10.5 Gyr, i.e.,sustantially younger than most age estimates for the halo globular clusters. After speculating on the significance of the results, expected observational and theoretical refinements which will further enhance the reliability of the method are discussed.

Playing the Numbers: The Best Bad Option

ERIC Educational Resources Information Center

Doyle, William R.

2012-01-01

College graduates and current students are swimming in a sea of debt. As of this writing, the total amount of outstanding student loan debt has been estimated at $960 billion. The Occupy Student Debt movement, inspired by Occupy Wall Street, has suggested that all student loan debt should be forgiven. As a starting point, members of the movement…

Valuing state parks: Accounting for diverse visitor perspectives

Treesearch

Jason W. Whiting; Lincoln R. Larson; Gary T. Green

2012-01-01

Current and estimated future changes in the United States population suggest that racial and ethnic minority groups are growing rapidly. Minority groups, however, continue to be underrepresented in visitation to state parks. It is also unclear how minority groups value natural settings, such as state parks. The lack of visitation and lack of information pertaining to...

Prolonged Exposure Therapy Following Awareness under Anesthesia: A Case Study

ERIC Educational Resources Information Center

Levinson, Cheri A.; Rodebaugh, Thomas L.; Bertelson, Amy D.

2013-01-01

Awareness during surgery is estimated to effect between 40,000 to 140,000 patients per year in the United States, and there is a growing literature suggesting that this event can lead to the development of posttraumatic stress disorder (PTSD). The current article describes treatment implemented from a manualized protocol of a woman diagnosed with…

Evaluating satellite imagery for estimating mountain pine beetle-caused lodgepole pine mortality: Current status

Treesearch

B. J. Bentz; D. Endreson

2004-01-01

Spatial accuracy in the detection and monitoring of mountain pine beetle populations is an important aspect of both forest research and management. Using ground-collected data, classification models to predict mountain pine beetle-caused lodgepole pine mortality were developed for Landsat TM, ETM+, and IKONOS imagery. Our results suggest that low-resolution imagery...

Trends in Timber Use and Product Recovery in New York

Treesearch

Eric H. Wharton; Thomas W. Birch; Thomas W. Birch

1999-01-01

High demand for a variety of timber products from New York's forests has stimulated increased timber utilization and product recovery. Utilization studies in New York suggest that the recovery of timber has improved over the years. Although current methods of multiproduct harvesting have improved recovery of residual material, an estimated 38.6 million cubic feet...

Curriculum-Based Measurement of Reading Progress Monitoring: The Importance of Growth Magnitude and Goal Setting in Decision Making

ERIC Educational Resources Information Center

Van Norman, Ethan R.; Christ, Theodore J.; Newell, Kirsten W.

2017-01-01

Research regarding the technical adequacy of growth estimates from curriculum-based measurement of reading progress monitoring data suggests that current decision-making frameworks are likely to yield inaccurate recommendations unless data are collected for extensive periods of time. Instances where data may not need to be collected for long…

Crustal growth of the Izu-Ogasawara arc estimated from structural characteristics of Oligocene arc

NASA Astrophysics Data System (ADS)

Takahashi, N.; Yamashita, M.; Kodaira, S.; Miura, S.; Sato, T.; No, T.; Tatsumi, Y.

2011-12-01

Japan Agency for Marine-Earth Science and Technology (JAMSTEC) carried out seismic surveys using a multichannel reflection system and ocean bottom seismographs, and we have clarified crustal structures of whole Izu-Ogasawara (Bonin)-Marina (IBM) arc since 2002. These refection images and velocity structures suggest that the crustal evolution in the intra-oceanic island arc accompanies with much interaction of materials between crust and mantle. Slow mantle velocity identified beneath the thick arc crusts suggests that dense crustal materials transformed into the mantle. On the other hand, high velocity lower crust can be seen around the bottom of the crust beneath the rifted region, and it suggests that underplating of mafic materials occurs there. Average crustal production rate of the entire arc is larger than expected one and approximately 200 km3/km/Ma. The production rate of basaltic magmas corresponds to that of oceanic ridge. Repeated crustal differentiation is indispensable to produce much light materials like continental materials, however, the real process cannot still be resolved yet. We, therefore, submitted drilling proposals to obtain in-situ middle crust with P-wave velocity of 6 km/s. In the growth history of the IBM arc, it is known by many papers that boninitic volcanisms preceded current bimodal volcanisms based on basaltic magmas. The current volcanisms accompanied with basaltic magmas have been occurred since Oligocene age, however, the tectonic differences to develop crustal architecture between Oligocene and present are not understood yet. We obtained new refraction/reflection data along an arc strike of N-S in fore-arc region. Then, we estimate crustal structure with severe change of the crustal thickness from refraction data, which are similar to that along the volcanic front. Interval for location of the thick arc crust along N-S is very similar to that along the volcanic front. The refection image indicates that the basement of the fore-arc is covered with thick sediments with the age of Oligocene and that half graben structures are much identified between the Oligocene arc and the current volcanic front. This may suggest that the Oligocene arc in current fore-arc basin is cut off from the current volcanic arc. Therefore, the Oligocene arc in the fore-arc may still keep structural characteristics inside the body since Oligocene age, which are before cutting off from the current volcanic front.

Using Remotely Sensed Information for Near Real-Time Landslide Hazard Assessment

NASA Technical Reports Server (NTRS)

Kirschbaum, Dalia; Adler, Robert; Peters-Lidard, Christa

2013-01-01

The increasing availability of remotely sensed precipitation and surface products provides a unique opportunity to explore how landslide susceptibility and hazard assessment may be approached at larger spatial scales with higher resolution remote sensing products. A prototype global landslide hazard assessment framework has been developed to evaluate how landslide susceptibility and satellite-derived precipitation estimates can be used to identify potential landslide conditions in near-real time. Preliminary analysis of this algorithm suggests that forecasting errors are geographically variable due to the resolution and accuracy of the current susceptibility map and the application of satellite-based rainfall estimates. This research is currently working to improve the algorithm through considering higher spatial and temporal resolution landslide susceptibility information and testing different rainfall triggering thresholds, antecedent rainfall scenarios, and various surface products at regional and global scales.

Simulating range-wide population and breeding habitat dynamics for an endangered woodland warbler in the face of uncertainty

USGS Publications Warehouse

Adam Duarte,; Hatfield, Jeffrey; Todd M. Swannack,; Michael R. J. Forstner,; M. Clay Green,; Floyd W. Weckerly,

2015-01-01

Population viability analyses provide a quantitative approach that seeks to predict the possible future status of a species of interest under different scenarios and, therefore, can be important components of large-scale species’ conservation programs. We created a model and simulated range-wide population and breeding habitat dynamics for an endangered woodland warbler, the golden-cheeked warbler (Setophaga chrysoparia). Habitat-transition probabilities were estimated across the warbler's breeding range by combining National Land Cover Database imagery with multistate modeling. Using these estimates, along with recently published demographic estimates, we examined if the species can remain viable into the future given the current conditions. Lastly, we evaluated if protecting a greater amount of habitat would increase the number of warblers that can be supported in the future by systematically increasing the amount of protected habitat and comparing the estimated terminal carrying capacity at the end of 50 years of simulated habitat change. The estimated habitat-transition probabilities supported the hypothesis that habitat transitions are unidirectional, whereby habitat is more likely to diminish than regenerate. The model results indicated population viability could be achieved under current conditions, depending on dispersal. However, there is considerable uncertainty associated with the population projections due to parametric uncertainty. Model results suggested that increasing the amount of protected lands would have a substantial impact on terminal carrying capacities at the end of a 50-year simulation. Notably, this study identifies the need for collecting the data required to estimate demographic parameters in relation to changes in habitat metrics and population density in multiple regions, and highlights the importance of establishing a common definition of what constitutes protected habitat, what management goals are suitable within those protected areas, and a standard operating procedure to identify areas of priority for habitat conservation efforts. Therefore, we suggest future efforts focus on these aspects of golden-cheeked warbler conservation and ecology.

A biome-scale assessment of the impact of invasive alien plants on ecosystem services in South Africa.

PubMed

van Wilgen, B W; Reyers, B; Le Maitre, D C; Richardson, D M; Schonegevel, L

2008-12-01

This paper reports an assessment of the current and potential impacts of invasive alien plants on selected ecosystem services in South Africa. We used data on the current and potential future distribution of 56 invasive alien plant species to estimate their impact on four services (surface water runoff, groundwater recharge, livestock production and biodiversity) in five terrestrial biomes. The estimated reductions in surface water runoff as a result of current invasions were >3000 million m(3) (about 7% of the national total), most of which is from the fynbos (shrubland) and grassland biomes; the potential reductions would be more than eight times greater if invasive alien plants were to occupy the full extent of their potential range. Impacts on groundwater recharge would be less severe, potentially amounting to approximately 1.5% of the estimated maximum reductions in surface water runoff. Reductions in grazing capacity as a result of current levels of invasion amounted to just over 1% of the potential number of livestock that could be supported. However, future impacts could increase to 71%. A 'biodiversity intactness index' (the remaining proportion of pre-modern populations) ranged from 89% to 71% for the five biomes. With the exception of the fynbos biome, current invasions have almost no impact on biodiversity intactness. Under future levels of invasion, however, these intactness values decrease to around 30% for the savanna, fynbos and grassland biomes, but to even lower values (13% and 4%) for the two karoo biomes. Thus, while the current impacts of invasive alien plants are relatively low (with the exception of those on surface water runoff), the future impacts could be very high. While the errors in these estimates are likely to be substantial, the predicted impacts are sufficiently large to suggest that there is serious cause for concern.

An algorithm for estimating aerosol optical depth from HIMAWARI-8 data over Ocean

NASA Astrophysics Data System (ADS)

Lee, Kwon Ho

2016-04-01

The paper presents currently developing algorithm for aerosol detection and retrieval over ocean for the next generation geostationary satellite, HIMAWARI-8. Enhanced geostationary remote sensing observations are now enables for aerosol retrieval of dust, smoke, and ash, which began a new era of geostationary aerosol observations. Sixteen channels of the Advanced HIMAWARI Imager (AHI) onboard HIMAWARI-8 offer capabilities for aerosol remote sensing similar to those currently provided by the Moderate Resolution Imaging Spectroradiometer (MODIS). Aerosols were estimated in detection processing from visible and infrared channel radiances, and in retrieval processing using the inversion-optimization of satellite-observed radiances with those calculated from radiative transfer model. The retrievals are performed operationally every ten minutes for pixel sizes of ~8 km. The algorithm currently under development uses a multichannel approach to estimate the effective radius, aerosol optical depth (AOD) simultaneously. The instantaneous retrieved AOD is evaluated by the MODIS level 2 operational aerosol products (C006), and the daily retrieved AOD was compared with ground-based measurements from the AERONET databases. The results show that the detection of aerosol and estimated AOD are in good agreement with the MODIS data and ground measurements with a correlation coefficient of ˜0.90 and a bias of 4%. These results suggest that the proposed method applied to the HIMAWARI-8 satellite data can accurately estimate continuous AOD. Acknowledgments This work was supported by "Development of Geostationary Meteorological Satellite Ground Segment(NMSC-2014-01)" program funded by National Meteorological Satellite Centre(NMSC) of Korea Meteorological Administration(KMA).

Self-reported concussion history: impact of providing a definition of concussion

PubMed Central

Robbins, Clifford A; Daneshvar, Daniel H; Picano, John D; Gavett, Brandon E; Baugh, Christine M; Riley, David O; Nowinski, Christopher J; McKee, Ann C; Cantu, Robert C; Stern, Robert A

2014-01-01

Background In recent years, the understanding of concussion has evolved in the research and medical communities to include more subtle and transient symptoms. The accepted definition of concussion in these communities has reflected this change. However, it is unclear whether this shift is also reflected in the understanding of the athletic community. What is known about the subject Self-reported concussion history is an inaccurate assessment of someone’s lifetime exposure to concussive brain trauma. However, unfortunately, in many cases it is the only available tool. Hypothesis/purpose We hypothesize that athletes’ self-reported concussion histories will be significantly greater after reading them the current definition of concussion, relative to the reporting when no definition was provided. An increase from baseline to post-definition response will suggest that athletes are unaware of the currently accepted medical definition. Study design Cross-sectional study of 472 current and former athletes. Methods Investigators conducted structured telephone interviews with current and former athletes between January 2010 and January 2013, asking participants to report how many concussions they had received in their lives. Interviewers then read participants a current definition of concussion, and asked them to re-estimate based on that definition. Results The two estimates were significantly different (Wilcoxon signed rank test: z=15.636, P<0.001). Comparison of the baseline and post-definition medians (7 and 15, respectively) indicated that the post-definition estimate was approximately twice the baseline. Follow-up analyses indicated that this effect was consistent across all levels of competition examined and across type of sport (contact versus non-contact). Conclusion Our results indicate that athletes’ current understandings of concussions are not consistent with a currently accepted medical definition. We strongly recommend that clinicians and researchers preface requests for self-reported concussion history with a definition. In addition, it is extremely important that researchers report the definition they used in published manuscripts of their work. What this study adds to existing knowledge Our study shows that unprompted reporting of concussion history produces results that are significantly different from those provided after a definition has been given, suggesting one possible mechanism to improve the reliability of self-reported concussion history across multiple individuals. PMID:24891816

Plastic and evolutionary responses of plankton to environmental change are influenced by drift in ocean currents

NASA Astrophysics Data System (ADS)

Doblin, M.; van Sebille, E.

2016-02-01

The analytical framework for understanding fluctuations in ocean habitats has typically involved a Eulerian view. However, for marine microbes, this framework does not take into account their transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Using a modelling approach, we show that generations of upper ocean microbes experience along-trajectory temperature variability up to 10°C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents contributes to environmental fluctuation experienced by microbes and suggests that microbial populations may be adapted to upstream rather than local conditions. In an empirical test, we demonstrate that microbes in a warm, poleward flowing western boundary current (East Australian Current) have a different thermal response curve to microbes in coastal water at the same latitude (p < 0.05). Our findings suggest that advection has the capacity to influence microbial community assemblies such that water masses with relatively small thermal fluctuations select for thermal specialists, and communities with broad temperature performance curves are found in locations where ocean currents are strong or along-trajectory temperature variation is high.

Plasma current start-up by the outer ohmic heating coils in the Saskatchewan TORus Modified (STOR-M) iron core tokamak

DOE PAGES

Mitarai, O.; Xiao, C.; McColl, D.; ...

2015-03-24

A plasma current up to 15 kA has been driven with outer ohmic heating (OH) coils in the STOR-M iron core tokamak. Even when the inner OH coil is disconnected, the outer OH coils alone can induce the plasma current as primary windings and initial breakdown are even easier in this coil layout. Our results suggest a possibility to use an iron core in a spherical tokamak to start up the plasma current without a central solenoid. Finally, the effect of the iron core saturation on the extension of the discharge pulse length has been estimated for further experiments inmore » the STOR-M tokamak.« less

Plasma current start-up by the outer ohmic heating coils in the Saskatchewan TORus Modified (STOR-M) iron core tokamak

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitarai, O.; Xiao, C.; McColl, D.

A plasma current up to 15 kA has been driven with outer ohmic heating (OH) coils in the STOR-M iron core tokamak. Even when the inner OH coil is disconnected, the outer OH coils alone can induce the plasma current as primary windings and initial breakdown are even easier in this coil layout. Our results suggest a possibility to use an iron core in a spherical tokamak to start up the plasma current without a central solenoid. Finally, the effect of the iron core saturation on the extension of the discharge pulse length has been estimated for further experiments inmore » the STOR-M tokamak.« less

Information spreading by a combination of MEG source estimation and multivariate pattern classification.

PubMed

Sato, Masashi; Yamashita, Okito; Sato, Masa-Aki; Miyawaki, Yoichi

2018-01-01

To understand information representation in human brain activity, it is important to investigate its fine spatial patterns at high temporal resolution. One possible approach is to use source estimation of magnetoencephalography (MEG) signals. Previous studies have mainly quantified accuracy of this technique according to positional deviations and dispersion of estimated sources, but it remains unclear how accurately MEG source estimation restores information content represented by spatial patterns of brain activity. In this study, using simulated MEG signals representing artificial experimental conditions, we performed MEG source estimation and multivariate pattern analysis to examine whether MEG source estimation can restore information content represented by patterns of cortical current in source brain areas. Classification analysis revealed that the corresponding artificial experimental conditions were predicted accurately from patterns of cortical current estimated in the source brain areas. However, accurate predictions were also possible from brain areas whose original sources were not defined. Searchlight decoding further revealed that this unexpected prediction was possible across wide brain areas beyond the original source locations, indicating that information contained in the original sources can spread through MEG source estimation. This phenomenon of "information spreading" may easily lead to false-positive interpretations when MEG source estimation and classification analysis are combined to identify brain areas that represent target information. Real MEG data analyses also showed that presented stimuli were able to be predicted in the higher visual cortex at the same latency as in the primary visual cortex, also suggesting that information spreading took place. These results indicate that careful inspection is necessary to avoid false-positive interpretations when MEG source estimation and multivariate pattern analysis are combined.

A Web-Based System for Bayesian Benchmark Dose Estimation.

PubMed

Shao, Kan; Shapiro, Andrew J

2018-01-11

Benchmark dose (BMD) modeling is an important step in human health risk assessment and is used as the default approach to identify the point of departure for risk assessment. A probabilistic framework for dose-response assessment has been proposed and advocated by various institutions and organizations; therefore, a reliable tool is needed to provide distributional estimates for BMD and other important quantities in dose-response assessment. We developed an online system for Bayesian BMD (BBMD) estimation and compared results from this software with U.S. Environmental Protection Agency's (EPA's) Benchmark Dose Software (BMDS). The system is built on a Bayesian framework featuring the application of Markov chain Monte Carlo (MCMC) sampling for model parameter estimation and BMD calculation, which makes the BBMD system fundamentally different from the currently prevailing BMD software packages. In addition to estimating the traditional BMDs for dichotomous and continuous data, the developed system is also capable of computing model-averaged BMD estimates. A total of 518 dichotomous and 108 continuous data sets extracted from the U.S. EPA's Integrated Risk Information System (IRIS) database (and similar databases) were used as testing data to compare the estimates from the BBMD and BMDS programs. The results suggest that the BBMD system may outperform the BMDS program in a number of aspects, including fewer failed BMD and BMDL calculations and estimates. The BBMD system is a useful alternative tool for estimating BMD with additional functionalities for BMD analysis based on most recent research. Most importantly, the BBMD has the potential to incorporate prior information to make dose-response modeling more reliable and can provide distributional estimates for important quantities in dose-response assessment, which greatly facilitates the current trend for probabilistic risk assessment. https://doi.org/10.1289/EHP1289.

Information spreading by a combination of MEG source estimation and multivariate pattern classification

PubMed Central

Sato, Masashi; Yamashita, Okito; Sato, Masa-aki

2018-01-01

To understand information representation in human brain activity, it is important to investigate its fine spatial patterns at high temporal resolution. One possible approach is to use source estimation of magnetoencephalography (MEG) signals. Previous studies have mainly quantified accuracy of this technique according to positional deviations and dispersion of estimated sources, but it remains unclear how accurately MEG source estimation restores information content represented by spatial patterns of brain activity. In this study, using simulated MEG signals representing artificial experimental conditions, we performed MEG source estimation and multivariate pattern analysis to examine whether MEG source estimation can restore information content represented by patterns of cortical current in source brain areas. Classification analysis revealed that the corresponding artificial experimental conditions were predicted accurately from patterns of cortical current estimated in the source brain areas. However, accurate predictions were also possible from brain areas whose original sources were not defined. Searchlight decoding further revealed that this unexpected prediction was possible across wide brain areas beyond the original source locations, indicating that information contained in the original sources can spread through MEG source estimation. This phenomenon of “information spreading” may easily lead to false-positive interpretations when MEG source estimation and classification analysis are combined to identify brain areas that represent target information. Real MEG data analyses also showed that presented stimuli were able to be predicted in the higher visual cortex at the same latency as in the primary visual cortex, also suggesting that information spreading took place. These results indicate that careful inspection is necessary to avoid false-positive interpretations when MEG source estimation and multivariate pattern analysis are combined. PMID:29912968

Ag electrode modified with polyhexamethylene biguanide stabilized silver nanoparticles: a new type of SERS substrates for detection of enzymatically generated thiocholine

NASA Astrophysics Data System (ADS)

Tepanov, A. A.; Nechaeva, N. L.; Prokopkina, T. A.; Kudrinskiy, A. A.; Kurochkin, I. N.; Lisichkin, G. V.

2015-11-01

The detection of thiocholine is one of the most widespread techniques for estimation of the cholinesterase activity - acetylcholinesterase and butyrylcholinesterase. Both cholinesterases can be inhibited by organophosphates and carbamates and accordingly can be considered for estimation of these pollutants in the environment. In the current work, SERS spectroscopy was applied for the thiocholine detection. The Ag electrodes modified with silver nanoparticles stabilized by polyhexamethylene biguanide were for the first time suggested as SERS-substrates for that purpose. Such electrodes can be applicable for SERS detection of submicromolar concentrations of thiocholine.

Predicting the Magnetic Properties of ICMEs: A Pragmatic View

NASA Astrophysics Data System (ADS)

Riley, P.; Linker, J.; Ben-Nun, M.; Torok, T.; Ulrich, R. K.; Russell, C. T.; Lai, H.; de Koning, C. A.; Pizzo, V. J.; Liu, Y.; Hoeksema, J. T.

2017-12-01

The southward component of the interplanetary magnetic field plays a crucial role in being able to successfully predict space weather phenomena. Yet, thus far, it has proven extremely difficult to forecast with any degree of accuracy. In this presentation, we describe an empirically-based modeling framework for estimating Bz values during the passage of interplanetary coronal mass ejections (ICMEs). The model includes: (1) an empirically-based estimate of the magnetic properties of the flux rope in the low corona (including helicity and field strength); (2) an empirically-based estimate of the dynamic properties of the flux rope in the high corona (including direction, speed, and mass); and (3) a physics-based estimate of the evolution of the flux rope during its passage to 1 AU driven by the output from (1) and (2). We compare model output with observations for a selection of events to estimate the accuracy of this approach. Importantly, we pay specific attention to the uncertainties introduced by the components within the framework, separating intrinsic limitations from those that can be improved upon, either by better observations or more sophisticated modeling. Our analysis suggests that current observations/modeling are insufficient for this empirically-based framework to provide reliable and actionable prediction of the magnetic properties of ICMEs. We suggest several paths that may lead to better forecasts.

The OPTN Deceased Donor Potential Study: Implications for Policy and Practice.

PubMed

Klassen, D K; Edwards, L B; Stewart, D E; Glazier, A K; Orlowski, J P; Berg, C L

2016-06-01

The Organ Procurement and Transplantation Network (OPTN) Deceased Donor Potential Study, funded by the Health Resources and Services Administration, characterized the current pool of potential deceased donors and estimated changes through 2020. The goal was to inform policy development and suggest practice changes designed to increase the number of donors and organ transplants. Donor estimates used filtering methodologies applied to datasets from the OPTN, the National Center for Health Statistics, and the Agency for Healthcare Research and Quality and used these estimates with the number of actual donors to estimate the potential donor pool through 2020. Projected growth of the donor pool was 0.5% per year through 2020. Potential donor estimates suggested unrealized donor potential across all demographic groups, with the most significant unrealized potential (70%) in the 50-75-year-old age group and potential Donation after Circulatory Death (DCD) donors. Actual transplants that may be realized from potential donors in these categories are constrained by confounding medical comorbidities not identified in administrative databases and by limiting utilization practices for organs from DCD donors. Policy, regulatory, and practice changes encouraging organ procurement and transplantation of a broader population of potential donors may be required to increase transplant numbers in the United States. © Copyright 2016 The American Society of Transplantation and the American Society of Transplant Surgeons.

An Update on Oceanic Precipitation Rate and its Zonal Distribution in Light of Advanced Observations from Space

NASA Technical Reports Server (NTRS)

Behrangi, Ali; Stephens, Graeme; Adler, Robert F.; Huffman, George J.; Lambrigsten, Bjorn; Lebstock, Matthew

2014-01-01

This study contributes to the estimation of the global mean and zonal distribution of oceanic precipitation rate using complementary information from advanced precipitation measuring sensors and provides an independent reference to assess current precipitation products. Precipitation estimates from the Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) and CloudSat cloud profiling radar (CPR) were merged, as the two complementary sensors yield an unprecedented range of sensitivity to quantify rainfall from drizzle through the most intense rates. At higher latitudes, where TRMM PR does not exist, precipitation estimates from Aqua's Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E) complemented CloudSat CPR to capture intense precipitation rates. The high sensitivity of CPR allows estimation of snow rate, an important type of precipitation at high latitudes, not directly observed in current merged precipitation products. Using the merged precipitation estimate from the CloudSat, TRMM, and Aqua platforms (this estimate is abbreviated to MCTA), the authors' estimate for 3-yr (2007-09) nearglobal (80degS-80degN) oceanic mean precipitation rate is approx. 2.94mm/day. This new estimate of mean global ocean precipitation is about 9% higher than that of the corresponding Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP) value (2.68mm/day) and about 4% higher than that of the Global Precipitation Climatology Project (GPCP; 2.82mm/day). Furthermore, MCTA suggests distinct differences in the zonal distribution of precipitation rate from that depicted in GPCPand CMAP, especially in the Southern Hemisphere.

Estimating dead wood during national forest inventories: a review of inventory methodologies and suggestions for harmonization

Treesearch

Christopher W. Woodall; Jacques Rondeux; Pieter J. Verkerk; G& #246; ran St& #229; hl

2009-01-01

Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) components around the world. Currently, information regarding the prevalence, status, and methods of DW inventories occurring in the world's forested landscapes is scattered. The goal of this study...

Estimating dead wood during national forest inventories: a review of inventory methodologies and suggestions for harmonization

Treesearch

Christopher W. Woodall; Jacques Rondeux; Pieter J. Verkerk; Goran Stahl

2009-01-01

Efforts to assess forest ecosystem carbon stocks, biodiversity, and fire hazards have spurred the need for comprehensive assessments of forest ecosystem dead wood (DW) attributes around the world. Currently, information regarding the prevalence, status, and methods of DW inventories occurring in the world?s forested landscapes is scattered. The goal of this study is to...

Mothers' Differential Treatment of Adolescent Siblings: Predicting College Attendance of Sisters versus Brothers

ERIC Educational Resources Information Center

Bissell-Havran, Joanna M.; Loken, Eric; McHale, Susan M.

2012-01-01

Current estimates suggest that by 2015, 60% of college students will be women, a change since 1970 when 59% were men. We investigated family dynamics that might explain the growing gender gap in college attendance, focusing on an ethnically diverse sample of 522 mixed sex sibling dyads from the National Longitudinal Study of Adolescent Health. We…

Comparison of wrist-worn and hip-worn activity monitors under free living conditions.

PubMed

Hargens, Trent A; Deyarmin, Kayla N; Snyder, Kelsey M; Mihalik, Allison G; Sharpe, Lauren E

2017-04-01

Current recommendations state that individuals engage in 150 min of moderate or 75 min of vigorous intensity physical activity (PA) each week. Commercial PA monitors are becoming popular for everyday use. The accuracy of these devices, however, is not well understood. We sought to examine the accuracy of two commercial devices, one wrist and one hip-worn, under free-living conditions. Twenty-two subjects wore two commercially available devices and one ActiGraph (AG) for seven consecutive days under normal activity. Mean steps per day between all three devices differed significantly. No differences were found in moderate-to-vigorous intensity physical activity (MPVA). Daily energy expenditure (EE) also differed significantly between the AG and the commercial devices. Bland-Altman analysis found poor agreement between the AG and the commercial devices with regards to steps and EE, but good agreement in MVPA. Results suggest that the commercial devices are less accurate in estimating steps and EE. These devices did show good agreement with regards to MVPA, suggesting that they may provide useful feedback for individuals seeking to achieve the current PA guidelines for MVPA. Improvements are needed with regards to steps and EE estimation.

Computing rank-revealing QR factorizations of dense matrices.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bischof, C. H.; Quintana-Orti, G.; Mathematics and Computer Science

1998-06-01

We develop algorithms and implementations for computing rank-revealing QR (RRQR) factorizations of dense matrices. First, we develop an efficient block algorithm for approximating an RRQR factorization, employing a windowed version of the commonly used Golub pivoting strategy, aided by incremental condition estimation. Second, we develop efficiently implementable variants of guaranteed reliable RRQR algorithms for triangular matrices originally suggested by Chandrasekaran and Ipsen and by Pan and Tang. We suggest algorithmic improvements with respect to condition estimation, termination criteria, and Givens updating. By combining the block algorithm with one of the triangular postprocessing steps, we arrive at an efficient and reliablemore » algorithm for computing an RRQR factorization of a dense matrix. Experimental results on IBM RS/6000 SGI R8000 platforms show that this approach performs up to three times faster that the less reliable QR factorization with column pivoting as it is currently implemented in LAPACK, and comes within 15% of the performance of the LAPACK block algorithm for computing a QR factorization without any column exchanges. Thus, we expect this routine to be useful in may circumstances where numerical rank deficiency cannot be ruled out, but currently has been ignored because of the computational cost of dealing with it.« less

Geothermal energy employment and requirements 1977-1990

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1981-12-01

An assessment of the manpower needs of the geothermal industry is presented. The specific objectives were to: derive a base line estimate of the manpower involved in geothermal activities, determine if there is any current or impending likelihood of skill shortages, forecast future employment in the geothermal industry, conduct a technology assessment to ascertain the possibilities of some sudden breakthrough, and suggest alternatives commensurate with the findings. The methodology for fulfilling the objectives is described. Detailed results of these pursuits (objectives) are presented. Alternatives that are suggested, based upon the findings of the study, are summarized.

Total choline and choline-containing moieties of commercially available pulses.

PubMed

Lewis, Erin D; Kosik, Sarah J; Zhao, Yuan-Yuan; Jacobs, René L; Curtis, Jonathan M; Field, Catherine J

2014-06-01

Estimating dietary choline intake can be challenging due to missing foods in the current United States Department of Agriculture (USDA) database. The objectives of the study were to quantify the choline-containing moieties and the total choline content of a variety of pulses available in North America and use the expanded compositional database to determine the potential contribution of pulses to dietary choline intake. Commonly consumed pulses (n = 32) were analyzed by hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC LC-MS/MS) and compared to the current USDA database. Cooking was found to reduce the relative percent from free choline and increased the contribution of phosphatidylcholine to total choline for most pulses (P < 0.05). Using the expanded database to estimate choline content of recipes using pulses as meat alternatives, resulted in a different estimation of choline content per serving (±30%), compared to the USDA database. These results suggest that when pulses are a large part of a meal or diet, the use of accurate food composition data should be used.

A comparison between a new model and current models for estimating trunk segment inertial parameters.

PubMed

Wicke, Jason; Dumas, Genevieve A; Costigan, Patrick A

2009-01-05

Modeling of the body segments to estimate segment inertial parameters is required in the kinetic analysis of human motion. A new geometric model for the trunk has been developed that uses various cross-sectional shapes to estimate segment volume and adopts a non-uniform density function that is gender-specific. The goal of this study was to test the accuracy of the new model for estimating the trunk's inertial parameters by comparing it to the more current models used in biomechanical research. Trunk inertial parameters estimated from dual X-ray absorptiometry (DXA) were used as the standard. Twenty-five female and 24 male college-aged participants were recruited for the study. Comparisons of the new model to the accepted models were accomplished by determining the error between the models' trunk inertial estimates and that from DXA. Results showed that the new model was more accurate across all inertial estimates than the other models. The new model had errors within 6.0% for both genders, whereas the other models had higher average errors ranging from 10% to over 50% and were much more inconsistent between the genders. In addition, there was little consistency in the level of accuracy for the other models when estimating the different inertial parameters. These results suggest that the new model provides more accurate and consistent trunk inertial estimates than the other models for both female and male college-aged individuals. However, similar studies need to be performed using other populations, such as elderly or individuals from a distinct morphology (e.g. obese). In addition, the effect of using different models on the outcome of kinetic parameters, such as joint moments and forces needs to be assessed.

Neighborhood social cohesion and smoking among legal and unauthorized Brazilian migrants in metropolitan Boston.

PubMed

Holmes, Louisa M; Marcelli, Enrico A

2014-12-01

Tobacco smoking is estimated to be the largest preventable cause of mortality in the USA, but little is known about the relationship between neighborhood social environment and current smoking behavior or how this may differ by population and geography. We investigate how neighborhood social cohesion and disorder are associated with smoking behavior among legal and unauthorized Brazilian migrant adults using data from the 2007 Harvard-UMASS Boston Metropolitan Immigrant Health and Legal Status Survey (BM-IHLSS), a probabilistic household survey of adult Brazilian migrants. We employ logistic regression to estimate associations between neighborhood social cohesion, neighborhood disorder, and current smoking. We find that neighborhood-level social cohesion is associated with lower likelihood of being a current smoker (O.R. = .836; p < .05), and neighborhood disorder, measured as crime experienced in the neighborhood, is not associated with current smoking. Neighborhood population density, age, being male, and residing with someone who smokes are each positively associated with current smoking (p < .10). The health of participants' parents at the age of 35, being married, and individual earnings are associated with a reduction in the probability of being a current smoker (p < .05). Migrant legal status and length of residence in the USA are not associated with current smoking. Our findings suggest that neighborhood social cohesion may be protective against smoking. Alternatively, neighborhood disorder does not appear to be related to current smoking among Brazilian migrants.

Thoracic and respirable particle definitions for human health risk assessment.

PubMed

Brown, James S; Gordon, Terry; Price, Owen; Asgharian, Bahman

2013-04-10

Particle size-selective sampling refers to the collection of particles of varying sizes that potentially reach and adversely affect specific regions of the respiratory tract. Thoracic and respirable fractions are defined as the fraction of inhaled particles capable of passing beyond the larynx and ciliated airways, respectively, during inhalation. In an attempt to afford greater protection to exposed individuals, current size-selective sampling criteria overestimate the population means of particle penetration into regions of the lower respiratory tract. The purpose of our analyses was to provide estimates of the thoracic and respirable fractions for adults and children during typical activities with both nasal and oral inhalation, that may be used in the design of experimental studies and interpretation of health effects evidence. We estimated the fraction of inhaled particles (0.5-20 μm aerodynamic diameter) penetrating beyond the larynx (based on experimental data) and ciliated airways (based on a mathematical model) for an adult male, adult female, and a 10 yr old child during typical daily activities and breathing patterns. Our estimates show less penetration of coarse particulate matter into the thoracic and gas exchange regions of the respiratory tract than current size-selective criteria. Of the parameters we evaluated, particle penetration into the lower respiratory tract was most dependent on route of breathing. For typical activity levels and breathing habits, we estimated a 50% cut-size for the thoracic fraction at an aerodynamic diameter of around 3 μm in adults and 5 μm in children, whereas current ambient and occupational criteria suggest a 50% cut-size of 10 μm. By design, current size-selective sample criteria overestimate the mass of particles generally expected to penetrate into the lower respiratory tract to provide protection for individuals who may breathe orally. We provide estimates of thoracic and respirable fractions for a variety of breathing habits and activities that may benefit the design of experimental studies and interpretation of particle size-specific health effects.

Thoracic and respirable particle definitions for human health risk assessment

PubMed Central

2013-01-01

Background Particle size-selective sampling refers to the collection of particles of varying sizes that potentially reach and adversely affect specific regions of the respiratory tract. Thoracic and respirable fractions are defined as the fraction of inhaled particles capable of passing beyond the larynx and ciliated airways, respectively, during inhalation. In an attempt to afford greater protection to exposed individuals, current size-selective sampling criteria overestimate the population means of particle penetration into regions of the lower respiratory tract. The purpose of our analyses was to provide estimates of the thoracic and respirable fractions for adults and children during typical activities with both nasal and oral inhalation, that may be used in the design of experimental studies and interpretation of health effects evidence. Methods We estimated the fraction of inhaled particles (0.5-20 μm aerodynamic diameter) penetrating beyond the larynx (based on experimental data) and ciliated airways (based on a mathematical model) for an adult male, adult female, and a 10 yr old child during typical daily activities and breathing patterns. Results Our estimates show less penetration of coarse particulate matter into the thoracic and gas exchange regions of the respiratory tract than current size-selective criteria. Of the parameters we evaluated, particle penetration into the lower respiratory tract was most dependent on route of breathing. For typical activity levels and breathing habits, we estimated a 50% cut-size for the thoracic fraction at an aerodynamic diameter of around 3 μm in adults and 5 μm in children, whereas current ambient and occupational criteria suggest a 50% cut-size of 10 μm. Conclusions By design, current size-selective sample criteria overestimate the mass of particles generally expected to penetrate into the lower respiratory tract to provide protection for individuals who may breathe orally. We provide estimates of thoracic and respirable fractions for a variety of breathing habits and activities that may benefit the design of experimental studies and interpretation of particle size-specific health effects. PMID:23575443

Variability of the Azores Current during October December 1993

NASA Astrophysics Data System (ADS)

Reverdin, Gilles; Hernandez, Fabrice

2001-05-01

The surface circulation is investigated during the autumn of 1993 in the vicinity of the Azores Current 18-28°W 31-36°N during the SEMAPHORE experiment. A total of 125 drifters were tracked by satellite, some of which were drogued, some not, some with long tethers and some were mixed layer drifters drogued at 15 m depth. The different types of drifters respond differently to the wind, the wave action and the mixed layer currents, resulting in differences in drifts sometimes exceeding 10 cm s -1. These effects can be partially taken into account statistically. After doing that, the different drift data were combined to map the near-surface quasi-geostrophic flow. The major currents in the area have a width of 100 km or larger, and changes in the shear happen over a shorter scale. The data density is sufficient to resolve scales of 50-100 km for 11 days averaged circulation and sea surface temperature (SST). The maps produced every 5 days portray the surface evolution of the Azores Current and of the eddy field for 2 months. The changes are large in the area where the Azores current interacts with a large anticylonic eddy A 1 associated with a Meddy. There are some closed eddy circulation present throughout the period, whereas other structures are relatively short-lived (a month or less). The general features of this analysis are reproduced in analyses of the circulation from altimetric data. The resolution of this analysis is much larger than what was earlier obtained from the hydrological surveys, enabling us to estimate the quasi-geostrophic mesoscale divergence field from the horizontal vorticity budget. The quasi-geostrophic horizontal vorticity advection provides the largest contribution to divergence and contributes to a series of convergence and divergence patches in the order of 1×10 -7 s -1 associated with the various ridges and troughs of the Azores Current. Although uncertainty is high in these estimates, this suggests that vertical temperature advection does not contribute much to the surface temperature evolution at the mesoscales of these surveys. Horizontal temperature advection is estimated from the current and surface temperature analysis. Away from the frontal area near 25°W, horizontal temperature advection is significantly non-zero, but does contribute only a small portion of the observed temperature change at the mesoscales. The budgets suggest that the area south of A 1 was the site of subduction in October-November.

Variability in modeled cloud feedback tied to differences in the climatological spatial pattern of clouds

NASA Astrophysics Data System (ADS)

Siler, Nicholas; Po-Chedley, Stephen; Bretherton, Christopher S.

2018-02-01

Despite the increasing sophistication of climate models, the amount of surface warming expected from a doubling of atmospheric CO_2 (equilibrium climate sensitivity) remains stubbornly uncertain, in part because of differences in how models simulate the change in global albedo due to clouds (the shortwave cloud feedback). Here, model differences in the shortwave cloud feedback are found to be closely related to the spatial pattern of the cloud contribution to albedo (α) in simulations of the current climate: high-feedback models exhibit lower (higher) α in regions of warm (cool) sea-surface temperatures, and therefore predict a larger reduction in global-mean α as temperatures rise and warm regions expand. The spatial pattern of α is found to be strongly predictive (r=0.84) of a model's global cloud feedback, with satellite observations indicating a most-likely value of 0.58± 0.31 Wm^{-2} K^{-1} (90% confidence). This estimate is higher than the model-average cloud feedback of 0.43 Wm^{-2} K^{-1}, with half the range of uncertainty. The observational constraint on climate sensitivity is weaker but still significant, suggesting a likely value of 3.68 ± 1.30 K (90% confidence), which also favors the upper range of model estimates. These results suggest that uncertainty in model estimates of the global cloud feedback may be substantially reduced by ensuring a realistic distribution of clouds between regions of warm and cool SSTs in simulations of the current climate.

Near-Earth-object survey progress and population of small near-Earth asteroids

NASA Astrophysics Data System (ADS)

Harris, A.

2014-07-01

Estimating the total population vs. size of NEAs and the completion of surveys is the same thing since the total population is just the number discovered divided by the estimated completion. I review the method of completion estimation based on ratio of re-detected objects to total detections (known plus new discoveries). The method is quite general and can be used for population estimations of all sorts, from wildlife to various classes of solar system bodies. Since 2001, I have been making estimates of population and survey progress approximately every two years. Plotted below, left, is my latest estimate, including NEA discoveries up to August, 2012. I plan to present an update at the meeting. All asteroids of a given size are not equally easy to detect because of specific orbital geometries. Thus a model of the orbital distribution is necessary, and computer simulations using those orbits need to establish the relation between the raw re-detection ratio and the actual completion fraction. This can be done for any sub-group population, allowing to estimate the population of a subgroup and the expected current completion. Once a reliable survey computer model has been developed and ''calibrated'' with respect to actual survey re-detections versus size, it can be extrapolated to smaller sizes to estimate completion even at very small size where re-detections are rare or even zero. I have recently investigated the subgroup of extremely low encounter velocity NEAs, the class of interest for the Asteroid Redirect Mission (ARM), recently proposed by NASA. I found that asteroids of diameter ˜ 10 m with encounter velocity with the Earth lower than 2.5 km/sec are detected by current surveys nearly 1,000 times more efficiently than the general background of NEAs of that size. Thus the current completion of these slow relative velocity objects may be around 1%, compared to 10^{-6} for that size objects of the general velocity distribution. Current surveys are nowhere near complete, but there may be fewer such objects than have been suggested. This conclusion is reinforced by the fact that at least a couple such discovered objects are known to be not real asteroids but spent rocket bodies in heliocentric orbit, of which there are only of the order of a hundred. Brown et al. (Nature 503, 238-241, 2013, below right, green squares are a re-plot of my blue circles on left plot) recently suggested that the population of small NEAs in the size range from roughly 5 to 50 meters in diameter may have been substantially under-estimated. To be sure, the greatest uncertainty in population estimates is in that range, since there are very few bolide events to use for estimation, and the surveys are extremely incomplete in that size range, so a factor of 3 or so discrepancy is not significant. However, the population estimated from surveys carried still smaller, where the bolide frequency becomes more secure, disagrees from the bolide estimate by even less than a factor of 3 and in fact intersects at about 3 m diameter. On the other hand, the shallow-sloping size-frequency distribution derived from the sparse large bolide data diverges badly from the survey estimates, in sizes where the survey estimates become ever-increasingly reliable, even by 100-200 m diameter. It appears that the bolide data provides a good "anchor" of the population in the size range up to about 5 m diameter, but above that one might do better just connecting that population with a straight line (on a log-log plot) with the survey-determined population at larger size, 50-100 m diameter or so.

Current land cover in the tropics and its potential for sequestering carbon

NASA Astrophysics Data System (ADS)

Houghton, R. A.; Unruh, J. D.; Lefebvre, P. A.

1993-06-01

Emissions of carbon dioxide and other greenhouse gases from human activity are increasing the concentrations of these gases in the atmosphere. The Earth is expected to warm as a result, with consequences that are potentially highly disruptive to human societies. Reductions in the use of fossil fuels and in rates of deforestation worldwide will reduce emissions of CO2, but atmospheric concentrations will continue to increase unless emissions are reduced by more than 60% (about 4.5 billion tons of carbon annually). Reforestation seems to offer one of the few means for reducing the atmospheric concentration of CO2 over periods as short as human generations. We report here an approach for evaluating the potential for reforestation to help stabilize or even reduce the concentration of CO2 in the atmosphere. Reforestation is defined broadly to include tree plantations, natural regrowth of secondary forests, and the practice of agroforestry. Our premise is that human use of the land has generally reduced woody biomass and that such lands have a potential for reaccumulating carbon if appropriately managed. We used published ground studies together with global vegetation index data from the NOAA 7 satellite to estimate current land cover in tropical regions. Then, superimposing this map of current land cover over maps depicting the distribution of vegetation cover prior to human disturbance, we obtained an estimate of about 3200 X 106 ha in the tropics (almost 60% of the total land area considered) where woody biomass had been decreased, and where carbon might again be sequestered. We calculated the amount of carbon that could be withdrawn from the atmosphere and stored in woody biomass if several management options were implemented. Biomass accumulations were determined from forestry statistics. Application of the data on biomass to the areas suitable for accumulation of carbon yielded an estimate of potential accumulation of 160-170 Pg carbon, an amount equivalent to the accumulation of carbon in the atmosphere since the start of the industrial revolution, or to about 25 years of fossil fuel emissions at current rates. Estimates of both area and potential accumulation of carbon were crude, probably not better than ±50%. They are useful for suggesting the role that tropical lands might play in stabilizing atmospheric concentrations of CO2, but they should not be used to suggest specific management options in individual countries. As maps with higher spatial resolution become available, however, the method should provide more precise estimates overall and in specific locations.

Improving the representation of Arctic photosynthesis in Earth System Models

NASA Astrophysics Data System (ADS)

Rogers, A.; Serbin, S.; Sloan, V. L.; Norby, R. J.; Wullschleger, S. D.

2014-12-01

The primary goal of Earth System Models (ESMs) is to improve understanding and projection of future global change. In order to do this models must accurately represent the terrestrial carbon cycle. Although Arctic carbon fluxes are small relative to global carbon fluxes, uncertainty is large. Photosynthetic CO2 uptake is well described by the Farquhar, von Caemmerer and Berry (FvCB) model of photosynthesis and most ESMs use a derivation of the FvCB model to calculate gross primary productivity. Two key parameters required by the FvCB model are an estimate of the maximum rate of carboxylation by the enzyme Rubisco (Vc,max) and the maximum rate of electron transport (Jmax). In ESMs the parameter Vc,max is typically fixed for a given plant functional type (PFT). Only four ESMs currently have an explicit Arctic PFT and the data used to derive Vc,max in these models relies on small data sets and unjustified assumptions. We examined the derivation of Vc,max and Jmax in current Arctic PFTs and estimated Vc,max and Jmax for a range of Arctic PFTs growing on the Barrow Environmental Observatory, Barrow, AK. We found that the values of Vc,max currently used to represent Arctic plants in ESMs are 70% lower than the values we measured, and contemporary temperature response functions for Vc,max also appear to underestimate Vc,max at low temperature. ESMs typically use a single multiplier (JVratio) to convert Vc,max to Jmax, however we found that the JVratio of Arctic plants is higher than current estimates suggesting that Arctic PFTs will be more responsive to rising carbon dioxide than currently projected. In addition we are exploring remotely sensed methods to scale up key biochemical (e.g. leaf N, leaf mass area) and physiological (e.g. Vc,max and Jmax) properties that drive model representation of photosynthesis in the Arctic. Our data suggest that the Arctic tundra has a much greater capacity for CO2 uptake, particularly at low temperature, and will be more CO2 responsive than is currently represented in ESMs. As we build robust relationships between physiology and spectral signatures we hope to provide spatially and temporally resolved trait maps of key model parameters that can be ingested by new model frameworks, or used to validate emergent model properties.

Improving the representation of Arctic photosynthesis in Earth system models

NASA Astrophysics Data System (ADS)

Rogers, A.; Serbin, S.; Ely, K.; Sloan, V. L.; Wyatt, R. A.; Kubien, D. S.; Ali, A. A.; Xu, C.; Wullschleger, S. D.

2015-12-01

The primary goal of Earth System Models (ESMs) is to improve understanding and projection of future global change. In order to do this they must accurately represent the carbon fluxes associated with the terrestrial carbon cycle. Although Arctic carbon fluxes are small - relative to global carbon fluxes - uncertainty is large. As part of a multidisciplinary project to improve the representation of the Arctic in ESMs (Next Generation Ecosystem Experiments - Arctic) we are examining the photosynthetic parameterization of the Arctic plant functional type (PFT) in ESMs. Photosynthetic CO2 uptake is well described by the Farquhar, von Caemmerer and Berry (FvCB) model of photosynthesis. Most ESMs use a derivation of the FvCB model to calculate gross primary productivity. Two key parameters required by the FvCB model are an estimate of the maximum rate of carboxylation by the enzyme Rubisco (Vc,max) and the maximum rate of electron transport (Jmax). In ESMs the parameter Vc,max is usually fixed for a given PFT. Only four ESMs currently have an explicit Arctic PFT and the data used to derive Vc,max for the Arctic PFT in these models relies on small data sets and unjustified assumptions. We examined the derivation of Vc,max and Jmax in current Arctic PFTs and estimated Vc,max and Jmax for 7 species representing both dominant vegetation and key Arctic PFTs growing on the Barrow Environmental Observatory, Barrow, AK. The values of Vc,max currently used to represent Arctic PFTs in ESMs are 70% lower than the values we measured in these species. Examination of the derivation of Vc,max in ESMs identified that the cause of the relatively low Vc,max value was the result of underestimating both the leaf N content and the investment of that N in Rubisco. Contemporary temperature response functions for Vc,max also appear to underestimate Vc,max at low temperature. ESMs typically use a single multiplier (JVratio) to convert Vc,max to Jmax for all PFTs. We found that the JVratio of Arctic plants is higher than current estimates suggesting that the Arctic PFT will be more responsive to rising carbon dioxide than currently projected. Our data suggest that the Arctic tundra has a much greater capacity for CO2 uptake, particularly at low temperature, and will be more CO2 responsive than is currently represented in ESMs.

Methane Emissions from United States Natural Gas Gathering and Processing.

PubMed

Marchese, Anthony J; Vaughn, Timothy L; Zimmerle, Daniel J; Martinez, David M; Williams, Laurie L; Robinson, Allen L; Mitchell, Austin L; Subramanian, R; Tkacik, Daniel S; Roscioli, Joseph R; Herndon, Scott C

2015-09-01

New facility-level methane (CH4) emissions measurements obtained from 114 natural gas gathering facilities and 16 processing plants in 13 U.S. states were combined with facility counts obtained from state and national databases in a Monte Carlo simulation to estimate CH4 emissions from U.S. natural gas gathering and processing operations. Total annual CH4 emissions of 2421 (+245/-237) Gg were estimated for all U.S. gathering and processing operations, which represents a CH4 loss rate of 0.47% (±0.05%) when normalized by 2012 CH4 production. Over 90% of those emissions were attributed to normal operation of gathering facilities (1697 +189/-185 Gg) and processing plants (506 +55/-52 Gg), with the balance attributed to gathering pipelines and processing plant routine maintenance and upsets. The median CH4 emissions estimate for processing plants is a factor of 1.7 lower than the 2012 EPA Greenhouse Gas Inventory (GHGI) estimate, with the difference due largely to fewer reciprocating compressors, and a factor of 3.0 higher than that reported under the EPA Greenhouse Gas Reporting Program. Since gathering operations are currently embedded within the production segment of the EPA GHGI, direct comparison to our results is complicated. However, the study results suggest that CH4 emissions from gathering are substantially higher than the current EPA GHGI estimate and are equivalent to 30% of the total net CH4 emissions in the natural gas systems GHGI. Because CH4 emissions from most gathering facilities are not reported under the current rule and not all source categories are reported for processing plants, the total CH4 emissions from gathering and processing reported under the EPA GHGRP (180 Gg) represents only 14% of that tabulated in the EPA GHGI and 7% of that predicted from this study.

Acute health impacts of airborne particles estimated from satellite remote sensing.

PubMed

Wang, Zhaoxi; Liu, Yang; Hu, Mu; Pan, Xiaochuan; Shi, Jing; Chen, Feng; He, Kebin; Koutrakis, Petros; Christiani, David C

2013-01-01

Satellite-based remote sensing provides a unique opportunity to monitor air quality from space at global, continental, national and regional scales. Most current research focused on developing empirical models using ground measurements of the ambient particulate. However, the application of satellite-based exposure assessment in environmental health is still limited, especially for acute effects, because the development of satellite PM(2.5) model depends on the availability of ground measurements. We tested the hypothesis that MODIS AOD (aerosol optical depth) exposure estimates, obtained from NASA satellites, are directly associated with daily health outcomes. Three independent healthcare databases were used: unscheduled outpatient visits, hospital admissions, and mortality collected in Beijing metropolitan area, China during 2006. We use generalized linear models to compare the short-term effects of air pollution assessed by ground monitoring (PM(10)) with adjustment of absolute humidity (AH) and AH-calibrated AOD. Across all databases we found that both AH-calibrated AOD and PM(10) (adjusted by AH) were consistently associated with elevated daily events on the current day and/or lag days for cardiovascular diseases, ischemic heart diseases, and COPD. The relative risks estimated by AH-calibrated AOD and PM(10) (adjusted by AH) were similar. Additionally, compared to ground PM(10), we found that AH-calibrated AOD had narrower confidence intervals for all models and was more robust in estimating the current day and lag day effects. Our preliminary findings suggested that, with proper adjustment of meteorological factors, satellite AOD can be used directly to estimate the acute health impacts of ambient particles without prior calibrating to the sparse ground monitoring networks. Copyright © 2012 Elsevier Ltd. All rights reserved.

Malaria prevalence metrics in low- and middle-income countries: an assessment of precision in nationally-representative surveys.

PubMed

Alegana, Victor A; Wright, Jim; Bosco, Claudio; Okiro, Emelda A; Atkinson, Peter M; Snow, Robert W; Tatem, Andrew J; Noor, Abdisalan M

2017-11-21

One pillar to monitoring progress towards the Sustainable Development Goals is the investment in high quality data to strengthen the scientific basis for decision-making. At present, nationally-representative surveys are the main source of data for establishing a scientific evidence base, monitoring, and evaluation of health metrics. However, little is known about the optimal precisions of various population-level health and development indicators that remains unquantified in nationally-representative household surveys. Here, a retrospective analysis of the precision of prevalence from these surveys was conducted. Using malaria indicators, data were assembled in nine sub-Saharan African countries with at least two nationally-representative surveys. A Bayesian statistical model was used to estimate between- and within-cluster variability for fever and malaria prevalence, and insecticide-treated bed nets (ITNs) use in children under the age of 5 years. The intra-class correlation coefficient was estimated along with the optimal sample size for each indicator with associated uncertainty. Results suggest that the estimated sample sizes for the current nationally-representative surveys increases with declining malaria prevalence. Comparison between the actual sample size and the modelled estimate showed a requirement to increase the sample size for parasite prevalence by up to 77.7% (95% Bayesian credible intervals 74.7-79.4) for the 2015 Kenya MIS (estimated sample size of children 0-4 years 7218 [7099-7288]), and 54.1% [50.1-56.5] for the 2014-2015 Rwanda DHS (12,220 [11,950-12,410]). This study highlights the importance of defining indicator-relevant sample sizes to achieve the required precision in the current national surveys. While expanding the current surveys would need additional investment, the study highlights the need for improved approaches to cost effective sampling.

A Bayesian evidence synthesis approach to estimate disease prevalence in hard-to-reach populations: hepatitis C in New York City.

PubMed

Tan, Sarah; Makela, Susanna; Heller, Daliah; Konty, Kevin; Balter, Sharon; Zheng, Tian; Stark, James H

2018-06-01

Existing methods to estimate the prevalence of chronic hepatitis C (HCV) in New York City (NYC) are limited in scope and fail to assess hard-to-reach subpopulations with highest risk such as injecting drug users (IDUs). To address these limitations, we employ a Bayesian multi-parameter evidence synthesis model to systematically combine multiple sources of data, account for bias in certain data sources, and provide unbiased HCV prevalence estimates with associated uncertainty. Our approach improves on previous estimates by explicitly accounting for injecting drug use and including data from high-risk subpopulations such as the incarcerated, and is more inclusive, utilizing ten NYC data sources. In addition, we derive two new equations to allow age at first injecting drug use data for former and current IDUs to be incorporated into the Bayesian evidence synthesis, a first for this type of model. Our estimated overall HCV prevalence as of 2012 among NYC adults aged 20-59 years is 2.78% (95% CI 2.61-2.94%), which represents between 124,900 and 140,000 chronic HCV cases. These estimates suggest that HCV prevalence in NYC is higher than previously indicated from household surveys (2.2%) and the surveillance system (2.37%), and that HCV transmission is increasing among young injecting adults in NYC. An ancillary benefit from our results is an estimate of current IDUs aged 20-59 in NYC: 0.58% or 27,600 individuals. Copyright © 2018 Elsevier B.V. All rights reserved.

Relationships between electronic game play, obesity, and psychosocial functioning in young men.

PubMed

Wack, Elizabeth; Tantleff-Dunn, Stacey

2009-04-01

Most estimates suggest that American youth are spending a large amount of time playing video and computer games, spurring researchers to examine the impact this media has on various aspects of health and psychosocial functioning. The current study investigated relationships between frequency of electronic game play and obesity, the social/emotional context of electronic game play, and academic performance among 219 college-aged males. Current game players reported a weekly average of 9.73 hours of game play, with almost 10% of current players reporting an average of 35 hours of play per week. Results indicated that frequency of play was not significantly related to body mass index or grade point average. However, there was a significant positive correlation between frequency of play and self-reported frequency of playing when bored, lonely, or stressed. As opposed to the general conception of electronic gaming as detrimental to functioning, the results suggest that gaming among college-aged men may provide a healthy source of socialization, relaxation, and coping.

He said, she said: The gender wage gap according to self and proxy reports in the Current Population Survey.

PubMed

Reynolds, Jeremy; Wenger, Jeffrey B

2012-03-01

Roughly half the labor force data in the Current Population Survey (CPS) are provided by proxy respondents, and since 1979, men's reliance on proxies has dropped dramatically while women's reliance on proxies has increased. Few authors, however, have examined how combining these first-hand and second-hand reports may influence our understanding of long-term economic trends. We exploit the outgoing rotation group structure of the CPS by matching individual records one year apart, and we find that self-reported wages are higher than proxy-reported wages even after controlling for all time invariant characteristics. Furthermore, we find that changes in the use of proxy respondents by men and women since 1979 have made current estimates of the gender wage gap larger than they would have been without changes in reporting status. This suggests that the gender wage gap has closed more than previously estimated. We recommend that researchers combine self and proxy responses with great care, especially when analyzing time trends or making gender comparisons. Copyright © 2011 Elsevier Inc. All rights reserved.

Maneuver Algorithm for Bearings-Only Target Tracking with Acceleration and Field of View Constraints

NASA Astrophysics Data System (ADS)

Roh, Heekun; Shim, Sang-Wook; Tahk, Min-Jea

2018-05-01

This paper proposes a maneuver algorithm for the agent performing target tracking with bearing angle information only. The goal of the agent is to estimate the target position and velocity based only on the bearing angle data. The methods of bearings-only target state estimation are outlined. The nature of bearings-only target tracking problem is then addressed. Based on the insight from above-mentioned properties, the maneuver algorithm for the agent is suggested. The proposed algorithm is composed of a nonlinear, hysteresis guidance law and the estimation accuracy assessment criteria based on the theory of Cramer-Rao bound. The proposed guidance law generates lateral acceleration command based on current field of view angle. The accuracy criteria supply the expected estimation variance, which acts as a terminal criterion for the proposed algorithm. The aforementioned algorithm is verified with a two-dimensional simulation.

Global estimates of shark catches using trade records from commercial markets.

PubMed

Clarke, Shelley C; McAllister, Murdoch K; Milner-Gulland, E J; Kirkwood, G P; Michielsens, Catherine G J; Agnew, David J; Pikitch, Ellen K; Nakano, Hideki; Shivji, Mahmood S

2006-10-01

Despite growing concerns about overexploitation of sharks, lack of accurate, species-specific harvest data often hampers quantitative stock assessment. In such cases, trade studies can provide insights into exploitation unavailable from traditional monitoring. We applied Bayesian statistical methods to trade data in combination with genetic identification to estimate by species, the annual number of globally traded shark fins, the most commercially valuable product from a group of species often unrecorded in harvest statistics. Our results provide the first fishery-independent estimate of the scale of shark catches worldwide and indicate that shark biomass in the fin trade is three to four times higher than shark catch figures reported in the only global data base. Comparison of our estimates to approximated stock assessment reference points for one of the most commonly traded species, blue shark, suggests that current trade volumes in numbers of sharks are close to or possibly exceeding the maximum sustainable yield levels.

RESPONDENT-DRIVEN SAMPLING AS MARKOV CHAIN MONTE CARLO

PubMed Central

GOEL, SHARAD; SALGANIK, MATTHEW J.

2013-01-01

Respondent-driven sampling (RDS) is a recently introduced, and now widely used, technique for estimating disease prevalence in hidden populations. RDS data are collected through a snowball mechanism, in which current sample members recruit future sample members. In this paper we present respondent-driven sampling as Markov chain Monte Carlo (MCMC) importance sampling, and we examine the effects of community structure and the recruitment procedure on the variance of RDS estimates. Past work has assumed that the variance of RDS estimates is primarily affected by segregation between healthy and infected individuals. We examine an illustrative model to show that this is not necessarily the case, and that bottlenecks anywhere in the networks can substantially affect estimates. We also show that variance is inflated by a common design feature in which sample members are encouraged to recruit multiple future sample members. The paper concludes with suggestions for implementing and evaluating respondent-driven sampling studies. PMID:19572381

Respondent-driven sampling as Markov chain Monte Carlo.

PubMed

Goel, Sharad; Salganik, Matthew J

2009-07-30

Respondent-driven sampling (RDS) is a recently introduced, and now widely used, technique for estimating disease prevalence in hidden populations. RDS data are collected through a snowball mechanism, in which current sample members recruit future sample members. In this paper we present RDS as Markov chain Monte Carlo importance sampling, and we examine the effects of community structure and the recruitment procedure on the variance of RDS estimates. Past work has assumed that the variance of RDS estimates is primarily affected by segregation between healthy and infected individuals. We examine an illustrative model to show that this is not necessarily the case, and that bottlenecks anywhere in the networks can substantially affect estimates. We also show that variance is inflated by a common design feature in which the sample members are encouraged to recruit multiple future sample members. The paper concludes with suggestions for implementing and evaluating RDS studies.

Fractal model of polarization switching kinetics in ferroelectrics under nonequilibrium conditions of electron irradiation

NASA Astrophysics Data System (ADS)

Maslovskaya, A. G.; Barabash, T. K.

2018-03-01

The paper presents the results of the fractal and multifractal analysis of polarization switching current in ferroelectrics under electron irradiation, which allows statistical memory effects to be estimated at dynamics of domain structure. The mathematical model of formation of electron beam-induced polarization current in ferroelectrics was suggested taking into account the fractal nature of domain structure dynamics. In order to realize the model the computational scheme was constructed using the numerical solution approximation of fractional differential equation. Evidences of electron beam-induced polarization switching process in ferroelectrics were specified at a variation of control model parameters.

Enlistment Decisions in the 1990s. Evidence From Individual-Level Data

DTIC Science & Technology

1990-01-01

Military Pay and the Decline in Real Wages of High School Graduates Another factor that is different for individuals considering enlistment in 1980 and...listment were estimated using data from 1980. Since then, many trends and events suggest that the enlistment likelihoods among different types of...Weekly hours worked currently (+) Family income (-) Not employed (+) Number of siblings (+) Weekly hours worked, previous job (+) Low wage

The Observational Determination of the Primordial Helium Abundance: a Y2K Status Report

NASA Astrophysics Data System (ADS)

Skillman, Evan D.

I review observational progress and assess the current state of the determination of the primordial helium abundance, Yp. At present there are two determinations with non-overlapping errors. My impression is that the errors have been under-estimated in both studies. I review recent work on errors assessment and give suggestions for decreasing systematic errors in future studies.

Assessment of distribution and abundance estimates for Mariana swiftlets (Aerodramus bartschi) via examination of survey methods

USGS Publications Warehouse

Johnson, Nathan C.; Haig, Susan M.; Mosher, Stephen M.

2018-01-01

We described past and present distribution and abundance data to evaluate the status of the endangered Mariana Swiftlet (Aerodramus bartschi), a little-known echolocating cave swiftlet that currently inhabits 3 of 5 formerly occupied islands in the Mariana archipelago. We then evaluated the survey methods used to attain these estimates via fieldwork carried out on an introduced population of Mariana Swiftlets on the island of O'ahu, Hawaiian Islands, to derive better methods for future surveys. We estimate the range-wide population of Mariana Swiftlets to be 5,704 individuals occurring in 15 caves on Saipan, Aguiguan, and Guam in the Marianas; and 142 individuals occupying one tunnel on O'ahu. We further confirm that swiftlets have been extirpated from Rota and Tinian and have declined on Aguiguan. Swiftlets have remained relatively stable on Guam and Saipan in recent years. Our assessment of survey methods used for Mariana Swiftlets suggests overestimates depending on the technique used. We suggest the use of night vision technology and other changes to more accurately reflect their distribution, abundance, and status.

Estimating patient dose from CT exams that use automatic exposure control: Development and validation of methods to accurately estimate tube current values.

PubMed

McMillan, Kyle; Bostani, Maryam; Cagnon, Christopher H; Yu, Lifeng; Leng, Shuai; McCollough, Cynthia H; McNitt-Gray, Michael F

2017-08-01

The vast majority of body CT exams are performed with automatic exposure control (AEC), which adapts the mean tube current to the patient size and modulates the tube current either angularly, longitudinally or both. However, most radiation dose estimation tools are based on fixed tube current scans. Accurate estimates of patient dose from AEC scans require knowledge of the tube current values, which is usually unavailable. The purpose of this work was to develop and validate methods to accurately estimate the tube current values prescribed by one manufacturer's AEC system to enable accurate estimates of patient dose. Methods were developed that took into account available patient attenuation information, user selected image quality reference parameters and x-ray system limits to estimate tube current values for patient scans. Methods consistent with AAPM Report 220 were developed that used patient attenuation data that were: (a) supplied by the manufacturer in the CT localizer radiograph and (b) based on a simulated CT localizer radiograph derived from image data. For comparison, actual tube current values were extracted from the projection data of each patient. Validation of each approach was based on data collected from 40 pediatric and adult patients who received clinically indicated chest (n = 20) and abdomen/pelvis (n = 20) scans on a 64 slice multidetector row CT (Sensation 64, Siemens Healthcare, Forchheim, Germany). For each patient dataset, the following were collected with Institutional Review Board (IRB) approval: (a) projection data containing actual tube current values at each projection view, (b) CT localizer radiograph (topogram) and (c) reconstructed image data. Tube current values were estimated based on the actual topogram (actual-topo) as well as the simulated topogram based on image data (sim-topo). Each of these was compared to the actual tube current values from the patient scan. In addition, to assess the accuracy of each method in estimating patient organ doses, Monte Carlo simulations were performed by creating voxelized models of each patient, identifying key organs and incorporating tube current values into the simulations to estimate dose to the lungs and breasts (females only) for chest scans and the liver, kidney, and spleen for abdomen/pelvis scans. Organ doses from simulations using the actual tube current values were compared to those using each of the estimated tube current values (actual-topo and sim-topo). When compared to the actual tube current values, the average error for tube current values estimated from the actual topogram (actual-topo) and simulated topogram (sim-topo) was 3.9% and 5.8% respectively. For Monte Carlo simulations of chest CT exams using the actual tube current values and estimated tube current values (based on the actual-topo and sim-topo methods), the average differences for lung and breast doses ranged from 3.4% to 6.6%. For abdomen/pelvis exams, the average differences for liver, kidney, and spleen doses ranged from 4.2% to 5.3%. Strong agreement between organ doses estimated using actual and estimated tube current values provides validation of both methods for estimating tube current values based on data provided in the topogram or simulated from image data. © 2017 American Association of Physicists in Medicine.

Concept designs for NASA's Solar Electric Propulsion Technology Demonstration Mission

NASA Technical Reports Server (NTRS)

Mcguire, Melissa L.; Hack, Kurt J.; Manzella, David H.; Herman, Daniel A.

2014-01-01

Multiple Solar Electric Propulsion Technology Demonstration Mission were developed to assess vehicle performance and estimated mission cost. Concepts ranged from a 10,000 kilogram spacecraft capable of delivering 4000 kilogram of payload to one of the Earth Moon Lagrange points in support of future human-crewed outposts to a 180 kilogram spacecraft capable of performing an asteroid rendezvous mission after launched to a geostationary transfer orbit as a secondary payload. Low-cost and maximum Delta-V capability variants of a spacecraft concept based on utilizing a secondary payload adapter as the primary bus structure were developed as were concepts designed to be co-manifested with another spacecraft on a single launch vehicle. Each of the Solar Electric Propulsion Technology Demonstration Mission concepts developed included an estimated spacecraft cost. These data suggest estimated spacecraft costs of $200 million - $300 million if 30 kilowatt-class solar arrays and the corresponding electric propulsion system currently under development are used as the basis for sizing the mission concept regardless of launch vehicle costs. The most affordable mission concept developed based on subscale variants of the advanced solar arrays and electric propulsion technology currently under development by the NASA Space Technology Mission Directorate has an estimated cost of $50M and could provide a Delta-V capability comparable to much larger spacecraft concepts.

Potential Improvements to Remote Primary Productivity Estimation in the Southern California Current System

NASA Astrophysics Data System (ADS)

Jacox, M.; Edwards, C. A.; Kahru, M.; Rudnick, D. L.; Kudela, R. M.

2012-12-01

A 26-year record of depth integrated primary productivity (PP) in the Southern California Current System (SCCS) is analyzed with the goal of improving satellite net primary productivity (PP) estimates. The ratio of integrated primary productivity to surface chlorophyll correlates strongly to surface chlorophyll concentration (chl0). However, chl0 does not correlate to chlorophyll-specific productivity, and appears to be a proxy for vertical phytoplankton distribution rather than phytoplankton physiology. Modest improvements in PP model performance are achieved by tuning existing algorithms for the SCCS, particularly by empirical parameterization of photosynthetic efficiency in the Vertically Generalized Production Model. Much larger improvements are enabled by improving accuracy of subsurface chlorophyll and light profiles. In a simple vertically resolved production model, substitution of in situ surface data for remote sensing estimates offers only marginal improvements in model r2 and total log10 root mean squared difference, while inclusion of in situ chlorophyll and light profiles improves these metrics significantly. Autonomous underwater gliders, capable of measuring subsurface fluorescence on long-term, long-range deployments, significantly improve PP model fidelity in the SCCS. We suggest their use (and that of other autonomous profilers such as Argo floats) in conjunction with satellites as a way forward for improved PP estimation in coastal upwelling systems.

Quantitative comparisons of cancer induction in humans by internally deposited radionuclides and external radiation.

PubMed

Harrison, J D; Muirhead, C R

2003-01-01

To compare quantitative estimates of lifetime cancer risk in humans for exposures to internally deposited radionuclides and external radiation. To assess the possibility that risks from radionuclide exposures may be underestimated. Risk estimates following internal exposures can be made for a small number of alpha-particle-emitting nuclides. (1) Lung cancer in underground miners exposed by inhalation to radon-222 gas and its short-lived progeny. Studies of residential (222)Rn exposure are generally consistent with predictions from the miner studies. (2) Liver cancer and leukaemia in patients given intravascular injections of Thorotrast, a thorium-232 oxide preparation that concentrates in liver, spleen and bone marrow. (3) Bone cancer in patients given injections of radium-224, and in workers exposed occupationally to (226)Ra and (228)Ra, mainly by ingestion. (4) Lung cancer in Mayak workers exposed to plutonium-239, mainly by inhalation. Liver and bone cancers were also seen, but the dosimetry is not yet sufficiently good enough to provide quantitative estimates of risks. Comparisons can be made between risk estimates for radiation-induced cancer derived for radionuclide exposure and those derived for the A-bomb survivors, exposed mainly to low-LET (linear energy transfer) external radiation. Data from animal studies, using dogs and rodents, allow comparisons of cancer induction by a range of alpha- and beta-/gamma-emitting radionuclides. They provide information on relative biological effectiveness (RBE), dose-response relationships, dose-rate effects and the location of target cells for different malignancies. For lung and liver cancer, the estimated values of risk per Sv for internal exposure, assuming an RBE for alpha-particles of 20, are reasonably consistent with estimates for external exposure to low-LET radiation. This also applies to bone cancer when risk is calculated on the basis of average bone dose, but consideration of dose to target cells on bone surfaces suggests a low RBE for alpha-particles. Similarly, for leukaemia, the comparison of risks from alpha-irradiation ((232)Th and progeny) and external radiation suggest a low alpha RBE; this conclusion is supported by animal data. Risk estimates for internal exposure are dependent on the assumptions made in calculating dose. Account is taken of the distribution of radionuclides within tissues and the distribution of target cells for cancer induction. For the lungs and liver, the available human and animal data provide support for current assumptions. However, for bone cancer and leukaemia, it may be that changes are required. Bone cancer risk may be best assessed by calculating dose to a 50 micro m layer of marrow adjacent to endosteal (inner) bone surfaces rather than to a single 10 micro m cell layer as currently assumed. Target cells for leukaemia may be concentrated towards the centre of marrow cavities so that the risk of leukaemia from bone-seeking radionuclides, particularly alpha emitters, may be overestimated by the current assumption of uniform distribution of target cells throughout red bone marrow. The lifetime risk estimates considered here for exposure to internally deposited radionuclides and to external radiation are subject to uncertainties, arising from the dosimetric assumptions made, from the quality of cancer incidence and mortality data and from aspects of risk modelling; including variations in baseline rates between populations for some cancer types. Bearing in mind such uncertainties, comparisons of risk estimates for internal emitters and external radiation show good agreement for lung and liver cancers. For leukaemia, the available data suggest that the assumption of an alpha-particle RBE of 20 can result in overestimates of risk. For bone cancer, it also appears that current assumptions will overestimate risks from alpha-particle-emitting nuclides, particularly at low doses.

The wind-forced response on a buoyant coastal current: Observations of the western Gulf of Maine plume

USGS Publications Warehouse

Fong, D.A.; Geyer, W.R.; Signell, R.P.

1997-01-01

The Freshwater plume in the western Gulf of Maine is being studied as part of an interdisciplinary investigation of the physical transport of a toxic alga. A field program was conducted in the springs of 1993 and 1994 to map the spatial and temporal patterns of salinity, currents and algal toxicity. The observations suggest that the plume's cross-shore structure varies markedly as a function of fluctuations in alongshore wind forcing. Consistent with Ekman drift dynamics, upwelling favorable winds spread the plume offshore, at times widening it to over 50 km in offshore extent, while downwelling favorable winds narrow the plume width to as little as 10 km. Using a simple slab model, we find qualitative agreement between the observed variations of plume width and those predicted by Ekman theory for short time scales of integration. Near surface current meters show significant correlations between cross-shore currents and alongshore wind stress, consistent with Ekman theory. Estimates of the terms in the alongshore momentum equation calculated from moored current meter arrays also indicate a dominant Ekman balance within the plume. A significant correlation between alongshore currents and winds suggests that interfacial drag may be important, although inclusion of a Raleigh drag term does not significantly improve the alongshore momentum balance.

Interhemispheric currents in the ring current region as seen by the Cluster spacecraft

NASA Astrophysics Data System (ADS)

Tenfjord, P.; Ostgaard, N.; Haaland, S.; Laundal, K.; Reistad, J. P.

2013-12-01

The existence of interhemispheric currents has been predicted by several authors, but their extent in the ring current has to our knowledge never been studied systematically by using in-situ measurements. These currents have been suggested to be associated with observed asymmetries of the aurora. We perform a statistical study of current density and direction during ring current crossings using the Cluster spacecraft. We analyse the extent of the interhemispheric field aligned currents for a wide range of solar wind conditions. Direct estimations of equatorial current direction and density are achieved through the curlometer technique. The curlometer technique is based on Ampere's law and requires magnetic field measurements from all four spacecrafts. The use of this method requires careful study of factors that limit the accuracy, such as tetrahedron shape and configuration. This significantly limits our dataset, but is a necessity for accurate current calculations. Our goal is to statistically investigate the occurrence of interhemispheric currents, and determine if there are parameters or magnetospheric states on which the current magnitude and directions depend upon.

Posthospitalization home health care use and changes in functional status in a Medicare population.

PubMed

Hadley, J; Rabin, D; Epstein, A; Stein, S; Rimes, C

2000-05-01

The objective of this work was to estimate the effect of Medicare beneficiaries' use of home health care (HHC) for 6 months after hospital discharge on the change in functional status over a 1-year period beginning before hospitalization. Data came from the Medicare Current Beneficiary Survey, which is a nationally representative sample of Medicare beneficiaries, in-person interview data, and Medicare claims for 1991 through 1994 for 2,127 nondisabled, community-dwelling, elderly Medicare beneficiaries who were hospitalized within 6 months of their annual in-person interviews. Econometric estimation with the instrumental variable method was used to correct for observational data bias, ie, the nonrandom allocation of discharged beneficiaries to the use of posthospitalization HHC. The analysis estimates a first-stage model of HHC use from which an instrumental variable estimate is constructed to estimate the effect on change in functional status. The instrumental variable estimates suggest that HHC users experienced greater improvements in functional status than nonusers as measured by the change in a continuous scale based on the number and mix of activities of daily living and instrumental activities of daily living before and after hospitalization. The estimated improvement in functional status could be as large as 13% for a 10% increase in HHC use. In contrast, estimation with the observational data on HHC use implies that HHC users had poorer health outcomes. Adjusting for potential observational data bias is critical to obtaining estimates of the relationship between the use of posthospitalization HHC and the change in health before and after hospitalization. After adjustment, the results suggest that efforts to constrain Medicare's spending for HHC, as required by the Balanced Budget Act of 1997, may lead to poorer health outcomes for some beneficiaries.

How many species of flowering plants are there?

PubMed Central

Joppa, Lucas N.; Roberts, David L.; Pimm, Stuart L.

2011-01-01

We estimate the probable number of flowering plants. First, we apply a model that explicitly incorporates taxonomic effort over time to estimate the number of as-yet-unknown species. Second, we ask taxonomic experts their opinions on how many species are likely to be missing, on a family-by-family basis. The results are broadly comparable. We show that the current number of species should grow by between 10 and 20 per cent. There are, however, interesting discrepancies between expert and model estimates for some families, suggesting that our model does not always completely capture patterns of taxonomic activity. The as-yet-unknown species are probably similar to those taxonomists have described recently—overwhelmingly rare and local, and disproportionately in biodiversity hotspots, where there are high levels of habitat destruction. PMID:20610425

Measles elimination in Italy: projected impact of the National Elimination Plan.

PubMed Central

Manfredi, P.; Williams, J. R.; Ciofi Degli Atti, M. L.; Salmaso, S.

2005-01-01

A mathematical model was used to evaluate the impact of the Italian Measles National Elimination Plan (NEP), and possible sources of failure in achieving its targets. The model considered two different estimates of force of infection, and the possible effect on measles transmission of the current Italian demographic situation, characterized by a below-replacement fertility. Results suggest that reaching all NEP targets will allow measles elimination to be achieved. In addition, the model suggests that achieving elimination by reaching a 95 % first-dose coverage appears unlikely; and that conducting catch-up activities, reaching high vaccination coverage, could interrupt virus circulation, but could not prevent the infection re-emerging before 2020. Also, the introduction of the second dose of measles vaccine seems necessary for achieving and maintaining elimination. Furthermore, current Italian demography appears to be favourable for reaching elimination. PMID:15724715

The rationale and suggested approaches for research geosynchronous satellite measurements for severe storm and mesoscale investigations

NASA Technical Reports Server (NTRS)

Shenk, W. E.; Adler, R. F.; Chesters, D.; Susskind, J.; Uccellini, L.

1984-01-01

The measurements from current and planned geosynchronous satellites provide quantitative estimates of temperature and moisture profiles, surface temperature, wind, cloud properties, and precipitation. A number of significant observation characteristics remain, they include: (1) temperature and moisture profiles in cloudy areas; (2) high vertical profile resolution; (3) definitive precipitation area mapping and precipitation rate estimates on the convective cloud scale; (4) winds from low level cloud motions at night; (5) the determination of convective cloud structure; and (6) high resolution surface temperature determination. Four major new observing capabilities are proposed to overcome these deficiencies: a microwave sounder/imager, a high resolution visible and infrared imager, a high spectral resolution infrared sounder, and a total ozone mapper. It is suggested that the four sensors are flown together and used to support major mesoscale and short range forecasting field experiments.

Logit-normal mixed model for Indian Monsoon rainfall extremes

NASA Astrophysics Data System (ADS)

Dietz, L. R.; Chatterjee, S.

2014-03-01

Describing the nature and variability of Indian monsoon rainfall extremes is a topic of much debate in the current literature. We suggest the use of a generalized linear mixed model (GLMM), specifically, the logit-normal mixed model, to describe the underlying structure of this complex climatic event. Several GLMM algorithms are described and simulations are performed to vet these algorithms before applying them to the Indian precipitation data procured from the National Climatic Data Center. The logit-normal model was applied with fixed covariates of latitude, longitude, elevation, daily minimum and maximum temperatures with a random intercept by weather station. In general, the estimation methods concurred in their suggestion of a relationship between the El Niño Southern Oscillation (ENSO) and extreme rainfall variability estimates. This work provides a valuable starting point for extending GLMM to incorporate the intricate dependencies in extreme climate events.

Two-Dimensional Analysis of Conical Pulsed Inductive Plasma Thruster Performance

NASA Technical Reports Server (NTRS)

Hallock, A. K.; Polzin, K. A.; Emsellem, G. D.

2011-01-01

A model of the maximum achievable exhaust velocity of a conical theta pinch pulsed inductive thruster is presented. A semi-empirical formula relating coil inductance to both axial and radial current sheet location is developed and incorporated into a circuit model coupled to a momentum equation to evaluate the effect of coil geometry on the axial directed kinetic energy of the exhaust. Inductance measurements as a function of the axial and radial displacement of simulated current sheets from four coils of different geometries are t to a two-dimensional expression to allow the calculation of the Lorentz force at any relevant averaged current sheet location. This relation for two-dimensional inductance, along with an estimate of the maximum possible change in gas-dynamic pressure as the current sheet accelerates into downstream propellant, enables the expansion of a one-dimensional circuit model to two dimensions. The results of this two-dimensional model indicate that radial current sheet motion acts to rapidly decouple the current sheet from the driving coil, leading to losses in axial kinetic energy 10-50 times larger than estimations of the maximum available energy in the compressed propellant. The decreased available energy in the compressed propellant as compared to that of other inductive plasma propulsion concepts suggests that a recovery in the directed axial kinetic energy of the exhaust is unlikely, and that radial compression of the current sheet leads to a loss in exhaust velocity for the operating conditions considered here.

Issues in assessing the contribution of research and development to productivity growth

NASA Technical Reports Server (NTRS)

Griliches, Z.

1979-01-01

The article outlines the production function approach to the estimation of the returns to R&D and then proceeds to discuss in turn two very difficult problems: the measurement of output in R&D intensive industries and the definition and measurement of the stock of R&D 'capital'. Multicollinearity and simultaneity are taken up in the next section and another section is devoted to estimation and inference problems arising more specifically in the R&D context. Several recent studies of returns to R&D are then surveyed, and the paper concludes with suggestions for ways of expanding the current data base in this field.

Population trajectory of burrowing owls (Athene cunicularia) in eastern Washington

USGS Publications Warehouse

Conway, C.J.; Pardieck, K.L.

2006-01-01

Anecdotal evidence suggests that burrowing owls have declined in Washington. The Washington Department of Fish and Wildlife is currently conducting a status review for burrowing owls which will help determine whether they should be listed as threatened or endangered in the state. To provide insights into the current status of burrowing owls (Athene cunicularia), we analyzed data from the North American Breeding Bird Survey using two analytical approaches to determine their current population trajectory in eastern Washington. We used a one-sample t-test to examine whether trend estimates across all BBS routes in Washington differed from zero. We also used a mixed model analysis to estimate the rate of decline in number of burrowing owls detected between 1968 and 2005. The slope in number of burrowing owls detected was negative for 12 of the 16 BBS routes in Washington that have detected burrowing owls. Numbers of breeding burrowing owls detected in eastern Washington declined at a rate of 1.5% annually. We suggest that all BBS routes that have detected burrowing owls in past years in eastern Washington be surveyed annually and additional surveys conducted to track population trends of burrowing owls at finer spatial scales in eastern Washington. In the meantime, land management and regulatory agencies should ensure that publicly managed areas with breeding burrowing owls are not degraded and should implement education and outreach programs to promote protection of privately owned areas with breeding owls.

Examining fluvial fish range loss with SDMs

USGS Publications Warehouse

Taylor, Andrew T.; Papeş, Monica; Long, James M.

2018-01-01

Fluvial fishes face increased imperilment from anthropogenic activities, but the specific factors contributing most to range declines are often poorly understood. For example, the range of the fluvial‐specialist shoal bass (Micropterus cataractae) continues to decrease, yet how perceived threats have contributed to range loss is largely unknown. We used species distribution models to determine which factors contributed most to shoal bass range loss. We estimated a potential distribution based on natural abiotic factors and a series of currently occupied distributions that incorporated variables characterizing land cover, non‐native species, and river fragmentation intensity (no fragmentation, dams only, and dams and large impoundments). We allowed interspecific relationships between non‐native congeners and shoal bass to vary across fragmentation intensities. Results from the potential distribution model estimated shoal bass presence throughout much of their native basin, whereas models of currently occupied distribution showed that range loss increased as fragmentation intensified. Response curves from models of currently occupied distribution indicated a potential interaction between fragmentation intensity and the relationship between shoal bass and non‐native congeners, wherein non‐natives may be favored at the highest fragmentation intensity. Response curves also suggested that >100 km of interconnected, free‐flowing stream fragments were necessary to support shoal bass presence. Model evaluation, including an independent validation, suggested that models had favorable predictive and discriminative abilities. Similar approaches that use readily available, diverse, geospatial data sets may deliver insights into the biology and conservation needs of other fluvial species facing similar threats.

Is the future already here? The impact of climate change on the distribution of the eastern coral snake (Micrurus fulvius).

PubMed

Archis, Jennifer N; Akcali, Christopher; Stuart, Bryan L; Kikuchi, David; Chunco, Amanda J

2018-01-01

Anthropogenic climate change is a significant global driver of species distribution change. Although many species have undergone range expansion at their poleward limits, data on several taxonomic groups are still lacking. A common method for studying range shifts is using species distribution models to evaluate current, and predict future, distributions. Notably, many sources of 'current' climate data used in species distribution modeling use the years 1950-2000 to calculate climatic averages. However, this does not account for recent (post 2000) climate change. This study examines the influence of climate change on the eastern coral snake ( Micrurus fulvius ). Specifically, we: (1) identified the current range and suitable environment of M. fulvius in the Southeastern United States, (2) investigated the potential impacts of climate change on the distribution of M. fulvius , and (3) evaluated the utility of future models in predicting recent (2001-2015) records. We used the species distribution modeling program Maxent and compared both current (1950-2000) and future (2050) climate conditions. Future climate models showed a shift in the distribution of suitable habitat across a significant portion of the range; however, results also suggest that much of the Southeastern United States will be outside the range of current conditions, suggesting that there may be no-analog environments in the future. Most strikingly, future models were more effective than the current models at predicting recent records, suggesting that range shifts may already be occurring. These results have implications for both M. fulvius and its Batesian mimics. More broadly, we recommend future Maxent studies consider using future climate data along with current data to better estimate the current distribution.

Decremental Response to High-Frequency Trains of Acetylcholine Pulses but Unaltered Fractional Ca2+ Currents in a Panel of “Slow-Channel Syndrome” Nicotinic Receptor Mutants

PubMed Central

Elenes, Sergio; Decker, Michael; Cymes, Gisela D.

2009-01-01

The slow-channel congenital myasthenic syndrome (SCCMS) is a disorder of the neuromuscular junction caused by gain-of-function mutations to the muscle nicotinic acetylcholine (ACh) receptor (AChR). Although it is clear that the slower deactivation time course of the ACh-elicited currents plays a central role in the etiology of this disease, it has been suggested that other abnormal properties of these mutant receptors may also be critical in this respect. We characterized the kinetics of a panel of five SCCMS AChRs (αS269I, βV266M, εL221F, εT264P, and εL269F) at the ensemble level in rapidly perfused outside-out patches. We found that, for all of these mutants, the peak-current amplitude decreases along trains of nearly saturating ACh pulses delivered at physiologically relevant frequencies in a manner that is consistent with enhanced entry into desensitization during the prolonged deactivation phase. This suggests that the increasingly reduced availability of activatable AChRs upon repetitive stimulation may well contribute to the fatigability and weakness of skeletal muscle that characterize this disease. Also, these results emphasize the importance of explicitly accounting for entry into desensitization as one of the pathways for burst termination, if meaningful mechanistic insight is to be inferred from the study of the effect of these naturally occurring mutations on channel function. Applying a novel single-channel–based approach to estimate the contribution of Ca2+ to the total cation currents, we also found that none of these mutants affects the Ca2+-conduction properties of the AChR to an extent that seems to be of physiological importance. Our estimate of the Ca2+-carried component of the total (inward) conductance of wild-type and SCCMS AChRs in the presence of 150 mM Na+, 1.8 mM Ca2+, and 1.7 mM Mg2+ on the extracellular side of cell-attached patches turned out be in the 5.0–9.4 pS range, representing a fractional Ca2+ current of ∼14%, on average. Remarkably, these values are nearly identical to those we estimated for the NR1-NR2A N-methyl-d-aspartate receptor (NMDAR), which has generally been considered to be the main neurotransmitter-gated pathway of Ca2+ entry into the cell. Our estimate of the rat NMDAR Ca2+ conductance (using the same single-channel approach as for the AChR but in the nominal absence of extracellular Mg2+) was 7.9 pS, corresponding to a fractional Ca2+ current of 13%. PMID:19171769

Variation of ultrasound image lateral spectrum with assumed speed of sound and true scatterer density.

PubMed

Gyöngy, Miklós; Kollár, Sára

2015-02-01

One method of estimating sound speed in diagnostic ultrasound imaging consists of choosing the speed of sound that generates the sharpest image, as evaluated by the lateral frequency spectrum of the squared B-mode image. In the current work, simulated and experimental data on a typical (47 mm aperture, 3.3-10.0 MHz response) linear array transducer are used to investigate the accuracy of this method. A range of candidate speeds of sound (1240-1740 m/s) was used, with a true speed of sound of 1490 m/s in simulations and 1488 m/s in experiments. Simulations of single point scatterers and two interfering point scatterers at various locations with respect to each other gave estimate errors of 0.0-2.0%. Simulations and experiments of scatterer distributions with a mean scatterer spacing of at least 0.5 mm gave estimate errors of 0.1-4.0%. In the case of lower scatterer spacing, the speed of sound estimates become unreliable due to a decrease in contrast of the sharpness measure between different candidate speeds of sound. This suggests that in estimating speed of sound in tissue, the region of interest should be dominated by a few, sparsely spaced scatterers. Conversely, the decreasing sensitivity of the sharpness measure to speed of sound errors for higher scatterer concentrations suggests a potential method for estimating mean scatterer spacing. Copyright © 2014 Elsevier B.V. All rights reserved.

Will choice-based reform work for Medicare? Evidence from the Federal Employees Health Benefits Program.

PubMed

Florence, Curtis S; Atherly, Adam; Thorpe, Kenneth E

2006-10-01

. To examine the effect of premiums and benefits on the health plan choices of older enrollees who choose Federal Employees Health Benefits Program (FEHBP) health plans as their primary payer. Administrative enrollment data from the Office of Personnel Management (OPM) and plan premiums and benefits data taken from the Checkbook Guide to health plans. We estimate individual plan choice models where the choice of health plan is a function of out-of-pocket premium, actuarial value, plan attributes, and individual characteristics. Plan attributes include plan structure (fee-for-service/preferred provider organization, point-of-service, or health maintenance organization), drug benefit structure, and whether or not the plan covers other types of spending such as dental services and diabetic supplies. The models are estimated by conditional logit. Our study focuses on three populations that currently choose FEHBP as their primary health care coverage and are similar to the Medicare population: current employees and retirees who are approaching the age of Medicare eligibility (ages 60-64) and current federal employees age 65+. Current employees age 65+ are eligible for Medicare, but their FEHBP plan is their primary payer. Retirees and employees 60-64 are not yet eligible for Medicare but are similar in many respects to recently age-eligible Medicare beneficiaries. We also estimate our model for current employees age 55 and younger as a comparison group. We select a random sample of retirees and employees age 60-64, as well as all current employees age 65+, from the OPM administrative database for the calendar year 2001. The plan choices available to each person are determined by the plans participating in their metropolitan statistical area. We match plan premium and attribute information from the Checkbook Guide to each plan in the enrollee's list of choices. We find that current workers 65+, 60-64, and non-Medicare eligible retirees are sensitive to variation in plan premiums. The premium elasticities for these groups are similar in magnitude to those of the age 55 and under employee group. Older workers and retirees not yet eligible for Medicare are willing to pay a substantial amount for plans with open provider networks. The willingness to pay for open networks is significantly greater for these groups than for younger employees. Willingness to pay for open network plans varies significantly by income, but varies little by age within group. Our finding that older workers and non-Medicare eligible retirees are sensitive to plan premiums suggests that choice-based reform of Medicare would lead to cost-conscious choices by Medicare beneficiaries. However, our finding that these groups are willing to pay more for open network plans than younger employees suggest that higher risk individuals may migrate toward higher benefit, higher cost plans. Our findings on the relationship between income and willingness to pay for open network plans suggest that means testing is a viable reform for lowering Medicare program costs.

Problems with sampling desert tortoises: A simulation analysis based on field data

USGS Publications Warehouse

Freilich, J.E.; Camp, R.J.; Duda, J.J.; Karl, A.E.

2005-01-01

The desert tortoise (Gopherus agassizii) was listed as a U.S. threatened species in 1990 based largely on population declines inferred from mark-recapture surveys of 2.59-km2 (1-mi2) plots. Since then, several census methods have been proposed and tested, but all methods still pose logistical or statistical difficulties. We conducted computer simulations using actual tortoise location data from 2 1-mi2 plot surveys in southern California, USA, to identify strengths and weaknesses of current sampling strategies. We considered tortoise population estimates based on these plots as "truth" and then tested various sampling methods based on sampling smaller plots or transect lines passing through the mile squares. Data were analyzed using Schnabel's mark-recapture estimate and program CAPTURE. Experimental subsampling with replacement of the 1-mi2 data using 1-km2 and 0.25-km2 plot boundaries produced data sets of smaller plot sizes, which we compared to estimates from the 1-mi 2 plots. We also tested distance sampling by saturating a 1-mi 2 site with computer simulated transect lines, once again evaluating bias in density estimates. Subsampling estimates from 1-km2 plots did not differ significantly from the estimates derived at 1-mi2. The 0.25-km2 subsamples significantly overestimated population sizes, chiefly because too few recaptures were made. Distance sampling simulations were biased 80% of the time and had high coefficient of variation to density ratios. Furthermore, a prospective power analysis suggested limited ability to detect population declines as high as 50%. We concluded that poor performance and bias of both sampling procedures was driven by insufficient sample size, suggesting that all efforts must be directed to increasing numbers found in order to produce reliable results. Our results suggest that present methods may not be capable of accurately estimating desert tortoise populations.

Fundamentals of health risk assessment. Use, derivation, validity and limitations of safety indices.

PubMed

Putzrath, R M; Wilson, J D

1999-04-01

We investigated the way results of human health risk assessments are used, and the theory used to describe those methods, sometimes called the "NAS paradigm." Contrary to a key tenet of that theory, current methods have strictly limited utility. The characterizations now considered standard, Safety Indices such as "Acceptable Daily Intake," "Reference Dose," and so on, usefully inform only decisions that require a choice between two policy alternatives (e.g., approve a food additive or not), decided solely on the basis of a finding of safety. Risk is characterized as the quotient of one of these Safety Indices divided by an estimate of exposure: a quotient greater than one implies that the situation may be considered safe. Such decisions are very widespread, both in the U.S. federal government and elsewhere. No current method is universal; different policies lead to different practices, for example, in California's "Proposition 65," where statutory provisions specify some practices. Further, an important kind of human health risk assessment is not recognized by this theory: this kind characterizes risk as likelihood of harm, given estimates of exposure consequent to various decision choices. Likelihood estimates are necessary whenever decision makers have many possible decision choices and must weigh more than two societal values, such as in EPA's implementation of "conventional air pollutants." These estimates can not be derived using current methods; different methods are needed. Our analysis suggests changes needed in both the theory and practice of human health risk assessment, and how what is done is depicted.

Women who take n-3 long-chain polyunsaturated fatty acid supplements during pregnancy and lactation meet the recommended intake.

PubMed

Jia, Xiaoming; Pakseresht, Mohammadreza; Wattar, Nour; Wildgrube, Jamie; Sontag, Stephanie; Andrews, Murphy; Subhan, Fatheema Begum; McCargar, Linda; Field, Catherine J

2015-05-01

The aim of the current study was to estimate total intake and dietary sources of eicosapentaenoic acid (EPA), docosapentanoic (DPA), and docosahexaenoic acid (DHA) and compare DHA intakes with the recommended intakes in a cohort of pregnant and lactating women. Twenty-four-hour dietary recalls and supplement intake questionnaires were collected from 600 women in the Alberta Pregnancy Outcomes and Nutrition (APrON) cohort at each trimester of pregnancy and 3 months postpartum. Dietary intake was estimated in 2 ways: by using a commercial software program and by using a database created for APrON. Only 27% of women during pregnancy and 25% at 3 months postpartum met the current European Union (EU) consensus recommendation for DHA. Seafood, fish, and seaweed products contributed to 79% of overall n-3 long-chain polyunsaturated fatty acids intake from foods, with the majority from salmon. The estimated intake of DHA and EPA was similar between databases, but the estimated DPA intake was 20%-30% higher using the comprehensive database built for this study. Women who took a supplement containing DHA were 10.6 and 11.1 times more likely to meet the current EU consensus recommendation for pregnancy (95% confidence interval (CI): 6.952-16.07; P<0.001) and postpartum (95% CI: 6.803-18.14; P<0.001), respectively. Our results suggest that the majority of women in the cohort were not meeting the EU recommendation for DHA during pregnancy and lactation, but taking a supplement significantly improved the likelihood that they would meet recommendations.

Influence of current climate, historical climate stability and topography on species richness and endemism in Mesoamerican geophyte plants

PubMed Central

2017-01-01

Background A number of biotic and abiotic factors have been proposed as drivers of geographic variation in species richness. As biotic elements, inter-specific interactions are the most widely recognized. Among abiotic factors, in particular for plants, climate and topographic variables as well as their historical variation have been correlated with species richness and endemism. In this study, we determine the extent to which the species richness and endemism of monocot geophyte species in Mesoamerica is predicted by current climate, historical climate stability and topography. Methods Using approximately 2,650 occurrence points representing 507 geophyte taxa, species richness (SR) and weighted endemism (WE) were estimated at a geographic scale using grids of 0.5 × 0.5 decimal degrees resolution using Mexico as the geographic extent. SR and WE were also estimated using species distributions inferred from ecological niche modeling for species with at least five spatially unique occurrence points. Current climate, current to Last Glacial Maximum temperature, precipitation stability and topographic features were used as predictor variables on multiple spatial regression analyses (i.e., spatial autoregressive models, SAR) using the estimates of SR and WE as response variables. The standardized coefficients of the predictor variables that were significant in the regression models were utilized to understand the observed patterns of species richness and endemism. Results Our estimates of SR and WE based on direct occurrence data and distribution modeling generally yielded similar results, though estimates based on ecological niche modeling indicated broader distribution areas for SR and WE than when species richness was directly estimated using georeferenced coordinates. The SR and WE of monocot geophytes were highest along the Trans-Mexican Volcanic Belt, in both cases with higher levels in the central area of this mountain chain. Richness and endemism were also elevated in the southern regions of the Sierra Madre Oriental and Occidental mountain ranges, and in the Tehuacán Valley. Some areas of the Sierra Madre del Sur and Sierra Madre Oriental had high levels of WE, though they are not the areas with the highest SR. The spatial regressions suggest that SR is mostly influenced by current climate, whereas endemism is mainly affected by topography and precipitation stability. Conclusions Both methods (direct occurrence data and ecological niche modeling) used to estimate SR and WE in this study yielded similar results and detected a key area that should be considered in plant conservation strategies: the central region of the Trans-Mexican Volcanic Belt. Our results also corroborated that species richness is more closely correlated with current climate factors while endemism is related to differences in topography and to changes in precipitation levels compared to the LGM climatic conditions. PMID:29062605

Spatial-altitudinal and temporal variation of Degree Day Factors (DDFs) in the Upper Indus Basin

NASA Astrophysics Data System (ADS)

Khan, Asif; Attaullah, Haleema; Masud, Tabinda; Khan, Mujahid

2017-04-01

Melt contribution from snow and ice in the Hindukush-Karakoram-Himalayan (HKH) region could account for more than 80% of annual river flows in the Upper Indus Basin (UIB). Increase or decrease in precipitation, energy input and glacier reserves can significantly affect water resources of this region. Therefore improved hydrological modelling and accurate future water resources prediction are vital for food production and hydro-power generation for millions of people living downstream, and are intensively needed. In mountain regions Degree Day Factors (DDFs) significantly vary on spatial and altitudinal basis, and are primary inputs of temperature-based hydrological modelling. However previous studies have used different DDFs as calibration parameters without due attention to the physical meaning of the values employed, and these estimates possess significant variability and uncertainty. This study provides estimates of DDFs for various altitudinal zones in the UIB at sub-basin level. Snow, clean ice and ice with debris cover bear different melt rates (or DDFs), therefore areally-averaged DDFs based on snow, clean and debris-covered ice classes in various altitudinal zones have been estimated for all sub-basins of the UIB. Zonal estimates of DDFs in the current study are significantly different from earlier adopted DDFs, hence suggest a revisit of previous hydrological modelling studies. DDFs presented in current study have been validated by using Snowmelt Runoff Model (SRM) in various sub-basins with good Nash Sutcliffe coefficients (R2 > 0.85) and low volumetric errors (Dv<10%). DDFs and methods provided in the current study can be used in future improved hydrological modelling and to provide accurate predictions of future river flows changes. The methodology used for estimation of DDFs is robust, and can be adopted to produce such estimates in other regions of the, particularly in the nearby other HKH basins.

Some comments on clinical studies in orthodontics and their applications to orthodontic treatment.

PubMed

Baumrind, S

1999-06-01

This article indicates the origins and background of the current series of National Institute of Dental and Craniofacial Research-funded, university-based clinical studies of orthodontic treatment. It suggests that future studies should be less focused on refining our estimates of mean changes during treatment and concentrate research on the systematic analysis of individual differences among patients' responses to treatment, and study how skilled clinicians make in-course corrections in response to unexpected changes in treatment conditions. Finally, some suggestions are made concerning optimization of decision making in the presence of uncertainty.

Diversification in Hawaiian long-legged flies (Diptera: Dolichopodidae: Campsicnemus): biogeographic isolation and ecological adaptation.

PubMed

Goodman, Kari Roesch; Evenhuis, Neal L; Bartošová-Sojková, Pavla; O'Grady, Patrick M

2014-12-01

Flies in the genus Campsicnemus have diversified into the second-largest adaptive radiation of Diptera in the Hawaiian Islands, with 179 Hawaiian endemic species currently described. Here we present the first phylogenetic analysis of Campsicnemus, with a focus on the Hawaiian fauna. We analyzed a combination of two nuclear (CAD, EF1α) and five mitochondrial (COI, COII, 12S, 16S, ND2) loci using Bayesian and maximum likelihood approaches to generate a phylogenetic hypothesis for the genus Campsicnemus. Our sampling included a total of 84 species (6 species from Europe, 1 from North America, 7 species from French Polynesia and 70 species from the Hawaiian Islands). The phylogenies were used to estimate divergence times, reconstruct biogeographic history, and infer ancestral ecological associations within this large genus. We found strong support for a South Pacific+Hawaiian clade, as well as for a monophyletic Hawaiian lineage. Divergence time estimates suggest that Hawaiian Islands were colonized approximately 4.6 million years ago, suggesting that most of the diversity within Campsicnemus evolved since the current high islands began forming ∼5 million years ago. We also observe a novel ecotype within the Pacific Campsicnemus; a widespread obligate water-skating form that has arisen multiple times across the Pacific Islands. Together, these analyses suggest that a combination of ecological, biogeographic and temporal factors have led to the impressive diversity of long-legged flies in Hawaii and elsewhere in the Pacific. Copyright © 2014 Elsevier Inc. All rights reserved.

Stroke survivors over-estimate their medication self-administration (MSA) ability, predicting memory loss.

PubMed

Barrett, A M; Galletta, Elizabeth E; Zhang, Jun; Masmela, Jenny R; Adler, Uri S

2014-01-01

Medication self-administration (MSA) may be cognitively challenging after stroke, but guidelines are currently lacking for identifying high-functioning stroke survivors who may have difficulty with this task. Complicating this matter, stroke survivors may not be aware of their cognitive problems (cognitive anosognosia) and may over-estimate their MSA competence. The authors wished to evaluate medication self-administration and MSA self-awareness in 24 consecutive acute stroke survivors undergoing inpatient rehabilitation, to determine if they would over-estimate their medication self-administration and if this predicted memory disorder. Stroke survivors were tested on the Hopkins Medication Schedule and also their memory, naming mood and dexterity were evaluated, comparing their performance to 17 matched controls. The anosognosia ratio indicated MSA over-estimation in stroke survivors compared with controls--no other over-estimation errors were noted relative to controls. A strong correlation was observed between over-estimation of MSA ability and verbal memory deficit, suggesting that formally assessing MSA and MSA self-awareness may help detect cognitive deficits. Assessing medication self-administration and MSA self-awareness may be useful in rehabilitation and successful community-return after stroke.

Disruption of State Estimation in the Human Lateral Cerebellum

PubMed Central

Miall, R. Chris; Christensen, Lars O. D; Cain, Owen; Stanley, James

2007-01-01

The cerebellum has been proposed to be a crucial component in the state estimation process that combines information from motor efferent and sensory afferent signals to produce a representation of the current state of the motor system. Such a state estimate of the moving human arm would be expected to be used when the arm is rapidly and skillfully reaching to a target. We now report the effects of transcranial magnetic stimulation (TMS) over the ipsilateral cerebellum as healthy humans were made to interrupt a slow voluntary movement to rapidly reach towards a visually defined target. Errors in the initial direction and in the final finger position of this reach-to-target movement were significantly higher for cerebellar stimulation than they were in control conditions. The average directional errors in the cerebellar TMS condition were consistent with the reaching movements being planned and initiated from an estimated hand position that was 138 ms out of date. We suggest that these results demonstrate that the cerebellum is responsible for estimating the hand position over this time interval and that TMS disrupts this state estimate. PMID:18044990

Bias of health estimates obtained from chronic disease and risk factor surveillance systems using telephone population surveys in Australia: results from a representative face-to-face survey in Australia from 2010 to 2013.

PubMed

Dal Grande, Eleonora; Chittleborough, Catherine R; Campostrini, Stefano; Taylor, Anne W

2016-04-18

Emerging communication technologies have had an impact on population-based telephone surveys worldwide. Our objective was to examine the potential biases of health estimates in South Australia, a state of Australia, obtained via current landline telephone survey methodologies and to report on the impact of mobile-only household on household surveys. Data from an annual multi-stage, systematic, clustered area, face-to-face population survey, Health Omnibus Survey (approximately 3000 interviews annually), included questions about telephone ownership to assess the population that were non-contactable by current telephone sampling methods (2006 to 2013). Univariable analyses (2010 to 2013) and trend analyses were conducted for sociodemographic and health indicator variables in relation to telephone status. Relative coverage biases (RCB) of two hypothetical telephone samples was undertaken by examining the prevalence estimates of health status and health risk behaviours (2010 to 2013): directory-listed numbers, consisting mainly of landline telephone numbers and a small proportion of mobile telephone numbers; and a random digit dialling (RDD) sample of landline telephone numbers which excludes mobile-only households. Telephone (landline and mobile) coverage in South Australia is very high (97%). Mobile telephone ownership increased slightly (7.4%), rising from 89.7% in 2006 to 96.3% in 2013; mobile-only households increased by 431% over the eight year period from 5.2% in 2006 to 27.6% in 2013. Only half of the households have either a mobile or landline number listed in the telephone directory. There were small differences in the prevalence estimates for current asthma, arthritis, diabetes and obesity between the hypothetical telephone samples and the overall sample. However, prevalence estimate for diabetes was slightly underestimated (RCB value of -0.077) in 2013. Mixed RCB results were found for having a mental health condition for both telephone samples. Current smoking prevalence was lower for both hypothetical telephone samples in absolute differences and RCB values: -0.136 to -0.191 for RDD landline samples and -0.129 to -0.313 for directory-listed samples. These findings suggest landline-based sampling frames used in Australia, when appropriately weighted, produce reliable representative estimates for some health indicators but not for all. Researchers need to be aware of their limitations and potential biased estimates.

Drift in ocean currents impacts intergenerational microbial exposure to temperature.

PubMed

Doblin, Martina A; van Sebille, Erik

2016-05-17

Microbes are the foundation of marine ecosystems [Falkowski PG, Fenchel T, Delong EF (2008) Science 320(5879):1034-1039]. Until now, the analytical framework for understanding the implications of ocean warming on microbes has not considered thermal exposure during transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Here we show that upper-ocean microbes experience along-trajectory temperature variability up to 10 °C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents can increase the thermal exposure of microbes and suggests that microbial populations with broad thermal tolerance will survive transport to distant regions of the ocean and invade new habitats. Our findings also suggest that advection has the capacity to influence microbial community assemblies, such that regions with strong currents and large thermal fluctuations select for communities with greatest plasticity and evolvability, and communities with narrow thermal performance are found where ocean currents are weak or along-trajectory temperature variation is low. Given that fluctuating environments select for individual plasticity in microbial lineages, and that physiological plasticity of ancestors can predict the magnitude of evolutionary responses of subsequent generations to environmental change [Schaum CE, Collins S (2014) Proc Biol Soc 281(1793):20141486], our findings suggest that microbial populations in the sub-Antarctic (∼40°S), North Pacific, and North Atlantic will have the most capacity to adapt to contemporary ocean warming.

Potential Global Partners for Smaller-Scale Contingencies

DTIC Science & Technology

2000-08-01

Current estimates4 suggest there are possibly as many as 32,000 NGOs formed in developed nations (northern hemisphere or global NGOs) that work in...organizations with an international perspective that originate in developed nations. It is important to keep in mind that there are both global and local NGOs...Coordination within the ECOSOC System The UNS includes two key committees that develop policy and effect interagency coordination and cooperation

Elastic anisotropy effects on the electrical responses of a thin sample of nematic liquid crystal.

PubMed

Gomes, O A; Yednak, C A R; Ribeiro de Almeida, R R; Teixeira-Souza, R T; Evangelista, L R

2017-03-01

The electrical responses of a nematic liquid crystal cell are investigated by means of the elastic continuum theory. The nematic medium is considered as a parallel circuit of a resistance and a capacitance and the electric current profile across the sample is determined as a function of the elastic constants. In the reorientation process of the nematic director, the resistance and capacitance of the sample are determined by taking into account the elastic anisotropy. A nonmonotonic profile for the current is observed in which a minimum value of the current may be used to estimate the elastic constants values. This scenario suggests a theoretical method to determine the values of the bulk elastic constants in a single planar aligned cell just by changing the direction of applied electrical field and measuring the resulting electrical current.

Altitudinal migration and the future of an iconic Hawaiian honeycreeper in response to climate change and management

USGS Publications Warehouse

Guillaumet, Alban; Kuntz, Wendy A.; Samuel, Michael D.; Paxton, Eben H.

2017-01-01

Altitudinal movement by tropical birds to track seasonally variable resources can move them from protected areas to areas of increased vulnerability. In Hawaiʻi, historical reports suggest that many Hawaiian honeycreepers such as the ‘I‘iwi (Drepanis coccinea) once undertook seasonal migrations, but the existence of such movements today is unclear. Because Hawaiian honeycreepers are highly susceptible to avian malaria, currently minimal in high-elevation forests, understanding the degree to which honeycreepers visit lower elevation forests may be critical to predict the current impact of malaria on population dynamics and how susceptible bird populations may respond to climate change and mitigation scenarios. Using radio telemetry data, we demonstrate for the first time that a large fraction of breeding adult and juvenile ‘I‘iwi originating from an upper-elevation (1,920 m) population at Hakalau Forest National Wildlife Refuge exhibit post-breeding movements well below the upper elevational limit for mosquitoes. Bloom data suggest seasonal variation in floral resources is the primary driver of seasonal movement for ‘I‘iwi. To understand the demographic implications of such movement, we developed a spatial individual-based model calibrated using previously published and original data. ʻI‘iwi dynamics were simulated backward in time, to estimate population levels in the absence of avian malaria, and forward in time, to assess the impact of climate warming as well as two potential mitigation actions. Even in disease-free ‘refuge’ populations, we found that breeding densities failed to reach the estimated carrying capacity, suggesting the existence of a seasonal “migration load” as a result of travel to disease-prevalent areas. We predict that ‘I‘iwi may be on the verge of extinction in 2100, with the total number of pairs reaching only ~ 0.2–12.3% of the estimated pre-malaria density, based on an optimistic climate change scenario. The probability of extinction of ‘I‘iwi populations, as measured by population estimates for 2100, is strongly related to their estimated migration propensity. Long-term conservation strategies likely will require a multi-pronged response including a reduction of malaria threats, habitat restoration and continued landscape-level access to seasonally variable nectar resources.

A genomic timescale of prokaryote evolution: insights into the origin of methanogenesis, phototrophy, and the colonization of land

NASA Technical Reports Server (NTRS)

Battistuzzi, Fabia U.; Feijao, Andreia; Hedges, S. Blair

2004-01-01

BACKGROUND: The timescale of prokaryote evolution has been difficult to reconstruct because of a limited fossil record and complexities associated with molecular clocks and deep divergences. However, the relatively large number of genome sequences currently available has provided a better opportunity to control for potential biases such as horizontal gene transfer and rate differences among lineages. We assembled a data set of sequences from 32 proteins (approximately 7600 amino acids) common to 72 species and estimated phylogenetic relationships and divergence times with a local clock method. RESULTS: Our phylogenetic results support most of the currently recognized higher-level groupings of prokaryotes. Of particular interest is a well-supported group of three major lineages of eubacteria (Actinobacteria, Deinococcus, and Cyanobacteria) that we call Terrabacteria and associate with an early colonization of land. Divergence time estimates for the major groups of eubacteria are between 2.5-3.2 billion years ago (Ga) while those for archaebacteria are mostly between 3.1-4.1 Ga. The time estimates suggest a Hadean origin of life (prior to 4.1 Ga), an early origin of methanogenesis (3.8-4.1 Ga), an origin of anaerobic methanotrophy after 3.1 Ga, an origin of phototrophy prior to 3.2 Ga, an early colonization of land 2.8-3.1 Ga, and an origin of aerobic methanotrophy 2.5-2.8 Ga. CONCLUSIONS: Our early time estimates for methanogenesis support the consideration of methane, in addition to carbon dioxide, as a greenhouse gas responsible for the early warming of the Earths' surface. Our divergence times for the origin of anaerobic methanotrophy are compatible with highly depleted carbon isotopic values found in rocks dated 2.8-2.6 Ga. An early origin of phototrophy is consistent with the earliest bacterial mats and structures identified as stromatolites, but a 2.6 Ga origin of cyanobacteria suggests that those Archean structures, if biologically produced, were made by anoxygenic photosynthesizers. The resistance to desiccation of Terrabacteria and their elaboration of photoprotective compounds suggests that the common ancestor of this group inhabited land. If true, then oxygenic photosynthesis may owe its origin to terrestrial adaptations.

Hyperhidrosis: an update on prevalence and severity in the United States.

PubMed

Doolittle, James; Walker, Patricia; Mills, Thomas; Thurston, Jane

2016-12-01

Current published estimates of the prevalence of hyperhidrosis in the United States are outdated and underestimate the true prevalence of the condition. The objectives of this study are to provide an updated estimate of the prevalence of hyperhidrosis in the US population and to further assess the severity and impact of sweating on those affected by the condition. For the purposes of obtaining prevalence, a nationally representative sample of 8160 individuals were selected using an online panel, and information as to whether or not they experience hyperhidrosis was obtained. The 393 individuals (210 female, 244 non-Hispanic white, 27 black, mean age 40.3, SE 0.64) who indicated that they have hyperhidrosis were asked further questions, including body areas impacted, severity of symptoms, age of onset, and socioemotional impact of the condition. Current results estimate the prevalence of hyperhidrosis at 4.8 %, which represents approximately 15.3 million people in the United States. Of these, 70 % report severe excessive sweating in at least one body area. In spite of this, only 51 % have discussed their excessive sweating with a healthcare professional. The main reasons are a belief that hyperhidrosis is not a medical condition and that no treatment options exist. The current study's findings with regard to age of onset and prevalence by body area generally align with the previous research. However, current findings suggest that the severity and prevalence are both higher than previously thought, indicating a need for greater awareness of the condition and its associated treatment options among medical professionals.

Assessing allometric models to predict vegetative growth of mango (Mangifera indica; Anacardiaceae) at the current-year branch scale.

PubMed

Normand, Frédéric; Lauri, Pierre-Éric

2012-03-01

Accurate and reliable predictive models are necessary to estimate nondestructively key variables for plant growth studies such as leaf area and leaf, stem, and total biomass. Predictive models are lacking at the current-year branch scale despite the importance of this scale in plant science. We calibrated allometric models to estimate leaf area and stem and branch (leaves + stem) mass of current-year branches, i.e., branches several months old studied at the end of the vegetative growth season, of four mango cultivars on the basis of their basal cross-sectional area. The effects of year, site, and cultivar were tested. Models were validated with independent data and prediction accuracy was evaluated with the appropriate statistics. Models revealed a positive allometry between dependent and independent variables, whose y-intercept but not the slope, was affected by the cultivar. The effects of year and site were negligible. For each branch characteristic, cultivar-specific models were more accurate than common models built with pooled data from the four cultivars. Prediction quality was satisfactory but with data dispersion around the models, particularly for large values. Leaf area and stem and branch mass of mango current-year branches could be satisfactorily estimated on the basis of branch basal cross-sectional area with cultivar-specific allometric models. The results suggested that, in addition to the heteroscedastic behavior of the variables studied, model accuracy was probably related to the functional plasticity of branches in relation to the light environment and/or to the number of growth units composing the branches.

Reassessment of spiny dogfish Squalus acanthias age and growth using vertebrae and dorsal-fin spines.

PubMed

Bubley, W J; Kneebone, J; Sulikowski, J A; Tsang, P C W

2012-04-01

Male and female spiny dogfish Squalus acanthias were collected in the western North Atlantic Ocean in the Gulf of Maine between July 2006 and June 2009. Squalus acanthias ranged from 25 to 102 cm stretch total length and were caught during all months of the year except January. Age estimates derived from banding patterns visible in both the vertebrae and second dorsal-fin spines were compared. Vertebral growth increments were visualized using a modified histological staining technique, which was verified as appropriate for obtaining age estimates. Marginal increment analysis of vertebrae verified the increment periodicity, suggesting annual band deposition. Based on increased precision and accuracy of age estimates, as well as more biologically realistic parameters generated in growth models, the current study found that vertebrae provided a more reliable and accurate means of estimating age in S. acanthias than the second dorsal-fin spine. Age estimates obtained from vertebrae ranged from <1 year-old to 17 years for male and 24 years for female S. acanthias. The two-parameter von Bertalanffy growth model fit to vertebrae-derived age estimates produced parameters of L∞ = 94·23 cm and k = 0·11 for males and L∞ = 100·76 cm and k = 0·12 for females. While these growth parameters differed from those previously reported for S. acanthias in the western North Atlantic Ocean, the causes of such differences were beyond the scope of the current study and remain to be determined. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Foraminiferal faunal estimates of paleotemperature: Circumventing the no-analog problem yields cool ice age tropics

USGS Publications Warehouse

Mix, A.C.; Morey, A.E.; Pisias, N.G.; Hostetler, S.W.

1999-01-01

The sensitivity of the tropics to climate change, particularly the amplitude of glacial-to-interglacial changes in sea surface temperature (SST), is one of the great controversies in paleoclimatology. Here we reassess faunal estimates of ice age SSTs, focusing on the problem of no-analog planktonic foraminiferal assemblages in the equatorial oceans that confounds both classical transfer function and modern analog methods. A new calibration strategy developed here, which uses past variability of species to define robust faunal assemblages, solves the no-analog problem and reveals ice age cooling of 5??to 6??C in the equatorial current systems of the Atlantic and eastern Pacific Oceans. Classical transfer functions underestimated temperature changes in some areas of the tropical oceans because core-top assemblages misrepresented the ice age faunal assemblages. Our finding is consistent with some geochemical estimates and model predictions of greater ice age cooling in the tropics than was inferred by Climate: Long-Range Investigation, Mapping, and Prediction (CLIMAP) [1981] and thus may help to resolve a long-standing controversy. Our new foraminiferal transfer function suggests that such cooling was limited to the equatorial current systems, however, and supports CLIMAP's inference of stability of the subtropical gyre centers.

Global gridded anthropogenic emissions inventory of carbonyl sulfide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zumkehr, Andrew; Hilton, Tim; Whelan, Mary

Atmospheric carbonyl sulfide (COS or OCS) is the most abundant sulfur containing gas in the troposphere and is an atmospheric tracer for the carbon cycle. Gridded inventories of global anthropogenic COS are used for interpreting global COS measurements. However, previous gridded anthropogenic data are a climatological estimate based on input data that is over three decades old and are not representative of current conditions. Here we develop a new gridded data set of global anthropogenic COS sources that includes more source sectors than previously available and uses the most current emissions factors and industry activity data as input. Additionally, themore » inventory is provided as annually varying estimates from years 1980–2012 and employs a source specific spatial scaling procedure. We estimate a global source in year 2012 of 406 Gg S y -1 (range of 223–586 Gg S y -1), which is highly concentrated in China and is twice as large as the previous gridded inventory. Our large upward revision in the bottom-up estimate of the source is consistent with a recent top-down estimate based on air-monitoring and Antarctic firn data. Furthermore, our inventory time trends, including a decline in the 1990's and growth after the year 2000, are qualitatively consistent with trends in atmospheric data. Lastly, similarities between the spatial distribution in this inventory and remote sensing data suggest that the anthropogenic source could potentially play a role in explaining a missing source in the global COS budget.« less

Global gridded anthropogenic emissions inventory of carbonyl sulfide

DOE PAGES

Zumkehr, Andrew; Hilton, Tim; Whelan, Mary; ...

2018-03-31

Atmospheric carbonyl sulfide (COS or OCS) is the most abundant sulfur containing gas in the troposphere and is an atmospheric tracer for the carbon cycle. Gridded inventories of global anthropogenic COS are used for interpreting global COS measurements. However, previous gridded anthropogenic data are a climatological estimate based on input data that is over three decades old and are not representative of current conditions. Here we develop a new gridded data set of global anthropogenic COS sources that includes more source sectors than previously available and uses the most current emissions factors and industry activity data as input. Additionally, themore » inventory is provided as annually varying estimates from years 1980–2012 and employs a source specific spatial scaling procedure. We estimate a global source in year 2012 of 406 Gg S y -1 (range of 223–586 Gg S y -1), which is highly concentrated in China and is twice as large as the previous gridded inventory. Our large upward revision in the bottom-up estimate of the source is consistent with a recent top-down estimate based on air-monitoring and Antarctic firn data. Furthermore, our inventory time trends, including a decline in the 1990's and growth after the year 2000, are qualitatively consistent with trends in atmospheric data. Lastly, similarities between the spatial distribution in this inventory and remote sensing data suggest that the anthropogenic source could potentially play a role in explaining a missing source in the global COS budget.« less

The California Environmental Technology Partnership and AB 2060 hazardous waste technology certification

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schofield, J.T.

The field of environmental technology is poised for explosive growth throughout this decade and beyond. Currently, the worldwide market for environmental goods and services is estimated to be over $200 billion according to the Environmental business Journal (EBJ). The EBJ estimates that US environmental firms have approximately $120 billion in revenues. Additionally, California`s environmental industry accounts for 17% of the US revenues and 7.5% of worldwide revenues. This amounts to a $20 and 25 billion industry in California. According to a July/August report by the Environmental Export Report, the worldwide environmental industry is estimated to be between $200 and $300more » billion and growing at least at 6% annually to between $300 and $400 billion by the year 2,000. The EBJ also estimates that US exporters have the potential to capture $1 billion a year in Western Europe and about half of that in Japan. California`s high environmental standards present unparalleled opportunities for economic growth and job creation. As environmental awareness and standards are raised throughout the world, California is widely recognized to have tremendous economic advantages in capturing these lucrative markets. This industry provides over 180,000 jobs in California. Current estimates suggest that by the year 2000 as much as 3% of the nation`s gross national product will be devoted to protecting the environment, and that the industry will exceed $170 billion by 1996.« less

Global gridded anthropogenic emissions inventory of carbonyl sulfide

NASA Astrophysics Data System (ADS)

Zumkehr, Andrew; Hilton, Tim W.; Whelan, Mary; Smith, Steve; Kuai, Le; Worden, John; Campbell, J. Elliott

2018-06-01

Atmospheric carbonyl sulfide (COS or OCS) is the most abundant sulfur containing gas in the troposphere and is an atmospheric tracer for the carbon cycle. Gridded inventories of global anthropogenic COS are used for interpreting global COS measurements. However, previous gridded anthropogenic data are a climatological estimate based on input data that is over three decades old and are not representative of current conditions. Here we develop a new gridded data set of global anthropogenic COS sources that includes more source sectors than previously available and uses the most current emissions factors and industry activity data as input. Additionally, the inventory is provided as annually varying estimates from years 1980-2012 and employs a source specific spatial scaling procedure. We estimate a global source in year 2012 of 406 Gg S y-1 (range of 223-586 Gg S y-1), which is highly concentrated in China and is twice as large as the previous gridded inventory. Our large upward revision in the bottom-up estimate of the source is consistent with a recent top-down estimate based on air-monitoring and Antarctic firn data. Furthermore, our inventory time trends, including a decline in the 1990's and growth after the year 2000, are qualitatively consistent with trends in atmospheric data. Finally, similarities between the spatial distribution in this inventory and remote sensing data suggest that the anthropogenic source could potentially play a role in explaining a missing source in the global COS budget.

It's positive to be negative: Achilles tendon work loops during human locomotion.

PubMed

Zelik, Karl E; Franz, Jason R

2017-01-01

Ultrasound imaging is increasingly used with motion and force data to quantify tendon dynamics during human movement. Frequently, tendon dynamics are estimated indirectly from muscle fascicle kinematics (by subtracting muscle from muscle-tendon unit length), but there is mounting evidence that this Indirect approach yields implausible tendon work loops. Since tendons are passive viscoelastic structures, when they undergo a loading-unloading cycle they must exhibit a negative work loop (i.e., perform net negative work). However, prior studies using this Indirect approach report large positive work loops, often estimating that tendons return 2-5 J of elastic energy for every 1 J of energy stored. More direct ultrasound estimates of tendon kinematics have emerged that quantify tendon elongations by tracking either the muscle-tendon junction or localized tendon tissue. However, it is unclear if these yield more plausible estimates of tendon dynamics. Our objective was to compute tendon work loops and hysteresis losses using these two Direct tendon kinematics estimates during human walking. We found that Direct estimates generally resulted in negative work loops, with average tendon hysteresis losses of 2-11% at 1.25 m/s and 33-49% at 0.75 m/s (N = 8), alluding to 0.51-0.98 J of tendon energy returned for every 1 J stored. We interpret this finding to suggest that Direct approaches provide more plausible estimates than the Indirect approach, and may be preferable for understanding tendon energy storage and return. However, the Direct approaches did exhibit speed-dependent trends that are not consistent with isolated, in vitro tendon hysteresis losses of about 5-10%. These trends suggest that Direct estimates also contain some level of error, albeit much smaller than Indirect estimates. Overall, this study serves to highlight the complexity and difficulty of estimating tendon dynamics non-invasively, and the care that must be taken to interpret biological function from current ultrasound-based estimates.

Estimating the NIH efficient frontier.

PubMed

Bisias, Dimitrios; Lo, Andrew W; Watkins, James F

2012-01-01

The National Institutes of Health (NIH) is among the world's largest investors in biomedical research, with a mandate to: "…lengthen life, and reduce the burdens of illness and disability." Its funding decisions have been criticized as insufficiently focused on disease burden. We hypothesize that modern portfolio theory can create a closer link between basic research and outcome, and offer insight into basic-science related improvements in public health. We propose portfolio theory as a systematic framework for making biomedical funding allocation decisions-one that is directly tied to the risk/reward trade-off of burden-of-disease outcomes. Using data from 1965 to 2007, we provide estimates of the NIH "efficient frontier", the set of funding allocations across 7 groups of disease-oriented NIH institutes that yield the greatest expected return on investment for a given level of risk, where return on investment is measured by subsequent impact on U.S. years of life lost (YLL). The results suggest that NIH may be actively managing its research risk, given that the volatility of its current allocation is 17% less than that of an equal-allocation portfolio with similar expected returns. The estimated efficient frontier suggests that further improvements in expected return (89% to 119% vs. current) or reduction in risk (22% to 35% vs. current) are available holding risk or expected return, respectively, constant, and that 28% to 89% greater decrease in average years-of-life-lost per unit risk may be achievable. However, these results also reflect the imprecision of YLL as a measure of disease burden, the noisy statistical link between basic research and YLL, and other known limitations of portfolio theory itself. Our analysis is intended to serve as a proof-of-concept and starting point for applying quantitative methods to allocating biomedical research funding that are objective, systematic, transparent, repeatable, and expressly designed to reduce the burden of disease. By approaching funding decisions in a more analytical fashion, it may be possible to improve their ultimate outcomes while reducing unintended consequences.

Empirical estimates to reduce modeling uncertainties of soil organic carbon in permafrost regions: a review of recent progress and remaining challenges

USGS Publications Warehouse

Mishra, U.; Jastrow, J.D.; Matamala, R.; Hugelius, G.; Koven, C.D.; Harden, Jennifer W.; Ping, S.L.; Michaelson, G.J.; Fan, Z.; Miller, R.M.; McGuire, A.D.; Tarnocai, C.; Kuhry, P.; Riley, W.J.; Schaefer, K.; Schuur, E.A.G.; Jorgenson, M.T.; Hinzman, L.D.

2013-01-01

The vast amount of organic carbon (OC) stored in soils of the northern circumpolar permafrost region is a potentially vulnerable component of the global carbon cycle. However, estimates of the quantity, decomposability, and combustibility of OC contained in permafrost-region soils remain highly uncertain, thereby limiting our ability to predict the release of greenhouse gases due to permafrost thawing. Substantial differences exist between empirical and modeling estimates of the quantity and distribution of permafrost-region soil OC, which contribute to large uncertainties in predictions of carbon–climate feedbacks under future warming. Here, we identify research challenges that constrain current assessments of the distribution and potential decomposability of soil OC stocks in the northern permafrost region and suggest priorities for future empirical and modeling studies to address these challenges.

Estimating Capacity Requirements for Mental Health Services After a Disaster Has Occurred: A Call for New Data

PubMed Central

Siegel, Carole E.; Laska, Eugene; Meisner, Morris

2004-01-01

Objectives. We sought to estimate the extended mental health service capacity requirements of persons affected by the September 11, 2001, terrorist attacks. Methods. We developed a formula to estimate the extended mental health service capacity requirements following disaster situations and assessed availability of the information required by the formula. Results. Sparse data exist on current services and supports used by people with mental health problems outside of the formal mental health specialty sector. There also are few systematically collected data on mental health sequelae of disasters. Conclusions. We recommend research-based surveys to understand service usage in non–mental health settings and suggest that federal guidelines be established to promote uniform data collection of a core set of items in studies carried out after disasters. PMID:15054009

Phase Helps Find Geometrically Optimal Gaits

NASA Astrophysics Data System (ADS)

Revzen, Shai; Hatton, Ross

Geometric motion planning describes motions of animals and machines governed by g ˙ = gA (q) q ˙ - a connection A (.) relating shape q and shape velocity q ˙ to body frame velocity g-1 g ˙ ∈ se (3) . Measuring the entire connection over a multidimensional q is often unfeasible with current experimental methods. We show how using a phase estimator can make tractable measuring the local structure of the connection surrounding a periodic motion q (φ) driven by a phase φ ∈S1 . This approach reduces the complexity of the estimation problem by a factor of dimq . The results suggest that phase estimation can be combined with geometric optimization into an iterative gait optimization algorithm usable on experimental systems, or alternatively, to allow the geometric optimality of an observed gait to be detected. ARO W911NF-14-1-0573, NSF 1462555.

The Effectiveness of Influenza Vaccination in Different Groups.

PubMed

Domínguez, Angela; Godoy, Pere; Torner, Nuria

2016-06-01

Annual administration of the seasonal influenza vaccine, especially to persons known to be at elevated risk for developing serious complications, is the focus of current efforts to reduce the impact of influenza. The main factors influencing estimated inactivated influenza vaccine efficacy and effectiveness, the results obtained in different population groups, current vaccination strategies and the possible advantages of new vaccines are discussed. The available evidence suggests that influenza vaccines are less effective in the elderly than in young adults, but vaccination is encouraged by public health institutions due to higher mortality and complications. There is no consensus on universal vaccination of children yet economic studies suggest that yearly paediatric vaccination is cost saving. The benefits of herd immunity generated by paediatric vaccination require further study. Newer vaccines should be more and more-broadly protective, stable, easy to manufacture and administer and highly immunogenic across all population groups.

A nurse staffing analysis at the largest hospital in the Gulf region

NASA Astrophysics Data System (ADS)

Louly, M.; Gharbi, A.; Azaiez, M. N.; Bouras, A.

2014-12-01

The paper considers a staffing problem at a local hospital. The managers consider they are understaffed and try to overwhelm the staffing deficit problem through overtime, rather than hiring additional nurses. However, the huge amount of allocated budget for overtime becomes a concern and needs some assessment, analysis and justification. The current hospital estimates suggests that the shortage at the hospital level corresponds to 300 full time equivalent (FTE) nurses, but the deficit is not basedon deep scientific approach. This paper deals with staffing model that provides the required scientific evidence on the deficit level. It also gives the accurate information on the overtime components. As a results, the suggested staffing model shows that some nursing units are unnecessarily overstaffed. Moreover, the current study reveals that the real deficit is of only 215 FTE resulting in a potential saving of 28%.

Acceptance and commitment therapy - Do we know enough? Cumulative and sequential meta-analyses of randomized controlled trials.

PubMed

Hacker, Thomas; Stone, Paul; MacBeth, Angus

2016-01-15

Acceptance and Commitment Therapy (ACT) has accrued a substantial evidence base. Recent systematic and meta-analytic reviews suggest that ACT is effective compared to control conditions. However, these reviews appraise the efficacy of ACT across a broad range of presenting problems, rather than addressing specific common mental health difficulties. Focussing on depression and anxiety we performed a meta-analysis of trials of ACT. We incorporated sequential meta-analysis (SMA) techniques to critically appraise the sufficiency of the existing evidence base. Findings suggest that ACT demonstrates at least moderate group and pre-post effects for symptom reductions for both anxiety and depression. However using SMA findings are more qualified. There is currently insufficient evidence to confidently conclude that ACT for anxiety is efficacious when compared to active control conditions or as primary treatment for anxiety. Similarly, using SMA, there is currently insufficient evidence to suggest a moderate efficacy of ACT for depression compared to active control conditions. To stimulate further research we offer specific estimates of additional numbers of participants required to reach sufficiency to help inform future studies. We also discuss the appropriate strategies for future research into ACT for anxiety given the current evidence suggests no differential efficacy of ACT in the treatment of anxiety compared to active control conditions. Copyright © 2015 Elsevier B.V. All rights reserved.

Widespread kelp-derived carbon in pelagic and benthic nearshore fishes suggested by stable isotope analysis

NASA Astrophysics Data System (ADS)

von Biela, Vanessa R.; Newsome, Seth D.; Bodkin, James L.; Kruse, Gordon H.; Zimmerman, Christian E.

2016-11-01

Kelp forests provide habitat for diverse and abundant fish assemblages, but the extent to which kelp provides a source of energy to fish and other predators is unclear. To examine the use of kelp-derived energy by fishes we estimated the contribution of kelp- and phytoplankton-derived carbon using carbon (δ13C) and nitrogen (δ15N) isotopes measured in muscle tissue. Benthic-foraging kelp greenling (Hexagrammos decagrammus) and pelagic-foraging black rockfish (Sebastes melanops) were collected at eight sites spanning ∼35 to 60°N from the California Current (upwelling) to Alaska Coastal Current (downwelling) in the northeast Pacific Ocean. Muscle δ13C values were expected to be higher for fish tissue primarily derived from kelp, a benthic macroalgae, and lower for tissue primarily derived from phytoplankton, pelagic microalgae. Muscle δ13C values were higher in benthic-feeding kelp greenling than in pelagic-feeding black rockfish at seven of eight sites, indicating more kelp-derived carbon in greenling as expected. Estimates of kelp carbon contributions ranged from 36 to 89% in kelp greenling and 32 to 65% in black rockfish using carbon isotope mixing models. Isotopic evidence suggests that these two nearshore fishes routinely derive energy from kelp and phytoplankton, across coastal upwelling and downwelling systems. Thus, the foraging mode of nearshore predators has a small influence on their ultimate energy source as energy produced by benthic macroalgae and pelagic microalgae were incorporated in fish tissue regardless of feeding mode and suggest strong and widespread benthic-pelagic coupling. Widespread kelp contributions to benthic- and pelagic-feeding fishes suggests that kelp energy provides a benefit to nearshore fishes and highlights the potential for kelp and fish production to be linked.

Investigating onychophoran gas exchange and water balance as a means to inform current controversies in arthropod physiology.

PubMed

Clusella-Trullas, Susana; Chown, Steven L

2008-10-01

Several controversies currently dominate the fields of arthropod metabolic rate, gas exchange and water balance, including the extent to which modulation of gas exchange reduces water loss, the origins of discontinuous gas exchange, the relationship between metabolic rate and life-history strategies, and the causes of Palaeozoic gigantism. In all of these areas, repeated calls have been made for the investigation of groups that might most inform the debates, especially of taxa in key phylogenetic positions. Here we respond to this call by investigating metabolic rate, respiratory water loss and critical oxygen partial pressure (Pc) in the onychophoran Peripatopsis capensis, a member of a group basal to the arthropods, and by synthesizing the available data on the Onychophora. The rate of carbon dioxide release (VCO2) at 20 degrees C in P. capensis is 0.043 ml CO2 h(-1), in keeping with other onychophoran species; suggesting that low metabolic rates in some arthropod groups are derived. Continuous gas exchange suggests that more complex gas exchange patterns are also derived. Total water loss in P. capensis is 57 mg H2O h(-1) at 20 degrees C, similar to modern estimates for another onychophoran species. High relative respiratory water loss rates ( approximately 34%; estimated using a regression technique) suggest that the basal condition in arthropods may be a high respiratory water loss rate. Relatively high Pc values (5-10% O2) suggest that substantial safety margins in insects are also a derived condition. Curling behaviour in P. capensis appears to be a strategy to lower energetic costs when resting, and the concomitant depression of water loss is a proximate consequence of this behaviour.

Influence function based variance estimation and missing data issues in case-cohort studies.

PubMed

Mark, S D; Katki, H

2001-12-01

Recognizing that the efficiency in relative risk estimation for the Cox proportional hazards model is largely constrained by the total number of cases, Prentice (1986) proposed the case-cohort design in which covariates are measured on all cases and on a random sample of the cohort. Subsequent to Prentice, other methods of estimation and sampling have been proposed for these designs. We formalize an approach to variance estimation suggested by Barlow (1994), and derive a robust variance estimator based on the influence function. We consider the applicability of the variance estimator to all the proposed case-cohort estimators, and derive the influence function when known sampling probabilities in the estimators are replaced by observed sampling fractions. We discuss the modifications required when cases are missing covariate information. The missingness may occur by chance, and be completely at random; or may occur as part of the sampling design, and depend upon other observed covariates. We provide an adaptation of S-plus code that allows estimating influence function variances in the presence of such missing covariates. Using examples from our current case-cohort studies on esophageal and gastric cancer, we illustrate how our results our useful in solving design and analytic issues that arise in practice.

Historical habitat connectivity affects current genetic structure in a grassland species.

PubMed

Münzbergová, Z; Cousins, S A O; Herben, T; Plačková, I; Mildén, M; Ehrlén, J

2013-01-01

Many recent studies have explored the effects of present and past landscape structure on species distribution and diversity. However, we know little about the effects of past landscape structure on distribution of genetic diversity within and between populations of a single species. Here we describe the relationship between present and past landscape structure (landscape connectivity and habitat size estimated from historical maps) and current genetic structure in a perennial herb, Succisa pratensis. We used allozymes as co-dominant markers to estimate genetic diversity and deviation from Hardy-Weinberg equilibrium in 31 populations distributed within a 5 km(2) agricultural landscape. The results showed that current genetic diversity of populations was related to habitat suitability, habitat age, habitat size and habitat connectivity in the past. The effects of habitat age and past connectivity on genetic diversity were in most cases also significant after taking the current landscape structure into account. Moreover, current genetic similarity between populations was affected by past connectivity after accounting for current landscape structure. In both cases, the oldest time layer (1850) was the most informative. Most populations showed heterozygote excess, indicating disequilibrium due to recent gene flow or selection against homozygotes. These results suggest that habitat age and past connectivity are important determinants of distribution of genetic diversity between populations at a scale of a few kilometres. Landscape history may significantly contribute to our understanding of distribution of current genetic structure within species and the genetic structure may be used to better understand landscape history, even at a small scale. © 2012 German Botanical Society and The Royal Botanical Society of the Netherlands.

German EstSmoke: estimating adult smoking-related costs and consequences of smoking cessation for Germany.

PubMed

Sonntag, Diana; Gilbody, Simon; Winkler, Volker; Ali, Shehzad

2018-01-01

We compared predicted life-time health-care costs for current, never and ex-smokers in Germany under the current set of tobacco control polices. We compared these economic consequences of the current situation with an alternative in which Germany were to implement more comprehensive tobacco control policies consistent with the World Health Organization (WHO) Framework Convention for Tobacco Control (FCTC) guidelines. German EstSmoke, an adapted version of the UK EstSmoke simulation model, applies the Markov modelling approach. Transition probabilities for (re-)currence of smoking-related diseases were calculated from large German disease-specific registries and the German Health Update (GEDA 2010). Estimations of both health-care costs and effect sizes of smoking cessation policies were taken from recent German studies and discounted at 3.5%/year. Germany. German population of prevalent current, never and ex-smokers in 2009. Life-time cost and outcomes in current, never and ex-smokers. If tobacco control policies are not strengthened, the German smoking population will incur €41.56 billion life-time excess costs compared with never smokers. Implementing tobacco control policies consistent with WHO FCTC guidelines would reduce the difference of life-time costs between current smokers and ex-smokers by at least €1.7 billion. Modelling suggests that the life-time healthcare costs of people in Germany who smoke are substantially greater than those of people who have never smoked. However, more comprehensive tobacco control policies could reduce health-care expenditures for current smokers by at least 4%. © 2017 Society for the Study of Addiction.

Development of a low-maintenance measurement approach to continuously estimate methane emissions: A case study.

PubMed

Riddick, S N; Hancock, B R; Robinson, A D; Connors, S; Davies, S; Allen, G; Pitt, J; Harris, N R P

2018-03-01

The chemical breakdown of organic matter in landfills represents a significant source of methane gas (CH 4 ). Current estimates suggest that landfills are responsible for between 3% and 19% of global anthropogenic emissions. The net CH 4 emissions resulting from biogeochemical processes and their modulation by microbes in landfills are poorly constrained by imprecise knowledge of environmental constraints. The uncertainty in absolute CH 4 emissions from landfills is therefore considerable. This study investigates a new method to estimate the temporal variability of CH 4 emissions using meteorological and CH 4 concentration measurements downwind of a landfill site in Suffolk, UK from July to September 2014, taking advantage of the statistics that such a measurement approach offers versus shorter-term, but more complex and instantaneously accurate, flux snapshots. Methane emissions were calculated from CH 4 concentrations measured 700m from the perimeter of the landfill with observed concentrations ranging from background to 46.4ppm. Using an atmospheric dispersion model, we estimate a mean emission flux of 709μgm -2 s -1 over this period, with a maximum value of 6.21mgm -2 s -1 , reflecting the wide natural variability in biogeochemical and other environmental controls on net site emission. The emissions calculated suggest that meteorological conditions have an influence on the magnitude of CH 4 emissions. We also investigate the factors responsible for the large variability observed in the estimated CH 4 emissions, and suggest that the largest component arises from uncertainty in the spatial distribution of CH 4 emissions within the landfill area. The results determined using the low-maintenance approach discussed in this paper suggest that a network of cheaper, less precise CH 4 sensors could be used to measure a continuous CH 4 emission time series from a landfill site, something that is not practical using far-field approaches such as tracer release methods. Even though there are limitations to the approach described here, this easy, low-maintenance, low-cost method could be used by landfill operators to estimate time-averaged CH 4 emissions and their impact downwind by simultaneously monitoring plume advection and CH 4 concentrations. Copyright © 2016. Published by Elsevier Ltd.

U.S. Virgin Islands Transportation Petroleum Reduction Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, C.

2011-09-01

This NREL technical report determines a way for USVI to meet its petroleum reduction goal in the transportation sector. It does so first by estimating current petroleum use and key statistics and characteristics of USVI transportation. It then breaks the goal down into subordinate goals and estimates the petroleum impacts of these goals with a wedge analysis. These goals focus on reducing vehicle miles, improving fuel economy, improving traffic flow, using electric vehicles, using biodiesel and renewable diesel, and using 10% ethanol in gasoline. The final section of the report suggests specific projects to achieve the goals, and ranks themore » projects according to cost, petroleum reduction, time frame, and popularity.« less

Electronic nicotine delivery system (ENDS) battery-related burns presenting to US emergency departments, 2016.

PubMed

Corey, Catherine G; Chang, Joanne T; Rostron, Brian L

2018-03-05

Currently, an estimated 7.9 million US adults use electronic nicotine delivery systems (ENDS). Although published reports have identified fires and explosions related to use of ENDS since 2009, these reports do not provide national estimates of burn injuries associated with ENDS batteries in the US. We analyzed nationally representative data provided in the National Electronic Injury Surveillance System (NEISS) to estimate the number of US emergency department (ED) visits for burn injuries associated with ENDS batteries. We reviewed the case narrative field to gain additional insights into the circumstances of the burn injury. In 2016, 26 ENDS battery-related burn cases were captured by NEISS, which translates to a national estimate of 1007 (95%CI: 357-1657) injuries presenting in US EDs. Most of the burns were thermal burns (80.4%) and occurred to the upper leg/lower trunk (77.3%). Examination of the case narrative field indicated that at least 20 of the burn injuries occurred while ENDS batteries were in the user's pocket. Our study provides valuable information for understanding the current burden of ENDS battery-related burn injuries treated in US EDs. The nature and circumstances of the injuries suggest these incidents were unintentional and would potentially be prevented through battery design requirements, battery testing standards and public education related to ENDS battery safety.

The current economic burden of illness of osteoporosis in Canada

PubMed Central

Burke, N.; Von Keyserlingk, C.; Leslie, W. D.; Morin, S. N.; Adachi, J. D.; Papaioannou, A.; Bessette, L.; Brown, J. P.; Pericleous, L.; Tarride, J.

2016-01-01

Summary We estimate the current burden of illness of osteoporosis in Canada is double ($4.6 billion) our previous estimates ($2.3 billion) due to improved data capture of the multiple encounters and services that accompany a fracture: emergency room, admissions to acute and step-down non-acute institutions, rehabilitation, home-assisted or long-term residency support. Introduction We previously estimated the economic burden of illness of osteoporosis-attributable fractures in Canada for the year 2008 to be $2.3 billion in the base case and as much as $3.9 billion. The aim of this study is to update the estimate of the economic burden of illness for osteoporosis-attributable fractures for Canada based on newly available home care and long-term care (LTC) data. Methods Multiple national databases were used for the fiscal-year ending March 31, 2011 (FY 2010/2011) for acute institutional care, emergency visits, day surgery, secondary admissions for rehabilitation, and complex continuing care, as well as national dispensing data for osteoporosis medications. Gaps in national data were supplemented by provincial and community survey data. Osteoporosis-attributable fractures for Canadians age 50+ were identified by ICD-10-CA codes. Costs were expressed in 2014 dollars. Results In FY 2010/2011, the number of osteoporosis-attributable fractures was 131,443 resulting in 64,884 acute care admissions and 983,074 acute hospital days. Acute care costs were $1.5 billion, an 18 % increase since 2008. The cost of LTC was 33.4 times the previous estimate ($31 million versus $1.03 billion) because of improved data capture. The cost for rehabilitation and secondary admissions increased 3.4 fold, while drug costs decreased 19 %. The overall cost of osteoporosis was over $4.6 billion, an increase of 83 % from the 2008 estimate. Conclusion Since the 2008 estimate, new Canadian data on home care and LTC are available which provided a better estimate of the burden of osteoporosis in Canada. This suggests that our previous estimates were seriously underestimated. PMID:27166680

The current economic burden of illness of osteoporosis in Canada.

PubMed

Hopkins, R B; Burke, N; Von Keyserlingk, C; Leslie, W D; Morin, S N; Adachi, J D; Papaioannou, A; Bessette, L; Brown, J P; Pericleous, L; Tarride, J

2016-10-01

We estimate the current burden of illness of osteoporosis in Canada is double ($4.6 billion) our previous estimates ($2.3 billion) due to improved data capture of the multiple encounters and services that accompany a fracture: emergency room, admissions to acute and step-down non-acute institutions, rehabilitation, home-assisted or long-term residency support. We previously estimated the economic burden of illness of osteoporosis-attributable fractures in Canada for the year 2008 to be $2.3 billion in the base case and as much as $3.9 billion. The aim of this study is to update the estimate of the economic burden of illness for osteoporosis-attributable fractures for Canada based on newly available home care and long-term care (LTC) data. Multiple national databases were used for the fiscal-year ending March 31, 2011 (FY 2010/2011) for acute institutional care, emergency visits, day surgery, secondary admissions for rehabilitation, and complex continuing care, as well as national dispensing data for osteoporosis medications. Gaps in national data were supplemented by provincial and community survey data. Osteoporosis-attributable fractures for Canadians age 50+ were identified by ICD-10-CA codes. Costs were expressed in 2014 dollars. In FY 2010/2011, the number of osteoporosis-attributable fractures was 131,443 resulting in 64,884 acute care admissions and 983,074 acute hospital days. Acute care costs were $1.5 billion, an 18 % increase since 2008. The cost of LTC was 33.4 times the previous estimate ($31 million versus $1.03 billion) because of improved data capture. The cost for rehabilitation and secondary admissions increased 3.4 fold, while drug costs decreased 19 %. The overall cost of osteoporosis was over $4.6 billion, an increase of 83 % from the 2008 estimate. Since the 2008 estimate, new Canadian data on home care and LTC are available which provided a better estimate of the burden of osteoporosis in Canada. This suggests that our previous estimates were seriously underestimated.

Near Real-time GNSS-based Ionospheric Model using Expanded Kriging in the East Asia Region

NASA Astrophysics Data System (ADS)

Choi, P. H.; Bang, E.; Lee, J.

2016-12-01

Many applications which utilize radio waves (e.g. navigation, communications, and radio sciences) are influenced by the ionosphere. The technology to provide global ionospheric maps (GIM) which show ionospheric Total Electron Content (TEC) has been progressed by processing GNSS data. However, the GIMs have limited spatial resolution (e.g. 2.5° in latitude and 5° in longitude), because they are generated using globally-distributed and thus relatively sparse GNSS reference station networks. This study presents a near real-time and high spatial resolution TEC model over East Asia by using ionospheric observables from both International GNSS Service (IGS) and local GNSS networks and the expanded kriging method. New signals from multi-constellation (e.g,, GPS L5, Galileo E5) were also used to generate high-precision TEC estimates. The newly proposed estimation method is based on the universal kriging interpolation technique, but integrates TEC data from previous epochs to those from the current epoch to improve the TEC estimation performance by increasing ionospheric observability. To propagate previous measurements to the current epoch, we implemented a Kalman filter whose dynamic model was derived by using the first-order Gauss-Markov process which characterizes temporal ionospheric changes under the nominal ionospheric conditions. Along with the TEC estimates at grids, the method generates the confidence bounds on the estimates using resulting estimation covariance. We also suggest to classify the confidence bounds into several categories to allow users to recognize the quality levels of TEC estimates according to the requirements for user's applications. This paper examines the performance of the proposed method by obtaining estimation results for both nominal and disturbed ionospheric conditions, and compares these results to those provided by GIM of the NASA Jet propulsion Laboratory. In addition, the estimation results based on the expanded kriging method are compared to the results from the universal kriging method for both nominal and disturbed ionospheric conditions.

Adult current smoking: differences in definitions and prevalence estimates--NHIS and NSDUH, 2008.

PubMed

Ryan, Heather; Trosclair, Angela; Gfroerer, Joe

2012-01-01

To compare prevalence estimates and assess issues related to the measurement of adult cigarette smoking in the National Health Interview Survey (NHIS) and the National Survey on Drug Use and Health (NSDUH). 2008 data on current cigarette smoking and current daily cigarette smoking among adults ≥18 years were compared. The standard NHIS current smoking definition, which screens for lifetime smoking ≥100 cigarettes, was used. For NSDUH, both the standard current smoking definition, which does not screen, and a modified definition applying the NHIS current smoking definition (i.e., with screen) were used. NSDUH consistently yielded higher current cigarette smoking estimates than NHIS and lower daily smoking estimates. However, with use of the modified NSDUH current smoking definition, a notable number of subpopulation estimates became comparable between surveys. Younger adults and racial/ethnic minorities were most impacted by the lifetime smoking screen, with Hispanics being the most sensitive to differences in smoking variable definitions among all subgroups. Differences in current cigarette smoking definitions appear to have a greater impact on smoking estimates in some sub-populations than others. Survey mode differences may also limit intersurvey comparisons and trend analyses. Investigators are cautioned to use data most appropriate for their specific research questions.

Use of acoustic backscatter and vertical velocity to estimate concentration and dynamics of suspended solids in Upper Klamath Lake, south-central Oregon: Implications for Aphanizomenon flos-aquae

USGS Publications Warehouse

Wood, Tamara M.; Gartner, Jeffrey W.

2010-01-01

Vertical velocity and acoustic backscatter measurements by acoustic Doppler current profilers were used to determine seasonal, subseasonal (days to weeks), and diel variation in suspended solids in a freshwater lake where massive cyanobacterial blooms occur annually. During the growing season, the suspended material in the lake is dominated by the buoyancy-regulating cyanobacteria, Aphanizomenon flos-aquae. Measured variables (water velocity, relative backscatter [RB], wind speed, and air and water temperatures) were averaged over the deployment season at each sample time of day to determine average diel cycles. Phase shifts between diel cycles in RB and diel cycles in wind speed, vertical water temperature differences (delta T(degree)), and horizontal current speeds were found by determining the lead or lag that maximized the linear correlation between the respective diel cycles. Diel cycles in RB were more in phase with delta T(degree) cycles, and, to a lesser extent, wind cycles, than to water current cycles but were out of phase with the cycle that would be expected if the vertical movement of buoyant cyanobacteria colonies was controlled primarily by light. Clear evidence of a diel cycle in vertical velocity was found only at the two deepest sites in the lake. Cycles of vertical velocity, where present, were out of phase with expected vertical motion of cyanobacterial colonies based on the theoretical cycle for light-driven vertical movement. This suggests that water column stability and turbulence were more important factors in controlling vertical distribution of colonies than light. Variations at subseasonal time scales were determined by filtering data to pass periods between 1.2 and 15 days. At subseasonal time scales, correlations between RB and currents or air temperature were consistent with increased concentration of cyanobacterial colonies near the surface when water column stability increased (higher air temperatures or weaker currents) and dispersal of colonies throughout the water column when the water column mixed more easily. RB was used to estimate suspended solids concentrations (SSC). Correlations of depth-integrated SSC with currents or air temperatures suggest that depth-integrated water column mass decreased under conditions of greater water column stability and weaker currents. Results suggest that the use of measured vertical velocity and acoustic backscatter as a surrogate for suspended material has the potential to contribute significant additional insight into dynamics of Aphanizomenon flos-aquae colonies in Upper Klamath Lake, south-central Oregon.

To predict the niche, model colonization and extinction

USGS Publications Warehouse

Yackulic, Charles B.; Nichols, James D.; Reid, Janice; Der, Ricky

2015-01-01

Ecologists frequently try to predict the future geographic distributions of species. Most studies assume that the current distribution of a species reflects its environmental requirements (i.e., the species' niche). However, the current distributions of many species are unlikely to be at equilibrium with the current distribution of environmental conditions, both because of ongoing invasions and because the distribution of suitable environmental conditions is always changing. This mismatch between the equilibrium assumptions inherent in many analyses and the disequilibrium conditions in the real world leads to inaccurate predictions of species' geographic distributions and suggests the need for theory and analytical tools that avoid equilibrium assumptions. Here, we develop a general theory of environmental associations during periods of transient dynamics. We show that time-invariant relationships between environmental conditions and rates of local colonization and extinction can produce substantial temporal variation in occupancy–environment relationships. We then estimate occupancy–environment relationships during three avian invasions. Changes in occupancy–environment relationships over time differ among species but are predicted by dynamic occupancy models. Since estimates of the occupancy–environment relationships themselves are frequently poor predictors of future occupancy patterns, research should increasingly focus on characterizing how rates of local colonization and extinction vary with environmental conditions.

Gap state analysis in electric-field-induced band gap for bilayer graphene.

PubMed

Kanayama, Kaoru; Nagashio, Kosuke

2015-10-29

The origin of the low current on/off ratio at room temperature in dual-gated bilayer graphene field-effect transistors is considered to be the variable range hopping in gap states. However, the quantitative estimation of gap states has not been conducted. Here, we report the systematic estimation of the energy gap by both quantum capacitance and transport measurements and the density of states for gap states by the conductance method. An energy gap of ~ 250 meV is obtained at the maximum displacement field of ~ 3.1 V/nm, where the current on/off ratio of ~ 3 × 10(3) is demonstrated at 20 K. The density of states for the gap states are in the range from the latter half of 10(12) to 10(13) eV(-1) cm(-2). Although the large amount of gap states at the interface of high-k oxide/bilayer graphene limits the current on/off ratio at present, our results suggest that the reduction of gap states below ~ 10(11) eV(-1) cm(-2) by continual improvement of the gate stack makes bilayer graphene a promising candidate for future nanoelectronic device applications.

The Bush Doctrine: Power Concepts, Preemption and the Global War on Terror

DTIC Science & Technology

2004-03-19

17013 Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour...including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports , 1215 Jefferson...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE

The Effect of Recent Tax Changes on Taxable Income: Evidence from a New Panel of Tax Returns

ERIC Educational Resources Information Center

Heim, Bradley T.

2009-01-01

This paper estimates the elasticity of taxable income to the net-of-tax share using a panel of tax returns that follows a random sample of taxpayers from 1999 to 2005, spanning the EGTRRA 2001 and JGTRRA 2003 tax changes. Results suggest that the elasticity of taxable income to the current year's net-of-tax share lies between 0.3 and 0.4 overall,…

Supply Chain Management/Strategic Acquisition: The Case for Professional Pay in the Army Acquisition Corps

DTIC Science & Technology

2012-04-01

Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour...including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports , 1215 Jefferson...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number. 1. REPORT DATE

A Software Toolbox for Systematic Evaluation of Seismometer-Digitizer System Responses

DTIC Science & Technology

2010-09-01

characteristics (e.g., borehole vs. surface installation) than the actual seismic noise characteristics. These results suggest that our best results of NOISETRAN...Award No. DE-FG02-09ER85548/Phase_I ABSTRACT Measurement of the absolute amplitudes of a seismic signal requires accurate knowledge of...power spectral density (PSD) estimator for background noise spectra at a seismic station. SACPSD differs from the current PSD used by NEIC and IRIS

Estimates of expansion time scales

NASA Astrophysics Data System (ADS)

Jones, E. M.

Monte Carlo simulations of the expansion of a spacefaring civilization show that descendants of that civilization should be found near virtually every useful star in the Galaxy in a time much less than the current age of the Galaxy. Only extreme assumptions about local population growth rates, emigration rates, or ship ranges can slow or halt an expansion. The apparent absence of extraterrestrials from the solar system suggests that no such civilization has arisen in the Galaxy.

Novel serologic biomarkers provide accurate estimates of recent Plasmodium falciparum exposure for individuals and communities

PubMed Central

Helb, Danica A.; Tetteh, Kevin K. A.; Felgner, Philip L.; Skinner, Jeff; Hubbard, Alan; Arinaitwe, Emmanuel; Mayanja-Kizza, Harriet; Ssewanyana, Isaac; Kamya, Moses R.; Beeson, James G.; Tappero, Jordan; Smith, David L.; Crompton, Peter D.; Rosenthal, Philip J.; Dorsey, Grant; Drakeley, Christopher J.; Greenhouse, Bryan

2015-01-01

Tools to reliably measure Plasmodium falciparum (Pf) exposure in individuals and communities are needed to guide and evaluate malaria control interventions. Serologic assays can potentially produce precise exposure estimates at low cost; however, current approaches based on responses to a few characterized antigens are not designed to estimate exposure in individuals. Pf-specific antibody responses differ by antigen, suggesting that selection of antigens with defined kinetic profiles will improve estimates of Pf exposure. To identify novel serologic biomarkers of malaria exposure, we evaluated responses to 856 Pf antigens by protein microarray in 186 Ugandan children, for whom detailed Pf exposure data were available. Using data-adaptive statistical methods, we identified combinations of antibody responses that maximized information on an individual’s recent exposure. Responses to three novel Pf antigens accurately classified whether an individual had been infected within the last 30, 90, or 365 d (cross-validated area under the curve = 0.86–0.93), whereas responses to six antigens accurately estimated an individual’s malaria incidence in the prior year. Cross-validated incidence predictions for individuals in different communities provided accurate stratification of exposure between populations and suggest that precise estimates of community exposure can be obtained from sampling a small subset of that community. In addition, serologic incidence predictions from cross-sectional samples characterized heterogeneity within a community similarly to 1 y of continuous passive surveillance. Development of simple ELISA-based assays derived from the successful selection strategy outlined here offers the potential to generate rich epidemiologic surveillance data that will be widely accessible to malaria control programs. PMID:26216993

Novel serologic biomarkers provide accurate estimates of recent Plasmodium falciparum exposure for individuals and communities.

PubMed

Helb, Danica A; Tetteh, Kevin K A; Felgner, Philip L; Skinner, Jeff; Hubbard, Alan; Arinaitwe, Emmanuel; Mayanja-Kizza, Harriet; Ssewanyana, Isaac; Kamya, Moses R; Beeson, James G; Tappero, Jordan; Smith, David L; Crompton, Peter D; Rosenthal, Philip J; Dorsey, Grant; Drakeley, Christopher J; Greenhouse, Bryan

2015-08-11

Tools to reliably measure Plasmodium falciparum (Pf) exposure in individuals and communities are needed to guide and evaluate malaria control interventions. Serologic assays can potentially produce precise exposure estimates at low cost; however, current approaches based on responses to a few characterized antigens are not designed to estimate exposure in individuals. Pf-specific antibody responses differ by antigen, suggesting that selection of antigens with defined kinetic profiles will improve estimates of Pf exposure. To identify novel serologic biomarkers of malaria exposure, we evaluated responses to 856 Pf antigens by protein microarray in 186 Ugandan children, for whom detailed Pf exposure data were available. Using data-adaptive statistical methods, we identified combinations of antibody responses that maximized information on an individual's recent exposure. Responses to three novel Pf antigens accurately classified whether an individual had been infected within the last 30, 90, or 365 d (cross-validated area under the curve = 0.86-0.93), whereas responses to six antigens accurately estimated an individual's malaria incidence in the prior year. Cross-validated incidence predictions for individuals in different communities provided accurate stratification of exposure between populations and suggest that precise estimates of community exposure can be obtained from sampling a small subset of that community. In addition, serologic incidence predictions from cross-sectional samples characterized heterogeneity within a community similarly to 1 y of continuous passive surveillance. Development of simple ELISA-based assays derived from the successful selection strategy outlined here offers the potential to generate rich epidemiologic surveillance data that will be widely accessible to malaria control programs.

How Far Could the Alien Boatman Trichocorixa verticalis verticalis Spread? Worldwide Estimation of Its Current and Future Potential Distribution

PubMed Central

Guareschi, Simone; Coccia, Cristina; Sánchez-Fernández, David; Carbonell, José Antonio; Velasco, Josefa; Boyero, Luz; Green, Andy J.; Millán, Andrés

2013-01-01

Invasions of alien species are considered among the least reversible human impacts, with diversified effects on aquatic ecosystems. Since prevention is the most cost-effective way to avoid biodiversity loss and ecosystem problems, one challenge in ecological research is to understand the limits of the fundamental niche of the species in order to estimate how far invasive species could spread. Trichocorixa verticalis verticalis (Tvv) is a corixid (Hemiptera) originally distributed in North America, but cited as an alien species in three continents. Its impact on native communities is under study, but it is already the dominant species in several saline wetlands and represents a rare example of an aquatic alien insect. This study aims: i) to estimate areas with suitable environmental conditions for Tvv at a global scale, thus identifying potential new zones of invasion; and ii) to test possible changes in this global potential distribution under a climate change scenario. Potential distributions were estimated by applying a multidimensional envelope procedure based on both climatic data, obtained from observed occurrences, and thermal physiological data. Our results suggest Tvv may expand well beyond its current range and find inhabitable conditions in temperate areas along a wide range of latitudes, with an emphasis on coastal areas of Europe, Northern Africa, Argentina, Uruguay, Australia, New Zealand, Myanmar, India, the western boundary between USA and Canada, and areas of the Arabian Peninsula. When considering a future climatic scenario, the suitability area of Tvv showed only limited changes compared with the current potential distribution. These results allow detection of potential contact zones among currently colonized areas and potential areas of invasion. We also identified zones with a high level of suitability that overlap with areas recognized as global hotspots of biodiversity. Finally, we present hypotheses about possible means of spread, focusing on different geographical scales. PMID:23555771

Current and Projected Heat-Related Morbidity and Mortality in Rhode Island.

PubMed

Kingsley, Samantha L; Eliot, Melissa N; Gold, Julia; Vanderslice, Robert R; Wellenius, Gregory A

2016-04-01

Climate change is expected to cause increases in heat-related mortality, especially among the elderly and very young. However, additional studies are needed to clarify the effects of heat on morbidity across all age groups and across a wider range of temperatures. We aimed to estimate the impact of current and projected future temperatures on morbidity and mortality in Rhode Island. We used Poisson regression models to estimate the association between daily maximum temperature and rates of all-cause and heat-related emergency department (ED) admissions and all-cause mortality. We then used downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5; a standardized set of climate change model simulations) projections to estimate the excess morbidity and mortality that would be observed if this population were exposed to the temperatures projected for 2046-2053 and 2092-2099 under two representative concentration pathways (RCP): RCP 8.5 and 4.5. Between 2005 and 2012, an increase in maximum daily temperature from 75 to 85°F was associated with 1.3% and 23.9% higher rates of all-cause and heat-related ED visits, respectively. The corresponding effect estimate for all-cause mortality from 1999 through 2011 was 4.0%. The association with all-cause ED admissions was strongest for those < 18 or ≥ 65 years of age, whereas the association with heat-related ED admissions was most pronounced among 18- to 64-year-olds. If this Rhode Island population were exposed to temperatures projected under RCP 8.5 for 2092-2099, we estimate that there would be 1.2% (range, 0.6-1.6%) and 24.4% (range, 6.9-41.8%) more all-cause and heat-related ED admissions, respectively, and 1.6% (range, 0.8-2.1%) more deaths annually between April and October. With all other factors held constant, our findings suggest that the current population of Rhode Island would experience substantially higher morbidity and mortality if maximum daily temperatures increase further as projected. Kingsley SL, Eliot MN, Gold J, Vanderslice RR, Wellenius GA. 2016. Current and projected heat-related morbidity and mortality in Rhode Island. Environ Health Perspect 124:460-467; http://dx.doi.org/10.1289/ehp.1408826.

Current exposure of 200 pregnant Danish women to phthalates, parabens and phenols.

PubMed

Tefre de Renzy-Martin, Katrine; Frederiksen, Hanne; Christensen, Jeppe Schultz; Boye Kyhl, Henriette; Andersson, Anna-Maria; Husby, Steffen; Barington, Torben; Main, Katharina M; Jensen, Tina Kold

2014-01-01

Many phthalates, parabens and phenols are suspected to have endocrine-disrupting properties in humans. They are found in consumer products, including food wrapping, cosmetics and building materials. The foetus is particularly vulnerable and exposure to these chemicals therefore is of concern for pregnant women. We investigated current exposure to several commonly used phthalates, parabens and phenols in healthy, pregnant Danish women. A total of 200 spot urine samples were collected between 8 and 30 weeks of gestation and analysed for metabolites of ten phenols, seven parabens and 16 phthalate by liquid chromatography-tandem mass spectrometry representing 26 non-persistent compounds. The majority of analytes were present in the urine sample collected from most women who participated. Thus, in 174 of the 200 women, metabolites of more than 13 (>50%) of 26 compounds were detected simultaneously. The number of compounds detected per woman (either as the parent compound or its metabolite(s)) ranged from 7 to 21 with a median of 16. The majority of compounds correlated positively with each other within and between chemical groups, suggesting combined exposure sources. Estimated daily intakes (DIs) of phthalates and bisphenol A (BPA) were below their individual tolerable DI (TDI) and with hazard quotients below 1. In conclusion, we found detectable levels of phthalate metabolites, parabens and phenols in almost all pregnant women, suggesting combined multiple exposures. Although the estimated DI of phthalates and BPA for an individual was below TDI, our results still raise concern, as current toxicological risk assessments in humans do not take into account simultaneous exposure. The true cumulative risk for the foetus may therefore be underestimated.

High mortality of blue, humpback and fin whales from modeling of vessel collisions on the U.S. West Coast suggests population impacts and insufficient protection

PubMed Central

Calambokidis, John; Jahncke, Jaime

2017-01-01

Mortality from collisions with vessels is one of the main human causes of death for large whales. Ship strikes are rarely witnessed and the distribution of strike risk and estimates of mortality remain uncertain at best. We estimated ship strike mortality for blue humpback and fin whales in U.S. West Coast waters using a novel application of a naval encounter model. Mortality estimates from the model were far higher than current minimum estimates derived from stranding records and are closer to extrapolations adjusted for detection probabilities of dead whales. Our most conservative model estimated mortality to be 7.8x, 2.0x and 2.7x the U.S. recommended limit for blue, humpback and fin whales, respectively, suggesting that death from vessel collisions may be a significant impediment to population growth and recovery. Comparing across the study area, the majority of strike mortality occurs in waters off California, from Bodega Bay south and tends to be concentrated in a band approximately 24 Nm (44.5 km) offshore and in designated shipping lanes leading to and from major ports. While some mortality risk exists across nearly all West Coast waters, 74%, 82% and 65% of blue, humpback and fin whale mortality, respectively, occurs in just 10% of the study area, suggesting conservation efforts can be very effective if focused in these waters. Risk is highest in the shipping lanes off San Francisco and Long Beach, but only a fraction of total estimated mortality occurs in these proportionally small areas, making any conservation efforts exclusively within these areas insufficient to address overall strike mortality. We recommend combining shipping lane modifications and re-locations, ship speed reductions and creation of ‘Areas to be Avoided’ by vessels in ecologically important locations to address this significant source of whale mortality. PMID:28827838

High mortality of blue, humpback and fin whales from modeling of vessel collisions on the U.S. West Coast suggests population impacts and insufficient protection.

PubMed

Rockwood, R Cotton; Calambokidis, John; Jahncke, Jaime

2017-01-01

Mortality from collisions with vessels is one of the main human causes of death for large whales. Ship strikes are rarely witnessed and the distribution of strike risk and estimates of mortality remain uncertain at best. We estimated ship strike mortality for blue humpback and fin whales in U.S. West Coast waters using a novel application of a naval encounter model. Mortality estimates from the model were far higher than current minimum estimates derived from stranding records and are closer to extrapolations adjusted for detection probabilities of dead whales. Our most conservative model estimated mortality to be 7.8x, 2.0x and 2.7x the U.S. recommended limit for blue, humpback and fin whales, respectively, suggesting that death from vessel collisions may be a significant impediment to population growth and recovery. Comparing across the study area, the majority of strike mortality occurs in waters off California, from Bodega Bay south and tends to be concentrated in a band approximately 24 Nm (44.5 km) offshore and in designated shipping lanes leading to and from major ports. While some mortality risk exists across nearly all West Coast waters, 74%, 82% and 65% of blue, humpback and fin whale mortality, respectively, occurs in just 10% of the study area, suggesting conservation efforts can be very effective if focused in these waters. Risk is highest in the shipping lanes off San Francisco and Long Beach, but only a fraction of total estimated mortality occurs in these proportionally small areas, making any conservation efforts exclusively within these areas insufficient to address overall strike mortality. We recommend combining shipping lane modifications and re-locations, ship speed reductions and creation of 'Areas to be Avoided' by vessels in ecologically important locations to address this significant source of whale mortality.

ON ESTIMATING FORCE-FREENESS BASED ON OBSERVED MAGNETOGRAMS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, X. M.; Zhang, M.; Su, J. T., E-mail: xmzhang@nao.cas.cn

It is a common practice in the solar physics community to test whether or not measured photospheric or chromospheric vector magnetograms are force-free, using the Maxwell stress as a measure. Some previous studies have suggested that magnetic fields of active regions in the solar chromosphere are close to being force-free whereas there is no consistency among previous studies on whether magnetic fields of active regions in the solar photosphere are force-free or not. Here we use three kinds of representative magnetic fields (analytical force-free solutions, modeled solar-like force-free fields, and observed non-force-free fields) to discuss how measurement issues such asmore » limited field of view (FOV), instrument sensitivity, and measurement error could affect the estimation of force-freeness based on observed magnetograms. Unlike previous studies that focus on discussing the effect of limited FOV or instrument sensitivity, our calculation shows that just measurement error alone can significantly influence the results of estimates of force-freeness, due to the fact that measurement errors in horizontal magnetic fields are usually ten times larger than those in vertical fields. This property of measurement errors, interacting with the particular form of a formula for estimating force-freeness, would result in wrong judgments of the force-freeness: a truly force-free field may be mistakenly estimated as being non-force-free and a truly non-force-free field may be estimated as being force-free. Our analysis calls for caution when interpreting estimates of force-freeness based on measured magnetograms, and also suggests that the true photospheric magnetic field may be further away from being force-free than it currently appears to be.« less

A reassessment of the emergence time of European bat lyssavirus type 1.

PubMed

Hughes, Gareth J

2008-12-01

The previous study of the evolutionary rates of European bat lyssavirus type 1 (EBLV-1) used a strict molecular clock to estimate substitution rates of the nucleoprotein gene and in turn times of the most recent common ancestor (tMRCA) of the entire genotype and the two major EBLV-1 lineages (EBLV-1A and EBLV-1B). The results of that study suggested that the evolutionary rate of EBLV-1 was one of the lowest recorded for RNA viruses and that genetic diversity of EBLV-1 arose 500-750 years ago. Here I have shown that the use of a relaxed molecular clock (allowing branch rates to vary within a phylogeny) shows that these previous estimates should be revised. The relaxed clock provides a significantly better fit to all datasets. The substitution rate of EBLV-1B is compatible to that expected given previous estimates for the N gene of rabies virus whilst rate estimations for EBLV-1A appear to be confounded by substantial rate variation within the phylogeny. The relaxed clock substitution rate for EBLV-1 (1.1 x 10(-4)) is higher than had been estimated previously, and closer to that expected for the N gene. Moreover, tMRCA estimates for EBLV-1 are substantially reduced using the relaxed molecular clock (70-300 years) although the differing dynamics of EBLV-1A and EBLV-1B confound the confidence in this estimate. Current diversity of both EBLV-1A and EBLV-1B appears to have emerged within the last 100 years. Reconstruction of the population histories suggests that EBLV-1B may be emerging whilst the signal derived from the EBLV-1A phylogeny may be dampened by clade-specific dynamics.

Uncertainty squared: Choosing among multiple input probability distributions and interpreting multiple output probability distributions in Monte Carlo climate risk models

NASA Astrophysics Data System (ADS)

Baer, P.; Mastrandrea, M.

2006-12-01

Simple probabilistic models which attempt to estimate likely transient temperature change from specified CO2 emissions scenarios must make assumptions about at least six uncertain aspects of the causal chain between emissions and temperature: current radiative forcing (including but not limited to aerosols), current land use emissions, carbon sinks, future non-CO2 forcing, ocean heat uptake, and climate sensitivity. Of these, multiple PDFs (probability density functions) have been published for the climate sensitivity, a couple for current forcing and ocean heat uptake, one for future non-CO2 forcing, and none for current land use emissions or carbon cycle uncertainty (which are interdependent). Different assumptions about these parameters, as well as different model structures, will lead to different estimates of likely temperature increase from the same emissions pathway. Thus policymakers will be faced with a range of temperature probability distributions for the same emissions scenarios, each described by a central tendency and spread. Because our conventional understanding of uncertainty and probability requires that a probabilistically defined variable of interest have only a single mean (or median, or modal) value and a well-defined spread, this "multidimensional" uncertainty defies straightforward utilization in policymaking. We suggest that there are no simple solutions to the questions raised. Crucially, we must dispel the notion that there is a "true" probability probabilities of this type are necessarily subjective, and reasonable people may disagree. Indeed, we suggest that what is at stake is precisely the question, what is it reasonable to believe, and to act as if we believe? As a preliminary suggestion, we demonstrate how the output of a simple probabilistic climate model might be evaluated regarding the reasonableness of the outputs it calculates with different input PDFs. We suggest further that where there is insufficient evidence to clearly favor one range of probabilistic projections over another, that the choice of results on which to base policy must necessarily involve ethical considerations, as they have inevitable consequences for the distribution of risk In particular, the choice to use a more "optimistic" PDF for climate sensitivity (or other components of the causal chain) leads to the allowance of higher emissions consistent with any specified goal for risk reduction, and thus leads to higher climate impacts, in exchange for lower mitigation costs.

A method for monitoring of oxygen saturation changes in brain tissue using diffuse reflectance spectroscopy.

PubMed

Rejmstad, Peter; Johansson, Johannes D; Haj-Hosseini, Neda; Wårdell, Karin

2017-03-01

Continuous measurement of local brain oxygen saturation (SO 2 ) can be used to monitor the status of brain trauma patients in the neurocritical care unit. Currently, micro-oxygen-electrodes are considered as the "gold standard" in measuring cerebral oxygen pressure (pO 2 ), which is closely related to SO 2 through the oxygen dissociation curve (ODC) of hemoglobin, but with the drawback of slow in response time. The present study suggests estimation of SO 2 in brain tissue using diffuse reflectance spectroscopy (DRS) for finding an analytical relation between measured spectra and the SO 2 for different blood concentrations. The P 3 diffusion approximation is used to generate a set of spectra simulating brain tissue for various levels of blood concentrations in order to estimate SO 2 . The algorithm is evaluated on optical phantoms mimicking white brain matter (blood volume of 0.5-2%) where pO 2 and temperature is controlled and on clinical data collected during brain surgery. The suggested method is capable of estimating the blood fraction and oxygen saturation changes from the spectroscopic signal and the hemoglobin absorption profile. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Impaired hand size estimation in CRPS.

PubMed

Peltz, Elena; Seifert, Frank; Lanz, Stefan; Müller, Rüdiger; Maihöfner, Christian

2011-10-01

A triad of clinical symptoms, ie, autonomic, motor and sensory dysfunctions, characterizes complex regional pain syndromes (CRPS). Sensory dysfunction comprises sensory loss or spontaneous and stimulus-evoked pain. Furthermore, a disturbance in the body schema may occur. In the present study, patients with CRPS of the upper extremity and healthy controls estimated their hand sizes on the basis of expanded or compressed schematic drawings of hands. In patients with CRPS we found an impairment in accurate hand size estimation; patients estimated their own CRPS-affected hand to be larger than it actually was when measured objectively. Moreover, overestimation correlated significantly with disease duration, neglect score, and increase of two-point-discrimination-thresholds (TPDT) compared to the unaffected hand and to control subjects' estimations. In line with previous functional imaging studies in CRPS patients demonstrating changes in central somatotopic maps, we suggest an involvement of the central nervous system in this disruption of the body schema. Potential cortical areas may be the primary somatosensory and posterior parietal cortices, which have been proposed to play a critical role in integrating visuospatial information. CRPS patients perceive their affected hand to be bigger than it is. The magnitude of this overestimation correlates with disease duration, decreased tactile thresholds, and neglect-score. Suggesting a disrupted body schema as the source of this impairment, our findings corroborate the current assumption of a CNS involvement in CRPS. Copyright © 2011 American Pain Society. Published by Elsevier Inc. All rights reserved.

Estimating the Relevance of World Disturbances to Explain Savings, Interference and Long-Term Motor Adaptation Effects

PubMed Central

Berniker, Max; Kording, Konrad P.

2011-01-01

Recent studies suggest that motor adaptation is the result of multiple, perhaps linear processes each with distinct time scales. While these models are consistent with some motor phenomena, they can neither explain the relatively fast re-adaptation after a long washout period, nor savings on a subsequent day. Here we examined if these effects can be explained if we assume that the CNS stores and retrieves movement parameters based on their possible relevance. We formalize this idea with a model that infers not only the sources of potential motor errors, but also their relevance to the current motor circumstances. In our model adaptation is the process of re-estimating parameters that represent the body and the world. The likelihood of a world parameter being relevant is then based on the mismatch between an observed movement and that predicted when not compensating for the estimated world disturbance. As such, adapting to large motor errors in a laboratory setting should alert subjects that disturbances are being imposed on them, even after motor performance has returned to baseline. Estimates of this external disturbance should be relevant both now and in future laboratory settings. Estimated properties of our bodies on the other hand should always be relevant. Our model demonstrates savings, interference, spontaneous rebound and differences between adaptation to sudden and gradual disturbances. We suggest that many issues concerning savings and interference can be understood when adaptation is conditioned on the relevance of parameters. PMID:21998574

Global Economic Impact of Dental Diseases.

PubMed

Listl, S; Galloway, J; Mossey, P A; Marcenes, W

2015-10-01

Reporting the economic burden of oral diseases is important to evaluate the societal relevance of preventing and addressing oral diseases. In addition to treatment costs, there are indirect costs to consider, mainly in terms of productivity losses due to absenteeism from work. The purpose of the present study was to estimate the direct and indirect costs of dental diseases worldwide to approximate the global economic impact. Estimation of direct treatment costs was based on a systematic approach. For estimation of indirect costs, an approach suggested by the World Health Organization's Commission on Macroeconomics and Health was employed, which factored in 2010 values of gross domestic product per capita as provided by the International Monetary Fund and oral burden of disease estimates from the 2010 Global Burden of Disease Study. Direct treatment costs due to dental diseases worldwide were estimated at US$298 billion yearly, corresponding to an average of 4.6% of global health expenditure. Indirect costs due to dental diseases worldwide amounted to US$144 billion yearly, corresponding to economic losses within the range of the 10 most frequent global causes of death. Within the limitations of currently available data sources and methodologies, these findings suggest that the global economic impact of dental diseases amounted to US$442 billion in 2010. Improvements in population oral health may imply substantial economic benefits not only in terms of reduced treatment costs but also because of fewer productivity losses in the labor market. © International & American Associations for Dental Research 2015.

B-2 Extremely High Frequency SATCOM and Computer Increment 1 (B-2 EHF Inc 1)

DTIC Science & Technology

2015-12-01

Confidence Level Confidence Level of cost estimate for current APB: 55% This APB reflects cost and funding data based on the B-2 EHF Increment I SCP...This cost estimate was quantified at the Mean (~55%) confidence level . Total Quantity Quantity SAR Baseline Production Estimate Current APB...Production Estimate Econ Qty Sch Eng Est Oth Spt Total 33.624 -0.350 1.381 0.375 0.000 -6.075 0.000 -0.620 -5.289 28.335 Current SAR Baseline to Current

Testing the limits of temporal stability: Willingness to pay values among Grand Canyon whitewater boaters across decades

USGS Publications Warehouse

Neher, Chris J.; Duffield, John; Bair, Lucas S.; Patterson, David A.; Neher, Katherine

2017-01-01

We directly compare trip willingness to pay (WTP) values between 1985 and 2015 stated preference surveys of private party Grand Canyon boaters using identically designed valuation methods. The temporal gap of 30 years between these two studies is well beyond that of any tests of WTP temporal stability in the literature. Comparisons were made of mean WTP estimates for four hypothetical Colorado River flow level scenarios. WTP values from the 1985 survey were adjusted to 2015 levels using the consumer price index. Mean WTP precision was estimated through simulation. No statistically significant differences were detected between the adjusted Bishop et al. (1987) and the current study mean WTP estimates. Examination of pooled models of the data from the studies suggest that while the estimated WTP values are stable over time, the underlying valuation functions may not be, particularly when the data and models are corrected to account for differing bid structures and possible panel effects.

A random cluster survey and a convenience sample give comparable estimates of immunity to vaccine preventable diseases in children of school age in Victoria, Australia.

PubMed

Kelly, Heath; Riddell, Michaela A; Gidding, Heather F; Nolan, Terry; Gilbert, Gwendolyn L

2002-08-19

We compared estimates of the age-specific population immunity to measles, mumps, rubella, hepatitis B and varicella zoster viruses in Victorian school children obtained by a national sero-survey, using a convenience sample of residual sera from diagnostic laboratories throughout Australia, with those from a three-stage random cluster survey. When grouped according to school age (primary or secondary school) there was no significant difference in the estimates of immunity to measles, mumps, hepatitis B or varicella. Compared with the convenience sample, the random cluster survey estimated higher immunity to rubella in samples from both primary (98.7% versus 93.6%, P = 0.002) and secondary school students (98.4% versus 93.2%, P = 0.03). Despite some limitations, this study suggests that the collection of a convenience sample of sera from diagnostic laboratories is an appropriate sampling strategy to provide population immunity data that will inform Australia's current and future immunisation policies. Copyright 2002 Elsevier Science Ltd.

Estimating alcohol content of traditional brew in Western Kenya using culturally relevant methods: the case for cost over volume.

PubMed

Papas, Rebecca K; Sidle, John E; Wamalwa, Emmanuel S; Okumu, Thomas O; Bryant, Kendall L; Goulet, Joseph L; Maisto, Stephen A; Braithwaite, R Scott; Justice, Amy C

2010-08-01

Traditional homemade brew is believed to represent the highest proportion of alcohol use in sub-Saharan Africa. In Eldoret, Kenya, two types of brew are common: chang'aa, spirits, and busaa, maize beer. Local residents refer to the amount of brew consumed by the amount of money spent, suggesting a culturally relevant estimation method. The purposes of this study were to analyze ethanol content of chang'aa and busaa; and to compare two methods of alcohol estimation: use by cost, and use by volume, the latter the current international standard. Laboratory results showed mean ethanol content was 34% (SD = 14%) for chang'aa and 4% (SD = 1%) for busaa. Standard drink unit equivalents for chang'aa and busaa, respectively, were 2 and 1.3 (US) and 3.5 and 2.3 (Great Britain). Using a computational approach, both methods demonstrated comparable results. We conclude that cost estimation of alcohol content is more culturally relevant and does not differ in accuracy from the international standard.

The Influence of Mean Trophic Level on Biomass and Production in Marine Ecosystems

NASA Astrophysics Data System (ADS)

Woodson, C. B.; Schramski, J.

2016-02-01

The oceans have faced rapid removal of top predators causing a reduction in the mean trophic level of many marine ecosystems due to fishing down the food web. However, estimating the pre-exploitation biomass of the ocean has been difficult. Historical population sizes have been estimated using population dynamics models, archaeological or historical records, fisheries data, living memory, ecological monitoring data, genetics, and metabolic theory. In this talk, we expand on the use of metabolic theory by including complex trophic webs to estimate pre-exploitation levels of marine biomass. Our results suggest that historical marine biomass could be as much as 10 times higher than current estimates and that the total carrying capacity of the ocean is sensitive to mean trophic level and trophic web complexity. We further show that the production levels needed to support the added biomass are possible due to biomass accumulation and predator-prey overlap in regions such as fronts. These results have important implications for marine biogeochemical cycling, fisheries management, and conservation efforts.

Testing the Limits of Temporal Stability: Willingness to Pay Values among Grand Canyon Whitewater Boaters Across Decades

NASA Astrophysics Data System (ADS)

Neher, Chris; Duffield, John; Bair, Lucas; Patterson, David; Neher, Katherine

2017-12-01

We directly compare trip willingness to pay (WTP) values between 1985 and 2015 stated preference surveys of private party Grand Canyon boaters using identically designed valuation methods. The temporal gap of 30 years between these two studies is well beyond that of any tests of WTP temporal stability in the literature. Comparisons were made of mean WTP estimates for four hypothetical Colorado River flow level scenarios. WTP values from the 1985 survey were adjusted to 2015 levels using the consumer price index. Mean WTP precision was estimated through simulation. No statistically significant differences were detected between the adjusted Bishop et al. (1987) and the current study mean WTP estimates. Examination of pooled models of the data from the studies suggest that while the estimated WTP values are stable over time, the underlying valuation functions may not be, particularly when the data and models are corrected to account for differing bid structures and possible panel effects.

Chlamydia sequelae cost estimates used in current economic evaluations: does one-size-fit-all?

PubMed

Ong, Koh Jun; Soldan, Kate; Jit, Mark; Dunbar, J Kevin; Woodhall, Sarah C

2017-02-01

Current evidence suggests that chlamydia screening programmes can be cost-effective, conditional on assumptions within mathematical models. We explored differences in cost estimates used in published economic evaluations of chlamydia screening from seven countries (four papers each from UK and the Netherlands, two each from Sweden and Australia, and one each from Ireland, Canada and Denmark). From these studies, we extracted management cost estimates for seven major chlamydia sequelae. In order to compare the influence of different sequelae considered in each paper and their corresponding management costs on the total cost per case of untreated chlamydia, we applied reported unit sequelae management costs considered in each paper to a set of untreated infection to sequela progression probabilities. All costs were adjusted to 2013/2014 Great British Pound (GBP) values. Sequelae management costs ranged from £171 to £3635 (pelvic inflammatory disease); £953 to £3615 (ectopic pregnancy); £546 to £6752 (tubal factor infertility); £159 to £3341 (chronic pelvic pain); £22 to £1008 (epididymitis); £11 to £1459 (neonatal conjunctivitis) and £433 to £3992 (neonatal pneumonia). Total cost of sequelae per case of untreated chlamydia ranged from £37 to £412. There was substantial variation in cost per case of chlamydia sequelae used in published chlamydia screening economic evaluations, which likely arose from different assumptions about disease management pathways and the country perspectives taken. In light of this, when interpreting these studies, the reader should be satisfied that the cost estimates used sufficiently reflect the perspective taken and current disease management for their respective context. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Estimation of Separation Buffers for Wind-Prediction Error in an Airborne Separation Assistance System

NASA Technical Reports Server (NTRS)

Consiglio, Maria C.; Hoadley, Sherwood T.; Allen, B. Danette

2009-01-01

Wind prediction errors are known to affect the performance of automated air traffic management tools that rely on aircraft trajectory predictions. In particular, automated separation assurance tools, planned as part of the NextGen concept of operations, must be designed to account and compensate for the impact of wind prediction errors and other system uncertainties. In this paper we describe a high fidelity batch simulation study designed to estimate the separation distance required to compensate for the effects of wind-prediction errors throughout increasing traffic density on an airborne separation assistance system. These experimental runs are part of the Safety Performance of Airborne Separation experiment suite that examines the safety implications of prediction errors and system uncertainties on airborne separation assurance systems. In this experiment, wind-prediction errors were varied between zero and forty knots while traffic density was increased several times current traffic levels. In order to accurately measure the full unmitigated impact of wind-prediction errors, no uncertainty buffers were added to the separation minima. The goal of the study was to measure the impact of wind-prediction errors in order to estimate the additional separation buffers necessary to preserve separation and to provide a baseline for future analyses. Buffer estimations from this study will be used and verified in upcoming safety evaluation experiments under similar simulation conditions. Results suggest that the strategic airborne separation functions exercised in this experiment can sustain wind prediction errors up to 40kts at current day air traffic density with no additional separation distance buffer and at eight times the current day with no more than a 60% increase in separation distance buffer.

State-Level Estimates of Cancer-Related Absenteeism Costs

PubMed Central

Tangka, Florence K.; Trogdon, Justin G.; Nwaise, Isaac; Ekwueme, Donatus U.; Guy, Gery P.; Orenstein, Diane

2016-01-01

Background Cancer is one of the top five most costly diseases in the United States and leads to substantial work loss. Nevertheless, limited state-level estimates of cancer absenteeism costs have been published. Methods In analyses of data from the 2004–2008 Medical Expenditure Panel Survey, the 2004 National Nursing Home Survey, the U.S. Census Bureau for 2008, and the 2009 Current Population Survey, we used regression modeling to estimate annual state-level absenteeism costs attributable to cancer from 2004 to 2008. Results We estimated that the state-level median number of days of absenteeism per year among employed cancer patients was 6.1 days and that annual state-level cancer absenteeism costs ranged from $14.9 million to $915.9 million (median = $115.9 million) across states in 2010 dollars. Absenteeism costs are approximately 6.5% of the costs of premature cancer mortality. Conclusions The results from this study suggest that lost productivity attributable to cancer is a substantial cost to employees and employers and contributes to estimates of the overall impact of cancer in a state population. PMID:23969498

State-level estimates of cancer-related absenteeism costs.

PubMed

Tangka, Florence K; Trogdon, Justin G; Nwaise, Isaac; Ekwueme, Donatus U; Guy, Gery P; Orenstein, Diane

2013-09-01

Cancer is one of the top five most costly diseases in the United States and leads to substantial work loss. Nevertheless, limited state-level estimates of cancer absenteeism costs have been published. In analyses of data from the 2004-2008 Medical Expenditure Panel Survey, the 2004 National Nursing Home Survey, the U.S. Census Bureau for 2008, and the 2009 Current Population Survey, we used regression modeling to estimate annual state-level absenteeism costs attributable to cancer from 2004 to 2008. We estimated that the state-level median number of days of absenteeism per year among employed cancer patients was 6.1 days and that annual state-level cancer absenteeism costs ranged from $14.9 million to $915.9 million (median = $115.9 million) across states in 2010 dollars. Absenteeism costs are approximately 6.5% of the costs of premature cancer mortality. The results from this study suggest that lost productivity attributable to cancer is a substantial cost to employees and employers and contributes to estimates of the overall impact of cancer in a state population.

The current duration design for estimating the time to pregnancy distribution: a nonparametric Bayesian perspective.

PubMed

Gasbarra, Dario; Arjas, Elja; Vehtari, Aki; Slama, Rémy; Keiding, Niels

2015-10-01

This paper was inspired by the studies of Niels Keiding and co-authors on estimating the waiting time-to-pregnancy (TTP) distribution, and in particular on using the current duration design in that context. In this design, a cross-sectional sample of women is collected from those who are currently attempting to become pregnant, and then by recording from each the time she has been attempting. Our aim here is to study the identifiability and the estimation of the waiting time distribution on the basis of current duration data. The main difficulty in this stems from the fact that very short waiting times are only rarely selected into the sample of current durations, and this renders their estimation unstable. We introduce here a Bayesian method for this estimation problem, prove its asymptotic consistency, and compare the method to some variants of the non-parametric maximum likelihood estimators, which have been used previously in this context. The properties of the Bayesian estimation method are studied also empirically, using both simulated data and TTP data on current durations collected by Slama et al. (Hum Reprod 27(5):1489-1498, 2012).

Prevalence of gluten-free diet adherence among individuals without celiac disease in the USA: results from the Continuous National Health and Nutrition Examination Survey 2009-2010.

PubMed

DiGiacomo, Daniel V; Tennyson, Christina A; Green, Peter H; Demmer, Ryan T

2013-08-01

Clinical inference suggests the prevalence of non-celiac gluten sensitivity is substantially higher than that of celiac disease in the USA. Unfortunately, there are currently no data supporting these claims. The authors analyzed nationally representative data to estimate the prevalence of adherence to a gluten-free diet among participants without celiac disease and also to characterize the demographics and general health status of these participants. The Continuous National Health and Nutrition Examination Survey (NHANES) 2009-2010 enrolled 7762 individuals representing the civilian, non-institutionalized, US population free of celiac disease. Participants responded to interviewer administered questionnaires regarding current adherence to a gluten-free diet. Prevalence estimates were computed using SAS survey procedures. There were 49 individuals who reported current adherence to a gluten-free diet reflecting a weighted prevalence of 0.548% (95% CI 0.206-0.889). The prevalence of a gluten-free diet was higher in females (0.58%) than males (0.37%), although this was not statistically significant (p = 0.34). Participants reporting a gluten-free diet were older (46.6 vs. 40.5 years, p = 0.005), had higher high-density lipoprotein, lower iron and lower body mass index. The estimated national prevalence of non-celiac gluten sensitivity is 0.548%, approximately half that of celiac disease. Future studies are merited in order to better understand the population burden of non-celiac gluten sensitivity.

Sliding mode observers for automotive alternator

NASA Astrophysics Data System (ADS)

Chen, De-Shiou

Estimator development for synchronous rectification of the automotive alternator is a desirable approach for estimating alternator's back electromotive forces (EMFs) without a direct mechanical sensor of the rotor position. Recent theoretical studies show that estimation of the back EMF may be observed based on system's phase current model by sensing electrical variables (AC phase currents and DC bus voltage) of the synchronous rectifier. Observer design of the back EMF estimation has been developed for constant engine speed. In this work, we are interested in nonlinear observer design of the back EMF estimation for the real case of variable engine speed. Initial back EMF estimate can be obtained from a first-order sliding mode observer (SMO) based on the phase current model. A fourth-order nonlinear asymptotic observer (NAO), complemented by the dynamics of the back EMF with time-varying frequency and amplitude, is then incorporated into the observer design for chattering reduction. Since the cost of required phase current sensors may be prohibitive, the most applicable approach in real implementation by measuring DC current of the synchronous rectifier is carried out in the dissertation. It is shown that the DC link current consists of sequential "windows" with partial information of the phase currents, hence, the cascaded NAO is responsible not only for the purpose of chattering reduction but also for necessarily accomplishing the process of estimation. Stability analyses of the proposed estimators are considered for most linear and time-varying cases. The stability of the NAO without speed information is substantiated by both numerical and experimental results. Prospective estimation algorithms for the case of battery current measurements are investigated. Theoretical study indicates that the convergence of the proposed LAO may be provided by high gain inputs. Since the order of the LAO/NAO for the battery current case is one order higher than that of the link current measurements, it is hard to find moderate values of the input gains for the real-time sampled-data systems. Technical difficulties in implementation of such high order discrete-time nonlinear estimators have been discussed. Directions of further investigations have been provided.

Current Term Enrollment Estimates: Spring 2014

ERIC Educational Resources Information Center

National Student Clearinghouse, 2014

2014-01-01

Current Term Enrollment Estimates, published every December and May by the National Student Clearinghouse Research Center, include national enrollment estimates by institutional sector, state, enrollment intensity, age group, and gender. Enrollment estimates are adjusted for Clearinghouse data coverage rates by institutional sector, state, and…

Current Term Enrollment Estimates: Fall 2014

ERIC Educational Resources Information Center

National Student Clearinghouse, 2014

2014-01-01

Current Term Enrollment Estimates, published every December and May by the National Student Clearinghouse Research Center (NSCRC), include national enrollment estimates by institutional sector, state, enrollment intensity, age group, and gender. Enrollment estimates are adjusted for Clearinghouse data coverage rates by institutional sector, state,…

Drift in ocean currents impacts intergenerational microbial exposure to temperature

PubMed Central

Doblin, Martina A.; van Sebille, Erik

2016-01-01

Microbes are the foundation of marine ecosystems [Falkowski PG, Fenchel T, Delong EF (2008) Science 320(5879):1034–1039]. Until now, the analytical framework for understanding the implications of ocean warming on microbes has not considered thermal exposure during transport in dynamic seascapes, implying that our current view of change for these critical organisms may be inaccurate. Here we show that upper-ocean microbes experience along-trajectory temperature variability up to 10 °C greater than seasonal fluctuations estimated in a static frame, and that this variability depends strongly on location. These findings demonstrate that drift in ocean currents can increase the thermal exposure of microbes and suggests that microbial populations with broad thermal tolerance will survive transport to distant regions of the ocean and invade new habitats. Our findings also suggest that advection has the capacity to influence microbial community assemblies, such that regions with strong currents and large thermal fluctuations select for communities with greatest plasticity and evolvability, and communities with narrow thermal performance are found where ocean currents are weak or along-trajectory temperature variation is low. Given that fluctuating environments select for individual plasticity in microbial lineages, and that physiological plasticity of ancestors can predict the magnitude of evolutionary responses of subsequent generations to environmental change [Schaum CE, Collins S (2014) Proc Biol Soc 281(1793):20141486], our findings suggest that microbial populations in the sub-Antarctic (∼40°S), North Pacific, and North Atlantic will have the most capacity to adapt to contemporary ocean warming. PMID:27140608

Will Choice-Based Reform Work for Medicare? Evidence from the Federal Employees Health Benefits Program

PubMed Central

Florence, Curtis S; Atherly, Adam; Thorpe, Kenneth E

2006-01-01

Objective To examine the effect of premiums and benefits on the health plan choices of older enrollees who choose Federal Employees Health Benefits Program (FEHBP) health plans as their primary payer. Data Sources Administrative enrollment data from the Office of Personnel Management (OPM) and plan premiums and benefits data taken from the Checkbook Guide to health plans. Study Design We estimate individual plan choice models where the choice of health plan is a function of out-of-pocket premium, actuarial value, plan attributes, and individual characteristics. Plan attributes include plan structure (fee-for-service/preferred provider organization, point-of-service, or health maintenance organization), drug benefit structure, and whether or not the plan covers other types of spending such as dental services and diabetic supplies. The models are estimated by conditional logit. Our study focuses on three populations that currently choose FEHBP as their primary health care coverage and are similar to the Medicare population: current employees and retirees who are approaching the age of Medicare eligibility (ages 60–64) and current federal employees age 65+. Current employees age 65+ are eligible for Medicare, but their FEHBP plan is their primary payer. Retirees and employees 60–64 are not yet eligible for Medicare but are similar in many respects to recently age-eligible Medicare beneficiaries. We also estimate our model for current employees age 55 and younger as a comparison group. Data Collection Methods We select a random sample of retirees and employees age 60–64, as well as all current employees age 65+, from the OPM administrative database for the calendar year 2001. The plan choices available to each person are determined by the plans participating in their metropolitan statistical area. We match plan premium and attribute information from the Checkbook Guide to each plan in the enrollee's list of choices. Principal Findings We find that current workers 65+, 60–64, and non-Medicare eligible retirees are sensitive to variation in plan premiums. The premium elasticities for these groups are similar in magnitude to those of the age 55 and under employee group. Older workers and retirees not yet eligible for Medicare are willing to pay a substantial amount for plans with open provider networks. The willingness to pay for open networks is significantly greater for these groups than for younger employees. Willingness to pay for open network plans varies significantly by income, but varies little by age within group. Conclusions Our finding that older workers and non-Medicare eligible retirees are sensitive to plan premiums suggests that choice-based reform of Medicare would lead to cost-conscious choices by Medicare beneficiaries. However, our finding that these groups are willing to pay more for open network plans than younger employees suggest that higher risk individuals may migrate toward higher benefit, higher cost plans. Our findings on the relationship between income and willingness to pay for open network plans suggest that means testing is a viable reform for lowering Medicare program costs. PMID:16987300

An automated multi-model based evapotranspiration estimation framework for understanding crop-climate interactions in India

NASA Astrophysics Data System (ADS)

Bhattarai, N.; Jain, M.; Mallick, K.

2017-12-01

A remote sensing based multi-model evapotranspiration (ET) estimation framework is developed using MODIS and NASA Merra-2 reanalysis data for data poor regions, and we apply this framework to the Indian subcontinent. The framework eliminates the need for in-situ calibration data and hence estimates ET completely from space and is replicable across all regions in the world. Currently, six surface energy balance models ranging from widely-used SEBAL, METRIC, and SEBS to moderately-used S-SEBI, SSEBop, and a relatively new model, STIC1.2 are being integrated and validated. Preliminary analysis suggests good predictability of the models for estimating near- real time ET under clear sky conditions from various crop types in India with coefficient of determination 0.32-0.55 and percent bias -15%-28%, when compared against Bowen Ratio based ET estimates. The results are particularly encouraging given that no direct ground input data were used in the analysis. The framework is currently being extended to estimate seasonal ET across the Indian subcontinent using a model-ensemble approach that uses all available MODIS 8-day datasets since 2000. These ET products are being used to monitor inter-seasonal and inter-annual dynamics of ET and crop water use across different crop and irrigation practices in India. Particularly, the potential impacts of changes in precipitation patterns and extreme heat (e.g., extreme degree days) on seasonal crop water consumption is being studied. Our ET products are able to locate the water stress hotspots that need to be targeted with water saving interventions to maintain agricultural production in the face of climate variability and change.

A Simulation Based Analysis of Motor Unit Number Index (MUNIX) Technique Using Motoneuron Pool and Surface Electromyogram Models

PubMed Central

Li, Xiaoyan; Rymer, William Zev; Zhou, Ping

2013-01-01

Motor unit number index (MUNIX) measurement has recently achieved increasing attention as a tool to evaluate the progression of motoneuron diseases. In our current study, the sensitivity of the MUNIX technique to changes in motoneuron and muscle properties was explored by a simulation approach utilizing variations on published motoneuron pool and surface electromyogram (EMG) models. Our simulation results indicate that, when keeping motoneuron pool and muscle parameters unchanged and varying the input motor unit numbers to the model, then MUNIX estimates can appropriately characterize changes in motor unit numbers. Such MUNIX estimates are not sensitive to different motor unit recruitment and rate coding strategies used in the model. Furthermore, alterations in motor unit control properties do not have a significant effect on the MUNIX estimates. Neither adjustment of the motor unit recruitment range nor reduction of the motor unit firing rates jeopardizes the MUNIX estimates. The MUNIX estimates closely correlate with the maximum M wave amplitude. However, if we reduce the amplitude of each motor unit action potential rather than simply reduce motor unit number, then MUNIX estimates substantially underestimate the motor unit numbers in the muscle. These findings suggest that the current MUNIX definition is most suitable for motoneuron diseases that demonstrate secondary evidence of muscle fiber reinnervation. In this regard, when MUNIX is applied, it is of much importance to examine a parallel measurement of motor unit size index (MUSIX), defined as the ratio of the maximum M wave amplitude to the MUNIX. However, there are potential limitations in the application of the MUNIX methods in atrophied muscle, where it is unclear whether the atrophy is accompanied by loss of motor units or loss of muscle fiber size. PMID:22514208

Power of magic hands: parent-driven application of habit reversal to treat complex stereotypy in a 3-year-old.

PubMed

Freeman, Kurt A; Duke, Danny C

2013-08-01

The authors assessed the effectiveness of habit reversal training (HRT) to treat a complex motor stereotypy in a healthy 3-year-old female. This data-based case study involved training parents in HRT to deliver the parent-driven intervention to the child. The frequency of the child's behaviors was estimated daily in 30-min intervals by her parents. Outcomes supported the effectiveness of the intervention, with the estimated frequency of the stereotypy decreasing from occurring during approximately 85% of recorded intervals to less than 2% over a period of 4 weeks. Further record keeping over 19 weeks suggested treatment gains were generally maintained over time. The current case study provides preliminary evidence supporting the effectiveness of modified HRT to reduce stereotypies in young children. Further, data suggest that the intervention may be extended to younger ages by teaching parents how to facilitate treatment delivery. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Geographic exposure risk of variant Creutzfeldt-Jakob disease in US blood donors: a risk-ranking model to evaluate alternative donor-deferral policies.

PubMed

Yang, Hong; Huang, Yin; Gregori, Luisa; Asher, David M; Bui, Travis; Forshee, Richard A; Anderson, Steven A

2017-04-01

Variant Creutzfeldt-Jakob disease (vCJD) has been transmitted by blood transfusion (TTvCJD). The US Food and Drug Administration (FDA) recommends deferring blood donors who resided in or traveled to 30 European countries where they may have been exposed to bovine spongiform encephalopathy (BSE) through beef consumption. Those recommendations warrant re-evaluation, because new cases of BSE and vCJD have markedly abated. The FDA developed a risk-ranking model to calculate the geographic vCJD risk using country-specific case rates and person-years of exposure of US blood donors. We used the reported country vCJD case rates, when available, or imputed vCJD case rates from reported BSE and UK beef exports during the risk period. We estimated the risk reduction and donor loss should the deferral be restricted to a few high-risk countries. We also estimated additional risk reduction by leukocyte reduction (LR) of red blood cells (RBCs). The United Kingdom, Ireland, and France had the greatest vCJD risk, contributing approximately 95% of the total risk. The model estimated that deferring US donors who spent extended periods of time in these three countries, combined with currently voluntary LR (95% of RBC units), would reduce the vCJD risk by 89.3%, a reduction similar to that achieved under the current policy (89.8%). Limiting deferrals to exposure in these three countries would potentially allow donations from an additional 100,000 donors who are currently deferred. Our analysis suggests that a deferral option focusing on the three highest risk countries would achieve a level of blood safety similar to that achieved by the current policy. © 2016 AABB.

Noise covariance incorporated MEG-MUSIC algorithm: a method for multiple-dipole estimation tolerant of the influence of background brain activity.

PubMed

Sekihara, K; Poeppel, D; Marantz, A; Koizumi, H; Miyashita, Y

1997-09-01

This paper proposes a method of localizing multiple current dipoles from spatio-temporal biomagnetic data. The method is based on the multiple signal classification (MUSIC) algorithm and is tolerant of the influence of background brain activity. In this method, the noise covariance matrix is estimated using a portion of the data that contains noise, but does not contain any signal information. Then, a modified noise subspace projector is formed using the generalized eigenvectors of the noise and measured-data covariance matrices. The MUSIC localizer is calculated using this noise subspace projector and the noise covariance matrix. The results from a computer simulation have verified the effectiveness of the method. The method was then applied to source estimation for auditory-evoked fields elicited by syllable speech sounds. The results strongly suggest the method's effectiveness in removing the influence of background activity.

Improving Factor Score Estimation Through the Use of Observed Background Characteristics

PubMed Central

Curran, Patrick J.; Cole, Veronica; Bauer, Daniel J.; Hussong, Andrea M.; Gottfredson, Nisha

2016-01-01

A challenge facing nearly all studies in the psychological sciences is how to best combine multiple items into a valid and reliable score to be used in subsequent modelling. The most ubiquitous method is to compute a mean of items, but more contemporary approaches use various forms of latent score estimation. Regardless of approach, outside of large-scale testing applications, scoring models rarely include background characteristics to improve score quality. The current paper used a Monte Carlo simulation design to study score quality for different psychometric models that did and did not include covariates across levels of sample size, number of items, and degree of measurement invariance. The inclusion of covariates improved score quality for nearly all design factors, and in no case did the covariates degrade score quality relative to not considering the influences at all. Results suggest that the inclusion of observed covariates can improve factor score estimation. PMID:28757790

Oceanic Fluxes of Mass, Heat and Freshwater: A Global Estimate and Perspective

NASA Technical Reports Server (NTRS)

MacDonald, Alison Marguerite

1995-01-01

Data from fifteen globally distributed, modern, high resolution, hydrographic oceanic transects are combined in an inverse calculation using large scale box models. The models provide estimates of the global meridional heat and freshwater budgets and are used to examine the sensitivity of the global circulation, both inter and intra-basin exchange rates, to a variety of external constraints provided by estimates of Ekman, boundary current and throughflow transports. A solution is found which is consistent with both the model physics and the global data set, despite a twenty five year time span and a lack of seasonal consistency among the data. The overall pattern of the global circulation suggested by the models is similar to that proposed in previously published local studies and regional reviews. However, significant qualitative and quantitative differences exist. These differences are due both to the model definition and to the global nature of the data set.

Winter bird population studies and project prairie birds for surveying grassland birds

USGS Publications Warehouse

Twedt, D.J.; Hamel, P.B.; Woodrey, M.S.

2008-01-01

We compared 2 survey methods for assessing winter bird communities in temperate grasslands: Winter Bird Population Study surveys are area-searches that have long been used in a variety of habitats whereas Project Prairie Bird surveys employ active-flushing techniques on strip-transects and are intended for use in grasslands. We used both methods to survey birds on 14 herbaceous reforested sites and 9 coastal pine savannas during winter and compared resultant estimates of species richness and relative abundance. These techniques did not yield similar estimates of avian populations. We found Winter Bird Population Studies consistently produced higher estimates of species richness, whereas Project Prairie Birds produced higher estimates of avian abundance for some species. When it is important to identify all species within the winter bird community, Winter Bird Population Studies should be the survey method of choice. If estimates of the abundance of relatively secretive grassland bird species are desired, the use of Project Prairie Birds protocols is warranted. However, we suggest that both survey techniques, as currently employed, are deficient and recommend distance- based survey methods that provide species-specific estimates of detection probabilities be incorporated into these survey methods.

Relations between Brain Structure and Attentional Function in Spina Bifida: Utilization of Robust Statistical Approaches

PubMed Central

Kulesz, Paulina A.; Tian, Siva; Juranek, Jenifer; Fletcher, Jack M.; Francis, David J.

2015-01-01

Objective Weak structure-function relations for brain and behavior may stem from problems in estimating these relations in small clinical samples with frequently occurring outliers. In the current project, we focused on the utility of using alternative statistics to estimate these relations. Method Fifty-four children with spina bifida meningomyelocele performed attention tasks and received MRI of the brain. Using a bootstrap sampling process, the Pearson product moment correlation was compared with four robust correlations: the percentage bend correlation, the Winsorized correlation, the skipped correlation using the Donoho-Gasko median, and the skipped correlation using the minimum volume ellipsoid estimator Results All methods yielded similar estimates of the relations between measures of brain volume and attention performance. The similarity of estimates across correlation methods suggested that the weak structure-function relations previously found in many studies are not readily attributable to the presence of outlying observations and other factors that violate the assumptions behind the Pearson correlation. Conclusions Given the difficulty of assembling large samples for brain-behavior studies, estimating correlations using multiple, robust methods may enhance the statistical conclusion validity of studies yielding small, but often clinically significant, correlations. PMID:25495830

Relations between volumetric measures of brain structure and attentional function in spina bifida: utilization of robust statistical approaches.

PubMed

Kulesz, Paulina A; Tian, Siva; Juranek, Jenifer; Fletcher, Jack M; Francis, David J

2015-03-01

Weak structure-function relations for brain and behavior may stem from problems in estimating these relations in small clinical samples with frequently occurring outliers. In the current project, we focused on the utility of using alternative statistics to estimate these relations. Fifty-four children with spina bifida meningomyelocele performed attention tasks and received MRI of the brain. Using a bootstrap sampling process, the Pearson product-moment correlation was compared with 4 robust correlations: the percentage bend correlation, the Winsorized correlation, the skipped correlation using the Donoho-Gasko median, and the skipped correlation using the minimum volume ellipsoid estimator. All methods yielded similar estimates of the relations between measures of brain volume and attention performance. The similarity of estimates across correlation methods suggested that the weak structure-function relations previously found in many studies are not readily attributable to the presence of outlying observations and other factors that violate the assumptions behind the Pearson correlation. Given the difficulty of assembling large samples for brain-behavior studies, estimating correlations using multiple, robust methods may enhance the statistical conclusion validity of studies yielding small, but often clinically significant, correlations. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Validation of an aggregate exposure model for substances in consumer products: a case study of diethyl phthalate in personal care products

PubMed Central

Delmaar, Christiaan; Bokkers, Bas; ter Burg, Wouter; Schuur, Gerlienke

2015-01-01

As personal care products (PCPs) are used in close contact with a person, they are a major source of consumer exposure to chemical substances contained in these products. The estimation of realistic consumer exposure to substances in PCPs is currently hampered by the lack of appropriate data and methods. To estimate aggregate exposure of consumers to substances contained in PCPs, a person-oriented consumer exposure model has been developed (the Probabilistic Aggregate Consumer Exposure Model, PACEM). The model simulates daily exposure in a population based on product use data collected from a survey among the Dutch population. The model is validated by comparing diethyl phthalate (DEP) dose estimates to dose estimates based on biomonitoring data. It was found that the model's estimates compared well with the estimates based on biomonitoring data. This suggests that the person-oriented PACEM model is a practical tool for assessing realistic aggregate exposures to substances in PCPs. In the future, PACEM will be extended with use pattern data on other product groups. This will allow for assessing aggregate exposure to substances in consumer products across different product groups. PMID:25352161

Improving accuracy of portion-size estimations through a stimulus equivalence paradigm.

PubMed

Hausman, Nicole L; Borrero, John C; Fisher, Alyssa; Kahng, SungWoo

2014-01-01

The prevalence of obesity continues to increase in the United States (Gordon-Larsen, The, & Adair, 2010). Obesity can be attributed, in part, to overconsumption of energy-dense foods. Given that overeating plays a role in the development of obesity, interventions that teach individuals to identify and consume appropriate portion sizes are warranted. Specifically, interventions that teach individuals to estimate portion sizes correctly without the use of aids may be critical to the success of nutrition education programs. The current study evaluated the use of a stimulus equivalence paradigm to teach 9 undergraduate students to estimate portion size accurately. Results suggested that the stimulus equivalence paradigm was effective in teaching participants to make accurate portion size estimations without aids, and improved accuracy was observed in maintenance sessions that were conducted 1 week after training. Furthermore, 5 of 7 participants estimated the target portion size of novel foods during extension sessions. These data extend existing research on teaching accurate portion-size estimations and may be applicable to populations who seek treatment (e.g., overweight or obese children and adults) to teach healthier eating habits. © Society for the Experimental Analysis of Behavior.

Precision and recall estimates for two-hybrid screens

PubMed Central

Huang, Hailiang; Bader, Joel S.

2009-01-01

Motivation: Yeast two-hybrid screens are an important method to map pairwise protein interactions. This method can generate spurious interactions (false discoveries), and true interactions can be missed (false negatives). Previously, we reported a capture–recapture estimator for bait-specific precision and recall. Here, we present an improved method that better accounts for heterogeneity in bait-specific error rates. Result: For yeast, worm and fly screens, we estimate the overall false discovery rates (FDRs) to be 9.9%, 13.2% and 17.0% and the false negative rates (FNRs) to be 51%, 42% and 28%. Bait-specific FDRs and the estimated protein degrees are then used to identify protein categories that yield more (or fewer) false positive interactions and more (or fewer) interaction partners. While membrane proteins have been suggested to have elevated FDRs, the current analysis suggests that intrinsic membrane proteins may actually have reduced FDRs. Hydrophobicity is positively correlated with decreased error rates and fewer interaction partners. These methods will be useful for future two-hybrid screens, which could use ultra-high-throughput sequencing for deeper sampling of interacting bait–prey pairs. Availability: All software (C source) and datasets are available as supplemental files and at http://www.baderzone.org under the Lesser GPL v. 3 license. Contact: joel.bader@jhu.edu Supplementary information: Supplementary data are available at Bioinformatics online. PMID:19091773

Anthropogenic CO2 invasion into the northeast Pacific based on concurrent δ13CDIC and nutrient profiles from the California Current

NASA Astrophysics Data System (ADS)

Ortiz, J. D.; Mix, A. C.; Wheeler, P. A.; Key, R. M.

2000-09-01

The stable isotopic signature of dissolved inorganic carbon (δ13CDIC) in the northeast Pacific Ocean is lower in near-surface waters by ≈1.1‰ relative to values predicted from global oceanic trends of δ13CDIC versus nutrients. A combination of anthropogenic carbon uptake from the atmosphere and thermodynamic, air-sea gas exchange processes in different water mass source areas account for the isotopic depletion. Here we evaluate the efficacy of using a concurrent nutrient-δ13C strategy to separate these two effects, with the goal of improving estimates of anthropogenic carbon uptake over the course of the Industrial Revolution. In depth profiles from the sea surface to 2500 m at four stations across the California Current (42°N), nitrate, rather than phosphate, is best correlated to δ13CDIC providing the best choice for this experiment. On the basis of an assumption of no anthropogenic carbon in North Pacific Deep Waters between 1000-2500 m depth (potential densities, σθ ˜ 27.3-27.7), the "anthropogenic— preanthropogenic" carbon isotope shift (Δδ13Ca-p) in near-surface waters of the northeast Pacific is inferred to be -0.62 ± 0.17‰, while the thermodynamic air-sea gas exchange signature is estimated at -0.48 ± 0.17‰. Values of Δδ13Ca-p (similar to the regional patterns of Δ14C and Tritium penetration) approach zero for σθ > 26.8, indicating little penetration of anthropogenic carbon into the North Pacific Intermediate Water or the upper North Pacific Deep Water. Our results suggest an upper North Pacific sink of anthropogenic carbon over the past ˜200 years that is ˜40% greater than that estimated for the interval between ˜1970 and ˜1990 by Quay et al., [1992]. Our estimate of the North Pacific inventory of anthropogenic carbon, added to published estimates from the North Atlantic and Indian Ocean, is smaller than model predictions of the total carbon sink, suggesting that a significant portion of anthropogenic carbon enters the deep sea via the Southern Ocean.

Manufacturing Energy Intensity and Opportunity Analysis for Fiber-Reinforced Polymer Composites and Other Lightweight Materials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liddell, Heather; Brueske, Sabine; Carpenter, Alberta

With their high strength-to-weight ratios, fiber-reinforced polymer (FRP) composites are important materials for lightweighting in structural applications; however, manufacturing challenges such as low process throughput and poor quality control can lead to high costs and variable performance, limiting their use in commercial applications. One of the most significant challenges for advanced composite materials is their high manufacturing energy intensity. This study explored the energy intensities of two lightweight FRP composite materials (glass- and carbon-fiber-reinforced polymers), with three lightweight metals (aluminum, magnesium, and titanium) and structural steel (as a reference material) included for comparison. Energy consumption for current typical and state-of-the-artmore » manufacturing processes were estimated for each material, deconstructing manufacturing process energy use by sub-process and manufacturing pathway in order to better understand the most energy intensive steps. Energy saving opportunities were identified and quantified for each production step based on a review of applied R&D technologies currently under development in order to estimate the practical minimum energy intensity. Results demonstrate that while carbon fiber reinforced polymer (CFRP) composites have the highest current manufacturing energy intensity of all materials considered, the large differences between current typical and state-of-the-art energy intensity levels (the 'current opportunity') and between state-of-the-art and practical minimum energy intensity levels (the 'R&D opportunity') suggest that large-scale energy savings are within reach.« less

You'll change more than I will: Adults' predictions about their own and others' future preferences.

PubMed

Renoult, Louis; Kopp, Leia; Davidson, Patrick S R; Taler, Vanessa; Atance, Cristina M

2016-01-01

It has been argued that adults underestimate the extent to which their preferences will change over time. We sought to determine whether such mispredictions are the result of a difficulty imagining that one's own current and future preferences may differ or whether it also characterizes our predictions about the future preferences of others. We used a perspective-taking task in which we asked young people how much they liked stereotypically young-person items (e.g., Top 40 music, adventure vacations) and stereotypically old-person items (e.g., jazz, playing bridge) now, and how much they would like them in the distant future (i.e., when they are 70 years old). Participants also made these same predictions for a generic same-age, same-sex peer. In a third condition, participants predicted how much a generic older (i.e., age 70) same-sex adult would like items from both categories today. Participants predicted less change between their own current and future preferences than between the current and future preferences of a peer. However, participants estimated that, compared to a current older adult today, their peer would like stereotypically young items more in the future and stereotypically old items less. The fact that peers' distant-future estimated preferences were different from the ones they made for "current" older adults suggests that even though underestimation of change of preferences over time is attenuated when thinking about others, a bias still exists.

A droplet in the inter-electrode gap during gas metal arc welding

NASA Astrophysics Data System (ADS)

Nemchinsky, Valerian

2011-11-01

Electrical current flowing through a metallic droplet after its detachment from the wire anode during gas metal arc welding (GMAW) is considered. Although the droplet has much higher electrical conductivity compared with the conductivity of the surrounding plasma, current cannot enter the droplet freely since doing so demands igniting of the cathode spot responsible for electron emission. A new mechanism of current flow through a metallic droplet is suggested: one part of the droplet has a potential, which is slightly below the floating potential; this part of the droplet collects ions from the plasma. The remaining portion of the droplet has a potential difference, which is slightly above the floating one. The latter section collects electrons which recombine with the ions collected by the rest of the droplet's surface. The maximum electric current that can flow through the droplet is estimated. It is shown that this current is on the order of a few tens of amperes.

Proof of concept Laplacian estimate derived for noninvasive tripolar concentric ring electrode with incorporated radius of the central disc and the widths of the concentric rings.

PubMed

Makeyev, Oleksandr; Lee, Colin; Besio, Walter G

2017-07-01

Tripolar concentric ring electrodes are showing great promise in a range of applications including braincomputer interface and seizure onset detection due to their superiority to conventional disc electrodes, in particular, in accuracy of surface Laplacian estimation. Recently, we proposed a general approach to estimation of the Laplacian for an (n + 1)-polar electrode with n rings using the (4n + 1)-point method for n ≥ 2 that allows cancellation of all the truncation terms up to the order of 2n. This approach has been used to introduce novel multipolar and variable inter-ring distances concentric ring electrode configurations verified using finite element method. The obtained results suggest their potential to improve Laplacian estimation compared to currently used constant interring distances tripolar concentric ring electrodes. One of the main limitations of the proposed (4n + 1)-point method is that the radius of the central disc and the widths of the concentric rings are not included and therefore cannot be optimized. This study incorporates these two parameters by representing the central disc and both concentric rings as clusters of points with specific radius and widths respectively as opposed to the currently used single point and concentric circles. A proof of concept Laplacian estimate is derived for a tripolar concentric ring electrode with non-negligible radius of the central disc and non-negligible widths of the concentric rings clearly demonstrating how both of these parameters can be incorporated into the (4n + 1)-point method.

Psychosocial risk factors and asthma among adults in Puerto Rico.

PubMed

Han, Yueh-Ying; Forno, Erick; Canino, Glorisa; Celedón, Juan C

2018-05-08

Asthma and psychosocial stressors are common among Puerto Rican adults living in the United States. We estimated the prevalence of current asthma, and examined potential psychosocial risk factors and current asthma, among adults in Puerto Rico. Cross-sectional study of 3,049 Puerto Ricans aged 18-64 years living in Puerto Rico between May 2014 and June 2016. A structured interview was conducted to obtain information on demographics, lifestyle, mental disorders, and respiratory health. Current asthma was defined as self-reported physician-diagnosed asthma and still having asthma. Multivariable logistic regression was used to examine psychosocial risk factors and current asthma. The estimated prevalence of current asthma was 10.2%. In a multivariable analysis, exposure to violence (odds ratio [OR] for each 1-point increment in a validated scale = 1.14, 95% confidence interval [CI] = 1.07 to 1.21) and a lifetime history of at least one suicide attempt (OR = 3.01, 95% CI = 1.80 to 5.01) were significantly associated with current asthma, independently of major depressive disorder. Moreover, a lifetime history of at least one suicide attempt was associated with co-existing asthma and chronic obstructive pulmonary disease (i.e., asthma-COPD overlap syndrome or ACOS (OR = 9.05, 95% CI = 3.32-24.67). Our findings suggest that asthma is a major health problem among adults in Puerto Rico, with psychosocial risk factors playing a significant role in asthma and ACOS. Addressing chronic stressors and mental illness should be part of comprehensive strategies to reduce asthma burden in this population.

Estimating Ocean Currents from Automatic Identification System Based Ship Drift Measurements

NASA Astrophysics Data System (ADS)

Jakub, Thomas D.

Ship drift is a technique that has been used over the last century and a half to estimate ocean currents. Several of the shortcomings of the ship drift technique include obtaining the data from multiple ships, the time delay in getting those ship positions to a data center for processing and the limited resolution based on the amount of time between position measurements. These shortcomings can be overcome through the use of the Automatic Identification System (AIS). AIS enables more precise ocean current estimates, the option of finer resolution and more timely estimates. In this work, a demonstration of the use of AIS to compute ocean currents is performed. A corresponding error and sensitivity analysis is performed to help identify under which conditions errors will be smaller. A case study in San Francisco Bay with constant AIS message updates was compared against high frequency radar and demonstrated ocean current magnitude residuals of 19 cm/s for ship tracks in a high signal to noise environment. These ship tracks were only minutes long compared to the normally 12 to 24 hour ship tracks. The Gulf of Mexico case study demonstrated the ability to estimate ocean currents over longer baselines and identified the dependency of the estimates on the accuracy of time measurements. Ultimately, AIS measurements when combined with ship drift can provide another method of estimating ocean currents, particularly when other measurements techniques are not available.

Estimating the density of honeybee colonies across their natural range to fill the gap in pollinator decline censuses.

PubMed

Jaffé, Rodolfo; Dietemann, Vincent; Allsopp, Mike H; Costa, Cecilia; Crewe, Robin M; Dall'olio, Raffaele; DE LA Rúa, Pilar; El-Niweiri, Mogbel A A; Fries, Ingemar; Kezic, Nikola; Meusel, Michael S; Paxton, Robert J; Shaibi, Taher; Stolle, Eckart; Moritz, Robin F A

2010-04-01

Although pollinator declines are a global biodiversity threat, the demography of the western honeybee (Apis mellifera) has not been considered by conservationists because it is biased by the activity of beekeepers. To fill this gap in pollinator decline censuses and to provide a broad picture of the current status of honeybees across their natural range, we used microsatellite genetic markers to estimate colony densities and genetic diversity at different locations in Europe, Africa, and central Asia that had different patterns of land use. Genetic diversity and colony densities were highest in South Africa and lowest in Northern Europe and were correlated with mean annual temperature. Confounding factors not related to climate, however, are also likely to influence genetic diversity and colony densities in honeybee populations. Land use showed a significantly negative influence over genetic diversity and the density of honeybee colonies over all sampling locations. In Europe honeybees sampled in nature reserves had genetic diversity and colony densities similar to those sampled in agricultural landscapes, which suggests that the former are not wild but may have come from managed hives. Other results also support this idea: putative wild bees were rare in our European samples, and the mean estimated density of honeybee colonies on the continent closely resembled the reported mean number of managed hives. Current densities of European honeybee populations are in the same range as those found in the adverse climatic conditions of the Kalahari and Saharan deserts, which suggests that beekeeping activities do not compensate for the loss of wild colonies. Our findings highlight the importance of reconsidering the conservation status of honeybees in Europe and of regarding beekeeping not only as a profitable business for producing honey, but also as an essential component of biodiversity conservation.

How Many Kinds of Birds Are There and Why Does It Matter?

PubMed

Barrowclough, George F; Cracraft, Joel; Klicka, John; Zink, Robert M

2016-01-01

Estimates of global species diversity have varied widely, primarily based on variation in the numbers derived from different inventory methods of arthropods and other small invertebrates. Within vertebrates, current diversity metrics for fishes, amphibians, and reptiles are known to be poor estimators, whereas those for birds and mammals are often assumed to be relatively well established. We show that avian evolutionary diversity is significantly underestimated due to a taxonomic tradition not found in most other taxonomic groups. Using a sample of 200 species taken from a list of 9159 biological species determined primarily by morphological criteria, we applied a diagnostic, evolutionary species concept to a morphological and distributional data set that resulted in an estimate of 18,043 species of birds worldwide, with a 95% confidence interval of 15,845 to 20,470. In a second, independent analysis, we examined intraspecific genetic data from 437 traditional avian species, finding an average of 2.4 evolutionary units per species, which can be considered proxies for phylogenetic species. Comparing recent lists of species to that used in this study (based primarily on morphology) revealed that taxonomic changes in the past 25 years have led to an increase of only 9%, well below what our results predict. Therefore, our molecular and morphological results suggest that the current taxonomy of birds understimates avian species diversity by at least a factor of two. We suggest that a revised taxonomy that better captures avian species diversity will enhance the quantification and analysis of global patterns of diversity and distribution, as well as provide a more appropriate framework for understanding the evolutionary history of birds.

National spending on health by source for 184 countries between 2013 and 2040.

PubMed

Dieleman, Joseph L; Templin, Tara; Sadat, Nafis; Reidy, Patrick; Chapin, Abigail; Foreman, Kyle; Haakenstad, Annie; Evans, Tim; Murray, Christopher J L; Kurowski, Christoph

2016-06-18

A general consensus exists that as a country develops economically, health spending per capita rises and the share of that spending that is prepaid through government or private mechanisms also rises. However, the speed and magnitude of these changes vary substantially across countries, even at similar levels of development. In this study, we use past trends and relationships to estimate future health spending, disaggregated by the source of those funds, to identify the financing trajectories that are likely to occur if current policies and trajectories evolve as expected. We extracted data from WHO's Health Spending Observatory and the Institute for Health Metrics and Evaluation's Financing Global Health 2015 report. We converted these data to a common purchasing power-adjusted and inflation-adjusted currency. We used a series of ensemble models and observed empirical norms to estimate future government out-of-pocket private prepaid health spending and development assistance for health. We aggregated each country's estimates to generate total health spending from 2013 to 2040 for 184 countries. We compared these estimates with each other and internationally recognised benchmarks. Global spending on health is expected to increase from US$7·83 trillion in 2013 to $18·28 (uncertainty interval 14·42-22·24) trillion in 2040 (in 2010 purchasing power parity-adjusted dollars). We expect per-capita health spending to increase annually by 2·7% (1·9-3·4) in high-income countries, 3·4% (2·4-4·2) in upper-middle-income countries, 3·0% (2·3-3·6) in lower-middle-income countries, and 2·4% (1·6-3·1) in low-income countries. Given the gaps in current health spending, these rates provide no evidence of increasing parity in health spending. In 1995 and 2015, low-income countries spent $0·03 for every dollar spent in high-income countries, even after adjusting for purchasing power, and the same is projected for 2040. Most importantly, health spending in many low-income countries is expected to remain low. Estimates suggest that, by 2040, only one (3%) of 34 low-income countries and 36 (37%) of 98 middle-income countries will reach the Chatham House goal of 5% of gross domestic product consisting of government health spending. Despite remarkable health gains, past health financing trends and relationships suggest that many low-income and lower-middle-income countries will not meet internationally set health spending targets and that spending gaps between low-income and high-income countries are unlikely to narrow unless substantive policy interventions occur. Although gains in health system efficiency can be used to make progress, current trends suggest that meaningful increases in health system resources will require concerted action. Bill & Melinda Gates Foundation. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multi-population Genomic Relationships for Estimating Current Genetic Variances Within and Genetic Correlations Between Populations.

PubMed

Wientjes, Yvonne C J; Bijma, Piter; Vandenplas, Jérémie; Calus, Mario P L

2017-10-01

Different methods are available to calculate multi-population genomic relationship matrices. Since those matrices differ in base population, it is anticipated that the method used to calculate genomic relationships affects the estimate of genetic variances, covariances, and correlations. The aim of this article is to define the multi-population genomic relationship matrix to estimate current genetic variances within and genetic correlations between populations. The genomic relationship matrix containing two populations consists of four blocks, one block for population 1, one block for population 2, and two blocks for relationships between the populations. It is known, based on literature, that by using current allele frequencies to calculate genomic relationships within a population, current genetic variances are estimated. In this article, we theoretically derived the properties of the genomic relationship matrix to estimate genetic correlations between populations and validated it using simulations. When the scaling factor of across-population genomic relationships is equal to the product of the square roots of the scaling factors for within-population genomic relationships, the genetic correlation is estimated unbiasedly even though estimated genetic variances do not necessarily refer to the current population. When this property is not met, the correlation based on estimated variances should be multiplied by a correction factor based on the scaling factors. In this study, we present a genomic relationship matrix which directly estimates current genetic variances as well as genetic correlations between populations. Copyright © 2017 by the Genetics Society of America.

The Pot Calling the Kettle Black? A Comparison of Measures of Current Tobacco Use

PubMed Central

ROSENMAN, ROBERT

2014-01-01

Researchers often use the discrepancy between self-reported and biochemically assessed active smoking status to argue that self-reported smoking status is not reliable, ignoring the limitations of biochemically assessed measures and treating it as the gold standard in their comparisons. Here, we employ econometric techniques to compare the accuracy of self-reported and biochemically assessed current tobacco use, taking into account measurement errors with both methods. Our approach allows estimating and comparing the sensitivity and specificity of each measure without directly observing true smoking status. The results, robust to several alternative specifications, suggest that there is no clear reason to think that one measure dominates the other in accuracy. PMID:25587199

A Review of the Impact of Maternal Obesity on the Cognitive Function and Mental Health of the Offspring.

PubMed

Contu, Laura; Hawkes, Cheryl A

2017-05-19

Globally, more than 20% of women of reproductive age are currently estimated to be obese. Children born to obese mothers are at higher risk of developing obesity, coronary heart disease, diabetes, stroke, and asthma in adulthood. Increasing clinical and experimental evidence suggests that maternal obesity also affects the health and function of the offspring brain across the lifespan. This review summarizes the current findings from human and animal studies that detail the impact of maternal obesity on aspects of learning, memory, motivation, affective disorders, attention-deficit hyperactivity disorder, autism spectrum disorders, and neurodegeneration in the offspring. Epigenetic mechanisms that may contribute to this mother-child interaction are also discussed.

Botanical medicine and cancer: a review of the safety and efficacy.

PubMed

Boon, Heather; Wong, Jacqueline

2004-12-01

It is currently estimated that > 50% of all patients diagnosed with cancer explore complementary and alternative medicine - especially herbal medicine. We conducted a comprehensive review to assess the safety and efficacy of herbal medicines commonly used by patients in an attempt to: prevent cancer; treat cancer; and treat adverse effects associated with conventional cancer treatments. Current evidence suggests that Asian ginseng, garlic, green tea, tomatoes and soy intake as part of the diet may be useful in preventing various cancers; additional research is needed in order to determine the efficacy of essiac, evening primrose oil, mistletoe, reishi, shiitake and turmeric as cancer treatments; and ginger may be effective in treating chemotherapy-induced nausea and vomiting.

Methods to estimate the between‐study variance and its uncertainty in meta‐analysis†

PubMed Central

Jackson, Dan; Viechtbauer, Wolfgang; Bender, Ralf; Bowden, Jack; Knapp, Guido; Kuss, Oliver; Higgins, Julian PT; Langan, Dean; Salanti, Georgia

2015-01-01

Meta‐analyses are typically used to estimate the overall/mean of an outcome of interest. However, inference about between‐study variability, which is typically modelled using a between‐study variance parameter, is usually an additional aim. The DerSimonian and Laird method, currently widely used by default to estimate the between‐study variance, has been long challenged. Our aim is to identify known methods for estimation of the between‐study variance and its corresponding uncertainty, and to summarise the simulation and empirical evidence that compares them. We identified 16 estimators for the between‐study variance, seven methods to calculate confidence intervals, and several comparative studies. Simulation studies suggest that for both dichotomous and continuous data the estimator proposed by Paule and Mandel and for continuous data the restricted maximum likelihood estimator are better alternatives to estimate the between‐study variance. Based on the scenarios and results presented in the published studies, we recommend the Q‐profile method and the alternative approach based on a ‘generalised Cochran between‐study variance statistic’ to compute corresponding confidence intervals around the resulting estimates. Our recommendations are based on a qualitative evaluation of the existing literature and expert consensus. Evidence‐based recommendations require an extensive simulation study where all methods would be compared under the same scenarios. © 2015 The Authors. Research Synthesis Methods published by John Wiley & Sons Ltd. PMID:26332144

Estimating Counterfactual Risk Under Hypothetical Interventions in the Presence of Competing Events: Crystalline Silica Exposure and Mortality From two Causes of Death.

PubMed

Neophytou, Andreas M; Picciotto, Sally; Brown, Daniel M; Gallagher, Lisa E; Checkoway, Harvey; Eisen, Ellen A; Costello, Sadie

2018-04-03

Exposure to silica has been linked to excess risk of lung cancer and non-malignant respiratory disease mortality. In this study we estimated risk for both these outcomes in relation to occupational silica exposure as well as the reduction in risk that would result from hypothetical interventions on exposure in a cohort of exposed workers. Analyses were carried out in an all-male study population consisting of 2342 California diatomaceous earth workers regularly exposed to crystalline silica, followed between 1942 and 2011. We estimated subdistribution risk for each event under the natural course and interventions of interest using the parametric g-formula to adjust for healthy worker survivor bias. The risk ratio for lung cancer mortality comparing an intervention in which a theoretical maximum exposure limit was set at 0.05 mg/m3 (the current U.S. regulatory limit) to the observed exposure concentrations was 0.86 (95% confidence interval: 0.63, 1.22). The corresponding risk ratio for non-malignant respiratory disease mortality was 0.69 (95% confidence interval: 0.52, 0.93). Our findings suggest that risks from both outcomes would have been considerably lower if historical silica exposures in this cohort had not exceeded current regulatory limits.

Recurrent vulvovaginal candidiasis.

PubMed

Blostein, Freida; Levin-Sparenberg, Elizabeth; Wagner, Julian; Foxman, Betsy

2017-09-01

Recurrent vulvovaginal candidiasis (RVVC), multiple episodes of vulvovaginal candidiasis (VVC; vaginal yeast infection) within a 12-month period, adversely affects quality of life, mental health, and sexual activity. Diagnosis is not straightforward, as VVC is defined by the combination of often nonspecific vaginal symptoms and the presence of yeast-which is a common vaginal commensal. Estimating the incidence and prevalence is challenging: most VVC is diagnosed and treated empirically, the availability for purchase of effective therapies over the counter enables self-diagnosis and treatment, and the duration of the relatively benign VVC symptoms is short, introducing errors into any estimates relying on medical records or patient recall. We evaluate current estimates of VVC and RVVC and provide new prevalence estimates using data from a 2011 seven-country (n = 7345) internet panel survey on VVC conducted by Ipsos Health (https://www.ipsos.com/en). We also evaluate information on VVC-associated visits using the National Ambulatory Medical Care Survey. The estimated probability of VVC by age 50 varied widely by country (from 23% to 49%, mean 39%), as did the estimated probability of RVVC after VVC (from 14% to 28%, mean 23%). However estimated, the probability of RVVC was high suggesting RVVC is a common condition. Copyright © 2017 Elsevier Inc. All rights reserved.

On the mass and orbit of the ninth planet

NASA Astrophysics Data System (ADS)

Ugwoke, Azubike Christian

2016-07-01

ON THE MASS AND ORBIT OF THE NINTH PLANET A new planet is currently being proposed in the literature.This yet to be observed planet has its mass and orbit yet to be determined. However, if this planet is to escape being labelled a plutinoid, it must posses all the characteristics of a planet as currently set by the IAU. In addition it must be massive enough to enable it couple into the gravitational potential of the sun. Our earlier paper on this issue has suggested that no new planets are expected beyond Neptune , due to the vanishing gravitational potential of the sun within that orbit.Any new planet must be indeed very massive to be gravitationally linked sufficiently to the sun. In the current paper we have obtained estimates for planet 9 orbit and mass using this method.

Convolution-based estimation of organ dose in tube current modulated CT

NASA Astrophysics Data System (ADS)

Tian, Xiaoyu; Segars, W. Paul; Dixon, Robert L.; Samei, Ehsan

2016-05-01

Estimating organ dose for clinical patients requires accurate modeling of the patient anatomy and the dose field of the CT exam. The modeling of patient anatomy can be achieved using a library of representative computational phantoms (Samei et al 2014 Pediatr. Radiol. 44 460-7). The modeling of the dose field can be challenging for CT exams performed with a tube current modulation (TCM) technique. The purpose of this work was to effectively model the dose field for TCM exams using a convolution-based method. A framework was further proposed for prospective and retrospective organ dose estimation in clinical practice. The study included 60 adult patients (age range: 18-70 years, weight range: 60-180 kg). Patient-specific computational phantoms were generated based on patient CT image datasets. A previously validated Monte Carlo simulation program was used to model a clinical CT scanner (SOMATOM Definition Flash, Siemens Healthcare, Forchheim, Germany). A practical strategy was developed to achieve real-time organ dose estimation for a given clinical patient. CTDIvol-normalized organ dose coefficients ({{h}\\text{Organ}} ) under constant tube current were estimated and modeled as a function of patient size. Each clinical patient in the library was optimally matched to another computational phantom to obtain a representation of organ location/distribution. The patient organ distribution was convolved with a dose distribution profile to generate {{≤ft(\\text{CTD}{{\\text{I}}\\text{vol}}\\right)}\\text{organ, \\text{convolution}}} values that quantified the regional dose field for each organ. The organ dose was estimated by multiplying {{≤ft(\\text{CTD}{{\\text{I}}\\text{vol}}\\right)}\\text{organ, \\text{convolution}}} with the organ dose coefficients ({{h}\\text{Organ}} ). To validate the accuracy of this dose estimation technique, the organ dose of the original clinical patient was estimated using Monte Carlo program with TCM profiles explicitly modeled. The discrepancy between the estimated organ dose and dose simulated using TCM Monte Carlo program was quantified. We further compared the convolution-based organ dose estimation method with two other strategies with different approaches of quantifying the irradiation field. The proposed convolution-based estimation method showed good accuracy with the organ dose simulated using the TCM Monte Carlo simulation. The average percentage error (normalized by CTDIvol) was generally within 10% across all organs and modulation profiles, except for organs located in the pelvic and shoulder regions. This study developed an improved method that accurately quantifies the irradiation field under TCM scans. The results suggested that organ dose could be estimated in real-time both prospectively (with the localizer information only) and retrospectively (with acquired CT data).

Alternating steady state free precession for estimation of current-induced magnetic flux density: A feasibility study.

PubMed

Lee, Hyunyeol; Jeong, Woo Chul; Kim, Hyung Joong; Woo, Eung Je; Park, Jaeseok

2016-05-01

To develop a novel, current-controlled alternating steady-state free precession (SSFP)-based conductivity imaging method and corresponding MR signal models to estimate current-induced magnetic flux density (Bz ) and conductivity distribution. In the proposed method, an SSFP pulse sequence, which is in sync with alternating current pulses, produces dual oscillating steady states while yielding nonlinear relation between signal phase and Bz . A ratiometric signal model between the states was analytically derived using the Bloch equation, wherein Bz was estimated by solving a nonlinear inverse problem for conductivity estimation. A theoretical analysis on the signal-to-noise ratio of Bz was given. Numerical and experimental studies were performed using SSFP-FID and SSFP-ECHO with current pulses positioned either before or after signal encoding to investigate the feasibility of the proposed method in conductivity estimation. Given all SSFP variants herein, SSFP-FID with alternating current pulses applied before signal encoding exhibits the highest Bz signal-to-noise ratio and conductivity contrast. Additionally, compared with conventional conductivity imaging, the proposed method benefits from rapid SSFP acquisition without apparent loss of conductivity contrast. We successfully demonstrated the feasibility of the proposed method in estimating current-induced Bz and conductivity distribution. It can be a promising, rapid imaging strategy for quantitative conductivity imaging. © 2015 Wiley Periodicals, Inc.

Current-induced alternating reversed dual-echo-steady-state for joint estimation of tissue relaxation and electrical properties.

PubMed

Lee, Hyunyeol; Sohn, Chul-Ho; Park, Jaeseok

2017-07-01

To develop a current-induced, alternating reversed dual-echo-steady-state-based magnetic resonance electrical impedance tomography for joint estimation of tissue relaxation and electrical properties. The proposed method reverses the readout gradient configuration of conventional, in which steady-state-free-precession (SSFP)-ECHO is produced earlier than SSFP-free-induction-decay (FID) while alternating current pulses are applied in between the two SSFPs to secure high sensitivity of SSFP-FID to injection current. Additionally, alternating reversed dual-echo-steady-state signals are modulated by employing variable flip angles over two orthogonal injections of current pulses. Ratiometric signal models are analytically constructed, from which T 1 , T 2 , and current-induced B z are jointly estimated by solving a nonlinear inverse problem for conductivity reconstruction. Numerical simulations and experimental studies are performed to investigate the feasibility of the proposed method in estimating relaxation parameters and conductivity. The proposed method, if compared with conventional magnetic resonance electrical impedance tomography, enables rapid data acquisition and simultaneous estimation of T 1 , T 2 , and current-induced B z , yielding a comparable level of signal-to-noise ratio in the parameter estimates while retaining a relative conductivity contrast. We successfully demonstrated the feasibility of the proposed method in jointly estimating tissue relaxation parameters as well as conductivity distributions. It can be a promising, rapid imaging strategy for quantitative conductivity estimation. Magn Reson Med 78:107-120, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Adult Current Smoking: Differences in Definitions and Prevalence Estimates—NHIS and NSDUH, 2008

PubMed Central

Ryan, Heather; Trosclair, Angela; Gfroerer, Joe

2012-01-01

Objectives. To compare prevalence estimates and assess issues related to the measurement of adult cigarette smoking in the National Health Interview Survey (NHIS) and the National Survey on Drug Use and Health (NSDUH). Methods. 2008 data on current cigarette smoking and current daily cigarette smoking among adults ≥18 years were compared. The standard NHIS current smoking definition, which screens for lifetime smoking ≥100 cigarettes, was used. For NSDUH, both the standard current smoking definition, which does not screen, and a modified definition applying the NHIS current smoking definition (i.e., with screen) were used. Results. NSDUH consistently yielded higher current cigarette smoking estimates than NHIS and lower daily smoking estimates. However, with use of the modified NSDUH current smoking definition, a notable number of subpopulation estimates became comparable between surveys. Younger adults and racial/ethnic minorities were most impacted by the lifetime smoking screen, with Hispanics being the most sensitive to differences in smoking variable definitions among all subgroups. Conclusions. Differences in current cigarette smoking definitions appear to have a greater impact on smoking estimates in some sub-populations than others. Survey mode differences may also limit intersurvey comparisons and trend analyses. Investigators are cautioned to use data most appropriate for their specific research questions. PMID:22649464

On the applicability of surrogate-based Markov chain Monte Carlo-Bayesian inversion to the Community Land Model: Case studies at flux tower sites: SURROGATE-BASED MCMC FOR CLM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan

2016-07-04

The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesianmore » model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically-average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. Analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.« less

On the applicability of surrogate-based MCMC-Bayesian inversion to the Community Land Model: Case studies at Flux tower sites

DOE PAGES

Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan; ...

2016-06-01

The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesianmore » model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. As a result, analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.« less

On the applicability of surrogate-based MCMC-Bayesian inversion to the Community Land Model: Case studies at Flux tower sites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan

The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesianmore » model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. As a result, analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.« less

On the applicability of surrogate-based Markov chain Monte Carlo-Bayesian inversion to the Community Land Model: Case studies at flux tower sites

NASA Astrophysics Data System (ADS)

Huang, Maoyi; Ray, Jaideep; Hou, Zhangshuan; Ren, Huiying; Liu, Ying; Swiler, Laura

2016-07-01

The Community Land Model (CLM) has been widely used in climate and Earth system modeling. Accurate estimation of model parameters is needed for reliable model simulations and predictions under current and future conditions, respectively. In our previous work, a subset of hydrological parameters has been identified to have significant impact on surface energy fluxes at selected flux tower sites based on parameter screening and sensitivity analysis, which indicate that the parameters could potentially be estimated from surface flux observations at the towers. To date, such estimates do not exist. In this paper, we assess the feasibility of applying a Bayesian model calibration technique to estimate CLM parameters at selected flux tower sites under various site conditions. The parameters are estimated as a joint probability density function (PDF) that provides estimates of uncertainty of the parameters being inverted, conditional on climatologically average latent heat fluxes derived from observations. We find that the simulated mean latent heat fluxes from CLM using the calibrated parameters are generally improved at all sites when compared to those obtained with CLM simulations using default parameter sets. Further, our calibration method also results in credibility bounds around the simulated mean fluxes which bracket the measured data. The modes (or maximum a posteriori values) and 95% credibility intervals of the site-specific posterior PDFs are tabulated as suggested parameter values for each site. Analysis of relationships between the posterior PDFs and site conditions suggests that the parameter values are likely correlated with the plant functional type, which needs to be confirmed in future studies by extending the approach to more sites.

Size, skills, and suffrage: Motivated distortions in perceived formidability of political leaders

PubMed Central

Blaker, Nancy M.; Pollet, Thomas V.

2017-01-01

Research shows that perception of physical size and status are positively associated. The current study was developed to replicate and extend earlier research on height perceptions of political leaders, indicating that supporters perceive their leaders as taller than non-supporters do, and winners are perceived as taller after the elections, while losers are perceived as shorter after the elections (winner/loser effects). Individuals use greater height and strength as indications of greater physical formidability. We hypothesized that in-group leaders’ height and strength, but not weight, would be overestimated more compared to out-group leaders’, and that this status-size association is not only driven by dominance, but also by prestige. We also tested whether previously found gender effects in estimates were due to using one’s own height as an anchor, and we used an improved methodological approach by relying on multiple measurements of physical formidability and a within-subject design for testing winner/loser effects. The results of a two-part longitudinal study (self-selected sample via voting advice website; NWave1 = 2,011; NWave2 = 322) suggest that estimated physical formidability of political leaders is affected by motivated perception, as prestige was positively associated with estimated formidability, and in-group leaders were estimated more formidable than out-group leaders. We conclude that distortions in judged formidability related to social status are the result of motivated social perception in order to promote group functioning and leadership. Although we did not replicate a winner-effect (greater estimations of formidability after winning the elections), we did find some evidence for a loser-effect. Earlier suggestions that men make larger estimations than women because of their own larger body size are not supported. Implications for theory and future research are discussed. PMID:29267275

Estimated numbers of men and women infected with HIV/AIDS in Tijuana, Mexico.

PubMed

Brouwer, Kimberly C; Strathdee, Steffanie A; Magis-Rodríguez, Carlos; Bravo-García, Enrique; Gayet, Cecilia; Patterson, Thomas L; Bertozzi, Stefano M; Hogg, Robert S

2006-03-01

Tijuana, Mexico, just south of San Diego, California, is located by the busiest land border crossing in the world. Although UNAIDS considers Mexico to be a country of "low prevalence, high risk," recent surveillance data among sentinel populations in Tijuana suggests HIV prevalence is increasing. The aim of this study was to estimate the number of men and women aged 15 to 49 years infected with HIV in Tijuana. Gender and age-specific estimates of the Tijuana population were obtained from the 2000 Mexican census. Population and HIV prevalence estimates for at-risk groups were obtained from published reports, community based studies, and data from the Centro Nacional para la Prevención y Control del VIH/SIDA (CENSIDA). Age-specific fertility rates for Mexico were used to derive the number of low and high-risk pregnant women. Numbers of HIV-positive men and women were estimated for each at-risk group and then aggregated. A high growth scenario based on current HIV prevalence and a conservative, low growth estimate were determined. A total of 686,600 men and women in Tijuana were aged 15 to 49 years at the time of the 2000 census. Considering both scenarios, the number of infected persons ranged from 1,803 to 5,472 (HIV prevalence: 0.26 to 0.80%). The majority of these persons were men (>70%). The largest number of infected persons were MSM (N = 1,146 to 3,300) and IDUs (N = 147 to 650). Our data suggest that up to one in every 125 persons aged 15-49 years in Tijuana is HIV-infected. Interventions to reduce ongoing spread of HIV are urgently needed.

Comparison of blood flow models and acquisitions for quantitative myocardial perfusion estimation from dynamic CT

NASA Astrophysics Data System (ADS)

Bindschadler, Michael; Modgil, Dimple; Branch, Kelley R.; La Riviere, Patrick J.; Alessio, Adam M.

2014-04-01

Myocardial blood flow (MBF) can be estimated from dynamic contrast enhanced (DCE) cardiac CT acquisitions, leading to quantitative assessment of regional perfusion. The need for low radiation dose and the lack of consensus on MBF estimation methods motivates this study to refine the selection of acquisition protocols and models for CT-derived MBF. DCE cardiac CT acquisitions were simulated for a range of flow states (MBF = 0.5, 1, 2, 3 ml (min g)-1, cardiac output = 3, 5, 8 L min-1). Patient kinetics were generated by a mathematical model of iodine exchange incorporating numerous physiological features including heterogenenous microvascular flow, permeability and capillary contrast gradients. CT acquisitions were simulated for multiple realizations of realistic x-ray flux levels. CT acquisitions that reduce radiation exposure were implemented by varying both temporal sampling (1, 2, and 3 s sampling intervals) and tube currents (140, 70, and 25 mAs). For all acquisitions, we compared three quantitative MBF estimation methods (two-compartment model, an axially-distributed model, and the adiabatic approximation to the tissue homogeneous model) and a qualitative slope-based method. In total, over 11 000 time attenuation curves were used to evaluate MBF estimation in multiple patient and imaging scenarios. After iodine-based beam hardening correction, the slope method consistently underestimated flow by on average 47.5% and the quantitative models provided estimates with less than 6.5% average bias and increasing variance with increasing dose reductions. The three quantitative models performed equally well, offering estimates with essentially identical root mean squared error (RMSE) for matched acquisitions. MBF estimates using the qualitative slope method were inferior in terms of bias and RMSE compared to the quantitative methods. MBF estimate error was equal at matched dose reductions for all quantitative methods and range of techniques evaluated. This suggests that there is no particular advantage between quantitative estimation methods nor to performing dose reduction via tube current reduction compared to temporal sampling reduction. These data are important for optimizing implementation of cardiac dynamic CT in clinical practice and in prospective CT MBF trials.

Characterization of X Chromosome Inactivation Using Integrated Analysis of Whole-Exome and mRNA Sequencing

PubMed Central

Szelinger, Szabolcs; Malenica, Ivana; Corneveaux, Jason J.; Siniard, Ashley L.; Kurdoglu, Ahmet A.; Ramsey, Keri M.; Schrauwen, Isabelle; Trent, Jeffrey M.; Narayanan, Vinodh; Huentelman, Matthew J.; Craig, David W.

2014-01-01

In females, X chromosome inactivation (XCI) is an epigenetic, gene dosage compensatory mechanism by inactivation of one copy of X in cells. Random XCI of one of the parental chromosomes results in an approximately equal proportion of cells expressing alleles from either the maternally or paternally inherited active X, and is defined by the XCI ratio. Skewed XCI ratio is suggestive of non-random inactivation, which can play an important role in X-linked genetic conditions. Current methods rely on indirect, semi-quantitative DNA methylation-based assay to estimate XCI ratio. Here we report a direct approach to estimate XCI ratio by integrated, family-trio based whole-exome and mRNA sequencing using phase-by-transmission of alleles coupled with allele-specific expression analysis. We applied this method to in silico data and to a clinical patient with mild cognitive impairment but no clear diagnosis or understanding molecular mechanism underlying the phenotype. Simulation showed that phased and unphased heterozygous allele expression can be used to estimate XCI ratio. Segregation analysis of the patient's exome uncovered a de novo, interstitial, 1.7 Mb deletion on Xp22.31 that originated on the paternally inherited X and previously been associated with heterogeneous, neurological phenotype. Phased, allelic expression data suggested an 83∶20 moderately skewed XCI that favored the expression of the maternally inherited, cytogenetically normal X and suggested that the deleterious affect of the de novo event on the paternal copy may be offset by skewed XCI that favors expression of the wild-type X. This study shows the utility of integrated sequencing approach in XCI ratio estimation. PMID:25503791

Assessment of Global Annual Atmospheric Energy Balance from Satellite Observations

NASA Technical Reports Server (NTRS)

Lin, Bing; Stackhouse, Paul; Minnis, Patrick; Wielicki, Bruce A.; Hu, Yongxiang; Sun, Wenbo; Fan, Tai-Fang (Alice); Hinkelman, Laura

2008-01-01

Global atmospheric energy balance is one of the fundamental processes for the earth's climate system. This study uses currently available satellite data sets of radiative energy at the top of atmosphere (TOA) and surface and latent and sensible heat over oceans for the year 2000 to assess the global annual energy budget. Over land, surface radiation data are used to constrain assimilated results and to force the radiation, turbulent heat, and heat storage into balance due to a lack of observation-based turbulent heat flux estimations. Global annual means of the TOA net radiation obtained from both direct measurements and calculations are close to zero. The net radiative energy fluxes into the surface and the surface latent heat transported into the atmosphere are about 113 and 86 Watts per square meter, respectively. The estimated atmospheric and surface heat imbalances are about -8 9 Watts per square meter, values that are within the uncertainties of surface radiation and sea surface turbulent flux estimates and likely systematic biases in the analyzed observations. The potential significant additional absorption of solar radiation within the atmosphere suggested by previous studies does not appear to be required to balance the energy budget the spurious heat imbalances in the current data are much smaller (about half) than those obtained previously and debated at about a decade ago. Progress in surface radiation and oceanic turbulent heat flux estimations from satellite measurements significantly reduces the bias errors in the observed global energy budgets of the climate system.

Effects of the opening of the Qinghai-Tibet Railway on municipal solid waste management generation in Lhasa.

PubMed

Ding, Xu-Tong; Wang, Ji-Hua

2018-03-01

Lhasa, the capital of Tibet, is located on the Tibetan Plateau. Accelerated economic development and flourishing tourism resulting from the opening of the Qinghai-Tibet Railway (QTR) have increased solid waste generation and contamination in recent years. Using data from Lhasa Statistical Yearbooks and previous studies, this study estimates the future population of permanent residents and tourists using the least squares method to extrapolate the population from 2015-2025, and evaluates the effects of the QTR on municipal solid waste (MSW) generation in Lhasa and estimates future MSW generation. There were approximately 1.35 million tourists in 2008 when the QTR had been operating for 2 years and MSW generation was approximately 470 tons per day. The amount of MSW generated increased dramatically with time after opening the QTR. This study estimates that MSW generation will reach 962 tons per day in 2025. Due to the existence of the QTR, increasing numbers of people are traveling to Lhasa, and tourism has driven the development of the local economy. During the studies, the proportion of MSW produced by tourists increased from 2.99% to 20.06%, and it is estimated that it will increase to 33.49% in 2025. If the current trend continues, Lhasa will face significant challenges from garbage disposal. This study analyzes the current situation of urban garbage treatment in Lhasa, and it suggests several options for improvement to MSW generation, transportation equipment, disposal, and resource recycling.

A direct estimate of poleward volume, heat, and freshwater fluxes at 59.5°N between Greenland and Scotland

NASA Astrophysics Data System (ADS)

Rossby, T.; Reverdin, Gilles; Chafik, Leon; Søiland, Henrik

2017-07-01

The meridional overturning circulation (MOC) in the North Atlantic plays a major role in the transport of heat from low to high latitudes. In this study, we combine recent measurements of currents from the surface to >700 m from a shipboard acoustic Doppler current profiler with Argo profiles (to 2000 m) to estimate poleward volume, heat, and freshwater flux at 59.5°N between Greenland and Scotland. This is made possible thanks to the vessel Nuka Arctica that operates on a 3 week schedule between Greenland and Denmark. For the period late 2012 to early 2016, the deseasoned mean meridional overturning circulation reaches a 18.4 ± 3.4 Sv maximum at the σθ = 27.55 kg m-3 isopycnal, which varies in depth from near the surface in the western Irminger Sea to 1000 m in Rockall Trough. The total heat and freshwater fluxes across 59.5°N = 399 ± 74 TW and -0.20 ± 0.04 Sv, where the uncertainties are principally due to that of the MOC. Analysis of altimetric sea surface height variations along exactly the same route reveals a somewhat stronger geostrophic flow north during this period compared to the 23 year mean suggesting that for a long-term mean the above flux estimates should be reduced slightly to 17.4 Sv, 377 TW, and -0.19 Sv, respectively, with the same estimate uncertainties. The ADCP program is ongoing.

Scoping the Impact of Changes in Population Age-Structure on the Future Burden of Foodborne Disease in The Netherlands, 2020–2060

PubMed Central

Bouwknegt, Martijn; van Pelt, Wilfrid; Havelaar, Arie H.

2013-01-01

A demographic shift towards a larger proportion of elderly in the Dutch population in the coming decades might change foodborne disease incidence and mortality. In the current study we focused on the age-specific changes in the occurrence of foodborne pathogens by combining age-specific demographic forecasts for 10-year periods between 2020 and 2060 with current age-specific infection probabilities for Campylobacter spp., non-typhoidal Salmonella, hepatitis A virus, acquired Toxoplasma gondii and Listeria monocytogenes. Disease incidence rates for the former three pathogens were estimated to change marginally, because increases and decreases in specific age groups cancelled out over all ages. Estimated incidence of reported cases per 100,000 for 2060 mounted to 12 (Salmonella), 51 (Campylobacter), 1.1 (hepatitis A virus) and 2.1 (Toxoplasma). For L. monocytogenes, incidence increased by 45% from 0.41 per 100,000 in 2011 to 0.60 per 100,000. Estimated mortality rates increased two-fold for Salmonella and Campylobacter to 0.5 and 0.7 per 100,000, and increased by 25% for Listeria from 0.06 to 0.08. This straightforward scoping effort does not suggest major changes in incidence and mortality for these food borne pathogens based on changes in de population age-structure as independent factor. Other factors, such as changes in health care systems, social clustering and food processing and preparation, could not be included in the estimates. PMID:23851976

Scoping the impact of changes in population age-structure on the future burden of foodborne disease in the Netherlands, 2020-2060.

PubMed

Bouwknegt, Martijn; van Pelt, Wilfrid; Havelaar, Arie H

2013-07-11

A demographic shift towards a larger proportion of elderly in the Dutch population in the coming decades might change foodborne disease incidence and mortality. In the current study we focused on the age-specific changes in the occurrence of foodborne pathogens by combining age-specific demographic forecasts for 10-year periods between 2020 and 2060 with current age-specific infection probabilities for Campylobacter spp., non-typhoidal Salmonella, hepatitis A virus, acquired Toxoplasma gondii and Listeria monocytogenes. Disease incidence rates for the former three pathogens were estimated to change marginally, because increases and decreases in specific age groups cancelled out over all ages. Estimated incidence of reported cases per 100,000 for 2060 mounted to 12 (Salmonella), 51 (Campylobacter), 1.1 (hepatitis A virus) and 2.1 (Toxoplasma). For L. monocytogenes, incidence increased by 45% from 0.41 per 100,000 in 2011 to 0.60 per 100,000. Estimated mortality rates increased two-fold for Salmonella and Campylobacter to 0.5 and 0.7 per 100,000, and increased by 25% for Listeria from 0.06 to 0.08. This straightforward scoping effort does not suggest major changes in incidence and mortality for these food borne pathogens based on changes in de population age-structure as independent factor. Other factors, such as changes in health care systems, social clustering and food processing and preparation, could not be included in the estimates.

A comparison of methods to estimate future sub-daily design rainfall

NASA Astrophysics Data System (ADS)

Li, J.; Johnson, F.; Evans, J.; Sharma, A.

2017-12-01

Warmer temperatures are expected to increase extreme short-duration rainfall due to the increased moisture-holding capacity of the atmosphere. While attention has been paid to the impacts of climate change on future design rainfalls at daily or longer time scales, the potential changes in short duration design rainfalls have been often overlooked due to the limited availability of sub-daily projections and observations. This study uses a high-resolution regional climate model (RCM) to predict the changes in sub-daily design rainfalls for the Greater Sydney region in Australia. Sixteen methods for predicting changes to sub-daily future extremes are assessed based on different options for bias correction, disaggregation and frequency analysis. A Monte Carlo cross-validation procedure is employed to evaluate the skill of each method in estimating the design rainfall for the current climate. It is found that bias correction significantly improves the accuracy of the design rainfall estimated for the current climate. For 1 h events, bias correcting the hourly annual maximum rainfall simulated by the RCM produces design rainfall closest to observations, whereas for multi-hour events, disaggregating the daily rainfall total is recommended. This suggests that the RCM fails to simulate the observed multi-duration rainfall persistence, which is a common issue for most climate models. Despite the significant differences in the estimated design rainfalls between different methods, all methods lead to an increase in design rainfalls across the majority of the study region.

Using change-point models to estimate empirical critical loads for nitrogen in mountain ecosystems.

PubMed

Roth, Tobias; Kohli, Lukas; Rihm, Beat; Meier, Reto; Achermann, Beat

2017-01-01

To protect ecosystems and their services, the critical load concept has been implemented under the framework of the Convention on Long-range Transboundary Air Pollution (UNECE) to develop effects-oriented air pollution abatement strategies. Critical loads are thresholds below which damaging effects on sensitive habitats do not occur according to current knowledge. Here we use change-point models applied in a Bayesian context to overcome some of the difficulties when estimating empirical critical loads for nitrogen (N) from empirical data. We tested the method using simulated data with varying sample sizes, varying effects of confounding variables, and with varying negative effects of N deposition on species richness. The method was applied to the national-scale plant species richness data from mountain hay meadows and (sub)alpine scrubs sites in Switzerland. Seven confounding factors (elevation, inclination, precipitation, calcareous content, aspect as well as indicator values for humidity and light) were selected based on earlier studies examining numerous environmental factors to explain Swiss vascular plant diversity. The estimated critical load confirmed the existing empirical critical load of 5-15 kg N ha -1 yr -1 for (sub)alpine scrubs, while for mountain hay meadows the estimated critical load was at the lower end of the current empirical critical load range. Based on these results, we suggest to narrow down the critical load range for mountain hay meadows to 10-15 kg N ha -1 yr -1 . Copyright © 2016 Elsevier Ltd. All rights reserved.

Demographic characteristics of an adfluvial bull trout population in Lake Pend Oreille, Idaho

USGS Publications Warehouse

McCubbins, Jonathan L; Hansen, Michael J.; DosSantos, Joseph M; Dux, Andrew M

2016-01-01

Introductions of nonnative species, habitat loss, and stream fragmentation have caused the Bull Trout Salvelinus confluentus to decline throughout much of its native distribution. Consequently, in June 1998, the Bull Trout was listed under the U.S. Endangered Species Act as threatened. The Bull Trout has existed in Lake Pend Oreille and its surrounding tributaries since the last ice age, and the lake once supported a world-renowned Bull Trout fishery. To quantify the current status of the Bull Trout population in Lake Pend Oreille, Idaho, we compared the mean age, growth, maturity, and abundance with reports in a study conducted one decade earlier. Abundance was estimated by mark–recapture for Bull Trout caught in trap nets and gill nets set in Lake Pend Oreille during ongoing suppression netting of Lake Trout S. namaycushin 2007–2008. Bull Trout sampled in 2006–2008 were used to estimate age structure, survival, growth, and maturity. Estimated Bull Trout abundance was similar to that estimated one decade earlier in Lake Pend Oreille. Bull Trout residing in Lake Pend Oreille between 2006 and 2008 were between ages 4 and 14 years; their growth was fastest between ages 1 and 2 and slowed thereafter. Male and female Bull Trout matured at a similar age, but females grew faster than males, thereby maturing at a larger size. Our findings suggest that management has effectively addressed current threats to increase the likelihood of long-term persistence of the Bull Trout population in Lake Pend Oreille.

Estimation of the number and demographics of companion dogs in the UK

PubMed Central

2011-01-01

Background Current estimates of the UK dog population vary, contain potential sources of bias and are based on expensive, large scale, public surveys. Here, we evaluate the potential of a variety of sources for estimation and monitoring of the companion dog population in the UK and associated demographic information. The sources considered were: a public survey; veterinary practices; pet insurance companies; micro-chip records; Kennel Club registrations; and the Pet Travel Scheme. The public survey and subpopulation estimates from veterinary practices, pet insurance companies and Kennel Club registrations, were combined to generate distinct estimates of the UK owned dog population using a Bayesian approach. Results We estimated there are 9.4 (95% CI: 8.1-11.5) million companion dogs in the UK according to the public survey alone, which is similar to other recent estimates. The population was judged to be over-estimated by combining the public and veterinary surveys (16.4, 95% CI: 12.5-21.5 million) and under-estimated by combining the public survey and insured dog numbers (4.8, 95% CI: 3.6-6.9 million). An estimate based on combining the public survey and Kennel Club registered dogs was 7.1 (95% CI: 4.5-12.9) million. Based on Bayesian estimations, 77 (95% CI: 62-92)% of the UK dog population were registered at a veterinary practice; 42 (95% CI: 29-55)% of dogs were insured; and 29 (95% CI: 17-43)% of dogs were Kennel Club registered. Breed demographics suggested the Labrador was consistently the most popular breed registered in micro-chip records, with the Kennel Club and with J. Sainsbury's PLC pet insurance. A comparison of the demographics between these sources suggested that popular working breeds were under-represented and certain toy, utility and miniature breeds were over- represented in the Kennel Club registrations. Density maps were produced from micro-chip records based on the geographical distribution of dogs. Conclusions A list containing the breed of each insured dog was provided by J. Sainsbury's PLC pet insurance without any accompanying information about the dog or owner. PMID:22112367

Tobacco Retail Environments and Social Inequalities in Individual-Level Smoking and Cessation Among Scottish Adults.

PubMed

Pearce, Jamie; Rind, Esther; Shortt, Niamh; Tisch, Catherine; Mitchell, Richard

2016-02-01

Many neighborhood characteristics may constrain or enable smoking. This study investigated whether the neighborhood tobacco retail environment was associated with individual-level smoking and cessation in Scottish adults, and whether inequalities in smoking status were related to tobacco retailing. Tobacco outlet density measures were developed for neighborhoods across Scotland using the September 2012 Scottish Tobacco Retailers Register. The outlet data were cleaned and geocoded (n = 10,161) using a Geographic Information System. Kernel density estimation was used to calculate an outlet density measure for each postcode. The kernel density estimation measures were then appended to data on individuals included in the 2008-2011 Scottish Health Surveys (n = 28,751 adults aged ≥16), via their postcode. Two-level logistic regression models examined whether neighborhood density of tobacco retailing was associated with current smoking status and smoking cessation and whether there were differences in the relationship between household income and smoking status, by tobacco outlet density. After adjustment for individual- and area-level confounders, compared to residents of areas with the lowest outlet densities, those living in areas with the highest outlet densities had a 6% higher chance of being a current smoker, and a 5% lower chance of being an ex-smoker. There was little evidence to suggest that inequalities in either current smoking or cessation were narrower in areas with lower availability of tobacco retailing. The findings suggest that residents of environments with a greater availability of tobacco outlets are more likely to start and/or sustain smoking, and less likely to quit. © The Author 2015. Published by Oxford University Press on behalf of the Society for Research on Nicotine and Tobacco. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

A genomic timescale of prokaryote evolution: insights into the origin of methanogenesis, phototrophy, and the colonization of land

PubMed Central

Battistuzzi, Fabia U; Feijao, Andreia; Hedges, S Blair

2004-01-01

Background The timescale of prokaryote evolution has been difficult to reconstruct because of a limited fossil record and complexities associated with molecular clocks and deep divergences. However, the relatively large number of genome sequences currently available has provided a better opportunity to control for potential biases such as horizontal gene transfer and rate differences among lineages. We assembled a data set of sequences from 32 proteins (~7600 amino acids) common to 72 species and estimated phylogenetic relationships and divergence times with a local clock method. Results Our phylogenetic results support most of the currently recognized higher-level groupings of prokaryotes. Of particular interest is a well-supported group of three major lineages of eubacteria (Actinobacteria, Deinococcus, and Cyanobacteria) that we call Terrabacteria and associate with an early colonization of land. Divergence time estimates for the major groups of eubacteria are between 2.5–3.2 billion years ago (Ga) while those for archaebacteria are mostly between 3.1–4.1 Ga. The time estimates suggest a Hadean origin of life (prior to 4.1 Ga), an early origin of methanogenesis (3.8–4.1 Ga), an origin of anaerobic methanotrophy after 3.1 Ga, an origin of phototrophy prior to 3.2 Ga, an early colonization of land 2.8–3.1 Ga, and an origin of aerobic methanotrophy 2.5–2.8 Ga. Conclusions Our early time estimates for methanogenesis support the consideration of methane, in addition to carbon dioxide, as a greenhouse gas responsible for the early warming of the Earths' surface. Our divergence times for the origin of anaerobic methanotrophy are compatible with highly depleted carbon isotopic values found in rocks dated 2.8–2.6 Ga. An early origin of phototrophy is consistent with the earliest bacterial mats and structures identified as stromatolites, but a 2.6 Ga origin of cyanobacteria suggests that those Archean structures, if biologically produced, were made by anoxygenic photosynthesizers. The resistance to desiccation of Terrabacteria and their elaboration of photoprotective compounds suggests that the common ancestor of this group inhabited land. If true, then oxygenic photosynthesis may owe its origin to terrestrial adaptations. PMID:15535883

Leadership training design, delivery, and implementation: A meta-analysis.

PubMed

Lacerenza, Christina N; Reyes, Denise L; Marlow, Shannon L; Joseph, Dana L; Salas, Eduardo

2017-12-01

Recent estimates suggest that although a majority of funds in organizational training budgets tend to be allocated to leadership training (Ho, 2016; O'Leonard, 2014), only a small minority of organizations believe their leadership training programs are highly effective (Schwartz, Bersin, & Pelster, 2014), calling into question the effectiveness of current leadership development initiatives. To help address this issue, this meta-analysis estimates the extent to which leadership training is effective and identifies the conditions under which these programs are most effective. In doing so, we estimate the effectiveness of leadership training across four criteria (reactions, learning, transfer, and results; Kirkpatrick, 1959) using only employee data and we examine 15 moderators of training design and delivery to determine which elements are associated with the most effective leadership training interventions. Data from 335 independent samples suggest that leadership training is substantially more effective than previously thought, leading to improvements in reactions (δ = .63), learning (δ = .73), transfer (δ = .82), and results (δ = .72), the strength of these effects differs based on various design, delivery, and implementation characteristics. Moderator analyses support the use of needs analysis, feedback, multiple delivery methods (especially practice), spaced training sessions, a location that is on-site, and face-to-face delivery that is not self-administered. Results also suggest that the content of training, attendance policy, and duration influence the effectiveness of the training program. Practical implications for training development and theoretical implications for leadership and training literatures are discussed. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Doping in Two Elite Athletics Competitions Assessed by Randomized-Response Surveys.

PubMed

Ulrich, Rolf; Pope, Harrison G; Cléret, Léa; Petróczi, Andrea; Nepusz, Tamás; Schaffer, Jay; Kanayama, Gen; Comstock, R Dawn; Simon, Perikles

2018-01-01

Doping in sports compromises fair play and endangers health. To deter doping among elite athletes, the World Anti-Doping Agency (WADA) oversees testing of several hundred thousand athletic blood and urine samples annually, of which 1-2% test positive. Measures using the Athlete Biological Passport suggest a higher mean prevalence of about 14% positive tests. Biological testing, however, likely fails to detect many cutting-edge doping techniques, and thus the true prevalence of doping remains unknown. We surveyed 2167 athletes at two sporting events: the 13th International Association of Athletics Federations Word Championships in Athletics (WCA) in Daegu, South Korea in August 2011 and the 12th Quadrennial Pan-Arab Games (PAG) in Doha, Qatar in December 2011. To estimate the prevalence of doping, we utilized a "randomized response technique," which guarantees anonymity for individuals when answering a sensitive question. We also administered a control question at PAG assessing past-year use of supplements. The estimated prevalence of past-year doping was 43.6% (95% confidence interval 39.4-47.9) at WCA and 57.1% (52.4-61.8) at PAG. The estimated prevalence of past-year supplement use at PAG was 70.1% (65.6-74.7%). Sensitivity analyses, assessing the robustness of these estimates under numerous hypothetical scenarios of intentional or unintentional noncompliance by respondents, suggested that we were unlikely to have overestimated the true prevalence of doping. Doping appears remarkably widespread among elite athletes, and remains largely unchecked despite current biological testing. The survey technique presented here will allow future investigators to generate continued reference estimates of the prevalence of doping.

New forecasting methodology indicates more disease and earlier mortality ahead for today's younger Americans.

PubMed

Reither, Eric N; Olshansky, S Jay; Yang, Yang

2011-08-01

Traditional methods of projecting population health statistics, such as estimating future death rates, can give inaccurate results and lead to inferior or even poor policy decisions. A new "three-dimensional" method of forecasting vital health statistics is more accurate because it takes into account the delayed effects of the health risks being accumulated by today's younger generations. Applying this forecasting technique to the US obesity epidemic suggests that future death rates and health care expenditures could be far worse than currently anticipated. We suggest that public policy makers adopt this more robust forecasting tool and redouble efforts to develop and implement effective obesity-related prevention programs and interventions.

Progress Toward HIV Eradication: Case Reports, Current Efforts, and the Challenges Associated with Cure.

PubMed

Martin, Alyssa R; Siliciano, Robert F

2016-01-01

An estimated 35 million people worldwide are infected with HIV, yet a widely applicable cure strategy remains elusive. Recent case reports have suggested that curing HIV infection is possible, renewing excitement about research efforts. We describe those cases and discuss their relevance to the global HIV epidemic. We also review ongoing cure strategies that are transitioning from the lab to the clinic, and the assays and clinical assessments that can be used to evaluate cure interventions.

Estimates of expansion time scales. [Settlement of Galaxy by spacefaring civilization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, E.M.

1979-01-01

Monte Carlo simulations of the expansion of a spacefaring civilization show that descendants of that civilization should be found near virtually every useful star in the Galaxy in a time much less than the current age of the Galaxy. Only extreme assumptions about local population growth rates, emigration rates, or ship ranges can slow or halt an expansion. The apparent absence of extraterrestrials from the solar system suggests that no such civilization has arisen in the Galaxy. 1 figure.

Public perceptions of a rip current hazard education program: "Break the Grip of the Rip!"

NASA Astrophysics Data System (ADS)

Houser, Chris; Trimble, Sarah; Brander, Robert; Brewster, B. Chris; Dusek, Greg; Jones, Deborah; Kuhn, John

2017-07-01

Rip currents pose a major global beach hazard; estimates of annual rip-current-related deaths in the United States alone range from 35 to 100 per year. Despite increased social research into beach-goer experience, little is known about levels of rip current knowledge within the general population. This study describes the results of an online survey to determine the extent of rip current knowledge across the United States, with the aim of improving and enhancing existing beach safety education material. Results suggest that the US-based Break the Grip of the Rip!® campaign has been successful in educating the public about rip current safety directly or indirectly, with the majority of respondents able to provide an accurate description of how to escape a rip current. However, the success of the campaign is limited by discrepancies between personal observations at the beach and rip forecasts that are broadcasted for a large area and time. It was the infrequent beach user that identified the largest discrepancies between the forecast and their observations. Since infrequent beach users also do not seek out lifeguards or take the same precautions as frequent beach users, it is argued that they are also at greatest risk of being caught in a dangerous situation. Results of this study suggest a need for the national campaign to provide greater focus on locally specific and verified rip forecasts and signage in coordination with lifeguards, but not at the expense of the successful national awareness program.

Estimating aboveground live understory vegetation carbon in the United States

NASA Astrophysics Data System (ADS)

Johnson, Kristofer D.; Domke, Grant M.; Russell, Matthew B.; Walters, Brian; Hom, John; Peduzzi, Alicia; Birdsey, Richard; Dolan, Katelyn; Huang, Wenli

2017-12-01

Despite the key role that understory vegetation plays in ecosystems and the terrestrial carbon cycle, it is often overlooked and has few quantitative measurements, especially at national scales. To understand the contribution of understory carbon to the United States (US) carbon budget, we developed an approach that relies on field measurements of understory vegetation cover and height on US Department of Agriculture Forest Service, Forest Inventory and Analysis (FIA) subplots. Allometric models were developed to estimate aboveground understory carbon. A spatial model based on stand characteristics and remotely sensed data was also applied to estimate understory carbon on all FIA plots. We found that most understory carbon was comprised of woody shrub species (64%), followed by nonwoody forbs and graminoid species (35%) and seedlings (1%). The largest estimates were found in temperate or warm humid locations such as the Pacific Northwest and southeastern US, thus following the same broad trend as aboveground tree biomass. The average understory aboveground carbon density was estimated to be 0.977 Mg ha-1, for a total estimate of 272 Tg carbon across all managed forest land in the US (approximately 2% of the total aboveground live tree carbon pool). This estimate is more than twice as low as previous FIA modeled estimates that did not rely on understory measurements, suggesting that this pool may currently be overestimated in US National Greenhouse Gas reporting.

Application of DNA barcoding in biodiversity studies of shallow-water octocorals: molecular proxies agree with morphological estimates of species richness in Palau

NASA Astrophysics Data System (ADS)

McFadden, C. S.; Brown, A. S.; Brayton, C.; Hunt, C. B.; van Ofwegen, L. P.

2014-06-01

The application of DNA barcoding to anthozoan cnidarians has been hindered by their slow rates of mitochondrial gene evolution and the failure to identify alternative molecular markers that distinguish species reliably. Among octocorals, however, multilocus barcodes can distinguish up to 70 % of morphospecies, thereby facilitating the identification of species that are ecologically important but still very poorly known taxonomically. We tested the ability of these imperfect DNA barcodes to estimate species richness in a biodiversity survey of the shallow-water octocoral fauna of Palau using multilocus ( COI, mtMutS, 28S rDNA) sequences obtained from 305 specimens representing 38 genera of octocorals. Numbers and identities of species were estimated independently (1) by a taxonomic expert using morphological criteria and (2) by assigning sequences to molecular operational taxonomic units (MOTUs) using predefined genetic distance thresholds. Estimated numbers of MOTUs ranged from 73 to 128 depending on the barcode and distance threshold applied, bracketing the estimated number of 118 morphospecies. Concordance between morphospecies identifications and MOTUs ranged from 71 to 75 % and differed little among barcodes. For the speciose and ecologically dominant genus Sinularia, however, we were able to identify 95 % of specimens correctly simply by comparing mtMutS sequences and in situ photographs of colonies to an existing vouchered database. Because we lack a clear understanding of species boundaries in most of these taxa, numbers of morphospecies and MOTUs are both estimates of the true species diversity, and we cannot currently determine which is more accurate. Our results suggest, however, that the two methods provide comparable estimates of species richness for shallow-water Indo-Pacific octocorals. Use of molecular barcodes in biodiversity surveys will facilitate comparisons of species richness and composition among localities and over time, data that do not currently exist for any octocoral community.

Sodium intake in US ethnic subgroups and potential impact of a new sodium reduction technology: NHANES Dietary Modeling.

PubMed

Fulgoni, Victor L; Agarwal, Sanjiv; Spence, Lisa; Samuel, Priscilla

2014-12-18

Because excessive dietary sodium intake is a major contributor to hypertension, a reduction in dietary sodium has been recommended for the US population. Using the National Health and Nutrition Examination Survey (NHANES) 2007-2010 data, we estimated current sodium intake in US population ethnic subgroups and modeled the potential impact of a new sodium reduction technology on sodium intake. NHANES 2007-2010 data were analyzed using The National Cancer Institute method to estimate usual intake in population subgroups. Potential impact of SODA-LO® Salt Microspheres sodium reduction technology on sodium intake was modeled using suggested sodium reductions of 20-30% in 953 foods and assuming various market penetrations. SAS 9.2, SUDAAN 11, and NHANES survey weights were used in all calculations with assessment across age, gender and ethnic groups. Current sodium intake across all population subgroups exceeds the Dietary Guidelines 2010 recommendations and has not changed during the last decade. However, sodium intake measured as a function of food intake has decreased significantly during the last decade for all ethnicities. "Grain Products" and "Meat, Poultry, Fish, & Mixtures" contribute about 2/3rd of total sodium intake. Sodium reduction, using SODA-LO® Salt Microspheres sodium reduction technology (with 100% market penetration) was estimated to be 185-323 mg/day or 6.3-8.4% of intake depending upon age, gender and ethnic group. Current sodium intake in US ethnic subgroups exceeds the recommendations and sodium reduction technologies could potentially help reduce dietary sodium intake among those groups.

Observations of the southern East Madagascar Current and undercurrent and countercurrent system

NASA Astrophysics Data System (ADS)

Nauw, J. J.; van Aken, H. M.; Webb, A.; Lutjeharms, J. R. E.; de Ruijter, W. P. M.

2008-08-01

In April 2001 four hydrographic sections perpendicular to the southern East Madagascar Current were surveyed as part of the Agulhas Current Sources Experiment. Observations with a vessel mounted and a lowered ADCP produced information on the current field while temperature, salinity, oxygen and nutrient data obtained with a CTD-Rosette system, gave information on the water mass structure of the currents southeast of Madagascar. The peak velocity in the pole-ward East Madagascar Current through these four sections had a typical magnitude of ˜110 cm/s, while the width of this current was of the order of 120 km. The mean pole-ward volume transport rate of this current during the survey above the 5°C isotherm was estimated to be 37 ± 10 Sv. On all four sections an undercurrent was observed at intermediate depths below the East Madagascar Current. Its equator-ward transport rate amounted to 2.8 ± 1.4 Sv. Offshore of the East Madagascar Current the shallow South Indian Ocean Countercurrent was observed. This eastward frontal jet coincided with the barotropic and thermohaline front that separates the saline Subtropical Surface Water from the fresher Tropical Surface Water in the East Madagascar Current. The near-surface geostrophic flow of the East Madagascar Current, derived from satellite altimetry data from 1992 to 2005, suggests a strong variability of this transport due to eddy variability and interannual changes. The long-term pole-ward mean transport of the East Madagascar Current, roughly estimated from those altimetry data amounts to 32 Sv. The upper-ocean water mass of the East Madagascar Current was very saline in 2001, compared to WOCE surveys from 1995. Comparison of our undercurrent data with those of the WOCE surveys in 1995 confirms that the undercurrent is a recurrent feature. Its water mass properties are relatively saline, due to the presence of water originating from the Red Sea outflow at intermediate levels. The saline water was advected from the Mozambique Channel to the eastern slope of Madagascar.

Dating the origin and dispersal of Human Papillomavirus type 16 on the basis of ancestral human migrations.

PubMed

Zehender, Gianguglielmo; Frati, Elena Rosanna; Martinelli, Marianna; Bianchi, Silvia; Amendola, Antonella; Ebranati, Erika; Ciccozzi, Massimo; Galli, Massimo; Lai, Alessia; Tanzi, Elisabetta

2016-04-01

A major limitation when reconstructing the origin and evolution of HPV-16 is the lack of reliable substitution rate estimates for the viral genes. On the basis of the hypothesis of human HPV-16 co-divergence, we estimated a mean evolutionary rate of 1.47×10(-7) (95% HPD=0.64-2.47×10(-7)) subs/site/year for the viral LCR region. The results of a Bayesian phylogeographical analysis suggest that the currently circulating HPV-16 most probably originated in Africa about 110 thousand years ago (Kya), before giving rise to four known geographical lineages: the Asian/European lineage, which most probably originated in Asia a mean 38 Kya, and the Asian/American and two African lineages, which probably respectively originated about 33 and 27 Kya. These data closely reflect current hypotheses concerning modern human expansion based on studies of mitochondrial DNA phylogeny. The correlation between ancient human migration and the present HPV phylogeny may be explained by the co-existence of modes of transmission other than sexual transmission. Copyright © 2016. Published by Elsevier B.V.

Observations of pockmark flow structure in Belfast Bay, Maine, Part 2: evidence for cavity flow

USGS Publications Warehouse

Fandel, Christina L.; Lippmann, Thomas C.; Foster, Diane L.; Brothers, Laura L.

2017-01-01

Pockmark flow circulation patterns were investigated through current measurements along the rim and center of two pockmarks in Belfast Bay, Maine. Observed time-varying current profiles have a complex vertical and directional structure that rotates significantly with depth and is strongly dependent on the phase of the tide. Observations of the vertical profiles of horizontal velocities in relation to relative geometric parameters of the pockmark are consistent with circulation patterns described qualitatively by cavity flow models (Ashcroft and Zhang 2005). The time-mean behavior of the shear layer is typically used to characterize cavity flow, and was estimated using vorticity thickness to quantify the growth rate of the shear layer horizontally across the pockmark. Estimated positive vorticity thickness spreading rates are consistent with cavity flow predictions, and occur at largely different rates between the two pockmarks. Previously modeled flow (Brothers et al. 2011) and laboratory measurements (Pau et al. 2014) over pockmarks of similar geometry to those examined herein are also qualitatively consistent with cavity flow circulation, suggesting that cavity flow may be a good first-order flow model for pockmarks in general.

Low helium flux from the mantle inferred from simulations of oceanic helium isotope data

NASA Astrophysics Data System (ADS)

Bianchi, Daniele; Sarmiento, Jorge L.; Gnanadesikan, Anand; Key, Robert M.; Schlosser, Peter; Newton, Robert

2010-09-01

The high 3He/ 4He isotopic ratio of oceanic helium relative to the atmosphere has long been recognized as the signature of mantle 3He outgassing from the Earth's interior. The outgassing flux of helium is frequently used to normalize estimates of chemical fluxes of elements from the solid Earth, and provides a strong constraint to models of mantle degassing. Here we use a suite of ocean general circulation models and helium isotope data obtained by the World Ocean Circulation Experiment to constrain the flux of helium from the mantle to the oceans. Our results suggest that the currently accepted flux is overestimated by a factor of 2. We show that a flux of 527 ± 102 mol year - 1 is required for ocean general circulation models that produce distributions of ocean ventilation tracers such as radiocarbon and chlorofluorocarbons that match observations. This new estimate calls for a reevaluation of the degassing fluxes of elements that are currently tied to the helium fluxes, including noble gases and carbon dioxide.

Comparative life-cycle air emissions of coal, domestic natural gas, LNG, and SNG for electricity generation.

PubMed

Jaramillo, Paulina; Griffin, W Michael; Matthews, H Scott

2007-09-01

The U.S. Department of Energy (DOE) estimates that in the coming decades the United States' natural gas (NG) demand for electricity generation will increase. Estimates also suggest that NG supply will increasingly come from imported liquefied natural gas (LNG). Additional supplies of NG could come domestically from the production of synthetic natural gas (SNG) via coal gasification-methanation. The objective of this study is to compare greenhouse gas (GHG), SOx, and NOx life-cycle emissions of electricity generated with NG/LNG/SNG and coal. This life-cycle comparison of air emissions from different fuels can help us better understand the advantages and disadvantages of using coal versus globally sourced NG for electricity generation. Our estimates suggest that with the current fleet of power plants, a mix of domestic NG, LNG, and SNG would have lower GHG emissions than coal. If advanced technologies with carbon capture and sequestration (CCS) are used, however, coal and a mix of domestic NG, LNG, and SNG would have very similar life-cycle GHG emissions. For SOx and NOx we find there are significant emissions in the upstream stages of the NG/ LNG life-cycles, which contribute to a larger range in SOx and NOx emissions for NG/LNG than for coal and SNG.

Piecemeal Rupture of the Mentawai Patch, Sumatra: The 2008 Mw 7.2 North Pagai Earthquake Sequence

NASA Astrophysics Data System (ADS)

Salman, Rino; Hill, Emma M.; Feng, Lujia; Lindsey, Eric O.; Mele Veedu, Deepa; Barbot, Sylvain; Banerjee, Paramesh; Hermawan, Iwan; Natawidjaja, Danny H.

2017-11-01

The 25 February 2008 Mw 7.2 North Pagai earthquake partially ruptured the middle section of the Mentawai patch of the Sunda megathrust, offshore Sumatra. The patch has been forecast to generate a great earthquake in the next few decades. However, in the current cycle the patch has so far broken in a sequence of partial ruptures, one of which was the 2008 event, illustrating the potential of the patch to generate a spectrum of earthquake sizes. We estimate the coseismic slip distribution of the 2008 event by jointly inverting coseismic offsets from GPS and interferometric synthetic aperture radar. We then estimate afterslip with 5.6 years of cumulative GPS displacements. Our results suggest that the estimated afterslip partially overlaps the coseismic rupture. The overlap of coseismic rupture and afterslip can be explained conceptually by a simple rate-and-state model where the degree of overlapping is controlled by the dynamic weakening and the critical nucleation size in the velocity-weakening area. Comparing our rate-and-state model results with our geodetic inversion results, we suggest that the part of the coseismic rupture that does not overlap with the afterslip may represent a velocity-weakening region, while the overlapping part may represent a velocity-strengthening region.

Does competition improve health care quality?

PubMed

Scanlon, Dennis P; Swaminathan, Shailender; Lee, Woolton; Chernew, Michael

2008-12-01

To identify the effect of competition on health maintenance organizations' (HMOs) quality measures. Longitudinal analysis of a 5-year panel of the Healthcare Effectiveness Data and Information Set (HEDIS) and Consumer Assessment of Health Plans Survey(R) (CAHPS) data (calendar years 1998-2002). All plans submitting data to the National Committee for Quality Assurance (NCQA) were included regardless of their decision to allow NCQA to disclose their results publicly. NCQA, Interstudy, the Area Resource File, and the Bureau of Labor Statistics. Fixed-effects models were estimated that relate HMO competition to HMO quality controlling for an unmeasured, time-invariant plan, and market traits. Results are compared with estimates from models reliant on cross-sectional variation. Estimates suggest that plan quality does not improve with increased levels of HMO competition (as measured by either the Herfindahl index or the number of HMOs). Similarly, increased HMO penetration is generally not associated with improved quality. Cross-sectional models tend to suggest an inverse relationship between competition and quality. The strategies that promote competition among HMOs in the current market setting may not lead to improved HMO quality. It is possible that price competition dominates, with purchasers and consumers preferring lower premiums at the expense of improved quality, as measured by HEDIS and CAHPS. It is also possible that the fragmentation associated with competition hinders quality improvement.

Widespread kelp-derived carbon in pelagic and benthic nearshore fishes

USGS Publications Warehouse

von Biela, Vanessa R.; Newsome, Seth D.; Bodkin, James L.; Kruse, Gordon H.; Zimmerman, Christian E.

2016-01-01

Kelp forests provide habitat for diverse and abundant fish assemblages, but the extent to which kelp provides a source of energy to fish and other predators is unclear. To examine the use of kelp-derived energy by fishes we estimated the contribution of kelp- and phytoplankton-derived carbon using carbon (δ13C) and nitrogen (δ15N) isotopes measured in muscle tissue. Benthic-foraging kelp greenling (Hexagrammos decagrammus) and pelagic-foraging black rockfish (Sebastes melanops) were collected at eight sites spanning ∼35 to 60°N from the California Current (upwelling) to Alaska Coastal Current (downwelling) in the northeast Pacific Ocean. Muscle δ13C values were expected to be higher for fish tissue primarily derived from kelp, a benthic macroalgae, and lower for tissue primarily derived from phytoplankton, pelagic microalgae. Muscle δ13C values were higher in benthic-feeding kelp greenling than in pelagic-feeding black rockfish at seven of eight sites, indicating more kelp-derived carbon in greenling as expected. Estimates of kelp carbon contributions ranged from 36 to 89% in kelp greenling and 32 to 65% in black rockfish using carbon isotope mixing models. Isotopic evidence suggests that these two nearshore fishes routinely derive energy from kelp and phytoplankton, across coastal upwelling and downwelling systems. Thus, the foraging mode of nearshore predators has a small influence on their ultimate energy source as energy produced by benthic macroalgae and pelagic microalgae were incorporated in fish tissue regardless of feeding mode and suggest strong and widespread benthic-pelagic coupling. Widespread kelp contributions to benthic- and pelagic-feeding fishes suggests that kelp energy provides a benefit to nearshore fishes and highlights the potential for kelp and fish production to be linked.

Heterogeneous Rates of Molecular Evolution and Diversification Could Explain the Triassic Age Estimate for Angiosperms.

PubMed

Beaulieu, Jeremy M; O'Meara, Brian C; Crane, Peter; Donoghue, Michael J

2015-09-01

Dating analyses based on molecular data imply that crown angiosperms existed in the Triassic, long before their undisputed appearance in the fossil record in the Early Cretaceous. Following a re-analysis of the age of angiosperms using updated sequences and fossil calibrations, we use a series of simulations to explore the possibility that the older age estimates are a consequence of (i) major shifts in the rate of sequence evolution near the base of the angiosperms and/or (ii) the representative taxon sampling strategy employed in such studies. We show that both of these factors do tend to yield substantially older age estimates. These analyses do not prove that younger age estimates based on the fossil record are correct, but they do suggest caution in accepting the older age estimates obtained using current relaxed-clock methods. Although we have focused here on the angiosperms, we suspect that these results will shed light on dating discrepancies in other major clades. ©The Author(s) 2015. Published by Oxford University Press, on behalf of the Society of Systematic Biologists. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Estimating the true global burden of mental illness.

PubMed

Vigo, Daniel; Thornicroft, Graham; Atun, Rifat

2016-02-01

We argue that the global burden of mental illness is underestimated and examine the reasons for under-estimation to identify five main causes: overlap between psychiatric and neurological disorders; the grouping of suicide and self-harm as a separate category; conflation of all chronic pain syndromes with musculoskeletal disorders; exclusion of personality disorders from disease burden calculations; and inadequate consideration of the contribution of severe mental illness to mortality from associated causes. Using published data, we estimate the disease burden for mental illness to show that the global burden of mental illness accounts for 32·4% of years lived with disability (YLDs) and 13·0% of disability-adjusted life-years (DALYs), instead of the earlier estimates suggesting 21·2% of YLDs and 7·1% of DALYs. Currently used approaches underestimate the burden of mental illness by more than a third. Our estimates place mental illness a distant first in global burden of disease in terms of YLDs, and level with cardiovascular and circulatory diseases in terms of DALYs. The unacceptable apathy of governments and funders of global health must be overcome to mitigate the human, social, and economic costs of mental illness. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of in-situ and optical current-meter estimates of rip-current circulation

NASA Astrophysics Data System (ADS)

Moulton, M.; Chickadel, C. C.; Elgar, S.; Raubenheimer, B.

2016-12-01

Rip currents are fast, narrow, seaward flows that transport material from the shoreline to the shelf. Spatially and temporally complex rip current circulation patterns are difficult to resolve with in-situ instrument arrays. Here, high spatial-resolution estimates of rip current circulation from remotely sensed optical images of the sea surface are compared with in-situ estimates of currents in and near channels ( 1- to 2-m deep and 30-m wide) dredged across the surf zone. Alongshore flows are estimated using the optical current-meter method, and cross-shore flows are derived with the assumption of continuity. The observations span a range of wave conditions, tidal elevations, and flow patterns, including meandering alongshore currents near and in the channel, and 0.5 m/s alongshore flows converging at a 0.8 m/s rip jet in the channel. In addition, the remotely sensed velocities are used to investigate features of the spatially complex flow patterns not resolved by the spatially sparse in-situ sensors, including the spatial extent of feeder current zones and the width, alongshore position, and cross-shore extent of rip current jets. Funded by ASD(R&E) and NSF.

Estimating the NIH Efficient Frontier

PubMed Central

2012-01-01

Background The National Institutes of Health (NIH) is among the world’s largest investors in biomedical research, with a mandate to: “…lengthen life, and reduce the burdens of illness and disability.” Its funding decisions have been criticized as insufficiently focused on disease burden. We hypothesize that modern portfolio theory can create a closer link between basic research and outcome, and offer insight into basic-science related improvements in public health. We propose portfolio theory as a systematic framework for making biomedical funding allocation decisions–one that is directly tied to the risk/reward trade-off of burden-of-disease outcomes. Methods and Findings Using data from 1965 to 2007, we provide estimates of the NIH “efficient frontier”, the set of funding allocations across 7 groups of disease-oriented NIH institutes that yield the greatest expected return on investment for a given level of risk, where return on investment is measured by subsequent impact on U.S. years of life lost (YLL). The results suggest that NIH may be actively managing its research risk, given that the volatility of its current allocation is 17% less than that of an equal-allocation portfolio with similar expected returns. The estimated efficient frontier suggests that further improvements in expected return (89% to 119% vs. current) or reduction in risk (22% to 35% vs. current) are available holding risk or expected return, respectively, constant, and that 28% to 89% greater decrease in average years-of-life-lost per unit risk may be achievable. However, these results also reflect the imprecision of YLL as a measure of disease burden, the noisy statistical link between basic research and YLL, and other known limitations of portfolio theory itself. Conclusions Our analysis is intended to serve as a proof-of-concept and starting point for applying quantitative methods to allocating biomedical research funding that are objective, systematic, transparent, repeatable, and expressly designed to reduce the burden of disease. By approaching funding decisions in a more analytical fashion, it may be possible to improve their ultimate outcomes while reducing unintended consequences. PMID:22567087

How well can we measure Earth's Energy Imbalance?

NASA Astrophysics Data System (ADS)

Hakuba, M. Z.; Stephens, G. L.; Landerer, F. W.; Webb, F.; Bettadpur, S. V.; Tapley, B. D.; Christophe, B.; Foulon, B.

2017-12-01

The direct measurement of Earth's energy imbalance (EEI) is one of the greatest challenges in climate research. The global mean EEI is the integrated value of global warming, while its spatial and temporal variability can tell us about the strength and direction of heat transports and reflects internal climate modes such as ENSO. These heat flows ultimately control the circulation in the atmosphere and ocean, and henceforth the water cycle and habitability of our planet. Current space-born systems measure the radiative components of the global mean energy budget with unprecedented accuracy and stability, but the residual budget derived from them has errors too large to determine the absolute magnitude of EEI. Best estimates of EEI are currently derived from changes in ocean heat content, which are afflicted with horizontal and vertical sampling issues. Hence, we see the need to improve on current approaches in order to circumvent calibration issues that are inevitable in radiometry, and sampling issues that are inevitable when profiling the ocean. We will present alternative methods to estimate the EEI by 1) exploiting existing datasets of ocean mass and sea level height from remote sensing. A combination of such datasets, as for example provided by the GRACE and Jason missions, provides a way of estimating the thermo-steric sea level rise and therefore the thermal expansion of the ocean due to heat uptake. Recent studies suggest the retrieval of ocean heat uptake is possible within acceptable error bounds, although the magnitude and sources of error are yet to be comprehensively defined. 2) To monitor the integrated value of EEI from space, we propose a method that aims at measuring the non-gravitational force due to radiation pressure acting on Earth orbiting spacecrafts. This requires measurements of acceleration at high accuracy. The concept of deriving EEI from radiation pressure has been explored in the past and today's advanced capabilities suggest it is feasible to measure the EEI accurately enough to answer the question: At what rate is our planet warming? This method provides little information on spectral distribution and spatiotemporal resolution. However, by directly measuring EEI, it could complement existing efforts and improve our understanding of the climatic changes our planet is subjected to.

Estimating infertility prevalence in low-to-middle-income countries: an application of a current duration approach to Demographic and Health Survey data.

PubMed

Polis, Chelsea B; Cox, Carie M; Tunçalp, Özge; McLain, Alexander C; Thoma, Marie E

2017-05-01

Can infertility prevalence be estimated using a current duration (CD) approach when applied to nationally representative Demographic and Health Survey (DHS) data collected routinely in low- or middle-income countries? Our analysis suggests that a CD approach applied to DHS data from Nigeria provides infertility prevalence estimates comparable to other smaller studies in the same region. Despite associations with serious negative health, social and economic outcomes, infertility in developing countries is a marginalized issue in sexual and reproductive health. Obtaining reliable, nationally representative prevalence estimates is critical to address the issue, but methodological and resource challenges have impeded this goal. This cross-sectional study was based on standard information available in the DHS core questionnaire and data sets, which are collected routinely among participating low-to-middle-income countries. Our research question was examined among women participating in the 2013 Nigeria DHS (n = 38 948). Among women eligible for the study, 98% were interviewed. We applied a CD approach (i.e. current length of time-at-risk of pregnancy) to estimate time-to-pregnancy (TTP) and 12-month infertility prevalence among women 'at risk' of pregnancy at the time of interview (n = 7063). Women who were 18-44 years old, married or cohabitating, sexually active within the past 4 weeks and not currently using contraception (and had not been sterilized) were included in the analysis. Estimates were based on parametric survival methods using bootstrap methods (500 bootstrap replicates) to obtain 95% CIs. The estimated median TTP among couples at risk of pregnancy was 5.1 months (95% CI: 4.2-6.3). The estimated percentage of infertile couples was 31.1% (95% CI: 27.9-34.7%)-consistent with other smaller studies from Nigeria. Primary infertility (17.4%, 95% CI: 12.9-23.8%) was substantially lower than secondary infertility (34.1%, 95% CI: 30.3-39.3%) in this population. Overall estimates for TTP >24 or >36 months dropped to 17.7% (95% CI: 15.7-20%) and 11.5% (95% CI: 10.2-13%), respectively. Subgroup analyses showed that estimates varied by age, coital frequency and fertility intentions, while being in a polygynous relationship showed minimal impact. The CD approach may be limited by assumptions on when exposure to risk of pregnancy began and methodologic assumptions required for estimation, which may be less accurate for particular subgroups or populations. Unrecognized pregnancies may have also biased our findings; however, we attempted to address this in our exclusion criteria. Limiting to married/cohabiting couples may have excluded women who are no longer in a relationship after being blamed for infertility. Although probably rare in this setting, we lack information on couples undergoing infertility treatment. Like other TTP measurement approaches, pregnancies resulting from contraceptive failure are not included, which may bias estimates. Nationally representative estimates of TTP and infertility based on a clinical definition of 12 months have been limited within developing countries. This approach represents a pragmatic advance in our ability to measure and monitor infertility in the developing world, with potentially far-reaching implications for policies and programs intended to address reproductive health. There are no competing interests and no financial support was provided for this study. Financial support for Open Access publication was provided by the World Health Organization. © The Author 2017. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.

CH-47F Improved Cargo Helicopter (CH-47F)

DTIC Science & Technology

2015-12-01

Confidence Level Confidence Level of cost estimate for current APB: 50% The Confidence Level of the CH-47F APB cost estimate, which was approved on April...M) Initial PAUC Development Estimate Changes PAUC Production Estimate Econ Qty Sch Eng Est Oth Spt Total 10.316 -0.491 3.003 -0.164 2.273 7.378...SAR Baseline to Current SAR Baseline (TY $M) Initial APUC Development Estimate Changes APUC Production Estimate Econ Qty Sch Eng Est Oth Spt Total

Estimating the risk of Amazonian forest dieback.

PubMed

Rammig, Anja; Jupp, Tim; Thonicke, Kirsten; Tietjen, Britta; Heinke, Jens; Ostberg, Sebastian; Lucht, Wolfgang; Cramer, Wolfgang; Cox, Peter

2010-08-01

*Climate change will very likely affect most forests in Amazonia during the course of the 21st century, but the direction and intensity of the change are uncertain, in part because of differences in rainfall projections. In order to constrain this uncertainty, we estimate the probability for biomass change in Amazonia on the basis of rainfall projections that are weighted by climate model performance for current conditions. *We estimate the risk of forest dieback by using weighted rainfall projections from 24 general circulation models (GCMs) to create probability density functions (PDFs) for future forest biomass changes simulated by a dynamic vegetation model (LPJmL). *Our probabilistic assessment of biomass change suggests a likely shift towards increasing biomass compared with nonweighted results. Biomass estimates range between a gain of 6.2 and a loss of 2.7 kg carbon m(-2) for the Amazon region, depending on the strength of CO(2) fertilization. *The uncertainty associated with the long-term effect of CO(2) is much larger than that associated with precipitation change. This underlines the importance of reducing uncertainties in the direct effects of CO(2) on tropical ecosystems.

A new mode of fear expression: perceptual bias in height fear.

PubMed

Teachman, Bethany A; Stefanucci, Jeanine K; Clerkin, Elise M; Cody, Meghan W; Proffitt, Dennis R

2008-04-01

Emotion and psychopathology researchers have described the fear response as consisting of four main components--subjective affect, physiology, cognition, and behavior. The current study provides evidence for an additional component in the domain of height fear (perception) and shows that it is distinct from measures of cognitive processing. Individuals High (N = 35) and Low (N = 36) in acrophobic symptoms looked over a two-story balcony ledge and estimated its vertical extent using a direct height estimation task (visual matching), and an indirect task (size estimation); the latter task seems to exhibit little influence from cognitive factors. In addition, implicit and explicit measures of cognitive processing were obtained. Results indicated that, as expected, the High Fear group showed greater relative, implicit height fear associations and explicit threat cognitions. Of primary interest, the High (compared to Low) Fear group estimated the vertical extent to be higher, and judged target sizes to be greater, even when controlling for the cognitive bias measures. These results suggest that emotional factors such as fear are related to perception. (Copyright) 2008 APA.

Geochemical Evidence for Calcification from the Drake Passage Time-series

NASA Astrophysics Data System (ADS)

Munro, D. R.; Lovenduski, N. S.; Takahashi, T.; Stephens, B. B.; Newberger, T.; Dierssen, H. M.; Randolph, K. L.; Freeman, N. M.; Bushinsky, S. M.; Key, R. M.; Sarmiento, J. L.; Sweeney, C.

2016-12-01

Satellite imagery suggests high particulate inorganic carbon within a circumpolar region north of the Antarctic Polar Front (APF), but in situ evidence for calcification in this region is sparse. Given the geochemical relationship between calcification and total alkalinity (TA), seasonal changes in surface concentrations of potential alkalinity (PA), which accounts for changes in TA due to variability in salinity and nitrate, can be used as a means to evaluate satellite-based calcification algorithms. Here, we use surface carbonate system measurements collected from 2002 to 2016 for the Drake Passage Time-series (DPT) to quantify rates of calcification across the Antarctic Circumpolar Current. We also use vertical PA profiles collected during two cruises across the Drake Passage in March 2006 and September 2009 to estimate the calcium carbonate to organic carbon export ratio. We find geochemical evidence for calcification both north and south of the APF with the highest rates observed north of the APF. Calcification estimates from the DPT are compared to satellite-based estimates and estimates based on hydrographic data from other regions around the Southern Ocean.

Estimating Alcohol Content of Traditional Brew in Western Kenya Using Culturally Relevant Methods: The Case for Cost Over Volume

PubMed Central

Sidle, John E.; Wamalwa, Emmanuel S.; Okumu, Thomas O.; Bryant, Kendall L.; Goulet, Joseph L.; Maisto, Stephen A.; Braithwaite, R. Scott; Justice, Amy C.

2010-01-01

Traditional homemade brew is believed to represent the highest proportion of alcohol use in sub-Saharan Africa. In Eldoret, Kenya, two types of brew are common: chang’aa, spirits, and busaa, maize beer. Local residents refer to the amount of brew consumed by the amount of money spent, suggesting a culturally relevant estimation method. The purposes of this study were to analyze ethanol content of chang’aa and busaa; and to compare two methods of alcohol estimation: use by cost, and use by volume, the latter the current international standard. Laboratory results showed mean ethanol content was 34% (SD = 14%) for chang’aa and 4% (SD = 1%) for busaa. Standard drink unit equivalents for chang’aa and busaa, respectively, were 2 and 1.3 (US) and 3.5 and 2.3 (Great Britain). Using a computational approach, both methods demonstrated comparable results. We conclude that cost estimation of alcohol content is more culturally relevant and does not differ in accuracy from the international standard. PMID:19015972

Cross-Cultural Invariance of the Mental Toughness Inventory Among Australian, Chinese, and Malaysian Athletes: A Bayesian Estimation Approach.

PubMed

Gucciardi, Daniel F; Zhang, Chun-Qing; Ponnusamy, Vellapandian; Si, Gangyan; Stenling, Andreas

2016-04-01

The aims of this study were to assess the cross-cultural invariance of athletes' self-reports of mental toughness and to introduce and illustrate the application of approximate measurement invariance using Bayesian estimation for sport and exercise psychology scholars. Athletes from Australia (n = 353, Mage = 19.13, SD = 3.27, men = 161), China (n = 254, Mage = 17.82, SD = 2.28, men = 138), and Malaysia (n = 341, Mage = 19.13, SD = 3.27, men = 200) provided a cross-sectional snapshot of their mental toughness. The cross-cultural invariance of the mental toughness inventory in terms of (a) the factor structure (configural invariance), (b) factor loadings (metric invariance), and (c) item intercepts (scalar invariance) was tested using an approximate measurement framework with Bayesian estimation. Results indicated that approximate metric and scalar invariance was established. From a methodological standpoint, this study demonstrated the usefulness and flexibility of Bayesian estimation for single-sample and multigroup analyses of measurement instruments. Substantively, the current findings suggest that the measurement of mental toughness requires cultural adjustments to better capture the contextually salient (emic) aspects of this concept.

Optimal designs based on the maximum quasi-likelihood estimator

PubMed Central

Shen, Gang; Hyun, Seung Won; Wong, Weng Kee

2016-01-01

We use optimal design theory and construct locally optimal designs based on the maximum quasi-likelihood estimator (MqLE), which is derived under less stringent conditions than those required for the MLE method. We show that the proposed locally optimal designs are asymptotically as efficient as those based on the MLE when the error distribution is from an exponential family, and they perform just as well or better than optimal designs based on any other asymptotically linear unbiased estimators such as the least square estimator (LSE). In addition, we show current algorithms for finding optimal designs can be directly used to find optimal designs based on the MqLE. As an illustrative application, we construct a variety of locally optimal designs based on the MqLE for the 4-parameter logistic (4PL) model and study their robustness properties to misspecifications in the model using asymptotic relative efficiency. The results suggest that optimal designs based on the MqLE can be easily generated and they are quite robust to mis-specification in the probability distribution of the responses. PMID:28163359

Single-ping ADCP measurements in the Strait of Gibraltar

NASA Astrophysics Data System (ADS)

Sammartino, Simone; García Lafuente, Jesús; Naranjo, Cristina; Sánchez Garrido, José Carlos; Sánchez Leal, Ricardo

2016-04-01

In most Acoustic Doppler Current Profiler (ADCP) user manuals, it is widely recommended to apply ensemble averaging of the single-pings measurements, in order to obtain reliable observations of the current speed. The random error related to the single-ping measurement is typically too high to be used directly, while the averaging operation reduces the ensemble error of a factor of approximately √N, with N the number of averaged pings. A 75 kHz ADCP moored in the western exit of the Strait of Gibraltar, included in the long-term monitoring of the Mediterranean outflow, has recently served as test setup for a different approach to current measurements. The ensemble averaging has been disabled, while maintaining the internal coordinate conversion made by the instrument, and a series of single-ping measurements has been collected every 36 seconds during a period of approximately 5 months. The huge amount of data has been fluently handled by the instrument, and no abnormal battery consumption has been recorded. On the other hand a long and unique series of very high frequency current measurements has been collected. Results of this novel approach have been exploited in a dual way: from a statistical point of view, the availability of single-ping measurements allows a real estimate of the (a posteriori) ensemble average error of both current and ancillary variables. While the theoretical random error for horizontal velocity is estimated a priori as ˜2 cm s-1 for a 50 pings ensemble, the value obtained by the a posteriori averaging is ˜15 cm s-1, with an asymptotical behavior starting from an averaging size of 10 pings per ensemble. This result suggests the presence of external sources of random error (e.g.: turbulence), of higher magnitude than the internal sources (ADCP intrinsic precision), which cannot be reduced by the ensemble averaging. On the other hand, although the instrumental configuration is clearly not suitable for a precise estimation of turbulent parameters, some hints of the turbulent structure of the flow can be obtained by the empirical computation of zonal Reynolds stress (along the predominant direction of the current) and rate of production and dissipation of turbulent kinetic energy. All the parameters show a clear correlation with tidal fluctuations of the current, with maximum values coinciding with flood tides, during the maxima of the outflow Mediterranean current.

Heritability of Individual Psychotic Experiences Captured by Common Genetic Variants in a Community Sample of Adolescents.

PubMed

Sieradzka, Dominika; Power, Robert A; Freeman, Daniel; Cardno, Alastair G; Dudbridge, Frank; Ronald, Angelica

2015-09-01

Occurrence of psychotic experiences is common amongst adolescents in the general population. Twin studies suggest that a third to a half of variance in adolescent psychotic experiences is explained by genetic influences. Here we test the extent to which common genetic variants account for some of the twin-based heritability. Psychotic experiences were assessed with the Specific Psychotic Experiences Questionnaire in a community sample of 2152 16-year-olds. Self-reported measures of Paranoia, Hallucinations, Cognitive Disorganization, Grandiosity, Anhedonia, and Parent-rated Negative Symptoms were obtained. Estimates of SNP heritability were derived and compared to the twin heritability estimates from the same sample. Three approaches to genome-wide restricted maximum likelihood (GREML) analyses were compared: (1) standard GREML performed on full genome-wide data; (2) GREML stratified by minor allele frequency (MAF); and (3) GREML performed on pruned data. The standard GREML revealed a significant SNP heritability of 20 % for Anhedonia (SE = 0.12; p < 0.046) and an estimate of 19 % for Cognitive Disorganization, which was close to significant (SE = 0.13; p < 0.059). Grandiosity and Paranoia showed modest SNP heritability estimates (17 %; SE = 0.13 and 14 %; SE = 0.13, respectively, both n.s.), and zero estimates were found for Hallucinations and Negative Symptoms. The estimates for Anhedonia, Cognitive Disorganization and Grandiosity accounted for approximately half the previously reported twin heritability. SNP heritability estimates from the MAF-stratified approach were mostly consistent with the standard estimates and offered additional information about the distribution of heritability across the MAF range of the SNPs. In contrast, the estimates derived from the pruned data were for the most part not consistent with the other two approaches. It is likely that the difference seen in the pruned estimates was driven by the loss of tagged causal variants, an issue fundamental to this approach. The current results suggest that common genetic variants play a role in the etiology of some adolescent psychotic experiences, however further research on larger samples is desired and the use of MAF-stratified approach recommended.

Spatial patterns of distribution, abundance, and species diversity of small odontocetes estimated using density surface modeling with line transect sampling

NASA Astrophysics Data System (ADS)

Kanaji, Yu; Okazaki, Makoto; Miyashita, Tomio

2017-06-01

Spatial patterns of distribution, abundance, and species diversity of small odontocetes including species in the Delphinidae and Phocoenidae families were investigated using long-term dedicated sighting survey data collected between 1983 and 2006 in the North Pacific. Species diversity indices were calculated from abundance estimated using density surface modeling of line-transect data. The estimated abundance ranged from 19,521 individuals in killer whale to 1,886,022 in pantropical spotted dolphin. The predicted density maps showed that the habitats of small odontocetes corresponded well with distinct oceanic domains. Species richness was estimated to be highest between 30 and 40°N where warm- and cold-water currents converge. Simpson's Diversity Index showed latitudinal diversity gradients of decreasing species numbers toward the poles. Higher diversity was also estimated in the coastal areas and the zonal areas around 35-42°N. Coastal-offshore gradients and latitudinal gradients are known for many taxa. The zonal areas around 35°N and 40°N coincide with the Kuroshio Current and its extension and the subarctic boundary, respectively. These results suggest that the species diversity of small odontocetes primarily follows general patterns of latitudinal and longitudinal gradients, while the confluence of faunas originating in distinct water masses increases species diversify in frontal waters around 30-40°N. Population densities tended to be higher for the species inhabiting higher latitudes, but were highest for intermediate latitudes at approximately 35-40°N. According to latitudinal gradients in water temperature and biological productivity, the costs for thermoregulation will decrease in warmer low latitudes, while feeding efficiency will increase in colder high latitudes. These trade-offs could optimize population density in intermediate latitudes.

Double neutron stars: merger rates revisited

NASA Astrophysics Data System (ADS)

Chruslinska, Martyna; Belczynski, Krzysztof; Klencki, Jakub; Benacquista, Matthew

2018-03-01

We revisit double neutron star (DNS) formation in the classical binary evolution scenario in light of the recent Laser Interferometer Gravitational-wave Observatory (LIGO)/Virgo DNS detection (GW170817). The observationally estimated Galactic DNS merger rate of R_MW = 21^{+28}_{-14} Myr-1, based on three Galactic DNS systems, fully supports our standard input physics model with RMW = 24 Myr-1. This estimate for the Galaxy translates in a non-trivial way (due to cosmological evolution of progenitor stars in chemically evolving Universe) into a local (z ≈ 0) DNS merger rate density of Rlocal = 48 Gpc-3 yr-1, which is not consistent with the current LIGO/Virgo DNS merger rate estimate (1540^{+3200}_{-1220} Gpc-3 yr-1). Within our study of the parameter space, we find solutions that allow for DNS merger rates as high as R_local ≈ 600^{+600}_{-300} Gpc-3 yr-1 which are thus consistent with the LIGO/Virgo estimate. However, our corresponding BH-BH merger rates for the models with high DNS merger rates exceed the current LIGO/Virgo estimate of local BH-BH merger rate (12-213 Gpc-3 yr-1). Apart from being particularly sensitive to the common envelope treatment, DNS merger rates are rather robust against variations of several of the key factors probed in our study (e.g. mass transfer, angular momentum loss, and natal kicks). This might suggest that either common envelope development/survival works differently for DNS (˜10-20 M⊙ stars) than for BH-BH (˜40-100 M⊙ stars) progenitors, or high black hole (BH) natal kicks are needed to meet observational constraints for both types of binaries. Our conclusion is based on a limited number of (21) evolutionary models and is valid within this particular DNS and BH-BH isolated binary formation scenario.

Suicide risk assessment: Trust an implicit probe or listen to the patient?

PubMed

Harrison, Dominique P; Stritzke, Werner G K; Fay, Nicolas; Hudaib, Abdul-Rahman

2018-05-21

Previous research suggests implicit cognition can predict suicidal behavior. This study examined the utility of the death/suicide implicit association test (d/s-IAT) in acute and prospective assessment of suicide risk and protective factors, relative to clinician and patient estimates of future suicide risk. Patients (N = 128; 79 female; 111 Caucasian) presenting to an emergency department were recruited if they reported current suicidal ideation or had been admitted because of an acute suicide attempt. Patients completed the d/s-IAT and self-report measures assessing three death-promoting (e.g., suicide ideation) and two life-sustaining (e.g., zest for life) factors, with self-report measures completed again at 3- and 6-month follow-ups. The clinician and patient provided risk estimates of that patient making a suicide attempt within the next 6 months. Results showed that among current attempters, the d/s-IAT differentiated between first time and multiple attempters; with multiple attempters having significantly weaker self-associations with life relative to death. The d/s-IAT was associated with concurrent suicidal ideation and zest for life, but only predicted the desire to die prospectively at 3 months. By contrast, clinician and patient estimates predicted suicide risk at 3- and 6-month follow-up, with clinician estimates predicting death-promoting factors, and only patient estimates predicting life-sustaining factors. The utility of the d/s-IAT was more pronounced in the assessment of concurrent risk. Prospectively, clinician and patient predictions complemented each other in predicting suicide risk and resilience, respectively. Our findings indicate collaborative rather than implicit approaches add greater value to the management of risk and recovery in suicidal patients. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Effects of life-history requirements on the distribution of a threatened reptile.

PubMed

Thompson, Denise M; Ligon, Day B; Patton, Jason C; Papeş, Monica

2017-04-01

Survival and reproduction are the two primary life-history traits essential for species' persistence; however, the environmental conditions that support each of these traits may not be the same. Despite this, reproductive requirements are seldom considered when estimating species' potential distributions. We sought to examine potentially limiting environmental factors influencing the distribution of an oviparous reptile of conservation concern with respect to the species' survival and reproduction and to assess the implications of the species' predicted climatic constraints on current conservation practices. We used ecological niche modeling to predict the probability of environmental suitability for the alligator snapping turtle (Macrochelys temminckii). We built an annual climate model to examine survival and a nesting climate model to examine reproduction. We combined incubation temperature requirements, products of modeled soil temperature data, and our estimated distributions to determine whether embryonic development constrained the northern distribution of the species. Low annual precipitation constrained the western distribution of alligator snapping turtles, whereas the northern distribution was constrained by thermal requirements during embryonic development. Only a portion of the geographic range predicted to have a high probability of suitability for alligator snapping turtle survival was estimated to be capable of supporting successful embryonic development. Historic occurrence records suggest adult alligator snapping turtles can survive in regions with colder climes than those associated with consistent and successful production of offspring. Estimated egg-incubation requirements indicated that current reintroductions at the northern edge of the species' range are within reproductively viable environmental conditions. Our results highlight the importance of considering survival and reproduction when estimating species' ecological niches, implicating conservation plans, and benefits of incorporating physiological data when evaluating species' distributions. © 2016 Society for Conservation Biology.

How far will they go? Assessing the travel distance of current and former drug users to access harm reduction services.

PubMed

Allen, Sean; Ruiz, Monica; O'Rourke, Allison

2015-03-01

Prior research has explored spatial access to syringe exchange programs (SEPs) among people who inject drugs (PWID), but little is known about service utilization by former PWID who continue to access services (e.g., HIV screenings and referrals for social services) at harm reduction providers. The purpose of this research is to examine differences in access to SEPs between current and former PWID seeking services at a mobile SEP in Washington, DC. A geometric point distance estimation technique was applied to data collected as part of a PWID population estimation study that took place in Washington, DC, in March and April 2014. We calculated the walking distance from the centroid point of home residence zip code to the mobile exchange site where PWID presented for services. An independent samples t-test was used to examine differences in walking distance measures between current and former PWID. Differences in mean walking distance were statistically significant with current and former PWID having mean walking distances of 2.75 and 1.80 miles, respectively. The results of this study suggest that former PWID who are engaging with SEPs primarily for non-needle exchange services (e.g., medical or social services) may have decreased access to SEPs than their counterparts who are active injectors. This research provides support for expanding SEP operations such that both active and former PWID have increased access to harm reduction providers and associated health and social services. Increasing service accessibility may help resolve unmet needs among current and former PWID.

Current and Projected Heat-Related Morbidity and Mortality in Rhode Island

PubMed Central

Kingsley, Samantha L.; Eliot, Melissa N.; Gold, Julia; Vanderslice, Robert R.; Wellenius, Gregory A.

2015-01-01

Background: Climate change is expected to cause increases in heat-related mortality, especially among the elderly and very young. However, additional studies are needed to clarify the effects of heat on morbidity across all age groups and across a wider range of temperatures. Objectives: We aimed to estimate the impact of current and projected future temperatures on morbidity and mortality in Rhode Island. Methods: We used Poisson regression models to estimate the association between daily maximum temperature and rates of all-cause and heat-related emergency department (ED) admissions and all-cause mortality. We then used downscaled Coupled Model Intercomparison Project Phase 5 (CMIP5; a standardized set of climate change model simulations) projections to estimate the excess morbidity and mortality that would be observed if this population were exposed to the temperatures projected for 2046–2053 and 2092–2099 under two representative concentration pathways (RCP): RCP 8.5 and 4.5. Results: Between 2005 and 2012, an increase in maximum daily temperature from 75 to 85°F was associated with 1.3% and 23.9% higher rates of all-cause and heat-related ED visits, respectively. The corresponding effect estimate for all-cause mortality from 1999 through 2011 was 4.0%. The association with all-cause ED admissions was strongest for those < 18 or ≥ 65 years of age, whereas the association with heat-related ED admissions was most pronounced among 18- to 64-year-olds. If this Rhode Island population were exposed to temperatures projected under RCP 8.5 for 2092–2099, we estimate that there would be 1.2% (range, 0.6–1.6%) and 24.4% (range, 6.9–41.8%) more all-cause and heat-related ED admissions, respectively, and 1.6% (range, 0.8–2.1%) more deaths annually between April and October. Conclusions: With all other factors held constant, our findings suggest that the current population of Rhode Island would experience substantially higher morbidity and mortality if maximum daily temperatures increase further as projected. Citation: Kingsley SL, Eliot MN, Gold J, Vanderslice RR, Wellenius GA. 2016. Current and projected heat-related morbidity and mortality in Rhode Island. Environ Health Perspect 124:460–467; http://dx.doi.org/10.1289/ehp.1408826 PMID:26251954

Reassessment of the predatory effects of rainbow smelt on ciscoes in Lake Superior

USGS Publications Warehouse

Myers, Jared T.; Jones, Michael L.; Stockwell, Jason D.; Yule, Daniel L.

2009-01-01

Evidence from small lakes suggests that predation on larval ciscoes Coregonus artedi by nonnative rainbow smelt Osmerus mordax can lead to cisco suppression or extirpation. However, evidence from larger lakes has led to equivocal conclusions. In this study, we examine the potential predation effects of rainbow smelt in two adjacent but contrasting embayments in Lake Superior (Thunder and Black bays, Ontario). During May 2006, we sampled the ichthyoplankton, pelagic fish communities, and diet composition of rainbow smelt in both bays. Using acoustics and midwater trawling, we estimated rainbow smelt densities to be 476 ± 34/ha (mean ± SE) in Thunder Bay and 3,435 ± 460/ha in Black Bay. We used a bioenergetics model to estimate the proportion of cisco larvae consumed by rainbow smelt. Our results suggest that predation by rainbow smelt accounts for 15–52% and 37–100% of the mortality of larval ciscoes in Thunder and Black bays, respectively, depending on the predator feeding rate and the scale of predator–prey overlap. We also examined the sensitivity of past conclusions (based on 1974 field collections) to assumptions of temporal overlap between rainbow smelt and larval ciscoes and estimates of rainbow smelt abundance derived from bottom trawl samples. After adjusting these parameters to reflect current understanding, we found that the previous predation estimates may have been conservative. We conclude that rainbow smelt may have been a more important contributor to the demise and slow recovery of ciscoes in Lake Superior than previously thought.

Parameter estimation for the exponential-normal convolution model for background correction of affymetrix GeneChip data.

PubMed

McGee, Monnie; Chen, Zhongxue

2006-01-01

There are many methods of correcting microarray data for non-biological sources of error. Authors routinely supply software or code so that interested analysts can implement their methods. Even with a thorough reading of associated references, it is not always clear how requisite parts of the method are calculated in the software packages. However, it is important to have an understanding of such details, as this understanding is necessary for proper use of the output, or for implementing extensions to the model. In this paper, the calculation of parameter estimates used in Robust Multichip Average (RMA), a popular preprocessing algorithm for Affymetrix GeneChip brand microarrays, is elucidated. The background correction method for RMA assumes that the perfect match (PM) intensities observed result from a convolution of the true signal, assumed to be exponentially distributed, and a background noise component, assumed to have a normal distribution. A conditional expectation is calculated to estimate signal. Estimates of the mean and variance of the normal distribution and the rate parameter of the exponential distribution are needed to calculate this expectation. Simulation studies show that the current estimates are flawed; therefore, new ones are suggested. We examine the performance of preprocessing under the exponential-normal convolution model using several different methods to estimate the parameters.

A Model To Estimate Carbon Dioxide Injectivity and Storage Capacity for Geological Sequestration in Shale Gas Wells.

PubMed

Edwards, Ryan W J; Celia, Michael A; Bandilla, Karl W; Doster, Florian; Kanno, Cynthia M

2015-08-04

Recent studies suggest the possibility of CO2 sequestration in depleted shale gas formations, motivated by large storage capacity estimates in these formations. Questions remain regarding the dynamic response and practicality of injection of large amounts of CO2 into shale gas wells. A two-component (CO2 and CH4) model of gas flow in a shale gas formation including adsorption effects provides the basis to investigate the dynamics of CO2 injection. History-matching of gas production data allows for formation parameter estimation. Application to three shale gas-producing regions shows that CO2 can only be injected at low rates into individual wells and that individual well capacity is relatively small, despite significant capacity variation between shale plays. The estimated total capacity of an average Marcellus Shale well in Pennsylvania is 0.5 million metric tonnes (Mt) of CO2, compared with 0.15 Mt in an average Barnett Shale well. Applying the individual well estimates to the total number of existing and permitted planned wells (as of March, 2015) in each play yields a current estimated capacity of 7200-9600 Mt in the Marcellus Shale in Pennsylvania and 2100-3100 Mt in the Barnett Shale.

Cost-benefit analysis involving addictive goods: contingent valuation to estimate willingness-to-pay for smoking cessation.

PubMed

Weimer, David L; Vining, Aidan R; Thomas, Randall K

2009-02-01

The valuation of changes in consumption of addictive goods resulting from policy interventions presents a challenge for cost-benefit analysts. Consumer surplus losses from reduced consumption of addictive goods that are measured relative to market demand schedules overestimate the social cost of cessation interventions. This article seeks to show that consumer surplus losses measured using a non-addicted demand schedule provide a better assessment of social cost. Specifically, (1) it develops an addiction model that permits an estimate of the smoker's compensating variation for the elimination of addiction; (2) it employs a contingent valuation survey of current smokers to estimate their willingness-to-pay (WTP) for a treatment that would eliminate addiction; (3) it uses the estimate of WTP from the survey to calculate the fraction of consumer surplus that should be viewed as consumer value; and (4) it provides an estimate of this fraction. The exercise suggests that, as a tentative first and rough rule-of-thumb, only about 75% of the loss of the conventionally measured consumer surplus should be counted as social cost for policies that reduce the consumption of cigarettes. Additional research to estimate this important rule-of-thumb is desirable to address the various caveats relevant to this study. Copyright (c) 2008 John Wiley & Sons, Ltd.

Puckering free energy of pyranoses: A NMR and metadynamics-umbrella sampling investigation

NASA Astrophysics Data System (ADS)

Autieri, E.; Sega, M.; Pederiva, F.; Guella, G.

2010-09-01

We present the results of a combined metadynamics-umbrella sampling investigation of the puckered conformers of pyranoses described using the GROMOS 45a4 force field. The free energy landscape of Cremer-Pople puckering coordinates has been calculated for the whole series of α and β aldohexoses, showing that the current force field parameters fail in reproducing proper puckering free energy differences between chair conformers. We suggest a modification to the GROMOS 45a4 parameter set which improves considerably the agreement of simulation results with theoretical and experimental estimates of puckering free energies. We also report on the experimental measurement of altrose conformer populations by means of NMR spectroscopy, which show good agreement with the predictions of current theoretical models.

Electromagnetic Model Of A Lightning Dart Leader In The Earth Atmosphere

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gordeev, A. V.; Losseva, T. V.

2006-01-15

The fundamentally new approach to the lightning step and dart leaders structure model is suggested, which shows a possibility of the drift propagation for the electrons in a plasma channel. Appearance of the strong Hall electric field in the current channel by the account of the magnetic field can result in the generation of the relativistic drifting electrons to be held in the channel due to the magnetic self-insulation effect. The range of the measured x-ray emission from the lightning channel 30-250 keV, which corresponds to the measured current value 4-11 kA, is in a reasonably good agreement with themore » estimates made in the framework of presented model.« less

Fast Radio Bursts

NASA Astrophysics Data System (ADS)

Kaspi, Victoria M.

2017-01-01

Fast Radio Bursts (FRBs) are a recently discovered phenomenon consisting of short (few ms) bursts of radio waves that have dispersion measures that strongly suggest an extragalactic and possibly cosmological origin. Current best estimates for the rate of FRBs is several thousand per sky per day at radio frequencies near 1.4 GHz. Even with so high a rate, to date, fewer than 20 FRBs have been reported, with one source showing repeated bursts. In this talk I will describe known FRB properties including what is known about the lone repeating source, as well as models for the origin of these mysterious events. I will also describe the CHIME radio telescope, currently under construction in Canada. Thanks to its great sensitivity and unprecedented field-of-view, CHIME promises major progress on FRBs.

Implications of Extended Solar Minima

NASA Technical Reports Server (NTRS)

Adams, Mitzi L.; Davis, J. M.

2009-01-01

Since the discovery of periodicity in the solar cycle, the historical record of sunspot number has been carefully examined, attempting to make predictions about the next cycle. Much emphasis has been on predicting the maximum amplitude and length of the next cycle. Because current space-based and suborbital instruments are designed to study active phenomena, there is considerable interest in estimating the length and depth of the current minimum. We have developed criteria for the definition of a minimum and applied it to the historical sunspot record starting in 1749. In doing so, we find that 1) the current minimum is not yet unusually long and 2) there is no obvious way of predicting when, using our definition, the current minimum may end. However, by grouping the data into 22- year cycles there is an interesting pattern of extended minima that recurs every fourth or fifth 22-year cycle. A preliminary comparison of this pattern with other records, suggests the possibility of a correlation between extended minima and lower levels of solar irradiance.

Effect of Surge Current Testing on Reliability of Solid Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2008-01-01

Tantalum capacitors manufactured per military specifications are established reliability components and have less than 0.001% of failures per 1000 hours for grades D or S, thus positioning these parts among electronic components with the highest reliability characteristics. Still, failures of tantalum capacitors do happen and when it occurs it might have catastrophic consequences for the system. To reduce this risk, further development of a screening and qualification system with special attention to the possible deficiencies in the existing procedures is necessary. The purpose of this work is evaluation of the effect of surge current stress testing on reliability of the parts at both steady-state and multiple surge current stress conditions. In order to reveal possible degradation and precipitate more failures, various part types were tested and stressed in the range of voltage and temperature conditions exceeding the specified limits. A model to estimate the probability of post-surge current testing-screening failures and measures to improve the effectiveness of the screening process has been suggested.

Leakage current transport mechanism under reverse bias in Au/Ni/GaN Schottky barrier diode

NASA Astrophysics Data System (ADS)

Peta, Koteswara Rao; Kim, Moon Deock

2018-01-01

The leakage current transport mechanism under reverse bias of Au/Ni/GaN Schottky diode is studied using temperature dependent current-voltage (I-V-T) and capacitance-voltage (C-V) characteristics. I-V measurement in this study is in the range of 140 K-420 K in steps of 10 K. A reduction in voltage dependent barrier height and a strong internal electric field in depletion region under reverse bias suggested electric field enhanced thermionic emission in carrier transport via defect states in Au/Ni/GaN SBD. A detailed analysis of reverse leakage current revealed two different predominant transport mechanisms namely variable-range hopping (VRH) and Poole-Frenkel (PF) emission conduction at low (<260 K) and high (>260 K) temperatures respectively. The estimated thermal activation energies (0.20-0.39 eV) from Arrhenius plot indicates a trap assisted tunneling of thermally activated electrons from a deep trap state into a continuum of states associated with each conductive threading dislocation.

Improved rice residue burning emissions estimates: Accounting for practice-specific emission factors in air pollution assessments of Vietnam.

PubMed

Lasko, Kristofer; Vadrevu, Krishna

2018-05-01

In Southeast Asia and Vietnam, rice residues are routinely burned after the harvest to prepare fields for the next season. Specific to Vietnam, the two prevalent burning practices include: a). piling the residues after hand harvesting; b). burning the residues without piling, after machine harvesting. In this study, we synthesized field and laboratory studies from the literature on rice residue burning emission factors for PM 2.5 . We found significant differences in the resulting burning-practice specific emission factors, with 16.9 g kg -2 (±6.9) for pile burning and 8.8 g kg -2 (±3.5) for non-pile burning. We calculated burning-practice specific emissions based on rice area data, region-specific fuel-loading factors, combined emission factors, and estimates of burning from the literature. Our results for year 2015 estimate 180 Gg of PM 2.5 result from the pile burning method and 130 Gg result from non-pile burning method, with the most-likely current emission scenario of 150 Gg PM 2.5 emissions for Vietnam. For comparison purposes, we calculated emissions using generalized agricultural emission factors employed in global biomass burning studies. These results estimate 80 Gg PM 2.5 , which is only 44% of the pile burning-based estimates, suggesting underestimation in previous studies. We compare our emissions to an existing all-combustion sources inventory, results show emissions account for 14-18% of Vietnam's total PM 2.5 depending on burning practice. Within the highly-urbanized and cloud-covered Hanoi Capital region (HCR), we use rice area from Sentinel-1A to derive spatially-explicit emissions and indirectly estimate residue burning dates. Results from HYSPLIT back-trajectory analysis stratified by season show autumn has most emission trajectories originating in the North, while spring has most originating in the South, suggesting the latter may have bigger impact on air quality. From these results, we highlight locations where emission mitigation efforts could be focused and suggest measures for pollutant mitigation. Our study demonstrates the need to account for emissions variation due to different burning practices. Copyright © 2018 Elsevier Ltd. All rights reserved.

A historical reconstruction of ships' fuel consumption and emissions

NASA Astrophysics Data System (ADS)

Endresen, Øyvind; Sørgârd, Eirik; Behrens, Hanna Lee; Brett, Per Olaf; Isaksen, Ivar S. A.

2007-06-01

Shipping activity has increased considerably over the last century and currently represents a significant contribution to the global emissions of pollutants and greenhouse gases. Despite this, information about the historical development of fuel consumption and emissions is generally limited, with little data published pre-1950 and large deviations reported for estimates covering the last 3 decades. To better understand the historical development in ship emissions and the uncertainties associated with the estimates, we present fuel-based CO2 and SO2 emission inventories from 1925 up to 2002 and activity-based estimates from 1970 up to 2000. The global CO2 emissions from ships in 1925 have been estimated to 229 Tg (CO2), growing to about 634 Tg (CO2) in 2002. The corresponding SO2 emissions are about 2.5 Tg (SO2) and 8.5 Tg (SO2), respectively. Our activity-based estimates of fuel consumption from 1970 to 2000, covering all oceangoing civil ships above or equal to 100 gross tonnage (GT), are lower compared to previous activity-based studies. We have applied a more detailed model approach, which includes variation in the demand for sea transport, as well as operational and technological changes of the past. This study concludes that the main reason for the large deviations found in reported inventories is the applied number of days at sea. Moreover, our modeling indicates that the ship size and the degree of utilization of the fleet, combined with the shift to diesel engines, have been the major factors determining yearly fuel consumption. Interestingly, the model results from around 1973 suggest that the fleet growth is not necessarily followed by increased fuel consumption, as technical and operational characteristics have changed. Results from this study indicate that reported sales over the last 3 decades seems not to be significantly underreported as previous simplified activity-based studies have suggested. The results confirm our previously reported modeling estimates for year 2000. Previous activity-based studies have not considered ships less than 100 GT (e.g., today some 1.3 million fishing vessels), and we suggest that this fleet could account for an important part of the total fuel consumption (˜10%).

Wind, Circulation, and Topographic Effects on Alongshore Phytoplankton Variability in the California Current

NASA Astrophysics Data System (ADS)

Fiechter, Jerome; Edwards, Christopher A.; Moore, Andrew M.

2018-04-01

A physical-biogeochemical model is used to produce a retrospective analysis at 3-km resolution of alongshore phytoplankton variability in the California Current during 1988-2010. The simulation benefits from downscaling a regional circulation reanalysis, which provides improved physical ocean state estimates in the high-resolution domain. The emerging pattern is one of local upwelling intensification in response to increased alongshore wind stress in the lee of capes, modulated by alongshore meanders in the geostrophic circulation. While stronger upwelling occurs near most major topographic features, substantial increases in phytoplankton biomass only ensue where local circulation patterns are conducive to on-shelf retention of upwelled nutrients. Locations of peak nutrient delivery and chlorophyll accumulation also exhibit interannual variability and trends noticeably larger than the surrounding shelf regions, thereby suggesting that long-term planktonic ecosystem response in the California Current exhibits a significant local scale (O(100 km)) alongshore component.

New method of a "point-like" neutron source creation based on sharp focusing of high-current deuteron beam onto deuterium-saturated target for neutron tomography

NASA Astrophysics Data System (ADS)

Golubev, S.; Skalyga, V.; Izotov, I.; Sidorov, A.

2017-02-01

A possibility of a compact powerful point-like neutron source creation is discussed. Neutron yield of the source based on deuterium-deuterium (D-D) reaction is estimated at the level of 1011 s-1 (1013 s-1 for deuterium-tritium reaction). The fusion takes place due to bombardment of deuterium- (or tritium) loaded target by high-current focused deuterium ion beam with energy of 100 keV. The ion beam is formed by means of high-current quasi-gasdynamic ion source of a new generation based on an electron cyclotron resonance (ECR) discharge in an open magnetic trap sustained by powerful microwave radiation. The prospects of proposed generator for neutron tomography are discussed. Suggested method is compared to the point-like neutron sources based on a spark produced by powerful femtosecond laser pulses.

Measuring premorbid IQ in traumatic brain injury: an examination of the validity of the Wechsler Test of Adult Reading (WTAR).

PubMed

Green, Robin E A; Melo, Brenda; Christensen, Bruce; Ngo, Le-Anh; Monette, Georges; Bradbury, Cheryl

2008-02-01

Estimation of premorbid IQ in traumatic brain injury (TBI) is clinically and scientifically valuable because it permits the quantification of the cognitive impact of injury. This is achieved by comparing performances on tests of current ability to estimates of premorbid IQ, thereby enabling current capacity to be interpreted in light of preinjury ability. However, the validity of premorbid IQ tests that are commonly used for TBI has been questioned. In the present study, we examined the psychometric properties of a recently developed test, the Wechsler Test of Adult Reading (WTAR), which has yet to be examined for TBI. The cognitive performance of a group of 24 patients recovering from TBI (with a mean Glasgow Coma Scale score in the severely impaired range) was measured at 2 and 5 months postinjury. On both occasions, patients were administered three tests that have been used to measure premorbid IQ (the WTAR and the Vocabulary and Matrix Reasoning subtests of the Wechsler Adult Intelligence Scale 3rd Edition, WAIS-III) and three tests of current ability (Symbol Digit Modalities Test-Oral and Similarities and Block Design subtests of the WAIS-III). We found that performance significantly improved on tests of current cognitive ability, confirming recovery. In contrast, stable performance was observed on the WTAR from Assessment 1 (M = 34.25/50) to Assessment 2 (M = 34.21/50; r = .970, p < .001). Mean improvement across assessments was negligible (t = -0.086, p = .47; Cohen's d = -.005), and minimal individual participant change was observed (modal scaled score change = 0). WTAR scores were also highly similar to scores on a demographic estimate of premorbid IQ. Thus, converging evidence--high stability during recovery from TBI and similar IQ estimates to those of a demographic equation suggests that the WTAR is a valid measure of premorbid IQ for TBI. Where word pronunciation tests are indicated (i.e., in patients for whom English is spoken and read fluently), these results endorse the use of the WTAR for patients with TBI.

Regulatory Drivers of Multimedia Reactive Nitrogen Research (Invited)

NASA Astrophysics Data System (ADS)

Shaw, S. L.; Knipping, E.; Kumar, N.

2010-12-01

The presence of nitrogenous compounds can impact biogeochemical processes in the atmosphere, oceans and freshwater, and land surfaces. As a result, a number of regulations exist that are intended to control the amount and forms of nitrogen present in the environment. These range from the newly proposed Transport Rule, both the primary and secondary National Ambient Air Quality Standards (NAAQS) for nitrogen oxide targeted at ozone and particulate matter formation and nitrogen deposition, and waterbody requirements such as the Total Maximum Daily Load. This talk will cover a subset of research activities at EPRI that inform environmental nitrogen concerns. A multimedia modeling framework has facilitated effect studies of atmospheric loadings on ecosystems. Improvements in emissions estimates, such as for mobile sources, suggest large current underestimates that will substantially impact air quality modeling of nitrogen oxides. Analyses of wintertime nitrate formation in the northern U.S. are demonstrating the roles of NH3 and NOx in particle formation there. Novel measurements of power plant stack emissions suggest operating configurations can influence the isotopic composition of emitted NOx. Novel instruments for ambient measurements of nitrogen, and suggestions for improved deposition estimates, are being developed. EPRI results suggest that multimedia solutions across multiple economic sectors, such as electrification of a wide variety of engines and water quality treatment and trading, have the potential to improve environmental quality effectively.

Comparison of capture-recapture and visual count indices of prairie dog densities in black-footed ferret habitat

USGS Publications Warehouse

Fagerstone, Kathleen A.; Biggins, Dean E.

1986-01-01

Black-footed ferrets (Mustela nigripes) are dependent on prairie dogs (Cynomys spp.) for food and on their burrows for shelter and rearing young. A stable prairie dog population may therefore be the most important factor determining the survival of ferrets. A rapid method of determining prairie dog density would be useful for assessing prairie dog density in colonies currently occupied by ferrets and for selecting prairie dog colonies in other areas for ferret translocation. This study showed that visual counts can provide a rapid density estimate. Visual counts of white-tailed prairie dogs (Cynomys leucurus) were significantly correlated (r = 0.95) with mark-recapture population density estimates on two study areas near Meeteetse, Wyoming. Suggestions are given for use of visual counts.

Suburban watershed nitrogen retention: Estimating the effectiveness of stormwater management structures

USGS Publications Warehouse

Koch, Benjamin J.; Febria, Catherine M.; Cooke, Roger M.; Hosen, Jacob D.; Baker, Matthew E.; Colson, Abigail R.; Filoso, Solange; Hayhoe, Katharine; Loperfido, J. V.; Stoner, Anne M.K.; Palmer, Margaret A.

2015-01-01

Expert knowledge indicated wide uncertainty in BMP performance, with N removal efficiencies ranging from <0% (BMP acting as a source of N during a rain event) to >40%. Experts believed that the amount of rain was the primary identifiable source of variability in BMP efficiency, which is relevant given climate projections of more frequent heavy rain events in the mid-Atlantic. To assess the extent to which those projected changes might alter N export from suburban BMPs and watersheds, we combined downscaled estimates of rainfall with distributions of N loads for different-sized rain events derived from our elicitation. The model predicted higher and more variable N loads under a projected future climate regime, suggesting that current BMP regulations for reducing nutrients may be inadequate in the future.

Brief Report: Quantifying the Impact of Autism Coverage on Private Insurance Premiums

PubMed Central

Bouder, James N.; Spielman, Stuart

2010-01-01

Many states are considering legislation requiring private insurance companies to pay for autism-related services. Arguments against mandates include that they will result in higher premiums. Using Pennsylvania legislation as an example, which proposed covering services up to $36,000 per year for individuals less than 21 years of age, this paper estimates potential premium increases. The estimate relies on autism treated prevalence, the number of individuals insured by affected plans, mean annual autism expenditures, administrative costs, medical loss ratio, and total insurer revenue. Current treated prevalence and expenditures suggests that premium increases would approximate 1%, with a lower bound of 0.19% and an upper bound of 2.31%. Policy makers can use these results to assess the cost-effectiveness of similar legislation. PMID:19214727

Brief report: Quantifying the impact of autism coverage on private insurance premiums.

PubMed

Bouder, James N; Spielman, Stuart; Mandell, David S

2009-06-01

Many states are considering legislation requiring private insurance companies to pay for autism-related services. Arguments against mandates include that they will result in higher premiums. Using Pennsylvania legislation as an example, which proposed covering services up to $36,000 per year for individuals less than 21 years of age, this paper estimates potential premium increases. The estimate relies on autism treated prevalence, the number of individuals insured by affected plans, mean annual autism expenditures, administrative costs, medical loss ratio, and total insurer revenue. Current treated prevalence and expenditures suggests that premium increases would approximate 1%, with a lower bound of 0.19% and an upper bound of 2.31%. Policy makers can use these results to assess the cost-effectiveness of similar legislation.

HIV model incorporating differential progression for treatment-naive and treatment-experienced infectives.

PubMed

Chigidi, Esther; Lungu, Edward M

2009-07-01

We formulate an HIV/AIDS deterministic model which incorporates differential infectivity and disease progression for treatment-naive and treatment-experienced HIV/AIDS infectives. To illustrate our model, we have applied it to estimate adult HIV prevalence, the HIV population, the number of new infectives and the number of AIDS deaths for Botswana for the period 1984 to 2012. It is found that the prevalence peaked in the year 2000 and the HIV population is now decreasing. We have also found that under the current conditions, the reproduction number is Rc approximately 13, which is less than the 2004 estimate of Rc approximately equal 4 by [11] and [13]. The results in this study suggest that the HAART program has yielded positive results for Botswana.

Steady, modest slip over multiple earthquake cycles on the Owens Valley and Little Lake fault zones

NASA Astrophysics Data System (ADS)

Amos, C. B.; Haddon, E. K.; Burgmann, R.; Zielke, O.; Jayko, A. S.

2015-12-01

A comprehensive picture of current plate-boundary deformation requires integration of short-term geodetic records with longer-term geologic strain. Comparing rates of deformation across these time intervals highlights potential time-dependencies in both geodetic and geologic records and yields critical insight into the earthquake deformation process. The southern Walker Lane Belt in eastern California represents one location where short-term strain recorded by geodesy apparently outpaces longer-term geologic fault slip measured from displaced rocks and landforms. This discrepancy persists both for individual structures and across the width of the deforming zone, where ~1 cm/yr of current dextral shear exceeds Quaternary slip rates summed across individual faults. The Owens Valley and Little Lake fault systems form the western boundary of the southern Walker Lane and host a range of published slip rate estimates from ~1 - 7 mm/yr over varying time intervals based on both geodetic and geologic measurements. New analysis of offset geomorphic piercing lines from airborne lidar and field measurements along the Owens Valley fault provides a snapshot of deformation during individual earthquakes and over many seismic cycles. Viewed in context of previously reported ages from pluvial and other landforms in Owens Valley, these offsets suggest slip rates of ~0.6 - 1.6 mm/yr over the past 103 - 105 years. Such rates agree with similar estimates immediately to the south on the Little Lake fault, where lidar measurements indicate dextral slip averaging ~0.6 - 1.3 mm/yr over comparable time intervals. Taken together, these results suggest steady, modest slip in the absence of significant variations over the Mid-to-Late Quaternary for a ~200 km span of the southwestern Walker Lane. Our findings argue against the presence of long-range fault interactions and slip-rate variations for this portion of the larger, regional fault network. This result also suggests that faster slip-rate estimates from geodetic measurements reflect transients over much shorter time scales. Additionally, the persistence of relatively faster geodetic shear in comparison with time-averaged fault slip leaves open the possibility of significant off-fault deformation or slip on subsidiary structures across the Owens Valley.

The future excess fraction of occupational cancer among those exposed to carcinogens at work in Australia in 2012.

PubMed

Carey, Renee N; Hutchings, Sally J; Rushton, Lesley; Driscoll, Timothy R; Reid, Alison; Glass, Deborah C; Darcey, Ellie; Si, Si; Peters, Susan; Benke, Geza; Fritschi, Lin

2017-04-01

Studies in other countries have generally found approximately 4% of current cancers to be attributable to past occupational exposures. This study aimed to estimate the future burden of cancer resulting from current occupational exposures in Australia. The future excess fraction method was used to estimate the future burden of occupational cancer (2012-2094) among the proportion of the Australian working population who were exposed to occupational carcinogens in 2012. Calculations were conducted for 19 cancer types and 53 cancer-exposure pairings, assuming historical trends and current patterns continued to 2094. The cohort of 14.6 million Australians of working age in 2012 will develop an estimated 4.8 million cancers during their lifetime, of which 68,500 (1.4%) are attributable to occupational exposure in those exposed in 2012. The majority of these will be lung cancers (n=26,000), leukaemias (n=8000), and malignant mesotheliomas (n=7500). A significant proportion of future cancers will result from occupational exposures. This estimate is lower than previous estimates in the literature; however, our estimate is not directly comparable to past estimates of the occupational cancer burden because they describe different quantities - future cancers in currently exposed versus current cancers due to past exposures. The results of this study allow us to determine which current occupational exposures are most important, and where to target exposure prevention. Copyright © 2016 Elsevier Ltd. All rights reserved.

Active tectonics of the southeastern Upper Rhine Graben, Freiburg area (Germany)

NASA Astrophysics Data System (ADS)

Nivière, B.; Bruestle, A.; Bertrand, G.; Carretier, S.; Behrmann, J.; Gourry, J.-C.

2008-03-01

The Upper Rhine Graben has two Plio-Quaternary depocentres usually interpreted as resulting from tectonic reactivation. The southern basin, near Freiburg im Breisgau (Germany), contains up to 250 m of sediments. Beneath the younger alluvial deposits related to the current drainage system, a former river network deeply entrenched in the substratum reveals a very low regional base level of early Pleistocene age. The offset of channels at faults allows us to infer a Pleistocene reactivation of the syn-rift fault pattern and the estimation of slip rates. Maximum vertical movements along the faults have not exceeded 0.1 mm/yr since the middle Pleistocene. Current activity is concentrated along the westernmost faults. Morphologic markers indicate late Pleistocene reactivation of the Rhine River fault, and geophysical prospecting suggests a near-surface offset of young sedimentary deposits. The size of the fault segments potentially reactivated suggests that earthquakes with magnitude larger than Mw=6.3 could be expected in the area with a return interval of about 8000 years. Extrapolated to the duration of the Plio-Pleistocene, the strain rate estimates reveal that the tectonic forcing may account for only one-third to one-half of the whole thickness of the Plio-Pleistocene sediments of the basin fill. Thus other processes must be invoked to understand the growth of the Plio-Pleistocene basin. Especially the piracy of the Rhine River to the north during the early Pleistocene could explain these effects.

The Interplay between Scientific Overlap and Cooperation and the Resulting Gain in Co-Authorship Interactions.

PubMed

Mayrose, Itay; Freilich, Shiri

2015-01-01

Considering the importance of scientific interactions, understanding the principles that govern fruitful scientific research is crucial to policy makers and scientists alike. The outcome of an interaction is to a large extent dependent on the balancing of contradicting motivations accompanying the establishment of collaborations. Here, we assembled a dataset of nearly 20,000 publications authored by researchers affiliated with ten top universities. Based on this data collection, we estimated the extent of different interaction types between pairwise combinations of researchers. We explored the interplay between the overlap in scientific interests and the tendency to collaborate, and associated these estimates with measures of scientific quality and social accessibility aiming at studying the typical resulting gain of different interaction patterns. Our results show that scientists tend to collaborate more often with colleagues with whom they share moderate to high levels of mutual interests and knowledge while cooperative tendency declines at higher levels of research-interest overlap, suggesting fierce competition, and at the lower levels, suggesting communication gaps. Whereas the relative number of alliances dramatically differs across a gradient of research overlap, the scientific impact of the resulting articles remains similar. When considering social accessibility, we find that though collaborations between remote researchers are relatively rare, their quality is significantly higher than studies produced by close-circle scientists. Since current collaboration patterns do not necessarily overlap with gaining optimal scientific quality, these findings should encourage scientists to reconsider current collaboration strategies.

Deep Impact: Effects of Mountaintop Mining on Surface Topography, Bedrock Structure, and Downstream Waters.

PubMed

Ross, Matthew R V; McGlynn, Brian L; Bernhardt, Emily S

2016-02-16

Land use impacts are commonly quantified and compared using 2D maps, limiting the scale of their reported impacts to surface area estimates. Yet, nearly all land use involves disturbances below the land surface. Incorporating this third dimension into our estimates of land use impact is especially important when examining the impacts of mining. Mountaintop mining is the most common form of coal mining in the Central Appalachian ecoregion. Previous estimates suggest that active, reclaimed, or abandoned mountaintop mines cover ∼7% of Central Appalachia. While this is double the areal extent of development in the ecoregion (estimated to occupy <3% of the land area), the impacts are far more extensive than areal estimates alone can convey as the impacts of mines extend 10s to 100s of meters below the current land surface. Here, we provide the first estimates for the total volumetric and topographic disturbance associated with mining in an 11 500 km(2) region of southern West Virginia. We find that the cutting of ridges and filling of valleys has lowered the median slope of mined landscapes in the region by nearly 10 degrees while increasing their average elevation by 3 m as a result of expansive valley filling. We estimate that in southern West Virginia, more than 6.4km(3) of bedrock has been broken apart and deposited into 1544 headwater valley fills. We used NPDES monitoring datatsets available for 91 of these valley fills to explore whether fill characteristics could explain variation in the pH or selenium concentrations reported for streams draining these fills. We found that the volume of overburden in individual valley fills correlates with stream pH and selenium concentration, and suggest that a three-dimensional assessment of mountaintop mining impacts is necessary to predict both the severity and the longevity of the resulting environmental impacts.

Healthy Worker Survivor Bias in the Colorado Plateau Uranium Miners Cohort

PubMed Central

Keil, Alexander P.; Richardson, David B.; Troester, Melissa A.

2015-01-01

Cohort mortality studies of underground miners have been used to estimate the number of lung cancer deaths attributable to radon exposure. However, previous studies of the radon–lung cancer association among underground miners may have been subject to healthy worker survivor bias, a type of time-varying confounding by employment status. We examined radon-mortality associations in a study of 4,124 male uranium miners from the Colorado Plateau who were followed from 1950 through 2005. We estimated the time ratio (relative change in median survival time) per 100 working level months (radon exposure averaging 130,000 mega-electron volts of potential α energy per liter of air, per working month) using G-estimation of structural nested models. After controlling for healthy worker survivor bias, the time ratio for lung cancer per 100 working level months was 1.168 (95% confidence interval: 1.152, 1.174). In an unadjusted model, the estimate was 1.102 (95% confidence interval: 1.099, 1.112)—39% lower. Controlling for this bias, we estimated that among 617 lung cancer deaths, 6,071 person-years of life were lost due to occupational radon exposure during follow-up. Our analysis suggests that healthy worker survivor bias in miner cohort studies can be substantial, warranting reexamination of current estimates of radon's estimated impact on lung cancer mortality. PMID:25837305

Estimation of Circadian Body Temperature Rhythm Based on Heart Rate in Healthy, Ambulatory Subjects.

PubMed

Sim, Soo Young; Joo, Kwang Min; Kim, Han Byul; Jang, Seungjin; Kim, Beomoh; Hong, Seungbum; Kim, Sungwan; Park, Kwang Suk

2017-03-01

Core body temperature is a reliable marker for circadian rhythm. As characteristics of the circadian body temperature rhythm change during diverse health problems, such as sleep disorder and depression, body temperature monitoring is often used in clinical diagnosis and treatment. However, the use of current thermometers in circadian rhythm monitoring is impractical in daily life. As heart rate is a physiological signal relevant to thermoregulation, we investigated the feasibility of heart rate monitoring in estimating circadian body temperature rhythm. Various heart rate parameters and core body temperature were simultaneously acquired in 21 healthy, ambulatory subjects during their routine life. The performance of regression analysis and the extended Kalman filter on daily body temperature and circadian indicator (mesor, amplitude, and acrophase) estimation were evaluated. For daily body temperature estimation, mean R-R interval (RRI), mean heart rate (MHR), or normalized MHR provided a mean root mean square error of approximately 0.40 °C in both techniques. The mesor estimation regression analysis showed better performance than the extended Kalman filter. However, the extended Kalman filter, combined with RRI or MHR, provided better accuracy in terms of amplitude and acrophase estimation. We suggest that this noninvasive and convenient method for estimating the circadian body temperature rhythm could reduce discomfort during body temperature monitoring in daily life. This, in turn, could facilitate more clinical studies based on circadian body temperature rhythm.

Looking at the world with your ears: how do we get the size of an object from its sound?

PubMed

Grassi, Massimo; Pastore, Massimiliano; Lemaitre, Guillaume

2013-05-01

Identifying the properties of on-going events by the sound they produce is crucial for our interaction with the environment when visual information is not available. Here, we investigated the ability of listeners to estimate the size of an object (a ball) dropped on a plate with ecological listening conditions (balls were dropped in real time) and response methods (listeners estimate ball-size by drawing a disk). Previous studies had shown that listeners can veridically estimate the size of objects by the sound they produce, but it is yet unclear which acoustical index listeners use to produce their estimates. In particular, it is unclear whether listeners listen to amplitude (related to loudness) or frequency (related to the sound's brightness) domain cue to produce their estimates. In the current study, in order to understand which cue is used by the listener to recover the size of the object, we manipulated the sound source event in such a way that frequency and amplitude cues provided contrasting size-information (balls were dropped from various heights). Results showed that listeners' estimations were accurate regardless of the experimental manipulations performed in the experiments. In addition, results suggest that listeners were likely integrating frequency and amplitude acoustical cues in order to produce their estimate and although these cues were often providing contrasting size-information. Copyright © 2013 Elsevier B.V. All rights reserved.

EVENT PREDICTION AND AFFECTIVE FORECASTING IN DEPRESSIVE COGNITION: USING EMOTION AS INFORMATION ABOUT THE FUTURE

PubMed Central

MARROQUÍN, BRETT; NOLEN-HOEKSEMA, SUSAN

2015-01-01

Depression is characterized by a bleak view of the future, but the mechanisms through which depressed mood is integrated into basic processes of future-oriented cognition are unclear. We hypothesized that dysphoric individuals’ predictions of what will happen in the future (likelihood estimation) and how the future will feel (affective forecasting) are attributable to individual differences in incorporating present emotion as judgment-relevant information. Dysphoric individuals (n = 77) made pessimistic likelihood estimates and blunted positive affective forecasts relative to controls (n = 84). These differences were mediated by dysphoric individuals’ tendencies to rely on negative emotion as information more than controls—and on positive emotion less—independent of anhedonia. These findings suggest that (1) blunted positive affective forecasting is a distinctive component of depressive future-oriented cognition, and (2) future-oriented cognitive processes are linked not just to current emotional state, but also to individual variation in using that emotion as information. This role of individual differences elucidates basic mechanisms in future-oriented cognition, and suggests routes for intervention on interrelated cognitive and affective processes in depression. PMID:26146452

Can uncertainties in sea ice albedo reconcile patterns of data-model discord for the Pliocene and 20th/21st centuries?

USGS Publications Warehouse

Howell, Fergus W.; Haywood, Alan M.; Dolan, Aisling M.; Dowsett, Harry J.; Francis, Jane E; Hill, Daniel J.; Pickering, Steven J.; Pope, James O.; Salzmann, Ulrich; Wade, Bidget S

2014-01-01

General Circulation Model simulations of the mid-Pliocene warm period (mPWP, 3.264 to 3.025 Myr ago) currently underestimate the level of warming that proxy data suggest existed at high latitudes, with discrepancies of up to 11°C for sea surface temperature estimates and 17°C for surface air temperature estimates. Sea ice has a strong influence on high-latitude climates, partly due to the albedo feedback. We present results demonstrating the effects of reductions in minimum sea ice albedo limits in general circulation model simulations of the mPWP. While mean annual surface air temperature increases of up to 6°C are observed in the Arctic, the maximum decrease in model-data discrepancies is just 0.81°C. Mean annual sea surface temperatures increase by up to 2°C, with a maximum model-data discrepancy improvement of 1.31°C. It is also suggested that the simulation of observed 21st century sea ice decline could be influenced by the adjustment of the sea ice albedo parameterization.

Can Canals Effectively Replace Groundwater Irrigation in Over-exploited Regions in India?

NASA Astrophysics Data System (ADS)

Jain, M.; Fishman, R.; Mondal, P.; Galford, G. L.; Bhattarai, N.; Naeem, S.; DeFries, R. S.

2017-12-01

We use high-resolution data on irrigation and cropping intensity across India to empirically estimate the impacts of losing access to groundwater irrigation in regions with critically exploited aquifers. India is the largest consumer of groundwater globally and is facing severe groundwater depletion. Canals are being promoted as an alternate irrigation source, yet few studies have quantified the effects that this transition may have on agricultural production. Our results suggest that farmers will be 50% less likely to plant a winter crop, have 20% less cropped area, and have cropped areas that are increasingly sensitive to rainfall variability when switching to canal irrigation. We estimate that national winter cropped area will decrease by approximately 13% if farmers lose access to groundwater irrigation in critically over-exploited regions, and 6% if farmers in these regions switch to canal irrigation. These results suggest that groundwater and canal irrigation are not substitutable, and farmers may have to switch to less water intensive crops or improve water use efficiency to maintain current levels of production in the future.

EVENT PREDICTION AND AFFECTIVE FORECASTING IN DEPRESSIVE COGNITION: USING EMOTION AS INFORMATION ABOUT THE FUTURE.

PubMed

Marroquín, Brett; Nolen-Hoeksema, Susan

2015-02-01

Depression is characterized by a bleak view of the future, but the mechanisms through which depressed mood is integrated into basic processes of future-oriented cognition are unclear. We hypothesized that dysphoric individuals' predictions of what will happen in the future ( likelihood estimation ) and how the future will feel ( affective forecasting ) are attributable to individual differences in incorporating present emotion as judgment-relevant information. Dysphoric individuals ( n = 77) made pessimistic likelihood estimates and blunted positive affective forecasts relative to controls ( n = 84). These differences were mediated by dysphoric individuals' tendencies to rely on negative emotion as information more than controls-and on positive emotion less-independent of anhedonia. These findings suggest that (1) blunted positive affective forecasting is a distinctive component of depressive future-oriented cognition, and (2) future-oriented cognitive processes are linked not just to current emotional state, but also to individual variation in using that emotion as information. This role of individual differences elucidates basic mechanisms in future-oriented cognition, and suggests routes for intervention on interrelated cognitive and affective processes in depression.

A self-sensing active magnetic bearing based on a direct current measurement approach.

PubMed

Niemann, Andries C; van Schoor, George; du Rand, Carel P

2013-09-11

Active magnetic bearings (AMBs) have become a key technology in various industrial applications. Self-sensing AMBs provide an integrated sensorless solution for position estimation, consolidating the sensing and actuating functions into a single electromagnetic transducer. The approach aims to reduce possible hardware failure points, production costs, and system complexity. Despite these advantages, self-sensing methods must address various technical challenges to maximize the performance thereof. This paper presents the direct current measurement (DCM) approach for self-sensing AMBs, denoting the direct measurement of the current ripple component. In AMB systems, switching power amplifiers (PAs) modulate the rotor position information onto the current waveform. Demodulation self-sensing techniques then use bandpass and lowpass filters to estimate the rotor position from the voltage and current signals. However, the additional phase-shift introduced by these filters results in lower stability margins. The DCM approach utilizes a novel PA switching method that directly measures the current ripple to obtain duty-cycle invariant position estimates. Demodulation filters are largely excluded to minimize additional phase-shift in the position estimates. Basic functionality and performance of the proposed self-sensing approach are demonstrated via a transient simulation model as well as a high current (10 A) experimental system. A digital implementation of amplitude modulation self-sensing serves as a comparative estimator.

Gyrotron-driven high current ECR ion source for boron-neutron capture therapy neutron generator

NASA Astrophysics Data System (ADS)

Skalyga, V.; Izotov, I.; Golubev, S.; Razin, S.; Sidorov, A.; Maslennikova, A.; Volovecky, A.; Kalvas, T.; Koivisto, H.; Tarvainen, O.

2014-12-01

Boron-neutron capture therapy (BNCT) is a perspective treatment method for radiation resistant tumors. Unfortunately its development is strongly held back by a several physical and medical problems. Neutron sources for BNCT currently are limited to nuclear reactors and accelerators. For wide spread of BNCT investigations more compact and cheap neutron source would be much more preferable. In present paper an approach for compact D-D neutron generator creation based on a high current ECR ion source is suggested. Results on dense proton beams production are presented. A possibility of ion beams formation with current density up to 600 mA/cm2 is demonstrated. Estimations based on obtained experimental results show that neutron target bombarded by such deuteron beams would theoretically yield a neutron flux density up to 6·1010 cm-2/s. Thus, neutron generator based on a high-current deuteron ECR source with a powerful plasma heating by gyrotron radiation could fulfill the BNCT requirements significantly lower price, smaller size and ease of operation in comparison with existing reactors and accelerators.

Effect of Compressive Stresses on Leakage Currents in Microchip Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander

2012-01-01

Microchip tantalum capacitors are manufactured using new technologies that allow for production of small size capacitors (down to EIA case size 0402) with volumetric efficiency much greater than for regular chip capacitors. Due to a small size of the parts and leadless design they might be more sensitive to mechanical stresses that develop after soldering onto printed wiring boards (PWB) compared to standard chip capacitors. In this work, the effect of compressive stresses on leakage currents in capacitors has been investigated in the range of stresses up to 200 MPa. Significant, up to three orders of magnitude, variations of currents were observed after the stress exceeds a certain critical level that varied from 10 MPa to 180 MPa for capacitors used in this study. A stress-induced generation of electron traps in tantalum pentoxide dielectric is suggested to explain reversible variations of leakage currents in tantalum capacitors. Thermo-mechanical characteristics of microchip capacitors have been studied to estimate the level of stresses caused by assembly onto PWB and assess the risk of stress-related degradation and failures. Keywords: tantalum capacitors, leakage current, soldering, reliability, mechanical stress.

Electromigration and morphological changes in Ag nanostructures

NASA Astrophysics Data System (ADS)

Chatterjee, A.; Bai, T.; Edler, F.; Tegenkamp, C.; Weide-Zaage, K.; Pfnür, H.

2018-02-01

Electromigration (EM) as a structuring tool was investigated in Ag nanowires (width 300 nm, thickness 25 nm) and partly in notched and bow-tie Ag structures on a Si(1 0 0) substrate in ultra-high vacuum using a four-tip scanning tunneling microscope in combination with a scanning electron microscope. From simulations of Ag nanowires we got estimates of temperature profiles, current density profiles, EM and thermal migration (TM) mass flux distributions within the nanowire induced by critical current densities of 108 A cm-2. At room temperature, the electron wind force at these current densities by far dominates over thermal diffusion, and is responsible for formation of voids at the cathode and hillocks at the anode side. For current densities that exceed the critical current densities necessary for EM, a new type of wire-like structure formation was found both at room temperature and at 100 K for notched and bow-tie structures. This suggests that the simultaneous action of EM and TM is structure forming, but with a very small influence of TM at low temperature.

The burden of cancer at work: estimation as the first step to prevention.

PubMed

Rushton, L; Hutchings, S; Brown, T

2008-12-01

Work-related cancers are largely preventable. The overall aim of this project is to estimate the current burden of cancer in Great Britain attributable to occupational factors, and identify carcinogenic agents, industries and occupations for targeting risk prevention. Attributable fractions and numbers were estimated for mortality and incidence for bladder, lung, non-melanoma skin, and sinonasal cancers, leukaemia and mesothelioma for agents and occupations classified as International Agency for Research on Cancer (IARC) Group 1 and 2A carcinogens with "strong" or "suggestive" evidence for carcinogenicity at the specific cancer site in humans. Risk estimates were obtained from published literature and national data sources used for estimating proportions exposed. In 2004, 78,237 men and 71,666 women died from cancer in Great Britain. Of these, 7317 (4.9%) deaths (men: 6259 (8%); women: 1058 (1.5%)) were estimated to be attributable to work-related carcinogens for the six cancers assessed. Incidence estimates were 13,338 (4.0%) registrations (men: 11,284 (6.7%); women 2054 (1.2%)). Asbestos contributed over half the occupational attributable deaths, followed by silica, diesel engine exhaust, radon, work as a painter, mineral oils in metal workers and in the printing industry, environmental tobacco smoke (non-smokers), work as a welder and dioxins. Occupational exposure to solar radiation, mineral oils and coal tars/pitches contributed 2557, 1867 and 550 skin cancer registrations, respectively. Industries/occupations with large numbers of deaths and/or registrations include construction, metal working, personal and household services, mining (not metals), land transport and services allied to transport, roofing, road repair/construction, printing, farming, the Armed Forces, some other service industry sectors and manufacture of transport equipment, fabricated metal products, machinery, non-ferrous metals and metal products, and chemicals. Estimates for all but leukaemia are greater than those currently used in UK health and safety strategy planning and contrast with small numbers (200-240 annually) from occupational accidents. Sources of uncertainty in the estimates arise principally from approximate data and methodological issues. On balance, the estimates are likely to be a conservative estimate of the true risk. Long latency means that past high exposures will continue to give substantial numbers in the near future. Although levels of many exposures have reduced, recent measurements of others, such as wood dust and respirable quartz, show continuing high levels.

Economic impacts of current-use assessment of rural land in the east Texas pineywoods region

Treesearch

Clifford A. Hickman; Kevin D. Crowther

1991-01-01

Those provisions of Texas law that authorize optional current-use property tax assessment for forest and other rural land were studied to: (1) estimate the extent of adoption by qualifying property owners, (2) estimate the effects on assessments and taxes of enrolled land, (3) estimate the impacts on revenues received by local units of government, (4) estimate the...

A Geography-Specific Approach to Estimating the Distributional Impact of Highway Tolls: An Application to the Puget Sound Region of Washington State

PubMed Central

Plotnick, Robert D.; Romich, Jennifer; Thacker, Jennifer; Dunbar, Matthew

2011-01-01

This study contributes to the debate about tolls’ equity impacts by examining the potential economic costs of tolling for low-income and non-low-income households. Using data from the Puget Sound metropolitan region in Washington State and GIS methods to map driving routes from home to work, we examine car ownership and transportation patterns among low-income and non-low-income households. We follow standard practice of estimating tolls’ potential impact only on households with workers who would drive on tolled and non-tolled facilities. We then redo the analysis including broader groups of households. We find that the degree of regressivity is quite sensitive to the set of households included in the analysis. The results suggest that distributional analyses of tolls should estimate impacts on all households in the relevant region in addition to impacts on just users of roads that are currently tolled or likely to be tolled. PMID:21818172

Cannabis Smoking and Diabetes Mellitus: Results from Meta-Analysis with Eight Independent Replication Samples

PubMed Central

Alshaarawy, Omayma; Anthony, James C.

2016-01-01

Background In preclinical animal studies, evidence links cannabis smoking (CS) with hyperphagia, obesity, and insulin resistance. Nonetheless, in humans, CS might protect against type 2 diabetes mellitus (DM). Here, we offer epidemiological estimates from eight independent replications from (1) the National Health and Nutrition Examination Surveys, and (2) the National Surveys on Drug Use and Health (2005-12). Methods For each national survey participant, computer-assisted self-interviews assess CS and physician-diagnosed DM; NHANES provides additional biomarker values and a composite DM diagnosis. Regression analyses produce estimates of CS-DM associations. Meta-analyses summarize the replication estimates. Results Recently active CS and DM are inversely associated. The meta-analytic summary odds ratio is 0.7 (95% CI = 0.6, 0.8). Conclusions Current evidence is too weak for causal inference, but there now is a more stable evidence base for new lines of clinical translational research on a possibly protective (or spurious) CS-DM association suggested in prior research. PMID:25978795

The Effect of Low Survey Response Rates on Estimates of Alcohol Consumption in a General Population Survey

PubMed Central

Meiklejohn, Jessica; Connor, Jennie; Kypri, Kypros

2012-01-01

Background Response rates for surveys of alcohol use are declining for all modes of administration (postal, telephone, face-to-face). Low response rates may result in estimates that are biased by selective non-response. We examined non-response bias in the NZ GENACIS survey, a postal survey of a random electoral roll sample, with a response rate of 49.5% (n = 1924). Our aim was to estimate the magnitude of non-response bias in estimating the prevalence of current drinking and heavy episodic (binge) drinking. Methods We used the “continuum of resistance” model to guide the investigation. In this model the likelihood of response by sample members is related to the amount of effort required from the researchers to elicit a response. First, the demographic characteristics of respondents and non-respondents were compared. Second, respondents who returned their questionnaire before the first reminder (early), before the second reminder (intermediate) or after the second reminder (late) were compared by demographic characteristics, 12-month prevalence of drinking and prevalence of binge drinking. Results Demographic characteristics and prevalence of binge drinking were significantly different between late respondents and early/intermediate respondents, with the demographics of early and intermediate respondents being similar to people who refused to participate while late respondents were similar to all other non-respondents. Assuming non-respondents who did not actively refuse to participate had the same drinking patterns as late respondents, the prevalence of binge drinking amongst current drinkers was underestimated. Adjusting the prevalence of binge drinkers amongst current drinkers using population weights showed that this method of adjustment still resulted in an underestimate of the prevalence. Conclusions The findings suggest non-respondents who did not actively refuse to participate are likely to have similar or more extreme drinking behaviours than late respondents, and that surveys of health compromising behaviours such as alcohol use are likely to underestimate the prevalence of these behaviours. PMID:22532858

Cost-benefit assessment of using electronic health records data for clinical research versus current practices: Contribution of the Electronic Health Records for Clinical Research (EHR4CR) European Project.

PubMed

Beresniak, Ariel; Schmidt, Andreas; Proeve, Johann; Bolanos, Elena; Patel, Neelam; Ammour, Nadir; Sundgren, Mats; Ericson, Mats; Karakoyun, Töresin; Coorevits, Pascal; Kalra, Dipak; De Moor, Georges; Dupont, Danielle

2016-01-01

The widespread adoption of electronic health records (EHR) provides a new opportunity to improve the efficiency of clinical research. The European EHR4CR (Electronic Health Records for Clinical Research) 4-year project has developed an innovative technological platform to enable the re-use of EHR data for clinical research. The objective of this cost-benefit assessment (CBA) is to assess the value of EHR4CR solutions compared to current practices, from the perspective of sponsors of clinical trials. A CBA model was developed using an advanced modeling approach. The costs of performing three clinical research scenarios (S) applied to a hypothetical Phase II or III oncology clinical trial workflow (reference case) were estimated under current and EHR4CR conditions, namely protocol feasibility assessment (S1), patient identification for recruitment (S2), and clinical study execution (S3). The potential benefits were calculated considering that the estimated reduction in actual person-time and costs for performing EHR4CR S1, S2, and S3 would accelerate time to market (TTM). Probabilistic sensitivity analyses using Monte Carlo simulations were conducted to manage uncertainty. Should the estimated efficiency gains achieved with the EHR4CR platform translate into faster TTM, the expected benefits for the global pharmaceutical oncology sector were estimated at €161.5m (S1), €45.7m (S2), €204.5m (S1+S2), €1906m (S3), and up to €2121.8m (S1+S2+S3) when the scenarios were used sequentially. The results suggest that optimizing clinical trial design and execution with the EHR4CR platform would generate substantial added value for pharmaceutical industry, as main sponsors of clinical trials in Europe, and beyond. Copyright © 2015 Elsevier Inc. All rights reserved.

Human SLC4A11 Is a Novel NH3/H+ Co-transporter*

PubMed Central

Zhang, Wenlin; Ogando, Diego G.; Bonanno, Joseph A.; Obukhov, Alexander G.

2015-01-01

SLC4A11 has been proposed to be an electrogenic membrane transporter, permeable to Na+, H+ (OH−), bicarbonate, borate, and NH4+. Recent studies indicate, however, that neither bicarbonate or borate is a substrate. Here, we examined potential NH4+, Na+, and H+ contributions to electrogenic ion transport through SLC4A11 stably expressed in Na+/H+ exchanger-deficient PS120 fibroblasts. Inward currents observed during exposure to NH4Cl were determined by the [NH3]o, not [NH4+]o, and current amplitudes varied with the [H+] gradient. These currents were relatively unaffected by removal of Na+, K+, or Cl− from the bath but could be reduced by inclusion of NH4Cl in the pipette solution. Bath pH changes alone did not generate significant currents through SLC4A11, except immediately following exposure to NH4Cl. Reversal potential shifts in response to changing [NH3]o and pHo suggested an NH3/H+-coupled transport mode for SLC4A11. Proton flux through SLC4A11 in the absence of ammonia was relatively small, suggesting that ammonia transport is of more physiological relevance. Methylammonia produced currents similar to NH3 but with reduced amplitude. Estimated stoichiometry of SLC4A11 transport was 1:2 (NH3/H+). NH3-dependent currents were insensitive to 10 μm ethyl-isopropyl amiloride or 100 μm 4,4′- diisothiocyanatostilbene-2,2′-disulfonic acid. We propose that SLC4A11 is an NH3/2H+ co-transporter exhibiting unique characteristics. PMID:26018076

Population-based cost-offset estimation for the treatment of borderline personality disorder: projected costs in a currently running, ideal health system.

PubMed

Wunsch, Eva-Maria; Kliem, Sören; Kröger, Christoph

2014-09-01

Borderline personality disorder (BPD) is considered one of the most expensive mental disorders in terms of direct and indirect costs. The aim of this study was to carry out a cost-offset estimation of disorder-specific psychotherapy for BPD at the population level. The study investigated whether the possible financial benefits of dialectical behavior therapy outweigh the therapy costs, assuming a currently running, ideal health system, and whether the estimated cost-benefit relationships change depending upon the number of patients willing to be treated. A formula was elaborated that allows the user to calculate cost-benefit relationships for various conservative or progressive scenarios, with different stages of individuals' willingness to be treated (10%-90%). The possible costs and benefits of BPD-related treatment were evaluated using a 12-month, prevalence-based approach. The annual costs for untreated BPD were 8.69 billion EUR annually. The cost-benefit relationship for the treatment remained constant at 1.52 for all scenarios, implying that for each EUR invested, 1.52 EUR can be gained within one year, independent of the willingness to be treated. Additional intangible benefits were calculated with the aid of Quality-Adjusted Life Years. Findings suggest that BPD-related treatment might well be efficient at the population level. Copyright © 2014 Elsevier Ltd. All rights reserved.

High performance computing enabling exhaustive analysis of higher order single nucleotide polymorphism interaction in Genome Wide Association Studies.

PubMed

Goudey, Benjamin; Abedini, Mani; Hopper, John L; Inouye, Michael; Makalic, Enes; Schmidt, Daniel F; Wagner, John; Zhou, Zeyu; Zobel, Justin; Reumann, Matthias

2015-01-01

Genome-wide association studies (GWAS) are a common approach for systematic discovery of single nucleotide polymorphisms (SNPs) which are associated with a given disease. Univariate analysis approaches commonly employed may miss important SNP associations that only appear through multivariate analysis in complex diseases. However, multivariate SNP analysis is currently limited by its inherent computational complexity. In this work, we present a computational framework that harnesses supercomputers. Based on our results, we estimate a three-way interaction analysis on 1.1 million SNP GWAS data requiring over 5.8 years on the full "Avoca" IBM Blue Gene/Q installation at the Victorian Life Sciences Computation Initiative. This is hundreds of times faster than estimates for other CPU based methods and four times faster than runtimes estimated for GPU methods, indicating how the improvement in the level of hardware applied to interaction analysis may alter the types of analysis that can be performed. Furthermore, the same analysis would take under 3 months on the currently largest IBM Blue Gene/Q supercomputer "Sequoia" at the Lawrence Livermore National Laboratory assuming linear scaling is maintained as our results suggest. Given that the implementation used in this study can be further optimised, this runtime means it is becoming feasible to carry out exhaustive analysis of higher order interaction studies on large modern GWAS.

Borderline features are associated with inaccurate trait self-estimations.

PubMed

Morey, Leslie C

2014-01-01

Many treatments for Borderline Personality Disorder (BPD) are based upon the hypothesis that gross distortion in perceptions and attributions related to self and others represent a core mechanism for the enduring difficulties displayed by such patients. However, available experimental evidence of such distortions provides equivocal results, with some studies suggesting that BPD is related to inaccuracy in such perceptions and others indicative of enhanced accuracy in some judgments. The current study uses a novel methodology to explore whether individuals with BPD features are less accurate in estimating their levels of universal personality characteristics as compared to community norms. One hundred and four students received course instruction on the Five Factor Model of personality, and then were asked to estimate their levels of these five traits relative to community norms. They then completed the NEO-Five Factor Inventory and the Personality Assessment Inventory-Borderline Features scale (PAI-BOR). Accuracy of estimates was calculated by computing squared differences between self-estimated trait levels and norm-referenced standardized scores in the NEO-FFI. There was a moderately strong relationship between PAI-BOR score and inaccuracy of trait level estimates. In particular, high BOR individuals dramatically overestimated their levels of Agreeableness and Conscientiousness, estimating themselves to be slightly above average on each of these characteristics but actually scoring well below average on both. The accuracy of estimates of levels of Neuroticism were unrelated to BOR scores, despite the fact that BOR scores were highly correlated with Neuroticism. These findings support the hypothesis that a key feature of BPD involves marked perceptual distortions of various aspects of self in relationship to others. However, the results also indicate that this is not a global perceptual deficit, as high BOR scorers accurately estimated that their emotional responsiveness was well above average. However, such individuals appear to have limited insight into their relative disadvantages in the capacity for cooperative relationships, or their limited ability to approach life in a planful and non-impulsive manner. Such results suggest important targets for treatments addressing problems in self-other representations.

A non-linear regression method for CT brain perfusion analysis

NASA Astrophysics Data System (ADS)

Bennink, E.; Oosterbroek, J.; Viergever, M. A.; Velthuis, B. K.; de Jong, H. W. A. M.

2015-03-01

CT perfusion (CTP) imaging allows for rapid diagnosis of ischemic stroke. Generation of perfusion maps from CTP data usually involves deconvolution algorithms providing estimates for the impulse response function in the tissue. We propose the use of a fast non-linear regression (NLR) method that we postulate has similar performance to the current academic state-of-art method (bSVD), but that has some important advantages, including the estimation of vascular permeability, improved robustness to tracer-delay, and very few tuning parameters, that are all important in stroke assessment. The aim of this study is to evaluate the fast NLR method against bSVD and a commercial clinical state-of-art method. The three methods were tested against a published digital perfusion phantom earlier used to illustrate the superiority of bSVD. In addition, the NLR and clinical methods were also tested against bSVD on 20 clinical scans. Pearson correlation coefficients were calculated for each of the tested methods. All three methods showed high correlation coefficients (>0.9) with the ground truth in the phantom. With respect to the clinical scans, the NLR perfusion maps showed higher correlation with bSVD than the perfusion maps from the clinical method. Furthermore, the perfusion maps showed that the fast NLR estimates are robust to tracer-delay. In conclusion, the proposed fast NLR method provides a simple and flexible way of estimating perfusion parameters from CT perfusion scans, with high correlation coefficients. This suggests that it could be a better alternative to the current clinical and academic state-of-art methods.

Group search algorithm recovers effective connectivity maps for individuals in homogeneous and heterogeneous samples.

PubMed

Gates, Kathleen M; Molenaar, Peter C M

2012-10-15

At its best, connectivity mapping can offer researchers great insight into how spatially disparate regions of the human brain coordinate activity during brain processing. A recent investigation conducted by Smith and colleagues (2011) on methods for estimating connectivity maps suggested that those which attempt to ascertain the direction of influence among ROIs rarely provide reliable results. Another problem gaining increasing attention is heterogeneity in connectivity maps. Most group-level methods require that the data come from homogeneous samples, and misleading findings may arise from current methods if the connectivity maps for individuals vary across the sample (which is likely the case). The utility of maps resulting from effective connectivity on the individual or group levels is thus diminished because they do not accurately inform researchers. The present paper introduces a novel estimation technique for fMRI researchers, Group Iterative Multiple Model Estimation (GIMME), which demonstrates that using information across individuals assists in the recovery of the existence of connections among ROIs used by Smith and colleagues (2011) and the direction of the influence. Using heterogeneous in-house data, we demonstrate that GIMME offers a unique improvement over current approaches by arriving at reliable group and individual structures even when the data are highly heterogeneous across individuals comprising the group. An added benefit of GIMME is that it obtains reliable connectivity map estimates equally well using the data from resting state, block, or event-related designs. GIMME provides researchers with a powerful, flexible tool for identifying directed connectivity maps at the group and individual levels. Copyright © 2012 Elsevier Inc. All rights reserved.

Estimating the proportion of healthcare-associated infections that are reasonably preventable and the related mortality and costs.

PubMed

Umscheid, Craig A; Mitchell, Matthew D; Doshi, Jalpa A; Agarwal, Rajender; Williams, Kendal; Brennan, Patrick J

2011-02-01

To estimate the proportion of healthcare-associated infections (HAIs) in US hospitals that are "reasonably preventable," along with their related mortality and costs. To estimate preventability of catheter-associated bloodstream infections (CABSIs), catheter-associated urinary tract infections (CAUTIs), surgical site infections (SSIs), and ventilator-associated pneumonia (VAP), we used a federally sponsored systematic review of interventions to reduce HAIs. Ranges of preventability included the lowest and highest risk reductions reported by US studies of "moderate" to "good" quality published in the last 10 years. We used the most recently published national data to determine the annual incidence of HAIs and associated mortality. To estimate incremental cost of HAIs, we performed a systematic review, which included costs from studies in general US patient populations. To calculate ranges for the annual number of preventable infections and deaths and annual costs, we multiplied our infection, mortality, and cost figures with our ranges of preventability for each HAI. As many as 65%-70% of cases of CABSI and CAUTI and 55% of cases of VAP and SSI may be preventable with current evidence-based strategies. CAUTI may be the most preventable HAI. CABSI has the highest number of preventable deaths, followed by VAP. CABSI also has the highest cost impact; costs due to preventable cases of VAP, CAUTI, and SSI are likely less. Our findings suggest that 100% prevention of HAIs may not be attainable with current evidence-based prevention strategies; however, comprehensive implementation of such strategies could prevent hundreds of thousands of HAIs and save tens of thousands of lives and billions of dollars.

Global Positioning System III (GPS III)

DTIC Science & Technology

2015-12-01

Vacuum (TVAC) testing on October 12, 2015, and successfully completed baseline TVAC testing on December 23, 2015 – a major system- level event...0.0 0.0 Total 4142.9 5285.2 N/A 5180.4 4269.8 5650.1 5557.4 Current APB Cost Estimate Reference SCP dated July 02, 2015 Confidence Level Confidence... Level of cost estimate for current APB: 60% The current APB is established at the 60% confidence level . This estimate is built upon the February 2015

Estimation and modeling of electrofishing capture efficiency for fishes in wadeable warmwater streams

USGS Publications Warehouse

Price, A.; Peterson, James T.

2010-01-01

Stream fish managers often use fish sample data to inform management decisions affecting fish populations. Fish sample data, however, can be biased by the same factors affecting fish populations. To minimize the effect of sample biases on decision making, biologists need information on the effectiveness of fish sampling methods. We evaluated single-pass backpack electrofishing and seining combined with electrofishing by following a dual-gear, mark–recapture approach in 61 blocknetted sample units within first- to third-order streams. We also estimated fish movement out of unblocked units during sampling. Capture efficiency and fish abundances were modeled for 50 fish species by use of conditional multinomial capture–recapture models. The best-approximating models indicated that capture efficiencies were generally low and differed among species groups based on family or genus. Efficiencies of single-pass electrofishing and seining combined with electrofishing were greatest for Catostomidae and lowest for Ictaluridae. Fish body length and stream habitat characteristics (mean cross-sectional area, wood density, mean current velocity, and turbidity) also were related to capture efficiency of both methods, but the effects differed among species groups. We estimated that, on average, 23% of fish left the unblocked sample units, but net movement varied among species. Our results suggest that (1) common warmwater stream fish sampling methods have low capture efficiency and (2) failure to adjust for incomplete capture may bias estimates of fish abundance. We suggest that managers minimize bias from incomplete capture by adjusting data for site- and species-specific capture efficiency and by choosing sampling gear that provide estimates with minimal bias and variance. Furthermore, if block nets are not used, we recommend that managers adjust the data based on unconditional capture efficiency.

Effects of land-use change on the carbon balance of terrestrial ecosystems

NASA Astrophysics Data System (ADS)

Houghton, R. A.; Goodale, C. L.

Most changes in land use affect the amount of carbon held in vegetation and soil, thereby, either releasing carbon dioxide (a greenhouse gas) to, or removing it from, the atmosphere. The greatest fluxes of carbon result from conversion of forests to open lands (and vice versa). Model-based estimates of the flux of carbon attributable to land-use change are highly variable, however, largely as a result of uncertainties in the areas annually affected by different types of land-use change. Uncertain rates of tropical deforestation, for example, account for more than half of the range in estimates of the global carbon flux. Three other factors account for much of the rest of the uncertainty: (1) the initial stocks of carbon in ecosystems affected by land-use change (i.e., spatial heterogeneity), (2) per hectare changes in carbon stocks in response to different types of land-use change, and (3) legacy effects; that is, the time it takes for carbon stocks to equilibrate following a change in land use. For the tropics, recent satellite-based estimates of deforestation are lower than previous estimates and yield calculated carbon emissions from land-use change that are similar to independently-derived estimates of the total net flux for the region. The similarity suggests that changes in land use account for the net flux of carbon from the tropics. For the northern mid-latitudes, the carbon sink attributed to land-use change is less than the sink obtained by other methods, suggesting either an incomplete accounting of land-use change or the importance of other factors in explaining the current carbon sink in that region.

Indirect Genetic Effects and the Spread of Infectious Disease: Are We Capturing the Full Heritable Variation Underlying Disease Prevalence?

PubMed Central

Lipschutz-Powell, Debby; Woolliams, John A.; Bijma, Piter; Doeschl-Wilson, Andrea B.

2012-01-01

Reducing disease prevalence through selection for host resistance offers a desirable alternative to chemical treatment. Selection for host resistance has proven difficult, however, due to low heritability estimates. These low estimates may be caused by a failure to capture all the relevant genetic variance in disease resistance, as genetic analysis currently is not taylored to estimate genetic variation in infectivity. Host infectivity is the propensity of transmitting infection upon contact with a susceptible individual, and can be regarded as an indirect effect to disease status. It may be caused by a combination of physiological and behavioural traits. Though genetic variation in infectivity is difficult to measure directly, Indirect Genetic Effect (IGE) models, also referred to as associative effects or social interaction models, allow the estimation of this variance from more readily available binary disease data (infected/non-infected). We therefore generated binary disease data from simulated populations with known amounts of variation in susceptibility and infectivity to test the adequacy of traditional and IGE models. Our results show that a conventional model fails to capture the genetic variation in infectivity inherent in populations with simulated infectivity. An IGE model, on the other hand, does capture some of the variation in infectivity. Comparison with expected genetic variance suggests that there is scope for further methodological improvement, and that potential responses to selection may be greater than values presented here. Nonetheless, selection using an index of estimated direct and indirect breeding values was shown to have a greater genetic selection differential and reduced future disease risk than traditional selection for resistance only. These findings suggest that if genetic variation in infectivity substantially contributes to disease transmission, then breeding designs which explicitly incorporate IGEs might help reduce disease prevalence. PMID:22768088

Possibilities for Estimating Horizontal Electrical Currents in Active Regions on the Sun

NASA Astrophysics Data System (ADS)

Fursyak, Yu. A.; Abramenko, V. I.

2017-12-01

Part of the "free" magnetic energy associated with electrical current systems in the active region (AR) is released during solar flares. This proposition is widely accepted and it has stimulated interest in detecting electrical currents in active regions. The vertical component of an electric current in the photosphere can be found by observing the transverse magnetic field. At present, however, there are no direct methods for calculating transverse electric currents based on these observations. These calculations require information on the field vector measured simultaneously at several levels in the photosphere, which has not yet been done with solar instrumentation. In this paper we examine an approach to calculating the structure of the square of the density of a transverse electrical current based on a magnetogram of the vertical component of the magnetic field in the AR. Data obtained with the Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamic Observatory (SDO) for the AR of NOAA AR 11283 are used. It is shown that (1) the observed variations in the magnetic field of a sunspot and the proposed estimate of the density of an annular horizontal current around the spot are consistent with Faraday's law and (2) the resulting estimates of the magnitude of the square of the density of the horizontal current {j}_{\\perp}^2 = (0.002- 0.004) A2/m4 are consistent with previously obtained values of the density of a vertical current in the photosphere. Thus, the proposed estimate is physically significant and this method can be used to estimate the density and structure of transverse electrical currents in the photosphere.

The carbon balance of South America: a review of the status, decadal trends and main determinants

NASA Astrophysics Data System (ADS)

Gloor, M.; Gatti, L.; Brienen, R.; Feldpausch, T. R.; Phillips, O. L.; Miller, J.; Ometto, J. P.; Rocha, H.; Baker, T.; de Jong, B.; Houghton, R. A.; Malhi, Y.; Aragão, L. E. O. C.; Guyot, J.-L.; Zhao, K.; Jackson, R.; Peylin, P.; Sitch, S.; Poulter, B.; Lomas, M.; Zaehle, S.; Huntingford, C.; Levy, P.; Lloyd, J.

2012-12-01

We summarise the contemporary carbon budget of South America and relate it to its dominant controls: population and economic growth, changes in land use practices and a changing atmospheric environment and climate. Component flux estimate methods we consider sufficiently reliable for this purpose encompass fossil fuel emission inventories, biometric analysis of old-growth rainforests, estimation of carbon release associated with deforestation based on remote sensing and inventories, and agricultural export data. Alternative methods for the estimation of the continental-scale net land to atmosphere CO2 flux, such as atmospheric transport inverse modelling and terrestrial biosphere model predictions, are, we find, hampered by the data paucity, and improved parameterisation and validation exercises are required before reliable estimates can be obtained. From our analysis of available data, we suggest that South America was a net source to the atmosphere during the 1980s (~ 0.3-0.4 Pg C a-1) and close to neutral (~ 0.1 Pg C a-1) in the 1990s. During the latter period, carbon uptake in old-growth forests nearly compensated for the carbon release associated with fossil fuel burning and deforestation. Annual mean precipitation over tropical South America as inferred from Amazon River discharge shows a long-term upward trend. Although, over the last decade dry seasons have tended to be drier, with the years 2005 and 2010 in particular experiencing strong droughts. On the other hand, precipitation during the wet seasons also shows an increasing trend. Air temperatures have also increased slightly. Also with increases in atmospheric CO2 concentrations, it is currently unclear what effect these climate changes are having on the forest carbon balance of the region. Current indications are that the forests of the Amazon Basin have acted as a substantial long-term carbon sink, but with the most recent measurements suggesting that this sink may be weakening. Economic development of the tropical regions of the continent is advancing steadily, with exports of agricultural products being an important driver and witnessing a strong upturn over the last decade.

Evidence for a Sizable Age Spread among Galaxies from the Ultraviolet-Upturn Phenomenon in Early-type Systems

NASA Astrophysics Data System (ADS)

Park, Jang-Hyun; Lee, Young-Wook

1997-02-01

The suggestion of Lee that the age spread among galaxies is responsible for the systematic variation of the ultraviolet upturn among early-type systems is examined here with detailed population synthesis models. Our models differ from previous ones by including (1) the effect of metallicity spreads and (2) detailed modeling of the variations in H-R diagram morphology (including the helium-burning phase) with age and metallicity. Our models suggest that the far-UV radiation of these systems is dominated by a minority population of metal-poor, hot horizontal-branch (HB) stars and their post-HB progeny, with some contribution from metal-rich post-asymptotic giant branch stars, while the optical radiation is dominated by a metal-rich population. The systematic variation of the UV upturn depends on the contribution from metal-poor, hot HB stars and their post-HB progeny, which in turn depends on the ages of old stellar populations in galaxies. Our result implies a prolonged epoch of galaxy formation, in the sense that more massive galaxies (in denser environments) formed first. With the assumption that the UV-upturn phenomenon is solely due to the age variations among galaxies, we estimate the difference in age between the giant elliptical galaxies and the spiral bulges of the Local Group to be ~3 Gyr. This suggests that the best estimate for the lower limit of the age of the universe is ~19 Gyr, which of course would be in conflict with the current estimate of H0, together with the standard cosmological models with zero cosmological constant.

Genetic Divergence Disclosing a Rapid Prehistorical Dispersion of Native Americans in Central and South America

PubMed Central

He, Yungang; Wang, Wei R.; Li, Ran; Wang, Sijia; Jin, Li

2012-01-01

An accurate estimate of the divergence time between Native Americans is important for understanding the initial entry and early dispersion of human beings in the New World. Current methods for estimating the genetic divergence time of populations could seriously depart from a linear relationship with the true divergence for multiple populations of a different population size and significant population expansion. Here, to address this problem, we propose a novel measure to estimate the genetic divergence time of populations. Computer simulation revealed that the new measure maintained an excellent linear correlation with the population divergence time in complicated multi-population scenarios with population expansion. Utilizing the new measure and microsatellite data of 21 Native American populations, we investigated the genetic divergences of the Native American populations. The results indicated that genetic divergences between North American populations are greater than that between Central and South American populations. None of the divergences, however, were large enough to constitute convincing evidence supporting the two-wave or multi-wave migration model for the initial entry of human beings into America. The genetic affinity of the Native American populations was further explored using Neighbor-Net and the genetic divergences suggested that these populations could be categorized into four genetic groups living in four different ecologic zones. The divergence of the population groups suggests that the early dispersion of human beings in America was a multi-step procedure. Further, the divergences suggest the rapid dispersion of Native Americans in Central and South Americas after a long standstill period in North America. PMID:22970308

Gaussian Process Model for Antarctic Surface Mass Balance and Ice Core Site Selection

NASA Astrophysics Data System (ADS)

White, P. A.; Reese, S.; Christensen, W. F.; Rupper, S.

2017-12-01

Surface mass balance (SMB) is an important factor in the estimation of sea level change, and data are collected to estimate models for prediction of SMB on the Antarctic ice sheet. Using Favier et al.'s (2013) quality-controlled aggregate data set of SMB field measurements, a fully Bayesian spatial model is posed to estimate Antarctic SMB and propose new field measurement locations. Utilizing Nearest-Neighbor Gaussian process (NNGP) models, SMB is estimated over the Antarctic ice sheet. An Antarctic SMB map is rendered using this model and is compared with previous estimates. A prediction uncertainty map is created to identify regions of high SMB uncertainty. The model estimates net SMB to be 2173 Gton yr-1 with 95% credible interval (2021,2331) Gton yr-1. On average, these results suggest lower Antarctic SMB and higher uncertainty than previously purported [Vaughan et al. (1999); Van de Berg et al. (2006); Arthern, Winebrenner and Vaughan (2006); Bromwich et al. (2004); Lenaerts et al. (2012)], even though this model utilizes significantly more observations than previous models. Using the Gaussian process' uncertainty and model parameters, we propose 15 new measurement locations for field study utilizing a maximin space-filling, error-minimizing design; these potential measurements are identied to minimize future estimation uncertainty. Using currently accepted Antarctic mass balance estimates and our SMB estimate, we estimate net mass loss [Shepherd et al. (2012); Jacob et al. (2012)]. Furthermore, we discuss modeling details for both space-time data and combining field measurement data with output from mathematical models using the NNGP framework.

Estimation of p,p'-DDT degradation in soil by modeling and constraining hydrological and biogeochemical controls.

PubMed

Sanka, Ondrej; Kalina, Jiri; Lin, Yan; Deutscher, Jan; Futter, Martyn; Butterfield, Dan; Melymuk, Lisa; Brabec, Karel; Nizzetto, Luca

2018-08-01

Despite not being used for decades in most countries, DDT remains ubiquitous in soils due to its persistence and intense past usage. Because of this it is still a pollutant of high global concern. Assessing long term dissipation of DDT from this reservoir is fundamental to understand future environmental and human exposure. Despite a large research effort, key properties controlling fate in soil (in particular, the degradation half-life (τ soil )) are far from being fully quantified. This paper describes a case study in a large central European catchment where hundreds of measurements of p,p'-DDT concentrations in air, soil, river water and sediment are available for the last two decades. The goal was to deliver an integrated estimation of τ soil by constraining a state-of-the-art hydrobiogeochemical-multimedia fate model of the catchment against the full body of empirical data available for this area. The INCA-Contaminants model was used for this scope. Good predictive performance against an (external) dataset of water and sediment concentrations was achieved with partitioning properties taken from the literature and τ soil estimates obtained from forcing the model against empirical historical data of p,p'-DDT in the catchment multicompartments. This approach allowed estimation of p,p'-DDT degradation in soil after taking adequate consideration of losses due to runoff and volatilization. Estimated τ soil ranged over 3000-3800 days. Degradation was the most important loss process, accounting on a yearly basis for more than 90% of the total dissipation. The total dissipation flux from the catchment soils was one order of magnitude higher than the total current atmospheric input estimated from atmospheric concentrations, suggesting that the bulk of p,p'-DDT currently being remobilized or lost is essentially that accumulated over two decades ago. Copyright © 2018 Elsevier Ltd. All rights reserved.

The application of Gaussian mixture models for signal quantification in MALDI-TOF mass spectrometry of peptides.

PubMed

Spainhour, John Christian G; Janech, Michael G; Schwacke, John H; Velez, Juan Carlos Q; Ramakrishnan, Viswanathan

2014-01-01

Matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) coupled with stable isotope standards (SIS) has been used to quantify native peptides. This peptide quantification by MALDI-TOF approach has difficulties quantifying samples containing peptides with ion currents in overlapping spectra. In these overlapping spectra the currents sum together, which modify the peak heights and make normal SIS estimation problematic. An approach using Gaussian mixtures based on known physical constants to model the isotopic cluster of a known compound is proposed here. The characteristics of this approach are examined for single and overlapping compounds. The approach is compared to two commonly used SIS quantification methods for single compound, namely Peak Intensity method and Riemann sum area under the curve (AUC) method. For studying the characteristics of the Gaussian mixture method, Angiotensin II, Angiotensin-2-10, and Angiotenisn-1-9 and their associated SIS peptides were used. The findings suggest, Gaussian mixture method has similar characteristics as the two methods compared for estimating the quantity of isolated isotopic clusters for single compounds. All three methods were tested using MALDI-TOF mass spectra collected for peptides of the renin-angiotensin system. The Gaussian mixture method accurately estimated the native to labeled ratio of several isolated angiotensin peptides (5.2% error in ratio estimation) with similar estimation errors to those calculated using peak intensity and Riemann sum AUC methods (5.9% and 7.7%, respectively). For overlapping angiotensin peptides, (where the other two methods are not applicable) the estimation error of the Gaussian mixture was 6.8%, which is within the acceptable range. In summary, for single compounds the Gaussian mixture method is equivalent or marginally superior compared to the existing methods of peptide quantification and is capable of quantifying overlapping (convolved) peptides within the acceptable margin of error.

How brain response and eating habits modulate food energy estimation.

PubMed

Mengotti, P; Aiello, M; Terenzi, D; Miniussi, C; Rumiati, R I

2018-05-01

The estimates we do of the energy content of different foods tend to be inaccurate, depending on several factors. The elements influencing such evaluation are related to the differences in the portion size of the foods shown, their energy density (kcal/g), but also to individual differences of the estimators, such as their body-mass index (BMI) or eating habits. Within this context the contribution of brain regions involved in food-related decisions to the energy estimation process is still poorly understood. Here, normal-weight and overweight/obese women with restrained or non-restrained eating habits, received anodal transcranial direct current stimulation (AtDCS) to modulate the activity of the left dorsolateral prefrontal cortex (dlPFC) while they performed a food energy estimation task. Participants were asked to judge the energy content of food images, unaware that all foods, for the quantity presented, shared the same energy content. Results showed that food energy density was a reliable predictor of their energy content estimates, suggesting that participants relied on their knowledge about the food energy density as a proxy for estimating food energy content. The neuromodulation of the dlPFC interacted with individual differences in restrained eating, increasing the precision of the energy content estimates in participants with higher scores in the restrained eating scale. Our study highlights the importance of eating habits, such as restrained eating, in modulating the activity of the left dlPFC during food appraisal. Copyright © 2018 Elsevier Inc. All rights reserved.

A comprehensive estimate of recent carbon sinks in China using both top-down and bottom-up approaches.

PubMed

Jiang, Fei; Chen, Jing M; Zhou, Lingxi; Ju, Weimin; Zhang, Huifang; Machida, Toshinobu; Ciais, Philippe; Peters, Wouter; Wang, Hengmao; Chen, Baozhang; Liu, Lixin; Zhang, Chunhua; Matsueda, Hidekazu; Sawa, Yousuke

2016-02-29

Atmospheric inversions use measurements of atmospheric CO2 gradients to constrain regional surface fluxes. Current inversions indicate a net terrestrial CO2 sink in China between 0.16 and 0.35 PgC/yr. The uncertainty of these estimates is as large as the mean because the atmospheric network historically contained only one high altitude station in China. Here, we revisit the calculation of the terrestrial CO2 flux in China, excluding emissions from fossil fuel burning and cement production, by using two inversions with three new CO2 monitoring stations in China as well as aircraft observations over Asia. We estimate a net terrestrial CO2 uptake of 0.39-0.51 PgC/yr with a mean of 0.45 PgC/yr in 2006-2009. After considering the lateral transport of carbon in air and water and international trade, the annual mean carbon sink is adjusted to 0.35 PgC/yr. To evaluate this top-down estimate, we constructed an independent bottom-up estimate based on ecosystem data, and giving a net land sink of 0.33 PgC/yr. This demonstrates closure between the top-down and bottom-up estimates. Both top-down and bottom-up estimates give a higher carbon sink than previous estimates made for the 1980s and 1990s, suggesting a trend towards increased uptake by land ecosystems in China.

Episodic Sediment Failure in Northern Flemish Pass, Eastern Canadian Margin: Interplay of Seismicity, Contour Current Winnowing, and Excess Pore Pressures

NASA Astrophysics Data System (ADS)

Piper, D.

2015-12-01

Episodic sediment failures are recognised on continental slopes around Flemish Pass and Orphan Basin from multibeam bathymetry, seismic reflection profiles and piston cores. Seismic stratigraphy is tied to published long cores with O-isotope data back to before MIS 6 and carbonate rich Heinrich layers in places produce marker reflections in high-resolution sparker profiles. Heinrich layers, radiocarbon dates and peaks in diatom abundance provide core chronology. Slope sedimentation was strongly influenced by the Labrador Current and the silty muds show architecture characteristic of contourites. Variation in Labrador Current strength is known from the sortable silt proxy over the past 125 ka. Large slope failures were mapped from seismic reflection profiles and their age estimated from seismic stratigraphy (3-5 ka resolution) and in some cases refined from cores (1-3 ka resolution). Large slope failures occurred apparently synchronously over margin lengths of 50-350 km. Such failures were earthquake triggered: other mechanisms for producing laterally extensive synchronous failure do not apply. Triaxial shear measurements show a Su/σ' ratio of typical slope sediment of 0.48, implying considerable stability. However, some silty muds have Atterberg limits that suggest susceptibility to liquefaction under cyclic loading, particularly in Holocene deposits and by analogy those of past full interglacials. Basal failure planes of some large failures correspond with either the last interglacial or the MIS 6 glacial maximum. Comparison with seismological models suggests that the observed slope failures represent earthquakes ranging from Mw ~5.6 to ~7.6. Mean recurrence interval of M = 7 earthquakes at any point on the margin is estimated at 30 ka from seismological models and 40 ka from the sediment failure record. In northern Flemish Pass, a spatial cluster of several failures over 30 ka preceded by a long interval with no failures suggests that some other mechanism has preconditioned the slope for earthquake triggering. There is circumstantial evidence that such preconditioning is related to excess pore pressures, released by fluid drainage at head scarps.

Louisiana Department of Transportation and Development's response to state concurrent resolution no. 126 : technical assistance report.

DOT National Transportation Integrated Search

1994-12-01

The objectives of this study were to: 1) estimate the situation in year 2005 with the current TIMED program in operation, 2) estimate how long current TIMED funding must be extended to fully fund the projects listed in the TIMED program, and 3) estim...

Common Genetic Contributions to Depressive Symptoms and Inflammatory Markers in Middle-Aged Men: The Twins Heart Study

PubMed Central

Su, Shaoyong; Miller, Andrew H.; Snieder, Harold; Bremner, J. Douglas; Ritchie, James; Maisano, Carisa; Jones, Linda; Murrah, Nancy V.; Goldberg, Jack; Vaccarino, Viola

2010-01-01

Objective To examine the extent to which a common genetic pathway is also involved in the relationship between depressive symptoms, in the absence of major depressive disorder (MDD), and inflammation. Recent data suggested that MDD and inflammation share common genes. Methods We recruited 188 male twins from the Vietnam Era Twin Registry who were free of symptomatic coronary artery disease and MDD, with mean ± standard deviation (SD) age of 55 ± 2.75 years, including 54 monozygotic and 40 dizygotic twin pairs. These pairs were assessed for two inflammatory markers, interleukin (IL)-6 and C-reactive protein (CRP). Current depressive symptoms were measured with the Beck Depression Inventory-II. Generalized estimating equations were used to examine the phenotypic association between depression and inflammatory markers. Biometrical genetic modeling was performed to estimate the genetic and environmental contributions to this association. Results An association was observed between severity of current depressive symptoms and increased levels of inflammatory markers (p < .001 for IL-6 and p = .005 for CRP). After adjustment for other factors, the association was slightly attenuated but remained statistically significant for IL-6 (p = .002). The heritability of IL-6, CRP, and depressive symptoms were estimated as 0.37, 0.65, and 0.48, respectively. Genetic modeling found a significant genetic correlation between IL-6 and depressive symptoms (rG = 0.22, p = .046), indicating that about 66% of the covariance between them can be explained by shared genetic influences. Conclusions Current depressive symptoms are significantly correlated with inflammatory markers. This covariation is due, in large part, to genes that are common to depressive symptoms and inflammation. PMID:19073752

Burden of Type 2 Diabetes in Mexico: Past, Current and Future Prevalence and Incidence Rates

PubMed Central

Meza, Rafael; Barrientos-Gutierrez, Tonatiuh; Rojas-Martinez, Rosalba; Reynoso-Noverón, Nancy; Palacio-Mejia, Lina Sofia; Lazcano-Ponce, Eduardo; Hernández-Ávila, Mauricio

2015-01-01

Introduction Mexico diabetes prevalence has increased dramatically in recent years. However, no national incidence estimates exist, hampering the assessment of diabetes trends and precluding the development of burden of disease analyses to inform public health policy decision-making. Here we provide evidence regarding current magnitude of diabetes in Mexico and its future trends. Methods We used data from the Mexico National Health and Nutrition Survey, and age-period-cohort models to estimate prevalence and incidence of self-reported diagnosed diabetes by age, sex, calendar-year (1960–2012), and birth-cohort (1920–1980). We project future rates under three alternative incidence scenarios using demographic projections of the Mexican population from 2010–2050 and a Multi-cohort Diabetes Markov Model. Results Adult (ages 20+) diagnosed diabetes prevalence in Mexico increased from 7% to 8.9% from 2006 to 2012. Diabetes prevalence increases with age, peaking around ages 65–68 to then decrease. Age-specific incidence follows similar patterns, but peaks around ages 57–59. We estimate that diagnosed diabetes incidence increased exponentially during 1960–2012, roughly doubling every 10 years. Projected rates under three age-specific incidence scenarios suggest diabetes prevalence among adults (ages 20+) may reach 13.7–22.5% by 2050, affecting 15–25 million individuals, with a lifetime risk of 1 in 3 to 1 in 2. Conclusions Diabetes prevalence in Mexico will continue to increase even if current incidence rates remain unchanged. Continued implementation of policies to reduce obesity rates, increase physical activity, and improve population diet, in tandem with diabetes surveillance and other risk control measures is paramount to substantially reduce the burden of diabetes in Mexico. PMID:26546108

Burden of type 2 diabetes in Mexico: past, current and future prevalence and incidence rates.

PubMed

Meza, Rafael; Barrientos-Gutierrez, Tonatiuh; Rojas-Martinez, Rosalba; Reynoso-Noverón, Nancy; Palacio-Mejia, Lina Sofia; Lazcano-Ponce, Eduardo; Hernández-Ávila, Mauricio

2015-12-01

Mexico diabetes prevalence has increased dramatically in recent years. However, no national incidence estimates exist, hampering the assessment of diabetes trends and precluding the development of burden of disease analyses to inform public health policy decision-making. Here we provide evidence regarding current magnitude of diabetes in Mexico and its future trends. We used data from the Mexico National Health and Nutrition Survey, and age-period-cohort models to estimate prevalence and incidence of self-reported diagnosed diabetes by age, sex, calendar-year (1960-2012), and birth-cohort (1920-1980). We project future rates under three alternative incidence scenarios using demographic projections of the Mexican population from 2010-2050 and a Multi-cohort Diabetes Markov Model. Adult (ages 20+) diagnosed diabetes prevalence in Mexico increased from 7% to 8.9% from 2006 to 2012. Diabetes prevalence increases with age, peaking around ages 65-68 to then decrease. Age-specific incidence follows similar patterns, but peaks around ages 57-59. We estimate that diagnosed diabetes incidence increased exponentially during 1960-2012, roughly doubling every 10 years. Projected rates under three age-specific incidence scenarios suggest diabetes prevalence among adults (ages 20+) may reach 13.7-22.5% by 2050, affecting 15-25 million individuals, with a lifetime risk of 1 in 3 to 1 in 2. Diabetes prevalence in Mexico will continue to increase even if current incidence rates remain unchanged. Continued implementation of policies to reduce obesity rates, increase physical activity, and improve population diet, in tandem with diabetes surveillance and other risk control measures is paramount to substantially reduce the burden of diabetes in Mexico. Copyright © 2015 Elsevier Inc. All rights reserved.

Estimating pixel variances in the scenes of staring sensors

DOEpatents

Simonson, Katherine M [Cedar Crest, NM; Ma, Tian J [Albuquerque, NM

2012-01-24

A technique for detecting changes in a scene perceived by a staring sensor is disclosed. The technique includes acquiring a reference image frame and a current image frame of a scene with the staring sensor. A raw difference frame is generated based upon differences between the reference image frame and the current image frame. Pixel error estimates are generated for each pixel in the raw difference frame based at least in part upon spatial error estimates related to spatial intensity gradients in the scene. The pixel error estimates are used to mitigate effects of camera jitter in the scene between the current image frame and the reference image frame.

Experimental game theory and behavior genetics.

PubMed

Cesarini, David; Dawes, Christopher T; Johannesson, Magnus; Lichtenstein, Paul; Wallace, Björn

2009-06-01

We summarize the findings from a research program studying the heritability of behavior in a number of widely used economic games, including trust, dictator, and ultimatum games. Results from the standard behavior genetic variance decomposition suggest that strategies and fundamental economic preference parameters are moderately heritable, with estimates ranging from 18 to 42%. In addition, we also report new evidence on so-called "hyperfair" preferences in the ultimatum game. We discuss the implications of our findings with special reference to current efforts that seek to understand the molecular genetic architecture of complex social behaviors.

Evolution of the climatic tolerance and postglacial range changes of the most primitive orchids (Apostasioideae) within Sundaland, Wallacea and Sahul.

PubMed

Kolanowska, Marta; Mystkowska, Katarzyna; Kras, Marta; Dudek, Magdalena; Konowalik, Kamil

2016-01-01

The location of possible glacial refugia of six Apostasioideae representatives is estimated based on ecological niche modeling analysis. The distribution of their suitable niches during the last glacial maximum (LGM) is compared with their current potential and documented geographical ranges. The climatic factors limiting the studied species occurrences are evaluated and the niche overlap between the studied orchids is assessed and discussed. The predicted niche occupancy profiles and reconstruction of ancestral climatic tolerances suggest high level of phylogenetic niche conservatism within Apostasioideae.

Crowdsourced estimation of cognitive decline and resilience in Alzheimer’s disease

PubMed Central

Allen, Genevera I; Amoroso, Nicola; Anghel, Catalina; Balagurusamy, Venkat; Bare, Christopher J; Beaton, Derek; Bellotti, Roberto; Bennett, David A; Boehme, Kevin; Boutros, Paul C; Caberlotto, Laura; Caloian, Cristian; Campbell, Frederick; Neto, Elias Chaibub; Chang, Yu-Chuan; Chen, Beibei; Chen, Chien-Yu; Chien, Ting-Ying; Clark, Tim; Das, Sudeshna; Davatzikos, Christos; Deng, Jieyao; Dillenberger, Donna; Dobson, Richard JB; Dong, Qilin; Doshi, Jimit; Duma, Denise; Errico, Rosangela; Erus, Guray; Everett, Evan; Fardo, David W; Friend, Stephen H; Fröhlich, Holger; Gan, Jessica; St George-Hyslop, Peter; Ghosh, Satrajit S; Glaab, Enrico; Green, Robert C; Guan, Yuanfang; Hong, Ming-Yi; Huang, Chao; Hwang, Jinseub; Ibrahim, Joseph; Inglese, Paolo; Jiang, Qijia; Katsumata, Yuriko; Kong, Dehan; Krause, Roland; Lalonde, Emilie; Lauria, Mario; Lee, Eunjee; Lin, Xihui; Liu, Zhandong; Livingstone, Julie; Logsdon, Benjamin A; Lovestone, Simon; Lyappan, Anandhi; Ma, Michelle; Malhotra, Ashutosh; Maxwell, Taylor J; Merrill, Emily; Nagorski, John; Namasivayam, Aishwarya; Narayan, Manjari; Naz, Mufassra; Newhouse, Stephen J; Norman, Thea C; Nurtdinov, Ramil N; Oyang, Yen-Jen; Pawitan, Yudi; Peng, Shengwen; Piccolo, Stephen R; Praveen, Paurush; Priami, Corrado; Sabelnykova, Veronica Y; Senger, Philipp; Shen, Xia; Simmons, Andrew; Sotiras, Aristeidis; Stolovitzky, Gustavo; Tangaro, Sabina; Tateo, Andrea; Tung, Yi-An; Tustison, Nicholas J; Varol, Erdem; Vradenburg, George; Weiner, Michael W; Xiao, Guanghua; Xie, Lei; Xie, Yang; Xu, Jia; Yang, Hojin; Zhan, Xiaowei; Zhou, Yunyun; Zhu, Fan; Zhu, Hongtu; Zhu, Shanfeng

2017-01-01

Identifying accurate biomarkers of cognitive decline is essential for advancing early diagnosis and prevention therapies in Alzheimer’s Disease. The Alzheimer’s Disease DREAM Challenge was designed as a computational crowdsourced project to benchmark the current state-of-the-art in predicting cognitive outcomes in Alzheimer’s Disease based on high-dimensional, publicly available genetic and structural imaging data. This meta-analysis failed to identify a meaningful predictor developed from either data modality, suggesting that alternate approaches should be considered for to prediction of cognitive performance. PMID:27079753

Robust Smoothing: Smoothing Parameter Selection and Applications to Fluorescence Spectroscopy∂

PubMed Central

Lee, Jong Soo; Cox, Dennis D.

2009-01-01

Fluorescence spectroscopy has emerged in recent years as an effective way to detect cervical cancer. Investigation of the data preprocessing stage uncovered a need for a robust smoothing to extract the signal from the noise. Various robust smoothing methods for estimating fluorescence emission spectra are compared and data driven methods for the selection of smoothing parameter are suggested. The methods currently implemented in R for smoothing parameter selection proved to be unsatisfactory, and a computationally efficient procedure that approximates robust leave-one-out cross validation is presented. PMID:20729976

Dynamic estimator for determining operating conditions in an internal combustion engine

DOEpatents

Hellstrom, Erik; Stefanopoulou, Anna; Jiang, Li; Larimore, Jacob

2016-01-05

Methods and systems are provided for estimating engine performance information for a combustion cycle of an internal combustion engine. Estimated performance information for a previous combustion cycle is retrieved from memory. The estimated performance information includes an estimated value of at least one engine performance variable. Actuator settings applied to engine actuators are also received. The performance information for the current combustion cycle is then estimated based, at least in part, on the estimated performance information for the previous combustion cycle and the actuator settings applied during the previous combustion cycle. The estimated performance information for the current combustion cycle is then stored to the memory to be used in estimating performance information for a subsequent combustion cycle.

Online Detection of Broken Rotor Bar Fault in Induction Motors by Combining Estimation of Signal Parameters via Min-norm Algorithm and Least Square Method

NASA Astrophysics Data System (ADS)

Wang, Pan-Pan; Yu, Qiang; Hu, Yong-Jun; Miao, Chang-Xin

2017-11-01

Current research in broken rotor bar (BRB) fault detection in induction motors is primarily focused on a high-frequency resolution analysis of the stator current. Compared with a discrete Fourier transformation, the parametric spectrum estimation technique has a higher frequency accuracy and resolution. However, the existing detection methods based on parametric spectrum estimation cannot realize online detection, owing to the large computational cost. To improve the efficiency of BRB fault detection, a new detection method based on the min-norm algorithm and least square estimation is proposed in this paper. First, the stator current is filtered using a band-pass filter and divided into short overlapped data windows. The min-norm algorithm is then applied to determine the frequencies of the fundamental and fault characteristic components with each overlapped data window. Next, based on the frequency values obtained, a model of the fault current signal is constructed. Subsequently, a linear least squares problem solved through singular value decomposition is designed to estimate the amplitudes and phases of the related components. Finally, the proposed method is applied to a simulated current and an actual motor, the results of which indicate that, not only parametric spectrum estimation technique.

Quantifying variety-specific heat resistance and the potential for adaptation to climate change.

PubMed

Tack, Jesse; Barkley, Andrew; Rife, Trevor W; Poland, Jesse A; Nalley, Lawton Lanier

2016-08-01

The impact of climate change on crop yields has become widely measured; however, the linkages for winter wheat are less studied due to dramatic weather changes during the long growing season that are difficult to model. Recent research suggests significant reductions under warming. A potential adaptation strategy involves the development of heat resistant varieties by breeders, combined with alternative variety selection by producers. However, the impact of heat on specific wheat varieties remains relatively unstudied due to limited data and the complex genetic basis of heat tolerance. Here, we provide a novel econometric approach that combines field-trial data with a genetic cluster mapping to group wheat varieties and estimate a separate extreme heat impact (temperatures over 34 °C) across 24 clusters spanning 197 varieties. We find a wide range of heterogeneous heat resistance and a trade-off between average yield and resistance. Results suggest that recently released varieties are less heat resistant than older varieties, a pattern that also holds for on-farm varieties. Currently released - but not yet adopted - varieties do not offer improved resistance relative to varieties currently grown on farm. Our findings suggest that warming impacts could be significantly reduced through advances in wheat breeding and/or adoption decisions by producers. However, current adaptation-through-adoption potential is limited under a 1 °C warming scenario as increased heat resistance cannot be achieved without a reduction in average yields. © 2015 John Wiley & Sons Ltd.

Organic geochemistry of the 9.6 km Bertha Rogers No. 1. well, Oklahoma

USGS Publications Warehouse

Price, L.C.; Clayton, J.L.; Rumen, L.L.

1981-01-01

Organic geochemical analyses of fine-grained rocks from the 9.590 km Bertha Rogers No. 1 well have been carried out: total organic carbon, Soxhlet extraction and silica gel chromatography, C15+ saturated and aromatic hydrocarbon gas chromatography and mass spectrometry, pyrolysis, kerogen analysis, X-ray diffraction and visual kerogen analysis. Rocks ranged in age from Permian to Ordovician; the well has an estimated bottom hole temperature of 225??C. Some data from this study are inconsistent with conventional theories concerning the generation and thermal destruction of hydrocarbons. For example, appreciable amounts of C15+ gas-condensate-like hydrocarbons are present in very old rocks currently at temperatures where current theory predicts that only methane and graphite should remain. Also, substantial amounts of pyrolyzable C15+ hydrocarbons remain on the kerogen in these deeply buried Paleozoic rocks. This suggests, at least in somes cases, that temperatures much higher than those predicted by current theory are required for generation and thermal destruction of hydrocarbons. The data from this well also suggest that original composition of organic matter and environment of deposition may have a much stronger influence on the organic geochemical characteristics of fine-grained sediments than has previously been ascribed to them. The results from this well, from other deep hot wells in which temperatures exceed 200??C, and from laboratory experiments, suggest that some of the basic concepts of the generation and maturation of petroleum hydrocarbons may be in error and perhaps should be reexamined. ?? 1981.

Sodium intake status in United States and potential reduction modeling: an NHANES 2007-2010 analysis.

PubMed

Agarwal, Sanjiv; Fulgoni, Victor L; Spence, Lisa; Samuel, Priscilla

2015-11-01

Limiting dietary sodium intake has been a consistent dietary recommendation. Using NHANES 2007-2010 data, we estimated current sodium intake and modeled the potential impact of a new sodium reduction technology on sodium intake. NHANES 2007-2010 data were used to assess current sodium intake. The National Cancer Institute method was used for usual intake determination. Suggested sodium reductions using SODA-LO (®) Salt Microspheres ranged from 20% to 30% in 953 foods and usual intakes were modeled by using various reduction factors and levels of market penetration. SAS 9.2, SUDAAN 11, and NHANES survey weights were used in all calculations with assessment across gender and age groups. Current (2007-2010) sodium intake (mg/day) exceeds recommendations across all age gender groups and has not changed during the last decade. However, sodium intake measured as a function of food intake (mg/g food) has decreased significantly during the last decade. Two food categories contribute about 2/3rd of total sodium intake: "Grain Products" and "Meat, Poultry, Fish & Mixtures". Sodium reduction, with 100% market penetration of the new technology, was estimated to be 230-300 mg/day or 7-9% of intake depending upon age and gender group. Sodium reduction innovations like SODA-LO (®) Salt Microspheres could contribute to meaningful reductions in sodium intake.

Surface electric fields for North America during historical geomagnetic storms

USGS Publications Warehouse

Wei, Lisa H.; Homeier, Nichole; Gannon, Jennifer L.

2013-01-01

To better understand the impact of geomagnetic disturbances on the electric grid, we recreate surface electric fields from two historical geomagnetic storms—the 1989 “Quebec” storm and the 2003 “Halloween” storms. Using the Spherical Elementary Current Systems method, we interpolate sparsely distributed magnetometer data across North America. We find good agreement between the measured and interpolated data, with larger RMS deviations at higher latitudes corresponding to larger magnetic field variations. The interpolated magnetic field data are combined with surface impedances for 25 unique physiographic regions from the United States Geological Survey and literature to estimate the horizontal, orthogonal surface electric fields in 1 min time steps. The induced horizontal electric field strongly depends on the local surface impedance, resulting in surprisingly strong electric field amplitudes along the Atlantic and Gulf Coast. The relative peak electric field amplitude of each physiographic region, normalized to the value in the Interior Plains region, varies by a factor of 2 for different input magnetic field time series. The order of peak electric field amplitudes (largest to smallest), however, does not depend much on the input. These results suggest that regions at lower magnetic latitudes with high ground resistivities are also at risk from the effect of geomagnetically induced currents. The historical electric field time series are useful for estimating the flow of the induced currents through long transmission lines to study power flow and grid stability during geomagnetic disturbances.

The distribution of seabirds and fish in relation to ocean currents in the southeastern Chukchi Sea

USGS Publications Warehouse

Piatt, John F.; Wells, John L.; MacCharles, Andrea; Fadely, Brian S.; Montevecchi, W.A.; Gaston, A.J.

1991-01-01

In late August 1988, we studied the distribution of seabirds in the southeastern Chukchi Sea, particularly in waters near a major seabird colony at Cape Thompson. Foraging areas were characterized using hydrographic data obtained from hydroacoustic surveys for fish. Murres (Uria spp.) and Black-legged Kitttiwakes Rissa tridactyla breeding at Cape Thompson fed mostly on Arctic cod, which are known from previous studies to be the most abundant pelagic fish in the region. Our hydroacoustic surveys revealed that pelagic fish were distributed widely, but densities were estimated to be low (e.g., 0.1-10 g∙m-3) throughout the study area and a few schools were recorded. Large feeding flocks of murres and kittiwakes were observed over fish schools with densities estimated to exceed 15 g∙m-3. Fish densities were higher in shallow Alaska Coastal Current waters than offshore in Bering Sea waters, and most piscivorous seabirds foraged in coastal waters. Poor kittiwake breeding success and a low frequency of fish in murre and kittiwake stomachs in late August suggested that fish densities were marginal for sustaining breeding seabirds at that time. Planktivorous Least Auklets Aethia pusilla and Parakeet Auklets Cyclorrhynchus psittacula foraged almost exclusively in Bering Sea waters. Short-tailed Shearwaters Puffinus tenuirostris and Tufted Puffins Fratercula cirrhata foraged in transitional waters at the front between Coastal and Bering Sea currents.

Geomagnetic spikes on the core-mantle boundary

NASA Astrophysics Data System (ADS)

Davies, Christopher; Constable, Catherine

2017-05-01

Extreme variations of Earth's magnetic field occurred in the Levant region around 1000 BC, when the field intensity rapidly rose and fell by a factor of 2. No coherent link currently exists between this intensity spike and the global field produced by the core geodynamo. Here we show that the Levantine spike must span >60° longitude at Earth's surface if it originates from the core-mantle boundary (CMB). Several low intensity data are incompatible with this geometric bound, though age uncertainties suggest these data could have sampled the field before the spike emerged. Models that best satisfy energetic and geometric constraints produce CMB spikes 8-22° wide, peaking at O(100) mT. We suggest that the Levantine spike reflects an intense CMB flux patch that grew in place before migrating northwest, contributing to growth of the dipole field. Estimates of Ohmic heating suggest that diffusive processes likely govern the ultimate decay of geomagnetic spikes.

Climate change. Accelerating extinction risk from climate change.

PubMed

Urban, Mark C

2015-05-01

Current predictions of extinction risks from climate change vary widely depending on the specific assumptions and geographic and taxonomic focus of each study. I synthesized published studies in order to estimate a global mean extinction rate and determine which factors contribute the greatest uncertainty to climate change-induced extinction risks. Results suggest that extinction risks will accelerate with future global temperatures, threatening up to one in six species under current policies. Extinction risks were highest in South America, Australia, and New Zealand, and risks did not vary by taxonomic group. Realistic assumptions about extinction debt and dispersal capacity substantially increased extinction risks. We urgently need to adopt strategies that limit further climate change if we are to avoid an acceleration of global extinctions. Copyright © 2015, American Association for the Advancement of Science.

Status of the Magma Energy Project

NASA Astrophysics Data System (ADS)

Dunn, J. C.

The current magma energy project is assessing the engineering feasibility of extracting thermal energy directly from crustal magma bodies. The estimated size of the U.S. resource (50,000 to 500,000 quads) suggests a considerable potential impact on future power generation. In a previous seven-year study, we concluded that there are no insurmountable barriers that would invalidate the magma energy concept. Several concepts for drilling, energy extraction, and materials survivability were successfully demonstrated in Kilauea Iki lava lake, Hawaii. The present program is addressing the engineering design problems associated with accessing magma bodies and extracting thermal energy for power generation. The normal stages for development of a geothermal resource are being investigated: exploration, drilling and completions, production, and surface power plant design. Current status of the engineering program and future plans are described.

What would menthol smokers do if menthol in cigarettes were banned? Behavioral intentions and simulated demand

PubMed Central

O'Connor, Richard J.; Bansal-Travers, Maansi; Carter, Lawrence P.; Cummings, K. Michael

2012-01-01

Aims The US Food and Drug Administration must consider whether to ban the use of menthol in cigarettes. This study examines how current smokers might respond to such a ban on menthol cigarettes. Design Convenience sample of adolescent and adult smokers recruited from an online survey panel. Setting United States, 2010. Participants 471 adolescent and adult current cigarette smokers. Measurements Respondents were asked a series of questions about how they might react if menthol cigarettes were banned. In addition, participants completed a simulation purchase task to estimate the demand for menthol and nonmenthol cigarettes across a range of prices. Findings Overall, 36% respondents said they always or usually smoked menthol cigarettes. When asked how they might respond to a ban on menthol cigarettes, 35% of current menthol smokers said they would stop smoking, and 25% said they would ‘find a way to buy a menthol brand.’ Those who reported they might quit tended to have greater current intentions to quit (OR=4.46), while those who reported they might seek illicit menthol cigarettes were far less likely to report current intentions to quit (OR = 0.06). Estimates for individual demand elasticity for preferred cigarette type were similar for menthol (α = .0051) and nonmenthol (α = .0049) smokers. Demand elasticity and peak consumption were related to usual cigarette type and cigarettes smoked per day, but did not appear to differ by race, gender, or age. Conclusions Preliminary evidence suggests that a significant minority of smokers of menthol cigarettes in the US would try to stop smoking altogether if such cigarettes were banned. PMID:22471735

Weak data do not make a free lunch, only a cheap meal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luo, Zhipu; Rajashankar, Kanagalaghatta; Dauter, Zbigniew

2014-01-17

Four data sets were processed at resolutions significantly exceeding the criteria traditionally used for estimating the diffraction data resolution limit. The analysis of these data and the corresponding model-quality indicators suggests that the criteria of resolution limits widely adopted in the past may be somewhat conservative. Various parameters, such asR mergeandI/σ(I), optical resolution and the correlation coefficients CC 1/2and CC*, can be used for judging the internal data quality, whereas the reliability factorsRandR freeas well as the maximum-likelihood target values and real-space map correlation coefficients can be used to estimate the agreement between the data and the refined model. However,more » none of these criteria provide a reliable estimate of the data resolution cutoff limit. The analysis suggests that extension of the maximum resolution by about 0.2 Å beyond the currently adopted limit where theI/σ(I) value drops to 2.0 does not degrade the quality of the refined structural models, but may sometimes be advantageous. Such an extension may be particularly beneficial for significantly anisotropic diffraction. Extension of the maximum resolution at the stage of data collection and structure refinement is cheap in terms of the required effort and is definitely more advisable than accepting a too conservative resolution cutoff, which is unfortunately quite frequent among the crystal structures deposited in the Protein Data Bank.« less

Indo-Pacific humpback dolphins (Sousa chinensis) in Hong Kong: Modelling demographic parameters with mark-recapture techniques.

PubMed

Chan, Stephen C Y; Karczmarski, Leszek

2017-01-01

Indo-Pacific humpback dolphins (Sousa chinensis) inhabiting Hong Kong waters are thought to be among the world's most anthropogenically impacted coastal delphinids. We have conducted a 5-year (2010-2014) photo-ID study and performed the first in this region comprehensive mark-recapture analysis applying a suite of open population models and robust design models. Cormack-Jolly-Seber (CJS) models suggested a significant transient effect and seasonal variation in apparent survival probabilities as result of a fluid movement beyond the study area. Given the spatial restrictions of our study, limited by an administrative border, if emigration was to be considered negligible the estimated survival rate of adults was 0.980. Super-population estimates indicated that at least 368 dolphins used Hong Kong waters as part of their range. Closed robust design models suggested an influx of dolphins from winter to summer and increased site fidelity in summer; and outflux, although less prominent, during summer-winter intervals. Abundance estimates in summer (N = 144-231) were higher than that in winter (N = 87-111), corresponding to the availability of prey resources which in Hong Kong waters peaks during summer months. We point out that the current population monitoring strategy used by the Hong Kong authorities is ill-suited for a timely detection of a population change and should be revised.

Indo-Pacific humpback dolphins (Sousa chinensis) in Hong Kong: Modelling demographic parameters with mark-recapture techniques

PubMed Central

2017-01-01

Indo-Pacific humpback dolphins (Sousa chinensis) inhabiting Hong Kong waters are thought to be among the world's most anthropogenically impacted coastal delphinids. We have conducted a 5-year (2010–2014) photo-ID study and performed the first in this region comprehensive mark-recapture analysis applying a suite of open population models and robust design models. Cormack-Jolly-Seber (CJS) models suggested a significant transient effect and seasonal variation in apparent survival probabilities as result of a fluid movement beyond the study area. Given the spatial restrictions of our study, limited by an administrative border, if emigration was to be considered negligible the estimated survival rate of adults was 0.980. Super-population estimates indicated that at least 368 dolphins used Hong Kong waters as part of their range. Closed robust design models suggested an influx of dolphins from winter to summer and increased site fidelity in summer; and outflux, although less prominent, during summer-winter intervals. Abundance estimates in summer (N = 144–231) were higher than that in winter (N = 87–111), corresponding to the availability of prey resources which in Hong Kong waters peaks during summer months. We point out that the current population monitoring strategy used by the Hong Kong authorities is ill-suited for a timely detection of a population change and should be revised. PMID:28355228

Valuing Non-CO2 GHG Emission Changes in Benefit-Cost ...

EPA Pesticide Factsheets

The climate impacts of greenhouse gas (GHG) emissions impose social costs on society. To date, EPA has not had an approach to estimate the economic benefits of reducing emissions of non-CO2 GHGs (or the costs of increasing them) that is consistent with the methodology underlying the U.S. Government’s current estimates of the social cost of carbon (SCC). A recently published paper presents estimates of the social cost of methane that are consistent with the SCC estimates. The Agency is seeking review of the potential application of these new benefit estimates to benefit cost analysis in relation to current practice in this area. The goal of this project is to improve upon the current treatment of non-CO2 GHG emission impacts in benefit-cost analysis.

The Sponge Pump: The Role of Current Induced Flow in the Design of the Sponge Body Plan

PubMed Central

Leys, Sally P.; Yahel, Gitai; Reidenbach, Matthew A.; Tunnicliffe, Verena; Shavit, Uri; Reiswig, Henry M.

2011-01-01

Sponges are suspension feeders that use flagellated collar-cells (choanocytes) to actively filter a volume of water equivalent to many times their body volume each hour. Flow through sponges is thought to be enhanced by ambient current, which induces a pressure gradient across the sponge wall, but the underlying mechanism is still unknown. Studies of sponge filtration have estimated the energetic cost of pumping to be <1% of its total metabolism implying there is little adaptive value to reducing the cost of pumping by using “passive” flow induced by the ambient current. We quantified the pumping activity and respiration of the glass sponge Aphrocallistes vastus at a 150 m deep reef in situ and in a flow flume; we also modeled the glass sponge filtration system from measurements of the aquiferous system. Excurrent flow from the sponge osculum measured in situ and in the flume were positively correlated (r>0.75) with the ambient current velocity. During short bursts of high ambient current the sponges filtered two-thirds of the total volume of water they processed daily. Our model indicates that the head loss across the sponge collar filter is 10 times higher than previously estimated. The difference is due to the resistance created by a fine protein mesh that lines the collar, which demosponges also have, but was so far overlooked. Applying our model to the in situ measurements indicates that even modest pumping rates require an energetic expenditure of at least 28% of the total in situ respiration. We suggest that due to the high cost of pumping, current-induced flow is highly beneficial but may occur only in thin walled sponges living in high flow environments. Our results call for a new look at the mechanisms underlying current-induced flow and for reevaluation of the cost of biological pumping and its evolutionary role, especially in sponges. PMID:22180779

Volcanic eruption volume flux estimations from very long period infrasound signals

NASA Astrophysics Data System (ADS)

Yamada, Taishi; Aoyama, Hiroshi; Nishimura, Takeshi; Iguchi, Masato; Hendrasto, Muhamad

2017-01-01

We examine very long period infrasonic signals accompanying volcanic eruptions near active vents at Lokon-Empung volcano in Indonesia, Aso, Kuchinoerabujima, and Kirishima volcanoes in Japan. The excitation of the very long period pulse is associated with an explosion, the emerging of an eruption column, and a pyroclastic density current. We model the excitation of the infrasound pulse, assuming a monopole source, to quantify the volume flux and cumulative volume of erupting material. The infrasound-derived volume flux and cumulative volume can be less than half of the video-derived results. A largely positive correlation can be seen between the infrasound-derived volume flux and the maximum eruption column height. Therefore, our result suggests that the analysis of very long period volcanic infrasound pulses can be helpful in estimating the maximum eruption column height.

Constraining estimates of methane emissions from Arctic permafrost regions with CARVE

NASA Astrophysics Data System (ADS)

Chang, R. Y.; Karion, A.; Sweeney, C.; Henderson, J.; Mountain, M.; Eluszkiewicz, J.; Luus, K. A.; Lin, J. C.; Dinardo, S.; Miller, C. E.; Wofsy, S. C.

2013-12-01

Permafrost in the Arctic contains large carbon pools that are currently non-labile, but can be released to the atmosphere as polar regions warm. In order to predict future climate scenarios, we need to understand the emissions of these greenhouse gases under varying environmental conditions. This study presents in-situ measurements of methane made on board an aircraft during the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), which sampled over the permafrost regions of Alaska. Using measurements from May to September 2012, seasonal emission rate estimates of methane from tundra are constrained using the Stochastic Time-Inverted Lagrangian Transport model, a Lagrangian particle dispersion model driven by custom polar-WRF fields. Preliminary results suggest that methane emission rates have not greatly increased since the Arctic Boundary Layer Experiment conducted in southwest Alaska in 1988.

Getting a Job is Only Half the Battle: Maternal Job Loss and Child Classroom Behavior in Low-Income Families

PubMed Central

Hill, Heather D.; Morris, Pamela A.; Castells, Nina; Walker, Jessica Thornton

2011-01-01

This study uses data from an experimental employment program and instrumental variables (IV) estimation to examine the effects of maternal job loss on child classroom behavior. Random assignment to the treatment at one of three program sites is an exogenous predictor of employment patterns. Cross-site variation in treatment-control differences is used to identify the effects of employment levels and transitions. Under certain assumptions, this method controls for unobserved correlates of job loss and child well-being, as well as measurement error and simultaneity. IV estimates suggest that maternal job loss sharply increases problem behavior but has neutral effects on positive social behavior. Current employment programs concentrate primarily on job entry, but these findings point to the importance of promoting job stability for workers and their children. PMID:22162901

Exposure to traffic-related air pollution during pregnancy and term low birth weight: estimation of causal associations in a semiparametric model.

PubMed

Padula, Amy M; Mortimer, Kathleen; Hubbard, Alan; Lurmann, Frederick; Jerrett, Michael; Tager, Ira B

2012-11-01

Traffic-related air pollution is recognized as an important contributor to health problems. Epidemiologic analyses suggest that prenatal exposure to traffic-related air pollutants may be associated with adverse birth outcomes; however, there is insufficient evidence to conclude that the relation is causal. The Study of Air Pollution, Genetics and Early Life Events comprises all births to women living in 4 counties in California's San Joaquin Valley during the years 2000-2006. The probability of low birth weight among full-term infants in the population was estimated using machine learning and targeted maximum likelihood estimation for each quartile of traffic exposure during pregnancy. If everyone lived near high-volume freeways (approximated as the fourth quartile of traffic density), the estimated probability of term low birth weight would be 2.27% (95% confidence interval: 2.16, 2.38) as compared with 2.02% (95% confidence interval: 1.90, 2.12) if everyone lived near smaller local roads (first quartile of traffic density). Assessment of potentially causal associations, in the absence of arbitrary model assumptions applied to the data, should result in relatively unbiased estimates. The current results support findings from previous studies that prenatal exposure to traffic-related air pollution may adversely affect birth weight among full-term infants.

Assessment of Global Mercury Deposition through Litterfall.

PubMed

Wang, Xun; Bao, Zhengduo; Lin, Che-Jen; Yuan, Wei; Feng, Xinbin

2016-08-16

There is a large uncertainty in the estimate of global dry deposition of atmospheric mercury (Hg). Hg deposition through litterfall represents an important input to terrestrial forest ecosystems via cumulative uptake of atmospheric Hg (most Hg(0)) to foliage. In this study, we estimate the quantity of global Hg deposition through litterfall using statistical modeling (Monte Carlo simulation) of published data sets of litterfall biomass production, tree density, and Hg concentration in litter samples. On the basis of the model results, the global annual Hg deposition through litterfall is estimated to be 1180 ± 710 Mg yr(-1), more than two times greater than the estimate by GEOS-Chem. Spatial distribution of Hg deposition through litterfall suggests that deposition flux decreases spatially from tropical to temperate and boreal regions. Approximately 70% of global Hg(0) dry deposition occurs in the tropical and subtropical regions. A major source of uncertainty in this study is the heterogeneous geospatial distribution of available data. More observational data in regions (Southeast Asia, Africa, and South America) where few data sets exist will greatly improve the accuracy of the current estimate. Given that the quantity of global Hg deposition via litterfall is typically 2-6 times higher than Hg(0) evasion from forest floor, global forest ecosystems represent a strong Hg(0) sink.

Hazardous alcohol levels in adolescents are underestimated by barkeepers and security personnel.

PubMed

Wurdak, Mara; Dörfler, Tobias; Mentz, Julia; Schmidt, Anika; Wolstein, Jörg

2012-12-01

Drunkenness among adolescents represents a significant problem and is associated with adverse consequences. A Licensing Act, which prohibits the dispensing of alcoholic beverages to visibly intoxicated individuals, was introduced in Germany to curb excessive drinking. The objective of the study was to explore whether it is possible for barkeepers and security personnel to correctly estimate the alcohol level (AL) of adolescents merely based on their outer appearance and self-report. In a commercial dance club, 89 adolescents reported their past and current alcohol consumption and estimated their own AL. Their breath alcohol level was measured with a breathalyzer. The sample was divided into "moderate drinkers" and "binge drinkers." Barkeepers and security personnel spoke to and examined the adolescents in order to estimate the adolescents' AL. Professional staff underestimated the ALs of adolescents in 60.7 % of all cases. Estimates of the personnel showed greater deviations from the measured AL of the adolescents as compared to estimates of the adolescents themselves, especially in the group of binge drinkers (t = 2.764; p = 0.009). It seems that adolescents suffer less from observable effects of alcohol, such as sedation or impairment of motor function. Consequently, we do not recommend the application of the Licensing Act to adolescents, but suggest its replacement by other restrictions and prevention measures.

Are Antarctic minke whales unusually abundant because of 20th century whaling?

PubMed

Ruegg, Kristen C; Anderson, Eric C; Scott Baker, C; Vant, Murdoch; Jackson, Jennifer A; Palumbi, Stephen R

2010-01-01

Severe declines in megafauna worldwide illuminate the role of top predators in ecosystem structure. In the Antarctic, the Krill Surplus Hypothesis posits that the killing of more than 2 million large whales led to competitive release for smaller krill-eating species like the Antarctic minke whale. If true, the current size of the Antarctic minke whale population may be unusually high as an indirect result of whaling. Here, we estimate the long-term population size of the Antarctic minke whale prior to whaling by sequencing 11 nuclear genetic markers from 52 modern samples purchased in Japanese meat markets. We use coalescent simulations to explore the potential influence of population substructure and find that even though our samples are drawn from a limited geographic area, our estimate reflects ocean-wide genetic diversity. Using Bayesian estimates of the mutation rate and coalescent-based analyses of genetic diversity across loci, we calculate the long-term population size of the Antarctic minke whale to be 670,000 individuals (95% confidence interval: 374,000-1,150,000). Our estimate of long-term abundance is similar to, or greater than, contemporary abundance estimates, suggesting that managing Antarctic ecosystems under the assumption that Antarctic minke whales are unusually abundant is not warranted.

Firing patterns of spontaneously active motor units in spinal cord-injured subjects.

PubMed

Zijdewind, Inge; Thomas, Christine K

2012-04-01

Involuntary motor unit activity at low rates is common in hand muscles paralysed by spinal cord injury. Our aim was to describe these patterns of motor unit behaviour in relation to motoneurone and motor unit properties. Intramuscular electromyographic activity (EMG), surface EMG and force were recorded for 30 min from thenar muscles of nine men with chronic cervical SCI. Motor units fired for sustained periods (>10 min) at regular (coefficient of variation ≤ 0.15, CV, n =19 units) or irregular intervals (CV>0.15, n =14). Regularly firing units started and stopped firing independently suggesting that intrinsic motoneurone properties were important for recruitment and derecruitment. Recruitment (3.6 Hz, SD 1.2), maximal (10.2 Hz, SD 2.3, range: 7.5-15.4 Hz) and derecruitment frequencies were low (3.3 Hz, SD 1.6), as were firing rate increases after recruitment (~20 intervals in 3 s). Once active, firing often covaried, promoting the idea that units received common inputs.Half of the regularly firing units showed a very slow decline (>40 s) in discharge before derecruitment and had interspike intervals longer than their estimated after hyperpolarisation potential (AHP) duration (estimated by death rate and breakpoint analyses). The other units were derecruited more abruptly and had shorter estimated AHP durations. Overall, regularly firing units had longer estimated AHP durations and were weaker than irregularly firing units, suggesting they were lower threshold units. Sustained firing of units at regular rates may reflect activation of persistent inward currents, visible here in the absence of voluntary drive, whereas irregularly firing units may only respond to synaptic noise.

Infralittoral mapping around an oceanic archipelago using MERIS FR satellite imagery and deep kelp observations: A new tool for assessing MPA coverage targets

NASA Astrophysics Data System (ADS)

Amorim, Patrícia; Atchoi, Elizabeth; Berecibar, Estibaliz; Tempera, Fernando

2015-06-01

This work presents the first climatologic maps of diffuse attenuation of down-welling solar radiation (KdPAR and Kd490 coefficients) for the Azores derived from full resolution (FR) MERIS satellite imagery. Associating this information with a new mesoscale bathymetry compilation permits estimating the percentage of surface light reaching the seabed. A video annotation dataset derived from a deep kelp survey conducted on the Formigas Bank is subsequently used to estimate the light levels experienced by these bionomically-crucial frondose algae. Empirical light-based thresholds for the lower infralittoral boundary in the Azores are derived from the deepest kelp occurrences. This information is eventually used to map the geographical extent of this major marine biological zone in the archipelago, yielding an area estimate of 894.7 km2. The average depth of the infralittoral limit in the Azores is established at 69 m. It is determined that the present Azores marine protected area (MPA) network already covers 28.9% of the region's infralittoral grounds. However, island-specific values highlight that MPA percentage coverage varies between islands with values ranging from a marginal coverage of 7.3% (on Terceira Island) to 100% coverage around the island of Corvo and the Formigas Bank. These results suggest that conservation managers may make use of the current spatially-based protection framework of the archipelago to, on the whole and for this specific major habitat, surpass the goals suggested by international conventions and conservation fora for MPA coverage. However, an analysis of the statutory MPA regulations further reveals that measures in place are insufficient to provide a no-take and no-disturbance protection of infralittoral biotopes. In order to achieve the recommended strict protection of the currently protected infralittoral zones, conservation measures ought to be enhanced.

Horizontal mixing in the Southern Ocean from Argo float trajectories

NASA Astrophysics Data System (ADS)

Roach, Christopher J.; Balwada, Dhruv; Speer, Kevin

2016-08-01

We provide the first observational estimate of the circumpolar distribution of cross-stream eddy diffusivity at 1000 m in the Southern Ocean using Argo float trajectories. We show that Argo float trajectories, from the float surfacing positions, can be used to estimate lateral eddy diffusivities in the ocean and that these estimates are comparable to those obtained from RAFOS floats, where they overlap. Using the Southern Ocean State Estimate (SOSE) velocity fields to advect synthetic particles with imposed behavior that is "Argo-like" and "RAFOS-like" diffusivity estimates from both sets of synthetic particles agreed closely at the three dynamically very different test sites, the Kerguelen Island region, the Southeast Pacific Ocean, and the Scotia Sea, and support our approach. Observed cross-stream diffusivities at 1000 m, calculated from Argo float trajectories, ranged between 300 and 2500 m2 s-1, with peaks corresponding to topographic features associated with the Scotia Sea, the Kerguelen Plateau, the Campbell Plateau, and the Southeast Pacific Ridge. These observational estimates agree with previous regional estimates from the Diapycnal and Isopycnal Mixing Experiment in the Southern Ocean (DIMES) near the Drake Passage, and other estimates from natural tracers (helium), inverse modeling studies, and current meter measurements. These estimates are also compared to the suppressed eddy diffusivity in the presence of mean flows. The comparison suggests that away from regions of strong topographic steering suppression explains both the structure and magnitude of eddy diffusivity but that eddy diffusivities in the regions of topographic steering are greater than what would be theoretically expected and the ACC experiences localized enhanced cross-stream mixing in these regions.

Estimating Am-241 activity in the body: comparison of direct measurements and radiochemical analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lynch, Timothy P.; Tolmachev, Sergei Y.; James, Anthony C.

2009-06-01

The assessment of dose and ultimately the health risk from intakes of radioactive materials begins with estimating the amount actually taken into the body. An accurate estimate provides the basis to best assess the distribution in the body, the resulting dose, and ultimately the health risk. This study continues the time-honored practice of evaluating the accuracy of results obtained using in vivo measurement methods and techniques. Results from the radiochemical analyses of the 241Am activity content of tissues and organs from four donors to the United States Transuranium and Uranium Registries were compared to the results from direct measurements ofmore » radioactive material in the body performed in vivo and post mortem. Two were whole body donations and two were partial body donations The skeleton was the organ with the highest deposition of 241Am activity in all four cases. The activities ranged from 30 Bq to 300 Bq. The skeletal estimates obtained from measurements over the forehead were within 20% of the radiochemistry results in three cases and differed by 78% in one case. The 241Am lung activity estimates ranged from 1 Bq to 30 Bq in the four cases. The results from the direct measurements were within 40% of the radiochemistry results in 3 cases and within a factor of 3 for the other case. The direct measurement estimates of liver activity ranged from 2 Bq to 60 Bq and were generally lower than the radiochemistry results. The results from this study suggest that the measurement methods and calibration techniques used at the In Vivo Radiobioassay and Research Facility to quantify the activity in the lungs, skeleton and liver are reasonable under the most challenging conditions where there is 241Am activity in multiple organs. These methods and techniques are comparable to those used at other Department of Energy sites. This suggests that the current in vivo methods and calibration techniques provide reasonable estimates of radioactive material in the body. Not unexpectedly, there can be significant uncertainty in the estimates especially when activity is also present in other organs.« less

Marginal regression approach for additive hazards models with clustered current status data.

PubMed

Su, Pei-Fang; Chi, Yunchan

2014-01-15

Current status data arise naturally from tumorigenicity experiments, epidemiology studies, biomedicine, econometrics and demographic and sociology studies. Moreover, clustered current status data may occur with animals from the same litter in tumorigenicity experiments or with subjects from the same family in epidemiology studies. Because the only information extracted from current status data is whether the survival times are before or after the monitoring or censoring times, the nonparametric maximum likelihood estimator of survival function converges at a rate of n(1/3) to a complicated limiting distribution. Hence, semiparametric regression models such as the additive hazards model have been extended for independent current status data to derive the test statistics, whose distributions converge at a rate of n(1/2) , for testing the regression parameters. However, a straightforward application of these statistical methods to clustered current status data is not appropriate because intracluster correlation needs to be taken into account. Therefore, this paper proposes two estimating functions for estimating the parameters in the additive hazards model for clustered current status data. The comparative results from simulation studies are presented, and the application of the proposed estimating functions to one real data set is illustrated. Copyright © 2013 John Wiley & Sons, Ltd.

Quantification of effective plant rooting depth: advancing global hydrological modelling

NASA Astrophysics Data System (ADS)

Yang, Y.; Donohue, R. J.; McVicar, T.

2017-12-01

Plant rooting depth (Zr) is a key parameter in hydrological and biogeochemical models, yet the global spatial distribution of Zr is largely unknown due to the difficulties in its direct measurement. Moreover, Zr observations are usually only representative of a single plant or several plants, which can differ greatly from the effective Zr over a modelling unit (e.g., catchment or grid-box). Here, we provide a global parameterization of an analytical Zr model that balances the marginal carbon cost and benefit of deeper roots, and produce a climatological (i.e., 1982-2010 average) global Zr map. To test the Zr estimates, we apply the estimated Zr in a highly transparent hydrological model (i.e., the Budyko-Choudhury-Porporato (BCP) model) to estimate mean annual actual evapotranspiration (E) across the globe. We then compare the estimated E with both water balance-based E observations at 32 major catchments and satellite grid-box retrievals across the globe. Our results show that the BCP model, when implemented with Zr estimated herein, optimally reproduced the spatial pattern of E at both scales and provides improved model outputs when compared to BCP model results from two already existing global Zr datasets. These results suggest that our Zr estimates can be effectively used in state-of-the-art hydrological models, and potentially biogeochemical models, where the determination of Zr currently largely relies on biome type-based look-up tables.

Post-mortem chemical excitability of the iris should not be used for forensic death time diagnosis.

PubMed

Koehler, Katja; Sehner, Susanne; Riemer, Martin; Gehl, Axel; Raupach, Tobias; Anders, Sven

2018-04-18

Post-mortem chemical excitability of the iris is one of the non-temperature-based methods in forensic diagnosis of the time since death. Although several authors reported on their findings, using different measurement methods, currently used time limits are based on a single dissertation which has recently been doubted to be applicable for forensic purpose. We investigated changes in pupil-iris ratio after application of acetylcholine (n = 79) or tropicamide (n = 58) and in controls at upper and lower time limits that are suggested in the current literature, using a digital photography-based measurement method with excellent reliability. We observed "positive," "negative," and "paradox" reactions in both intervention and control conditions at all investigated post-mortem time points, suggesting spontaneous changes in pupil size to be causative for the finding. According to our observations, post-mortem chemical excitability of the iris should not be used in forensic death time estimation, as results may cause false conclusions regarding the correct time point of death and might therefore be strongly misleading.

Evaluating Bay Area Methane Emission Inventory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, Marc; Jeong, Seongeun

As a regulatory agency, evaluating and improving estimates of methane (CH4) emissions from the San Francisco Bay Area is an area of interest to the Bay Area Air Quality Management District (BAAQMD). Currently, regional, state, and federal agencies generally estimate methane emissions using bottom-up inventory methods that rely on a combination of activity data, emission factors, biogeochemical models and other information. Recent atmospheric top-down measurement estimates of methane emissions for the US as a whole (e.g., Miller et al., 2013) and in California (e.g., Jeong et al., 2013; Peischl et al., 2013) have shown inventories underestimate total methane emissions bymore » ~ 50% in many areas of California, including the SF Bay Area (Fairley and Fischer, 2015). The goal of this research is to provide information to help improve methane emission estimates for the San Francisco Bay Area. The research effort builds upon our previous work that produced methane emission maps for each of the major source sectors as part of the California Greenhouse Gas Emissions Measurement (CALGEM) project (http://calgem.lbl.gov/prior_emission.html; Jeong et al., 2012; Jeong et al., 2013; Jeong et al., 2014). Working with BAAQMD, we evaluate the existing inventory in light of recently published literature and revise the CALGEM CH4 emission maps to provide better specificity for BAAQMD. We also suggest further research that will improve emission estimates. To accomplish the goals, we reviewed the current BAAQMD inventory, and compared its method with those from the state inventory from the California Air Resources Board (CARB), the CALGEM inventory, and recent published literature. We also updated activity data (e.g., livestock statistics) to reflect recent changes and to better represent spatial information. Then, we produced spatially explicit CH4 emission estimates on the 1-km modeling grid used by BAAQMD. We present the detailed activity data, methods and derived emission maps by sector. In total, we estimate the anthropogenic emissions for BAAQMD to be 116.4 Gg (1 Gg = 109 g) CH4/yr, with a likely uncertainty of ~ 50% or more (e.g., NRC, 2010; US-EPA, 2015). Including the emissions from wetland (Jeong et al., 2013), the total CH4 emission estimate for BAAQMD is 120.1 Gg CH4/yr. Table 1 summarizes the estimated CH4 emissions for 2011 by sector. The sectors were categorized following those that are used in recent regional emission quantification studies (e.g., Jeong et al., 2013; Peischl et al., 2013; Wecht et al., 2014). However, we note that this result is marginally lower than the top-down estimate of 240 ± 60 Gg CH4/yr (at 95% confidence) reported by Fairley and Fischer (2015), suggesting some combination of systematic error in the top-down estimate, underestimation of emissions from known sources, or as yet unidentified sources may be present. With respect to the relative contributions from different source sectors, the CH4 emissions from the region are dominated by urban activities. Landfill emissions represent 53% of the District’s total emission followed by livestock (16%) and natural gas (15%). These three dominant sectors account for 84% of the total anthropogenic emission in BAAQMD. This suggests that mitigation efforts need to focus on these three sources. Figure 1 shows the gridded anthropogenic CH4 emissions on the BAAQMD’s 1-km grid. In general, the spatial pattern of emissions follows the density of population while strong point sources are also distributed in the rural areas of the District. Detailed methods and emissions for each sector and county are described in the following sections.« less

Evaluating models of population process in a threatened population of Steller’s eiders: A retrospective approach

USGS Publications Warehouse

Dunham, Kylee; Grand, James B.

2016-10-11

The Alaskan breeding population of Steller’s eiders (Polysticta stelleri) was listed as threatened under the Endangered Species Act in 1997 in response to perceived declines in abundance throughout their breeding and nesting range. Aerial surveys suggest the breeding population is small and highly variable in number, with zero birds counted in 5 of the last 25 years. Research was conducted to evaluate competing population process models of Alaskan-breeding Steller’s eiders through comparison of model projections to aerial survey data. To evaluate model efficacy and estimate demographic parameters, a Bayesian state-space modeling framework was used and each model was fit to counts from the annual aerial surveys, using sequential importance sampling and resampling. The results strongly support that the Alaskan breeding population experiences population level nonbreeding events and is open to exchange with the larger Russian-Pacific breeding population. Current recovery criteria for the Alaskan breeding population rely heavily on the ability to estimate population viability. The results of this investigation provide an informative model of the population process that can be used to examine future population states and assess the population in terms of the current recovery and reclassification criteria.

Statistical inference for the within-device precision of quantitative measurements in assay validation.

PubMed

Liu, Jen-Pei; Lu, Li-Tien; Liao, C T

2009-09-01

Intermediate precision is one of the most important characteristics for evaluation of precision in assay validation. The current methods for evaluation of within-device precision recommended by the Clinical Laboratory Standard Institute (CLSI) guideline EP5-A2 are based on the point estimator. On the other hand, in addition to point estimators, confidence intervals can provide a range for the within-device precision with a probability statement. Therefore, we suggest a confidence interval approach for assessment of the within-device precision. Furthermore, under the two-stage nested random-effects model recommended by the approved CLSI guideline EP5-A2, in addition to the current Satterthwaite's approximation and the modified large sample (MLS) methods, we apply the technique of generalized pivotal quantities (GPQ) to derive the confidence interval for the within-device precision. The data from the approved CLSI guideline EP5-A2 illustrate the applications of the confidence interval approach and comparison of results between the three methods. Results of a simulation study on the coverage probability and expected length of the three methods are reported. The proposed method of the GPQ-based confidence intervals is also extended to consider the between-laboratories variation for precision assessment.

Dental Use and Expenditures for Older Uninsured Americans: The Simulated Impact of Expanded Coverage

PubMed Central

Manski, Richard J; Moeller, John F; Chen, Haiyan; Schimmel, Jody; Pepper, John V; St Clair, Patricia A

2015-01-01

Objective To determine if providing dental insurance to older Americans would close the current gaps in dental use and expenditure between insured and uninsured older Americans. Data Sources/Study Setting We used data from the 2008 Health and Retirement Survey (HRS) supplemented by data from the 2006 Medical Expenditure Panel Survey (MEPS). Study Design We compared the simulated dental use and expenditures rates of newly insured persons against the corresponding rates for those previously insured. Data Collection/Extraction Methods The HRS is a nationally representative survey administered by the Institute for Social Research (ISR). The MEPS is a nationally representative household survey sponsored by the Agency for Healthcare Research and Quality (AHRQ). Principal Findings We found that expanding dental coverage to older uninsured Americans would close previous gaps in dental use and expense between uninsured and insured noninstitutionalized Americans 55 years and older. Conclusions Providing dental coverage to previously uninsured older adults would produce estimated monthly costs net of markups for administrative costs that comport closely to current market rates. Estimates also suggest that the total cost of providing dental coverage targeted specifically to nonusers of dental care may be less than similar costs for prior users. PMID:25040355

DOE Office of Scientific and Technical Information (OSTI.GOV)

G. CANAVAN

Space Based Interceptor (SBI) have ranges that are adequate to address rogue ICBMs. They are not overly sensitive to 30-60 s delay times. Current technologies would support boost phase intercept with about 150 interceptors. Higher acceleration and velocity could reduce than number by about a factor of 3 at the cost of heavier and more expensive Kinetic Kill Vehicles (KKVs). 6g SBI would reduce optimal constellation costs by about 35%; 8g SBI would reduce them another 20%. Interceptor ranges fall rapidly with theater missile range. Constellations increase significantly for ranges under 3,000 km, even with advanced interceptor technology. For distributedmore » launches, these estimates recover earlier strategic scalings, which demonstrate the improved absentee ratio for larger or multiple launch areas. Constellations increase with the number of missiles and the number of interceptors launched at each. The economic estimates above suggest that two SBI per missile with a modest midcourse underlay is appropriate. The SBI KKV technology would appear to be common for space- and surface-based boost phase systems, and could have synergisms with improved midcourse intercept and discrimination systems. While advanced technology could be helpful in reducing costs, particularly for short range theater missiles, current technology appears adequate for pressing rogue ICBM, accidental, and unauthorized launches.« less

The Cancer Genomics Hub (CGHub): overcoming cancer through the power of torrential data

PubMed Central

Wilks, Christopher; Cline, Melissa S.; Weiler, Erich; Diehkans, Mark; Craft, Brian; Martin, Christy; Murphy, Daniel; Pierce, Howdy; Black, John; Nelson, Donavan; Litzinger, Brian; Hatton, Thomas; Maltbie, Lori; Ainsworth, Michael; Allen, Patrick; Rosewood, Linda; Mitchell, Elizabeth; Smith, Bradley; Warner, Jim; Groboske, John; Telc, Haifang; Wilson, Daniel; Sanford, Brian; Schmidt, Hannes; Haussler, David; Maltbie, Daniel

2014-01-01

The Cancer Genomics Hub (CGHub) is the online repository of the sequencing programs of the National Cancer Institute (NCI), including The Cancer Genomics Atlas (TCGA), the Cancer Cell Line Encyclopedia (CCLE) and the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) projects, with data from 25 different types of cancer. The CGHub currently contains >1.4 PB of data, has grown at an average rate of 50 TB a month and serves >100 TB per week. The architecture of CGHub is designed to support bulk searching and downloading through a Web-accessible application programming interface, enforce patient genome confidentiality in data storage and transmission and optimize for efficiency in access and transfer. In this article, we describe the design of these three components, present performance results for our transfer protocol, GeneTorrent, and finally report on the growth of the system in terms of data stored and transferred, including estimated limits on the current architecture. Our experienced-based estimates suggest that centralizing storage and computational resources is more efficient than wide distribution across many satellite labs. Database URL: https://cghub.ucsc.edu PMID:25267794

Prevalence, correlates, comorbidity and severity of generalized anxiety disorder in Singapore.

PubMed

Lee, Siau Pheng; Sagayadevan, Vathsala; Abdin, Edimansyah; Vaingankar, Janhavi Ajit; Chong, Siow Ann; Subramaniam, Mythily

2016-10-01

Despite its pervasiveness and associated impairment, generalized anxiety disorder (GAD) remains a poorly recognized disorder. Furthermore, given that GAD has been relatively understudied in Asia, the current study examined the prevalence, correlates and co-morbid conditions of this disorder in a multi-ethnic population of Singapore. Data was utilized from the Singapore Mental Health Study (SMHS), a cross-sectional epidemiological survey conducted among the adult population (n=6616) aged 18 years and above. The Composite International Diagnostic Interview version 3.0 (CIDI v3.0) was used to assess co-morbidity as well as the life-time and 12-month prevalence of disorders. Functional impairment and treatment-seeking behavior were also assessed. The life-time (0.9%) and 12-month (0.4%) prevalence estimates in the current study were found to be lower than those reported in Western populations but comparable to the prevalence estimates found in Asian countries. The relatively lower prevalence rate of GAD in this study suggests the possible role of culture in reporting and manifestation of anxiety symptomatology. The failure of a substantial proportion of individuals to seek treatment despite self-reported impairment was also identified as an area of concern. Copyright © 2015 Elsevier B.V. All rights reserved.

Health Impacts of the Built Environment: Within-Urban Variability in Physical Inactivity, Air Pollution, and Ischemic Heart Disease Mortality

PubMed Central

Hankey, Steve; Brauer, Michael

2011-01-01

Background: Physical inactivity and exposure to air pollution are important risk factors for death and disease globally. The built environment may influence exposures to these risk factors in different ways and thus differentially affect the health of urban populations. Objective: We investigated the built environment’s association with air pollution and physical inactivity, and estimated attributable health risks. Methods: We used a regional travel survey to estimate within-urban variability in physical inactivity and home-based air pollution exposure [particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5), nitrogen oxides (NOx), and ozone (O3)] for 30,007 individuals in southern California. We then estimated the resulting risk for ischemic heart disease (IHD) using literature-derived dose–response values. Using a cross-sectional approach, we compared estimated IHD mortality risks among neighborhoods based on “walkability” scores. Results: The proportion of physically active individuals was higher in high- versus low-walkability neighborhoods (24.9% vs. 12.5%); however, only a small proportion of the population was physically active, and between-neighborhood variability in estimated IHD mortality attributable to physical inactivity was modest (7 fewer IHD deaths/100,000/year in high- vs. low-walkability neighborhoods). Between-neighborhood differences in estimated IHD mortality from air pollution were comparable in magnitude (9 more IHD deaths/100,000/year for PM2.5 and 3 fewer IHD deaths for O3 in high- vs. low-walkability neighborhoods), suggesting that population health benefits from increased physical activity in high-walkability neighborhoods may be offset by adverse effects of air pollution exposure. Policy implications: Currently, planning efforts mainly focus on increasing physical activity through neighborhood design. Our results suggest that differences in population health impacts among neighborhoods are similar in magnitude for air pollution and physical activity. Thus, physical activity and exposure to air pollution are critical aspects of planning for cleaner, health-promoting cities. PMID:22004949

Health impacts of the built environment: within-urban variability in physical inactivity, air pollution, and ischemic heart disease mortality.

PubMed

Hankey, Steve; Marshall, Julian D; Brauer, Michael

2012-02-01

Physical inactivity and exposure to air pollution are important risk factors for death and disease globally. The built environment may influence exposures to these risk factors in different ways and thus differentially affect the health of urban populations. We investigated the built environment's association with air pollution and physical inactivity, and estimated attributable health risks. We used a regional travel survey to estimate within-urban variability in physical inactivity and home-based air pollution exposure [particulate matter with aerodynamic diameter ≤ 2.5 μm (PM2.5), nitrogen oxides (NOx), and ozone (O3)] for 30,007 individuals in southern California. We then estimated the resulting risk for ischemic heart disease (IHD) using literature-derived dose-response values. Using a cross-sectional approach, we compared estimated IHD mortality risks among neighborhoods based on "walkability" scores. The proportion of physically active individuals was higher in high- versus low-walkability neighborhoods (24.9% vs. 12.5%); however, only a small proportion of the population was physically active, and between-neighborhood variability in estimated IHD mortality attributable to physical inactivity was modest (7 fewer IHD deaths/100,000/year in high- vs. low-walkability neighborhoods). Between-neighborhood differences in estimated IHD mortality from air pollution were comparable in magnitude (9 more IHD deaths/100,000/year for PM2.5 and 3 fewer IHD deaths for O3 in high- vs. low-walkability neighborhoods), suggesting that population health benefits from increased physical activity in high-walkability neighborhoods may be offset by adverse effects of air pollution exposure. Currently, planning efforts mainly focus on increasing physical activity through neighborhood design. Our results suggest that differences in population health impacts among neighborhoods are similar in magnitude for air pollution and physical activity. Thus, physical activity and exposure to air pollution are critical aspects of planning for cleaner, health-promoting cities.

Identifying Programmatic Gaps: Inequities in Harm Reduction Service Utilization among Male and Female Drug Users in Dar es Salaam, Tanzania

PubMed Central

Lambdin, Barrot H.; Bruce, R. Douglas; Chang, Olivia; Nyandindi, Cassian; Sabuni, Norman; Zamudio-Haas, Sophia; McCurdy, Sheryl; Masao, Frank; Ivo, Yovin; Msami, Amani; Ubuguy, Omar; Mbwambo, Jessie

2013-01-01

Introduction Current estimates suggest an HIV prevalence of 42% among people who inject drugs (PWIDs) in Dar es Salaam, while HIV prevalence is estimated to be 8.8% among the general population in the city. To address the HIV epidemic in this population, the government of Tanzania began establishing HIV prevention, treatment and care services including outreach and medication assisted treatment (MAT) for PWIDs in 2010. We assessed gender inequities in utilization of outreach and MAT services and evaluated differences in HIV risk behaviors between female and male PWIDs. Materials and Methods Routine outreach data between December 2010 to mid-August 2012 and baseline data on clients enrolling in methadone from February 2011 to August 2012 were utilized. Binomial regression was used to estimate adjusted relative risk estimates comparing females to males. Results From December 2010 to August 2012, 8,578 contacts were made to drug users; among them 1,898 were injectors. A total of 453 injectors were eligible and referred to MAT, of which, 443 enrolled in treatment. However, regarding total outreach contacts, outreach to PWID, referral to MAT and enrollment in MAT, 8% or less of drug users accessing services were women. In contrast, weighted estimations from surveys suggest that 34% of PWIDs are female, and this approximation is similar to recent population size estimations. Overall, 43% of traditional outreach workers conducting outreach with drug users were female. Though reporting higher levels of condom usage, female PWID were more likely to report multiple sex partners, anal sex, commercial sex work and struggle under a higher burden of addiction, mental disorders and abuse. Conclusions Services have not been mobilized adequately to address the clear needs of females who inject drugs. A clear and urgent need exists for women-centered strategies that effectively engage female PWID into HIV prevention services. PMID:23825620

Imputing forest carbon stock estimates from inventory plots to a nationally continuous coverage

PubMed Central

2013-01-01

The U.S. has been providing national-scale estimates of forest carbon (C) stocks and stock change to meet United Nations Framework Convention on Climate Change (UNFCCC) reporting requirements for years. Although these currently are provided as national estimates by pool and year to meet greenhouse gas monitoring requirements, there is growing need to disaggregate these estimates to finer scales to enable strategic forest management and monitoring activities focused on various ecosystem services such as C storage enhancement. Through application of a nearest-neighbor imputation approach, spatially extant estimates of forest C density were developed for the conterminous U.S. using the U.S.’s annual forest inventory. Results suggest that an existing forest inventory plot imputation approach can be readily modified to provide raster maps of C density across a range of pools (e.g., live tree to soil organic carbon) and spatial scales (e.g., sub-county to biome). Comparisons among imputed maps indicate strong regional differences across C pools. The C density of pools closely related to detrital input (e.g., dead wood) is often highest in forests suffering from recent mortality events such as those in the northern Rocky Mountains (e.g., beetle infestations). In contrast, live tree carbon density is often highest on the highest quality forest sites such as those found in the Pacific Northwest. Validation results suggest strong agreement between the estimates produced from the forest inventory plots and those from the imputed maps, particularly when the C pool is closely associated with the imputation model (e.g., aboveground live biomass and live tree basal area), with weaker agreement for detrital pools (e.g., standing dead trees). Forest inventory imputed plot maps provide an efficient and flexible approach to monitoring diverse C pools at national (e.g., UNFCCC) and regional scales (e.g., Reducing Emissions from Deforestation and Forest Degradation projects) while allowing timely incorporation of empirical data (e.g., annual forest inventory). PMID:23305341

On the Estimation of Time Dependent Lift of a European Starling (Sturnus vulgaris) during Flapping Flight.

PubMed

Stalnov, Oksana; Ben-Gida, Hadar; Kirchhefer, Adam J; Guglielmo, Christopher G; Kopp, Gregory A; Liberzon, Alexander; Gurka, Roi

2015-01-01

We study the role of unsteady lift in the context of flapping wing bird flight. Both aerodynamicists and biologists have attempted to address this subject, yet it seems that the contribution of unsteady lift still holds many open questions. The current study deals with the estimation of unsteady aerodynamic forces on a freely flying bird through analysis of wingbeat kinematics and near wake flow measurements using time resolved particle image velocimetry. The aerodynamic forces are obtained through two approaches, the unsteady thin airfoil theory and using the momentum equation for viscous flows. The unsteady lift is comprised of circulatory and non-circulatory components. Both approaches are presented over the duration of wingbeat cycles. Using long-time sampling data, several wingbeat cycles have been analyzed in order to cover both the downstroke and upstroke phases. It appears that the unsteady lift varies over the wingbeat cycle emphasizing its contribution to the total lift and its role in power estimations. It is suggested that the circulatory lift component cannot assumed to be negligible and should be considered when estimating lift or power of birds in flapping motion.

Analysis of current assessments and perspectives of ESR tooth dosimetry for radiation dose reconstruction of the population residing near the Semipalatinsk nuclear test site.

PubMed

Romanyukha, Alex; Schauer, David A; Malikov, Yurii K

2006-02-01

Between 1949 and 1989 the Semipalatinsk nuclear test site (SNTS), an area of 19,000 square km in northeastern Kazakhstan, was the location of over 400 nuclear test explosions with a total explosive energy of 6.6 Mt TNT (trinitrotoluene or trotyl) equivalent. It is estimated that the bulk of the radiation exposure to the population resulted from three tests, conducted in 1949, 1951, and 1953 although estimations of radiation doses received by the local population have varied significantly. Analysis of the published ESR dose reconstruction results for residents of the villages near the SNTS show that they do not correlate well with other methods of dose assessment (e.g. model dose calculation and thermo luminescence dosimetry (TLD) in bricks). The most significant difference in dose estimations was found for the population of Dolon, which was exposed as result of the first Soviet nuclear test in 1949. Published results of ESR measurements in tooth enamel are considerably lower than other dose estimations. Detailed analysis of these results is provided and a possible explanation for this discrepancy and ways to eliminate it are suggested.

Methodology and Implications of Maximum Paleodischarge Estimates for

USGS Publications Warehouse

Channels, M.; Pruess, J.; Wohl, E.E.; Jarrett, R.D.

1998-01-01

Historical and geologic records may be used to enhance magnitude estimates for extreme floods along mountain channels, as demonstrated in this study from the San Juan Mountains of Colorado. Historical photographs and local newspaper accounts from the October 1911 flood indicate the likely extent of flooding and damage. A checklist designed to organize and numerically score evidence of flooding was used in 15 field reconnaissance surveys in the upper Animas River valley of southwestern Colorado. Step-backwater flow modeling estimated the discharges necessary to create longitudinal flood bars observed at 6 additional field sites. According to these analyses, maximum unit discharge peaks at approximately 1.3 m3 s~' km"2 around 2200 m elevation, with decreased unit discharges at both higher and lower elevations. These results (1) are consistent with Jarrett's (1987, 1990, 1993) maximum 2300-m elevation limit for flash-flooding in the Colorado Rocky Mountains, and (2) suggest that current Probable Maximum Flood (PMF) estimates based on a 24-h rainfall of 30 cm at elevations above 2700 m are unrealistically large. The methodology used for this study should be readily applicable to other mountain regions where systematic streamflow records are of short duration or nonexistent. ?? 1998 Regents of the University of Colorado.

Towards a more consistent picture of isopycnal mixing in climate models

NASA Astrophysics Data System (ADS)

Gnanadesikan, A.; Pradal, M. A. S.; Koszalka, I.; Abernathey, R. P.

2014-12-01

The stirring of tracers by mesoscale eddies along isopycnal surfaces is often represented in coarse-resolution models by the Redi diffusion parameter ARedi. Theoretical treatments of ARedi often assume it should scale as the eddy energy or the growth rate of mesoscale eddies,. producing a picture where it is high in boundary currents and low )of order a few hundred m2/s) in the gyre interiors. However, observational estimates suggest that ARedi should be very large (of order thousands of m2/s) in the gyre interior. We present results of recent simulations comparing a range of spatially constant values ARedi (with values of 400, 800, 1200 and 2400 m2/s) to a spatially resolved estimate based on altimetry and a zonally averaged version of the same estimate. In general, increasing the ARedi coefficient destratifies and warms the high latitudes. Relative to our control simulation, the spatially dependent coefficient is lower in the Southern Ocean, but high in the North Pacific, and so the temperature changes mirror this. We also examine the response of ocean hypoxia to these changes. In general, the zonally averaged version of the altimetry-based estimate of ARedi does not capture the full 2d representation.

On the Estimation of Time Dependent Lift of a European Starling (Sturnus vulgaris) during Flapping Flight

PubMed Central

Stalnov, Oksana; Ben-Gida, Hadar; Kirchhefer, Adam J.; Guglielmo, Christopher G.; Kopp, Gregory A.; Liberzon, Alexander; Gurka, Roi

2015-01-01

We study the role of unsteady lift in the context of flapping wing bird flight. Both aerodynamicists and biologists have attempted to address this subject, yet it seems that the contribution of unsteady lift still holds many open questions. The current study deals with the estimation of unsteady aerodynamic forces on a freely flying bird through analysis of wingbeat kinematics and near wake flow measurements using time resolved particle image velocimetry. The aerodynamic forces are obtained through two approaches, the unsteady thin airfoil theory and using the momentum equation for viscous flows. The unsteady lift is comprised of circulatory and non-circulatory components. Both approaches are presented over the duration of wingbeat cycles. Using long-time sampling data, several wingbeat cycles have been analyzed in order to cover both the downstroke and upstroke phases. It appears that the unsteady lift varies over the wingbeat cycle emphasizing its contribution to the total lift and its role in power estimations. It is suggested that the circulatory lift component cannot assumed to be negligible and should be considered when estimating lift or power of birds in flapping motion. PMID:26394213

EA 18G Growler Aircraft (EA 18G)

DTIC Science & Technology

2015-12-01

10051.9 N/A 13186.9 8636.4 11550.1 15672.4 1 APB Breach Confidence Level Confidence Level of cost estimate for current APB: 50% The current...estimate recommendation aims to provide sufficient resources to execute the program under normal conditions, encountering average levels of technical...TY $M) Initial PAUC Development Estimate Changes PAUC Production Estimate Econ Qty Sch Eng Est Oth Spt Total 93.573 4.150 1.442 -0.319 0.947 -0.348

Radio Science from an Optical Communications Signal

NASA Technical Reports Server (NTRS)

Moision, Bruce; Asmar, Sami; Oudrhiri, Kamal

2013-01-01

NASA is currently developing the capability to deploy deep space optical communications links. This creates the opportunity to utilize the optical link to obtain range, doppler, and signal intensity estimates. These may, in turn, be used to complement or extend the capabilities of current radio science. In this paper we illustrate the achievable precision in estimating range, doppler, and received signal intensity of an non-coherent optical link (the current state-of-the-art for a deep-space link). We provide a joint estimation algorithm with performance close to the bound. We draw comparisons to estimates based on a coherent radio frequency signal, illustrating that large gains in either precision or observation time are possible with an optical link.

What is the lifetime risk of developing cancer?: the effect of adjusting for multiple primaries

PubMed Central

Sasieni, P D; Shelton, J; Ormiston-Smith, N; Thomson, C S; Silcocks, P B

2011-01-01

Background: The ‘lifetime risk' of cancer is generally estimated by combining current incidence rates with current all-cause mortality (‘current probability' method) rather than by describing the experience of a birth cohort. As individuals may get more than one type of cancer, what is generally estimated is the average (mean) number of cancers over a lifetime. This is not the same as the probability of getting cancer. Methods: We describe a method for estimating lifetime risk that corrects for the inclusion of multiple primary cancers in the incidence rates routinely published by cancer registries. The new method applies cancer incidence rates to the estimated probability of being alive without a previous cancer. The new method is illustrated using data from the Scottish Cancer Registry and is compared with ‘gold-standard' estimates that use (unpublished) data on first primaries. Results: The effect of this correction is to make the estimated ‘lifetime risk' smaller. The new estimates are extremely similar to those obtained using incidence based on first primaries. The usual ‘current probability' method considerably overestimates the lifetime risk of all cancers combined, although the correction for any single cancer site is minimal. Conclusion: Estimation of the lifetime risk of cancer should either be based on first primaries or should use the new method. PMID:21772332

Potential Distribution Predicted for Rhynchophorus ferrugineus in China under Different Climate Warming Scenarios.

PubMed

Ge, Xuezhen; He, Shanyong; Wang, Tao; Yan, Wei; Zong, Shixiang

2015-01-01

As the primary pest of palm trees, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) has caused serious harm to palms since it first invaded China. The present study used CLIMEX 1.1 to predict the potential distribution of R. ferrugineus in China according to both current climate data (1981-2010) and future climate warming estimates based on simulated climate data for the 2020s (2011-2040) provided by the Tyndall Center for Climate Change Research (TYN SC 2.0). Additionally, the Ecoclimatic Index (EI) values calculated for different climatic conditions (current and future, as simulated by the B2 scenario) were compared. Areas with a suitable climate for R. ferrugineus distribution were located primarily in central China according to the current climate data, with the northern boundary of the distribution reaching to 40.1°N and including Tibet, north Sichuan, central Shaanxi, south Shanxi, and east Hebei. There was little difference in the potential distribution predicted by the four emission scenarios according to future climate warming estimates. The primary prediction under future climate warming models was that, compared with the current climate model, the number of highly favorable habitats would increase significantly and expand into northern China, whereas the number of both favorable and marginally favorable habitats would decrease. Contrast analysis of EI values suggested that climate change and the density of site distribution were the main effectors of the changes in EI values. These results will help to improve control measures, prevent the spread of this pest, and revise the targeted quarantine areas.

Potential Distribution Predicted for Rhynchophorus ferrugineus in China under Different Climate Warming Scenarios

PubMed Central

Ge, Xuezhen; He, Shanyong; Wang, Tao; Yan, Wei; Zong, Shixiang

2015-01-01

As the primary pest of palm trees, Rhynchophorus ferrugineus (Olivier) (Coleoptera: Curculionidae) has caused serious harm to palms since it first invaded China. The present study used CLIMEX 1.1 to predict the potential distribution of R. ferrugineus in China according to both current climate data (1981–2010) and future climate warming estimates based on simulated climate data for the 2020s (2011–2040) provided by the Tyndall Center for Climate Change Research (TYN SC 2.0). Additionally, the Ecoclimatic Index (EI) values calculated for different climatic conditions (current and future, as simulated by the B2 scenario) were compared. Areas with a suitable climate for R. ferrugineus distribution were located primarily in central China according to the current climate data, with the northern boundary of the distribution reaching to 40.1°N and including Tibet, north Sichuan, central Shaanxi, south Shanxi, and east Hebei. There was little difference in the potential distribution predicted by the four emission scenarios according to future climate warming estimates. The primary prediction under future climate warming models was that, compared with the current climate model, the number of highly favorable habitats would increase significantly and expand into northern China, whereas the number of both favorable and marginally favorable habitats would decrease. Contrast analysis of EI values suggested that climate change and the density of site distribution were the main effectors of the changes in EI values. These results will help to improve control measures, prevent the spread of this pest, and revise the targeted quarantine areas. PMID:26496438

Historical declines and disparities in cigarette coupon saving among adolescents in the United States, 1997-2013.

PubMed

Owotomo, Olusegun; Maslowsky, Julie; Pasch, Keryn E

2017-07-01

Exposure to cigarette coupons is associated with smoking initiation and likelihood of cigarette purchase among adolescents. Some adolescents who are exposed to cigarette coupons take a step further by choosing to save or collect these coupons, a further risk factor for cigarette smoking. This study examines historical trends and disparities in cigarette coupon saving among adolescents in the United States from 1997 to 2013. National samples of 10th and 12th grade students (n=129,111) were obtained from Monitoring the Future surveys in 1997-2013. Prevalence of lifetime and current cigarette coupon saving was estimated in each year in the overall adolescent population, and in race/ethnicity, parent education level, sex, and urban/rural subgroups. Prevalence of lifetime and current cigarette coupon saving was then estimated in each year based on smoking status. Prevalence of cigarette coupon saving has decreased dramatically among adolescents; only 1.2% reported currently saving coupons in 2013. However, disparities in cigarette coupon saving remain with prevalence higher among rural, White, and low parental education level students. Adolescent smokers continue to save coupons at high rates; 21.2% had ever saved coupons and 6.9% currently saved coupons as of 2013. Despite overall declines in adolescent cigarette coupon saving, existing sociodemographic disparities and the considerably high prevalence of coupon saving among adolescent smokers suggest that cigarette coupons remain a threat to smoking prevention among youth. Additional research is needed to further elucidate longitudinal associations between cigarette coupon saving and smoking initiation and maintenance among adolescents. Copyright © 2017 Elsevier Inc. All rights reserved.

Neutron generator for BNCT based on high current ECR ion source with gyrotron plasma heating.

PubMed

Skalyga, V; Izotov, I; Golubev, S; Razin, S; Sidorov, A; Maslennikova, A; Volovecky, A; Kalvas, T; Koivisto, H; Tarvainen, O

2015-12-01

BNCT development nowadays is constrained by a progress in neutron sources design. Creation of a cheap and compact intense neutron source would significantly simplify trial treatments avoiding use of expensive and complicated nuclear reactors and accelerators. D-D or D-T neutron generator is one of alternative types of such sources for. A so-called high current quasi-gasdynamic ECR ion source with plasma heating by millimeter wave gyrotron radiation is suggested to be used in a scheme of D-D neutron generator in the present work. Ion source of that type was developed in the Institute of Applied Physics of Russian Academy of Sciences (Nizhny Novgorod, Russia). It can produce deuteron ion beams with current density up to 700-800 mA/cm(2). Generation of the neutron flux with density at the level of 7-8·10(10) s(-1) cm(-2) at the target surface could be obtained in case of TiD2 target bombardment with deuteron beam accelerated to 100 keV. Estimations show that it is enough for formation of epithermal neutron flux with density higher than 10(9) s(-1) cm(-2) suitable for BNCT. Important advantage of described approach is absence of Tritium in the scheme. First experiments performed in pulsed regime with 300 mA, 45 kV deuteron beam directed to D2O target demonstrated 10(9) s(-1) neutron flux. This value corresponds to theoretical estimations and proofs prospects of neutron generator development based on high current quasi-gasdynamic ECR ion source. Copyright © 2015 Elsevier Ltd. All rights reserved.

Estimating Drivers of Autochthonous Transmission of Chikungunya Virus in its Invasion of the Americas

PubMed Central

Perkins, T. Alex; Metcalf, C. Jessica E.; Grenfell, Bryan T.; Tatem, Andrew J.

2015-01-01

Background Chikungunya is an emerging arbovirus that has caused explosive outbreaks in Africa and Asia for decades and invaded the Americas just over a year ago. During this ongoing invasion, it has spread to 45 countries where it has been transmitted autochthonously, infecting nearly 1.3 million people in total. Methods Here, we made use of weekly, country-level case reports to infer relationships between transmission and two putative climatic drivers: temperature and precipitation averaged across each country on a monthly basis. To do so, we used a TSIR model that enabled us to infer a parametric relationship between climatic drivers and transmission potential, and we applied a new method for incorporating a probabilistic description of the serial interval distribution into the TSIR framework. Results We found significant relationships between transmission and linear and quadratic terms for temperature and precipitation and a linear term for log incidence during the previous pathogen generation. The lattermost suggests that case numbers three to four weeks ago are largely predictive of current case numbers. This effect is quite nonlinear at the country level, however, due to an estimated mixing parameter of 0.74. Relationships between transmission and the climatic variables that we estimated were biologically plausible and in line with expectations. Conclusions Our analysis suggests that autochthonous transmission of Chikungunya in the Americas can be correlated successfully with putative climatic drivers, even at the coarse scale of countries and using long-term average climate data. Overall, this provides a preliminary suggestion that successfully forecasting the future trajectory of a Chikungunya outbreak and the receptivity of virgin areas may be possible. Our results also provide tentative estimates of timeframes and areas of greatest risk, and our extension of the TSIR model provides a novel tool for modeling vector-borne disease transmission. PMID:25737803

A Multi-Scale Distribution Model for Non-Equilibrium Populations Suggests Resource Limitation in an Endangered Rodent

PubMed Central

Bean, William T.; Stafford, Robert; Butterfield, H. Scott; Brashares, Justin S.

2014-01-01

Species distributions are known to be limited by biotic and abiotic factors at multiple temporal and spatial scales. Species distribution models, however, frequently assume a population at equilibrium in both time and space. Studies of habitat selection have repeatedly shown the difficulty of estimating resource selection if the scale or extent of analysis is incorrect. Here, we present a multi-step approach to estimate the realized and potential distribution of the endangered giant kangaroo rat. First, we estimate the potential distribution by modeling suitability at a range-wide scale using static bioclimatic variables. We then examine annual changes in extent at a population-level. We define “available” habitat based on the total suitable potential distribution at the range-wide scale. Then, within the available habitat, model changes in population extent driven by multiple measures of resource availability. By modeling distributions for a population with robust estimates of population extent through time, and ecologically relevant predictor variables, we improved the predictive ability of SDMs, as well as revealed an unanticipated relationship between population extent and precipitation at multiple scales. At a range-wide scale, the best model indicated the giant kangaroo rat was limited to areas that received little to no precipitation in the summer months. In contrast, the best model for shorter time scales showed a positive relation with resource abundance, driven by precipitation, in the current and previous year. These results suggest that the distribution of the giant kangaroo rat was limited to the wettest parts of the drier areas within the study region. This multi-step approach reinforces the differing relationship species may have with environmental variables at different scales, provides a novel method for defining “available” habitat in habitat selection studies, and suggests a way to create distribution models at spatial and temporal scales relevant to theoretical and applied ecologists. PMID:25237807

Atmospheric Sulfur Hexafluoride: Sources, Sinks and Greenhouse Warming

NASA Technical Reports Server (NTRS)

Sze, Nien Dak; Wang, Wei-Chyung; Shia, George; Goldman, Aaron; Murcray, Frank J.; Murcray, David G.; Rinsland, Curtis P.

1993-01-01

Model calculations using estimated reaction rates of sulfur hexafluoride (SF6) with OH and 0('D) indicate that the atmospheric lifetime due to these processes may be very long (25,000 years). An upper limit for the UV cross section would suggest a photolysis lifetime much longer than 1000 years. The possibility of other removal mechanisms are discussed. The estimated lifetimes are consistent with other estimated values based on recent laboratory measurements. There appears to be no known natural source of SF6. An estimate of the current production rate of SF6 is about 5 kt/yr. Based on historical emission rates, we calculated a present-day atmospheric concentrations for SF6 of about 2.5 parts per trillion by volume (pptv) and compared the results with available atmospheric measurements. It is difficult to estimate the atmospheric lifetime of SF6 based on mass balance of the emission rate and observed abundance. There are large uncertainties concerning what portion of the SF6 is released to the atmosphere. Even if the emission rate were precisely known, it would be difficult to distinguish among lifetimes longer than 100 years since the current abundance of SF6 is due to emission in the past three decades. More information on the measured trends over the past decade and observed vertical and latitudinal distributions of SF6 in the lower stratosphere will help to narrow the uncertainty in the lifetime. Based on laboratory-measured IR absorption cross section for SF6, we showed that SF6 is about 3 times more effective as a greenhouse gas compared to CFC 11 on a per molecule basis. However, its effect on atmospheric warming will be minimal because of its very small concentration. We estimated the future concentration of SF6 at 2010 to be 8 and 10 pptv based on two projected emission scenarios. The corresponding equilibrium warming of 0.0035 C and 0.0043 C is to be compared with the estimated warming due to CO2 increase of about 0.8 C in the same period.

Developing Bayesian adaptive methods for estimating sensitivity thresholds (d′) in Yes-No and forced-choice tasks

PubMed Central

Lesmes, Luis A.; Lu, Zhong-Lin; Baek, Jongsoo; Tran, Nina; Dosher, Barbara A.; Albright, Thomas D.

2015-01-01

Motivated by Signal Detection Theory (SDT), we developed a family of novel adaptive methods that estimate the sensitivity threshold—the signal intensity corresponding to a pre-defined sensitivity level (d′ = 1)—in Yes-No (YN) and Forced-Choice (FC) detection tasks. Rather than focus stimulus sampling to estimate a single level of %Yes or %Correct, the current methods sample psychometric functions more broadly, to concurrently estimate sensitivity and decision factors, and thereby estimate thresholds that are independent of decision confounds. Developed for four tasks—(1) simple YN detection, (2) cued YN detection, which cues the observer's response state before each trial, (3) rated YN detection, which incorporates a Not Sure response, and (4) FC detection—the qYN and qFC methods yield sensitivity thresholds that are independent of the task's decision structure (YN or FC) and/or the observer's subjective response state. Results from simulation and psychophysics suggest that 25 trials (and sometimes less) are sufficient to estimate YN thresholds with reasonable precision (s.d. = 0.10–0.15 decimal log units), but more trials are needed for FC thresholds. When the same subjects were tested across tasks of simple, cued, rated, and FC detection, adaptive threshold estimates exhibited excellent agreement with the method of constant stimuli (MCS), and with each other. These YN adaptive methods deliver criterion-free thresholds that have previously been exclusive to FC methods. PMID:26300798

Comparison of remote sensing and fixed-site monitoring approaches for examining air pollution and health in a national study population

NASA Astrophysics Data System (ADS)

Prud'homme, Genevieve; Dobbin, Nina A.; Sun, Liu; Burnett, Richard T.; Martin, Randall V.; Davidson, Andrew; Cakmak, Sabit; Villeneuve, Paul J.; Lamsal, Lok N.; van Donkelaar, Aaron; Peters, Paul A.; Johnson, Markey

2013-12-01

Satellite remote sensing (RS) has emerged as a cutting edge approach for estimating ground level ambient air pollution. Previous studies have reported a high correlation between ground level PM2.5 and NO2 estimated by RS and measurements collected at regulatory monitoring sites. The current study examined associations between air pollution and adverse respiratory and allergic health outcomes using multi-year averages of NO2 and PM2.5 from RS and from regulatory monitoring. RS estimates were derived using satellite measurements from OMI, MODIS, and MISR instruments. Regulatory monitoring data were obtained from Canada's National Air Pollution Surveillance Network. Self-reported prevalence of doctor-diagnosed asthma, current asthma, allergies, and chronic bronchitis were obtained from the Canadian Community Health Survey (a national sample of individuals 12 years of age and older). Multi-year ambient pollutant averages were assigned to each study participant based on their six digit postal code at the time of health survey, and were used as a marker for long-term exposure to air pollution. RS derived estimates of NO2 and PM2.5 were associated with 6-10% increases in respiratory and allergic health outcomes per interquartile range (3.97 μg m-3 for PM2.5 and 1.03 ppb for NO2) among adults (aged 20-64) in the national study population. Risk estimates for air pollution and respiratory/allergic health outcomes based on RS were similar to risk estimates based on regulatory monitoring for areas where regulatory monitoring data were available (within 40 km of a regulatory monitoring station). RS derived estimates of air pollution were also associated with adverse health outcomes among participants residing outside the catchment area of the regulatory monitoring network (p < 0.05). The consistency between risk estimates based on RS and regulatory monitoring as well as the associations between air pollution and health among participants living outside the catchment area for regulatory monitoring suggest that RS can provide useful estimates of long-term ambient air pollution in epidemiologic studies. This is particularly important in rural communities and other areas where monitoring and modeled air pollution data are limited or unavailable.

Estimating organ doses from tube current modulated CT examinations using a generalized linear model.

PubMed

Bostani, Maryam; McMillan, Kyle; Lu, Peiyun; Kim, Grace Hyun J; Cody, Dianna; Arbique, Gary; Greenberg, S Bruce; DeMarco, John J; Cagnon, Chris H; McNitt-Gray, Michael F

2017-04-01

Currently, available Computed Tomography dose metrics are mostly based on fixed tube current Monte Carlo (MC) simulations and/or physical measurements such as the size specific dose estimate (SSDE). In addition to not being able to account for Tube Current Modulation (TCM), these dose metrics do not represent actual patient dose. The purpose of this study was to generate and evaluate a dose estimation model based on the Generalized Linear Model (GLM), which extends the ability to estimate organ dose from tube current modulated examinations by incorporating regional descriptors of patient size, scanner output, and other scan-specific variables as needed. The collection of a total of 332 patient CT scans at four different institutions was approved by each institution's IRB and used to generate and test organ dose estimation models. The patient population consisted of pediatric and adult patients and included thoracic and abdomen/pelvis scans. The scans were performed on three different CT scanner systems. Manual segmentation of organs, depending on the examined anatomy, was performed on each patient's image series. In addition to the collected images, detailed TCM data were collected for all patients scanned on Siemens CT scanners, while for all GE and Toshiba patients, data representing z-axis-only TCM, extracted from the DICOM header of the images, were used for TCM simulations. A validated MC dosimetry package was used to perform detailed simulation of CT examinations on all 332 patient models to estimate dose to each segmented organ (lungs, breasts, liver, spleen, and kidneys), denoted as reference organ dose values. Approximately 60% of the data were used to train a dose estimation model, while the remaining 40% was used to evaluate performance. Two different methodologies were explored using GLM to generate a dose estimation model: (a) using the conventional exponential relationship between normalized organ dose and size with regional water equivalent diameter (WED) and regional CTDI vol as variables and (b) using the same exponential relationship with the addition of categorical variables such as scanner model and organ to provide a more complete estimate of factors that may affect organ dose. Finally, estimates from generated models were compared to those obtained from SSDE and ImPACT. The Generalized Linear Model yielded organ dose estimates that were significantly closer to the MC reference organ dose values than were organ doses estimated via SSDE or ImPACT. Moreover, the GLM estimates were better than those of SSDE or ImPACT irrespective of whether or not categorical variables were used in the model. While the improvement associated with a categorical variable was substantial in estimating breast dose, the improvement was minor for other organs. The GLM approach extends the current CT dose estimation methods by allowing the use of additional variables to more accurately estimate organ dose from TCM scans. Thus, this approach may be able to overcome the limitations of current CT dose metrics to provide more accurate estimates of patient dose, in particular, dose to organs with considerable variability across the population. © 2017 American Association of Physicists in Medicine.

Action potentials and ion conductances in wild-type and CALHM1-knockout type II taste cells

PubMed Central

Saung, Wint Thu; Foskett, J. Kevin

2017-01-01

Taste bud type II cells fire action potentials in response to tastants, triggering nonvesicular ATP release to gustatory neurons via voltage-gated CALHM1-associated ion channels. Whereas CALHM1 regulates mouse cortical neuron excitability, its roles in regulating type II cell excitability are unknown. In this study, we compared membrane conductances and action potentials in single identified TRPM5-GFP-expressing circumvallate papillae type II cells acutely isolated from wild-type (WT) and Calhm1 knockout (KO) mice. The activation kinetics of large voltage-gated outward currents were accelerated in cells from Calhm1 KO mice, and their associated nonselective tail currents, previously shown to be highly correlated with ATP release, were completely absent in Calhm1 KO cells, suggesting that CALHM1 contributes to all of these currents. Calhm1 deletion did not significantly alter resting membrane potential or input resistance, the amplitudes and kinetics of Na+ currents either estimated from action potentials or recorded from steady-state voltage pulses, or action potential threshold, overshoot peak, afterhyperpolarization, and firing frequency. However, Calhm1 deletion reduced the half-widths of action potentials and accelerated the deactivation kinetics of transient outward currents, suggesting that the CALHM1-associated conductance becomes activated during the repolarization phase of action potentials. NEW & NOTEWORTHY CALHM1 is an essential ion channel component of the ATP neurotransmitter release mechanism in type II taste bud cells. Its contribution to type II cell resting membrane properties and excitability is unknown. Nonselective voltage-gated currents, previously associated with ATP release, were absent in cells lacking CALHM1. Calhm1 deletion was without effects on resting membrane properties or voltage-gated Na+ and K+ channels but contributed modestly to the kinetics of action potentials. PMID:28202574

Action potentials and ion conductances in wild-type and CALHM1-knockout type II taste cells.

PubMed

Ma, Zhongming; Saung, Wint Thu; Foskett, J Kevin

2017-05-01

Taste bud type II cells fire action potentials in response to tastants, triggering nonvesicular ATP release to gustatory neurons via voltage-gated CALHM1-associated ion channels. Whereas CALHM1 regulates mouse cortical neuron excitability, its roles in regulating type II cell excitability are unknown. In this study, we compared membrane conductances and action potentials in single identified TRPM5-GFP-expressing circumvallate papillae type II cells acutely isolated from wild-type (WT) and Calhm1 knockout (KO) mice. The activation kinetics of large voltage-gated outward currents were accelerated in cells from Calhm1 KO mice, and their associated nonselective tail currents, previously shown to be highly correlated with ATP release, were completely absent in Calhm1 KO cells, suggesting that CALHM1 contributes to all of these currents. Calhm1 deletion did not significantly alter resting membrane potential or input resistance, the amplitudes and kinetics of Na + currents either estimated from action potentials or recorded from steady-state voltage pulses, or action potential threshold, overshoot peak, afterhyperpolarization, and firing frequency. However, Calhm1 deletion reduced the half-widths of action potentials and accelerated the deactivation kinetics of transient outward currents, suggesting that the CALHM1-associated conductance becomes activated during the repolarization phase of action potentials. NEW & NOTEWORTHY CALHM1 is an essential ion channel component of the ATP neurotransmitter release mechanism in type II taste bud cells. Its contribution to type II cell resting membrane properties and excitability is unknown. Nonselective voltage-gated currents, previously associated with ATP release, were absent in cells lacking CALHM1. Calhm1 deletion was without effects on resting membrane properties or voltage-gated Na + and K + channels but contributed modestly to the kinetics of action potentials. Copyright © 2017 the American Physiological Society.

Chronic and Acute Stress Promote Overexploitation in Serial Decision Making

PubMed Central

Lenow, Jennifer K.; Constantino, Sara M.

2017-01-01

Many decisions that humans make resemble foraging problems in which a currently available, known option must be weighed against an unknown alternative option. In such foraging decisions, the quality of the overall environment can be used as a proxy for estimating the value of future unknown options against which current prospects are compared. We hypothesized that such foraging-like decisions would be characteristically sensitive to stress, a physiological response that tracks biologically relevant changes in environmental context. Specifically, we hypothesized that stress would lead to more exploitative foraging behavior. To test this, we investigated how acute and chronic stress, as measured by changes in cortisol in response to an acute stress manipulation and subjective scores on a questionnaire assessing recent chronic stress, relate to performance in a virtual sequential foraging task. We found that both types of stress bias human decision makers toward overexploiting current options relative to an optimal policy. These findings suggest a possible computational role of stress in decision making in which stress biases judgments of environmental quality. SIGNIFICANCE STATEMENT Many of the most biologically relevant decisions that we make are foraging-like decisions about whether to stay with a current option or search the environment for a potentially better one. In the current study, we found that both acute physiological and chronic subjective stress are associated with greater overexploitation or staying at current options for longer than is optimal. These results suggest a domain-general way in which stress might bias foraging decisions through changing one's appraisal of the overall quality of the environment. These novel findings not only have implications for understanding how this important class of foraging decisions might be biologically implemented, but also for understanding the computational role of stress in behavior and cognition more broadly. PMID:28483979

Wintering Sandhill Crane exposure to wind energy development in the central and southern Great Plains, USA

USGS Publications Warehouse

Pearse, Aaron T.; Brandt, David; Krapu, Gary

2016-01-01

Numerous wind energy projects have been constructed in the central and southern Great Plains, USA, the main wintering area for midcontinental Sandhill Cranes (Grus canadensis). In an initial assessment of the potential risks of wind towers to cranes, we estimated spatial overlap, investigated potential avoidance behavior, and determined the habitat associations of cranes. We used data from cranes marked with platform transmitting terminals (PTTs) with and without global positioning system (GPS) capabilities. We estimated the wintering distributions of PTT-marked cranes prior to the construction of wind towers, which we compared with current tower locations. Based on this analysis, we found 7% spatial overlap between the distributions of cranes and towers. When we looked at individually marked cranes, we found that 52% would have occurred within 10 km of a tower at some point during winter. Using data from cranes marked after tower construction, we found a potential indication of avoidance behavior, whereby GPS-marked cranes generally used areas slightly more distant from existing wind towers than would be expected by chance. Results from a habitat selection model suggested that distances between crane locations and towers may have been driven more by habitat selection than by avoidance, as most wind towers were constructed in locations not often selected by wintering cranes. Our findings of modest regional overlap and that few towers have been placed in preferred crane habitat suggest that the current distribution of wind towers may be of low risk to the continued persistence of wintering midcontinental Sandhill Cranes in the central and southern Great Plains.

Model-based meta-analysis to evaluate optimal doses of direct oral factor Xa inhibitors in atrial fibrillation patients

PubMed Central

Yoshioka, Hideki; Sato, Hiromi; Hatakeyama, Hiroto

2018-01-01

The noninferiority of direct oral factor Xa (FXa) inhibitors (rivaroxaban, apixaban, and edoxaban) in treatment of atrial fibrillation were demonstrated compared with warfarin by several large clinical trials; however, subsequent meta-analyses reported a higher risk of major bleeding with rivaroxaban than with the other FXa inhibitors. In the present study, we first estimated the changes of prothrombin time (PT) in 5 randomized trials based on reported population pharmacokinetic and pharmacodynamic models and then carried out a model-based meta-analysis to obtain models describing the relationship between PT changes and the event rates of ischemic stroke/systemic embolism (SE) and of major bleeding. By using the models, we simulated the optimal therapeutic doses for each FXa inhibitor. It was suggested that dose reduction of rivaroxaban from the current 20 mg/d to 10 mg/d would decrease patient deaths from major bleeding (hazard ratio [HR], 0.69; 95% confidence interval [CI], 0.64-0.74) with little increase in those for ischemic stroke/SE (HR, 1.11; 95% CI, 1.07-1.20). The overall decrease in the mortality caused by both events was estimated as 5.81 per 10 000 patient-years (95% CI, 3.92-8.16), with an HR of 0.87 (95% CI, 0.83-0.91). For apixaban and edoxaban, no distinct change in the overall mortality was simulated by dose modification. This study suggested that the current dose of rivaroxaban might be excessive and would need to be reduced to decrease the excess risk of major bleeding. PMID:29760204

Historical and current introgression in a Mesoamerican hummingbird species complex: a biogeographic perspective

PubMed Central

Jiménez, Rosa Alicia

2016-01-01

The influence of geologic and Pleistocene glacial cycles might result in morphological and genetic complex scenarios in the biota of the Mesoamerican region. We tested whether berylline, blue-tailed and steely-blue hummingbirds, Amazilia beryllina, Amazilia cyanura and Amazilia saucerottei, show evidence of historical or current introgression as their plumage colour variation might suggest. We also analysed the role of past and present climatic events in promoting genetic introgression and species diversification. We collected mitochondrial DNA (mtDNA) sequence data and microsatellite loci scores for populations throughout the range of the three Amazilia species, as well as morphological and ecological data. Haplotype network, Bayesian phylogenetic and divergence time inference, historical demography, palaeodistribution modelling, and niche divergence tests were used to reconstruct the evolutionary history of this Amazilia species complex. An isolation-with-migration coalescent model and Bayesian assignment analysis were assessed to determine historical introgression and current genetic admixture. mtDNA haplotypes were geographically unstructured, with haplotypes from disparate areas interdispersed on a shallow tree and an unresolved haplotype network. Assignment analysis of the nuclear genome (nuDNA) supported three genetic groups with signs of genetic admixture, corresponding to: (1) A. beryllina populations located west of the Isthmus of Tehuantepec; (2) A. cyanura populations between the Isthmus of Tehuantepec and the Nicaraguan Depression (Nuclear Central America); and (3) A. saucerottei populations southeast of the Nicaraguan Depression. Gene flow and divergence time estimates, and demographic and palaeodistribution patterns suggest an evolutionary history of introgression mediated by Quaternary climatic fluctuations. High levels of gene flow were indicated by mtDNA and asymmetrical isolation-with-migration, whereas the microsatellite analyses found evidence for three genetic clusters with distributions corresponding to isolation by the Isthmus of Tehuantepec and the Nicaraguan Depression and signs of admixture. Historical levels of migration between genetically distinct groups estimated using microsatellites were higher than contemporary levels of migration. These results support the scenario of secondary contact and range contact during the glacial periods of the Pleistocene and strongly imply that the high levels of structure currently observed are a consequence of the limited dispersal of these hummingbirds across the isthmus and depression barriers. PMID:26788433

10 CFR Appendix D to Part 30 - Criteria Relating to Use of Financial Tests and Self-Guarantee for Providing Reasonable Assurance...

Code of Federal Regulations, 2012 CFR

2012-01-01

... will be available for decommissioning costs and on a demonstration that the company passes the... total current decommissioning cost estimate (or the current amount required if certification is used... percent of total assets or at least 10 times the total current decommissioning cost estimate (or the...

State of Washington Population Trends, 1975. Washington State Information Report.

ERIC Educational Resources Information Center

Washington State Office of Program Planning and Fiscal Management, Olympia.

As of April 1, 1975, Washington's population was estimated at 3,494,124--an increase of 80,874 since 1970. Prepared yearly, this report presents tabular data pertaining to: (1) current April 1 estimates for cities, towns, and counties; (2) current decline in household size; (3) the use of postal vacancy surveys in estimating vacancy rates; and (4)…

Series resistance compensation for whole-cell patch-clamp studies using a membrane state estimator

PubMed Central

Sherman, AJ; Shrier, A; Cooper, E

1999-01-01

Whole-cell patch-clamp techniques are widely used to measure membrane currents from isolated cells. While suitable for a broad range of ionic currents, the series resistance (R(s)) of the recording pipette limits the bandwidth of the whole-cell configuration, making it difficult to measure rapid ionic currents. To increase bandwidth, it is necessary to compensate for R(s). Most methods of R(s) compensation become unstable at high bandwidth, making them hard to use. We describe a novel method of R(s) compensation that overcomes the stability limitations of standard designs. This method uses a state estimator, implemented with analog computation, to compute the membrane potential, V(m), which is then used in a feedback loop to implement a voltage clamp; we refer to this as state estimator R(s) compensation. To demonstrate the utility of this approach, we built an amplifier incorporating state estimator R(s) compensation. In benchtop tests, our amplifier showed significantly higher bandwidths and improved stability when compared with a commercially available amplifier. We demonstrated that state estimator R(s) compensation works well in practice by recording voltage-gated Na(+) currents under voltage-clamp conditions from dissociated neonatal rat sympathetic neurons. We conclude that state estimator R(s) compensation should make it easier to measure large rapid ionic currents with whole-cell patch-clamp techniques. PMID:10545359

Acceleration and Storage of Energetic Electrons in Magnetic Loops in the Course of Electric Current Oscillations

NASA Astrophysics Data System (ADS)

Zaitsev, V. V.; Stepanov, A. V.

2017-10-01

A mechanism of electron acceleration and storage of energetic particles in solar and stellar coronal magnetic loops, based on oscillations of the electric current, is considered. The magnetic loop is presented as an electric circuit with the electric current generated by convective motions in the photosphere. Eigenoscillations of the electric current in a loop induce an electric field directed along the loop axis. It is shown that the sudden reductions that occur in the course of type IV continuum and pulsating type III observed in various frequency bands (25 - 180 MHz, 110 - 600 MHz, 0.7 - 3.0 GHz) in solar flares provide evidence for acceleration and storage of the energetic electrons in coronal magnetic loops. We estimate the energization rate and the energy of accelerated electrons and present examples of the storage of energetic electrons in loops in the course of flares on the Sun or on ultracool stars. We also discuss the efficiency of the suggested mechanism as compared with the electron acceleration during the five-minute photospheric oscillations and with the acceleration driven by the magnetic Rayleigh-Taylor instability.