Evaluation of data from the Vaisala CT25K for Estimation of PM10 Concentration and Mixing Heights in an Urban Environment

NASA Astrophysics Data System (ADS)

Gunter, R. L.; Hosker, R. P.

2005-12-01

During the month of August, the Urban Dispersion Project was conducted in New York City. NOAA's Atmospheric and Turbulence Division (ATDD), Oak Ridge, TN operated a Vaisala CT25K Ceilometer for a two-week timeframe during the project. Typically, ceilometer measurements are used for cloud height determination. It has been found that during dry conditions, there is a good correlation between the ceilometer near- range backscatter and in situ PM10 concentration readings. In addition, it also has been determined that the ceilometer is a suitable instrument for determining the convective mixing height (MH). Aerosol concentrations are calculated and mixing heights are estimated using data from the ceilometer during dry conditions in Manhattan. Mixing heights are compared to radiosonde data taken during the project.

Geometric effects on mixing performance in a novel passive micromixer with trapezoidal-zigzag channels

NASA Astrophysics Data System (ADS)

Le The, Hai; Ta, Bao Quoc; Le Thanh, Hoa; Dong, Tao; Nguyen Thoi, Trung; Karlsen, Frank

2015-09-01

A novel passive micromixer, called a trapezoidal-zigzag micromixer (TZM), is reported. A TZM is composed of trapezoidal channels in a zigzag and split-recombine arrangement that enables multiple mixing mechanisms, including splitting-recombining, twisting, transversal flows, vortices, and chaotic advection. The effects of geometric parameters of the TZM on mixing performance are systematically investigated by the Taguchi method and numerical simulations in COMSOL Multiphysics. The number of mixing units, the slope angle of the trapezoidal channel, the height of the constriction element, and the width ratio between the middle-trapezoidal channel and the side-trapezoidal channel are the four parameters under study. The mixing performance of the TZM is investigated at three different Reynolds number (Re) values of 0.5, 5, and 50. The results showed that a TZM with six mixing units, a trapezoidal slope angle of 75°, a constricting height of 100 µm, and a width ratio of 0.5 has the highest mixing efficiency. This optimal TZM has a mixing efficiency greater than 85% for Re values from 0.1 to 80. In particular, for Re  ⩽  0.9 and Re  ⩾  20, the mixing efficiency of the optimal TZM is greater than 90%. The proposed TZM has a higher mixing efficiency and a smaller footprint than previously reported micromixers.

Variation in Loblolly pine cross-sectional microfibril angle with tree height and physiographic region

Treesearch

Lewis Jordon; Rechum Re; Daniel B. Hall; Alexander Clark; Richard F. Daniels

2006-01-01

The effect of height and physiographic region on whole disk cross-sectional microfibril angle (CSMFA) in loblolly pine (Pinus raeda L.) in the southern United States was evaluated. Whole disk CSMFA was determined at 1.4, 4.6, 7.6, 10.7, and 13.7 m up the stem of 59 trees, representing five physiographic regions. A mixed-effects analysis of variance was performed to...

The seasonal cycle of the mixing layer height and its impact on black carbon concentrations in the Kathmandu Valley (Nepal)

NASA Astrophysics Data System (ADS)

Mues, Andrea; Rupakheti, Maheswar; Hoor, Peter; Bozem, Heiko; Münkel, Christoph; Lauer, Axel; Butler, Tim

2016-04-01

The properties and the vertical structure of the mixing layer as part of the planetary boundary layer are of key importance for local air quality. They have a substantial impact on the vertical dispersion of pollutants in the lower atmosphere and thus on their concentrations near the surface. In this study, ceilometer measurements taken within the framework of the SusKat project (Sustainable Atmosphere for the Kathmandu Valley) are used to investigate the mixing layer height in the Kathmandu Valley, Nepal. The applied method is based on the assumption that the aerosol concentration is nearly constant in the vertical and distinctly higher within the mixing layer than in the air above. Thus, the height with the steepest gradient within the ceilometer backscatter profile marks the top of the mixing layer. Ceilometer and black carbon (BC) measurements conducted from March 2013 through February 2014 provide a unique and important dataset for the analysis of the meteorological and air quality conditions in the Kathmandu Valley. In this study the mean diurnal cycle of the mixing layer height in the Kathmandu Valley for each season (pre-monsoon, monsoon, post-monsoon and winter season) and its dependency on the meteorological situation is investigated. In addition, the impact of the mixing layer height on the BC concentration is analyzed and compared to the relevance of other important processes such as emissions, horizontal advection and deposition. In all seasons the diurnal cycle is typically characterized by low mixing heights during the night, gradually increasing after sun rise reaching to maximum values in the afternoon before decreasing again. Seasonal differences can be seen particularly in the height of the mixing layer, e.g. from on average 153/1200 m (pre-monsoon) to 241/755 m (monsoon season) during the night/day, and the duration of enhanced mixing layer heights during daytime (around 12 hours (pre-monsoon season) to 8 hours (winter)). During the monsoon season, the observed diurnal cycle typically shows the lowest amplitude and the lowest mixing height during the day and the highest in the night and morning hours of all seasons. These characteristics can mainly be explained with frequently present clouds and the associated lack of incoming solar radiation and outgoing longwave radiation. In general there is a clear anti-correlation of the BC concentration and the mixing layer height although this relation is less pronounced in the monsoon season. The shape and magnitude of the BC diurnal cycle differs between the seasons (e.g., daily maximum concentration from around 6 to 50 μg/m3 depending on the season). This is partly due to the different meteorological conditions including the mixing layer height but also caused by the different (seasonal and diurnal) time profiles of the main emission sources. From late December to April, for instance, brick kilns are major emitters of black carbon. The brick kilns emit continuously throughout the day whereas in the other months sources with more pronounced diurnal cycles, such as traffic and cooking activities, are dominating the total emissions.

Responses of hardwood advace regeneration to seasonal prescribed fires in oak-dominated shelterwood stands

Treesearch

Patrick H. Brose; David H. Van Lear

1998-01-01

Effects of seasonal prescribed fires of varying intensities on density, mortality, stem form, height, and height growth of hardwood advance regeneration were investigated. Three mixed-hardwood stands on productive upland sites were cut using a shelterwood technique, each forming a block of spring burn, summer burn, winter burn, and control treatments. Advance...

A merchantable and total height model for tree species in Maine

Treesearch

James A. Westfall; Kenneth M. Laustsen

2006-01-01

A model for predicting merchantable and total tree height for 18 species groups in Maine is presented. Only tree-level predictor variables are used, so stand-level attributes, such as age and site quality, are not required. A mixed-effects modeling approach accounts for the correlated within-tree measurements. Data-collection protocols encompass situations in which...

Maps and models of density and stiffness within individual Douglas-fir trees

Treesearch

Christine L. Todoroki; Eini C. Lowell; Dennis P. Dykstra; David G. Briggs

2012-01-01

Spatial maps of density and stiffness patterns within individual trees were developed using two methods: (1) measured wood properties of veneer sheets; and (2) mixed effects models, to test the hypothesis that within-tree patterns could be predicted from easily measurable tree variables (height, taper, breast-height diameter, and acoustic velocity). Sample trees...

Evidence for competition and cooperation among climbing plants.

PubMed

Biernaskie, Jay M

2011-07-07

A plant's best strategy for acquiring resources may often depend on the identity of neighbours. Here, I ask whether plants adjust their strategy to local relatedness: individuals may cooperate (reduce competitiveness) with kin but compete relatively intensely with non-kin. In a greenhouse experiment with Ipomoea hederacea, neighbouring siblings from the same inbred line were relatively uniform in height; groups of mixed lines, however, were increasingly variable as their mean height increased. The reproductive yield of mixed and sibling groups was similar overall, but when adjusted to a common mean height and height inequality, the yield of mixed groups was significantly less. Where this difference in yield was most pronounced (among groups that varied most in height), mixed groups tended to allocate more mass to roots than comparable sibling groups, and overall, mixed groups produced significantly fewer seeds per unit mass of roots. These results suggest that, from the group perspective, non-kin may have wasted resources in below-ground competition at the expense of reproduction; kin groups, on the other hand, displayed the relative efficiency that is expected of reduced competitiveness.

Vertical distribution of ozone and the variation of tropopause heights based on ozonesonde and satellite observations. [Contract title: Internal Wave Motion

NASA Technical Reports Server (NTRS)

Hung, R. J.; Liu, J. M.

1986-01-01

The distribution of atmospheric ozone is nonuniform both in space and time. Local ozone concentration vary with altitude, latitude, longitude, and season. Two year ozonesonde data, January 1981 to December 1982, observed at four Canadian stations and 2.5 year backscattered ultraviolet experiment data on the Nimbus-4 satellite, April 1970 to August 1972, observed over five American stations were used to study the relationship between the total ozone, vertical height distribution of the ozone mixing ratio, vertical height distribution of half total ozone, and the local tropopause height. The results show that there is a postive correlation between total ozone in Dobson Units and the tropopause height in terms of atmospheric pressure. This result suggests that local intrusion of the statosphere into the troposphere, or the local decreasing of tropopause height could occur if there is a local increasing of total ozone. A comparison of the vertical height distribution of the ozone mixing ratio, the modified pressure height of half total ozone and the tropopause height shows that the pressure height of an ozone mixing ratio of 0.3 micrograms/g, and the modified pressure height of half total ozone are very well correlated with the tropopause pressure height.

Multilevel nonlinear mixed-effects models for the modeling of earlywood and latewood microfibril angle

Treesearch

Lewis Jordon; Richard F. Daniels; Alexander Clark; Rechun He

2005-01-01

Earlywood and latewood microfibril angle (MFA) was determined at I-millimeter intervals from disks at 1.4 meters, then at 3-meter intervals to a height of 13.7 meters, from 18 loblolly pine (Pinus taeda L.) trees grown in southeastern Texas. A modified three-parameter logistic function with mixed effects is used for modeling earlywood and latewood...

Impact of wave mixing on the sea ice cover

NASA Astrophysics Data System (ADS)

Rynders, Stefanie; Aksenov, Yevgeny; Madec, Gurvan; Nurser, George; Feltham, Daniel

2017-04-01

As information on surface waves in ice-covered regions becomes available in ice-ocean models, there is an opportunity to model wave-related processes more accurate. Breaking waves cause mixing of the upper water column and present mixing schemes in ocean models take this into account through surface roughness. A commonly used approach is to calculate surface roughness from significant wave height, parameterised from wind speed. We present results from simulations using modelled significant wave height instead, which accounts for the presence of sea ice and the effect of swell. The simulations use the NEMO ocean model coupled to the CICE sea ice model, with wave information from the ECWAM model of the European Centre for Medium-Range Weather Forecasts (ECMWF). The new waves-in-ice module allows waves to propagate in sea ice and attenuates waves according to multiple scattering and non-elastic losses. It is found that in the simulations with wave mixing the mixed layer depth (MLD) under ice cover is reduced, since the parameterisation from wind speed overestimates wave height in the ice-covered regions. The MLD change, in turn, affects sea ice concentration and ice thickness. In the Arctic, reduced MLD in winter translates into increased ice thicknesses overall, with higher increases in the Western Arctic and decreases along the Siberian coast. In summer, shallowing of the mixed layer results in more heat accumulating in the surface ocean, increasing ice melting. In the Southern Ocean the meridional gradient in ice thickness and concentration is increased. We argue that coupling waves with sea ice - ocean models can reduce negative biases in sea ice cover, affecting the distribution of nutrients and, thus, biological productivity and ecosystems. This coupling will become more important in the future, when wave heights in a large part of the Arctic are expected to increase due to sea ice retreat and a larger wave fetch. Therefore, wave mixing constitutes a possible positive feedback mechanism.

Evaluation of the Barr & Stroud FP15 and Criterion 400 laser dendrometers for measuring upper stem diameters and heights

Treesearch

Michael S. Williams; Kenneth L. Cormier; Ronald G. Briggs; Donald L. Martinez

1999-01-01

Calibrated Barr & Stroud FP15 and Criterion 400 laser dendrometers were tested for reliability in measuring upper stem diameters and heights under typical field conditions. Data were collected in the Black Hills National Forest, which covers parts of South Dakota and Wyoming in the United States. Mixed effects models were employed to account for differences between...

Mixing-height measurement by lidar, particle counter, and rawinsonde in the Williamette Valley, Oregon

NASA Technical Reports Server (NTRS)

Mccormick, M. P.; Melfi, S. H.; Olsson, L. E.; Tuft, W. L.; Elliott, W. P.; Egami, R.

1972-01-01

The feasibility of using laser radar (lidar) to measure the spatial distribution of aerosols and water vapor in the earth's mixing or boundary layer is shown. From these data the important parameter of actual mixing height was determined, that is, the maximum height to which particulate pollutants actually mix. Data are shown for simultaneous lidar, rawinsonde, and aircraft-mounted condensation nuclei counter and temperature measurements. The synoptic meteorology is also presented. The Williamette Valley, Oregon, was chosen for the measurements because of its unique combination of meteorology, terrain, and pollutant source, along with an ongoing Oregon State University study of the natural ventilation of this valley.

Mixing device for materials with large density differences

DOEpatents

Gregg, David W.

1994-01-01

An auger-tube pump mixing device for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided.

Mixing device for materials with large density differences

DOEpatents

Gregg, D.W.

1994-08-16

An auger-tube pump mixing device is disclosed for mixing materials with large density differences while maintaining low stirring RPM and low power consumption. The mixing device minimizes the formation of vortexes and minimizes the incorporation of small bubbles in the liquid during mixing. By avoiding the creation of a vortex the device provides efficient stirring of full containers without spillage over the edge. Also, the device solves the problem of effective mixing in vessels where the liquid height is large compared to the diameter. Because of the gentle stirring or mixing by the device, it has application for biomedical uses where cell damage is to be avoided. 2 figs.

Laboratory simulations of the atmospheric mixed-layer in flow ...

EPA Pesticide Factsheets

A laboratory study of the influence of complex terrain on the interface between a well-mixed boundary layer and an elevated stratified layer was conducted in the towing-tank facility of the U.S. Environmental Protection Agency. The height of the mixed layer in the daytime boundary layer can have a strong influence on the concentration of pollutants within this layer. Deflections of streamlines at the height of the interface are primarily a function of hill Froude number (Fr), the ratio of mixed-layer height (zi) to terrain height (h), and the crosswind dimension of the terrain. The magnitude of the deflections increases as Fr increases and zi / h decreases. For mixing-height streamlines that are initially below the terrain top, the response is linear with Fr; for those initially above the terrain feature the response to Fr is more complex. Once Fr exceeds about 2, the terrain related response of the mixed layer interface decreases somewhat with increasing Fr (toward more neutral flow). Deflections are also shown to increase as the crosswind dimensions of the terrain increases. Comparisons with numerical modeling, limited field data and other laboratory measurements reported in the literature are favorable. Additionally, visual observations of dye streamers suggests that the flow structure exhibited for our elevated inversions passing over three dimensional hills is similar to that reported in the literature for continuously stratified flow over two-dimensional h

Estimating Mixing Heights Using Microwave Temperature Profiler

NASA Technical Reports Server (NTRS)

Nielson-Gammon, John; Powell, Christina; Mahoney, Michael; Angevine, Wayne

2008-01-01

A paper describes the Microwave Temperature Profiler (MTP) for making measurements of the planetary boundary layer thermal structure data necessary for air quality forecasting as the Mixing Layer (ML) height determines the volume in which daytime pollution is primarily concentrated. This is the first time that an airborne temperature profiler has been used to measure the mixing layer height. Normally, this is done using a radar wind profiler, which is both noisy and large. The MTP was deployed during the Texas 2000 Air Quality Study (TexAQS-2000). An objective technique was developed and tested for estimating the ML height from the MTP vertical temperature profiles. In order to calibrate the technique and evaluate the usefulness of this approach, estimates from a variety of measurements during the TexAQS-2000 were compared. Estimates of ML height were used from radiosondes, radar wind profilers, an aerosol backscatter lidar, and in-situ aircraft measurements in addition to those from the MTP.

Pre-natal exposures to cocaine and alcohol and physical growth patterns to age 8 years

PubMed Central

Lumeng, Julie C.; Cabral, Howard J.; Gannon, Katherine; Heeren, Timothy; Frank, Deborah A.

2007-01-01

Two hundred and two primarily African American/Caribbean children (classified by maternal report and infant meconium as 38 heavier, 74 lighter and 89 not cocaine-exposed) were measured repeatedly from birth to age 8 years to assess whether there is an independent effect of prenatal cocaine exposure on physical growth patterns. Children with fetal alcohol syndrome identifiable at birth were excluded. At birth, cocaine and alcohol exposures were significantly and independently associated with lower weight, length and head circumference in cross-sectional multiple regression analyses. The relationship over time of pre-natal exposures to weight, height, and head circumference was then examined by multiple linear regression using mixed linear models including covariates: child’s gestational age, gender, ethnicity, age at assessment, current caregiver, birth mother’s use of alcohol, marijuana and tobacco during the pregnancy and pre-pregnancy weight (for child’s weight) and height (for child’s height and head circumference). The cocaine effects did not persist beyond infancy in piecewise linear mixed models, but a significant and independent negative effect of pre-natal alcohol exposure persisted for weight, height, and head circumference. Catch-up growth in cocaine-exposed infants occurred primarily by 6 months of age for all growth parameters, with some small fluctuations in growth rates in the preschool age range but no detectable differences between heavier versus unexposed nor lighter versus unexposed thereafter. PMID:17412558

Genetic determination of height-mediated mate choice.

PubMed

Tenesa, Albert; Rawlik, Konrad; Navarro, Pau; Canela-Xandri, Oriol

2016-01-19

Numerous studies have reported positive correlations among couples for height. This suggests that humans find individuals of similar height attractive. However, the answer to whether the choice of a mate with a similar phenotype is genetically or environmentally determined has been elusive. Here we provide an estimate of the genetic contribution to height choice in mates in 13,068 genotyped couples. Using a mixed linear model we show that 4.1% of the variation in the mate height choice is determined by a person's own genotype, as expected in a model where one's height determines the choice of mate height. Furthermore, the genotype of an individual predicts their partners' height in an independent dataset of 15,437 individuals with 13% accuracy, which is 64% of the theoretical maximum achievable with a heritability of 0.041. Theoretical predictions suggest that approximately 5% of the heritability of height is due to the positive covariance between allelic effects at different loci, which is caused by assortative mating. Hence, the coupling of alleles with similar effects could substantially contribute to the missing heritability of height. These estimates provide new insight into the mechanisms that govern mate choice in humans and warrant the search for the genetic causes of choice of mate height. They have important methodological implications and contribute to the missing heritability debate.

Experiments in dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, J. D.; Srinivasan, R.; Berenfeld, A.

1983-01-01

Experimental results are given on the mixing of a single row of jets with an isothermal mainstream in a straight duct, to include flow and geometric variations typical of combustion chambers in gas turbine engines. The principal conclusions reached from these experiments were: at constant momentum ratio, variations in density ratio have only a second-order effect on the profiles; a first-order approximation to the mixing of jets with a variable temperature mainstream can be obtained by superimposing the jets-in-an isothermal-crossflow and mainstream profiles; flow area convergence, especially injection-wall convergence, significantly improves the mixing; for opposed rows of jets, with the orifice centerlines in-line, the optimum ratio of orifice spacing to duct height is one half of the optimum value for single side injection at the same momentum ratio; and for opposed rows of jets, with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is twice the optimum value for single side injection at the same momentum ratio.

Testing Extensions of Our Quantitative Daily of San Joaquin Wintertime Aerosols Using MAIAC and Meteorology Without Transport/Transformation Assumptions

NASA Technical Reports Server (NTRS)

Chatfield, Robert B.; Sorek Hamer, Meytar; Esswein, Robert F.

2017-01-01

The Western US and many regions globally present daunting difficulties in understanding and mapping PM2.5 episodes. We evaluate extensions of a method independent of source-description and transport/transformation. These regions suffer frequent few-day episodes due to shallow mixing; low satellite AOT and bright surfaces complicate the description. Nevertheless, we expect residual errors in our maps of less than 8 ug/m^3 in episodes reaching 60-100 ug/m^3; maps which detail pollution from Interstate 5. Our current success is due to use of physically meaningful functions of MODIS-MAIAC-derived AOD, afternoon mixed-layer height, and relative humidity for a basin in which the latter are correlated. A mixed-effects model then describes a daily AOT-to-PM2.5 relationship. (Note: in other published mixed-effects models, AOT contributes minimally. We seek to extend on these to develop useful estimation methods for similar situations. We evaluate existing but more spotty information on size distribution (AERONET, MISR, MAIA, CALIPSO, other remote sensing). We also describe the usefulness of an equivalent mixing depth for water vapor vs meteorological boundary layer height. Each has virtues and limitations. Finally, we begin to evaluate methods for removing the complications due to detached but polluted layers (which don't mix to the surface) using geographical, meteorological, and remotely sensed data.

[Characteristics of Winter Atmospheric Mixing Layer Height in Beijing-Tianjin-Hebei Region and Their Relationship with the Atmospheric Pollution].

PubMed

Li, Meng; Tang, Gui-qian; Huang, Jun; Liu, Zi-rui; An, Jun-lin; Wang, Yue-si

2015-06-01

Atmospheric mixing layer height (MLH) is one of the main factors affecting the atmospheric diffusion and plays an important role in air quality assessment and distribution of the pollutants. Based on the ceilometers data, this paper has made synchronous observation on MLH in Beijing-Tianjin-Hebei region (Beijing, Tianjin, Shijiazhuang and Qinhuangdao) in heavy polluted February 2014 and analyzed the respective overall change and its regional features. Results show that in February 2014,the average of mixing layer height in Qinhuangdao is the highest, up to 865 +/- 268 m, and in Shijiazhuang is the lowest (568 +/- 207 m), Beijing's and Tianjin's are in between, 818 +/- 319 m and 834 +/- 334 m respectively; Combined with the meteorological data, we find that radiation and wind speed are main factors of the mixing layer height; The relationship between the particle concentration and mixing layer height in four sites suggests that mixing layer is less than 800 m, concentration of fine particulate matter in four sites will exceed the national standard (GB 3095-2012, 75 microg x m(-3)). During the period of observation, the proportion of days that mixing layer is less than 800 m in Beijing, Tianjin, Shijiazhuang and Qinhuangdao are 50%, 43%, 80% and 50% respectively. Shijiazhuang though nearly formation contaminant concentration is high, within the atmospheric mixed layer pollutant load is not high. Unfavorable atmospheric diffusion conditions are the main causes of heavy pollution in Shijiazhuang for a long time. The results of the study are of great significance for cognitive Beijing-Tianjin-Hebei area pollution distribution, and can provide a scientific reference for reasonable distribution of regional pollution sources.

Growth of site trees and stand structure in mixed stands of Pacific silver fir and western hemlock.

Treesearch

Marshall D. Murray; Peggy C. Leonard

1990-01-01

Height and diameter growth of Pacific silver fir (Abies amabilis Dougl. ex Forbes) and western hemlock (Tsuga heterophylla (Raf.) Sarg.) site trees, as well as overall stand structure on 0.15-acre plots, were analyzed in mixed stands 43 to 57 years old in breast height age at six locations in western Washington. These mixed...

Assessment of mixed-layer height estimation from single-wavelength ceilometer profiles

EPA Science Inventory

Differing boundary/mixed-layer height measurement methods were assessed in moderately polluted and clean environments, with a focus on the Vaisala CL51 ceilometer. This intercomparison was performed as part of ongoing measurements at the Chemistry And Physics of the Atmospheric B...

A GIS-based approach to stand visualization and spatial pattern analysis in a mixed hardwood forest in West Virginia

Treesearch

Benktesh D. Sharma; Jingxin Wang; Gary Miller

2008-01-01

Tree spatial patterns were characterized for a 75-year-old mixed hardwood forest dominated by northern red oak, chestnut oak, red maple and yellow-poplar. All trees ≥5 inches diameter at breast height (d.b.h.) were measured for diameter, total height, crown height, and crown width along with their locations in the field over an area of 8 acres. The spatial...

A variable mixing-length ratio for convection theory

NASA Technical Reports Server (NTRS)

Chan, K. L.; Wolff, C. L.; Sofia, S.

1981-01-01

It is argued that a natural choice for the local mixing length in the mixing-length theory of convection has a value proportional to the local density scale height of the convective bubbles. The resultant variable mixing-length ratio (the ratio between the mixing length and the pressure scale height) of this theory is enhanced in the superadiabatic region and approaches a constant in deeper layers. Numerical tests comparing the new mixing length successfully eliminate most of the density inversion that typically plagues conventional results. The new approach also seems to indicate the existence of granular motion at the top of the convection zone.

Modelling individual tree height to crown base of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.)

PubMed Central

Jansa, Václav

2017-01-01

Height to crown base (HCB) of a tree is an important variable often included as a predictor in various forest models that serve as the fundamental tools for decision-making in forestry. We developed spatially explicit and spatially inexplicit mixed-effects HCB models using measurements from a total 19,404 trees of Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) on the permanent sample plots that are located across the Czech Republic. Variables describing site quality, stand density or competition, and species mixing effects were included into the HCB model with use of dominant height (HDOM), basal area of trees larger in diameters than a subject tree (BAL- spatially inexplicit measure) or Hegyi’s competition index (HCI—spatially explicit measure), and basal area proportion of a species of interest (BAPOR), respectively. The parameters describing sample plot-level random effects were included into the HCB model by applying the mixed-effects modelling approach. Among several functional forms evaluated, the logistic function was found most suited to our data. The HCB model for Norway spruce was tested against the data originated from different inventory designs, but model for European beech was tested using partitioned dataset (a part of the main dataset). The variance heteroscedasticity in the residuals was substantially reduced through inclusion of a power variance function into the HCB model. The results showed that spatially explicit model described significantly a larger part of the HCB variations [R2adj = 0.86 (spruce), 0.85 (beech)] than its spatially inexplicit counterpart [R2adj = 0.84 (spruce), 0.83 (beech)]. The HCB increased with increasing competitive interactions described by tree-centered competition measure: BAL or HCI, and species mixing effects described by BAPOR. A test of the mixed-effects HCB model with the random effects estimated using at least four trees per sample plot in the validation data confirmed that the model was precise enough for the prediction of HCB for a range of site quality, tree size, stand density, and stand structure. We therefore recommend measuring of HCB on four randomly selected trees of a species of interest on each sample plot for localizing the mixed-effects model and predicting HCB of the remaining trees on the plot. Growth simulations can be made from the data that lack the values for either crown ratio or HCB using the HCB models. PMID:29049391

Rapid and efficient mixing in a slip-driven three-dimensional flow in a rectangular channel

NASA Astrophysics Data System (ADS)

Pacheco, J. Rafael; Ping Chen, Kang; Hayes, Mark A.

2006-08-01

A method for generating mixing in an electroosmotic flow of an electrolytic solution in a three-dimensional channel is proposed. When the width-to-height aspect ratio of the channel cross-section is large, mixing of a blob of a solute in a slip-driven three-dimensional flow in a rectangular channel can be used to model and assess the effectiveness of this method. It is demonstrated through numerical simulations that under certain operating conditions, rapid and efficient mixing can be achieved. Future investigation will include the solution of the exact equations and experimentation.

Large-Scale Mixed Temperate Forest Mapping at the Single Tree Level using Airborne Laser Scanning

NASA Astrophysics Data System (ADS)

Scholl, V.; Morsdorf, F.; Ginzler, C.; Schaepman, M. E.

2017-12-01

Monitoring vegetation on a single tree level is critical to understand and model a variety of processes, functions, and changes in forest systems. Remote sensing technologies are increasingly utilized to complement and upscale the field-based measurements of forest inventories. Airborne laser scanning (ALS) systems provide valuable information in the vertical dimension for effective vegetation structure mapping. Although many algorithms exist to extract single tree segments from forest scans, they are often tuned to perform well in homogeneous coniferous or deciduous areas and are not successful in mixed forests. Other methods are too computationally expensive to apply operationally. The aim of this study was to develop a single tree detection workflow using leaf-off ALS data for the canton of Aargau in Switzerland. Aargau covers an area of over 1,400km2 and features mixed forests with various development stages and topography. Forest type was classified using random forests to guide local parameter selection. Canopy height model-based treetop maxima were detected and maintained based on the relationship between tree height and window size, used as a proxy to crown diameter. Watershed segmentation was used to generate crown polygons surrounding each maximum. The location, height, and crown dimensions of single trees were derived from the ALS returns within each polygon. Validation was performed through comparison with field measurements and extrapolated estimates from long-term monitoring plots of the Swiss National Forest Inventory within the framework of the Swiss Federal Institute for Forest, Snow, and Landscape Research. This method shows promise for robust, large-scale single tree detection in mixed forests. The single tree data will aid ecological studies as well as forest management practices. Figure description: Height-normalized ALS point cloud data (top) and resulting single tree segments (bottom) on the Laegeren mountain in Switzerland.

Satellite remote sensing and ozonesonde observation of ozone vertical profile and severe storm development

NASA Technical Reports Server (NTRS)

Hung, R. J.; Liu, J. M.

1988-01-01

Two year ozonesonde data, January 1981 to December 1982, observed at four Canadian stations, and two-and-a-half year backscattered ultraviolet experiment data on the Nimbus-4 satellite, April 1970 to August 1972, observed over five U.S. stations, were used to study the relationship between the total ozone, vertical distribution of the ozone mixing ratio, height of half the total ozone, and the variation of local tropopause height. In view of the correlation between the variation of the tropopause height and the possible development of severe storms, a better understanding of the effect of the vertical distribution of the local ozone profile on the variation of the tropopause height can give considerable insight into the development of severe storms.

Amendment to "Analytical Solution for the Convectively-Mixed Atmospheric Boundary Layer": Inclusion of Subsidence

NASA Astrophysics Data System (ADS)

Ouwersloot, H. G.; de Arellano, J. Vilà-Guerau

2013-09-01

In Ouwersloot and Vilà-Guerau de Arellano (Boundary-Layer Meteorol. doi: 10.1007/s10546-013-9816-z , 2013, this issue), the analytical solutions for the boundary-layer height and scalar evolutions are derived for the convective boundary layer, based on the prognostic equations of mixed-layer slab models without taking subsidence into account. Here, we include and quantify the added effect of subsidence if the subsidence velocity scales linearly with height throughout the atmosphere. This enables analytical analyses for a wider range of observational cases. As a demonstration, the sensitivity of the boundary-layer height and the potential temperature jump to subsidence and the free tropospheric stability is graphically presented. The new relations show the importance of the temporal distribution of the surface buoyancy flux in determining the evolution if there is subsidence.

Individual tree height increment model for managed even-aged stands of ponderosa pine throughout the western United States using linear mixed effects models

Treesearch

Fabian Uzoh; William W. Oliver

2006-01-01

A height increment model is developed and evaluated for individual trees of ponderosa pine throughout the species range in western United States. The data set used in this study came from long-term permanent research plots in even-aged, pure stands both planted and of natural origin. The data base consists of six levels-of-growing stock studies supplemented by initial...

Fitting and Calibrating a Multilevel Mixed-Effects Stem Taper Model for Maritime Pine in NW Spain

PubMed Central

Arias-Rodil, Manuel; Castedo-Dorado, Fernando; Cámara-Obregón, Asunción; Diéguez-Aranda, Ulises

2015-01-01

Stem taper data are usually hierarchical (several measurements per tree, and several trees per plot), making application of a multilevel mixed-effects modelling approach essential. However, correlation between trees in the same plot/stand has often been ignored in previous studies. Fitting and calibration of a variable-exponent stem taper function were conducted using data from 420 trees felled in even-aged maritime pine (Pinus pinaster Ait.) stands in NW Spain. In the fitting step, the tree level explained much more variability than the plot level, and therefore calibration at plot level was omitted. Several stem heights were evaluated for measurement of the additional diameter needed for calibration at tree level. Calibration with an additional diameter measured at between 40 and 60% of total tree height showed the greatest improvement in volume and diameter predictions. If additional diameter measurement is not available, the fixed-effects model fitted by the ordinary least squares technique should be used. Finally, we also evaluated how the expansion of parameters with random effects affects the stem taper prediction, as we consider this a key question when applying the mixed-effects modelling approach to taper equations. The results showed that correlation between random effects should be taken into account when assessing the influence of random effects in stem taper prediction. PMID:26630156

Experiments in dilution jet mixing

NASA Technical Reports Server (NTRS)

Holdeman, J. D.; Srinivasan, R.; Berenfeld, A.

1983-01-01

Experimental results are presented on the mixing of a single row of jets with an isothermal mainstream in a straight duct, with flow and geometric variations typical of combustion chambers in gas turbine engines included. It is found that at a constant momentum ratio, variations in the density ratio have only a second-order effect on the profiles. A first-order approximation to the mixing of jets with a variable temperature mainstream can, it is found, be obtained by superimposing the jets-in-an-isothermal-crossflow and mainstream profiles. Another finding is that the flow area convergence, especially injection-wall convergence, significantly improves the mixing. For opposed rows of jets with the orifice cone centerlines in-line, the optimum ratio of orifice spacing to duct height is determined to be 1/2 of the optimum value for single injection at the same momentum ratio. For opposed rows of jets with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is found to be twice the optimum value for single side injection at the same momentum ratio.

Air pollution potential: Regional study in Argentina

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

Gassmann, M.I.; Mazzeo, N.A.

2000-04-01

Air pollution potential is a measure of the atmospheric conditions that are unable to transport and dilute pollutants into the air, independently of the existence of sources. This potential can be determined from two atmospheric parameters; mixing height and transport wind. In this paper a statistical analysis of the mixing height and transport wind, in order to determine the areas with high or poor atmospheric ventilation in Argentina, is presented. In order to achieve this, meteorological data registered during 1979--1982 at eight meteorological stations were used. Daily values of the maximum mixing height were calculated from observations of daily temperaturesmore » at different heights and maximum surface temperature. At the same time as the maximum mixing height, the values of the transport wind were determined from the surface windspeed and the characteristics of the ground in the surroundings of each meteorological station. The mean seasonal values for both parameters were obtained. Isopleths of the mean seasonal of the maximum mixing heights were drawn. The percentage of seasonal frequencies of poor ventilation conditions were calculated and the frequency isopleths were also drawn to determine areas with minor and major relative frequencies. It was found that the northeastern and central-eastern regions of Argentina had a high air pollution potential during the whole year. Unfavorable atmospheric ventilation conditions were also found in the central-western side of the country during the cold seasons (37.5% in autumn and 56.9% in winter). The region with the greatest atmospheric ventilation is located south of 40{degree}S, where the frequency of poor ventilation varies between 8.0% in summer and 10.8% in winter.« less

Influence of vegetation structure on lidar-derived canopy height and fractional cover in forested riparian buffers during leaf-off and leaf-on conditions.

PubMed

Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

2013-01-01

Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available.

Influence of Vegetation Structure on Lidar-derived Canopy Height and Fractional Cover in Forested Riparian Buffers During Leaf-Off and Leaf-On Conditions

PubMed Central

Wasser, Leah; Day, Rick; Chasmer, Laura; Taylor, Alan

2013-01-01

Estimates of canopy height (H) and fractional canopy cover (FC) derived from lidar data collected during leaf-on and leaf-off conditions are compared with field measurements from 80 forested riparian buffer plots. The purpose is to determine if existing lidar data flown in leaf-off conditions for applications such as terrain mapping can effectively estimate forested riparian buffer H and FC within a range of riparian vegetation types. Results illustrate that: 1) leaf-off and leaf-on lidar percentile estimates are similar to measured heights in all plots except those dominated by deciduous compound-leaved trees where lidar underestimates H during leaf off periods; 2) canopy height models (CHMs) underestimate H by a larger margin compared to percentile methods and are influenced by vegetation type (conifer needle, deciduous simple leaf or deciduous compound leaf) and canopy height variability, 3) lidar estimates of FC are within 10% of plot measurements during leaf-on periods, but are underestimated during leaf-off periods except in mixed and conifer plots; and 4) depth of laser pulse penetration lower in the canopy is more variable compared to top of the canopy penetration which may influence within canopy vegetation structure estimates. This study demonstrates that leaf-off lidar data can be used to estimate forested riparian buffer canopy height within diverse vegetation conditions and fractional canopy cover within mixed and conifer forests when leaf-on lidar data are not available. PMID:23382966

Trabecular Meshwork Height in Primary Open-Angle Glaucoma Versus Primary Angle-Closure Glaucoma.

PubMed

Masis, Marisse; Chen, Rebecca; Porco, Travis; Lin, Shan C

2017-11-01

To determine if trabecular meshwork (TM) height differs between primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG) eyes. Prospective, cross-sectional clinical study. Adult patients were consecutively recruited from glaucoma clinics at the University of California, San Francisco, from January 2012 to July 2015. Images were obtained from spectral-domain optical coherence tomography (Cirrus OCT; Carl Zeiss Meditec, Inc, Dublin, California, USA). Univariate and multivariate linear mixed models comparing TM height and glaucoma type were performed to assess the relationship between TM height and glaucoma subtype. Mixed-effects regression was used to adjust for the use of both eyes in some subjects. The study included 260 eyes from 161 subjects, composed of 61 men and 100 women. Mean age was 70 years (SD 11.77). There were 199 eyes (123 patients) in the POAG group and 61 eyes (38 patients) in the PACG group. Mean TM heights in the POAG and PACG groups were 812 ± 13 μm and 732 ± 27 μm, respectively, and the difference was significant in univariate analysis (P = .004) and in multivariate analysis (β = -88.7 [24.05-153.5]; P = .008). In this clinic-based population, trabecular meshwork height is shorter in PACG patients compared to POAG patients. This finding may provide insight into the pathophysiology of angle closure and provide assistance in future diagnosis, prevention, and management of the angle-closure spectrum of disorders. Copyright © 2017 Elsevier Inc. All rights reserved.

Vertical distribution of hydrocarbons in the low troposphere below and above the mixing height: tethered balloon measurements in Milan, Italy.

PubMed

Sangiorgi, G; Ferrero, L; Perrone, M G; Bolzacchini, E; Duane, M; Larsen, B R

2011-12-01

A novel approach for measuring vertical profiles of HCs and particle number concentrations was described and applied in the low troposphere over Milan (Italy) during typical spring and summer days. Particle profiles yielded nearly homogeneous concentrations below the mixing height, with level-to-ground concentration ratios of 92-97%, while HCs showed a more pronounced decrease (74-95%). Vertical mixing and photochemical loss of HCs were demonstrated to cause these gradients. Much lower concentrations were observed for the profiles above the mixing height, where the HC mixtures showed also a different composition, which was partially explained by the horizontal advection of air with HC sources different to those prevailing at the site. The application of pseudo-first order kinetics for reactions between HCs and the hydroxyl radical allowed for the estimation of the vertical mixing time scale in the order of 100 ± 20 min. Copyright © 2011 Elsevier Ltd. All rights reserved.

Spatiotemporal Variability in Observations of Urban Mixed-Layer Heights from Surface-based Lidar Systems during DISCOVER-AQ 2011

NASA Astrophysics Data System (ADS)

Lewis, J. R.; Banks, R. F.; Berkoff, T.; Welton, E. J.; Joseph, E.; Thompson, A. M.; Decola, P.; Hegarty, J. D.

2015-12-01

Accurate characterization of the planetary boundary layer height is crucial for numerical weather prediction, estimating pollution emissions and modeling air quality. More so, given the increasing trend in global urban populations, there is a growing need to improve our understanding of the urban boundary layer structure and development. The Deriving Information on Surface conditions from COlumn and VERtically resolved observations relevant to Air Quality (DISCOVER-AQ) 2011 field campaign, which took place in the Baltimore-Washington DC region, offered a unique opportunity to study boundary layer processes in an urban area using a geographically dense collection of surface-based lidar systems (see figure). Lidars use aerosols as tracers for atmospheric boundary layer dynamics with high vertical and temporal resolutions. In this study, we use data from two permanent Micropulse Lidar Network (MPLNET) sites and five field deployed Micropulse lidar (MPL) systems in order to observe spatiotemporal variations in the daytime mixed layer height. We present and compare lidar-derived retrievals of the mixed layer height using two different methods. The first method uses the wavelet covariance transform and a "fuzzy logic" attribution scheme in order to determine the mixed layer height. The second method uses an objective approach utilizing a time-adaptive extended Kalman filter. Independent measurements of the boundary layer height are obtained using profiles from ozonesonde launches at the Beltsville and Edgewood sites for comparison with lidar observations.

Workload of horses on a water treadmill: effect of speed and water height on oxygen consumption and cardiorespiratory parameters.

PubMed

Greco-Otto, Persephone; Bond, Stephanie; Sides, Raymond; Kwong, Grace P S; Bayly, Warwick; Léguillette, Renaud

2017-11-28

Despite the use of water treadmills (WT) in conditioning horses, the intensity of WT exercise has not been well documented. The workload on a WT is a function of water height and treadmill speed. Therefore, the purpose of this study was to determine the effects of these factors on workload during WT exercise. Fifteen client-owned Quarter Horses were used in a randomized, controlled study. Three belt speeds and three water heights (mid cannon, carpus and stifle), along with the control condition (dry treadmill, all three speeds), were tested. Measured outcomes were oxygen consumption (V̇O 2 ), ventilation (respiratory frequency, tidal volume (V T )), heart rate (HR), and blood lactate. An ergospirometry system was used to measure V̇O 2 and ventilation. Linear mixed effects models were used to examine the effects of presence or absence of water, water height and speed (as fixed effects) on measured outcomes. Water height and its interaction with speed had a significant effect on V̇O 2 , V T and HR, all peaking at the highest water level and speed (stifle at 1.39 m/s, median V̇O 2  = 16.70 ml/(kg.min), V T  = 6 L, HR = 69 bpm). Respiratory frequency peaked with water at the carpus at 1.39 m/s (median 49 breaths/min). For a given water height, the small increments in speed did not affect the measured outcomes. Post-exercise blood lactate concentration did not change. Varying water height and speed affects the workload associated with WT exercise. The conditions utilized in this study were associated with low intensity exercise. Water height had a greater impact on exercise intensity than speed.

Experimental Study of Static Contact-angle on Peak-like Microstructural Surfaces Produced by PIII Technology

NASA Astrophysics Data System (ADS)

Yang, Runhua; Yang, Lixin

2018-06-01

Plasma immersion ion implantation (PIII) was used to fabricate micro/nano structures on monocrystalline Si surfaces with different ratios of mixed gases (SF6/O2). The micro/nano structures on the surfaces of the sample were characterized by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results showed that with increasing ratio of mixed gases (SF6/O2), the height of the micro/nano structures first increased and then decreased. Contact-angle measurements indicated that the surfaces' micro/nano structures have an obvious effect on the contact-angle, and could cause a change in surface wettability. The theoretical analysis of contact-angle showed that the Wenzel and Cassie theories cannot predict the contact-angle of a roughened surface accurately, and should be corrected for practical applications using an actual model. Moreover, the contact-angle first increased and then decreased with increasing ratio of mixed gases (SF6/O2), which is in accordance with the change of the height of micro/nano structures.

Individual tree diameter increment model for managed even-aged stands of ponderosa pine throughout the western United States using a multilevel linear mixed effects model

Treesearch

Fabian C.C. Uzoh; William W. Oliver

2008-01-01

A diameter increment model is developed and evaluated for individual trees of ponderosa pine throughout the species range in the United States using a multilevel linear mixed model. Stochastic variability is broken down among period, locale, plot, tree and within-tree components. Covariates acting at tree and stand level, as breast height diameter, density, site index...

Red maple development in mixed hardwood stands in West Virginia

Treesearch

Brian Tift

1997-01-01

Recent evidence has shown that red maple (Acer rubrum) may become a more prominent species in eastern mixed hardwood stands. This study will examine the strategies used by red maple to reach dominant and codominant canopy positions on two different stands (one mesic and one drier). Stand level data such as dbh, height, crown class, height class, and...

Experimental investigation of crossflow jet mixing in a rectangular duct

NASA Technical Reports Server (NTRS)

Liscinsky, D. S.; True, B.; Holdeman, J. D.

1993-01-01

An experimental investigation of the mixing of nonreacting opposed rows of jets injected normal to a confined rectangular crossflow has been conducted. Planar Mie-scattering was used to measure the time-average concentration distribution of the jet fluid in planes perpendicular to the duct axis. The mixing effectiveness of round orifice injectors was measured as a function of orifice spacing and orifice diameter. Mixing effectiveness was determined using a spatial unmixedness parameter based on the variance of mean jet concentration distributions. Optimum mixing was obtained when the spacing-to-duct height ratio was inversely proportional to the square root of the jet-to-mainstream momentum-flux ratio. For opposed rows of round holes with centerlines inline, mixing was similar for blockages up to 75 percent. Lower levels of unmixedness were obtained as a function of downstream location when axial injection length was minimized. Mixing may be enhanced if orifice centerlines of opposed rows are staggered, but note that blockage must be less than 50 percent for this configuration.

Height, selected genetic markers and prostate cancer risk: results from the PRACTICAL consortium.

PubMed

Lophatananon, Artitaya; Stewart-Brown, Sarah; Kote-Jarai, Zsofia; Olama, Ali Amin Al; Garcia, Sara Benlloch; Neal, David E; Hamdy, Freddie C; Donovan, Jenny L; Giles, Graham G; Fitzgerald, Liesel M; Southey, Melissa C; Pharoah, Paul; Pashayan, Nora; Gronberg, Henrik; Wiklund, Fredrik; Aly, Markus; Stanford, Janet L; Brenner, Hermann; Dieffenbach, Aida K; Arndt, Volker; Park, Jong Y; Lin, Hui-Yi; Sellers, Thomas; Slavov, Chavdar; Kaneva, Radka; Mitev, Vanio; Batra, Jyotsna; Spurdle, Amanda; Clements, Judith A; Easton, Douglas; Eeles, Rosalind A; Muir, Kenneth

2017-08-22

Evidence on height and prostate cancer risk is mixed, however, recent studies with large data sets support a possible role for its association with the risk of aggressive prostate cancer. We analysed data from the PRACTICAL consortium consisting of 6207 prostate cancer cases and 6016 controls and a subset of high grade cases (2480 cases). We explored height, polymorphisms in genes related to growth processes as main effects and their possible interactions. The results suggest that height is associated with high-grade prostate cancer risk. Men with height >180 cm are at a 22% increased risk as compared to men with height <173 cm (OR 1.22, 95% CI 1.01-1.48). Genetic variants in the growth pathway gene showed an association with prostate cancer risk. The aggregate scores of the selected variants identified a significantly increased risk of overall prostate cancer and high-grade prostate cancer by 13% and 15%, respectively, in the highest score group as compared to lowest score group. There was no evidence of gene-environment interaction between height and the selected candidate SNPs.Our findings suggest a role of height in high-grade prostate cancer. The effect of genetic variants in the genes related to growth is seen in all cases and high-grade prostate cancer. There is no interaction between these two exposures.

Airborne Lidar measurements of aerosols, mixed layer heights, and ozone during the 1980 PEPE/NEROS summer field experiment

NASA Technical Reports Server (NTRS)

Browell, E. V.; Shipley, S. T.; Butler, C. F.; Ismail, S.

1985-01-01

A detailed summary of the NASA Ultraviolet Differential Absorption Lidar (UV DIAL) data archive obtained during the EPA Persistent Elevated Pollution Episode/Northeast Regional Oxidant Study (PEPE/NEROS) Summer Field Experiment Program (July through August 1980) is presented. The UV dial data set consists of remote measurements of mixed layer heights, aerosol backscatter cross sections, and sequential ozone profiles taken during 14 long-range flights onboard the NASA Wallops Flight Center Electra aircraft. These data are presented in graphic and tabular form, and they have been submitted to the PEPE/NEROS data archive on digital magnetic tape. The derivation of mixing heights and ozone profiles from UV Dial signals is discussed, and detailed intercomparisons with measurements obtained by in situ sensors are presented.

FORMAL UNCERTAINTY ANALYSIS OF A LAGRANGIAN PHOTOCHEMICAL AIR POLLUTION MODEL. (R824792)

EPA Science Inventory

This study applied Monte Carlo analysis with Latin
hypercube sampling to evaluate the effects of uncertainty
in air parcel trajectory paths, emissions, rate constants,
deposition affinities, mixing heights, and atmospheric stability
on predictions from a vertically...

Assessing values of air quality and visibility at risk from wildland fires.

Treesearch

Sue A. Ferguson; Steven J. McKay; David E. Nagel; Trent Piepho; Miriam L. Rorig; Casey Anderson; Lara Kellogg

2003-01-01

To assess values of air quality and visibility at risk from wildland fire in the United States, we generated a 40-year database that includes twice daily values of wind, mixing height, and a ventilation index that is the product of windspeed and mixing height. The database provides the first nationally consistent map of surface wind and ventilation index. In addition,...

Vehicle height and posture control of the electronic air suspension system using the hybrid system approach

NASA Astrophysics Data System (ADS)

Sun, Xiaoqiang; Cai, Yingfeng; Chen, Long; Liu, Yanling; Wang, Shaohua

2016-03-01

The electronic air suspension (EAS) system can improve ride comfort, fuel economy and handling safety of vehicles by adjusting vehicle height. This paper describes the development of a novel controller using the hybrid system approach to adjust the vehicle height (height control) and to regulate the roll and pitch angles of the vehicle body during the height adjustment process (posture control). The vehicle height adjustment system of EAS poses challenging hybrid control problems, since it features different discrete modes of operation, where each mode has an associated linear continuous-time dynamic. In this paper, we propose a novel approach to the modelling and controller design problem for the vehicle height adjustment system of EAS. The system model is described firstly in the hybrid system description language (HYSDEL) to obtain a mixed logical dynamical (MLD) hybrid model. For the resulting model, a hybrid model predictive controller is tuned to improve the vehicle height and posture tracking accuracy and to achieve the on-off statuses direct control of solenoid valves. The effectiveness and performance of the proposed approach are demonstrated by simulations and actual vehicle tests.

47 CFR 73.525 - TV Channel 6 protection.

Code of Federal Regulations, 2011 CFR

2011-10-01

.... (4) The maximum permissible effective radiated power (ERP) and antenna height may be adjusted for..., the maximum permissible vertically polarized ERP will be the maximum horizontally polarized ERP... it does not. (ii) If the applicant chooses to use mixed polarity, the permissible ERP is as follows...

Effect of water volume based on water absorption and mixing time on physical properties of tapioca starch – wheat composite bread

NASA Astrophysics Data System (ADS)

Prameswari, I. K.; Manuhara, G. J.; Amanto, B. S.; Atmaka, W.

2018-05-01

Tapioca starch application in bread processing change water absorption level by the dough, while sufficient mixing time makes the optimal water absorption. This research aims to determine the effect of variations in water volume and mixing time on physical properties of tapioca starch – wheat composite bread and the best method for the composite bread processing. This research used Complete Randomized Factorial Design (CRFD) with two factors: variations of water volume (111,8 ml, 117,4 ml, 123 ml) and mixing time (16 minutes, 17 minutes 36 seconds, 19 minutes 12 seconds). The result showed that water volume significantly affected on dough volume, bread volume and specific volume, baking expansion, and crust thickness. Mixing time significantly affected on dough volume and specific volume, bread volume and specific volume, baking expansion, bread height, and crust thickness. While the combination of water volume and mixing time significantly affected for all physical properties parameters except crust thickness.

On Displacement Height, from Classical to Practical Formulation: Stress, Turbulent Transport and Vorticity Considerations

NASA Astrophysics Data System (ADS)

Sogachev, Andrey; Kelly, Mark

2016-03-01

Displacement height ( d) is an important parameter in the simple modelling of wind speed and vertical fluxes above vegetative canopies, such as forests. Here we show that, aside from implicit definition through a (displaced) logarithmic profile, accepted formulations for d do not consistently predict flow properties above a forest. Turbulent transport can affect the displacement height, and is an integral part of what is called the roughness sublayer. We develop a more general approach for estimation of d, through production of turbulent kinetic energy and turbulent transport, and show how previous stress-based formulations for displacement height can be seen as simplified cases of a more general definition including turbulent transport. Further, we also give a simplified and practical form for d that is in agreement with the general approach, exploiting the concept of vortex thickness scale from mixing-layer theory. We assess the new and previous displacement height formulations by using flow statistics derived from the atmospheric boundary-layer Reynolds-averaged Navier-Stokes model SCADIS as well as from wind-tunnel observations, for different vegetation types and flow regimes in neutral conditions. The new formulations tend to produce smaller d than stress-based forms, falling closer to the classic logarithmically-defined displacement height. The new, more generally defined, displacement height appears to be more compatible with profiles of components of the turbulent kinetic energy budget, accounting for the combined effects of turbulent transport and shear production. The Coriolis force also plays a role, introducing wind-speed dependence into the behaviour of the roughness sublayer; this affects the turbulent transport, shear production, stress, and wind speed, as well as the displacement height, depending on the character of the forest. We further show how our practical (`mixing-layer') form for d matches the new turbulence-based relation, as well as correspondence to previous (stress-based) formulations.

Effect of Liquid Surface Turbulent Motion on the Vapor Condensation in a Mixing Tank

NASA Technical Reports Server (NTRS)

Lin, C. S.; Hasan, M. M.

1991-01-01

The effect of liquid surface motion on the vapor condensation in a tank mixed by an axial turbulent jet is numerically investigated. The average value (over the interface area) of the root-mean-squared (rms) turbulent velocity at the interface is shown to be linearly increasing with decreasing liquid height and increasing jet diameter for a given tank size. The average rms turbulent velocity is incorporated in Brown et al. (1990) condensation correlation to predict the condensation of vapor on a liquid surface. The results are in good agreement with available condensation data.

The Martian atmospheric planetary boundary layer stability, fluxes, spectra, and similarity

NASA Technical Reports Server (NTRS)

Tillman, James E.

1994-01-01

This is the first analysis of the high frequency data from the Viking lander and spectra of wind, in the Martian atmospheric surface layer, along with the diurnal variation of the height of the mixed surface layer, are calculated for the first time for Mars. Heat and momentum fluxes, stability, and z(sub O) are estimated for early spring, from a surface temperature model and from Viking Lander 2 temperatures and winds at 44 deg N, using Monin-Obukhov similarity theory. The afternoon maximum height of the mixed layer for these seasons and conditions is estimated to lie between 3.6 and 9.2 km. Estimations of this height is of primary importance to all models of the boundary layer and Martian General Circulation Models (GCM's). Model spectra for two measuring heights and three surface roughnesses are calculated using the depth of the mixed layer, and the surface layer parameters and flow distortion by the lander is also taken into account. These experiments indicate that z(sub O), probably lies between 1.0 and 3.0 cm, and most likely is closer to 1.0 cm. The spectra are adjusted to simulate aliasing and high frequency rolloff, the latter caused both by the sensor response and the large Kolmogorov length on Mars. Since the spectral models depend on the surface parameters, including the estimated surface temperature, their agreement with the calculated spectra indicates that the surface layer estimates are self consistent. This agreement is especially noteworthy in that the inertial subrange is virtually absent in the Martian atmosphere at this height, due to the large Kolmogorov length scale. These analyses extend the range of applicability of terrestrial results and demonstrate that it is possible to estimate the effects of severe aliasing of wind measurements, to produce a models which agree well with the measured spectra. The results show that similarity theory developed for Earth applies to Mars, and that the spectral models are universal.

Performance Investigation of A Mix Wind Turbine Using A Clutch Mechanism At Low Wind Speed Condition

NASA Astrophysics Data System (ADS)

Jamanun, M. J.; Misaran, M. S.; Rahman, M.; Muzammil, W. K.

2017-07-01

Wind energy is one of the methods that generates energy from sustainable resources. This technology has gained prominence in this era because it produces no harmful product to the society. There is two fundamental type of wind turbine are generally used this day which is Horizontal axis wind turbine (HAWT) and Vertical axis wind turbine (VAWT). The VAWT technology is more preferable compare to HAWT because it gives better efficiency and cost effectiveness as a whole. However, VAWT is known to have distinct disadvantage compared to HAWT; self-start ability and efficiency at low wind speed condition. Different solution has been proposed to solve these issues which includes custom design blades, variable angle of attack mechanism and mix wind turbine. A new type of clutch device was successfully developed in UMS to be used in a mix Savonius-Darrieus wind turbine configuration. The clutch system which barely audible when in operation compared to a ratchet clutch system interconnects the Savonius and Darrieus rotor; allowing the turbine to self-start at low wind speed condition as opposed to a standalone Darrieus turbine. The Savonius height were varied at three different size in order to understand the effect of the Savonius rotor to the mix wind turbine performance. The experimental result shows that the fabricated Savonius rotor show that the height of the Savonius rotor affecting the RPM for the turbine. The swept area (SA), aspect ratio (AR) and tip speed ratio (TSR) also calculated in this paper. The highest RPM recorded in this study is 90 RPM for Savonius rotor 0.22-meter height at 2.75 m/s. The Savonius rotor 0.22-meter also give the highest TSR for each range of speed from 0.75 m/s, 1.75 m/s and 2.75 m/s where it gives 1.03 TSR, 0.76 TSR, and 0.55 TSR.

Quantifying the relationship between PM2.5 concentration, visibility and planetary boundary layer height for long-lasting haze and fog-haze mixed events in Beijing

NASA Astrophysics Data System (ADS)

Luan, Tian; Guo, Xueliang; Guo, Lijun; Zhang, Tianhang

2018-01-01

Air quality and visibility are strongly influenced by aerosol loading, which is driven by meteorological conditions. The quantification of their relationships is critical to understanding the physical and chemical processes and forecasting of the polluted events. We investigated and quantified the relationship between PM2.5 (particulate matter with aerodynamic diameter is 2.5 µm and less) mass concentration, visibility and planetary boundary layer (PBL) height in this study based on the data obtained from four long-lasting haze events and seven fog-haze mixed events from January 2014 to March 2015 in Beijing. The statistical results show that there was a negative exponential function between the visibility and the PM2.5 mass concentration for both haze and fog-haze mixed events (with the same R2 of 0.80). However, the fog-haze events caused a more obvious decrease of visibility than that for haze events due to the formation of fog droplets that could induce higher light extinction. The PM2.5 concentration had an inversely linear correlation with PBL height for haze events and a negative exponential correlation for fog-haze mixed events, indicating that the PM2.5 concentration is more sensitive to PBL height in fog-haze mixed events. The visibility had positively linear correlation with the PBL height with an R2 of 0.35 in haze events and positive exponential correlation with an R2 of 0.56 in fog-haze mixed events. We also investigated the physical mechanism responsible for these relationships between visibility, PM2.5 concentration and PBL height through typical haze and fog-haze mixed event and found that a double inversion layer formed in both typical events and played critical roles in maintaining and enhancing the long-lasting polluted events. The variations of the double inversion layers were closely associated with the processes of long-wave radiation cooling in the nighttime and short-wave solar radiation reduction in the daytime. The upper-level stable inversion layer was formed by the persistent warm and humid southwestern airflow, while the low-level inversion layer was initially produced by the surface long-wave radiation cooling in the nighttime and maintained by the reduction of surface solar radiation in the daytime. The obvious descending process of the upper-level inversion layer induced by the radiation process could be responsible for the enhancement of the low-level inversion layer and the lowering PBL height, as well as high aerosol loading for these polluted events. The reduction of surface solar radiation in the daytime could be around 35 % for the haze event and 94 % for the fog-haze mixed event. Therefore, the formation and subsequent descending processes of the upper-level inversion layer should be an important factor in maintaining and strengthening the long-lasting severe polluted events, which has not been revealed in previous publications. The interactions and feedbacks between PM2.5 concentration and PBL height linked by radiation process caused a more significant and long-lasting deterioration of air quality and visibility in fog-haze mixed events. The interactions and feedbacks of all processes were particularly strong when the PM2.5 mass concentration was larger than 150-200 µg m-3.

Multiple jet study

NASA Technical Reports Server (NTRS)

Walker, R. E.; Kors, D. L.

1973-01-01

Test data is presented which allows determination of jet penetration and mixing of multiple cold air jets into a ducted subsonic heated mainstream flow. Jet-to-mainstream momentum flux ratios ranged from 6 to 60. Temperature profile data is presented at various duct locations up to 24 orifice diameters downstream of the plane of jet injection. Except for two configurations, all geometries investigated had a single row of constant diameter orifices located transverse to the main flow direction. Orifice size and spacing between orifices were varied. Both of these were found to have a significant effect on jet penetration and mixing. The best mixing of the hot and cold streams was achieved with duct height.

Internal friction and vulnerability of mixed alkali glasses.

PubMed

Peibst, Robby; Schott, Stephan; Maass, Philipp

2005-09-09

Based on a hopping model we show how the mixed alkali effect in glasses can be understood if only a small fraction c(V) of the available sites for the mobile ions is vacant. In particular, we reproduce the peculiar behavior of the internal friction and the steep fall ("vulnerability") of the mobility of the majority ion upon small replacements by the minority ion. The single and mixed alkali internal friction peaks are caused by ion-vacancy and ion-ion exchange processes. If c(V) is small, they can become comparable in height even at small mixing ratios. The large vulnerability is explained by a trapping of vacancies induced by the minority ions. Reasonable choices of model parameters yield typical behaviors found in experiments.

Aerosol lidar observations of atmospheric mixing in Los Angeles: Climatology and implications for greenhouse gas observations.

PubMed

Ware, John; Kort, Eric A; DeCola, Phil; Duren, Riley

2016-08-27

Atmospheric observations of greenhouse gases provide essential information on sources and sinks of these key atmospheric constituents. To quantify fluxes from atmospheric observations, representation of transport-especially vertical mixing-is a necessity and often a source of error. We report on remotely sensed profiles of vertical aerosol distribution taken over a 2 year period in Pasadena, California. Using an automated analysis system, we estimate daytime mixing layer depth, achieving high confidence in the afternoon maximum on 51% of days with profiles from a Sigma Space Mini Micropulse LiDAR (MiniMPL) and on 36% of days with a Vaisala CL51 ceilometer. We note that considering ceilometer data on a logarithmic scale, a standard method, introduces, an offset in mixing height retrievals. The mean afternoon maximum mixing height is 770 m Above Ground Level in summer and 670 m in winter, with significant day-to-day variance (within season σ = 220m≈30%). Taking advantage of the MiniMPL's portability, we demonstrate the feasibility of measuring the detailed horizontal structure of the mixing layer by automobile. We compare our observations to planetary boundary layer (PBL) heights from sonde launches, North American regional reanalysis (NARR), and a custom Weather Research and Forecasting (WRF) model developed for greenhouse gas (GHG) monitoring in Los Angeles. NARR and WRF PBL heights at Pasadena are both systematically higher than measured, NARR by 2.5 times; these biases will cause proportional errors in GHG flux estimates using modeled transport. We discuss how sustained lidar observations can be used to reduce flux inversion error by selecting suitable analysis periods, calibrating models, or characterizing bias for correction in post processing.

Response of a boreal forest to canopy opening: assessing vertical and lateral tree growth with multi-temporal lidar data.

PubMed

Vepakomma, Udayalakshmi; St-Onge, Benoit; Kneeshaw, Daniel

2011-01-01

Fine-scale height-growth response of boreal trees to canopy openings is difficult to measure from the ground, and there are important limitations in using stereophotogrammetry in defining gaps and determining individual crowns and height. However, precise knowledge on height growth response to different openings is critical for refining partial harvesting techniques. In this study, we question whether conifers and hardwoods respond equally in terms of sapling growth or lateral growth to openings. We also ask to what distance gaps affect tree growth into the forest. We use multi-temporal lidar to characterize tree/sapling height and lateral growth responses over five years to canopy openings and high resolution images to identify conifers and hardwoods. Species-class-wise height-growth patterns of trees/saplings in various neighborhood contexts were determined across a 6-km matrix of Canadian boreal mixed deciduous coniferous forests. We then use statistical techniques to probe how these growth responses vary by spatial location with respect to the gap edge. Results confirm that both mechanisms of gap closure contribute to the closing of canopies at a rate of 1.2% per annum. Evidence also shows that both hardwood and conifer gap edge trees have a similar lateral growth (average of 22 cm/yr) and similar rates of height growth irrespective of their location and initial height. Height growth of all saplings, however, was strongly dependent on their position within the gap and the size of the gap. Results suggest that hardwood and softwood saplings in gaps have greatest growth rates at distances of 0.5-2 m and 1.5-4 m from the gap edge and in openings smaller than 800 m2 and 250 m2, respectively. Gap effects on the height growth of trees in the intact forest were evident up to 30 m and 20 m from gap edges for hardwood and softwood overstory trees, respectively. Our results thus suggest that foresters should consider silvicultural techniques that create many small openings in mixed coniferous deciduous boreal forests to maximize the growth response of both residual and regenerating trees.

Observational Characteristics of the Tropopause Inversion Layer derived from CHAMP/GRACE Radio Occultations and MOZAIC Aircraft Data

NASA Astrophysics Data System (ADS)

Schmidt, T.; Cammas, J.; Heise, S.; Wickert, J.; Haser, A.

2010-12-01

In this study we discuss characteristics of the northern hemisphere (NH) midlatitude (40°N-60°N) tropopause inversion layer (TIL) based on two datasets. First, temperature measurements from GPS radio occultation data (CHAMP and GRACE) for the time interval 2001-2009 are used to exhibit seasonal properties of the TIL bottom height defined here as the height of the squared buoyancy frequency minimum N2 below the thermal tropopause, the TIL maximum height as the height of the N2 maximum above the tropopause and the TIL top height as the height of the temperature maximum above the tropopause. Mean values of the TIL bottom, TIL maximum and TIL top heights relative to the thermal tropopause for the NH midlatitudes are (-2.08±0.35) km, (0.52±0.10) km and (2.10±0.23) km, respectively. A seasonal cycle of the TIL bottom and TIL top height is observed with values closer to the thermal tropopause during summer. Secondly, high-resolution temperature and trace gas profile measurements onboard commercial aircrafts (MOZAIC program) from 2001-2008 for the NH midlatitude (40°N-60°N) region are used to characterize the TIL as a mixing layer around the tropopause. Mean TIL bottom, TIL maximum and TIL top heights based on the MOZAIC temperature (N2) measurements confirm the results from the GPS data, even though most of the MOZAIC profiles used here are available under cyclonic situations. Further, we demonstrate that the mixing ratio gradients of ozone (O3) and carbon monoxide (CO) are suitable parameters for characterizing the TIL structure. Using O3-CO correlations we also show that on average the highest mixing occurs in a layer less than 1 km above the thermal tropopause, i.e., within the TIL.

Deriving Surface NO2 Mixing Ratios from DISCOVER-AQ ACAM Observations: A Method to Assess Surface NO2 Spatial Variability

NASA Astrophysics Data System (ADS)

Silverman, M. L.; Szykman, J.; Chen, G.; Crawford, J. H.; Janz, S. J.; Kowalewski, M. G.; Lamsal, L. N.; Long, R.

2015-12-01

Studies have shown that satellite NO2 columns are closely related to ground level NO2 concentrations, particularly over polluted areas. This provides a means to assess surface level NO2 spatial variability over a broader area than what can be monitored from ground stations. The characterization of surface level NO2 variability is important to understand air quality in urban areas, emissions, health impacts, photochemistry, and to evaluate the performance of chemical transport models. Using data from the NASA DISCOVER-AQ campaign in Baltimore/Washington we calculate NO2 mixing ratios from the Airborne Compact Atmospheric Mapper (ACAM), through four different methods to derive surface concentration from column measurements. High spectral resolution lidar (HSRL) mixed layer heights, vertical P3B profiles, and CMAQ vertical profiles are used to scale ACAM vertical column densities. The derived NO2 mixing ratios are compared to EPA ground measurements taken at Padonia and Edgewood. We find similar results from scaling with HSRL mixed layer heights and normalized P3B vertical profiles. The HSRL mixed layer heights are then used to scale ACAM vertical column densities across the DISCOVER-AQ flight pattern to assess spatial variability of NO2 over the area. This work will help define the measurement requirements for future satellite instruments.

Genetic and environmental influences on growth.

PubMed

Rona, R J; Chinn, S

1995-01-01

To provide an overview of the factors associated with growth in primary school children in England and Scotland and to provide information about the secular trend of growth in the last 20 years. Representative English and Scottish samples and an English inner city sample. The study had a mixed longitudinal design from 1972 to 1994. Between 8000 and 10,000 children participated in each survey. Height was measured in at least 95% of the children in most surveys, and 75% to 85% of parents provided information about family background. Main results are based on published information. Multiple regression was used for most of the analyses. Parents' height, child's birth weight, mother's age at child's delivery, ethnic background and, in white children, family size are the only factors markedly associated with height. Variables that have traditionally been used to assess the possible effect of social conditions were generally not associated with height. The height increase was more marked in Scotland than England over the period 1972 to 1990, and the differences in height of children in the two countries is now minimal. Most factors cannot be neatly classified as purely genetic or environmental, but seem to indicate that genes are relatively more important. Social factors usually assessed in growth studies do not have an important effect on growth. The marked increase of height over time indicates that the environment and social conditions have allowed children to grow taller. Sibship size is the only factor that was shown to be related to the secular trend in growth.

Summer effects on body mass index (BMI) gain and growth patterns of American Indian children from kindergarten to first grade: a prospective study

PubMed Central

2011-01-01

Background Overweight and obesity are highly prevalent among American Indian children, especially those living on reservations. There is little scientific evidence about the effects of summer vacation on obesity development in children. The purpose of this study was to investigate the effects of summer vacation between kindergarten and first grade on growth in height, weight, and body mass index (BMI) for a sample of American Indian children. Methods Children had their height and weight measured in four rounds of data collection (yielded three intervals: kindergarten, summer vacation, and first grade) as part of a school-based obesity prevention trial (Bright Start) in a Northern Plains Indian Reservation. Demographic variables were collected at baseline from parent surveys. Growth velocities (Z-score units/year) for BMI, weight, and height were estimated and compared for each interval using generalized linear mixed models. Results The children were taller and heavier than median of same age counterparts. Height Z-scores were positively associated with increasing weight status category. The mean weight velocity during summer was significantly less than during the school year. More rapid growth velocity in height during summer than during school year was observed. Obese children gained less adjusted-BMI in the first grade after gaining more than their counterparts during the previous two intervals. No statistically significant interval effects were found for height and BMI velocities. Conclusions There was no indication of a significant summer effect on children's BMI. Rather than seasonal or school-related patterns, the predominant pattern indicated by weight-Z and BMI-Z velocities might be related to age or maturation. Trial registration Bright Start: Obesity Prevention in American Indian Children Clinical Trial Govt ID# NCT00123032 PMID:22192795

Assessment of Mixed-Layer Height Estimation from Single-wavelength Ceilometer Profiles.

PubMed

Knepp, Travis N; Szykman, James J; Long, Russell; Duvall, Rachelle M; Krug, Jonathan; Beaver, Melinda; Cavender, Kevin; Kronmiller, Keith; Wheeler, Michael; Delgado, Ruben; Hoff, Raymond; Berkoff, Timothy; Olson, Erik; Clark, Richard; Wolfe, Daniel; Van Gilst, David; Neil, Doreen

2017-01-01

Differing boundary/mixed-layer height measurement methods were assessed in moderately-polluted and clean environments, with a focus on the Vaisala CL51 ceilometer. This intercomparison was performed as part of ongoing measurements at the Chemistry And Physics of the Atmospheric Boundary Layer Experiment (CAPABLE) site in Hampton, Virginia and during the 2014 Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaign that took place in and around Denver, Colorado. We analyzed CL51 data that were collected via two different methods (BLView software, which applied correction factors, and simple terminal emulation logging) to determine the impact of data collection methodology. Further, we evaluated the STRucture of the ATmosphere (STRAT) algorithm as an open-source alternative to BLView (note that the current work presents an evaluation of the BLView and STRAT algorithms and does not intend to act as a validation of either). Filtering criteria were defined according to the change in mixed-layer height (MLH) distributions for each instrument and algorithm and were applied throughout the analysis to remove high-frequency fluctuations from the MLH retrievals. Of primary interest was determining how the different data-collection methodologies and algorithms compare to each other and to radiosonde-derived boundary-layer heights when deployed as part of a larger instrument network. We determined that data-collection methodology is not as important as the processing algorithm and that much of the algorithm differences might be driven by impacts of local meteorology and precipitation events that pose algorithm difficulties. The results of this study show that a common processing algorithm is necessary for LIght Detection And Ranging (LIDAR)-based MLH intercomparisons, and ceilometer-network operation and that sonde-derived boundary layer heights are higher (10-15% at mid-day) than LIDAR-derived mixed-layer heights. We show that averaging the retrieved MLH to 1-hour resolution (an appropriate time scale for a priori data model initialization) significantly improved correlation between differing instruments and differing algorithms.

Consistency evaluation of values of weight, height, and body mass index in Food Intake and Physical Activity of School Children: the quality control of data entry in the computerized system.

PubMed

Jesus, Gilmar Mercês de; Assis, Maria Alice Altenburg de; Kupek, Emil; Dias, Lizziane Andrade

2017-01-01

The quality control of data entry in computerized questionnaires is an important step in the validation of new instruments. The study assessed the consistency of recorded weight and height on the Food Intake and Physical Activity of School Children (Web-CAAFE) between repeated measures and against directly measured data. Students from the 2nd to the 5th grade (n = 390) had their weight and height directly measured and then filled out the Web-CAAFE. A subsample (n = 92) filled out the Web-CAAFE twice, three hours apart. The analysis included hierarchical linear regression, mixed linear regression model, to evaluate the bias, and intraclass correlation coefficient (ICC), to assess consistency. Univariate linear regression assessed the effect of gender, reading/writing performance, and computer/internet use and possession on residuals of fixed and random effects. The Web-CAAFE showed high values of ICC between repeated measures (body weight = 0.996, height = 0.937, body mass index - BMI = 0.972), and regarding the checked measures (body weight = 0.962, height = 0.882, BMI = 0.828). The difference between means of body weight, height, and BMI directly measured and recorded was 208 g, -2 mm, and 0.238 kg/m², respectively, indicating slight BMI underestimation due to underestimation of weight and overestimation of height. This trend was related to body weight and age. Height and weight data entered in the Web-CAAFE by children were highly correlated with direct measurements and with the repeated entry. The bias found was similar to validation studies of self-reported weight and height in comparison to direct measurements.

Planetary Boundary Layer from AERI and MPL

DOE Data Explorer

Sawyer, Virginia

2014-02-13

The distribution and transport of aerosol emitted to the lower troposphere is governed by the height of the planetary boundary layer (PBL), which limits the dilution of pollutants and influences boundary-layer convection. Because radiative heating and cooling of the surface strongly affect the PBL top height, it follows diurnal and seasonal cycles and may vary by hundreds of meters over a 24-hour period. The cap the PBL imposes on low-level aerosol transport makes aerosol concentration an effective proxy for PBL height: the top of the PBL is marked by a rapid transition from polluted, well-mixed boundary-layer air to the cleaner, more stratified free troposphere. Micropulse lidar (MPL) can provide much higher temporal resolution than radiosonde and better vertical resolution than infrared spectrometer (AERI), but PBL heights from all three instruments at the ARM SGP site are compared to one another for validation. If there is agreement among them, the higher-resolution remote sensing-derived PBL heights can accurately fill in the gaps left by the low frequency of radiosonde launches, and thus improve model parameterizations and our understanding of boundary-layer processes.

Habitat and landscape effects on abundance of Missouri's grassland birds

USGS Publications Warehouse

Jacobs, R.B.; Thompson, F.R.; Koford, Rolf R.; La Sorte, F.A.; Woodward, H.D.; Fitzgerald, J.A.

2012-01-01

Of 6 million ha of prairie that once covered northern and western Missouri, <36,500 ha remain, with planted, managed, and restored grasslands comprising most contemporary grasslands. Most grasslands are used as pasture or hayfields. Native grasses largely have been replaced by fescue (Festuca spp.) on most private lands (almost 7 million ha). Previously cropped fields set aside under the Conservation Reserve Program (CRP) varied from a mix of cool-season grasses and forbs, or mix of native warm-season grasses and forbs, to simple tall-grass monocultures. We used generalized linear mixed models and distance sampling to assess abundance of 8 species of breeding grassland birds on 6 grassland types commonly associated with farm practices in Missouri and located in landscapes managed for grassland-bird conservation. We selected Bird Conservation Areas (BCAs) for their high percentage of grasslands and grassland-bird species, and for <5% forest cover. We used an information-theoretic approach to assess the relationship between bird abundance and 6 grassland types, 3 measures of vegetative structure, and 2 landscape variables (% grassland and edge density within a 1-km radius). We found support for all 3 levels of model parameters, although there was less support for landscape than vegetation structure effects likely because we studied high-percentage-grassland landscapes (BCAs). Henslow's sparrow (Ammodramus henslowii) counts increased with greater percentage of grassland, vegetation height-density, litter depth, and shrub cover and lower edge density. Henslow's sparrow counts were greatest in hayed native prairie. Dickcissel (Spiza americana) counts increased with greater vegetation height-density and were greatest in planted CRP grasslands. Grasshopper sparrow (A. savannarum) counts increased with lower vegetation height, litter depth, and shrub cover. Based on distance modeling, breeding densities of Henslow's sparrow, dickcissel, and grasshopper sparrow in the 6 grassland types ranged 0.9-2.6, 1.4-3.2, and 0.1-1.5 birds/ha, respectively. We suggest different grassland types and structures (vegetation height, litter depth, shrub cover) are needed to support priority grassland-bird species in Missouri. ?? 2011 The Wildlife Society.

Habitat and landscape effects on abundance of Missouri's grassland birds

USGS Publications Warehouse

Jacobson, Robert B.; Thompson, Frank R.; Koford, Rolf R.; La Sorte, Frank A.; Woodward, Hope D.; Fitzgerald, Jane A.

2012-01-01

Of 6 million ha of prairie that once covered northern and western Missouri, <36,500 ha remain, with planted, managed, and restored grasslands comprising most contemporary grasslands. Most grasslands are used as pasture or hayfields. Native grasses largely have been replaced by fescue (Festuca spp.) on most private lands (almost 7 million ha). Previously cropped fields set aside under the Conservation Reserve Program (CRP) varied from a mix of cool-season grasses and forbs, or mix of native warm-season grasses and forbs, to simple tall-grass monocultures. We used generalized linear mixed models and distance sampling to assess abundance of 8 species of breeding grassland birds on 6 grassland types commonly associated with farm practices in Missouri and located in landscapes managed for grassland-bird conservation. We selected Bird Conservation Areas (BCAs) for their high percentage of grasslands and grassland-bird species, and for <5% forest cover. We used an information-theoretic approach to assess the relationship between bird abundance and 6 grassland types, 3 measures of vegetative structure, and 2 landscape variables (% grassland and edge density within a 1-km radius). We found support for all 3 levels of model parameters, although there was less support for landscape than vegetation structure effects likely because we studied high-percentage-grassland landscapes (BCAs). Henslow's sparrow (Ammodramus henslowii) counts increased with greater percentage of grassland, vegetation height-density, litter depth, and shrub cover and lower edge density. Henslow's sparrow counts were greatest in hayed native prairie. Dickcissel (Spiza americana) counts increased with greater vegetation height-density and were greatest in planted CRP grasslands. Grasshopper sparrow (A. savannarum) counts increased with lower vegetation height, litter depth, and shrub cover. Based on distance modeling, breeding densities of Henslow's sparrow, dickcissel, and grasshopper sparrow in the 6 grassland types ranged 0.9–2.6, 1.4–3.2, and 0.1–1.5 birds/ha, respectively. We suggest different grassland types and structures (vegetation height, litter depth, shrub cover) are needed to support priority grassland-bird species in Missouri.

Defense Coastal/Estuarine Research Program (DCERP1)

DTIC Science & Technology

2013-05-10

also showed that the greater the mixing height and ventilation rate, the lower the PM2.5 concentrations, which points to the diluting effect of these... ventilation rate, the lower the resulting PM2.5 concentrations, which points to the diluting effects of these parameters on ambient PM2.5 concentration...and discharge (New River, tributary creeks) Chemistry: Nutrients, salinity, pH, oxygen , temperature (New River, NRE, tributary creeks) Sedimentology

Aerosol lidar observations of atmospheric mixing in Los Angeles: Climatology and implications for greenhouse gas observations

NASA Astrophysics Data System (ADS)

Ware, John; Kort, Eric A.; DeCola, Phil; Duren, Riley

2016-08-01

Atmospheric observations of greenhouse gases provide essential information on sources and sinks of these key atmospheric constituents. To quantify fluxes from atmospheric observations, representation of transport—especially vertical mixing—is a necessity and often a source of error. We report on remotely sensed profiles of vertical aerosol distribution taken over a 2 year period in Pasadena, California. Using an automated analysis system, we estimate daytime mixing layer depth, achieving high confidence in the afternoon maximum on 51% of days with profiles from a Sigma Space Mini Micropulse LiDAR (MiniMPL) and on 36% of days with a Vaisala CL51 ceilometer. We note that considering ceilometer data on a logarithmic scale, a standard method, introduces, an offset in mixing height retrievals. The mean afternoon maximum mixing height is 770 m Above Ground Level in summer and 670 m in winter, with significant day-to-day variance (within season σ = 220m≈30%). Taking advantage of the MiniMPL's portability, we demonstrate the feasibility of measuring the detailed horizontal structure of the mixing layer by automobile. We compare our observations to planetary boundary layer (PBL) heights from sonde launches, North American regional reanalysis (NARR), and a custom Weather Research and Forecasting (WRF) model developed for greenhouse gas (GHG) monitoring in Los Angeles. NARR and WRF PBL heights at Pasadena are both systematically higher than measured, NARR by 2.5 times; these biases will cause proportional errors in GHG flux estimates using modeled transport. We discuss how sustained lidar observations can be used to reduce flux inversion error by selecting suitable analysis periods, calibrating models, or characterizing bias for correction in post processing.

An Algorithm for the Vertical Structure of Aerosol Extinction in the Lowest Kilometer of the Atmosphere: Rev. 1

DTIC Science & Technology

2017-11-01

inversion layer, or the well-mixed boundary layer. In such cases a low cloud ceiling is not present. In all instances the atmospheric extinction profiles...height, radiation fog depth, or the inversion layer height. The visibility regions and several representative vertical profiles of extinction are...the coefficient B can be found by B = ln(D/A) . (2) The coefficient B is sometimes a function of the cloud ceiling height, the inversion layer height

Effect of empty fruit bunch to the accumulated plant height, mass of fresh and dry weight of tomato plant treated with organic and inorganic fertilizer

NASA Astrophysics Data System (ADS)

Elias, Aishah; Mutalib, Sahilah Abd.; Mustapha, Wan Aida Wan

2016-11-01

A glasshouse experiment was conducted to study the effect of different type of compost and fertilizers on the growth of tomato (Lycopersicon esculentum). The experiment consisted of sixteen treatments. Compost of Empty fruit bunch (EFB) and cow dung is mixed in the ratio of 3:2:1 (soil: compost: sand) and put into 25.4 mm2 polyethylene bag. Organic fertilizer of 10 ml were added twice a week, while inorganic fertilizer was applied at the rate of 3 g per polyethylene bag of soil three weeks after sowing. Treatment without fertilizer application was established as a control. The treatments were laid in a split-split plot design with three replications. Plant growth was assessed using accumulating plant height, fresh weight and dry weight. The application of organic plus inorganic fertilizer had significant effects on plant height. The application of organic fertilizer combination with cow dung gave significant difference to plant mass (fresh and dry). The data obtained from these treatments were significantly higher than the data obtained from the control (without fertilizer). In conclusion, the type of compost did not gave significant difference towards plant height while it only gave significant difference towards plant mass.

Socioeconomic Status and Longitudinal Lung Function of Healthy Mexican Children

PubMed Central

Martínez-Briseño, David; Fernández-Plata, Rosario; Gochicoa-Rangel, Laura; Torre-Bouscoulet, Luis; Rojas-Martínez, Rosalba; Mendoza-Alvarado, Laura; García-Sancho, Cecilia; Pérez-Padilla, Rogelio

2015-01-01

Introduction Our aim was to estimate the longitudinal effect of Socioeconomic status (SES) on lung function growth of Mexican children and adolescents. Materials and Methods A cohort of Mexican children in third grade of primary school was followed with spirometry twice a year for 6 years through secondary school. Multilevel mixed-effects lineal models were fitted for the spirometric variables of 2,641 respiratory-healthy Mexican children. Monthly family income (in 2002 U.S. dollars [USD]) and parents’ years completed at school were used as proxies of SES. Results Individuals with higher SES tended to have greater height for age, and smaller sitting height/standing height and crude lung function. For each 1-year increase of parents’ schooling, Forced expiratory volume in 1 sec (FEV1) and Forced vital capacity (FVC) increased 8.5 (0.4%) and 10.6 mL (0.4%), respectively (p <0.05) when models were adjusted for gender. Impact of education on lung function was reduced drastically or abolished on adjusting by anthropometric variables and ozone. Conclusions Higher parental schooling and higher monthly family income were associated with higher lung function in healthy Mexican children, with the majority of the effect likely due to the increase in height-for-age. PMID:26379144

Laboratory simulations of the atmospheric mixed-layer in flow over complex topography

EPA Science Inventory

A laboratory study of the influence of complex terrain on the interface between a well-mixed boundary layer and an elevated stratified layer was conducted in the towing-tank facility of the U.S. Environmental Protection Agency. The height of the mixed layer in the daytime boundar...

Chemical transport models: the combined non-local diffusion and mixing schemes, and calculation of in-canopy resistance for dry deposition fluxes.

PubMed

Mihailovic, Dragutin T; Alapaty, Kiran; Podrascanin, Zorica

2009-03-01

Improving the parameterization of processes in the atmospheric boundary layer (ABL) and surface layer, in air quality and chemical transport models. To do so, an asymmetrical, convective, non-local scheme, with varying upward mixing rates is combined with the non-local, turbulent, kinetic energy scheme for vertical diffusion (COM). For designing it, a function depending on the dimensionless height to the power four in the ABL is suggested, which is empirically derived. Also, we suggested a new method for calculating the in-canopy resistance for dry deposition over a vegetated surface. The upward mixing rate forming the surface layer is parameterized using the sensible heat flux and the friction and convective velocities. Upward mixing rates varying with height are scaled with an amount of turbulent kinetic energy in layer, while the downward mixing rates are derived from mass conservation. The vertical eddy diffusivity is parameterized using the mean turbulent velocity scale that is obtained by the vertical integration within the ABL. In-canopy resistance is calculated by integration of inverse turbulent transfer coefficient inside the canopy from the effective ground roughness length to the canopy source height and, further, from its the canopy height. This combination of schemes provides a less rapid mass transport out of surface layer into other layers, during convective and non-convective periods, than other local and non-local schemes parameterizing mixing processes in the ABL. The suggested method for calculating the in-canopy resistance for calculating the dry deposition over a vegetated surface differs remarkably from the commonly used one, particularly over forest vegetation. In this paper, we studied the performance of a non-local, turbulent, kinetic energy scheme for vertical diffusion combined with a non-local, convective mixing scheme with varying upward mixing in the atmospheric boundary layer (COM) and its impact on the concentration of pollutants calculated with chemical and air-quality models. In addition, this scheme was also compared with a commonly used, local, eddy-diffusivity scheme. Simulated concentrations of NO2 by the COM scheme and new parameterization of the in-canopy resistance are closer to the observations when compared to those obtained from using the local eddy-diffusivity scheme. Concentrations calculated with the COM scheme and new parameterization of in-canopy resistance, are in general higher and closer to the observations than those obtained by the local, eddy-diffusivity scheme (on the order of 15-22%). To examine the performance of the scheme, simulated and measured concentrations of a pollutant (NO2) were compared for the years 1999 and 2002. The comparison was made for the entire domain used in simulations performed by the chemical European Monitoring and Evaluation Program Unified model (version UNI-ACID, rv2.0) where schemes were incorporated.

Comparison of mixed layer heights from airborne high spectral resolution lidar, ground-based measurements, and the WRF-Chem model during CalNex and CARES

NASA Astrophysics Data System (ADS)

Scarino, A. J.; Obland, M. D.; Fast, J. D.; Burton, S. P.; Ferrare, R. A.; Hostetler, C. A.; Berg, L. K.; Lefer, B.; Haman, C.; Hair, J. W.; Rogers, R. R.; Butler, C.; Cook, A. L.; Harper, D. B.

2013-05-01

The California Research at the Nexus of Air Quality and Climate Change (CalNex) and Carbonaceous Aerosol and Radiative Effects Study (CARES) field campaigns during May and June 2010 provided a data set appropriate for studying characteristics of the planetary boundary layer (PBL). The NASA Langley Research Center (LaRC) airborne High Spectral Resolution Lidar (HSRL) was deployed to California onboard the NASA LaRC B-200 aircraft to aid in characterizing aerosol properties during these two field campaigns. Measurements of aerosol extinction (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm) profiles during 31 flights, many in coordination with other research aircraft and ground sites, constitute a diverse data set for use in characterizing the spatial and temporal distribution of aerosols, as well as the depth and variability of the daytime mixed layer (ML), which is a subset within the PBL. This work illustrates the temporal and spatial variability of the ML in the vicinity of Los Angeles and Sacramento, CA. ML heights derived from HSRL measurements are compared to PBL heights derived from radiosonde profiles, ML heights measured from ceilometers, and simulated PBL heights from the Weather Research and Forecasting Chemistry (WRF-Chem) community model. Comparisons between the HSRL ML heights and the radiosonde profiles in Sacramento result in a correlation coefficient value (R) of 0.93 (root-mean-square (RMS) difference of 157 m and bias difference (HSRL - radiosonde) of 57 m). HSRL ML heights compare well with those from the ceilometer in the LA Basin with an R of 0.89 (RMS difference of 108 m and bias difference (HSRL - Ceilometer) of -9.7 m) for distances of up to 30 km between the B-200 flight track and the ceilometer site. Simulated PBL heights from WRF-Chem were compared with those obtained from all flights for each campaign, producing an R of 0.58 (RMS difference of 604 m and a bias difference (WRF-Chem - HSRL) of -157 m) for CalNex and 0.59 (RMS difference of 689 m and a bias difference (WRF-Chem - HSRL) of 220 m) for CARES. Aerosol backscatter simulations are also available from WRF-Chem and are compared to those from HSRL to examine differences among the methods used to derive ML heights.

Effect of shock interactions on mixing layer between co-flowing supersonic flows in a confined duct

NASA Astrophysics Data System (ADS)

Rao, S. M. V.; Asano, S.; Imani, I.; Saito, T.

2018-03-01

Experiments are conducted to observe the effect of shock interactions on a mixing layer generated between two supersonic streams of Mach number M _{1} = 1.76 and M _{2} = 1.36 in a confined duct. The development of this mixing layer within the duct is observed using high-speed schlieren and static pressure measurements. Two-dimensional, compressible Reynolds averaged Navier-Stokes equations are solved using the k-ω SST turbulence model in Fluent. Further, adverse pressure gradients are imposed by placing inserts of small (<7% of duct height) but finite (> boundary layer thickness) thickness on the walls of the test section. The unmatched pressures cause the mixing layer to bend and lead to the formation of shock structures that interact with the mixing layer. The mixing layer growth rate is found to increase after the shock interaction (nearly doubles). The strongest shock is observed when a wedge insert is placed in the M _{2} flow. This shock interacts with the mixing layer exciting flow modes that produce sinusoidal flapping structures which enhance the mixing layer growth rate to the maximum (by 1.75 times). Shock fluctuations are characterized, and it is observed that the maximum amplitude occurs when a wedge insert is placed in the M _{2} flow.

Numerical investigation on layout optimization of obstacles in a three-dimensional passive micromixer.

PubMed

Chen, Xueye; Zhao, Zhongyi

2017-04-29

This paper aims at layout optimization design of obstacles in a three-dimensional T-type micromixer. Numerical analysis shows that the direction of flow velocity change constantly due to the obstacles blocking, which produces the chaotic convection and increases species mixing effectively. The orthogonal experiment method was applied for determining the effects of some key parameters on mixing efficiency. The weights in the order are: height of obstacles > geometric shape > symmetry = number of obstacles. Based on the optimized results, a multi-units obstacle micromixer was designed. Compared with T-type micromixer, the multi-units obstacle micromixer is more efficient, and more than 90% mixing efficiency were obtained for a wide range of peclet numbers. It can be demonstrated that the presented optimal design method of obstacles layout in three-dimensional microchannels is a simple and effective technology to improve species mixing in microfluidic devices. The obstacles layout methodology has the potential for applications in chemical engineering and bioengineering. Copyright © 2017 Elsevier B.V. All rights reserved.

Bed mixing and leachate recycling strategies to overcome pressure drop buildup in the biofiltration of hydrogen sulfide.

PubMed

Roshani, Babak; Torkian, Ayoob; Aslani, Hasan; Dehghanzadeh, Reza

2012-04-01

The effects of leachate recycling and bed mixing on the removal rate of H(2)S from waste gas stream were investigated. The experimental setup consisted of an epoxy-coated three-section biofilter with an ID of 8 cm and effective bed height of 120 cm. Bed material consisted of municipal solid waste compost and PVC bits with an overall porosity of 54% and dry bulk density of 0.456 g cm(-3). Leachate recycling had a positive effect of increasing elimination capacity (EC) up to 21 g S m(-3) bed h(-1) at recycling rates of 75 ml d(-1), but in the bed mixing period EC declined to 8 g S m(-3) bed h(-1). Pressure drop had a range of zero to 18 mm H(2)O m(-1) in the course of leachate recycling. Accumulation of sulfur reduced removal efficiency and increased pressure drop up to 110 mm H(2)O m(-1) filter during the bed mixing stage. Copyright © 2012 Elsevier Ltd. All rights reserved.

Patterns of Growth after Kidney Transplantation among Children with ESRD

PubMed Central

Franke, Doris; Thomas, Lena; Steffens, Rena; Pavičić, Leo; Gellermann, Jutta; Froede, Kerstin; Querfeld, Uwe; Haffner, Dieter

2015-01-01

Background and objectives Poor linear growth is a frequent complication of CKD. This study evaluated the effect of kidney transplantation on age-related growth of linear body segments in pediatric renal transplant recipients who were enrolled from May 1998 until August 2013 in the CKD Growth and Development observational cohort study. Design, setting, participants, & measurements Linear growth (height, sitting height, arm and leg lengths) was prospectively investigated during 1639 annual visits in a cohort of 389 pediatric renal transplant recipients ages 2–18 years with a median follow-up of 3.4 years (interquartile range, 1.9–5.9 years). Linear mixed-effects models were used to assess age-related changes and predictors of linear body segments. Results During early childhood, patients showed lower mean SD scores (SDS) for height (−1.7) and a markedly elevated sitting height index (ratio of sitting height to total body height) compared with healthy children (1.6 SDS), indicating disproportionate stunting (each P<0.001). After early childhood a sustained increase in standardized leg length and a constant decrease in standardized sitting height were noted (each P<0.001), resulting in significant catch-up growth and almost complete normalization of sitting height index by adult age (0.4 SDS; P<0.01 versus age 2–4 years). Time after transplantation, congenital renal disease, bone maturation, steroid exposure, degree of metabolic acidosis and anemia, intrauterine growth restriction, and parental height were significant predictors of linear body dimensions and body proportions (each P<0.05). Conclusions Children with ESRD present with disproportionate stunting. In pediatric renal transplant recipients, a sustained increase in standardized leg length and total body height is observed from preschool until adult age, resulting in restoration of body proportions in most patients. Reduction of steroid exposure and optimal metabolic control before and after transplantation are promising measures to further improve growth outcome. PMID:25352379

Patterns of growth after kidney transplantation among children with ESRD.

PubMed

Franke, Doris; Thomas, Lena; Steffens, Rena; Pavičić, Leo; Gellermann, Jutta; Froede, Kerstin; Querfeld, Uwe; Haffner, Dieter; Živičnjak, Miroslav

2015-01-07

Poor linear growth is a frequent complication of CKD. This study evaluated the effect of kidney transplantation on age-related growth of linear body segments in pediatric renal transplant recipients who were enrolled from May 1998 until August 2013 in the CKD Growth and Development observational cohort study. Linear growth (height, sitting height, arm and leg lengths) was prospectively investigated during 1639 annual visits in a cohort of 389 pediatric renal transplant recipients ages 2-18 years with a median follow-up of 3.4 years (interquartile range, 1.9-5.9 years). Linear mixed-effects models were used to assess age-related changes and predictors of linear body segments. During early childhood, patients showed lower mean SD scores (SDS) for height (-1.7) and a markedly elevated sitting height index (ratio of sitting height to total body height) compared with healthy children (1.6 SDS), indicating disproportionate stunting (each P<0.001). After early childhood a sustained increase in standardized leg length and a constant decrease in standardized sitting height were noted (each P<0.001), resulting in significant catch-up growth and almost complete normalization of sitting height index by adult age (0.4 SDS; P<0.01 versus age 2-4 years). Time after transplantation, congenital renal disease, bone maturation, steroid exposure, degree of metabolic acidosis and anemia, intrauterine growth restriction, and parental height were significant predictors of linear body dimensions and body proportions (each P<0.05). Children with ESRD present with disproportionate stunting. In pediatric renal transplant recipients, a sustained increase in standardized leg length and total body height is observed from preschool until adult age, resulting in restoration of body proportions in most patients. Reduction of steroid exposure and optimal metabolic control before and after transplantation are promising measures to further improve growth outcome. Copyright © 2015 by the American Society of Nephrology.

Walking variations in healthy women wearing high-heeled shoes: Shoe size and heel height effects.

PubMed

Di Sipio, Enrica; Piccinini, Giulia; Pecchioli, Cristiano; Germanotta, Marco; Iacovelli, Chiara; Simbolotti, Chiara; Cruciani, Arianna; Padua, Luca

2018-05-03

The use of high heels is widespread in modern society in professional and social contests. Literature showed that wearing high heels can produce injurious effects on several structures from the toes to the pelvis. No studies considered shoe length as an impacting factor on walking with high heels. The aim of this study is to evaluate walking parameters in young healthy women wearing high heels, considering not only the heel height but also the foot/shoe size. We evaluate spatio-temporal, kinematic and kinetic data, collected using a 8-camera motion capture system, in a sample of 21 healthy women in three different walking conditions: 1) barefoot, 2) wearing 12 cm high heel shoes independently from shoe size, and 3) wearing shoes with heel height based on shoe size, keeping the ankles' plantar flexion angle constant. The main outcome measures were: spatio-temporal parameters, gait harmony measurement, range of motion, flexion and extension maximal values, power and moment of lower limb joints. Comparing the three walking conditions, the Mixed Anova test, showed significant differences between both high heeled conditions (variable and constant height) and barefoot in spatio-temporal, kinematic and kinetic parameters. Regardless of the shoe size, both heeled conditions presented a similar gait pattern and were responsible for negative effects on walking parameters. Considering our results and the relevance of the heel height, further studies are needed to identify a threshold, over which it is possible to observe that wearing high heels could cause harmful effects, independently from the foot/shoe size. Copyright © 2018 Elsevier B.V. All rights reserved.

A unified view of convective transports by stratocumulus clouds, shallow cumulus clouds, and deep convection

NASA Technical Reports Server (NTRS)

Randall, David A.

1990-01-01

A bulk planetary boundary layer (PBL) model was developed with a simple internal vertical structure and a simple second-order closure, designed for use as a PBL parameterization in a large-scale model. The model allows the mean fields to vary with height within the PBL, and so must address the vertical profiles of the turbulent fluxes, going beyond the usual mixed-layer assumption that the fluxes of conservative variables are linear with height. This is accomplished using the same convective mass flux approach that has also been used in cumulus parameterizations. The purpose is to show that such a mass flux model can include, in a single framework, the compensating subsidence concept, downgradient mixing, and well-mixed layers.

New Models for Predicting Diameter at Breast Height from Stump Dimensions

Treesearch

James A. Westfall

2010-01-01

Models to predict dbh from stump dimensions are presented for 18 species groups. Data used to fit the models were collected across thirteen states in the northeastern United States. Primarily because of the presence of multiple measurements from each tree, a mixed-effects modeling approach was used to account for the lack of independence among observations. The...

Height-growth response to climatic changes differs among populations of Douglas-fir: A novel analysis of historic data

Treesearch

Laura P. Leites; Andrew P. Robinson; Gerald E. Rehfeldt; John D. Marshall; Nicholas L. Crookston

2012-01-01

Projected climate change will affect existing forests, as substantial changes are predicted to occur during their life spans. Species that have ample intraspecific genetic differentiation, such as Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), are expected to display population-specific growth responses to climate change. Using a mixed-effects modeling approach,...

Deer exclusion effects on understory development following partial cutting in a Pennsylvania oak stand

Treesearch

Larry H. McCormick; John W. Groninger; Kathy A. Penrod; Todd E. Ristau

1993-01-01

Forty fenced and unfenced paired plots were established in a central Pennsylvania mixed oak stand following an improvement shelterwood cut to assess the influence of deer exclusion on the establishment and development of understory vegetation during the first four years following cutting. Exclusion of deer increased the abundance and height growth of woody regeneration...

A mixed-effects model for the dbh-height relationship of shortleaf pine (Pinus echinata Mill.)

Treesearch

Chakra B. Budhathoki; Thomas B. Lynch; James M. Guldin

2008-01-01

Individual tree measurements were available from over 200 permanent plots established during 1985-1987 and later remeasured in naturally regenerated even-aged stands of shortleaf pine (Pinus echinata Mill.) in western Arkansas and eastern Oklahoma. The objective of this study was to model shortleaf pine growth in natural stands for the region. As a...

Improving ergonomics in milking parlors: empirical findings for optimal working heights in five milking parlor types.

PubMed

Cockburn, M; Savary, P; Kauke, M; Schick, M; Hoehne-Hückstädt, U; Hermanns, I; Ellegast, R

2015-02-01

Milking postures have shifted from seated milking in tethered stalls to milking in a standing position in parlors. However, the musculoskeletal workload of dairy farmers remains high. Previous studies have shown that different working heights affect ergonomics, but they could not objectively evaluate and quantify the workload. The aim of the present study was to assess the effect of working height in different milking parlor types on the milker's workload during the task of attaching milking clusters. Computer-assisted recording and long-term analysis of movements were used to record positions of joints and body regions while performing certain tasks in terms of angular degrees of joints (ADJ) according to the neutral zero method. The 5th, 50th, and 95th percentiles described the distribution of angular degree values measured for each joint. The ADJ were evaluated according to international standards and other scientific literature on the issue to assess the muscular load. The workload was compared between 5 parlor types (auto tandem, herringbone 30°, herringbone 50°, parallel, and rotary) on 15 farms with 2 subjects per parlor and 1 milking period per subject. The working height was defined as a coefficient based on the milker's body height, the floor level, and the cow's udder height. The data recorded during the attachment task were analyzed using generalized linear mixed-effects models taking into account the hierarchical experimental design. The results indicated that the interaction of the cow's udder height, the milker's body height, and the parlor type had a larger effect on ergonomics than each parameter had independently. The interaction was significant in at least 1 of the 3 percentiles in 28 out of 31 ADJ. The postural differences between parlor types, however, were minor. A milking health formula was created to calculate the ideal depth of pit by considering the parlor type, the milker's height, and the mean herd udder height. This formula can be used to develop individual recommendations for future parlor construction. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

An examination of environmental correlates with childhood height-for-age in Ghana.

PubMed

Nikoi, Ebenezer; Anthamatten, Peter

2013-01-01

The relationship between a child's environment and nutritional status is difficult to examine yet could offer an important guide to policy. The objective of the present work was to examine individual and environmental correlates with childhood height-for-age in Ghana. Data were derived from the 2008 MEASURE Demographic and Health Survey in Ghana, the 2000 Ghana Population and Housing Census, and the World Wide Fund for Nature's eco-regions database. A generalized linear mixed regression model was used to estimate the effects of individual and environmental correlates on height-for-age. The study examined 2225 Ghanaian children aged 0-59 months. The setting was all districts in Ghana for the year 2008. After accounting for individual characteristics of children, mothers and households, height-for-age was significantly associated with population density. Other significantly associated variables in the final model were the age of the child, vaccination status, the size of the child at birth, months of breast-feeding, mother's BMI, whether the child's mother had health insurance and wealth quintile. In addition to a number of characteristics of the children and their households, the social milieu is important to understanding differences in height-for-age among children in Ghana. The biophysical environment was not associated with height-for-age.

Pulse Jet Mixing Tests With Noncohesive Solids

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

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.

2012-02-17

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid. The tests were conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants, and the test data were used to develop models predicting two measures of mixing performance for full-scale WTP vessels. The models predict the cloud height (the height to which solids will be lifted by the PJM action) and the critical suspension velocity (the minimum velocity needed to ensure allmore » solids are suspended off the floor, though not fully mixed). From the cloud height, the concentration of solids at the pump inlet can be estimated. The predicted critical suspension velocity for lifting all solids is not precisely the same as the mixing requirement for 'disturbing' a sufficient volume of solids, but the values will be similar and closely related. These predictive models were successfully benchmarked against larger scale tests and compared well with results from computational fluid dynamics simulations. The application of the models to assess mixing in WTP vessels is illustrated in examples for 13 distinct designs and selected operational conditions. The values selected for these examples are not final; thus, the estimates of performance should not be interpreted as final conclusions of design adequacy or inadequacy. However, this work does reveal that several vessels may require adjustments to design, operating features, or waste feed properties to ensure confidence in operation. The models described in this report will prove to be valuable engineering tools to evaluate options as designs are finalized for the WTP. Revision 1 refines data sets used for model development and summarizes models developed since the completion of Revision 0.« less

Realization of a passive micromixer using herringbone structure

NASA Astrophysics Data System (ADS)

Whulanza, Yudan; Utomo, Muhammad S.; Hilman, Adam

2018-02-01

Micromixing is an important research area for a variety of applications in sensing and diagnostics. In this paper, we are trying to develop an overall understanding of the process of mixing by allowing two fluid flows to flow through various asymmetrical structures. We have successfully realized and compared the performance of different passive micromixer designs based on the idea of staggered herringbone micromixer. The herringbone structure is expected to affect the flow rate. We design few microchannels using varieties on velocity, height and distance between herringbone. The layout of the structure is based on the staggered herringbone bilayers where the layer is positioned on the bottom wall of the microchannel. From simulation and experiment, it is known that the height of the channel and herringbone structure affect the flow, and the most effective height of the main channel and herringbone structure is 0.3 and 0.14 mm (2:1 ratio).

Experimental Measurements of Heat Transfer through a Lunar Regolith Simulant in a Vibro-Fluidized Reactor Oven

NASA Technical Reports Server (NTRS)

Nayagam, Vedha; Berger, Gordon M.; Sacksteder, Kurt R.; Paz, Aaron

2012-01-01

Extraction of mission consumable resources such as water and oxygen from the planetary environment provides valuable reduction in launch-mass and potentially extends the mission duration. Processing of lunar regolith for resource extraction necessarily involves heating and chemical reaction of solid material with processing gases. Vibrofluidization is known to produce effective mixing and control of flow within granular media. In this study we present experimental results for vibrofluidized heat transfer in lunar regolith simulants (JSC-1 and JSC-1A) heated up to 900 C. The results show that the simulant bed height has a significant influence on the vibration induced flow field and heat transfer rates. A taller bed height leads to a two-cell circulation pattern whereas a single-cell circulation was observed for a shorter height. Lessons learned from these test results should provide insight into efficient design of future robotic missions involving In-Situ Resource Utilization.

Assessment of Mixed-Layer Height Estimation from Single-wavelength Ceilometer Profiles

PubMed Central

Knepp, Travis N.; Szykman, James J.; Long, Russell; Duvall, Rachelle M.; Krug, Jonathan; Beaver, Melinda; Cavender, Kevin; Kronmiller, Keith; Wheeler, Michael; Delgado, Ruben; Hoff, Raymond; Berkoff, Timothy; Olson, Erik; Clark, Richard; Wolfe, Daniel; Van Gilst, David; Neil, Doreen

2018-01-01

Differing boundary/mixed-layer height measurement methods were assessed in moderately-polluted and clean environments, with a focus on the Vaisala CL51 ceilometer. This intercomparison was performed as part of ongoing measurements at the Chemistry And Physics of the Atmospheric Boundary Layer Experiment (CAPABLE) site in Hampton, Virginia and during the 2014 Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) field campaign that took place in and around Denver, Colorado. We analyzed CL51 data that were collected via two different methods (BLView software, which applied correction factors, and simple terminal emulation logging) to determine the impact of data collection methodology. Further, we evaluated the STRucture of the ATmosphere (STRAT) algorithm as an open-source alternative to BLView (note that the current work presents an evaluation of the BLView and STRAT algorithms and does not intend to act as a validation of either). Filtering criteria were defined according to the change in mixed-layer height (MLH) distributions for each instrument and algorithm and were applied throughout the analysis to remove high-frequency fluctuations from the MLH retrievals. Of primary interest was determining how the different data-collection methodologies and algorithms compare to each other and to radiosonde-derived boundary-layer heights when deployed as part of a larger instrument network. We determined that data-collection methodology is not as important as the processing algorithm and that much of the algorithm differences might be driven by impacts of local meteorology and precipitation events that pose algorithm difficulties. The results of this study show that a common processing algorithm is necessary for LIght Detection And Ranging (LIDAR)-based MLH intercomparisons, and ceilometer-network operation and that sonde-derived boundary layer heights are higher (10–15% at mid-day) than LIDAR-derived mixed-layer heights. We show that averaging the retrieved MLH to 1-hour resolution (an appropriate time scale for a priori data model initialization) significantly improved correlation between differing instruments and differing algorithms. PMID:29682087

Mixed-Forest Species Establishment in a Monodominant Forest in Central Africa: Implications for Tropical Forest Invasibility

PubMed Central

Peh, Kelvin S.-H.; Sonké, Bonaventure; Séné, Olivier; Djuikouo, Marie-Noël K.; Nguembou, Charlemagne K.; Taedoumg, Hermann; Begne, Serge K.; Lewis, Simon L.

2014-01-01

Background Traits of non-dominant mixed-forest tree species and their synergies for successful co-occurrence in monodominant Gilbertiodendron dewevrei forest have not yet been investigated. Here we compared the tree species diversity of the monodominant forest with its adjacent mixed forest and then determined which fitness proxies and life history traits of the mixed-forest tree species were most associated with successful co-existence in the monodominant forest. Methodology/Principal Findings We sampled all trees (diameter in breast height [dbh]≥10 cm) within 6×1 ha topographically homogenous areas of intact central African forest in SE Cameroon, three independent patches of G. dewevrei-dominated forest and three adjacent areas (450–800 m apart). Monodominant G. dewevrei forest had lower sample-controlled species richness, species density and population density than its adjacent mixed forest in terms of stems with dbh≥10 cm. Analysis of a suite of population-level characteristics, such as relative abundance and geographical distribution, and traits such as wood density, height, diameter at breast height, fruit/seed dispersal mechanism and light requirement–revealed after controlling for phylogeny, species that co-occur with G. dewevrei tend to have higher abundance in adjacent mixed forest, higher wood density and a lower light requirement. Conclusions/Significance Our results suggest that certain traits (wood density and light requirement) and population-level characteristics (relative abundance) may increase the invasibility of a tree species into a tropical closed-canopy system. Such knowledge may assist in the pre-emptive identification of invasive tree species. PMID:24844914

Analytic Closed-Form Solution of a Mixed Layer Model for Stratocumulus Clouds

NASA Astrophysics Data System (ADS)

Akyurek, Bengu Ozge

Stratocumulus clouds play an important role in climate cooling and are hard to predict using global climate and weather forecast models. Thus, previous studies in the literature use observations and numerical simulation tools, such as large-eddy simulation (LES), to solve the governing equations for the evolution of stratocumulus clouds. In contrast to the previous works, this work provides an analytic closed-form solution to the cloud thickness evolution of stratocumulus clouds in a mixed-layer model framework. With a focus on application over coastal lands, the diurnal cycle of cloud thickness and whether or not clouds dissipate are of particular interest. An analytic solution enables the sensitivity analysis of implicitly interdependent variables and extrema analysis of cloud variables that are hard to achieve using numerical solutions. In this work, the sensitivity of inversion height, cloud-base height, and cloud thickness with respect to initial and boundary conditions, such as Bowen ratio, subsidence, surface temperature, and initial inversion height, are studied. A critical initial cloud thickness value that can be dissipated pre- and post-sunrise is provided. Furthermore, an extrema analysis is provided to obtain the minima and maxima of the inversion height and cloud thickness within 24 h. The proposed solution is validated against LES results under the same initial and boundary conditions. Then, the proposed analytic framework is extended to incorporate multiple vertical columns that are coupled by advection through wind flow. This enables a bridge between the micro-scale and the mesoscale relations. The effect of advection on cloud evolution is studied and a sensitivity analysis is provided.

An electrohydrodynamic technique for rapid mixing in stationary droplets on digital microfluidic platforms.

PubMed

Samiei, Ehsan; de Leon Derby, Maria Diaz; den Berg, Andre Van; Hoorfar, Mina

2017-01-17

This paper presents an electrohydrodynamic technique for rapid mixing of droplets in open and closed digital microfluidic (DMF) platforms. Mixing is performed by applying a high frequency AC voltage to the coplanar or parallel electrodes, inducing circulation zones inside the droplet which results in rapid mixing of the content. The advantages of the proposed method in comparison to conventional mixing methods that operate based on transporting the droplet back and forth and side to side include 1) a shorter mixing time (as fast as 0.25 s), 2) the use of a fewer number of electrodes, reducing the size of the chip, and 3) the stationary nature of the technique which reduces the chance of cross-contamination and surface biofouling. Mixing using the proposed method is performed to create a uniform mixture after merging a water droplet with another droplet containing either particles or dye. The results show that increasing the frequency, and or the amplitude of the applied voltage, enhances the mixing process. However, actuation with a very high frequency and voltage may result in shedding pico-liter satellite droplets. Therefore, for each frequency there is an effective range of the amplitude which provides rapid mixing and avoids shedding satellite droplets. Also, the increase in the gap height between the two plates (for the closed DMF platforms) significantly enhances the mixing efficiency due to the lower viscous effects. Effects of the addition of salts and DNA to the samples were also studied. The electrothermal effect decreased for these cases, which was solved by increasing the frequency of the applied voltage. To assure the high frequency actuation does not increase the sample temperature excessively, the temperature change was monitored using a thermal imaging camera and it was found that the increase in temperature is negligible.

Implications of Upwells as Hydrodynamic Jets in a Pulse Jet Mixed System

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

Pease, Leonard F.; Bamberger, Judith A.; Minette, Michael J.

2015-08-01

This report evaluates the physics of the upwell flow in pulse jet mixed systems in the Hanford Tank Waste Treatment and Immobilization Plant (WTP). Although the initial downward flow and radial flow from pulse jet mixers (PJMs) has been analyzed in some detail, the upwells have received considerably less attention despite having significant implications for vessel mixing. Do the upwells behave like jets? How do the upwells scale? When will the central upwell breakthrough? What proportion of the vessel is blended by the upwells themselves? Indeed, how the physics of the central upwell is affected by multiple PJMs (e.g., sixmore » in the proposed mixing vessels), non-Newtonian rheology, and significant multicomponent solids loadings remain unexplored. The central upwell must satisfy several criteria to be considered a free jet. First, it must travel for several diameters in a nearly constant direction. Second, its velocity must decay with the inverse of elevation. Third, it should have an approximately Gaussian profile. Fourth, the influence of surface or body forces must be negligible. A combination of historical data in a 12.75 ft test vessel, newly analyzed data from the 8 ft test vessel, and conservation of momentum arguments derived specifically for PJM operating conditions demonstrate that the central upwell satisfies these criteria where vigorous breakthrough is achieved. An essential feature of scaling from one vessel to the next is the requirement that the underlying physics does not change adversely. One may have confidence in scaling if (1) correlations and formulas capture the relevant physics; (2) the underlying physics does not change from the conditions under which it was developed to the conditions of interest; (3) all factors relevant to scaling have been incorporated, including flow, material, and geometric considerations; and (4) the uncertainty in the relationships is sufficiently narrow to meet required specifications. Although the central upwell satisfies these criteria when vigorous breakthrough is achieved, not all available data follow the free jet profile for the central upwell, particularly at lower nozzle velocities. Alternative flow regimes are considered and new models for cloud height, “cavern height,” and the rate of jet penetration (jet celerity) are benchmarked against data to anchor scaling analyses. This analytical modeling effort to provide a technical basis for scaling PJM mixed vessels has significant implications for vessel mixing, because jet physics underlies “cavern” height, cloud height, and the volume of mixing considerations. A new four-parameter cloud height model compares favorably to experimental results. This model is predictive of breakthrough in 8 ft vessel tests with the two-part simulant. Analysis of the upwell in the presence of yield stresses finds evidence of expanding turbulent jets, confined turbulent jets, and confined laminar flows. For each, the critical elevation at which jet momentum depletes is predicted, which compare favorably to experimental cavern height data. Partially coupled momentum and energy balances suggest that these are limiting cases of a gradual transition from a turbulent expanding flow to a confined laminar flow. This analysis of the central upwell alone lays essential groundwork for complete analysis of mode three mixing (i.e., breakthrough with slow peripheral mixing). Consideration of jet celerity shows that the rate of jet penetration is a governing consideration in breakthrough to the surface. Estimates of the volume of mixing are presented. This analysis shows that flow along the vessel wall is sluggish such that the central upwell governs the volume of mixing. This analysis of the central upwell alone lays essential groundwork for complete analysis of mode three mixing and estimates of hydrogen release rates from first principles.« less

Observational characteristics of the tropopause inversion layer derived from CHAMP/GRACE radio occultations and MOZAIC aircraft data

NASA Astrophysics Data System (ADS)

Schmidt, T.; Cammas, J.-P.; Smit, H. G. J.; Heise, S.; Wickert, J.; Haser, A.

2010-12-01

In this study we discuss characteristics of the Northern Hemisphere (NH) midlatitude (40°N-60°N) tropopause inversion layer (TIL) based on two data sets. First, temperature measurements from GPS radio occultation data (CHAMP and GRACE) for the time interval 2001-2009 are used to exhibit seasonal properties of the TIL bottom height defined here as the height of the squared buoyancy frequency minimum N2 below the thermal tropopause, the TIL maximum height as the height of the N2 maximum above the tropopause, and the TIL top height as the height of the temperature maximum above the tropopause. Mean values of the TIL bottom, TIL maximum, and TIL top heights relative to the thermal tropopause for the NH midlatitudes are (-2.08 ± 0.35) km, (0.52 ± 0.10) km and (2.10 ± 0.23) km, respectively. A seasonal cycle of the TIL bottom and TIL top height is observed with values closer to the thermal tropopause during summer. Secondly, high-resolution temperature and trace gas profile measurements on board commercial aircrafts (Measurement of Ozone and Water Vapor by Airbus In-Service Aircraft (MOZAIC) program) from 2001-2008 for the NH midlatitude (40°N-60°N) region are used to characterize the TIL as a mixing layer around the tropopause. Mean TIL bottom, TIL maximum, and TIL top heights based on the MOZAIC temperature (N2) measurements confirm the results from the GPS data, even though most of the MOZAIC profiles used here are available under cyclonic situations. Further, we demonstrate that the mixing ratio gradients of ozone (O3) and carbon monoxide (CO) are suitable parameters for characterizing the TIL structure.

Infrared Measurements of Atmospheric Ethane (C2H6) From Aircraft and Ground-Based Solar Absorption Spectra in the 3000/ cm Region

NASA Technical Reports Server (NTRS)

Coffey, M. T.; Mankin, W. G.; Goldman, A.; Rinsland, C. P.; Harvey, G. A.; Devi, V. Malathy; Stokes, G. M.

1985-01-01

A number or prominent Q-branches or the upsilon(sub 7) band or C2H6 have been identified near 3000/ cm in aircraft and ground-based infrared solar absorption spectra. The aircraft spectra provide the column amount above 12 km at various altitudes. The column amount is strongly correlated with tropopause height and can be described by a constant mixing ratio of 0.46 ppbv in the upper troposphere and a mixing ratio scale height of 3.9 km above the tropopause. The, ground-based spectra yield a column of 9.0 x 10(exp 15) molecules/sq cm above 2.1 km; combining these results implies a tropospheric mixing ratio of approximately 0.63 ppbv.

Infrared measurements of atmospheric ethane (C2H6) from aircraft and ground-based solar absorption spectra in the 3000/cm region

NASA Technical Reports Server (NTRS)

Coffey, M. T.; Mankin, W. G.; Goldman, A.; Rinsland, C. P.; Harvey, G. A.; Devi, V. M.; Stokes, G. M.

1985-01-01

A number of prominent Q-branches of the nu-7 band of C2H6 have been identified near 3000/cm in aircraft and ground-based infrared solar absorption spectra. The aircraft spectra provide the column amount above 12 km at various altitudes. The column amount is strongly correlated with tropopause height and can be described by a constant mixing ratio of 0.46 ppbv in the upper troposphere and a mixing ratio scale height of 3.9 km above the tropopause. The ground-based spectra yield a column of 9.0 x 10 to the 15th molecules/sq cm above 2.1 km; combining these results implies a tropospheric mixing ratio of approximately 0.63 ppbv.

Vertical profiles of black carbon concentration and particle number size distribution in the North China Plain

NASA Astrophysics Data System (ADS)

Ran, L.; Deng, Z.

2013-12-01

The vertical distribution of aerosols is of great importance to our understanding in the impacts of aerosols on radiation balance and climate, as well as air quality and public health. To better understand and estimate the effects of atmospheric components including trace gases and aerosols on atmospheric environment and climate, an intensive field campaign, Vertical Observations of trace Gases and Aerosols in the North China Plain (VOGA-NCP), was carried out from late July to early August 2013 over a rural site in the polluted NCP. During the campaign, vertical profiles of black carbon (BC) concentration and particle number size distribution were measured respectively by a micro-Aethalometer and an optical particle counter attached to a tethered balloon within 1000 m height. Meteorological parameters, including temperature, relative humidity, wind speed and wind direction, were measured simultaneously by a radiosonde also attached to the tethered balloon. Preliminary results showed distinct diurnal variations of the vertical distribution of aerosol total number concentration and BC concentration, following the development of the mixing layer. Generally, there was a well mixing of aerosols within the mixing layer and a sharp decrease above the mixing layer. Particularly, a small peak of BC concentrations was observed around 400-500 m height for several profiles. Further analysis would be needed to explain such phenomenon. It was also found that measured vertical profiles of BC using the filter-based method might be affected by the vertical distribution of relative humidity.

Comparative genetic responses to climate in the varieties of Pinus ponderosa and Pseudotsuga menziesii: clines in growth potential

Treesearch

Gerald E. Rehfeldt; Laura P. Leites; J. Bradley St Clair; Barry C. Jaquish; Cuauhtemoc Saenz-Romero; Javier Lopez-Upton; Dennis G. Joyce

2014-01-01

Height growth data were assembled from 10 Pinus ponderosa and 17 Pseudotsuga menziesii provenance tests. Data from the disparate studies were scaled according to climate similarities of the provenances to provide single datasets for 781 P. ponderosa and 1193 P. menziesii populations. Mixed effects models were used for two sub-specific varieties of each species to...

Impact of wind-induced microsites and disturbance severity on tree regeneration patterns: Results from the first post-storm decade

Treesearch

Floor Vodde; Kalev Jogiste; Jeroen Engelhart; Lee E. Frelich; W. Keith Moser; Alan Sims; Marek Metslaid

2015-01-01

In two hemiboreal mixed spruce-hardwood forests in north-east Estonia, we studied (1) which factors affect tree regeneration survival and development during the first post-storm decade and (2) how these effects change in time. Regeneration height and mortality of the tree species black alder (Alnus glutinosa (L.) J. Gaertn.), birch (Betula pendula Roth., Betula...

Effects of Different Cutting Height on Nutritional Quality of Whole Crop Barley Silage and Feed Value on Hanwoo Heifers.

PubMed

Kim, Dong Hyeon; Amanullah, Sardar M; Lee, Hyuk Jun; Joo, Young Ho; Han, Ouk Kyu; Adesogan, Adegbola T; Kim, Sam Churl

2016-09-01

The present study evaluated the effects of different cutting height on nutritive value, fermentation quality, in vitro and in vivo digestibility of whole crop barley silage. Whole crop barley forage (Yuyeon hybrid) was harvested at height of 5, 10, and 15 cm from the ground level. Each cutting height was rolled to make round bale and ensiled for 100 days. After 100 days of ensiling, pH of silage was lower (p<0.05) in 5 cm, but no difference between 10 and 15 cm of cutting height. The content of lactate and lactate to acetate ratio were increased (p<0.05) in 5 cm of cutting height, whereas the acetate content was higher (p<0.05) in 10 and 15 cm than that of 5 cm cutting height. Aerobic stability was greater (p<0.05) in silages of 10 and 15 cm of cutting height. Three total mixed rations (TMR) were formulated with silages from the three different cutting heights (TMR5, TMR10, and TMR15) incorporated as forage at 70:30 ratio with concentrate (dry matter [DM] basis). In vitro dry matter digestibility was higher (p<0.05) in the TMR5 and TMR10 than that in TMR15, whereas in vitro neutral detergent fiber digestibility was higher (p<0.05) in the TMR10 and TMR15 than that in TMR5. Concentration of NH3-N was highest (p<0.05) in the TMR10 followed by TMR15 and TMR5. Total volatile fatty acid was decreased (p<0.05) with increased cutting height. The digestibility of DM and neutral detergent fiber were highest (p<0.05) in TMR15, than those in TMR5 and TMR10, whereas acid detergent fiber digestibility was higher (p<0.05) in TMR5 than that in TMR10. The results showed that increasing cutting height, at least up to 10 to 15 cm, of whole crop barley forage at harvest (Yuyeon) may be beneficial for making silage for TMR formulation and increasing digestibility of DM and NDF.

Effects of Different Cutting Height on Nutritional Quality of Whole Crop Barley Silage and Feed Value on Hanwoo Heifers

PubMed Central

Kim, Dong Hyeon; Amanullah, Sardar M.; Lee, Hyuk Jun; Joo, Young Ho; Han, Ouk Kyu; Adesogan, Adegbola T.; Kim, Sam Churl

2016-01-01

The present study evaluated the effects of different cutting height on nutritive value, fermentation quality, in vitro and in vivo digestibility of whole crop barley silage. Whole crop barley forage (Yuyeon hybrid) was harvested at height of 5, 10, and 15 cm from the ground level. Each cutting height was rolled to make round bale and ensiled for 100 days. After 100 days of ensiling, pH of silage was lower (p<0.05) in 5 cm, but no difference between 10 and 15 cm of cutting height. The content of lactate and lactate to acetate ratio were increased (p<0.05) in 5 cm of cutting height, whereas the acetate content was higher (p<0.05) in 10 and 15 cm than that of 5 cm cutting height. Aerobic stability was greater (p<0.05) in silages of 10 and 15 cm of cutting height. Three total mixed rations (TMR) were formulated with silages from the three different cutting heights (TMR5, TMR10, and TMR15) incorporated as forage at 70:30 ratio with concentrate (dry matter [DM] basis). In vitro dry matter digestibility was higher (p<0.05) in the TMR5 and TMR10 than that in TMR15, whereas in vitro neutral detergent fiber digestibility was higher (p<0.05) in the TMR10 and TMR15 than that in TMR5. Concentration of NH3-N was highest (p<0.05) in the TMR10 followed by TMR15 and TMR5. Total volatile fatty acid was decreased (p<0.05) with increased cutting height. The digestibility of DM and neutral detergent fiber were highest (p<0.05) in TMR15, than those in TMR5 and TMR10, whereas acid detergent fiber digestibility was higher (p<0.05) in TMR5 than that in TMR10. The results showed that increasing cutting height, at least up to 10 to 15 cm, of whole crop barley forage at harvest (Yuyeon) may be beneficial for making silage for TMR formulation and increasing digestibility of DM and NDF. PMID:27165022

Large Eddy Simulations of a Bottom Boundary Layer Under a Shallow Geostrophic Front

NASA Astrophysics Data System (ADS)

Bateman, S. P.; Simeonov, J.; Calantoni, J.

2017-12-01

The unstratified surf zone and the stratified shelf waters are often separated by dynamic fronts that can strongly impact the character of the Ekman bottom boundary layer. Here, we use large eddy simulations to study the turbulent bottom boundary layer associated with a geostrophic current on a stratified shelf of uniform depth. The simulations are initialized with a spatially uniform vertical shear that is in geostrophic balance with a pressure gradient due to a linear horizontal temperature variation. Superposed on the temperature front is a stable vertical temperature gradient. As turbulence develops near the bottom, the turbulence-induced mixing gradually erodes the initial uniform temperature stratification and a well-mixed layer grows in height until the turbulence becomes fully developed. The simulations provide the spatial distribution of the turbulent dissipation and the Reynolds stresses in the fully developed boundary layer. We vary the initial linear stratification and investigate its effect on the height of the bottom boundary layer and the turbulence statistics. The results are compared to previous models and simulations of stratified bottom Ekman layers.

The use of LIDAR Technology for Measuring Mixing Heights under the Photochemical Assessment Monitoring Program; leveraging research under the joint DISCOVER-AQ/FRAPPÉ Missions

EPA Science Inventory

The operational use of ceilometers across the United States has been limited to detection of cloud-base heights across the Automatic Surface Observing Systems (ASOS) primarily operated by the National Weather Service and the Federal Aviation Administration. Continued improvements...

EuroForMix: An open source software based on a continuous model to evaluate STR DNA profiles from a mixture of contributors with artefacts.

PubMed

Bleka, Øyvind; Storvik, Geir; Gill, Peter

2016-03-01

We have released a software named EuroForMix to analyze STR DNA profiles in a user-friendly graphical user interface. The software implements a model to explain the allelic peak height on a continuous scale in order to carry out weight-of-evidence calculations for profiles which could be from a mixture of contributors. Through a properly parameterized model we are able to do inference on mixture proportions, the peak height properties, stutter proportion and degradation. In addition, EuroForMix includes models for allele drop-out, allele drop-in and sub-population structure. EuroForMix supports two inference approaches for likelihood ratio calculations. The first approach uses maximum likelihood estimation of the unknown parameters. The second approach is Bayesian based which requires prior distributions to be specified for the parameters involved. The user may specify any number of known and unknown contributors in the model, however we find that there is a practical computing time limit which restricts the model to a maximum of four unknown contributors. EuroForMix is the first freely open source, continuous model (accommodating peak height, stutter, drop-in, drop-out, population substructure and degradation), to be reported in the literature. It therefore serves an important purpose to act as an unrestricted platform to compare different solutions that are available. The implementation of the continuous model used in the software showed close to identical results to the R-package DNAmixtures, which requires a HUGIN Expert license to be used. An additional feature in EuroForMix is the ability for the user to adapt the Bayesian inference framework by incorporating their own prior information. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Comparison of Mixed Layer Heights from Airborne High Spectral Resolution Lidar, Ground-based Measurements, and the WRP-Chem Model during CalNex and CARES

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

Scarino, Amy Jo; Obland, Michael; Fast, Jerome D.

2014-06-05

The California Research at the Nexus of Air Quality and Climate Change (CalNex) and Carbonaceous Aerosol and Radiative Effects Study (CARES) field campaigns during May and June 2010 provided a data set appropriate for studying characteristics of the planetary boundary layer (PBL). The NASA Langley Research Center (LaRC) airborne High Spectral Resolution Lidar (HSRL) was deployed to California onboard the NASA LaRC B-200 aircraft to aid incharacterizing aerosol properties during these two field campaigns. Measurements of aerosol extinction (532 nm), backscatter (532 and 1064 nm), and depolarization (532 and 1064 nm) profiles during 31 flights, many in coordination with othermore » research aircraft and ground sites, constitute a diverse data set for use in characterizing the spatial and temporal distribution of aerosols, as well as the depth and variability of the daytime mixed layer (ML), which is a subset within the PBL. This work illustrates the temporal and spatial variability of the ML in the vicinity of Los Angeles and Sacramento, CA. ML heights derived from HSRL measurements are compared to PBL heights derived from radiosonde profiles, ML heights measured from ceilometers, and simulated PBL heights from the Weather Research and Forecasting Chemistry (WRF-Chem) community model. Comparisons between the HSRL ML heights and the radiosonde profiles in Sacramento result in a correlation coefficient value (R) of 0.93 (root7 mean-square (RMS) difference of 157 m and bias difference (HSRL radiosonde) of 5 m). HSRL ML heights compare well with those from the ceilometer in the LA Basin with an R of 0.89 (RMS difference of 108 m and bias difference (HSRL Ceilometer) of -9.7 m) for distances of up to 30 km between the B-200 flight track and the ceilometer site. Simulated PBL heights from WRF-Chem were compared with those obtained from all flights for each campaign, producing an R of 0.58 (RMS difference of 604 m and a bias difference (WRF-Chem HSRL) of -157 m) for CalNex and 0.59 (RMS difference of 689 m and a bias difference (WRF-Chem HSRL) of 220 m) for CARES. Aerosol backscatter simulations are also available from WRF15 Chem and are compared to those from HSRL to examine differences among the methods used to derive ML heights.« less

Wave attenuation in the shallows of San Francisco Bay

USGS Publications Warehouse

Lacy, Jessica R.; MacVean, Lissa J.

2016-01-01

Waves propagating over broad, gently-sloped shallows decrease in height due to frictional dissipation at the bed. We quantified wave-height evolution across 7 km of mudflat in San Pablo Bay (northern San Francisco Bay), an environment where tidal mixing prevents the formation of fluid mud. Wave height was measured along a cross shore transect (elevation range−2mto+0.45mMLLW) in winter 2011 and summer 2012. Wave height decreased more than 50% across the transect. The exponential decay coefficient λ was inversely related to depth squared (λ=6×10−4h−2). The physical roughness length scale kb, estimated from near-bed turbulence measurements, was 3.5×10−3 m in winter and 1.1×10−2 m in summer. Estimated wave friction factor fw determined from wave-height data suggests that bottom friction dominates dissipation at high Rew but not at low Rew. Predictions of near-shore wave height based on offshore wave height and a rough formulation for fw were quite accurate, with errors about half as great as those based on the smooth formulation for fw. Researchers often assume that the wave boundary layer is smooth for settings with fine-grained sediments. At this site, use of a smooth fw results in an underestimate of wave shear stress by a factor of 2 for typical waves and as much as 5 for more energetic waves. It also inadequately captures the effectiveness of the mudflats in protecting the shoreline through wave attenuation.

Investigating land-atmosphere coupling and convective triggering associated with the moistening of the northern North American Great Plains

NASA Astrophysics Data System (ADS)

Gerken, Tobias; Bromley, Gabriel; Stoy, Paul

2017-04-01

Parts of the North American northern Great Plains have undergone a 6 W m-2 decrease in summertime radiative forcing. At the same time agricultural practices have shifted from keeping fields fallow during the summer ("summer fallow") towards no-till cropping systems that increase summertime evapotranspiration and decrease soil carbon loss. MERRA (Modern-Era Retrospective analysis for Research and Applications) for the area near Fort Peck, Montana, (a FLUXNET site established in 2000) shows a decrease of summertime (June-August) sensible heat fluxes ranging from -3.6 to -8.5 W m-2 decade-1, which is associated with an increase of latent heat fluxes of similar magnitude (5.2-9.1 W m-2 decade-1). While net radiation changed little, increasing downward longwave radiation (2.2-4.6 W m-2 decade-1) due to greater cloud cover, was mostly compensated by reduced solar irradiance. The result was a strong decrease of summer Bowen ratios from 1.5-2 in 1980 to approximately 1-1.25 in 2015. At the same time, atmospheric soundings have shown significant increases in both convective available convective energy (CAPE) and convective inhibition (CIN) for the same time span. Overall, these findings are consistent with the effects on increased summertime evapotranspiration due to reduction in summer fallow that should lead to smaller Bowen ratios and a larger build-up of moist static energy as expressed in higher values of CAPE. In order to further investigate the impact of the surface energy balance and flux partitioning on convective development and local land-atmosphere coupling in the North American prairies, a 1-dimensional mixed-layer model is used to compare the evolution of mixed-layer heights to the lifted condensation level, a necessary but not sufficient condition for the occurrence of convective precipitation. Using summertime eddy covariance data from Fort Peck and atmospheric soundings from the nearby Glasgow airport, we establish that the mixed-layer model adequately captures mixed-layer heights and timing of locally triggered convection at the site. The model is then used to quantify the sensitivity of mixing-layer height, CAPE and convective triggering potential, in response to changes in surface flux partitioning between latent and sensible heat due to changes in soil moisture and agricultural management. Results are used to establish the exact nature or land-atmosphere coupling associated with moistening of the atmospheric boundary-layer and increases in convective triggering and will contribute to disentangling local and regional effects on trends in observed precipitation in the northern Great Plains.

An Investigation of Instantaneous Plume Rise from Rocket Exhaust

DTIC Science & Technology

1996-12-01

METERS) TOP = 2973.48 BASE= 210.62 SIGMAR (AZ) AT THE SURFACE (DEGREES) 13.5054 SIGMER(EL) AT THE SURFACE (DEGREES) 2.9738 MET. WIND WIND LAYER WIND SPEED...SELECTED LAYER HEIGHT- (METERS) TOP = 2973.48 BASE= 210.62 SIGMAR (AZ) AT THE SURFACE (DEGREES) 13.6911 SIGMER(EL) AT THE SURFACE (DEGREES) 2.9738 MET...TIME (SECS) 368.08 FIRST MIXING LAYER HEIGHT- (METERS) TOP = 210.62 BASE= 0.00 SECOND SELECTED LAYER HEIGHT- (METERS) TOP = 2973.48 BASE= 210.62 SIGMAR

Mixed Layer Heights Derived from the NASA Langley Research Center Airborne High Spectral Resolution Lidar

NASA Technical Reports Server (NTRS)

Scarino, Amy J.; Burton, Sharon P.; Ferrare, Rich A.; Hostetler, Chris A.; Hair, Johnathan W.; Obland, Michael D.; Rogers, Raymond R.; Cook, Anthony L.; Harper, David B.; Fast, Jerome;

Nest habitat use of Rio Grande wild turkeys

USGS Publications Warehouse

Schmutz, Joel A.; Braun, Clait E.; Andelt, William F.

1989-01-01

Nest habitat use of Rio Grande Wild Turkeys (Meleagris gallopavo intermedia) was studied along the South Platte River in northeast Colorado in 1986-87. Thirty-three of 35 nests were in riparian habitats. Nests were either in western snowberry (Symphoricarpos occidentalis) (67%) or mixed forbs and grasses (33%). Early season nests were more likely to be in snowberry than late season nests. Nest sites were characterized by greater overstory canopy cover, more shrubs, fewer grasses, and greater understory cover and height than surrounding areas. These areas had more shrubs, fewer large trees, and greater understory cover and height than riparian habitats throughout the study area. Phenology of understory vegetation and the effect of such vegetation on nest predation may influence temporal patterns of nest habitat use.

The reliability of vertical jump tests between the Vertec and My Jump phone application.

PubMed

Yingling, Vanessa R; Castro, Dimitri A; Duong, Justin T; Malpartida, Fiorella J; Usher, Justin R; O, Jenny

2018-01-01

The vertical jump is used to estimate sports performance capabilities and physical fitness in children, elderly, non-athletic and injured individuals. Different jump techniques and measurement tools are available to assess vertical jump height and peak power; however, their use is limited by access to laboratory settings, excessive cost and/or time constraints thus making these tools oftentimes unsuitable for field assessment. A popular field test uses the Vertec and the Sargent vertical jump with countermovement; however, new low cost, easy to use tools are becoming available, including the My Jump iOS mobile application (app). The purpose of this study was to assess the reliability of the My Jump relative to values obtained by the Vertec for the Sargent stand and reach vertical jump (VJ) test. One hundred and thirty-five healthy participants aged 18-39 years (94 males, 41 females) completed three maximal Sargent VJ with countermovement that were simultaneously measured using the Vertec and the My Jump . Jump heights were quantified for each jump and peak power was calculated using the Sayers equation. Four separate ICC estimates and their 95% confidence intervals were used to assess reliability. Two analyses (with jump height and calculated peak power as the dependent variables, respectively) were based on a single rater, consistency, two-way mixed-effects model, while two others (with jump height and calculated peak power as the dependent variables, respectively) were based on a single rater, absolute agreement, two-way mixed-effects model. Moderate to excellent reliability relative to the degree of consistency between the Vertec and My Jump values was found for jump height (ICC = 0.813; 95% CI [0.747-0.863]) and calculated peak power (ICC = 0.926; 95% CI [0.897-0.947]). However, poor to good reliability relative to absolute agreement for VJ height (ICC = 0.665; 95% CI [0.050-0.859]) and poor to excellent reliability relative to absolute agreement for peak power (ICC = 0.851; 95% CI [0.272-0.946]) between the Vertec and My Jump values were found; Vertec VJ height, and thus, Vertec calculated peak power values, were significantly higher than those calculated from My Jump values ( p < 0.0001). The My Jump app may provide a reliable measure of vertical jump height and calculated peak power in multiple field and laboratory settings without the need of costly equipment such as force plates or Vertec. The reliability relative to degree of consistency between the Vertec and My Jump app was moderate to excellent. However, the reliability relative to absolute agreement between Vertec and My Jump values contained significant variation (based on CI values), thus, it is recommended that either the My Jump or the Vertec be used to assess VJ height in repeated measures within subjects' designs; these measurement tools should not be considered interchangeable within subjects or in group measurement designs.

The reliability of vertical jump tests between the Vertec and My Jump phone application

PubMed Central

Castro, Dimitri A.; Duong, Justin T.; Malpartida, Fiorella J.; Usher, Justin R.; O, Jenny

2018-01-01

Background The vertical jump is used to estimate sports performance capabilities and physical fitness in children, elderly, non-athletic and injured individuals. Different jump techniques and measurement tools are available to assess vertical jump height and peak power; however, their use is limited by access to laboratory settings, excessive cost and/or time constraints thus making these tools oftentimes unsuitable for field assessment. A popular field test uses the Vertec and the Sargent vertical jump with countermovement; however, new low cost, easy to use tools are becoming available, including the My Jump iOS mobile application (app). The purpose of this study was to assess the reliability of the My Jump relative to values obtained by the Vertec for the Sargent stand and reach vertical jump (VJ) test. Methods One hundred and thirty-five healthy participants aged 18–39 years (94 males, 41 females) completed three maximal Sargent VJ with countermovement that were simultaneously measured using the Vertec and the My Jump. Jump heights were quantified for each jump and peak power was calculated using the Sayers equation. Four separate ICC estimates and their 95% confidence intervals were used to assess reliability. Two analyses (with jump height and calculated peak power as the dependent variables, respectively) were based on a single rater, consistency, two-way mixed-effects model, while two others (with jump height and calculated peak power as the dependent variables, respectively) were based on a single rater, absolute agreement, two-way mixed-effects model. Results Moderate to excellent reliability relative to the degree of consistency between the Vertec and My Jump values was found for jump height (ICC = 0.813; 95% CI [0.747–0.863]) and calculated peak power (ICC = 0.926; 95% CI [0.897–0.947]). However, poor to good reliability relative to absolute agreement for VJ height (ICC = 0.665; 95% CI [0.050–0.859]) and poor to excellent reliability relative to absolute agreement for peak power (ICC = 0.851; 95% CI [0.272–0.946]) between the Vertec and My Jump values were found; Vertec VJ height, and thus, Vertec calculated peak power values, were significantly higher than those calculated from My Jump values (p < 0.0001). Discussion The My Jump app may provide a reliable measure of vertical jump height and calculated peak power in multiple field and laboratory settings without the need of costly equipment such as force plates or Vertec. The reliability relative to degree of consistency between the Vertec and My Jump app was moderate to excellent. However, the reliability relative to absolute agreement between Vertec and My Jump values contained significant variation (based on CI values), thus, it is recommended that either the My Jump or the Vertec be used to assess VJ height in repeated measures within subjects’ designs; these measurement tools should not be considered interchangeable within subjects or in group measurement designs. PMID:29692955

Electrokinetic mixing at high zeta potentials: ionic size effects on cross stream diffusion.

PubMed

Ahmadian Yazdi, Alireza; Sadeghi, Arman; Saidi, Mohammad Hassan

2015-03-15

The electrokinetic phenomena at high zeta potentials may show several unique features which are not normally observed. One of these features is the ionic size (steric) effect associated with the solutions of high ionic concentration. In the present work, attention is given to the influences of finite ionic size on the cross stream diffusion process in an electrokinetically actuated Y-shaped micromixer. The method consists of a finite difference based numerical approach for non-uniform grid which is applied to the dimensionless form of the governing equations, including the modified Poisson-Boltzmann equation. The results reveal that, neglecting the ionic size at high zeta potentials gives rise to the overestimation of the mixing length, because the steric effects retard liquid flow, thereby enhancing the mixing efficiency. The importance of steric effects is found to be more intense for channels of smaller width to height ratio. It is also observed that, in sharp contrast to the conditions that the ions are treated as point charges, increasing the zeta potential improves the cross stream diffusion when incorporating the ionic size. Moreover, increasing the EDL thickness decreases the mixing length, whereas the opposite is true for the channel aspect ratio. Copyright © 2014 Elsevier Inc. All rights reserved.

The vertical development of early successional forests in northern Michigan, USA

Treesearch

Kurt S. Pregitzer; Brain J. Palik

1993-01-01

1. Studies have shown that differences in height growth rates are characteristic of tree species that differ in understory tolerance and relative successional status. Less-tolerant species have greater juvenile height growth rates than more-tolerant species and thus, in a mixed-species forest, the former gain an early competitive advantage after a stand-initiating...

A modified shark-fin test simulating the single-step/double-mix technique: A comparison of three groups of elastomers.

PubMed

Huettig, Fabian; Chekhani, Usama; Klink, Andrea; Said, Fadi; Rupp, Frank

2018-06-08

The shark-fin test was modified to convey the clinical application of a single-step/double-mix technique assessing the behavior of two viscosities applied at one point in time. A medium and light body polyether (PE), a medium and light body polyvinylsiloxane (PVS), and a medium as well as heavy and light body vinyl polyether silicone (PVXE) impression material were analyzed solely, and in a layered mixture of 1:1 and 3:1 at working times of 50, 80, and 120 s. The fin heights were measured with a digital ruler. The wettability was measured 50 and 80 s after mixing by drop shape analysis. The results showed a synergistic effect of the medium and light body PE. This was not observed in PVXE and PVS. Interestingly, PVXE showed an antagonistic flow behavior in 3:1 mixture with medium body. PVXE was more hydrophilic than PE and PVS. Future rheological studies should clarify the detected flow effects.

Vertical velocity variance in the mixed layer from radar wind profilers

USGS Publications Warehouse

Eng, K.; Coulter, R.L.; Brutsaert, W.

2003-01-01

Vertical velocity variance data were derived from remotely sensed mixed layer turbulence measurements at the Atmospheric Boundary Layer Experiments (ABLE) facility in Butler County, Kansas. These measurements and associated data were provided by a collection of instruments that included two 915 MHz wind profilers, two radio acoustic sounding systems, and two eddy correlation devices. The data from these devices were available through the Atmospheric Boundary Layer Experiment (ABLE) database operated by Argonne National Laboratory. A signal processing procedure outlined by Angevine et al. was adapted and further built upon to derive vertical velocity variance, w_pm???2, from 915 MHz wind profiler measurements in the mixed layer. The proposed procedure consisted of the application of a height-dependent signal-to-noise ratio (SNR) filter, removal of outliers plus and minus two standard deviations about the mean on the spectral width squared, and removal of the effects of beam broadening and vertical shearing of horizontal winds. The scatter associated with w_pm???2 was mainly affected by the choice of SNR filter cutoff values. Several different sets of cutoff values were considered, and the optimal one was selected which reduced the overall scatter on w_pm???2 and yet retained a sufficient number of data points to average. A similarity relationship of w_pm???2 versus height was established for the mixed layer on the basis of the available data. A strong link between the SNR and growth/decay phases of turbulence was identified. Thus, the mid to late afternoon hours, when strong surface heating occurred, were observed to produce the highest quality signals.

Anthropometry and blood pressure changes in a Caribbean adolescent population of African ancestry: an evaluation of longitudinal data using a multilevel mixed regression approach.

PubMed

Nichols, S; Cadogan, F

2012-10-01

The aim of this study was to determine the effect of growth pattern on blood pressure changes in an adolescent population of African ancestry based on longitudinal data and to compare this with estimates derived from cross-sectional data. Participants had measurements of weight, height, blood pressure and percentage body fat taken annually using standardized procedures. Annual blood pressure and anthropometry velocities as well as one- and three-year interval gender specific tracking coefficients were computed. We investigated whether changes in blood pressure could be explained by measures of growth using a multilevel mixed regression approach. The results showed that systolic blood pressure (SBP) increased by 1.27 and 3.09 mmHg per year among females and males, respectively. Similarly, diastolic blood pressure (DBP) increased by 1.16 and 1.92 mmHg per year among females and males, respectively. Multilevel analyses suggested that weight, body mass index, percentage body fat and height were the strongest anthropometric determinants of blood pressure change in this population. The results also suggest that there are gender differences in the relative importance of these anthropometric measures with height playing a minor role in predicting blood pressure changes among adolescent females. With the exception of DBP at 18 years among females, there were no significant differences between mean blood pressure generated from cross-sectional and longitudinal data by age in both males and females. Anthropometric measures are important covariates of age-related blood pressure changes and cross-sectional data may provide a more cost-effective and useful proxy for generating age-related blood pressure estimates in this population.

Disposition of Orange Herbicide by Incineration. Revised Draft Environmental Statement

DTIC Science & Technology

1974-04-01

a ship , the "Vulcanls," has beer equipped to carry certain hazardous liquid chemical cargoes ...dispersed. For this analyses the dispersion zone is based on a one knot wind speed , "crosswind" of the ship’s course, 10 knot speed for the ship during... shipping company; the wind speed and effective mixing height are very con- servative. For such a low wind speed , it is anticipated that the

Improving Lidar-based Aboveground Biomass Estimation with Site Productivity for Central Hardwood Forests, USA

NASA Astrophysics Data System (ADS)

Shao, G.; Gallion, J.; Fei, S.

2016-12-01

Sound forest aboveground biomass estimation is required to monitor diverse forest ecosystems and their impacts on the changing climate. Lidar-based regression models provided promised biomass estimations in most forest ecosystems. However, considerable uncertainties of biomass estimations have been reported in the temperate hardwood and hardwood-dominated mixed forests. Varied site productivities in temperate hardwood forests largely diversified height and diameter growth rates, which significantly reduced the correlation between tree height and diameter at breast height (DBH) in mature and complex forests. It is, therefore, difficult to utilize height-based lidar metrics to predict DBH-based field-measured biomass through a simple regression model regardless the variation of site productivity. In this study, we established a multi-dimension nonlinear regression model incorporating lidar metrics and site productivity classes derived from soil features. In the regression model, lidar metrics provided horizontal and vertical structural information and productivity classes differentiated good and poor forest sites. The selection and combination of lidar metrics were discussed. Multiple regression models were employed and compared. Uncertainty analysis was applied to the best fit model. The effects of site productivity on the lidar-based biomass model were addressed.

Adult height variants affect birth length and growth rate in children.

PubMed

Paternoster, Lavinia; Howe, Laura D; Tilling, Kate; Weedon, Michael N; Freathy, Rachel M; Frayling, Timothy M; Kemp, John P; Smith, George Davey; Timpson, Nicholas J; Ring, Susan M; Evans, David M; Lawlor, Debbie A

2011-10-15

Previous studies identified 180 single nucleotide polymorphisms (SNPs) associated with adult height, explaining ∼10% of the variance. The age at which these begin to affect growth is unclear. We modelled the effect of these SNPs on birth length and childhood growth. A total of 7768 participants in the Avon Longitudinal Study of Parents and Children had data available. Individual growth trajectories from 0 to 10 years were estimated using mixed-effects linear spline models and differences in trajectories by individual SNPs and allelic score were determined. The allelic score was associated with birth length (0.026 cm increase per 'tall' allele, SE = 0.003, P = 1 × 10(-15), equivalent to 0.017 SD). There was little evidence of association between the allelic score and early infancy growth (0-3 months), but there was evidence of association between the allelic score and later growth. This association became stronger with each consecutive growth period, per 'tall' allele per month effects were 0.015 SD (3 months-1 year, SE = 0.004), 0.023 SD (1-3 years, SE = 0.003) and 0.028 SD (3-10 years, SE = 0.003). By age 10, the mean height difference between individuals with ≤170 versus ≥191 'tall' alleles (the top and bottom 10%) was 4.7 cm (0.8 SD), explaining ∼5% of the variance. There was evidence of associations with specific growth periods for some SNPs (rs3791675, EFEMP1 and rs6569648, L3MBTL3) and supportive evidence for previously reported age-dependent effects of HHIP and SOCS2 SNPs. SNPs associated with adult height influence birth length and have an increasing effect on growth from late infancy through to late childhood. By age 10, they explain half the height variance (∼5%) of that explained in adults (∼10%).

[Growth effect of eucalyptus-acacia mixed plantation in South China].

PubMed

Yang, Zeng-Jiang; Xu, Da-Ping; Chen, Wen-Ping; Huang, Lie-Jian; Li, Shang-Jun; Chen, Yuan

2009-10-01

Eucalyptus U6 and Acacia crassicarpa were mixed planted with different ratios and modes to investigate the growth parameters of the two tree species. In the 2-3 years old mixed plantation, the wind-throw of A. crassicarpa decreased markedly with increasing ratio of Eucalyptus U6, the decrement being 26.14% when the Eucalyptus U6/A. crassicarpa ratio was 3 : 1, but the survival rates of Eucalyptus U6 and A. crassicarpa had no significant difference under different planting modes. Mixed planting retarded the A. crassicarpa growth to some extent, with the DBH being 90% of that in pure A. crassicarpa stand. The mixed planting had little effects on the height growth of Eucalyptus U6, but promoted its DBH growth markedly, and the beneficial effect increased with increasing ratio of A. crassicarpa. In the 6 years old 1 : 1 Eucalyptus U6/A. crassicarpa plantation, the Eucalyptus U6 individuals with DBH > 15 cm occupied 32.1%; while in pure Eucalyptus U6 stand, they only accounted for 5.83%. Mixed planting with 2 : 1 Eucalyptus U6/A. crassicarpa could obtain a maximum total biomass of 198.8 m3 x hm(-2), which was 118.8% of the total biomass in pure Eucalyptus U6 stand, or 169.9% of that in pure A. crassicarpa stand. Mixture of Eucalyptus with Acacia would be a good choice to produce Eucalyptus trees with larger DBH.

Simple method for direct crown base height estimation of individual conifer trees using airborne LiDAR data.

PubMed

Luo, Laiping; Zhai, Qiuping; Su, Yanjun; Ma, Qin; Kelly, Maggi; Guo, Qinghua

2018-05-14

Crown base height (CBH) is an essential tree biophysical parameter for many applications in forest management, forest fuel treatment, wildfire modeling, ecosystem modeling and global climate change studies. Accurate and automatic estimation of CBH for individual trees is still a challenging task. Airborne light detection and ranging (LiDAR) provides reliable and promising data for estimating CBH. Various methods have been developed to calculate CBH indirectly using regression-based means from airborne LiDAR data and field measurements. However, little attention has been paid to directly calculate CBH at the individual tree scale in mixed-species forests without field measurements. In this study, we propose a new method for directly estimating individual-tree CBH from airborne LiDAR data. Our method involves two main strategies: 1) removing noise and understory vegetation for each tree; and 2) estimating CBH by generating percentile ranking profile for each tree and using a spline curve to identify its inflection points. These two strategies lend our method the advantages of no requirement of field measurements and being efficient and effective in mixed-species forests. The proposed method was applied to a mixed conifer forest in the Sierra Nevada, California and was validated by field measurements. The results showed that our method can directly estimate CBH at individual tree level with a root-mean-squared error of 1.62 m, a coefficient of determination of 0.88 and a relative bias of 3.36%. Furthermore, we systematically analyzed the accuracies among different height groups and tree species by comparing with field measurements. Our results implied that taller trees had relatively higher uncertainties than shorter trees. Our findings also show that the accuracy for CBH estimation was the highest for black oak trees, with an RMSE of 0.52 m. The conifer species results were also good with uniformly high R 2 ranging from 0.82 to 0.93. In general, our method has demonstrated high accuracy for individual tree CBH estimation and strong potential for applications in mixed species over large areas.

Population pharmacokinetics of aripiprazole in healthy Korean subjects.

PubMed

Jeon, Ji-Young; Chae, Soo-Wan; Kim, Min-Gul

2016-04-01

Aripiprazole is widely used to treat schizophrenia and bipolar disorder. This study aimed to develop a combined population pharmacokinetic model for aripiprazole in healthy Korean subjects and to identify the significant covariates in the pharmacokinetic variability of aripiprazole. Aripiprazole plasma concentrations and demographic data were collected retrospectively from previous bioequivalence studies that were conducted in Chonbuk National University Hospital. Informed consent was obtained from subjects for cytochrome P450 (CYP) genotyping. The population pharmacokinetic parameters of aripiprazole were estimated using nonlinear mixed-effect modeling with first-order conditional estimation with interaction method. The effects of age, sex, weight, height, and CYP genotype were assessed as covariates. A total of 1,508 samples from 88 subjects in three bioequivalence studies were collected. The two-compartment model was adopted, and the final population model showed that the CYP2D6 genotype polymorphism, height and weight significantly affect aripiprazole disposition. The bootstrap and visual predictive check results were evaluated, showing that the accuracy of the pharmacokinetic model was acceptable. A population pharmacokinetic model of aripiprazole was developed for Korean subjects. CYP2D6 genotype polymorphism, weight, and height were included as significant factors affecting aripiprazole disposition. The population pharmacokinetic parameters of aripiprazole estimated in the present study may be useful for individualizing clinical dosages and for studying the concentration-effect relationship of the drug.

Twenty-nine years of development in planted cherrybark oak-sweetgum mixtures: implications for future mixed-species hardwood plantations

Treesearch

Brian Roy Lockhart; Andrew W. Ezell; John D. Hodges; Wayne K. Clatterbuck

2012-01-01

Results from a long-term planted mixture of cherrybark oak (Quercus pagoda Raf.) and sweetgum (Liquidambar styraciflua L.) showed sweetgum taller in height and larger in diameter than cherrybark oak early in plantation development. By age 17, cherrybark oak was similar in height and diameter with sweetgum and by age 21 was taller...

Nitric Acid and Benomyl Stimulate Rapid Height Growth of Longleaf Pine

Treesearch

A.G. Kais; R.C. Hare; J.P. Barnett

1984-01-01

Rapid height growth of longleaf pine seedlings, important to production of uniform, even-aged stands, can be promoted by controlling brown-spot needle blight and weed competition, and by increasing soil fertility. Root systems of container-grown longleaf pine seedlings were dip-treated in either benomyl/clay mix (10 percent a.i. benomyl) or clay control and planted...

Mixing and solid-liquid mass-transfer rates in a creusot-loire uddeholm vessel: A water model case study

NASA Astrophysics Data System (ADS)

Nyoka, M.; Akdogan, G.; Eric, R. H.; Sutcliffe, N.

2003-12-01

The process of mixing and solid-liquid mass transfer in a one-fifth scale water model of a 100-ton Creusot-Loire Uddeholm (CLU) converter was investigated. The modified Froude number was used to relate gas flow rates between the model and its protoype. The influences of gas flow rate between 0.010 and 0.018 m3/s and bath height from 0.50 to 0.70 m on mixing time were examined. The results indicated that mixing time decreased with increasing gas flow rate and increased with increasing bath height. The mixing time results were evaluated in terms of specific energy input and the following correlation was proposed for estimating mixing times in the model CLU converter: T mix=1.08Q -1.05 W 0.35, where Q (m3/s) is the gas flow rate and W (tons) is the model bath weight. Solid-liquid mass-transfer rates from benzoic acid specimens immersed in the gas-agitated liquid phase were assessed by a weight loss measurement technique. The calculated mass-transfer coefficients were highest at the bath surface reaching a value of 6.40 × 10-5 m/s in the sprout region. Mass-transfer coefficients and turbulence parameters decreased with depth, reaching minimum values at the bottom of the vessel.

Combined Use of Airborne Lidar and DBInSAR Data to Estimate LAI in Temperate Mixed Forests

NASA Technical Reports Server (NTRS)

Peduzzi, Alicia; Wynne, Randolph Hamilton; Thomas, Valerie A.; Nelson, Ross F.; Reis, James J.; Sanford, Mark

2012-01-01

The objective of this study was to determine whether leaf area index (LAI) in temperate mixed forests is best estimated using multiple-return airborne laser scanning (lidar) data or dual-band, single-pass interferometric synthetic aperture radar data (from GeoSAR) alone, or both in combination. In situ measurements of LAI were made using the LiCor LAI-2000 Plant Canopy Analyzer on 61 plots (21 hardwood, 36 pine, 4 mixed pine hardwood; stand age ranging from 12-164 years; mean height ranging from 0.4 to 41.2 m) in the Appomattox-Buckingham State Forest, Virginia, USA. Lidar distributional metrics were calculated for all returns and for ten one meter deep crown density slices (a new metric), five above and five below the mode of the vegetation returns for each plot. GeoSAR metrics were calculated from the X-band backscatter coefficients (four looks) as well as both X- and P-band interferometric heights and magnitudes for each plot. Lidar metrics alone explained 69% of the variability in LAI, while GeoSAR metrics alone explained 52%. However, combining the lidar and GeoSAR metrics increased the R2 to 0.77 with a CV-RMSE of 0.42. This study indicates the clear potential for X-band backscatter and interferometric height (both now available from spaceborne sensors), when combined with small-footprint lidar data, to improve LAI estimation in temperate mixed forests.

Accuracy of Jump-Mat Systems for Measuring Jump Height.

PubMed

Pueo, Basilio; Lipinska, Patrycja; Jiménez-Olmedo, José M; Zmijewski, Piotr; Hopkins, Will G

2017-08-01

Vertical-jump tests are commonly used to evaluate lower-limb power of athletes and nonathletes. Several types of equipment are available for this purpose. To compare the error of measurement of 2 jump-mat systems (Chronojump-Boscosystem and Globus Ergo Tester) with that of a motion-capture system as a criterion and to determine the modifying effect of foot length on jump height. Thirty-one young adult men alternated 4 countermovement jumps with 4 squat jumps. Mean jump height and standard deviations representing technical error of measurement arising from each device and variability arising from the subjects themselves were estimated with a novel mixed model and evaluated via standardization and magnitude-based inference. The jump-mat systems produced nearly identical measures of jump height (differences in means and in technical errors of measurement ≤1 mm). Countermovement and squat-jump height were both 13.6 cm higher with motion capture (90% confidence limits ±0.3 cm), but this very large difference was reduced to small unclear differences when adjusted to a foot length of zero. Variability in countermovement and squat-jump height arising from the subjects was small (1.1 and 1.5 cm, respectively, 90% confidence limits ±0.3 cm); technical error of motion capture was similar in magnitude (1.7 and 1.6 cm, ±0.3 and ±0.4 cm), and that of the jump mats was similar or smaller (1.2 and 0.3 cm, ±0.5 and ±0.9 cm). The jump-mat systems provide trustworthy measurements for monitoring changes in jump height. Foot length can explain the substantially higher jump height observed with motion capture.

Height extrapolation of wind data

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

Mikhail, A.S.

1982-11-01

Hourly average data for a period of 1 year from three tall meteorological towers - the Erie tower in Colorado, the Goodnoe Hills tower in Washington and the WKY-TV tower in Oklahoma - were used to analyze the wind shear exponent variabiilty with various parameters such as thermal stability, anemometer level wind speed, projection height and surface roughness. Different proposed models for prediction of height variability of short-term average wind speeds were discussed. Other models that predict the height dependence of Weilbull distribution parameters were tested. The observed power law exponent for all three towers showed strong dependence on themore » anemometer level wind speed and stability (nighttime and daytime). It also exhibited a high degree of dependence on extrapolation height with respect to anemometer height. These dependences became less severe as the anemometer level wind speeds were increased due to the turbulent mixing of the atmospheric boundary layer. The three models used for Weibull distribution parameter extrapolation were he velocity-dependent power law model (Justus), the velocity, surface roughness, and height-dependent model (Mikhail) and the velocity and surface roughness-dependent model (NASA). The models projected the scale parameter C fairly accurately for the Goodnoe Hills and WKY-TV towers and were less accurate for the Erie tower. However, all models overestimated the C value. The maximum error for the Mikhail model was less than 2% for Goodnoe Hills, 6% for WKY-TV and 28% for Erie. The error associated with the prediction of the shape factor (K) was similar for the NASA, Mikhail and Justus models. It ranged from 20 to 25%. The effect of the misestimation of hub-height distribution parameters (C and K) on average power output is briefly discussed.« less

Examining Atmospheric and Ecological Drivers of Wildfires, Modeling Wildfire Occurrence in the Southwest United States, and Using Atmospheric Sounding Observations to Verify National Weather Service Spot Forecasts

NASA Astrophysics Data System (ADS)

Nauslar, Nicholas J.

This dissertation is comprised of three different papers that all pertain to wildland fire applications. The first paper performs a verification analysis on mixing height, transport winds, and Haines Index from National Weather Service spot forecasts across the United States. The final two papers, which are closely related, examine atmospheric and ecological drivers of wildfire for the Southwest Area (SWA) (Arizona, New Mexico, west Texas, and Oklahoma panhandle) to better equip operational fire meteorologists and managers to make informed decisions on wildfire potential in this region. The verification analysis here utilizes NWS spot forecasts of mixing height, transport winds and Haines Index from 2009-2013 issued for a location within 50 km of an upper sounding location and valid for the day of the fire event. Mixing height was calculated from the 0000 UTC sounding via the Stull, Holzworth, and Richardson methods. Transport wind speeds were determined by averaging the wind speed through the boundary layer as determined by the three mixing height methods from the 0000 UTC sounding. Haines Index was calculated at low, mid, and high elevation based on the elevation of the sounding and spot forecast locations. Mixing height forecasts exhibited large mean absolute errors and biased towards over forecasting. Forecasts of transport wind speeds and Haines Index outperformed mixing height forecasts with smaller errors relative to their respective means. The rainfall and lightning associated with the North American Monsoon (NAM) can vary greatly intra- and inter-annually and has a large impact on wildfire activity across the SWA by igniting or suppressing wildfires. NAM onset thresholds and subsequent dates are determined for the SWA and each Predictive Service Area (PSA), which are sub-regions used by operational fire meteorologists to predict wildfire potential within the SWA, April through September from 1995-2013. Various wildfire activity thresholds using the number of wildfires and large wildfires identified days or time periods with increased wildfire activity for each PSA and the SWA. Self-organizing maps utilizing 500 and 700 hPa geopotential heights and precipitable water were implemented to identify atmospheric patterns contributing to the NAM onset and busy days/periods for each PSA and the SWA. Resulting SOM map types also showed the transition to, during, and from the NAM. Northward and eastward displacements of the subtropical ridge (i.e., four-corners high) over the SWA were associated with NAM onset, and a suppressed subtropical ridge and breakdown of the subtropical ridge map types over the SWA were associated with increased wildfire activity. We implemented boosted regression trees (BRT) to model wildfire occurrence for all and large wildfires for different wildfire types (i.e., lightning, human) across the SWA by PSA. BRT models for all wildfires demonstrated relatively small mean and mean absolute errors and showed better predictability on days with wildfires. Cross-validated accuracy assessments for large wildfires demonstrated the ability to discriminate between large wildfire and non-large wildfire days across all wildfire types. Measurements describing fuel conditions (i.e., 100 and 1000-hour dead fuel moisture, energy release component) were the most important predictors when considering all wildfire types and sizes. However, a combination of fuels and atmospheric predictors (i.e., lightning, temperature) proved most predictive for large wildfire occurrence, and the number of relevant predictors increases for large wildfires indicating more conditions need to align to support large wildfires.

Forest regeneration composition and development in upland, mixed-oak forests.

PubMed

Fei, Songlin; Gould, Peter J; Steiner, Kim C; Finley, James C; McDill, Marc E

2005-12-01

Advance regeneration in 52 mature mixed-oak stands was analyzed and described. Red maple (Acer rubrum L.) was the most abundant species in the study area. Among oak (Quercus) species, northern red oak (Q. rubra L.) was the most abundant within the Allegheny Plateau physiographic province, whereas chestnut oak (Q. montana L.) was the most abundant within the Ridge and Valley physiographic province. Sixteen stands, for which data are available through the fourth growing season following harvest, were used to describe stand development. Cumulative height, a composite measure of size and density, was used to describe early stand development. Black gum (Nyssa sylvatica Marsh.) and black birch (Betula lenta L.) had dramatic increases in stand density and cumulative height after overstory removal. Cumulative height of northern red oak and chestnut oak showed a faster positive response to overstory removal than red maple. Oak retained its dominance in cumulative height for at least 4 years after harvest. Red maple nevertheless remained the most abundant tree species after overstory removal. Our results suggest that the principal advantage of red maple regeneration is its ability to accumulate in large numbers prior to harvest.

Timing of Maternal Depression and Sex-specific Child Growth, the Upstate KIDS Study

PubMed Central

Park, Hyojun; Sundaram, Rajeshwari; Gilman, Stephen E.; Bell, Griffith; Buck Louis, Germaine M.; Yeung, Edwina H.

2017-01-01

Objective Equivocal findings have been reported between maternal depression and children’s growth possibly given limited attention to its disproportionate impact by child sex. We assessed the relationship between the timing of maternal depression and children’s growth in a population-based prospective birth cohort with particular attention to sex differences. Methods The Upstate KIDS Study comprised 4,394 children followed through 3 years of age from 2008 to 2010. Maternal depression was measured antenatally by linkage with hospital discharge records before delivery, and postnatally, by depressive symptoms reported from questionnaires. Child’s growth was measured by sex-and-age-specific weight, height, weight-for-height, and body mass index. Adjusted linear mixed effects models were used to estimate growth outcomes for the full sample and separately by plurality and sex. Results Antenatal depression was associated with lower weight-for-age (−0.24 z-score units; 95%CI: −0.43, −0.05) and height-for-age (−0.26; −0.51, −0.02) among singleton boys. Postnatal depressive symptoms were associated with higher weight-for-height (0.21; 0.01, 0.42) among singleton girls. Conclusions Our findings suggest that antenatal depression was associated with lower weight and smaller height only for boys, while postnatal depressive symptom was associated with higher weight-for- height only for girls. Timing of depression and the mechanisms of sex-specific responses require further examination. PMID:29090856

Developing a global mixed-canopy, height-variable vegetation structure dataset for estimating global vegetation albedo and biomass in the NASA Ent Terrestrial Biosphere Model and GISS GCM

NASA Astrophysics Data System (ADS)

Montes, C.; Kiang, N. Y.; Yang, W.; Ni-Meister, W.; Schaaf, C.; Aleinov, I. D.; Jonas, J.; Zhao, F. A.; Yao, T.; Wang, Z.; Sun, Q.

2015-12-01

Processes determining biosphere-atmosphere coupling are strongly influenced by vegetation structure. Thus, ecosystem carbon sequestration and evapotranspiration affecting global carbon and water balances will depend upon the spatial extent of vegetation, its vertical structure, and its physiological variability. To represent this globally, Dynamic Global Vegetation Models (DGVMs) coupled to General Circulation Models (GCMs) make use of satellite and/or model-based vegetation classifications often composed by homogeneous communities. This work aims at developing a new Global Vegetation Structure Dataset (GVSD) by incorporating varying vegetation heights for mixed plant communities to be used as input to the Ent Terrestrial Biosphere Model (TBM), the DGVM coupled to the NASA Goddard Institute for Space Studies (GISS) GCM. Information sources include the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover and plant functional types (PFTs) (Friedl et al., 2010), vegetation height from the Geoscience Laser Altimeter System (GLAS) on board ICESat (Ice, Cloud, and land Elevation Satellite) (Simard et al., 2011; Tang et al., 2014) along with the Global Data Sets of Vegetation Leaf Area Index (LAI)3g (Zhu et al. 2013). Further PFT partitioning is performed according to a climate classification utilizing the Climate Research Unit (CRU) and the NOAA Global Precipitation Climatology Centre (GPCC) data. Final products are a GVSD consisting of mixed plant communities (e.g. mixed forests, savannas, mixed PFTs) following the Ecosystem Demography model (Moorcroft et al., 2001) approach represented by multi-cohort community patches at the sub-grid level of the GCM, which are ensembles of identical individuals whose differences are represented by PFTs, canopy height, density and vegetation structure sensitivity to allometric parameters. To assess the sensitivity of the GISS GCM to vegetation structure, we produce a range of estimates of Ent TBM biomass and plant densities by varying allometric specifications. Ultimately, this GVSD will serve as a template for community data sets, and be used as boundary conditions to the Ent TBM for prediction of canopy albedo in the Analytical Clumped Two-Stream canopy radiative transfer scheme, biomass, primary productivity, respiration, and GISS GCM climate.

Electroosmotic flow mixing in zigzag microchannels.

PubMed

Chen, Jia-Kun; Yang, Ruey-Jen

2007-03-01

In this study we performed numerical and experimental investigations into the mixing of EOFs in zigzag microchannels with two different corner geometries, namely sharp corners and flat corners. In the zigzag microchannel with sharp corners, the flow travels more rapidly near the inner wall of the corner than near the outer wall as a result of the higher electric potential drop. The resulting velocity gradient induces a racetrack effect, which enhances diffusion within the fluid and hence improves the mixing performance. The simulation results reveal that the mixing index is approximately 88.83%. However, the sharp-corner geometry causes residual liquid or bubbles to become trapped in the channel at the point where the flow is almost stationary, when the channel is in the process of cleaning. Accordingly, a zigzag microchannel with flat-corner geometry is developed. The flat-corner geometry forms a convergent-divergent type nozzle which not only enhances the mixing performance in the channel, but also prevents the accumulation of residual liquid or bubbles. Scaling analysis reveals that this corner geometry leads to an effective increase in the mixing length. The experimental results reveal that the mixing index is increased to 94.30% in the flat-corner zigzag channel. Hence, the results demonstrate that the mixing index of the flat-corner zigzag channel is better than that of the conventional sharp-corner microchannel. Finally, the results of Taguchi analysis indicate that the attainable mixing index is determined primarily by the number of corners in the microchannel and by the flow passing height at each corner.

Selection of an actinobacteria mixed culture for chlordane remediation. Pesticide effects on microbial morphology and bioemulsifier production.

PubMed

Fuentes, María S; Colin, Verónica L; Amoroso, María J; Benimeli, Claudia S

2016-02-01

Chlordane bioremediation using actinobacteria mixed culture is an attractive clean-up technique. Their ability to produce bioemulsifiers could increase the bioavailability of this pesticide. In order to select a defined actinobacteria mixed culture for chlordane remediation, compatibility assays were performed among six Streptomyces strains. The strains did not show growth inhibition, and they were assayed for chlordane removal, either as pure or as mixed cultures. In pure cultures, all of the strains showed specific dechlorination activity (1.42-24.20 EU mg(-1)) and chlordane removal abilities (91.3-95.5%). The specific dechlorination activity was mainly improved with cultures of three or four microorganisms. The mixed culture consisting of Streptomyces sp. A2-A5-A13 was selected. Their ability to produce bioemulsifiers in the presence of glucose or chlordane was tested, but no significant differences were observed (p > 0.05). However, the stability of the emulsions formed was linked to the carbon source used. Only in chlordane presence the emulsions retained 100% of their initial height. Finally, the selected consortium showed a high degree of sporulation in the pesticide presence. This is the first study on the effects that chlordane exerts on microbe morphology and emulsifier production for a defined mixed culture of Streptomyces with ability to remediate the pesticide. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

CFD Assessment of Orifice Aspect Ratio and Mass Flow Ratio on Jet Mixing in Rectangular Ducts

NASA Technical Reports Server (NTRS)

Bain, D. B.; Smith, C. E.; Holdeman, J. D.

1994-01-01

Isothermal CFD analysis was performed on axially opposed rows of jets mixing with cross flow in a rectangular duct. Laterally, the jets' centerlines were aligned with each other on the top and bottom walls. The focus of this study was to characterize the effects of orifice aspect ratio and jet-to-mainstream mass flow ratio on jet penetration and mixing. Orifice aspect ratios (L/W) of 4-to-1, 2-to-1, and 1-to-1, along with circular holes, were parametrically analyzed. Likewise, jet-to-mainstream mass flow ratios (MR) of 2.0, 0.5, and 0.25 were systematically investigated. The jet-to-mainstream momentum-flux ratio (J) was maintained at 36 for all cases, and the orifice spacing-to-duct height (S/H) was varied until optimum mixing was attained for each configuration. The numerical results showed that orifice aspect ratio (and likewise orifice blockage) had little effect on jet penetration and mixing. Based on mixing characteristics alone, the 4-to-1 slot was comparable to the circular orifice. The 4-to-1 slot has a smaller jet wake which may be advantageous for reducing emissions. However, the axial length of a 4-to-1 slot may be prohibitively long for practical application, especially for MR of 2.0. The jet-to-mainstream mass flow ratio had a more significant effect on jet penetration and mixing. For a 4-to-1 aspect ratio orifice, the design correlating parameter for optimum mixing (C = (S/H)(sq. root J)) varied from 2.25 for a mass flow ratio of 2.0 to 1.5 for a mass flow ratio of 0.25.

Dome effect of black carbon and its key influencing factors: a one-dimensional modelling study

NASA Astrophysics Data System (ADS)

Wang, Zilin; Huang, Xin; Ding, Aijun

2018-02-01

Black carbon (BC) has been identified to play a critical role in aerosol-planetary boundary layer (PBL) interaction and further deterioration of near-surface air pollution in megacities, which has been referred to as the dome effect. However, the impacts of key factors that influence this effect, such as the vertical distribution and aging processes of BC, as well as the underlying land surface, have not been quantitatively explored yet. Here, based on available in situ measurements of meteorology and atmospheric aerosols together with the meteorology-chemistry online coupled model WRF-Chem, we conduct a set of parallel simulations to quantify the roles of these factors in influencing the BC dome effect and surface haze pollution. Furthermore, we discuss the main implications of the results to air pollution mitigation in China. We found that the impact of BC on the PBL is very sensitive to the altitude of aerosol layer. The upper-level BC, especially that near the capping inversion, is more essential in suppressing the PBL height and weakening the turbulent mixing. The dome effect of BC tends to be significantly intensified as BC mixed with scattering aerosols during winter haze events, resulting in a decrease in PBL height by more than 15 %. In addition, the dome effect is more substantial (up to 15 %) in rural areas than that in the urban areas with the same BC loading, indicating an unexpected regional impact of such an effect to air quality in countryside. This study indicates that China's regional air pollution would greatly benefit from BC emission reductions, especially those from elevated sources from chimneys and also domestic combustion in rural areas, through weakening the aerosol-boundary layer interactions that are triggered by BC.

The Influence of Study-Level Inference Models and Study Set Size on Coordinate-Based fMRI Meta-Analyses

PubMed Central

Bossier, Han; Seurinck, Ruth; Kühn, Simone; Banaschewski, Tobias; Barker, Gareth J.; Bokde, Arun L. W.; Martinot, Jean-Luc; Lemaitre, Herve; Paus, Tomáš; Millenet, Sabina; Moerkerke, Beatrijs

2018-01-01

Given the increasing amount of neuroimaging studies, there is a growing need to summarize published results. Coordinate-based meta-analyses use the locations of statistically significant local maxima with possibly the associated effect sizes to aggregate studies. In this paper, we investigate the influence of key characteristics of a coordinate-based meta-analysis on (1) the balance between false and true positives and (2) the activation reliability of the outcome from a coordinate-based meta-analysis. More particularly, we consider the influence of the chosen group level model at the study level [fixed effects, ordinary least squares (OLS), or mixed effects models], the type of coordinate-based meta-analysis [Activation Likelihood Estimation (ALE) that only uses peak locations, fixed effects, and random effects meta-analysis that take into account both peak location and height] and the amount of studies included in the analysis (from 10 to 35). To do this, we apply a resampling scheme on a large dataset (N = 1,400) to create a test condition and compare this with an independent evaluation condition. The test condition corresponds to subsampling participants into studies and combine these using meta-analyses. The evaluation condition corresponds to a high-powered group analysis. We observe the best performance when using mixed effects models in individual studies combined with a random effects meta-analysis. Moreover the performance increases with the number of studies included in the meta-analysis. When peak height is not taken into consideration, we show that the popular ALE procedure is a good alternative in terms of the balance between type I and II errors. However, it requires more studies compared to other procedures in terms of activation reliability. Finally, we discuss the differences, interpretations, and limitations of our results. PMID:29403344

Demonstration and Optimization of BNFL's Pulsed Jet Mixing and RFD Sampling Systems Using NCAW Simulant

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

JR Bontha; GR Golcar; N Hannigan

2000-08-29

The BNFL Inc. flowsheet for the pretreatment and vitrification of the Hanford High Level Tank waste includes the use of several hundred Reverse Flow Diverters (RFDs) for sampling and transferring the radioactive slurries and Pulsed Jet mixers to homogenize or suspend the tank contents. The Pulsed Jet mixing and the RFD sampling devices represent very simple and efficient methods to mix and sample slurries, respectively, using compressed air to achieve the desired operation. The equipment has no moving parts, which makes them very suitable for mixing and sampling highly radioactive wastes. However, the effectiveness of the mixing and sampling systemsmore » are yet to be demonstrated when dealing with Hanford slurries, which exhibit a wide range of physical and theological properties. This report describes the results of the testing of BNFL's Pulsed Jet mixing and RFD sampling systems in a 13-ft ID and 15-ft height dish-bottomed tank at Battelle's 336 building high-bay facility using AZ-101/102 simulants containing up to 36-wt% insoluble solids. The specific objectives of the work were to: Demonstrate the effectiveness of the Pulsed Jet mixing system to thoroughly homogenize Hanford-type slurries over a range of solids loading; Minimize/optimize air usage by changing sequencing of the Pulsed Jet mixers or by altering cycle times; and Demonstrate that the RFD sampler can obtain representative samples of the slurry up to the maximum RPP-WTP baseline concentration of 25-wt%.« less

Vegetation as an Agronomic Method of Dust Control on Helicopter Training Areas at Fort Rucker, Alabama

DTIC Science & Technology

1991-09-01

effectiveness and cost of these materials vary greatly. Admix methods include the mixing of cement, hydrated lime , cutback asphalt, and similar...the information needed to determine fertilizer and lime requirements for the soil. The mowing height should be raised to keep the vegetation at a mini...Methods Year 1 In February 1988, soil samples were collected from the site for analysis to determine lime and fertilizer requirements. Area RT14 was

Inventory of File nam.t00z.awiphi00.tm00.grib2

Science.gov Websites

Factor [non-dim] 041 50 mb HGT analysis Geopotential Height [gpm] 042 50 mb TMP analysis Temperature [K /kg] 052 50 mb RIME analysis Rime Factor [non-dim] 053 75 mb HGT analysis Geopotential Height [gpm SNMR analysis Snow Mixing Ratio [kg/kg] 064 75 mb RIME analysis Rime Factor [non-dim] 065 100 mb HGT

Automated estimation of individual conifer tree height and crown diameter via Two-dimensional spatial wavelet analysis of lidar data

Treesearch

Michael J. Falkowski; Alistair M.S. Smith; Andrew T. Hudak; Paul E. Gessler; Lee A. Vierling; Nicholas L. Crookston

2006-01-01

We describe and evaluate a new analysis technique, spatial wavelet analysis (SWA), to automatically estimate the location, height, and crown diameter of individual trees within mixed conifer open canopy stands from light detection and ranging (lidar) data. Two-dimensional Mexican hat wavelets, over a range of likely tree crown diameters, were convolved with lidar...

Understory plant diversity in riparian alder-conifer stands after logging in southeast Alaska.

Treesearch

Robert L. Deal

1997-01-01

Stand structure, tree height growth, and understory plant diversity were assessed in five mixed alder-conifer stands after logging in southeast Alaska. Tree species composition ranged from 7- to 91-percent alder, and basal area ranged from 30 to 55 m2/ha. The alder exhibited rapid early height growth, but recent growth has slowed considerably. Some conifers have...

Selecting elephant grass families and progenies to produce bioenergy through mixed models (REML/BLUP).

PubMed

Rodrigues, E V; Daher, R F; Dos Santos, A; Vivas, M; Machado, J C; Gravina, G do A; de Souza, Y P; Vidal, A K; Rocha, A Dos S; Freitas, R S

2017-05-18

Brazil has great potential to produce bioenergy since it is located in a tropical region that receives high incidence of solar energy and presents favorable climatic conditions for such purpose. However, the use of bioenergy in the country is below its productivity potential. The aim of the current study was to select full-sib progenies and families of elephant grass (Pennisetum purpureum S.) to optimize phenotypes relevant to bioenergy production through mixed models (REML/BLUP). The circulating diallel-based crossing of ten elephant grass genotypes was performed. An experimental design using the randomized block methodology, with three repetitions, was set to assess both the hybrids and the parents. Each plot comprised 14-m rows, 1.40 m spacing between rows, and 1.40 m spacing between plants. The number of tillers, plant height, culm diameter, fresh biomass production, dry biomass rate, and the dry biomass production were assessed. Genetic-statistical analyses were performed through mixed models (REML/BLUP). The genetic variance in the assessed families was explained through additive genetic effects and dominance genetic effects; the dominance variance was prevalent. Families such as Capim Cana D'África x Guaçu/I.Z.2, Cameroon x Cuba-115, CPAC x Cuba-115, Cameroon x Guaçu/I.Z.2, and IAC-Campinas x CPAC showed the highest dry biomass production. The family derived from the crossing between Cana D'África and Guaçu/I.Z.2 showed the largest number of potential individuals for traits such as plant height, culm diameter, fresh biomass production, dry biomass production, and dry biomass rate. The individual 5 in the family Cana D'África x Guaçu/I.Z.2, planted in blocks 1 and 2, showed the highest dry biomass production.

Modeling Atmospheric Transport for Greenhouse Gas Observations within the Urban Dome

NASA Astrophysics Data System (ADS)

Nehrkorn, T.; Sargent, M. R.; Wofsy, S. C.

2016-12-01

Observations of CO2, CH4, and other greenhouse gases (GHGs) within the urban dome of major cities generally show large enhancements over background values, and large sensitivity to surface fluxes (as measured by the footprints computed by Lagrangian Particle Dispersion Models, LPDMs) within the urban dome. However, their use in top-down inversion studies to constrain urban emission estimates is complicated by difficulties in proper modeling of the atmospheric transport. We are conducting experiments with the Weather Research and Forecast model (WRF) coupled to the STILT LPDM to improve model simulation of atmospheric transport on spatial scales of a few km in urban domains, because errors in transport on short time/space scales are amplified by the patchiness of GHG emissions and may engender systematic errors of simulated concentrations.We are evaluating the quality of the meteorological simulations from model configurations with different resolutions and PBL packages, using both standard and non-standard (Lidar PBL height and ACARS aircraft profile) observations. To take into account the effect of building scale eddies for observations located on top of buildings, we are modifying the basic STILT algorithm for the computation of footprints by replacing the nominal receptor height by an effective sampling height. In addition, the footprint computations for near-field emissions make use of the vertical particle spread within the LPDM to arrive at a more appropriate estimate of mixing heights in the immediate vicinity of receptors. We present the effect of these and similar modifications on simulated concentrations and their level of agreement with observed values.

Sensitivity of Above-Ground Biomass Estimates to Height-Diameter Modelling in Mixed-Species West African Woodlands

PubMed Central

Aynekulu, Ermias; Pitkänen, Sari; Packalen, Petteri

2016-01-01

It has been suggested that above-ground biomass (AGB) inventories should include tree height (H), in addition to diameter (D). As H is a difficult variable to measure, H-D models are commonly used to predict H. We tested a number of approaches for H-D modelling, including additive terms which increased the complexity of the model, and observed how differences in tree-level predictions of H propagated to plot-level AGB estimations. We were especially interested in detecting whether the choice of method can lead to bias. The compared approaches listed in the order of increasing complexity were: (B0) AGB estimations from D-only; (B1) involving also H obtained from a fixed-effects H-D model; (B2) involving also species; (B3) including also between-plot variability as random effects; and (B4) involving multilevel nested random effects for grouping plots in clusters. In light of the results, the modelling approach affected the AGB estimation significantly in some cases, although differences were negligible for some of the alternatives. The most important differences were found between including H or not in the AGB estimation. We observed that AGB predictions without H information were very sensitive to the environmental stress parameter (E), which can induce a critical bias. Regarding the H-D modelling, the most relevant effect was found when species was included as an additive term. We presented a two-step methodology, which succeeded in identifying the species for which the general H-D relation was relevant to modify. Based on the results, our final choice was the single-level mixed-effects model (B3), which accounts for the species but also for the plot random effects reflecting site-specific factors such as soil properties and degree of disturbance. PMID:27367857

Experiments and modeling of dilution jet flow fields

NASA Technical Reports Server (NTRS)

Holdeman, James D.

1986-01-01

Experimental and analytical results of the mixing of single, double, and opposed rows of jets with an isothermal or variable-temperature main stream in a straight duct are presented. This study was performed to investigate flow and geometric variations typical of the complex, three-dimensional flow field in the dilution zone of gas-turbine-engine combustion chambers. The principal results, shown experimentally and analytically, were the following: (1) variations in orifice size and spacing can have a significant effect on the temperature profiles; (2) similar distributions can be obtained, independent of orifice diameter, if momentum-flux ratio and orifice spacing are coupled; (3) a first-order approximation of the mixing of jets with a variable-temperature main stream can be obtained by superimposing the main-stream and jets-in-an-isothermal-crossflow profiles; (4) the penetration of jets issuing mixing is slower and is asymmetric with respect to the jet centerplanes, which shift laterally with increasing downstream distance; (5) double rows of jets give temperature distributions similar to those from a single row of equally spaced, equal-area circular holes; (6) for opposed rows of jets, with the orifice centerlines in line, the optimum ratio of orifice spacing to duct height is one-half the optimum value for single-side injection at the same momentum-flux ratiol and (7) for opposed rows of jets, with the orifice centerlines staggered, the optimum ratio of orifice spacing to duct height is twice the optimum value for single-side injection at the same momentum-flux ratio.

77 FR 24976 - Draft Environmental Impact Statement for the Proposed Spokane Tribe of Indians West Plains Casino...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-26

... DEPARTMENT OF THE INTERIOR Bureau of Indian Affairs Draft Environmental Impact Statement for the Proposed Spokane Tribe of Indians West Plains Casino and Mixed Use Project, City of Airway Heights, Spokane... Impact Statement (DEIS) for the Spokane Tribe of Indians West Plains casino and mixed use project, City...

Stocking equations for regeneration in mixed oak stands

Treesearch

Songlin Fei; Kim C. Steiner; James C. Finley

2007-01-01

Regeneration stocking equations for mixed-oak stands were developed based on data collected from nearly 14,000 plots in the central Appalachians. Maximum stand density was identified by plotting aggregate height against number of seedlings per plot, and was used as the reference level of the average maximum stand density (100 percent stocking or A-level stocking)....

Stand dynamics of mixed red alder-conifer forests of southeast Alaska.

Treesearch

Robert L. Deal; Paul E. Hennon; Ewa H. Orlikowska; David V. D' Amore

2004-01-01

Stand structure and dynamics were evaluated in mixed red alder (Alnus rubra Bong.) - conifer forests of southeast Alaska. We assessed stand development, tree density, total basal area, diameter distribution of live and dead trees, height distribution of live trees, and mean diameter of all and largest conifers in 40-year-old red alder - conifer...

Reconstructing the competitive dynamics of mixed-oak neighborhoods

Treesearch

Eric K. Zenner; Daniel J. Heggenstaller; Patrick H. Brose; JeriLynn E. Peck; Kim C. Steiner

2012-01-01

The disparity between the potential for latent oak dominance within a stand and their region-wide decline in importance value raises questions about the competitiveness of oaks in early stand dynamics. We reconstructed tree height growth dynamics in mixed-species neighborhoods to determine if currently dominant oaks were ever shorter than their competitors and at what...

Kidney transplantation fails to provide adequate growth in children with chronic kidney disease born small for gestational age.

PubMed

Franke, Doris; Steffens, Rena; Thomas, Lena; Pavičić, Leo; Ahlenstiel, Thurid; Pape, Lars; Gellermann, Jutta; Müller, Dominik; Querfeld, Uwe; Haffner, Dieter; Živičnjak, Miroslav

2017-03-01

Children with chronic kidney disease are frequently born small for gestational age (SGA) and prone to disproportionately short stature. It is unclear how SGA affects growth after kidney transplantation (KTx). Linear growth (height, sitting height, and leg length) was prospectively investigated in a cohort of 322 pediatric KTx recipients, with a mean follow-up of 4.9 years. Sitting height index (ratio of sitting height to total body height) was used to assess body proportions. Predictors of growth outcome in KTx patients with (n = 94) and without (n = 228) an SGA history were evaluated by the use of linear mixed-effects models. Mean z-scores for all linear body dimensions were lower in SGA compared with non-SGA patients (p < 0.001). SGA patients presented with higher target height deficit and degree of body disproportion (p < 0.001). The latter was mainly due to reduced leg growth during childhood. Pubertal trunk growth was diminished in SGA patients, and the pubertal growth spurt of legs was delayed in both groups, resulting in further impairment of adult height, which was more frequently reduced in SGA than in non-SGA patients (50 % vs 18 %, p < 0.001). Use of growth hormone treatment in the pre-transplant period, preemptive KTx, transplant function, and control of metabolic acidosis were the only potentially modifiable correlates of post-transplant growth in SGA groups. By contrast, living related KTx, steroid exposure, and degree of anemia proved to be correlates in non-SGA only. In children born SGA, growth outcome after KTx is significantly more impaired and affected by different clinical parameters compared with non-SGA patients.

Vertical distributions of aerosols under different weather conditions: Analysis of in-situ aircraft measurements in Beijing, China

NASA Astrophysics Data System (ADS)

Zhang, Qiang; Ma, XinCheng; Tie, Xuexi; Huang, Mengyu; Zhao, Chunsheng

In this study, aerosol vertical distributions of 17 in-situ aircraft measurements during 2005 and 2006 springs are analyzed. The 17 flights are carefully selected to exclude dust events, and the analyses are focused on the vertical distributions of aerosol particles associated with anthropogenic activities. The results show that the vertical distributions of aerosol particles are strongly affected by weather and meteorological conditions, and 3 different types of aerosol vertical distributions corresponding to different weather systems are defined in this study. The measurement with a flat vertical gradient and low surface aerosol concentrations is defined as type-1; a gradual decrease of aerosols with altitudes and modest surface aerosol concentrations is defined as type-2; a sharp vertical gradient (aerosols being strongly depressed in the PBL) with high surface aerosol concentrations is defined as type-3. The weather conditions corresponding to the 3 different aerosol types are high pressure, between two high pressures, and low pressure systems (frontal inversions), respectively. The vertical mixing and horizontal transport for the 3 different vertical distributions are analyzed. Under the type-1 condition, the vertical mixing and horizontal transport were rapid, leading to strong dilution of aerosols in both vertical and horizontal directions. As a result, the aerosol concentrations in PBL (planetary boundary layer) were very low, and the vertical distribution was flat. Under the type-2 condition, the vertical mixing was strong and there was no strong barrier at the PBL height. The horizontal transport (wind flux) was modest. As a result, the aerosol concentrations were gradually reduced with altitude, with modest surface aerosol concentrations. Under the type-3 condition, there was a cold front near the region. As a result, a frontal inversion associated with weak vertical mixing appeared at the top of the inversion layer, forming a very strong barrier to prevent aerosol particles being exchanged from the PBL height to the free troposphere. As a result, the aerosol particles were strongly depressed in the PBL height, producing high surface aerosol concentrations. The measured vertical aerosol distributions have important implications for studying the effects of aerosols on photochemistry. The J[O 3] values are reduced by 11%, 48%, and 50%, under the type-1, type-2, and type-3 conditions, respectively. This result reveals that atmospheric oxidant capacity (OH concentrations) is modestly reduced under the type-1 condition, but is significantly reduced under the type-2 and type-3 conditions. This result also suggests that the effect of aerosol particles on surface solar flux is an integrated column effect, and detailed vertical distributions of aerosol particles are very important for assessing the impacts of aerosol on photochemistry.

Design and Test of Mixed-flow Impellers III : Design and Experimental Results for Impeller Model MFI-2A and Comparison with Impeller Model MFI-1A

NASA Technical Reports Server (NTRS)

Hamrick, Joseph T; Osborn, Walter M; Beede, William L

1953-01-01

A mixed-flow impeller was designed to give a prescribed blade-surface velocity distribution at mean blade height for a given hub-shroud profile. The blade shape at mean blade height, which was produced by the prescribed velocity distribution, was extended by means of radial lines to form the composite blade shape from hub to shroud. The resulting blade was relatively thick; therefore, it was necessary to retain the inverse blade taper which resulted from extension of the radial lines in order to prevent merging or near merging of the separate blades near the hub. For the first test version of the impeller, designated the MFI-2A, the blade height was arbitrarily made greater than that for the basic impeller (the MFI-2) to allow for viscous effects. At design equivalent speed of 1400 feet per second the peak pressure ratio and maximum adiabatic efficiency were 3.95 and 79 percent, respectively. The adiabatic efficiency of the MFI-2A is four points lower than that for impeller model MFI-1A, but because of the higher slip factor for the MFI-2A, the pressure ratios are approximately equal. The procedures followed in the design of the MFI-1A and MFI-2A were, in general, the same; and, although the prescribed initial condition resulted in geometrical configurations that were quite dissimilar, the resulting performance characteristics compare favorably with designs for which considerable development work has been necessary.

Inventory of File nam.t00z.awipak00.tm00.grib2

Science.gov Websites

Rime Factor [non-dim] 009 1 hybrid level HGT analysis Geopotential Height [gpm] 010 1 hybrid level TMP [kg/kg] 040 30 mb SNMR analysis Snow Mixing Ratio [kg/kg] 041 30 mb RIME analysis Rime Factor [non-dim Factor [non-dim] 054 75 mb HGT analysis Geopotential Height [gpm] 055 75 mb TMP analysis Temperature [K

Thermodynamic Conditions Favorable to Superlative Thunderstorm Updraft, Mixed Phase Microphysics and Lightning Flash Rate. Revised

NASA Technical Reports Server (NTRS)

Williams, E.; Mushtak, V.; Rosenfeld, D.; Goodman, S.; Boccippio, D.

2004-01-01

Satellite observations of lightning flash rate have been merged with proximal surface station thermodynamic observations toward improving the understanding of the response of the updraft and lightning activity in the tropical atmosphere to temperature. The tropical results have led in turn to an examination of thermodynamic climatology over the continental United States in summertime and its comparison with exceptional electrical conditions documented in earlier studies. The tropical and mid-latitude results taken together support an important role for cloud base height in regulating the transfer of Convective Available Potential Energy (CAPE) to updraft kinetic energy in thunderstorms. In the tropics, cloud base height is dominated by the dry bulb temperature over the wet bulb temperature as the lightning-regulating temperature in regions characterized by moist convection. In the extratropics, an elevated cloud base height may enable larger cloud water concentrations in the mixed phase region, a favorable condition for the positive charging of large ice particles that may result in thunderclouds with a reversed polarity of the main cloud dipole. The combined requirements of instability and cloud base height serve to confine the region of superlative electrification to the vicinity of the ridge in moist entropy in the western Great Plains.

Cross-sectional growth changes in skeletal and soft tissue cephalometric landmarks of children.

PubMed

Inada, Emi; Saitoh, Issei; Hayasaki, Haruaki; Yamada, Chiaki; Iwase, Yoko; Takemoto, Yoshihiko; Matsumoto, Yuko; Yamasaki, Youichi

2008-07-01

In order to provide standard values for craniofacial growth of normal children, we evaluated the growth changes of skeletal and soft tissue cephalometric landmarks from lateral cephalograms of 180 Japanese children. They were divided into three groups: primary dentition, mixed dentition, and permanent dentition. Specific skeletal angles and distances showed significant gender differences with increasing age. The only significant soft tissue gender difference was nose height in the oldest group. Upper pharynx dimension and nose height differed significantly among the groups in both genders. Positions of both the upper and lower lip changed significantly between the intermediate and oldest groups of both genders. Nasolabial angle did not change significantly with growth. The results of this study should be useful for predicting craniofacial growth and development or determining the effect of orthodontic treatment.

Reaching new heights: the effect of an environmentally enhanced outdoor enclosure on gibbons in a zoo setting.

PubMed

Anderson, Megan R

2014-01-01

Gibbons have adapted to live in the canopy layer of the rainforest. Gibbons in the wild predominantly spend their time high in the trees resting, traveling, and foraging for food. Comparatively, gibbons in the zoo often rest and search for their food terrestrially. The purpose of this study was to provide these arboreal smaller apes with more opportunities to utilize more vertical space. Six gibbons (4 Nomascus leucogenys and 2 Symphalangus syndactylus) were observed in 2 phases of an observational study. The 1st phase measured space utilization and behaviors of the zoo-housed gibbons in their original outdoor enclosures using instantaneous sampling. The 2nd phase measured the same space usage and behaviors after several modifications were made to the environmental structures in the same outdoor enclosures. A 2-way mixed-model analysis of variance tested the height utilization of the 6 gibbons. The gibbons chose to spend significantly more time outside and at higher heights when the new structures were added. This study shows that given the opportunity, gibbons will exhibit more species-appropriate behaviors.

The additional effects of a probiotic mix on abdominal adiposity and antioxidant Status: A double-blind, randomized trial.

PubMed

Gomes, Aline Corado; de Sousa, Rávila Graziany Machado; Botelho, Patrícia Borges; Gomes, Tatyanne Letícia Nogueira; Prada, Patrícia Oliveira; Mota, João Felipe

2017-01-01

To investigate whether a probiotic mix has additional effects when compared with an isolated dietary intervention on the body composition, lipid profile, endotoxemia, inflammation, and antioxidant profile. Women who had excess weight or obesity were recruited to a randomized, double-blind trial and received a probiotic mix (Lactobacillus acidophilus and casei; Lactococcus lactis; Bifidobacterium bifidum and lactis; 2 × 10 10 colony-forming units/day) (n = 21) or placebo (n = 22) for 8 weeks. Both groups received a dietary prescription. Body composition was assessed by anthropometry and dual-energy X-ray absorptiometry. The lipid profile, lipid accumulation product, plasma fatty acids, lipopolysaccharide, interleukin-6, interleukin-10, tumor necrosis factor-α, adiponectin, and the antioxidant enzymes activities were analyzed. In comparison with the dietary intervention group, the dietary intervention + probiotic mix group showed a greater reduction in the waist circumference (-3.40% vs. -5.48%, P = 0.03), waist-height ratio (-3.27% vs. -5.00%, P = 0.02), conicity index (-2.43% vs. -4.09% P = 0.03), and plasma polyunsaturated fatty acids (5.65% vs. -18.63%, P = 0.04) and an increase in the activity of glutathione peroxidase (-16.67% vs. 15.62%, P < 0.01). Supplementation of a probiotic mix reduced abdominal adiposity and increased antioxidant enzyme activity in a more effective way than an isolated dietary intervention. © 2016 The Obesity Society.

Timing of Maternal Depression and Sex-Specific Child Growth, the Upstate KIDS Study.

PubMed

Park, Hyojun; Sundaram, Rajeshwari; Gilman, Stephen E; Bell, Griffith; Louis, Germaine M Buck; Yeung, Edwina H

2018-01-01

Equivocal findings have been reported on the association between maternal depression and children's growth, possibly because of the limited attention to its disproportionate impact by child sex. The relationship between the timing of maternal depression and children's growth was assessed in a population-based prospective birth cohort, with particular attention to sex differences. The Upstate KIDS Study comprised 4,394 children followed through 3 years of age from 2008 to 2010. Maternal depression was measured antenatally by linkage with hospital discharge records before delivery and postnatally by depressive symptoms reported from questionnaires. Children's growth was measured by sex- and age-specific weight, height, weight for height, and BMI. Adjusted linear mixed effects models were used to estimate growth outcomes for the full sample and separately by plurality and sex. Antenatal depression was associated with lower weight for age (-0.24 z score units; 95% confidence interval [CI]: -0.43, -0.05) and height for age (-0.26 z score units; 95% CI: -0.51, -0.02) among singleton boys. Postnatal depressive symptoms were associated with higher weight for height (0.21 z score units; 95% CI: 0.01, 0.42) among singleton girls. The findings of this study suggest that antenatal depression was associated with lower weight and smaller height only for boys, whereas postnatal depressive symptoms were associated with higher weight for height only for girls. The timing of depression and the mechanisms of sex-specific responses require further examination. Published 2017. This article is a U.S. Government work and is in the public domain in the USA.

Alcohol-Induced Physiological Displacements and Their Effects on Flight-Related Functions

DTIC Science & Technology

1982-03-01

measured height and weight (6). One part bourbon per two parts of Coca Cola were mixed, divided equally into three drinks and drunk at an even rate over a...temporary protection against a plasma volume decrease (21). In our study, the imbibed volume of alcohol plus Coca Cola (about 350-550 ml) temporarily...amE E T Office of Aviation Medicine MAY 2 7 1982 Washington, D.C. 20591A~A C.-, t(Jin NOTICE This document is disseminated under the sponsorship of

Estimating Mixed Broadleaves Forest Stand Volume Using Dsm Extracted from Digital Aerial Images

NASA Astrophysics Data System (ADS)

Sohrabi, H.

2012-07-01

In mixed old growth broadleaves of Hyrcanian forests, it is difficult to estimate stand volume at plot level by remotely sensed data while LiDar data is absent. In this paper, a new approach has been proposed and tested for estimating stand forest volume. The approach is based on this idea that forest volume can be estimated by variation of trees height at plots. In the other word, the more the height variation in plot, the more the stand volume would be expected. For testing this idea, 120 circular 0.1 ha sample plots with systematic random design has been collected in Tonekaon forest located in Hyrcanian zone. Digital surface model (DSM) measure the height values of the first surface on the ground including terrain features, trees, building etc, which provides a topographic model of the earth's surface. The DSMs have been extracted automatically from aerial UltraCamD images so that ground pixel size for extracted DSM varied from 1 to 10 m size by 1m span. DSMs were checked manually for probable errors. Corresponded to ground samples, standard deviation and range of DSM pixels have been calculated. For modeling, non-linear regression method was used. The results showed that standard deviation of plot pixels with 5 m resolution was the most appropriate data for modeling. Relative bias and RMSE of estimation was 5.8 and 49.8 percent, respectively. Comparing to other approaches for estimating stand volume based on passive remote sensing data in mixed broadleaves forests, these results are more encouraging. One big problem in this method occurs when trees canopy cover is totally closed. In this situation, the standard deviation of height is low while stand volume is high. In future studies, applying forest stratification could be studied.

Mixed sand and gravel beaches: accurate measurement of active layer depth and sediment transport volumes using PIT tagged tracer pebbles

NASA Astrophysics Data System (ADS)

Holland, A.; Moses, C.; Sear, D. A.; Cope, S.

2016-12-01

As sediments containing significant gravel portions are increasingly used for beach replenishment projects globally, the total number of beaches classified as `mixed sand and gravel' (MSG) increases. Calculations for required replenishment sediment volumes usually assume a uniform layer of sediment transport across and along the beach, but research into active layer (AL) depth has shown variations both across shore and according to sediment size distribution. This study addresses the need for more accurate calculations of sediment transport volumes on MSG beaches by using more precise measurements of AL depth and width, and virtual velocity of tracer pebbles. Variations in AL depth were measured along three main profile lines (from MHWS to MLWN) at Eastoke, Hayling Island (Hampshire, UK). Passive Integrated Transponder (PIT) tagged pebbles were deployed in columns, and their new locations repeatedly surveyed with RFID technology. These data were combined with daily dGPS beach profiles and sediment sampling for detailed analysis of the influence of beach morphodynamics on sediment transport volumes. Data were collected over two consecutive winter seasons: 2014-15 (relatively calm, average wave height <1 m) and 2015-16 (prolonged periods of moderate storminess, wave heights of 1-2 m). The active layer was, on average, 22% of wave height where beach slope (tanβ) is 0.1, with variations noted according to slope angle, sediment distribution, and beach groundwater level. High groundwater levels and a change in sediment proportions in the sandy lower foreshore reduced the AL to 10% of wave height in this area. The disparity in AL depth across the beach profile indicates that traditional models are not accurately representing bulk sediment transport on MSG beaches. It is anticipated that by improving model inputs, beach managers will be better able to predict necessary volumes and sediment grain size proportions of replenishment material for effective management of MSG beaches.

Impact of surrounding environment evolution on long-term gas flux measurements in a temperate mixed forest

NASA Astrophysics Data System (ADS)

Hurdebise, Quentin; Rixen, Toma; De Ligne, Anne; Vincke, Caroline; Heinesch, Bernard; Aubinet, Marc

2016-04-01

With the development of eddy covariance networks like Fluxnet, ICOS or NEON, long-term data series of carbon dioxide, water vapor and other gas exchanges between terrestrial ecosystems and atmosphere will become more and more numerous. However, long-term analyses of such exchanges require a good understanding of measurement conditions during the investigated period. Independently of climate drivers, measurements may indeed be influenced by measurement conditions themselves subjected to long-term variability due to vegetation growth or set-up changes. The present research refers to the Vielsalm Terrestrial Observatory (VTO) where fluxes of momentum, carbon dioxide, latent and sensible heat have been continuously measured by eddy covariance during twenty years. VTO is an ICOS site installed in a mixed forest (beech, silver fir, Douglas fir, Norway spruce) in the Belgian Ardennes. A multidisciplinary approach was developed in order to investigate the spatial and temporal evolution of several site characteristics: -displacement height (d) and relative measurement height (z-d) were determined using a spectral approach that compared observed and theoretical cospectra; -turbulence statistics were analyzed in the context of Monin-Obukhov similarity theory; -tree height during the measurement period was obtained by combining tree height inventories, a LIDAR survey and tree growth models; -measurement footprint was determined by using a footprint model. A good agreement was found between the three first approaches. Results show notably that z-d was subjected to both temporal and spatial evolution. Temporal evolution resulted from continuous tree growth as well as from a tower raise, achieved in 2009. Spatial evolution, due to canopy heterogeneity, was also observed. The impacts of these changes on measurements are investigated. In particular, it was shown that they affect measurement footprint, flux spectral corrections and flux quality. All these effects must be taken into consideration in order to disentangle long-term flux evolutions due to climate or phenology from changes resulting from measurement set-up changes.

Characterization of vertical mixing in oscillatory vegetated flows

NASA Astrophysics Data System (ADS)

Abdolahpour, M.; Ghisalberti, M.; Lavery, P.; McMahon, K.

2016-02-01

Seagrass meadows are primary producers that provide important ecosystem services, such as improved water quality, sediment stabilisation and trapping and recycling of nutrients. Most of these ecological services are strongly influenced by the vertical exchange of water across the canopy-water interface. That is, vertical mixing is the main hydrodynamic process governing the large-scale ecological and environmental impact of seagrass meadows. The majority of studies into mixing in vegetated flows have focused on steady flow environments whereas many coastal canopies are subjected to oscillatory flows driven by surface waves. It is known that the rate of mass transfer will vary greatly between unidirectional and oscillatory flows, necessitating a specific investigation of mixing in oscillatory canopy flows. In this study, we conducted an extensive laboratory investigation to characterise the rate of vertical mixing through a vertical turbulent diffusivity (Dt,z). This has been done through gauging the evolution of vertical profiles of concentration (C) of a dye sheet injected into a wave-canopy flow. Instantaneous measurement of the variance of the vertical concentration distribution ( allowed the estimation of a vertical turbulent diffusivity (). Two types of model canopies, rigid and flexible, with identical heights and frontal areas, were subjected to a wide and realistic range of wave height and period. The results showed two important mechanisms that dominate vertical mixing under different conditions: a shear layer that forms at the top of the canopy and wake turbulence generated by the stems. By allowing a coupled contribution of wake and shear layer mixing, we present a relationship that can be used to predict the rate of vertical mixing in coastal canopies. The results further showed that the rate of vertical mixing within flexible vegetation was always lower than the corresponding rigid canopy, confirming the impact of plant flexibility on canopy-flow interactions.

Convective boundary layer heights over mountainous terrain - A review of concepts -

NASA Astrophysics Data System (ADS)

De Wekker, Stephan; Kossmann, Meinolf

2015-12-01

Mountainous terrain exerts an important influence on the Earth's atmosphere and affects atmospheric transport and mixing at a wide range of temporal and spatial scales. The vertical scale of this transport and mixing is determined by the height of the atmospheric boundary layer, which is therefore an important parameter in air pollution studies, weather forecasting, climate modeling, and many other applications. It is recognized that the spatio-temporal structure of the daytime convective boundary layer (CBL) height is strongly modified and more complex in hilly and mountainous terrain compared to flat terrain. While the CBL over flat terrain is mostly dominated by turbulent convection, advection from multi-scale thermally driven flows plays an important role for the CBL evolution over mountainous terrain. However, detailed observations of the CBL structure and understanding of the underlying processes are still limited. Characteristics of CBL heights in mountainous terrain are reviewed for dry, convective conditions. CBLs in valleys and basins, where hazardous accumulation of pollutants is of particular concern, are relatively well-understood compared to CBLs over slopes, ridges, or mountain peaks. Interests in the initiation of shallow and deep convection, and of budgets and long-range transport of air pollutants and trace gases, have triggered some recent studies on terrain induced exchange processes between the CBL and the overlying atmosphere. These studies have helped to gain more insight into CBL structure over complex mountainous terrain, but also show that the universal definition of CBL height over mountains remains an unresolved issue. The review summarizes the progress that has been made in documenting and understanding spatio-temporal behavior of CBL heights in mountainous terrain and concludes with a discussion of open research questions and opportunities for future research.

On the performance of surface renewal analysis to estimate sensible heat flux over two growing rice fields under the influence of regional advection

NASA Astrophysics Data System (ADS)

Castellví, F.; Snyder, R. L.

2009-09-01

SummaryHigh-frequency temperature data were recorded at one height and they were used in Surface Renewal (SR) analysis to estimate sensible heat flux during the full growing season of two rice fields located north-northeast of Colusa, CA (in the Sacramento Valley). One of the fields was seeded into a flooded paddy and the other was drill seeded before flooding. To minimize fetch requirements, the measurement height was selected to be close to the maximum expected canopy height. The roughness sub-layer depth was estimated to discriminate if the temperature data came from the inertial or roughness sub-layer. The equation to estimate the roughness sub-layer depth was derived by combining simple mixing-length theory, mixing-layer analogy, equations to account for stable atmospheric surface layer conditions, and semi-empirical canopy-architecture relationships. The potential for SR analysis as a method that operates in the full surface boundary layer was tested using data collected over growing vegetation at a site influenced by regional advection of sensible heat flux. The inputs used to estimate the sensible heat fluxes included air temperature sampled at 10 Hz, the mean and variance of the horizontal wind speed, the canopy height, and the plant area index for a given intermediate height of the canopy. Regardless of the stability conditions and measurement height above the canopy, sensible heat flux estimates using SR analysis gave results that were similar to those measured with the eddy covariance method. Under unstable cases, it was shown that the performance was sensitive to estimation of the roughness sub-layer depth. However, an expression was provided to select the crucial scale required for its estimation.

Mixed Species Flock, Nest Height, and Elevation Partially Explain Avian Haemoparasite Prevalence in Colombia

PubMed Central

González, Angie D.; Matta, Nubia E.; Ellis, Vincenzo A.; Miller, Eliot T.; Ricklefs, Robert E.; Gutiérrez, H. Rafael

2014-01-01

The high avian biodiversity present in the Neotropical region offers a great opportunity to explore the ecology of host-parasite relationships. We present a survey of avian haemoparasites in a megadiverse country and explore how parasite prevalences are related to physical and ecological host characteristics. Using light microscopy, we documented the presence of haemoparasites in over 2000 individuals belonging to 246 species of wild birds, from nine localities and several ecosystems of Colombia. We analysed the prevalence of six avian haemoparasite taxa in relation to elevation and the following host traits: nest height, nest type, foraging strata, primary diet, sociality, migratory behaviour, and participation in mixed species flocks. Our analyses indicate significant associations between both mixed species flocks and nest height and Haemoproteus and Leucocytozoon prevalence. The prevalence of Leucocytozoon increased with elevation, whereas the prevalence of Trypanosoma and microfilariae decreased. Plasmodium and Haemoproteus prevalence did not vary significantly with elevation; in fact, both parasites were found up to 3300m above sea level. The distribution of parasite prevalence across the phylogeny of bird species included in this study showed little host phylogenetic signal indicating that infection rates in this system are evolutionarily labile. Vector distribution as well as the biology of transmission and the maintenance of populations of avian haemoparasites deserve more detailed study in this system. PMID:24950223

Mixed species flock, nest height, and elevation partially explain avian haemoparasite prevalence in Colombia.

PubMed

González, Angie D; Matta, Nubia E; Ellis, Vincenzo A; Miller, Eliot T; Ricklefs, Robert E; Gutiérrez, H Rafael

2014-01-01

The high avian biodiversity present in the Neotropical region offers a great opportunity to explore the ecology of host-parasite relationships. We present a survey of avian haemoparasites in a megadiverse country and explore how parasite prevalences are related to physical and ecological host characteristics. Using light microscopy, we documented the presence of haemoparasites in over 2000 individuals belonging to 246 species of wild birds, from nine localities and several ecosystems of Colombia. We analysed the prevalence of six avian haemoparasite taxa in relation to elevation and the following host traits: nest height, nest type, foraging strata, primary diet, sociality, migratory behaviour, and participation in mixed species flocks. Our analyses indicate significant associations between both mixed species flocks and nest height and Haemoproteus and Leucocytozoon prevalence. The prevalence of Leucocytozoon increased with elevation, whereas the prevalence of Trypanosoma and microfilariae decreased. Plasmodium and Haemoproteus prevalence did not vary significantly with elevation; in fact, both parasites were found up to 3300 m above sea level. The distribution of parasite prevalence across the phylogeny of bird species included in this study showed little host phylogenetic signal indicating that infection rates in this system are evolutionarily labile. Vector distribution as well as the biology of transmission and the maintenance of populations of avian haemoparasites deserve more detailed study in this system.

Estimating past diameters of mixed conifer species in the central Sierra Nevada

Treesearch

K. Leroy Dolph

1981-01-01

Tree diameter outside bark at an earlier period of growth can be estimated from the linear relationship of present inside bark and outside bark diameters at breast height. This note presents equations for estimating inside bark diameters, outside bark diameters, and past outside bark diameters for each of the mixed-conifer species in the central Sierra Nevada.

Flora and fauna associated with prairie dog colonies and adjacent ungrazed mixed-grass prairie in western South Dakota

Treesearch

William Agnew; Daniel W. Uresk; Richard M. Hansen

1986-01-01

Vegetation, small rodents, and birds were sampled during the growing seasons of 2 years on prairie dog (Cynomys ludovicianus) colonies and adjacent mixed-grass prairie in western South Dakota. Prairie dog grazing decreased mulch cover, maximum height of vegetation, plant species richness, and tended to decrease live plant canopy cover compared to...

Development of the RGB LEDs color mixing mechanism for stability the color temperature at different projection distances.

PubMed

Hung, Chih-Ching

2015-01-01

In lighting application, the color mixing of the RGB LEDs can provide more color selection in correlated color temperature and color rendering. Therefore, the purpose of this study is to propose a RGB color mixing mechanism by applying the mechanism design. Three sets of lamp-type RGB LEDs are individually installed on three four-bar linkages. A crank is used to drive three groups of RGB LEDs lamp-type to project lights onto a single plane in order to mix the lights. And, simulations of the illuminance and associated color temperatures are conducted by changing the distance to the projection plane, under the assumption that the stability of the color temperature of the projected light does not change according to the projecting height. Thus, the effect of change in the color temperature on color determination by the humans' eyes was avoided. The success of the proposed method will allow medical personnel to choose suitable wavelengths and color temperatures according to the particular requirements of their medical-examination environments.

Joint-level energetics differentiate isoinertial from speed-power resistance training-a Bayesian analysis.

PubMed

Liew, Bernard X W; Drovandi, Christopher C; Clifford, Samuel; Keogh, Justin W L; Morris, Susan; Netto, Kevin

2018-01-01

There is convincing evidence for the benefits of resistance training on vertical jump improvements, but little evidence to guide optimal training prescription. The inability to detect small between modality effects may partially reflect the use of ANOVA statistics. This study represents the results of a sub-study from a larger project investigating the effects of two resistance training methods on load carriage running energetics. Bayesian statistics were used to compare the effectiveness of isoinertial resistance against speed-power training to change countermovement jump (CMJ) and squat jump (SJ) height, and joint energetics. Active adults were randomly allocated to either a six-week isoinertial ( n  = 16; calf raises, leg press, and lunge), or a speed-power training program ( n  = 14; countermovement jumps, hopping, with hip flexor training to target pre-swing running energetics). Primary outcome variables included jump height and joint power. Bayesian mixed modelling and Functional Data Analysis were used, where significance was determined by a non-zero crossing of the 95% Bayesian Credible Interval (CrI). The gain in CMJ height after isoinertial training was 1.95 cm (95% CrI [0.85-3.04] cm) greater than the gain after speed-power training, but the gain in SJ height was similar between groups. In the CMJ, isoinertial training produced a larger increase in power absorption at the hip by a mean 0.018% (equivalent to 35 W) (95% CrI [0.007-0.03]), knee by 0.014% (equivalent to 27 W) (95% CrI [0.006-0.02]) and foot by 0.011% (equivalent to 21 W) (95% CrI [0.005-0.02]) compared to speed-power training. Short-term isoinertial training improved CMJ height more than speed-power training. The principle adaptive difference between training modalities was at the level of hip, knee and foot power absorption.

Frequency Variation of the Polarimetric Scattering Mechanisms of Forests and its Consequences on Biomass Estimation using InSAR

NASA Astrophysics Data System (ADS)

Thirion-Lefevre, L.; Guinvarc'h, R.

2016-12-01

InSAR provides forest height estimation that can be used to evaluate the aboveground biomass (AGB). This estimation depends on frequency, polarization and forest structure. If the forest is dense, high frequency gives a good estimation of the AGB whatever the polarization. For other forests, the response is a mix of scattering mechanisms with different phase centers. For instance at P-band, more information can be obtained on the structure thanks to a deeper penetration. However, double bounce mechanism can be strong with its phase center closer to the ground. As a consequence, AGB is underestimated. Quantifying double bounce mechanism can therefore help to assess this estimation. This mechanism can actually be significantly lowered using the Double Brewster Effect (DBE). The latter occurs for a dielectric dihedral and results in a reduced VV component by more than 10 dB for a large angular bandwidth, typically from 20° to 70° (HH is not affected). It consists in two successive Brewster effects, one for the ground, one for the trunk. This DBE is then dependent on the frequency and on the properties of the scatterers (moisture, ground composition, etc). It gives a new light on the interpretation of InSAR height estimation, based on a phenomenology study. We will first quantify this effect on real data at P- and L-bands. We will then present the relation between DBE and the interferometric height using a coherent scattering electromagnetic model previously validated on forests at P- and L-bands. Actually, the interferometric coherence of a forest can be modeled for each polarization by a simple summation of the coherence of the main scattering mechanisms (single and double bounce scattering), weighted by their respective magnitude. Thus, at HH, the resulting height will be determined by the relative weight of the scattering mechanisms. At VV, if DBE is strong, then the interferometric height will depend on the single scattering only.

Effectiveness of a self-regulated remedial program for handwriting difficulties.

PubMed

Van Waelvelde, Hilde; De Roubaix, Amy; Steppe, Lien; Troubleyn, Evy; De Mey, Barbara; Dewitte, Griet; Debrabant, Julie; Van de Velde, Dominique

2017-09-01

Handwriting difficulties may have pervasive effects on a child's school performance. I Can! is a remedial handwriting program with a focus on self-regulated learning and applying motor learning principles combined with a behavioural approach. It is developed for typically developing children with handwriting problems. The study aim was to evaluate the program's effectiveness. Thirty-one children aged 7-8 year participated in a cross-over study. Handwriting quality and speed were repeatedly assessed by means of the Systematic Screening of Handwriting Difficulties test. Difficulties addressed were fluency in letter formation, fluency in letter connections, letter height, regularity of letter height, space between words, and line path. Mixed model analysis revealed improved quality of writing and speed for all children but significantly more improvement in handwriting quality for the children participating in the program. Although writing speed improved over time, no additional effects of the program occurred. 'I Can!' is found to be an effective instructive program to ameliorate handwriting quality in typically developing children with handwriting difficulties. The program's success was by a therapy burst of only 7 weeks focusing on the child's self-regulated learning capacities, within an individualized education plan according to their needs and goals.

Tree height-diameter allometry across the United States.

PubMed

Hulshof, Catherine M; Swenson, Nathan G; Weiser, Michael D

2015-03-01

The relationship between tree height and diameter is fundamental in determining community and ecosystem structure as well as estimates of biomass and carbon storage. Yet our understanding of how tree allometry relates to climate and whole organismal function is limited. We used the Forest Inventory and Analysis National Program database to determine height-diameter allometries of 2,976,937 individuals of 293 tree species across the United States. The shape of the allometric relationship was determined by comparing linear and nonlinear functional forms. Mixed-effects models were used to test for allometric differences due to climate and floristic (between angiosperms and gymnosperms) and functional groups (leaf habit and shade tolerance). Tree allometry significantly differed across the United States largely because of climate. Temperature, and to some extent precipitation, in part explained tree allometric variation. The magnitude of allometric variation due to climate, however, had a phylogenetic signal. Specifically, angiosperm allometry was more sensitive to differences in temperature compared to gymnosperms. Most notably, angiosperm height was more negatively influenced by increasing temperature variability, whereas gymnosperm height was negatively influenced by decreasing precipitation and increasing altitude. There was little evidence to suggest that shade tolerance influenced tree allometry except for very shade-intolerant trees which were taller for any given diameter. Tree allometry is plastic rather than fixed and scaling parameters vary around predicted central tendencies. This allometric variation provides insight into life-history strategies, phylogenetic history, and environmental limitations at biogeographical scales.

Soil intake of lactating dairy cows in intensive strip grazing systems.

PubMed

Jurjanz, S; Feidt, C; Pérez-Prieto, L A; Ribeiro Filho, H M N; Rychen, G; Delagarde, R

2012-08-01

Involuntary soil intake by cows on pasture can be a potential route of entry for pollutants into the food chain. Therefore, it appears necessary to know and quantify factors affecting soil intake in order to ensure the food safety in outside rearing systems. Thus, soil intake was determined in two Latin square trials with 24 and 12 lactating dairy cows. In Trial 1, the effect of pasture allowance (20 v. 35 kg dry matter (DM) above ground level/cow daily) was studied for two sward types (pure perennial ryegrass v. mixed perennial ryegrass-white clover) in spring. In Trial 2, the effect of pasture allowance (40 v. 65 kg DM above ground level/cow daily) was studied at two supplementation levels (0 or 8 kg DM of a maize silage-based supplement) in autumn. Soil intake was determined by the method based on acid-insoluble ash used as an internal marker. The daily dry soil intake ranged, between treatments, from 0.17 to 0.83 kg per cow in Trial 1 and from 0.15 to 0.85 kg per cow in Trial 2, reaching up to 1.3 kg during some periods. In both trials, soil intake increased with decreasing pasture allowance, by 0.46 and 0.15 kg in Trials 1 and 2, respectively. In Trial 1, this pasture allowance effect was greater on mixed swards than on pure ryegrass swards (0.66 v. 0.26 kg reduction of daily soil intake between medium and low pasture allowance, respectively). In Trial 2, the pasture allowance effect was similar at both supplementation levels. In Trial 2, supplemented cows ate much less soil than unsupplemented cows (0.20 v. 0.75 kg/day, respectively). Differences in soil intake between trials and treatments can be related to grazing conditions, particularly pre-grazing and post-grazing sward height, determining at least in part the time spent grazing close to the ground. A post-grazing sward height lower than 50 mm can be considered as a critical threshold. Finally, a dietary supplement and a low grazing pressure, that is, high pasture allowance increasing post-grazing sward height, would efficiently limit the risk for high level of soil intake, especially when grazing conditions are difficult. Pre-grazing and post-grazing sward heights, as well as faecal crude ash concentration appear to be simple and practical tools for evaluating the risk for critical soil intake in grazing dairy cows.

Food insecurity and linear growth of adolescents in Jimma Zone, Southwest Ethiopia.

PubMed

Belachew, Tefera; Lindstrom, David; Hadley, Craig; Gebremariam, Abebe; Kasahun, Wondwosen; Kolsteren, Patrick

2013-05-02

Although many studies showed that adolescent food insecurity is a pervasive phenomenon in Southwest Ethiopia, its effect on the linear growth of adolescents has not been documented so far. This study therefore aimed to longitudinally examine the association between food insecurity and linear growth among adolescents. Data for this study were obtained from a longitudinal survey of adolescents conducted in Jimma Zone, which followed an initial sample of 2084 randomly selected adolescents aged 13-17 years. We used linear mixed effects model for 1431 adolescents who were interviewed in three survey rounds one year apart to compare the effect of food insecurity on linear growth of adolescents. Overall, 15.9% of the girls and 12.2% of the boys (P=0.018) were food insecure both at baseline and on the year 1 survey, while 5.5% of the girls and 4.4% of the boys (P=0.331) were food insecure in all the three rounds of the survey. In general, a significantly higher proportion of girls (40%) experienced food insecurity at least in one of the survey rounds compared with boys (36.6%) (P=0.045).The trend of food insecurity showed a very sharp increase over the follow period from the baseline 20.5% to 48.4% on the year 1 survey, which again came down to 27.1% during the year 2 survey.In the linear mixed effects model, after adjusting for other covariates, the mean height of food insecure girls was shorter by 0.87 cm (P<0.001) compared with food secure girls at baseline. However, during the follow up period on average, the heights of food insecure girls increased by 0.38 cm more per year compared with food secure girls (P<0.066). However, the mean height of food insecure boys was not significantly different from food secure boys both at baseline and over the follow up period. Over the follow-up period, adolescents who live in rural and semi-urban areas grew significantly more per year than those who live in the urban areas both for girls (P<0.01) and for boys (P<0.01). Food insecurity is negatively associated with the linear growth of adolescents, especially on girls. High rate of childhood stunting in Ethiopia compounded with lower height of food insecure adolescents compared with their food secure peers calls for the development of direct nutrition interventions targeting adolescents to promote catch-up growth and break the intergenerational cycle of malnutrition.

[Effects of precipitation and interspecific competition on Quercus mongolica and pinus koraiensis seedlings growth].

PubMed

Wu, Jing-Lian; Wang, Miao; Lin, Fei; Hao, Zhan-Qing; Ji, Lan-Zhu; Liu, Ya-Qin

2009-02-01

Aiming at the variation of precipitation pattern caused by global warming, a field simulation experiment was conducted to study the effects of 30% increase (+W) and decrease (-W) of precipitation on the morphology, growth, and biomass partitioning of mono- and mixed cultured seedlings of Quercus mongolica and Pinus koraiensis, the two dominant tree species in temperate broad-leaved Korean pine mixed forest in Changbai Mountains. Comparing with monoculture, mixed culture increased the canopy width and main root length of Q. mongolica seedlings, but decreased the basal diameter, plant height, leaf number, and dry masses of root, stem, leaf and whole plant of P. koraiensis seedlings significantly. Treatment (-W) increased the stem/mass ratio while decreased the main root length of Q. mongolica seedlings, and decreased the main root length, leaf number, dry masses of leaf and whole plant, and leaf/mass ratio, while increased the stem/mass ratio of P. koraiensis seedlings significantly, compared with treatment CK. Treatment (+W) had no significant effect on these indices of the two species. At early growth stage, interspecific competition and precipitation pattern had significant effects on the morphology and growth of the seedlings, and the responses were much stronger for P. koraiensis than for Q. mongolica.

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

Newsom, R. K.; Sivaraman, C.; Shippert, T. R.

Accurate height-resolved measurements of higher-order statistical moments of vertical velocity fluctuations are crucial for improved understanding of turbulent mixing and diffusion, convective initiation, and cloud life cycles. The Atmospheric Radiation Measurement (ARM) Climate Research Facility operates coherent Doppler lidar systems at several sites around the globe. These instruments provide measurements of clear-air vertical velocity profiles in the lower troposphere with a nominal temporal resolution of 1 sec and height resolution of 30 m. The purpose of the Doppler lidar vertical velocity statistics (DLWSTATS) value-added product (VAP) is to produce height- and time-resolved estimates of vertical velocity variance, skewness, and kurtosismore » from these raw measurements. The VAP also produces estimates of cloud properties, including cloud-base height (CBH), cloud frequency, cloud-base vertical velocity, and cloud-base updraft fraction.« less

Absolute calibration of the Jenoptik CHM15k-x ceilometer and its applicability for quantitative aerosol monitoring

NASA Astrophysics Data System (ADS)

Geiß, Alexander; Wiegner, Matthias

2014-05-01

The knowledge of the spatiotemporal distribution of atmospheric aerosols and its optical characterization is essential for the understanding of the radiation budget, air quality, and climate. For this purpose, lidar is an excellent system as it is an active remote sensing technique. As multi-wavelength research lidars with depolarization channels are quite complex and cost-expensive, increasing attention is paid to so-called ceilometers. They are simple one-wavelength backscatter lidars with low pulse energy for eye-safe operation. As maintenance costs are low and continuous and unattended measurements can be performed, they are suitable for long-term aerosol monitoring in a network. However, the signal-to-noise ratio is low, and the signals are not calibrated. The only optical property that can be derived from a ceilometer is the particle backscatter coefficient, but even this quantity requires a calibration of the signals. With four years of measurements from a Jenoptik ceilometer CHM15k-x, we developed two methods for an absolute calibration on this system. This advantage of our approach is that only a few days with favorable meteorological conditions are required where Rayleigh-calibration and comparison with our research lidar is possible to estimate the lidar constant. This method enables us to derive the particle backscatter coefficient at 1064 nm, and we retrieved for the first time profiles in near real-time within an accuracy of 10 %. If an appropriate lidar ratio is assumed the aerosol optical depth of e.g. the mixing layer can be determined with an accuracy depending on the accuracy of the lidar ratio estimate. Even for 'simple' applications, e.g. assessment of the mixing layer height, cloud detection, detection of elevated aerosol layers, the particle backscatter coefficient has significant advantages over the measured (uncalibrated) attenuated backscatter. The possibility of continuous operation under nearly any meteorological condition with temporal resolution in the order of 30 seconds makes it also possible to apply time-height-tracking methods for detecting mixing layer heights. The combination of methods for edge detection (e.g. wavelet covariance transform, gradient method, variance method) and edge tracking techniques is used to increase the reliability of the layer detection and attribution. Thus, a feature mask of aerosols and clouds can be derived. Four years of measurements constitute an excellent basis for a climatology including a homogeneous time series of mixing layer heights, aerosol layers and cloud base heights of the troposphere. With a low overlap region of 180 m of the Jenoptik CHM15k-x even very narrow mixing layers, typical for winter conditions, can be considered.

Predictions and Verification of an Isotope Marine Boundary Layer Model

NASA Astrophysics Data System (ADS)

Feng, X.; Posmentier, E. S.; Sonder, L. J.; Fan, N.

2017-12-01

A one-dimensional (1D), steady state isotope marine boundary layer (IMBL) model is constructed. The model includes meteorologically important features absent in Craig and Gordon type models, namely height-dependent diffusion/mixing and convergence of subsiding external air. Kinetic isotopic fractionation results from this height-dependent diffusion which starts as pure molecular diffusion at the air-water interface and increases linearly with height due to turbulent mixing. The convergence permits dry, isotopically depleted air subsiding adjacent to the model column to mix into ambient air. In δD-δ18O space, the model results fill a quadrilateral, of which three sides represent 1) vapor in equilibrium with various sea surface temperatures (SSTs) (high d18O boundary of quadrilateral); 2) mixture of vapor in equilibrium with seawater and vapor in the subsiding air (lower boundary depleted in both D and 18O); and 3) vapor that has experienced the maximum possible kinetic fractionation (high δD upper boundary). The results can be plotted in d-excess vs. δ18O space, indicating that these processes all cause variations in d-excess of MBL vapor. In particular, due to relatively high d-excess in the descending air, mixing of this air into the MBL causes an increase in d-excess, even without kinetic isotope fractionation. The model is tested by comparison with seven datasets of marine vapor isotopic ratios, with excellent correspondence; >95% of observational data fall within the quadrilateral area predicted by the model. The distribution of observations also highlights the significant influence of vapor from the nearby converging descending air on isotopic variations in the MBL. At least three factors may explain the <5% of observations that fall slightly outside of the predicted region in both δD-δ18O and d-excess - δ18O space: 1) variations in seawater isotopic ratios, 2) variations in isotopic composition of subsiding air, and 3) influence of sea spray. The model can be used for understanding the effects of boundary layer processes and meteorological conditions on isotopic composition of vapor within, and vapor fluxes through the MBL, and how changes in moisture source regions affect the isotopic composition of precipitation. The model can be applied to modern as well as paleo- climate conditions.

Skeletal Growth Dysregulation in Australian Male Infants and Toddlers With Autism Spectrum Disorder.

PubMed

Green, Cherie C; Dissanayake, Cheryl; Loesch, Danuta Z; Bui, Minh; Barbaro, Josephine

2018-06-01

Recent findings suggest that children with Autism Spectrum Disorder (ASD) are larger in size for head circumference (HC), height, and weight compared to typically developing (TD) children; however, little is known about their rate of growth, especially in height and weight. The current study aimed to: (a) confirm and extend upon previous findings of early generalized overgrowth in ASD; and (b) determine if there were any differences in the rate of growth between infants and toddlers with ASD compared to their TD peers. Measurements of HC, height, and weight were available for 135 boys with ASD and 74 TD boys, from birth through 3 years of age. Size and growth rate in HC, height, and weight were analyzed using a linear mixed-effects model. Infants with ASD were significantly smaller in size at birth for HC, body length, and weight compared to TD infants (all P < 0.05); however, they grew at a significantly faster rate in HC and height in comparison to the TD children (P < 0.001); there was no significant difference between the groups in growth rate for weight (P > 0.05). The results confirmed that male infants and toddlers with ASD exhibit skeletal growth dysregulation early in life. Autism Res 2018, 11: 846-856. © 2018 International Society for Autism Research, Wiley Periodicals, Inc. Recent findings suggest that infants with Autism Spectrum Disorder (ASD) are smaller in size at birth compared to typically developing infants but grow larger than their peers during the first year. Little is known about their rate of growth, especially for height and weight. Our findings confirmed that infants with ASD are smaller in size at birth for head circumference (HC), height, and weight, but grow at a faster rate in HC and height than their peers from birth to 3 years. © 2018 International Society for Autism Research, Wiley Periodicals, Inc.

Anatomical characterization of hoof growth pattern in six Iranian sheep breeds and its possible implication for trimming recommendations.

PubMed

Azarpajouh, S; Marchewka, J; Segura Correa, J C; Calderón Díaz, J A

2018-03-11

The objective of this study was to compare hoof anatomy, hoof growth pattern, and hoof weight-bearing surface of six different Iranian sheep breeds to identify possible differences in the hoof anatomical features that could help to minimize adverse effects of hoof trimming methods. Front and hind hooves of 2-year-old, previously untrimmed, pastured dairy ewes of six Iranian breeds (Afshari, Moghani, Kurdi, Makoui, Chaleshtori, and Lori-Bakhtiari; n = 180 ewes; 30 ewes per breed) were collected after slaughter. Medial and lateral claws were incised sagittally and anatomical measurements such as toe length, heel height, toe height, sole thickness, sole length, and toe angle were recorded in each claw. Data were analyzed using mixed model equations including breed, claw (lateral or medial), hoof (front or hind) and their interactions as fixed effects, and ewe as random effect. Breed differences were observed for all hoof measurements (P < 0.05). Chaleshtori sheep had higher measurements for most of the traits studied while Afshari and Makoui sheep had lower measurements. All measurements, except for toe length and toe height to solar surface to heel height ratio, were significantly greater in the front hooves than in the hind hooves (P < 0.05). Soles were longer in the medial claws compared to the lateral claws of the front hooves (P < 0.05). Results suggest the observed breed differences could interfere with establishing a standard, uniform hoof trimming method for sheep. For instance, it might be possible that while Afshari and Makoui sheep could require more conservative trimming, Chaleshtori sheep could require to be trimmed more. In consequence, hoof trimming methods might need to be adjusted to specific breed characteristics to avoid possible tissue damage.

Mixed convection in a horizontal rectangular channel - Experimental and numerical velocity distributions

NASA Technical Reports Server (NTRS)

Nyce, Thomas A.; Quazzani, Jalil; Durand-Daubin, Arnaud; Rosenberger, Franz

1992-01-01

Mixed convection in a rectangular channel (width/height = 2) with bottom-heated and top-cooled sections is studied by laser Doppler anemometry in nitrogen at Ra = 22,200 and Re = 18.75, 36, and 54. At the lower Re values, symmetry breaking is observed in steady but spatially oscillating flows that prevail over a certain distance from the leading edge of the differentially heated section. Further downstream, unsteady flows are found even for Re = 18.75. Numerical models are used to investigate the effects of adiabatic, conducting (with a conductive-convective heat transfer coefficient), and perfectly conducting side walls; channel tilts and Prandtl number dependence. Good agreement between calculations and experiment is obtained for longitudinal convective roll velocities. The transverse velocities are found to be independent of Re.

A New Approach for Estimating Entrainment Rate in Cumulus Clouds

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

Lu C.; Liu, Y.; Yum, S. S.

2012-02-16

A new approach is presented to estimate entrainment rate in cumulus clouds. The new approach is directly derived from the definition of fractional entrainment rate and relates it to mixing fraction and the height above cloud base. The results derived from the new approach compare favorably with those obtained with a commonly used approach, and have smaller uncertainty. This new approach has several advantages: it eliminates the need for in-cloud measurements of temperature and water vapor content, which are often problematic in current aircraft observations; it has the potential for straightforwardly connecting the estimation of entrainment rate and the microphysicalmore » effects of entrainment-mixing processes; it also has the potential for developing a remote sensing technique to infer entrainment rate.« less

Production and optimization of biodiesel using mixed immobilized biocatalysts in packed bed reactor.

PubMed

Bakkiyaraj, S; Syed, Mahin Basha; Devanesan, M G; Thangavelu, Viruthagiri

2016-05-01

Vegetable oils are used as raw materials for biodiesel production using transesterification reaction. Several methods for the production of biodiesel were developed using chemical (alkali and acidic compounds) and biological catalysts (lipases). Biodiesel production catalyzed by lipases is energy and cost-saving processes and is carried out at normal temperature and pressure. The need for an efficient method for screening larger number of variables has led to the adoption of statistical experimental design. In the present study, packed bed reactor was designed to study with mixed immobilized biocatalysts to have higher productivity under optimum conditions. Contrary to the single-step acyl migration mechanism, a two-step stepwise reaction mechanism involving immobilized Candida rugosa lipase and immobilized Rhizopus oryzae cells was employed for the present work. This method was chosen because enzymatic hydrolysis followed by esterification can tolerate high free fatty acid containing oils. The effects of flow rate and bed height on biodiesel yield were studied using two factors five-level central composite design (CCD) and response surface methodology (RSM). Maximum biodiesel yield of 85 and 81 % was obtained for jatropha oil and karanja oil with the optimum bed height and optimum flow rate of 32.6 cm and 1.35 L/h, and 32.6 cm and 1.36 L/h, respectively.

Arm span and ulnar length are reliable and accurate estimates of recumbent length and height in a multiethnic population of infants and children under 6 years of age.

PubMed

Forman, Michele R; Zhu, Yeyi; Hernandez, Ladia M; Himes, John H; Dong, Yongquan; Danish, Robert K; James, Kyla E; Caulfield, Laura E; Kerver, Jean M; Arab, Lenore; Voss, Paula; Hale, Daniel E; Kanafani, Nadim; Hirschfeld, Steven

2014-09-01

Surrogate measures are needed when recumbent length or height is unobtainable or unreliable. Arm span has been used as a surrogate but is not feasible in children with shoulder or arm contractures. Ulnar length is not usually impaired by joint deformities, yet its utility as a surrogate has not been adequately studied. In this cross-sectional study, we aimed to examine the accuracy and reliability of ulnar length measured by different tools as a surrogate measure of recumbent length and height. Anthropometrics [recumbent length, height, arm span, and ulnar length by caliper (ULC), ruler (ULR), and grid (ULG)] were measured in 1479 healthy infants and children aged <6 y across 8 study centers in the United States. Multivariate mixed-effects linear regression models for recumbent length and height were developed by using ulnar length and arm span as surrogate measures. The agreement between the measured length or height and the predicted values by ULC, ULR, ULG, and arm span were examined by Bland-Altman plots. All 3 measures of ulnar length and arm span were highly correlated with length and height. The degree of precision of prediction equations for length by ULC, ULR, and ULG (R(2) = 0.95, 0.95, and 0.92, respectively) was comparable with that by arm span (R(2) = 0.97) using age, sex, and ethnicity as covariates; however, height prediction by ULC (R(2) = 0.87), ULR (R(2) = 0.85), and ULG (R(2) = 0.88) was less comparable with arm span (R(2) = 0.94). Our study demonstrates that arm span and ULC, ULR, or ULG can serve as accurate and reliable surrogate measures of recumbent length and height in healthy children; however, ULC, ULR, and ULG tend to slightly overestimate length and height in young infants and children. Further testing of ulnar length as a surrogate is warranted in physically impaired or nonambulatory children. © 2014 American Society for Nutrition.

Effects of dietary inclusion of silymarin on performance, intestinal morphology and ileal bacterial count in aflatoxin-challenged broiler chicks.

PubMed

Jahanian, E; Mahdavi, A H; Asgary, S; Jahanian, R

2017-10-01

This study was conducted to investigate the effect of dietary supplementation of silymarin on performance, jejunal morphology and ileal bacterial population in broiler chicks intoxicated with a mix of aflatoxins. A total of three hundred thirty six 7-day-old Ross broiler chicks were randomly distributed between seven experimental groups with four replicates of 12 birds each. Experimental treatments consisted of a control group (unchallenged), and a 2 × 3 factorial arrangement, including two aflatoxin levels (0.5 and 2 ppm) and three levels of silymarin (0, 500 and 1000 ppm). Birds were challenged with a mix of aflatoxins from 7 to 28 days of age. Results showed that increasing aflatoxin level resulted in decreased average daily feed intake (ADFI) and weight gain (ADWG), consequently impaired feed conversion ratio (FCR) throughout the trial period. Dietary supplementation of silymarin resulted in the marked increases in ADFI and ADWG, and improved FCR values in aflatoxin-challenged chicks. Ileal bacterial populations at days 28 and 42 of age were increased by incremental levels of aflatoxins. On the other hand, dietary silymarin supplementation suppressed ileal populations of Escherichia coli, Salmonella, Klebsiella and total negative bacteria in aflatoxicated birds. Increase in dietary aflatoxin level resulted in the decreased villi height, villi height-to-crypt depth ratio (VH:CD), villi surface area and apparent villi absorptive area, while it increased crypt depth, goblet cell count and lymphoid follicular diameter. Feeding silymarin at the level of 1000 ppm increased villi height and VH:CD in aflatoxicated birds. Present results indicate that dietary inclusion of silymarin could improve performance by suppressing ileal bacteria and enhancing absorptive surface area in aflatoxin-challenged broiler chicks. Journal of Animal Physiology and Animal Nutrition © 2017 Blackwell Verlag GmbH.

Disentangling degenerate solutions from primary transit and secondary eclipse spectroscopy of exoplanets.

PubMed

Griffith, Caitlin A

2014-04-28

Infrared transmission and emission spectroscopy of exoplanets, recorded from primary transit and secondary eclipse measurements, indicate the presence of the most abundant carbon and oxygen molecular species (H2O, CH4, CO and CO2) in a few exoplanets. However, efforts to constrain the molecular abundances to within several orders of magnitude are thwarted by the broad range of degenerate solutions that fit the data. Here, we explore, with radiative transfer models and analytical approximations, the nature of the degenerate solution sets resulting from the sparse measurements of 'hot Jupiter' exoplanets. As demonstrated with simple analytical expressions, primary transit measurements probe roughly four atmospheric scale heights at each wavelength band. Derived mixing ratios from these data are highly sensitive to errors in the radius of the planet at a reference pressure. For example, an uncertainty of 1% in the radius of a 1000 K and H2-based exoplanet with Jupiter's radius and mass causes an uncertainty of a factor of approximately 100-10,000 in the derived gas mixing ratios. The degree of sensitivity depends on how the line strength increases with the optical depth (i.e. the curve of growth) and the atmospheric scale height. Temperature degeneracies in the solutions of the primary transit data, which manifest their effects through the scale height and absorption coefficients, are smaller. We argue that these challenges can be partially surmounted by a combination of selected wavelength sampling of optical and infrared measurements and, when possible, the joint analysis of transit and secondary eclipse data of exoplanets. However, additional work is needed to constrain other effects, such as those owing to planetary clouds and star spots. Given the current range of open questions in the field, both observations and theory, there is a need for detailed measurements with space-based large mirror platforms (e.g. James web space telescope) and smaller broad survey telescopes as well as ground-based efforts.

Evaluation of parameters in mixed male DNA profiles for the Identifiler® multiplex system

PubMed Central

HU, NA; CONG, BIN; GAO, TAO; HU, RONG; CHEN, YI; TANG, HUI; XUE, LUYAN; LI, SHUJIN; MA, CHUNLING

2014-01-01

The analysis of complex DNA mixtures is challenging for forensic DNA testing. Accurate and sensitive methods for profiling these samples are urgently required. In this study, we developed 11 groups of mixed male DNA samples (n=297) with scientific validation of D-value [>95% of D-values ≤0.1 with average peak height (APH) of the active alleles ≤2,500 rfu]. A strong linear correlation was detected between the peak height (PH) and peak area (PA) in the curve fit using the least squares method (P<2e-16). The Kruskal-Wallis rank-sum test revealed significant differences in the heterozygote balance ratio (Hb) at 16 short tandem repeat (STR) loci (P=0.0063) and 9 mixed gradients (P=0.02257). Locally weighted regression fitting of APH and Hb (inflection point at APH = 1,250 rfu) showed 92.74% of Hb >0.6 with the APH ≥1,250. The variation of Hb distribution in the different STR loci suggested the different forensic efficiencies of these loci. Allelic drop-out (ADO) correlated with the APH and mixed gradient. All ADOs had an APH of <1,000 rfu, and the number of ADO increased when the APH of mixed DNA profiles gradually decreased. These results strongly suggest that calibration parameters should be introduced to correct the deviation in the APH at each STR locus during the analysis of mixed DNA samples. PMID:24821391

The Relationship of PM Variation with Visibility and Mixing-Layer Height under Hazy/Foggy Conditions in the Multi-Cities of Northeast China.

PubMed

Zhao, Hujia; Che, Huizheng; Ma, Yanjun; Wang, Yangfeng; Yang, Hongbin; Liu, Yuche; Wang, Yaqiang; Wang, Hong; Zhang, Xiaoye

2017-04-29

The variations of visibility, PM-mass concentration and mixing-layer height (MLH) in four major urban/industry regions (Shenyang, Anshan, Benxi and Fushun) of central Liaoning in Northeast China are evaluated from 2009 to 2012 to characterize their dynamic effect on air pollution. The annual mean visibilities are about 13.7 ± 7.8, 13.5 ± 6.5, 12.8 ± 6.1 and 11.5 ± 6.8 km in Shenyang, Anshan, Benxi and Fushun, respectively. The pollution load (PM × MLH) shows a weaker vertical diffusion in Anshan, with a higher PM concentration near the surface. High concentrations of fine-mode particles may be partially attributed to the biomass-burning emissions from September in Liaoning Province and surrounding regions in Northeast China as well as the coal burning during the heating period with lower MLH in winter. The visibility on non-hazy fog days is about 2.5-3.0 times higher than that on hazy and foggy days. The fine-particle concentrations of PM 2.5 and PM 1.0 on hazy and foggy days are ~1.8-1.9 times and ~1.5 times higher than those on non-hazy foggy days. The MLH declined more severely during fog pollution than in haze pollution. The results of this study can provide useful information to better recognize the effects of vertical pollutant diffusion on air quality in the multi-cities of central Liaoning Province in Northeast China.

The Vertical Profile of Ocean Mixing

NASA Astrophysics Data System (ADS)

Ferrari, R. M.; Nikurashin, M.; McDougall, T. J.; Mashayek, A.

2014-12-01

The upwelling of bottom waters through density surfaces in the deep ocean is not possible unless the sloping nature of the sea floor is taken into account. The bottom--intensified mixing arising from interaction of internal tides and geostrophic motions with bottom topography implies that mixing is a decreasing function of height in the deep ocean. This would further imply that the diapycnal motion in the deep ocean is downward, not upwards as is required by continuity. This conundrum regarding ocean mixing and upwelling in the deep ocean will be resolved by appealing to the fact that the ocean does not have vertical side walls. Implications of the conundrum for the representation of ocean mixing in climate models will be discussed.

Birth weight, childhood body mass index, and height in relation to mammographic density and breast cancer: a register-based cohort study.

PubMed

Andersen, Zorana J; Baker, Jennifer L; Bihrmann, Kristine; Vejborg, Ilse; Sørensen, Thorkild I A; Lynge, Elsebeth

2014-01-20

High breast density, a strong predictor of breast cancer may be determined early in life. Childhood anthropometric factors have been related to breast cancer and breast density, but rarely simultaneously. We examined whether mammographic density (MD) mediates an association of birth weight, childhood body mass index (BMI), and height with the risk of breast cancer. 13,572 women (50 to 69 years) in the Copenhagen mammography screening program (1991 through 2001) with childhood anthropometric measurements in the Copenhagen School Health Records Register were followed for breast cancer until 2010. With logistic and Cox regression models, we investigated associations among birth weight, height, and BMI at ages 7 to 13 years with MD (mixed/dense or fatty) and breast cancer, respectively. 8,194 (60.4%) women had mixed/dense breasts, and 716 (5.3%) developed breast cancer. Childhood BMI was significantly inversely related to having mixed/dense breasts at all ages, with odds ratios (95% confidence intervals) ranging from 0.69 (0.66 to 0.72) at age 7 to 0.56 (0.53 to 0.58) at age 13, per one-unit increase in z-score. No statistically significant associations were detected between birth weight and MD, height and MD, or birth weight and breast cancer risk. BMI was inversely associated with breast cancer, with hazard ratios of 0.91 (0.83 to 0.99) at age 7 and 0.92 (0.84 to 1.00) at age 13, whereas height was positively associated with breast cancer risk (age 7, 1.06 (0.98 to 1.14) and age 13, 1.08 (1.00 to 1.16)). After additional adjustment for MD, associations of BMI with breast cancer diminished (age 7, 0.97 (0.88 to 1.06) and age 13, 1.01 (0.93 to 1.11)), but remained with height (age 7, 1.06 (0.99 to 1.15) and age 13, 1.09 (1.01 to 1.17)). Among women 50 years and older, childhood body fatness was inversely associated with the breast cancer risk, possibly via a mechanism mediated by MD, at least partially. Childhood tallness was positively associated with breast cancer risk, seemingly via a pathway independent of MD. Birth weight was not associated with MD or breast cancer in this age group.

Effect of plant density and mixing ratio on crop yield in sweet corn/mungbean intercropping.

PubMed

Sarlak, S; Aghaalikhani, M; Zand, B

2008-09-01

In order to evaluate the ear and forage yield of sweet corn (Zea mays L. var. Saccarata) in pure stand and intercropped with mung bean (Vigna radiata L.), a field experiment was conducted at Varamin region on summer 2006. Experiment was carried out in a split plot design based on randomized complete blocks with 4 replications. Plant density with 3 levels [Low (D1), Mean (D2) and High (D3) respecting 6, 8 and 10 m(-2) for sweet corn, cultivar S.C.403 and 10, 20 and 30 m(-2) for mung bean cultivar, Partow] was arranged in main plots and 5 mixing ratios [(P1) = 0/100, (P2) = 25/75, (P3) = 50/50, (P4) = 75/25, (P5) = 100/0% for sweet corn/mung bean, respectively] were arranged in subplots. Quantitative attributes such as plant height, sucker numbers, LER, dry matter distribution in different plant organs were measured in sweet corn economical maturity. Furthermore the yield of cannable ear corn and yield components of sweet corn and mung bean were investigated. Results showed that plant density has not any significant effect on evaluated traits, while the effect of mixing ratio was significant (p < 0.01). Therefore, the mixing ratio of 75/25 (sweet corn/mung bean) could be introduced as the superior mixing ratio; because of it's maximum rate of total sweet corn's biomass, forage yield, yield and yield components of ear corn in intercropping. Regarding to profitability indices of intercropping, the mixing ratio 75/25 (sweet corn/mung bean) in low density (D1P2) which showed the LER = 1.03 and 1.09 for total crop yield before ear harvesting and total forage yield after ear harvest respectively, was better than corn or mung bean monoculture.

Dissecting repulsion linkage in the dwarfing gene Dw3 region for sorghum plant height provides insights into heterosis.

PubMed

Li, Xin; Li, Xianran; Fridman, Eyal; Tesso, Tesfaye T; Yu, Jianming

2015-09-22

Heterosis is a main contributor to yield increase in many crop species. Different mechanisms have been proposed for heterosis: dominance, overdominance, epistasis, epigenetics, and protein metabolite changes. However, only limited examples of molecular dissection and validation of these mechanisms are available. Here, we present an example of discovery and validation of heterosis generated by a combination of repulsion linkage and dominance. Using a recombinant inbred line population, a separate quantitative trait locus (QTL) for plant height (qHT7.1) was identified near the genomic region harboring the known auxin transporter Dw3 gene. With two loci having repulsion linkage between two inbreds, heterosis in the hybrid can appear as a single locus with an overdominance mode of inheritance (i.e., pseudo-overdominance). Individually, alleles conferring taller plant height exhibited complete dominance over alleles conferring shorter height. Detailed analyses of different height components demonstrated that qHT7.1 affects both the upper and lower parts of the plant, whereas Dw3 affects only the part below the flag leaf. Computer simulations show that repulsion linkage could influence QTL detection and estimation of effect in segregating populations. Guided by findings in linkage mapping, a genome-wide association study of plant height with a sorghum diversity panel pinpointed genomic regions underlying the trait variation, including Dw1, Dw2, Dw3, Dw4, and qHT7.1. Multilocus mixed model analysis confirmed the advantage of complex trait dissection using an integrated approach. Besides identifying a specific genetic example of heterosis, our research indicated that integrated molecular dissection of complex traits in different population types can enable plant breeders to fine tune the breeding process for crop production.

Raman Scattering from Atmospheric Nitrogen in the Stratosphere

NASA Technical Reports Server (NTRS)

Garvey, M. J.; Kent, G. S.

1973-01-01

The Mark II laser radar system at Kingston, Jamaica, has been used to make observations on the Raman shifted line from atmospheric nitrogen at 828.5 nm. The size of the system makes it possible to detect signals from heights of up to 40 kilometres. The effects of aerosol scattering observed using a single wavelength are almost eliminated, and a profile of nitrogen density may be obtained. Assuming a constant mixing ratio, this may be interpreted as a profile of atmospheric density whose accuracy is comparable to that obtained from routine meteorological soundings. In order to obtain an accurate profile several interfering effects have had to be examined and, where necessary, eliminated. These include: 1) Fluorescence in optical components 2) Leakage of signal at 694.3 nm. 3) Overload effects and non-linearities in the receiving and counting electronics. Most of these effects have been carefully examined and comparisons are being made between the observed atmospheric density profiles and local meteorological radio-sonde measurements. Good agreement has been obtained over the region of overlap (15 - 30 KID), discrepancies being of the same order as the experimental accuracy (1-10%), depending on height and length of period of observation.

Modelling subject-specific childhood growth using linear mixed-effect models with cubic regression splines.

PubMed

Grajeda, Laura M; Ivanescu, Andrada; Saito, Mayuko; Crainiceanu, Ciprian; Jaganath, Devan; Gilman, Robert H; Crabtree, Jean E; Kelleher, Dermott; Cabrera, Lilia; Cama, Vitaliano; Checkley, William

2016-01-01

Childhood growth is a cornerstone of pediatric research. Statistical models need to consider individual trajectories to adequately describe growth outcomes. Specifically, well-defined longitudinal models are essential to characterize both population and subject-specific growth. Linear mixed-effect models with cubic regression splines can account for the nonlinearity of growth curves and provide reasonable estimators of population and subject-specific growth, velocity and acceleration. We provide a stepwise approach that builds from simple to complex models, and account for the intrinsic complexity of the data. We start with standard cubic splines regression models and build up to a model that includes subject-specific random intercepts and slopes and residual autocorrelation. We then compared cubic regression splines vis-à-vis linear piecewise splines, and with varying number of knots and positions. Statistical code is provided to ensure reproducibility and improve dissemination of methods. Models are applied to longitudinal height measurements in a cohort of 215 Peruvian children followed from birth until their fourth year of life. Unexplained variability, as measured by the variance of the regression model, was reduced from 7.34 when using ordinary least squares to 0.81 (p < 0.001) when using a linear mixed-effect models with random slopes and a first order continuous autoregressive error term. There was substantial heterogeneity in both the intercept (p < 0.001) and slopes (p < 0.001) of the individual growth trajectories. We also identified important serial correlation within the structure of the data (ρ = 0.66; 95 % CI 0.64 to 0.68; p < 0.001), which we modeled with a first order continuous autoregressive error term as evidenced by the variogram of the residuals and by a lack of association among residuals. The final model provides a parametric linear regression equation for both estimation and prediction of population- and individual-level growth in height. We show that cubic regression splines are superior to linear regression splines for the case of a small number of knots in both estimation and prediction with the full linear mixed effect model (AIC 19,352 vs. 19,598, respectively). While the regression parameters are more complex to interpret in the former, we argue that inference for any problem depends more on the estimated curve or differences in curves rather than the coefficients. Moreover, use of cubic regression splines provides biological meaningful growth velocity and acceleration curves despite increased complexity in coefficient interpretation. Through this stepwise approach, we provide a set of tools to model longitudinal childhood data for non-statisticians using linear mixed-effect models.

[Effects of shading on two Sphagnum species growth and their interactions].

PubMed

Ma, Jin-Ze; Bu, Zhao-Jun; Zheng, Xing-Xing; Li, Shan-Lin; Zeng, Jing; Zhao, Gao-Lin

2012-02-01

Taking Sphagnum palustre and S. fallax as test materials, this paper studied their growth and interactions under shading. In monoculture, shading promoted the height growth of S. palustre markedly, but had no effect on the growth of S. fallax and the biomass and branching of S. palustre. In mixed culture, S. fallax suppressed the increase of biomass and branching of S. palustre, while S. palustre had no effects on S. fallax. With the increase of shading stress, the competition of neighbour on S. fallax intensified. When the stress increased further, neighbor effect on S. fallax tended to be positive. However, the effect of neighbour on S. palustre was always competitive and did not change with the increase of shading stress.

AmeriFlux CA-Let Alberta - Mixed Grass Prairie

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

Flanagan, Lawrence B.

This is the AmeriFlux version of the carbon flux data for the site CA-Let Alberta - Mixed Grass Prairie. Site Description - Latitude 49.43° N; Longitude 112.56° W, altitude 951 meters,Mixed Grass Prairie that includes the following major species: Agropyron spp. (Wheat Grasses), Tragopogon dubius (Goat’s Beard), Vicia americana (Wild Vetch), Koleria cristata (June Grass), Eurotia lanata (Winter Fat), Stipa comata (Spear Grass), Achillea millefolium (Yarrow); Artemisia frigida (Pasture Sage); Carex spp. (Sedges), Bouteloua gracilis (Blue Grama Grass). Maximum canopy height varies from year to year

The impact of a nutrition education programme on the anthropometric nutritional status of low-income children in South Africa.

PubMed

Walsh, C M; Dannhauser, A; Joubert, G

2002-02-01

The study determined the impact of a community-based nutrition education programme, using trained community nutrition advisors, on the anthropometric nutritional status of mixed-race children aged between 2 and 5 years. The programme was implemented over two years in four study areas in the Free State and Northern Cape Provinces. Two control areas were included to differentiate between the effect of the education programme and a food aid programme that were implemented simultaneously. Weight-for-age, height-for-age and weight-for-height were summarised using standard deviations from the NCHS reference median. For each of the indicators, the difference in the percentage of children below minus two standard deviations from the reference NCHS median in the initial and follow-up surveys was determined. Initially 536 children were measured and, after two years of intervention, 815. Weight-for-age improved in all areas, but only significantly in boys and girls in the urban study area, and in boys in one rural study area. No significant improvement in height-for-age occurred in any area. Weight-for-height improved significantly in the urban study area. The education programme in combination with food aid succeeded in improving the weight status of children, but was unable to facilitate catch-up growth in stunted children after two years of intervention.

Longitudinal Lung Function Growth of Mexican Children Compared with International Studies

PubMed Central

Martínez-Briseño, David; Fernández-Plata, Rosario; Gochicoa-Rangel, Laura; Torre-Bouscoulet, Luis; Rojas-Martínez, Rosalba; Mendoza, Laura; García-Sancho, Cecilia; Pérez-Padilla, Rogelio

2013-01-01

Introduction Our aim was to compare the longitudinal lung function growth of Mexican children and adolescents with the collated spirometric reference proposed for international use and with that of Mexican-Americans from the National Health State Examination Survey III (NHANES) III study. Materials and Methods A cohort of Mexican children in third year of primary school was followed with spirometry twice a year through secondary school. Multilevel mixed-effects lineal models separated by gender were fit for the spirometric variables of 2,641 respiratory-healthy Mexican children expressed as Z-scores of tested reference equations. Impact of adjustment by sitting height on differences with Mexican-American children was observed in a subsample of 1,987 children. Results At same gender, age, and height, Mexican children had increasingly higher forced expiratory volume in 1 s (FEV1) and Forced vital capacity (FVC) than the children from the collated reference study (mean Z-score, 0.68 for FEV1 and 0.51 for FVC) and than Mexican-American children (Z-score, 0.23 for FEV1 and 0.21 for FVC) respectively. Differences with Mexican-Americans were not reduced by adjusting by sitting height. Conclusions For reasons that remain unclear, the gender-, age-, and height-adjusted lung function of children from Mexico City is higher than that reported by several international studies. PMID:24143231

The Effects of Bottom Ash on Setting Time and Compressive Strength of Fly Ash Geopolymer Paste

NASA Astrophysics Data System (ADS)

Affandhie, B. A.; Kurniasari, P. T.; Darmawan, M. S.; Subekti, S.; Wibowo, B.; Husin, N. A.; Bayuaji, R.; Irawan, S.

2017-11-01

This research is to find out the contribution of waste energy utilization of fly ash and bottom ash coal as binding agent of geopolymer concrete. This research methodology uses experimental approach in laboratory by making cylinder paste test object with dimension diameter of 2.5 cm x height 5 cm with some combination of fly ash and bottom ash mix with time setting test (ASTM C 191-04a) and compressive strength (ASTM C 39-04a). The research concludes that the effect of bottom ash on fly ash-based geopolymer paste shows good results in setting time and compressive strength.

Methodological Considerations in Estimation of Phenotype Heritability Using Genome-Wide SNP Data, Illustrated by an Analysis of the Heritability of Height in a Large Sample of African Ancestry Adults

PubMed Central

Chen, Fang; He, Jing; Zhang, Jianqi; Chen, Gary K.; Thomas, Venetta; Ambrosone, Christine B.; Bandera, Elisa V.; Berndt, Sonja I.; Bernstein, Leslie; Blot, William J.; Cai, Qiuyin; Carpten, John; Casey, Graham; Chanock, Stephen J.; Cheng, Iona; Chu, Lisa; Deming, Sandra L.; Driver, W. Ryan; Goodman, Phyllis; Hayes, Richard B.; Hennis, Anselm J. M.; Hsing, Ann W.; Hu, Jennifer J.; Ingles, Sue A.; John, Esther M.; Kittles, Rick A.; Kolb, Suzanne; Leske, M. Cristina; Monroe, Kristine R.; Murphy, Adam; Nemesure, Barbara; Neslund-Dudas, Christine; Nyante, Sarah; Ostrander, Elaine A; Press, Michael F.; Rodriguez-Gil, Jorge L.; Rybicki, Ben A.; Schumacher, Fredrick; Stanford, Janet L.; Signorello, Lisa B.; Strom, Sara S.; Stevens, Victoria; Van Den Berg, David; Wang, Zhaoming; Witte, John S.; Wu, Suh-Yuh; Yamamura, Yuko; Zheng, Wei; Ziegler, Regina G.; Stram, Alexander H.; Kolonel, Laurence N.; Marchand, Loïc Le; Henderson, Brian E.; Haiman, Christopher A.; Stram, Daniel O.

2015-01-01

Height has an extremely polygenic pattern of inheritance. Genome-wide association studies (GWAS) have revealed hundreds of common variants that are associated with human height at genome-wide levels of significance. However, only a small fraction of phenotypic variation can be explained by the aggregate of these common variants. In a large study of African-American men and women (n = 14,419), we genotyped and analyzed 966,578 autosomal SNPs across the entire genome using a linear mixed model variance components approach implemented in the program GCTA (Yang et al Nat Genet 2010), and estimated an additive heritability of 44.7% (se: 3.7%) for this phenotype in a sample of evidently unrelated individuals. While this estimated value is similar to that given by Yang et al in their analyses, we remain concerned about two related issues: (1) whether in the complete absence of hidden relatedness, variance components methods have adequate power to estimate heritability when a very large number of SNPs are used in the analysis; and (2) whether estimation of heritability may be biased, in real studies, by low levels of residual hidden relatedness. We addressed the first question in a semi-analytic fashion by directly simulating the distribution of the score statistic for a test of zero heritability with and without low levels of relatedness. The second question was addressed by a very careful comparison of the behavior of estimated heritability for both observed (self-reported) height and simulated phenotypes compared to imputation R2 as a function of the number of SNPs used in the analysis. These simulations help to address the important question about whether today's GWAS SNPs will remain useful for imputing causal variants that are discovered using very large sample sizes in future studies of height, or whether the causal variants themselves will need to be genotyped de novo in order to build a prediction model that ultimately captures a large fraction of the variability of height, and by implication other complex phenotypes. Our overall conclusions are that when study sizes are quite large (5,000 or so) the additive heritability estimate for height is not apparently biased upwards using the linear mixed model; however there is evidence in our simulation that a very large number of causal variants (many thousands) each with very small effect on phenotypic variance will need to be discovered to fill the gap between the heritability explained by known versus unknown causal variants. We conclude that today's GWAS data will remain useful in the future for causal variant prediction, but that finding the causal variants that need to be predicted may be extremely laborious. PMID:26125186

Methodological Considerations in Estimation of Phenotype Heritability Using Genome-Wide SNP Data, Illustrated by an Analysis of the Heritability of Height in a Large Sample of African Ancestry Adults.

PubMed

Chen, Fang; He, Jing; Zhang, Jianqi; Chen, Gary K; Thomas, Venetta; Ambrosone, Christine B; Bandera, Elisa V; Berndt, Sonja I; Bernstein, Leslie; Blot, William J; Cai, Qiuyin; Carpten, John; Casey, Graham; Chanock, Stephen J; Cheng, Iona; Chu, Lisa; Deming, Sandra L; Driver, W Ryan; Goodman, Phyllis; Hayes, Richard B; Hennis, Anselm J M; Hsing, Ann W; Hu, Jennifer J; Ingles, Sue A; John, Esther M; Kittles, Rick A; Kolb, Suzanne; Leske, M Cristina; Millikan, Robert C; Monroe, Kristine R; Murphy, Adam; Nemesure, Barbara; Neslund-Dudas, Christine; Nyante, Sarah; Ostrander, Elaine A; Press, Michael F; Rodriguez-Gil, Jorge L; Rybicki, Ben A; Schumacher, Fredrick; Stanford, Janet L; Signorello, Lisa B; Strom, Sara S; Stevens, Victoria; Van Den Berg, David; Wang, Zhaoming; Witte, John S; Wu, Suh-Yuh; Yamamura, Yuko; Zheng, Wei; Ziegler, Regina G; Stram, Alexander H; Kolonel, Laurence N; Le Marchand, Loïc; Henderson, Brian E; Haiman, Christopher A; Stram, Daniel O

2015-01-01

Height has an extremely polygenic pattern of inheritance. Genome-wide association studies (GWAS) have revealed hundreds of common variants that are associated with human height at genome-wide levels of significance. However, only a small fraction of phenotypic variation can be explained by the aggregate of these common variants. In a large study of African-American men and women (n = 14,419), we genotyped and analyzed 966,578 autosomal SNPs across the entire genome using a linear mixed model variance components approach implemented in the program GCTA (Yang et al Nat Genet 2010), and estimated an additive heritability of 44.7% (se: 3.7%) for this phenotype in a sample of evidently unrelated individuals. While this estimated value is similar to that given by Yang et al in their analyses, we remain concerned about two related issues: (1) whether in the complete absence of hidden relatedness, variance components methods have adequate power to estimate heritability when a very large number of SNPs are used in the analysis; and (2) whether estimation of heritability may be biased, in real studies, by low levels of residual hidden relatedness. We addressed the first question in a semi-analytic fashion by directly simulating the distribution of the score statistic for a test of zero heritability with and without low levels of relatedness. The second question was addressed by a very careful comparison of the behavior of estimated heritability for both observed (self-reported) height and simulated phenotypes compared to imputation R2 as a function of the number of SNPs used in the analysis. These simulations help to address the important question about whether today's GWAS SNPs will remain useful for imputing causal variants that are discovered using very large sample sizes in future studies of height, or whether the causal variants themselves will need to be genotyped de novo in order to build a prediction model that ultimately captures a large fraction of the variability of height, and by implication other complex phenotypes. Our overall conclusions are that when study sizes are quite large (5,000 or so) the additive heritability estimate for height is not apparently biased upwards using the linear mixed model; however there is evidence in our simulation that a very large number of causal variants (many thousands) each with very small effect on phenotypic variance will need to be discovered to fill the gap between the heritability explained by known versus unknown causal variants. We conclude that today's GWAS data will remain useful in the future for causal variant prediction, but that finding the causal variants that need to be predicted may be extremely laborious.

VizieR Online Data Catalog: Stellar models. 0.85

NASA Astrophysics Data System (ADS)

Charbonnel, C.; Decressin, T.; Lagarde, N.; Gallet, F.; Palacios, A.; Auriere, M.; Konstantinova-Antova, R.; Mathis, S.; Anderson, R. I.; Dintrans, B.

2018-02-01

Grid of stellar models and convective turnover timescale for four metallicities (Z= 0.0001, 0.002, 0.004, and 0.014) in the mass range from 0.85 to 6.0Mȯ. The models are computed either with standard prescriptions or including both thermohaline convection and rotation-induced mixing. For the whole grid, we provide the usual stellar parameters (luminosity, effective temperature, lifetimes, ...), together with the turnover timescale estimated a different heights in the convective envelope and their corresponding Rossby number. (4 data files).

Effects of surface roughness and electrokinetic heterogeneity on electroosmotic flow in microchannel

NASA Astrophysics Data System (ADS)

Masilamani, Kannan; Ganguly, Suvankar; Feichtinger, Christian; Bartuschat, Dominik; Rüde, Ulrich

2015-06-01

In this paper, a hybrid lattice-Boltzmann and finite-difference (LB-FD) model is applied to simulate the effects of three-dimensional surface roughness and electrokinetic heterogeneity on electroosmotic flow (EOF) in a microchannel. The lattice-Boltzmann (LB) method has been employed to obtain the flow field and a finite-difference (FD) method is used to solve the Poisson-Boltzmann (PB) equation for the electrostatic potential distribution. Numerical simulation of flow through a square cross-section microchannel with designed roughness is conducted and the results are critically analysed. The effects of surface heterogeneity on the electroosmotic transport are investigated for different roughness height, width, roughness interval spacing, and roughness surface potential. Numerical simulations reveal that the presence of surface roughness changes the nature of electroosmotic transport through the microchannel. It is found that the electroosmotic velocity decreases with the increase in roughness height and the velocity profile becomes asymmetric. For the same height of the roughness elements, the EOF velocity rises with the increase in roughness width. For the heterogeneously charged rough channel, the velocity profile shows a distinct deviation from the conventional plug-like flow pattern. The simulation results also indicate locally induced flow vortices which can be utilized to enhance the flow and mixing within the microchannel. The present study has important implications towards electrokinetic flow control in the microchannel, and can provide an efficient way to design a microfluidic system of practical interest.

Changes in forest floor and soil nutrients in a mixed oak forest 33 years after stem only and whole-tree harvest

Treesearch

D.W. Johnson; C.C. Trettin; D.E. Todd

2016-01-01

Vegetation, forest floor, and soils were resampled at a mixed oak site in eastern Tennessee that had been subjected to stem only (SOH), whole-tree harvest (WTH), and no harvest (REF) 33 years previously. Although differences between harvest treatments were not statistically significant (P < 0.05), average diameter, height, basal...

An optimal proportion of mixing broad-leaved forest for enhancing the effective productivity of moso bamboo.

PubMed

Cheng, Xiao-Fei; Shi, Pei-Jian; Hui, Cang; Wang, Fu-Sheng; Liu, Guo-Hua; Li, Bai-Lian

2015-04-01

Moso bamboos (Phyllostachys edulis) are important forestry plants in southern China, with substantial roles to play in regional economic and ecological systems. Mixing broad-leaved forests and moso bamboos is a common management practice in China, and it is fundamental to elucidate the interactions between broad-leaved trees and moso bamboos for ensuring the sustainable provision of ecosystem services. We examine how the proportion of broad-leaved forest in a mixed managed zone, topology, and soil profile affects the effective productivity of moso bamboos (i.e., those with significant economic value), using linear regression and generalized additive models. Bamboo's diameter at breast height follows a Weibull distribution. The importance of these variables to bamboo productivity is, respectively, slope (25.9%), the proportion of broad-leaved forest (24.8%), elevation (23.3%), gravel content by volume (16.6%), slope location (8.3%), and soil layer thickness (1.2%). Highest productivity is found on the 25° slope, with a 600-m elevation, and 30% broad-leaved forest. As such, broad-leaved forest in the upper slope can have a strong influence on the effective productivity of moso bamboo, ranking only after slope and before elevation. These factors can be considered in future management practice.

Height Growth and Percentage of Body Fat in Relation to Early Menarche in Girls from Merida, Yucatan, Mexico.

PubMed

Datta Banik, Sudip; Mendez, Nina; Dickinson, Federico

2015-01-01

Early menarche (EM) (i.e., age at menarche [AAM] <12 years of age) is related to short height and higher body fatness. In a mixed-longitudinal study done in Merida, Yucatan, height, body mass index (BMI), and percentage of body fat (BF%) were recorded at a one-year interval among 258 postmenarcheal (EM = 94) girls. Anthropometric measurements were recorded of the age cohorts in 2008-09 when participants were 13-17 years of age (baseline), and in the one-year follow-up study (± 6 days) the girls were 14-18 years of age. The BF% was estimated through bioelectrical impedance analysis. Mean AAM was 10.59 years in EM girls and 12.54 years in not early menarche (NEM) girls. Height growth (cm/year) was greater in NEM girls. Mean values of BMI, BF%, and frequencies of stunting (low height-for-age) and excess weight (overweight + obesity) were higher in EM girls than in their NEM age peers.

A note on the effect of wind waves on vertical mixing in Franks Tract, Sacramento-San Joaquin Delta, California, USA

USGS Publications Warehouse

Thompson, Janet K.; Jones, Nicole L.; Stephen G. Monismith,

2008-01-01

A one-dimensional numerical model that simulates the effects of whitecapping waves was used to investigate the importance of whitecapping waves to vertical mixing at a 3-meter-deep site in Franks Tract in the Sacramento-San Joaquin Delta over an 11-day period. Locally-generated waves of mean period approximately 2 s were generated under strong wind conditions; significant wave heights ranged from 0 to 0.3 m. A surface turbulent kinetic energy flux was used to model whitecapping waves during periods when wind speeds > 5 m s-1 (62% of observations). The surface was modeled as a wind stress log-layer for the remaining 38% of the observations. The model results demonstrated that under moderate wind conditions (5–8 m s-1 at 10 m above water level), and hence moderate wave heights, whitecapping waves provided the dominant source of turbulent kinetic energy to only the top 10% of the water column. Under stronger wind (> 8 m s-1), and hence larger wave conditions, whitecapping waves provided the dominant source of turbulent kinetic energy over a larger portion of the water column; however, this region extended to the bottom half of the water column for only 7% of the observation period. The model results indicated that phytoplankton concentrations close to the bed were unlikely to be affected by the whitecapping of waves, and that the formation of concentration boundary layers due to benthic grazing was unlikely to be disrupted by whitecapping waves. Furthermore, vertical mixing of suspended sediment was unlikely to be affected by whitecapping waves under the conditions experienced during the 11-day experiment. Instead, the bed stress provided by tidal currents was the dominant source of turbulent kinetic energy over the bottom half of the water column for the majority of the 11-day period.

Velocity Measurement in a Dual-Mode Supersonic Combustor using Particle Image Velocimetry

NASA Technical Reports Server (NTRS)

Goyne, C. P.; McDaniel, J. C.; Krauss, R. H.; Day, S. W.; Reubush, D. E. (Technical Monitor); McClinton, C. R. (Technical Monitor); Reubush, D. E.

2001-01-01

Temporally and spatially-resolved, two-component measurements of velocity in a supersonic hydrogen-air combustor are reported. The combustor had a single unswept ramp fuel injector and operated with an inlet Mach number of 2 and a flow total temperature approaching 1200 K. The experiment simulated the mixing and combustion processes of a dual-mode scramjet operating at a flight Mach number near 5. The velocity measurements were obtained by seeding the fuel with alumina particles and performing Particle Image Velocimetry on the mixing and combustion wake of the ramp injector. To assess the effects of combustion on the fuel air-mixing process, the distribution of time-averaged velocity and relative turbulence intensity was determined for the cases of fuel-air mixing and fuel-air reacting. Relative to the mixing case, the near field core velocity of the reacting fuel jet had a slower streamwise decay. In the far field, downstream of 4 to 6 ramp heights from the ramp base, the heat release of combustion resulted in decreased flow velocity and increased turbulence levels. The reacting measurements were also compared with a computational fluid dynamics solution of the flow field. Numerically predicted velocity magnitudes were higher than that measured and the jet penetration was lower.

Peak bone mass and patterns of change in total bone mineral density and bone mineral contents from childhood into young adulthood

PubMed Central

Lu, Juan; Shin, Yongyun; Yen, Miao-Shan; Sun, Shumei S.

2014-01-01

The literature has not reached a consensus on the age when peak bone mass is achieved. This study examines growth patterns of TBMC and TBMD, peak bone mass, effect of concurrent anthropometry measures and physical activity on growth patterns in a sample of 312 white males and 343 females aged eight to 30 years. We analyzed data from participants enrolled in Fels Longitudinal Study. Descriptive analysis was used to ascertain characteristics of participants and growth patterns of TBMC and TBMD. Mixed effects models were applied to predict ages at attainment of peak TBMC and TBMD and assess effects of height, weight, BMI and habitual physical activity on the attainment. Significant differences between sexes were observed for measures of TBMC and TBMD, and differences varied with age. For females, predicted median ages at peak TBMC and TBMD attainments are 21.96 (IQR: 21.81–22.21) and 22.31 (IQR: 21.95–22.59) years, respectively. For males, predicted median ages are 23.34 (IQR: 24.34–26.19) and 26.86 (IQR: 25.14–27.98) respectively. For females, height, weight and BMI, but not physical activity, had significant influences on attainment of TBMC and TBMD (P <0.01). For males, weight and BMI, but not height and physical activity, exerted significant influence on attainment of TBMC and TBMD (P<0.01), and also modified correlations between age and peak TBMC and TBMD. Our results suggest that (1) for both sexes, trajectories of TBMC and TBMD follow a curvilinear pattern between ages eight and 30 years; (2) predicted ages at peak TBMC and TBMD are from early to late 20s for both white males and females, with females reaching their peaks significantly earlier than males; and (3) concurrent height, weight and BMI, but not habitual physical activity, exert significant effects on trajectories of TBMC and TBMD. PMID:25440183

A comparison of burn season effects on nesting birds in North Dakota mixed-grass prairie

USGS Publications Warehouse

Higgins, K.F.

1986-01-01

During 1982-1985, the effects of single spring and fall burn treatments on ground nesting birds and residual cover were studied on five paired areas of native mixed-grass prairie in northwestern Stutsman County, ND. Annually, visual obstruction readings to index the height-density of residual cover were taken once and nest searches were made four times on each area. Residual nesting cover on fall burn plots averaged taller and denser than on spring burn plots during post-fire growing years 2-4. A total of 259 duck nests and 63 nests of non-passerine birds were found during the four years. Duck nesting success was significantly greater (P < 0.05) in fall burn plots than in spring burn plots for all species and years combined. Too few nests of other bird species were found for valid comparisons. Results suggest that vegetation structure and duck nesting response to spring and fall burns became similar again by the third post-fire growing season.

Relationship between boundary layer heights and growth rates with ground-level ozone in Houston, Texas

NASA Astrophysics Data System (ADS)

Haman, C. L.; Couzo, E.; Flynn, J. H.; Vizuete, W.; Heffron, B.; Lefer, B. L.

2014-05-01

Measurements and predictions of ambient ozone (O3), planetary boundary layer (PBL) height, the surface energy budget, wind speed, and other meteorological parameters were made near downtown Houston, Texas, and were used to investigate meteorological controls on elevated levels of ground-level O3. Days during the study period (1 April 2009 to 31 December 2010 for measurements and 15 April 2009 to 17 October 2009 for modeled) were classified into low (LO3) and high ozone (HO3) days. The majority of observed high HO3 days occurred in a postfrontal environment. Observations showed there is not a significant difference in daily maximum PBL heights on HO3 and LO3 days. Modeling results showed large differences between maximum PBL heights on HO3 and LO3 days. Nighttime and early morning observed and modeled PBL heights are consistently lower on HO3 days than on LO3 days. The observed spring LO3 days had the most rapid early morning PBL growth (~350 m h-1) while the fall HO3 group had the slowest (~200 m h-1). The predicted maximum average hourly morning PBL growth rates were greater on HO3 (624 m h-1) days than LO3 days (361 m h-1). Observed turbulent mixing parameters were up to 2-3 times weaker on HO3 days, which indicate large-scale subsidence associated with high-pressure systems (leading to clear skies and weak winds) substantially suppresses mixing. Lower surface layer ventilation coefficients were present in the morning on HO3 days in the spring and fall, which promotes the accumulation of O3 precursors near the surface.

Planetary Boundary Layer Dynamics over Reno, Nevada in Summer

NASA Astrophysics Data System (ADS)

Liming, A.; Sumlin, B.; Loria Salazar, S. M.; Holmes, H.; Arnott, W. P.

2014-12-01

Quantifying the height of the planetary boundary layer (PBL) is important to understand the transport behavior, mixing, and surface concentrations of air pollutants. In Reno, NV, located in complex, mountainous terrain with high desert climate, the daytime boundary layer can rise to an estimated 3km or more on a summer day due to surface heating and convection. The nocturnal boundary layer, conversely, tends to be much lower and highly stable due to radiative cooling from the surface at night and downslope flow of cool air from nearby mountains. With limited availability of radiosonde data, current estimates of the PBL height at any given time or location are potentially over or underestimated. To better quantify the height and characterize the PBL physics, we developed portable, lightweight sensors that measure CO2 concentrations, temperature, pressure, and humidity every 5 seconds. Four of these sensors are used on a tethered balloon system to monitor CO2 concentrations from the surface up to 300m. We will combine this data with Radio Acoustic Sounding System (RASS) data that measures vertical profiles of wind speed, temperature, and humidity from 40m to 400m. This experiment will characterize the diurnal evolution of CO2 concentrations at multiple heights in the PBL, provide insight into PBL physics during stability transition periods at sunrise and sunset, and estimate the nighttime PBL depth during August in Reno. Further, we expect to gain a better understanding of the impact of mixing volume changes (i.e., PBL height) on air quality and pollution concentrations in Reno. The custom portable sensor design will also be presented. It is expected that these instruments can be used for indoor or outdoor air quality studies, where lightness, small size, and battery operation can be of benefit.

Regional Distribution of Forest Height and Biomass from Multisensor Data Fusion

NASA Technical Reports Server (NTRS)

Yu, Yifan; Saatchi, Sassan; Heath, Linda S.; LaPoint, Elizabeth; Myneni, Ranga; Knyazikhin, Yuri

2010-01-01

Elevation data acquired from radar interferometry at C-band from SRTM are used in data fusion techniques to estimate regional scale forest height and aboveground live biomass (AGLB) over the state of Maine. Two fusion techniques have been developed to perform post-processing and parameter estimations from four data sets: 1 arc sec National Elevation Data (NED), SRTM derived elevation (30 m), Landsat Enhanced Thematic Mapper (ETM) bands (30 m), derived vegetation index (VI) and NLCD2001 land cover map. The first fusion algorithm corrects for missing or erroneous NED data using an iterative interpolation approach and produces distribution of scattering phase centers from SRTM-NED in three dominant forest types of evergreen conifers, deciduous, and mixed stands. The second fusion technique integrates the USDA Forest Service, Forest Inventory and Analysis (FIA) ground-based plot data to develop an algorithm to transform the scattering phase centers into mean forest height and aboveground biomass. Height estimates over evergreen (R2 = 0.86, P < 0.001; RMSE = 1.1 m) and mixed forests (R2 = 0.93, P < 0.001, RMSE = 0.8 m) produced the best results. Estimates over deciduous forests were less accurate because of the winter acquisition of SRTM data and loss of scattering phase center from tree ]surface interaction. We used two methods to estimate AGLB; algorithms based on direct estimation from the scattering phase center produced higher precision (R2 = 0.79, RMSE = 25 Mg/ha) than those estimated from forest height (R2 = 0.25, RMSE = 66 Mg/ha). We discuss sources of uncertainty and implications of the results in the context of mapping regional and continental scale forest biomass distribution.

Development of MCNPX-ESUT computer code for simulation of neutron/gamma pulse height distribution

NASA Astrophysics Data System (ADS)

Abolfazl Hosseini, Seyed; Vosoughi, Naser; Zangian, Mehdi

2015-05-01

In this paper, the development of the MCNPX-ESUT (MCNPX-Energy Engineering of Sharif University of Technology) computer code for simulation of neutron/gamma pulse height distribution is reported. Since liquid organic scintillators like NE-213 are well suited and routinely used for spectrometry in mixed neutron/gamma fields, this type of detectors is selected for simulation in the present study. The proposed algorithm for simulation includes four main steps. The first step is the modeling of the neutron/gamma particle transport and their interactions with the materials in the environment and detector volume. In the second step, the number of scintillation photons due to charged particles such as electrons, alphas, protons and carbon nuclei in the scintillator material is calculated. In the third step, the transport of scintillation photons in the scintillator and lightguide is simulated. Finally, the resolution corresponding to the experiment is considered in the last step of the simulation. Unlike the similar computer codes like SCINFUL, NRESP7 and PHRESP, the developed computer code is applicable to both neutron and gamma sources. Hence, the discrimination of neutron and gamma in the mixed fields may be performed using the MCNPX-ESUT computer code. The main feature of MCNPX-ESUT computer code is that the neutron/gamma pulse height simulation may be performed without needing any sort of post processing. In the present study, the pulse height distributions due to a monoenergetic neutron/gamma source in NE-213 detector using MCNPX-ESUT computer code is simulated. The simulated neutron pulse height distributions are validated through comparing with experimental data (Gohil et al. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 664 (2012) 304-309.) and the results obtained from similar computer codes like SCINFUL, NRESP7 and Geant4. The simulated gamma pulse height distribution for a 137Cs source is also compared with the experimental data.

Longitudinal Lung Function Decrease in Subjects with Spontaneous Healed Pulmonary Tuberculosis.

PubMed

Lee, Seung Heon; Kwon, Amy M; Yang, Hae-Chung; Lee, Seung Ku; Kim, Young; Choi, Jong Hyun; Kim, Je Hyeong; Shin, Chol

2016-01-01

We compared the longitudinal course of post-bronchodilator Forced Expiratory Volume in 1 second (pFEV1) over a 10-year period in subjects with spontaneous healed pulmonary tuberculosis (SHPTB) with that in normal subjects. We prospectively investigated 339 subjects with SHPTB and 3211 normal subjects. pFEV1 values measured biannually over 10 years were analyzed using mixed effects model. At baseline, there were no differences in gender, smoking amount, and mean height, except mean age (50.0 ± 8.1 VS. 48.1 ± 7.3, P< 0.001) between the SHPTB and normal group. 52% of the 339 participants with SHPTB and 56% of the 3211 normal participants participated till the end of study. According to the final model, the SHPTB group showed significantly larger decrease in the average pFEV1 over the time than the normal group (P< 0.001) adjusted for gender, age, height, smoking pack years, and time effects. Especially, the interaction effect between time and group was statistically significant (P = 0.036). The average lung function in terms of pFEV1 decreases faster in subjects with SHPTB than in normal individuals over time.

Fuel consumption and fire characteristics during understory burning in a mixed white pine-hardwood stand in the Southern Appalachians.

Treesearch

Barton D. Clinton; James M. Vose; Wayne T. Swank; Erik C. Berg; David L. Loftis

1998-01-01

We characterized tire behavior and fuel consumption resulting from an understory prescribed burn in a mixed eastern white pine-hardwood stand in the Southern Appalachians. These stands were used for the treatment. Flame lengths, ranging from 0.3 to 1.5 meters (m) for backing fires and from 1.2 to 4.5 m for head fires, reached maximum heights where evergreen understory...

Intra-annual growth and mortality of four Populus clones in pure and mixed plantings

Treesearch

Warren D. Devine; Constance A. Harrington; Dean S. DeBell

2010-01-01

Intra-annual growth rates were assessed during 3 years for four Populus clones grown in pure and mixed clonal stands at square spacings of 0.5, 1.0, and 1.5 m in western Washington, USA. Height growth rate peaked in August, except at the 0.5-m spacing where it peaked in July and June in years 2 and 3, respectively. Diameter growth rate generally...

X-LAG: How did they grow so tall?

PubMed

Beckers, Albert; Rostomyan, Liliya; Potorac, Iulia; Beckers, Pablo; Daly, Adrian F

2017-06-01

X-linked acrogigantism (XLAG) is a new, pediatric-onset genetic syndrome, due to Xq26.3 microduplications encompassing the GPR101 gene. XLAG has a remarkably distinct phenotype with disease onset occurring before the age of 5 in all cases described to date, which is significantly younger than in other forms of pituitary gigantism. These patients have mixed GH and prolactin positive adenomas and/or mixed-cell hyperplasia and highly elevated levels of GH/IGF-1 and prolactin. Given their particularly young age of onset, the significant GH hypersecretion can lead to a phenotype of severe gigantism with very advanced age-specific height Z-scores. If not adequately treated in childhood, this condition results in extreme final adult height. XLAG has a clinical course that is highly similar to some of the tallest people with gigantism in history. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Method for using acoustic sounder categories to determine atmospheric stability

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

Schubert, J.F.

1979-01-01

Capabilities of the diffusion meteorologist have been expanded by the acoustic sounder, an economical tool for monitoring in real time the height of the mixed layer. The acoustic sounder continuously measures the rate of change in the height of the mixed layer which is an important parameter in calculating the transport and diffusion of radioactive and nonradioactive air pollutants. Continuous record of convective cells, gravity waves, inversions, and frontal systems permit analysis of the synoptic (analysis of stability in terms of simultaneous weather information) and complex (analysis of the stability of a single place by the relative frequencies of variousmore » stability types or groups of such types) stabilities of the local area. Sounder data obtained at the Savannah River Plant was compared on an hourly basis to data obtained at the WJBF-TV tower located approximately 20 km northwest of the acoustic sounder site.« less

Estimation of columnar concentrations of absorbing and scattering fine mode aerosol components using AERONET data

NASA Astrophysics Data System (ADS)

Choi, Yongjoo; Ghim, Young Sung

2016-11-01

Columnar concentrations of absorbing and scattering components of fine mode aerosols were estimated using Aerosol Robotic Network (AERONET) data for a site downwind of Seoul. The study period was between March 2012 and April 2013 including the period of the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-Asia campaign in March to May 2012. The Maxwell Garnett mixing rule was assumed for insoluble components embedded in a host solution, while the volume average mixing rule was assumed for the aqueous solution of soluble components. During the DRAGON-Asia campaign the surface concentrations of major components of fine particles were measured. The columnar mass fractions of black carbon (BC), organic carbon (OC), mineral dust (MD), and ammonium sulfate (AS) were 1.5, 5.9, 6.6, and 52%, respectively, which were comparable to the mass fractions measured at the surface for BC, OC, and secondary inorganic aerosols at 2.3, 18, and 55%. The vertical distributions of BC and AS were investigated by employing the concept of a column height. While the column height for BC was similar to the planetary boundary layer (PBL) height, that for AS was 4.4 times higher than the PBL height and increased with air temperature from March to May. The monthly variations of the columnar mass concentrations during the study period were generally well explained in term of meteorology and emission characteristics. However, certain variations of MD were different from those typically observed primarily because only fine mode aerosols were considered.

The Relationship of PM Variation with Visibility and Mixing-Layer Height under Hazy/Foggy Conditions in the Multi-Cities of Northeast China

PubMed Central

Zhao, Hujia; Che, Huizheng; Ma, Yanjun; Wang, Yangfeng; Yang, Hongbin; Liu, Yuche; Wang, Yaqiang; Wang, Hong; Zhang, Xiaoye

2017-01-01

The variations of visibility, PM-mass concentration and mixing-layer height (MLH) in four major urban/industry regions (Shenyang, Anshan, Benxi and Fushun) of central Liaoning in Northeast China are evaluated from 2009 to 2012 to characterize their dynamic effect on air pollution. The annual mean visibilities are about 13.7 ± 7.8, 13.5 ± 6.5, 12.8 ± 6.1 and 11.5 ± 6.8 km in Shenyang, Anshan, Benxi and Fushun, respectively. The pollution load (PM × MLH) shows a weaker vertical diffusion in Anshan, with a higher PM concentration near the surface. High concentrations of fine-mode particles may be partially attributed to the biomass-burning emissions from September in Liaoning Province and surrounding regions in Northeast China as well as the coal burning during the heating period with lower MLH in winter. The visibility on non-hazy fog days is about 2.5–3.0 times higher than that on hazy and foggy days. The fine-particle concentrations of PM2.5 and PM1.0 on hazy and foggy days are ~1.8–1.9 times and ~1.5 times higher than those on non-hazy foggy days. The MLH declined more severely during fog pollution than in haze pollution. The results of this study can provide useful information to better recognize the effects of vertical pollutant diffusion on air quality in the multi-cities of central Liaoning Province in Northeast China. PMID:28468246

Electrodynamic properties and height of atmospheric convective boundary layer

NASA Astrophysics Data System (ADS)

Anisimov, S. V.; Galichenko, S. V.; Mareev, E. A.

2017-09-01

We consider the relations between the mixed layer height and atmospheric electric parameters affected by convective mixing. Vertical turbulent transport of radon, its progeny and electrically charged particles is described under Lagrangian stochastic framework, which is the next step to develop a consistent model for the formation of electrical conditions in the atmospheric boundary layer. Using the data from detailed and complex measurements of vertical profiles of the temperature and turbulence statistics as input, we calculated non-stationary vertical profiles of radon and its daughter products concentrations, atmospheric electric conductivity and intensity of electric field in the convective boundary layer from the morning transition through early afternoon quasi-stationary conditions. These profiles demonstrate substantial variability due to the changing turbulent regime in the evolving boundary layer. We obtained quantitative estimates of the atmospheric electric field variability range essentially related to the sunrise and convection development. It is shown that the local change in the electrical conductivity is the only factor that can change the intensity of electric field at the earth's surface more than twice during the transition from night to day. The established relations between electric and turbulent parameters of the boundary layer indicate that the effect of sunrise is more pronounced in the case when development of convection is accompanied by an increase in aerosol concentration and, hence, a decrease in local conductivity.

Canopy Flow Analysis Reveals the Advantage of Size in the Oldest Communities of Multicellular Eukaryotes

PubMed Central

Ghisalberti, Marco; Gold, David A.; Laflamme, Marc; Clapham, Matthew E.; Narbonne, Guy M.; Summons, Roger E.; Johnston, David T.; Jacobs, David K.

2015-01-01

Summary At Mistaken Point, Newfoundland, Canada, rangeomorph “fronds” dominate the earliest (579–565 million years ago) fossil communities of large (0.1 to 2 m height) multicellular benthic eukaryotes. They lived in low-flow environments, fueled by uptake [1–3] of dissolved reactants (osmotrophy). However, prokaryotes are effective osmotrophs, and the advantage of taller eukaryotic osmotrophs in this deepwater community context has not been addressed. We reconstructed flow-velocity profiles and vertical mixing using canopy flow models appropriate to the densities of the observed communities. Further modeling of processes at organismal surfaces documents increasing uptake with height in the community as a function of thinning of the diffusive boundary layer with increased velocity. The velocity profile, produced by canopy flow in the community, generates this advantage of upward growth. Alternative models of upward growth advantage based on redox/resource gradients fail, given the efficiency of vertical mixing. In benthic communities of osmotrophs of sufficient density, access to flow in low-flow settings provides an advantage to taller architecture, providing a selectional driver for communities of tall eukaryotes in contexts where phototropism cannot contribute to upward growth. These Ediacaran deep-sea fossils were preserved during the increasing oxygenation prior to the Cambrian radiation of animals and likely represent an important phase in the ecological and evolutionary transition to more complex eukaryotic forms. PMID:24462003

The Effects of Maxillary Protraction with or without Rapid Maxillary Expansion and Age Factors in Treating Class III Malocclusion: A Meta-Analysis

PubMed Central

Zhang, Wei; Qu, Hong-Chen; Yu, Mo; Zhang, Yang

2015-01-01

We conducted a comprehensive meta-analysis of 12 studies to examine whether maxillary protraction face mask associated with rapid maxillary expansion (FM/RME) could be an effective treatment for Class III malocclusion and to evaluate the effect of timing on treatment response. Patients with a maxillary deficiency who were treated with FM with or without RME were compared with those who had an untreated Class III malocclusion. In both treatment groups, forward displacement of the maxilla and skeletal changes were found to be statistically significant. In addition, posterior rotation of the mandible and increased facial height were more evident in the FM group compared with the control group. However, no significant differences were observed between the early treatment groups and late treatment groups. The results indicated that both FM/RME and FM therapy produced favorable skeletal changes for correcting anterior crossbite, and the curative time was not affected by the presence of deciduous teeth, early mixed dentition or late mixed dentition in the patient. PMID:26068221

Effect of Zinc Supplementation on Growth Outcomes in Children under 5 Years of Age.

PubMed

Liu, Enju; Pimpin, Laura; Shulkin, Masha; Kranz, Sarah; Duggan, Christopher P; Mozaffarian, Dariush; Fawzi, Wafaie W

2018-03-20

(1) Background: The effects of zinc supplementation on child growth, and prior reviews of these studies, have shown mixed results. We aim to systematically review and meta-analyze randomized controlled trials evaluating effects of preventive zinc supplementation for 3 months or longer during pregnancy or in children up to age 5 years on pregnancy outcomes and child growth; (2) Methods: We searched PubMed, EMBASE, Cochrane Library, Web of Science, and trial registries for eligible trials up to October 10, 2017. Inclusion selection and data extractions were performed independently and in duplicate. Study quality was evaluated by the Cochrane Risk of Bias tool. Findings were pooled using random effects meta-analysis, with heterogeneity assessed by I ² and τ² statistic, stratified analyses, and meta-regression, and publication bias by Egger's and Begg's tests; (3) Results: Seventy-eight trials with 34,352 unique participants were identified, including 24 during pregnancy and 54 in infancy/childhood. Maternal zinc supplementation did not significantly increase birth weight (weighted mean difference (WMD) = 0.08 kg, 95%CI: -0.05, 0.22) or decrease the risk of low birth weight (RR = 0.76, 95%CI: 0.52-1.11). Zinc supplementation after birth increased height (WMD = 0.23 cm, 95%CI: 0.09-0.38), weight (WMD = 0.14 kg, 95%CI: 0.07-0.21), and weight-for-age Z -score (WMD = 0.04, 95%CI: 0.001-0.087), but not height-for-age Z -score (WMD = 0.02, 95%CI: -0.01-0.06) or weight-for-height Z score (WMD = 0.02, 95%CI: -0.03-0.06). Child age at zinc supplementation appeared to modify the effects on height ( P -interaction = 0.002) and HAZ ( P -interaction = 0.06), with larger effects of supplementation starting at age ≥2 years (WMD for height = 1.37 cm, 95%CI: 0.50-2.25; WMD for HAZ = 0.12, 95%CI: 0.05-0.19). No significant effects of supplementation were found on the risk of stunting, underweight or wasting; (4) Conclusion: Although the possibility of publication bias and small study effect could not be excluded, the current meta-analysis indicates that zinc supplementation in infants and early childhood, but not pregnancy, increases specific growth outcomes, with evidence for a potentially stronger effect after 2 years of age. These findings inform recommendation and policy development for zinc supplementation to improve growth among young children.

Whole Genome Association Mapping of Plant Height in Winter Wheat (Triticum aestivum L.)

PubMed Central

Zanke, Christine D.; Ling, Jie; Plieske, Jörg; Kollers, Sonja; Ebmeyer, Erhard; Korzun, Viktor; Argillier, Odile; Stiewe, Gunther; Hinze, Maike; Neumann, Kerstin; Ganal, Martin W.; Röder, Marion S.

2014-01-01

The genetic architecture of plant height was investigated in a set of 358 recent European winter wheat varieties plus 14 spring wheat varieties based on field data in eight environments. Genotyping of diagnostic markers revealed the Rht-D1b mutant allele in 58% of the investigated varieties, while the Rht-B1b mutant was only present in 7% of the varieties. Rht-D1 was significantly associated with plant height by using a mixed linear model and employing a kinship matrix to correct for population stratification. Further genotyping data included 732 microsatellite markers, resulting in 770 loci, of which 635 markers were placed on the ITMI map plus a set of 7769 mapped SNP markers genotyped with the 90 k iSELECT chip. When Bonferroni correction was applied, a total of 153 significant marker-trait associations (MTAs) were observed for plant height and the SSR markers (−log10 (P-value) ≥4.82) and 280 (−log10 (P-value) ≥5.89) for the SNPs. Linear regression between the most effective markers and the BLUEs for plant height indicated additive effects for the MTAs of different chromosomal regions. Analysis of syntenic regions in the rice genome revealed closely linked rice genes related to gibberellin acid (GA) metabolism and perception, i.e. GA20 and GA2 oxidases orthologous to wheat chromosomes 1A, 2A, 3A, 3B, 5B, 5D and 7B, ent-kaurenoic acid oxidase orthologous to wheat chromosome 7A, ent-kaurene synthase on wheat chromosome 2B, as well as GA-receptors like DELLA genes orthologous to wheat chromosomes 4B, 4D and 7A and genes of the GID family orthologous to chromosomes 2B and 5B. The data indicated that besides the widely used GA-insensitive dwarfing genes Rht-B1 and Rht-D1 there is a wide spectrum of loci available that could be used for modulating plant height in variety development. PMID:25405621

Long-term response to recombinant human growth hormone treatment: a new predictive mathematical method.

PubMed

Migliaretti, G; Ditaranto, S; Guiot, C; Vannelli, S; Matarazzo, P; Cappello, N; Stura, I; Cavallo, F

2018-07-01

Recombinant GH has been offered to GH-deficient (GHD) subjects for more than 30 years, in order to improve height and growth velocity in children and to enhance metabolic effects in adults. The aim of our work is to describe the long-term effect of rhGH treatment in GHD pediatric patients, suggesting a growth prediction model. A homogeneous database is defined for diagnosis and treatment modalities, based on GHD patients afferent to Hospital Regina Margherita in Turin (Italy). In this study, 232 GHD patients are selected (204 idiopathic GHD and 28 organic GHD). Each measure is shown in terms of mean with relative standard deviations (SD) and 95% confidence interval (95% CI). To estimate the final height of each patient on the basis of few measures, a mathematical growth prediction model [based on Gompertzian function and a mixed method based on the radial basis functions (RBFs) and the particle swarm optimization (PSO) models] was performed. The results seem to highlight the benefits of an early start of treatment, further confirming what is suggested by the literature. Generally, the RBF-PSO method shows a good reliability in the prediction of the final height. Indeed, RMSE is always lower than 4, i.e., in average the forecast will differ at most of 4 cm to the real value. In conclusion, the large and accurate database of Italian GHD patients allowed us to assess the rhGH treatment efficacy and compare the results with those obtained in other Countries. Moreover, we proposed and validated a new mathematical model forecasting the expected final height after therapy which was validated on our cohort.

Age-associated changes in obstacle negotiation strategies: Does size and timing matter?

PubMed

Maidan, I; Eyal, S; Kurz, I; Geffen, N; Gazit, E; Ravid, L; Giladi, N; Mirelman, A; Hausdorff, J M

2018-01-01

Tripping over an obstacle is one of the most common causes of falls among older adults. However, the effects of aging, obstacle height and anticipation time on negotiation strategies have not been systematically evaluated. Twenty older adults (ages: 77.7±3.4years; 50% women) and twenty young adults (age: 29.3±3.8years; 50% women) walked through an obstacle course while negotiating anticipated and unanticipated obstacles at heights of 25mm and 75mm. Kinect cameras captured the: (1) distance of the subject's trailing foot before the obstacles, (2) distance of the leading foot after the obstacles, (3) clearance of the leading foot above the obstacles, and (4) clearance of the trailing foot above the obstacles. Linear-mix models assessed changes between groups and conditions. Older adults placed their leading foot closer to the obstacle after landing, compared to young adults (p<0.001). This pattern was enhanced in high obstacles (group*height interaction, p=0.033). Older adults had lower clearance over the obstacles, compared to young adults (p=0.007). This was more pronounced during unanticipated obstacles (group*ART interaction, p=0.003). The distance of the leading foot and clearance of the trailing foot after the obstacles were correlated with motor, cognitive, and functional abilities. These findings suggest that there are age-related changes in obstacle crossing strategies that are dependent on the specific characteristics of the obstacle. The results have important implications for clinical practice, suggesting that functional exercise should include obstacle negotiation training with variable practice of height and available response times. Further studies are needed to better understand the effects of motor and cognitive abilities. Copyright © 2017 Elsevier B.V. All rights reserved.

Predictors for Physical Activity in Adolescent Girls Using Statistical Shrinkage Techniques for Hierarchical Longitudinal Mixed Effects Models

PubMed Central

Grant, Edward M.; Young, Deborah Rohm; Wu, Tong Tong

2015-01-01

We examined associations among longitudinal, multilevel variables and girls’ physical activity to determine the important predictors for physical activity change at different adolescent ages. The Trial of Activity for Adolescent Girls 2 study (Maryland) contributed participants from 8th (2009) to 11th grade (2011) (n=561). Questionnaires were used to obtain demographic, and psychosocial information (individual- and social-level variables); height, weight, and triceps skinfold to assess body composition; interviews and surveys for school-level data; and self-report for neighborhood-level variables. Moderate to vigorous physical activity minutes were assessed from accelerometers. A doubly regularized linear mixed effects model was used for the longitudinal multilevel data to identify the most important covariates for physical activity. Three fixed effects at the individual level and one random effect at the school level were chosen from an initial total of 66 variables, consisting of 47 fixed effects and 19 random effects variables, in additional to the time effect. Self-management strategies, perceived barriers, and social support from friends were the three selected fixed effects, and whether intramural or interscholastic programs were offered in middle school was the selected random effect. Psychosocial factors and friend support, plus a school’s physical activity environment, affect adolescent girl’s moderate to vigorous physical activity longitudinally. PMID:25928064

An empirical relationship between mesoscale carbon monoxide concentrations and vehicular emission rates : final report.

DOT National Transportation Integrated Search

1979-01-01

Presented is a relatively simple empirical equation that reasonably approximates the relationship between mesoscale carbon monoxide (CO) concentrations, areal vehicular CO emission rates, and the meteorological factors of wind speed and mixing height...

A model for microwave emission from vegetation-covered fields

NASA Technical Reports Server (NTRS)

Mo, T.; Choudhury, B. J.; Schmugge, T. J.; Wang, J. R.; Jackson, T. J.

1982-01-01

The measured brightness temperatures over vegetation-covered fields are simulated by a radiative transfer model which treats the vegetation as a uniform canopy with a constant temperature, over a moist soil which emits polarized microwave radiation. The analytic formula for the microwave emission has four parameters: roughness height, polarization mixing factor, effective canopy optical thickness, and single scattering albedo. A good representation has been obtained with the model for both the horizontally and vertically polarized brightness temperatures at 1.4 and 5 GHz frequencies, over fields covered with grass, soybean and corn. A directly proportional relation is found between effective canopy optical thickness and the amount of water present in the vegetation canopy. The effective canopy single scattering albedo depends on vegetation type.

Role of jet spacing and strut geometry on the formation of large scale structures and mixing characteristics

NASA Astrophysics Data System (ADS)

Soni, Rahul Kumar; De, Ashoke

2018-05-01

The present study primarily focuses on the effect of the jet spacing and strut geometry on the evolution and structure of the large-scale vortices which play a key role in mixing characteristics in turbulent supersonic flows. Numerically simulated results corresponding to varying parameters such as strut geometry and jet spacing (Xn = nDj such that n = 2, 3, and 5) for a square jet of height Dj = 0.6 mm are presented in the current study, while the work also investigates the presence of the local quasi-two-dimensionality for the X2(2Dj) jet spacing; however, the same is not true for higher jet spacing. Further, the tapered strut (TS) section is modified into the straight strut (SS) for investigation, where the remarkable difference in flow physics is unfolded between the two configurations for similar jet spacing (X2: 2Dj). The instantaneous density and vorticity contours reveal the structures of varying scales undergoing different evolution for the different configurations. The effect of local spanwise rollers is clearly manifested in the mixing efficiency and the jet spreading rate. The SS configuration exhibits excellent near field mixing behavior amongst all the arrangements. However, in the case of TS cases, only the X2(2Dj) configuration performs better due to the presence of local spanwise rollers. The qualitative and quantitative analysis reveals that near-field mixing is strongly affected by the two-dimensional rollers, while the early onset of the wake mode is another crucial parameter to have improved mixing. Modal decomposition performed for the SS arrangement sheds light onto the spatial and temporal coherence of the structures, where the most dominant structures are found to be the von Kármán street vortices in the wake region.

The gait speed advantage of taller stature is lost with age.

PubMed

Elbaz, Alexis; Artaud, Fanny; Dugravot, Aline; Tzourio, Christophe; Singh-Manoux, Archana

2018-01-24

Taller individuals walk faster but it is unknown whether this advantage persists at older ages. We examined the cross-sectional/longitudinal associations of height with gait speed (GS) in participants from the Dijon-Three-City cohort study (France) over 11 years. In 4011 participants (65-85 y), we measured usual/fast GS (6 m) up to five times. We examined whether the baseline height-GS association varied with age using linear regression, and whether height influenced GS change using linear mixed models. Taller participants 65 y at baseline walked faster than shorter ones (fast GS difference between top/bottom height quartiles, 0.100 m/s, P < 0.001); this association weakened with age (P-interaction = 0.02), with a 0.012 m/s (P = 0.57) difference at 80 y. Ten-year fast GS decline was 51% greater (P < 0.001) in younger participants in the top height quartile (-0.183 m/s) compared to those in the bottom quartile (-0.121 m/s), leading the GS difference between the two groups to be attenuated by 50% over the follow-up. The height-related difference in fast GS decline was not explained by time-dependent comorbidities or height shrinkage. Analyses for usual GS yielded consistent findings. The height-GS relation is more complex than previously thought, as the height related advantage in GS disappears as persons grow older due to faster decline in taller compared to shorter persons.

Pathfinder: applying graph theory to consistent tracking of daytime mixed layer height with backscatter lidar

NASA Astrophysics Data System (ADS)

de Bruine, Marco; Apituley, Arnoud; Donovan, David Patrick; Klein Baltink, Hendrik; Jorrit de Haij, Marijn

2017-05-01

The height of the atmospheric boundary layer or mixing layer is an important parameter for understanding the dynamics of the atmosphere and the dispersion of trace gases and air pollution. The height of the mixing layer (MLH) can be retrieved, among other methods, from lidar or ceilometer backscatter data. These instruments use the vertical backscatter lidar signal to infer MLHL, which is feasible because the main sources of aerosols are situated at the surface and vertical gradients are expected to go from the aerosol loaded mixing layer close to the ground to the cleaner free atmosphere above. Various lidar/ceilometer algorithms are currently applied, but accounting for MLH temporal development is not always well taken care of. As a result, MLHL retrievals may jump between different atmospheric layers, rather than reliably track true MLH development over time. This hampers the usefulness of MLHL time series, e.g. for process studies, model validation/verification and climatology. Here, we introduce a new method pathfinder, which applies graph theory to simultaneously evaluate time frames that are consistent with scales of MLH dynamics, leading to coherent tracking of MLH. Starting from a grid of gradients in the backscatter profiles, MLH development is followed using Dijkstra's shortest path algorithm (Dijkstra, 1959). Locations of strong gradients are connected under the condition that subsequent points on the path are limited to a restricted vertical range. The search is further guided by rules based on the presence of clouds and residual layers. After being applied to backscatter lidar data from Cabauw, excellent agreement is found with wind profiler retrievals for a 12-day period in 2008 (R2 = 0.90) and visual judgment of lidar data during a full year in 2010 (R2 = 0.96). These values compare favourably to other MLHL methods applied to the same lidar data set and corroborate more consistent MLH tracking by pathfinder.

A multivariate mixed model system for wood specific gravity and moisture content of planted loblolly pine stands in the southern United States

Treesearch

Finto Antony; Laurence R. Schimleck; Alex Clark; Richard F. Daniels

2012-01-01

Specific gravity (SG) and moisture content (MC) both have a strong influence on the quantity and quality of wood fiber. We proposed a multivariate mixed model system to model the two properties simultaneously. Disk SG and MC at different height levels were measured from 3 trees in 135 stands across the natural range of loblolly pine and the stand level values were used...

The vertical distribution and origin of HCN in Neptune's atmosphere

NASA Technical Reports Server (NTRS)

Lellouch, Emmanuel; Romani, Paul N.; Rosenqvist, Jan

1994-01-01

Measurements and modeling of the (3-2) rotational line of hydrogen cyanide at 265.9 GHz in Neptune's atmosphere are presented. High signal-to-noise observations provide information on the HCN vertical distribution in Neptune's stratosphere. The HCN mixing ratio is found to be nearly uniform with height above the condensation level. Best fits occur for HCN distributions that have a slight increase with altitude. A least-squares analysis yields a mixing ratio of (3.2 +/- 0.8)10(exp -10) at 2 mbar and a mean mixing ratio scale height of 250(sup 750)(sub -110) km in the 0.1-3 mbar region. To interpret these results, we developed a photochemical model of HCN. HCN formation is initiated by the reaction between CH3 radicals, produced from methane photochemistry, and N atoms. The primary sink for HCN is condensation, with minor contributions from photolysis and chemical losses. Two possible sources of N atoms are investigated: (1) infall of N escaped from Triton's upper atmosphere, and (2) galactic cosmic ray (GCR) impact on internal N2. Given the uncertainties on (i) the transport and possible ionization of N in Neptune's magnetosphere, and the fate of N(+) reaching Neptune's upper atmosphere and (ii) the N2 mixing ratio in Neptune's deep atmosphere, we suggest that both sources of N atoms may significantly contibute to the formation of HCN.

Direct 3D-printing of cell-laden constructs in microfluidic architectures.

PubMed

Liu, Justin; Hwang, Henry H; Wang, Pengrui; Whang, Grace; Chen, Shaochen

2016-04-21

Microfluidic platforms have greatly benefited the biological and medical fields, however standard practices require a high cost of entry in terms of time and energy. The utilization of three-dimensional (3D) printing technologies has greatly enhanced the ability to iterate and build functional devices with unique functions. However, their inability to fabricate within microfluidic devices greatly increases the cost of producing several different devices to examine different scientific questions. In this work, a variable height micromixer (VHM) is fabricated using projection 3D-printing combined with soft lithography. Theoretical and flow experiments demonstrate that altering the local z-heights of VHM improved mixing at lower flow rates than simple geometries. Mixing of two fluids occurs as low as 320 μL min(-1) in VHM whereas the planar zigzag region requires a flow rate of 2.4 mL min(-1) before full mixing occurred. Following device printing, to further demonstrate the ability of this projection-based method, complex, user-defined cell-laden scaffolds are directly printed inside the VHM. The utilization of this unique ability to produce 3D tissue models within a microfluidic system could offer a unique platform for medical diagnostics and disease modeling.

Microreactor-based mixing strategy suppresses product inhibition to enhance sugar yields in enzymatic hydrolysis for cellulosic biofuel production.

PubMed

Chakraborty, Saikat; Singh, Prasun Kumar; Paramashetti, Pawan

2017-08-01

A novel microreactor-based energy-efficient process of using complete convective mixing in a macroreactor till an optimal mixing time followed by no mixing in 200-400μl microreactors enhances glucose and reducing sugar yields by upto 35% and 29%, respectively, while saving 72-90% of the energy incurred on reactor mixing in the enzymatic hydrolysis of cellulose. Empirical exponential relations are provided for determining the optimal mixing time, during which convective mixing in the macroreactor promotes mass transport of the cellulase enzyme to the solid Avicel substrate, while the latter phase of no mixing in the microreactor suppresses product inhibition by preventing the inhibitors (glucose and cellobiose) from homogenizing across the reactor. Sugar yield increases linearly with liquid to solid height ratio (r h ), irrespective of substrate loading and microreactor size, since large r h allows the inhibitors to diffuse in the liquid away from the solids, thus reducing product inhibition. Copyright © 2017 Elsevier Ltd. All rights reserved.

Prediction of genetic gains by selection indices using mixed models in elephant grass for energy purposes.

PubMed

Silva, V B; Daher, R F; Araújo, M S B; Souza, Y P; Cassaro, S; Menezes, B R S; Gravina, L M; Novo, A A C; Tardin, F D; Júnior, A T Amaral

2017-09-27

Genetically improved cultivars of elephant grass need to be adapted to different ecosystems with a faster growth speed and lower seasonality of biomass production over the year. This study aimed to use selection indices using mixed models (REML/BLUP) for selecting families and progenies within full-sib families of elephant grass (Pennisetum purpureum) for biomass production. One hundred and twenty full-sib progenies were assessed from 2014 to 2015 in a randomized block design with three replications. During this period, the traits dry matter production, the number of tillers, plant height, stem diameter, and neutral detergent fiber were assessed. Families 3 and 1 were the best classified, being the most indicated for selection effect. Progenies 40, 45, 46, and 49 got the first positions in the three indices assessed in the first cut. The gain for individual 40 was 161.76% using Mulamba and Mock index. The use of selection indices using mixed models is advantageous in elephant grass since they provide high gains with the selection, which are distributed among all the assessed traits in the most appropriate situation to breeding programs.

A new scaling law for temperature variance profile in the mixing zone of turbulent Rayleigh-Bénard convection

NASA Astrophysics Data System (ADS)

Wang, Yin; Xu, Wei; He, Xiao-Zhou; Yik, Hiu-Fai; Wang, Xiao-Ping; Schumacher, Jorg; Tong, Penger

2017-11-01

We report a combined experimental and numerical study of the scaling properties of the temperature variance profile η(z) along the central z axis of turbulent Rayleigh-Bénard convection in a thin disk cell and an upright cylinder of aspect ratio unity. In the mixing zone outside the thermal boundary layer region, the measured η(z) is found to scale with the cell height H in both cells and obey a power law, η(z) (z/H)ɛ, with the obtained values of ɛ being very close to -1. Based on the experimental and numerical findings, we derive a new equation for η(z) in the mixing zone, which has a power-law solution in good agreement with the experimental and numerical results. Our work thus provides a common framework for understanding the effect of boundary layer fluctuations on the scaling properties of the temperature variance profile in turbulent Rayleigh-Bénard convection. This work was supported in part by Hong Kong Research Grants Council.

Macroscopic lateral heterogeneity observed in a laterally mobile immiscible mixed polyelectrolyte-neutral polymer brush

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

Lee, Hoyoung; Tsouris, Vasilios; Lim, Yunho

We studied mixed poly(ethylene oxide) (PEO) and poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) brushes. The question we attempted to answer was: when the chain grafting points are laterally mobile, how will this lateral mobility influence the structure and phase behavior of the mixed brush? Three different model mixed PEO/PDMAEMA brush systems were prepared: (1) a laterally mobile mixed brush by spreading onto the air–water interface a mixture of poly(ethylene oxide)–poly(n-butyl acrylate) (PEO–PnBA) and poly(2-(dimethylamino)ethyl methacrylate)–poly(n-butyl acrylate) (PDMAEMA–PnBA) diblock copolymers (the specific diblock copolymers used will be denoted as PEO 113–PnBA 100 and PDMAEMA 118–PnBA 100, where the subscripts refer to the number-average degreesmore » of polymerization of the individual blocks), (2) a mobility-restricted (inseparable) version of the above mixed brush prepared using a PEO–PnBA–PDMAEMA triblock copolymer (denoted as PEO 113–PnBA 89–PDMAEMA 120) having respective brush molecular weights matched with those of the diblock copolymers, and (3) a different laterally mobile mixed PEO and PDMAEMA brush prepared from a PEO 113–PnBA 100 and PDMAEMA 200–PnBA 103 diblock copolymer combination, which represents a further more height-mismatched mixed brush situation than described in (1). These three mixed brush systems were investigated by surface pressure–area isotherm and X-ray (XR) reflectivity measurements. These experimental data were analyzed within the theoretical framework of a continuum self-consistent field (SCF) polymer brush model. The combined experimental and theoretical results suggest that the mobile mixed brush derived using the PEO 113–PnBA 100 and PDMAEMA 118–PnBA 100 combination (i.e., mixed brush System #1) undergoes a lateral macroscopic phase separation at high chain grafting densities, whereas the more height-mismatched system (System #3) is only microscopically phase separated under comparable brush density conditions even though the lateral mobility of the grafted chains is unrestricted. The macroscopic phase separation observed in the laterally mobile mixed brush system is in contrast with the microphase separation behavior commonly observed in two-dimensional laterally mobile charged small molecule mixtures. Further study is needed to determine the detailed morphologies of the macro- and microphase-separated mixed PEO/PDMAEMA brushes.« less

Effects of body height, notebook computer size, and workstation height on recommended adjustments for proper work posture when operating a notebook computer.

PubMed

Nanthavanij, Suebsak; Jalil, Sakib; Ammarapala, Veeris

2008-12-01

Factors which are likely to affect recommended workstation and notebook computer (NBC) adjustments to obtain ergonomic work posture during NBC operation are investigated. They are: (1) body height, (2) NBC size, and (3) workstation height (i.e., seat and work surface heights). Six recommended adjustments which are evaluated include: (1) footrest height, (2) seat support height, (3) NBC base support height, (4) distance between the user's body and NBC (or user-NBC distance), (5) tilt angle of NBC base, and (6) screen angle. It is found that body height has a significant effect on footrest height and user-NBC distance while NBC size has a significant effect on user-NBC distance, tilt angle of NBC base, and screen angle. Workstation height, on the other hand, does not show any effect on the six recommended adjustments. However, the results suggest that there are interactions between body height and NBC size, and between body height and workstation height when evaluating their effects on footrest height, tilt angle of NBC base, and screen angle.

Application of linear mixed models to study genetic stability of height and body mass index across countries and time.

PubMed

Trzaskowski, Maciej; Lichtenstein, Paul; Magnusson, Patrik K; Pedersen, Nancy L; Plomin, Robert

2016-01-27

It is now possible to estimate genetic correlations between two independent samples when there is no overlapping phenotypic information. We applied the latest bivariate genomic methods to children in the UK and older adults in Sweden to ask two questions. Are the same variants driving individual differences in anthropometric traits in these two populations, and are these variants as important in childhood as they are later in life? A sample of 3152 11-year-old children in the UK was compared with a sample of 6813 adults with an average age of 65 in Sweden. Genotypes were imputed from 1000 genomes with combined 9 767 136 single nucleotide polymorphisms meeting quality control criteria in both samples. Two cross-sample GCTA-GREML analyses and linkage disequilibrium (LD) score regressions were conducted to assess genetic correlations across more than 50 years: child versus adult height and child versus adult body mass index (BMI). Consistency of effects was tested using the recently proposed polygenic scoring method. For height, GCTA-GREML and LD score indicated strong genetic stability between children and adults, 0.58 (0.16) and 1.335 (1.09), respectively. For BMI, both methods produced similarly strong estimates of genetic stability 0.75 (0.26) and 0.855 (0.49), respectively. In height, adult polygenic score explained 60% of genetic variance in childhood and 10% of variance in BMI. Here we replicated and extended previous findings of longitudinal genetic stability in anthropometric traits to cross-cultural dimensions, and showed that for height but not BMI these variants are as important in childhood as they are in adulthood. © The Author 2016. Published by Oxford University Press on behalf of the International Epidemiological Association.

Insights into intraspecific wood density variation and its relationship to growth, height and elevation in a treeline species.

PubMed

Fajardo, A

2018-05-01

The wood economics spectrum provides a general framework for interspecific trait-trait coordination across wide environmental gradients. Whether global patterns are mirrored within species constitutes a poorly explored subject. In this study, I first determined whether wood density co-varies together with elevation, tree growth and height at the within-species level. Second, I determined the variation of wood density in different stem parts (trunk, branch and twigs). In situ trunk sapwood, trunk heartwood, branch and twig densities, in addition to stem growth rates and tree height were determined in adult trees of Nothofagus pumilio at four elevations in five locations spanning 18° of latitude. Mixed effects models were fitted to test relationships among variables. The variation in wood density reported in this study was narrow (ca. 0.4-0.6 g cm -3 ) relative to global density variation (ca. 0.3-1.0 g cm -3 ). There was no significant relationship between stem growth rates and wood density. Furthermore, the elevation gradient did not alter the wood density of any stem part. Trunk sapwood density was negatively related to tree height. Twig density was higher than branch and trunk densities. Trunk heartwood density was always significantly higher than sapwood density. Negative across-species trends found in the growth-wood density relationship may not emerge as the aggregate of parallel intraspecific patterns. Actually, trees with contrasting growth rates show similar wood density values. Tree height, which is tightly related to elevation, showed a negative relationship with sapwood density. © 2018 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

Comparisons of Angus, Charolais, Galloway, Hereford, Longhorn, Nellore, Piedmontese, Salers, and Shorthorn breeds for weight, weight adjusted for condition score, height, and condition score of cows.

PubMed

Arango, J A; Cundiff, L V; Van Vleck, L D

2004-01-01

Breed differences for weight (CW), height (CH), and condition score (CS) were estimated from records (n = 12,188) of 2- to 6-yr-old cows (n = 744) from Cycle IV of the U.S. Meat Animal Research Center's Germplasm Evaluation (GPE) Program. Cows were produced from mating Angus and Hereford dams to Angus, Hereford, Charolais, Shorthorn, Galloway, Longhorn, Nellore, Piedmontese, and Salers sires. Samples of Angus and Hereford sires were 1) reference sires born from 1962 through 1970 and 2) 1980s sires born in 1980 through 1987. The mixed model included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation code (PL), and breedgroup as fixed effects for CW and CS. Analyses of weight adjusted for condition score included CS as a linear covariate. The model for CH excluded PL. Random effects were additive genetic and permanent environmental effects associated with the cow. Differences among breed groups were significant (P < 0.05) for all traits and were maintained through maturity with few interchanges in ranking. The order of F1 cows for weight was as follows: Charolais (506 to 635 kg for different ages), Shorthorn and Salers, reciprocal Hereford-Angus (HA) with 1980s sires, Nellore, HA with reference sires, Galloway, Piedmontese, and Longhorn (412 to 525 kg for different ages). Order for height was as follows: Nellore (136 to 140 cm), Charolais, Shorthorn, Salers, HA with 1980s sires, Piedmontese, Longhorn, Galloway and HA with reference sires (126 to 128 cm). Hereford and Angus cows with reference sires were generally lighter than those with 1980s sires. In general, breed differences for height followed those for weight except that F1 Nellore cows were tallest, which may in part be due to Bos taurus-Bos indicus heterosis for size.

Acute effects of fine particulate air pollution on ST segment height: A longitudinal study

PubMed Central

2010-01-01

Background The mechanisms for the relationship between particulate air pollution and cardiac disease are not fully understood. Air pollution-induced myocardial ischemia is one of the potentially important mechanisms. Methods We investigate the acute effects and the time course of fine particulate pollution (PM2.5) on myocardium ischemic injury as assessed by ST-segment height in a community-based sample of 106 healthy non-smokers. Twenty-four hour beat-to-beat electrocardiogram (ECG) data were obtained using a high resolution 12-lead Holter ECG system. After visually identifying and removing all the artifacts and arrhythmic beats, we calculated beat-to-beat ST-height from ten leads (inferior leads II, III, and aVF; anterior leads V3 and V4; septal leads V1 and V2; lateral leads I, V5, and V6,). Individual-level 24-hour real-time PM2.5 concentration was obtained by a continuous personal PM2.5 monitor. We then calculated, on a 30-minute basis, the corresponding time-of-the-day specific average exposure to PM2.5 for each participant. Distributed lag models under a linear mixed-effects models framework were used to assess the regression coefficients between 30-minute PM2.5 and ST-height measures from each lead; i.e., one lag indicates a 30-minute separation between the exposure and outcome. Results The mean (SD) age was 56 (7.6) years, with 41% male and 74% white. The mean (SD) PM2.5 exposure was 14 (22) μg/m3. All inferior leads (II, III, and aVF) and two out of three lateral leads (I and V6), showed a significant association between higher PM2.5 levels and higher ST-height. Most of the adverse effects occurred within two hours after PM2.5 exposure. The multivariable adjusted regression coefficients β (95% CI) of the cumulative effect due to a 10 μg/m3 increase in Lag 0-4 PM2.5 on ST-I, II, III, aVF and ST-V6 were 0.29 (0.01-0.56) μV, 0.79 (0.20-1.39) μV, 0.52 (0.01-1.05) μV, 0.65 (0.11-1.19) μV, and 0.58 (0.07-1.09) μV, respectively, with all p < 0.05. Conclusions Increased PM2.5 concentration is associated with immediate increase in ST-segment height in inferior and lateral leads, generally within two hours. Such an acute effect of PM2.5 may contribute to increased potential for regional myocardial ischemic injury among healthy individuals. PMID:21059260

I get height with a little help from my friends: herd protection from sanitation on child growth in rural Ecuador

PubMed Central

Fuller, James A; Villamor, Eduardo; Cevallos, William; Trostle, James; Eisenberg, Joseph NS

2016-01-01

Abstract Background: Infectious disease interventions, such as vaccines and bed nets, have the potential to provide herd protection to non-recipients. Similarly, improved sanitation in one household may provide community-wide benefits if it reduces contamination in the shared environment. Sanitation at the household level is an important predictor of child growth, but less is known about the effect of sanitation coverage in the community. Methods: From 2008 to 2013, we took repeated anthropometric measurements on 1314 children under 5 years of age in 24 rural Ecuadorian villages. Using mixed effects regression, we estimated the association between sanitation coverage in surrounding households and child growth. Results: Sanitation coverage in the surrounding households was strongly associated with child height, as those with 100% coverage in their surroundings had a 67% lower prevalence of stunting [prevalence ratio (PR) 0.32, 95% CI 0.15-0.69] compared with those with 0% coverage. Children from households with improved sanitation had a lower prevalence of stunting (PR 0.86, 95% CI 0.64-1.15). When analysing height as a continuous outcome, the protective effect of sanitation coverage is manifested primarily among girls during the second year of life, the time at which growth faltering is most likely to occur. Conclusions: Our study highlights that a household’s sanitation practices can provide herd protection to the overall community. Studies which fail to account for the positive externalities that sanitation provides will underestimate the overall protective effect. Future studies could seek to identify a threshold of sanitation coverage, similar to a herd immunity threshold, to provide coverage and compliance targets. PMID:26936912

Interactive effects of substrate, hydroperiod, and nutrients on seedling growth of Salix nigra and Taxodium distichum

USGS Publications Warehouse

Day, Richard H.; Doyle, T.W.; Draugelis-Dale, R. O.

2006-01-01

The large river swamps of Louisiana have complex topography and hydrology, characterized by black willow (Salix nigra) dominance on accreting alluvial sediments and vast areas of baldcypress (Taxodium distichum) deepwater swamps with highly organic substrates. Seedling survival of these two wetland tree species is influenced by their growth rate in relation to the height and duration of annual flooding in riverine environments. This study examines the interactive effects of substrate, hydroperiod, and nutrients on growth rates of black willow and baldcypress seedlings. In a greenhouse experiment with a split-split-plot design, 1-year seedlings of black willow and baldcypress were subjected to two nutrient treatments (unfertilized versus fertilized), two hydroperiods (continuously flooded versus twice daily flooding/draining), and two substrates (sand versus commercial peat mix). Response variables included height, diameter, lateral branch count, biomass, and root:stem ratio. Black willow growth in height and diameter, as well as all biomass components, were significantly greater in peat substrate than in sand. Black willow showed a significant hydroperiod-nutrient interaction wherein fertilizer increased stem and root biomass under drained conditions, but flooded plants did not respond to fertilization. Baldcypress diameter and root biomass were higher in peat than in sand, and the same two variables increased with fertilization in flooded as well as drained treatments. These results can be used in Louisiana wetland forest models as inputs of seedling growth and survival, regeneration potential, and biomass accumulation rates of black willow and baldcypress.

Abutment height influences the effect of platform switching on peri-implant marginal bone loss.

PubMed

Galindo-Moreno, Pablo; León-Cano, Ana; Monje, Alberto; Ortega-Oller, Inmaculada; O'Valle, Francisco; Catena, Andrés

2016-02-01

The purpose was to radiographically analyze and compare the marginal bone loss (MBL) between implants with different mismatching distance and to study the influence of the prosthetic abutment height on the MBL in association with the related mismatching distances. This retrospective study included 108 patients in whom 228 implants were placed, 180 with diameter of 4.5 mm and 48 with diameter of 5 mm. All patients received OsseoSpeed™ implants with internal tapered conical connection (Denstply Implants). Different mismatching distances were obtained, given that all implants were loaded with the same uni-abutment type (Lilac; Denstply Implants). Data were gathered on age, gender, bone substratum, smoking habits, previous history of periodontitis, and prosthetic features. MBL was analyzed radiographically at 6 and 18 months post-loading. Mixed linear analysis of mesial and distal MBL values yielded significant effects of abutment, implant diameter, follow-up period, bone substratum, smoking, and abutment × time interaction. MBL was greater at 18 vs. 6 months, for short vs. long abutments, for grafted vs. pristine bone, for a heavier smoking habit, and for implants with a diameter of 5.0 vs. 4.5 mm. Greater mismatching does not minimize the MBL; abutment height, smoking habit, and bone substratum may play a role in the MBL over the short- and medium term. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Influences of Patellofemoral Pain and Fatigue in Female Dancers during Ballet Jump-Landing.

PubMed

Peng, H-T; Chen, W C; Kernozek, T W; Kim, K; Song, C-Y

2015-08-01

This study investigated the influence of patellofemoral pain (PFP) and fatigue on lower-extremity joint biomechanics in female dancers during consecutive simple ground échappé. 3-dimensional joint mechanics were analyzed from the no-fatigue to fatigue conditions. 2-way mixed ANOVAs were used to compare the differences of the kinematic and kinetic variables between groups and conditions. Group main effects were seen in increased jump height (p=0.03), peak vertical ground reaction force (p=0.01), knee joint power absorption (p=0.04), and patellofemoral joint stress (PFJS, p=0.04) for PFP group. Fatigue main effects were found for decreased jump height (p<0.01), decreased ankle plantarflexion at initial foot-ground contact (p=0.01), and decreased ankle displacement (p<0.01). Hip external rotation impulse and hip joint stiffness increased (both p<0.01) while knee extension and external rotation moment, and ankle joint power absorption decreased (p<0.01, p=0.02, p<0.01, respectively) after fatigue. The peak PFJS also decreased after fatigue (p<0.01). Female ballet dancers with PFP sustained great ground impact and loads on the knee probably due to higher jump height compared to the controls. All dancers presented diminished knee joint loading for the protective mechanism and endurance of ankle joint musculature required for the dissipation of loads and displayed a distal-to-proximal dissipation strategy after fatigue. © Georg Thieme Verlag KG Stuttgart · New York.

Modelling forest canopy height by integrating airborne LiDAR samples with satellite Radar and multispectral imagery

NASA Astrophysics Data System (ADS)

García, Mariano; Saatchi, Sassan; Ustin, Susan; Balzter, Heiko

2018-04-01

Spatially-explicit information on forest structure is paramount to estimating aboveground carbon stocks for designing sustainable forest management strategies and mitigating greenhouse gas emissions from deforestation and forest degradation. LiDAR measurements provide samples of forest structure that must be integrated with satellite imagery to predict and to map landscape scale variations of forest structure. Here we evaluate the capability of existing satellite synthetic aperture radar (SAR) with multispectral data to estimate forest canopy height over five study sites across two biomes in North America, namely temperate broadleaf and mixed forests and temperate coniferous forests. Pixel size affected the modelling results, with an improvement in model performance as pixel resolution coarsened from 25 m to 100 m. Likewise, the sample size was an important factor in the uncertainty of height prediction using the Support Vector Machine modelling approach. Larger sample size yielded better results but the improvement stabilised when the sample size reached approximately 10% of the study area. We also evaluated the impact of surface moisture (soil and vegetation moisture) on the modelling approach. Whereas the impact of surface moisture had a moderate effect on the proportion of the variance explained by the model (up to 14%), its impact was more evident in the bias of the models with bias reaching values up to 4 m. Averaging the incidence angle corrected radar backscatter coefficient (γ°) reduced the impact of surface moisture on the models and improved their performance at all study sites, with R2 ranging between 0.61 and 0.82, RMSE between 2.02 and 5.64 and bias between 0.02 and -0.06, respectively, at 100 m spatial resolution. An evaluation of the relative importance of the variables in the model performance showed that for the study sites located within the temperate broadleaf and mixed forests biome ALOS-PALSAR HV polarised backscatter was the most important variable, with Landsat Tasselled Cap Transformation components barely contributing to the models for two of the study sites whereas it had a significant contribution at the third one. Over the temperate conifer forests, Landsat Tasselled Cap variables contributed more than the ALOS-PALSAR HV band to predict the landscape height variability. In all cases, incorporation of multispectral data improved the retrieval of forest canopy height and reduced the estimation uncertainty for tall forests. Finally, we concluded that models trained at one study site had higher uncertainty when applied to other sites, but a model developed from multiple sites performed equally to site-specific models to predict forest canopy height. This result suggest that a biome level model developed from several study sites can be used as a reliable estimator of biome-level forest structure from existing satellite imagery.

Habitat use of woodpeckers in the Big Woods of eastern Arkansas

USGS Publications Warehouse

Krementz, David G.; Lehnen, Sarah E.; Luscier, J.D.

2012-01-01

The Big Woods of eastern Arkansas contain some of the highest densities of woodpeckers recorded within bottomland hardwood forests of the southeastern United States. A better understanding of habitat use patterns by these woodpeckers is a priority for conservationists seeking to maintain these high densities in the Big Woods and the Lower Mississippi Alluvial Valley as a whole. Hence, we used linear mixed-effects and linear models to estimate the importance of habitat characteristics to woodpecker density in the Big Woods during the breeding seasons of 2006 and 2007 and the winter of 2007. Northern flicker Colaptes auratus density was negatively related to tree density both for moderate (. 25 cm diameter at breast height) and larger trees (>61 cm diameter at breast height). Red-headed woodpeckers Melanerpes erythrocephalus also had a negative relationship with density of large (. 61 cm diameter at breast height) trees. Bark disfiguration (an index of tree health) was negatively related to red-bellied woodpecker Melanerpes carolinus and yellow-bellied sapsucker Sphyrapicus varius densities. No measured habitat variables explained pileated woodpecker Dryocopus pileatus density. Overall, the high densities of woodpeckers observed in our study suggest that the current forest management of the Big Woods of Arkansas is meeting the nesting, roosting, and foraging requirements for these birds.

Wind-Tunnel Simulation of Weakly and Moderately Stable Atmospheric Boundary Layers

NASA Astrophysics Data System (ADS)

Hancock, Philip E.; Hayden, Paul

2018-07-01

The simulation of horizontally homogeneous boundary layers that have characteristics of weakly and moderately stable atmospheric flow is investigated, where the well-established wind engineering practice of using `flow generators' to provide a deep boundary layer is employed. Primary attention is given to the flow above the surface layer, in the absence of an overlying inversion, as assessed from first- and second-order moments of velocity and temperature. A uniform inlet temperature profile ahead of a deep layer, allowing initially neutral flow, results in the upper part of the boundary layer remaining neutral. A non-uniform inlet temperature profile is required but needs careful specification if odd characteristics are to be avoided, attributed to long-lasting effects inherent of stability, and to a reduced level of turbulent mixing. The first part of the wind-tunnel floor must not be cooled if turbulence quantities are to vary smoothly with height. Closely horizontally homogeneous flow is demonstrated, where profiles are comparable or closely comparable with atmospheric data in terms of local similarity and functions of normalized height. The ratio of boundary-layer height to surface Obukhov length, and the surface heat flux, are functions of the bulk Richardson number, independent of horizontal homogeneity. Surface heat flux rises to a maximum and then decreases.

Wind-Tunnel Simulation of Weakly and Moderately Stable Atmospheric Boundary Layers

NASA Astrophysics Data System (ADS)

Hancock, Philip E.; Hayden, Paul

2018-02-01

The simulation of horizontally homogeneous boundary layers that have characteristics of weakly and moderately stable atmospheric flow is investigated, where the well-established wind engineering practice of using `flow generators' to provide a deep boundary layer is employed. Primary attention is given to the flow above the surface layer, in the absence of an overlying inversion, as assessed from first- and second-order moments of velocity and temperature. A uniform inlet temperature profile ahead of a deep layer, allowing initially neutral flow, results in the upper part of the boundary layer remaining neutral. A non-uniform inlet temperature profile is required but needs careful specification if odd characteristics are to be avoided, attributed to long-lasting effects inherent of stability, and to a reduced level of turbulent mixing. The first part of the wind-tunnel floor must not be cooled if turbulence quantities are to vary smoothly with height. Closely horizontally homogeneous flow is demonstrated, where profiles are comparable or closely comparable with atmospheric data in terms of local similarity and functions of normalized height. The ratio of boundary-layer height to surface Obukhov length, and the surface heat flux, are functions of the bulk Richardson number, independent of horizontal homogeneity. Surface heat flux rises to a maximum and then decreases.

Gate-controlled tunneling of quantum Hall edge states in bilayer graphene

NASA Astrophysics Data System (ADS)

Zhu, Jun; Li, Jing; Wen, Hua

Controlled tunneling of integer and fractional quantum Hall edge states provides a powerful tool to probe the physics of 1D systems and exotic particle statistics. Experiments in GaAs 2DEGs employ either a quantum point contact or a line junction tunnel barrier. It is generally difficult to independently control the filling factors νL and νR on the two sides of the barrier. Here we show that in bilayer graphene both νL and νR as well as their Landau level structures can be independently controlled using a dual-split-gate structure. In addition, the height of the line-junction tunnel barrier implemented in our experiments is tunable via a 5th gate. By measuring the tunneling resistance across the junction RT we examine the equilibration of the edge states in a variety of νL/νR scenarios and under different barrier heights. Edge states from both sides are fully mixed in the case of a low barrier. As the barrier height increases, we observe plateaus in RT that correspond to sequential complete backscattering of edge states. Gate-controlled manipulation of edge states offers a new angle to the exploration of quantum Hall magnetism and fractional quantum Hall effect in bilayer graphene.

Kinetic Temperature and Electron Density Measurement in an Inductively Coupled Plasma Torch using Degenerate Four-Wave Mixing

NASA Technical Reports Server (NTRS)

Schafer, Julia; Lyons, Wendy; Tong, WIlliam G.; Danehy, Paul M.

2008-01-01

Laser wave mixing is presented as an effective technique for spatially resolved kinetic temperature measurements in an atmospheric-pressure radio-frequency inductively-coupled plasma. Measurements are performed in a 1 kW, 27 MHz RF plasma using a continuous-wave, tunable 811.5-nm diode laser to excite the 4s(sup 3)P2 approaches 4p(sup 3)D3 argon transition. Kinetic temperature measurements are made at five radial steps from the center of the torch and at four different torch heights. The kinetic temperature is determined by measuring simultaneously the line shape of the sub-Doppler backward phase-conjugate degenerate four-wave mixing and the Doppler-broadened forward-scattering degenerate four-wave mixing. The temperature measurements result in a range of 3,500 to 14,000 K+/-150 K. Electron densities measured range from 6.1 (+/-0.3) x 10(exp 15)/cu cm to 10.1 (+/-0.3) x 10(exp 15)/cu cm. The experimental spectra are analyzed using a perturbative treatment of the backward phase-conjugate and forward-geometry wave-mixing theory. Stark width is determined from the collisional broadening measured in the phase-conjugate geometry. Electron density measurements are made based on the Stark width. The kinetic temperature of the plasma was found to be more than halved by adding deionized water through the nebulizer.

Observations of the atmospheric boundary layer height over Abu Dhabi, United Arab Emirates: Investigating boundary layer climatology in arid regions

NASA Astrophysics Data System (ADS)

Marzooqi, Mohamed Al; Basha, Ghouse; Ouarda, Taha B. M. J.; Armstrong, Peter; Molini, Annalisa

2014-05-01

Strong sensible heat fluxes and deep turbulent mixing - together with marked dustiness and a low substrate water content - represent a characteristic signature in the boundary layer over hot deserts, resulting in "thicker" mixing layers and peculiar optical properties. Beside these main features however, desert ABLs present extremely complex local structures that have been scarcely addressed in the literature, and whose understanding is essential in modeling processes such as the transport of dust and pollutants, and turbulent fluxes of momentum, heat and water vapor in hyper-arid regions. In this study, we analyze a continuous record of observations of the atmospheric boundary layer (ABL) height from a single lens LiDAR ceilometer operated at Masdar Institute Field Station (24.4oN, 54.6o E, Abu Dhabi, United Arab Emirates), starting March 2013. We compare different methods for the estimation of the ABL height from Ceilometer data such as, classic variance-, gradient-, log gradient- and second derivation-methods as well as recently developed techniques such as the Bayesian Method and Wavelet covariance transform. Our goal is to select the most suited technique for describing the climatology of the ABL in desert environments. Comparison of our results with radiosonde observations collected at the nearby airport of Abu Dhabi indicate that the WCT and the Bayesian method are the most suitable tools to accurately identify the ABL height in all weather conditions. These two methods are used for the definition of diurnal and seasonal climatologies of the boundary layer conditional to different atmospheric stability classes.

Preliminary Results of Double-Sample Forest Inventory of Pine and Mixed Stands with High- and Low-Density LiDAR

Treesearch

Robert C. Parker; Patrick A. Glass

2004-01-01

LiDAR data (0.5 and 1 m postings) were used in a double-sample forest inventory on the Lee Experimental Forest, Louisiana. Phase 2 plots were established with DGPS. Tree d.b.h. (> 4.5 inches) and two sample heights were measured on every 10 th plot of the Phase 1 sample. Volume was computed for natural and planted pine and mixed hardwood species. LiDAR trees were...

Lidar measurements of the atmospheric entrainment zone and the potential temperature jump across the top of the mixed layer

NASA Technical Reports Server (NTRS)

Boers, R.; Eloranta, E. W.

1986-01-01

Lidar data of the atmospheric entrainment zone from six days of clear air convection obtained in central Illinois during July 1979 are presented. A new method to measure the potential temperature jump across the entrainment zone based on only one temperature sounding and continuous lidar measurements of the mixed layer height is developed. An almost linear dependence is found between the normalized entrainment rate and the normalized thickness of the entrainment zone.

Cloud-Scale Vertical Velocity and Turbulent Dissipation Rate Retrievals

DOE Data Explorer

Shupe, Matthew

2013-05-22

Time-height fields of retrieved in-cloud vertical wind velocity and turbulent dissipation rate, both retrieved primarily from vertically-pointing, Ka-band cloud radar measurements. Files are available for manually-selected, stratiform, mixed-phase cloud cases observed at the North Slope of Alaska (NSA) site during periods covering the Mixed-Phase Arctic Cloud Experiment (MPACE, late September through early November 2004) and the Indirect and Semi-Direct Aerosol Campaign (ISDAC, April-early May 2008). These time periods will be expanded in a future submission.

Developing a global mixed-canopy, height-variable vegetation structure dataset for estimating global vegetation albedo by a clumped canopy radiative transfer scheme in the NASA Ent Terrestrial Biosphere Model and GISS GCM

NASA Astrophysics Data System (ADS)

Montes, Carlo; Kiang, Nancy Y.; Ni-Meister, Wenge; Yang, Wenze; Schaaf, Crystal; Aleinov, Igor; Jonas, Jeffrey A.; Zhao, Feng; Yao, Tian; Wang, Zhuosen; Sun, Qingsong; Carrer, Dominique

2016-04-01

Processes determining biosphere-atmosphere coupling are strongly influenced by vegetation structure. Thus, ecosystem carbon sequestration and evapotranspiration affecting global carbon and water balances will depend upon the spatial extent of vegetation, its vertical structure, and its physiological variability. To represent this globally, Dynamic Global Vegetation Models (DGVMs) coupled to General Circulation Models (GCMs) make use of satellite and/or model-based vegetation classifications often composed by homogeneous communities. This work aims at developing a new Global Vegetation Structure Dataset (GVSD) by incorporating varying vegetation heights for mixed plant communities to be used as boundary conditions to the Analytical Clumped Two-Stream (ACTS) canopy radiative transfer scheme (Ni-Meister et al., 2010) incorporated into the NASA Ent Terrestrial Biosphere Model (TBM), the DGVM coupled to the NASA Goddard Institute for Space Studies (GISS) GCM. Information sources about land surface and vegetation characteristics obtained from a number of earth observation platforms and algorithms include the Moderate Resolution Imaging Spectroradiometer (MODIS) land cover and plant functional types (PFTs) (Friedl et al., 2010), soil albedo derived from MODIS (Carrer et al., 2014), along with vegetation height from the Geoscience Laser Altimeter System (GLAS) on board ICESat (Ice, Cloud, and land Elevation Satellite) (Simard et al., 2011; Tang et al., 2014). Three widely used Leaf Area Index (LAI) products are compared as input to the GVSD and ACTS forcing in terms of vegetation albedo: Global Data Sets of Vegetation (LAI)3g (Zhu et al. 2013), Beijing Normal University LAI (Yuan et al., 2011), and MODIS MOD15A2H product (Yang et al., 2006). Further PFT partitioning is performed according to a climate classification utilizing the Climate Research Unit (CRU; Harris et al., 2013) and the NOAA Global Precipitation Climatology Centre (GPCC; Scheider et al., 2014) data. Final products are a GVSD consisting of mixed plant communities (e.g. mixed forests, savannas, mixed PFTs) following the Ecosystem Demography model (Moorcroft et al., 2001) approach represented by multi-cohort community patches at the sub-grid level of the GCM, which are ensembles of identical individuals whose differences are represented by PFTs, canopy height, density and vegetation structure sensitivity to allometric parameters. The performance of the Ent TBM in estimating VIS-NIR vegetation albedo by the new GVSD and ACTS is assessed first by comparison against the previous GISS GCM vegetation classification and prescribed Lambertian albedoes of Matthews (1984), and secondly, against MODIS global estimations and FLUXNET site-scale observations. Ultimately, this GVSD will serve as a template for community data sets, and be used as boundary conditions to the Ent TBM for prediction of biomass, carbon balances and GISS GCM climate.

Effects of Grazing Management in Brachiaria grass-forage Peanut Pastures on Canopy Structure and Forage Intake.

PubMed

Gomes, F K; Oliveira, M D B L; Homem, B G C; Boddey, R M; Bernardes, T F; Gionbelli, M P; Lara, M A S; Casagrande, D R

2018-06-13

Maintenance of mixed grass-legume pastures for stand longevity and improved animal utilization is a challenge in warm-season climates. The goal of this study was to assess grazing management on stand persistence, forage intake, and N balance of beef heifers grazing mixed pastures of Brachiaria brizantha and Arachis pintoi. A two-year experiment was carried out in Brazil, where four grazing management were assessed: rest period interrupted at 90%, 95%, and 100% of light interception (LI) and a fixed rest period of 42 days (90LI, 95LI, 100LI, and 42D, respectively). The LI were taken at 50 points at ground level and at five points above the canopy for each paddock using a canopy analyzer. For all treatments, the post-grazing stubble height was 15 cm. Botanical composition and canopy structure characteristics such as canopy height, forage mass, and vertical distribution of the morphological composition were evaluated pre-and post-grazing. Forage chemical composition, intake, and microbial synthesis were also determined. A randomized complete block design was used, considering the season of the year as a repeated measure over time. Grazing management and season were considered fixed, while block and year were considered random effects. In the summer, legume mass accounted for 19% of the canopy at 100LI, which was less than other treatments (a mean of 30%). The 100LI treatment had a greater grass stem mass compared with other treatments. In terms of vertical distribution for 100LI, 38.6% of the stem mass was above the stubble height, greater than the 5.7% for other treatments. The canopy structure limited neutral detergent fiber intake (P = 0.007) at 100LI (1.02% of BW/d), whereas 42D, 90LI, and 95LI treatments had NDF intake close to 1.2% of BW/d. The intake of digestible organic matter (OM; P = 0.007) and the ratio of crude protein/digestible OM (P < 0.001) were less at 100LI in relation to the other treatments. The production of microbial N (P < 0.001) and efficiency of microbial synthesis (P = 0.023) were greater at 95LI and 90LI, followed by 42D and less at 100LI. Overall, the range from 90 to 95% of LI is the recommendation to interrupt the rest period, since this strategy enhanced community stability, forage intake, and nutritional value of the diet. Under on-farm conditions, brachiaria grass and forage peanut pastures should be managed at a range height of 24 to 30 cm.

In silico mapping of quantitative trait loci in maize.

PubMed

Parisseaux, B; Bernardo, R

2004-08-01

Quantitative trait loci (QTL) are most often detected through designed mapping experiments. An alternative approach is in silico mapping, whereby genes are detected using existing phenotypic and genomic databases. We explored the usefulness of in silico mapping via a mixed-model approach in maize (Zea mays L.). Specifically, our objective was to determine if the procedure gave results that were repeatable across populations. Multilocation data were obtained from the 1995-2002 hybrid testing program of Limagrain Genetics in Europe. Nine heterotic patterns comprised 22,774 single crosses. These single crosses were made from 1,266 inbreds that had data for 96 simple sequence repeat (SSR) markers. By a mixed-model approach, we estimated the general combining ability effects associated with marker alleles in each heterotic pattern. The numbers of marker loci with significant effects--37 for plant height, 24 for smut [Ustilago maydis (DC.) Cda.] resistance, and 44 for grain moisture--were consistent with previous results from designed mapping experiments. Each trait had many loci with small effects and few loci with large effects. For smut resistance, a marker in bin 8.05 on chromosome 8 had a significant effect in seven (out of a maximum of 18) instances. For this major QTL, the maximum effect of an allele substitution ranged from 5.4% to 41.9%, with an average of 22.0%. We conclude that in silico mapping via a mixed-model approach can detect associations that are repeatable across different populations. We speculate that in silico mapping will be more useful for gene discovery than for selection in plant breeding programs. Copyright 2004 Springer-Verlag

Water vapor variance measurements using a Raman lidar

NASA Technical Reports Server (NTRS)

Evans, K.; Melfi, S. H.; Ferrare, R.; Whiteman, D.

1992-01-01

Because of the importance of atmospheric water vapor variance, we have analyzed data from the NASA/Goddard Raman lidar to obtain temporal scales of water vapor mixing ratio as a function of altitude over observation periods extending to 12 hours. The ground-based lidar measures water vapor mixing ration from near the earth's surface to an altitude of 9-10 km. Moisture profiles are acquired once every minute with 75 m vertical resolution. Data at each 75 meter altitude level can be displayed as a function of time from the beginning to the end of an observation period. These time sequences have been spectrally analyzed using a fast Fourier transform technique. An example of such a temporal spectrum obtained between 00:22 and 10:29 UT on December 6, 1991 is shown in the figure. The curve shown on the figure represents the spectral average of data from 11 height levels centered on an altitude of 1 km (1 plus or minus .375 km). The spectra shows a decrease in energy density with frequency which generally follows a -5/3 power law over the spectral interval 3x10 (exp -5) to 4x10 (exp -3) Hz. The flattening of the spectrum for frequencies greater than 6x10 (exp -3) Hz is most likely a measure of instrumental noise. Spectra like that shown in the figure are calculated for other altitudes and show changes in spectral features with height. Spectral analysis versus height have been performed for several observation periods which demonstrate changes in water vapor mixing ratio spectral character from one observation period to the next. The combination of these temporal spectra with independent measurements of winds aloft provide an opportunity to infer spatial scales of moisture variance.

Validating LiDAR Derived Estimates of Canopy Height, Structure and Fractional Cover in Riparian Areas: A Comparison of Leaf-on and Leaf-off LiDAR Data

NASA Astrophysics Data System (ADS)

Wasser, L. A.; Chasmer, L. E.; Taylor, A.; Day, R.

2010-12-01

Characterization of riparian buffers is integral to understanding the landscape scale impacts of disturbance on wildlife and aquatic ecosystems. Riparian buffers may be characterized using in situ plot sampling or via high resolution remote sensing. Field measurements are time-consuming and may not cover a broad range of ecosystem types. Further, spectral remote sensing methods introduce a compromise between spatial resolution (grain) and area extent. Airborne LiDAR can be used to continuously map and characterize riparian vegetation structure and composition due to the three-dimensional reflectance of laser pulses within and below the canopy, understory and at the ground surface. The distance between reflections (or ‘returns’) allows for detection of narrow buffer corridors at the landscape scale. There is a need to compare leaf-off and leaf-on surveyed LiDAR data with in situ measurements to assess accuracy in landscape scale analysis. These comparisons are particularly important considering increased availability of leaf-off surveyed LiDAR datasets. And given this increased availability, differences between leaf-on and leaf-off derived LiDAR metrics are largely unknown for riparian vegetation of varying composition and structure. This study compares the effectiveness of leaf-on and leaf-off LiDAR in characterizing riparian buffers of varying structure and composition as compared to field measurements. Field measurements were used to validate LiDAR derived metrics. Vegetation height, canopy cover, density and overstory and understory species composition were recorded in 80 random plots of varying vegetation type, density and structure within a Pennsylvania watershed (-77.841, 40.818). Plot data were compared with LiDAR data collected during leaf on and leaf off conditions to determine 1) accuracy of LiDAR derived metrics compared to field measures and 2) differences between leaf-on and leaf-off LiDAR metrics. Results illustrate that differences exist between metrics derived from leaf on and leaf-off surveyed LiDAR. There is greater variability between the two datasets within taller deciduous and mixed (conifer and deciduous) vegetation compared to shorter deciduous and mixed vegetation. Differences decrease as stand density increases for both mixed and deciduous forests. LiDAR derived canopy height is more sensitive to understory vegetation as stand density decreases making measurement of understory vegetation in the field important in the validation process. Finally, while leaf-on LiDAR is often preferred for vegetation analysis, results suggest that leaf-off LiDAR may be sufficient to categorize vegetation into height classes to be used for landscape scale habitat models.

Magma mixing during caldera forming eruptions

NASA Astrophysics Data System (ADS)

Kennedy, B.; Jellinek, M.; Stix, J.

2006-12-01

During explosive caldera-forming eruptions magma erupts through a ring dyke. Flow is driven, in part, by foundering of a magma chamber roof into underlying buoyant magma. One intriguing and poorly understood characteristic of deposits from calderas is that bulk ignimbrite, pumices, and crystals can show complex stratigraphic zonation. We propose that zonation patterns can be explained by different, and temporally evolving subsidence styles, and that the geometry imposed by subsidence can affect flow and cause mixing in the chamber and ring dyke. We use two series of laboratory experiments to investigate aspects of the mixing properties of flow in the chamber and ring dike during caldera collapse. In the first series, cylindrical blocks of height, h, and diameter, d, are released into circular analog magma chambers of diameter D and height H, containing buoyant fluids with viscosities that we vary. Subsidence occurs as a result of flow through the annular gap (ring dike) between the block and the wall of the surrounding tank of width, w = D-d. Three dimensionless parameters characterize the nature and evolution of the subsidence, and the resulting flow: A Reynolds number, Re, a tilt number, T = w/h and a subsidence number, S = w/H. Whereas Re indicates the importance of inertia for flow and mixing, T and S are geometric parameters that govern the extent of roof tilting, the spatial variation in w during collapse and the wavelength and structure of fluid motions. On the basis of field observations and theoretical arguments we fix T ≍ 0.14 and characterize subsidence and the corresponding flow over a wide range of Re - S parameter space appropriate to silicic caldera systems. Where S < 2 and Re < 103 the roof can rotate or tilt as it sinks and a spectrum of fluid mechanical behavior within the ring dike are observed. The combination of roof rotation and tilting drives unsteady, 3D overturning motions within the ring dike that are inferred to cause extensive mixing. In the absence of tilting and rotation flow is quasi-steady, there is negligible overturning and mixing. Where S > 2 and Re < 10^1 there is a "locking regime" in which the roof the roof rotates as it sinks but does not settle to the floor. The resulting flow leads to little overturning and mixing. Where S > 2 and Re > 10^1 the roof block settles with negligible tilting. Unsteady laminar overturning (Re < 102) and turbulent motions (Re > 103) produce extensive mixing in the ring dike. In a second series of experiments, motivated by the "piecemeal" collapse of many calderas, we investigate additional effects arising in the presence of two blocks. In contrast to the single-block case, the relative motions of the blocks cause extensive overturning and mixing in the chamber as well as the ring dike. Our experimental results are applied to understand the subsidence behavior and the mixing properties of a number of natural cases. Our work suggests that during most caldera-forming eruptions mixing is an inevitable consequence of synchronous eruption and subsidence. In addition, extensive mechanical mixing within the ring dike can explain the cumulate and mingled textures characteristic of many ring dikes.

Static stability and thermal wind in an atmosphere of variable composition Applications to Mars

NASA Technical Reports Server (NTRS)

Hess, S. L.

1979-01-01

Radiometric measurements of the temperature of the south polar cap of Mars in winter have yielded values significantly below the expected 148 K. One proposed explanation for this result is a substantial reduction in the CO2 content of the atmosphere and a lowering of the mean molecule weight near the surface. The meteorological consequences of this explanation are explored by deriving a criterion for vertical static stability and a thermal wind law for an atmosphere of variable composition. The atmosphere proves to be statically unstable unless the anomaly in the CO2 mixing ratio extends to heights of tens of kilometers. The effect of varying molecular weight exceeds the effect of temperature gradient, producing shears with height of reversed sign. The shears are baroclinically unstable, and this instability would eradicate the latitudinal gradient of molecular weight. This inconsistency can be resolved by invoking a reasonable elevation of the central polar cap and by imposing an adequate zonal wind. It is concluded that if the explanation requiring a change in atmospheric composition is correct, it must be accompanied by other special circumstances to make it meteorologically consistent.

Examining the association between livestock ownership typologies and child nutrition in the Luangwa Valley, Zambia

PubMed Central

Kassa, Lea; Young, Sera L.; Travis, Alexander J.

2018-01-01

Objective To investigate the association between livestock ownership and dietary diversity, animal-source food consumption, height-for-age z-score, and stunting among children living in wildlife “buffer zones” of Zambia’s Luangwa Valley using a novel livestock typology approach. Methods We conducted a cross-sectional study of 838 children aged 6–36 months. Households were categorized into typologies based on the types and numbers of animals owned, ranging from no livestock to large numbers of mixed livestock. We used multilevel mixed-effects linear and logistic regression to examine the association between livestock typologies and four nutrition-related outcomes of interest. Results were compared with analyses using more common binary and count measures of livestock ownership. Results No measure of livestock ownership was significantly associated with children’s odds of animal-source food consumption, child height-for-age z-score, or stunting odds. Livestock ownership Type 2 (having a small number of poultry) was surprisingly associated with decreased child dietary diversity (β = -0.477; p<0.01) relative to owning no livestock. Similarly, in comparison models, chicken ownership was negatively associated with dietary diversity (β = -0.320; p<0.01), but increasing numbers of chickens were positively associated with dietary diversity (β = 0.022; p<0.01). Notably, neither child dietary diversity nor animal-source food consumption was significantly associated with height, perhaps due to unusually high prevalences of morbidities. Conclusions Our novel typologies methodology allowed for an efficient and a more in-depth examination of the differential impact of livestock ownership patterns compared to typical binary or count measures of livestock ownership. We found that these patterns were not positively associated with child nutrition outcomes in this context. Development and conservation programs focusing on livestock must carefully consider the complex, context-specific relationship between livestock ownership and nutrition outcomes–including how livestock are utilized by the target population–when attempting to use livestock as a means of improving child nutrition. PMID:29408920

Examining the association between livestock ownership typologies and child nutrition in the Luangwa Valley, Zambia.

PubMed

Dumas, Sarah E; Kassa, Lea; Young, Sera L; Travis, Alexander J

2018-01-01

To investigate the association between livestock ownership and dietary diversity, animal-source food consumption, height-for-age z-score, and stunting among children living in wildlife "buffer zones" of Zambia's Luangwa Valley using a novel livestock typology approach. We conducted a cross-sectional study of 838 children aged 6-36 months. Households were categorized into typologies based on the types and numbers of animals owned, ranging from no livestock to large numbers of mixed livestock. We used multilevel mixed-effects linear and logistic regression to examine the association between livestock typologies and four nutrition-related outcomes of interest. Results were compared with analyses using more common binary and count measures of livestock ownership. No measure of livestock ownership was significantly associated with children's odds of animal-source food consumption, child height-for-age z-score, or stunting odds. Livestock ownership Type 2 (having a small number of poultry) was surprisingly associated with decreased child dietary diversity (β = -0.477; p<0.01) relative to owning no livestock. Similarly, in comparison models, chicken ownership was negatively associated with dietary diversity (β = -0.320; p<0.01), but increasing numbers of chickens were positively associated with dietary diversity (β = 0.022; p<0.01). Notably, neither child dietary diversity nor animal-source food consumption was significantly associated with height, perhaps due to unusually high prevalences of morbidities. Our novel typologies methodology allowed for an efficient and a more in-depth examination of the differential impact of livestock ownership patterns compared to typical binary or count measures of livestock ownership. We found that these patterns were not positively associated with child nutrition outcomes in this context. Development and conservation programs focusing on livestock must carefully consider the complex, context-specific relationship between livestock ownership and nutrition outcomes-including how livestock are utilized by the target population-when attempting to use livestock as a means of improving child nutrition.

Weight Regain, But Not Weight Loss, Is Related to Competitive Success in Real-life Mixed Martial Arts Competition.

PubMed

Coswig, Victor Silveira; Miarka, Bianca; Pires, Daniel Alvarez; da Silva, Levy Mendes; Bartel, Charles; Del Vecchio, Fabrício Boscolo

2018-05-14

We aimed to describe the nutritional and behavioural strategies for rapid weight loss (RWL), investigate the effects of RWL and weight regain (WRG) in winners and losers and verify mood state and technical-tactical/time-motion parameters in Mixed Martial Arts (MMA). The sample consisted of MMA athletes after a single real match and was separated into two groups: Winners (n=8, age: 25.4±6.1yo., height: 173.9±0.2cm, habitual body mass (BM): 89.9±17.3kg) and Losers (n=7, age: 24.4±6.8yo., height: 178.4±0.9cm, habitual BM: 90.8±19.5kg). Both groups exhibited RWL and WRG, verified their macronutrient intake, underwent weight and height assessments and completed two questionnaires (POMS and RWL) at i) 24 h before weigh-in, ii) weigh-in, iii) post-bout and iv) during a validated time-motion and technical-tactical analysis during the bout. Variance analysis, repeated measures and a logistic regression analysis were used. The main results showed significant differences between the time points in terms of total caloric intake as well as carbohydrate, protein and lipid ingestion. Statistical differences in combat analysis were observed between the winners and losers in terms of high-intensity relative time [58(10;98) s and 32(1;60) s, respectively], lower limb sequences [3.5(1.0;7.5) sequences and 1.0(0.0;1.0) sequences, respectively], and ground and pound actions [2.5(0.0;4.5) actions and 0.0(0.0;0.5) actions, respectively], and logistic regression confirmed the importance of high-intensity relative time and lower limb sequences on MMA performance. RWL and WRG strategies were related to technical-tactical and time-motion patterns as well as match outcomes. Weight management should be carefully supervised by specialized professionals to reduce health risks and raise competitive performance.

Further evidence for CCN aerosol concentrations determining the height of warm rain and ice initiation in convective clouds over the Amazon basin

NASA Astrophysics Data System (ADS)

Campos Braga, Ramon; Rosenfeld, Daniel; Weigel, Ralf; Jurkat, Tina; Andreae, Meinrat O.; Wendisch, Manfred; Pöschl, Ulrich; Voigt, Christiane; Mahnke, Christoph; Borrmann, Stephan; Albrecht, Rachel I.; Molleker, Sergej; Vila, Daniel A.; Machado, Luiz A. T.; Grulich, Lucas

2017-12-01

We have investigated how aerosols affect the height above cloud base of rain and ice hydrometeor initiation and the subsequent vertical evolution of cloud droplet size and number concentrations in growing convective cumulus. For this purpose we used in situ data of hydrometeor size distributions measured with instruments mounted on HALO aircraft during the ACRIDICON-CHUVA campaign over the Amazon during September 2014. The results show that the height of rain initiation by collision and coalescence processes (Dr, in units of meters above cloud base) is linearly correlated with the number concentration of droplets (Nd in cm-3) nucleated at cloud base (Dr ≈ 5 ṡ Nd). Additional cloud processes associated with Dr, such as GCCN, cloud, and mixing with ambient air and other processes, produce deviations of ˜ 21 % in the linear relationship, but it does not mask the clear relationship between Dr and Nd, which was also found at different regions around the globe (e.g., Israel and India). When Nd exceeded values of about 1000 cm-3, Dr became greater than 5000 m, and the first observed precipitation particles were ice hydrometeors. Therefore, no liquid water raindrops were observed within growing convective cumulus during polluted conditions. Furthermore, the formation of ice particles also took place at higher altitudes in the clouds in polluted conditions because the resulting smaller cloud droplets froze at colder temperatures compared to the larger drops in the unpolluted cases. The measured vertical profiles of droplet effective radius (re) were close to those estimated by assuming adiabatic conditions (rea), supporting the hypothesis that the entrainment and mixing of air into convective clouds is nearly inhomogeneous. Additional CCN activation on aerosol particles from biomass burning and air pollution reduced re below rea, which further inhibited the formation of raindrops and ice particles and resulted in even higher altitudes for rain and ice initiation.

Impact of Footprint Diameter and Off-Nadir Pointing on the Precision of Canopy Height Estimates from Spaceborne Lidar

NASA Technical Reports Server (NTRS)

Pang, Yong; Lefskky, Michael; Sun, Guoqing; Ranson, Jon

2011-01-01

A spaceborne lidar mission could serve multiple scientific purposes including remote sensing of ecosystem structure, carbon storage, terrestrial topography and ice sheet monitoring. The measurement requirements of these different goals will require compromises in sensor design. Footprint diameters that would be larger than optimal for vegetation studies have been proposed. Some spaceborne lidar mission designs include the possibility that a lidar sensor would share a platform with another sensor, which might require off-nadir pointing at angles of up to 16 . To resolve multiple mission goals and sensor requirements, detailed knowledge of the sensitivity of sensor performance to these aspects of mission design is required. This research used a radiative transfer model to investigate the sensitivity of forest height estimates to footprint diameter, off-nadir pointing and their interaction over a range of forest canopy properties. An individual-based forest model was used to simulate stands of mixed conifer forest in the Tahoe National Forest (Northern California, USA) and stands of deciduous forests in the Bartlett Experimental Forest (New Hampshire, USA). Waveforms were simulated for stands generated by a forest succession model using footprint diameters of 20 m to 70 m. Off-nadir angles of 0 to 16 were considered for a 25 m diameter footprint diameter. Footprint diameters in the range of 25 m to 30 m were optimal for estimates of maximum forest height (R(sup 2) of 0.95 and RMSE of 3 m). As expected, the contribution of vegetation height to the vertical extent of the waveform decreased with larger footprints, while the contribution of terrain slope increased. Precision of estimates decreased with an increasing off-nadir pointing angle, but off-nadir pointing had less impact on height estimates in deciduous forests than in coniferous forests. When pointing off-nadir, the decrease in precision was dependent on local incidence angle (the angle between the off-nadir beam and a line normal to the terrain surface) which is dependent on the off-nadir pointing angle, terrain slope, and the difference between the laser pointing azimuth and terrain aspect; the effect was larger when the sensor was aligned with the terrain azimuth but when aspect and azimuth are opposed, there was virtually no effect on R2 or RMSE. A second effect of off-nadir pointing is that the laser beam will intersect individual crowns and the canopy as a whole from a different angle which had a distinct effect on the precision of lidar estimates of height, decreasing R2 and increasing RMSE, although the effect was most pronounced for coniferous crowns.

The relationship between foot arch measurements and walking parameters in children.

PubMed

Gill, Simone V; Keimig, Sara; Kelty-Stephen, Damian; Hung, Ya-Ching; DeSilva, Jeremy M

2016-01-23

Walking mechanics are influenced by body morphology. Foot arch height is one aspect of body morphology central to walking. However, generalizations about the relationship between arch height and walking are limited due to previous methodologies used for measuring the arch and the populations that have been studied. To gain the knowledge needed to support healthy gait in children and adults, we need to understand this relationship in unimpaired, typically developing children and adults using dynamic measures. The purpose of the current study was to examine the relationship between arch height and gait in a sample of healthy children and adults using dynamic measures. Data were collected from 638 participants (n = 254 children and n = 384 adults) at the Museum of Science, Boston (MOS) and from 18 4- to 8-year-olds at the Motor Development and Motor Control Laboratories. Digital footprints were used to calculate two arch indices: the Chippaux-Smirak (CSI) and the Keimig Indices (KI). The height of the navicular bone was measured. Gait parameters were captured with a mechanized gait carpet at the MOS and three-dimensional motion analyses and in-ground force plates in the Motor Development and Motor Control Laboratories. Linear regression analyses on data from the MOS confirmed that as age increases, step length increases. With a linear mixed effect regression model, we found that individuals who took longer steps had higher arches as measured by the KI. However, this relationship was no longer significant when only adults were included in the model. A model restricted to children found that amongst this sample, those with higher CSI and higher KI values take longer relative step lengths. Data from the Motor Development and Motor Control Laboratories showed that both CSI and KI added to the prediction; children with lower anterior ground reaction forces had higher CSI and higher KI values. Arch height indices were correlated with navicular height. These results suggest that more than one measure of the arch may be needed elucidate the relationship between arch height and gait.

The relative efficacy of three recovery modalities after professional rugby league matches.

PubMed

Webb, Nicholas P; Harris, Nigel K; Cronin, John B; Walker, Craig

2013-09-01

This study investigated the relative efficacy of postgame recovery modalities on jump height performance and subjective ratings of muscle soreness and muscle damage at 1, 18, and 42 hours after professional rugby league competition games. Twenty-one professional rugby league players performed 3 different postmatch recovery modalities: cold water immersion (CWI), contrast water therapy (CWT), and active recovery (ACT). The effects of the recovery treatments were analyzed with mixed modeling including a covariate (fatigue score) to adjust for changes in the intensity of each match on the postmatch values of the dependent variables of interest. Standardization of effects was used to make magnitude-based inferences, presented as mean with ±90% confidence limits. Cold water immersion and CWT clearly recovered jump height performance (CWI 2.3 ± 3.7%; CWT 3.5 ± 4.1%), reduced muscle soreness (CWI -0.95 ± 0.37; CWT -0.55 ± 0.37), and decreased creatine kinase (CWI -11.0 ± 15.1%; CWT 18.2 ± 20.1%) by 42 hours postgame compared with ACT. Contrast water therapy was however clearly more effective compared with CWI on the recovery of muscle soreness and creatine kinase by 42 hours postgame. Based on these findings, CWT recovery is recommended postmatch for team rugby sports.

UV reactor flow visualization and mixing quantification using three-dimensional laser-induced fluorescence.

PubMed

Gandhi, Varun; Roberts, Philip J W; Stoesser, Thorsten; Wright, Harold; Kim, Jae-Hong

2011-07-01

Three-dimensional laser-induced fluorescence (3DLIF) was applied to visualize and quantitatively analyze mixing in a lab-scale UV reactor consisting of one lamp sleeve placed perpendicular to flow. The recirculation zone and the von Karman vortex shedding that commonly occur in flows around bluff bodies were successfully visualized. Multiple flow paths were analyzed by injecting the dye at various heights with respect to the lamp sleeve. A major difference in these pathways was the amount of dye that traveled close to the sleeve, i.e., a zone of higher residence time and higher UV exposure. Paths away from the center height had higher velocities and hence minimal influence by the presence of sleeve. Approach length was also characterized in order to increase the probability of microbes entering the region around the UV lamp. The 3DLIF technique developed in this study is expected to provide new insight on UV dose delivery useful for the design and optimization of UV reactors. Copyright © 2011 Elsevier Ltd. All rights reserved.

An analysis of the AVE-SESAME I period using statistical structure and correlation functions. [Atmospheric Variability Experiment-Severe Environmental Storm and Mesoscale Experiment

NASA Technical Reports Server (NTRS)

Fuelberg, H. E.; Meyer, P. J.

1984-01-01

Structure and correlation functions are used to describe atmospheric variability during the 10-11 April day of AVE-SESAME 1979 that coincided with the Red River Valley tornado outbreak. The special mesoscale rawinsonde data are employed in calculations involving temperature, geopotential height, horizontal wind speed and mixing ratio. Functional analyses are performed in both the lower and upper troposphere for the composite 24 h experiment period and at individual 3 h observation times. Results show that mesoscale features are prominent during the composite period. Fields of mixing ratio and horizontal wind speed exhibit the greatest amounts of small-scale variance, whereas temperature and geopotential height contain the least. Results for the nine individual times show that small-scale variance is greatest during the convective outbreak. The functions also are used to estimate random errors in the rawinsonde data. Finally, sensitivity analyses are presented to quantify confidence limits of the structure functions.

Airborne LIDAR Measurements of Aerosol and Ozone Above the Alberta Oil Sands Region

NASA Astrophysics Data System (ADS)

Aggarwal, M.; Whiteway, J. A.; Seabrook, J.; Gray, L. H.

2014-12-01

Lidar measurements of ozone and aerosol were conducted from a Twin Otter aircraft above the oil sands region of northern Alberta. The field campaign was carried out with a total of five flights out of Fort McMurray, Alberta during the period between August 22 and August 26, 2013. Significant amounts of aerosol were observed within the boundary layer, up to a height of 1.6 km, but the ozone concentration remained at or below background levels. On August 24th the lidar observed a separated layer of aerosol above the boundary layer, at a height of 1.8 km, in which the ozone mixing ratio increased to 70 ppbv. Backward trajectory calculations revealed that the air containing this separated aerosol layer had passed over an area of forest fires. Directly below the layer of forest fire smoke, in the pollution from the oil sands industry, the measured ozone mixing ratio was lower than the background levels (≤35 ppbv).

Self-curing concrete with different self-curing agents

NASA Astrophysics Data System (ADS)

Gopala krishna sastry, K. V. S.; manoj kumar, Putturu

2018-03-01

Concrete is recognised as a versatile construction material globally. Properties of concrete depend upon, to a greater extent, the hydration of cement and microstructure of hydrated cement. Congenial atmosphere would aid the hydration of cement and hence curing of concrete becomes essential, till a major portion of the hydration process is completed. But in areas of water inadequacy and concreting works at considerable heights, curing is problematic. Self-Curing or Internal Curing technique overcomes these problems. It supplies redundant moisture, for more than sufficient hydration of cement and diminish self-desiccation. Self-Curing agents substantially help in the conservation of water in concrete, by bringing down the evaporation during the hydration of Concrete. The present study focuses on the impact of self-curing agents such as Poly Ethylene Glycol (PEG), Poly Vinyl Alcohol (PVA) and Super Absorbent Polymer (SAP) on the concrete mix of M25 grade (reference mix). The effect of these agents on strength properties of Concrete such as compressive strength, split tensile strength and flexural strength was observed on a comparative basis which revealed that PEG 4000 was the most effective among all the agents.

Aggregate Effect on the Concrete Cone Capacity of an Undercut Anchor under Quasi-Static Tensile Load

PubMed Central

Marcon, Marco; Ninčević, Krešimir; Boumakis, Ioannis; Czernuschka, Lisa-Marie

2018-01-01

In the last decades, fastening systems have become an essential part of the construction industry. Post-installed mechanical anchors are frequently used in concrete members to connect them with other load bearing structural members, or to attach appliances. Their performance is limited by the concrete related failure modes which are highly influenced by the concrete mix design. This paper aims at investigating the effect that different aggregates used in the concrete mix have on the capacity of an undercut anchor under tensile quasi-static loading. Three concrete batches were cast utilising three different aggregate types. For two concrete ages (28 and 70 days), anchor tensile capacity and concrete properties were obtained. Concrete compressive strength, fracture energy and elastic modulus are used to normalize and compare the undercut anchor concrete tensile capacity employing some of the most widely used prediction models. For a more insightful comparison, a statistical method that yields also scatter information is introduced. Finally, the height and shape of the concrete cones are compared by highly precise and objective photogrammetric means. PMID:29723972

Aggregate Effect on the Concrete Cone Capacity of an Undercut Anchor under Quasi-Static Tensile Load.

PubMed

Marcon, Marco; Ninčević, Krešimir; Boumakis, Ioannis; Czernuschka, Lisa-Marie; Wan-Wendner, Roman

2018-05-01

In the last decades, fastening systems have become an essential part of the construction industry. Post-installed mechanical anchors are frequently used in concrete members to connect them with other load bearing structural members, or to attach appliances. Their performance is limited by the concrete related failure modes which are highly influenced by the concrete mix design. This paper aims at investigating the effect that different aggregates used in the concrete mix have on the capacity of an undercut anchor under tensile quasi-static loading. Three concrete batches were cast utilising three different aggregate types. For two concrete ages (28 and 70 days), anchor tensile capacity and concrete properties were obtained. Concrete compressive strength, fracture energy and elastic modulus are used to normalize and compare the undercut anchor concrete tensile capacity employing some of the most widely used prediction models. For a more insightful comparison, a statistical method that yields also scatter information is introduced. Finally, the height and shape of the concrete cones are compared by highly precise and objective photogrammetric means.

First Look at the Upper Tropospheric Ozone Mixing Ratio from OMI Estimated using the Cloud Slicing Technique

NASA Technical Reports Server (NTRS)

Bhartia, Pawan K.; Ziemke, Jerry; Chandra, Sushil; Joiner, Joanna; Vassilkov, Alexandra; Taylor, Steven; Yang, Kai; Ahn, Chang-Woo

2004-01-01

The Cloud Slicing technique has emerged as a powerful tool for the study of ozone in the upper troposphere. In this technique one looks at the variation with cloud height of the above-cloud column ozone derived from the backscattered ultraviolet instruments, such as TOMS, to determine the ozone mixing ratio. For this technique to work properly one needs an instrument with relatively good horizontal resolution with very good signal to noise in measuring above-cloud column ozone. In addition, one needs the (radiatively) effective cloud pressure rather than the cloud-top pressure, for the ultraviolet photons received by a satellite instrument are scattered from inside the cloud rather than from the top. For this study we use data from the OMI sensor, which was recently launched on the EOS Aura satellite. OMI is a W-Visible backscattering instrument with a nadir pixel size of 13 x 24 km. The effective cloud pressure is derived from a new algorithm based on Rotational Raman Scattering and O2-O2, absorption in the 340-400 nm band of OMI.

Growth in children with pulmonary arterial hypertension: a longitudinal retrospective multiregistry study.

PubMed

Ploegstra, Mark-Jan; Ivy, D Dunbar; Wheeler, Jeremy G; Brand, Monika; Beghetti, Maurice; Rosenzweig, Erika B; Humpl, Tilman; Iriart, Xavier; Rouzic, Erwan Muros-Le; Bonnet, Damien; Berger, Rolf M F

2016-04-01

To enable adequate interpretation of growth measurements in the management of children with pulmonary arterial hypertension (PAH), we assessed growth and its associated determinants in children with PAH. We did a retrospective longitudinal study of height and body-mass index in reference to WHO growth standards by pooling data from four contemporary prospective registries of paediatric PAH representing 53 centres in 19 countries. The main outcome measures were median height for age and body-mass index for age percentiles and longitudinal deviation of height for age and body-mass index for age Z scores from WHO standards. 601 children were followed up for a median of 2·9 years (IQR 1·5-4·4). Baseline median height for age percentile was 26 (IQR 4-54) and baseline median body-mass index for age percentile was 41 (IQR 12-79). Mean height for age Z score was significantly lower than the reference (-0·81, 95% CI -0·93 to -0·69; p<0·0001), as was body-mass index for age Z score (-0·12, -0·25 to -0·01; p=0·047). Height for age Z score was particularly decreased in young patients (aged ≤5 years) with idiopathic or hereditary PAH and in all patients with PAH associated with congenital heart disease. Although Z scores increased in some patients and decreased in others, we detected no significant trend in height for age Z score (p=0·57) or body-mass index for age Z score (p=0·48) before taking account of covariates. Multivariable linear mixed effects modelling showed that age, cause of PAH, ex-prematurity, WHO functional class, trisomy 21, and time since diagnosis were associated with height for age Z score, whereas age, ethnicity, and trisomy 21 were associated with body-mass index for age Z score. A favourable WHO functional class course was independently associated with increases in height for age Z score. PAH is associated with impaired growth, especially in younger children and those with pulmonary arterial hypertension associated with congenital heart disease. The degree of impairment is independently associated with cause of PAH and comorbidities, but also with disease severity and duration. Because a favourable clinical course was associated with catch-up growth, height for age could serve as an additional and globally available clinical parameter to monitor patients' clinical condition. Actelion Pharmaceuticals. Copyright © 2016 Elsevier Ltd. All rights reserved.

Retrievals of Jovian Tropospheric Phosphine from Cassini/CIRS

NASA Technical Reports Server (NTRS)

Irwin, P. G. J.; Parrish, P.; Fouchet, T.; Calcutt, S. B.; Taylor, F. W.; Simon-Miller, A. A.; Nixon, C. A.

2004-01-01

On December 30th 2000, the Cassini-Huygens spacecraft reached the perijove milestone on its continuing journey to the Saturnian system. During an extended six-month encounter, the Composite Infrared Spectrometer (CIRS) returned spectra of the Jovian atmosphere, rings and satellites from 10-1400 cm(exp -1) (1000-7 microns) at a programmable spectral resolution of 0.5 to 15 cm(exp -1). The improved spectral resolution of CIRS over previous IR instrument-missions to Jupiter, the extended spectral range, and higher signal-to-noise performance provide significant advantages over previous data sets. CIRS global observations of the mid-infrared spectrum of Jupiter at medium resolution (2.5 cm(exp -1)) have been analysed both with a radiance differencing scheme and an optimal estimation retrieval model to retrieve the spatial variation of phosphine and ammonia fractional scale height in the troposphere between 60 deg S and 60 deg N at a spatial resolution of 6 deg. The ammonia fractional scale height appears to be high over the Equatorial Zone (EZ) but low over the North Equatorial Belt (NEB) and South Equatorial Belt (SEB) indicating rapid uplift or strong vertical mixing in the EZ. The abundance of phosphine shows a similar strong latitudinal variation which generally matches that of the ammonia fractional scale height. However while the ammonia fractional scale height distribution is to a first order symmetric in latitude, the phosphine distribution shows a North/South asymmetry at mid latitudes with higher amounts detected at 40 deg N than 40 deg S. In addition the data show that while the ammonia fractional scale height at this spatial resolution appears to be low over the Great Red Spot (GRS), indicating reduced vertical mixing above the approx. 500 mb level, the abundance of phosphine at deeper levels may be enhanced at the northern edge of the GRS indicating upwelling.

Ozone and stratospheric height waves for opposite phases of the QBO

NASA Technical Reports Server (NTRS)

Mo, Kingtse C.; Nogues-Paegle, Julia

1994-01-01

The stratospheric quasi-biennial oscillation (QBO) provides an important source of interannual variations in the Northern Hemisphere. O'sullivan and Salby (1990) related extra-tropical eddy transport with the phase of the tropical QBO. When the tropical wind is easterly, the zero wind line is shifted into the winter hemisphere. Enhanced wave activity in middle latitudes acts to weaken the polar vortex. When the tropical wind is in the westerly phase the situation reverses. Heights at 30 mb and ozone configurations are contrasted in this paper for these two QBO phases. When the winter vortex deforms due to the amplification of planetary waves 1 and 2, extends westward and equatorward, the complementary band of low vorticity air spirals in toward the pole from lower latitudes. Sometimes, these planetary waves break (Juckes and McIntyre, 1987) and an irreversible mixing of air takes place between high and mid-latitudes. Global ozone patterns, as obtained form satellite observations, appear to be affected by planetary wave breaking (Leovy et al. 1985). This mixing results on regions with uniform ozone and potential vorticity. In the Southern Hemisphere (SH), Newman and Randel (1988) using Total Ozone Mapping Spectrometer (TOMS) data and the NMC analyses have found strong spatial correlation between the October mean temperature in the lower stratosphere and total ozone for the 1979 through 1986 years. Recently Nogues-Paegle et al.(1992) analyzed SH ozone and height data from 1986 to 1989. They found that leading empirical orthogonal functions (EOFs) for both ozone and 50 mb heights exhibit zonal wave 1 and 2 and that the correlations between ozone and 50 mb principal components (PCs) are high. The results were found to be consistent with a linear planetary wave advecting a passive tracer. In this paper, the dominant patterns of variability for 30 mb NMC heights and TOMS total ozone are obtained for the winter to summer transition (January to May) in the Northern Hemisphere (NH) for the years 1987-1990.

Maximal bite force, facial morphology and sucking habits in young children with functional posterior crossbite.

PubMed

Castelo, Paula Midori; Gavião, Maria Beatriz Duarte; Pereira, Luciano José; Bonjardim, Leonardo Rigoldi

2010-01-01

The maintenance of normal conditions of the masticatory function is determinant for the correct growth and development of its structures. Thus, the aims of this study were to evaluate the influence of sucking habits on the presence of crossbite and its relationship with maximal bite force, facial morphology and body variables in 67 children of both genders (3.5-7 years) with primary or early mixed dentition. The children were divided in four groups: primary-normocclusion (PN, n=19), primary-crossbite (PC, n=19), mixed-normocclusion (MN, n=13), and mixed-crossbite (MC, n=16). Bite force was measured with a pressurized tube, and facial morphology was determined by standardized frontal photographs: AFH (anterior face height) and BFW (bizygomatic facial width). It was observed that MC group showed lower bite force than MN, and AFH/BFW was significantly smaller in PN than PC (t-test). Weight and height were only significantly correlated with bite force in PC group (Pearson's correlation test). In the primary dentition, AFH/BFW and breast-feeding (at least six months) were positive and negatively associated with crossbite, respectively (multiple logistic regression). In the mixed dentition, breast-feeding and bite force showed negative associations with crossbite (univariate regression), while nonnutritive sucking (up to 3 years) associated significantly with crossbite in all groups (multiple logistic regression). In the studied sample, sucking habits played an important role in the etiology of crossbite, which was associated with lower bite force and long-face tendency.

Vapor condensation on liquid surface due to laminar jet-induced mixing: The effects of system parameters

NASA Technical Reports Server (NTRS)

Lin, Chin-Shun; Hasan, Mohammad M.

1989-01-01

The effects of system parameters on the interface condensation rate in a laminar jet induced mixing tank are numerically studied. The physical system consists of a partially filled cylindrical tank with a slightly subcooled jet discharged from the center of the tank bottom toward the liquid-vapor interface which is at a saturation temperature corresponding to the constant tank pressure. Liquid is also withdrawn from the outer part of the tank bottom to maintain the constant liquid level. The jet velocity is selected to be low enough such that the free surface is approximately flat. The effect of vapor superheat is assumed to be negligible. Therefore, the interface condensation rate can be determined from the resulting temperature field in the liquid region alone. The nondimensional form of the steady state conservation equations are solved by a finite difference method for various system parameters including liquid height to tank diameter ratio, tank to jet diameter ratio, liquid inflow to outflow area ratio, and a heat leak parameter which characterizes the uniform wall heat flux. Detailed analyses based on the numerical solutions are performed and simplified equations are suggested for the prediction of condensation rate.

Study of dilution, height, and lateral spread of vertical dense jets in marine shallow water.

PubMed

Ahmad, Nadeem; Suzuki, Takayuki

2016-01-01

This study provides information for the design of sea outfalls to dispose of brine from desalination plants into shallow lagoons of the sea. The behavior of vertical dense jets was studied experimentally by discharging cold saline water vertically upward into a tank filled with hot freshwater under stagnant ambient conditions. The minimum return point dilution, μmin, was determined using thermocouples, and the maximum height, Z(m), and the lateral spread, R(sp), of the fountains were determined by observing shadowgraph pictures. The flow was turbulent and the densimetric Froude number Fr(0) varied from 9 to 18.8. Three mixing regimes were identified: deep, intermediate, and impinging mixing regimes. In the intermediate mixing regime, μ(min) and Z(m) were analyzed and compared with the results of deep water studies. The μ(min) and Z(m) values of fountains at an intermediate water depth were found to be higher than those of fountains at deep water depths. In the impinging regime, μ(min) decreases rapidly when a fountain starts to continuously impinge on the water surface, showing a noticeable disturbance in the water surface. Therefore, a good rule of thumb is to reduce the flow through multiport diffusers from desalination plants when the noticeable disturbance is observed from the top water surface.

MODELED MESOSCALE METEOROLOGICAL FIELDS WITH FOUR-DIMENSIONAL DATA ASSIMILATION IN REGIONAL SCALE AIR QUALITY MODELS

EPA Science Inventory

This paper addresses the need to increase the temporal and spatial resolution of meteorological data currently used in air quality simulation models, AQSMs. ransport and diffusion parameters including mixing heights and stability used in regulatory air quality dispersion models a...

Phenological responses of juvenile pecan and white oak on an upland site

USDA-ARS?s Scientific Manuscript database

Pecan (Carya illinoiensis) and white oak (Quercus alba) produce multiple products and wildlife values, but their phenological responses to N fertilization have not been well characterized in an mixed species agroforestry practice. We compared tree height at planting and for six consecutive growing ...

Interannual variability of trace gases in the subtropical winter stratosphere

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

Gray, L.J.; Russell, J.M. III

1999-04-01

Measurements of water vapor and methane from the Halogen Occultation Experiment instrument on board the Upper Atmosphere Research Satellite are used to study the interannual variability of trace gas distributions in the atmosphere. Particular attention is paid to the mechanisms influencing trace gas distributions in the subtropics. The study highlights the quasi-biennial oscillation (QBO) dependence of subtropical tracer distributions more clearly than in previous studies. There is a strong correlation between the equatorial wind QBO and the slope of the tracer isolines in the Northern Hemisphere subtropics, with steeper subtropical isoline slopes in the easterly phase compared with the westerlymore » phase. This is particularly so in the lower stratosphere. Two possible mechanisms for the QBO signal in subtropical isoline slopes are identified: advection by the mean circulation and isentropic mixing. A comparison between the QBO signal in the slope of the tracer isolines and the isentropic tracer gradients is proposed as a method of determining which process is dominant. The authors suggest that the behavior of these two data diagnostics provides a stringent constraint on computer models of the atmosphere. On the basis of these diagnostics three height regions of the subtropical atmosphere are identified. (1) Below 450--500 K isentropic mixing associated with tropospheric disturbances penetrating the lower stratosphere is dominant. (2) In the region 500--750 K the data suggest that advection by the mean meridional circulation is important and that the role of isentropic mixing by eddies is relatively small. (3) Above 750 K isentropic mixing becomes increasingly important with height, and both advection and mixing are influential in determining the subtropical tracer distributions.« less

Influence of an urban canopy model and PBL schemes on vertical mixing for air quality modeling over Greater Paris

NASA Astrophysics Data System (ADS)

Kim, Youngseob; Sartelet, Karine; Raut, Jean-Christophe; Chazette, Patrick

2015-04-01

Impacts of meteorological modeling in the planetary boundary layer (PBL) and urban canopy model (UCM) on the vertical mixing of pollutants are studied. Concentrations of gaseous chemical species, including ozone (O3) and nitrogen dioxide (NO2), and particulate matter over Paris and the near suburbs are simulated using the 3-dimensional chemistry-transport model Polair3D of the Polyphemus platform. Simulated concentrations of O3, NO2 and PM10/PM2.5 (particulate matter of aerodynamic diameter lower than 10 μm/2.5 μm, respectively) are first evaluated using ground measurements. Higher surface concentrations are obtained for PM10, PM2.5 and NO2 with the MYNN PBL scheme than the YSU PBL scheme because of lower PBL heights in the MYNN scheme. Differences between simulations using different PBL schemes are lower than differences between simulations with and without the UCM and the Corine land-use over urban areas. Regarding the root mean square error, the simulations using the UCM and the Corine land-use tend to perform better than the simulations without it. At urban stations, the PM10 and PM2.5 concentrations are over-estimated and the over-estimation is reduced using the UCM and the Corine land-use. The ability of the model to reproduce vertical mixing is evaluated using NO2 measurement data at the upper air observation station of the Eiffel Tower, and measurement data at a ground station near the Eiffel Tower. Although NO2 is under-estimated in all simulations, vertical mixing is greatly improved when using the UCM and the Corine land-use. Comparisons of the modeled PM10 vertical distributions to distributions deduced from surface and mobile lidar measurements are performed. The use of the UCM and the Corine land-use is crucial to accurately model PM10 concentrations during nighttime in the center of Paris. In the nocturnal stable boundary layer, PM10 is relatively well modeled, although it is over-estimated on 24 May and under-estimated on 25 May. However, PM10 is under-estimated on both days in the residual layer, and over-estimated on both days over the residual layer. The under-estimations in the residual layer are partly due to difficulties to estimate the PBL height, to an over-estimation of vertical mixing during nighttime at high altitudes and to uncertainties in PM10 emissions. The PBL schemes and the UCM influence the PM vertical distributions not only because they influence vertical mixing (PBL height and eddy-diffusion coefficient), but also horizontal wind fields and humidity. However, for the UCM, it is the influence on vertical mixing that impacts the most the PM10 vertical distribution below 1.5 km.

IUE observations of blue halo high luminosity stars

NASA Technical Reports Server (NTRS)

Hack, M.; Franco, M. L.; Stalio, R.

1981-01-01

Two high luminosity population II blue stars of high galactic latitude, BD+33 deg 2642 and HD 137569 were observed at high resolution. The stellar spectra show the effect of mass loss in BD+33 deg 2642 and abnormally weak metallic lines in HD 137569. The interstellar lines in the direction of BD+33 deg 2642, which lies at a height z greater than or equal to 6.2 kpc from the galactic plane, are split into two components. No high ionization stages are found at the low velocity component; nor can they be detected in the higher velocity clouds because of mixing with the corresponding stellar/circumstellar lines.

Convection in Slab and Spheroidal Geometries

NASA Technical Reports Server (NTRS)

Porter, David H.; Woodward, Paul R.; Jacobs, Michael L.

2000-01-01

Three-dimensional numerical simulations of compressible turbulent thermally driven convection, in both slab and spheroidal geometries, are reviewed and analyzed in terms of velocity spectra and mixing-length theory. The same ideal gas model is used in both geometries, and resulting flows are compared. The piecewise-parabolic method (PPM), with either thermal conductivity or photospheric boundary conditions, is used to solve the fluid equations of motion. Fluid motions in both geometries exhibit a Kolmogorov-like k(sup -5/3) range in their velocity spectra. The longest wavelength modes are energetically dominant in both geometries, typically leading to one convection cell dominating the flow. In spheroidal geometry, a dipolar flow dominates the largest scale convective motions. Downflows are intensely turbulent and up drafts are relatively laminar in both geometries. In slab geometry, correlations between temperature and velocity fluctuations, which lead to the enthalpy flux, are fairly independent of depth. In spheroidal geometry this same correlation increases linearly with radius over the inner 70 percent by radius, in which the local pressure scale heights are a sizable fraction of the radius. The effects from the impenetrable boundary conditions in the slab geometry models are confused with the effects from non-local convection. In spheroidal geometry nonlocal effects, due to coherent plumes, are seen as far as several pressure scale heights from the lower boundary and are clearly distinguishable from boundary effects.

Advanced simulation of mixed-material erosion/evolution and application to low and high-Z containing plasma facing components

NASA Astrophysics Data System (ADS)

Brooks, J. N.; Hassanein, A.; Sizyuk, T.

2013-07-01

Plasma interactions with mixed-material surfaces are being analyzed using advanced modeling of time-dependent surface evolution/erosion. Simulations use the REDEP/WBC erosion/redeposition code package coupled to the HEIGHTS package ITMC-DYN mixed-material formation/response code, with plasma parameter input from codes and data. We report here on analysis for a DIII-D Mo/C containing tokamak divertor. A DIII-D/DiMES probe experiment simulation predicts that sputtered molybdenum from a 1 cm diameter central spot quickly saturates (˜4 s) in the 5 cm diameter surrounding carbon probe surface, with subsequent re-sputtering and transport to off-probe divertor regions, and with high (˜50%) redeposition on the Mo spot. Predicted Mo content in the carbon agrees well with post-exposure probe data. We discuss implications and mixed-material analysis issues for Be/W mixing at the ITER outer divertor, and Li, C, Mo mixing at an NSTX divertor.

Phase mixing of Alfvén waves in axisymmetric non-reflective magnetic plasma configurations

NASA Astrophysics Data System (ADS)

Petrukhin, N. S.; Ruderman, M. S.; Shurgalina, E. G.

2018-02-01

We study damping of phase-mixed Alfvén waves propagating in non-reflective axisymmetric magnetic plasma configurations. We derive the general equation describing the attenuation of the Alfvén wave amplitude. Then we applied the general theory to a particular case with the exponentially divergent magnetic field lines. The condition that the configuration is non-reflective determines the variation of the plasma density along the magnetic field lines. The density profiles exponentially decreasing with the height are not among non-reflective density profiles. However, we managed to find non-reflective profiles that fairly well approximate exponentially decreasing density. We calculate the variation of the total wave energy flux with the height for various values of shear viscosity. We found that to have a substantial amount of wave energy dissipated at the lower corona, one needs to increase shear viscosity by seven orders of magnitude in comparison with the value given by the classical plasma theory. An important result that we obtained is that the efficiency of the wave damping strongly depends on the density variation with the height. The stronger the density decrease, the weaker the wave damping is. On the basis of this result, we suggested a physical explanation of the phenomenon of the enhanced wave damping in equilibrium configurations with exponentially diverging magnetic field lines.

Stratospheric CFCl3, CF2Cl2, and N2O height profile measurements at several latitudes

NASA Astrophysics Data System (ADS)

Goldan, P. D.; Kuster, W. C.; Albritton, D. L.; Schmeltekopf, A. L.

1980-01-01

The mixing ratios of CFCl3, CF2Cl2, and N2O have been measured as a function of altitude from 6 to 37 km above sea level by using a balloon-borne grab-sampling system. The 24 flights were made during the period July 1976 to March 1979 from Wyoming, Panama, Brazil, and Antarctica. These data are reported here both numerically and graphically, the latter being examined for latitudinal and temporal trends. A mean tropopause height for each location and date was used as the reference for the height profiles. The resulting set of CF2Cl2 and N2O profiles show a discernible dependence on latitude; the lapse rate of these mixing ratios is greater for the mid-latitudes when compared to the equatorial latitudes. The upper tropospheric portion of the CFCl3 and CF2Cl2 data show annual increases of 10.4±3.9 and 10.7±1.9%/yr, respectively, in the northern hemisphere for the middle of the measurement period (end of 1977). Furthermore, the limited number of southern hemispheric data for these constituents are about 8% lower than the northern hemispheric values but have a comparable annual increase. The corresponding N2O data show no interhemispheric differences and the possibility of only a slight increase (less than 2%/yr).

Dominance of an alien shrub Rhus typhina over a native shrub Vitex negundo var. heterophylla under variable water supply patterns

PubMed Central

Du, Ning; Tan, Xiangfeng; Li, Qiang; Liu, Xiao; Zhang, Wenxin; Wang, Renqing; Liu, Jian; Guo, Weihua

2017-01-01

Temporal heterogeneity of a resource supply can have a profound effect on the interactions between alien and native plant species and their potential invasiveness. Precipitation patterns may be variable and result in a higher heterogeneity of water supply with global climate change. In this study, an alien shrub species, Rhus typhina, introduced to China from North America and a native shrub species, Vitex negundo var. heterophylla, were grown in monoculture and mixed culture under different water supply regimes, with four levels of water supply frequencies but with a constant level of total supplied water. After 60 days of treatments, the alien species was found to be the superior competitor in the mixed culture and was unaffected by changes in the water supply pattern. The dominance of R. typhina was mainly owing to its greater biomass and effective modulation of leaf physiology. However, in the mixed culture, V. negundo var. heterophylla exhibited both leaf- and whole-plant-level acclimations, including higher leaf length to petiole length and root to shoot biomass ratios, and lower specific leaf weight and leaf length to leaf width ratio. Plant height of V. negundo var. heterophylla was comparable to that of R. typhina in the mixed culture, which is a strategy to escape shading. Although water treatments had little effect on most traits in both species, the possible influence of water regimes should not be neglected. Compared with high-frequency water supply treatments, more individuals of V. negundo var. heterophylla died in low-water-frequency treatments when in competition with R. typhina, which may lead to species turnover in the field. The authors recommended that caution should be exercised when introducing R. typhina to non-native areas in the context of global climate change. PMID:28445505

Dominance of an alien shrub Rhus typhina over a native shrub Vitex negundo var. heterophylla under variable water supply patterns.

PubMed

Du, Ning; Tan, Xiangfeng; Li, Qiang; Liu, Xiao; Zhang, Wenxin; Wang, Renqing; Liu, Jian; Guo, Weihua

2017-01-01

Temporal heterogeneity of a resource supply can have a profound effect on the interactions between alien and native plant species and their potential invasiveness. Precipitation patterns may be variable and result in a higher heterogeneity of water supply with global climate change. In this study, an alien shrub species, Rhus typhina, introduced to China from North America and a native shrub species, Vitex negundo var. heterophylla, were grown in monoculture and mixed culture under different water supply regimes, with four levels of water supply frequencies but with a constant level of total supplied water. After 60 days of treatments, the alien species was found to be the superior competitor in the mixed culture and was unaffected by changes in the water supply pattern. The dominance of R. typhina was mainly owing to its greater biomass and effective modulation of leaf physiology. However, in the mixed culture, V. negundo var. heterophylla exhibited both leaf- and whole-plant-level acclimations, including higher leaf length to petiole length and root to shoot biomass ratios, and lower specific leaf weight and leaf length to leaf width ratio. Plant height of V. negundo var. heterophylla was comparable to that of R. typhina in the mixed culture, which is a strategy to escape shading. Although water treatments had little effect on most traits in both species, the possible influence of water regimes should not be neglected. Compared with high-frequency water supply treatments, more individuals of V. negundo var. heterophylla died in low-water-frequency treatments when in competition with R. typhina, which may lead to species turnover in the field. The authors recommended that caution should be exercised when introducing R. typhina to non-native areas in the context of global climate change.

Vertically resolved characteristics of air pollution during two severe winter haze episodes in urban Beijing, China

NASA Astrophysics Data System (ADS)

Wang, Qingqing; Sun, Yele; Xu, Weiqi; Du, Wei; Zhou, Libo; Tang, Guiqian; Chen, Chen; Cheng, Xueling; Zhao, Xiujuan; Ji, Dongsheng; Han, Tingting; Wang, Zhe; Li, Jie; Wang, Zifa

2018-02-01

We conducted the first real-time continuous vertical measurements of particle extinction (bext), gaseous NO2, and black carbon (BC) from ground level to 260 m during two severe winter haze episodes at an urban site in Beijing, China. Our results illustrated four distinct types of vertical profiles: (1) uniform vertical distributions (37 % of the time) with vertical differences less than 5 %, (2) higher values at lower altitudes (29 %), (3) higher values at higher altitudes (16 %), and (4) significant decreases at the heights of ˜ 100-150 m (14 %). Further analysis demonstrated that vertical convection as indicated by mixing layer height, temperature inversion, and local emissions are three major factors affecting the changes in vertical profiles. Particularly, the formation of type 4 was strongly associated with the stratified layer that was formed due to the interactions of different air masses and temperature inversions. Aerosol composition was substantially different below and above the transition heights with ˜ 20-30 % higher contributions of local sources (e.g., biomass burning and cooking) at lower altitudes. A more detailed evolution of vertical profiles and their relationship with the changes in source emissions, mixing layer height, and aerosol chemistry was illustrated by a case study. BC showed overall similar vertical profiles as those of bext (R2 = 0.92 and 0.69 in November and January, respectively). While NO2 was correlated with bext for most of the time, the vertical profiles of bext / NO2 varied differently for different profiles, indicating the impact of chemical transformation on vertical profiles. Our results also showed that more comprehensive vertical measurements (e.g., more aerosol and gaseous species) at higher altitudes in the megacities are needed for a better understanding of the formation mechanisms and evolution of severe haze episodes in China.

Carbon dioxide dangers demonstration model

USGS Publications Warehouse

Venezky, Dina; Wessells, Stephen

2010-01-01

Carbon dioxide is a dangerous volcanic gas. When carbon dioxide seeps from the ground, it normally mixes with the air and dissipates rapidly. However, because carbon dioxide gas is heavier than air, it can collect in snowbanks, depressions, and poorly ventilated enclosures posing a potential danger to people and other living things. In this experiment we show how carbon dioxide gas displaces oxygen as it collects in low-lying areas. When carbon dioxide, created by mixing vinegar and baking soda, is added to a bowl with candles of different heights, the flames are extinguished as if by magic.

Timeline of Intestinal Adaptation After Malabsortive Surgery: Effect of Luminal Nutrients, Biliopancreatic Secretion, and Glutamine Supplementation.

PubMed

Martínez Moreno, José Manuel; Reyes-Ortiz, Alexander; Lage Sánchez, José María; Sánchez-Gallegos, Pilar; Garcia-Caballero, Manuel

2017-12-01

The aim of this study was to study the process of intestinal adaptation in the three limbs of the small intestine after malabsorptive bariatric surgery: the biliopancreatic limb, the alimentary limb, and the common channel. These limbs are exposed to different stimuli, namely, gastrointestinal transit and nutrients in the alimentary limb, biliopancreatic secretions in the biliopancreatic limb, and a mix of both in the common channel. We also wished to investigate the effect of glutamine supplementation on the adaptation process. Three types of surgery were performed using a porcine model: biliopancreatic bypass (BPBP), massive (75%) short bowel resection as the positive control, and a sham operation (transection) as the negative control. We measured the height and width of intestinal villi, histidine decarboxylase (HDC) activity, and amount of HDC messenger RNA (mRNA) (standard diet or a diet supplemented with glutamine). An increase in HDC activity and mRNA expression was observed in the BPBP group. This increase coincided with an increase in the height and width of the intestinal villi. The increase in villus height was observed immediately after surgery and peaked at 2 weeks. Levels remained higher than those observed in sham-operated pigs for a further 4 weeks. The intestinal adaptation process in animals that underwent BPBP was less intense than in those that underwent massive short bowel resection and more intense than in those that underwent transection only. Supplementation with glutamine did not improve any of the parameters studied, although it did appear to accelerate the adaptive process.

The Effect of Diet Mixing on a Nonselective Herbivore

PubMed Central

2016-01-01

The balanced-diet hypothesis states that a diverse prey community is beneficial to consumers due to resource complementarity among the prey species. Nonselective consumer species cannot differentiate between prey items and are therefore not able to actively regulate their diet intake. We thus wanted to test whether the balanced-diet hypothesis is applicable to nonselective consumers. We conducted a laboratory experiment in which a nonselective model grazer, the freshwater gastropod Lymnaea stagnalis, was fed benthic green algae as single species or as a multi-species mixture and quantified the snails’ somatic growth rates and shell lengths over a seven-week period. Gastropods fed the mixed diet were found to exhibit a higher somatic growth rate than the average of the snails fed single prey species. However, growth on the multi-species mixture did not exceed the growth rate obtained on the best single prey species. Similar results were obtained regarding the animals’ shell height increase over time. The mixed diet did not provide the highest growth rate, which confirms our hypothesis. We thus suggest that the balanced-diet hypothesis is less relevant for non-selective generalist consumers, which needs to be considered in estimates of secondary production. PMID:27391787

Tests of two convection theories for red giant and red supergiant envelopes

NASA Technical Reports Server (NTRS)

Stothers, Richard B.; Chin, Chao-Wen

1995-01-01

Two theories of stellar envelope convection are considered here in the context of red giants and red supergiants of intermediate to high mass: Boehm-Vitense's standard mixing-length theory (MLT) and Canuto & Mazzitelli's new theory incorporating the full spectrum of turbulence (FST). Both theories assume incompressible convection. Two formulations of the convective mixing length are also evaluated: l proportional to the local pressure scale height (H(sub P)) and l proportional to the distance from the upper boundary of the convection zone (z). Applications to test both theories are made by calculating stellar evolutionary sequences into the red zone (z). Applications to test both theories are made by calculating stellar evolutionary sequences into the red phase of core helium burning. Since the theoretically predicted effective temperatures for cool stars are known to be sensitive to the assigned value of the mixing length, this quantity has been individually calibrated for each evolutionary sequence. The calibration is done in a composite Hertzsprung-Russell diagram for the red giant and red supergiant members of well-observed Galactic open clusters. The MLT model requires the constant of proportionality for the convective mixing length to vary by a small but statistically significant amount with stellar mass, whereas the FST model succeeds in all cases with the mixing lenghth simply set equal to z. The structure of the deep stellar interior, however, remains very nearly unaffected by the choices of convection theory and mixing lenghth. Inside the convective envelope itself, a density inversion always occurs, but is somewhat smaller for the convectively more efficient MLT model. On physical grounds the FST model is preferable, and seems to alleviate the problem of finding the proper mixing length.

Approximate analytical solution to diurnal atmospheric boundary-layer growth under well-watered conditions

USDA-ARS?s Scientific Manuscript database

The system of governing equations of a simplified slab model of the uniformly-mixed, purely convective, diurnal atmospheric boundary layer (ABL) is shown to allow immediate solutions for the potential temperature and specific humidity as functions of the ABL height and net radiation when expressed i...

The Influence of Atmosphere-Ocean Interaction on MJO Development and Propagation

DTIC Science & Technology

2013-09-30

MJO initiation. Figure 3. Time-height cross section of COAMPS grid 3 domain-averaged (a) diabatic heating, (b) perturbation mixing ratio...moist phase. The diurnal variability of 7 precipitation and diabatic heating that can be seen in Figs. 2 and 3 is not observed in the simulation with

SPATIAL VARIATION OF THE EVOLUTION AND STRUCTURE OF THE URBAN BOUNDARY LAYER

EPA Science Inventory

The spatial variation of the nocturnal urban boundary layer structure and the time variation of the mixing height, the nocturnal inversion top and strength after sunrise are presented for urban sites located upwind, downwind, and near the center of the heat island and for upwind ...

Multiple Solvent Extraction System with Flow Injection Technology.

DTIC Science & Technology

1981-09-30

encounters a back extraction step where the direction of the extraction is from organic to aqueous solvent. Thus it is advantageous to incorporate both...stainless steel ( Alltech Associates, Arlington Heights, IQ) and prepared from a single section of 180 cmn in length. The Section 2 mixing and extraction

47 CFR 80.763 - Effective antenna height.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Effective antenna height. 80.763 Section 80.763... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.763 Effective antenna height. The effective height of the antenna is the vertical distance between the center of the radiating...

47 CFR 80.763 - Effective antenna height.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Effective antenna height. 80.763 Section 80.763... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.763 Effective antenna height. The effective height of the antenna is the vertical distance between the center of the radiating...

47 CFR 80.763 - Effective antenna height.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Effective antenna height. 80.763 Section 80.763... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.763 Effective antenna height. The effective height of the antenna is the vertical distance between the center of the radiating...

47 CFR 80.763 - Effective antenna height.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Effective antenna height. 80.763 Section 80.763... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.763 Effective antenna height. The effective height of the antenna is the vertical distance between the center of the radiating...

47 CFR 80.763 - Effective antenna height.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Effective antenna height. 80.763 Section 80.763... MARITIME SERVICES Standards for Computing Public Coast Station VHF Coverage § 80.763 Effective antenna height. The effective height of the antenna is the vertical distance between the center of the radiating...

Effect of radiocesium transfer on ambient dose rate in forest environments affected by the Fukushima Nuclear Power Plant accident

NASA Astrophysics Data System (ADS)

Kato, H.

2015-12-01

We investigated the transfer of canopy-intercepted radiocesium to the forest floor during 3 years following the Fukushima Daiichi Nuclear Power Plant accident. The cesium-137 (Cs-137) contents in throughfall, stemflow, and litterfall were monitored in two coniferous stands (plantation of Japanese cedar) and a deciduous broad-leaved forest stand (Japanese oak with red pine). We also measured the ambient dose rate (ADR) at different heights in the forest using a survey meter and a portable Ge gamma-ray detector. Total Cs-137 deposition flux from the canopy to forest floor for the mature cedar, young cedar, and the mixed broad-leaved stands were 166 kBq/m2, 174 kBq/m2, and 60 kBq/m2, respectively. These values correspond to 38%, 40% and 13% of total atmospheric input after the accident. The ambient dose rate in forest exhibited height dependency and its vertical distribution varied with forest type and stand age. The ambient dose rate showed an exponential decrease with time for all the forest sites, however the decreasing trend differed depending on the height of dose measurement and forest type. The ambient dose rate at the canopy (approx. 10 m-height) decreased faster than that expected from physical decay of the two radiocesium isotopes, whereas those at the forest floor varied between the three forest stands. The radiocesium deposition via throughfall seemed to increase ambient dose rate during the first 200 days after the accident, however there was no clear relationship between litterfall and ambient dose rate since 400 days after the accident. These data suggested that the ambient dose rate in forest environment varied both spatially and temporally reflecting the transfer of radiocesium from canopy to forest floor. However, further monitoring investigation and analysis are required to determine the effect of litterfall on long-term trend of ambient dose rate in forest environments.

Changes in physical size among major league baseball players and its attribution to elite offensive performance.

PubMed

Crotin, Ryan L; Forsythe, Charles M; Bhan, Shivam; Karakolis, Thomas

2014-10-01

Major League Baseball (MLB) players have not been longitudinally examined for changes in physical size. Height, weight, and body mass indices (BMIs) were examined among offensive league leaders (OLL) and MLB reference cohorts at 1970, 1990, and 2010. Anthropometric values were expected to increase successively, where OLL were expected to be larger at each respective time point. A Mixed Model analysis of variance (p ≤ 0.05) examined anthropometric differences over time within and between groups. Mass and BMI increased over successive years with the largest effect seen between 1990 and 2010 (p < 0.001). A significant height reduction was shown for OLL from 1970 to 1990 (p ≤ 0.05), being the only significant decrease in physical size; yet, leaders were heavier and taller compared with the MLB reference population (p < 0.014). Results show that physical size has evolved in MLB, with the OLL being the largest players shown at each year in succession. Professional baseball scouts may have been influenced by greater offensive prowess shown by larger athletes; yet, increased secular anthropometrics must also be factored in greater heights, weights, BMIs shown over time in MLB. It is possible that greater participation in strength and conditioning programs at an earlier age, advances in sport nutrition, and potential abuse of anabolic drugs are factors perpetuating growth rates at present.

Effects of shape parameters on the attractiveness of a female body.

PubMed

Fan, J; Dai, W; Qian, X; Chau, K P; Liu, Q

2007-08-01

Various researchers have suggested that certain anthropometric ratios can be used to measure female body attractiveness, including the waist to hip ratio, Body Mass Index (BMI), and the body volume divided by the square of the height (Volume-Height Index). Based on a wide range of female subjects and virtual images of bodies with different ratios, Volume-Height Index was found to provide the best fit with female body attractiveness, and the effect of Volume-Height Index can be fitted with two half bell-shaped exponential curves with an optimal Volume-Height Index at 14.2 liter/m2. It is suggested that the general trend of the effect of Volume-Height Index may be culturally invariant, but the optimal value of Volume-Height Index may vary from culture to culture. In addition to Volume-Height Index, other body parameters or ratios which reflect body proportions and the traits of feminine characteristics had smaller but significant effects on female body attractiveness, and such effects were stronger at optimum Volume-Height Index.

Boundary Layer Depth In Coastal Regions

NASA Astrophysics Data System (ADS)

Porson, A.; Schayes, G.

The results of earlier studies performed about sea breezes simulations have shown that this is a relevant feature of the Planetary Boundary Layer that still requires effort to be diagnosed properly by atmospheric models. Based on the observations made during the ESCOMPTE campaign, over the Mediterranean Sea, different CBL and SBL height estimation processes have been tested with a meso-scale model, TVM. The aim was to compare the critical points of the BL height determination computed using turbulent kinetic energy profile with some other standard evaluations. Moreover, these results have been analysed with different mixing length formulation. The sensitivity of formulation is also analysed with a simple coastal configuration.

A study of tornadic thunderstorm interactions with thermal boundaries

NASA Technical Reports Server (NTRS)

Maddox, R. A.; Hoxit, L. R.; Chappell, C. F.

1980-01-01

A study of tornadic thunderstorm interactions with thermal boundaries using a model of subcloud wind profiles is presented. Within a hot, moist, and conditionally unstable air mass, warm thermal advection and surface friction cause the winds to veer and increase with height, while within a cool, moist air mass cool thermal advection and friction combine to produce a wind profile that has maximum speeds near the surface and veers little with height. The spatial distribution of different wind profiles and moisture contents within the boundary layer may act together to maximize mesoscale moisture contents, convergence, and cyclonic vorticity within a narrow mixing zone along the thermal boundary.

Scramjet Combustor Characteristics at Hypervelocity Condition over Mach 10 Flight

NASA Astrophysics Data System (ADS)

Takahashi, M.; Komuro, T.; Sato, K.; Kodera, M.; Tanno, H.; Itoh, K.

2009-01-01

To investigate possibility of reduction of a scramjet combustor size without thrust performance loss, a two-dimensional constant-area combustor of a previous engine model was replaced with the one with 23% lower-height. With the application of the lower-height combustor, the pressure in the combustor becomes 50% higher and the combustor length for the optimal performance becomes 43% shorter than the original combustor. The combustion tests of the modified engine model were conducted using a large free-piston driven shock tunnel at flow conditions corresponding to the flight Mach number from 9 to 14. CFD was also applied to the engine internal flows. The results showed that the mixing and combustion heat release progress faster to the distance and the combustor performance similar to that of the previous engine was obtained with the modified engine. The reduction of the combustor size without the thrust performance loss is successfully achieved by applying the lower-height combustor.

The effect of step stool use and provider height on CPR quality during pediatric cardiac arrest: A simulation-based multicentre study.

PubMed

Cheng, Adam; Lin, Yiqun; Nadkarni, Vinay; Wan, Brandi; Duff, Jonathan; Brown, Linda; Bhanji, Farhan; Kessler, David; Tofil, Nancy; Hecker, Kent; Hunt, Elizabeth A

2018-01-01

We aimed to explore whether a) step stool use is associated with improved cardiopulmonary resuscitation (CPR) quality; b) provider adjusted height is associated with improved CPR quality; and if associations exist, c) determine whether just-in-time (JIT) CPR training and/or CPR visual feedback attenuates the effect of height and/or step stool use on CPR quality. We analysed data from a trial of simulated cardiac arrests with three study arms: No intervention; CPR visual feedback; and JIT CPR training. Step stool use was voluntary. We explored the association between 1) step stool use and CPR quality, and 2) provider adjusted height and CPR quality. Adjusted height was defined as provider height + 23 cm (if step stool was used). Below-average height participants were ≤ gender-specific average height; the remainder were above average height. We assessed for interaction between study arm and both adjusted height and step stool use. One hundred twenty-four subjects participated; 1,230 30-second epochs of CPR were analysed. Step stool use was associated with improved compression depth in below-average (female, p=0.007; male, p<0.001) and above-average (female, p=0.001; male, p<0.001) height providers. There is an association between adjusted height and compression depth (p<0.001). Visual feedback attenuated the effect of height (p=0.025) on compression depth; JIT training did not (p=0.918). Visual feedback and JIT training attenuated the effect of step stool use (p<0.001) on compression depth. Step stool use is associated with improved compression depth regardless of height. Increased provider height is associated with improved compression depth, with visual feedback attenuating the effects of height and step stool use.

Experimental investigation of five parallel plane jets with variation of Reynolds number and outlet conditions

NASA Astrophysics Data System (ADS)

Daubner, Tomas; Kizhofer, Jens; Dinulescu, Mircea

2018-06-01

This article describes an experimental investigation in the near field of five parallel plane jets. The study applies 2D Particle Image Velocimetry (PIV) for ventilated and unventilated jets, where ventilated means exiting into a duct with expansion ratio 3.5 and unventilated means exiting to the free atmosphere. Results are presented for Reynolds numbers 1408, 5857 and 10510. The Reynolds number is calculated for the middle channel and is based on the height of the nozzle (channel) equivalent diameter 2h. All characteristic regions of the methodology to describe multiple interacting jets are observed by the PIV measurements - converging, merging and combined. Each of the five parallel channels has an aspect ratio of 25 defined as nozzle width (w) to height (h). The channels have a length of 185 times the channel height guaranteeing a fully developed velocity profile at the exit from the channel. Spacing between the single plane jets is 3 times the channel height. The near field of multiple mixing jets is depended on outlet nozzle geometry. Blunt geometry of the nozzle was chosen (sudden contraction).

Diffusion in coastal and harbour zones, effects of Waves,Wind and Currents

NASA Astrophysics Data System (ADS)

Diez, M.; Redondo, J. M.

2009-04-01

As there are multiple processes at different scales that produce turbulent mixing in the ocean, thus giving a large variation of horizontal eddy diffusivities, we use a direct method to evaluate the influence of different ambient parameters such as wave height and wind on coastal dispersion. Measurements of the diffusivity are made by digital processing of images taken from from video recordings of the sea surface near the coast. The use of image analysis allows to estimate both spatial and temporal characteristics of wave fields, surface circulation and mixing in the surf zone, near Wave breakers and inside Harbours. The study of near-shore dispersion [1], with the added complexity of the interaction between wave fields, longshore currents, turbulence and beach morphology, needs detailed measurements of simple mixing processes to compare the respective influences of forcings at different scales. The measurements include simultaneous time series of waves, currents, wind velocities from the studied area. Cuantitative information from the video images is accomplished using the DigImage video processing system [3], and a frame grabber. The video may be controlled by the computer, allowing, remote control of the processing. Spectral analysis on the images has also used n order to estimate dominant wave periods as well as the dispersion relations of dominant instabilities. The measurements presented here consist mostly on the comarison of difussion coeficients measured by evaluating the spread of blobs of dye (milk) as well as by measuring the separation between different buoys released at the same time. We have used a techniques, developed by Bahia(1997), Diez(1998) and Bezerra(2000)[1-3] to study turbulent diffusion by means of digital processing of images taken from remote sensing and video recordings of the sea surface. The use of image analysis allows to measure variations of several decades in horizontal diffusivity values, the comparison of the diffusivities between different sites is not direct and a good understanding of the dominant mixing processes is needed. There is an increase of diffusivity with wave height but only for large Wave Reynolds numbers. Other important factors are wind speed and tidal currents. The horizontal diffusivity shows a marked anisotropy as a function of wave height and distance from the coast. The measurements were performed under a variety of weather conditions conditional sampling has been used to identify the different influences of the environmental agents on the actual effective horizontal diffusion[4]. [1] Bahia E. (1998) "Un estudio numerico experimental de la dispersion de contaminantes en aguas costeras, PhD Tesis UPC, Barcelona. [2] Bezerra M.O., (2000) "Diffusion de contaminantes en la costa. , PhD Tesis Uni. De Barcelona, Barcelona. [3] Diez M. (1998) "Estudio de la Hidrodinamica de la zona de rompientes mediante el analisis digital de imagenes. Master Thesis, UPC, Barcelona. [4] Artale V., Boffetta G., Celani A., Cencini M. and Vulpiani A., 1997, "Dispersion of passive tracers in closed basins: Beyond the diffusion coefficient", Physics of Fluids, vol 9, pp 3162-1997

Rapid three-dimensional microfluidic mixer for high viscosity solutions to unravel earlier folding kinetics of G-quadruplex under molecular crowding conditions.

PubMed

Liu, Chao; Li, Ying; Li, Yiwei; Chen, Peng; Feng, Xiaojun; Du, Wei; Liu, Bi-Feng

2016-01-01

Rapid mixing of highly viscous solutions is a great challenge, which helps to analyze the reaction kinetics in viscous liquid phase, particularly to discover the folding kinetics of macromolecules under molecular crowding conditions mimicking the conditions inside cells. Here, we demonstrated a novel microfluidic mixer based on Dean flows with three-dimensional (3D) microchannel configuration for fast mixing of high-viscosity fluids. The main structure contained three consecutive subunits, each consisting of a "U"-type channel followed by a chamber with different width and height. Thus, the two solutions injected from the two inlets would undergo a mixing in the first "U"-type channel due to the Dean flow effect, and simultaneous vortices expansions in both horizontal and vertical directions in the following chamber. Numerical simulations and experimental characterizations confirmed that the micromixer could achieve a mixing time of 122.4μs for solutions with viscosities about 33.6 times that of pure water. It was the fastest micromixer for high viscosity solutions compared with previous reports. With this highly efficient 3D microfluidic mixer, we further characterized the early folding kinetics of human telomere G-quadruplex under molecular crowding conditions, and unravelled a new folding process within 550μs. Copyright © 2015 Elsevier B.V. All rights reserved.

Maximal bite force, facial morphology and sucking habits in young children with functional posterior crossbite

PubMed Central

CASTELO, Paula Midori; GAVIÃO, Maria Beatriz Duarte; PEREIRA, Luciano José; BONJARDIM, Leonardo Rigoldi

2010-01-01

Objective The maintenance of normal conditions of the masticatory function is determinant for the correct growth and development of its structures. Thus, the aims of this study were to evaluate the influence of sucking habits on the presence of crossbite and its relationship with maximal bite force, facial morphology and body variables in 67 children of both genders (3.5-7 years) with primary or early mixed dentition. Material and methods The children were divided in four groups: primary-normocclusion (PN, n=19), primary-crossbite (PC, n=19), mixed-normocclusion (MN, n=13), and mixed-crossbite (MC, n=16). Bite force was measured with a pressurized tube, and facial morphology was determined by standardized frontal photographs: AFH (anterior face height) and BFW (bizygomatic facial width). Results It was observed that MC group showed lower bite force than MN, and AFH/ BFW was significantly smaller in PN than PC (t-test). Weight and height were only significantly correlated with bite force in PC group (Pearson’s correlation test). In the primary dentition, AFH/BFW and breast-feeding (at least six months) were positive and negatively associated with crossbite, respectively (multiple logistic regression). In the mixed dentition, breastfeeding and bite force showed negative associations with crossbite (univariate regression), while nonnutritive sucking (up to 3 years) associated significantly with crossbite in all groups (multiple logistic regression). Conclusions In the studied sample, sucking habits played an important role in the etiology of crossbite, which was associated with lower bite force and long-face tendency. PMID:20485925

Longitudinal Growth, Diet, and Physical Activity in Young Children With Cerebral Palsy.

PubMed

Oftedal, Stina; Davies, Peter S W; Boyd, Roslyn N; Stevenson, Richard D; Ware, Robert S; Keawutan, Piyapa; Benfer, Katherine A; Bell, Kristie L

2016-10-01

To describe the longitudinal relationship between height-for-age z score (HZ), growth velocity z score, energy intake, habitual physical activity (HPA), and sedentary time across Gross Motor Function Classification System (GMFCS) levels I to V in preschoolers with cerebral palsy (CP). Children with CP (n = 175 [109 (62.2%) boys]; mean recruitment age 2 years, 10 months [SD 11 months]; GMFCS I = 83 [47.2%], II = 21 [11.9%], III = 28 [15.9%], IV = 19 [10.8%], V = 25 [14.2%]) were assessed 440 times between the age of 18 months and 5 years. Height/length ratio was measured or estimated via knee height. Population-based standards were used to calculate HZ and growth velocity z-score by age and sex categories. Feeding method (oral or tube) and gestational age at birth (GA) were collected from parents. Three-day ActiGraph and food diary data were used to measure HPA/sedentary time ratio and energy intake, respectively. Oropharyngeal dysphagia was rated with the Dysphagia Disorder Survey (part 2, Pediatric). Analysis was undertaken with mixed-effects regression models. For GMFCS level I, height and growth velocity did not differ from population-level growth standards. Children in levels II to V were significantly shorter, and those in levels III to V grew significantly more slowly than those in level I. There was a significant positive association between HZ and GA at all GMFCS levels. Energy intake, HPA, sedentary time, Dysphagia Disorder Survey score, and feeding method were not significantly associated with either height or growth velocity once GMFCS level was accounted for. Functional status and GA should be considered when assessing the growth of a child with CP. Research into interventions aimed at increasing active movement in GMFCS levels III to V and their efficacy in improving growth and health outcomes is warranted. Copyright © 2016 by the American Academy of Pediatrics.

Thermodynamic constraint on the depth of the global tropospheric circulation.

PubMed

Thompson, David W J; Bony, Sandrine; Li, Ying

2017-08-01

The troposphere is the region of the atmosphere characterized by low static stability, vigorous diabatic mixing, and widespread condensational heating in clouds. Previous research has argued that in the tropics, the upper bound on tropospheric mixing and clouds is constrained by the rapid decrease with height of the saturation water vapor pressure and hence radiative cooling by water vapor in clear-sky regions. Here the authors contend that the same basic physics play a key role in constraining the vertical structure of tropospheric mixing, tropopause temperature, and cloud-top temperature throughout the globe. It is argued that radiative cooling by water vapor plays an important role in governing the depth and amplitude of large-scale dynamics at extratropical latitudes.

Cumulus cloud venting of mixed layer ozone

NASA Technical Reports Server (NTRS)

Ching, J. K. S.; Shipley, S. T.; Browell, E. V.; Brewer, D. A.

1985-01-01

Observations are presented which substantiate the hypothesis that significant vertical exchange of ozone and aerosols occurs between the mixed layer and the free troposphere during cumulus cloud convective activity. The experiments utilized the airborne Ultra-Violet Differential Absorption Lidar (UV-DIAL) system. This system provides simultaneous range resolved ozone concentration and aerosol backscatter profiles with high spatial resolution. Evening transects were obtained in the downwind area where the air mass had been advected. Space-height analyses for the evening flight show the cloud debris as patterns of ozone typically in excess of the ambient free tropospheric background. This ozone excess was approximately the value of the concentration difference between the mixed layer and free troposphere determined from independent vertical soundings made by another aircraft in the afternoon.

Hydraulic architecture and photosynthetic capacity as constraints on release from suppression in Douglas-fir and western hemlock.

PubMed

Renninger, Heidi J; Meinzer, Frederick C; Gartner, Barbara L

2007-01-01

We compared hydraulic architecture, photosynthesis and growth in Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), a shade-intolerant species, and western hemlock (Tsuga heterophylla (Raf.) Sarg.), a shade-tolerant species, to study the temporal pattern of release from suppressive shade. In particular, we sought to determine whether hydraulic architecture or photosynthetic capacity is most important in constraining release. The study was conducted at two sites with mixed stands of 10- to 20-year-old Douglas-fir and western hemlock. At one site, the stand had been thinned allowing release of the understory trees, whereas at the other site, the stand remained unthinned. Douglas-fir had lower height growth (from 1998-2003) and lower relative height growth (height growth from 1998 to 2003/height in 1998) than western hemlock. However, relative height growth of released versus suppressed trees was higher in Douglas-fir (130%) than in western hemlock (65%), indicating that, although absolute height growth was less, Douglas-fir did release from suppression. Release seemed to be constrained initially by a limited photosynthetic capacity in both species. Five years after release, Douglas-fir trees had 14 times the leaf area and 1.5 times the leaf nitrogen concentration (N (area)) of suppressed trees. Needles of released western hemlock trees had about twice the maximum assimilation rate (A (max)) at ambient [CO(2)] as needles of suppressed trees and exhibited no photoinhibition at the highest irradiances. After release, trees increased in leaf area, leaf N concentration and overall photosynthetic capacity. Subsequently, hydraulic architecture appeared to constrain release in Douglas-fir and, to a lesser extent, in western hemlock. Released trees had significantly less negative foliar delta(13)C values than suppressed trees and showed a positive relationship between leaf area:sapwood area ratio (A (L)/A (S)) and delta(13)C, suggesting that trees with more leaf area for a given sapwood area experienced a stomatal limitation on carbon gain. Nonetheless, these changes had no significant effects on leaf specific conductivities of suppressed versus released trees of either species, but leaf specific root conductance was significantly lower in released Douglas-fir.

Association between Adult Height and Risk of Colorectal, Lung, and Prostate Cancer: Results from Meta-analyses of Prospective Studies and Mendelian Randomization Analyses.

PubMed

Khankari, Nikhil K; Shu, Xiao-Ou; Wen, Wanqing; Kraft, Peter; Lindström, Sara; Peters, Ulrike; Schildkraut, Joellen; Schumacher, Fredrick; Bofetta, Paolo; Risch, Angela; Bickeböller, Heike; Amos, Christopher I; Easton, Douglas; Eeles, Rosalind A; Gruber, Stephen B; Haiman, Christopher A; Hunter, David J; Chanock, Stephen J; Pierce, Brandon L; Zheng, Wei

2016-09-01

Observational studies examining associations between adult height and risk of colorectal, prostate, and lung cancers have generated mixed results. We conducted meta-analyses using data from prospective cohort studies and further carried out Mendelian randomization analyses, using height-associated genetic variants identified in a genome-wide association study (GWAS), to evaluate the association of adult height with these cancers. A systematic review of prospective studies was conducted using the PubMed, Embase, and Web of Science databases. Using meta-analyses, results obtained from 62 studies were summarized for the association of a 10-cm increase in height with cancer risk. Mendelian randomization analyses were conducted using summary statistics obtained for 423 genetic variants identified from a recent GWAS of adult height and from a cancer genetics consortium study of multiple cancers that included 47,800 cases and 81,353 controls. For a 10-cm increase in height, the summary relative risks derived from the meta-analyses of prospective studies were 1.12 (95% CI 1.10, 1.15), 1.07 (95% CI 1.05, 1.10), and 1.06 (95% CI 1.02, 1.11) for colorectal, prostate, and lung cancers, respectively. Mendelian randomization analyses showed increased risks of colorectal (odds ratio [OR] = 1.58, 95% CI 1.14, 2.18) and lung cancer (OR = 1.10, 95% CI 1.00, 1.22) associated with each 10-cm increase in genetically predicted height. No association was observed for prostate cancer (OR = 1.03, 95% CI 0.92, 1.15). Our meta-analysis was limited to published studies. The sample size for the Mendelian randomization analysis of colorectal cancer was relatively small, thus affecting the precision of the point estimate. Our study provides evidence for a potential causal association of adult height with the risk of colorectal and lung cancers and suggests that certain genetic factors and biological pathways affecting adult height may also affect the risk of these cancers.

Effect of different professions' clothing on children's height perception.

PubMed

Rashidi, Mahmoud; Keshtkaran, Katayoun; Zabihidan, Sahar; Hosseinchari, Masoud; Pazhoohi, Farid

2012-11-01

Height is a biological factor that can affect how others perceive and behave toward an individual. Height is a biological factor that can affect how others perceive and behave toward an individual. Clothing, as a non-biological factor, can affect these perceptions of height. In this study weClothing, as a non-biological factor, can affect these perceptions of height. In this study we investigated the effect of different professions' clothing on children's perceptions of height. One investigated the effect of different professions' clothing on children's perceptions of height. One hundred and eighty primary school students participated in this study and estimated the height of an actor in the clothing of four different professions which differed in terms of prestige. The results of study showed that the difference between the perceived and actual height was larger when participants estimated the height of socially esteemed professions. Also there was no difference between girls' and boys' estimation of different professions' height. The implications of these findings are discussed.

Air quality climate in the Columbia River Basin.

Treesearch

Sue A. Ferguson

1998-01-01

Aspects of climate that influence air quality in the Columbia River basin of the Northwestern United States are described. A few, relatively simple, analytical tools were developed to show the spatial and temporal patterns of mean-monthly mixing heights, precipitation scavenging, upper level and surface trajectory winds, and drought that inhibit pollution uptake. Also...

Growth curves and the international standard: How children's growth reflects challenging conditions in rural Timor-Leste.

PubMed

Spencer, Phoebe R; Sanders, Katherine A; Judge, Debra S

2018-02-01

Population-specific growth references are important in understanding local growth variation, especially in developing countries where child growth is poor and the need for effective health interventions is high. In this article, we use mixed longitudinal data to calculate the first growth curves for rural East Timorese children to identify where, during development, deviation from the international standards occurs. Over an eight-year period, 1,245 children from two ecologically distinct rural areas of Timor-Leste were measured a total of 4,904 times. We compared growth to the World Health Organization (WHO) standards using z-scores, and modeled height and weight velocity using the SuperImposition by Translation And Rotation (SITAR) method. Using the Generalized Additive Model for Location, Scale and Shape (GAMLSS) method, we created the first growth curves for rural Timorese children for height, weight and body mass index (BMI). Relative to the WHO standards, children show early-life growth faltering, and stunting throughout childhood and adolescence. The median height and weight for this population tracks below the WHO fifth centile. Males have poorer growth than females in both z-BMI (p = .001) and z-height-for-age (p = .018) and, unlike females, continue to grow into adulthood. This is the most comprehensive investigation to date of rural Timorese children's growth, and the growth curves created may potentially be used to identify future secular trends in growth as the country develops. We show significant deviation from the international standard that becomes most pronounced at adolescence, similar to the growth of other Asian populations. Males and females show different growth responses to challenging conditions in this population. © 2017 Wiley Periodicals, Inc.

Peak Weight and Height Velocity to Age 36 Months and Asthma Development: The Norwegian Mother and Child Cohort Study

PubMed Central

Magnus, Maria C.; Stigum, Hein; Håberg, Siri E.; Nafstad, Per; London, Stephanie J.; Nystad, Wenche

2015-01-01

Background The immediate postnatal period is the period of the fastest growth in the entire life span and a critical period for lung development. Therefore, it is interesting to examine the association between growth during this period and childhood respiratory disorders. Methods We examined the association of peak weight and height velocity to age 36 months with maternal report of current asthma at 36 months (n = 50,311), recurrent lower respiratory tract infections (LRTIs) by 36 months (n = 47,905) and current asthma at 7 years (n = 24,827) in the Norwegian Mother and Child Cohort Study. Peak weight and height velocity was calculated using the Reed1 model through multilevel mixed-effects linear regression. Multivariable log-binomial regression was used to calculate adjusted relative risks (adj.RR) and 95% confidence intervals (CI). We also conducted a sibling pair analysis using conditional logistic regression. Results Peak weight velocity was positively associated with current asthma at 36 months [adj.RR 1.22 (95%CI: 1.18, 1.26) per standard deviation (SD) increase], recurrent LRTIs by 36 months [adj.RR 1.14 (1.10, 1.19) per SD increase] and current asthma at 7 years [adj.RR 1.13 (95%CI: 1.07, 1.19) per SD increase]. Peak height velocity was not associated with any of the respiratory disorders. The positive association of peak weight velocity and asthma at 36 months remained in the sibling pair analysis. Conclusions Higher peak weight velocity, achieved during the immediate postnatal period, increased the risk of respiratory disorders. This might be explained by an influence on neonatal lung development, shared genetic/epigenetic mechanisms and/or environmental factors. PMID:25635872

Analyzing the Impact of Different Pcv Calibration Models on Height Determination Using Gps/Glonass Observations from Asg-Eupos Network

NASA Astrophysics Data System (ADS)

Dawidowicz, Karol

2014-12-01

The integration of GPS with GLONASS is very important in satellite-based positioning because it can clearly improve reliability and availability. However, unlike GPS, GLONASS satellites transmit signals at different frequencies. This results in significant difficulties in modeling and ambiguity resolution for integrated GNSS positioning. There are also some difficulties related to the antenna Phase Center Variations (PCV) problem because, as is well known, the PCV is dependent on the received signal frequency dependent. Thus, processing simultaneous observations from different positioning systems, e.g. GPS and GLONASS, we can expect complications resulting from the different structure of signals and differences in satellite constellations. The ASG-EUPOS multifunctional system for precise satellite positioning is a part of the EUPOS project involving countries of Central and Eastern Europe. The number of its users is increasing rapidly. Currently 31 of 101 reference stations are equipped with GPS/GLONASS receivers and the number is still increasing. The aim of this paper is to study the height solution differences caused by using different PCV calibration models in integrated GPS/GLONASS observation processing. Studies were conducted based on the datasets from the ASG-EUPOS network. Since the study was intended to evaluate the impact on height determination from the users' point of view, a so-called "commercial" software was chosen for post-processing. The analysis was done in a baseline mode: 3 days of GNSS data collected with three different receivers and antennas were used. For the purposes of research the daily observations were divided into different sessions with a session length of one hour. The results show that switching between relative and absolute PCV models may cause an obvious effect on height determination. This issue is particularly important when mixed GPS/GLONASS observations are post-processed.

Dual polarization micropulse lidar observations of the diurnal evolution of atmospheric boundary layer over a tropical coastal station

NASA Astrophysics Data System (ADS)

Rajeev, K.; Mishra, Manoj K.; Sunilkumar, S. V.; Sijikumar, S.

2016-05-01

High-resolution dual polarized micropulse lidar (MPL) observations have been used to investigate the diurnal evolution of atmospheric boundary layer (ABL) during winter (2008-2011) over Thiruvananthapuram (8.5°N, 77°E), a tropical coastal station located at southwest Peninsular India, adjoining the Arabian Sea. The lidar observations are compared with the boundary layer characteristics derived from concurrent balloon-borne radiosonde observations. This study shows that the mixed layer height over this coastal station generally increases from <300 m in the morning to 1500 m by the afternoon. Growth rate of the mixed layer height is rapid ( 350 m/hr) during 09-11 IST and slows down with time to <150 m/hr during 11-14 IST and <90 m/hr during 14-16 IST. Thermal internal boundary layer during the afternoon, caused by sea breeze circulation, extends up to 500 m altitude and is characterized by highly spherical aerosols, while a distinctly non-spherical aerosol layer appear above this altitude, in the return flow arising from the landmass.

Dryline on 22 May 2002 During IHOP: Convective Scale Measurements at the Profiling Site

NASA Technical Reports Server (NTRS)

Demoz, Belay; Flamant, Cyrille; Miller, David; Evans, Keith; Fabry, Federic; DiGirolamo, Paolo; Whiteman, David; Geerts, Bart; Weckwerth, Tammy; Brown, William

2004-01-01

A unique set of measurements of wind, water vapor mixing ratio and boundary layer height variability was observed during the first MOP dryline mission of 22 May 2002. Water vapor mixing ratio from the Scanning Raman Lidar (SRL), high-resolution profiles of aerosol backscatter from the HARLIE and wind profiles from the GLOW are combined with the vertical velocity derived from the NCAR/ISS/MAPR and the high-resolution FMCW radar to reveal the convective variability of the cumulus cloud-topped boundary layer. A combined analysis of the in-situ and remote sensing data from aircraft, radiosonde, lidars, and radars reveals moisture variability within boundary layer updraft and downdraft regions as well as characterizes the boundary layer height variability in the dry and moist sides of the dryline. The profiler site measurements will be tied to aircraft data to reveal the relative intensity and location of these updrafts to the dry line. This study provides unprecedented high temporal and spatial resolution measurements of wind, moisture and backscatter within a dryline and the associated convective boundary layer.

Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya.

PubMed

Lieberman, Daniel E; Castillo, Eric R; Otarola-Castillo, Erik; Sang, Meshack K; Sigei, Timothy K; Ojiambo, Robert; Okutoyi, Paul; Pitsiladis, Yannis

2015-01-01

Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces.

Effects of socioeconomic position and social mobility on linear growth from early childhood until adolescence.

PubMed

Muraro, Ana Paula; Souza, Rita Adriana Gomes de; Rodrigues, Paulo Rogério Melo; Ferreira, Márcia Gonçalves; Sichieri, Rosely

2017-01-01

To assess the effect of socioeconomic position (SEP) in childhood and social mobility on linear growth through adolescence in a population-based cohort. Children born in Cuiabá-MT, central-western Brazil, were evaluated during 1994 - 1999. They were first assessed during 1999 - 2000 (0 - 5 years) and again during 2009 - 2011 (10 - 17 years), and their height-for-age was evaluated during these two periods.Awealth index was used to classify the SEP of each child's family as low, medium, or high. Social mobility was categorized as upward mobility or no upward mobility. Linear mixed models were used. We evaluated 1,716 children (71.4% of baseline) after 10 years, and 60.6% of the families showed upward mobility, with a higher percentage among the lowest economic classes. A higher height-for-age was also observed among those from families with a high SEP both in childhood (low SEP= -0.35 z-score; high SEP= 0.15 z-score, p < 0.01) and adolescence (low SEP= -0.01 z-score; high SEP= 0.45 z-score, p < 0.01), whereas upward mobility did not affect their linear growth. Expressive social mobility was observed, but SEP in childhood and social mobility did not greatly influence linear growth through childhood in this central-western Brazilian cohort.

Do human parents face a quantity-quality tradeoff?: evidence from a Shuar community.

PubMed

Hagen, Edward H; Barrett, H Clark; Price, Michael E

2006-07-01

A number of evolutionary theories of human life history assume a quantity-quality tradeoff for offspring production: parents with fewer offspring can have higher biological fitness than those with more. Direct evidence for such a tradeoff, however, is mixed. We tested this assumption in a community of Ecuadorian Shuar hunter-horticulturalists, using child anthropometry as a proxy for fitness. We measured the impact of household consumer/producer (CP) ratio on height, weight, skinfold thicknesses, and arm and calf circumferences of 85 children and young adults. To control for possible "phenotypic" correlates that might mask the effect of CP ratio on anthropometry, we also measured household garden productivity, wealth, and social status. Regression models of the age-standardized variables indicated a significant negative impact of CP ratio on child growth and nutrition. The age-standardized height and weight of children in households with the largest CP ratio (10) were 1.38 and 1.44 standard deviations, respectively, below those of children in households with the smallest CP ratio (2). Surprisingly, garden productivity, wealth, and status had little to no effect on the fitness proxies. There was, however, an interesting and unexpected interaction between status and sex: for females, but not males, higher father status correlated significantly with higher values on the proxies.

Inverted Polarity Thunderstorms Linked with Elevated Cloud Base Height

NASA Astrophysics Data System (ADS)

Cummins, K. L.; Williams, E.

2016-12-01

The great majority of thunderstorms worldwide exhibit gross positive dipole structure, produce intracloud lightning that reduces this positive dipole (positive intracloud flashes), and produce negative cloud-to-ground lightning from the lower negative end of this dipole. During the STEPS experiment in 2000 much new evidence for thunderstorms (or cells within multi-cellular storms) with inverted polarity came to light, both from balloon soundings of electric field and from LMA analysis. Many of the storms with inverted polarity cells developed in eastern Colorado. Fleenor et al. (2009) followed up after STEPS to document a dominance of positive polarity CG lightning in many of these cases. In the present study, surface thermodynamic observations (temperature and dew point temperature) have been used to estimate the cloud base heights and temperatures at the time of the Fleenor et al. lightning observations. It was found that when more than 90% of the observed CG lightning polarity within a storm is negative, the cloud base heights were low (2000 m AGL or lower, and warmer, with T>10 C), and when more than 90% of the observed CG lightning within a storm was positive, the cloud base heights were high (3000 m AGL or higher, and colder, with T< 2 C). Multi-cellular storms or temporally-evolving storms with mixed polarity were generally associated with intermediate cloud base heights. These findings on inverted polarity thunderstorms are remarkably consistent with results in other parts of the world where strong instability prevails in the presence of high cloud base height: the plateau regions of China (Liu et al., 1989; Qie et al., 2005), and in pre-monsoon India (Pawar et al., 2016), particularly when mixed polarity cases are excluded. Calculations of adiabatic cloud water content for lifting from near 0 oC cast some doubt on earlier speculation (Williams et al., 2005) that the graupel particles in these inverted polarity storms attain a wet growth condition, and so exhibit positive charging following laboratory experiments. This mechanism will be contrasted with the possibility of positive graupel charging associated with small droplet sizes (consistent with high cloud base) or through involvement of ice nuclei (Pawar et al., 2016) in the semiarid environments that frequently accompany inverted polarity storms.

A Markov decision process for managing habitat for Florida scrub-jays

USGS Publications Warehouse

Johnson, Fred A.; Breininger, David R.; Duncan, Brean W.; Nichols, James D.; Runge, Michael C.; Williams, B. Ken

2011-01-01

Florida scrub-jays Aphelocoma coerulescens are listed as threatened under the Endangered Species Act due to loss and degradation of scrub habitat. This study concerned the development of an optimal strategy for the restoration and management of scrub habitat at Merritt Island National Wildlife Refuge, which contains one of the few remaining large populations of scrub-jays in Florida. There are documented differences in the reproductive and survival rates of scrubjays among discrete classes of scrub height (<120 cm or "short"; 120-170 cm or "optimal"; .170 cm or "tall"; and a combination of tall and optimal or "mixed"), and our objective was to calculate a state-dependent management strategy that would maximize the long-term growth rate of the resident scrub-jay population. We used aerial imagery with multistate Markov models to estimate annual transition probabilities among the four scrub-height classes under three possible management actions: scrub restoration (mechanical cutting followed by burning), a prescribed burn, or no intervention. A strategy prescribing the optimal management action for management units exhibiting different proportions of scrub-height classes was derived using dynamic programming. Scrub restoration was the optimal management action only in units dominated by mixed and tall scrub, and burning tended to be the optimal action for intermediate levels of short scrub. The optimal action was to do nothing when the amount of short scrub was greater than 30%, because short scrub mostly transitions to optimal height scrub (i.e., that state with the highest demographic success of scrub-jays) in the absence of intervention. Monte Carlo simulation of the optimal policy suggested that some form of management would be required every year. We note, however, that estimates of scrub-height transition probabilities were subject to several sources of uncertainty, and so we explored the management implications of alternative sets of transition probabilities. Generally, our analysis demonstrated the difficulty of managing for a species that requires midsuccessional habitat, and suggests that innovative management tools may be needed to help ensure the persistence of scrub-jays at Merritt Island National Wildlife Refuge. The development of a tailored monitoring program as a component of adaptive management could help reduce uncertainty about controlled and uncontrolled variation in transition probabilities of scrub-height and thus lead to improved decision making.

Nitrogen deposition outweighs climatic variability in driving annual growth rate of canopy beech trees: Evidence from long-term growth reconstruction across a geographic gradient.

PubMed

Gentilesca, Tiziana; Rita, Angelo; Brunetti, Michele; Giammarchi, Francesco; Leonardi, Stefano; Magnani, Federico; van Noije, Twan; Tonon, Giustino; Borghetti, Marco

2018-07-01

In this study, we investigated the role of climatic variability and atmospheric nitrogen deposition in driving long-term tree growth in canopy beech trees along a geographic gradient in the montane belt of the Italian peninsula, from the Alps to the southern Apennines. We sampled dominant trees at different developmental stages (from young to mature tree cohorts, with tree ages spanning from 35 to 160 years) and used stem analysis to infer historic reconstruction of tree volume and dominant height. Annual growth volume (G V ) and height (G H ) variability were related to annual variability in model simulated atmospheric nitrogen deposition and site-specific climatic variables, (i.e. mean annual temperature, total annual precipitation, mean growing period temperature, total growing period precipitation, and standard precipitation evapotranspiration index) and atmospheric CO 2 concentration, including tree cambial age among growth predictors. Generalized additive models (GAM), linear mixed-effects models (LMM), and Bayesian regression models (BRM) were independently employed to assess explanatory variables. The main results from our study were as follows: (i) tree age was the main explanatory variable for long-term growth variability; (ii) GAM, LMM, and BRM results consistently indicated climatic variables and CO 2 effects on G V and G H were weak, therefore evidence of recent climatic variability influence on beech annual growth rates was limited in the montane belt of the Italian peninsula; (iii) instead, significant positive nitrogen deposition (N dep ) effects were repeatedly observed in G V and G H ; the positive effects of N dep on canopy height growth rates, which tended to level off at N dep values greater than approximately 1.0 g m -2  y -1 , were interpreted as positive impacts on forest stand above-ground net productivity at the selected study sites. © 2018 John Wiley & Sons Ltd.

Effects of two litter amendments on air NH3 levels in broiler closed-houses

PubMed Central

Atapattu, N. S. B. M; Lakmal, L. G. E.; Perera, P. W. A.

2017-01-01

Objective High NH3 emissions from poultry houses are reported to have negative impacts on health, welfare and safety of birds and humans, and on the environment. Objective of the present study was to determine the effects of two litter amendments on the NH3 levels in broiler closed houses under hot-humid conditions. Methods Giving a completely randomize design, nine closed houses, each housed 32,500 birds on paddy husk litter, were randomly allocated into two treatment (Mizuho; a bacterial culture mix and Rydall OE; an enzymatic biocatalyst) and control groups. NH3 levels were determined thrice a day (0600, 1200, and 1800 h), at three heights from the litter surface (30, 90, and 150 cm), at 20 predetermined locations of a house, from day 1 to 41. Results Rydall significantly reduced the NH3 level compared to control and Mizuho. NH3 levels at 30 cm were significantly higher than that of 90 and 150 cm. The NH3 levels at 30 cm height were higher than 25 ppm level from day 9, 11, and 13 in Mizuho, control, and Rydall groups, respectively to day 41. NH3 levels at 150 cm height were higher than maximum threshold limit of 50 ppm for human exposure from day 12, 14, and 15 in Mizuho, control, and Rydall groups, respectively to day 33. Being significantly different among each other, the NH3 level was highest and lowest at 0600 and 1800 h. Litter amendments had no significant effects on growth performance. Rydall significantly increased the litter N content on day 24. Conclusion It was concluded that the NH3 levels of closed house broiler production facilities under tropical condition are so high that both birds and workers are exposed to above recommended levels during many days of the growing period. Compared to microbial culture, the enzymatic biocatalyst was found to be more effective in reducing NH3 level. PMID:28423888

A height-for-age growth reference for children with achondroplasia: Expanded applications and comparison with original reference data.

PubMed

Hoover-Fong, Julie; McGready, John; Schulze, Kerry; Alade, Adekemi Yewande; Scott, Charles I

2017-05-01

The height-for-age (HA) reference currently used for children with achondroplasia is not adaptable for electronic records or calculation of HA Z-scores. We report new HA curves and tables of mean and standard deviation (SD) HA, for calculating Z-scores, from birth-16 years in achondroplasia. Mixed longitudinal data were abstracted from medical records of achondroplasia patients from a single clinical practice (CIS, 1967-2004). Gender-specific height percentiles (5, 25, 50, 75, 95th) were estimated across the age continuum, using a 2 month window per time point smoothed by a quadratic smoothing algorithm. HA curves were constructed for 0-36 months and 2-16 years to optimize resolution for younger children. Mean monthly height (SD) was tabulated. These novel HA curves were compared to reference data currently in use for children with achondroplasia. 293 subjects (162 male/131 female) contributed 1,005 and 932 height measures, with greater data paucity with age. Mean HA tracked with original achondroplasia norms, particularly through mid-childhood (2-9 years), but with no evidence of a pubertal growth spurt. Standard deviation of height at each month interval increased from birth through 16 years. Birth length was lower in achondroplasia than average stature and, as expected, height deficits increased with age. A new HA reference is available for longitudinal growth assessment in achondroplasia, taking advantage of statistical modeling techniques and allowing for Z-score calculations. This is an important contribution to clinical care and research endeavors for the achondroplasia population. © 2017 Wiley Periodicals, Inc.

[A site index model for Larix principis-rupprechtii plantation in Saihanba, north China].

PubMed

Wang, Dong-zhi; Zhang, Dong-yan; Jiang, Feng-ling; Bai, Ye; Zhang, Zhi-dong; Huang, Xuan-rui

2015-11-01

It is often difficult to estimate site indices for different types of plantation by using an ordinary site index model. The objective of this paper was to establish a site index model for plantations in varied site conditions, and assess the site qualities. In this study, a nonlinear mixed site index model was constructed based on data from the second class forest resources inventory and 173 temporary sample plots. The results showed that the main limiting factors for height growth of Larix principis-rupprechtii were elevation, slope, soil thickness and soil type. A linear regression model was constructed for the main constraining site factors and dominant tree height, with the coefficient of determination being 0.912, and the baseline age of Larix principis-rupprechtii determined as 20 years. The nonlinear mixed site index model parameters for the main site types were estimated (R2 > 0.85, the error between the predicted value and the actual value was in the range of -0.43 to 0.45, with an average root mean squared error (RMSE) in the range of 0.907 to 1.148). The estimation error between the predicted value and the actual value of dominant tree height for the main site types was in the confidence interval of [-0.95, 0.95]. The site quality of the high altitude-shady-sandy loam-medium soil layer was the highest and that of low altitude-sunny-sandy loam-medium soil layer was the lowest, while the other two sites were moderate.

Nitrogen oxides and ozone fluxes from an oilseed-rape management cycle: the influence of cattle slurry application

NASA Astrophysics Data System (ADS)

Vuolo, Raffaella M.; Loubet, Benjamin; Mascher, Nicolas; Gueudet, Jean-Christophe; Durand, Brigitte; Laville, Patricia; Zurfluh, Olivier; Ciuraru, Raluca; Stella, Patrick; Trebs, Ivonne

2017-05-01

This study reports NO, NO2 and O3 mixing ratios and flux measurements using the eddy covariance method during a 7-month period over an oilseed-rape field, spanning an organic and a mineral fertilisation event. Cumulated NO emissions during the whole period were in agreement with previous studies and showed quite low emissions of 0.26 kg N ha-1 with an emission factor of 0.27 %, estimated as the ratio between total N emitted in the form of NO and total N input. The NO emissions were higher following organic fertilisation in August due to conditions favouring nitrification (soil water content around 20 % and high temperatures), while mineral fertilisation in February did not result in high emissions. The ozone deposition velocity increased significantly after organic fertilisation. The analysis of the chemical and turbulent transport times showed that reactions between NO, NO2 and O3 below the measurement height occurred constantly throughout the 7-month period. Following organic fertilisation, the NO ground fluxes were 30 % larger than the NO fluxes at the measurement height (3.2 m), while the NO2 fluxes switched from deposition to emission during certain periods, being negative at the surface and positive at the measurement height. This phenomenon of apparent NO2 emissions appears to be significant during strong NO emissions and high O3 ambient mixing ratios, even on a bare soil during August.

Mesoporous mixed metal oxides derived from P123-templated Mg-Al layered double hydroxides

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

Wang Jun, E-mail: zhqw1888@sohu.co; College of Chemical Engineering, Harbin Institute of Technology, Harbin 150001; Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, 150001

2010-11-15

We report the preparation of mesoporous mixed metal oxides (MMOs) through a soft template method. Different amounts of P123 were used as structure directing agent to synthesize P123-templated Mg-Al layered double hydroxides (LDHs). After calcination of as-synthesized LDHs at 500 {sup o}C, the ordered mesopores were obtained by removal of P123. The mesoporous Mg-Al MMOs fabricated by using 2 wt% P123 exhibited a high specific surface area of 108.1 m{sup 2}/g, and wide distribution of pore size (2-18 nm). An investigation of the 'memory effect' of the mesoporous MMOs revealed that they were successfully reconstructed to ibuprofen intercalated LDHs havingmore » different gallery heights, which indicated different intercalation capacities. Due to their mesoporosity these unique MMOs have particular potential as drug or catalyst carriers. - Graphical abstract: Ordered mesoporous Mg-Al MMOs can be obtained through the calcination of P123-templated Mg-Al-CO{sub 3} LDHs. The pore diameter is 2.2 nm. At the presence of ibuprofen, the Mg-Al MMOs can recover to Mg-Al-IBU LDHs, based on its 'remember effect'. Display Omitted« less

A Model for Interpreting High-Tower CO2 Concentration Records for the Surface Carbon Balance Information

NASA Astrophysics Data System (ADS)

Chen, B.; Chen, J. M.; Higuchi, K.; Chan, D.; Shashkov, A.

2002-05-01

Atmospheric CO2 concentration measurements have been made by scientists of Meteorological Service of Canada on a 40 m tower for the last 10 years at 15 minute intervals over a mostly intact boreal forest near Fraserdale (50N, 81W), Ontario, Canada. The long time records of CO2 as well as basic meteorological variables provide a unique opportunity to investigate any potential changes in the ecosystem in terms of carbon balance. A model is needed to decipher the carbon cycle signals from the diurnal and seasonal variation patterns in the CO2 record. For this purpose, the Boreal Ecosystem Productivity Simulator (BEPS) is expanded to include a one-dimensional CO2 vertical transfer model involving the interaction between plant canopies and the atmosphere in the surface layer and the diurnal dynamics of the mixed layer. An analytical solution of the scalar transfer equation within the surface layer is found using an assumption that the diurnal oscillation of CO2 concentration at a given height is sinusoidal, which is suitable for the investigation of the changes in diurnal variation pattern over the 10 year period. The complex interactions between the daily cycle of the atmosphere and vegetation CO2 exchange and the daily evolution of mixed layer entrainment of CO2 determines the CO2 variation pattern at a given height. The expanded BEPS can simulate within ñ2 ppm the hourly CO2 records at the 40 m measurement height. The annual totals of gross primary productivity (GPP), net primary productivity (NPP) and net ecosystem productivity (NEP), summed up from the hourly results, agree within 5% of previous estimates of BEPS at daily steps, indicating the internal consistency of the hourly model. The model is therefore ready for exploring changes in the CO2 record as affected by changes in the forest ecosystems upwind of the tower. Preliminary results indicate that the diurnal variation amplitude of CO2 has increased by 10-20% over the 10 years period, and this change can largely be attributed to enhanced growth of the forest. The uncertainties are large because the record is short relative to boreal carbon residence time. There is also a possibility of long-term changes in the mixed layer dynamics which affect the diurnal variation pattern at the measurement height.

Observations of the Evolution of Turbulent Dissipation within the Ocean Surface Boundary Layer: an OSMOSIS study

NASA Astrophysics Data System (ADS)

Lucas, N. S.; Allen, J.; Belcher, S. E.; Boyd, T.; Brannigan, L.; Inall, M.; Palmer, M.; Polton, J.; Rippeth, T. P.

2016-02-01

This study presents a new 9.5 day dataset showing the evolution of the Ocean Surface Boundary Layer (OSBL) and dissipation of turbulence kinetic energy (TKE), carried out as part of OSMOSIS[i], at a location in the North East Atlantic Ocean in September 2012. The TKE dissipation measurements were made using three methods; (i) repeated profiling between 100m and the surface by an Ocean Microstructure glider, (ii) three series of profiles made using a loosely tethered velocity microstructure glider and (iii) a moored pulse-pulse coherent high frequency ADCP. Supporting measurements show the evolution of the water column structure, including surface wave measurements from a TRIAXYS wave buoy. This data shows two distinct regimes; the first, spanning 4 days with relatively low winds, displays a distinct diurnal cycle with the deepening of the active mixing layer during the night which shoaled during the day. The second spanned a significant storm, (with maximum winds speeds reaching 20 m s-1 and significant wave heights reaching 6 m), during which, rather than a deepening of the mixed layer as predicted by classical theory, the primary effect was a broadening of the transition layer, similar to that found by Dohan and Davies (2011). During the storm, significant dissipation was observed throughout the surface mixed layer and into the transition layer, driving fluxes of heat downwards through the base of the surface mixed layer. [i] Ocean Surface Mixing and Submesoscale Interaction Study Dohan, K. & Davis, R.E., 2011. Mixing in the Transition Layer during Two Storm Events. Journal of Physical Oceanography. 41 (1). pp. 42-66.

The Characterization of Atmospheric Boundary Layer Depth and Turbulence in a Mixed Rural and Urban Convective Environment

NASA Astrophysics Data System (ADS)

Hicks, Micheal M.

A comprehensive analysis of surface-atmosphere flux exchanges over a mixed rural and urban convective environment is conducted at Howard University Beltsville, MD Research Campus. This heterogeneous site consists of rural, suburban and industrial surface covers to its south, east and west, within a 2 km radius of a flux sensor. The eddy covariance method is utilized to estimate surface-atmosphere flux exchanges of momentum, heat and moisture. The attributes of these surface flux exchanges are contrasted to those of classical homogeneous sites and assessed for accuracy, to evaluate the following: (I) their similarity to conventional convective boundary layer (CBL) processes and (II) their representativeness of the surrounding environment's turbulent properties. Both evaluations are performed as a function of upwind surface conditions. In particular, the flux estimates' obedience to spectrum power laws and similarity theory relationships is used for performing the first evaluation, and their ability to close the surface energy balance and accurately model CBL heights is used for the latter. An algorithm that estimates atmospheric boundary layer heights from observed lidar extinction backscatter was developed, tested and applied in this study. The derived lidar based CBL heights compared well with those derived from balloon borne soundings, with an overall Pearson correlation coefficient and standard deviation of 0.85 and 223 m, respectively. This algorithm assisted in the evaluation of the response of CBL processes to surface heterogeneity, by deriving high temporal CBL heights and using them as independent references of the surrounding area averaged sensible heat fluxes. This study found that the heterogeneous site under evaluation was rougher than classical homogeneous sites, with slower dissipation rates of turbulent kinetic energy. Flux measurements downwind of the industrial complexes exhibited enhanced efficiency in surface-atmosphere momentum, heat, and moisture transport relative to their similarity theory predictions. In addition, these enhanced heat flux estimates ingested into the CBL slab model overestimated observed CBL heights. More spatial flux observations are needed to better understand the role that the industrial complexes are playing in enhancing the efficiency of turbulent processes, which may have important implications on the role humans are assuming in regional climate change.

Analysis of mixing-layer height retrieval methods using backscatter lidar returns and microwave-radiometer temperature observations in the context of synergy

NASA Astrophysics Data System (ADS)

Saeed, Umar; Rocadenbosch, Francesc

2017-04-01

Mixing Layer Height (MLH) is an important parameter in many different atmospheric and meteorological applications. However, there does not exist a single instrument or method which provides accurate and physically consistent estimates of MLH. Instead, there are several methods for MLH estimation based on the measurements of different atmospheric tracers using different instruments [1, 2]. In this work, MLH retrieval methods using backscattered lidar signals and Microwave Radiometer (MWR)-retrieved potential-temperature profiles are compared in terms of their associated uncertainties. The Extended Kalman Filter (EKF) is used for MLH retrieval from backscattered lidar signals [3] and parcel method [4] is used for MLH retrieval from MWR-retrieved potential-temperature profiles. Measurement and retrieval errors are revisited and incorporated into the MLH estimation methods used. Uncertainties on MLH estimates from the two methods are compared along with a combined MLH-retrieval discussion case. The uncertainty analysis is validated using long-term lidar and MWR measurement data, under different atmospheric conditions, from the HD(CP)2 Observational Prototype Experiment (HOPE) campaign at Jülich, Germany [5]. MLH estimates from a Doppler wind lidar and radiosondes are used as reference. This work has received funding from the European Union Seventh Framework Programme, FP7 People, ITN Marie Curie Actions Programme (2012-2016) in the frame of ITaRS project (GA 289923), H2020 programme under ACTRIS-2 project (GA 654109), the Spanish Ministry of Economy and Competitiveness - European Regional Development Funds under TEC2015-63832-P project, and from the Generalitat de Catalunya (Grup de Recerca Consolidat) 2014-SGR-583. [1] S. Emeis, Surface-based Remote Sensing of the Atmospheric Boundary Layer. 978-90-481-9339-4, Springer, 2010. [2] P. Seibert, F. Beyrich, S.-E. Gryning, S. Joffre, A. Rasmussen, and P. Tercier, "Review and intercomparison of operational methods for the determination of the mixing height," Atmospheric Environment, vol. 34, pp. 1352-2310, 2000. [3] D. Lange, J. Tiana-Alsina, U. Saeed, S. Tomás, and F. Rocadenbosch, "Atmospheric-boundary-layer height monitoring using a Kalman filter and backscatter lidar returns," IEEE Transactions on Geoscience and Remote Sensing, vol. 52, no. 8, pp. 4717-4728, 2014. [4] G. Holzworth, "Estimates of mean maximum mixing depths in the contiguous United States," Monthly Weather Review, vol. 92, pp. 235-242, 1964. [5] U. Löhnert, J. H. Schween, C. Acquistapace, K. Ebell, M. Maahn, M. Barrera-Verdejo, A. Hirsikko, B. Bohn, A. Knaps, E. O'Connor, C. Simmer, A. Wahner, and S. Crewell, "JOYCE: Jülich Observatory for Cloud Evolution," Bull. Amer. Meteor. Soc., vol. 96, no. 7, pp. 1157-1174, 2015.

Effects of anthropogenic heat due to air-conditioning systems on an extreme high temperature event in Hong Kong

NASA Astrophysics Data System (ADS)

Wang, Y.; Li, Y.; Di Sabatino, S.; Martilli, A.; Chan, P. W.

2018-03-01

Anthropogenic heat flux is the heat generated by human activities in the urban canopy layer, which is considered the main contributor to the urban heat island (UHI). The UHI can in turn increase the use and energy consumption of air-conditioning systems. In this study, two effective methods for water-cooling air-conditioning systems in non-domestic areas, including the direct cooling system and central piped cooling towers (CPCTs), are physically based, parameterized, and implemented in a weather research and forecasting model at the city scale of Hong Kong. An extreme high temperature event (June 23-28, 2016) in the urban areas was examined, and we assessed the effects on the surface thermal environment, the interaction of sea-land breeze circulation and urban heat island circulation, boundary layer dynamics, and a possible reduction of energy consumption. The results showed that both water-cooled air-conditioning systems could reduce the 2 m air temperature by around 0.5 °C-0.8 °C during the daytime, and around 1.5 °C around 7:00-8:00 pm when the planetary boundary layer (PBL) height was confined to a few hundred meters. The CPCT contributed around 80%-90% latent heat flux and significantly increased the water vapor mixing ratio in the atmosphere by around 0.29 g kg-1 on average. The implementation of the two alternative air-conditioning systems could modify the heat and momentum of turbulence, which inhibited the evolution of the PBL height (a reduction of 100-150 m), reduced the vertical mixing, presented lower horizontal wind speed and buoyant production of turbulent kinetic energy, and reduced the strength of sea breeze and UHI circulation, which in turn affected the removal of air pollutants. Moreover, the two alternative air-conditioning systems could significantly reduce the energy consumption by around 30% during extreme high temperature events. The results of this study suggest potential UHI mitigation strategies and can be extended to other megacities to enable them to be more resilient to UHI effects.

Resistance Exercise Impacts Lean Muscle Mass in Women with Polycystic Ovary Syndrome.

PubMed

Kogure, Gislaine Satyko; Miranda-Furtado, Cristiana Libardi; Silva, Rafael Costa; Melo, Anderson Sanches; Ferriani, Rui Alberto; De Sá, Marcos Felipe Silva; Dos Reis, Rosana Maria

2016-04-01

This study investigated the effects of progressive resistance training (PRT) on lean muscle mass (LMM) in women with or without polycystic ovary syndrome (PCOS) and its effects on metabolic factors and concentrations of related steroid hormones. This was a nonrandomized, therapeutic, open, single-arm study. All in all, 45 sedentary women with PCOS and 52 without (non-PCOS), 18-37 yr of age, with body mass indexes (BMI) of 18-39.9 kg·m(-2) of all races and social status, performed PRT three times a week for 4 months. Before and after PRT, the concentrations of hormones and metabolic factors and waist circumference were measured. LMM and total body fat percentage were determined using dual-energy x-ray absorptiometry. Clinical characteristics, LMM, and fasting glucose were adjusted for confounding covariables and compared using general linear mixed models. Each patient's menstrual history was taken before study enrollment and after PRT. PRT resulted in reduced plasma testosterone and fasting glucose levels. After PRT, the androstenedione concentration increased and the sex hormone-binding globulin concentration decreased in women with PCOS. The waist circumference was reduced (P < 0.01) and the muscle mass index, lean mass (LM)/height2, increased in women with PCOS (P = 0.04). Women with PCOS showed increased muscle mass indexes of appendicular LM/height2 (P = 0.03) and LM/height2 (P < 0.01) compared with the baseline. Total LM and trunk LM were elevated in women with PCOS (P = 0.01) at the baseline and after PRT. To our knowledge, this is the first report to show that resistance exercise alone can improve hyperandrogenism, reproductive function, and body composition by decreasing visceral fat and increasing LMM, but it has no metabolic impact on women with PCOS.

Responses of neotropical mangrove seedlings grown in monoculture and mixed culture under treatments of hydroperiod and salinity

USGS Publications Warehouse

Cardona-Olarte, P.; Twilley, R.R.; Krauss, K.W.; Rivera-Monroy, V.

2006-01-01

We investigated the combined effects of salinity and hydroperiod on seedlings of Rhizophora mangle and Laguncularia racemosa grown under experimental conditions of monoculture and mixed culture by using a simulated tidal system. The objective was to test hypotheses relative to species interactions to either tidal or permanent flooding at salinities of 10 or 40 g/l. Four-month-old seedlings were experimentally manipulated under these environmental conditions in two types of species interactions: (1) seedlings of the same species were grown separately in containers from September 2000 to August 2001 to evaluate intraspecific response and (2) seedlings of each species were mixed in containers to evaluate interspecific, competitive responses from August 2002 to April 2003. Overall, L. racemosa was strongly sensitive to treatment combinations while R. mangle showed little effect. Most plant responses of L. racemosa were affected by both salinity and hydroperiod, with hydroperiod inducing more effects than salinity. Compared to R. mangle, L. racemosa in all treatment combinations had higher relative growth rate, leaf area ratio, specific leaf area, stem elongation, total length of branches, net primary production, and stem height. Rhizophora mangle had higher biomass allocation to roots. Species growth differentiation was more pronounced at low salinity, with few species differences at high salinity under permanent flooding. These results suggest that under low to mild stress by hydroperiod and salinity, L. racemosa exhibits responses that favor its competitive dominance over R. mangle. This advantage, however, is strongly reduced as stress from salinity and hydroperiod increase. ?? Springer 2006.

The Effect of Adolescent Experience on Labor Market Outcomes: The Case of Height.

ERIC Educational Resources Information Center

Persico, Nicola; Postlewaite, Andrew; Silverman, Dan

2004-01-01

Taller workers receive a wage premium. Net of differences in family background, the disparity is similar in magnitude to the race and gender gaps. We exploit variation in an individual's height over time to explore how height affects wages. Controlling for teen height essentially eliminates the effect of adult height on wages for white men. The…

Pulse Jet Mixing Tests With Noncohesive Solids

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

Meyer, Perry A.; Bamberger, Judith A.; Enderlin, Carl W.

2009-05-11

This report summarizes results from pulse jet mixing (PJM) tests with noncohesive solids in Newtonian liquid conducted during FY 2007 and 2008 to support the design of mixing systems for the Hanford Waste Treatment and Immobilization Plant (WTP). Tests were conducted at three geometric scales using noncohesive simulants. The test data were used to independently develop mixing models that can be used to predict full-scale WTP vessel performance and to rate current WTP mixing system designs against two specific performance requirements. One requirement is to ensure that all solids have been disturbed during the mixing action, which is important tomore » release gas from the solids. The second requirement is to maintain a suspended solids concentration below 20 weight percent at the pump inlet. The models predict the height to which solids will be lifted by the PJM action, and the minimum velocity needed to ensure all solids have been lifted from the floor. From the cloud height estimate we can calculate the concentration of solids at the pump inlet. The velocity needed to lift the solids is slightly more demanding than "disturbing" the solids, and is used as a surrogate for this metric. We applied the models to assess WTP mixing vessel performance with respect to the two perform¬ance requirements. Each mixing vessel was evaluated against these two criteria for two defined waste conditions. One of the wastes was defined by design limits and one was derived from Hanford waste characterization reports. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The assessment predicts that three vessel types will satisfy the design criteria for all conditions evaluated. Seven vessel types will not satisfy the performance criteria used for any of the conditions evaluated. The remaining three vessel types provide varying assessments when the different particle characteristics are evaluated. The HLP-022 vessel was also evaluated using 12 m/s pulse jet velocity with 6-in. nozzles, and this design also did not satisfy the criteria for all of the conditions evaluated.« less

Relative importance of expertise, lifting height and weight lifted on posture and lumbar external loading during a transfer task in manual material handling.

PubMed

Plamondon, André; Larivière, Christian; Delisle, Alain; Denis, Denys; Gagnon, Denis

2012-01-01

The objective of this study was to measure the effect size of three important factors in manual material handling, namely expertise, lifting height and weight lifted. The effect of expertise was evaluated by contrasting 15 expert and 15 novice handlers, the effect of the weight lifted with a 15-kg box and a 23-kg box and the effect of lifting height with two different box heights: ground level and a 32 cm height. The task consisted of transferring a series of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables (moments) while expertise had low impact. On the other hand, expertise showed a significant effect of posture variables on the lumbar spine and knees. All three factors are important, but for a reduction of external back loading, the focus should be on the lifting height and weight lifted. The objective was to measure the effect size of three important factors in a transfer of boxes from a conveyor to a hand trolley. Lifting height and weight lifted had more effect size than expertise on external back loading variables but expertise was a major determinant in back posture.

Ethnic differences in trabecular meshwork height by optical coherence tomography.

PubMed

Chen, Rebecca I; Barbosa, Diego T; Hsu, Chi-Hsin; Porco, Travis C; Lin, Shan C

2015-04-01

Differences in ocular anatomy may contribute to ethnic differences in glaucoma risk. Because the trabecular meshwork (TM) plays an important role in aqueous outflow, its anatomy in relation to at-risk populations may provide insight into a potential contributor to elevated intraocular pressure and thus to probability of glaucoma development. To investigate whether differences exist in TM height between ethnic groups. This prospective study took place from January 1, 2012, to December 31, 2013. Adult patients who self-reported as being of white, Asian, Hispanic, or African American ethnicity were recruited from ophthalmology clinics at the University of California, San Francisco. The TM height was assessed using spectral-domain anterior segment optical coherence tomography. Trabecular meshwork height was measured from the scleral spur to the Schwalbe line. We hypothesized that ethnicities with a higher prevalence of glaucoma would tend to have shorter TM heights. We collected data from 460 eyes of 291 participants after excluding 34 optical coherence tomographic scans owing to poor image quality. The final sample was 32.2% white, 45.1% Asian, 10.5% African American, and 12.1% Hispanic. There were 64.2% women, and the mean age was 68.1 years. The mean (SD) TM height among all eyes included in the study was 836 (131) μm. The mean (SD) TM height was characterized among white (851 [131] μm), Asian (843 [126] μm), Hispanic (822 [147] μm), and African American (771 [118] μm) persons. Ethnicity was not associated with TM height overall (P = .23, linear mixed regression model). However, the TM heights of African American participants (771 μm) were shorter than those of white (851 μm; adjusted difference 95% CI, -119.8 to -8.1; P = .02) and Asian (843 μm; adjusted difference 95% CI, -117.4 to -10.8; P = .02) participants. Although TM height is not associated with ethnicity overall, African American individuals have shorter TM heights compared with Asian and white persons. Trabecular meshwork size may play a role in ethnic differences of glaucoma risk and be a new risk factor to consider in primary open-angle glaucoma.

Predicting logging residues: an interim equation for Appalachian oak sawtimber

Treesearch

A. Jeff Martin

1975-01-01

An equation, using dbh, dbh², bole length, and sawlog height to predict the cubic-foot volume of logging residue per tree, was developed from data collected on 36 mixed oaks in southwestern Virginia. The equation produced reliable results for small sawtimber trees, but additional research is needed for other species, sites, and utilization practices.

Size of Douglas-fir trees in relation to distance from a mixed red alder - Douglas-fir stand

Treesearch

R.E. Miller; D.L. Reukema; T.A. Max

1993-01-01

Variation in diameter, height, and stem volume of 57-year-old Douglas-fir(Pseudotsuga menziesii var. menziesii (Mirb.) Franco) was related to distance of these trees from a 27 m wide strip in the same Douglas-fir plantation that had been interplanted with red alder (Alnus rubra Bong.). Within the...

Red alder stand development and dynamics.

Treesearch

R.L. Deal

2006-01-01

This paper synthesizes information on the development of natural pure red alder stands and dynamics of mixed alder-conifer stands. Early research on red alder growth and yield focused on developing stand volume and normal yield. tables for alder in the Pacific Northwest. Recent site-index estimation and height-growth curves were developed on a 20-year site base age....

Growth and stocking of eastern hemlock (Tsuga canadensis) in New England

Treesearch

Dale S. Solomon; William B. Leak

2000-01-01

Summarization of the limited growth information in mixed-species stands in New England indicates that eastern hemlock (Tsuga canadensis) may be one of the fastest growing species in diameter, second only to white pine. However, on some sites hemlock diameter growth is about equal to that of associated hardwoods. Hemlock grows slowly in height and...

Field trial of a tree injector in a weeding in West Virginia

Treesearch

Carter B. Gibbs

1963-01-01

In June 1960 a 5-acre plot of mixed hardwoods under intensive selection management on the Fernow Experimental Forest in West Virginia was weeded to eliminate poor-quality stems that were competing directly with desirable regeneration. Treatment was confined to stems in the 1- to 5-inch diameter (at breast height) classes.

Diurnal cycling of urban aerosols under different weather regimes

NASA Astrophysics Data System (ADS)

Gregorič, Asta; Drinovec, Luka; Močnik, Griša; Remškar, Maja; Vaupotič, Janja; Stanič, Samo

2016-04-01

A one month measurement campaign was performed in summer 2014 in Ljubljana, the capital of Slovenia (population 280,000), aiming to study temporal and spatial distribution of urban aerosols and the mixing state of primary and secondary aerosols. Two background locations were chosen for this purpose, the first one in the city center (urban background - KIS) and the second one in the suburban background (Brezovica). Simultaneous measurements of black carbon (BC) and particle number size distribution of submicron aerosols (PM1) were conducted at both locations. In the summer season emission from traffic related sources is expected to be the main local contribution to BC concentration. Concentrations of aerosol species and gaseous pollutants within the planetary boundary layer are controlled by the balance between emission sources of primary aerosols and gases, production of secondary aerosols, chemical reactions of precursor gases under solar radiation and the rate of dilution by mixing within the planetary boundary layer (PBL) as well as with tropospheric air. Only local emission sources contribute to BC concentration during the stable PBL with low mixing layer height, whereas during the time of fully mixed PBL, regionally transported BC and other aerosols can contribute to the surface measurements. The study describes the diurnal behaviour of the submicron aerosol at the urban and suburban background location under different weather regimes. Particles in three size modes - nucleation (< 25 nm, NUM), Aitken (25 - 90 nm, AIM) and accumulation mode (90 - 800 nm, ACM), as well as BC mass concentration were evaluated separately for sunny, cloudy and rainy days, taking into account modelled values of PBL height. Higher particle number and black carbon concentrations were observed at the urban background (KIS) than at the suburban background location (Brezovica). Significant diurnal pattern of total particle concentration and black carbon concentration was observed at both locations, with a distinct morning and late afternoon peak. As a consequence of different PBL dynamics and atmospheric processes (photochemical effects, humidity, wind speed and direction), diurnal profile differs for sunny, cloudy and rainy days. Nucleation mode particles were found to be subjected to lower daily variation and only slightly influenced by weather, as opposed to Aitken and accumulation mode particles. The highest correlation between BC and particle number concentration is observed during stable atmospheric conditions in the night and morning hours and is attributed to different particle size modes, depending on the distance to local BC emission sources. In sunny weather conditions, correlation between BC and particle number concentration decreases during the day due to mixing in the atmosphere and formation of secondary aerosols. Black carbon aging and mixing with secondary aerosols was additionally studied on the aerosol samples taken from the morning to the evening of a sunny day using SEM-EDX technique.

Mixed, short rotation culture of red alder and black cottonwood: growth, coppicing, nitrogen fixation, and allelopathy

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

Heilman, P.; Stettler, R.F.

1985-01-01

Alnus rubra seedlings were grown in a 1:1 mixture at a spacing of 1.2 x 1.2 m with 28 Populus clones (25 clones pf P. trichocarpa, 2 of P. deltoides x P. trichocarpa, and one P. deltoides x P. nigra) in a study established in W. Washington in March 1979. Trees were harvested at 4 yr old. At harvest, average heights were: pure Populus, 10.2 m; Populus in the mixed stand 11.0 m; and alder 8.4 m. Most Populus sprouted satisfactorily after harvest (6.6 shoots/plant when pure, 7.6 shoots/plant in the mixture), but alder sprouted poorly (3.6 shoots/plant). Above-ground biomassmore » at harvest was 15.9 t/ha p.a. for the mixture and 16.7 t/ha p.a. for pure Populus, although the mixture had been more productive at 2 yr. Nitrogenase activity (nitrogen fixation as measured by acetylene reduction) of alder declines in the 4th season; competition was the most important factor influencing this decline. Soil N content had no effect on fixation. A pot study showed that ground Populus leaf and litter material inhibited the growth of red alder seedlings, although soil collected from Populus plots had no effect. Results indicated that allelopathy is probably a minor factor under field conditions, at most, and that growing mixed stands may, on balance, be beneficial. 20 references.« less

Numerical study on the lubrication performance of compression ring-cylinder liner system with spherical dimples

PubMed Central

Liu, Cheng; Zhang, Yong-Fang; Li, Sha; Müller, Norbert

2017-01-01

The effects of surface texture on the lubrication performance of a compression ring-cylinder liner system are studied in this paper. By considering the surface roughness of the compression ring and cylinder liner, a mixed lubrication model is presented to investigate the tribological behaviors of a barrel-shaped compression ring-cylinder liner system with spherical dimples on the liner. In order to determine the rupture and reformulation positions of fluid film accurately, the Jacoboson-Floberg-Olsson (JFO) cavitation boundary condition is applied to the mixed lubrication model for ensuring the mass-conservative law. On this basis, the minimum oil film thickness and average friction forces in the compression ring-cylinder liner system are investigated under the engine-like conditions by changing the dimple area density, radius, and depth. The wear load, average friction forces, and power loss of the compression ring-cylinder liner system with and without dimples are also compared for different compression ring face profiles. The results show that the spherical dimples can produce a larger reduction of friction in mixed lubrication region, and reduce power loss significantly in the middle of the strokes. In addition, higher reduction percentages of average friction forces and wear are obtained for smaller crown height or larger axial width. PMID:28732042

[Effects of target tree tending on community structure and diversity in subtropical natural secondary shrubs].

PubMed

Zhang, Hui; Zhou, Guo Mo; Bai, Shang Bin; Wang, Yi Xiang; You, Yu Jie; Zhu, Ting Ting; Zhang, Hua Feng

2017-05-18

The typical natural secondary shrub community was chosen in Lin'an of Zhejiang Pro-vince to discover its possibility of restoration to arbor forest with three kinds of forest management models being taken, i.e., no care as control, closed forest management and target tree tending. Over four years growth, compared with control, closed forest management significantly increased average DBH and height by 130% and 50%, respectively, while 260% and 110% for target tree tending. In target tree tending plots, larger trees had been emerging with 4.5-8.5 cm diameter class and 4.5-8.5 m height class and formed a new storey of 4 m compared with control. The species biodiversity indexes at shrub layer were significantly increased in closed management plots, and did not decrease in target tree tending plots. Closed forest management did not change the tree species composition, following its previous succession direction. However, target tree tending increased the importance value of target species with the high potential succession direction of mixed coniferous-broadleaved forest. The results revealed that the secondary shrub community with target tree tending achieved more desired goals on DBH and height growth of dominant trees and species composition improvement compared with closed management. If the secondary shrub community could be managed when the operational conditions existed, target tree tending model should be selected to accelerate the restoration of shrub toward arbor forest.

Tree height–diameter allometry across the United States

PubMed Central

Hulshof, Catherine M; Swenson, Nathan G; Weiser, Michael D

2015-01-01

The relationship between tree height and diameter is fundamental in determining community and ecosystem structure as well as estimates of biomass and carbon storage. Yet our understanding of how tree allometry relates to climate and whole organismal function is limited. We used the Forest Inventory and Analysis National Program database to determine height–diameter allometries of 2,976,937 individuals of 293 tree species across the United States. The shape of the allometric relationship was determined by comparing linear and nonlinear functional forms. Mixed-effects models were used to test for allometric differences due to climate and floristic (between angiosperms and gymnosperms) and functional groups (leaf habit and shade tolerance). Tree allometry significantly differed across the United States largely because of climate. Temperature, and to some extent precipitation, in part explained tree allometric variation. The magnitude of allometric variation due to climate, however, had a phylogenetic signal. Specifically, angiosperm allometry was more sensitive to differences in temperature compared to gymnosperms. Most notably, angiosperm height was more negatively influenced by increasing temperature variability, whereas gymnosperm height was negatively influenced by decreasing precipitation and increasing altitude. There was little evidence to suggest that shade tolerance influenced tree allometry except for very shade-intolerant trees which were taller for any given diameter. Tree allometry is plastic rather than fixed and scaling parameters vary around predicted central tendencies. This allometric variation provides insight into life-history strategies, phylogenetic history, and environmental limitations at biogeographical scales. PMID:25859325

Characteristics of Precipitation, Cloud, and Latent Heating Associated with the Madden-Julian Oscillation

NASA Technical Reports Server (NTRS)

Lau, K-M.; Wu, H-T.

2010-01-01

This study investigates the evolution of cloud and rainfall structures associated with Madden Julian oscillation (MJO) using Tropical Rainfall Measuring Mission (TRMM) data. Two complementary indices are used to define MJO phases. Joint probability distribution functions (PDFs) of cloud-top temperature and radar echo-top height are constructed for each of the eight MJO phases. The genesis stage of MJO convection over the western Pacific (phases 1 and 2) features a bottom-heavy PDF, characterized by abundant warm rain, low clouds, suppressed deep convection, and higher sea surface temperature (SST). As MJO convection develops (phases 3 and 4), a transition from the bottom-heavy to top-heavy PDF occurs. The latter is associated with the development of mixed-phase rain and middle-to-high clouds, coupled with rapid SST cooling. At the MJO convection peak (phase 5), a top-heavy PDF contributed by deep convection with mixed-phase and ice-phase rain and high echo-top heights (greater than 5 km) dominates. The decaying stage (phases 6 and 7) is characterized by suppressed SST, reduced total rain, increased contribution from stratiform rain, and increased nonraining high clouds. Phase 7, in particular, signals the beginning of a return to higher SST and increased warm rain. Phase 8 completes the MJO cycle, returning to a bottom-heavy PDF and SST conditions similar to phase 1. The structural changes in rain and clouds at different phases of MJO are consistent with corresponding changes in derived latent heating profiles, suggesting the importance of a diverse mix of warm, mixed-phase, and ice-phase rain associated with low-level, congestus, and high clouds in constituting the life cycle and the time scales of MJO.

A Broad Continuum of Aeolian Impact Ripple Sizes on Mars is Allowed by Low Dynamic Wind Pressures

NASA Astrophysics Data System (ADS)

Sullivan, R. J., Jr.; Kok, J. F.; Yizhaq, H.

2017-12-01

Aeolian impact ripples are generated by impacts of wind-blown sand grains, and are common in environments with loose sand on Earth and Mars. Previous work has shown that, within a fully developed saltation cloud, impact ripple height grows upward into the boundary layer until limited by the effects of increasing wind dynamic pressure at the crest (e.g., lengthening of splash trajectories, or direct entrainment of grains by the wind). On Earth, this process limits ripples of well-sorted 250 µm dune sands to heights of millimeters, and strong winds can impose sufficient lateral dynamic pressure to flatten and erase these ripples. Rover observations show much larger ripple-like bedforms on Mars, raising questions about their formative mechanism. Here, we hypothesize that two factors allow impact ripples to grow much higher on Mars than on Earth: (1) previous work predicts a much larger difference between impact threshold and fluid threshold wind speeds on Mars than on Earth; and (2) recent analysis has revealed how low saltation flux can be initiated and sustained well below fluid threshold on Mars, allowing impact ripples to migrate entirely under prevailing conditions of relatively low wind speeds in the thin martian atmosphere. Under these circumstances, martian ripples would need to grow much larger than on Earth before reaching their maximum height limited by wind dynamic pressure effects. Because the initial size of impact ripples is similar on Mars and Earth, this should generate a much broader continuum of impact ripple sizes on Mars. Compared with Earth, far more time should be needed on Mars for impact ripples to achieve their maximum possible size. Consequently, in cases where wind azimuths are mixed but one azimuth is more dominant than others, martian impact ripples of all sizes can exist together in the same setting, with the largest examples reflecting the most common/formative wind azimuths. In cases where wind azimuth is not dominated by a single azimuth over others, ripple height should vary with orientation and the maximum possible height might never have the chance to be achieved. Our hypothesis could explain the wide range of observed ripple sizes on Mars having wavelengths from cm to several m, and suggests that the largest martian ripples are in fact large impact ripples.

Air quality modeling for effective environmental management in the mining region.

PubMed

Asif, Zunaira; Chen, Zhi; Han, Yi

2018-04-18

Air quality in the mining sector is a serious environmental concern and associated with many health issues. The air quality management in mining region has been facing many challenges due to lack of understanding of atmospheric factors and physical removal mechanism. A modeling approach called mining air dispersion model (MADM) is developed to predict air pollutants concentration in the mining region while considering the deposition effect. The model is taken into account through the planet's boundary conditions and assuming that the eddy diffusivity depends on the downwind distance. The developed MADM is applied to a mining site in Canada. The model provides values as the predicted concentrations of PM 10 , PM 2.5 , TSP, NO 2 and six heavy metals (As, Pb, Hg, Cd, Zn, Cr) at various receptor locations. The model shows that neutral stability conditions are dominant for the study site. The maximum mixing height is achieved (1280 m) during the evening of summer, and minimum mixing height (380 m) is attained during the evening of winter. The dust fall (PM coarse) deposition flux is maximum during February and March with the deposition velocity of 4.67 cm/s. The results are evaluated with the monitoring field values, revealing a good agreement for the target air pollutants with R-squared ranging from 0.72 to 0.96 for PM 2.5 ; 0.71 to 0.82 for PM 10 and from 0.71 to 0.89 for NO 2 . The analyses illustrate that presented algorithm in this model can be used to assess air quality for the mining site in a systematic way. The comparison of MADM and CALPUFF modeling values are made for four different pollutants (PM 2.5 , PM 10 , TSP, and NO 2 ) under three different atmospheric stability classes (stable, neutral and unstable). Further, MADM results are statistically tested against CALPUFF for the air pollutants and model performance is found satisfactory.

Generic biomass functions for Norway spruce in Central Europe--a meta-analysis approach toward prediction and uncertainty estimation.

PubMed

Wirth, Christian; Schumacher, Jens; Schulze, Ernst-Detlef

2004-02-01

To facilitate future carbon and nutrient inventories, we used mixed-effect linear models to develop new generic biomass functions for Norway spruce (Picea abies (L.) Karst.) in Central Europe. We present both the functions and their respective variance-covariance matrices and illustrate their application for biomass prediction and uncertainty estimation for Norway spruce trees ranging widely in size, age, competitive status and site. We collected biomass data for 688 trees sampled in 102 stands by 19 authors. The total number of trees in the "base" model data sets containing the predictor variables diameter at breast height (D), height (H), age (A), site index (SI) and site elevation (HSL) varied according to compartment (roots: n = 114, stem: n = 235, dry branches: n = 207, live branches: n = 429 and needles: n = 551). "Core" data sets with about 40% fewer trees could be extracted containing the additional predictor variables crown length and social class. A set of 43 candidate models representing combinations of lnD, lnH, lnA, SI and HSL, including second-order polynomials and interactions, was established. The categorical variable "author" subsuming mainly methodological differences was included as a random effect in a mixed linear model. The Akaike Information Criterion was used for model selection. The best models for stem, root and branch biomass contained only combinations of D, H and A as predictors. More complex models that included site-related variables resulted for needle biomass. Adding crown length as a predictor for needles, branches and roots reduced both the bias and the confidence interval of predictions substantially. Applying the best models to a test data set of 17 stands ranging in age from 16 to 172 years produced realistic allocation patterns at the tree and stand levels. The 95% confidence intervals (% of mean prediction) were highest for crown compartments (approximately +/- 12%) and lowest for stem biomass (approximately +/- 5%), and within each compartment, they were highest for the youngest and oldest stands, respectively.

[Short, medium and long-term benefits of human milk intake in very-low-birth-weight infants].

PubMed

Chinea Jiménez, Bibiana; Awad Parada, Yumana; Villarino Marín, Antonio; Sáenz de Pipaón Marcos, Miguel

2017-10-24

The aim of the present study is to evaluate the effect of human milk feeding during the first weeks of life in very low birth weight infants on weight gain at discharge, length of hospitalization, postmenstrual age at discharge and nutritional assessment, growth and neurodevelopment at two and five years. Longitudinal study of very-low-birth-weight infants (< 1,500 grams) admitted to the Neonatal Intensive Care Unit of La Paz University Hospital, from January 1st 2009 to December 31st 2009, followed in the follow-up clinic. Their parents agreed to perform a more exhaustive anthropometric study at five years, classified according to the type of feeding at the time of discharge (exclusive human milk, formula milk or mixed). Initial hospital duration and anthropometry at discharge were evaluated. At two years of age, anthropometric data (weight, height and head circumference) were collected and neurodevelopment was assessed according to the Bayley scale of child development. Data at five years were collected prospectively. Measurements of weight, height and head circumference, waist circumference, hip, relaxed and contracted arm, thigh and middle leg, bicipital, triceps, subscapular, suprailiac and leg skin folds were performed. For patients older than five years, the Kaufman test battery for children was used. The effect of human milk on the variables of interest was investigated using a multivariate analysis correcting for gestational age and weight at birth. One hundred and fifty-two infants born in 2009 were discharged from our unit: exclusive breast milk (59), formula (55) or mixed milk (38). More detailed follow-up was carried out for 61 of them. Human milk during the first admission decreases the initial hospital stay, and is associated with a higher head circumference at two and five years, and a better score in the global and verbal cognitive area at five years. Our results suggest that maternal milk feeding during initial admission should be encouraged because it can improve neurodevelopment at five years of age.

The Summertime Arctic Atmosphere: Meteorological Measurements during the Arctic Ocean Experiment 2001.

NASA Astrophysics Data System (ADS)

Tjernström, Michael; Leck, Caroline; Persson, P. Ola G.; Jensen, Michael L.; Oncley, Steven P.; Targino, Admir

2004-09-01

An atmospheric boundary layer experiment into the high Arctic was carried out on the Swedish ice-breaker Oden during the summer of 2001, with the primary boundary layer observations obtained while the icebreaker drifted with the ice near 89°N during 3 weeks in August. The purposes of the experiment were to gain an understanding of atmospheric boundary layer structure and transient mixing mechanisms, in addition to their relationships to boundary layer clouds and aerosol production. Using a combination of in situ and remote sensing instruments, with temporal and spatial resolutions previously not deployed in the Arctic, continuous measurements of the lower-troposphere structure and boundary layer turbulence were taken concurrently with atmospheric gas and particulate chemistry, and marine biology measurements.The boundary layer was strongly controlled by ice thermodynamics and local turbulent mixing. Near-surface temperatures mostly remained between near the melting points of the sea- and freshwater, and near-surface relative humidity was high. Low clouds prevailed and fog appeared frequently. Visibility outside of fog was surprisingly good even with very low clouds, probably due to a lack of aerosol particles preventing the formation of haze. The boundary layer was shallow but remained well mixed, capped by an occasionally very strong inversion. Specific humidity often increased with height across the capping inversion.In contrast to the boundary layer, the free troposphere often retained its characteristics from well beyond the Arctic. Elevated intrusions of warm, moist air from open seas to the south were frequent. The picture that the Arctic atmosphere is less affected by transport from lower latitudes in summer than the winter may, thus, be an artifact of analyzing only surface measurements. The transport of air from lower latitudes at heights above the boundary layer has a major impact on the Arctic boundary layer, even very close to the North Pole. During a few week-long periods synoptic-scale weather systems appeared, while weaker and shallower mesoscale fronts were frequent. While frontal passages changed the properties of the free troposphere, changes in the boundary layer were more determined by local effects that often led to changes contrary to those aloft. For example, increasing winds associated with a cold front often led to a warming of the near-surface air by mixing and entrainment.

Transfection effect of microbubbles on cells in superposed ultrasound waves and behavior of cavitation bubble.

PubMed

Kodama, Tetsuya; Tomita, Yukio; Koshiyama, Ken-Ichiro; Blomley, Martin J K

2006-06-01

The combination of ultrasound and ultrasound contrast agents (UCAs) is able to induce transient membrane permeability leading to direct delivery of exogenous molecules into cells. Cavitation bubbles are believed to be involved in the membrane permeability; however, the detailed mechanism is still unknown. In the present study, the effects of ultrasound and the UCAs, Optison on transfection in vitro for different medium heights and the related dynamic behaviors of cavitation bubbles were investigated. Cultured CHO-E cells mixed with reporter genes (luciferase or beta-gal plasmid DNA) and UCAs were exposed to 1 MHz ultrasound in 24-well plates. Ultrasound was applied from the bottom of the well and reflected at the free surface of the medium, resulting in the superposition of ultrasound waves within the well. Cells cultured on the bottom of 24-well plates were located near the first node (displacement node) of the incident ultrasound downstream. Transfection activity was a function determined with the height of the medium (wave traveling distance), as well as the concentration of UCAs and the exposure time was also determined with the concentration of UCAs and the exposure duration. Survival fraction was determined by MTT assay, also changes with these values in the reverse pattern compared with luciferase activity. With shallow medium height, high transfection efficacy and high survival fraction were obtained at a low concentration of UCAs. In addition, capillary waves and subsequent atomized particles became significant as the medium height decreased. These phenomena suggested cavitation bubbles were being generated in the medium. To determine the effect of UCAs on bubble generation, we repeated the experiments using crushed heat-treated Optison solution instead of the standard microbubble preparation. The transfection ratio and survival fraction showed no additional benefit when ultrasound was used. These results suggested that cavitation bubbles created by the collapse of UCAs were a key factor for transfection, and their intensities were enhanced by the interaction of the superpose ultrasound with the decreasing the height of the medium. Hypothesizing that free cavitation bubbles were generated from cavitation nuclei created by fragmented UCA shells, we carried out numerical analysis of a free spherical bubble motion in the field of ultrasound. Analyzing the interaction of the shock wave generated by a cavitation bubble and a cell membrane, we estimated the shock wave propagation distance that would induce cell membrane damage from the center of the cavitation bubble.

Physical growth curves of indigenous Xavante children in Central Brazil: results from a longitudinal study (2009-2012).

PubMed

Ferreira, Aline A; Welch, James R; Cunha, Geraldo Marcelo; Coimbra, Carlos E A

2016-07-01

The nutritional profile of Indigenous children in Brazil is comparable to those observed in some of the least developed regions of the world. Weight and height growth curves were characterised based on longitudinal data from a local Indigenous population experiencing the double burden of child under-nutrition and adult obesity. Anthropometric data were collected in six waves from 2009-2011 for children <10 in two proximate Xavante villages in Central Brazil. Prevalence rates for stunting, wasting and thinness were calculated using WHO references. Weight and height data were adjusted for generalised additive mixed models to generate growth curves. Prevalence rates of stunting and wasting were high, but cases of thinness and excess weight were negligible. Weight and height began close to WHO medians, but fell substantially before 12 months. Boys but not girls were able to catch-up in weight before age 10. From 3-10 years, height for both sexes remained between -2 and 0 z-scores. Impaired Xavante growth before 1 year followed by inconsistent recovery before 10 years reflects health and wellbeing disparities with regard to the Brazilian national population and a complex epidemiology of growth involving rapid nutritional change.

Aerosol-cloud interactions in mixed-phase convective clouds - Part 1: Aerosol perturbations

NASA Astrophysics Data System (ADS)

Miltenberger, Annette K.; Field, Paul R.; Hill, Adrian A.; Rosenberg, Phil; Shipway, Ben J.; Wilkinson, Jonathan M.; Scovell, Robert; Blyth, Alan M.

2018-03-01

Changes induced by perturbed aerosol conditions in moderately deep mixed-phase convective clouds (cloud top height ˜ 5 km) developing along sea-breeze convergence lines are investigated with high-resolution numerical model simulations. The simulations utilise the newly developed Cloud-AeroSol Interacting Microphysics (CASIM) module for the Unified Model (UM), which allows for the representation of the two-way interaction between cloud and aerosol fields. Simulations are evaluated against observations collected during the COnvective Precipitation Experiment (COPE) field campaign over the southwestern peninsula of the UK in 2013. The simulations compare favourably with observed thermodynamic profiles, cloud base cloud droplet number concentrations (CDNC), cloud depth, and radar reflectivity statistics. Including the modification of aerosol fields by cloud microphysical processes improves the correspondence with observed CDNC values and spatial variability, but reduces the agreement with observations for average cloud size and cloud top height. Accumulated precipitation is suppressed for higher-aerosol conditions before clouds become organised along the sea-breeze convergence lines. Changes in precipitation are smaller in simulations with aerosol processing. The precipitation suppression is due to less efficient precipitation production by warm-phase microphysics, consistent with parcel model predictions. In contrast, after convective cells organise along the sea-breeze convergence zone, accumulated precipitation increases with aerosol concentrations. Condensate production increases with the aerosol concentrations due to higher vertical velocities in the convective cores and higher cloud top heights. However, for the highest-aerosol scenarios, no further increase in the condensate production occurs, as clouds grow into an upper-level stable layer. In these cases, the reduced precipitation efficiency (PE) dominates the precipitation response and no further precipitation enhancement occurs. Previous studies of deep convective clouds have related larger vertical velocities under high-aerosol conditions to enhanced latent heating from freezing. In the presented simulations changes in latent heating above the 0°C are negligible, but latent heating from condensation increases with aerosol concentrations. It is hypothesised that this increase is related to changes in the cloud field structure reducing the mixing of environmental air into the convective core. The precipitation response of the deeper mixed-phase clouds along well-established convergence lines can be the opposite of predictions from parcel models. This occurs when clouds interact with a pre-existing thermodynamic environment and cloud field structural changes occur that are not captured by simple parcel model approaches.

Chronobiological Hypothesis about the Association Between Height Growth Seasonality and Geographical Differences in Body Height According to Effective Day Length

PubMed Central

Higuchi, Yukito

2016-01-01

Studies on growth hormone therapy in children have shown that height velocity is greater in summer than in winter and that this difference increases with latitude. It is hypothesized that summer daylight is a causative factor and that geographical distribution of body height will approximate the distribution of summer day length over time. This is an ecological analysis of prefecture-level data on the height of Japanese youth. Mesh climatic data of effective day length were collated. While height velocity was greatest during the summer, the height of Japanese youth was strongly and negatively correlated with the distribution of winter effective day length. Therefore, it is anticipated that summer height velocity is greater according to winter day length (dark period). This may be due to epigenetic modifications, involving reversible DNA methylation and thyroid hormone regulation found in the reproductive system of seasonal breeding vertebrates. If the function is applicable to humans, summer height growth may quantitatively increase with winter day length, and height growth seasonality can be explained by thyroid hormone activities that-induced by DNA methylation-change depending on the seasonal difference in day length. Moreover, geographical differences in body height may be caused by geographical differences in effective day length, which could influence melatonin secretion among subjects who spend a significant time indoors.

Effects of Wheelchair Seat-height Settings on Alternating Lower Limb Propulsion With Both Legs.

PubMed

Murata, Tomoyuki; Asami, Toyoko; Matsuo, Kiyomi; Kubo, Atsuko; Okigawa, Etsumi

2014-01-01

This study investigated the effects of seat-height settings of wheelchairs with alternating propulsion with both legs. Seven healthy individuals with no orthopedic disease participated. Flexion angles at initial contact (FA-IC) of each joint, range of motion during propulsion period (ROM-PP), and ground reaction force (GRF) were measured using a three dimensional motion capture system and force plates, and compared with different seat-height settings. Statistically significant relationships were found between seat-height and speed, stride length, knee FA-IC, ankle FA-IC, hip ROM-PP, vertical ground reaction force (VGRF), and anterior posterior ground reaction force (APGRF). Speed, hip ROM-PP, VGRF and APGRF increased as the seat-height was lowered. This effect diminished when the seat-height was set below -40 mm. VGRF increased as the seat-height was lowered. The results suggest that the seat-height effect can be attributed to hip ROM-PP; therefore, optimal foot propulsion cannot be achieved when the seat height is set either too high or too low. Efficient foot propulsion of the wheelchair can be achieved by setting the seat height to lower leg length according to a combination of physical characteristics, such as the user's physical functions, leg muscles, and range of motion.

Can the physical properties associated with uncertainties in the NASA MODIS AOD retrievals in the western U.S. be determined?

NASA Astrophysics Data System (ADS)

Loria Salazar, S. M.; Holmes, H.; Panorska, A. K.; Arnott, W. P.; Barnard, J.

2016-12-01

Previous investigations have used satellite remote sensing to estimate surface air pollution concentrations. While most of these studies rely on models developed for the dark-vegetated eastern U.S., they are being used in the semi-arid western U.S without modifications. These models are not robust in the western U.S. due to: 1. Irregular topography that leads to complicated boundary layer physics, 2. Pollutant mixtures, 3. Heterogeneous vertical profile of aerosol concentrations, and 4. High surface reflectance. Here, results from Nevada and California demonstrate poor AOD correlation between AERONET MODIS retrievals. Smoke from wildfires strengthened the aerosol signal, but the MODIS versus AERONET AOD correlation did not improve significantly during fire events [r2 0.17 (non-fire), r2 0.2 (fire)]. Furthermore, aerosol from fires increased the normalized mean bias (NMB) of MODIS retrievals of AOD[NMB 82% (non-fire), NMB 146% (fire)]. Additional results of this investigation found that aerosol plumes confined with the boundary layer improves MODIS AOD retrievals. However, when this condition is not met (i.e., 70% of the time downwind of mountains regions) MODIS AOD has a poor correlation and high bias with respect to AERONET AOD. Fire injection height, complicated boundary layer mixing, and entrainment disperse smoke plumes into the free atmosphere. Therefore, smoke plumes exacerbate the complex aerosol transport typical in the western U.S. and the non-linear relationship between surface pollutant concentrations and conditions aloft. This work uses stochastic methods, including regression to investigate the influence of each of these physical behaviors on the MODIS, AERONET AOD discrepancy using surrogates for each physical phenomenon, e.g., surface albedo for surface reflectance, boundary layer height and elevation for complex mixing, aerosol optical height for vertical aerosol concentrations, and fire radiative power for smoke plume injection height.

Factors dominating 3-dimensional ozone distribution during high tropospheric ozone period.

PubMed

Chen, Xiaoyang; Liu, Yiming; Lai, Anqi; Han, Shuangshuang; Fan, Qi; Wang, Xuemei; Ling, Zhenhao; Huang, Fuxiang; Fan, Shaojia

2018-01-01

Data from an in situ monitoring network and five ozone sondes are analysed during August of 2012, and a high tropospheric ozone episode is observed around the 8th of AUG. The Community Multi-scale Air Quality (CMAQ) model and its process analysis tool were used to study factors and mechanisms for high ozone mixing ratio at different levels of ozone vertical profiles. A sensitive scenario without chemical initial and boundary conditions (ICBCs) from MOZART4-GEOS5 was applied to study the impact of stratosphere-troposphere exchange (STE) on vertical ozone. The simulation results indicated that the first high ozone peak near the tropopause was dominated by STE. Results from process analysis showed that: in the urban area, the second peak at approximately 2 km above ground height was mainly caused by local photochemical production. The third peak (near surface) was mainly caused by the upwind transportation from the suburban/rural areas; in the suburban/rural areas, local photochemical production of ozone dominated the high ozone mixing ratio from the surface to approximately 3 km height. Furthermore, the capability of indicators to distinguish O 3 -precursor sensitivity along the vertical O 3 profiles was investigated. Two sensitive scenarios, which had cut 30% anthropogenic NO X or VOC emissions, showed that O 3 -precursor indicators, specifically the ratios of O 3 /NOy, H 2 O 2 /HNO 3 or H 2 O 2 /NO Z , could partly distinguish the O 3 -precursor sensitivity between VOCs-sensitive and NOx-sensitive along the vertical profiles. In urban area, the O 3 -precursor relationship transferred from VOCs-sensitive within the boundary layer to NOx-sensitive at approximately 1-3 km above ground height, further confirming the dominant roles of transportation and photochemical production in high O 3 peaks at the near-ground layer and 2 km above ground height, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Optical Coherence Tomographic and Visual Results at Six Months after Transitioning to Aflibercept for Patients on Prior Ranibizumab or Bevacizumab Treatment for Exudative Age-Related Macular Degeneration (An American Ophthalmological Society Thesis)

PubMed Central

Chan, Clement K.; Jain, Atul; Sadda, Srinivas; Varshney, Neeta

2014-01-01

Purpose: To study optical coherence tomographic (OCT) results and vision at 6 months after transition (post-Tx) from intravitreal bevacizumab and/or ranibizumab to aflibercept for treatment of neovascular age-related macular degeneration (nAMD). The null hypothesis was the lack of improvements in OCT metrics and vision outcome in study eyes at 6 months after transitioning from bevacizumab or ranibizumab to aflibercept. Methods: This retrospective study assessed 6 monthly OCT (Cirrus) data after transitioning to aflibercept for eyes on prior Legacy-ranibizumab, Legacy-bevacizumab, or mixed treatment for nAMD. Outcome measures were subretinal fluid (SRF), cystoid macular edema (CME), pigment epithelial detachment (PED) heights and volumes, central 1- and 3-mm subfield, Macular Volume, and best spectacle and pinhole visual acuity (VA). A single masked investigator performed all OCT measurements. Results: One hundred eighty-nine eyes in 172 patients in Legacy-bevacizumab (95 eyes), Legacy-ranibizumab (84 eyes), or Mixed Group(10 eyes) were switched to aflibercept and followed for 6 months. Significant post-Tx reductions were noted in SRF/CME heights and volumes (all P<.001). Similar findings were noted for PED heights (122.8 μm vs 79.4 μm) and PED volumes (all P<.001). Post-Tx VA was better (20/43 vs 20/51, P<.001). There were no differences between Legacy-bevacizumab and Legacy-ranibizumab groups in OCT and VA changes. Post-Tx VA, SRF/CME, and PED heights and volumes were improved for Nonresponders (suboptimal response to bevacizumab/ranibizumab) (P=.001 to <.001), but not Responders (good responses to same). The only adverse event was a retinal pigment epithelial tear in one eye. Conclusions: Significant improvements in vision and OCT metrics developed in Nonresponders but not in Responders. Post-Tx VA and OCT measures were similar for eyes on prior bevacizumab or ranibizumab. Post-Tx adverse events were uncommon. PMID:25646034

Combining 3D structure of real video and synthetic objects

NASA Astrophysics Data System (ADS)

Kim, Man-Bae; Song, Mun-Sup; Kim, Do-Kyoon

1998-04-01

This paper presents a new approach of combining real video and synthetic objects. The purpose of this work is to use the proposed technology in the fields of advanced animation, virtual reality, games, and so forth. Computer graphics has been used in the fields previously mentioned. Recently, some applications have added real video to graphic scenes for the purpose of augmenting the realism that the computer graphics lacks in. This approach called augmented or mixed reality can produce more realistic environment that the entire use of computer graphics. Our approach differs from the virtual reality and augmented reality in the manner that computer- generated graphic objects are combined to 3D structure extracted from monocular image sequences. The extraction of the 3D structure requires the estimation of 3D depth followed by the construction of a height map. Graphic objects are then combined to the height map. The realization of our proposed approach is carried out in the following steps: (1) We derive 3D structure from test image sequences. The extraction of the 3D structure requires the estimation of depth and the construction of a height map. Due to the contents of the test sequence, the height map represents the 3D structure. (2) The height map is modeled by Delaunay triangulation or Bezier surface and each planar surface is texture-mapped. (3) Finally, graphic objects are combined to the height map. Because 3D structure of the height map is already known, Step (3) is easily manipulated. Following this procedure, we produced an animation video demonstrating the combination of the 3D structure and graphic models. Users can navigate the realistic 3D world whose associated image is rendered on the display monitor.

Growth status and estimated growth rate of youth football players: a community-based study.

PubMed

Malina, Robert M; Morano, Peter J; Barron, Mary; Miller, Susan J; Cumming, Sean P

2005-05-01

To characterize the growth status of participants in community-sponsored youth football programs and to estimate rates of growth in height and weight. Mixed-longitudinal over 2 seasons. Two communities in central Michigan. Members of 33 youth football teams in 2 central Michigan communities in the 2000 and 2001 seasons (Mid-Michigan PONY Football League). Height and weight of all participants were measured prior to each season, 327 in 2000 and 326 in 2001 (n = 653). The body mass index (kg/m) was calculated. Heights and weights did not differ from season to season and between the communities; the data were pooled and treated cross-sectionally. Increments of growth in height and weight were estimated for 166 boys with 2 measurements approximately 1 year apart to provide an estimate of growth rate. Growth status (size-attained) of youth football players relative to reference data (CDC) for American boys and estimated growth rate relative to reference values from 2 longitudinal studies of American boys. Median heights of youth football players approximate the 75th percentiles, while median weights approximate the 75th percentiles through 11 years and then drift toward the 90th percentiles of the reference. Median body mass indexes of youth football players fluctuate about the 85th percentiles of the reference. Estimated growth rates in height approximate the reference and may suggest earlier maturation, while estimated growth rates in weight exceed the reference. Youth football players are taller and especially heavier than reference values for American boys. Estimated rates of growth in height approximate medians for American boys and suggest earlier maturation. Estimated rates of growth in weight exceed those of the reference and may place many youth football players at risk for overweight/obesity, which in turn may be a risk factor for injury.

Degraded dryland rehabilitation: boosting seedling survival using zeolitic tuff

NASA Astrophysics Data System (ADS)

Alhamad, Mohammad Noor; Alrbabah, Mohammad; Athamneh, Hana

2016-04-01

More than 90% of Jordan is broadly defined as rangelands. Most rangelands are located within the arid zone of the country. Extensive grazing occurs across much of the natural pastures resulting in serious environmental degradation of natural resources in these rangelands. Several programs were carried out for rangeland conservation and rehabilitation in the country. However, these programs face a major challenge of the low survival rate of transplanted shrub seedlings. Seeking innovative approaches to assure healthy establishment of seedling is a big challenge to achieve successful rehabilitation programs. Drought is considered one of the major problems in rehabilitation. Promoting survival and growth, using zeolitic tuff added to planting holes is suggested to be a possible solution. The experiment was conducted on a factorial arrangement within RCBD design. Two shrub species (Atriplex halimus, Atriplex nummularia) were transplanted into holes prepared with three levels of tuff treatments (mulching, mixing and control) under rainfed condition. The result showed insignificant effect of tuff on seedling survival percentage, when mixing tuff with plantation soil or adding tuff as mulch. Also, the two species showed similar survival percentages over two measured dates. However, mixing tuff with soil during hole preparation significantly enhanced seedling heights. Furthers, The Australian atriplex (Atriplex nummularia) species significantly grow higher than Atriplex halimus. The study results suggested that mixing zeoltic tuff with soil during transplantation of seedling is promising in improving the success of rangeland rehabilitation in dry areas in Jordan.

Anogenital distance: A longitudinal evaluation of its variants and indices in boys and girls of Sonora, Mexico.

PubMed

Loreto-Gómez, Carmen; Farías, Paulina; Moreno-Macías, Hortensia; Romano-Riquer, S P; Riojas-Rodríguez, Horacio

2017-10-01

There is no consensus on which anogenital distance (AGD) variant to use and how to adjust it by body size in humans. This study quantitatively evaluated AGD variants and body size adjustments to determine which would be the best choice. AGD variants, height, and weight were measured on five occasions during the first year of life of 307 infants. The ratio of anoscrotal distance (ASD) in boys and anofourchette distance (AFD) in girls increased from 1.9 at birth to 2.3 at 12 months of age. Each AGD variant was divided by each body size variable to generate different indices. Such indices were standardized to make them comparable when analyzing their performance through mixed models. ASD and AFD adjusted by height generated precise (p<0.05) AGD indices: 0.4-0.5 and 0.2, respectively. Results suggest that the best body size adjustment for all AGD variants in the first year of life is height. Copyright © 2017 Elsevier Inc. All rights reserved.

Typical tropospheric aerosol backscatter profiles for Southern Ireland: The Cork Raman lidar

NASA Astrophysics Data System (ADS)

McAuliffe, Michael A. P.; Ruth, Albert A.

2013-02-01

A Raman lidar instrument (UCLID) was established at the University College Cork as part of the European lidar network EARLINET. Raman backscatter coefficients, extinction coefficients and lidar ratios were measured within the period 28/08/2010 and 24/04/2011. Typical atmospheric scenarios over Southern Ireland in terms of the aerosol load in the planetary boundary layer are outlined. The lidar ratios found are typical for marine atmospheric condition (lidar ratio ca. 20-25 sr). The height of the planetary boundary layer is below 1000 m and therefore low in comparison to heights found at other lidar sites in Europe. On the 21st of April a large aerosol load was detected, which was assigned to a Saharan dust event based on HYSPLIT trajectories and DREAM forecasts along with the lidar ratio (70 sr) for the period concerned. The dust was found at two heights, pure dust at 2.5 km and dust mixing with pollution from 0.7 to 1.8 km with a lidar ratio of 40-50 sr.

How thick are lunar mare basalts

NASA Technical Reports Server (NTRS)

Hoerz, F.

1978-01-01

It is argued that De Hon's estimates of the thickness of lunar mare basalts, made by analyzing 'ghost' craters on mare surfaces, were inflated as the result of the crater morphometric data of Pike (1977) to reconstruct rim heights of degraded craters. Crater rim heights of 82 randomly selected highland craters of various states of degradation were determined, and median rim height was compared to that of corresponding fresh impact structures. Results indicate that the thickness estimates of De Hon may be reduced by a factor of 2, and that the total volume of mare basalt produced throughout lunar history could be as little as 1-2 million cubic kilometers. A survey of geochemical and petrographic evidence indicates that lateral transport of regolith components over distances of much greater than 10 km is relatively inefficient; it is suggested that vertical mixing of a highland substrate underlying the basaltic fill may have had a primordial role in generating the observed mare width distributions and high concentrations of exotic components in intrabasin regoliths.

A comparative analysis of rawinsonde and NIMBUS 6 and TIROS N satellite profile data

NASA Technical Reports Server (NTRS)

Scoggins, J. R.; Carle, W. E.; Knight, K.; Moyer, V.; Cheng, N. M.

1981-01-01

Comparisons are made between rawinsonde and satellite profiles in seven areas for a wide range of surface and weather conditions. Variables considered include temperature, dewpoint temperature, thickness, precipitable water, lapse rate of temperature, stability, geopotential height, mixing ratio, wind direction, wind speed, and kinematic parameters, including vorticity and the advection of vorticity and temperature. In addition, comparisons are made in the form of cross sections and synoptic fields for selected variables. Sounding data from the NIMBUS 6 and TIROS N satellites were used. Geostrophic wind computed from smoothed geopotential heights provided large scale flow patterns that agreed well with the rawinsonde wind fields. Surface wind patterns as well as magnitudes computed by use of the log law to extrapolate wind to a height of 10 m agreed with observations. Results of this study demonstrate rather conclusively that satellite profile data can be used to determine characteristics of large scale systems but that small scale features, such as frontal zones, cannot yet be resolved.

Laser heterodyne system for obtaining height profiles of minor species in the atmosphere

NASA Technical Reports Server (NTRS)

Jain, S. L.; Saha, A. K.

1986-01-01

An infrared laser heterodyne system for obtaining height profiles of minor constituents of the atmosphere was developed and erected. A brief discription of the system is given. The system consists of a tunable CO2 waveguide laser in the 9 to 11 micrometer band, that is used as a local oscillator and a heliostat that follows the sun and brings in solar radiation, that is mixed with the laser beam in a high speed liquid nitrogen cooled mercury cadmium telluride detector. The detected signal is analysed in a RF spectrum analyser that allows tracing absorption line profiles. Absorption lines of a number of minor constituents in the troposphere and stratosphere, such as O3, NH3, H2O, SO2, ClO, N2O, are in the 9 to 11 micrometer band and overlap with that of CO2 laser range. The experimental system has been made operational and trial observations taken. Current measurements are limited to ozone height profiles. Results are presented.

Acid deposition in east Asia

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

Phadnis, M.J.; Carmichael, G.R.; Ichikawa, Y.

1996-12-31

A comparison between transport models was done to study the acid deposition in east Asia. The two models in question were different in the way the treated the pollutant species and the way simulation was carried out. A single-layer, trajectory model with simple (developed by the Central Research Institute of Electric Power Industry (CRIEPI), Japan) was compared with a multi-layered, eulerian type model (Sulfur Transport Eulerian Model - II [STEM-II]) treating the chemical processes in detail. The acidic species used in the simulation were sulfur dioxide and sulfate. The comparison was done for two episodes: each a month long inmore » winter (February) and summer (August) of 1989. The predicted results from STEM-II were compared with the predicted results from the CRIEPI model as well as the observed data at twenty-one stations in Japan. The predicted values from STEM-II were similar to the ones from the CRIEPI results and the observed values in regards to the transport features. The average monthly values of SO{sub 2} in air, sulfate in air and sulfate in precipitation were in good agreement. Sensitivity studies were carried out under different scenarios of emissions, dry depositions velocities and mixing heights. The predicted values in these sensitivity studies showed a strong dependence on the mixing heights. The predicted wet deposition of sulfur for the two months is 0.7 gS/m2.mon, while the observed deposition is around 1.1 gS/m2.mon. It was also observed that the wet deposition on the Japan sea side of the islands is more than those on the Pacific side and the Okhotsk sea, mainly because of the continental outflow of pollutant air masses from mainland China and Korea. The effects of emissions from Russia and volcanoes were also evaluated.« less

Monoterpene chemical speciation in a tropical rainforest:variation with season, height, and time of dayat the Amazon Tall Tower Observatory (ATTO)

NASA Astrophysics Data System (ADS)

María Yáñez-Serrano, Ana; Nölscher, Anke Christine; Bourtsoukidis, Efstratios; Gomes Alves, Eliane; Ganzeveld, Laurens; Bonn, Boris; Wolff, Stefan; Sa, Marta; Yamasoe, Marcia; Williams, Jonathan; Andreae, Meinrat O.; Kesselmeier, Jürgen

2018-03-01

Speciated monoterpene measurements in rainforest air are scarce, but they are essential for understanding the contribution of these compounds to the overall reactivity of volatile organic compound (VOC) emissions towards the main atmospheric oxidants, such as hydroxyl radicals (OH), ozone (O3) and nitrate radicals (NO3). In this study, we present the chemical speciation of gas-phase monoterpenes measured in the tropical rainforest at the Amazon Tall Tower Observatory (ATTO, Amazonas, Brazil). Samples of VOCs were collected by two automated sampling systems positioned on a tower at 12 and 24 m height and analysed using gas chromatography-flame ionization detection. The samples were collected in October 2015, representing the dry season, and compared with previous wet and dry season studies at the site. In addition, vertical profile measurements (at 12 and 24 m) of total monoterpene mixing ratios were made using proton-transfer-reaction mass spectrometry. The results showed a distinctly different chemical speciation between day and night. For instance, α-pinene was more abundant during the day, whereas limonene was more abundant at night. Reactivity calculations showed that higher abundance does not generally imply higher reactivity. Furthermore, inter- and intra-annual results demonstrate similar chemodiversity during the dry seasons analysed. Simulations with a canopy exchange modelling system show simulated monoterpene mixing ratios that compare relatively well with the observed mixing ratios but also indicate the necessity of more experiments to enhance our understanding of in-canopy sinks of these compounds.

Determination of fungal diseases, site and stand characteristics in mixed stands in Ilgaz-Yenice forest district, Cankiri, Turkey.

PubMed

Oner, Nuri; Dogan, Hasan Huseyin; Ozturk, Celaleddin; Gurer, Meral

2009-07-01

Fungal diseases, site and stand characteristics were investigated in Yenice forest sub-district headquarters belonging to Ilgaz forest enterprise. Diseases and wood decaying fungi on fallen and cut tree stumps were determined on scots pine (Pinus sylvestris), crimean pine (P. nigra subsp. nigra varcaramanica), and uludag fir (Abies nordmanniana subsp. bommulleriana). Altitude (m), exposure, slope (%), relief, rate of mixture (%) and anthropogenic effects were noted for 56 sample plots which have various stand compositions. Age, breast height diameter (cm), top height (m), crown and bole quality regeneration quality and development of representative tree species were also recorded into vegetation forms. Yellow witches' broom (Melampsorella caryophyllacearum), which caused drying of uludag fir trees, was determined. Besides, 53 macrofungi species belonging to 3 divisions, 10 orders, 25 families and 36 genera were determined. Some of them cause white and brown decay on living and core wood. The most common parasitic and saprobe fungi are Galerina Ganoderma, Gloeophyllum, Gymnopilus, Hypholoma, Lentinus, Phellinus, Pleurotus, Polyporus and Stereum species in the research area. Trichaptum abietinum is also typical wood decay fungi for living or cut fir trees and it is very common in the research area.

Association between Adult Height and Risk of Colorectal, Lung, and Prostate Cancer: Results from Meta-analyses of Prospective Studies and Mendelian Randomization Analyses

PubMed Central

Khankari, Nikhil K.; Shu, Xiao-Ou; Wen, Wanqing; Kraft, Peter; Lindström, Sara; Peters, Ulrike; Schildkraut, Joellen; Schumacher, Fredrick; Bofetta, Paolo; Risch, Angela; Bickeböller, Heike; Amos, Christopher I.; Easton, Douglas; Gruber, Stephen B.; Haiman, Christopher A.; Hunter, David J.; Chanock, Stephen J.; Pierce, Brandon L.; Zheng, Wei

2016-01-01

Background Observational studies examining associations between adult height and risk of colorectal, prostate, and lung cancers have generated mixed results. We conducted meta-analyses using data from prospective cohort studies and further carried out Mendelian randomization analyses, using height-associated genetic variants identified in a genome-wide association study (GWAS), to evaluate the association of adult height with these cancers. Methods and Findings A systematic review of prospective studies was conducted using the PubMed, Embase, and Web of Science databases. Using meta-analyses, results obtained from 62 studies were summarized for the association of a 10-cm increase in height with cancer risk. Mendelian randomization analyses were conducted using summary statistics obtained for 423 genetic variants identified from a recent GWAS of adult height and from a cancer genetics consortium study of multiple cancers that included 47,800 cases and 81,353 controls. For a 10-cm increase in height, the summary relative risks derived from the meta-analyses of prospective studies were 1.12 (95% CI 1.10, 1.15), 1.07 (95% CI 1.05, 1.10), and 1.06 (95% CI 1.02, 1.11) for colorectal, prostate, and lung cancers, respectively. Mendelian randomization analyses showed increased risks of colorectal (odds ratio [OR] = 1.58, 95% CI 1.14, 2.18) and lung cancer (OR = 1.10, 95% CI 1.00, 1.22) associated with each 10-cm increase in genetically predicted height. No association was observed for prostate cancer (OR = 1.03, 95% CI 0.92, 1.15). Our meta-analysis was limited to published studies. The sample size for the Mendelian randomization analysis of colorectal cancer was relatively small, thus affecting the precision of the point estimate. Conclusions Our study provides evidence for a potential causal association of adult height with the risk of colorectal and lung cancers and suggests that certain genetic factors and biological pathways affecting adult height may also affect the risk of these cancers. PMID:27598322

Predictions of H-mode performance in ITER

NASA Astrophysics Data System (ADS)

Budny, Robert

2008-11-01

Time-dependent integrated predictions of performance metrics such as the fusion power PDT, QDT≡ PDT/Pext, and alpha profiles are presented. The PTRANSP [1] code is used, along with GLF23 to predict plasma profiles, NUBEAM for NNBI and alpha heating, TORIC for ICRH, and TORAY for ECRH. Effects of sawteeth mixing, beam steering, beam shine-through, radiation loss, ash accumulation, and toroidal rotation are included. A total heating of Pext=73MW is assumed to achieve H-mode during the density and current ramp-up phase. Various mixes of NNBI, ICRH, and ECRH heating schemes are compared. After steady state conditions are achieved, Pext is stepped down to lower values to explore high QDT. Physics and computation uncertainties lead to ranges in predictions for PDT and QDT. Physics uncertainties include the L->H and H->L threshold powers, pedestal height, impurity and ash transport, and recycling. There are considerably more uncertainties predicting the peak value for QDT than for PDT. [0pt] [1] R.V. Budny, R. Andre, G. Bateman, F. Halpern, C.E. Kessel, A. Kritz, and D. McCune, Nuclear Fusion 48 (2008) 075005.

Analysis of granular flow in a pebble-bed nuclear reactor.

PubMed

Rycroft, Chris H; Grest, Gary S; Landry, James W; Bazant, Martin Z

2006-08-01

Pebble-bed nuclear reactor technology, which is currently being revived around the world, raises fundamental questions about dense granular flow in silos. A typical reactor core is composed of graphite fuel pebbles, which drain very slowly in a continuous refueling process. Pebble flow is poorly understood and not easily accessible to experiments, and yet it has a major impact on reactor physics. To address this problem, we perform full-scale, discrete-element simulations in realistic geometries, with up to 440,000 frictional, viscoelastic 6-cm-diam spheres draining in a cylindrical vessel of diameter 3.5m and height 10 m with bottom funnels angled at 30 degrees or 60 degrees. We also simulate a bidisperse core with a dynamic central column of smaller graphite moderator pebbles and show that little mixing occurs down to a 1:2 diameter ratio. We analyze the mean velocity, diffusion and mixing, local ordering and porosity (from Voronoi volumes), the residence-time distribution, and the effects of wall friction and discuss implications for reactor design and the basic physics of granular flow.

Growth in stature in fragile X families: A mixed longitudinal study

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

Loesch, D.Z.; Huggins, R.M.; Hoang, N.H.

1995-09-11

The effect of fragile X on growth in stature was estimated in individuals aged 5-20 years from 50 fragile X families. The multivariate normal model for pedigree analysis was applied to the mixed longitudinal data, which varied with regard to intervals between the measurements and their number in individual subjects, totalling 349 measurement data points from fragile X families, and 292 data points from unrelated normal subjects. The results of genetic and regression analysis showed that, in fragile X boys and girls, total pubertal height gain is impaired, whereas the rate of growth during the preadolescent period is increased, comparedmore » with the growth rate of nonfragile X subjects. Moreover, the growth parameters in fragile X males were found to be correlated with the size of CGG trinucleotide expansion. The hypothesis of premature activation of the hypothalamo-pituitary gonadal axis is postulated as the cause of growth impairment in fragile X boys and girls, which should be verified by data on the timing of pubertal stages, hormone levels, and bone maturation. 33 refs., 2 figs., 3 tabs.« less

The upper atmosphere of Uranus - Mean temperature and temperature variations

NASA Technical Reports Server (NTRS)

Dunham, E.; Elliot, J. L.; Gierasch, P. J.

1980-01-01

The number-density, pressure, and temperature profiles of the Uranian atmosphere in the pressure interval from 0.3 to 30 dynes/sq cm are derived from observations of the occultation of SAO 158687 by Uranus on 1977 March 10, observations made from the Kuiper Airborne Observatory and the Cape Town station of the South African Astronomical Observatory. The mean temperature is found to be about 95 K, but peak-to-peak variations from 10 K to 20 K or more exist on a scale of 150 km or 3 scale heights. The existence of a thermal inversion is established, but the inversion is much weaker than the analogous inversion on Neptune. The mean temperature can be explained by solar heating in the 3.3 micron methane band with a methane mixing ratio of 4 x 10 to the -6th combined with the cooling effect of ethane with a mixing ratio of not greater than 4 x 10 to the -6th. The temperature variations are probably due to a photochemical process that has formed a Chapman layer.

Faster growth in warmer winters for large trees in a Mediterranean-climate ecosystem

Treesearch

Seth W. Bigelow; Michael J. Papaik; Caroline Caum; Malcolm P. North

2014-01-01

Large trees (>76 cm breast-height diameter) are vital components of Sierra Nevada/Cascades mixed-conifer ecosystems because of their fire resistance, ability to sequester large amounts of carbon, and role as preferred habitat for sensitive species such as the California spotted owl. To investigate the likely performance of large trees in a rapidly changing...

Performance of mixed pine-hardwood stands 16 years after fell-and-burn treatments

Treesearch

Elizabeth M. Blizzard; David H. van Lear; G. Geoff Wang; Thomas A. Waldrop

2006-01-01

Four variations of the fell-and-burn technique were compared for height and volume production on dry Piedmont sites. A two-factorial randomized complete block design of winter versus spring felling, with and without a summer burn, was implemented, followed by planting of loblolly pine (Pinus taeda L.) at 15 x 15 foot spacing. After 16 growing seasons...

Perennial grasses reduce woody plant seedlings...on mixed conifer fuel-break

Treesearch

Harry E. Schimke Lisle R. Green Danny Heavilin

1970-01-01

After initial clearing, parts of a fuelbreak on the Stanislaus Nationd Forest, central California, were planted to perennial grasses; other parts were not. After 5 years, a comparison between adjacent seeded sand unseeded strips shows that the perernnials had reduced the number of woody plant seedlings by a factor of 8, height of seedlings by 50 percent, and amount of...

Rapid growth of mineral deposits at artificial seafloor hydrothermal vents

PubMed Central

Nozaki, Tatsuo; Ishibashi, Jun-Ichiro; Shimada, Kazuhiko; Nagase, Toshiro; Takaya, Yutaro; Kato, Yasuhiro; Kawagucci, Shinsuke; Watsuji, Tomoo; Shibuya, Takazo; Yamada, Ryoichi; Saruhashi, Tomokazu; Kyo, Masanori; Takai, Ken

2016-01-01

Seafloor massive sulphide deposits are potential resources for base and precious metals (Cu-Pb-Zn ± Ag ± Au), but difficulties in estimating precise reserves and assessing environmental impacts hinder exploration and commercial mining. Here, we report petrological and geochemical properties of sulphide chimneys less than 2 years old that formed where scientific boreholes vented hydrothermal fluids in the Iheya-North field, Okinawa Trough, in East China Sea. One of these infant chimneys, dominated by Cu-Pb-Zn-rich sulphide minerals, grew a height of 15 m within 25 months. Portions of infant chimneys are dominated by sulphate minerals. Some infant chimneys are sulphide-rich similar to high-grade Cu-Pb-Zn bodies on land, albeit with relatively low As and Sb concentrations. The high growth rate reaching the 15 m height within 25 months is attributed to the large hydrothermal vent more than 50 cm in diameter created by the borehole, which induced slow mixing with the ambient seawater and enhanced efficiency of sulphide deposition. These observations suggest the possibility of cultivating seafloor sulphide deposits and even controlling their growth and grades through manipulations of how to mix and quench hydrothermal fluids with the ambient seawater. PMID:26911272

Volume I: fluidized-bed code documentation, for the period February 28, 1983-March 18, 1983

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

Piperopoulou, H.; Finson, M.; Bloomfield, D.

1983-03-01

This documentation supersedes the previous documentation of the Fluidized-Bed Gasifier code. Volume I documents a simulation program of a Fluidized-Bed Gasifier (FBG), and Volume II documents a systems model of the FBG. The FBG simulation program is an updated version of the PSI/FLUBED code which is capable of modeling slugging beds and variable bed diameter. In its present form the code is set up to model a Westinghouse commercial scale gasifier. The fluidized bed gasifier model combines the classical bubbling bed description for the transport and mixing processes with PSI-generated models for coal chemistry. At the distributor plate, the bubblemore » composition is that of the inlet gas and the initial bubble size is set by the details of the distributor plate. Bubbles grow by coalescence as they rise. The bubble composition and temperature change with height due to transport to and from the cloud as well as homogeneous reactions within the bubble. The cloud composition also varies with height due to cloud/bubble exchange, cloud/emulsion, exchange, and heterogeneous coal char reactions. The emulsion phase is considered to be well mixed.« less

Predicting forest height using the GOST, Landsat 7 ETM+, and airborne LiDAR for sloping terrains in the Greater Khingan Mountains of China

NASA Astrophysics Data System (ADS)

Gu, Chengyan; Clevers, Jan G. P. W.; Liu, Xiao; Tian, Xin; Li, Zhouyuan; Li, Zengyuan

2018-03-01

Sloping terrain of forests is an overlooked factor in many models simulating the canopy bidirectional reflectance distribution function, which limits the estimation accuracy of forest vertical structure parameters (e.g., forest height). The primary objective of this study was to predict forest height on sloping terrain over large areas with the Geometric-Optical Model for Sloping Terrains (GOST) using airborne Light Detection and Ranging (LiDAR) data and Landsat 7 imagery in the western Greater Khingan Mountains of China. The Sequential Maximum Angle Convex Cone (SMACC) algorithm was used to generate image endmembers and corresponding abundances in Landsat imagery. Then, LiDAR-derived forest metrics, topographical factors and SMACC abundances were used to calibrate and validate the GOST, which aimed to accurately decompose the SMACC mixed forest pixels into sunlit crown, sunlit background and shade components. Finally, the forest height of the study area was retrieved based on a back-propagation neural network and a look-up table. Results showed good performance for coniferous forests on all slopes and at all aspects, with significant coefficients of determination above 0.70 and root mean square errors (RMSEs) between 0.50 m and 1.00 m based on ground observed validation data. Higher RMSEs were found in areas with forest heights below 5 m and above 17 m. For 90% of the forested area, the average RMSE was 3.58 m. Our study demonstrates the tremendous potential of the GOST for quantitative mapping of forest height on sloping terrains with multispectral and LiDAR inputs.

Caliper Method Versus Digital Photogrammetry for Assessing Arch Height Index in Pregnant Women.

PubMed

Harrison, Kathryn D; McCrory, Jean L

2016-11-01

Foot anthropometry may be altered during pregnancy. Pregnant women often report lower-extremity pain that may be related to these alterations. The Arch Height Index Measurement System is a common method of foot arch assessment; however, the required calipers are costly and are not widely available. Thus, we compared the reliability of a digital photogrammetry method of arch height index (AHI) assessment with that of the Arch Height Index Measurement System. Ten pregnant women (mean ± SD: age, 29 ± 4 years; height, 166.9 ± 6.8 cm; weight, 63.3 ± 8.8 kg) in their second trimester were recruited to participate, along with a control group of 10 nulliparous weight-matched women (mean ± SD: age, 22 ± 2 years; height, 164.6 ± 4.8 cm; weight, 61.5 ± 8.1 kg). During the second and third trimesters, and once postpartum, AHI was assessed using calipers and using digital photogrammetry. Mixed model absolute agreement type intraclass correlation coefficient (ICC) was used to determine correlation between the two methods for sitting and standing AHI. The ICC results for sitting AHI only (0.819-0.968) were reasonable for clinical measures; ICC values for standing AHI (0.674-0.789) did not reach values deemed reasonable for clinical use. Caliper and digital photogrammetry methods of AHI assessment are correlated in pregnant women; however, for standing AHI, the correlation is not sufficient for clinical use. Photogrammetry may still be appropriate for clinical use, as long as values from this method are not substituted directly for results obtained from calipers.

Modeling the CAPTEX Vertical Tracer Concentration Profiles.

NASA Astrophysics Data System (ADS)

Draxler, Roland R.; Stunder, Barbara J. B.

1988-05-01

Perfluorocarbon tracer concentration profiles measured by aircraft 600-900 km downwind of the release locations during CAPTEX are discussed and compared with some model results. In general, the concentrations decreased with height in the upper half of the boundary layer where the aircraft measurements were made. The results of a model sensitivity study suggested that the shape of the profile was primarily due to winds increasing with height and relative position of the sampling with respect to the upwind and downwind edge of the plume. Further modeling studies showed that relatively simple vertical mixing parameterizations could account for the complex vertical plume structure when the model had sufficient vertical resolution. In general, the model performed better with slower winds and corresponding longer transport times.

Aerosol optical characteristics and their vertical distributions under enhanced haze pollution events: effect of the regional transport of different aerosol types over eastern China

NASA Astrophysics Data System (ADS)

Sun, Tianze; Che, Huizheng; Qi, Bing; Wang, Yaqiang; Dong, Yunsheng; Xia, Xiangao; Wang, Hong; Gui, Ke; Zheng, Yu; Zhao, Hujia; Ma, Qianli; Du, Rongguang; Zhang, Xiaoye

2018-03-01

The climatological variation of aerosol properties and the planetary boundary layer (PBL) during 2013-2015 over the Yangtze River Delta (YRD) region were investigated by employing ground-based Micro Pulse Lidar (MPL) and CE-318 sun-photometer observations. Combining Moderate Resolution Imaging Spectroradiometer (MODIS) and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite products, enhanced haze pollution events affected by different types of aerosol over the YRD region were analyzed through vertical structures, spatial distributions, backward trajectories, and the potential source contribution function (PSCF) model. The results show that aerosols in the YRD are dominated by fine-mode particles, except in March. The aerosol optical depth (AOD) in June and September is higher due to high single scattering albedo (SSA) from hygroscopic growth, but it is lower in July and August due to wet deposition from precipitation. The PBL height (PBLH) is greater (means ranging from 1.23 to 1.84 km) and more variable in the warmer months of March to August, due to the stronger diurnal cycle and exchange of heat. Northern fine-mode pollutants are brought to the YRD at a height of 1.5 km. The SSA increases, blocking the radiation to the surface, and cooling the surface, thereby weakening turbulence, lowering the PBL, and in turn accelerating the accumulation of pollutants, creating a feedback to the cooling effect. Originated from the deserts in Xinjiang and Inner Mongolia, long-range transported dust masses are seen at heights of about 2 km over the YRD region with an SSA440 nm below 0.84, which heat air and raise the PBL, accelerating the diffusion of dust particles. Regional transport from biomass-burning spots to the south of the YRD region bring mixed aerosol particles at a height below 1.5 km, resulting in an SSA440 nm below 0.89. During the winter, the accumulation of the local emission layer is facilitated by stable weather conditions, staying within the PBL even below 0.5 km.

Divergent trait and environment relationships among parallel radiations in Pelargonium (Geraniaceae): a role for evolutionary legacy?

PubMed

Moore, Timothy E; Schlichting, Carl D; Aiello-Lammens, Matthew E; Mocko, Kerri; Jones, Cynthia S

2018-05-11

Functional traits in closely related lineages are expected to vary similarly along common environmental gradients as a result of shared evolutionary and biogeographic history, or legacy effects, and as a result of biophysical tradeoffs in construction. We test these predictions in Pelargonium, a relatively recent evolutionary radiation. Bayesian phylogenetic mixed effects models assessed, at the subclade level, associations between plant height, leaf area, leaf nitrogen content and leaf mass per area (LMA), and five environmental variables capturing temperature and rainfall gradients across the Greater Cape Floristic Region of South Africa. Trait-trait integration was assessed via pairwise correlations within subclades. Of 20 trait-environment associations, 17 differed among subclades. Signs of regression coefficients diverged for height, leaf area and leaf nitrogen content, but not for LMA. Subclades also differed in trait-trait relationships and these differences were modulated by rainfall seasonality. Leave-one-out cross-validation revealed that whether trait variation was better predicted by environmental predictors or trait-trait integration depended on the clade and trait in question. Legacy signals in trait-environment and trait-trait relationships were apparently lost during the earliest diversification of Pelargonium, but then retained during subsequent subclade evolution. Overall, we demonstrate that global-scale patterns are poor predictors of patterns of trait variation at finer geographic and taxonomic scales. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.

Variation in Foot Strike Patterns among Habitually Barefoot and Shod Runners in Kenya

PubMed Central

Lieberman, Daniel E.; Castillo, Eric R.; Otarola-Castillo, Erik; Sang, Meshack K.; Sigei, Timothy K.; Ojiambo, Robert; Okutoyi, Paul; Pitsiladis, Yannis

2015-01-01

Runners are often categorized as forefoot, midfoot or rearfoot strikers, but how much and why do individuals vary in foot strike patterns when running on level terrain? This study used general linear mixed-effects models to explore both intra- and inter-individual variations in foot strike pattern among 48 Kalenjin-speaking participants from Kenya who varied in age, sex, body mass, height, running history, and habitual use of footwear. High speed video was used to measure lower extremity kinematics at ground contact in the sagittal plane while participants ran down 13 meter-long tracks with three variables independently controlled: speed, track stiffness, and step frequency. 72% of the habitually barefoot and 32% of the habitually shod participants used multiple strike types, with significantly higher levels of foot strike variation among individuals who ran less frequently and who used lower step frequencies. There was no effect of sex, age, height or weight on foot strike angle, but individuals were more likely to midfoot or forefoot strike when they ran on a stiff surface, had a high preferred stride frequency, were habitually barefoot, and had more experience running. It is hypothesized that strike type variation during running, including a more frequent use of forefoot and midfoot strikes, used to be greater before the introduction of cushioned shoes and paved surfaces. PMID:26154285

Sublingual administration of detomidine in horses: sedative effect, analgesia and detection time.

PubMed

L'Ami, Jiske J; Vermunt, Lian E; van Loon, Johannes P A M; Sloet van Oldruitenborgh-Oosterbaan, Marianne M

2013-05-01

A single dose of 40 μg/kg bodyweight (BW) of oromucosal detomidine gel was administered sublingually to 10 healthy Dutch Warmblood mares aged 7 ± 4 years (mean ± SD) and BW 580 ± 69 kg. Blood and urine samples were collected before and for 8 days following administration and evaluated qualitatively in an FEI Reference Laboratory and quantitatively in a research laboratory. Clinical effects were evaluated at baseline and for 24 h after administration. Sedation was determined using head height and scores of reaction to auditory and mixed auditory/sensory stimuli. Mechanical nociceptive thresholds (MNTs) were assessed using pressure algometry to evaluate analgesia. Heart rate (HR) was measured and ataxia scored. All horses were considered negative for detomidine in blood samples by 48 h post-administration and in urine by 60 h. These results indicated that a safe withdrawal time for detomidine oromucosal gel may be 72 h following a single sublingual administration of 40 μg/kgBW. Decreases in HR and head height were maximal at 40 and 60 min post-administration, respectively. The maximal decrease in response to stimuli was observed at 100 min. Ataxia was maximal at 60 min. At 40 and 80 min MNTs were significantly increased compared to baseline. All parameters, except the MNTs of two locations, which were decreased, returned to baseline values within 24 h post-administration. Copyright © 2012 Elsevier Ltd. All rights reserved.

Aerosol Activation Properties within and above Mixing Layer in the North China Plain

NASA Astrophysics Data System (ADS)

Deng, Z.; Ran, L.

2013-12-01

Aerosol particles, serving as cloud condensation nuclei (CCN), may modify the properties of clouds and have an impact on climate. The vertical distribution of aerosols and their activation properties is critical to quantify the effect of aerosols on clouds. An intensive field campaign, Vertical Observations of trace Gases and Aerosols in the North China Plain (VOGA-NCP 2013), was conducted in the North China Plain during the late July and early August 2013 to measure the vertical profiles of atmospheric components in this polluted region and estimate their effects on atmospheric environment and climate. Aerosols were measured with in-situ instruments and Lidar. Particularly, the aerosols were collected at 1000 m height with a 1 m3 bag sampler attached to a tethered balloon, and subsequently measured with combined scanning mobility particle sizer (SMPS) and CCN counter. Comparisons of size-resolved activation ratios at ground level and 1000 m height showed that aerosols in upper atmosphere were not only less concentrated, but also less CCN-active than those at the surface. The difference in aerosol properties between upper atmosphere and the ground indicates that the analysis of impacts of aerosols on cloud might be misleading in heavily polluted region based on the relationship of cloud properties and surface aerosols or column without considering the vertical distribution of aerosol activation abilities.

The surface roughness effect on the performance of supersonic ejectors

NASA Astrophysics Data System (ADS)

Brezgin, D. V.; Aronson, K. E.; Mazzelli, F.; Milazzo, A.

2017-07-01

The paper presents the numerical simulation results of the surface roughness influence on gas-dynamic processes inside flow parts of a supersonic ejector. These simulations are performed using two commercial CFD solvers (Star- CCM+ and Fluent). The results are compared to each other and verified by a full-scale experiment in terms of global flow parameters (the entrainment ratio: the ratio between secondary to primary mass flow rate - ER hereafter) and local flow parameters distribution (the static pressure distribution along the mixing chamber and diffuser walls). A detailed comparative study of the employed methods and approaches in both CFD packages is carried out in order to estimate the roughness effect on the logarithmic law velocity distribution inside the boundary layer. Influence of the surface roughness is compared with the influence of the backpressure (static pressure at the ejector outlet). It has been found out that increasing either the ejector backpressure or the surface roughness height, the shock position displaces upstream. Moreover, the numerical simulation results of an ejector with rough walls in the both CFD solvers are well quantitatively agreed with each other in terms of the mean ER and well qualitatively agree in terms of the local flow parameters distribution. It is found out that in the case of exceeding the "critical roughness height" for the given boundary conditions and ejector's geometry, the ejector switches to the "off-design" mode and its performance decreases considerably.

Dietary microbial phytase exerts mixed effects on the gut health of tilapia: a possible reason for the null effect on growth promotion.

PubMed

Hu, Jun; Ran, Chao; He, Suxu; Cao, Yanan; Yao, Bin; Ye, Yuantu; Zhang, Xuezhen; Zhou, Zhigang

2016-06-01

The present study evaluated the effects of dietary microbial phytase on the growth and gut health of hybrid tilapia (Oreochromis niloticus ♀×Oreochromis aureus ♂), focusing on the effect on intestinal histology, adhesive microbiota and expression of immune-related cytokine genes. Tilapia were fed either control diet or diet supplemented with microbial phytase (1000 U/kg). Each diet was randomly assigned to four groups of fish reared in cages (3×3×2 m). After 12 weeks of feeding, weight gain and feed conversion ratio of tilapia were not significantly improved by dietary microbial phytase supplementation. However, significantly higher level of P content in the scales, tighter and more regular intestinal mucosa folds were observed in the microbial phytase group and the microvilli density was significantly increased. The adhesive gut bacterial communities were strikingly altered by microbial phytase supplementation (0·41

Effect of bed height and use of hands on trunk angular velocity during the sit-to-stand transfer.

PubMed

Lindemann, Ulrich; van Oosten, Leon; Evers, Jordi; Becker, Clemens; van Dieen, Jaap H; van Lummel, Rob C

2014-01-01

The ability to rise from a chair or bed is critical to an individual's quality of life because it determines functional independence. This study was to investigate the effect of bed height and use of hands on trunk angular velocity and trunk angles during the sit-to-stand (STS) performance. Twenty-four older persons (median age 74 years) were equipped with a body-fixed gyroscopic sensor and stood up from a bed adjusted to different heights, with and without the use of hands at each height. Peak angular velocity and trunk range of motion decreased with increasing bed height (all p ≤ 0.038) and were lower using hands during STS transfer indicating less effort. In conclusion, gyroscopic sensor data of the STS transfer of older persons show differences as an effect of bed height and use of hands. These results provide the rationale for recommending a relatively high bed height for most of the older persons. To minimise the effort during sit-to-stand transfer performance from bed, it is necessary to understand the effect of bed height and use of hands. It is concluded that a relatively high bed height and the use of hands is helpful for most of the older persons during sit-to-stand transfer.

The interactive effects of age, education, and BMI on cognitive functioning.

PubMed

Kirton, Joshua W; Dotson, Vonetta M

2016-01-01

We examined the moderating effects of age and cognitive reserve on the relationship between body mass index (BMI) and processing speed, executive function, and working memory based on the literature suggesting that obese individuals perform more poorly on measures of these abilities. Fifty-six healthy, dementia-free community-dwelling older (mean age 65.72 ± 7.40) and younger (mean age 21.10 ± 2.33) adults completed a neuropsychological battery and reported height and weight. Mixed effects models were used to evaluate the interactive effects of age, education (a proxy for cognitive reserve), and BMI on cognitive scores. Higher education was protective for executive deficits in younger, but not older adults. Age differences in executive functions were reduced at higher education levels but increased in individuals with higher BMI. Results suggest the inter-relationships between cognitive reserve - as measured by education - and BMI differ across age, and that obesity may accelerate the cognitive aging process.

Analysis and characterization of the vertical wind profile in UAE

NASA Astrophysics Data System (ADS)

Lee, W.; Ghedira, H.; Ouarda, T.; Gherboudj, I.

2011-12-01

In this study, temporal and spatial analysis of the vertical wind profiles in the UAE has been performed to estimate wind resource potential. Due to the very limited number of wind masts (only two wind masts in the UAE, operational for less than three years), the wind potential analysis will be mainly derived from numerical-based models. Additional wind data will be derived from the UAE met stations network (at 10 m elevation) managed by the UAE National Center of Meteorology and Seismology. However, since wind turbines are generally installed at elevations higher than 80 m, it is vital to extrapolate wind speed correctly from low heights to wind turbine hub heights to predict potential wind energy properly. To do so, firstly two boundary layer based models, power law and logarithmic law, were tested to find the best fitting model. Power law is expressed as v/v0 =(H/H0)^α and logarithmic law is represented as v/v0 =[ln(H/Z0))/(ln(H0/Z0)], where V is the wind speed [m/s] at height H [m] and V0 is the known wind speed at a reference height H0. The exponent (α) coefficient is an empirically derived value depending on the atmospheric stability and z0 is the roughness coefficient length [m] that depends on topography, land roughness and spacing. After testing the two models, spatial and temporal analysis for wind profile was performed. Many studies about wind in different regions have shown that wind profile parameters have hourly, monthly and seasonal variations. Therefore, it can be examined whether UAE wind characteristics follow general wind characteristics observed in other regions or have specific wind features due to its regional condition. About 3 years data from August 2008 to February 2011 with 10-minutes resolution were used to derive monthly variation. The preliminary results(Fig.1) show that during that period, wind profile parameters like alpha from power law and roughness length from logarithmic law have monthly variation. Both alpha and roughness have low values during summer and high values during winter. This variation is mainly explained by the direct effect of air temperature on atmospheric stability. When the surface temperature becomes high, air is mixed well in atmospheric boundary layer. This phenomenon leads to vertically low wind speed change indicating low wind profile parameter. On the contrary, cold surface temperature prevents air from being mixed well in the boundary layer. This analysis is applied to different regions to see the spatial characteristics of wind in UAE. As a next step, a mesoscale model coupled with UAE roughness maps will be used to predict elevated wind speed. A micro-scale modeling approach will be also used to capture small-scale wind speed variability. This data will be combined with the NCMS data and tailored to the UAE by modeling the effects due to local changes in terrain elevation and local surface roughness changes and obstacles.

Vertical profiles of aerosol absorption coefficient from micro-Aethalometer data and Mie calculation over Milan.

PubMed

Ferrero, L; Mocnik, G; Ferrini, B S; Perrone, M G; Sangiorgi, G; Bolzacchini, E

2011-06-15

Vertical profiles of aerosol number-size distribution and black carbon (BC) concentration were measured between ground-level and 500m AGL over Milan. A tethered balloon was fitted with an instrumentation package consisting of the newly-developed micro-Aethalometer (microAeth® Model AE51, Magee Scientific, USA), an optical particle counter, and a portable meteorological station. At the same time, PM(2.5) samples were collected both at ground-level and at a high altitude sampling site, enabling particle chemical composition to be determined. Vertical profiles and PM(2.5) data were collected both within and above the mixing layer. Absorption coefficient (b(abs)) profiles were calculated from the Aethalometer data: in order to do so, an optical enhancement factor (C), accounting for multiple light-scattering within the filter of the new microAeth® Model AE51, was determined for the first time. The value of this parameter C (2.05±0.03 at λ=880nm) was calculated by comparing the Aethalometer attenuation coefficient and aerosol optical properties determined from OPC data along vertical profiles. Mie calculations were applied to the OPC number-size distribution data, and the aerosol refractive index was calculated using the effective medium approximation applied to aerosol chemical composition. The results compare well with AERONET data. The BC and b(abs) profiles showed a sharp decrease at the mixing height (MH), and fairly constant values of b(abs) and BC were found above the MH, representing 17±2% of those values measured within the mixing layer. The BC fraction of aerosol volume was found to be lower above the MH: 48±8% of the corresponding ground-level values. A statistical mean profile was calculated, both for BC and b(abs), to better describe their behaviour; the model enabled us to compute their average behaviour as a function of height, thus laying the foundations for valid parametrizations of vertical profile data which can be useful in both remote sensing and climatic studies. Copyright © 2011 Elsevier B.V. All rights reserved.

Parentally-adjusted deficit of height as a prognostic factor of the effectiveness of growth hormone (GH) therapy in children with GH deficiency.

PubMed

Hilczer, Maciej; Smyczyńska, Joanna; Lewiński, Andrzej

2006-01-01

Parental height is the most important identifiable factor influencing final height (FH) of children with growth hormone (GH) deficiency (GHD), treated with GH. Assessment of FH of patients with GHD--classified into familial short stature (FSS) and non-familial short stature (non-FSS) according to parentally adjusted deficit of height. The analysis comprised 101 patients (76 boys) with childhood-onset GHD. Final height was compared with patients' height before GH therapy, predicted adult height (PAH) and target height (TH). Both GH peak in stimulating tests and height standard deviation score (SDS) before the therapy were significantly lower in non-FSS than in FSS. Target height was significantly lower in FSS than in non-FSS. Parentally-adjusted deficit of height was significantly more profound in non-FSS than in FSS. The prognosis of adult height was very similar in both groups of patients, being significantly worse in non-FSS than in FSS while corrected by TH. The absolute FH was similar in FSS and non-FSS, being, however, significantly lower in non-FSS than in FSS while corrected by TH. Improvement of height was significantly better in non-FSS than in FSS. In both groups, FH SDS was significantly better than height SDS before the therapy (H0SDS). In FSS group, PAH was similar to TH, moreover, FH corresponded to both PAH and TH. In non-FSS group FH was significantly higher than PAH, but both FH and PAH were significantly lower than TH. 1) Growth hormone therapy was more effective in the patients with non-FSS than in those with FSS. 2) Parentally-adjusted deficit of height is an important prognostic factor of GH therapy effectiveness.

Effects of box handle position and carrying range on bi-manual carrying capacity for females.

PubMed

Wu, Swei-Pi; Loiu, Yi; Chien, Te Hong

2015-01-01

This study utilizes a psychophysical approach to examine the effects on carrying capacity for bi-manual carrying tasks involving different handle positions and carrying ranges. A total of 16 female subjects participated in the experiment in groups of two people, and each group of subjects performed the tasks in a random order with 12 different combinations of carrying task. The independent variables are handle position (upper, middle, lower) and carrying range (F-F: floor height carried to floor height, F-W: floor height carried to waist height, W-W: waist height carried to waist height, W-F: waist height carried to floor height), the dependent variable is the maximum acceptable carried weight (MAWC), heart rate (HR), and the rating of perceived exertion (RPE). The results show that the handle position has a significant effect on MAWC and overall RPE but no significant effect on HR. Carrying range has a significant effect on the MAWC and HR, but no significant effect on overall HR. The handle position and carrying range have a significant interaction on the MAWC and HR. The RPE for different body parts shows significant differences, and the hands feel the most tired. Overall, this study confirms that the lower handle position with the W-W carrying range is the best combination for a two-person carrying task.

A Laboratory Study of River Discharges into Shallow Seas

NASA Astrophysics Data System (ADS)

Crawford, T. J.; Linden, P. F.

2016-02-01

We present an experimental study that aims to simulate the buoyancy driven coastal currents produced by estuarine freshwater discharges into the ocean. The currents are generated inside a rotating tank filled with saltwater by the continuous release of buoyant freshwater from a source structure located at the fluid surface. The freshwater is discharged horizontally from a finite-depth source, giving rise to significant momentum-flux effects and a non-zero potential vorticity. We perform a parametric study in which we vary the rotation rate, freshwater discharge magnitude, the density difference and the source cross-sectional area. The parameter values are chosen to match the regimes appropriate to the River Rhine and River Elbe when entering the North Sea. Persistent features of an anticyclonic outflow vortex and a propagating boundary current were identified and their properties quantified. We also present a finite potential vorticity, geostrophic model that provides theoretical predictions for the current height, width and velocity as functions of the experimental parameters. The experiments and model are compared with each other in terms of a set of non-dimensional parameters identified in the theoretical analysis of the problem. Good agreement between the model and the experimental data is found. The effect of mixing in the turbulent ocean is also addressed with the addition of an oscillating grid to the experimental setup. The grid generates turbulence in the saltwater ambient that is designed to represent the mixing effects of the wind, tides and bathymetry in a shallow shelf sea. The impact of the addition of turbulence is discussed in terms of the experimental data and through modifications to the theoretical model to include mixing. Once again, good agreement is seen between the experiments and the model.

Immediate effects of different types of stretching exercises on badminton jump smash.

PubMed

Jang, Hwi S; Kim, Daeho; Park, Jihong

2018-01-01

Since different types of stretching exercises may alter athletic performance, we compared the effects of three types of stretching exercises on badminton jump smash. Sixteen male collegiate badminton players performed one of three different stretching exercises in a counterbalanced order on different days. Static stretching had seven typical stretches, while dynamic stretching involved nine dynamic movements, and resistance dynamic stretching was performed with weighted vests and dumbbells. Before and after each stretching exercise, subjects performed 20 trials of jump smashes. Dependent measurements were the jump heights during jump smashes, velocities of jump-smashed shuttlecocks, and drop point of jump-smashed shuttlecocks. To test the effects of each stretching exercise, we performed mixed model ANOVAs and calculated between-time effect sizes (ES). Each stretching exercise improved the jump heights during jump smashes (type main effect: F(2,75)=1.19, P=0.31; static stretching: 22.1%, P<0.01, ES=0.98; dynamic stretching: 30.1%, P<0.01, ES=1.49; resistance dynamic stretching: 17.7%, P=0.03, ES=0.98) and velocities of jump-smashed shuttlecocks (type main effect: F(2,75)=2.18, P=0.12; static stretching: 5.7%, P=0.61, ES=0.39; dynamic stretching: 3.4%, P=0.94, ES=0.28; resistance dynamic stretching: 6%, P=0.50, ES=0.66). However, there were no differences among the stretching exercises for any measurement. The drop point of jump-smashed shuttlecocks did not change (interaction: F(2,75)=0.88, P=0.42). All stretching exercises improved badminton jump smash performance, but we could not determine the best protocol. Since badminton requires high-speed movement and explosive force, we suggest performing dynamic stretching or resistance dynamic stretching.

Effects of stand density on top height estimation for ponderosa pine

Treesearch

Martin Ritchie; Jianwei Zhang; Todd Hamilton

2012-01-01

Site index, estimated as a function of dominant-tree height and age, is often used as an expression of site quality. This expression is assumed to be effectively independent of stand density. Observation of dominant height at two different ponderosa pine levels-of-growing-stock studies revealed that top height stability with respect to stand density depends on the...

Turbulent mixing and removal of ozone within an Amazon rainforest canopy

NASA Astrophysics Data System (ADS)

Freire, L. S.; Gerken, T.; Ruiz-Plancarte, J.; Wei, D.; Fuentes, J. D.; Katul, G. G.; Dias, N. L.; Acevedo, O. C.; Chamecki, M.

2017-03-01

Simultaneous profiles of turbulence statistics and mean ozone mixing ratio are used to establish a relation between eddy diffusivity and ozone mixing within the Amazon forest. A one-dimensional diffusion model is proposed and used to infer mixing time scales from the eddy diffusivity profiles. Data and model results indicate that during daytime conditions, the upper (lower) half of the canopy is well (partially) mixed most of the time and that most of the vertical extent of the forest can be mixed in less than an hour. During nighttime, most of the canopy is predominantly poorly mixed, except for periods with bursts of intermittent turbulence. Even though turbulence is faster than chemistry during daytime, both processes have comparable time scales in the lower canopy layers during nighttime conditions. Nonchemical loss time scales (associated with stomatal uptake and dry deposition) for the entire forest are comparable to turbulent mixing time scale in the lower canopy during the day and in the entire canopy during the night, indicating a tight coupling between turbulent transport and dry deposition and stomatal uptake processes. Because of the significant time of day and height variability of the turbulent mixing time scale inside the canopy, it is important to take it into account when studying chemical and biophysical processes happening in the forest environment. The method proposed here to estimate turbulent mixing time scales is a reliable alternative to currently used models, especially for situations in which the vertical distribution of the time scale is relevant.

Functional trait responses to grazing are mediated by soil moisture and plant functional group identity

PubMed Central

Zheng, Shuxia; Li, Wenhuai; Lan, Zhichun; Ren, Haiyan; Wang, Kaibo

2015-01-01

Abundant evidence has shown that grazing alters plant functional traits, community structure and ecosystem functioning of grasslands. Few studies, however, have tested how plant responses to grazing are mediated by resource availability and plant functional group identity. We examined the effects of grazing on functional traits across a broad range of species along a soil moisture gradient in Inner Mongolia grassland. Our results showed that trait syndromes of plant size (individual biomass) and shoot growth (leaf N content and leaf density) distinguished plant species responses to grazing. The effects of grazing on functional traits were mediated by soil moisture and dependent on functional group identity. For most species, grazing decreased plant height but increased leaf N and specific leaf area (SLA) along the moisture gradient. Grazing enhanced the community-weighted attributes (leaf NCWM and SLACWM), which were triggered mainly by the positive trait responses of annuals and biennials and perennial grasses, and increased relative abundance of perennial forbs. Our results suggest that grazing-induced species turnover and increased intraspecific trait variability are two drivers for the observed changes in community weighted attributes. The dominant perennial bunchgrasses exhibited mixed tolerance–resistance strategies to grazing and mixed acquisitive–conservative strategies in resource utilization. PMID:26655858

Functional trait responses to grazing are mediated by soil moisture and plant functional group identity.

PubMed

Zheng, Shuxia; Li, Wenhuai; Lan, Zhichun; Ren, Haiyan; Wang, Kaibo

2015-12-11

Abundant evidence has shown that grazing alters plant functional traits, community structure and ecosystem functioning of grasslands. Few studies, however, have tested how plant responses to grazing are mediated by resource availability and plant functional group identity. We examined the effects of grazing on functional traits across a broad range of species along a soil moisture gradient in Inner Mongolia grassland. Our results showed that trait syndromes of plant size (individual biomass) and shoot growth (leaf N content and leaf density) distinguished plant species responses to grazing. The effects of grazing on functional traits were mediated by soil moisture and dependent on functional group identity. For most species, grazing decreased plant height but increased leaf N and specific leaf area (SLA) along the moisture gradient. Grazing enhanced the community-weighted attributes (leaf NCWM and SLACWM), which were triggered mainly by the positive trait responses of annuals and biennials and perennial grasses, and increased relative abundance of perennial forbs. Our results suggest that grazing-induced species turnover and increased intraspecific trait variability are two drivers for the observed changes in community weighted attributes. The dominant perennial bunchgrasses exhibited mixed tolerance-resistance strategies to grazing and mixed acquisitive-conservative strategies in resource utilization.

Acute Effect of Foam Rolling and Dynamic Stretching on Flexibility and Jump Height.

PubMed

Smith, Jason C; Pridgeon, Brooke; Hall, MacGregor C

2018-04-04

Smith, JC, Pridgeon, B, and Hall, MC. Acute effect of foam rolling and dynamic stretching on flexibility and jump height. J Strength Cond Res XX(X): 000-000, 2017-Dynamic stretching (DS) can acutely improve vertical jump (VJ) performance but its effect lasts no more than 5 minutes. Foam rolling (FR), a form of self-myofascial release, can acutely increase range of motion (ROM) with this effect lasting less than 10 minutes. Therefore, the purpose of this study was to evaluate the time course of these effects, separately and combined, on VJ height and ROM. Twenty-nine university students completed 4 different sessions (control, FR, DS, and combo) in a randomized order. After a warm-up and baseline assessments of VJ height and sit-and-reach, participants rested (control) and performed FR, DS, and the combination of FR and DS (combo). Vertical jump height and ROM were assessed every 5 minutes for 20 minutes after treatment. Mean scores at each time point were expressed as a percent change from baseline scores. Immediately after FR, sit-and-reach was significantly greater than control (p = 0.003). Vertical jump height immediately after treatment for DS and combo was significantly greater than the control and FR counterparts (p ≤ 0.002). Vertical jump height for DS and combo was also significantly greater than the control counterpart at 5 minutes after treatment (p < 0.001). At 15 minutes after treatment, the percent change in VJ height for the combo was significantly greater than the control counterpart (p = 0.002). Although FR has no effect on VJ performance, it can acutely increase ROM, but its effect was quickly dissipated. Foam rolling does not seem to enhance VJ height either alone or in combination with DS.

Rearfoot eversion has indirect effects on plantar fascia tension by changing the amount of arch collapse.

PubMed

Lee, Sae Yong; Hertel, Jay; Lee, Sung Cheol

2010-01-01

Rearfoot eversion motion and arch height are believed to contribute to increased tension on the plantar fascia and arch collapse during gait but the specifics of these relationships are not clear. To examine the relationships among static arch height, rearfoot eversion, dynamic arch height, and plantar fascia tension. 28 healthy males participated. After static arch height was measured, the subjects were asked to run at 4.5m/s while frontal plane rearfoot motion, dynamic arch height, and ground reaction forces were collected. The relationships among variables were examined with bivariate correlations and path analysis. The results indicated a high correlation between dynamic arch height and static arch height (r=0.642), plantar fascia tension (r=-0.797), and maximum rearfoot eversion motion during gait (r=-0.518). The path analysis model without the direct rearfoot eversion effect explained 81.2% of the variance in plantar fascia tension, while the model with the direct rearfoot eversion effect explained 82.1% of the variance in plantar fascia tension. Including the indirect effect of maximum rearfoot eversion motion on plantar fascia tension through control of dynamic arch height is the model that best explains the interrelationships of these foot characteristics. The amount of maximum rearfoot eversion motion itself is not a good predictor of plantar fascia tension, however, together with the arch height, maximum rearfoot eversion motion is a good predictor because it has a pronounced indirect effect on plantar fascia tension. Copyright 2010. Published by Elsevier Ltd.

Estimating the Prevalence of Childhood Obesity in Alaska Using Partial, Nonrandom Measurement Data

PubMed Central

Boles, Myde; Fink, Karol; Topol, Rebecca; Fenaughty, Andrea

2016-01-01

Although monitoring childhood obesity prevalence is critical for state public health programs to assess trends and the effectiveness of interventions, few states have comprehensive body mass index measurement systems in place. In some states, however, assorted school districts collect measurements on student height and weight as part of annual health screenings. To estimate childhood obesity prevalence in Alaska, we created a logistic regression model using such annual measurements along with public data on demographics and socioeconomic status. Our mixed-effects model-generated prevalence estimates validated well against weighted estimates, with 95% confidence intervals overlapping between methodologies among 7 of 8 participating school districts. Our methodology accounts for variation in school-level and student-level demographic factors across the state, and the approach we describe can be applied by other states that have existing nonrandom student measurement data to estimate childhood obesity prevalence. PMID:27010843

Heterointerface engineering of broken-gap InAs/GaSb multilayer structures.

PubMed

Liu, Jheng-Sin; Zhu, Yan; Goley, Patrick S; Hudait, Mantu K

2015-02-04

Broken-gap InAs/GaSb strain balanced multilayer structures were grown by molecular beam epitaxy (MBE), and their structural, morphological, and band alignment properties were analyzed. Precise shutter sequence during the MBE growth process, enable to achieve the strain balanced structure. Cross-sectional transmission electron microscopy exhibited sharp heterointerfaces, and the lattice line extended from the top GaSb layer to the bottom InAs layer. X-ray analysis further confirmed a strain balanced InAs/GaSb multilayer structure. A smooth surface morphology with surface roughness of ∼0.5 nm was demonstrated. The effective barrier height -0.15 eV at the GaSb/InAs heterointerface was determined by X-ray photoelectron spectroscopy, and it was further corroborated by simulation. These results are important to demonstrate desirable characteristics of mixed As/Sb material systems for high-performance and low-power tunnel field-effect transistor applications.

Parametric studies with an atmospheric diffusion model that assesses toxic fuel hazards due to the ground clouds generated by rocket launches

NASA Technical Reports Server (NTRS)

Stewart, R. B.; Grose, W. L.

1975-01-01

Parametric studies were made with a multilayer atmospheric diffusion model to place quantitative limits on the uncertainty of predicting ground-level toxic rocket-fuel concentrations. Exhaust distributions in the ground cloud, cloud stabilized geometry, atmospheric coefficients, the effects of exhaust plume afterburning of carbon monoxide CO, assumed surface mixing-layer division in the model, and model sensitivity to different meteorological regimes were studied. Large-scale differences in ground-level predictions are quantitatively described. Cloud alongwind growth for several meteorological conditions is shown to be in error because of incorrect application of previous diffusion theory. In addition, rocket-plume calculations indicate that almost all of the rocket-motor carbon monoxide is afterburned to carbon dioxide CO2, thus reducing toxic hazards due to CO. The afterburning is also shown to have a significant effect on cloud stabilization height and on ground-level concentrations of exhaust products.

Fashion versus perception: the impact of surface lightness on the perceived dimensions of interior space.

PubMed

Oberfeld, Daniel; Hecht, Heiko

2011-06-01

We compare expert opinion with perceptual judgment regarding the influence of color on the perceived height and width of interior rooms. We hypothesize that contrary to popular belief, ceiling and wall lightness have additive effects on perceived height, whereas the lightness contrast between these surfaces is less important. We assessed the intuitions of architectural experts as to which surface colors maximize apparent height and compared these intuitions with psychophysical height and width estimates for rooms differing in ceiling, floor, and wall lightness. Experiment 1 was a survey of architectural experts and nonexperts. Experiments 2 and 3 presented virtual rooms varying in physical height, physical width, and surface lightness. In Experiment 1, both experts and nonexperts erroneously assumed that the lightness contrast between ceiling and walls influences perceived height Experiment 2 showed that the lightness contrast does not determine apparent height but that ceiling and wall lightness have additive effects. Experiment 3 demonstrated a decrease in perceived width with physical height, whereas the perceived height was not related to physical width. Apparent width was unaffected by ceiling lightness. Light ceiling and light walls make a room appear higher, whereas floor color has a weaker effect. We also found evidence for an asymmetric interaction between height and width. The question of how to color walls and ceiling to maximize the apparent size of a room can be answered empirically. Aesthetic considerations may interfere with the correct assessment of the effects of color in experts.

Global effects of income and income inequality on adult height and sexual dimorphism in height.

PubMed

Bogin, Barry; Scheffler, Christiane; Hermanussen, Michael

2017-03-01

Average adult height of a population is considered a biomarker of the quality of the health environment and economic conditions. The causal relationships between height and income inequality are not well understood. We analyze data from 169 countries for national average heights of men and women and national-level economic factors to test two hypotheses: (1) income inequality has a greater association with average adult height than does absolute income; and (2) neither income nor income inequality has an effect on sexual dimorphism in height. Average height data come from the NCD-RisC health risk factor collaboration. Economic indicators are derived from the World Bank data archive and include gross domestic product (GDP), Gross National Income per capita adjusted for personal purchasing power (GNI_PPP), and income equality assessed by the Gini coefficient calculated by the Wagstaff method. Hypothesis 1 is supported. Greater income equality is most predictive of average height for both sexes. GNI_PPP explains a significant, but smaller, amount of the variation. National GDP has no association with height. Hypothesis 2 is rejected. With greater average adult height there is greater sexual dimorphism. Findings support a growing literature on the pernicious effects of inequality on growth in height and, by extension, on health. Gradients in height reflect gradients in social disadvantage. Inequality should be considered a pollutant that disempowers people from the resources needed for their own healthy growth and development and for the health and good growth of their children. © 2017 Wiley Periodicals, Inc.

Comparing the role of the height of men and women in the marriage market.

PubMed

Yamamura, Eiji; Tsutsui, Yoshiro

2017-08-01

This paper explores how the role of men and women's height in the marriage market has changed across generations. Using individual-level data from Japan, we compared the effect of height on marriages between men and women, and investigated how the effect of height on marriage has changed across generations. Our key findings are: (1) for men born before 1965, a 1% increase in height led to an approximately 0.56% increase in the probability of being married. Conversely, for women born before 1965, a 1% increase in height led to an approximately 0.56% decrease in the probability of being married. (2) For men born in or after 1965, a 1% increase in height led to an approximately 1.05% (0.18%) increase (decrease) in the probability of being married (divorced). However, the height effect was not present for women. Japan experienced astounding economic development after World War II, which resulted in changes in its economic and social structure. These changes may have also altered the role of height for Japanese men and women in the marriage market. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparison of regional air dispersion simulation and ambient air monitoring data for the soil fumigant 1,3-dichloropropene.

PubMed

van Wesenbeeck, I J; Cryer, S A; de Cirugeda Helle, O; Li, C; Driver, J H

2016-11-01

SOFEA v2.0 is an air dispersion modeling tool used to predict acute and chronic pesticide concentrations in air for large air sheds resulting from agronomic practices. A 1,3-dichloropropene (1,3-D) air monitoring study in high use townships in Merced County, CA, logged 3-day average air concentrations at nine locations over a 14.5month period. SOFEA, using weather data measured at the site, and using a historical CDPR regulatory assumption of a constant 320m mixing height, predicted the general pattern and correct order of magnitude for 1,3-D air concentrations as a function of time, but failed to estimate the highest observed 1,3-D concentrations of the monitoring study. A time series and statistical comparison of the measured and modeled data indicated that the model underestimated 1,3-D concentrations during calm periods (wind speed <1m/s), such that the annual average concentration was under predicted by approximately 4.7-fold, and the variability was not representative of the measured data. Calm periods are associated with low mixing heights (MHs) and are more prevalent in the Central Valley of CA during the winter months, and thus the assumption of a constant 320m mixing height is not appropriate. An algorithm was developed to calculate the MH using the air temperature in the weather file when the wind speed was <1m/s. When the model was run using the revised MHs, the average of the modeled 1,3-D concentration Probability Distribution Function (PDF) was within 5% of the measured PDF, and the variability in modeled concentrations more closely matched the measured dataset. Use of the PCRAMMET processed weather data from the site (including PCRAMMET MH) resulted in the global annual average concentration within 2-fold of measured data. Receptor density was also found to have an effect on the modeled 1,3-D concentration PDF, and a 50×50 receptor grid in the nine township domain captured the measured 1,3-D concentration distribution much better than a 3×3 receptor grid (i.e., simulated receptors at the nine monitoring locations). Comparison of the monitored and simulated PDF for 72-h 1,3-D concentrations indicated that SOFEA slightly over predicts the 1,3-D concentration distribution at all percentiles below the 99th with slight under prediction of the 99-100th percentile values. This suggests that without further refinement, the SOFEA2 model, based upon field validation observations, will result in representative but conservative estimates of lifetime exposure to 1,3-D for bystanders in 1,3-D use areas. Copyright © 2016. Published by Elsevier B.V.

Monodisperse granular flows in viscous dispersions in a centrifugal acceleration field

NASA Astrophysics Data System (ADS)

Cabrera, Miguel Angel; Wu, Wei

2016-04-01

Granular flows are encountered in geophysical flows and innumerable industrial applications with particulate materials. When mixed with a fluid, a complex network of interactions between the particle- and fluid-phase develops, resulting in a compound material with a yet unclear physical behaviour. In the study of granular suspensions mixed with a viscous dispersion, the scaling of the stress-strain characteristics of the fluid phase needs to account for the level of inertia developed in experiments. However, the required model dimensions and amount of material becomes a main limitation for their study. In recent years, centrifuge modelling has been presented as an alternative for the study of particle-fluid flows in a reduced scaled model in an augmented acceleration field. By formulating simple scaling principles proportional to the equivalent acceleration Ng in the model, the resultant flows share many similarities with field events. In this work we study the scaling principles of the fluid phase and its effects on the flow of granular suspensions. We focus on the dense flow of a monodisperse granular suspension mixed with a viscous fluid phase, flowing down an inclined plane and being driven by a centrifugal acceleration field. The scaled model allows the continuous monitoring of the flow heights, velocity fields, basal pressure and mass flow rates at different Ng levels. The experiments successfully identify the effects of scaling the plastic viscosity of the fluid phase, its relation with the deposition of particles over the inclined plane, and allows formulating a discussion on the suitability of simulating particle-fluid flows in a centrifugal acceleration field.

Shrub succession on eight mixed-severity wildfires in western Montana, northeastern Oregon, and northern Idaho

Treesearch

Dennis E. Ferguson; John C. Byrne

2016-01-01

The response of 28 shrub species to wildfire burn severity was assessed for 8 wildfires on 6 national forests in the northern Rocky Mountains, USA. Stratified random sampling was used to choose 224 stands based on burn severity, habitat type series, slope steepness, stand height, and stand density, which resulted in 896 plots measured at approximately 2-year intervals...

Individual tree detection from Unmanned Aerial Vehicle (UAV) derived canopy height model in an open canopy mixed conifer forest

Treesearch

Midhun Mohan; Carlos Alberto Silva; Carine Klauberg; Prahlad Jat; Glenn Catts; Adrian Cardil; Andrew Thomas Hudak; Mahendra Dia

2017-01-01

Advances in Unmanned Aerial Vehicle (UAV) technology and data processing capabilities have made it feasible to obtain high-resolution imagery and three dimensional (3D) data which can be used for forest monitoring and assessing tree attributes. This study evaluates the applicability of low consumer grade cameras attached to UAVs and structure-from-motion (SfM)...

Conifer regeneration on burned and unburned clearcuts on granitic soils of the Klamath National Forest

Treesearch

Danny Heavilan

1977-01-01

Regeneration was studied on a mixed conifer stand on granitic soils on the Klamath National Forest. Six years after logging and hand planting with Douglas-fir, stocking and growth on cutblocks where slash had been broadcast burned was compared with that on similar unburned cutblocks. Conifers were seven times more plentiful on the unburned areas, the average height of...

Development of epicormic sprouts in Sitka spruce following thinning and pruning in south-east Alaska.

Treesearch

Robert L. Deal; R. James Barbour; Michael H. McClellan; Dean L. Parry

2003-01-01

The frequency and size of epicormic sprouts in Sitka spruce (Picea sitchensis (Bong.) Carr.) were assessed in five 23-29 year-old mixed Sitka spruce-western hemlock (Tsuga heterophylla (Raf.) Sarg.) stands that were uniformly thinned and pruned to 2.4, 3.7 and 5.2 m lift heights. Six to nine years after treatment sprouts were...

Regeneration in windthrow areas in hemiboreal forests: the influence of microsite on the height growths of different tree species

Treesearch

F. Vodde; K. Jõgiste; L. Gruson; T. Ilisson; K. Köster; J.A. Stanturf

2010-01-01

Natural regeneration of windthrow areas is an important issue when planning forestry measures after forest disturbances. Seedling recruitment was investigated in storm-damaged hemiboreal mixed forests in eastern Estonia. The establishment and growth of seedlings from natural regeneration was registered for tree species in soil pits and in mounds of uprooted trees in...

Development of a Mixed-Shrub-Planted Ponderosa Pine Communicty on a Poor Site After Site Preparation and Release

Treesearch

Philip M. McDonald

2003-01-01

On a poor site in northern California, a mature brushfield was treated in various ways that left initial density categories of light, medium, and heavy shrubs. Density, foliar cover, and height of seven shrub species (alone and combined) and ponderosa pine seedlings in these categories were quantified from 1967 through 1978. Heretofore, density and development data for...

PROFIT-PC: a program for estimating maximum net revenue from multiproduct harvests in Appalachian hardwoods

Treesearch

Chris B. LeDoux; John E. Baumgras; R. Bryan Selbe

1989-01-01

PROFIT-PC is a menu driven, interactive PC (personal computer) program that estimates optimum product mix and maximum net harvesting revenue based on projected product yields and stump-to-mill timber harvesting costs. Required inputs include the number of trees/acre by species and 2 inches diameter at breast-height class, delivered product prices by species and product...

Army Helicopter Crashworthiness

DTIC Science & Technology

1983-10-01

protect the structure surrounding the occupied Cabin volume. Components. An important part of this program was to evaluate analysis methods that could...rigid (nonstroking) seats and the production BLACK HAWK helicopter crashworthy crewseat. Tests of three embalmed cadavers in the rigid seat gave mixed...CONDITIONS FOR RIGID SEAT TESTS WITH EMBALMED CADAVERS 1 CADAVER WEIGHT PEAK TEST NO. NO. AGE HEIGHT (LB) SEX ACCEL. (G) FRACTURE CONDITION SERIES #1

Modelling diameter distributions of two-cohort forest stands with various proportions of dominant species: a two-component mixture model approach.

Treesearch

Rafal Podlaski; Francis Roesch

2014-01-01

In recent years finite-mixture models have been employed to approximate and model empirical diameter at breast height (DBH) distributions. We used two-component mixtures of either the Weibull distribution or the gamma distribution for describing the DBH distributions of mixed-species, two-cohort forest stands, to analyse the relationships between the DBH components,...

Measurement and modeling of diel variability of polybrominated diphenyl ethers and chlordanes in air.

PubMed

Moeckel, Claudia; Macleod, Matthew; Hungerbühler, Konrad; Jones, Kevin C

2008-05-01

Short-term variability of concentrations of polybrominated diphenyl ethers (PBDEs) and chlordanes in air at a semirural site in England over a 5 day period is reported. Four-hour air samples were collected during a period dominated by a high pressure system that produced stable diel (24-h) patterns of meteorological conditions such as temperature and atmospheric boundary layer height. PBDE and chlordane concentrations showed clear diel variability with concentrations in the afternoon and evening being 1.9 - 2.7 times higher than in the early morning. The measurements are interpreted using a multimedia mass balance model parametrized with forcing functions representing local temperature, atmospheric boundary layer height, wind speed and hydroxyl radical concentrations. Model results indicate that reversible, temperature-controlled air-surface exchange is the primary driver of the diel concentration pattern observed for chlordanes and PBDE 28. For higher brominated PBDE congeners (47, 99 and 100), the effect of variable atmospheric mixing height in combination with irreversible deposition on aerosol particles is dominant and explains the diel patterns almost entirely. Higher concentrations of chlordanes and PBDEs in air observed at the end of the study period could be related to likely source areas using back trajectory analysis. This is the first study to clearly document diel variability in concentrations of PBDEs in air over a period of several days. Our model analysis indicates that high daytime and low nighttime concentrations of semivolatile organic chemicals can arise from different underlying driving processes, and are not necessarily evidence of reversible air-surface exchange on a 24-h time scale.

Primary and secondary pesticide drift profiles from a peach orchard.

PubMed

Zivan, Ohad; Bohbot-Raviv, Yardena; Dubowski, Yael

2017-06-01

Atmospheric drift is considered a major loss path of pesticide from target areas, but there is still a large gap of knowledge regarding this complex phenomenon. Pesticide drift may occur during application (Primary drift) and after it (Secondary drift). The present study focuses on primary and secondary drift from ground applications in peach orchard (tree height of 3 m), under Mediterranean climate. Detailed and prolonged vertical drift profiles at close proximity to orchard are presented, together with detailed measurements of key meteorological parameters. The effect of volatility on drift was also studied by simultaneously applying two pesticides that differ in their volatility. Drifting airborne pesticides were detected both during and after applications at sampling distances of 7 and 20 m away from orchard edge. Concentrations ranged between hundreds ng m -3 to a few μg m -3 and showed clear decrease with time and with upwind conditions. Almost no decline in concentrations with height was observed up to thrice canopy height (i.e., 10 m). These homogeneous profiles indicate strong mixing near orchard and are in line with the unstable atmospheric conditions that prevailed during measurements. While air concentrations during pesticide application were higher than after it, overall pesticide load drifted from the orchard during primary and secondary drift are comparable. To the best of our knowledge this is the first work to show such large vertical dispersion and long duration of secondary drift following ground application in orchards. The obtained information indicates that secondary drift should not be neglected in exposure and environmental impact estimations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tornado occurrences related to overshooting cloud-top heights as determined from ATS pictures

NASA Technical Reports Server (NTRS)

Fujita, T. T.

1972-01-01

A sequence of ATS 3 pictures including the development history of large anvil clouds near Salina, Kansas was enlarged by NASA into 8X negatives which were used to obtain the best quality prints by mixing scan lines in 8 steps to minimize checker-board patterns. These images resulted in the best possible resolution, permitting use to compute the heights of overshooting tops above environmental anvil levels based on cloud shadow relationships along with the techniques of lunar topographic mapping. Of 39 heights computed, 6 were within 15 miles of reported positions of 3 tornadoes. It was found that the tornado proximity tops were mostly less than 5000 ft, with one exception of 7000 ft, suggesting that tornadoes are most likely to occur when overshooting height decreases. In order to simulate surface vortices induced by cloud-scale rotation and updraft fields, a laboratory model was constructed. The model experiment has shown that the rotation or updraft field induces a surface vortex but their combination does prevent the formation of the surface vortex. This research leads to a conclusion that the determination of the cloud-top topography and its time variation is of extreme importance in predicting severe local storms for a period of 0 to 6 hours.

Finding missing heritability in less significant Loci and allelic heterogeneity: genetic variation in human height.

PubMed

Zhang, Ge; Karns, Rebekah; Sun, Guangyun; Indugula, Subba Rao; Cheng, Hong; Havas-Augustin, Dubravka; Novokmet, Natalija; Durakovic, Zijad; Missoni, Sasa; Chakraborty, Ranajit; Rudan, Pavao; Deka, Ranjan

2012-01-01

Genome-wide association studies (GWAS) have identified many common variants associated with complex traits in human populations. Thus far, most reported variants have relatively small effects and explain only a small proportion of phenotypic variance, leading to the issues of 'missing' heritability and its explanation. Using height as an example, we examined two possible sources of missing heritability: first, variants with smaller effects whose associations with height failed to reach genome-wide significance and second, allelic heterogeneity due to the effects of multiple variants at a single locus. Using a novel analytical approach we examined allelic heterogeneity of height-associated loci selected from SNPs of different significance levels based on the summary data of the GIANT (stage 1) studies. In a sample of 1,304 individuals collected from an island population of the Adriatic coast of Croatia, we assessed the extent of height variance explained by incorporating the effects of less significant height loci and multiple effective SNPs at the same loci. Our results indicate that approximately half of the 118 loci that achieved stringent genome-wide significance (p-value<5×10(-8)) showed evidence of allelic heterogeneity. Additionally, including less significant loci (i.e., p-value<5×10(-4)) and accounting for effects of allelic heterogeneity substantially improved the variance explained in height.

Waist-to-Height Gain and Triiodothyronine Concentrations in a Cohort of Socially Vulnerable Short-Stature Women: A Four-Year Follow-Up Study.

PubMed

Florêncio, Telma M M T; Bueno, Nassib B; Britto, Revilane A P; Albuquerque, Fabiana C A; Lins, Isabela L L; Sawaya, Ana L

2016-01-01

Short stature that results from undernourishment during perinatal period is associated with an increased risk of diabetes and cardiovascular diseases in adulthood, particularly in poor populations. The present study investigated changes on anthropometric and metabolic parameters of socially vulnerable women with short stature. A prospective study with 48 women (19-45 years) who were mothers of undernourished children was conducted. Twenty-five of them were short (height ≤150 cm), and 23 were not short, to serve as a control (height >159 cm). Biochemical, anthropometric and dietary intake data were collected, before and after 4 years of follow-up. A mixed within-between analysis of covariance was used to assess the interaction between 'group' and 'time'. Waist-to-height ratio increased only in the short stature group, with significant interaction (+0.03 ± 0.03 in short group vs. +0.01 ± 0.03 in control; p for interaction = 0.04). The short stature group showed a significant decrease in the plasma triiodothyronine (T3) concentrations, without significant interaction (-0.16 ± 0.23 ng/ml in short group vs. -0.04 ± 0.29 ng/ml in control; p for interaction = 0.20). Women of short stature presented an increase in waist-to-height ratio, with a simultaneous decrease in total plasma T3. These alterations may lead them to increased risk of comorbidities. © 2016 S. Karger AG, Basel.

Near-adult height in male kidney transplant recipients started on growth hormone treatment in late puberty.

PubMed

Gil, Silvia; Aziz, Mariana; Adragna, Marta; Monteverde, Marta; Belgorosky, Alicia

2018-01-01

Growth retardation and its impact on adult height is considered to be one of the most common complications in patients with chronic kidney disease (CKD). Treatment with recombinant human growth hormone (rhGH) has been effective in improving growth in kidney transplantation (KTx) patients, but little data are available on adult height in patients who began rhGh treatment in late puberty. Near-adult height was evaluated in 13 KTx patients treated with rhGH [growth hormone group (GHGr); dose 9.33 mg/m 2 per week] for a period of at least 18 months. At initiation of rhGH treatment, testicular volume was >8 ml and serum testosterone was >1 ng/ml compared with the control group (CGr) of ten KTx patients who did not receive rHGH. All subjects were of similar chronological age and bone age and had similar creatinine clearance (CrCl) levels, cumulative corticoid dose, height standard deviation score (SDS), target height SDS, and target height:initial height at the beginning of the study. Near-adult height was significantly greater in the GHGr than in the CGr (-1.8 ± 0.8 vs. -2.9 ± 1.1; p = 0.018). The difference between initial height and near-adult height in the GHGr revealed a significant height gain (initial height -3.1 ± 1.1; near-adult height -1.8 ± 0.8 SDS, respectively; delta 1.2 ± 0.3; p = 0.021). The CrCl level was not significantly different between the GHGr and CGr at either at study initiation or when attaining near-adult height (p = 0.74 and p = 0.23, respectively). Treatment with rhGH was effective in improving adult height in KTx patients who began treatment in late puberty, without any effect on renal function.

Longitudinal analysis of large social networks: Estimating the effect of health traits on changes in friendship ties

PubMed Central

O'Malley, A James; Christakis, Nicholas A

2011-01-01

We develop novel mixed effects models to examine the role of health traits on the status of peoples' close friendship nominations in the Framingham Heart Study. The health traits considered are both mutable (body mass index (BMI), smoking, blood pressure, body proportion, muscularity, and depression) and, for comparison, basically immutable (height, birth order, personality type, only child, and handedness); and the traits have varying degrees of observability. We test the hypotheses that existing ties (i.e. close friendship nominations) are more likely to dissolve between people with dissimilar (mutable and observable) health traits whereas new ties are more likely to form between those with similar (mutable and observable) traits while controlling for persons' age, gender, geographic separation, and education. The mixed effects models contain random effects for both the nominator (ego) and nominated (alter) persons in a tie to account for the fact that people were involved in multiple relationships and contributed observations at multiple exams. Results for BMI support the hypotheses that people of similar BMI are less likely to dissolve existing ties and more likely to form ties, while smoker to non-smoker ties were the least likely to dissolve and smoker to smoker ties were the most likely to form. We also validated previously known findings regarding homophily on age and gender, and found evidence that homophily also depends upon geographic separation. Copyright © 2011 John Wiley & Sons, Ltd. PMID:21287589

Longitudinal analysis of large social networks: estimating the effect of health traits on changes in friendship ties.

PubMed

O'Malley, A James; Christakis, Nicholas A

2011-04-30

We develop novel mixed effects models to examine the role of health traits on the status of peoples' close friendship nominations in the Framingham Heart Study. The health traits considered are both mutable (body mass index (BMI), smoking, blood pressure, body proportion, muscularity, and depression) and, for comparison, basically immutable (height, birth order, personality type, only child, and handedness); and the traits have varying degrees of observability. We test the hypotheses that existing ties (i.e. close friendship nominations) are more likely to dissolve between people with dissimilar (mutable and observable) health traits whereas new ties are more likely to form between those with similar (mutable and observable) traits while controlling for persons' age, gender, geographic separation, and education. The mixed effects models contain random effects for both the nominator (ego) and nominated (alter) persons in a tie to account for the fact that people were involved in multiple relationships and contributed observations at multiple exams. Results for BMI support the hypotheses that people of similar BMI are less likely to dissolve existing ties and more likely to form ties, while smoker to non-smoker ties were the least likely to dissolve and smoker to smoker ties were the most likely to form. We also validated previously known findings regarding homophily on age and gender, and found evidence that homophily also depends upon geographic separation. Copyright © 2011 John Wiley & Sons, Ltd.

Field- and Remote Sensing-based Structural Attributes Measured at Multiple Scales Influence the Relationship Between Nitrogen and Reflectance of Forest Canopies

NASA Astrophysics Data System (ADS)

Sullivan, F.; Ollinger, S. V.; Palace, M. W.; Ouimette, A.; Sanders-DeMott, R.; Lepine, L. C.

2017-12-01

The correlation between near-infrared reflectance and forest canopy nitrogen concentration has been demonstrated at varying scales using a range of optical sensors on airborne and satellite platforms. Although the mechanism underpinning the relationship is unclear, at its basis are biologically-driven functional relationships of multiple plant traits that affect canopy chemistry and structure. The link between near-infrared reflectance and canopy nitrogen has been hypothesized to be partially driven by covariation of canopy nitrogen with canopy structure. In this study, we used a combination of airborne LiDAR data and field measured leaf and canopy chemical and structural traits to explore interrelationships between canopy nitrogen, near-infrared reflectance, and canopy structure on plots at Bartlett Experimental Forest in the White Mountain National Forest, New Hampshire. Over each plot, we developed a 1-meter resolution canopy height profile and a 1-meter resolution canopy height model. From canopy height profiles and canopy height models, we calculated a set of metrics describing the plot-level variability, breadth, depth, and arrangement of LiDAR returns. This combination of metrics was used to describe both vertical and horizontal variation in structure. In addition, we developed and measured several field-based metrics of leaf and canopy structure at the plot scale by directly measuring the canopy or by weighting leaf-level metrics by species leaf area contribution. We assessed relationships between leaf and structural metrics, near-infrared reflectance and canopy nitrogen concentration using multiple linear regression and mixed effects modeling. Consistent with our hypothesis, we found moderately strong links between both near-infrared reflectance and canopy nitrogen concentration with LiDAR-derived structural metrics, and we additionally found that leaf-level metrics scaled to the plot level share an important role in canopy reflectance. We suggest that canopy structure has a governing role in canopy reflectance, reducing maximum potential reflectance as structural complexity increases, and therefore also influences the relationship between canopy nitrogen and NIR reflectance.

Using models to interpret the impact of roadside barriers on near-road air quality

NASA Astrophysics Data System (ADS)

Amini, Seyedmorteza; Ahangar, Faraz Enayati; Schulte, Nico; Venkatram, Akula

2016-08-01

The question this paper addresses is whether semi-empirical dispersion models based on data from controlled wind tunnel and tracer experiments can describe data collected downwind of a sound barrier next to a real-world urban highway. Both models are based on the mixed wake model described in Schulte et al. (2014). The first neglects the effects of stability on dispersion, and the second accounts for reduced entrainment into the wake of the barrier under unstable conditions. The models were evaluated with data collected downwind of a kilometer-long barrier next to the I-215 freeway running next to the University of California campus in Riverside. The data included measurements of 1) ultrafine particle (UFP) concentrations at several distances from the barrier, 2) micrometeorological variables upwind and downwind of the barrier, and 3) traffic flow separated by automobiles and trucks. Because the emission factor for UFP is highly uncertain, we treated it as a model parameter whose value is obtained by fitting model estimates to observations of UFP concentrations measured at distances where the barrier impact is not dominant. Both models provide adequate descriptions of both the magnitude and the spatial variation of observed concentrations. The good performance of the models reinforces the conclusion from Schulte et al. (2014) that the presence of the barrier is equivalent to shifting the line sources on the road upwind by a distance of about HU/u∗ where H is the barrier height, U is the wind velocity at half of the barrier height, and u∗ is the friction velocity. The models predict that a 4 m barrier results in a 35% reduction in average concentration within 40 m (10 times the barrier height) of the barrier, relative to the no-barrier site. This concentration reduction is 55% if the barrier height is doubled.

Canopy transpiration of pure and mixed forest stands with variable abundance of European beech

NASA Astrophysics Data System (ADS)

Gebauer, Tobias; Horna, Viviana; Leuschner, Christoph

2012-06-01

SummaryThe importance of tree species identity and diversity for biogeochemical cycles in forests is not well understood. In the past, forestry has widely converted mixed forests to pure stands while contemporary forest policy often prefers mixed stands again. However, the hydrological consequences of these changes remain unclear. We tested the hypotheses (i) that significant differences in water use per ground area exist among the tree species of temperate mixed forests and that these differences are more relevant for the amount of stand-level canopy transpiration (Ec) than putative complementarity effects of tree water use, and (ii) that the seasonal patterns of Ec in mixed stands are significantly influenced by the identity of the present tree species. We measured xylem sap flux during 2005 (average precipitation) and 2006 (relatively dry) synchronously in three nearby old-growth forest stands on similar soil differing in the abundance of European beech (pure beech stand, 3-species stand with 70% beech, 5-species stand with <10% beech). In summer 2005 with average rainfall, Ec was 50% higher in the beech-poor 5-species stand than in the two stands with moderate to high beech presence (158 vs. 97 and 101 mm yr-1); in the dry summer 2006, all stands converged toward similar Ec totals (128-139 mm yr-1). Species differences in Ec were large on a sapwood area basis, reflecting a considerable variation in hydraulic architecture and leaf conductance regulation among the co-existing species. Moreover, transpiration per crown projection area (ECA) also differed up to 5-fold among the different species in the mixed stands, probably reflecting contrasting sapwood/crown area ratios. We conclude that Ec is not principally higher in mixed forests than in pure beech stands. However, tree species-specific traits have an important influence on the height of Ec and affect its seasonal variation. Species with a relatively high ECA (notably Tilia) may exhaust soil water reserves early in summer, thereby increasing drought stress in dry years and possibly reducing ecosystem stability in mixed forests.

Tree species diversity promotes aboveground carbon storage through functional diversity and functional dominance.

PubMed

Mensah, Sylvanus; Veldtman, Ruan; Assogbadjo, Achille E; Glèlè Kakaï, Romain; Seifert, Thomas

2016-10-01

The relationship between biodiversity and ecosystem function has increasingly been debated as the cornerstone of the processes behind ecosystem services delivery. Experimental and natural field-based studies have come up with nonconsistent patterns of biodiversity-ecosystem function, supporting either niche complementarity or selection effects hypothesis. Here, we used aboveground carbon (AGC) storage as proxy for ecosystem function in a South African mistbelt forest, and analyzed its relationship with species diversity, through functional diversity and functional dominance. We hypothesized that (1) diversity influences AGC through functional diversity and functional dominance effects; and (2) effects of diversity on AGC would be greater for functional dominance than for functional diversity. Community weight mean (CWM) of functional traits (wood density, specific leaf area, and maximum plant height) were calculated to assess functional dominance (selection effects). As for functional diversity (complementarity effects), multitrait functional diversity indices were computed. The first hypothesis was tested using structural equation modeling. For the second hypothesis, effects of environmental variables such as slope and altitude were tested first, and separate linear mixed-effects models were fitted afterward for functional diversity, functional dominance, and both. Results showed that AGC varied significantly along the slope gradient, with lower values at steeper sites. Species diversity (richness) had positive relationship with AGC, even when slope effects were considered. As predicted, diversity effects on AGC were mediated through functional diversity and functional dominance, suggesting that both the niche complementarity and the selection effects are not exclusively affecting carbon storage. However, the effects were greater for functional diversity than for functional dominance. Furthermore, functional dominance effects were strongly transmitted by CWM of maximum plant height, reflecting the importance of forest vertical stratification for diversity-carbon relationship. We therefore argue for stronger complementary effects that would be induced also by complementary light-use efficiency of tree and species growing in the understory layer.

Scaling Constraints in Junior Tennis: The Influence of Net Height on Skilled Players' Match-Play Performance

ERIC Educational Resources Information Center

Limpens, Vera; Buszard, Tim; Shoemaker, Emma; Savelsbergh, Geert J. P.; Reid, Machar

2018-01-01

Purpose: The net height in tennis (0.91 m) is approximately 50% of a professional tennis player's height. Children are also expected to play with this net height, even though it is approximately 70% of the average 10-year-old's height. This study examined the immediate effect of lowering net height on the performance characteristics of skilled…

Growth references for Tsimane forager-horticulturalists of the Bolivian Amazon

PubMed Central

Blackwell, Aaron D.; Urlacher, Samuel S.; Beheim, Bret; von Rueden, Christopher; Jaeggi, Adrian; Stieglitz, Jonathan; Trumble, Benjamin C.; Gurven, Michael; Kaplan, Hillard

2016-01-01

Objectives Growth standards and references currently used to assess population and individual health are derived primarily from urban populations, including few individuals from indigenous or subsistence groups. Given environmental and genetic differences, growth may vary in these populations. Thus, there is a need to assess whether international standards are appropriate for all populations, and to produce population specific references if growth differs. Here we present and assess growth references for the Tsimane, an indigenous population of Bolivian forager-horticulturalists. Methods Mixed cross-sectional/longitudinal anthropometrics (9,614 individuals; 30,118 observations; ages 0–29 years) were used to generate centile curves and Lambda-Mu-Sigma (LMS) tables for height-for-age, weight-for-age, body mass index (BMI)-for-age, and weight-for-height (WFH) using Generalized Additive Models for Location Shape and Scale (GAMLSS). Velocity curves were generated using SuperImposition by Translation and Rotation (SITAR). Tsimane ≤5 years were compared World Health Organization (WHO) standards while those >5 years were compared to WHO school age references. All ages were compared to published references for Shuar forager-horticulturalists of the Ecuadorian Amazon. Results Tsimane growth differs from WHO values in height and weight, but is similar for BMI and WFH. Tsimane growth is characterized by slow height velocity in childhood and early adolescent peak height velocity at 11.3 and 13.2 years for girls and boys. Tsimane growth patterns are similar to Shuar, suggesting shared features of growth among indigenous South Americans. Conclusions International references for BMI-for-age and WFH are likely appropriate for Tsimane, but differences in height-for-age and weight-for-age suggest Tsimane specific references may be useful for these measures. PMID:28218400

Growth references for Tsimane forager-horticulturalists of the Bolivian Amazon.

PubMed

Blackwell, Aaron D; Urlacher, Samuel S; Beheim, Bret; von Rueden, Christopher; Jaeggi, Adrian; Stieglitz, Jonathan; Trumble, Benjamin C; Gurven, Michael; Kaplan, Hillard

2017-03-01

Growth standards and references currently used to assess population and individual health are derived primarily from urban populations, including few individuals from indigenous or subsistence groups. Given environmental and genetic differences, growth may vary in these populations. Thus, there is a need to assess whether international standards are appropriate for all populations, and to produce population specific references if growth differs. Here we present and assess growth references for the Tsimane, an indigenous population of Bolivian forager-horticulturalists. Mixed cross-sectional/longitudinal anthropometrics (9,614 individuals; 30,118 observations; ages 0-29 years) were used to generate centile curves and Lambda-Mu-Sigma (LMS) tables for height-for-age, weight-for-age, body mass index (BMI)-for-age, and weight-for-height (WFH) using Generalized Additive Models for Location Shape and Scale (GAMLSS). Velocity curves were generated using SuperImposition by Translation and Rotation (SITAR). Tsimane ≤5 years were compared to World Health Organization (WHO) standards while those >5 years were compared to WHO school age references. All ages were compared to published references for Shuar forager-horticulturalists of the Ecuadorian Amazon. Tsimane growth differs from WHO values in height and weight, but is similar for BMI and WFH. Tsimane growth is characterized by slow height velocity in childhood and early adolescent peak height velocity at 11.3 and 13.2 years for girls and boys. Tsimane growth patterns are similar to Shuar, suggesting shared features of growth among indigenous South Americans. International references for BMI-for-age and WFH are likely appropriate for Tsimane, but differences in height-for-age and weight-for-age suggest Tsimane specific references may be useful for these measures. © 2016 Wiley Periodicals, Inc.

Observations of the Early Morning Boundary-Layer Transition with Small Remotely-Piloted Aircraft

NASA Astrophysics Data System (ADS)

Wildmann, Norman; Rau, Gerrit Anke; Bange, Jens

2015-12-01

A remotely-piloted aircraft (RPA), equipped with a high resolution thermodynamic sensor package, was used to investigate physical processes during the morning transition of the atmospheric boundary layer over land. Experiments were conducted at a test site in heterogeneous terrain in south-west Germany on 5 days from June to September 2013 in an evolving shallow convective boundary layer, which then developed into a well-mixed layer later in the day. A combination of vertical profiling and constant-altitude profiling (CAP) at 100 m height above ground level was chosen as the measuring strategy throughout the experiment. The combination of flight strategies allows the application of mixed-layer scaling using the boundary-layer height z_i, convective velocity scale w_* and convective temperature scale θ _*. The hypothesis that mixed-layer theory is valid during the whole transition was not confirmed for all parameters. A good agreement is found for temperature variances, especially in the upper half of the boundary layer, and the normalized heat-flux profile. The results were compared to a previous study with the helicopter-borne turbulence probe Helipod, and it was found that similar data quality can be achieved with the RPA. On all days, the CAP flight level was within the entrainment zone for a short time, and the horizontal variability of temperature and water vapour along the flight path is presented as an example of the inhomogeneity of layer interfaces in the boundary layer. The study serves as a case study of the possibilities and limitations with state-of-the-art RPA technology in micrometeorology.

Observational characteristics of the tropopause inversion layer derived from CHAMP/GRACE radio occultations and MOZAIC aircraft data

NASA Astrophysics Data System (ADS)

Schmidt, Torsten; Cammas, Jean-Pierre; Heise, Stefan; Wickert, Jens; Haser, Antonia

2010-05-01

In this study we discuss characteristics of the tropopause inversion layer (TIL) based on two datasets. Temperature measurements from GPS radio occultation (RO) data (CHAMP and GRACE) for the time interval 2001-2009 are used to exhibit seasonal properties of the TIL on a global scale. In agreement with previous studies the vertical structure of the TIL is investigated using the square of the buoyancy frequency N. For the extratropics on both hemispheres N2 has an universal distribution independent from season: a local minimum about 2 km below the lapse rate tropopause height (LRTH), an absolute maximum about 1 km above the LRTH, and a local minimum about 4 km above the LRTH. In the tropics (15°N-15°S) the N2 maximum above the tropopause is 200-300 m higher compared with the extratropics and the local minimum of N2 below the tropopause appears about 4 km below the LRTH. Trace gas measurements onboard commercial aircrafts from 2001-2007 are used as a complementary dataset (MOZAIC program). We demonstrate that the mixing ratio gradients of ozone, carbon monoxide and water vapor are suitable parameters for characterizing the TIL reproducing most of the vertical structure of N2. We also show that the LRTH is strongly correlated with the absolute maxima of ozone and carbon monoxide mixing ratio gradients. Mean deviations of the heights of the absolute maxima of mixing ratio gradients from O3 and CO to the LRTH are (-0.02±1.51) km and (-0.35±1.28) km, respectively.

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 5 2012-10-01 2012-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 5 2010-10-01 2010-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 5 2014-10-01 2014-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 5 2011-10-01 2011-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

47 CFR 90.635 - Limitations on power and antenna height.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 5 2013-10-01 2013-10-01 false Limitations on power and antenna height. 90.635... and antenna height. (a) The effective radiated power and antenna height for base stations may not... justify power levels and antenna heights requested. (b) The maximum output power of the transmitter for...

Seasonal, interannual and long-term variabilities and tendencies of water vapour in the upper stratosphere and mesospheric region over tropics (30°N-30°S)

NASA Astrophysics Data System (ADS)

Nath, Oindrila; Sridharan, S.; Naidu, C. V.

2018-01-01

Tropical water vapour volume mixing ratio (WVMR) data for October 2004-September 2015 obtained from the Microwave Limb Sounder are used to study its long-term variabilities and tendencies in the height region 12.1-0.002 hPa. Above 0.01 hPa, the WVMR shows minimum March-May and September-November (∼0.7-0.8 ppmv) and maximum during June-August. It shows a large interannual variability at 31-64 km. The results from multivariate regression analysis show an increasing trend with maximum value of ∼0.045 ppmv/yr at 1.21-0.41 hPa. It shows a significant negative solar cycle response at mesospheric heights.

Dynamics of interacting edge defects in copolymer lamellae

NASA Astrophysics Data System (ADS)

Dalnoki-Veress, Kari; McGraw, Joshua D.; Rowe, Ian D. W.

2011-03-01

It is known that terraces at the interface of lamella forming diblock copolymers do not make discontinuous jumps in height. Rather, their profiles are smoothly varying. The width of the transition region between two lamellar heights is typically several hundreds of nanometres, resulting from a balance between surface tension, chain stretching penalties, and the enthalpy of mixing. What is less well known in these systems is what happens when two transition regions approach one another. In this study, we show that time dependent experimental data of interacting copolymer lamellar edges is consistent with a model that assumes a repulsion between adjacent edges. The range of the interaction between edge defects is consistent with the profile width of noninteracting diblock terraces. Financial support from NSERC of Canada is gratefully acknowledged.

The association between height and birth order: evidence from 652,518 Swedish men.

PubMed

Myrskylä, Mikko; Silventoinen, Karri; Jelenkovic, Aline; Tynelius, Per; Rasmussen, Finn

2013-07-01

Birth order is associated with outcomes such as birth weight and adult socioeconomic position (SEP), but little is known about the association with adult height. This potential birth order-height association is important because height predicts health, and because the association may help explain population-level height trends. We studied the birth order-height association and whether it varies by family characteristics or birth cohort. We used the Swedish Military Conscription Register to analyse adult height among 652,518 men born in 1951-1983 using fixed effects regression models that compare brothers and account for genetic and social factors shared by brothers. We stratified the analysis by family size, parental SEP and birth cohort. We compared models with and without birth weight and birth length controls. Unadjusted analyses showed no differences between the first two birth orders but in the fixed effects regression, birth orders 2, 3 and 4 were associated with 0.4, 0.7 and 0.8 cm (p<0.001 for each) shorter height than birth order 1, respectively. The associations were similar in large and small and high-SEP and low-SEP families, but were attenuated in recent cohorts. Birth characteristics did not explain these associations. Birth order is an important determinant of height. The height difference between birth orders 3 and 1 is larger than the population-level height increase achieved over 10 years. The attenuation of the effect over cohorts may reflect improvements in living standards. Decreases in family size may explain some of the secular-height increases in countries with decreasing fertility.

[Effects of neighbor competition on growth, fine root morphology and distribution of Schima superba and Cunninghamia lanceolata in different nutrient environments].

PubMed

Yao, Jia Bao; Chu, Xiu Li; Zhou, Zhi Chun; Tong, Jian She; Wang, Hui; Yu, Jia Zhong

2017-05-18

Taking Schima superba and Cunninghamia lanceolata as test materials, a pot experiment was conducted to simulate the heterogeneous and homogeneous forest soil nutrient environments, and design three planting modes including single plant, two-strain pure plant and two-strain mixed ones to reason the promotion in mixed S. superba and C. lanceolata plantation and the competitive advantage of S. superba. Results showed that compared with the homogeneous nutrient environment, both S. superba and C. lanceolata had the higher seedling height and dry matter accumulation, when mixed in the heterogeneous nutrient environment, S. superba displayed the obviously competitive advantage, which related to its root plasticity. The fine root of S. superba mixed in each diameter class showed a lot of hyperplasia, and the root total length, surface area and volume of which were 80%-180% higher than that of C. lanceolata. S. superba took the advantage of the compensatory growth strategy of vertical direction in fine roots, namely, they still multiplied to gain greater competitive advantage in low nutrient patches, besides occupying eutrophic surface. The different soil colonization and niche differentiation in fine root of S. superba and C. lanceolata alleviated the strong competition for nutrients of the roots of the two species, and improved the mixed-plantation production. Pure plantation of S. superba harvested the lower yield, which due to the root self-recognition inhibited the growth of root system. Fine roots staggered and evenly distributed on the space might be a reason for stable structure of pure S. superba plantation. So, it was recommended that block surface layer soil preparation and fertilization are used to improve the soil nutrient distribution, and the mixed plantation is constructed to promote the growth of S. superba and C. lanceolata, at the same time, the stand density is regulated to promote tree growth for the pure artificial S. superba plantation which had already been built.

Effects of geometric modulation and surface potential heterogeneity on electrokinetic flow and solute transport in a microchannel

NASA Astrophysics Data System (ADS)

Bera, Subrata; Bhattacharyya, S.

2017-12-01

A numerical investigation is performed on the electroosmotic flow (EOF) in a surface-modulated microchannel to induce enhanced solute mixing. The channel wall is modulated by placing surface-mounted obstacles of trigonometric shape along which the surface potential is considered to be different from the surface potential of the homogeneous part of the wall. The characteristics of the electrokinetic flow are governed by the Laplace equation for the distribution of external electric potential; the Poisson equation for the distribution of induced electric potential; the Nernst-Planck equations for the distribution of ions; and the Navier-Stokes equations for fluid flow simultaneously. These nonlinear coupled set of governing equations are solved numerically by a control volume method over the staggered system. The influence of the geometric modulation of the surface, surface potential heterogeneity and the bulk ionic concentration on the EOF is analyzed. Vortical flow develops near a surface modulation, and it becomes stronger when the surface potential of the modulated region is in opposite sign to the surface potential of the homogeneous part of the channel walls. Vortical flow also depends on the Debye length when the Debye length is in the order of the channel height. Pressure drop along the channel length is higher for a ribbed wall channel compared to the grooved wall case. The pressure drop decreases with the increase in the amplitude for a grooved channel, but increases for a ribbed channel. The mixing index is quantified through the standard deviation of the solute distribution. Our results show that mixing index is higher for the ribbed channel compared to the grooved channel with heterogeneous surface potential. The increase in potential heterogeneity in the modulated region also increases the mixing index in both grooved and ribbed channels. However, the mixing performance, which is the ratio of the mixing index to pressure drop, reduces with the rise in the surface potential heterogeneity.