Statistical issues in reporting quality data: small samples and casemix variation.

PubMed

Zaslavsky, A M

2001-12-01

To present two key statistical issues that arise in analysis and reporting of quality data. Casemix variation is relevant to quality reporting when the units being measured have differing distributions of patient characteristics that also affect the quality outcome. When this is the case, adjustment using stratification or regression may be appropriate. Such adjustments may be controversial when the patient characteristic does not have an obvious relationship to the outcome. Stratified reporting poses problems for sample size and reporting format, but may be useful when casemix effects vary across units. Although there are no absolute standards of reliability, high reliabilities (interunit F > or = 10 or reliability > or = 0.9) are desirable for distinguishing above- and below-average units. When small or unequal sample sizes complicate reporting, precision may be improved using indirect estimation techniques that incorporate auxiliary information, and 'shrinkage' estimation can help to summarize the strength of evidence about units with small samples. With broader understanding of casemix adjustment and methods for analyzing small samples, quality data can be analysed and reported more accurately.

Estimating the breeding population of long-billed curlew in the United States

USGS Publications Warehouse

Stanley, T.R.; Skagen, S.K.

2007-01-01

Determining population size and long-term trends in population size for species of high concern is a priority of international, national, and regional conservation plans. Long-billed curlews (Numenius americanus) are a species of special concern in North America due to apparent declines in their population. Because long-billed curlews are not adequately monitored by existing programs, we undertook a 2-year study with the goals of 1) determining present long-billed curlew distribution and breeding population size in the United States and 2) providing recommendations for a long-term long-billed curlew monitoring protocol. We selected a stratified random sample of survey routes in 16 western states for sampling in 2004 and 2005, and we analyzed count data from these routes to estimate detection probabilities and abundance. In addition, we evaluated habitat along roadsides to determine how well roadsides represented habitat throughout the sampling units. We estimated there were 164,515 (SE = 42,047) breeding long-billed curlews in 2004, and 109,533 (SE = 31,060) breeding individuals in 2005. These estimates far exceed currently accepted estimates based on expert opinion. We found that habitat along roadsides was representative of long-billed curlew habitat in general. We make recommendations for improving sampling methodology, and we present power curves to provide guidance on minimum sample sizes required to detect trends in abundance.

Estimating the quadratic mean diameter of fine woody debris for forest type groups of the United States

Treesearch

Christopher W. Woodall; Vicente J. Monleon

2009-01-01

The Forest Inventory and Analysis program of the Forest Service, U.S. Department of Agriculture conducts a national inventory of fine woody debris (FWD); however, the sampling protocols involve tallying only the number of FWD pieces by size class that intersect a sampling transect with no measure of actual size. The line intersect estimator used with those samples...

Effects of crystallite size on the structure and magnetism of ferrihydrite

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

Wang, Xiaoming; Zhu, Mengqiang; Koopal, Luuk K.

2015-12-15

The structure and magnetic properties of nano-sized (1.6 to 4.4 nm) ferrihydrite samples are systematically investigated through a combination of X-ray diffraction (XRD), X-ray pair distribution function (PDF), X-ray absorption spectroscopy (XAS) and magnetic analyses. The XRD, PDF and Fe K-edge XAS data of the ferrihydrite samples are all fitted well with the Michel ferrihydrite model, indicating similar local-, medium- and long-range ordered structures. PDF and XAS fitting results indicate that, with increasing crystallite size, the average coordination numbers of Fe–Fe and the unit cell parameter c increase, while Fe2 and Fe3 vacancies and the unit cell parameter a decrease.more » Mössbauer results indicate that the surface layer is relatively disordered, which might have been caused by the random distribution of Fe vacancies. These results support Hiemstra's surface-depletion model in terms of the location of disorder and the variations of Fe2 and Fe3 occupancies with size. Magnetic data indicate that the ferrihydrite samples show antiferromagnetism superimposed with a ferromagnetic-like moment at lower temperatures (100 K and 10 K), but ferrihydrite is paramagnetic at room temperature. In addition, both the magnetization and coercivity decrease with increasing ferrihydrite crystallite size due to strong surface effects in fine-grained ferrihydrites. Smaller ferrihydrite samples show less magnetic hyperfine splitting and a lower unblocking temperature (T B) than larger samples. The dependence of magnetic properties on grain size for nano-sized ferrihydrite provides a practical way to determine the crystallite size of ferrihydrite quantitatively in natural environments or artificial systems.« less

A sampling system for estimating the cultivation of wheat (Triticum aestivum L) from LANDSAT data. M.S. Thesis - 21 Jul. 1983

NASA Technical Reports Server (NTRS)

Parada, N. D. J. (Principal Investigator); Moreira, M. A.

1983-01-01

Using digitally processed MSS/LANDSAT data as auxiliary variable, a methodology to estimate wheat (Triticum aestivum L) area by means of sampling techniques was developed. To perform this research, aerial photographs covering 720 sq km in Cruz Alta test site at the NW of Rio Grande do Sul State, were visually analyzed. LANDSAT digital data were analyzed using non-supervised and supervised classification algorithms; as post-processing the classification was submitted to spatial filtering. To estimate wheat area, the regression estimation method was applied and different sample sizes and various sampling units (10, 20, 30, 40 and 60 sq km) were tested. Based on the four decision criteria established for this research, it was concluded that: (1) as the size of sampling units decreased the percentage of sampled area required to obtain similar estimation performance also decreased; (2) the lowest percentage of the area sampled for wheat estimation with relatively high precision and accuracy through regression estimation was 90% using 10 sq km s the sampling unit; and (3) wheat area estimation by direct expansion (using only aerial photographs) was less precise and accurate when compared to those obtained by means of regression estimation.

Forestry inventory based on multistage sampling with probability proportional to size

NASA Technical Reports Server (NTRS)

Lee, D. C. L.; Hernandez, P., Jr.; Shimabukuro, Y. E.

1983-01-01

A multistage sampling technique, with probability proportional to size, is developed for a forest volume inventory using remote sensing data. The LANDSAT data, Panchromatic aerial photographs, and field data are collected. Based on age and homogeneity, pine and eucalyptus classes are identified. Selection of tertiary sampling units is made through aerial photographs to minimize field work. The sampling errors for eucalyptus and pine ranged from 8.34 to 21.89 percent and from 7.18 to 8.60 percent, respectively.

Dispersion and sampling of adult Dermacentor andersoni in rangeland in Western North America.

PubMed

Rochon, K; Scoles, G A; Lysyk, T J

2012-03-01

A fixed precision sampling plan was developed for off-host populations of adult Rocky Mountain wood tick, Dermacentor andersoni (Stiles) based on data collected by dragging at 13 locations in Alberta, Canada; Washington; and Oregon. In total, 222 site-date combinations were sampled. Each site-date combination was considered a sample, and each sample ranged in size from 86 to 250 10 m2 quadrats. Analysis of simulated quadrats ranging in size from 10 to 50 m2 indicated that the most precise sample unit was the 10 m2 quadrat. Samples taken when abundance < 0.04 ticks per 10 m2 were more likely to not depart significantly from statistical randomness than samples taken when abundance was greater. Data were grouped into ten abundance classes and assessed for fit to the Poisson and negative binomial distributions. The Poisson distribution fit only data in abundance classes < 0.02 ticks per 10 m2, while the negative binomial distribution fit data from all abundance classes. A negative binomial distribution with common k = 0.3742 fit data in eight of the 10 abundance classes. Both the Taylor and Iwao mean-variance relationships were fit and used to predict sample sizes for a fixed level of precision. Sample sizes predicted using the Taylor model tended to underestimate actual sample sizes, while sample sizes estimated using the Iwao model tended to overestimate actual sample sizes. Using a negative binomial with common k provided estimates of required sample sizes closest to empirically calculated sample sizes.

10 CFR 431.135 - Units to be tested.

Code of Federal Regulations, 2011 CFR

2011-01-01

... EQUIPMENT Automatic Commercial Ice Makers Test Procedures § 431.135 Units to be tested. For each basic model of automatic commercial ice maker selected for testing, a sample of sufficient size shall be selected...

Compiling and editing agricultural strata boundaries with remotely sensed imagery and map attribute data using graphics workstations

NASA Technical Reports Server (NTRS)

Cheng, Thomas D.; Angelici, Gary L.; Slye, Robert E.; Ma, Matt

1991-01-01

The USDA presently uses labor-intensive photographic interpretation procedures to delineate large geographical areas into manageable size sampling units for the estimation of domestic crop and livestock production. Computer software to automate the boundary delineation procedure, called the computer-assisted stratification and sampling (CASS) system, was developed using a Hewlett Packard color-graphics workstation. The CASS procedures display Thematic Mapper (TM) satellite digital imagery on a graphics display workstation as the backdrop for the onscreen delineation of sampling units. USGS Digital Line Graph (DLG) data for roads and waterways are displayed over the TM imagery to aid in identifying potential sample unit boundaries. Initial analysis conducted with three Missouri counties indicated that CASS was six times faster than the manual techniques in delineating sampling units.

Distribution of muscle fibre conduction velocity for representative samples of motor units in the full recruitment range of the tibialis anterior muscle.

PubMed

Del Vecchio, A; Negro, F; Felici, F; Farina, D

2018-02-01

Motor units are recruited in an orderly manner according to the size of motor neurones. Moreover, because larger motor neurones innervate fibres with larger diameters than smaller motor neurones, motor units should be recruited orderly according to their conduction velocity (MUCV). Because of technical limitations, these relations have been previously tested either indirectly or in small motor unit samples that revealed weak associations between motor unit recruitment threshold (RT) and MUCV. Here, we analyse the relation between MUCV and RT for large samples of motor units. Ten healthy volunteers completed a series of isometric ankle dorsiflexions at forces up to 70% of the maximum. Multi-channel surface electromyographic signals recorded from the tibialis anterior muscle were decomposed into single motor unit action potentials, from which the corresponding motor unit RT, MUCV and action potential amplitude were estimated. Established relations between muscle fibre diameter and CV were used to estimate the fibre size. Within individual subjects, the distributions of MUCV and fibre diameters were unimodal and did not show distinct populations. MUCV was strongly correlated with RT (mean (SD) R 2  = 0.7 (0.09), P < 0.001; 406 motor units), which supported the hypothesis that fibre diameter is associated with RT. The results provide further evidence for the relations between motor neurone and muscle fibre properties for large samples of motor units. The proposed methodology for motor unit analysis has also the potential to open new perspectives in the study of chronic and acute neuromuscular adaptations to ageing, training and pathology. © 2017 Scandinavian Physiological Society. Published by John Wiley & Sons Ltd.

Stocking, Forest Type, and Stand Size Class - The Southern Forest Inventory and Analysis Unit's Calculation of Three Important Stand Descriptors

Treesearch

Dennis M. May

1990-01-01

The procedures by which the Southern Forest Inventory and Analysis unit calculates stocking from tree data collected on inventory sample plots are described in this report. Stocking is then used to ascertain two other important stand descriptors: forest type and stand size class. Inventory data for three plots from the recently completed 1989 Tennessee survey are used...

Computer-aided boundary delineation of agricultural lands

NASA Technical Reports Server (NTRS)

Cheng, Thomas D.; Angelici, Gary L.; Slye, Robert E.; Ma, Matt

1989-01-01

The National Agricultural Statistics Service of the United States Department of Agriculture (USDA) presently uses labor-intensive aerial photographic interpretation techniques to divide large geographical areas into manageable-sized units for estimating domestic crop and livestock production. Prototype software, the computer-aided stratification (CAS) system, was developed to automate the procedure, and currently runs on a Sun-based image processing system. With a background display of LANDSAT Thematic Mapper and United States Geological Survey Digital Line Graph data, the operator uses a cursor to delineate agricultural areas, called sampling units, which are assigned to strata of land-use and land-cover types. The resultant stratified sampling units are used as input into subsequent USDA sampling procedures. As a test, three counties in Missouri were chosen for application of the CAS procedures. Subsequent analysis indicates that CAS was five times faster in creating sampling units than the manual techniques were.

Evaluation of single and two-stage adaptive sampling designs for estimation of density and abundance of freshwater mussels in a large river

USGS Publications Warehouse

Smith, D.R.; Rogala, J.T.; Gray, B.R.; Zigler, S.J.; Newton, T.J.

2011-01-01

Reliable estimates of abundance are needed to assess consequences of proposed habitat restoration and enhancement projects on freshwater mussels in the Upper Mississippi River (UMR). Although there is general guidance on sampling techniques for population assessment of freshwater mussels, the actual performance of sampling designs can depend critically on the population density and spatial distribution at the project site. To evaluate various sampling designs, we simulated sampling of populations, which varied in density and degree of spatial clustering. Because of logistics and costs of large river sampling and spatial clustering of freshwater mussels, we focused on adaptive and non-adaptive versions of single and two-stage sampling. The candidate designs performed similarly in terms of precision (CV) and probability of species detection for fixed sample size. Both CV and species detection were determined largely by density, spatial distribution and sample size. However, designs did differ in the rate that occupied quadrats were encountered. Occupied units had a higher probability of selection using adaptive designs than conventional designs. We used two measures of cost: sample size (i.e. number of quadrats) and distance travelled between the quadrats. Adaptive and two-stage designs tended to reduce distance between sampling units, and thus performed better when distance travelled was considered. Based on the comparisons, we provide general recommendations on the sampling designs for the freshwater mussels in the UMR, and presumably other large rivers.

Measures of precision for dissimilarity-based multivariate analysis of ecological communities

PubMed Central

Anderson, Marti J; Santana-Garcon, Julia

2015-01-01

Ecological studies require key decisions regarding the appropriate size and number of sampling units. No methods currently exist to measure precision for multivariate assemblage data when dissimilarity-based analyses are intended to follow. Here, we propose a pseudo multivariate dissimilarity-based standard error (MultSE) as a useful quantity for assessing sample-size adequacy in studies of ecological communities. Based on sums of squared dissimilarities, MultSE measures variability in the position of the centroid in the space of a chosen dissimilarity measure under repeated sampling for a given sample size. We describe a novel double resampling method to quantify uncertainty in MultSE values with increasing sample size. For more complex designs, values of MultSE can be calculated from the pseudo residual mean square of a permanova model, with the double resampling done within appropriate cells in the design. R code functions for implementing these techniques, along with ecological examples, are provided. PMID:25438826

A comparison of two sampling approaches for assessing the urban forest canopy cover from aerial photography.

Treesearch

Ucar Zennure; Pete Bettinger; Krista Merry; Jacek Siry; J.M. Bowker

2016-01-01

Two different sampling approaches for estimating urban tree canopy cover were applied to two medium-sized cities in the United States, in conjunction with two freely available remotely sensed imagery products. A random point-based sampling approach, which involved 1000 sample points, was compared against a plot/grid sampling (cluster sampling) approach that involved a...

Fish habitat conditions: Using the Northern/Intermountain Regions' inventory procedures for detecting differences on two differently managed watersheds

Treesearch

C. Kerry Overton; Michael A. Radko; Rodger L. Nelson

1993-01-01

Differences in fish habitat variables between two studied watersheds may be related to differences in land management. In using the R1/R4 Watershed-Scale Fish Habitat Inventory Process, for most habitat variables, evaluations of sample sizes of at least 30 habitat units were adequate. Guidelines will help land managers in determining sample sizes required to detect...

Threshold-dependent sample sizes for selenium assessment with stream fish tissue

USGS Publications Warehouse

Hitt, Nathaniel P.; Smith, David R.

2015-01-01

Natural resource managers are developing assessments of selenium (Se) contamination in freshwater ecosystems based on fish tissue concentrations. We evaluated the effects of sample size (i.e., number of fish per site) on the probability of correctly detecting mean whole-body Se values above a range of potential management thresholds. We modeled Se concentrations as gamma distributions with shape and scale parameters fitting an empirical mean-to-variance relationship in data from southwestern West Virginia, USA (63 collections, 382 individuals). We used parametric bootstrapping techniques to calculate statistical power as the probability of detecting true mean concentrations up to 3 mg Se/kg above management thresholds ranging from 4 to 8 mg Se/kg. Sample sizes required to achieve 80% power varied as a function of management thresholds and Type I error tolerance (α). Higher thresholds required more samples than lower thresholds because populations were more heterogeneous at higher mean Se levels. For instance, to assess a management threshold of 4 mg Se/kg, a sample of eight fish could detect an increase of approximately 1 mg Se/kg with 80% power (given α = 0.05), but this sample size would be unable to detect such an increase from a management threshold of 8 mg Se/kg with more than a coin-flip probability. Increasing α decreased sample size requirements to detect above-threshold mean Se concentrations with 80% power. For instance, at an α-level of 0.05, an 8-fish sample could detect an increase of approximately 2 units above a threshold of 8 mg Se/kg with 80% power, but when α was relaxed to 0.2, this sample size was more sensitive to increasing mean Se concentrations, allowing detection of an increase of approximately 1.2 units with equivalent power. Combining individuals into 2- and 4-fish composite samples for laboratory analysis did not decrease power because the reduced number of laboratory samples was compensated for by increased precision of composites for estimating mean conditions. However, low sample sizes (<5 fish) did not achieve 80% power to detect near-threshold values (i.e., <1 mg Se/kg) under any scenario we evaluated. This analysis can assist the sampling design and interpretation of Se assessments from fish tissue by accounting for natural variation in stream fish populations.

7 CFR 52.775 - Sample unit size.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... extraneous material—The total contents of each container in the sample. Factors of Quality ...

7 CFR 52.775 - Sample unit size.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... extraneous material—The total contents of each container in the sample. Factors of Quality ...

7 CFR 52.775 - Sample unit size.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... extraneous material—The total contents of each container in the sample. Factors of Quality ...

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

NONE

A test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPs) was conducted . Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical characterization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on the relative toxicological effects of exposure to particulate emissions. Field testing was conducted in twomore » phases. The Phase I field program was performed over the period of August 24 through September 20, 1992, at the Tennessee Valley Authority Widows Creek Unit 8 Power Station, located near Stevenson (Jackson County), Alabama, on the Tennessee River. Sampling activities for Phase II were conducted from September 11 through October 14, 1993. Widows Creek Unit 8 is a 575-megawatt plant that uses bituminous coal averaging 3.7% sulfur and 13% ash. Downstream of the boiler, a venture wet scrubbing system is used for control of both sulfur dioxide and particulate emissions. There is no electrostatic precipitator (ESP) in this system. This system is atypical and represents only about 5% of the US utility industry. However, this site was chosen for this study because of the lack of information available for this particulate emission control system.« less

EX VIVO MODEL FOR THE CHARACTERIZATION AND IDENTIFICATION OF DRYWALL INTRAOCULAR FOREIGN BODIES ON COMPUTED TOMOGRAPHY.

PubMed

Syed, Reema; Kim, Sung-Hye; Palacio, Agustina; Nunery, William R; Schaal, Shlomit

2017-06-06

The study was inspired after the authors encountered a patient with a penetrating globe injury due to drywall, who had retained intraocular drywall foreign body. Computed tomography (CT) was read as normal in this patient. Open globe injury with drywall has never been reported previously in the literature and there are no previous studies describing its radiographic features. The case report is described in detail elsewhere. This was an experimental study. An ex vivo model of 15 porcine eyes with 1 mm to 5 mm fragments of implanted drywall, 2 vitreous only samples with drywall and 3 control eyes were used. Eyes and vitreous samples were CT scanned on Days 0, 1, and 3 postimplantation. Computed ocular images were analyzed by masked observers. Size and radiodensity of intraocular drywall were measured using Hounsfield units (HUs) over time. Intraocular drywall was hyperdense on CT. All sizes studied were detectable on Day 0 of scanning. Mean intraocular drywall foreign body density was 171 ± 52 Hounsfield units (70-237) depending on fragment size. Intraocular drywall foreign body decreased in size whereas Hounsfield unit intensity increased over time. Drywall dissolves in the eye and becomes denser over time as air in the drywall is replaced by fluid. This study identified Hounsfield Units specific to intraocular drywall foreign body over time.

Returns and determinants of technical efficiency in small-scale Malabari goat production units in Kerala, India.

PubMed

Alex, Rani; Kunniyoor Cheemani, Raghavan; Thomas, Naicy

2013-11-01

A stochastic frontier production function was employed to measure technical efficiency and its determinants in smallholder Malabari goat production units in Kerala, India. Data were obtained from 100 goat farmers in northern Kerala, selected using multistage random sampling. The parameters of the stochastic frontier production function were estimated using the maximum likelihood method. Cost and return analysis showed that the major expenditure was feed and fodder, and veterinary expenses were secondary. The chief returns were the sale of live animals, milk and manure. Individual farm technical efficiency ranged from 0.34 to 0.97 with a mean of 0.88. The study found herd size (number of animal units) and centre (locality of farm) significantly affected technical efficiency, but sex of farmer, education, land size and family size did not. Technical efficiency decreased as herd size increased; half the units with five or more adult animals had technical efficiency below 60 %.

Sampling--how big a sample?

PubMed

Aitken, C G

1999-07-01

It is thought that, in a consignment of discrete units, a certain proportion of the units contain illegal material. A sample of the consignment is to be inspected. Various methods for the determination of the sample size are compared. The consignment will be considered as a random sample from some super-population of units, a certain proportion of which contain drugs. For large consignments, a probability distribution, known as the beta distribution, for the proportion of the consignment which contains illegal material is obtained. This distribution is based on prior beliefs about the proportion. Under certain specific conditions the beta distribution gives the same numerical results as an approach based on the binomial distribution. The binomial distribution provides a probability for the number of units in a sample which contain illegal material, conditional on knowing the proportion of the consignment which contains illegal material. This is in contrast to the beta distribution which provides probabilities for the proportion of a consignment which contains illegal material, conditional on knowing the number of units in the sample which contain illegal material. The interpretation when the beta distribution is used is much more intuitively satisfactory. It is also much more flexible in its ability to cater for prior beliefs which may vary given the different circumstances of different crimes. For small consignments, a distribution, known as the beta-binomial distribution, for the number of units in the consignment which are found to contain illegal material, is obtained, based on prior beliefs about the number of units in the consignment which are thought to contain illegal material. As with the beta and binomial distributions for large samples, it is shown that, in certain specific conditions, the beta-binomial and hypergeometric distributions give the same numerical results. However, the beta-binomial distribution, as with the beta distribution, has a more intuitively satisfactory interpretation and greater flexibility. The beta and the beta-binomial distributions provide methods for the determination of the minimum sample size to be taken from a consignment in order to satisfy a certain criterion. The criterion requires the specification of a proportion and a probability.

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

NONE

Under contract with the US Department of Energy (DE-AC22-92PCO0367), Pittsburgh Energy Technology Center, Radian Corporation has conducted a test program to collect and analyze size-fractionated stack gas particulate samples for selected inorganic hazardous air pollutants (HAPS). Specific goals of the program are (1) the collection of one-gram quantities of size-fractionated stack gas particulate matter for bulk (total) and surface chemical charactization, and (2) the determination of the relationship between particle size, bulk and surface (leachable) composition, and unit load. The information obtained from this program identifies the effects of unit load, particle size, and wet FGD system operation on themore » relative toxicological effects of exposure to particulate emissions.« less

Mourning dove population trend estimates from Call-Count and North American Breeding Bird Surveys

USGS Publications Warehouse

Sauer, J.R.; Dolton, D.D.; Droege, S.

1994-01-01

The mourning dove (Zenaida macroura) Callcount Survey and the North American Breeding Bird Survey provide information on population trends of mourning doves throughout the continental United States. Because surveys are an integral part of the development of hunting regulations, a need exists to determine which survey provides precise information. We estimated population trends from 1966 to 1988 by state and dove management unit, and assessed the relative efficiency of each survey. Estimates of population trend differ (P lt 0.05) between surveys in 11 of 48 states; 9 of 11 states with divergent results occur in the Eastern Management Unit. Differences were probably a consequence of smaller sample sizes in the Callcount Survey. The Breeding Bird Survey generally provided trend estimates with smaller variances than did the Callcount Survey. Although the Callcount Survey probably provides more withinroute accuracy because of survey methods and timing, the Breeding Bird Survey has a larger sample size of survey routes and greater consistency of coverage in the Eastern Unit.

Multi-species attributes as the condition for adaptive sampling of rare species using two-stage sequential sampling with an auxiliary variable

USGS Publications Warehouse

Panahbehagh, B.; Smith, D.R.; Salehi, M.M.; Hornbach, D.J.; Brown, D.J.; Chan, F.; Marinova, D.; Anderssen, R.S.

2011-01-01

Assessing populations of rare species is challenging because of the large effort required to locate patches of occupied habitat and achieve precise estimates of density and abundance. The presence of a rare species has been shown to be correlated with presence or abundance of more common species. Thus, ecological community richness or abundance can be used to inform sampling of rare species. Adaptive sampling designs have been developed specifically for rare and clustered populations and have been applied to a wide range of rare species. However, adaptive sampling can be logistically challenging, in part, because variation in final sample size introduces uncertainty in survey planning. Two-stage sequential sampling (TSS), a recently developed design, allows for adaptive sampling, but avoids edge units and has an upper bound on final sample size. In this paper we present an extension of two-stage sequential sampling that incorporates an auxiliary variable (TSSAV), such as community attributes, as the condition for adaptive sampling. We develop a set of simulations to approximate sampling of endangered freshwater mussels to evaluate the performance of the TSSAV design. The performance measures that we are interested in are efficiency and probability of sampling a unit occupied by the rare species. Efficiency measures the precision of population estimate from the TSSAV design relative to a standard design, such as simple random sampling (SRS). The simulations indicate that the density and distribution of the auxiliary population is the most important determinant of the performance of the TSSAV design. Of the design factors, such as sample size, the fraction of the primary units sampled was most important. For the best scenarios, the odds of sampling the rare species was approximately 1.5 times higher for TSSAV compared to SRS and efficiency was as high as 2 (i.e., variance from TSSAV was half that of SRS). We have found that design performance, especially for adaptive designs, is often case-specific. Efficiency of adaptive designs is especially sensitive to spatial distribution. We recommend that simulations tailored to the application of interest are highly useful for evaluating designs in preparation for sampling rare and clustered populations.

Annual design-based estimation for the annualized inventories of forest inventory and analysis: sample size determination

Treesearch

Hans T. Schreuder; Jin-Mann S. Lin; John Teply

2000-01-01

The Forest Inventory and Analysis units in the USDA Forest Service have been mandated by Congress to go to an annualized inventory where a certain percentage of plots, say 20 percent, will be measured in each State each year. Although this will result in an annual sample size that will be too small for reliable inference for many areas, it is a sufficiently large...

Elemental Analysis of Beryllium Samples Using a Microzond-EGP-10 Unit

NASA Astrophysics Data System (ADS)

Buzoverya, M. E.; Karpov, I. A.; Gorodnov, A. A.; Shishpor, I. V.; Kireycheva, V. I.

2017-12-01

Results concerning the structural and elemental analysis of beryllium samples obtained via different technologies using a Microzond-EGP-10 unit with the help of the PIXE and RBS methods are presented. As a result, the overall chemical composition and the nature of inclusions were determined. The mapping method made it possible to reveal the structural features of beryllium samples: to select the grains of the main substance having different size and chemical composition, to visualize the interfaces between the regions of different composition, and to describe the features of the distribution of impurities in the samples.

Soil sedimentology at Gusev Crater from Columbia Memorial Station to Winter Haven

USGS Publications Warehouse

Cabrol, N.A.; Herkenhoff, K. E.; Greeley, R.; Grin, E.A.; Schroder, C.; d'Uston, C.; Weitz, C.; Yingst, R.A.; Cohen, B. A.; Moore, J.; Knudson, A.; Franklin, B.; Anderson, R.C.; Li, R.

2008-01-01

A total of 3140 individual particles were examined in 31 soils along Spirit's traverse. Their size, shape, and texture were quantified and classified. They represent a unique record of 3 years of sedimentologic exploration from landing to sol 1085 covering the Plains Unit to Winter Haven where Spirit spent the Martian winter of 2006. Samples in the Plains Unit and Columbia Hills appear as reflecting contrasting textural domains. One is heterogeneous, with a continuum of angular-to-round particles of fine sand to pebble sizes that are generally dust covered and locally cemented in place. The second shows the effect of a dominant and ongoing dynamic aeolian process that redistributes a uniform population of medium-size sand. The texture of particles observed in the samples at Gusev Crater results from volcanic, aeolian, impact, and water-related processes. Copyright 2008 by the American Geophysical Union.

7 CFR 52.775 - Sample unit size.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... material)—100 cherries. (c) Harmless extraneous material—The total contents of each container in the sample...

7 CFR 52.775 - Sample unit size.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Regulations of the Department of Agriculture AGRICULTURAL MARKETING SERVICE (Standards, Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE REGULATIONS AND STANDARDS UNDER THE AGRICULTURAL MARKETING ACT OF 1946... material)—100 cherries. (c) Harmless extraneous material—The total contents of each container in the sample...

Sample size calculations for cluster randomised crossover trials in Australian and New Zealand intensive care research.

PubMed

Arnup, Sarah J; McKenzie, Joanne E; Pilcher, David; Bellomo, Rinaldo; Forbes, Andrew B

2018-06-01

The cluster randomised crossover (CRXO) design provides an opportunity to conduct randomised controlled trials to evaluate low risk interventions in the intensive care setting. Our aim is to provide a tutorial on how to perform a sample size calculation for a CRXO trial, focusing on the meaning of the elements required for the calculations, with application to intensive care trials. We use all-cause in-hospital mortality from the Australian and New Zealand Intensive Care Society Adult Patient Database clinical registry to illustrate the sample size calculations. We show sample size calculations for a two-intervention, two 12-month period, cross-sectional CRXO trial. We provide the formulae, and examples of their use, to determine the number of intensive care units required to detect a risk ratio (RR) with a designated level of power between two interventions for trials in which the elements required for sample size calculations remain constant across all ICUs (unstratified design); and in which there are distinct groups (strata) of ICUs that differ importantly in the elements required for sample size calculations (stratified design). The CRXO design markedly reduces the sample size requirement compared with the parallel-group, cluster randomised design for the example cases. The stratified design further reduces the sample size requirement compared with the unstratified design. The CRXO design enables the evaluation of routinely used interventions that can bring about small, but important, improvements in patient care in the intensive care setting.

Factors Associated with the Performance and Cost-Effectiveness of Using Lymphatic Filariasis Transmission Assessment Surveys for Monitoring Soil-Transmitted Helminths: A Case Study in Kenya

PubMed Central

Smith, Jennifer L.; Sturrock, Hugh J. W.; Assefa, Liya; Nikolay, Birgit; Njenga, Sammy M.; Kihara, Jimmy; Mwandawiro, Charles S.; Brooker, Simon J.

2015-01-01

Transmission assessment surveys (TAS) for lymphatic filariasis have been proposed as a platform to assess the impact of mass drug administration (MDA) on soil-transmitted helminths (STHs). This study used computer simulation and field data from pre- and post-MDA settings across Kenya to evaluate the performance and cost-effectiveness of the TAS design for STH assessment compared with alternative survey designs. Variations in the TAS design and different sample sizes and diagnostic methods were also evaluated. The district-level TAS design correctly classified more districts compared with standard STH designs in pre-MDA settings. Aggregating districts into larger evaluation units in a TAS design decreased performance, whereas age group sampled and sample size had minimal impact. The low diagnostic sensitivity of Kato-Katz and mini-FLOTAC methods was found to increase misclassification. We recommend using a district-level TAS among children 8–10 years of age to assess STH but suggest that key consideration is given to evaluation unit size. PMID:25487730

Remote Sensing, Sampling and Simulation Applications in Analyses of Insect Dispersion and Abundance in Cotton

Treesearch

J. L. Willers; J. M. McKinion; J. N. Jenkins

2006-01-01

Simulation was employed to create stratified simple random samples of different sample unit sizes to represent tarnished plant bug abundance at different densities within various habitats of simulated cotton fields. These samples were used to investigate dispersion patterns of this cotton insect. It was found that the assessment of spatial pattern varied as a function...

Measures of precision for dissimilarity-based multivariate analysis of ecological communities.

PubMed

Anderson, Marti J; Santana-Garcon, Julia

2015-01-01

Ecological studies require key decisions regarding the appropriate size and number of sampling units. No methods currently exist to measure precision for multivariate assemblage data when dissimilarity-based analyses are intended to follow. Here, we propose a pseudo multivariate dissimilarity-based standard error (MultSE) as a useful quantity for assessing sample-size adequacy in studies of ecological communities. Based on sums of squared dissimilarities, MultSE measures variability in the position of the centroid in the space of a chosen dissimilarity measure under repeated sampling for a given sample size. We describe a novel double resampling method to quantify uncertainty in MultSE values with increasing sample size. For more complex designs, values of MultSE can be calculated from the pseudo residual mean square of a permanova model, with the double resampling done within appropriate cells in the design. R code functions for implementing these techniques, along with ecological examples, are provided. © 2014 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.

Adaptive significance of small body size: strength and motor performance of school children in Mexico and Papua New Guinea.

PubMed

Malina, R M; Little, B B; Shoup, R F; Buschang, P H

1987-08-01

The postulated superior functional efficiency in association with reduced body size under conditions of chronic protein-energy undernutrition was considered in school children from rural Mexico and coastal Papua New Guinea. Grip strength and three measures of motor performance were measured in cross-sectional samples of children 6-16 years of age from a rural agricultural community in Oaxaca, Mexico, and from the coastal community Pere on Manus Island, Papua New Guinea. The strength and performance of a mixed-longitudinal sample of well nourished children from Philadelphia was used as a reference. The Oaxaca and Pere children are significantly shorter and lighter and are not as strong as the well nourished children. Motor performances of Pere children compare favorably to those of the better-nourished Philadelphia children, whereas those of the Oaxaca children are poorer. Throwing performance is more variable. When expressed relative to body size, strength is similar in the three samples, but the running and jumping performances of Pere children per unit body size are better than the relative performances of Oaxaca and Philadelphia children. Throwing performance per unit body size is better in the undernourished children. The influence of age, stature, and weight on the performance of Oaxaca and Pere children is generally similar to that for well nourished children. These results suggest that the hypothesized adaptive significance of small body size for the functional efficiency of populations living under conditions of chronic undernutrition varies between populations and with performance tasks.

Drawing a representative sample from the NCSS soil database: Building blocks for the national wind erosion network

USDA-ARS?s Scientific Manuscript database

Developing national wind erosion models for the continental United States requires a comprehensive spatial representation of continuous soil particle size distributions (PSD) for model input. While the current coverage of soil survey is nearly complete, the most detailed particle size classes have c...

High-Throughput and Label-Free Single Nanoparticle Sizing Based on Time-Resolved On-Chip Microscopy

DTIC Science & Technology

2015-02-17

12,13 soot ,6,14 ice crystals in clouds,15 and engineered nano- materials,16 among others. While there exist various nanoparticle detection and sizing...the sample of interest is placed on an optoelectronic sensor -array with typically less than 0.5 mm gap (z2) between the sample and sensor planes such...that, under unit mag- nification, the entire sensor active area serves as the imaging FOV, easily reaching >2030 mm2 with state-of-the-art CMOS

Use of units of measurement error in anthropometric comparisons.

PubMed

Lucas, Teghan; Henneberg, Maciej

2017-09-01

Anthropometrists attempt to minimise measurement errors, however, errors cannot be eliminated entirely. Currently, measurement errors are simply reported. Measurement errors should be included into analyses of anthropometric data. This study proposes a method which incorporates measurement errors into reported values, replacing metric units with 'units of technical error of measurement (TEM)' by applying these to forensics, industrial anthropometry and biological variation. The USA armed forces anthropometric survey (ANSUR) contains 132 anthropometric dimensions of 3982 individuals. Concepts of duplication and Euclidean distance calculations were applied to the forensic-style identification of individuals in this survey. The National Size and Shape Survey of Australia contains 65 anthropometric measurements of 1265 women. This sample was used to show how a woman's body measurements expressed in TEM could be 'matched' to standard clothing sizes. Euclidean distances show that two sets of repeated anthropometric measurements of the same person cannot be matched (> 0) on measurements expressed in millimetres but can in units of TEM (= 0). Only 81 women can fit into any standard clothing size when matched using centimetres, with units of TEM, 1944 women fit. The proposed method can be applied to all fields that use anthropometry. Units of TEM are considered a more reliable unit of measurement for comparisons.

76 FR 31575 - United States Standards for Grades of Frozen Onions

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-01

... processors of frozen onions in the United States. The petition provided information on style, sample size... change in the style designations for minced style, and a correction to the text. The members agreed with the proposed section concerning requirements for Styles, Type I, Whole onions and Type II, Pearl...

10 CFR 431.325 - Units to be tested.

Code of Federal Regulations, 2011 CFR

2011-01-01

... EQUIPMENT Metal Halide Lamp Ballasts and Fixtures Test Procedures § 431.325 Units to be tested. For each basic model of metal halide lamp ballast selected for testing, a sample of sufficient size, no less than... energy efficiency calculated as the measured output power to the lamp divided by the measured input power...

Unit-level voluntary turnover rates and customer service quality: implications of group cohesiveness, newcomer concentration, and size.

PubMed

Hausknecht, John P; Trevor, Charlie O; Howard, Michael J

2009-07-01

Despite substantial growth in the service industry and emerging work on turnover consequences, little research examines how unit-level turnover rates affect essential customer-related outcomes. The authors propose an operational disruption framework to explain why voluntary turnover impairs customers' service quality perceptions. On the basis of a sample of 75 work units and data from 5,631 employee surveys, 59,602 customer surveys, and organizational records, results indicate that unit-level voluntary turnover rates are negatively related to service quality perceptions. The authors also examine potential boundary conditions related to the disruption framework. Of 3 moderators studied (group cohesiveness, group size, and newcomer concentration), results show that turnover's negative effects on service quality are more pronounced in larger units and in those with a greater concentration of newcomers.

Fixed-Precision Sequential Sampling Plans for Estimating Alfalfa Caterpillar, Colias lesbia, Egg Density in Alfalfa, Medicago sativa, Fields in Córdoba, Argentina

PubMed Central

Serra, Gerardo V.; Porta, Norma C. La; Avalos, Susana; Mazzuferi, Vilma

2013-01-01

The alfalfa caterpillar, Colias lesbia (Fabricius) (Lepidoptera: Pieridae), is a major pest of alfalfa, Medicago sativa L. (Fabales: Fabaceae), crops in Argentina. Its management is based mainly on chemical control of larvae whenever the larvae exceed the action threshold. To develop and validate fixed-precision sequential sampling plans, an intensive sampling programme for C. lesbia eggs was carried out in two alfalfa plots located in the Province of Córdoba, Argentina, from 1999 to 2002. Using Resampling for Validation of Sampling Plans software, 12 additional independent data sets were used to validate the sequential sampling plan with precision levels of 0.10 and 0.25 (SE/mean), respectively. For a range of mean densities of 0.10 to 8.35 eggs/sample, an average sample size of only 27 and 26 sample units was required to achieve a desired precision level of 0.25 for the sampling plans of Green and Kuno, respectively. As the precision level was increased to 0.10, average sample size increased to 161 and 157 sample units for the sampling plans of Green and Kuno, respectively. We recommend using Green's sequential sampling plan because it is less sensitive to changes in egg density. These sampling plans are a valuable tool for researchers to study population dynamics and to evaluate integrated pest management strategies. PMID:23909840

A dataset of housing market and self-attitudes towards housing location choices in Alexandria, Egypt.

PubMed

Ibrahim, Mohamed R

2017-04-01

A survey, of sample size 224, is designed to include the different related-factors to housing location choice, such as; socioeconomic factors, housing characteristics, travel behavior, current self-selection factors, housing demand and future location preferences. It comprises 16 questions, categorized into three different sections; socioeconomic (5 Questions), current dwelling unit characteristics (7 Questions), and housing demand characteristics (4 Questions). The first part, socioeconomic, covers the basic information about the respondent, such as; age, gender, marital status, employment, and car ownership. While the second part, current dwelling unit characteristics, covers different aspect concerning the residential unit typology, financial aspects, and travel behavior of the respondent. It includes the tenure types of the residential unit, estimation of the unit price (in the case of ownership or renting), housing typologies, the main reason for choosing the unit, in case of working, the modes of travel to work, and time to reach it, residential mobility in the last decade, and the ownership of any other residential units. The last part, housing demand characteristics, covers the size of the demand for a residential unit, preference in living in a certain area and the reason to choose it, and the preference of residential unit׳s tenure. This survey is a representative sample for the population in Alexandria, Egypt. The data in this article is represented in: How do people select their residential locations in Egypt? The case of Alexandria; JCIT1757.

Comparison. US P-61 and Delft sediment samplers

USGS Publications Warehouse

Beverage, Joseph P.; Williams, David T.

1990-01-01

The Delft Bottle (DB) is a flow-through device designed by the Delft Hydraulic Laboratory (DHL), The Netherlands, to sample sand-sized sediment suspended in streams. The US P-61 sampler was designed by the Federal Interagency Sedimentation Project (FISP) at the St. Anthony Falls Hydraulic Laboratory, Minneapolis, Minnesota, to collect suspended sediment from deep, swift rivers. The results of two point-sampling tests in the United States, the Mississippi River near Vicksburg, Mississippi, in 1983 and the Colorado River near Blythe, California, in 1984, are provided in this report. These studies compare sand-transport rates, rather than total sediment-transport rates, because fine material washes through the DB sampler. In the United States, the commonly used limits for sand-sized material are 0.062 mm to 2.00 mm (Vanoni 1975).

Gaps in Survey Data on Cancer in American Indian and Alaska Native Populations: Examination of US Population Surveys, 1960–2010

PubMed Central

Duran, Tinka; Stimpson, Jim P.; Smith, Corey

2013-01-01

Introduction Population-based data are essential for quantifying the problems and measuring the progress made by comprehensive cancer control programs. However, cancer information specific to the American Indian/Alaska Native (AI/AN) population is not readily available. We identified major population-based surveys conducted in the United States that contain questions related to cancer, documented the AI/AN sample size in these surveys, and identified gaps in the types of cancer-related information these surveys collect. Methods We conducted an Internet query of US Department of Health and Human Services agency websites and a Medline search to identify population-based surveys conducted in the United States from 1960 through 2010 that contained information about cancer. We used a data extraction form to collect information about the purpose, sample size, data collection methods, and type of information covered in the surveys. Results Seventeen survey sources met the inclusion criteria. Information on access to and use of cancer treatment, follow-up care, and barriers to receiving timely and quality care was not consistently collected. Estimates specific to the AI/AN population were often lacking because of inadequate AI/AN sample size. For example, 9 national surveys reviewed reported an AI/AN sample size smaller than 500, and 10 had an AI/AN sample percentage less than 1.5%. Conclusion Continued efforts are needed to increase the overall number of AI/AN participants in these surveys, improve the quality of information on racial/ethnic background, and collect more information on treatment and survivorship. PMID:23517582

Effects of Laser Energies on Wear and Tensile Properties of Biomimetic 7075 Aluminum Alloy

NASA Astrophysics Data System (ADS)

Yuan, Yuhuan; Zhang, Peng; Zhao, Guoping; Gao, Yang; Tao, Lixi; Chen, Heng; Zhang, Jianlong; Zhou, Hong

2018-03-01

Inspired by the non-smooth surface of certain animals, a biomimetic coupling unit with various sizes, microstructure, and hardness was prepared on the surface of 7075 aluminum alloy. Following experimental studies were conducted to investigate the wear and tensile properties with various laser energy inputs. The results demonstrated that the non-smooth surface with biomimetic coupling units had a positive effect on both the wear resistance and tensile property of 7075 aluminum alloy. In addition, the sample with the unit fabricated by the laser energy of 420.1 J/cm2 exhibited the most significant improvement on the wear and tensile properties owing to the minimum grain size and the highest microhardness. Also, the weight loss of the sample was one-third of the untreated one's, and the yield strength, the ultimate tensile strength, and the elongation improved by 20, 20, and 34% respectively. Moreover, the mechanisms of wear and tensile properties improvement were also analyzed.

Gear and seasonal bias associated with abundance and size structure estimates for lentic freshwater fishes

USGS Publications Warehouse

Fischer, Jesse R.; Quist, Michael C.

2014-01-01

All freshwater fish sampling methods are biased toward particular species, sizes, and sexes and are further influenced by season, habitat, and fish behavior changes over time. However, little is known about gear-specific biases for many common fish species because few multiple-gear comparison studies exist that have incorporated seasonal dynamics. We sampled six lakes and impoundments representing a diversity of trophic and physical conditions in Iowa, USA, using multiple gear types (i.e., standard modified fyke net, mini-modified fyke net, sinking experimental gill net, bag seine, benthic trawl, boat-mounted electrofisher used diurnally and nocturnally) to determine the influence of sampling methodology and season on fisheries assessments. Specifically, we describe the influence of season on catch per unit effort, proportional size distribution, and the number of samples required to obtain 125 stock-length individuals for 12 species of recreational and ecological importance. Mean catch per unit effort generally peaked in the spring and fall as a result of increased sampling effectiveness in shallow areas and seasonal changes in habitat use (e.g., movement offshore during summer). Mean proportional size distribution decreased from spring to fall for white bass Morone chrysops, largemouth bass Micropterus salmoides, bluegill Lepomis macrochirus, and black crappie Pomoxis nigromaculatus, suggesting selectivity for large and presumably sexually mature individuals in the spring and summer. Overall, the mean number of samples required to sample 125 stock-length individuals was minimized in the fall with sinking experimental gill nets, a boat-mounted electrofisher used at night, and standard modified nets for 11 of the 12 species evaluated. Our results provide fisheries scientists with relative comparisons between several recommended standard sampling methods and illustrate the effects of seasonal variation on estimates of population indices that will be critical to the future development of standardized sampling methods for freshwater fish in lentic ecosystems.

Improving the accuracy of livestock distribution estimates through spatial interpolation.

PubMed

Bryssinckx, Ward; Ducheyne, Els; Muhwezi, Bernard; Godfrey, Sunday; Mintiens, Koen; Leirs, Herwig; Hendrickx, Guy

2012-11-01

Animal distribution maps serve many purposes such as estimating transmission risk of zoonotic pathogens to both animals and humans. The reliability and usability of such maps is highly dependent on the quality of the input data. However, decisions on how to perform livestock surveys are often based on previous work without considering possible consequences. A better understanding of the impact of using different sample designs and processing steps on the accuracy of livestock distribution estimates was acquired through iterative experiments using detailed survey. The importance of sample size, sample design and aggregation is demonstrated and spatial interpolation is presented as a potential way to improve cattle number estimates. As expected, results show that an increasing sample size increased the precision of cattle number estimates but these improvements were mainly seen when the initial sample size was relatively low (e.g. a median relative error decrease of 0.04% per sampled parish for sample sizes below 500 parishes). For higher sample sizes, the added value of further increasing the number of samples declined rapidly (e.g. a median relative error decrease of 0.01% per sampled parish for sample sizes above 500 parishes. When a two-stage stratified sample design was applied to yield more evenly distributed samples, accuracy levels were higher for low sample densities and stabilised at lower sample sizes compared to one-stage stratified sampling. Aggregating the resulting cattle number estimates yielded significantly more accurate results because of averaging under- and over-estimates (e.g. when aggregating cattle number estimates from subcounty to district level, P <0.009 based on a sample of 2,077 parishes using one-stage stratified samples). During aggregation, area-weighted mean values were assigned to higher administrative unit levels. However, when this step is preceded by a spatial interpolation to fill in missing values in non-sampled areas, accuracy is improved remarkably. This counts especially for low sample sizes and spatially even distributed samples (e.g. P <0.001 for a sample of 170 parishes using one-stage stratified sampling and aggregation on district level). Whether the same observations apply on a lower spatial scale should be further investigated.

Estimating accuracy of land-cover composition from two-stage cluster sampling

USGS Publications Warehouse

Stehman, S.V.; Wickham, J.D.; Fattorini, L.; Wade, T.D.; Baffetta, F.; Smith, J.H.

2009-01-01

Land-cover maps are often used to compute land-cover composition (i.e., the proportion or percent of area covered by each class), for each unit in a spatial partition of the region mapped. We derive design-based estimators of mean deviation (MD), mean absolute deviation (MAD), root mean square error (RMSE), and correlation (CORR) to quantify accuracy of land-cover composition for a general two-stage cluster sampling design, and for the special case of simple random sampling without replacement (SRSWOR) at each stage. The bias of the estimators for the two-stage SRSWOR design is evaluated via a simulation study. The estimators of RMSE and CORR have small bias except when sample size is small and the land-cover class is rare. The estimator of MAD is biased for both rare and common land-cover classes except when sample size is large. A general recommendation is that rare land-cover classes require large sample sizes to ensure that the accuracy estimators have small bias. ?? 2009 Elsevier Inc.

Variation in aluminum, iron, and particle concentrations in oxic groundwater samples collected by use of tangential-flow ultrafiltration with low-flow sampling

NASA Astrophysics Data System (ADS)

Szabo, Zoltan; Oden, Jeannette H.; Gibs, Jacob; Rice, Donald E.; Ding, Yuan

2002-02-01

Particulates that move with ground water and those that are artificially mobilized during well purging could be incorporated into water samples during collection and could cause trace-element concentrations to vary in unfiltered samples, and possibly in filtered samples (typically 0.45-um (micron) pore size) as well, depending on the particle-size fractions present. Therefore, measured concentrations may not be representative of those in the aquifer. Ground water may contain particles of various sizes and shapes that are broadly classified as colloids, which do not settle from water, and particulates, which do. In order to investigate variations in trace-element concentrations in ground-water samples as a function of particle concentrations and particle-size fractions, the U.S. Geological Survey, in cooperation with the U.S. Air Force, collected samples from five wells completed in the unconfined, oxic Kirkwood-Cohansey aquifer system of the New Jersey Coastal Plain. Samples were collected by purging with a portable pump at low flow (0.2-0.5 liters per minute and minimal drawdown, ideally less than 0.5 foot). Unfiltered samples were collected in the following sequence: (1) within the first few minutes of pumping, (2) after initial turbidity declined and about one to two casing volumes of water had been purged, and (3) after turbidity values had stabilized at less than 1 to 5 Nephelometric Turbidity Units. Filtered samples were split concurrently through (1) a 0.45-um pore size capsule filter, (2) a 0.45-um pore size capsule filter and a 0.0029-um pore size tangential-flow filter in sequence, and (3), in selected cases, a 0.45-um and a 0.05-um pore size capsule filter in sequence. Filtered samples were collected concurrently with the unfiltered sample that was collected when turbidity values stabilized. Quality-assurance samples consisted of sequential duplicates (about 25 percent) and equipment blanks. Concentrations of particles were determined by light scattering.

Effect of the three-dimensional microstructure on the sound absorption of foams: A parametric study.

PubMed

Chevillotte, Fabien; Perrot, Camille

2017-08-01

The purpose of this work is to systematically study the effect of the throat and the pore sizes on the sound absorbing properties of open-cell foams. The three-dimensional idealized unit cell used in this work enables to mimic the acoustical macro-behavior of a large class of cellular solid foams. This study is carried out for a normal incidence and also for a diffuse field excitation, with a relatively large range of sample thicknesses. The transport and sound absorbing properties are numerically studied as a function of the throat size, the pore size, and the sample thickness. The resulting diagrams show the ranges of the specific throat sizes and pore sizes where the sound absorption grading is maximized due to the pore morphology as a function of the sample thickness, and how it correlates with the corresponding transport parameters. These charts demonstrate, together with typical examples, how the morphological characteristics of foam could be modified in order to increase the visco-thermal dissipation effects.

Bottom sediments and nutrients in the tidal Potomac system, Maryland and Virginia

USGS Publications Warehouse

Glenn, Jerry L.

1988-01-01

The characteristics and distributions of near-surface bottom sediments and of nutrients in the sediments provide information on modern sediment and nutrient sources, sedimentation environments, and geochemical reactions in the tidal Potomac system, Maryland and Virginia. This information is fundamental to an improved understanding of sedimentation and eutrophication problems in the tidal Potomac system. The tidal Potomac system consists of 1,230 square kilometers of intertidal to subtidal Potomac mainstem and tributary streambed from the heads-of-tides to Chesapeake Bay. Tidal Potomac sediments are dominantly silt and clay except in local areas. An average sediment sample is about two-thirds silt and clay (fine) particles and one-third sand (coarse) particles. The mean of the median size of all samples is 6.60 phi, or 0.010 millimeters. Sorting generally is poor and the average sediment is skewed toward the fine tail of the size-distribution curve. Mean particle-size measures have large standard deviations. Among geomorphic units, two distinctly different size populations are found; fine (median phi about 9), and poorly sorted (sorting about 3) sediments in the channel and the smooth flat, and coarse (median phi about 2), and well sorted (sorting about 1) sediments in the shoreline flat and the irregular slope. Among mainstem hydrologic divisions, an average sediment from the river and the estuary division is coarser and more variable than an average sediment from the transition division. Substantial concentrations of total carbon, total nitrogen, and total phosphorus, and limited amounts of inorganic carbon, ammonia nitrogen and nitrite plus nitrate nitrogen occur in tidal Potomac sediments. An average tidal Potomac sediment sample weighing 1 kilogram contains about 21,000 milligrams of total carbon, 2,400 milligrams of total nitrogen, 1,200 milligrams of total phosphorus, 600 milligrams of inorganic carbon, 170 milligrams of ammonia nitrogen, and 2 milligrams of nitrite plus nitrate nitrogen. Total carbon, nitrogen, and phosphorus have an average ratio by weight of 18:2:1 and an average ratio by atoms of 94:8:1. Nutrient concentrations and nutrient ratios have large ranges and standard deviations. Nutrient concentrations usually are closely related to particle size; large concentrations are characteristic of fine sediments in the channel and the smooth flat, and small concentrations are typical of coarse sediments in the shoreline flat and the irregular slope. Concentrations typically decrease from the river division to the estuary division. Mainstem and tributaries show no statistically significant difference in mean particle-size measures or mean nutrient concentrations. Tributaries do not contribute large quantities of sediment with diverse texture or nutrient content to the Potomac mainstem. Particle-size measures and nutrient concentrations in the mainstem are significantly related to hydrologic divisions and geomorphic units; that is, particle size and nutrients vary significantly along and across the Potomac mainstem. Lateral variations in particle size and nutrient content are more pronounced and contribute more to significant relations than longitudinal variations contribute. The mean values for the median particle size and for the percentage of sand indicate significant variations among hydrologic divisions for samples from a geomorphic unit, and among geomorphic units, for samples from a hydrologic division. Sediments of channels and smooth flats in the river division commonly are coarser than sediments of channels and smooth flats in the transition and the estuary divisions. Shoreline flats in the estuary division are coarser than shoreline flats in the river division. Shoreline flats and irregular slopes in each hydrologic division generally are significantly coarser than channels and smooth flats. Relations between particle-size measures and geomorphic units show progressively larger cor

Estimating numbers of females with cubs-of-the-year in the Yellowstone grizzly bear population

USGS Publications Warehouse

Keating, K.A.; Schwartz, C.C.; Haroldson, M.A.; Moody, D.

2001-01-01

For grizzly bears (Ursus arctos horribilis) in the Greater Yellowstone Ecosystem (GYE), minimum population size and allowable numbers of human-caused mortalities have been calculated as a function of the number of unique females with cubs-of-the-year (FCUB) seen during a 3- year period. This approach underestimates the total number of FCUB, thereby biasing estimates of population size and sustainable mortality. Also, it does not permit calculation of valid confidence bounds. Many statistical methods can resolve or mitigate these problems, but there is no universal best method. Instead, relative performances of different methods can vary with population size, sample size, and degree of heterogeneity among sighting probabilities for individual animals. We compared 7 nonparametric estimators, using Monte Carlo techniques to assess performances over the range of sampling conditions deemed plausible for the Yellowstone population. Our goal was to estimate the number of FCUB present in the population each year. Our evaluation differed from previous comparisons of such estimators by including sample coverage methods and by treating individual sightings, rather than sample periods, as the sample unit. Consequently, our conclusions also differ from earlier studies. Recommendations regarding estimators and necessary sample sizes are presented, together with estimates of annual numbers of FCUB in the Yellowstone population with bootstrap confidence bounds.

Anthropometric Characteristics of Columbia, South Carolina, Youth Baseball Players and Dixie Youth World Series Players

ERIC Educational Resources Information Center

French, Karen E.; Spurgeon, John H.; Nevett, Michael E.

2007-01-01

The purpose of this study was to compare measures of body size in two samples of youth baseball players with normative data from the United States National Center for Health Statistics (NCHS) growth charts. One sample of youth baseball players participated in a local little league. The second sample of youth baseball players were members of eight…

Open-water and under-ice seasonal variations in trace element content and physicochemical associations in fluvial bed sediment.

PubMed

Doig, Lorne E; Carr, Meghan K; Meissner, Anna G N; Jardine, Tim D; Jones, Paul D; Bharadwaj, Lalita; Lindenschmidt, Karl-Erich

2017-11-01

Across the circumpolar world, intensive anthropogenic activities in the southern reaches of many large, northward-flowing rivers can cause sediment contamination in the downstream depositional environment. The influence of ice cover on concentrations of inorganic contaminants in bed sediment (i.e., sediment quality) is unknown in these rivers, where winter is the dominant season. A geomorphic response unit approach was used to select hydraulically diverse sampling sites across a northern test-case system, the Slave River and delta (Northwest Territories, Canada). Surface sediment samples (top 1 cm) were collected from 6 predefined geomorphic response units (12 sites) to assess the relationships between bed sediment physicochemistry (particle size distribution and total organic carbon content) and trace element content (mercury and 18 other trace elements) during open-water conditions. A subset of sites was resampled under-ice to assess the influence of season on these relationships and on total trace element content. Concentrations of the majority of trace elements were strongly correlated with percent fines and proxies for grain size (aluminum and iron), with similar trace element grain size/grain size proxy relationships between seasons. However, finer materials were deposited under ice with associated increases in sediment total organic carbon content and the concentrations of most trace elements investigated. The geomorphic response unit approach was effective at identifying diverse hydrological environments for sampling prior to field operations. Our data demonstrate the need for under-ice sampling to confirm year-round consistency in trace element-geochemical relationships in fluvial systems and to define the upper extremes of these relationships. Whether contaminated or not, under-ice bed sediment can represent a "worst-case" scenario in terms of trace element concentrations and exposure for sediment-associated organisms in northern fluvial systems. Environ Toxicol Chem 2017;36:2916-2924. © 2017 SETAC. © 2017 SETAC.

Ethnicity and Body Dissatisfaction among Women in the United States: A Meta-Analysis

ERIC Educational Resources Information Center

Grabe, Shelly; Hyde, Janet Shibley

2005-01-01

The prevailing view in popular culture and the psychological literature is that White women have greater body dissatisfaction than women of color. In this meta-analysis, 6 main effect sizes were obtained for differences among Asian American, Black, Hispanic, and White women with a sample of 98 studies, yielding 222 effect sizes. The average d for…

Treatment Trials for Neonatal Seizures: The Effect of Design on Sample Size

PubMed Central

Stevenson, Nathan J.; Boylan, Geraldine B.; Hellström-Westas, Lena; Vanhatalo, Sampsa

2016-01-01

Neonatal seizures are common in the neonatal intensive care unit. Clinicians treat these seizures with several anti-epileptic drugs (AEDs) to reduce seizures in a neonate. Current AEDs exhibit sub-optimal efficacy and several randomized control trials (RCT) of novel AEDs are planned. The aim of this study was to measure the influence of trial design on the required sample size of a RCT. We used seizure time courses from 41 term neonates with hypoxic ischaemic encephalopathy to build seizure treatment trial simulations. We used five outcome measures, three AED protocols, eight treatment delays from seizure onset (Td) and four levels of trial AED efficacy to simulate different RCTs. We performed power calculations for each RCT design and analysed the resultant sample size. We also assessed the rate of false positives, or placebo effect, in typical uncontrolled studies. We found that the false positive rate ranged from 5 to 85% of patients depending on RCT design. For controlled trials, the choice of outcome measure had the largest effect on sample size with median differences of 30.7 fold (IQR: 13.7–40.0) across a range of AED protocols, Td and trial AED efficacy (p<0.001). RCTs that compared the trial AED with positive controls required sample sizes with a median fold increase of 3.2 (IQR: 1.9–11.9; p<0.001). Delays in AED administration from seizure onset also increased the required sample size 2.1 fold (IQR: 1.7–2.9; p<0.001). Subgroup analysis showed that RCTs in neonates treated with hypothermia required a median fold increase in sample size of 2.6 (IQR: 2.4–3.0) compared to trials in normothermic neonates (p<0.001). These results show that RCT design has a profound influence on the required sample size. Trials that use a control group, appropriate outcome measure, and control for differences in Td between groups in analysis will be valid and minimise sample size. PMID:27824913

Recruitment, Job Search, and the United States Employment Service. Volume II: Tables and Methods.

ERIC Educational Resources Information Center

Camil Associates, Inc., Philadelphia, PA.

This volume contains the appendixes to Volume I of the report on recruitment, job search, and the United States Employment Service in 20 middle-sized American cities. Appendix A contains 165 pages of tables. Appendix B (63 pages) contains details of sample design, data analysis, and estimate precision under the categories of: Overview of the study…

Particle Size Distribution in Aluminum Manufacturing Facilities

PubMed Central

Liu, Sa; Noth, Elizabeth M.; Dixon-Ernst, Christine; Eisen, Ellen A.; Cullen, Mark R.; Hammond, S. Katharine

2015-01-01

As part of exposure assessment for an ongoing epidemiologic study of heart disease and fine particle exposures in aluminum industry, area particle samples were collected in production facilities to assess instrument reliability and particle size distribution at different process areas. Personal modular impactors (PMI) and Minimicro-orifice uniform deposition impactors (MiniMOUDI) were used. The coefficient of variation (CV) of co-located samples was used to evaluate the reproducibility of the samplers. PM2.5 measured by PMI was compared to PM2.5 calculated from MiniMOUDI data. Mass median aerodynamic diameter (MMAD) and concentrations of sub-micrometer (PM1.0) and quasi-ultrafine (PM0.56) particles were evaluated to characterize particle size distribution. Most of CVs were less than 30%. The slope of the linear regression of PMI_PM2.5 versus MiniMOUDI_PM2.5 was 1.03 mg/m3 per mg/m3 (± 0.05), with correlation coefficient of 0.97 (± 0.01). Particle size distribution varied substantively in smelters, whereas it was less variable in fabrication units with significantly smaller MMADs (arithmetic mean of MMADs: 2.59 μm in smelters vs. 1.31 μm in fabrication units, p = 0.001). Although the total particle concentration was more than two times higher in the smelters than in the fabrication units, the fraction of PM10 which was PM1.0 or PM0.56 was significantly lower in the smelters than in the fabrication units (p < 0.001). Consequently, the concentrations of sub-micrometer and quasi-ultrafine particles were similar in these two types of facilities. It would appear, studies evaluating ultrafine particle exposure in aluminum industry should focus on not only the smelters, but also the fabrication facilities. PMID:26478760

Particle Size Distribution in Aluminum Manufacturing Facilities.

PubMed

Liu, Sa; Noth, Elizabeth M; Dixon-Ernst, Christine; Eisen, Ellen A; Cullen, Mark R; Hammond, S Katharine

2014-10-01

As part of exposure assessment for an ongoing epidemiologic study of heart disease and fine particle exposures in aluminum industry, area particle samples were collected in production facilities to assess instrument reliability and particle size distribution at different process areas. Personal modular impactors (PMI) and Minimicro-orifice uniform deposition impactors (MiniMOUDI) were used. The coefficient of variation (CV) of co-located samples was used to evaluate the reproducibility of the samplers. PM 2.5 measured by PMI was compared to PM 2.5 calculated from MiniMOUDI data. Mass median aerodynamic diameter (MMAD) and concentrations of sub-micrometer (PM 1.0 ) and quasi-ultrafine (PM 0.56) particles were evaluated to characterize particle size distribution. Most of CVs were less than 30%. The slope of the linear regression of PMI_PM 2.5 versus MiniMOUDI_PM 2.5 was 1.03 mg/m 3 per mg/m 3 (± 0.05), with correlation coefficient of 0.97 (± 0.01). Particle size distribution varied substantively in smelters, whereas it was less variable in fabrication units with significantly smaller MMADs (arithmetic mean of MMADs: 2.59 μm in smelters vs. 1.31 μm in fabrication units, p = 0.001). Although the total particle concentration was more than two times higher in the smelters than in the fabrication units, the fraction of PM 10 which was PM 1.0 or PM 0.56 was significantly lower in the smelters than in the fabrication units (p < 0.001). Consequently, the concentrations of sub-micrometer and quasi-ultrafine particles were similar in these two types of facilities. It would appear, studies evaluating ultrafine particle exposure in aluminum industry should focus on not only the smelters, but also the fabrication facilities.

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE FOR FIELD USE OF THE PARTICULATE SAMPLER (UA-F-3.1)

EPA Science Inventory

The purpose of this SOP is to describe the in-field use of the particulate sampling system (pumping, control unit, and size selective inlet impactors) for collecting samples of particulate matter from the air during a predetermined time period during the Arizona NHEXAS project an...

21 CFR 161.173 - Canned wet pack shrimp in transparent or nontransparent containers.

Code of Federal Regulations, 2010 CFR

2010-04-01

... (dorsal tract, back vein, or sand vein). (ii) Deveined shrimp containing not less than 95 percent by...) Acceptable quality level (AQL). The maximum percent of defective sample units permitted in a lot that will be accepted approximately 95 percent of the time. (ii) Sampling plans: Acceptable Quality Level 6.5 Lot size...

Impact of Different Visual Field Testing Paradigms on Sample Size Requirements for Glaucoma Clinical Trials.

PubMed

Wu, Zhichao; Medeiros, Felipe A

2018-03-20

Visual field testing is an important endpoint in glaucoma clinical trials, and the testing paradigm used can have a significant impact on the sample size requirements. To investigate this, this study included 353 eyes of 247 glaucoma patients seen over a 3-year period to extract real-world visual field rates of change and variability estimates to provide sample size estimates from computer simulations. The clinical trial scenario assumed that a new treatment was added to one of two groups that were both under routine clinical care, with various treatment effects examined. Three different visual field testing paradigms were evaluated: a) evenly spaced testing, b) United Kingdom Glaucoma Treatment Study (UKGTS) follow-up scheme, which adds clustered tests at the beginning and end of follow-up in addition to evenly spaced testing, and c) clustered testing paradigm, with clusters of tests at the beginning and end of the trial period and two intermediary visits. The sample size requirements were reduced by 17-19% and 39-40% using the UKGTS and clustered testing paradigms, respectively, when compared to the evenly spaced approach. These findings highlight how the clustered testing paradigm can substantially reduce sample size requirements and improve the feasibility of future glaucoma clinical trials.

Optimal Inspection of Imports to Prevent Invasive Pest Introduction.

PubMed

Chen, Cuicui; Epanchin-Niell, Rebecca S; Haight, Robert G

2018-03-01

The United States imports more than 1 billion live plants annually-an important and growing pathway for introduction of damaging nonnative invertebrates and pathogens. Inspection of imports is one safeguard for reducing pest introductions, but capacity constraints limit inspection effort. We develop an optimal sampling strategy to minimize the costs of pest introductions from trade by posing inspection as an acceptance sampling problem that incorporates key features of the decision context, including (i) simultaneous inspection of many heterogeneous lots, (ii) a lot-specific sampling effort, (iii) a budget constraint that limits total inspection effort, (iv) inspection error, and (v) an objective of minimizing cost from accepted defective units. We derive a formula for expected number of accepted infested units (expected slippage) given lot size, sample size, infestation rate, and detection rate, and we formulate and analyze the inspector's optimization problem of allocating a sampling budget among incoming lots to minimize the cost of slippage. We conduct an empirical analysis of live plant inspection, including estimation of plant infestation rates from historical data, and find that inspections optimally target the largest lots with the highest plant infestation rates, leaving some lots unsampled. We also consider that USDA-APHIS, which administers inspections, may want to continue inspecting all lots at a baseline level; we find that allocating any additional capacity, beyond a comprehensive baseline inspection, to the largest lots with the highest infestation rates allows inspectors to meet the dual goals of minimizing the costs of slippage and maintaining baseline sampling without substantial compromise. © 2017 Society for Risk Analysis.

A thermal desorption mass spectrometer for freshly nucleated secondary aerosol particles

NASA Astrophysics Data System (ADS)

Held, A.; Gonser, S. G.

2012-04-01

Secondary aerosol formation in the atmosphere is observed in a large variety of locations worldwide, introducing new particles to the atmosphere which can grow to sizes relevant for health and climate effects of aerosols. The chemical reactions leading to atmospheric secondary aerosol formation are not yet fully understood. At the same time, analyzing the chemical composition of freshly nucleated particles is still a challenging task. We are currently finishing the development of a field portable aerosol mass spectrometer for nucleation particles with diameters smaller than 30 nm. This instrument consists of a custom-built aerosol sizing and collection unit coupled to a time-of-flight mass spectrometer (TOF-MS). The aerosol sizing and collection unit is composed of three major parts: (1) a unipolar corona aerosol charger, (2) a radial differential mobility analyzer (rDMA) for aerosol size separation, and (3) an electrostatic precipitator for aerosol collection. After collection, the aerosol sample is thermally desorbed, and the resulting gas sample is transferred to the TOF-MS for chemical analysis. The unipolar charger is based on corona discharge from carbon fibres (e.g. Han et al., 2008). This design allows efficient charging at voltages below 2 kV, thus eliminating the potential for ozone production which would interfere with the collected aerosol. With the current configuration the extrinsic charging efficiency for 20 nm particles is 32 %. The compact radial DMA similar to the design of Zhang et al. (1995) is optimized for a diameter range from 1 nm to 100 nm. Preliminary tests show that monodisperse aerosol samples (geometric standard deviation of 1.09) at 10 nm, 20 nm, and 30 nm can easily be separated from the ambient polydisperse aerosol population. Finally, the size-segregated aerosol sample is collected on a high-voltage biased metal filament. The collected sample is protected from contamination using a He sheath counterflow. Resistive heating of the filament allows temperature-controlled desorption of compounds of different volatility. We will present preliminary characterization experiments of the aerosol sizing and collection unit coupled to the mass spectrometer. Funding by the German Research Foundation (DFG) under grant DFG HE5214/3-1 is gratefully acknowledged. Han, B., Kim, H.J., Kim, Y.J., and Sioutas, C. (2008) Unipolar charging of ultrafine particles using carbon fiber ionizers. Aerosol Sci. Technol, 42, 793-800. Zhang, S.-H., Akutsu, Y., Russell, L.M., Flagan, R.C., and Seinfeld, J.H. (1995) Radial Differential Mobility Analyzer. Aerosol Sci. Technol, 23, 357-372.

Capsule- and disk-filter procedure

USGS Publications Warehouse

Skrobialowski, Stanley C.

2016-01-01

Capsule and disk filters are disposable, self-contained units composed of a pleated or woven filter medium encased in a polypropylene or other plastic housing that can be connected inline to a sample-delivery system (such as a submersible or peristaltic pump) that generates sufficient pressure (positive or negative) to force water through the filter. Filter media are available in several pore sizes, but 0.45 µm is the pore size used routinely for most studies at this time. Capsule or disk filters (table 5.2.1.A.1) are required routinely for most studies when filtering samples for trace-element analyses and are recommended when filtering samples for major-ion or other inorganic-constituent analyses.

Preconcentration and speciation of ultra-trace Se (IV) and Se (VI) in environmental water samples with nano-sized TiO2 colloid and determination by HG-AFS.

PubMed

Fu, Jiaqi; Zhang, Xu; Qian, Shahua; Zhang, Lin

2012-05-30

A united method for speciation analysis of Se (IV) and Se (VI) in environmental water samples was developed using nano-sized TiO(2) colloid as adsorbent and hydride generation atomic fluorescence spectrometry (HG-AFS) as determination means. When the pH values of bulk solution were between 6.0 and 7.0, successful adsorption onto 1 mL nano-sized TiO(2) colloid (0.2%) was achieved for more than 97.0% of Se (IV) while Se (VI) barely got adsorbed. Therefore, the method made it possible to preconcentrate and determine Se (IV) and Se (VI) separately. The precipitated TiO(2) with concentrated selenium was directly converted to colloid without desorption. Selenium in the resulting colloid was then determined by HG-AFS. The detection limits (3σ) and relative standard deviations (R.S.D) of this method were 24 ng/L and 42 ng/L, 7.8% (n=6) and 7.0% (n=6) for Se (IV) and Se (VI), respectively. This simple, sensitive, and united method was successfully applied to the separation and speciation of ultra-trace Se (IV) and Se (VI) in environmental water samples. Copyright © 2012 Elsevier B.V. All rights reserved.

Insensitivity to Flaws Leads to Damage Tolerance in Brittle Architected Meta-Materials

NASA Astrophysics Data System (ADS)

Montemayor, L. C.; Wong, W. H.; Zhang, Y.-W.; Greer, J. R.

2016-02-01

Cellular solids are instrumental in creating lightweight, strong, and damage-tolerant engineering materials. By extending feature size down to the nanoscale, we simultaneously exploit the architecture and material size effects to substantially enhance structural integrity of architected meta-materials. We discovered that hollow-tube alumina nanolattices with 3D kagome geometry that contained pre-fabricated flaws always failed at the same load as the pristine specimens when the ratio of notch length (a) to sample width (w) is no greater than 1/3, with no correlation between failure occurring at or away from the notch. Samples with (a/w) > 0.3, and notch length-to-unit cell size ratios of (a/l) > 5.2, failed at a lower peak loads because of the higher sample compliance when fewer unit cells span the intact region. Finite element simulations show that the failure is governed by purely tensile loading for (a/w) < 0.3 for the same (a/l); bending begins to play a significant role in failure as (a/w) increases. This experimental and computational work demonstrates that the discrete-continuum duality of architected structural meta-materials may give rise to their damage tolerance and insensitivity of failure to the presence of flaws even when made entirely of intrinsically brittle materials.

Aircrew Sizing Survey 2011

DTIC Science & Technology

2014-10-01

Resource JSF Joint Strike Fighter JPATS Joint Primary Aircraft Training System USMC United States Marine Corps USAF United States Air Force LIST...Surface Anthropometry Resource (CAESAR) was developed for the Joint Strike Fighter (JSF) program. The ACSS was intended to replace the JSF-CAESAR...an aircrew sample was made in 2003 by Hudson et al. They extracted a subset, named JSF CAESAR (Joint Strike Fighter), from the Civilian American and

Descartes region - Evidence for Copernican-age volcanism.

NASA Technical Reports Server (NTRS)

Head, J. W., III; Goetz, A. F. H.

1972-01-01

A model that suggests that the high-albedo central region of the Descartes Formation was formed by Copernican-age volcanism was developed from Orbiter photography, Apollo 12 multispectral photography, earth-based spectrophotometry, and thermal IR and radar data. The bright surface either is abundant in centimeter-sized rocks or is formed from an insulating debris layer overlying a surface with an abundance of rocks in the 1- to 20-cm size range. On the basis of these data, the bright unit is thought to be a young pyroclastic deposit mantling older volcanic units of the Descartes Formation. Since the Apollo 16 target point is only 50 km NW of the central part of this unit, evidence for material associated with this unique highland formation should be searched for in returned soil and rock samples.

Practical sampling plans for Varroa destructor (Acari: Varroidae) in Apis mellifera (Hymenoptera: Apidae) colonies and apiaries.

PubMed

Lee, K V; Moon, R D; Burkness, E C; Hutchison, W D; Spivak, M

2010-08-01

The parasitic mite Varroa destructor Anderson & Trueman (Acari: Varroidae) is arguably the most detrimental pest of the European-derived honey bee, Apis mellifera L. Unfortunately, beekeepers lack a standardized sampling plan to make informed treatment decisions. Based on data from 31 commercial apiaries, we developed sampling plans for use by beekeepers and researchers to estimate the density of mites in individual colonies or whole apiaries. Beekeepers can estimate a colony's mite density with chosen level of precision by dislodging mites from approximately to 300 adult bees taken from one brood box frame in the colony, and they can extrapolate to mite density on a colony's adults and pupae combined by doubling the number of mites on adults. For sampling whole apiaries, beekeepers can repeat the process in each of n = 8 colonies, regardless of apiary size. Researchers desiring greater precision can estimate mite density in an individual colony by examining three, 300-bee sample units. Extrapolation to density on adults and pupae may require independent estimates of numbers of adults, of pupae, and of their respective mite densities. Researchers can estimate apiary-level mite density by taking one 300-bee sample unit per colony, but should do so from a variable number of colonies, depending on apiary size. These practical sampling plans will allow beekeepers and researchers to quantify mite infestation levels and enhance understanding and management of V. destructor.

Effect of Cu Salt Molarity on the Nanostructure of CuO Prolate Spheroid

NASA Astrophysics Data System (ADS)

Sabeeh, Sabah H.; Hussein, Hashim Abed; Judran, Hadia Kadhim

Copper sulfate pentahydrate was used as a source of Cu ion with five different molarities (0.02, 0.05, 0.1, 0.15, 2 and 0.25M). XRD, FE-SEM and TEM techniques all showed that CuO samples have polycrystalline monoclinic structure. CuO prolate spheroid is assembled from nanoparticles as building units. It was demonstrated that the purity, morphology, size range of prolate spheroid and density of nano building units are significantly influenced by Cu precursor’s molarity. The pure phase of CuO prolate spheroid was produced via molarity of 0.2M with crystallite size of 15.1565nm while the particle size of building units ranges from 16nm to 21nm. The stability of CuO nanosuspension or nanofluid was evaluated by zeta potential analysis. The obtained properties of specific structure with large surface area of CuO prolate spheroid make it a promising candidate for wide range of potential applications as in nanofluids for cooling purposes.

Rutile and topaz in Precambrian gneiss, Jefferson and Clear Creek Counties, Colorado

USGS Publications Warehouse

Sheridan, Douglas M.; Taylor, Richard B.; Marsh, Sherman P.

1968-01-01

Disseminated rutile and major amounts of topaz have been identified in Precambrian topaz-quartz gneiss northwest of Evergreen, Colo. The rutile occurs in quartz-topaz-sillimanite gneiss that forms a stratigraphic unit which is 11 to 100 feet thick and is identified along strike for more than 7,000 feet. Three composite chip samples taken across this unit contain 2.2 to 4.2 percent of rutile, by weight, in grains averaging from 0.1 to 0.3 millimeter in size. The topaz content, by weight, in the same samples ranges from 23 to 67 percent.

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

Sivakumar Babu, G.L., E-mail: gls@civil.iisc.ernet.in; Lakshmikanthan, P., E-mail: lakshmikanthancp@gmail.com; Santhosh, L.G., E-mail: lgsanthu2006@gmail.com

Highlights: • Shear strength properties of mechanically biologically treated municipal solid waste. • Effect of unit weight and particle size on the shear strength of waste. • Effect of particle size on the strength properties. • Stiffness ratio and the strength ratio of MSW. - Abstract: Strength and stiffness properties of municipal solid waste (MSW) are important in landfill design. This paper presents the results of comprehensive testing of shear strength properties of mechanically biologically treated municipal solid waste (MBT-MSW) in laboratory. Changes in shear strength of MSW as a function of unit weight and particle size were investigated bymore » performing laboratory studies on the MSW collected from Mavallipura landfill site in Bangalore. Direct shear tests, small scale and large scale consolidated undrained and drained triaxial tests were conducted on reconstituted compost reject MSW samples. The triaxial test results showed that the MSW samples exhibited a strain-hardening behaviour and the strength of MSW increased with increase in unit weight. Consolidated drained tests showed that the mobilized shear strength of the MSW increased by 40% for a unit weight increase from 7.3 kN/m{sup 3} to 10.3 kN/m{sup 3} at 20% strain levels. The mobilized cohesion and friction angle ranged from 5 to 9 kPa and 8° to 33° corresponding to a strain level of 20%. The consolidated undrained tests exhibited reduced friction angle values compared to the consolidated drained tests. The friction angle increased with increase in the unit weight from 8° to 55° in the consolidated undrained tests. Minor variations were found in the cohesion values. Relationships for strength and stiffness of MSW in terms of strength and stiffness ratios are developed and discussed. The stiffness ratio and the strength ratio of MSW were found to be 10 and 0.43.« less

Imaging of zymogen granules in fully wet cells: evidence for restricted mechanism of granule growth.

PubMed

Hammel, Ilan; Anaby, Debbie

2007-09-01

The introduction of wet SEM imaging technology permits electron microscopy of wet samples. Samples are placed in sealed specimen capsules and are insulated from the vacuum in the SEM chamber by an impermeable, electron-transparent membrane. The complete insulation of the sample from the vacuum allows direct imaging of fully hydrated, whole-mount tissue. In the current work, we demonstrate direct inspection of thick pancreatic tissue slices (above 400 mum). In the case of scanning of the pancreatic surface, the boundaries of intracellular features are seen directly. Thus no unfolding is required to ascertain the actual particle size distribution based on the sizes of the sections. This method enabled us to investigate the true granule size distribution and confirm early studies of improved conformity to a Poisson-like distribution, suggesting that the homotypic granule growth results from a mechanism, which favors the addition of a single unit granule to mature granules.

Evaluating multi-level models to test occupancy state responses of Plethodontid salamanders

USGS Publications Warehouse

Kroll, Andrew J.; Garcia, Tiffany S.; Jones, Jay E.; Dugger, Catherine; Murden, Blake; Johnson, Josh; Peerman, Summer; Brintz, Ben; Rochelle, Michael

2015-01-01

Plethodontid salamanders are diverse and widely distributed taxa and play critical roles in ecosystem processes. Due to salamander use of structurally complex habitats, and because only a portion of a population is available for sampling, evaluation of sampling designs and estimators is critical to provide strong inference about Plethodontid ecology and responses to conservation and management activities. We conducted a simulation study to evaluate the effectiveness of multi-scale and hierarchical single-scale occupancy models in the context of a Before-After Control-Impact (BACI) experimental design with multiple levels of sampling. Also, we fit the hierarchical single-scale model to empirical data collected for Oregon slender and Ensatina salamanders across two years on 66 forest stands in the Cascade Range, Oregon, USA. All models were fit within a Bayesian framework. Estimator precision in both models improved with increasing numbers of primary and secondary sampling units, underscoring the potential gains accrued when adding secondary sampling units. Both models showed evidence of estimator bias at low detection probabilities and low sample sizes; this problem was particularly acute for the multi-scale model. Our results suggested that sufficient sample sizes at both the primary and secondary sampling levels could ameliorate this issue. Empirical data indicated Oregon slender salamander occupancy was associated strongly with the amount of coarse woody debris (posterior mean = 0.74; SD = 0.24); Ensatina occupancy was not associated with amount of coarse woody debris (posterior mean = -0.01; SD = 0.29). Our simulation results indicate that either model is suitable for use in an experimental study of Plethodontid salamanders provided that sample sizes are sufficiently large. However, hierarchical single-scale and multi-scale models describe different processes and estimate different parameters. As a result, we recommend careful consideration of study questions and objectives prior to sampling data and fitting models.

Estimating the quadratic mean diameters of fine woody debris in forests of the United States

Treesearch

Christopher W. Woodall; Vicente J. Monleon

2010-01-01

Most fine woody debris (FWD) line-intersect sampling protocols and associated estimators require an approximation of the quadratic mean diameter (QMD) of each individual FWD size class. There is a lack of empirically derived QMDs by FWD size class and species/forest type across the U.S. The objective of this study is to evaluate a technique known as the graphical...

A new look at the Lake Superior biomass size spectrum

USGS Publications Warehouse

Yurista, Peder M.; Yule, Daniel L.; Balge, Matt; VanAlstine, Jon D.; Thompson, Jo A.; Gamble, Allison E.; Hrabik, Thomas R.; Kelly, John R.; Stockwell, Jason D.; Vinson, Mark

2014-01-01

We synthesized data from multiple sampling programs and years to describe the Lake Superior pelagic biomass size structure. Data consisted of Coulter counts for phytoplankton, optical plankton counts for zooplankton, and acoustic surveys for pelagic prey fish. The size spectrum was stable across two time periods separated by 5 years. The primary scaling or overall slope of the normalized biomass size spectra for the combined years was −1.113, consistent with a previous estimate for Lake Superior (−1.10). Periodic dome structures within the overall biomass size structure were fit to polynomial regressions based on the observed sub-domes within the classical taxonomic positions (algae, zooplankton, and fish). This interpretation of periodic dome delineation was aligned more closely with predator–prey size relationships that exist within the zooplankton (herbivorous, predacious) and fish (planktivorous, piscivorous) taxonomic positions. Domes were spaced approximately every 3.78 log10 units along the axis and with a decreasing peak magnitude of −4.1 log10 units. The relative position of the algal and herbivorous zooplankton domes predicted well the subsequent biomass domes for larger predatory zooplankton and planktivorous prey fish.

Comparative toxicity of size-fractionated airborne particulate matter obtained from different cities in the United States

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

Gilmour, M.I.; McGee, J.; Duvall, R.M.

2007-07-01

Hundreds of epidemiological studies have shown that exposure to ambient particulate matter (PM) is associated with dose-dependent increases in morbidity and mortality. While early reports focused on PM less than 10 {mu}m (PM10), numerous studies have since shown that the effects can occur with PM stratified into ultrafine (UF), fine (FI), and coarse (CO) size modes despite the fact that these materials differ significantly in both evolution and chemistry. Furthermore the chemical makeup of these different size fractions can vary tremendously depending on location, meteorology, and source profile. For this reason, high-volume three-stage particle impactors with the capacity to collectmore » UF, FI, and CO particles were deployed to four different locations in the United States (Seattle, WA; Salt Lake City, UT; Sterling Forest and South Bronx, NY), and weekly samples were collected for 1 mo in each place. The particles were extracted, assayed for a standardized battery of chemical components, and instilled into mouse lungs (female BALB/c) at doses of 25 and 100 {mu}g. Eighteen hours later animals were euthanized and parameters of injury and inflammation were monitored in the bronchoalveolar lavage fluid and plasma. Of the four locations, the South Bronx coarse fraction was the most potent sample in both pulmonary and systemic biomarkers. Receptor source modeling on the PM2.5 samples showed that the South Bronx sample was heavily influenced by emissions from coal fired power plants (31%) and mobile sources (22%). Further studies will assess how source profiles correlate with the observed effects for all locations and size fractions.« less

Discerning some Tylenol brands using attenuated total reflection Fourier transform infrared data and multivariate analysis techniques.

PubMed

Msimanga, Huggins Z; Ollis, Robert J

2010-06-01

Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to classify acetaminophen-containing medicines using their attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectra. Four formulations of Tylenol (Arthritis Pain Relief, Extra Strength Pain Relief, 8 Hour Pain Relief, and Extra Strength Pain Relief Rapid Release) along with 98% pure acetaminophen were selected for this study because of the similarity of their spectral features, with correlation coefficients ranging from 0.9857 to 0.9988. Before acquiring spectra for the predictor matrix, the effects on spectral precision with respect to sample particle size (determined by sieve size opening), force gauge of the ATR accessory, sample reloading, and between-tablet variation were examined. Spectra were baseline corrected and normalized to unity before multivariate analysis. Analysis of variance (ANOVA) was used to study spectral precision. The large particles (35 mesh) showed large variance between spectra, while fine particles (120 mesh) indicated good spectral precision based on the F-test. Force gauge setting did not significantly affect precision. Sample reloading using the fine particle size and a constant force gauge setting of 50 units also did not compromise precision. Based on these observations, data acquisition for the predictor matrix was carried out with the fine particles (sieve size opening of 120 mesh) at a constant force gauge setting of 50 units. After removing outliers, PCA successfully classified the five samples in the first and second components, accounting for 45.0% and 24.5% of the variances, respectively. The four-component PLS-DA model (R(2)=0.925 and Q(2)=0.906) gave good test spectra predictions with an overall average of 0.961 +/- 7.1% RSD versus the expected 1.0 prediction for the 20 test spectra used.

Origin and heterogeneity of pore sizes in the Mount Simon Sandstone and Eau Claire Formation: Implications for multiphase fluid flow

DOE PAGES

Mozley, Peter S.; Heath, Jason E.; Dewers, Thomas A.; ...

2016-01-01

The Mount Simon Sandstone and Eau Claire Formation represent a principal reservoir - caprock system for wastewater disposal, geologic CO 2 storage, and compressed air energy storage (CAES) in the Midwestern United States. Of primary concern to site performance is heterogeneity in flow properties that could lead to non-ideal injectivity and distribution of injected fluids (e.g., poor sweep efficiency). Using core samples from the Dallas Center Structure, Iowa, we investigate pore structure that governs flow properties of major lithofacies of these formations. Methods include gas porosimetry and permeametry, mercury intrusion porosimetry, thin section petrography, and X-ray diffraction. The lithofacies exhibitmore » highly variable intra- and inter-informational distributions of pore throat and body sizes. Based on pore-throat size, samples fall into four distinct groups. Micropore-throat dominated samples are from the Eau Claire Formation, whereas the macropore-, mesopore-, and uniform-dominated samples are from the Mount Simon Sandstone. Complex paragenesis governs the high degree of pore and pore-throat size heterogeneity, due to an interplay of precipitation, non-uniform compaction, and later dissolution of cements. Furthermore, the cement dissolution event probably accounts for much of the current porosity in the unit. The unusually heterogeneous nature of the pore networks in the Mount Simon Sandstone indicates that there is a greater-than-normal opportunity for reservoir capillary trapping of non-wetting fluids — as quantified by CO 2 and air column heights — which should be taken into account when assessing the potential of the reservoir-caprock system for CO 2 storage and CAES.« less

An Investigation of the Relationship of Achievement Motivation with Achievement in Mathematics for Students in the United States and Japan.

ERIC Educational Resources Information Center

Harnisch, Delwyn L.; Ryan, Katherine E.

A study was made of cross-cultural patterns of achievement motivation in relationship to the mathematics achievement of Japanese and American boys and girls approximately 16 years of age. Sample sizes were 9,582 for the United States subjects (specifically, from Illinois) and 1,700 for the participants from Japan. Data came from performance on the…

A comparative study of the physical properties of Cu-Zn ferrites annealed under different atmospheres and temperatures: Magnetic enhancement of Cu0.5Zn0.5Fe2O4 nanoparticles by a reducing atmosphere

NASA Astrophysics Data System (ADS)

Gholizadeh, Ahmad

2018-04-01

In the present work, the influence of different sintering atmospheres and temperatures on physical properties of the Cu0.5Zn0.5Fe2O4 nanoparticles including the redistribution of Zn2+ and Fe3+ ions, the oxidation of Fe atoms in the lattice, crystallite sizes, IR bands, saturation magnetization and magnetic core sizes have been investigated. The fitting of XRD patterns by using Fullprof program and also FT-IR measurement show the formation of a cubic structure with no presence of impurity phase for all the samples. The unit cell parameter of the samples sintered at the air- and inert-ambient atmospheres trend to decrease with sintering temperature, but for the samples sintered under carbon monoxide-ambient atmosphere increase. The magnetization curves versus the applied magnetic field, indicate different behaviour for the samples sintered at 700 °C with the respect to the samples sintered at 300 °C. Also, the saturation magnetization increases with the sintering temperature and reach a maximum 61.68 emu/g in the sample sintered under reducing atmosphere at 600 °C. The magnetic particle size distributions of samples have been calculated by fitting the M-H curves with the size distributed Langevin function. The results obtained from the XRD and FTIR measurements suggest that the magnetic core size has the dominant effect in variation of the saturation magnetization of the samples.

Monitoring of bioaerosol inhalation risks in different environments using a six-stage Andersen sampler and the PCR-DGGE method.

PubMed

Xu, Zhenqiang; Yao, Maosheng

2013-05-01

Increasing evidences show that inhalation of indoor bioaerosols has caused numerous adverse health effects and diseases. However, the bioaerosol size distribution, composition, and concentration level, representing different inhalation risks, could vary with different living environments. The six-stage Andersen sampler is designed to simulate the sampling of different human lung regions. Here, the sampler was used in investigating the bioaerosol exposure in six different environments (student dorm, hospital, laboratory, hotel room, dining hall, and outdoor environment) in Beijing. During the sampling, the Andersen sampler was operated for 30 min for each sample, and three independent experiments were performed for each of the environments. The air samples collected onto each of the six stages of the sampler were incubated on agar plates directly at 26 °C, and the colony forming units (CFU) were manually counted and statistically corrected. In addition, the developed CFUs were washed off the agar plates and subjected to polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE) for diversity analysis. Results revealed that for most environments investigated, the culturable bacterial aerosol concentrations were higher than those of culturable fungal aerosols. The culturable bacterial and fungal aerosol fractions, concentration, size distribution, and diversity were shown to vary significantly with the sampling environments. PCR-DGGE analysis indicated that different environments had different culturable bacterial aerosol compositions as revealed by distinct gel band patterns. For most environments tested, larger (>3 μm) culturable bacterial aerosols with a skewed size distribution were shown to prevail, accounting for more than 60 %, while for culturable fungal aerosols with a normal size distribution, those 2.1-4.7 μm dominated, accounting for 20-40 %. Alternaria, Cladosporium, Chaetomium, and Aspergillus were found abundant in most environments studied here. Viable microbial load per unit of particulate matter was also shown to vary significantly with the sampling environments. The results from this study suggested that different environments even with similar levels of total microbial culturable aerosol concentrations could present different inhalation risks due to different bioaerosol particle size distribution and composition. This work fills literature gaps regarding bioaerosol size and composition-based exposure risks in different human dwellings in contrast to a vast body of total bioaerosol levels.

Evaluation of vacuum filter sock surface sample collection method for Bacillus spores from porous and non-porous surfaces.

PubMed

Brown, Gary S; Betty, Rita G; Brockmann, John E; Lucero, Daniel A; Souza, Caroline A; Walsh, Kathryn S; Boucher, Raymond M; Tezak, Matthew S; Wilson, Mollye C

2007-07-01

Vacuum filter socks were evaluated for recovery efficiency of powdered Bacillus atrophaeus spores from two non-porous surfaces, stainless steel and painted wallboard and two porous surfaces, carpet and bare concrete. Two surface coupons were positioned side-by-side and seeded with aerosolized Bacillus atrophaeus spores. One of the surfaces, a stainless steel reference coupon, was sized to fit into a sample vial for direct spore removal, while the other surface, a sample surface coupon, was sized for a vacuum collection application. Deposited spore material was directly removed from the reference coupon surface and cultured for enumeration of colony forming units (CFU), while deposited spore material was collected from the sample coupon using the vacuum filter sock method, extracted by sonication and cultured for enumeration. Recovery efficiency, which is a measure of overall transfer effectiveness from the surface to culture, was calculated as the number of CFU enumerated from the filter sock sample per unit area relative to the number of CFU enumerated from the co-located reference coupon per unit area. The observed mean filter sock recovery efficiency from stainless steel was 0.29 (SD = 0.14, n = 36), from painted wallboard was 0.25 (SD = 0.15, n = 36), from carpet was 0.28 (SD = 0.13, n = 40) and from bare concrete was 0.19 (SD = 0.14, n = 44). Vacuum filter sock recovery quantitative limits of detection were estimated at 105 CFU m(-2) from stainless steel and carpet, 120 CFU m(-2) from painted wallboard and 160 CFU m(-2) from bare concrete. The method recovery efficiency and limits of detection established in this work provide useful guidance for the planning of incident response environmental sampling for biological agents such as Bacillus anthracis.

Differential Risk of Injury to Child Occupants by SUV Size

PubMed Central

Kallan, Michael J.; Durbin, Dennis R.; Elliott, Michael R.; Arbogast, Kristy B.; Winston, Flaura K.

2004-01-01

In the United States, the sport utility vehicle (SUV) is the fastest growing segment of the passenger vehicle fleet, yet SUVs vary widely in size and crashworthiness. Using data collected from a population-based sample of crashes in insured vehicles, we quantified the risk of injury to child occupants in SUVs by vehicle weight. There is an increased risk in both Small and Midsize SUVs when compared to Large SUVs. Parents who are purchasing a SUV should strongly consider the size of the vehicle and its crashworthiness. PMID:15319119

Size Matters: Assessing Optimum Soil Sample Size for Fungal and Bacterial Community Structure Analyses Using High Throughput Sequencing of rRNA Gene Amplicons

PubMed Central

Penton, C. Ryan; Gupta, Vadakattu V. S. R.; Yu, Julian; Tiedje, James M.

2016-01-01

We examined the effect of different soil sample sizes obtained from an agricultural field, under a single cropping system uniform in soil properties and aboveground crop responses, on bacterial and fungal community structure and microbial diversity indices. DNA extracted from soil sample sizes of 0.25, 1, 5, and 10 g using MoBIO kits and from 10 and 100 g sizes using a bead-beating method (SARDI) were used as templates for high-throughput sequencing of 16S and 28S rRNA gene amplicons for bacteria and fungi, respectively, on the Illumina MiSeq and Roche 454 platforms. Sample size significantly affected overall bacterial and fungal community structure, replicate dispersion and the number of operational taxonomic units (OTUs) retrieved. Richness, evenness and diversity were also significantly affected. The largest diversity estimates were always associated with the 10 g MoBIO extractions with a corresponding reduction in replicate dispersion. For the fungal data, smaller MoBIO extractions identified more unclassified Eukaryota incertae sedis and unclassified glomeromycota while the SARDI method retrieved more abundant OTUs containing unclassified Pleosporales and the fungal genera Alternaria and Cercophora. Overall, these findings indicate that a 10 g soil DNA extraction is most suitable for both soil bacterial and fungal communities for retrieving optimal diversity while still capturing rarer taxa in concert with decreasing replicate variation. PMID:27313569

Workplace Health Promotion Implementation, Readiness, and Capacity Among Mid-Sized Employers in Low-Wage Industries: A National Survey

PubMed Central

Hannon, Peggy A.; Garson, Gayle; Harris, Jeffrey R.; Hammerback, Kristen; Sopher, Carrie J.; Clegg-Thorp, Catherine

2012-01-01

Objective To describe workplace health promotion (WHP) implementation, readiness, and capacity among mid-sized employers in low-wage industries in the United States. Methods A cross-sectional survey of a national sample of mid-sized employers (100–4,999 employees) representing five low-wage industries. Results Employers’ WHP implementation for both employees and employees’ spouses and partners was low. Readiness scales showed that employers believe WHP would benefit their employees and their companies, but they were less likely to believe that WHP was feasible for their companies. Employers’ capacity to implement WHP was very low; nearly half the sample reported no capacity. Conclusion Mid-sized employers in low-wage industries implement few WHP programs; their responses to readiness and capacity measures indicate that low capacity may be one of the principal barriers to WHP implementation. PMID:23090160

Increased Oxidative Burden Associated with Traffic Component of Ambient Particulate Matter at Roadside and Urban Background Schools Sites in London

PubMed Central

Godri, Krystal J.; Harrison, Roy M.; Evans, Tim; Baker, Timothy; Dunster, Christina; Mudway, Ian S.; Kelly, Frank J.

2011-01-01

As the incidence of respiratory and allergic symptoms has been reported to be increased in children attending schools in close proximity to busy roads, it was hypothesised that PM from roadside schools would display enhanced oxidative potential (OP). Two consecutive one-week air quality monitoring campaigns were conducted at seven school sampling sites, reflecting roadside and urban background in London. Chemical characteristics of size fractionated particulate matter (PM) samples were related to the capacity to drive biological oxidation reactions in a synthetic respiratory tract lining fluid. Contrary to hypothesised contrasts in particulate OP between school site types, no robust size-fractionated differences in OP were identified due high temporal variability in concentrations of PM components over the one-week sampling campaigns. For OP assessed both by ascorbate (OPAA m−3) and glutathione (OPGSH m−3) depletion, the highest OP per cubic metre of air was in the largest size fraction, PM1.9–10.2. However, when expressed per unit mass of particles OPAA µg−1 showed no significant dependence upon particle size, while OPGSH µg−1 had a tendency to increase with increasing particle size, paralleling increased concentrations of Fe, Ba and Cu. The two OP metrics were not significantly correlated with one another, suggesting that the glutathione and ascorbate depletion assays respond to different components of the particles. Ascorbate depletion per unit mass did not show the same dependence as for GSH and it is possible that other trace metals (Zn, Ni, V) or organic components which are enriched in the finer particle fractions, or the greater surface area of smaller particles, counter-balance the redox activity of Fe, Ba and Cu in the coarse particles. Further work with longer-term sampling and a larger suite of analytes is advised in order to better elucidate the determinants of oxidative potential, and to fuller explore the contrasts between site types. PMID:21818283

GREAT III Erosion and Sediment Inventory (Saverton, Missouri to Cairo, Illinois).

DTIC Science & Technology

1982-06-01

Berkas (Don Coffin) (Horace Jeffery) Illinois Tim Lazaro (Doug Glysson) University of Missouri at Rolla, 140 (Dr. Glendon Stevens) Dr. Charles Morris...sediment sampling began with periodic particle size samples of suspended material, bedload, and bad material. All data collection at this station has been... Berkas , W.D., Personal Communication, Hydrologist, Water Resources * Division, Missouri, United States Geological Survey, Rolla, Missouri, 1981. 3

Reconstructing an Explosive Basaltic Eruption in the Pinacate Volcanic Field, NW Sonora, Mexico

NASA Astrophysics Data System (ADS)

Zawacki, E. E.; Clarke, A. B.; Arrowsmith, R.; Lynch, D. J.

2017-12-01

Tephra deposits from explosive volcanic eruptions provide a means to reconstruct eruption characteristics, such as column height and erupted volume. Parameters like these are essential in assessing the explosivity of past eruptions and associated volcanic hazards. We applied such methods to a basaltic tephra deposit from one of the youngest eruptions in the Pinacate volcanic field (NW Sonora, Mexico). This roughly circular tephra blanket extends 13 km E-W and 13 km N-S, and covers an area of at least 135 km2. The source vent of this eruption is hypothesized to be the Tecolote volcano (lat 31.877, long -113.362), which is dated to 27 ± 6 ka (40Ar/39Ar). Fifty-three pits were dug across the extent of the tephra deposit to measure its thickness, record stratigraphy, characterize grain size distribution, and determine maximum clast size. Isopleth and isopach maps were created from these data to determine the column height (>9 km), estimate mass eruption rate (>2.1x106 kg/s), and calculate the erupted volume (>4.2x10-2 km3). Stratigraphic descriptions support two distinct episodes of tephra production. Unit A is dispersed in an approximately circular pattern ( 6.5 km radius) with its center shifted to the east of the vent. The distribution of Unit B is oblate ( 9.5 km major axis, 4.5 km minor axis) and trends to the southeast of the vent. Lava samples were collected from each of the seven Tecolote flows for XRF and ICP-MS geochemical analyses. These samples were compared to geochemical signatures from a Tecolote bomb, tephra from Units A and B, and cinder from the La Laja cone, which is the youngest dated cone in the field at 12 ± 4 ka (40Ar/39Ar). The La Laja sample is geochemically distinct from all Tecolote samples, confirming that it did not contribute to the two tephra units. Tephra from Unit A and Unit B have distinct signatures and fit within the geochemical evolution of the Tecolote lavas, supporting two explosive episodes from the Tecolote volcano, which has two cones. To provide a stronger age constraint on the eruption, samples for optically stimulated luminescence (OSL) dating were collected from the sandy silt unit below the tephra in two pits. Data for these dates are being analyzed.

Analysis of five-year trends in self-reported language preference and issues of item non-response among Hispanic persons in a large cross-sectional health survey: implications for the measurement of an ethnic minority population

PubMed Central

2010-01-01

Background Significant differences in health outcomes have been documented among Hispanic persons, the fastest-growing demographic segment of the United States. The objective of this study was to examine trends in population growth and the collection of health data among Hispanic persons, including issues of language preference and survey completion using a national health survey to highlight issues of measurement of an increasingly important demographic segment of the United States. Design Data from the 2003-2007 United States Census and the Behavioral Risk Factor Surveillance System were used to compare trends in population growth and survey sample size as well as differences in survey response based on language preference among a Hispanic population. Percentages of item non-response on selected survey questions were compared for Hispanic respondents choosing to complete the survey in Spanish and those choosing to complete the survey in English. The mean number of attempts to complete the survey was also compared based on language preference among Hispanic respondents. Results The sample size of Hispanic persons in the Behavioral Risk Factor Surveillance System saw little growth compared to the actual growth of the Hispanic population in the United States. Significant differences in survey item non-response for nine of 15 survey questions were seen based on language preference. Hispanic respondents choosing to complete the survey in Spanish had a significantly fewer number of call attempts for survey completion compared to their Hispanic counterparts choosing to communicate in English. Conclusions Including additional measures of acculturation and increasing the sample size of Hispanic persons in a national health survey such as the Behavioral Risk Factor Surveillance System may result in more precise findings that could be used to better target prevention and health care needs for an ethnic minority population. PMID:20412575

Aspects of the reproductive ecology of female turtles in New Mexico

USGS Publications Warehouse

Lovich, Jeffrey E.; Agha, Mickey; Painter, Charlie; Cole, Levi; Fitzgerald, Austin; Narum, Kevin; Jennings, Randy

2016-01-01

Data on reproductive ecology of turtles in New Mexico are limited, and some species living there are among the least studied in the United States. We trapped 4 native species of turtles (Apalone spinifera, Chrysemys picta, Pseudemys gorzugi, and Trachemys gaigeae gaigeae) in the Rio Grande and Black River (Pecos River drainage) of New Mexico in June 2012 and 2013 to collect data on female reproductive ecology, including clutch size, egg size, timing of egg production, and percentage of gravid females. During our sampling, we found shelled eggs via X-radiography in only 3 native species: C. picta, P. gorzugi, and T. g. gaigeae. Clutch and egg sizes were within the range of previously reported values, although clutch size for P. gorzugi (10 eggs) is only the second published record for that data-deficient species. Clutch size increased with body size in T. g. gaigeae. We observed few differences between reproductive parameters for turtles in New Mexico and their conspecifics and congeners elsewhere in the United States, other than the observation that female C. picta may mature at smaller body sizes in New Mexico relative to other western populations elsewhere in its vast, primarily eastern North American range.

Observed intra-cluster correlation coefficients in a cluster survey sample of patient encounters in general practice in Australia

PubMed Central

Knox, Stephanie A; Chondros, Patty

2004-01-01

Background Cluster sample study designs are cost effective, however cluster samples violate the simple random sample assumption of independence of observations. Failure to account for the intra-cluster correlation of observations when sampling through clusters may lead to an under-powered study. Researchers therefore need estimates of intra-cluster correlation for a range of outcomes to calculate sample size. We report intra-cluster correlation coefficients observed within a large-scale cross-sectional study of general practice in Australia, where the general practitioner (GP) was the primary sampling unit and the patient encounter was the unit of inference. Methods Each year the Bettering the Evaluation and Care of Health (BEACH) study recruits a random sample of approximately 1,000 GPs across Australia. Each GP completes details of 100 consecutive patient encounters. Intra-cluster correlation coefficients were estimated for patient demographics, morbidity managed and treatments received. Intra-cluster correlation coefficients were estimated for descriptive outcomes and for associations between outcomes and predictors and were compared across two independent samples of GPs drawn three years apart. Results Between April 1999 and March 2000, a random sample of 1,047 Australian general practitioners recorded details of 104,700 patient encounters. Intra-cluster correlation coefficients for patient demographics ranged from 0.055 for patient sex to 0.451 for language spoken at home. Intra-cluster correlations for morbidity variables ranged from 0.005 for the management of eye problems to 0.059 for management of psychological problems. Intra-cluster correlation for the association between two variables was smaller than the descriptive intra-cluster correlation of each variable. When compared with the April 2002 to March 2003 sample (1,008 GPs) the estimated intra-cluster correlation coefficients were found to be consistent across samples. Conclusions The demonstrated precision and reliability of the estimated intra-cluster correlations indicate that these coefficients will be useful for calculating sample sizes in future general practice surveys that use the GP as the primary sampling unit. PMID:15613248

Quantifying the size-resolved dynamics of indoor bioaerosol transport and control.

PubMed

Kunkel, S A; Azimi, P; Zhao, H; Stark, B C; Stephens, B

2017-09-01

Understanding the bioaerosol dynamics of droplets and droplet nuclei emitted during respiratory activities is important for understanding how infectious diseases are transmitted and potentially controlled. To this end, we conducted experiments to quantify the size-resolved dynamics of indoor bioaerosol transport and control in an unoccupied apartment unit operating under four different HVAC particle filtration conditions. Two model organisms (Escherichia coli K12 and bacteriophage T4) were aerosolized under alternating low and high flow rates to roughly represent constant breathing and periodic coughing. Size-resolved aerosol sampling and settle plate swabbing were conducted in multiple locations. Samples were analyzed by DNA extraction and quantitative polymerase chain reaction (qPCR). DNA from both organisms was detected during all test conditions in all air samples up to 7 m away from the source, but decreased in magnitude with the distance from the source. A greater fraction of T4 DNA was recovered from the aerosol size fractions smaller than 1 μm than E. coli K12 at all air sampling locations. Higher efficiency HVAC filtration also reduced the amount of DNA recovered in air samples and on settle plates located 3-7 m from the source. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Indicators of quality of antenatal care: a pilot study.

PubMed

Vause, S; Maresh, M

1999-03-01

To pilot a list of indicators of quality of antenatal care across a range of maternity care settings. For each indicator to determine what is achieved in current clinical practice, to facilitate the setting of audit standards and calculation of appropriate sample sizes for audit. A multicentre retrospective observational study. Nine maternity units in the United Kingdom. 20,771 women with a singleton pregnancy, who were delivered between 1 August 1994 and 31 July 1995. Nine of the eleven suggested indicators were successfully piloted. Two indicators require further development. In seven of the nine hospitals external cephalic version was not commonly performed. There were wide variations in the proportions of women screened for asymptomatic bacteriuria. Screening of women from ethnic minorities for haemoglobinopathy was more likely in hospitals with a large proportion of non-caucasian women. A large number of Rhesus negative women did not have a Rhesus antibody check performed after 28 weeks of gestation and did not receive anti-D immunoglobulin after a potentially sensitising event during pregnancy. As a result of the study appropriate sample sizes for future audit could be calculated. Measuring the extent to which evidence-based interventions are used in routine clinical practice provides a more detailed picture of the strengths and weaknesses in an antenatal service than traditional outcomes such as perinatal mortality rates. Awareness of an appropriate sample size should prevent waste of time and resources on inconclusive audits.

The SDSS-IV MaNGA Sample: Design, Optimization, and Usage Considerations

NASA Astrophysics Data System (ADS)

Wake, David A.; Bundy, Kevin; Diamond-Stanic, Aleksandar M.; Yan, Renbin; Blanton, Michael R.; Bershady, Matthew A.; Sánchez-Gallego, José R.; Drory, Niv; Jones, Amy; Kauffmann, Guinevere; Law, David R.; Li, Cheng; MacDonald, Nicholas; Masters, Karen; Thomas, Daniel; Tinker, Jeremy; Weijmans, Anne-Marie; Brownstein, Joel R.

2017-09-01

We describe the sample design for the SDSS-IV MaNGA survey and present the final properties of the main samples along with important considerations for using these samples for science. Our target selection criteria were developed while simultaneously optimizing the size distribution of the MaNGA integral field units (IFUs), the IFU allocation strategy, and the target density to produce a survey defined in terms of maximizing signal-to-noise ratio, spatial resolution, and sample size. Our selection strategy makes use of redshift limits that only depend on I-band absolute magnitude (M I ), or, for a small subset of our sample, M I and color (NUV - I). Such a strategy ensures that all galaxies span the same range in angular size irrespective of luminosity and are therefore covered evenly by the adopted range of IFU sizes. We define three samples: the Primary and Secondary samples are selected to have a flat number density with respect to M I and are targeted to have spectroscopic coverage to 1.5 and 2.5 effective radii (R e ), respectively. The Color-Enhanced supplement increases the number of galaxies in the low-density regions of color-magnitude space by extending the redshift limits of the Primary sample in the appropriate color bins. The samples cover the stellar mass range 5× {10}8≤slant {M}* ≤slant 3× {10}11 {M}⊙ {h}-2 and are sampled at median physical resolutions of 1.37 and 2.5 kpc for the Primary and Secondary samples, respectively. We provide weights that will statistically correct for our luminosity and color-dependent selection function and IFU allocation strategy, thus correcting the observed sample to a volume-limited sample.

Effect of Sampling Plans on the Risk of Escherichia coli O157 Illness.

PubMed

Kiermeier, Andreas; Sumner, John; Jenson, Ian

2015-07-01

Australia exports about 150,000 to 200,000 tons of manufacturing beef to the United States annually. Each lot is tested for Escherichia coli O157 using the N-60 sampling protocol, where 60 small pieces of surface meat from each lot of production are tested. A risk assessment of E. coli O157 illness from the consumption of hamburgers made from Australian manufacturing meat formed the basis to evaluate the effect of sample size and amount on the number of illnesses predicted. The sampling plans evaluated included no sampling (resulting in an estimated 55.2 illnesses per annum), the current N-60 plan (50.2 illnesses), N-90 (49.6 illnesses), N-120 (48.4 illnesses), and a more stringent N-60 sampling plan taking five 25-g samples from each of 12 cartons (47.4 illnesses per annum). While sampling may detect some highly contaminated lots, it does not guarantee that all such lots are removed from commerce. It is concluded that increasing the sample size or sample amount from the current N-60 plan would have a very small public health effect.

Developing optimum sample size and multistage sampling plans for Lobesia botrana (Lepidoptera: Tortricidae) larval infestation and injury in northern Greece.

PubMed

Ifoulis, A A; Savopoulou-Soultani, M

2006-10-01

The purpose of this research was to quantify the spatial pattern and develop a sampling program for larvae of Lobesia botrana Denis and Schiffermüller (Lepidoptera: Tortricidae), an important vineyard pest in northern Greece. Taylor's power law and Iwao's patchiness regression were used to model the relationship between the mean and the variance of larval counts. Analysis of covariance was carried out, separately for infestation and injury, with combined second and third generation data, for vine and half-vine sample units. Common regression coefficients were estimated to permit use of the sampling plan over a wide range of conditions. Optimum sample sizes for infestation and injury, at three levels of precision, were developed. An investigation of a multistage sampling plan with a nested analysis of variance showed that if the goal of sampling is focusing on larval infestation, three grape clusters should be sampled in a half-vine; if the goal of sampling is focusing on injury, then two grape clusters per half-vine are recommended.

Large scale 20mm photography for range resources analysis in the Western United States. [Casa Grande, Arizona, Mercury, Nevada, and Mojave Desert

NASA Technical Reports Server (NTRS)

Tueller, P. T.

1977-01-01

Large scale 70mm aerial photography is a valuable supplementary tool for rangeland studies. A wide assortment of applications were developed varying from vegetation mapping to assessing environmental impact on rangelands. Color and color infrared stereo pairs are useful for effectively sampling sites limited by ground accessibility. They allow an increased sample size at similar or lower cost than ground sampling techniques and provide a permanent record.

Thermophoretic separation of aerosol particles from a sampled gas stream

DOEpatents

Postma, A.K.

1984-09-07

This disclosure relates to separation of aerosol particles from gas samples withdrawn from within a contained atmosphere, such as containment vessels for nuclear reactors or other process equipment where remote gaseous sampling is required. It is specifically directed to separation of dense aerosols including particles of any size and at high mass loadings and high corrosivity. The United States Government has rights in this invention pursuant to Contract DE-AC06-76FF02170 between the US Department of Energy and Westinghouse Electric Corporation.

Statistical methods for identifying and bounding a UXO target area or minefield

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

McKinstry, Craig A.; Pulsipher, Brent A.; Gilbert, Richard O.

2003-09-18

The sampling unit for minefield or UXO area characterization is typically represented by a geographical block or transect swath that lends itself to characterization by geophysical instrumentation such as mobile sensor arrays. New spatially based statistical survey methods and tools, more appropriate for these unique sampling units have been developed and implemented at PNNL (Visual Sample Plan software, ver. 2.0) with support from the US Department of Defense. Though originally developed to support UXO detection and removal efforts, these tools may also be used in current form or adapted to support demining efforts and aid in the development of newmore » sensors and detection technologies by explicitly incorporating both sampling and detection error in performance assessments. These tools may be used to (1) determine transect designs for detecting and bounding target areas of critical size, shape, and density of detectable items of interest with a specified confidence probability, (2) evaluate the probability that target areas of a specified size, shape and density have not been missed by a systematic or meandering transect survey, and (3) support post-removal verification by calculating the number of transects required to achieve a specified confidence probability that no UXO or mines have been missed.« less

Estimation of within-stratum variance for sample allocation: Foreign commodity production forecasting

NASA Technical Reports Server (NTRS)

Chhikara, R. S.; Perry, C. R., Jr. (Principal Investigator)

1980-01-01

The problem of determining the stratum variances required for an optimum sample allocation for remotely sensed crop surveys is investigated with emphasis on an approach based on the concept of stratum variance as a function of the sampling unit size. A methodology using the existing and easily available information of historical statistics is developed for obtaining initial estimates of stratum variances. The procedure is applied to variance for wheat in the U.S. Great Plains and is evaluated based on the numerical results obtained. It is shown that the proposed technique is viable and performs satisfactorily with the use of a conservative value (smaller than the expected value) for the field size and with the use of crop statistics from the small political division level.

Evaluating single-pass catch as a tool for identifying spatial pattern in fish distribution

USGS Publications Warehouse

Bateman, Douglas S.; Gresswell, Robert E.; Torgersen, Christian E.

2005-01-01

We evaluate the efficacy of single-pass electrofishing without blocknets as a tool for collecting spatially continuous fish distribution data in headwater streams. We compare spatial patterns in abundance, sampling effort, and length-frequency distributions from single-pass sampling of coastal cutthroat trout (Oncorhynchus clarki clarki) to data obtained from a more precise multiple-pass removal electrofishing method in two mid-sized (500–1000 ha) forested watersheds in western Oregon. Abundance estimates from single- and multiple-pass removal electrofishing were positively correlated in both watersheds, r = 0.99 and 0.86. There were no significant trends in capture probabilities at the watershed scale (P > 0.05). Moreover, among-sample variation in fish abundance was higher than within-sample error in both streams indicating that increased precision of unit-scale abundance estimates would provide less information on patterns of abundance than increasing the fraction of habitat units sampled. In the two watersheds, respectively, single-pass electrofishing captured 78 and 74% of the estimated population of cutthroat trout with 7 and 10% of the effort. At the scale of intermediate-sized watersheds, single-pass electrofishing exhibited a sufficient level of precision to be effective in detecting spatial patterns of cutthroat trout abundance and may be a useful tool for providing the context for investigating fish-habitat relationships at multiple scales.

Factors Affecting Pathogen Survival in Finished Dairy Compost with Different Particle Sizes Under Greenhouse Conditions.

PubMed

Diao, Junshu; Chen, Zhao; Gong, Chao; Jiang, Xiuping

2015-09-01

This study investigated the survival of Escherichia coli O157:H7 and Salmonella Typhimurium in finished dairy compost with different particle sizes during storage as affected by moisture content and temperature under greenhouse conditions. The mixture of E. coli O157:H7 and S. Typhimurium strains was inoculated into the finished composts with moisture contents of 20, 30, and 40%, separately. The finished compost samples were then sieved into 3 different particle sizes (>1000, 500-1000, and <500 μm) and stored under greenhouse conditions. For compost samples with moisture contents of 20 and 30%, the average Salmonella reductions in compost samples with particle sizes of >1000, 500-1000, and <500 μm were 2.15, 2.27, and 2.47 log colony-forming units (CFU) g(-1) within 5 days of storage in summer, respectively, as compared with 1.60, 2.03, and 2.26 log CFU g(-1) in late fall, respectively, and 2.61, 3.33, and 3.67 log CFU g(-1) in winter, respectively. The average E. coli O157:H7 reductions in compost samples with particle sizes of >1000, 500-1000, and <500 μm were 1.98, 2.30, and 2.54 log CFU g(-1) within 5 days of storage in summer, respectively, as compared with 1.70, 2.56, and 2.90 log CFU g(-1) in winter, respectively. Our results revealed that both Salmonella and E. coli O157:H7 in compost samples with larger particle size survived better than those with smaller particle sizes, and the initial rapid moisture loss in compost may contribute to the fast inactivation of pathogens in the finished compost. For the same season, the pathogens in the compost samples with the same particle size survived much better at the initial moisture content of 20% compared to 40%.

Magnetic properties of M0.3Fe2.7O4 (M = Fe, Zn and Mn) ferrites nanoparticles

NASA Astrophysics Data System (ADS)

Modaresi, Nahid; Afzalzadeh, Reza; Aslibeiki, Bagher; Kameli, Parviz

2018-06-01

In the present article a comparative study on the structural and magnetic properties of nano-sized M0.3Fe0.7Fe2O4 (M = Fe, Zn and Mn) ferrites have been reported. The X-ray diffraction (XRD) patterns show that the crystallite size depends on the cation distribution. The Rietveld refinement of XRD patterns using MAUD software determines the distribution of cations and unit cell dimensions. The magnetic measurements show that the maximum and minimum value of saturation magnetization is obtained for Zn and Mn doped samples, respectively. The peak temperature of AC magnetic susceptibility of Zn and Fe doped samples below 300 K shows the superparamagnetic behavior in these samples at room temperature. the AC susceptibility results confirm the presence of strong interactions between the nanoparticles which leads to a superspin glass state in the samples at low temperatures.

The effect of doped zinc on the structural properties of nano-crystalline (Se0.8Te0.2)100-xZnx

NASA Astrophysics Data System (ADS)

Kumar, Arun; Singh, Harkawal; Gill, P. S.; Goyal, Navdeep

2016-05-01

The effect of metallic zinc (Zn) on the structural properties of (Se0.8Te0.2)1-XZnX (x=0, 2, 6, 8, 10) samples analyzed by X-ray Diffraction (XRD). The presence of sharp peaks in XRD patterns confirmed the crystalline nature of the samples and is indexed in orthorhombic crystal structure. XRD studies predicts that the average particle size of all the samples are about 46.29 nm, which is less than 100 nm and hence have strong tendency of agglomeration. Williamson-Hall plot method was used to evaluate the lattice strain. The dislocation density and no. of unit cells of the samples were calculated which show the inverse relation with each other. Morphology index derived from FWHM of XRD data explains the direct relationship with the particle size.

Interaction of attentional and motor control processes in handwriting.

PubMed

Brown, T L; Donnenwirth, E E

1990-01-01

The interaction between attentional capacity, motor control processes, and strategic adaptations to changing task demands was investigated in handwriting, a continuous (rather than discrete) skilled performance. Twenty-four subjects completed 12 two-minute handwriting samples under instructions stressing speeded handwriting, normal handwriting, or highly legible handwriting. For half of the writing samples, a concurrent auditory monitoring task was imposed. Subjects copied either familiar (English) or unfamiliar (Latin) passages. Writing speed, legibility ratings, errors in writing and in the secondary auditory task, and a derived measure of the average number of characters held in short-term memory during each sample ("planning unit size") were the dependent variables. The results indicated that the ability to adapt to instructions stressing speed or legibility was substantially constrained by the concurrent listening task and by text familiarity. Interactions between instructions, task concurrence, and text familiarity in the legibility ratings, combined with further analyses of planning unit size, indicated that information throughput from temporary storage mechanisms to motor processes mediated the loss of flexibility effect. Overall, the results suggest that strategic adaptations of a skilled performance to changing task circumstances are sensitive to concurrent attentional demands and that departures from "normal" or "modal" performance require attention.

Size Matters: Assessing Optimum Soil Sample Size for Fungal and Bacterial Community Structure Analyses Using High Throughput Sequencing of rRNA Gene Amplicons

DOE PAGES

Penton, C. Ryan; Gupta, Vadakattu V. S. R.; Yu, Julian; ...

2016-06-02

We examined the effect of different soil sample sizes obtained from an agricultural field, under a single cropping system uniform in soil properties and aboveground crop responses, on bacterial and fungal community structure and microbial diversity indices. DNA extracted from soil sample sizes of 0.25, 1, 5, and 10 g using MoBIO kits and from 10 and 100 g sizes using a bead-beating method (SARDI) were used as templates for high-throughput sequencing of 16S and 28S rRNA gene amplicons for bacteria and fungi, respectively, on the Illumina MiSeq and Roche 454 platforms. Sample size significantly affected overall bacterial and fungalmore » community structure, replicate dispersion and the number of operational taxonomic units (OTUs) retrieved. Richness, evenness and diversity were also significantly affected. The largest diversity estimates were always associated with the 10 g MoBIO extractions with a corresponding reduction in replicate dispersion. For the fungal data, smaller MoBIO extractions identified more unclassified Eukaryota incertae sedis and unclassified glomeromycota while the SARDI method retrieved more abundant OTUs containing unclassified Pleosporales and the fungal genera Alternaria and Cercophora. Overall, these findings indicate that a 10 g soil DNA extraction is most suitable for both soil bacterial and fungal communities for retrieving optimal diversity while still capturing rarer taxa in concert with decreasing replicate variation.« less

Size Matters: Assessing Optimum Soil Sample Size for Fungal and Bacterial Community Structure Analyses Using High Throughput Sequencing of rRNA Gene Amplicons

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

Penton, C. Ryan; Gupta, Vadakattu V. S. R.; Yu, Julian

We examined the effect of different soil sample sizes obtained from an agricultural field, under a single cropping system uniform in soil properties and aboveground crop responses, on bacterial and fungal community structure and microbial diversity indices. DNA extracted from soil sample sizes of 0.25, 1, 5, and 10 g using MoBIO kits and from 10 and 100 g sizes using a bead-beating method (SARDI) were used as templates for high-throughput sequencing of 16S and 28S rRNA gene amplicons for bacteria and fungi, respectively, on the Illumina MiSeq and Roche 454 platforms. Sample size significantly affected overall bacterial and fungalmore » community structure, replicate dispersion and the number of operational taxonomic units (OTUs) retrieved. Richness, evenness and diversity were also significantly affected. The largest diversity estimates were always associated with the 10 g MoBIO extractions with a corresponding reduction in replicate dispersion. For the fungal data, smaller MoBIO extractions identified more unclassified Eukaryota incertae sedis and unclassified glomeromycota while the SARDI method retrieved more abundant OTUs containing unclassified Pleosporales and the fungal genera Alternaria and Cercophora. Overall, these findings indicate that a 10 g soil DNA extraction is most suitable for both soil bacterial and fungal communities for retrieving optimal diversity while still capturing rarer taxa in concert with decreasing replicate variation.« less

Differential risk of injury in child occupants by passenger car classification.

PubMed

Kallan, Michael J; Durbin, Dennis R; Elliott, Michael R; Menon, Rajiv A; Winston, Flaura K

2003-01-01

In the United States, passenger cars are the most common passenger vehicle, yet they vary widely in size and crashworthiness. Using data collected from a population-based sample of crashes in State Farm-insured vehicles, we quantified the risk of injury to child occupants by passenger car size and classification. Injury risk is predicted by vehicle weight; however, there is an increased risk in both Large vs. Luxury and Sports vs. Small cars, despite similar average vehicle weights in both comparisons. Parents who are purchasing passenger cars should strongly consider the size of the vehicle and its crashworthiness.

Differential Risk of Injury in Child Occupants by Passenger Car Classification

PubMed Central

Kallan, Michael J.; Durbin, Dennis R.; Elliott, Michael R.; Menon, Rajiv A.; Winston, Flaura K.

2003-01-01

In the United States, passenger cars are the most common passenger vehicle, yet they vary widely in size and crashworthiness. Using data collected from a population-based sample of crashes in State Farm-insured vehicles, we quantified the risk of injury to child occupants by passenger car size and classification. Injury risk is predicted by vehicle weight; however, there is an increased risk in both Large vs. Luxury and Sports vs. Small cars, despite similar average vehicle weights in both comparisons. Parents who are purchasing passenger cars should strongly consider the size of the vehicle and its crashworthiness. PMID:12941234

Transgender Population Size in the United States: a Meta-Regression of Population-Based Probability Samples

PubMed Central

Sevelius, Jae M.

2017-01-01

Background. Transgender individuals have a gender identity that differs from the sex they were assigned at birth. The population size of transgender individuals in the United States is not well-known, in part because official records, including the US Census, do not include data on gender identity. Population surveys today more often collect transgender-inclusive gender-identity data, and secular trends in culture and the media have created a somewhat more favorable environment for transgender people. Objectives. To estimate the current population size of transgender individuals in the United States and evaluate any trend over time. Search methods. In June and July 2016, we searched PubMed, Cumulative Index to Nursing and Allied Health Literature, and Web of Science for national surveys, as well as “gray” literature, through an Internet search. We limited the search to 2006 through 2016. Selection criteria. We selected population-based surveys that used probability sampling and included self-reported transgender-identity data. Data collection and analysis. We used random-effects meta-analysis to pool eligible surveys and used meta-regression to address our hypothesis that the transgender population size estimate would increase over time. We used subsample and leave-one-out analysis to assess for bias. Main results. Our meta-regression model, based on 12 surveys covering 2007 to 2015, explained 62.5% of model heterogeneity, with a significant effect for each unit increase in survey year (F = 17.122; df = 1,10; b = 0.026%; P = .002). Extrapolating these results to 2016 suggested a current US population size of 390 adults per 100 000, or almost 1 million adults nationally. This estimate may be more indicative for younger adults, who represented more than 50% of the respondents in our analysis. Authors’ conclusions. Future national surveys are likely to observe higher numbers of transgender people. The large variety in questions used to ask about transgender identity may account for residual heterogeneity in our models. Public health implications. Under- or nonrepresentation of transgender individuals in population surveys is a barrier to understanding social determinants and health disparities faced by this population. We recommend using standardized questions to identify respondents with transgender and nonbinary gender identities, which will allow a more accurate population size estimate. PMID:28075632

Sub-sampling genetic data to estimate black bear population size: A case study

USGS Publications Warehouse

Tredick, C.A.; Vaughan, M.R.; Stauffer, D.F.; Simek, S.L.; Eason, T.

2007-01-01

Costs for genetic analysis of hair samples collected for individual identification of bears average approximately US$50 [2004] per sample. This can easily exceed budgetary allowances for large-scale studies or studies of high-density bear populations. We used 2 genetic datasets from 2 areas in the southeastern United States to explore how reducing costs of analysis by sub-sampling affected precision and accuracy of resulting population estimates. We used several sub-sampling scenarios to create subsets of the full datasets and compared summary statistics, population estimates, and precision of estimates generated from these subsets to estimates generated from the complete datasets. Our results suggested that bias and precision of estimates improved as the proportion of total samples used increased, and heterogeneity models (e.g., Mh[CHAO]) were more robust to reduced sample sizes than other models (e.g., behavior models). We recommend that only high-quality samples (>5 hair follicles) be used when budgets are constrained, and efforts should be made to maximize capture and recapture rates in the field.

Cross-Cultural Validity of the Ruminative Responses Scale in Argentina and the United States.

PubMed

Arana, Fernán G; Rice, Kenneth G

2017-09-01

Although frequently used in the United States, the Ruminative Response Scale (RRS) has not been extensively studied in cross-cultural samples. The present study evaluated the factor structure of Treynor et al.'s 10-item version of the RRS in samples from Argentina ( N = 308) and the United States ( N = 371). In addition to testing measurement invariance between the countries, we evaluated whether the maladaptive implications of rumination were weaker for the Argentinians than for the U.S. group. Self-critical perfectionism was the criterion in those tests. Partial scalar invariance supported an 8-item version of the RRS. There were no differences in factor means or factor correlations in RRS dimensions between countries. Brooding and Reflection were positively correlated with self-critical perfectionism in both countries, with no significant differences in the sizes of these relations between the two samples. Results are discussed in terms of psychometric and cross-cultural implications for rumination.

The fundamentals of average local variance--Part II: Sampling simple regular patterns with optical imagery.

PubMed

Bøcher, Peder Klith; McCloy, Keith R

2006-02-01

In this investigation, the characteristics of the average local variance (ALV) function is investigated through the acquisition of images at different spatial resolutions of constructed scenes of regular patterns of black and white squares. It is shown that the ALV plot consistently peaks at a spatial resolution in which the pixels has a size corresponding to half the distance between scene objects, and that, under very specific conditions, it also peaks at a spatial resolution in which the pixel size corresponds to the whole distance between scene objects. It is argued that the peak at object distance when present is an expression of the Nyquist sample rate. The presence of this peak is, hence, shown to be a function of the matching between the phase of the scene pattern and the phase of the sample grid, i.e., the image. When these phases match, a clear and distinct peak is produced on the ALV plot. The fact that the peak at half the distance consistently occurs in the ALV plot is linked to the circumstance that the sampling interval (distance between pixels) and the extent of the sampling unit (size of pixels) are equal. Hence, at twice the Nyquist sampling rate, each fundamental period of the pattern is covered by four pixels; therefore, at least one pixel is always completely embedded within one pattern element, regardless of sample scene phase. If the objects in the scene are scattered with a distance larger than their extent, the peak will be related to the size by a factor larger than 1/2. This is suggested to be the explanation to the results presented by others that the ALV plot is related to scene-object size by a factor of 1/2-3/4.

Intra-class correlation estimates for assessment of vitamin A intake in children.

PubMed

Agarwal, Girdhar G; Awasthi, Shally; Walter, Stephen D

2005-03-01

In many community-based surveys, multi-level sampling is inherent in the design. In the design of these studies, especially to calculate the appropriate sample size, investigators need good estimates of intra-class correlation coefficient (ICC), along with the cluster size, to adjust for variation inflation due to clustering at each level. The present study used data on the assessment of clinical vitamin A deficiency and intake of vitamin A-rich food in children in a district in India. For the survey, 16 households were sampled from 200 villages nested within eight randomly-selected blocks of the district. ICCs and components of variances were estimated from a three-level hierarchical random effects analysis of variance model. Estimates of ICCs and variance components were obtained at village and block levels. Between-cluster variation was evident at each level of clustering. In these estimates, ICCs were inversely related to cluster size, but the design effect could be substantial for large clusters. At the block level, most ICC estimates were below 0.07. At the village level, many ICC estimates ranged from 0.014 to 0.45. These estimates may provide useful information for the design of epidemiological studies in which the sampled (or allocated) units range in size from households to large administrative zones.

& Source apportionment of particulate matter in the United States and associations with lung inflammatory Markers

EPA Science Inventory

Size-fractionated particulate matter (PM) samples were collected from six U.S. cities and chemically analyzed as part of the Multiple Air Pollutant Study. Particles were administered to cultured lung cells and the production of three different proinflammatory markers was measured...

Size-Differentiated Chemical Composition of Re-Suspended Soil Dust from the Desert Southwest United States

EPA Science Inventory

As part of the Desert Southwest Coarse Particulate Matter Study which characterized the composition of fine and coarse particulate matter in Pinal County, AZ, several source samples were collected from several different soil types to assist in source apportionment analysis of the...

Quantifying viruses and bacteria in wastewater - results, quality control, and interpretation methods

USDA-ARS?s Scientific Manuscript database

Membrane bioreactors (MBR), used for wastewater treatment in Ohio and elsewhere in the United States, have pore sizes large enough to theoretically reduce concentrations of protozoa and bacteria, but not viruses. Sampling for viruses in wastewater is seldom done and not required. Instead, the bac...

ACCURACY OF THE 1992 NATIONAL LAND COVER DATASET AREA ESTIMATES: AN ANALYSIS AT MULTIPLE SPATIAL EXTENTS

EPA Science Inventory

Abstract for poster presentation:

Site-specific accuracy assessments evaluate fine-scale accuracy of land-use/land-cover(LULC) datasets but provide little insight into accuracy of area estimates of LULC

classes derived from sampling units of varying size. Additiona...

Utilization of Yatagan Power Plant Fly Ash in Production of Building Bricks

NASA Astrophysics Data System (ADS)

Önel, Öznur; Tanriverdi, Mehmet; Cicek, Tayfun

2017-12-01

Fly ash is a by-product of coal combustion, which accumulates in large quantities near the coal-fired power plants as waste material. Fly ash causes serious operational and environmental problems. In this study, fly ash from Yatağgan thermal power plant was used to produce light-weight building bricks. The study aimed to reduce the problems related to fly ash by creating a new area for their use. The optimum process parameters were determined for the production of real size bricks to be used in construction industry. The commercial size bricks (200 × 200 × 90-110 mm) were manufactured using pilot size equipment. Mechanical properties, thermal conductivity coefficients, freezing and thawing strengths, water absorption rates, and unit volume weights of the bricks were determined. Etringite (Ca6Al2 (SO4)3 (OH)12 25(H2O)) and Calcium Silicate Hydrate (2CaO.SiO2.4H2O) were identified as the binding phases in the real size brick samples after 2 days of pre-curing and 28 days curing at 50° C and 95% relative moisture. The water absorption rate was found to be 27.7 % in terms of mass. The mechanical and bending strength of the brick samples with unit volume weight of 1.29 g.cm-3 were determined as 6.75 MPa and 1,56 MPa respectively. The thermal conductivity of the fly ash bricks was measured in average as 0,340 W m-1 K-1. The fly ash sample produced was subjected to toxic leaching tests (Toxic Property Leaching Procedure (EPA-TCLP 1311), Single-step BATCH Test and Method-A Disintegration Procedure (ASTM)). The results of these tests suggested that the materials could be classified as non-hazardous wastes / materials.

Overlap between treatment and control distributions as an effect size measure in experiments.

PubMed

Hedges, Larry V; Olkin, Ingram

2016-03-01

The proportion π of treatment group observations that exceed the control group mean has been proposed as an effect size measure for experiments that randomly assign independent units into 2 groups. We give the exact distribution of a simple estimator of π based on the standardized mean difference and use it to study the small sample bias of this estimator. We also give the minimum variance unbiased estimator of π under 2 models, one in which the variance of the mean difference is known and one in which the variance is unknown. We show how to use the relation between the standardized mean difference and the overlap measure to compute confidence intervals for π and show that these results can be used to obtain unbiased estimators, large sample variances, and confidence intervals for 3 related effect size measures based on the overlap. Finally, we show how the effect size π can be used in a meta-analysis. (c) 2016 APA, all rights reserved).

Efficiency of a new bioaerosol sampler in sampling Betula pollen for antigen analyses.

PubMed

Rantio-Lehtimäki, A; Kauppinen, E; Koivikko, A

1987-01-01

A new bioaerosol sampler consisting of Liu-type atmospheric aerosol sampling inlet, coarse particle inertial impactor, two-stage high-efficiency virtual impactor (aerodynamic particle sizes respectively in diameter: greater than or equal to 8 microns, 8-2.5 microns, and 2.5 microns; sampling on filters) and a liquid-cooled condenser was designed, fabricated and field-tested in sampling birch (Betula) pollen grains and smaller particles containing Betula antigens. Both microscopical (pollen counts) and immunochemical (enzyme-linked immunosorbent assay) analyses of each stage were carried out. The new sampler was significantly more efficient than Burkard trap e.g. in sampling particles of Betula pollen size (ca. 25 microns in diameter). This was prominent during pollen peak periods (e.g. May 19th, 1985, in the virtual impactor 9482 and in the Burkard trap 2540 Betula p.g. X m-3 of air). Betula antigens were detected also in filter stages where no intact pollen grains were found; in the condenser unit the antigen concentrations instead were very low.

Stratum variance estimation for sample allocation in crop surveys. [Great Plains Corridor

NASA Technical Reports Server (NTRS)

Perry, C. R., Jr.; Chhikara, R. S. (Principal Investigator)

1980-01-01

The problem of determining stratum variances needed in achieving an optimum sample allocation for crop surveys by remote sensing is investigated by considering an approach based on the concept of stratum variance as a function of the sampling unit size. A methodology using the existing and easily available information of historical crop statistics is developed for obtaining initial estimates of tratum variances. The procedure is applied to estimate stratum variances for wheat in the U.S. Great Plains and is evaluated based on the numerical results thus obtained. It is shown that the proposed technique is viable and performs satisfactorily, with the use of a conservative value for the field size and the crop statistics from the small political subdivision level, when the estimated stratum variances were compared to those obtained using the LANDSAT data.

Textural analysis of marine sediments at the USGS Woods Hole Science Center; methodology and data on DVD

USGS Publications Warehouse

Poppe, Lawrence J.; Williams, S. Jeffress; Paskevich, Valerie F.

2006-01-01

Marine sediments off the eastern United States vary markedly in texture (i.e., the size, shape, composition, and arrangement of their grains) due to a complex geologic history. For descriptive purposes, however, it is typically most useful to classify these sediments according to their grain-size distributions. In 1962, the U.S. Geological Survey began a program to study the marine geology of the continental margin off the Atlantic coast of the United States. As part of this program and numerous subsequent projects, thousands of sediment grab samples and cores were collected and analyzed for grain size at the Woods Hole Science Center. USGS Open-File Report 2005-1001 (Poppe et al., 2005), available on DVD and online, describes the field methods used to collect marine sediment samples as well as the laboratory methods used to determine and characterize grain-size distributions, and presents these data in several formats that can be readily employed by interested parties. The report is divided into three sections. The first section discusses procedures and contains pictures of the equipment, analytical flow diagrams, video clips with voice commentary, classification schemes, useful forms and compiled and uncompiled versions of the data-acquisition and data-processing software with documentation. The second section contains the grain-size data for more than 23,000 analyses in two “flat-file” formats, a data dictionary, and color-coded browse maps. The third section provides a GIS data catalog of the available point, interpretive, and baseline data layers, with FGDC-compliant metadata to help users visualize the textural information in a geographic context.

Catch of channel catfish with tandem-set hoop nets and gill nets in lentic systems of Nebraska

USGS Publications Warehouse

Richters, Lindsey K.; Pope, Kevin L.

2011-01-01

Twenty-six Nebraska water bodies representing two ecosystem types (small standing waters and large standing waters) were surveyed during 2008 and 2009 with tandem-set hoop nets and experimental gill nets to determine if similar trends existed in catch rates and size structures of channel catfish Ictalurus punctatus captured with these gears. Gear efficiency was assessed as the number of sets (nets) that would be required to capture 100 channel catfish given observed catch per unit effort (CPUE). Efficiency of gill nets was not correlated with efficiency of hoop nets for capturing channel catfish. Small sample sizes prohibited estimation of proportional size distributions in most surveys; in the four surveys for which sample size was sufficient to quantify length-frequency distributions of captured channel catfish, distributions differed between gears. The CPUE of channel catfish did not differ between small and large water bodies for either gear. While catch rates of hoop nets were lower than rates recorded in previous studies, this gear was more efficient than gill nets at capturing channel catfish. However, comparisons of size structure between gears may be problematic.

Sampling design and procedures for fixed surface-water sites in the Georgia-Florida coastal plain study unit, 1993

USGS Publications Warehouse

Hatzell, H.H.; Oaksford, E.T.; Asbury, C.E.

1995-01-01

The implementation of design guidelines for the National Water-Quality Assessment (NAWQA) Program has resulted in the development of new sampling procedures and the modification of existing procedures commonly used in the Water Resources Division of the U.S. Geological Survey. The Georgia-Florida Coastal Plain (GAFL) study unit began the intensive data collection phase of the program in October 1992. This report documents the implementation of the NAWQA guidelines by describing the sampling design and procedures for collecting surface-water samples in the GAFL study unit in 1993. This documentation is provided for agencies that use water-quality data and for future study units that will be entering the intensive phase of data collection. The sampling design is intended to account for large- and small-scale spatial variations, and temporal variations in water quality for the study area. Nine fixed sites were selected in drainage basins of different sizes and different land-use characteristics located in different land-resource provinces. Each of the nine fixed sites was sampled regularly for a combination of six constituent groups composed of physical and chemical constituents: field measurements, major ions and metals, nutrients, organic carbon, pesticides, and suspended sediments. Some sites were also sampled during high-flow conditions and storm events. Discussion of the sampling procedure is divided into three phases: sample collection, sample splitting, and sample processing. A cone splitter was used to split water samples for the analysis of the sampling constituent groups except organic carbon from approximately nine liters of stream water collected at four fixed sites that were sampled intensively. An example of the sample splitting schemes designed to provide the sample volumes required for each sample constituent group is described in detail. Information about onsite sample processing has been organized into a flowchart that describes a pathway for each of the constituent groups.

Emission characteristics and chemical components of size-segregated particulate matter in iron and steel industry

NASA Astrophysics Data System (ADS)

Jia, Jia; Cheng, Shuiyuan; Yao, Sen; Xu, Tiebing; Zhang, Tingting; Ma, Yuetao; Wang, Hongliang; Duan, Wenjiao

2018-06-01

As one of the highest energy consumption and pollution industries, the iron and steel industry is regarded as a most important source of particulate matter emission. In this study, chemical components of size-segregated particulate matters (PM) emitted from different manufacturing units in iron and steel industry were sampled by a comprehensive sampling system. Results showed that the average particle mass concentration was highest in sintering process, followed by puddling, steelmaking and then rolling processes. PM samples were divided into eight size fractions for testing the chemical components, SO42- and NH4+ distributed more into fine particles while most of the Ca2+ was concentrated in coarse particles, the size distribution of mineral elements depended on the raw materials applied. Moreover, local database with PM chemical source profiles of iron and steel industry were built and applied in CMAQ modeling for simulating SO42- and NO3- concentration, results showed that the accuracy of model simulation improved with local chemical source profiles compared to the SPECIATE database. The results gained from this study are expected to be helpful to understand the components of PM in iron and steel industry and contribute to the source apportionment researches.

24 CFR 983.259 - Overcrowded, under-occupied, and accessible units.

Code of Federal Regulations, 2010 CFR

2010-04-01

...-occupied, and accessible units. (a) Family occupancy of wrong-size or accessible unit. The PHA subsidy standards determine the appropriate unit size for the family size and composition. If the PHA determines that a family is occupying a: (1) Wrong-size unit, or (2) Unit with accessibility features that the...

An estimate of field size distributions for selected sites in the major grain producing countries

NASA Technical Reports Server (NTRS)

Podwysocki, M. H.

1977-01-01

The field size distributions for the major grain producing countries of the World were estimated. LANDSAT-1 and 2 images were evaluated for two areas each in the United States, People's Republic of China, and the USSR. One scene each was evaluated for France, Canada, and India. Grid sampling was done for representative sub-samples of each image, measuring the long and short axes of each field; area was then calculated. Each of the resulting data sets was computer analyzed for their frequency distributions. Nearly all frequency distributions were highly peaked and skewed (shifted) towards small values, approaching that of either a Poisson or log-normal distribution. The data were normalized by a log transformation, creating a Gaussian distribution which has moments readily interpretable and useful for estimating the total population of fields. Resultant predictors of the field size estimates are discussed.

Cu-doped Cd1- x Zn x S alloy: synthesis and structural investigations

NASA Astrophysics Data System (ADS)

Yadav, Indu; Ahlawat, Dharamvir Singh; Ahlawat, Rachna

2016-03-01

Copper doped Cd1- x Zn x S ( x ≤ 1) quantum dots have been synthesized using chemical co-precipitation method. Structural investigation of the synthesized nanomaterials has been carried out by powder XRD method. The XRD results have confirmed that as-prepared Cu-doped Cd1- x Zn x S quantum dots have hexagonal structure. The average nanocrystallite size was estimated in the range 2-12 nm using Debye-Scherrer formula. The lattice constants, lattice plane, d-spacing, unit cell volume, Lorentz factor and dislocation density were also calculated from XRD data. The change in particle size was observed with the change in Zn concentration. Furthermore, FTIR spectra of the prepared samples were observed for identification of COO- and O-H functional groups. The TEM study has also reported the same size range of nanoparticles. The increase in agglomeration has been observed with the increase in Zn concentration in the prepared samples.

Molecular-Size-Separated Brown Carbon Absorption for Biomass-Burning Aerosol at Multiple Field Sites.

PubMed

Di Lorenzo, Robert A; Washenfelder, Rebecca A; Attwood, Alexis R; Guo, Hongyu; Xu, Lu; Ng, Nga L; Weber, Rodney J; Baumann, Karsten; Edgerton, Eric; Young, Cora J

2017-03-21

Biomass burning is a known source of brown carbon aerosol in the atmosphere. We collected filter samples of biomass-burning emissions at three locations in Canada and the United States with transport times of 10 h to >3 days. We analyzed the samples with size-exclusion chromatography coupled to molecular absorbance spectroscopy to determine absorbance as a function of molecular size. The majority of absorption was due to molecules >500 Da, and these contributed an increasing fraction of absorption as the biomass-burning aerosol aged. This suggests that the smallest molecular weight fraction is more susceptible to processes that lead to reduced light absorption, while larger-molecular-weight species may represent recalcitrant brown carbon. We calculate that these large-molecular-weight species are composed of more than 20 carbons with as few as two oxygens and would be classified as extremely low volatility organic compounds (ELVOCs).

Studies on the primary structure of short polysaccharides using SEC MALDI mass spectroscopy.

PubMed

Garozzo, D; Spina, E; Cozzolino, R; Cescutti, P; Fett, W F

2000-01-12

The introduction of size-exclusion chromatography (SEC) analysis of polysaccharides prior to MALDI mass spectroscopy accounts for the determination of the molecular mass of the repeating unit when neutral homopolymers are investigated. In the case of natural polysaccharides characterised by more complicated structural features (presence of non-carbohydrate substituents, charged groups, etc.), this mass value usually is in agreement with more than one sugar composition. Therefore, it is not sufficient to give the correct monosaccharidic composition of the polysaccharide investigated. To solve this problem, MALDI spectra were recorded on the permethylated sample and post-source decay experiments were performed on precursor ions. In this way, the composition (in terms of Hex, HexNAc, etc.), size and sequence of the repeating unit were determined.

Assessing the Attitudes of Administrators to Include Students with Disabilities

ERIC Educational Resources Information Center

Abernathy, Frederick Douglas

2012-01-01

The purpose of this research was to assess the attitudes of administrators in a medium sized school district in the Southeastern region of the United States. The researcher used a quantitative descriptive comparative pre-test and post-test design with a convenience sampling of the district administrators. There were 21 administrators at the…

The Kindness of Strangers Revisited: A Comparison of 24 US Cities

ERIC Educational Resources Information Center

Levine, Robert V.; Reysen, Stephen; Ganz, Ellen

2008-01-01

Three field studies compared helping behavior across a sample of 24 small, medium and large cities across the United States. The relationship of helping to statistics reflecting the demographic, social, and economic characteristics of these communities was then examined. The strongest predictors of city differences in helping were population size,…

Exercise and Fitness: Association with Cigarette and Smokeless Tobacco Use.

ERIC Educational Resources Information Center

Conway, Terry L.; Cronan, Terry A.

This study examined the relationships among physical fitness, exercise activity, and both cigarette smoking and smokeless tobacco use among 2,800 United States Navy men. Subgrouping individuals according to their self-reported use of tobacco resulted in maximum sample sizes of 1,406 nonusers, 161 smokeless tobacco users, and 1,233 cigarette…

Electronic Resource Expenditure and the Decline in Reference Transaction Statistics in Academic Libraries

ERIC Educational Resources Information Center

Dubnjakovic, Ana

2012-01-01

The current study investigates factors influencing increase in reference transactions in a typical week in academic libraries across the United States of America. Employing multiple regression analysis and general linear modeling, variables of interest from the "Academic Library Survey (ALS) 2006" survey (sample size 3960 academic libraries) were…

Anomalous dismeter distribution shifts estimated from FIA inventories through time

Treesearch

Francis A. Roesch; Paul C. Van Deusen

2010-01-01

In the past decade, the United States Department of Agriculture Forest Service’s Forest Inventory and Analysis Program (FIA) has replaced regionally autonomous, periodic, state-wide forest inventories using various probability proportional to tree size sampling designs with a nationally consistent annual forest inventory design utilizing systematically spaced clusters...

Intrafamilial clustering of anti-ATLA-positive persons.

PubMed

Kajiyama, W; Kashiwagi, S; Hayashi, J; Nomura, H; Ikematsu, H; Okochi, K

1986-11-01

A total of 1,333 persons in 627 families were surveyed for presence of antibody to adult T-cell leukemia-associated antigen (anti-ATLA). Each person was classified according to the anti-ATLA status (positive for sample 1, negative for sample 2) of the head of household of his or her family. In sample 1, the sex- and age-standardized prevalence of anti-ATLA was 38.5%. This was five times as high as the standardized prevalence in sample 2 (7.8%). There were significant differences in prevalence of anti-ATLA between males in samples 1 and 2 and between females in samples 1 and 2. In every age group, prevalence in sample 1 was greater than that in sample 2 except for males aged 60-69 years. In each of four subareas, families in sample 1 had higher standardized prevalence (29.6-42.5%) than families in sample 2 (6.0-9.7%). Although crude prevalence decreased with family size in sample 1 (62.1-25.4%) as well as in sample 2, indirectly standardized prevalence was almost equal within each sample, regardless of number of family members. The degree of aggregation was independent of locality and family size. These data suggest that anti-ATLA-positive persons aggregate in family units.

Allogenic sedimentary components of Bear Lake, Utah and Idaho

USGS Publications Warehouse

Rosenbaum, J.G.; Dean, W.E.; Reynolds, R.L.; Reheis, M.C.

2009-01-01

Bear Lake is a long-lived lake filling a tectonic depression between the Bear River Range to the west and the Bear River Plateau to the east, and straddling the border between Utah and Idaho. Mineralogy, elemental geochemistry, and magnetic properties provide information about variations in provenance of allogenic lithic material in last-glacial-age, quartz-rich sediment in Bear Lake. Grain-size data from the siliciclastic fraction of late-glacial to Holocene carbonate-rich sediments provide information about variations in lake level. For the quartz-rich lower unit, which was deposited while the Bear River fl owed into and out of the lake, four source areas are recognized on the basis of modern fluvial samples with contrasting properties that reflect differences in bedrock geology and in magnetite content from dust. One of these areas is underlain by hematite-rich Uinta Mountain Group rocks in the headwaters of the Bear River. Although Uinta Mountain Group rocks make up a small fraction of the catchment, hematite-rich material from this area is an important component of the lower unit. This material is interpreted to be glacial fl our. Variations in the input of glacial flour are interpreted as having caused quasi-cyclical variations in mineralogical and elemental concentrations, and in magnetic properties within the lower unit. The carbonate-rich younger unit was deposited under conditions similar to those of the modern lake, with the Bear River largely bypassing the lake. For two cores taken in more than 30 m of water, median grain sizes in this unit range from ???6 ??m to more than 30 ??m, with the coarsest grain sizes associated with beach or shallow-water deposits. Similar grain-size variations are observed as a function of water depth in the modern lake and provide the basis for interpreting the core grain-size data in terms of lake level. Copyright ?? 2009 The Geological Society of America.

Geotechnical soil characterization of intact Quaternary deposits forming the March 22, 2014 SR-530 (Oso) landslide, Snohomish County, Washington

USGS Publications Warehouse

Riemer, Michael F.; Collins, Brian D.; Badger, Thomas C.; Toth, Csilla; Yu, Yat Chun

2015-01-01

This report provides a description of the methods used to obtain and test the intact soil stratigraphy behind the headscarp of the March 22 landslide. Detailed geotechnical index testing results are presented for 24 soil samples representing the stratigraphy at 19 different depths along a 650 ft (198 m) soil profile. The results include (1) the soil's in situ water content and unit weight (where applicable); (2) specific gravity of soil solids; and (3) each sample's grain-size distribution, critical limits for fine-grain water content states (that is, the Atterberg limits), and official Unified Soil Classification System (USCS) designation. In addition, preliminary stratigraphy and geotechnical relations within and between soil units are presented.

A USANS/SANS study of the accessibility of pores in the Barnett Shale to methane and water

USGS Publications Warehouse

Ruppert, Leslie F.; Sakurovs, Richard; Blach, Tomasz P.; He, Lilin; Melnichenko, Yuri B.; Mildner, David F.; Alcantar-Lopez, Leo

2013-01-01

Shale is an increasingly important source of natural gas in the United States. The gas is held in fine pores that need to be accessed by horizontal drilling and hydrofracturing techniques. Understanding the nature of the pores may provide clues to making gas extraction more efficient. We have investigated two Mississippian Barnett Shale samples, combining small-angle neutron scattering (SANS) and ultrasmall-angle neutron scattering (USANS) to determine the pore size distribution of the shale over the size range 10 nm to 10 μm. By adding deuterated methane (CD4) and, separately, deuterated water (D2O) to the shale, we have identified the fraction of pores that are accessible to these compounds over this size range. The total pore size distribution is essentially identical for the two samples. At pore sizes >250 nm, >85% of the pores in both samples are accessible to both CD4 and D2O. However, differences in accessibility to CD4 are observed in the smaller pore sizes (~25 nm). In one sample, CD4 penetrated the smallest pores as effectively as it did the larger ones. In the other sample, less than 70% of the smallest pores (4, but they were still largely penetrable by water, suggesting that small-scale heterogeneities in methane accessibility occur in the shale samples even though the total porosity does not differ. An additional study investigating the dependence of scattered intensity with pressure of CD4 allows for an accurate estimation of the pressure at which the scattered intensity is at a minimum. This study provides information about the composition of the material immediately surrounding the pores. Most of the accessible (open) pores in the 25 nm size range can be associated with either mineral matter or high reflectance organic material. However, a complementary scanning electron microscopy investigation shows that most of the pores in these shale samples are contained in the organic components. The neutron scattering results indicate that the pores are not equally proportioned in the different constituents within the shale. There is some indication from the SANS results that the composition of the pore-containing material varies with pore size; the pore size distribution associated with mineral matter is different from that associated with organic phases.

Modeling abundance using hierarchical distance sampling

USGS Publications Warehouse

Royle, Andy; Kery, Marc

2016-01-01

In this chapter, we provide an introduction to classical distance sampling ideas for point and line transect data, and for continuous and binned distance data. We introduce the conditional and the full likelihood, and we discuss Bayesian analysis of these models in BUGS using the idea of data augmentation, which we discussed in Chapter 7. We then extend the basic ideas to the problem of hierarchical distance sampling (HDS), where we have multiple point or transect sample units in space (or possibly in time). The benefit of HDS in practice is that it allows us to directly model spatial variation in population size among these sample units. This is a preeminent concern of most field studies that use distance sampling methods, but it is not a problem that has received much attention in the literature. We show how to analyze HDS models in both the unmarked package and in the BUGS language for point and line transects, and for continuous and binned distance data. We provide a case study of HDS applied to a survey of the island scrub-jay on Santa Cruz Island, California.

Effects of grain size, mineralogy, and acid-extractable grain coatings on the distribution of the fallout radionuclides 7Be, 10Be, 137Cs, and 210Pb in river sediment

NASA Astrophysics Data System (ADS)

Singleton, Adrian A.; Schmidt, Amanda H.; Bierman, Paul R.; Rood, Dylan H.; Neilson, Thomas B.; Greene, Emily Sophie; Bower, Jennifer A.; Perdrial, Nicolas

2017-01-01

Grain-size dependencies in fallout radionuclide activity have been attributed to either increase in specific surface area in finer grain sizes or differing mineralogical abundances in different grain sizes. Here, we consider a third possibility, that the concentration and composition of grain coatings, where fallout radionuclides reside, controls their activity in fluvial sediment. We evaluated these three possible explanations in two experiments: (1) we examined the effect of sediment grain size, mineralogy, and composition of the acid-extractable materials on the distribution of 7Be, 10Be, 137Cs, and unsupported 210Pb in detrital sediment samples collected from rivers in China and the United States, and (2) we periodically monitored 7Be, 137Cs, and 210Pb retention in samples of known composition exposed to natural fallout in Ohio, USA for 294 days. Acid-extractable materials (made up predominately of Fe, Mn, Al, and Ca from secondary minerals and grain coatings produced during pedogenesis) are positively related to the abundance of fallout radionuclides in our sediment samples. Grain-size dependency of fallout radionuclide concentrations was significant in detrital sediment samples, but not in samples exposed to fallout under controlled conditions. Mineralogy had a large effect on 7Be and 210Pb retention in samples exposed to fallout, suggesting that sieving sediments to a single grain size or using specific surface area-based correction terms may not completely control for preferential distribution of these nuclides. We conclude that time-dependent geochemical, pedogenic, and sedimentary processes together result in the observed differences in nuclide distribution between different grain sizes and substrate compositions. These findings likely explain variability of measured nuclide activities in river networks that exceeds the variability introduced by analytical techniques as well as spatial and temporal differences in erosion rates and processes. In short, we suggest that presence and amount of pedogenic grain coatings is more important than either specific surface area or surface charge in setting the distribution of fallout radionuclides.

Sample Size Requirements for Studies of Treatment Effects on Beta-Cell Function in Newly Diagnosed Type 1 Diabetes

PubMed Central

Lachin, John M.; McGee, Paula L.; Greenbaum, Carla J.; Palmer, Jerry; Gottlieb, Peter; Skyler, Jay

2011-01-01

Preservation of -cell function as measured by stimulated C-peptide has recently been accepted as a therapeutic target for subjects with newly diagnosed type 1 diabetes. In recently completed studies conducted by the Type 1 Diabetes Trial Network (TrialNet), repeated 2-hour Mixed Meal Tolerance Tests (MMTT) were obtained for up to 24 months from 156 subjects with up to 3 months duration of type 1 diabetes at the time of study enrollment. These data provide the information needed to more accurately determine the sample size needed for future studies of the effects of new agents on the 2-hour area under the curve (AUC) of the C-peptide values. The natural log(), log(+1) and square-root transformations of the AUC were assessed. In general, a transformation of the data is needed to better satisfy the normality assumptions for commonly used statistical tests. Statistical analysis of the raw and transformed data are provided to estimate the mean levels over time and the residual variation in untreated subjects that allow sample size calculations for future studies at either 12 or 24 months of follow-up and among children 8–12 years of age, adolescents (13–17 years) and adults (18+ years). The sample size needed to detect a given relative (percentage) difference with treatment versus control is greater at 24 months than at 12 months of follow-up, and differs among age categories. Owing to greater residual variation among those 13–17 years of age, a larger sample size is required for this age group. Methods are also described for assessment of sample size for mixtures of subjects among the age categories. Statistical expressions are presented for the presentation of analyses of log(+1) and transformed values in terms of the original units of measurement (pmol/ml). Analyses using different transformations are described for the TrialNet study of masked anti-CD20 (rituximab) versus masked placebo. These results provide the information needed to accurately evaluate the sample size for studies of new agents to preserve C-peptide levels in newly diagnosed type 1 diabetes. PMID:22102862

Sample size requirements for studies of treatment effects on beta-cell function in newly diagnosed type 1 diabetes.

PubMed

Lachin, John M; McGee, Paula L; Greenbaum, Carla J; Palmer, Jerry; Pescovitz, Mark D; Gottlieb, Peter; Skyler, Jay

2011-01-01

Preservation of β-cell function as measured by stimulated C-peptide has recently been accepted as a therapeutic target for subjects with newly diagnosed type 1 diabetes. In recently completed studies conducted by the Type 1 Diabetes Trial Network (TrialNet), repeated 2-hour Mixed Meal Tolerance Tests (MMTT) were obtained for up to 24 months from 156 subjects with up to 3 months duration of type 1 diabetes at the time of study enrollment. These data provide the information needed to more accurately determine the sample size needed for future studies of the effects of new agents on the 2-hour area under the curve (AUC) of the C-peptide values. The natural log(x), log(x+1) and square-root (√x) transformations of the AUC were assessed. In general, a transformation of the data is needed to better satisfy the normality assumptions for commonly used statistical tests. Statistical analysis of the raw and transformed data are provided to estimate the mean levels over time and the residual variation in untreated subjects that allow sample size calculations for future studies at either 12 or 24 months of follow-up and among children 8-12 years of age, adolescents (13-17 years) and adults (18+ years). The sample size needed to detect a given relative (percentage) difference with treatment versus control is greater at 24 months than at 12 months of follow-up, and differs among age categories. Owing to greater residual variation among those 13-17 years of age, a larger sample size is required for this age group. Methods are also described for assessment of sample size for mixtures of subjects among the age categories. Statistical expressions are presented for the presentation of analyses of log(x+1) and √x transformed values in terms of the original units of measurement (pmol/ml). Analyses using different transformations are described for the TrialNet study of masked anti-CD20 (rituximab) versus masked placebo. These results provide the information needed to accurately evaluate the sample size for studies of new agents to preserve C-peptide levels in newly diagnosed type 1 diabetes.

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

Aznar, Alexandra; Day, Megan; Doris, Elizabeth

The report analyzes and presents information learned from a sample of 20 cities across the United States, from New York City to Park City, Utah, including a diverse sample of population size, utility type, region, annual greenhouse gas reduction targets, vehicle use, and median household income. The report compares climate, sustainability, and energy plans to better understand where cities are taking energy-related actions and how they are measuring impacts. Some common energy-related goals focus on reducing city-wide carbon emissions, improving energy efficiency across sectors, increasing renewable energy, and increasing biking and walking.

PM2.5 Monitors in New England | Air Quality Planning Unit ...

EPA Pesticide Factsheets

2017-04-10

The New England states are currently operating a network of 58 ambient PM2.5 air quality monitors that meet EPA's Federal Reference Method (FRM) for PM2.5, which is necessary in order for the resultant data to be used for attainment/non-attainment purposes. These monitors collect particles in the ambient air smaller than 2.5 microns in size on a filter, which is weighed prior and post sampling to produce a 24-hour sample concentration.

Endotoxin and dust at respirable and nonrespirable particle sizes are not consistent between cage- and floor-housed poultry operations.

PubMed

Kirychuk, Shelley P; Reynolds, Stephen J; Koehncke, Niels K; Lawson, Joshua; Willson, Philip; Senthilselvan, Ambikaipakan; Marciniuk, Darcy; Classen, Henry L; Crowe, Trever; Just, Natasha; Schneberger, David; Dosman, James A

2010-10-01

Individuals engaged in work in intensive animal houses experience some of the highest rates of occupationally related respiratory symptoms. Organic dust and in particular endotoxin has been most closely associated with respiratory symptoms and lung function changes in workers. It has previously been shown that for intensive poultry operations, type of poultry housing [cage-housed (CH) versus floor-housed (FH)] can influence the levels of environmental contaminants. The goal of the study was to determine the differences in endotoxin and dust levels at different size fractions between CH and FH poultry operations. Fifteen CH and 15 FH poultry operations were sampled for stationary measurements (area) of dust and associated endotoxin. Fractioned samples were collected utilizing Marple cascade impactors. Gravimetric and endotoxin analysis were conducted on each of the filters. When assessed by individual Marple stage, there was significantly greater airborne endotoxin concentration (endotoxin units per cubic meter) in the size fraction >9.8 μm for the FH operations whereas at the size fraction 1.6-3.5 μm, the CH operations had significantly greater airborne endotoxin concentration than the FH operations. Endotoxin concentration in the dust mass (endotoxin units per milligram) was significantly greater in the CH operations as compared to the FH operations for all size fractions >1.6 μm. As such, endotoxin in the respirable fraction accounted for 24% of the total endotoxin in the CH operations whereas it accounted for only 11% in the FH operations. There was significantly more dust in all size fractions in the FH operations as compared to the CH poultry operations. There is more endotoxin in the presence of significantly lower dust levels in the respirable particle size fractions in CH poultry operations as compared to the FH poultry operations. This difference in respirable endotoxin may be important in relation to the differential respiratory response experienced by CH and FH poultry operation workers.

Risk of Suicide Attempt Associated with Previous Attempts in One’s Army Unit

PubMed Central

Ursano, Robert J.; Kessler, Ronald C.; Naifeh, James A.; Mash, Holly Herberman; Fullerton, Carol S.; Bliese, Paul D.; Zaslavsky, Alan M.; Ng, Tsz Hin Hinz; Aliaga, Pablo A.; Wynn, Gary H.; Dinh, Hieu M.; McCarroll, James E.; Sampson, Nancy A.; Kao, Tzu-Cheg; Schoenbaum, Michael; Heeringa, Steven G.; Stein, Murray B.

2017-01-01

Objective Soldiers’ mental health is adversely affected by the death and injury of other unit members, but it is not known if risk of suicide attempt is influenced by previous suicide attempts in one’s unit. Method Using administrative data from the Army Study to Assess Risk and Resilience in Servicemembers (Army STARRS), we identified person-month records for all active duty Regular Army enlisted soldiers who attempted suicide from 2004–2009 (n=9,650) and an equal-probability sample of control person-months (n=153,528). Logistic regression analyses examined the number of past-year suicide attempts in one’s unit as a predictor of subsequent suicide attempt, controlling for socio-demographics, service-related characteristics, prior mental health diagnosis, and other unit variables, including suicide-, combat-, and accident-related unit deaths. We also examined whether the influence of previous unit suicide attempts varied by military occupational specialty (MOS) and unit size. Results In adjusted models, soldiers were more likely to attempt suicide if one or more suicide attempts occurred in their unit during the past year (OR=1.4–2.3; p<0.001), with odds increasing as the number of unit attempts increased. The odds of suicide attempt among soldiers in a unit with five or more past-year attempts was more than twice that of soldiers in a unit with no previous attempts (OR=2.3; 95% CI=2.1–2.6). The association of previous unit suicide attempts with subsequent risk was significant whether soldiers had a combat arms MOS or other MOS (OR=1.4–2.3; p<0.001). It was also significant regardless of unit size, with the highest risk for those in smaller units (1–40 soldiers) (OR=2.1–5.9; p<0.001). The population-attributable risk proportion for one or more unit suicide attempts in the past year indicated that if this risk could be reduced to no unit attempts, 18.2% of attempts would not occur. Conclusions Soldiers’ risk of suicide attempt increased as the number of past-year suicide attempts within their unit increased. This was true for both combat arms and other MOSs, and for units of any size, but particularly for smaller units. Units with a history of suicide attempts may be important targets for preventive interventions. PMID:28746705

From the field: Efficacy of detecting Chronic Wasting Disease via sampling hunter-killed white-tailed deer

USGS Publications Warehouse

Diefenbach, D.R.; Rosenberry, C.S.; Boyd, Robert C.

2004-01-01

Surveillance programs for Chronic Wasting Disease (CWD) in free-ranging cervids often use a standard of being able to detect 1% prevalence when determining minimum sample sizes. However, 1% prevalence may represent >10,000 infected animals in a population of 1 million, and most wildlife managers would prefer to detect the presence of CWD when far fewer infected animals exist. We wanted to detect the presence of CWD in white-tailed deer (Odocoileus virginianus) in Pennsylvania when the disease was present in only 1 of 21 wildlife management units (WMUs) statewide. We used computer simulation to estimate the probability of detecting CWD based on a sampling design to detect the presence of CWD at 0.1% and 1.0% prevalence (23-76 and 225-762 infected deer, respectively) using tissue samples collected from hunter-killed deer. The probability of detection at 0.1% prevalence was <30% with sample sizes of ???6,000 deer, and the probability of detection at 1.0% prevalence was 46-72% with statewide sample sizes of 2,000-6,000 deer. We believe that testing of hunter-killed deer is an essential part of any surveillance program for CWD, but our results demonstrated the importance of a multifaceted surveillance approach for CWD detection rather than sole reliance on testing hunter-killed deer.

[Analysis of the patient safety culture in hospitals of the Spanish National Health System].

PubMed

Saturno, P J; Da Silva Gama, Z A; de Oliveira-Sousa, S L; Fonseca, Y A; de Souza-Oliveira, A C; Castillo, Carmen; López, M José; Ramón, Teresa; Carrillo, Andrés; Iranzo, M Dolores; Soria, Victor; Saturno, Pedro J; Parra, Pedro; Gomis, Rafael; Gascón, Juan José; Martinez, José; Arellano, Carmen; Gama, Zenewton A Da Silva; de Oliveira-Sousa, Silvana L; de Souza-Oliveira, Adriana C; Fonseca, Yadira A; Ferreira, Marta Sobral

2008-12-01

A safety culture is essential to minimize errors and adverse events. Its measurement is needed to design activities in order to improve it. This paper describes the methods and main results of a study on safety climate in a nation-wide representative sample of public hospitals of the Spanish NHS. The Hospital Survey on Patient Safety Culture questionnaire was distributed to a random sample of health professionals in a representative sample of 24 hospitals, proportionally stratified by hospital size. Results are analyzed to provide a description of safety climate, its strengths and weaknesses. Differences by hospital size, type of health professional and service are analyzed using ANOVA. A total of 2503 responses are analyzed (response rate: 40%, (93% from professionals with direct patient contact). A total of 50% gave patient safety a score from 6 to 8 (on a 10-point scale); 95% reported < 2 events last year. Dimensions "Teamwork within hospital units" (71.8 [1.8]) and "Supervisor/Manager expectations and actions promoting safety" (61.8 [1.7]) have the highest percentage of positive answers. "Staffing", "Teamwork across hospital units", "Overall perceptions of safety" and "Hospital management support for patient safety" could be identified as weaknesses. Significant differences by hospital size, type of professional and service suggest a generally more positive attitude in small hospitals and Pharmacy services, and a more negative one in physicians. Strengths and weaknesses of the safety climate in the hospitals of the Spanish NHS have been identified and they are used to design appropriate strategies for improvement.

Variation in aluminum, iron, and particle concentrations in oxic ground-water samples collected by use of tangential-flow ultrafiltration with low-flow sampling

USGS Publications Warehouse

Szabo, Z.; Oden, J.H.; Gibs, J.; Rice, D.E.; Ding, Y.; ,

2001-01-01

Particulates that move with ground water and those that are artificially mobilized during well purging could be incorporated into water samples during collection and could cause trace-element concentrations to vary in unfiltered samples, and possibly in filtered samples (typically 0.45-um (micron) pore size) as well, depending on the particle-size fractions present. Therefore, measured concentrations may not be representative of those in the aquifer. Ground water may contain particles of various sizes and shapes that are broadly classified as colloids, which do not settle from water, and particulates, which do. In order to investigate variations in trace-element concentrations in ground-water samples as a function of particle concentrations and particle-size fractions, the U.S. Geological Survey, in cooperation with the U.S. Air Force, collected samples from five wells completed in the unconfined, oxic Kirkwood-Cohansey aquifer system of the New Jersey Coastal Plain. Samples were collected by purging with a portable pump at low flow (0.2-0.5 liters per minute and minimal drawdown, ideally less than 0.5 foot). Unfiltered samples were collected in the following sequence: (1) within the first few minutes of pumping, (2) after initial turbidity declined and about one to two casing volumes of water had been purged, and (3) after turbidity values had stabilized at less than 1 to 5 Nephelometric Turbidity Units. Filtered samples were split concurrently through (1) a 0.45-um pore size capsule filter, (2) a 0.45-um pore size capsule filter and a 0.0029-um pore size tangential-flow filter in sequence, and (3), in selected cases, a 0.45-um and a 0.05-um pore size capsule filter in sequence. Filtered samples were collected concurrently with the unfiltered sample that was collected when turbidity values stabilized. Quality-assurance samples consisted of sequential duplicates (about 25 percent) and equipment blanks. Concentrations of particles were determined by light scattering. Variations in concentrations aluminum and iron (1 -74 and 1-199 ug/L (micrograms per liter), respectively), common indicators of the presence of particulate-borne trace elements, were greatest in sample sets from individual wells with the greatest variations in turbidity and particle concentration. Differences in trace-element concentrations in sequentially collected unfiltered samples with variable turbidity were 5 to 10 times as great as those in concurrently collected samples that were passed through various filters. These results indicate that turbidity must be both reduced and stabilized even when low-flow sample-collection techniques are used in order to obtain water samples that do not contain considerable particulate artifacts. Currently (2001) available techniques need to be refined to ensure that the measured trace-element concentrations are representative of those that are mobile in the aquifer water.

Detectability of the emerald ash borer (Coleoptera: Buprestidae) in asymptomatic urban trees by using branch samples.

PubMed

Ryall, Krista L; Fidgen, Jeffrey G; Turgeon, Jean J

2011-06-01

The emerald ash borer, Agrilus planipennis Fairmaire, is an exotic invasive insect causing extensive mortality to ash trees, Fraxinus spp., in Canada and the United States. Detection of incipient populations of this pest is difficult because of its cryptic life stages and a multiyear time lag between initial attack and the appearance of signs or symptoms of infestation. We sampled branches from open-grown urban ash trees to develop a sample unit suitable for detecting low density A. planipennis infestation before any signs or symptoms are evident. The sample unit that maximized detection rates consisted of one 50-cm-long piece from the base of a branch ≥6 cm diameter in the midcrown. The optimal sample size was two such branches per tree. This sampling method detected ≈75% of asymptomatic trees known to be infested by using more intensive sampling and ≈3 times more trees than sampling one-fourth of the circumference of the trunk at breast height. The method is less conspicuous and esthetically damaging to a tree than the removal of bark from the main stem or the use of trap trees, and could be incorporated into routine sanitation or maintenance of city-owned trees to identify and delineate infested areas. This research indicates that branch sampling greatly reduces false negatives associated with visual surveys and window sampling at breast height. Detection of A. planipennis-infested asymptomatic trees through branch sampling in urban centers would provide landowners and urban foresters with more time to develop and implement management tactics.

Protocol for determining bull trout presence

USGS Publications Warehouse

Peterson, James; Dunham, Jason B.; Howell, Philip; Thurow, Russell; Bonar, Scott

2002-01-01

The Western Division of the American Fisheries Society was requested to develop protocols for determining presence/absence and potential habitat suitability for bull trout. The general approach adopted is similar to the process for the marbled murrelet, whereby interim guidelines are initially used, and the protocols are subsequently refined as data are collected. Current data were considered inadequate to precisely identify suitable habitat but could be useful in stratifying sampling units for presence/absence surveys. The presence/absence protocol builds on previous approaches (Hillman and Platts 1993; Bonar et al. 1997), except it uses the variation in observed bull trout densities instead of a minimum threshold density and adjusts for measured differences in sampling efficiency due to gear types and habitat characteristics. The protocol consists of: 1. recommended sample sizes with 80% and 95% detection probabilities for juvenile and resident adult bull trout for day and night snorkeling and electrofishing adjusted for varying habitat characteristics for 50m and 100m sampling units, 2. sampling design considerations, including possible habitat characteristics for stratification, 3. habitat variables to be measured in the sampling units, and 3. guidelines for training sampling crews. Criteria for habitat strata consist of coarse, watershed-scale characteristics (e.g., mean annual air temperature) and fine-scale, reach and habitat-specific features (e.g., water temperature, channel width). The protocols will be revised in the future using data from ongoing presence/absence surveys, additional research on sampling efficiencies, and development of models of habitat/species occurrence.

24 CFR 982.505 - Voucher tenancy: How to calculate housing assistance payment.

Code of Federal Regulations, 2010 CFR

2010-04-01

... unit size; or (ii) The payment standard amount for the size of the dwelling unit rented by the family... effective date of the increase in the payment standard amount. (5) Change in family unit size during the HAP... size increases or decreases during the HAP contract term, the new family unit size must be used to...

Evaluation of the organization of the homoionic smectite layers (Na(+) or Ca(2+)) in diluted dispersions using granulometry, microscopy and rheometry.

PubMed

Paumier, S; Pantet, A; Monnet, P

2008-09-01

Smectites are swelling clay materials with pronounced colloidal properties that are widely used in industry. These properties originate in the electrokinetic properties of the smectite layers and their linkage capacities. Thin layers may be dispersed or aggregated according to many parameters, such as concentration, particle size and morphology, exchangeable cation nature and chemical environment (pH, ionic strength). The literature usually provides general rules, like the sodium dispersion contains a lot of small units whereas the calcium dispersion contains a few large units. A volume of water molecules bound to the clay surface is considered as the immobile water phase that behaves like the solid phase obstructing the flow. The water immobilized around layers and trapped inside aggregates cannot participate to the flow. In this study, we evaluated the volume occupied by calcium and sodium units inside the dispersion containing the immobile water phase. First, the smectite was cautiously extracted from a raw bentonite and its physicochemical properties were determined. A large quantity of extracted and saturated smectite (Na-smectite and Ca-smectite) was obtained. Second, the unit size and a shape factor for each sample were evaluated using granulometry and scanning transmission electron microscopy on wet samples (Wet STEM) and some flow curves. Na-smectite dispersions contain 0.13 microm(2) surface units with a shape factor of 50. Ca-smectite dispersions contain 0.32 microm(2) surface units with a shape factor of 3.3. Finally, rheometry allowed us to evaluate the unit occupancy using an adaptation of the Krieger-Dougherty law. We used shape factors and evaluated the concentration from which the entire immobile volume was connected (6.4% for Na-smectite and 11.9% for Ca-smectite). This study explains the evolution of flow properties with increasing concentrations by the evolution of layer interactions at the microscopic scale for homoionic smectite particles in diluted dispersions.

The contribution of cluster and discriminant analysis to the classification of complex aquifer systems.

PubMed

Panagopoulos, G P; Angelopoulou, D; Tzirtzilakis, E E; Giannoulopoulos, P

2016-10-01

This paper presents an innovated method for the discrimination of groundwater samples in common groups representing the hydrogeological units from where they have been pumped. This method proved very efficient even in areas with complex hydrogeological regimes. The proposed method requires chemical analyses of water samples only for major ions, meaning that it is applicable to most of cases worldwide. Another benefit of the method is that it gives a further insight of the aquifer hydrogeochemistry as it provides the ions that are responsible for the discrimination of the group. The procedure begins with cluster analysis of the dataset in order to classify the samples in the corresponding hydrogeological unit. The feasibility of the method is proven from the fact that the samples of volcanic origin were separated into two different clusters, namely the lava units and the pyroclastic-ignimbritic aquifer. The second step is the discriminant analysis of the data which provides the functions that distinguish the groups from each other and the most significant variables that define the hydrochemical composition of the aquifer. The whole procedure was highly successful as the 94.7 % of the samples were classified to the correct aquifer system. Finally, the resulted functions can be safely used to categorize samples of either unknown or doubtful origin improving thus the quality and the size of existing hydrochemical databases.

Impregnating unconsolidated pyroclastic sequences: A tool for detailed facies analysis

NASA Astrophysics Data System (ADS)

Klapper, Daniel; Kueppers, Ulrich; Castro, Jon M.; Pacheco, Jose M. R.; Dingwell, Donald B.

2010-05-01

The interpretation of volcanic eruptions is usually derived from direct observation and the thorough analysis of the deposits. Processes in vent-proximal areas are usually not directly accessible or likely to be obscured. Hence, our understanding of proximal deposits is often limited as they were produced by the simultaneous events stemming from primary eruptive, transportative, and meteorological conditions. Here we present a method that permits for a direct and detailed quasi in-situ investigation of loose pyroclastic units that are usually analysed in the laboratory for their 1) grain-size distribution, 2) componentry, and 3) grain morphology. As the clast assembly is altered during sampling, the genesis of a stratigraphic unit and the relative importance of the above mentioned deposit characteristics is hard to achieve. In an attempt to overcome the possible loss of information during conventional sampling techniques, we impregnated the cleaned surfaces of proximal, unconsolidated units of the 1957-58 Capelinhos eruption on Faial, Azores. During this basaltic, emergent eruption, fluxes in magma rise rate led to a repeated build-up and collapse of tuff cones and consequently to a shift between phreatomagmatic and magmatic eruptive style. The deposits are a succession of generally parallel bedded, cm- to dm-thick layers with a predominantly ashy matrix. The lapilli content is varying gradually; the content of bombs is enriched in discrete layers without clear bomb sags. The sample areas have been cleaned and impregnated with two-component glue (EPOTEK 301). For approx. 10 * 10 cm, a volume of mixed glue of 20 ml was required. Using a syringe, this low-viscosity, transparent glue could be easily applied on the target area. We found that the glue permeated the deposit as deep as 5 mm. After > 24 h, the glue was sufficiently dry to enable the sample to be laid open. This impregnation method renders it possible to cut and polish the sample and investigate grain-size distribution, componentry, and grain morphology in situ in a 2D-plane. In a first step, the sample surface has been scanned and analysed by means of image analysis software (Image J). After that, selected areas were investigated through thin section analysis. We were able to define depositional units in the (sub)-mm scale and the show the varying relative importance of 1) eruptive style, 2) transportation mode, and 3) the influence of wind and (air) humidity. The presented method is an easy and efficient tool for a detailed stratigraphic investigation of unconsolidated pyroclastic units.

A Survey of Theatre in American Secondary Schools.

ERIC Educational Resources Information Center

Gillespie, Patti; And Others

In a survey of the status of theatre in high schools throughout the United States, questionnaires were sent to a random sample of high schools stratified by state and by school size. Analysis of the responses obtained from 606 schools (20.2% return) indicated that most secondary-school drama programs operate on the cocurricular level and emphasize…

Emerging Answers: Research Findings on Programs To Reduce Teen Pregnancy.

ERIC Educational Resources Information Center

Kirby, Douglas

This report summarizes three bodies of research on teenage pregnancy and programs to reduce the risk of teenage pregnancy. Studies included in this report were completed in 1980 or later, conducted in the United States or Canada, targeted adolescents, employed an experimental or quasi-experimental design, had a sample size of at least 100 in the…

Randomness, Sample Size, Imagination and Metacognition: Making Judgments about Differences in Data Sets

ERIC Educational Resources Information Center

Stack, Sue; Watson, Jane

2013-01-01

There is considerable research on the difficulties students have in conceptualising individual concepts of probability and statistics (see for example, Bryant & Nunes, 2012; Jones, 2005). The unit of work developed for the action research project described in this article is specifically designed to address some of these in order to help…

Longitudinal Monitoring of Successive Commercial Layer Flocks for Salmonella enterica Serovar Enteritidis.

PubMed

Denagamage, Thomas N; Patterson, Paul; Wallner-Pendleton, Eva; Trampel, Darrell; Shariat, Nikki; Dudley, Edward G; Jayarao, Bhushan M; Kariyawasam, Subhashinie

2016-11-01

The Pennsylvania Egg Quality Assurance Program (EQAP) provided the framework for Salmonella Enteritidis (SE) control programs, including the Food and Drug Administration (FDA) mandated Final Egg Rule, for commercial layer facilities throughout the United States. Although flocks with ≥3000 birds must comply with the FDA Final Egg Rule, smaller flocks are exempted from the rule. As a result, eggs produced by small layer flocks may pose a greater public health risk than those from larger flocks. It is also unknown if the EQAPs developed with large flocks in mind are suitable for small- and medium-sized flocks. Therefore, a study was performed to evaluate the effectiveness of best management practices included in EQAPs in reducing SE contamination of small- and medium-sized flocks by longitudinal monitoring of their environment and eggs. A total of 59 medium-sized (3000 to 50,000 birds) and small-sized (<3000 birds) flocks from two major layer production states of the United States were enrolled and monitored for SE by culturing different types of environmental samples and shell eggs for two consecutive flock cycles. Isolated SE was characterized by phage typing, pulsed-field gel electrophoresis (PFGE), and clustered regularly interspaced short palindromic repeats-multi-virulence-locus sequence typing (CRISPR-MVLST). Fifty-four Salmonella isolates belonging to 17 serovars, 22 of which were SE, were isolated from multiple sample types. Typing revealed that SE isolates belonged to three phage types (PTs), three PFGE fingerprint patterns, and three CRISPR-MVLST SE Sequence Types (ESTs). The PT8 and JEGX01.0004 PFGE pattern, the most predominant SE types associated with foodborne illness in the United States, were represented by a majority (91%) of SE. Of the three ESTs observed, 85% SE were typed as EST4. The proportion of SE-positive hen house environment during flock cycle 2 was significantly less than the flock cycle 1, demonstrating that current EQAP practices were effective in reducing SE contamination of medium and small layer flocks.

Statistical characterization of a large geochemical database and effect of sample size

USGS Publications Warehouse

Zhang, C.; Manheim, F.T.; Hinde, J.; Grossman, J.N.

2005-01-01

The authors investigated statistical distributions for concentrations of chemical elements from the National Geochemical Survey (NGS) database of the U.S. Geological Survey. At the time of this study, the NGS data set encompasses 48,544 stream sediment and soil samples from the conterminous United States analyzed by ICP-AES following a 4-acid near-total digestion. This report includes 27 elements: Al, Ca, Fe, K, Mg, Na, P, Ti, Ba, Ce, Co, Cr, Cu, Ga, La, Li, Mn, Nb, Nd, Ni, Pb, Sc, Sr, Th, V, Y and Zn. The goal and challenge for the statistical overview was to delineate chemical distributions in a complex, heterogeneous data set spanning a large geographic range (the conterminous United States), and many different geological provinces and rock types. After declustering to create a uniform spatial sample distribution with 16,511 samples, histograms and quantile-quantile (Q-Q) plots were employed to delineate subpopulations that have coherent chemical and mineral affinities. Probability groupings are discerned by changes in slope (kinks) on the plots. Major rock-forming elements, e.g., Al, Ca, K and Na, tend to display linear segments on normal Q-Q plots. These segments can commonly be linked to petrologic or mineralogical associations. For example, linear segments on K and Na plots reflect dilution of clay minerals by quartz sand (low in K and Na). Minor and trace element relationships are best displayed on lognormal Q-Q plots. These sensitively reflect discrete relationships in subpopulations within the wide range of the data. For example, small but distinctly log-linear subpopulations for Pb, Cu, Zn and Ag are interpreted to represent ore-grade enrichment of naturally occurring minerals such as sulfides. None of the 27 chemical elements could pass the test for either normal or lognormal distribution on the declustered data set. Part of the reasons relate to the presence of mixtures of subpopulations and outliers. Random samples of the data set with successively smaller numbers of data points showed that few elements passed standard statistical tests for normality or log-normality until sample size decreased to a few hundred data points. Large sample size enhances the power of statistical tests, and leads to rejection of most statistical hypotheses for real data sets. For large sample sizes (e.g., n > 1000), graphical methods such as histogram, stem-and-leaf, and probability plots are recommended for rough judgement of probability distribution if needed. ?? 2005 Elsevier Ltd. All rights reserved.

Influences of different parameters on the microstructure of magnetic-field-induced self-assembled film

NASA Astrophysics Data System (ADS)

Dan, X.; Yang, J. J.

2016-07-01

Self-assembled films with needle-like microarrays were fabricated using a mixture of cobalt and fluorocarbon resin under a magnetic field. The various influences of magnetic powder content, viscosity and size distribution on the structure of the self-assembled films were investigated. The self-assembled film morphologies were characterized by stereomicroscope and scanning electron microscopy. Experimental results indicate that an increase in magnetic powder content results in greater unit height and diameter, and that a reduction in viscosity results in increasing array density and decreasing unit width. Additionally, particles with narrow size distribution were able to attain more regular microarray structures. The structural alterations were closely related to numerous effects such as van der Waals forces, dipole-dipole interactions, and external-dipole interactions. The self-assembled film demonstrated magnetic anisotropy, as identified by vibrating sample magnetometry (VSM).

Thermal conductivity measurements of particulate materials under Martian conditions

NASA Technical Reports Server (NTRS)

Presley, M. A.; Christensen, P. R.

1993-01-01

The mean particle diameter of surficial units on Mars has been approximated by applying thermal inertia determinations from the Mariner 9 Infrared Radiometer and the Viking Infrared Thermal Mapper data together with thermal conductivity measurement. Several studies have used this approximation to characterize surficial units and infer their nature and possible origin. Such interpretations are possible because previous measurements of the thermal conductivity of particulate materials have shown that particle size significantly affects thermal conductivity under martian atmospheric pressures. The transfer of thermal energy due to collisions of gas molecules is the predominant mechanism of thermal conductivity in porous systems for gas pressures above about 0.01 torr. At martian atmospheric pressures the mean free path of the gas molecules becomes greater than the effective distance over which conduction takes place between the particles. Gas particles are then more likely to collide with the solid particles than they are with each other. The average heat transfer distance between particles, which is related to particle size, shape and packing, thus determines how fast heat will flow through a particulate material.The derived one-to-one correspondence of thermal inertia to mean particle diameter implies a certain homogeneity in the materials analyzed. Yet the samples used were often characterized by fairly wide ranges of particle sizes with little information about the possible distribution of sizes within those ranges. Interpretation of thermal inertia data is further limited by the lack of data on other effects on the interparticle spacing relative to particle size, such as particle shape, bimodal or polymodal mixtures of grain sizes and formation of salt cements between grains. To address these limitations and to provide a more comprehensive set of thermal conductivities vs. particle size a linear heat source apparatus, similar to that of Cremers, was assembled to provide a means of measuring the thermal conductivity of particulate samples. In order to concentrate on the dependence of the thermal conductivity on particle size, initial runs will use spherical glass beads that are precision sieved into relatively small size ranges and thoroughly washed.

Characterization of fly ash from low-sulfur and high-sulfur coal sources: Partitioning of carbon and trace elements with particle size

USGS Publications Warehouse

Hower, J.C.; Trimble, A.S.; Eble, C.F.; Palmer, C.A.; Kolker, A.

1999-01-01

Fly ash samples were collected in November and December of 1994, from generating units at a Kentucky power station using high- and low-sulfur feed coals. The samples are part of a two-year study of the coal and coal combustion byproducts from the power station. The ashes were wet screened at 100, 200, 325, and 500 mesh (150, 75, 42, and 25 ??m, respectively). The size fractions were then dried, weighed, split for petrographic and chemical analysis, and analyzed for ash yield and carbon content. The low-sulfur "heavy side" and "light side" ashes each have a similar size distribution in the November samples. In contrast, the December fly ashes showed the trend observed in later months, the light-side ash being finer (over 20 % more ash in the -500 mesh [-25 ??m] fraction) than the heavy-side ash. Carbon tended to be concentrated in the coarse fractions in the December samples. The dominance of the -325 mesh (-42 ??m) fractions in the overall size analysis implies, though, that carbon in the fine sizes may be an important consideration in the utilization of the fly ash. Element partitioning follows several patterns. Volatile elements, such as Zn and As, are enriched in the finer sizes, particularly in fly ashes collected at cooler, light-side electrostatic precipitator (ESP) temperatures. The latter trend is a function of precipitation at the cooler-ESP temperatures and of increasing concentration with the increased surface area of the finest fraction. Mercury concentrations are higher in high-carbon fly ashes, suggesting Hg adsorption on the fly ash carbon. Ni and Cr are associated, in part, with the spinel minerals in the fly ash. Copyright ?? 1999 Taylor & Francis.

Increasing efficiency of preclinical research by group sequential designs

PubMed Central

Piper, Sophie K.; Rex, Andre; Florez-Vargas, Oscar; Karystianis, George; Schneider, Alice; Wellwood, Ian; Siegerink, Bob; Ioannidis, John P. A.; Kimmelman, Jonathan; Dirnagl, Ulrich

2017-01-01

Despite the potential benefits of sequential designs, studies evaluating treatments or experimental manipulations in preclinical experimental biomedicine almost exclusively use classical block designs. Our aim with this article is to bring the existing methodology of group sequential designs to the attention of researchers in the preclinical field and to clearly illustrate its potential utility. Group sequential designs can offer higher efficiency than traditional methods and are increasingly used in clinical trials. Using simulation of data, we demonstrate that group sequential designs have the potential to improve the efficiency of experimental studies, even when sample sizes are very small, as is currently prevalent in preclinical experimental biomedicine. When simulating data with a large effect size of d = 1 and a sample size of n = 18 per group, sequential frequentist analysis consumes in the long run only around 80% of the planned number of experimental units. In larger trials (n = 36 per group), additional stopping rules for futility lead to the saving of resources of up to 30% compared to block designs. We argue that these savings should be invested to increase sample sizes and hence power, since the currently underpowered experiments in preclinical biomedicine are a major threat to the value and predictiveness in this research domain. PMID:28282371

Sampling scales define occupancy and underlying occupancy-abundance relationships in animals.

PubMed

Steenweg, Robin; Hebblewhite, Mark; Whittington, Jesse; Lukacs, Paul; McKelvey, Kevin

2018-01-01

Occupancy-abundance (OA) relationships are a foundational ecological phenomenon and field of study, and occupancy models are increasingly used to track population trends and understand ecological interactions. However, these two fields of ecological inquiry remain largely isolated, despite growing appreciation of the importance of integration. For example, using occupancy models to infer trends in abundance is predicated on positive OA relationships. Many occupancy studies collect data that violate geographical closure assumptions due to the choice of sampling scales and application to mobile organisms, which may change how occupancy and abundance are related. Little research, however, has explored how different occupancy sampling designs affect OA relationships. We develop a conceptual framework for understanding how sampling scales affect the definition of occupancy for mobile organisms, which drives OA relationships. We explore how spatial and temporal sampling scales, and the choice of sampling unit (areal vs. point sampling), affect OA relationships. We develop predictions using simulations, and test them using empirical occupancy data from remote cameras on 11 medium-large mammals. Surprisingly, our simulations demonstrate that when using point sampling, OA relationships are unaffected by spatial sampling grain (i.e., cell size). In contrast, when using areal sampling (e.g., species atlas data), OA relationships are affected by spatial grain. Furthermore, OA relationships are also affected by temporal sampling scales, where the curvature of the OA relationship increases with temporal sampling duration. Our empirical results support these predictions, showing that at any given abundance, the spatial grain of point sampling does not affect occupancy estimates, but longer surveys do increase occupancy estimates. For rare species (low occupancy), estimates of occupancy will quickly increase with longer surveys, even while abundance remains constant. Our results also clearly demonstrate that occupancy for mobile species without geographical closure is not true occupancy. The independence of occupancy estimates from spatial sampling grain depends on the sampling unit. Point-sampling surveys can, however, provide unbiased estimates of occupancy for multiple species simultaneously, irrespective of home-range size. The use of occupancy for trend monitoring needs to explicitly articulate how the chosen sampling scales define occupancy and affect the occupancy-abundance relationship. © 2017 by the Ecological Society of America.

An evaluation of the ELT-8 hematology analyzer.

PubMed

Raik, E; McPherson, J; Barton, L; Hewitt, B S; Powell, E G; Gordon, S

1982-04-01

The TMELT-8 Hematology Analyzer is a fully automated cell counter which utilizes laser light scattering and hydrodynamic focusing to provide an 8 parameter whole blood count. The instrument consists of a sample handler with ticket printer, and a data handler with visual display unit, It accepts 100 microliter samples of venous or capillary blood and prints the values for WCC, RCC, Hb, Hct, MCV, MCH, MCHC and platelet count on to a standard result card. All operational and quality control functions, including graphic display of relative cell size distribution, can be obtained from the visual display unit and can also be printed as a permanent record if required. In a limited evaluation of the ELT-8, precision, linearity, accuracy, lack of sample carry-over and user acceptance were excellent. Reproducible values were obtained for all parameters after overnight storage of samples. Reagent usage and running costs were lower than for the Coulter S and the Coulter S Plus. The ease of processing capillary samples was considered to be a major advantage. The histograms served to alert the operator to a number of abnormalities, some of which were clinically significant.

24 CFR 81.17 - Affordability-Income level definitions-family size and income known (owner-occupied units, actual...

Code of Federal Regulations, 2010 CFR

2010-04-01

... definitions-family size and income known (owner-occupied units, actual tenants, and prospective tenants). 81...—Income level definitions—family size and income known (owner-occupied units, actual tenants, and...-income families, where the unit is owner-occupied or, for rental housing, family size and income...

High-pressure size exclusion chromatography analysis of dissolved organic matter isolated by tangential-flow ultra filtration

USGS Publications Warehouse

Everett, C.R.; Chin, Y.-P.; Aiken, G.R.

1999-01-01

A 1,000-Dalton tangential-flow ultrafiltration (TFUF) membrane was used to isolate dissolved organic matter (DOM) from several freshwater environments. The TFUF unit used in this study was able to completely retain a polystyrene sulfonate 1,800-Dalton standard. Unaltered and TFUF-fractionated DOM molecular weights were assayed by high-pressure size exclusion chromatography (HPSEC). The weight-averaged molecular weights of the retentates were larger than those of the raw water samples, whereas the filtrates were all significantly smaller and approximately the same size or smaller than the manufacturer-specified pore size of the membrane. Moreover, at 280 nm the molar absorptivity of the DOM retained by the ultrafilter is significantly larger than the material in the filtrate. This observation suggests that most of the chromophoric components are associated with the higher molecular weight fraction of the DOM pool. Multivalent metals in the aqueous matrix also affected the molecular weights of the DOM molecules. Typically, proton-exchanged DOM retentates were smaller than untreated samples. This TFUF system appears to be an effective means of isolating aquatic DOM by size, but the ultimate size of the retentates may be affected by the presence of metals and by configurational properties unique to the DOM phase.

Detector-unit-dependent calibration for polychromatic projections of rock core CT.

PubMed

Li, Mengfei; Zhao, Yunsong; Zhang, Peng

2017-01-01

Computed tomography (CT) plays an important role in digital rock analysis, which is a new prospective technique for oil and gas industry. But the artifacts in CT images will influence the accuracy of the digital rock model. In this study, we proposed and demonstrated a novel method to restore detector-unit-dependent functions for polychromatic projection calibration by scanning some simple shaped reference samples. As long as the attenuation coefficients of the reference samples are similar to the scanned object, the size or position is not needed to be exactly known. Both simulated and real data were used to verify the proposed method. The results showed that the new method reduced both beam hardening artifacts and ring artifacts effectively. Moreover, the method appeared to be quite robust.

Small-business employment in 22 rich economies.

PubMed

Schmitt, John; Lane, Nathan

2010-01-01

Opponents of health care reform in the United States have often argued that such reform will be detrimental to small and medium-sized enterprises. The authors review the most recent data from a sample of 22 rich countries in the Organization for Economic Cooperation and Development (OECD), all of which, except the United States, have universal health care systems. By every measure of small-business employment, the United States has among the world's smallest small-business sectors (as a proportion of total national employment). These findings hold for self-employed workers and across all industry groups for which the Paris-based OECD publishes internationally comparable data, including manufacturing, computer-related services, and research and development.

Development of blood extraction system for health monitoring system

NASA Astrophysics Data System (ADS)

Tsuchiya, Kazuyoshi; Nakanishi, Naoyuki; Nakamachi, Eiji

2004-03-01

The purpose of this research is to develop the compact human blood sampling device applied for a health monitoring system(HMS), which is called "Mobile Hospital". The HMS consists of (1) a micro electrical pumping system for blood extraction, (2) a bio-sensor to detect and evaluate an amount of Glucose, Cholesterol and Urea in extracted blood, by using enzyme such as Glucoseoxidase (GOD), Cholesteroloxidase and Urease. The mechanical design elements of the device are bio-compatible microneedle, indentation unit using a shape memory alloy(SMA) actuator and pumping unit using a piezoelectric microactuator. The design concept is the biomimetic micromachine of female mosquito"s blood sampling mechanism. The performances of the main mechanical elements such as indentation force of the microneedle, actual stroke of the indentation unit using a SMA actuator and liquid sampling ability of the pumping unit using PZT piezoelectric microactuator were measured. The 3 mm stroke of the indentation load generated by SMA actuator was 0.8mN. The amount of imitation blood extracted by using bimorph PZT actuators was about 0.5 microliters for 10 sec. A 60-micrometer outer diameter and 25-micrometer inner diameter Titanium microneedle, which size is same as female mosquito"s labium, was produced by sputter deposition.

Determination of exposure to respirable quartz in the stone crushing units at Azendarian-West of Iran.

PubMed

Bahrami, Abdul Rahman; Golbabai, Faridah; Mahjub, Hossien; Qorbani, Farshid; Aliabadi, Mohsan; Barqi, Mohamadali

2008-08-01

The purpose of this study is to describe the personal exposure to respirable dust and quartz and in stone crushing units located at west of Iran. A size of 40 personal samples and 40 stationary samples were obtained and analysis was done by X-ray diffraction (XRD). The results of personal sampling were shown the concentrations of respirable dust exposure level in workers of process, hopper and drivers were 1.90, 2.22, 1.41 times greater than Occupational Safety and Health Administration permissible exposure limit (OSHA PEL). The average value of total dust and respirable dust emission from stationary sources was 9.46 mg/m(3), 1.24 mg/m(3) respectively, showing that 13.8 % of total dust is respirable. The efficiency of local exhaust ventilation (LEV) to control of particles inside of industrial units was greater than 99%. It is concluded from this research the particulate generated from stone crushing activities contain a significant amount of respirable particle. The amount of free silica in stone quartz is 85 to 97 percent that emission of particles effect to health workers. LEV has important effect in the removal of silica particles in stone crushing units. The worker of hoppers still exposed to silica more than standard limits.

Inter-rater reliability of motor unit number estimates and quantitative motor unit analysis in the tibialis anterior muscle.

PubMed

Boe, S G; Dalton, B H; Harwood, B; Doherty, T J; Rice, C L

2009-05-01

To establish the inter-rater reliability of decomposition-based quantitative electromyography (DQEMG) derived motor unit number estimates (MUNEs) and quantitative motor unit (MU) analysis. Using DQEMG, two examiners independently obtained a sample of needle and surface-detected motor unit potentials (MUPs) from the tibialis anterior muscle from 10 subjects. Coupled with a maximal M wave, surface-detected MUPs were used to derive a MUNE for each subject and each examiner. Additionally, size-related parameters of the individual MUs were obtained following quantitative MUP analysis. Test-retest MUNE values were similar with high reliability observed between examiners (ICC=0.87). Additionally, MUNE variability from test-retest as quantified by a 95% confidence interval was relatively low (+/-28 MUs). Lastly, quantitative data pertaining to MU size, complexity and firing rate were similar between examiners. MUNEs and quantitative MU data can be obtained with high reliability by two independent examiners using DQEMG. Establishing the inter-rater reliability of MUNEs and quantitative MU analysis using DQEMG is central to the clinical applicability of the technique. In addition to assessing response to treatments over time, multiple clinicians may be involved in the longitudinal assessment of the MU pool of individuals with disorders of the central or peripheral nervous system.

Water-quality assessment of the Ozark Plateaus study unit, Arkansas, Kansas, Missouri, and Oklahoma; nutrients, bacteria, organic carbon, and suspended sediment in surface water, 1993-95

USGS Publications Warehouse

Davis, Jerri V.; Bell, Richard W.

1998-01-01

Nutrient, bacteria, organic carbon, and suspended- sediment samples were collected from 1993-95 at 43 surface-water-quality sampling sites within the Ozark Plateaus National Water- Quality Assessment Program study unit. Most surface-water-quality sites have small or medium drainage basins, near-homogenous land uses (primarily agricultural or forest), and are located predominantly in the Springfield and Salem Plateaus. The water-quality data were analyzed using selected descriptive and statistical methods to determine factors affecting occurrence in streams in the study unit. Nitrogen and phosphorus fertilizer use increased in the Ozark Plateaus study unit for the period 1965-85, but the application rates are well below the national median. Fertilizer use differed substantially among the major river basins and physiographic areas in the study unit. Livestock and poultry waste is a major source of nutrient loading in parts of the study unit. The quantity of nitrogen and phosphorus from livestock and poultry wastes differed substantially among the river basins of the study unit's sampling network. Eighty six municipal sewage-treatment plants in the study unit have effluents of 0.5 million gallons per day or more (for the years 1985-91). Statistically significant differences existed in surface-water quality that can be attributed to land use, physiography, and drainage basin size. Dissolved nitrite plus nitrate, total phosphorus, fecal coliform bacteria, and dissolved organic carbon concentrations generally were larger at sites associated with agricultural basins than at sites associated with forested basins. A large difference in dissolved nitrite plus nitrate concentrations occurred between streams draining basins with agricultural land use in the Springfield and Salem Plateaus. Streams draining both small and medium agricultural basins in the Springfield Plateau had much larger concentrations than their counterparts in the Salem Plateau. Drainage basin size was not a significant factor in affecting total phosphorus, fecal coliform bacteria, or dissolved organic carbon concentrations. Suspended-sediment concentrations generally were small and indicative of the clear water in streams in the Ozark Plateaus. A comparison of the dissolved nitrite plus nitrate, total phosphorus, and fecal coliform data collected at the fixed and synoptic sites indicates that generally the data for streams draining basins of similar physiography, land-use setting, and drainage basin size group together. Many of the variations are most likely the result of differences in percent agricultural land use between the sites being compared or are discharge related. The relation of dissolved nitrite plus nitrate, total phosphorus, and fecal coliform concentration to percent agricultural land use has a strong positive 2 Water-Quality Assessment-Nutrients, Bacteria, Organic Carbon, and Suspended Sediment in Surface Water, 1993-95 correlation, with percent agricultural land use accounting for between 42 and 60 percent of the variation in the observed concentrations.

The effect of head nurse behaviors on nurse job satisfaction and performance.

PubMed

Sorrentino, E A; Nalli, B; Schriesheim, C

1992-01-01

Many nursing executives ponder the repeated problems at the unit level and occasionally surmise that effective supervision at that level holds the key to quality patient care. These pragmatic concerns, while commonplace, have yet to be explored empirically. The relationship of head nurse direction and support on subordinate job satisfaction and performance is not clearly understood. This study examines these relationships in the context of three moderating factors--role clarity, job anxiety, and unit size. Additionally, head nurse support is examined as a moderator of relationships between head nurse direction and subordinate satisfaction and job performance. Using a sample of 103 registered nurses in a medium-capacity metropolitan general hospital, the results show some significant correlations between head nurse behavior and job satisfaction and performance, and in moderating the effects of job anxiety, unit size, and support. The study highlights the need for replication in other settings. Additionally, other variables relevant to job satisfaction and performance such as life stressors (death or illness in the family) require investigation. The findings of this study reveal implications for management at the unit level and the importance of understanding subordinate behaviors in the context of head nurse support and direction.

Genetic structure of Culex erraticus populations across the Americas.

PubMed

Mendenhall, Ian H; Bahl, Justin; Blum, Michael J; Wesson, Dawn M

2012-05-01

Culex erraticus (Dyar & Knab) is a potential competent vector for several arboviruses such as Eastern and Venezuelan equine encephalitis viruses and West Nile virus. It therefore may play a role in the maintenance and spread of viral populations in areas of concern, including the United States where it occurs in >33 states. However, little information is available on potential barriers to movement across the species' distribution. Here, we analyze genetic variation among Cx. erraticus collected from Colombia, Guatemala, and nine locations in the United States to better understand population structure and connectivity. Comparative sequence analysis of the second internal transcribed spacer and mitochondrial NADH dehydrogenase genes identified two major lineages of sampled populations. One lineage represented the central and eastern United States, whereas the other corresponded to Central America, South America, and the western United States. Hierarchical analysis of genetic variation provided further evidence of regional population structure, although the majority of genetic variation was found to reside within populations, suggestive of large population sizes. Although significant physical barriers such as the Chihuahuan Desert probably constrain the spread of Cx. erraticus, large population sizes and connectivity within regions remain important risk factors that probably contribute to the movement of arboviruses within and between these regions.

Change in Sediment Provenance Near the Current Estuary of Yellow River Since the Holocene Transgression

NASA Astrophysics Data System (ADS)

Song, Sheng; Feng, Xiuli; Li, Guogang; Liu, Xiao; Xiao, Xiao; Feng, Li

2018-06-01

Sedimentary sequence and sediment provenance are important factors when it comes to the studies on marine sedimentation. This paper studies grain size distribution, lithological characteristics, major and rare earth elemental compositions, micropaleontological features and 14C ages in order to examine sedimentary sequence and sediment provenance of the core BH6 drilled at the mouth of the Yellow River in Bohai Sea. According to the grain size and the micropaleontological compositions, 4 sedimentary units have been identified. Unit 1 (0-8.08 mbsf) is of the delta sedimentary facies, Unit 2 (8.08-12.08 mbsf) is of the neritic shelf facies, Unit 3 (12.08-23.85 mbsf) is of near-estuary beach-tidal facies, and Unit 4 (23.85 mbsf-) is of the continental lake facies. The deposits from Unit 1 to Unit 3 have been found to be marine strata formed after the Holocene transgression at about 10 ka BP, while Unit 4 is continental lacustrine deposit formed before 10 ka BP. The provenances of core BH6 sediments show properties of the continental crust and vary in different sedimentary periods. For Unit 4 sediments, the source regions are dispersed while the main provenance is not clear, although the parent rock characteristics of a few samples are similar to the Luanhe River sediments. For Unit 3, sediments at 21.1-23.85 mbsf have been mainly transported from the Liaohe River, while sediments above 21.1 mbsf are mainly from the Yellow River and partially from the Liaohe River. For Unit 2, the sediments have been mainly transported from the Yellow River, with a small amount from other rivers. For Unit 1, the provenance is mainly the Yellow River catchment. These results help in better understanding the evolution of the Yellow River Delta.

Residential scene classification for gridded population sampling in developing countries using deep convolutional neural networks on satellite imagery.

PubMed

Chew, Robert F; Amer, Safaa; Jones, Kasey; Unangst, Jennifer; Cajka, James; Allpress, Justine; Bruhn, Mark

2018-05-09

Conducting surveys in low- and middle-income countries is often challenging because many areas lack a complete sampling frame, have outdated census information, or have limited data available for designing and selecting a representative sample. Geosampling is a probability-based, gridded population sampling method that addresses some of these issues by using geographic information system (GIS) tools to create logistically manageable area units for sampling. GIS grid cells are overlaid to partition a country's existing administrative boundaries into area units that vary in size from 50 m × 50 m to 150 m × 150 m. To avoid sending interviewers to unoccupied areas, researchers manually classify grid cells as "residential" or "nonresidential" through visual inspection of aerial images. "Nonresidential" units are then excluded from sampling and data collection. This process of manually classifying sampling units has drawbacks since it is labor intensive, prone to human error, and creates the need for simplifying assumptions during calculation of design-based sampling weights. In this paper, we discuss the development of a deep learning classification model to predict whether aerial images are residential or nonresidential, thus reducing manual labor and eliminating the need for simplifying assumptions. On our test sets, the model performs comparable to a human-level baseline in both Nigeria (94.5% accuracy) and Guatemala (96.4% accuracy), and outperforms baseline machine learning models trained on crowdsourced or remote-sensed geospatial features. Additionally, our findings suggest that this approach can work well in new areas with relatively modest amounts of training data. Gridded population sampling methods like geosampling are becoming increasingly popular in countries with outdated or inaccurate census data because of their timeliness, flexibility, and cost. Using deep learning models directly on satellite images, we provide a novel method for sample frame construction that identifies residential gridded aerial units. In cases where manual classification of satellite images is used to (1) correct for errors in gridded population data sets or (2) classify grids where population estimates are unavailable, this methodology can help reduce annotation burden with comparable quality to human analysts.

Computerised lung sound monitoring to assess effectiveness of chest physiotherapy and secretion removal: a feasibility study.

PubMed

Ntoumenopoulos, G; Glickman, Y

2012-09-01

To explore the feasibility of computerised lung sound monitoring to evaluate secretion removal in intubated and mechanically ventilated adult patients. Before and after observational investigation. Intensive care unit. Fifteen intubated and mechanically ventilated adult patients receiving chest physiotherapy. Chest physiotherapy included combinations of standard closed airway suctioning, saline lavage, postural drainage, chest wall vibrations, manual-assisted cough and/or lung hyperinflation, dependent upon clinical indications. Lung sound amplitude at peak inspiration was assessed using computerised lung sound monitoring. Measurements were performed immediately before and after chest physiotherapy. Data are reported as mean [standard deviation (SD)], mean difference and 95% confidence intervals (CI). Significance testing was not performed due to the small sample size and the exploratory nature of the study. Fifteen patients were included in the study [11 males, four females, mean age 65 (SD 14) years]. The mean total lung sound amplitude at peak inspiration decreased two-fold from 38 (SD 59) units before treatment to 17 (SD 19) units after treatment (mean difference 22, 95% CI of difference -3 to 46). The mean total lung sound amplitude from the lungs of patients with a large amount of secretions (n=9) was over four times 'louder' than the lungs of patients with a moderate or small amount of secretions (n=6) [56 (SD 72) units vs 12 (13) units, respectively; mean difference -44, 95% CI of difference -100 to 11]. The mean total lung sound amplitude decreased in the group of 'loud' right and left lungs (n=15) from 37 (SD 36) units before treatment to 15 (SD 13) units after treatment (mean difference 22, 95% CI of difference 6 to 38). Computerised lung sound monitoring in this small group of patients demonstrated a two-fold decrease in lung sound amplitude following chest physiotherapy. Subgroup analysis also demonstrated decreasing trends in lung sound amplitude in the group of 'loud' lungs following chest physiotherapy. Due to the small sample size and large SDs with high variability in the lung sound amplitude measurements, significance testing was not reported. Further investigation is needed in a larger sample of patients with more accurate measurement of sputum wet weight in order to distinguish between secretion-related effects and changes due to other factors such as airflow rate and pattern. Copyright © 2012 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Size effects on electrical properties of chemically grown zinc oxide nanoparticles

NASA Astrophysics Data System (ADS)

Rathod, K. N.; Joshi, Zalak; Dhruv, Davit; Gadani, Keval; Boricha, Hetal; Joshi, A. D.; Solanki, P. S.; Shah, N. A.

2018-03-01

In the present article, we study ZnO nanoparticles grown by cost effective sol–gel technique for various electrical properties. Structural studies performed by x-ray diffraction (XRD) revealed hexagonal unit cell phase with no observed impurities. Transmission electron microscopy (TEM) and particle size analyzer showed increased average particle size due to agglomeration effect with higher sintering. Dielectric constant (ε‧) decreases with increase in frequency because of the disability of dipoles to follow higher electric field. With higher sintering, dielectric constant reduced owing to the important role of increased formation of oxygen vacancy defects. Universal dielectric response (UDR) was verified by straight line fitting of log (fε‧) versus log (f) plots. All samples exhibit UDR behavior and with higher sintering more contribution from crystal cores. Impedance studies suggest an important role of boundary density while Cole–Cole (Z″ versus Z‧) plots have been studied for the relaxation behavior of the samples. Average normalized change (ANC) in impedance has been studied for all the samples wherein boundaries play an important role. Frequency dependent electrical conductivity has been understood on the basis of Jonscher’s universal power law. Jonscher’s law fits suggest that conduction of charge carrier is possible in the context of correlated barrier hopping (CBH) mechanism for lower temperature sintered sample while for higher temperature sintered ZnO samples, Maxwell–Wagner (M–W) relaxation process has been determined.

Geostatistics and the representative elementary volume of gamma ray tomography attenuation in rocks cores

USGS Publications Warehouse

Vogel, J.R.; Brown, G.O.

2003-01-01

Semivariograms of samples of Culebra Dolomite have been determined at two different resolutions for gamma ray computed tomography images. By fitting models to semivariograms, small-scale and large-scale correlation lengths are determined for four samples. Different semivariogram parameters were found for adjacent cores at both resolutions. Relative elementary volume (REV) concepts are related to the stationarity of the sample. A scale disparity factor is defined and is used to determine sample size required for ergodic stationarity with a specified correlation length. This allows for comparison of geostatistical measures and representative elementary volumes. The modifiable areal unit problem is also addressed and used to determine resolution effects on correlation lengths. By changing resolution, a range of correlation lengths can be determined for the same sample. Comparison of voxel volume to the best-fit model correlation length of a single sample at different resolutions reveals a linear scaling effect. Using this relationship, the range of the point value semivariogram is determined. This is the range approached as the voxel size goes to zero. Finally, these results are compared to the regularization theory of point variables for borehole cores and are found to be a better fit for predicting the volume-averaged range.

Determination of respirable-sized crystalline silica in different ambient environments in the United Kingdom with a mobile high flow rate sampler utilising porous foams to achieve the required particle size selection

NASA Astrophysics Data System (ADS)

Stacey, Peter; Thorpe, Andrew; Roberts, Paul; Butler, Owen

2018-06-01

Inhalation of respirable crystalline silica (RCS) can cause diseases including silicosis and cancer. Levels of RCS close to an emission source are measured but little is known about the wider ambient exposure from industry emissions or natural sources. The aim of this work is to report the RCS concentrations obtained from a variety of ambient environments using a new mobile respirable (PM4) sampler. A mobile battery powered high flow rate (52 L min-1) sampler was developed and evaluated for particulate aerosol sampling employing foams to select the respirable particle size fraction. Sampling was conducted in the United Kingdom at site boundaries surrounding seven urban construction and demolition and five sand quarry sites. These are compared with data from twelve urban aerosol samples and from repeat measurements from a base line study at a single rural site. The 50% particle size penetration (d50) through the foam was 4.3 μm. Over 85% of predict bias values were with ±10% of the respirable convention, which is based on a log normal curve. Results for RCS from all construction and quarry activities are generally low with a 95 th percentile of 11 μg m-3. Eighty percent of results were less than the health benchmark value of 3 μg m-3 used in some states in America for ambient concentrations. The power cutting of brick and the largest demolition activities gave the highest construction levels. Measured urban background RCS levels were typically below 0.3 μg m-3 and the median RCS level, at a rural background location, was 0.02 μg m-3. These reported ambient RCS concentrations may provide useful baseline values to assess the wider impact of fugitive, RCS containing, dust emissions into the wider environment.

Learning Progress in Evolution Theory: Climbing a Ladder or Roaming a Landscape?

ERIC Educational Resources Information Center

Zabel, Jorg; Gropengiesser, Harald

2011-01-01

The objective of this naturalistic study was to explore, model and visualise the learning progress of 13-year-old students in the domain of evolution theory. Data were collected under actual classroom conditions and with a sample size of 107 learners, which followed a teaching unit on Darwin's theory of natural selection. Before and after the…

Intraclass Correlation Coefficients for Obesity Indicators and Energy Balance-Related Behaviors among New York City Public Elementary Schools

ERIC Educational Resources Information Center

Gray, Heewon Lee; Burgermaster, Marissa; Tipton, Elizabeth; Contento, Isobel R.; Koch, Pamela A.; Di Noia, Jennifer

2016-01-01

Objective: Sample size and statistical power calculation should consider clustering effects when schools are the unit of randomization in intervention studies. The objective of the current study was to investigate how student outcomes are clustered within schools in an obesity prevention trial. Method: Baseline data from the Food, Health &…

Predicting Meaningful Employment for Refugees: The Influence of Personal Characteristics and Developmental Factors on Employment Status and Hourly Wages

ERIC Educational Resources Information Center

Codell, Jonathan D.; Hill, Robert D.; Woltz, Dan J.; Gore, Paul A.

2011-01-01

Refugee demographic and developmental variables were evaluated as predictors of employment outcomes following a six-month non-governmental organization (NGO) directed resettlement period. The sample consisted of 85 refugee adults (18 to 54 years) who were resettling in a medium sized urban setting in the western United States. Demographics…

Using small area estimation and Lidar-derived variables for multivariate prediction of forest attributes

Treesearch

F. Mauro; Vicente Monleon; H. Temesgen

2015-01-01

Small area estimation (SAE) techniques have been successfully applied in forest inventories to provide reliable estimates for domains where the sample size is small (i.e. small areas). Previous studies have explored the use of either Area Level or Unit Level Empirical Best Linear Unbiased Predictors (EBLUPs) in a univariate framework, modeling each variable of interest...

Reporting unit size and measurement uncertainty: current Australian practice in clinical chemistry and haematology.

PubMed

Hawkins, Robert C; Badrick, Tony

2015-08-01

In this study we aimed to compare the reporting unit size used by Australian laboratories for routine chemistry and haematology tests to the unit size used by learned authorities and in standard laboratory textbooks and to the justified unit size based on measurement uncertainty (MU) estimates from quality assurance program data. MU was determined from Royal College of Pathologists of Australasia (RCPA) - Australasian Association of Clinical Biochemists (AACB) and RCPA Haematology Quality Assurance Program survey reports. The reporting unit size implicitly suggested in authoritative textbooks, the RCPA Manual, and the General Serum Chemistry program itself was noted. We also used published data on Australian laboratory practices.The best performing laboratories could justify their chemistry unit size for 55% of analytes while comparable figures for the 50% and 90% laboratories were 14% and 8%, respectively. Reporting unit size was justifiable for all laboratories for red cell count, >50% for haemoglobin but only the top 10% for haematocrit. Few, if any, could justify their mean cell volume (MCV) and mean cell haemoglobin concentration (MCHC) reporting unit sizes.The reporting unit size used by many laboratories is not justified by present analytical performance. Using MU estimates to determine the reporting interval for quantitative laboratory results ensures reporting practices match local analytical performance and recognises the inherent error of the measurement process.

Nature's crucible: Manufacturing optical nonlinearities for high resolution, high sensitivity encoding in the compound eye of the fly, Musca domestica

NASA Technical Reports Server (NTRS)

Wilcox, Mike

1993-01-01

The number of pixels per unit area sampling an image determines Nyquist resolution. Therefore, the highest pixel density is the goal. Unfortunately, as reduction in pixel size approaches the wavelength of light, sensitivity is lost and noise increases. Animals face the same problems and have achieved novel solutions. Emulating these solutions offers potentially unlimited sensitivity with detector size approaching the diffraction limit. Once an image is 'captured', cellular preprocessing of information allows extraction of high resolution information from the scene. Computer simulation of this system promises hyperacuity for machine vision.

Micropillar Compression Technique Applied to Micron-Scale Mudstone Elasto-Plastic Deformation

NASA Astrophysics Data System (ADS)

Dewers, T. A.; Boyce, B.; Buchheit, T.; Heath, J. E.; Chidsey, T.; Michael, J.

2010-12-01

Mudstone mechanical testing is often limited by poor core recovery and sample size, preservation and preparation issues, which can lead to sampling bias, damage, and time-dependent effects. A micropillar compression technique, originally developed by Uchic et al. 2004, here is applied to elasto-plastic deformation of small volumes of mudstone, in the range of cubic microns. This study examines behavior of the Gothic shale, the basal unit of the Ismay zone of the Pennsylvanian Paradox Formation and potential shale gas play in southeastern Utah, USA. Precision manufacture of micropillars 5 microns in diameter and 10 microns in length are prepared using an ion-milling method. Characterization of samples is carried out using: dual focused ion - scanning electron beam imaging of nano-scaled pores and distribution of matrix clay and quartz, as well as pore-filling organics; laser scanning confocal (LSCM) 3D imaging of natural fractures; and gas permeability, among other techniques. Compression testing of micropillars under load control is performed using two different nanoindenter techniques. Deformation of 0.5 cm in diameter by 1 cm in length cores is carried out and visualized by a microscope loading stage and laser scanning confocal microscopy. Axisymmetric multistage compression testing and multi-stress path testing is carried out using 2.54 cm plugs. Discussion of results addresses size of representative elementary volumes applicable to continuum-scale mudstone deformation, anisotropy, and size-scale plasticity effects. Other issues include fabrication-induced damage, alignment, and influence of substrate. This work is funded by the US Department of Energy, Office of Basic Energy Sciences. Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.

Genomic analyses of Northern snakehead (Channa argus) populations in North America

PubMed Central

Resh, Carlee A.; Galaska, Matthew P.

2018-01-01

Background The introduction of northern snakehead (Channa argus; Anabantiformes: Channidae) and their subsequent expansion is one of many problematic biological invasions in the United States. This harmful aquatic invasive species has become established in various parts of the eastern United States, including the Potomac River basin, and has recently become established in the Mississippi River basin in Arkansas. Effective management of C. argus and prevention of its further spread depends upon knowledge of current population structure in the United States. Methods Novel methods for invasive species using whole genomic scans provide unprecedented levels of data, which are able to investigate fine scale differences between and within populations of organisms. In this study, we utilize 2b-RAD genomic sequencing to recover 1,007 single-nucleotide polymorphism (SNP) loci from genomic DNA extracted from 165 C. argus individuals: 147 individuals sampled along the East Coast of the United States and 18 individuals sampled throughout Arkansas. Results Analysis of those SNP loci help to resolve existing population structure and recover five genetically distinct populations of C. argus in the United States. Additionally, information from the SNP loci enable us to begin to calculate the long-term effective population size ranges of this harmful aquatic invasive species. We estimate long-term Ne to be 1,840,000–18,400,000 for the Upper Hudson River basin, 4,537,500–45,375,000 for the Lower Hudson River basin, 3,422,500–34,225,000 for the Potomac River basin, 2,715,000–7,150,000 for Philadelphia, and 2,580,000–25,800,000 for Arkansas populations. Discussion and Conclusions This work provides evidence for the presence of more genetic populations than previously estimated and estimates population size, showing the invasive potential of C. argus in the United States. The valuable information gained from this study will allow effective management of the existing populations to avoid expansion and possibly enable future eradication efforts. PMID:29637024

Genomic analyses of Northern snakehead (Channa argus) populations in North America.

PubMed

Resh, Carlee A; Galaska, Matthew P; Mahon, Andrew R

2018-01-01

The introduction of northern snakehead ( Channa argus ; Anabantiformes: Channidae) and their subsequent expansion is one of many problematic biological invasions in the United States. This harmful aquatic invasive species has become established in various parts of the eastern United States, including the Potomac River basin, and has recently become established in the Mississippi River basin in Arkansas. Effective management of C. argus and prevention of its further spread depends upon knowledge of current population structure in the United States. Novel methods for invasive species using whole genomic scans provide unprecedented levels of data, which are able to investigate fine scale differences between and within populations of organisms. In this study, we utilize 2b-RAD genomic sequencing to recover 1,007 single-nucleotide polymorphism (SNP) loci from genomic DNA extracted from 165 C. argus individuals: 147 individuals sampled along the East Coast of the United States and 18 individuals sampled throughout Arkansas. Analysis of those SNP loci help to resolve existing population structure and recover five genetically distinct populations of C. argus in the United States. Additionally, information from the SNP loci enable us to begin to calculate the long-term effective population size ranges of this harmful aquatic invasive species. We estimate long-term N e to be 1,840,000-18,400,000 for the Upper Hudson River basin, 4,537,500-45,375,000 for the Lower Hudson River basin, 3,422,500-34,225,000 for the Potomac River basin, 2,715,000-7,150,000 for Philadelphia, and 2,580,000-25,800,000 for Arkansas populations. This work provides evidence for the presence of more genetic populations than previously estimated and estimates population size, showing the invasive potential of C. argus in the United States. The valuable information gained from this study will allow effective management of the existing populations to avoid expansion and possibly enable future eradication efforts.

Preliminary report on deposit models for sand and gravel in the Cache la Poudre River valley

USGS Publications Warehouse

Langer, W.H.; Lindsey, D.A.

1999-01-01

The stratigraphy, sedimentary features, and physical characteristics of gravel deposits in the Cache la Poudre River valley were studied to establish geologic models for these deposits. Because most of the gravel mined in the valley is beneath the low terraces and floodplain, the quality of these deposits for aggregate was studied in detail at eight sites in a 25.5-mile reach between Fort Collins and Greeley, Colorado. Aggregate quality was determined by field and laboratory measurements on samples collected under a consistent sampling plan. The Broadway terrace is underlain by Pleistocene alluvium and, at some places, by fine-grained wind-blown deposits. The Piney Creek terrace, low terraces, and floodplain are primarily underlain by Holocene alluvium. Pleistocene alluvium may underlie these terraces at isolated locations along the river. Gravels beneath the Piney Creek terrace, low terraces, and floodplain are divisible into two units that are poorly distinguishable at the upstream end of the study area, but are readily distinguishable about 7 miles downstream. Where distinguished, the two gravel units are separated by a sharp, locally erosional, contact. The upper gravel is probably of Holocene age, but the lower gravel is considered to be Holocene and Pleistocene. The primary variation in particle size of the gravels beneath the floodplain and low terraces of the Cache la Poudre River valley is the downstream decrease in the proportion of particles measuring 3/4 inch and larger. Above Fort Collins, about 60 pct of the gravel collects on the 3/4 inch sieve, whereas about 50 pct of gravel collects on the same sieve size at Greeley. For 1.5-inch sieves, the corresponding values are about 50 pct for Fort Collins and only about 30 pct for Greeley. Local differences in particle size and sorting between the upper and lower gravel units were observed in the field, but only the coarsest particle sizes appear to have been concentrated in the lower unit. Field measurements of aggregate quality, pebble lithology, and shape show little significant downstream variation. Pebble lithology is about 25 percent granite; 48 percent pegmatite; 5-7 percent each of gneiss, quartz, and quartzite; and minor amounts of diabase, schist, volcanic porphyry, and sandstone. Among the rock types, only the volcanic porphyries might be reactive with Portland cement. Pebble shape is dominantly equidimensional with a tendency to form thick, disc-shaped particles. Disc-shaped and spherical particles comprise about 39 percent and 31 percent of the pebble-size fraction, respectively. Rod and blade shapes comprise about 18 and 12 percent of the pebble-size fraction, respectively. The relatively large proportion of equidimensional particles in the Cache la Poudre may be due to the small proportion of layered gneiss in gravel. Pebbles having axial ratios less than 0.5, which might be structurally weak, are rare. The two gravel units show subtle local differences and evidence for derivation of the younger gravel from the older gravel. At many sites, the upper gravel unit tends to contain more quartz plus quartzite, has poorer physical quality, and contains more angular pebbles than the lower gravel. Weathering, followed by transport in the river, might be expected to concentrate quartz and quartzite, degrade physical quality, and break pebbles into angular fragments. This conclusion is consistent with local evidence of an erosional contact between the two gravel units.

Synthesis of Mn doped ZnS nanocrystals: Crystallographic and morphological study

NASA Astrophysics Data System (ADS)

Shaikh, Azharuddin Z.; Shirsath, Narendra B.; Sonawane, Prabhakar S.

2018-05-01

The influence of doping concentration on the physical properties of ZnS nanocrystals synthesized using coprecipitation method at room temperature is reported in this paper. In particular, we have studied the structural properties of Zn1-xMnxS where (x=0.01, 0.03, 0.05) by X-ray diffraction. X-ray peak broadening analysis used to calculate the crystalline sizes, lattice parameters, number of unit cell per particle and volume of unit cell. Crystalline ZnS with a cubic structure is confirmed by XRD results. The grain size of pure and Mn doped samples were found in the range of 7nm to 9nm. All the physical parameters of cubic ZnS nanocrystals were calculated are similar with standard values. The scanning electron microscope (SEM) which revealed that the synthesized nanocrystals are well-crystalline and possessing cubic phase.

Criteria for the recognition and correlation of sandstone units in the Precambrian and Paleozoic-Mesozoic clastic sequence in the near east

NASA Astrophysics Data System (ADS)

Weissbrod, T.; Perath, I.

A systematic study of the Precambrian and Paleozoic-Mesozoic clastic sequences (Nubian Sandstone) in Israel and Sinai, and a comparative analysis of its stratigraphy in neighbouring countries, has shown that besides the conventional criteria of subdivision (lithology, field appearance, photogeological features, fossil content), additional criteria can be applied, which singly or in mutual conjuction enable the recognition of widespread units and boundaries. These criteria show lateral constancy, and recurrence of a similar vertical sequence over great distances, and are therefore acceptable for the identification of synchronous, region-wide sedimentary units (and consequently, major unconformities). They also enable, once the units are established, to identify detached (not in situ) samples, samples from isolated or discontinous outcrops, borehole material or archive material. The following rock properties were tested and found to be usefuls in stratigraphic interpretation, throughout large distribution areas of the clastic sequence: Landscape, which is basically the response of a particular textural-chemic al aggregate to atmospheric weathering. Characteristic outcrop feature — styles of roundness or massivity, fissuring or fliatin, slope profile, bedding — express a basic uniformity of these platform-type clastics. Colors are often stratigraphically constant over hundreds of kilometers, through various climates and topographies, and express some intrinsic unity of the rock bodies. Grain size and sorting, when cross-plotted, enable to differentiate existing unit. The method requires the analysis of representative numbers of samples. Vertical trends of median grain size and sorting show reversals, typically across unconformities. Feldstar content diminishes from 15-50% in Precambrian-Paleozoic rocks to a mere 5% or less in Mesozoic sandstones — a distinctive regionwide time trend. Dominance of certain feldstar types characterizes Precambrian and Paleozoic units. Clay minerals, though subordinate, characterize certain units. Illite is usually the dominant clay mineral in the Precambrain-Paleozoic sediments, showing different degress of crystallization in different units. Kaolinite is the main, often the only clay mineral in Mesozoic units. Heavy minerals, whose species spectra reflect on parent rock and provenance terrain and whose differential response to degradation points to the sedimentary history of the deposit, show certain vertical regularities, such as the abrupt disappearance of species or whole assemblages at certain levels, indicating unconformities. Trace metals, which in places reach ore concentrations (e.g. copper), are often extensive, though of well-defined vertical distribution. They express adsorptive capacity of specific widespread lithologies, enabling the discrimination of units. Even though each of these criteria is not always by itself diagnostic, they may in conjuction with one or more other criteria amount to a petrographic fingerprint that enables fairly accurate identification of the age interval of the unit, and its relation both to the regional and the local stratigraphic sequence.

Effect of high pressure processing on dispersive and aggregative properties of almond milk.

PubMed

Dhakal, Santosh; Giusti, M Monica; Balasubramaniam, V M

2016-08-01

A study was conducted to investigate the impact of high pressure (450 and 600 MPa at 30 °C) and thermal (72, 85 and 99 °C at 0.1 MPa) treatments on dispersive and aggregative characteristics of almond milk. Experiments were conducted using a kinetic pressure testing unit and water bath. Particle size distribution, microstructure, UV absorption spectra, pH and color changes of processed and unprocessed samples were analyzed. Raw almond milk represented the mono model particle size distribution with average particle diameters of 2 to 3 µm. Thermal or pressure treatment of almond milk shifted the particle size distribution towards right and increased particle size by five- to six-fold. Micrographs confirmed that both the treatments increased particle size due to aggregation of macromolecules. Pressure treatment produced relatively more and larger aggregates than those produced by heat treated samples. The apparent aggregation rate constant for 450 MPa and 600 MPa processed samples were k450MPa,30°C  = 0.0058 s(-1) and k600MPa,30°C  = 0.0095 s(-1) respectively. This study showed that dispersive and aggregative properties of high pressure and heat-treated almond milk were different due to differences in protein denaturation, particles coagulation and aggregates morphological characteristics. Knowledge gained from the study will help food processors to formulate novel plant-based beverages treated with high pressure. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

Insights into bioassessment of marine pollution using body-size distinctness of planktonic ciliates based on a modified trait hierarchy.

PubMed

Xu, Henglong; Jiang, Yong; Xu, Guangjian

2016-06-15

Based on a modified trait hierarchy of body-size units, the feasibility for bioassessment of water pollution using body-size distinctness of planktonic ciliates was studied in a semi-enclosed bay, northern China. An annual dataset was collected at five sampling stations within a gradient of heavy metal contaminants. Results showed that: (1) in terms of probability density, the body-size spectra of the ciliates represented significant differences among the five stations; (2) bootstrap average analysis demonstrated a spatial variation in body-size rank patterns in response to pollution stress due to heavy metals; and (3) the average body-size distinctness (Δz(+)) and variation in body-size distinctness (Λz(+)), based on the modified trait hierarchy, revealed a clear departure pattern from the expected body-size spectra in areas with pollutants. These results suggest that the body-size diversity measures based on the modified trait hierarchy of the ciliates may be used as a potential indicator of marine pollution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Prevalence, level and distribution of Salmonella in shipments of imported capsicum and sesame seed spice offered for entry to the United States: observations and modeling results.

PubMed

Van Doren, Jane M; Blodgett, Robert J; Pouillot, Régis; Westerman, Ann; Kleinmeier, Daria; Ziobro, George C; Ma, Yinqing; Hammack, Thomas S; Gill, Vikas; Muckenfuss, Martin F; Fabbri, Linda

2013-12-01

In response to increased concerns about spice safety, the United States Food and Drug Administration (FDA) initiated research to characterize the prevalence and levels of Salmonella in imported spices. 299 imported dried capsicum shipments and 233 imported sesame seed shipments offered for entry to the United States were sampled. Observed Salmonella shipment prevalence was 3.3% (1500 g examined; 95% CI 1.6-6.1%) for capsicum and 9.9% (1500 g; 95% Confidence Interval (CI) 6.3-14%) for sesame seed. Within shipment contamination was not inconsistent with a Poisson distribution. Shipment mean Salmonella level estimates among contaminated shipments ranged from 6 × 10(-4) to 0.09 (capsicum) or 6 × 10(-4) to 0.04 (sesame seed) MPN/g. A gamma-Poisson model provided the best fit to observed data for both imported shipments of capsicum and imported shipments of sesame seed sampled in this study among the six parametric models considered. Shipment mean levels of Salmonella vary widely between shipments; many contaminated shipments contain low levels of contamination. Examination of sampling plan efficacy for identifying contaminated spice shipments from these distributions indicates that sample size of spice examined is critical. Sampling protocols examining 25 g samples are predicted to be able to identify a small fraction of contaminated shipments of imported capsicum or sesame seeds. Published by Elsevier Ltd.

OLT-centralized sampling frequency offset compensation scheme for OFDM-PON.

PubMed

Chen, Ming; Zhou, Hui; Zheng, Zhiwei; Deng, Rui; Chen, Qinghui; Peng, Miao; Liu, Cuiwei; He, Jing; Chen, Lin; Tang, Xionggui

2017-08-07

We propose an optical line terminal (OLT)-centralized sampling frequency offset (SFO) compensation scheme for adaptively-modulated OFDM-PON systems. By using the proposed SFO scheme, the phase rotation and inter-symbol interference (ISI) caused by SFOs between OLT and multiple optical network units (ONUs) can be centrally compensated in the OLT, which reduces the complexity of ONUs. Firstly, the optimal fast Fourier transform (FFT) size is identified in the intensity-modulated and direct-detection (IMDD) OFDM system in the presence of SFO. Then, the proposed SFO compensation scheme including phase rotation modulation (PRM) and length-adaptive OFDM frame has been experimentally demonstrated in the downlink transmission of an adaptively modulated optical OFDM with the optimal FFT size. The experimental results show that up to ± 300 ppm SFO can be successfully compensated without introducing any receiver performance penalties.

Origin of magnetization in lunar breccias - An example of thermal overprinting

NASA Technical Reports Server (NTRS)

Gose, W. A.; Strangway, D. W.; Pearce, G. W.

1978-01-01

Twenty six samples from seven hand specimens, collected from the station 6 boulder at the Apollo 17 landing site, were studied magnetically. The boulder is a breccia consisting of three lithologic units distinguished by their clast population. The direction of magnetization of samples from unit B which is almost devoid of large clasts cluster fairly well after alternating field demagnetization. Samples from unit C which is characterized by abundant large clasts up to 1 m in size do not contain a uniform direction of magnetization but the distribution is not random. Based on these data we propose that the natural remanent magnetization (NRM) in these breccias is the vector sum of two magnetizations, a pre-impact magnetization and a partial thermoremanence acquired during breccia formation. The relative contribution of the two components is controlled by the thermal history of the ejecta, which in turn is determined by its clast population. Depending on the clast population, the NRM can be a total thermoremanence, a partial thermoremanence plus a pre-impact magnetization, or a pre-impact magnetization. This model of thermal overprinting might be applicable to all lunar breccias of medium and higher metamorphic grade.

A Stratigraphic, Granulometric, and Textural Comparison of recent pyroclastic density current deposits exposed at West Island and Burr Point, Augustine Volcano, Alaska

NASA Astrophysics Data System (ADS)

Rath, C. A.; Browne, B. L.

2011-12-01

Augustine Volcano (Alaska) is the most active volcano in the eastern Aleutian Islands, with 6 violent eruptions over the past 200 years and at least 12 catastrophic debris-avalanche deposits over the past ~2,000 years. The frequency and destructive nature of these eruptions combined with the proximity of Augustine Volcano to commercial ports and populated areas represents a significant hazard to the Cook Inlet region of Alaska. The focus of this study examines the relationship between debris-avalanche events and the subsequent emplacement of pyroclastic density currents by comparing the stratigraphic, granulometric, and petrographic characteristics of pyroclastic deposits emplaced following the 1883 A.D. Burr Point debris-avalanche and those emplaced following the ~370 14C yr B.P. West Island debris-avalanche. Data from this study combines grain size and componentry analysis of pyroclastic deposits with density, textural, and compositional analysis of juvenile clasts contained in the pyroclastic deposits. The 1883 A.D. Burr Point pyroclastic unit immediately overlies the 1883 debris avalanche deposit and underlies the 1912 Katmai ash. It ranges in thickness from 4 to 48 cm and consists of fine to medium sand-sized particles and coarser fragments of andesite. In places, this unit is normally graded and exhibits cross-bedding. Many of these samples are fines-enriched, with sorting coefficients ranging from -0.1 to 1.9 and median grain size ranging from 0.1 to 2.4 mm. The ~370 14C yr B.P. West Island pyroclastic unit is sandwiched between the underlying West Island debris-avalanche deposit and the overlying 1912 Katmai Ash deposit, and at times a fine-grained gray ash originating from the 1883 eruption. West Island pyroclastic deposit is sand to coarse-sand-sized and either normally graded or massive with sorting coefficients ranging from 0.9 to 2.8 and median grain sizes ranging from 0.4 to 2.6 mm. Some samples display a bimodal distribution of grain sizes, while most display a fines-depleted distribution. Juvenile andesite clasts exist as either subrounded to subangular fragments with abundant vesicles that range in color from white to brown or dense clasts characterized by their porphyritic and glassy texture. Samples from neither eruption correlate in sorting or grain size with distance from the vent. Stratigraphic and granulometric data suggest differences in the manner in which these two pyroclastic density currents traveled and groundmass textures are interpreted as recording differences in how the two magmas ascended and erupted, whereas juvenile Burr Point clasts resemble other lava flows erupted from Augustine Volcano, vesicular and glassy juvenile West Island clasts bear resemblance to clasts derived from so-called "blast-generated" pyroclastic density deposits at Mt. St. Helens in 1980 and Bezymianny in 1956.

The use of mini-samples in palaeomagnetism

NASA Astrophysics Data System (ADS)

Böhnel, Harald; Michalk, Daniel; Nowaczyk, Norbert; Naranjo, Gildardo Gonzalez

2009-10-01

Rock cores of ~25 mm diameter are widely used in palaeomagnetism. Occasionally smaller diameters have been used as well which represents distinct advantages in terms of throughput, weight of equipment and core collections. How their orientation precision compares to 25 mm cores, however, has not been evaluated in detail before. Here we compare the site mean directions and their statistical parameters for 12 lava flows sampled with 25 mm cores (standard samples, typically 8 cores per site) and with 12 mm drill cores (mini-samples, typically 14 cores per site). The site-mean directions for both sample sizes appear to be indistinguishable in most cases. For the mini-samples, site dispersion parameters k on average are slightly lower than for the standard samples reflecting their larger orienting and measurement errors. Applying the Wilcoxon signed-rank test the probability that k or α95 have the same distribution for both sizes is acceptable only at the 17.4 or 66.3 per cent level, respectively. The larger mini-core numbers per site appears to outweigh the lower k values yielding also slightly smaller confidence limits α95. Further, both k and α95 are less variable for mini-samples than for standard size samples. This is interpreted also to result from the larger number of mini-samples per site, which better averages out the detrimental effect of undetected abnormal remanence directions. Sampling of volcanic rocks with mini-samples therefore does not present a disadvantage in terms of the overall obtainable uncertainty of site mean directions. Apart from this, mini-samples do present clear advantages during the field work, as about twice the number of drill cores can be recovered compared to 25 mm cores, and the sampled rock unit is then more widely covered, which reduces the contribution of natural random errors produced, for example, by fractures, cooling joints, and palaeofield inhomogeneities. Mini-samples may be processed faster in the laboratory, which is of particular advantage when carrying out palaeointensity experiments.

Hygroscopicity- and Size-Resolved Measurements of Submicron Aerosol on the East Coast of the United States

NASA Astrophysics Data System (ADS)

Phillips, B. N.; Royalty, T. M.; Dawson, K. W.; Reed, R.; Petters, M. D.; Meskhidze, N.

2018-02-01

Atmospheric measurements of aerosol size-resolved hygroscopicity at submicron sizes are carried out at the United States Army Corps of Engineers Field Research Facility in Duck, North Carolina. The scientific aim of the field deployment is to gain improved understanding of the springtime advection of aerosols from the East Coast of the United States over the Atlantic and help to constrain assessments of anthropogenic particle contributions to the marine boundary layer aerosol budget. Air mass back trajectories show that the aerosol sampled at the coast is largely of continental origin that either gets transported directly from the land or spends some time over the Atlantic Ocean. Aerosol size-resolved hygroscopicity measurements are consistent with air masses of both continental and marine background that are heavily influenced by the continental outflow. Aitken and accumulation mode mean diameters range from 49.1 ± 1.7 nm to 66.9 ± 0.8 nm and 142.8 ± 1.1 nm to 155.0 ± 2.8 nm, respectively. Hygroscopicity distributions for 96 nm, 188 nm, and 284 nm dry-sized particles show the mode hygroscopicity parameter range from 0.20 ± 0.01 to 0.54 ± 0.03, suggesting the presence of anthropogenic aerosols. We have used the method described by Royalty et al. (2017) to decompose the hygroscopicity distributions into three distinct classes based on the ambient aerosol hygroscopic properties relative to the hygroscopic properties of a reference compound. The method shows that continental outflow heavily influences aerosol chemical and physical properties at the East Coast, with hygroscopicities of submicron aerosols consistent with sulfate-containing species (62% to 83%), with small contributions from sodium- and carbon-containing particles (up to 9% and 37%, respectively).

Impact of organizational policies and practices on workplace injuries in a hospital setting.

PubMed

Tveito, T H; Sembajwe, G; Boden, L I; Dennerlein, J T; Wagner, G R; Kenwood, C; Stoddard, A M; Reme, S E; Hopcia, K; Hashimoto, D; Shaw, W S; Sorensen, G

2014-08-01

This study aimed to assess relationships between perceptions of organizational practices and policies (OPP), social support, and injury rates among workers in hospital units. A total of 1230 hospital workers provided survey data on OPP, job flexibility, and social support. Demographic data and unit injury rates were collected from the hospitals' administrative databases. Injury rates were lower in units where workers reported higher OPP scores and high social support. These relationships were mainly observed among registered nurses. Registered nurses perceived coworker support and OPP as less satisfactory than patient care associates (PCAs). Nevertheless, because of the low number of PCAs at each unit, results for the PCAs are preliminary and should be further researched in future studies with larger sample sizes. Employers aiming to reduce injuries in hospitals could focus on good OPP and supportive work environment.

A simple method to recover Norovirus from fresh produce with large sample size by using histo-blood group antigens conjugated magnetic beads re-circulating immunomagnetic separation system

USDA-ARS?s Scientific Manuscript database

Noroviruses (NoV) annually cause millions of cases of gastrointestinal disease in the United States. Although NoV outbreaks are generally associated with raw shellfish, particularly oysters, outbreaks have also been known to occur from other common-source food-borne vehicles such as lettuce, frozen...

POLYBROMINATED DIPHENYL ETHER (PBDE) LEVELS IN AN EXPANDED MARKET BASKET SURVEY OF UNITED STATES (U.S) FOOD AND ESTIMATED PBDE DIETARY INTAKE BY AGE AND SEX

EPA Science Inventory

This study enhances a previously reported U.S. market basket survey of food for polybrominated diphenyl ether (PBDE) levels with a larger sample size of 62 individual analyses for 13 congeners. In addition, it estimates levels of PBDE intake from food by gender and age for the U....

Flotation Experiments with Seafloor-Sampled Pumice Lapilli, IODP 340 - Preliminary Results

NASA Astrophysics Data System (ADS)

Jutzeler, M.; Manga, M.; White, J. D.

2012-12-01

A 1.25-m-thick, unconsolidated unit of pink pumice lapilli was recovered at site U1396, IODP expedition 340. The drilling site lies at the top of an entirely submarine ridge in a back-arc of the Lesser Antilles volcanic arc, 35 km offshore from Montserrat Island. The unit was recovered from 122 m below sea floor, at a water depth of ~800 m. Preliminary biostratigraphy and paleomagnetic analysis yield an age of ~4 Ma. This age is much older than any rocks from the island of Montserrat, suggesting that the pumice lapilli unit may have submarine origin. In addition, the pumice lapilli unit has a grading and sorting that does not match conventional eruption-fed products from air-fall or turbidity currents. The pumice lapilli unit was recovered at two holes 40 m apart, and is identical in the two cores. The change in grain size in the stratigraphy of the unit defines a weak stratification. The pumice lapilli unit comprises two main sub-units, with four ash-rich intervals. The lower sub-unit is ~20 cm thick, framework-supported, and dominated by angular white tube-pumice lapilli (2-4 mm); dense lithic clasts (2 mm) are concentrated at the base of this sub-unit. The upper sub-unit is 1 m thick, and mostly composed of angular to sub-angular, white tube pumice lapilli (average 4 mm, max 32 mm), in a pink ash matrix. The ash is chiefly composed of micro-pumice clasts, feldspar and ferromagnesian crystal fragments, glass shards, and lithic clasts that commonly contain fresh pyrite. Three main parameters constrain the floatability of pumice clasts in water: vesicularity, clast size and shape, and clast temperature. The connected vesicularity of the pumice clasts was measured by subtracting the weight of dry pumice clasts from their water-saturated weight, and by functional stereology applied on SEM images. Clast-size distribution and clast shape were measured by particle size analyzer (CILAS) and sieving. We carried out pyroclast flotation and settling experiments in an attempt to find the best eruption and transport scenarios that match the distinctive grading and sorting of the natural unit. Hot and cold pumice clasts picked from every 3 cm in the entire stratigraphy were left to sink in water. Floating time and discrete sinking time were calculated for each pumice clast. To document different behavior in the ingestion of water by the pumice lapilli, two temperatures were used in the experiments: room temperature and ~500°C. These experiments narrowed the possible scenarios of eruption and transport processes by determining the time elapsed between eruption and final deposition of the pink pumice lapilli unit.

Synergistic effect of ultrasonic pre-treatment combined with UV irradiation for secondary effluent disinfection.

PubMed

Jin, Xin; Li, Zifu; Xie, Lanlan; Zhao, Yuan; Wang, Tingting

2013-11-01

The ultraviolet (UV) disinfection efficiency is often affected by suspended solids (SS). Given their high concentration or large particle size, SS can scatter UV light and provide shielding for bacteria. Thus, ultrasound is often employed as a pre-treatment process to improve UV disinfection. This work investigated the synergistic effect of ultrasound combined with UV for secondary effluent disinfection. Bench-scale experiments were conducted in using samples obtained from secondary sedimentation tanks. These tanks belonged to three wastewater treatment plants in Beijing that use different kinds of biological treatment methods. Several parameters may contribute to the changes in the efficiency of ultrasound and UV disinfection. Thus, the frequency and energy density of ultrasound, as well as the SS, were investigated. Results demonstrated that samples which have relatively higher SS concentrations or higher percentages of larger particles have less disinfection efficiency using UV disinfection alone. However, the presence of ultrasound could improve the disinfection efficiency because it has synergistic effect. Changes in the particle size distribution and SS concentration notably affected the efficiency of UV disinfection. The efficiency of Escherichia coli elimination can be decreased by 1.2 log units as the SS concentration increases from 16.9 mg/l to 25.4 mg/l at a UV energy density of 40 mJ/cm(2). UV disinfection alone reduced the E. coli population by 3.4 log units. However, the synergistic disinfection of ultrasound and UV could reach 5.4 log units during the reduction of E. coli at a 40 kHz frequency and an energy density of 2.64 kJ/l. The additional synergistic effect is 1.1 log units. Copyright © 2013 Elsevier B.V. All rights reserved.

On the influence of crystal size and wavelength on native SAD phasing.

PubMed

Liebschner, Dorothee; Yamada, Yusuke; Matsugaki, Naohiro; Senda, Miki; Senda, Toshiya

2016-06-01

Native SAD is an emerging phasing technique that uses the anomalous signal of native heavy atoms to obtain crystallographic phases. The method does not require specific sample preparation to add anomalous scatterers, as the light atoms contained in the native sample are used as marker atoms. The most abundant anomalous scatterer used for native SAD, which is present in almost all proteins, is sulfur. However, the absorption edge of sulfur is at low energy (2.472 keV = 5.016 Å), which makes it challenging to carry out native SAD phasing experiments as most synchrotron beamlines are optimized for shorter wavelength ranges where the anomalous signal of sulfur is weak; for longer wavelengths, which produce larger anomalous differences, the absorption of X-rays by the sample, solvent, loop and surrounding medium (e.g. air) increases tremendously. Therefore, a compromise has to be found between measuring strong anomalous signal and minimizing absorption. It was thus hypothesized that shorter wavelengths should be used for large crystals and longer wavelengths for small crystals, but no thorough experimental analyses have been reported to date. To study the influence of crystal size and wavelength, native SAD experiments were carried out at different wavelengths (1.9 and 2.7 Å with a helium cone; 3.0 and 3.3 Å with a helium chamber) using lysozyme and ferredoxin reductase crystals of various sizes. For the tested crystals, the results suggest that larger sample sizes do not have a detrimental effect on native SAD data and that long wavelengths give a clear advantage with small samples compared with short wavelengths. The resolution dependency of substructure determination was analyzed and showed that high-symmetry crystals with small unit cells require higher resolution for the successful placement of heavy atoms.

Measuring β-diversity with species abundance data.

PubMed

Barwell, Louise J; Isaac, Nick J B; Kunin, William E

2015-07-01

In 2003, 24 presence-absence β-diversity metrics were reviewed and a number of trade-offs and redundancies identified. We present a parallel investigation into the performance of abundance-based metrics of β-diversity. β-diversity is a multi-faceted concept, central to spatial ecology. There are multiple metrics available to quantify it: the choice of metric is an important decision. We test 16 conceptual properties and two sampling properties of a β-diversity metric: metrics should be 1) independent of α-diversity and 2) cumulative along a gradient of species turnover. Similarity should be 3) probabilistic when assemblages are independently and identically distributed. Metrics should have 4) a minimum of zero and increase monotonically with the degree of 5) species turnover, 6) decoupling of species ranks and 7) evenness differences. However, complete species turnover should always generate greater values of β than extreme 8) rank shifts or 9) evenness differences. Metrics should 10) have a fixed upper limit, 11) symmetry (βA,B  = βB,A ), 12) double-zero asymmetry for double absences and double presences and 13) not decrease in a series of nested assemblages. Additionally, metrics should be independent of 14) species replication 15) the units of abundance and 16) differences in total abundance between sampling units. When samples are used to infer β-diversity, metrics should be 1) independent of sample sizes and 2) independent of unequal sample sizes. We test 29 metrics for these properties and five 'personality' properties. Thirteen metrics were outperformed or equalled across all conceptual and sampling properties. Differences in sensitivity to species' abundance lead to a performance trade-off between sample size bias and the ability to detect turnover among rare species. In general, abundance-based metrics are substantially less biased in the face of undersampling, although the presence-absence metric, βsim , performed well overall. Only βBaselga R turn , βBaselga B-C turn and βsim measured purely species turnover and were independent of nestedness. Among the other metrics, sensitivity to nestedness varied >4-fold. Our results indicate large amounts of redundancy among existing β-diversity metrics, whilst the estimation of unseen shared and unshared species is lacking and should be addressed in the design of new abundance-based metrics. © 2015 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Geomorphology and Geology of the Southwestern Margaritifer Sinus and Argyre Regions of Mars. Part 2: Crater Size-frequency Distribution Curves and Geomorphic Unit Ages

NASA Technical Reports Server (NTRS)

Parker, T. J.; Pieri, D. C.

1985-01-01

In assessing the relative ages of the geomorphic/geologic units, crater counts of the entire unit or nearly the entire unit were made and summed in order to get a more accurate value than obtainable by counts of isolated sections of each unit. Cumulative size-frequency counts show some interesting relationships. Most of the units show two distinct crater populations with a flattening out of the distribution curve at and below 10 km diameter craters. Above this crater size the curves for the different units diverge most notably. In general, the variance may reflect the relative ages of these units. At times, however, in the larger crater size range, these curves can overlap and cross on another. Also the error bars at these larger sizes are broader (and thus more suspect), since counts of larger craters show more scatter, whereas the unit areas remain constant. Occasional clusters of relatively large craters within a given unit, particularly one of limited areal extent, can affect the curve so that the unit might seem to be older than units which it overlies or cuts.

Advanced hierarchical distance sampling

USGS Publications Warehouse

Royle, Andy

2016-01-01

In this chapter, we cover a number of important extensions of the basic hierarchical distance-sampling (HDS) framework from Chapter 8. First, we discuss the inclusion of “individual covariates,” such as group size, in the HDS model. This is important in many surveys where animals form natural groups that are the primary observation unit, with the size of the group expected to have some influence on detectability. We also discuss HDS integrated with time-removal and double-observer or capture-recapture sampling. These “combined protocols” can be formulated as HDS models with individual covariates, and thus they have a commonality with HDS models involving group structure (group size being just another individual covariate). We cover several varieties of open-population HDS models that accommodate population dynamics. On one end of the spectrum, we cover models that allow replicate distance sampling surveys within a year, which estimate abundance relative to availability and temporary emigration through time. We consider a robust design version of that model. We then consider models with explicit dynamics based on the Dail and Madsen (2011) model and the work of Sollmann et al. (2015). The final major theme of this chapter is relatively newly developed spatial distance sampling models that accommodate explicit models describing the spatial distribution of individuals known as Point Process models. We provide novel formulations of spatial DS and HDS models in this chapter, including implementations of those models in the unmarked package using a hack of the pcount function for N-mixture models.

Sample size planning for composite reliability coefficients: accuracy in parameter estimation via narrow confidence intervals.

PubMed

Terry, Leann; Kelley, Ken

2012-11-01

Composite measures play an important role in psychology and related disciplines. Composite measures almost always have error. Correspondingly, it is important to understand the reliability of the scores from any particular composite measure. However, the point estimates of the reliability of composite measures are fallible and thus all such point estimates should be accompanied by a confidence interval. When confidence intervals are wide, there is much uncertainty in the population value of the reliability coefficient. Given the importance of reporting confidence intervals for estimates of reliability, coupled with the undesirability of wide confidence intervals, we develop methods that allow researchers to plan sample size in order to obtain narrow confidence intervals for population reliability coefficients. We first discuss composite reliability coefficients and then provide a discussion on confidence interval formation for the corresponding population value. Using the accuracy in parameter estimation approach, we develop two methods to obtain accurate estimates of reliability by planning sample size. The first method provides a way to plan sample size so that the expected confidence interval width for the population reliability coefficient is sufficiently narrow. The second method ensures that the confidence interval width will be sufficiently narrow with some desired degree of assurance (e.g., 99% assurance that the 95% confidence interval for the population reliability coefficient will be less than W units wide). The effectiveness of our methods was verified with Monte Carlo simulation studies. We demonstrate how to easily implement the methods with easy-to-use and freely available software. ©2011 The British Psychological Society.

Recruitment and retention of participants in randomised controlled trials: a review of trials funded and published by the United Kingdom Health Technology Assessment Programme.

PubMed

Walters, Stephen J; Bonacho Dos Anjos Henriques-Cadby, Inês; Bortolami, Oscar; Flight, Laura; Hind, Daniel; Jacques, Richard M; Knox, Christopher; Nadin, Ben; Rothwell, Joanne; Surtees, Michael; Julious, Steven A

2017-03-20

Substantial amounts of public funds are invested in health research worldwide. Publicly funded randomised controlled trials (RCTs) often recruit participants at a slower than anticipated rate. Many trials fail to reach their planned sample size within the envisaged trial timescale and trial funding envelope. To review the consent, recruitment and retention rates for single and multicentre randomised control trials funded and published by the UK's National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme. HTA reports of individually randomised single or multicentre RCTs published from the start of 2004 to the end of April 2016 were reviewed. Information was extracted, relating to the trial characteristics, sample size, recruitment and retention by two independent reviewers. Target sample size and whether it was achieved; recruitment rates (number of participants recruited per centre per month) and retention rates (randomised participants retained and assessed with valid primary outcome data). This review identified 151 individually RCTs from 787 NIHR HTA reports. The final recruitment target sample size was achieved in 56% (85/151) of the RCTs and more than 80% of the final target sample size was achieved for 79% of the RCTs (119/151). The median recruitment rate (participants per centre per month) was found to be 0.92 (IQR 0.43-2.79) and the median retention rate (proportion of participants with valid primary outcome data at follow-up) was estimated at 89% (IQR 79-97%). There is considerable variation in the consent, recruitment and retention rates in publicly funded RCTs. Investigators should bear this in mind at the planning stage of their study and not be overly optimistic about their recruitment projections. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Recruitment and retention of participants in randomised controlled trials: a review of trials funded and published by the United Kingdom Health Technology Assessment Programme

PubMed Central

Bonacho dos Anjos Henriques-Cadby, Inês; Bortolami, Oscar; Flight, Laura; Hind, Daniel; Knox, Christopher; Nadin, Ben; Rothwell, Joanne; Surtees, Michael; Julious, Steven A

2017-01-01

Background Substantial amounts of public funds are invested in health research worldwide. Publicly funded randomised controlled trials (RCTs) often recruit participants at a slower than anticipated rate. Many trials fail to reach their planned sample size within the envisaged trial timescale and trial funding envelope. Objectives To review the consent, recruitment and retention rates for single and multicentre randomised control trials funded and published by the UK's National Institute for Health Research (NIHR) Health Technology Assessment (HTA) Programme. Data sources and study selection HTA reports of individually randomised single or multicentre RCTs published from the start of 2004 to the end of April 2016 were reviewed. Data extraction Information was extracted, relating to the trial characteristics, sample size, recruitment and retention by two independent reviewers. Main outcome measures Target sample size and whether it was achieved; recruitment rates (number of participants recruited per centre per month) and retention rates (randomised participants retained and assessed with valid primary outcome data). Results This review identified 151 individually RCTs from 787 NIHR HTA reports. The final recruitment target sample size was achieved in 56% (85/151) of the RCTs and more than 80% of the final target sample size was achieved for 79% of the RCTs (119/151). The median recruitment rate (participants per centre per month) was found to be 0.92 (IQR 0.43–2.79) and the median retention rate (proportion of participants with valid primary outcome data at follow-up) was estimated at 89% (IQR 79–97%). Conclusions There is considerable variation in the consent, recruitment and retention rates in publicly funded RCTs. Investigators should bear this in mind at the planning stage of their study and not be overly optimistic about their recruitment projections. PMID:28320800

24 CFR 886.325 - Overcrowded and underoccupied units.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of a change in family composition and shall transfer to an appropriate size dwelling unit, based on.... Such a family shall have priority over a family on the owner's waiting list seeking the same size unit... notification by the family of a change in the family size, the owner agrees to offer the family a suitable unit...

Evaluation of a Progressive Mobility Protocol in Postoperative Cardiothoracic Surgical Patients.

PubMed

Floyd, Shawn; Craig, Sarah W; Topley, Darla; Tullmann, Dorothy

2016-01-01

Cardiothoracic surgical patients are at high risk for complications related to immobility, such as increased intensive care and hospital length of stay, intensive care unit readmission, pressure ulcer development, and deep vein thrombosis/pulmonary embolus. A progressive mobility protocol was started in the thoracic cardiovascular intensive care unit in a rural academic medical center. The purpose of the progressive mobility protocol was to increase mobilization of postoperative patients and decrease complications related to immobility in this unique patient population. A matched-pairs design was used to compare a randomly selected sample of the preintervention group (n = 30) to a matched postintervention group (n = 30). The analysis compared outcomes including intensive care unit and hospital length of stay, intensive care unit readmission occurrence, pressure ulcer prevalence, and deep vein thrombosis/pulmonary embolism prevalence between the 2 groups. Although this comparison does not achieve statistical significance (P < .05) for any of the outcomes measured, it does show clinical significance in a reduction in hospital length of stay, intensive care unit days, in intensive care unit readmission rate, and a decline in pressure ulcer prevalence, which is the overall goal of progressive mobility. This study has implications for nursing, hospital administration, and therapy services with regard to staffing and cost savings related to fewer complications of immobility. Future studies with a larger sample size and other populations are warranted.

A field examination of two measures of work motivation as predictors of leaders' influence tactics.

PubMed

Barbuto, John E; Fritz, Susan M; Marx, David

2002-10-01

The authors tested 2 motivation measures, the Motivation Sources Inventory (MSI; J. E. Barbuto & R. W. Scholl, 1998) and the Job Choice Decision-Making Exercise (A. M. Harrell & M. J. Stahl, 1981) as predictors of leaders' influence tactics. The authors sampled 219 leader-member dyads from a variety of organizations and communities throughout the central United States. Results strongly favored the MSI as a predictor of influence tactics. Limitations of the study include low power of relationships, sample size as limited by the research design, and education levels of participants. Future researchers should use larger and more diverse samples and test other relevant antecedents of leaders' behaviors.

Modeling the development of written language

PubMed Central

Puranik, Cynthia S.; Foorman, Barbara; Foster, Elizabeth; Wilson, Laura Gehron; Tschinkel, Erika; Kantor, Patricia Thatcher

2011-01-01

Alternative models of the structure of individual and developmental differences of written composition and handwriting fluency were tested using confirmatory factor analysis of writing samples provided by first- and fourth-grade students. For both groups, a five-factor model provided the best fit to the data. Four of the factors represented aspects of written composition: macro-organization (use of top sentence and number and ordering of ideas), productivity (number and diversity of words used), complexity (mean length of T-unit and syntactic density), and spelling and punctuation. The fifth factor represented handwriting fluency. Handwriting fluency was correlated with written composition factors at both grades. The magnitude of developmental differences between first grade and fourth grade expressed as effect sizes varied for variables representing the five constructs: large effect sizes were found for productivity and handwriting fluency variables; moderate effect sizes were found for complexity and macro-organization variables; and minimal effect sizes were found for spelling and punctuation variables. PMID:22228924

Validation of a New Metric for Assessing the Integration of Health Protection and Health Promotion in a Sample of Small- and Medium-Sized Employer Groups.

PubMed

Williams, Jessica A R; Nelson, Candace C; Cabán-Martinez, Alberto J; Katz, Jeffrey N; Wagner, Gregory R; Pronk, Nicolaas P; Sorensen, Glorian; McLellan, Deborah L

2015-09-01

To conduct validation analyses for a new measure of the integration of worksite health protection and health promotion approaches developed in earlier research. A survey of small- to medium-sized employers located in the United States was conducted between October 2013 and March 2014 (n = 111). Cronbach α coefficient was used to assess reliability, and Pearson correlation coefficients were used to assess convergent validity. The integration score was positively associated with the measures of occupational safety and health and health promotion activities/policies-supporting its convergent validity (Pearson correlation coefficients of 0.32 to 0.47). Cronbach α coefficient was 0.94, indicating excellent reliability. The integration score seems to be a promising tool for assessing integration of health promotion and health protection. Further work is needed to test its dimensionality and validate its use in other samples.

Nursing Unit Design, Nursing Staff Communication Networks, and Patient Falls: Are They Related?

PubMed

Brewer, Barbara B; Carley, Kathleen M; Benham-Hutchins, Marge; Effken, Judith A; Reminga, Jeffrey

2018-01-01

The purpose of this research is to (1) investigate the impact of nursing unit design on nursing staff communication patterns and, ultimately, on patient falls in acute care nursing units; and (2) evaluate whether differences in fall rates, if found, were associated with the nursing unit physical structure (shape) or size. Nursing staff communication and nursing unit design are frequently linked to patient safety outcomes, yet little is known about the impact of specific nursing unit designs on nursing communication patterns that might affect patient falls. An exploratory longitudinal correlational design was used to measure nursing unit communication structures using social network analysis techniques. Data were collected 4 times over a 7-month period. Floor plans were used to determine nursing unit design. Fall rates were provided by hospital coordinators. An analysis of covariance controlling for hospitals resulted in a statistically significant interaction of unit shape and size (number of beds). The interaction occurred when medium- and large-sized racetrack-shaped units intersected with medium- and large-sized cross-shaped units. The results suggest that nursing unit design shape impacts nursing communication patterns, and the interaction of shape and size may impact patient falls. How those communication patterns affect patient falls should be considered when planning hospital construction of nursing care units.

Urban land-use study plan for the National Water-Quality Assessment Program

USGS Publications Warehouse

Squillace, P.J.; Price, C.V.

1996-01-01

This study plan is for Urban Land-Use Studies initiated as part of the U.S. Geological Survey's National Water-Quality Assessment (NAWQA) Program. There are two Urban Land-Use Study objectives: (1) Define the water quality in recharge areas of shallow aquifers underlying areas of new residential and commercial land use in large metropolitan areas, and (2) determine which natural and human factors most strongly affect the occurrence of contaminants in these shallow aquifers. To meet objective 1, each NAWQA Study Unit will install and collect water samples from at least 30 randomly located monitoring wells in a metropolitan area. To meet objective 2, aquifer characteristics and land-use information will be documented. This includes particle-size analysis of each major lithologic unit both in the unsaturated zone and in the aquifer near the water table. The percentage of organic carbon also will be determined for each lithologic unit. Geographic information system coverages will be created that document existing land use around the wells. These data will aid NAWQA personnel in relating natural and human factors to the occurrence of contaminants. Water samples for age dating also will be collected from all monitoring wells, but the samples will be stored until the occurrence of contaminants has been determined. Age-date analysis will be done only on those samples that have no detectable concentrations of anthropogenic contaminants.

COMPACT CASCADE IMPACTS

DOEpatents

Lippmann, M.

1964-04-01

A cascade particle impactor capable of collecting particles and distributing them according to size is described. In addition the device is capable of collecting on a pair of slides a series of different samples so that less time is required for the changing of slides. Other features of the device are its compactness and its ruggedness making it useful under field conditions. Essentially the unit consists of a main body with a series of transverse jets discharging on a pair of parallel, spaced glass plates. The plates are capable of being moved incremental in steps to obtain the multiple samples. (AEC)

Microstress, strain, band gap tuning and photocatalytic properties of thermally annealed and Cu-doped ZnO nanoparticles

NASA Astrophysics Data System (ADS)

Prasad, Neena; V. M. M, Saipavitra; Swaminathan, Hariharan; Thangaraj, Pandiyarajan; Ramalinga Viswanathan, Mangalaraja; Balasubramanian, Karthikeyan

2016-06-01

ZnO nanoparticles and Cu-doped ZnO nanoparticles were prepared by co-precipitation method. Also, a part of the pure ZnO nanoparticles were annealed at 750 °C for 3, 6, and 9 h. X-ray diffraction studies were carried out and the lattice parameters, unit cell volume, interplanar spacing, and Young's modulus were calculated for all the samples, and also the crystallite size was found using the Scherrer method. X-ray peak broadening analysis was used to estimate the crystallite sizes and the strain using the Williamson-Hall (W-H) method and the size-strain plot (SSP) method. Stress and the energy density were calculated using the W-H method assuming different models such as uniform deformation model, uniform strain deformation model, uniform deformation energy density model, and the SSP method. Optical absorption properties of the samples were understood from their UV-visible spectra. Photocatalytic activities of ZnO and 5 % Cu-doped ZnO were observed by the degradation of methylene blue dye in aqueous medium under the irradiation of 20-W compact fluorescent lamp for an hour.

ORIGIN OF QUARTZ IN COAL.

USGS Publications Warehouse

Ruppert, Leslie F.; Cecil, C. Blaine; Stanton, Ronald W.

1984-01-01

Both a scanning electron microscope and an electron microprobe (EMP) were used in this study to analyze the cathodoluminescence properties of quartz grains in samples of the Upper Freeport coal bed because quartz grains in coal are small (silt sized) and below the resolution capabilities of a standard luminoscope. Quartz grains were identified by the detection of silicon alone with energy dispersive X-ray units attached to both the SEM and the EMP.

1979 Reserve Force Studies Surveys: User’s Manual and Codebooks.

DTIC Science & Technology

1981-09-01

units, for instance, artillery, which have the same manpower demand characteristics (similar size, skills and grade structure) provided better...personnel groups. With random cluster sampling, the pattern of questionnaire returns for each group of analytic interest should match the Guard and...marking the matching bubbles. First, although the instructions ask the respondent to "zero-fill" and "right-justify," some respondents entered the value

The effect of journal impact factor, reporting conflicts, and reporting funding sources, on standardized effect sizes in back pain trials: a systematic review and meta-regression.

PubMed

Froud, Robert; Bjørkli, Tom; Bright, Philip; Rajendran, Dévan; Buchbinder, Rachelle; Underwood, Martin; Evans, David; Eldridge, Sandra

2015-11-30

Low back pain is a common and costly health complaint for which there are several moderately effective treatments. In some fields there is evidence that funder and financial conflicts are associated with trial outcomes. It is not clear whether effect sizes in back pain trials relate to journal impact factor, reporting conflicts of interest, or reporting funding. We performed a systematic review of English-language papers reporting randomised controlled trials of treatments for non-specific low back pain, published between 2006-2012. We modelled the relationship using 5-year journal impact factor, and categories of reported of conflicts of interest, and categories of reported funding (reported none and reported some, compared to not reporting these) using meta-regression, adjusting for sample size, and publication year. We also considered whether impact factor could be predicted by the direction of outcome, or trial sample size. We could abstract data to calculate effect size in 99 of 146 trials that met our inclusion criteria. Effect size is not associated with impact factor, reporting of funding source, or reporting of conflicts of interest. However, explicitly reporting 'no trial funding' is strongly associated with larger absolute values of effect size (adjusted β=1.02 (95 % CI 0.44 to 1.59), P=0.001). Impact factor increases by 0.008 (0.004 to 0.012) per unit increase in trial sample size (P<0.001), but does not differ by reported direction of the LBP trial outcome (P=0.270). The absence of associations between effect size and impact factor, reporting sources of funding, and conflicts of interest reflects positively on research and publisher conduct in the field. Strong evidence of a large association between absolute magnitude of effect size and explicit reporting of 'no funding' suggests authors of unfunded trials are likely to report larger effect sizes, notwithstanding direction. This could relate in part to quality, resources, and/or how pragmatic a trial is.

Performance of terahertz metamaterials as high-sensitivity sensor

NASA Astrophysics Data System (ADS)

He, Yanan; Zhang, Bo; Shen, Jingling

2017-09-01

A high-sensitivity sensor based on the resonant transmission characteristics of terahertz (THz) metamaterials was investigated, with the proposal and fabrication of rectangular bar arrays of THz metamaterials exhibiting a period of 180 μm on a 25 μm thick flexible polyimide. Varying the size of the metamaterial structure revealed that the length of the rectangular unit modulated the resonant frequency, which was verified by both experiment and simulation. The sensing characteristics upon varying the surrounding media in the sample were tested by simulation and experiment. Changing the surrounding medium from that of air to that of alcohol or oil produced resonant frequency redshifts of 80 GHz or 150 GHz, respectively, which indicates that the sensor possessed a high sensitivity of 667 GHz per unit of refractive index. Finally, the influence of the sample substrate thickness on the sensor sensitivity was investigated by simulation. It may be a reference for future sensor design.

Multifunctional Water Sensors for pH, ORP, and Conductivity Using Only Microfabricated Platinum Electrodes

PubMed Central

Lin, Wen-Chi; Brondum, Klaus; Monroe, Charles W.; Burns, Mark A.

2017-01-01

Monitoring of the pH, oxidation-reduction-potential (ORP), and conductivity of aqueous samples is typically performed using multiple sensors. To minimize the size and cost of these sensors for practical applications, we have investigated the use of a single sensor constructed with only bare platinum electrodes deposited on a glass substrate. The sensor can measure pH from 4 to 10 while simultaneously measuring ORP from 150 to 800 mV. The device can also measure conductivity up to 8000 μS/cm in the range of 10 °C to 50 °C, and all these measurements can be made even if the water samples contain common ions found in residential water. The sensor is inexpensive (i.e., ~$0.10/unit) and has a sensing area below 1 mm2, suggesting that the unit is cost-efficient, robust, and widely applicable, including in microfluidic systems. PMID:28753913

Manganese modified structural and optical properties of zinc soda lime silica glasses.

PubMed

Samsudin, Nur Farhana; Matori, Khamirul Amin; Wahab, Zaidan Abdul; Fen, Yap Wing; Liew, Josephine Ying Chi; Lim, Way Foong; Mohd Zaid, Mohd Hafiz; Omar, Nur Alia Sheh

2016-03-20

A series of MnO-doped zinc soda lime silica glass systems was prepared by a conventional melt and quenching technique. In this study, the x-ray diffraction analysis was applied to confirm the amorphous nature of the glasses. Fourier transform infrared spectroscopy shows the glass network consists of MnO₄, SiO₄, and ZnO₄ units as basic structural units. The glass samples under field emission scanning electron microscopy observation demonstrated irregularity in shape and size with glassy phase-like structure. The optical absorption studies revealed that the optical bandgap (E_opt) values decrease with an increase of MnO content. Through the results of various measurements, the doping of MnO in the glass matrix had effects on the performance of the glasses and significantly improved the properties of the glass sample as a potential host for phosphor material.

Fine refinement of solid state structure of racemic form of phospho-tyrosine employing NMR Crystallography approach.

PubMed

Paluch, Piotr; Pawlak, Tomasz; Oszajca, Marcin; Lasocha, Wieslaw; Potrzebowski, Marek J

2015-02-01

We present step by step facets important in NMR Crystallography strategy employing O-phospho-dl-tyrosine as model sample. The significance of three major techniques being components of this approach: solid state NMR (SS NMR), X-ray diffraction of powdered sample (PXRD) and theoretical calculations (Gauge Invariant Projector Augmented Wave; GIPAW) is discussed. Each experimental technique provides different set of structural constraints. From the PXRD measurement the size of the unit cell, space group and roughly refined molecular structure are established. SS NMR provides information about content of crystallographic asymmetric unit, local geometry, molecular motion in the crystal lattice and hydrogen bonding pattern. GIPAW calculations are employed for validation of quality of elucidation and fine refinement of structure. Crystal and molecular structure of O-phospho-dl-tyrosine solved by NMR Crystallography is deposited at Cambridge Crystallographic Data Center under number CCDC 1005924. Copyright © 2014 Elsevier Inc. All rights reserved.

Population densities of painted buntings in the southeastern United States

USGS Publications Warehouse

Meyers, J. Michael

2011-01-01

The eastern population trend of Passerina ciris (Painted Bunting) declined 3.5% annually during the first 30 yrs of the Breeding Bird Survey (BBS, 1966–1996). Recently, the US Fish and Wildlife Service listed Painted Buntings as a focal species. Surveys for this focal species for the next 10 yrs (BBS, 1997–2007), however, are too low (2 in young pine plantations to 42 per km2 in maritime shrub. Effective detection radii for habitats varied from 64 to 90 m and were slightly higher in developed than in undeveloped habitats. Distance sampling is recommended to determine densities of Painted Buntings; however, large sample sizes (70–100 detections/habitat type) are required to monitor Painted Bunting densities in most habitats in the Atlantic coastal region of the southeastern United States. Special attention should be given to maritime shrub habitats, which may be important to maintaining the Painted Bunting population in the southeastern US.

Testing of commonly used mixing and sampling procedures to evaluate fertilizer blends prepared with matched and mismatched particle sizes.

PubMed

Hall, William L; Ramsey, Charles; Falls, J Harold

2014-01-01

Bulk blending of dry fertilizers is a common practice in the United States and around the world. This practice involves the mixing (either physically or volumetrically) of concentrated, high analysis raw materials. Blending is followed by bagging (for small volume application such as lawn and garden products), loading into truck transports, and spreading. The great majority of bulk blended products are not bagged but handled in bulk and transferred from the blender to a holding hopper. The product is then transferred to a transport vehicle, which may, or may not, also be a spreader. If the primary transport vehicle is not a spreader, then there is another transfer at the user site to a spreader for application. Segregation of materials that are mismatched due to size, density, or shape is an issue when attempting to effectively sample or evenly spread bulk blended products. This study, prepared in coordination with and supported by the Florida Department of Agriculture and Consumer Services and the Florida Fertilizer and Agrochemical Association, looks at the impact of varying particle size as it relates to blending, sampling, and application of bulk blends. The study addresses blends containing high ratios of N-P-K materials and varying (often small) quantities of the micronutrient Zn.

Multilevel Factorial Experiments for Developing Behavioral Interventions: Power, Sample Size, and Resource Considerations†

PubMed Central

Dziak, John J.; Nahum-Shani, Inbal; Collins, Linda M.

2012-01-01

Factorial experimental designs have many potential advantages for behavioral scientists. For example, such designs may be useful in building more potent interventions, by helping investigators to screen several candidate intervention components simultaneously and decide which are likely to offer greater benefit before evaluating the intervention as a whole. However, sample size and power considerations may challenge investigators attempting to apply such designs, especially when the population of interest is multilevel (e.g., when students are nested within schools, or employees within organizations). In this article we examine the feasibility of factorial experimental designs with multiple factors in a multilevel, clustered setting (i.e., of multilevel multifactor experiments). We conduct Monte Carlo simulations to demonstrate how design elements such as the number of clusters, the number of lower-level units, and the intraclass correlation affect power. Our results suggest that multilevel, multifactor experiments are feasible for factor-screening purposes, because of the economical properties of complete and fractional factorial experimental designs. We also discuss resources for sample size planning and power estimation for multilevel factorial experiments. These results are discussed from a resource management perspective, in which the goal is to choose a design that maximizes the scientific benefit using the resources available for an investigation. PMID:22309956

Crospovidone interactions with water. II. Dynamic vapor sorption analysis of the effect of Polyplasdone particle size on its uptake and distribution of water.

PubMed

Saripella, Kalyan K; Mallipeddi, Rama; Neau, Steven H

2014-11-20

Polyplasdone of different particle size was used to study the sorption, desorption, and distribution of water, and to seek evidence that larger particles can internalize water. The three samples were Polyplasdone® XL, XL-10, and INF-10. Moisture sorption and desorption isotherms at 25 °C at 5% intervals from 0 to 95% relative humidity (RH) were generated by dynamic vapor sorption analysis. The three products provided similar data, judged to be Type III with a small hysteresis that appears when RH is below 65%. An absent rounded knee in the sorption curve suggests that multilayers form before the monolayer is completed. The hysteresis indicates that internally absorbed moisture is trapped as the water is desorbed and the polymer sample shrinks, thus requiring a lower level of RH to continue desorption. The fit of the Guggenheim-Anderson-de Boer (GAB) and the Young and Nelson equations was accomplished in the data analysis. The W(m), C(G), and K values from GAB analysis are similar across the three samples, revealing 0.962 water molecules per repeating unit in the monolayer. A small amount of absorbed water is identified, but this is consistent across the three particle sizes. Copyright © 2014 Elsevier B.V. All rights reserved.

Multilevel factorial experiments for developing behavioral interventions: power, sample size, and resource considerations.

PubMed

Dziak, John J; Nahum-Shani, Inbal; Collins, Linda M

2012-06-01

Factorial experimental designs have many potential advantages for behavioral scientists. For example, such designs may be useful in building more potent interventions by helping investigators to screen several candidate intervention components simultaneously and to decide which are likely to offer greater benefit before evaluating the intervention as a whole. However, sample size and power considerations may challenge investigators attempting to apply such designs, especially when the population of interest is multilevel (e.g., when students are nested within schools, or when employees are nested within organizations). In this article, we examine the feasibility of factorial experimental designs with multiple factors in a multilevel, clustered setting (i.e., of multilevel, multifactor experiments). We conduct Monte Carlo simulations to demonstrate how design elements-such as the number of clusters, the number of lower-level units, and the intraclass correlation-affect power. Our results suggest that multilevel, multifactor experiments are feasible for factor-screening purposes because of the economical properties of complete and fractional factorial experimental designs. We also discuss resources for sample size planning and power estimation for multilevel factorial experiments. These results are discussed from a resource management perspective, in which the goal is to choose a design that maximizes the scientific benefit using the resources available for an investigation. (c) 2012 APA, all rights reserved

Design and Weighting Methods for a Nationally Representative Sample of HIV-infected Adults Receiving Medical Care in the United States-Medical Monitoring Project

PubMed Central

Iachan, Ronaldo; H. Johnson, Christopher; L. Harding, Richard; Kyle, Tonja; Saavedra, Pedro; L. Frazier, Emma; Beer, Linda; L. Mattson, Christine; Skarbinski, Jacek

2016-01-01

Background: Health surveys of the general US population are inadequate for monitoring human immunodeficiency virus (HIV) infection because the relatively low prevalence of the disease (<0.5%) leads to small subpopulation sample sizes. Objective: To collect a nationally and locally representative probability sample of HIV-infected adults receiving medical care to monitor clinical and behavioral outcomes, supplementing the data in the National HIV Surveillance System. This paper describes the sample design and weighting methods for the Medical Monitoring Project (MMP) and provides estimates of the size and characteristics of this population. Methods: To develop a method for obtaining valid, representative estimates of the in-care population, we implemented a cross-sectional, three-stage design that sampled 23 jurisdictions, then 691 facilities, then 9,344 HIV patients receiving medical care, using probability-proportional-to-size methods. The data weighting process followed standard methods, accounting for the probabilities of selection at each stage and adjusting for nonresponse and multiplicity. Nonresponse adjustments accounted for differing response at both facility and patient levels. Multiplicity adjustments accounted for visits to more than one HIV care facility. Results: MMP used a multistage stratified probability sampling design that was approximately self-weighting in each of the 23 project areas and nationally. The probability sample represents the estimated 421,186 HIV-infected adults receiving medical care during January through April 2009. Methods were efficient (i.e., induced small, unequal weighting effects and small standard errors for a range of weighted estimates). Conclusion: The information collected through MMP allows monitoring trends in clinical and behavioral outcomes and informs resource allocation for treatment and prevention activities. PMID:27651851

Soil Carbon Variability and Change Detection in the Forest Inventory Analysis Database of the United States

NASA Astrophysics Data System (ADS)

Wu, A. M.; Nater, E. A.; Dalzell, B. J.; Perry, C. H.

2014-12-01

The USDA Forest Service's Forest Inventory Analysis (FIA) program is a national effort assessing current forest resources to ensure sustainable management practices, to assist planning activities, and to report critical status and trends. For example, estimates of carbon stocks and stock change in FIA are reported as the official United States submission to the United Nations Framework Convention on Climate Change. While the main effort in FIA has been focused on aboveground biomass, soil is a critical component of this system. FIA sampled forest soils in the early 2000s and has remeasurement now underway. However, soil sampling is repeated on a 10-year interval (or longer), and it is uncertain what magnitude of changes in soil organic carbon (SOC) may be detectable with the current sampling protocol. We aim to identify the sensitivity and variability of SOC in the FIA database, and to determine the amount of SOC change that can be detected with the current sampling scheme. For this analysis, we attempt to answer the following questions: 1) What is the sensitivity (power) of SOC data in the current FIA database? 2) How does the minimum detectable change in forest SOC respond to changes in sampling intervals and/or sample point density? Soil samples in the FIA database represent 0-10 cm and 10-20 cm depth increments with a 10-year sampling interval. We are investigating the variability of SOC and its change over time for composite soil data in each FIA region (Pacific Northwest, Interior West, Northern, and Southern). To guide future sampling efforts, we are employing statistical power analysis to examine the minimum detectable change in SOC storage. We are also investigating the sensitivity of SOC storage changes under various scenarios of sample size and/or sample frequency. This research will inform the design of future FIA soil sampling schemes and improve the information available to international policy makers, university and industry partners, and the public.

Complementary-relationship-based 30 year normals (1981-2010) of monthly latent heat fluxes across the contiguous United States

NASA Astrophysics Data System (ADS)

Szilagyi, Jozsef

2015-11-01

Thirty year normal (1981-2010) monthly latent heat fluxes (ET) over the conterminous United States were estimated by a modified Advection-Aridity model from North American Regional Reanalysis (NARR) radiation and wind as well as Parameter-Elevation Regressions on Independent Slopes Model (PRISM) air and dew-point temperature data. Mean annual ET values were calibrated with PRISM precipitation (P) and validated against United States Geological Survey runoff (Q) data. At the six-digit Hydrologic Unit Code level (sample size of 334) the estimated 30 year normal runoff (P - ET) had a bias of 18 mm yr-1, a root-mean-square error of 96 mm yr-1, and a linear correlation coefficient value of 0.95, making the estimates on par with the latest Land Surface Model results but without the need for soil and vegetation information or any soil moisture budgeting.

Lot quality assurance sampling techniques in health surveys in developing countries: advantages and current constraints.

PubMed

Lanata, C F; Black, R E

1991-01-01

Traditional survey methods, which are generally costly and time-consuming, usually provide information at the regional or national level only. The utilization of lot quality assurance sampling (LQAS) methodology, developed in industry for quality control, makes it possible to use small sample sizes when conducting surveys in small geographical or population-based areas (lots). This article describes the practical use of LQAS for conducting health surveys to monitor health programmes in developing countries. Following a brief description of the method, the article explains how to build a sample frame and conduct the sampling to apply LQAS under field conditions. A detailed description of the procedure for selecting a sampling unit to monitor the health programme and a sample size is given. The sampling schemes utilizing LQAS applicable to health surveys, such as simple- and double-sampling schemes, are discussed. The interpretation of the survey results and the planning of subsequent rounds of LQAS surveys are also discussed. When describing the applicability of LQAS in health surveys in developing countries, the article considers current limitations for its use by health planners in charge of health programmes, and suggests ways to overcome these limitations through future research. It is hoped that with increasing attention being given to industrial sampling plans in general, and LQAS in particular, their utilization to monitor health programmes will provide health planners in developing countries with powerful techniques to help them achieve their health programme targets.

Does size matter? Animal units and animal unit months

Treesearch

Lamar Smith; Joe Hicks; Scott Lusk; Mike Hemmovich; Shane Green; Sarah McCord; Mike Pellant; John Mitchell; Judith Dyess; Jim Sprinkle; Amanda Gearhart; Sherm Karl; Mike Hannemann; Ken Spaeth; Jason Karl; Matt Reeves; Dave Pyke; Jordan Spaak; Andrew Brischke; Del Despain; Matt Phillippi; Dave Weixelmann; Alan Bass; Jessie Page; Lori Metz; David Toledo; Emily Kachergis

2017-01-01

The concepts of animal units, animal unit months, and animal unit equivalents have long been used as standards for range management planning, estimating stocking rates, reporting actual use, assessing grazing fees, ranch appraisal, and other purposes. Increasing size of cattle on rangelands has led some to suggest that the definition of animal units and animal unit...

Using LIDAR and UAV-derived point clouds to evaluate surface roughness in a gravel-bed braided river (Vénéon river, French Alps)

NASA Astrophysics Data System (ADS)

Vázquez Tarrío, Daniel; Borgniet, Laurent; Recking, Alain; Liebault, Frédéric; Vivier, Marie

2016-04-01

The present research is focused on the Vénéon river at Plan du Lac (Massif des Ecrins, France), an alpine braided gravel bed stream with a glacio-nival hydrological regime. It drains a catchment area of 316 km2. The present research is focused in a 2.5 km braided reach placed immediately upstream of a small hydropower dam. An airbone LIDAR survey was accomplished in October, 2014 by EDF (the company managing the small hydropower dam), and data coming from this LIDAR survey were available for the present research. Point density of the LIDAR-derived 3D-point cloud was between 20-50 points/m2, with a vertical precision of 2-3 cm over flat surfaces. Moreover, between April and Juin, 2015, we carried out a photogrammetrical campaign based in aerial images taken with an UAV-drone. The UAV-derived point-cloud has a point density of 200-300 points/m2, and a vertical precision over flat control surfaces comparable to that of the LIDAR point cloud (2-3 cm). Simultaneously to the UAV campaign, we took several Wolman samples with the aim of characterizing the grain size distribution of bed sediment. Wolman samples were taken following a geomorphological criterion (unit bars, head/tail of compound bars). Furthermore, some of the Wolman samples were repeated with the aim of defining the uncertainty of our sampling protocol. LIDAR and UAV-derived point clouds were treated in order to check whether both point-clouds were correctly co-aligned. After that, we estimated bed roughness using the detrended standard deviation of heights, in a 40-cm window. For all this data treatment we used CloudCompare. Then, we measured the distribution of roughness in the same geomorphological units where we took the Wolman samples, and we compared with the grain size distributions measured in the field: differences between UAV-point cloud roughness distributions and measured-grain size distribution (~1-2 cm) are in the same order of magnitude of the differences found between the repeated Wolman samples (~0.5-1.5 cm). Differences with LIDAR-derived roughness distributions are only slightly higher, which could be due to the lower point density of the LIDAR point clouds.

Visual sensitivity to spatially sampled modulation in human observers

NASA Technical Reports Server (NTRS)

Mulligan, Jeffrey B.; Macleod, Donald I. A.

1991-01-01

Thresholds were measured for detecting spatial luminance modulation in regular lattices of visually discrete dots. Thresholds for modulation of a lattice are generally higher than the corresponding threshold for modulation of a continuous field, and the size of the threshold elevation, which depends on the spacing of the lattice elements, can be as large as a one log unit. The largest threshold elevations are seen when the sample spacing is 12 min arc or greater. Theories based on response compression cannot explain the further observation that the threshold elevations due to spatial sampling are also dependent on modulation frequency: the greatest elevations occur with higher modulation frequencies. The idea that this is due to masking of the modulation frequency by the spatial frequencies in the sampling lattice is considered.

Developing effective sampling designs for monitoring natural resources in Alaskan national parks: an example using simulations and vegetation data

USGS Publications Warehouse

Thompson, William L.; Miller, Amy E.; Mortenson, Dorothy C.; Woodward, Andrea

2011-01-01

Monitoring natural resources in Alaskan national parks is challenging because of their remoteness, limited accessibility, and high sampling costs. We describe an iterative, three-phased process for developing sampling designs based on our efforts to establish a vegetation monitoring program in southwest Alaska. In the first phase, we defined a sampling frame based on land ownership and specific vegetated habitats within the park boundaries and used Path Distance analysis tools to create a GIS layer that delineated portions of each park that could be feasibly accessed for ground sampling. In the second phase, we used simulations based on landcover maps to identify size and configuration of the ground sampling units (single plots or grids of plots) and to refine areas to be potentially sampled. In the third phase, we used a second set of simulations to estimate sample size and sampling frequency required to have a reasonable chance of detecting a minimum trend in vegetation cover for a specified time period and level of statistical confidence. Results of the first set of simulations indicated that a spatially balanced random sample of single plots from the most common landcover types yielded the most efficient sampling scheme. Results of the second set of simulations were compared with field data and indicated that we should be able to detect at least a 25% change in vegetation attributes over 31. years by sampling 8 or more plots per year every five years in focal landcover types. This approach would be especially useful in situations where ground sampling is restricted by access.

The widespread misuse of effect sizes.

PubMed

Dankel, Scott J; Mouser, J Grant; Mattocks, Kevin T; Counts, Brittany R; Jessee, Matthew B; Buckner, Samuel L; Loprinzi, Paul D; Loenneke, Jeremy P

2017-05-01

Studies comparing multiple groups (i.e., experimental and control) often examine the efficacy of an intervention by calculating within group effect sizes using Cohen's d. This method is inappropriate and largely impacted by the pre-test variability as opposed to the variability in the intervention itself. Furthermore, the percentage change is often analyzed, but this is highly impacted by the baseline values and can be potentially misleading. Thus, the objective of this study was to illustrate the common misuse of the effect size and percent change measures. Here we provide a realistic sample data set comparing two resistance training groups with the same pre-test to post-test change. Statistical tests that are commonly performed within the literature were computed. Analyzing the within group effect size favors the control group, while the percent change favors the experimental group. The most appropriate way to present the data would be to plot the individual responses or, for larger samples, provide the mean change and 95% confidence intervals of the mean change. This details the magnitude and variability within the response to the intervention itself in units that are easily interpretable. This manuscript demonstrates the common misuse of the effect size and details the importance for investigators to always report raw values, even when alternative statistics are performed. Copyright © 2016 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Distribution of molar mass and branching index of natural rubber from Hevea brasiliensis trees of different age by size exclusion chromatography coupled with online viscometry.

PubMed

Phan, T N; Lan, N T; Nga, N T

2004-05-01

Natural rubber from hevea brasiliensis trees (Thailand, RRIM 600 clone) of different age (8, 20, and 35 years) were characterized by size exclusion chromatography coupled with online viscometry according to their distribution of molar mass and branching index at a temperature of 70 degrees C using cyclohexane as solvent. Washing with an aqueous solution of sodium dodecylsulfate and subsequent saponification purified the natural rubber samples. With this procedure physical branching points caused by phospholipids, proteins and hydrophobic terminal units, mainly fatty acids, of the natural rubber (cis-1,4-polyisoprene) molecule, could be removed leading to completely soluble polymer samples. All samples investigated possess a very broad (10 to 50,000 kg/mol) and distinct bimodal molar mass distribution. With increasing age the peak area in the low molar mass region decreases favoring the peak area in the high molar mass region. By plotting the branching index as a function of the both, the molar mass and the age of the trees.

Expertise in Problem Solving.

DTIC Science & Technology

1981-05-18

determining our subsequent experimental procedure. Figures 2 - Ishow two samples of protocols, one from Expert R.E. and the oth,_ Irom Novice C.H., both on...in press). This is also true of older versus younger children (Chi, 1976), and fast as compared with slow learners. For example, good readers can...Using chunks as a defining unit of knowledge structure, Chase and Simon set out to experimentally identify the structure and size of chunks in the

Knowledge and attitudes of nurses on a regional neurological intensive therapy unit towards brain stem death and organ donation.

PubMed

Davies, C

1997-01-01

The study aimed to explore nurses knowledge and attitudes towards brain stem death and organ donation. An ex post facto research design was used to determine relationships between variables. A 16 item questionnaire was used to collect data. Statistical analysis revealed one significant result. The limitations of the sample size is acknowledged and the conclusion suggests a larger study is required.

Droplet-size distribution and stability of commercial injectable lipid emulsions containing fish oil.

PubMed

Gallegos, Críspulo; Valencia, Concepción; Partal, Pedro; Franco, José M; Maglio, Omay; Abrahamsson, Malin; Brito-de la Fuente, Edmundo

2012-08-01

The droplet size of commercial fish oil-containing injectable lipid emulsions, including conformance to United States Pharmacopeia (USP) standards on fat-globule size, was investigated. A total of 18 batches of three multichamber parenteral products containing the emulsion SMOFlipid as a component were analyzed. Samples from multiple lots of the products were evaluated to determine compliance with standards on the volume-weighted percentage of fat exceeding 0.05% (PFAT(5)) specified in USP chapter 729 to ensure the physical stability of i.v. lipid emulsions. The products were also analyzed to determine the effects of various storage times (3, 6, 9, and 12 months) and storage temperatures (25, 30, and 40 °C) on product stability. Larger-size lipid particles were quantified via single-particle optical sensing (SPOS). The emulsion's droplet-size distribution was determined via laser light scattering. SPOS and light-scattering analysis demonstrated mean PFAT(5) values well below USP-specified globule-size limits for all the tested products under all study conditions. In addition, emulsion aging at any storage temperature in the range studied did not result in a significant increase of PFAT(5) values, and mean droplet-size values did not change significantly during storage of up to 12 months at temperatures of 25-40 °C. PFAT(5) values were below the USP upper limits in SMOFlipid samples from multiple lots of three multichamber products after up to 12 months of storage at 25 or 30 °C or 6 months of storage at 40 °C.

Designing a multi-objective, multi-support accuracy assessment of the 2001 National Land Cover Data (NLCD 2001) of the conterminous United States

USGS Publications Warehouse

Stehman, S.V.; Wickham, J.D.; Wade, T.G.; Smith, J.H.

2008-01-01

The database design and diverse application of NLCD 2001 pose significant challenges for accuracy assessment because numerous objectives are of interest, including accuracy of land-cover, percent urban imperviousness, percent tree canopy, land-cover composition, and net change. A multi-support approach is needed because these objectives require spatial units of different sizes for reference data collection and analysis. Determining a sampling design that meets the full suite of desirable objectives for the NLCD 2001 accuracy assessment requires reconciling potentially conflicting design features that arise from targeting the different objectives. Multi-stage cluster sampling provides the general structure to achieve a multi-support assessment, and the flexibility to target different objectives at different stages of the design. We describe the implementation of two-stage cluster sampling for the initial phase of the NLCD 2001 assessment, and identify gaps in existing knowledge where research is needed to allow full implementation of a multi-objective, multi-support assessment. ?? 2008 American Society for Photogrammetry and Remote Sensing.

Gravitational Effects on Closed-Cellular-Foam Microstructure

NASA Technical Reports Server (NTRS)

Noever, David A.; Cronise, Raymond J.; Wessling, Francis C.; McMannus, Samuel P.; Mathews, John; Patel, Darayas

1996-01-01

Polyurethane foam has been produced in low gravity for the first time. The cause and distribution of different void or pore sizes are elucidated from direct comparison of unit-gravity and low-gravity samples. Low gravity is found to increase the pore roundness by 17% and reduce the void size by 50%. The standard deviation for pores becomes narrower (a more homogeneous foam is produced) in low gravity. Both a Gaussian and a Weibull model fail to describe the statistical distribution of void areas, and hence the governing dynamics do not combine small voids in either a uniform or a dependent fashion to make larger voids. Instead, the void areas follow an exponential law, which effectively randomizes the production of void sizes in a nondependent fashion consistent more with single nucleation than with multiple or combining events.

Nano sized La2Co2O6 double perovskite synthesized by sol gel method

NASA Astrophysics Data System (ADS)

Solanki, Neha; Lodhi, Pavitra Devi; Choudhary, K. K.; Kaurav, Netram

2018-05-01

We report here the synthesis of double perovskite La2Co2O6 (LCO) compound by a sol gel route method. The double perovskite structure of LCO system was confirmed via X-ray diffraction (XRD) analysis. Further, the lattice parameter, unit cell volume and bond length were refined by means of rietveld analysis using the full proof software. Debye Scherer formula was used to determine the particle size. The compound crystallized in triclinic structure with space group P-1 in ambient condition. We also obtained Raman modes from XRD spectra of poly-crystalline LCO sample. These results were interpreted for the observation of phonon excitations in this compound.

The influence of nursing care integration services on nurses' work satisfaction and quality of nursing care.

PubMed

Ryu, Jeong-Im; Kim, Kisook

2018-06-20

To investigate differences in work satisfaction and quality of nursing services between nurses from the nursing care integration service and general nursing units in Korea. The nursing care integration service was recently introduced in Korea to improve patient health outcomes through the provision of high quality nursing services and to relieve the caregiving burden of patients' families. In this cross-sectional study, data were collected from a convenience sample of 116 and 156 nurses working in nursing care integration service and general units, respectively. The data were analysed using descriptive statistics, t tests and one-way analysis of variance. Regarding work satisfaction, nursing care integration service nurses scored higher than general unit nurses on professional status, autonomy and task requirements, but the overall scores showed no significant differences. Scores on overall quality of nursing services, responsiveness and assurance were higher for nursing care integration service nurses than for general unit nurses. Nursing care integration service nurses scored higher than general unit nurses on some aspects of work satisfaction and quality of nursing services. Further studies with larger sample sizes will contribute to improving the quality of nursing care integration service units. These findings can help to establish strategies for the implementation and efficient operation of the nursing care integration service system, for the improvement of the quality of nursing services, and for successfully implementing and expanding nursing care integration service services in other countries. © 2018 John Wiley & Sons Ltd.

[Calculating the optimum size of a hemodialysis unit based on infrastructure potential].

PubMed

Avila-Palomares, Paula; López-Cervantes, Malaquías; Durán-Arenas, Luis

2010-01-01

To estimate the optimum size for hemodialysis units to maximize production given capital constraints. A national study in Mexico was conducted in 2009. Three possible methods for estimating a units optimum size were analyzed: hemodialysis services production under monopolistic market, under a perfect competitive market and production maximization given capital constraints. The third method was considered best based on the assumptions made in this paper; an optimal size unit should have 16 dialyzers (15 active and one back up dialyzer) and a purifier system able to supply all. It also requires one nephrologist, five nurses per shift, considering four shifts per day. Empirical evidence shows serious inefficiencies in the operation of units throughout the country. Most units fail to maximize production due to not fully utilizing equipment and personnel, particularly their water purifier potential which happens to be the most expensive asset for these units.

Martian crater counts on Elysium Mons

NASA Technical Reports Server (NTRS)

Mcbride, Kathleen; Barlow, Nadine G.

1990-01-01

Without returned samples from the Martian surface, relative age chronologies and stratigraphic relationships provide the best information for determining the ages of geomorphic features and surface regions. Crater-size frequency distributions of six recently mapped geological units of Elysium Mons were measured to establish their relative ages. Most of the craters on Elysium Mons and the adjacent plains units are between 500 and 1000 meters in diameter. However, only craters 1 km in diameter or larger were used because of inadequate spatial resolution of some of the Viking images and to reduce probability of counting secondary craters. The six geologic units include all of the Elysium Mons construct and a portion of the plains units west of the volcano. The surface area of the units studied is approximately 128,000 sq km. Four of the geologic units were used to create crater distribution curves. There are no craters larger than 1 km within the Elysium Mons caldera. Craters that lacked raised rims, were irregularly shaped, or were arranged in a linear pattern were assumed to be endogenic in origin and not counted. A crater frequency distribution analysis is presented.

Relationships between motor unit size and recruitment threshold in older adults: implications for size principle.

PubMed

Fling, Brett W; Knight, Christopher A; Kamen, Gary

2009-08-01

As a part of the aging process, motor unit reorganization occurs in which small motoneurons reinnervate predominantly fast-twitch muscle fibers that have lost their innervation. We examined the relationship between motor unit size and the threshold force for recruitment in two muscles to determine whether older individuals might develop an alternative pattern of motor unit activation. Young and older adults performed isometric contractions ranging from 0 to 50% of maximal voluntary contraction in both the first dorsal interosseous (FDI) and tibialis anterior (TA) muscles. Muscle fiber action potentials were recorded with an intramuscular needle electrode and motor unit size was computed using spike-triggered averaging of the global EMG signal (macro EMG), which was also obtained from the intramuscular needle electrode. As expected, older individuals exhibited larger motor units than young subjects in both the FDI and the TA. However, moderately strong correlations were obtained for the macro EMG amplitude versus recruitment threshold relationship in both the young and older adults within both muscles, suggesting that the size principle of motor unit recruitment seems to be preserved in older adults.

Cr3+ and Nb5+ co-doped Ti2Nb10O29 materials for high-performance lithium-ion storage

NASA Astrophysics Data System (ADS)

Yang, Chao; Yu, Shu; Ma, Yu; Lin, Chunfu; Xu, Zhihao; Zhao, Hua; Wu, Shunqing; Zheng, Peng; Zhu, Zi-Zhong; Li, Jianbao; Wang, Ning

2017-08-01

Ti2Nb10O29 is an advanced anode material for lithium-ion batteries due to its large specific capacity and high safety. However, its poor electronic/ionic conductivity significantly limits its rate capability. To tackle this issue, a Cr3+-Nb5+ co-doping is employed, and a series of CrxTi2-2xNb10+xO29 compounds are prepared. The co-doping does not change the Wadsley-Roth shear structure but increases the unit-cell volume and decreases the particle size. Due to the increased unit-cell volumes, the co-doped samples show increased Li+-ion diffusion coefficients. Experimental data and first-principle calculations reveal significantly increased electronic conductivities arising from the formation of impurity bands after the co-doping. The improvements of the electronic/ionic conductivities and the smaller particle sizes in the co-doped samples significantly contribute to improving their electrochemical properties. During the first cycle at 0.1 C, the optimized Cr0.6Ti0.8Nb10.6O29 sample delivers a large reversible capacity of 322 mAh g-1 with a large first-cycle Coulombic efficiency of 94.7%. At 10 C, it retains a large capacity of 206 mAh g-1, while that of Ti2Nb10O29 is only 80 mAh g-1. Furthermore, Cr0.6Ti0.8Nb10.6O29 shows high cyclic stability as demonstrated in over 500 cycles at 10 C with tiny capacity loss of only 0.01% per cycle.

Surveillance plan for the early detection of H5N1 highly pathogenic avian influenza virus in migratory birds in the United States: surveillance year 2009

USGS Publications Warehouse

Brand, Christopher J.

2009-01-01

Executive Summary: This Surveillance Plan (Plan) describes plans for conducting surveillance of wild birds in the United States and its Territories and Freely-Associated States to provide for early detection of the introduction of the H5N1 Highly Pathogenic Avian Influenza (HPAI) subtype of the influenza A virus by migratory birds during the 2009 surveillance year, spanning the period of April 1, 2009 - March 31, 2010. The Plan represents a continuation of surveillance efforts begun in 2006 under the Interagency Strategic Plan for the Early Detection of H5N1 Highly Pathogenic Avian Influenza in Wild Migratory Birds (U.S. Department of Agriculture and U.S. Department of the Interior, 2006). The Plan sets forth sampling plans by: region, target species or species groups to be sampled, locations of sampling, sample sizes, and sampling approaches and methods. This Plan will be reviewed annually and modified as appropriate for subsequent surveillance years based on evaluation of information from previous years of surveillance, changing patterns and threats of H5N1 HPAI, and changes in funding availability for avian influenza surveillance. Specific sampling strategies will be developed accordingly within each of six regions, defined here as Alaska, Hawaiian/Pacific Islands, Lower Pacific Flyway (Washington, Oregon, California, Idaho, Nevada, Arizona), Central Flyway, Mississippi Flyway, and Atlantic Flyway.

Characterization of Natural Organic Matter in Conventional Water Treatment Processes and Evaluation of THM Formation with Chlorine

PubMed Central

Özdemır, Kadir

2014-01-01

This study investigates the fractions of natural organic matter (NOM) and trihalomethane (THM) formation after chlorination in samples of raw water and the outputs from ozonation, coagulation-flocculation, and conventional filtration treatment units. All the water samples are passed through various ultrafiltration (UF) membranes. UF membranes with different molecular size ranges based on apparent molecular weight (AMW), such as 1000, 3000, 10,000, and 30,000 Daltons (Da), are commonly used. The NOM fraction with AMW < 1000 Da (1 K) is the dominant fraction within all the fractionated water samples. Its maximum percentage is 85.86% after the filtration process and the minimum percentage is 65.01% in raw water samples. The total THM (TTHM) yield coefficients range from 22.5 to 42 μg-TTHM/mg-DOC in all fractionated samples, which is related to their specific ultraviolet Absorbance (SUVA) levels. As the molecular weight of the fractions decreased, the TTHM yield coefficients increased. The NOM fractions with AMW values less than 1 K had lower SUVA values (<3 L/mg·m) for all treatment stages and also they had higher yield of TTHM per unit of DOC. The NOM fraction with AMW < 1 K for chlorinated raw water samples has the highest yield coefficient (42 μg-TTHM/mg-DOC). PMID:24558323

Performance of the University of Denver Low Turbulence, Airborne Aerosol Inlet in ACE-Asia

NASA Astrophysics Data System (ADS)

Lafleur, B.; Wilson, J. C.; Seebaugh, W. R.; Gesler, D.; Hilbert, H.; Mullen, J.; Reeves, J. M.

2002-12-01

The University of Denver Low Turbulence Inlet (DULTI) was flown on the NCAR C-130 in ACE-Asia. This inlet delivered large sample flows at velocities of a few meters per second at the exit of the inlet. This flow was slowed from the true air speed of the aircraft (100 to 150 m/s) to a few meters per second in a short diffuser with porous walls. The flow in the diffusing section was laminar. The automatic control system kept the inlet operating at near isokinetic intake velocities and in laminar flow for nearly all the flight time. The DULTI permits super micron particles to be sampled and delivered with high efficiency to the interior of the aircraft where they can be measured or collected. Because most of the air entering the inlet is removed through the porous medium, the sample flow experiences inertial enhancements. Because these enhancements occur in laminar flow, they are calculable using FLUENT. Enhancement factors are defined as the ratio of the number of particles of a given size per unit mass of air in the sample to the number of particles of that size per unit mass of air in the ambient. Experimenters divide measured mixing ratios of the aerosol by the enhancement factor to get the ambient mixing ratio of the particles. The diffuser used in ACE-Asia differed from that used in PELTI (2000), TexAQS2000 (2000) and ITCT (2002). In this poster, the flow parameters measured in the inlet in flight are compared with those calculated from FLUENT. And enhancement factors are presented for flight conditions. The enhancement factors are found to depend upon the Stokes number of particles in the entrance to the inlet and the ratio of the mass flow rate of air removed by suction to the mass flow rate delivered as sample.

Chi-Squared Test of Fit and Sample Size-A Comparison between a Random Sample Approach and a Chi-Square Value Adjustment Method.

PubMed

Bergh, Daniel

2015-01-01

Chi-square statistics are commonly used for tests of fit of measurement models. Chi-square is also sensitive to sample size, which is why several approaches to handle large samples in test of fit analysis have been developed. One strategy to handle the sample size problem may be to adjust the sample size in the analysis of fit. An alternative is to adopt a random sample approach. The purpose of this study was to analyze and to compare these two strategies using simulated data. Given an original sample size of 21,000, for reductions of sample sizes down to the order of 5,000 the adjusted sample size function works as good as the random sample approach. In contrast, when applying adjustments to sample sizes of lower order the adjustment function is less effective at approximating the chi-square value for an actual random sample of the relevant size. Hence, the fit is exaggerated and misfit under-estimated using the adjusted sample size function. Although there are big differences in chi-square values between the two approaches at lower sample sizes, the inferences based on the p-values may be the same.

Anthropometric Sizing, Fit-Testing and Evaluation of the MBU-12/P Oral-Nasal Oxygen Mask

DTIC Science & Technology

1979-08-01

Engineering Company, Sierra Madre , California, has a low profile single-unit facepiece in which a deformable silicone rubber face form is bonded to a...Churchill & Truett, 1957; Hertzberg et al., 1954). This comparison indicated that the 1967 sample was, on the average, older (2.64 years), taller (1.78...Support Special Projects Office, Wright-Patterson Air Force Base, Ohio, which, in turn, contracted with Sierra Engineering Company, Sierra Madre , California

Toxic Hazards Research Unit Annual Technical Report: 1975

DTIC Science & Technology

1975-10-01

by different sampling rates 160 21 Particle size distribution curves 167 22 Effect of 03 or N02 concentrations on rat lung weight 177 23 Relationship...previously, consisted of female C57 black/6 mice obtained from Jackson Laboratories, male CDF (Fischer 344 derived) albino rats from Charles River...the exposure phase of the study but made at the conclusion of the 5 ppm and 0. 5 ppm experiments were: Blood urea nitrogen SGOT Chloride Prothrombin

Sequential sampling and biorational chemistries for management of lepidopteran pests of vegetable amaranth in the Caribbean.

PubMed

Clarke-Harris, Dionne; Fleischer, Shelby J

2003-06-01

Although vegetable amaranth, Amaranthus viridis L. and A. dubius Mart. ex Thell., production and economic importance is increasing in diversified peri-urban farms in Jamaica, lepidopteran herbivory is common even during weekly pyrethroid applications. We developed and validated a sampling plan, and investigated insecticides with new modes of action, for a complex of five species (Pyralidae: Spoladea recurvalis (F.), Herpetogramma bipunctalis (F.), Noctuidae: Spodoptera exigua (Hubner), S. frugiperda (J. E. Smith), and S. eridania Stoll). Significant within-plant variation occurred with H. bipunctalis, and a six-leaf sample unit including leaves from the inner and outer whorl was selected to sample all species. Larval counts best fit a negative binomial distribution. We developed a sequential sampling plan using a threshold of one larva per sample unit and the fitted distribution with a k(c) of 0.645. When compared with a fixed plan of 25 plants, sequential sampling recommended the same management decision on 87.5%, additional samples on 9.4%, and gave inaccurate recommendations on 3.1% of 32 farms, while reducing sample size by 46%. Insecticide frequency was reduced 33-60% when management decisions were based on sampled data compared with grower-standards, with no effect on crop damage. Damage remained high or variable (10-46%) with pyrethroid applications. Lepidopteran control was dramatically improved with ecdysone agonists (tebufenozide) or microbial metabolites (spinosyns and emamectin benzoate). This work facilitates resistance management efforts concurrent with the introduction of newer modes of action for lepidopteran control in leafy vegetable production in the Caribbean.

Firefighter Hand Anthropometry and Structural Glove Sizing: A New Perspective.

PubMed

Hsiao, Hongwei; Whitestone, Jennifer; Kau, Tsui-Ying; Hildreth, Brooke

2015-12-01

We evaluated the current use and fit of structural firefighting gloves and developed an improved sizing scheme that better accommodates the U.S. firefighter population. Among surveys, 24% to 30% of men and 31% to 62% of women reported experiencing problems with the fit or bulkiness of their structural firefighting gloves. An age-, race/ethnicity-, and gender-stratified sample of 863 male and 88 female firefighters across the United States participated in the study. Fourteen hand dimensions relevant to glove design were measured. A cluster analysis of the hand dimensions was performed to explore options for an improved sizing scheme. The current national standard structural firefighting glove-sizing scheme underrepresents firefighter hand size range and shape variation. In addition, mismatch between existing sizing specifications and hand characteristics, such as hand dimensions, user selection of glove size, and the existing glove sizing specifications, is significant. An improved glove-sizing plan based on clusters of overall hand size and hand/finger breadth-to-length contrast has been developed. This study presents the most up-to-date firefighter hand anthropometry and a new perspective on glove accommodation. The new seven-size system contains narrower variations (standard deviations) for almost all dimensions for each glove size than the current sizing practices. The proposed science-based sizing plan for structural firefighting gloves provides a step-forward perspective (i.e., including two women hand model-based sizes and two wide-palm sizes for men) for glove manufacturers to advance firefighter hand protection. © 2015, Human Factors and Ergonomics Society.

A generalized least squares regression approach for computing effect sizes in single-case research: application examples.

PubMed

Maggin, Daniel M; Swaminathan, Hariharan; Rogers, Helen J; O'Keeffe, Breda V; Sugai, George; Horner, Robert H

2011-06-01

A new method for deriving effect sizes from single-case designs is proposed. The strategy is applicable to small-sample time-series data with autoregressive errors. The method uses Generalized Least Squares (GLS) to model the autocorrelation of the data and estimate regression parameters to produce an effect size that represents the magnitude of treatment effect from baseline to treatment phases in standard deviation units. In this paper, the method is applied to two published examples using common single case designs (i.e., withdrawal and multiple-baseline). The results from these studies are described, and the method is compared to ten desirable criteria for single-case effect sizes. Based on the results of this application, we conclude with observations about the use of GLS as a support to visual analysis, provide recommendations for future research, and describe implications for practice. Copyright © 2011 Society for the Study of School Psychology. Published by Elsevier Ltd. All rights reserved.

Sensitivity of super-efficient data envelopment analysis results to individual decision-making units: an example of surgical workload by specialty.

PubMed

Dexter, Franklin; O'Neill, Liam; Xin, Lei; Ledolter, Johannes

2008-12-01

We use resampling of data to explore the basic statistical properties of super-efficient data envelopment analysis (DEA) when used as a benchmarking tool by the manager of a single decision-making unit. Our focus is the gaps in the outputs (i.e., slacks adjusted for upward bias), as they reveal which outputs can be increased. The numerical experiments show that the estimates of the gaps fail to exhibit asymptotic consistency, a property expected for standard statistical inference. Specifically, increased sample sizes were not always associated with more accurate forecasts of the output gaps. The baseline DEA's gaps equaled the mode of the jackknife and the mode of resampling with/without replacement from any subset of the population; usually, the baseline DEA's gaps also equaled the median. The quartile deviations of gaps were close to zero when few decision-making units were excluded from the sample and the study unit happened to have few other units contributing to its benchmark. The results for the quartile deviations can be explained in terms of the effective combinations of decision-making units that contribute to the DEA solution. The jackknife can provide all the combinations contributing to the quartile deviation and only needs to be performed for those units that are part of the benchmark set. These results show that there is a strong rationale for examining DEA results with a sensitivity analysis that excludes one benchmark hospital at a time. This analysis enhances the quality of decision support using DEA estimates for the potential ofa decision-making unit to grow one or more of its outputs.

The Unique Properties of Agricultural Aerosols Measured at a Cattle Feeding Operation

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

Hiranuma, Naruki; Brooks, S. D.; Gramann, J.

2011-05-11

Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the nominally upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portablemore » Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 μm diameter. Raman microspectroscopy (RM) was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of fugitive dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 µm or less) were as high as 1200 μg/m3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant fraction of the organic particles was composed of internally mixed with salts. Basic characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences will lead to serious errors in estimates of aerosol effects on climate, visibility, and public health.« less

The unique properties of agricultural aerosols measured at a cattle feeding operation

NASA Astrophysics Data System (ADS)

Hiranuma, N.; Brooks, S. D.; Gramann, J.; Auvermann, B. W.

2011-05-01

Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the nominally upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portable Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 μm diameter. Raman microspectroscopy (RM) was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of fugitive dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 μm or less) were as high as 1200 μg m-3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant percentage of the organic particles, up to 28 %, were composed of internally mixed with salts. Basic characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences will lead to serious errors in estimates of aerosol effects on climate, visibility, and public health.

High concentrations of coarse particles emitted from a cattle feeding operation

NASA Astrophysics Data System (ADS)

Hiranuma, N.; Brooks, S. D.; Gramann, J.; Auvermann, B. W.

2011-08-01

Housing roughly 10 million head of cattle in the United States alone, open air cattle feedlots represent a significant but poorly constrained source of atmospheric particles. Here we present a comprehensive characterization of physical and chemical properties of particles emitted from a large representative cattle feedlot in the Southwest United States. In the summer of 2008, measurements and samplings were conducted at the upwind and downwind edges of the facility. A series of far-field measurements and samplings was also conducted 3.5 km north of the facility. Two instruments, a GRIMM Sequential Mobility Particle Sizer (SMPS) and a GRIMM Portable Aerosol Spectrometer (PAS), were used to measure particle size distributions over the range of 0.01 to 25 μm diameter. Raman microspectroscopy was used to determine the chemical composition of particles on a single particle basis. Volume size distributions of dust were dominated by coarse mode particles. Twenty-four hour averaged concentrations of PM10 (particulate matter with a diameter of 10 μm or less) were as high as 1200 μg m-3 during the campaign. The primary constituents of the particulate matter were carbonaceous materials, such as humic acid, water soluble organics, and less soluble fatty acids, including stearic acid and tristearin. A significant fraction of the organic particles was present in internal mixtures with salts. Basic characteristics such as size distribution and composition of agricultural aerosols were found to be different than the properties of those found in urban and semi-urban aerosols. Failing to account for such differences may lead to errors in estimates of aerosol effects on local air quality, visibility, and public health.

Distribution of metals in various particle-size fractions in topsoils of a small dry valley system (European Russia, forest zone)

NASA Astrophysics Data System (ADS)

Samonova, Olga; Aseyeva, Elena

2017-04-01

A detailed study of heavy metals distribution in various soil grain-size fractions helps to increase the knowledge about the complex nature of metals' occurrence and their distribution pathways in the environment. On the basis of particle size fractionation of topsoil horizons we examined the specific behavior of heavy metals in a small erosional landform located in the humid temperate zone of the Russian Plain. The object of the study is a 400 m small U-shaped dry valley (balka in Russian) with a catchment area of 32.8 ha located in the central part of the Protva river basin, 100 km southwest of Moscow. The uppermost parts of the landform are incised in Late Pleistocene loessial loams, which cover significant portions of interfluve area in the region, while the middle and the lower parts cut through Middle Pleistocene glacial sediments. A total of 50 samples were collected from topsoil horizons of different landform geomorphic units along three cross-sections as well as along the bottom of the landform and its detrital fan. Samples were analyzed for Mn, Cu, Ni, Co, Cr, Zn, Pb, Ti, Zr, and Fe content. Eleven samples were chosen for physical fractionation into 5 grain-size fractions (1-0.25 mm, 0.25-0.05 mm, 0.05-0.01 mm, 0.01-0.001 mm and <0.001 mm) and further analysis for fractionized metal contents. Across the grain-size fractions the maximum Zr content was observed in the coarse silt fraction and Ti - in the medium and fine silt fraction, while other metals, such as Fe, Mn, Co, Ni, Cr, Pb, and Zn revealed their highest concentrations in the clay fraction. For Fe, Mn, Co and Ni a second concentration peak was observed in the coarse and medium sand fraction. Due to probably eolian genesis and (or) transformation during weathering, the coarse silt fraction in comparison to other fractions showed a depletion of the majority of metals while the minimum concentrations of Ti, Zr and Cr were limited to the coarse and medium sand. Statistical analysis showed that the variation of metal contents depends on particle sizes: the Cv coefficients calculated for Cu, Ni, Co, Fe, Mn, Ti and Zr reach their maximum in the 1-0.25 mm fraction (for Cu and Ni exceeding 75%, for Ti, Zr being around 40%). For Zn, Cr and Pb the maximum variation (50-60%) was found in the 0.25-0.05 mm fraction. In contrast, the two studied silt fractions and also the clay showed very low variations of all metal contents (except for Mn) characteristically in the range between 6% (Cr) and 23.5% (Zn). Unlike the finer fractions, which displayed very poor geochemical differentiation across the landform's geomorphic units, the coarser (sand) fractions showed distinct spatial patterns in the elements' distribution, possibly related to migration processes, the depletion of metals in the landforms' slopes and their prevalent enrichment in the bottom unit is observed.

Evidence for spawning aggregations of the endangered Atlantic goliath grouper Epinephelus itajara in southern Brazil.

PubMed

Bueno, L S; Bertoncini, A A; Koenig, C C; Coleman, F C; Freitas, M O; Leite, J R; De Souza, T F; Hostim-Silva, M

2016-07-01

In this study, seasonal numerical abundance of the critically endangered Atlantic goliath grouper Epinephelus itajara was estimated by conducting scuba dive surveys and calculating sightings-per-unit-effort (SPUE) at three sites in southern Brazil. Seasonal differences in size and reproductive condition of captured or confiscated specimens were compared. The SPUE differed significantly with season, increasing in late spring and peaking during the austral summer months. A significant effect was observed in the number of fish relative to the lunar cycle. All females sampled during the summer were spawning capable, while all those sampled during other seasons were either regressing or regenerating. What these data strongly infer is that the E. itajara spawning aggregation sites have been located in the southern state of Paraná and the northern state of Santa Catarina and summer is the most likely spawning season. Size frequency distributions, abundance and reproductive state were estimated and correlated with environmental variables. © 2016 The Fisheries Society of the British Isles.

Laser stimulated third harmonic generation studies in ZnO-Ta2O5-B2O3 glass ceramics entrenched with Zn3Ta2O8 crystal phases

NASA Astrophysics Data System (ADS)

Siva Sesha Reddy, A.; Jedryka, J.; Ozga, K.; Ravi Kumar, V.; Purnachand, N.; Kityk, I. V.; Veeraiah, N.

2018-02-01

In this study zinc borate glasses doped with different concentrations Ta2O5 were synthesized and were crystallized by heat treatment for prolonged times. The samples were characterized by XRD, SEM, IR and Raman spectroscopy techniques. The SEM images of the crystallized samples have indicated that the samples contain randomly distributed crystal grains with size ∼1 μm entrenched in the residual amorphous phase. XRD studies have exhibited diffraction peaks identified as being due to the reflections from (1 1 1) planes of monoclinic Zn3Ta2O8 crystal phase that contains intertwined tetrahedral zinc and octahedral tantalate structural units. The concentration of such crystal phases in the bulk samples is observed to increase with increase of Ta2O5 up to 3.0 mol%. The IR and Raman spectroscopy studies have confirmed the presence of ZnO4 and TaO6 structural units in the glass network in addition to the conventional borate structural units. For measuring third harmonic generation (THG) in the samples, the samples were irradiated with 532 nm laser beam and the intensity of THG of probing beam (Nd:YAG λ = 1064 nm 20 ns pulsed laser (ω)) is measured as a function of fundamental beam power varying up to 200 J/m2. The intensity of THG is found to be increasing with increase of fundamental beam power and found to be the maximal for the glass crystallized with 3.0 mol% of Ta2O5. The intensity of THG of the ceramicized samples is found to be nearly 5 times higher with respect to that of pre-crystallized samples. The generation of 3ω is attributed to the perturbation/interaction between Zn3Ta2O8 anisotropic crystal grains and the incident probing beam.

Lithological indicators of loess sedimentation of SW Poland

NASA Astrophysics Data System (ADS)

Krawczyk, Marcin; Ryzner, Kamila; Skurzyński, Jacek; Jary, Zdzisław

2017-12-01

High-resolution grain-size investigations were carried out in two SW Polish loess sections: Biały Kościół (Niemcza-Strzelin Hills) and Zaprężyn (Trzebnica Hills). Each sequence was sampled by using the same methodology and samples were taken at 5 centimeters intervals. The particle size distribution was obtained with a Mastersizer 2000 laser, used for diffraction methods. From the obtained results the basic parameters and grain size indicators were calculated: Mz, Grain Size Index ratio, U-ratio and the percentage content of clay (< 4μm) and sand (> 63 μm). Both loess-soil sequences are composed of interfluve and slope loess facies and consist of five litho-pedostratigraphic units developed during the Late Pleistocene and Holocene: two loess units L1LL1, L1LL2 and three polygenetic fossil soils sets S0, S1 and L1SS1. The distance between these two profiles is about 60 km. Zaprężyn, as a section located more to the north, has almost no lower younger loess and higher level of weathering which could be related to proximity of this site to the Ice Sheet margin. The climate here was more extreme and harsh. What is more, the difference in development of soil L1SS1 can be observed: while in Biały Kościół pedogenesis process was slower and less disturbed than in Zaprężyn. The upper part of L1SS1 in Biały Kościół was deformed by gelifluction, frost heave and other periglacial processes. Mz indicator by the grain-size distribution in these sediments reflects subtle variations in the climatic system. Moreover, in Zaprężyn the content of sand fraction is higher than in Biały Kościół what can be the evidence of short episodes of strong winds during cold period of sedimentation. The aim of this paper is to compare two loess profiles by their stratigraphical and lithological similarities which are result of climate conditions and features of surrounding environment.

Structure and builtup of the Middle Bengal Fan at 8°N from multichannel seismic surveys and the IODP Expedition 354 drilling transect

NASA Astrophysics Data System (ADS)

Spiess, V.; Bergmann, F.; Schwenk, T.; Lantzsch, H.; Bahk, J. J.; Weber, M. E.; France-Lanord, C.; Klaus, A.

2016-12-01

IODP Expedition 354 to the Bengal Fan drilled a 320 km long e-W transect at 8°N with 7 drill sites, fully covering the uppermost 150-200 meters of fan deposits at distances of 50 km, originating from Himalayan mountain ranges and the Ganges-Brahmaputra river system. A major goal of this transect approach was to ensure a continuous record of turbiditic material delivered over the last appx. 1 million year, considering frequent longitudinal depocenter shifts of the active channel. By extensively utilizing the new half-APC coring technique, high quality and high recovery cores could be retrieved representing a wide range of grain sizes from hemipelagic deposits through clay rich turbidites to coarse silt and sandy units. Up to medium sand grain sizes were retrieved within the basal units of levees, which correspond to high-reflectivity units in high-resolution multichannel seismic profiles. Finely laminated sections with mm to cm-thick turbidites represents levee formations. At Site U1453 for example, core logging and downhole logging data confirm the representative sampling based on a very good match of several physical property data sets. An expanded section was cored at Site U1454, where the presumably currently active channel has built a levee, which likely represents major sediment supply within the last 30 kyr. A spatial grid of seismic and echosounder data in the vicinity of the active channel reveals a high spatial variability in sedimentation rates and distinct depocenter shifts in response to changes in channel geometry. Site U1452 has provided a full record a levee growth including interlevee sedimentation, sandy basal units characterized by a lobe formation, and a pronounced fining upward trend following the phase of channel erosion and levee builtup. From all sites, detailed comparisons of physical and sedimentological shipboard results with seismic data will be presented. Expedition 354 has provided a unique sample and data set to better understand fan deposition and channel-levee growth including silt and sand grain sizes. It will also provide valuable constraints on the volume, nature and composition of suspension flows contributing to fan growth in the Middle Bengal Fan.

Updating the planetary time scale: focus on Mars

USGS Publications Warehouse

Tanaka, Kenneth L.; Quantin-Nataf, Cathy

2013-01-01

Formal stratigraphic systems have been developed for the surface materials of the Moon, Mars, Mercury, and the Galilean satellite Ganymede. These systems are based on geologic mapping, which establishes relative ages of surfaces delineated by superposition, morphology, impact crater densities, and other relations and features. Referent units selected from the mapping determine time-stratigraphic bases and/or representative materials characteristic of events and periods for definition of chronologic units. Absolute ages of these units in some cases can be estimated using crater size-frequency data. For the Moon, the chronologic units and cratering record are calibrated by radiometric ages measured from samples collected from the lunar surface. Model ages for other cratered planetary surfaces are constructed primarily by estimating cratering rates relative to that of the Moon. Other cratered bodies with estimated surface ages include Venus and the Galilean satellites of Jupiter. New global geologic mapping and crater dating studies of Mars are resulting in more accurate and detailed reconstructions of its geologic history.

Cultural beliefs and attitudes toward health and health care among Asian-born women in the United States.

PubMed

Zhao, Meng; Esposito, Noreen; Wang, Kefang

2010-01-01

To describe Asian-born women's cultural beliefs and attitudes towards health, illness, and health care practices. Online databases PubMed and CINAHL. Twenty-four studies published between January 2000 and May 2009 were retrieved based on the inclusion criteria. Data on publication year, authors, study sample, sample size (only Asian women in the United States were included), design, and related key findings were extracted. Data were organized under three categories: Asian cultural beliefs about health and illness, health promotion and illness prevention, and health care practices. Common beliefs across groups and unique beliefs within specific Asian ethnic groups were synthesized. The results indicated that different Asian ethnic groups share some health beliefs, but each group also has unique health beliefs. Existing literature on cultural health beliefs of Asian-born women is limited. Health care providers can use the findings of this review to improve health care utilization among Asian-born women.

Geometric morphometric analysis of allometric variation in the mandibular morphology of the hominids of Atapuerca, Sima de los Huesos site.

PubMed

Rosas, Antonio; Bastir, Markus

2004-06-01

Allometry is an important factor of morphological integration that contributes to the organization of the phenotype and its variation. Variation in the allometric shape of the mandible is particularly important in hominid evolution because the mandible carries important taxonomic traits. Some of these traits are known to covary with size, particularly the retromolar space, symphyseal curvature, and position of the mental foramen. The mandible is a well studied system in the context of the evolutionary development of complex morphological structures because it is composed of different developmental units that are integrated within a single bone. In the present study, we investigated the allometric variation of two important developmental units that are separated by the inferior nerve (a branch of CN V3). We tested the null hypothesis that there would be no difference in allometric variation between the two components. Procrustes-based geometric morphometrics of 20 two-dimensional (2D) landmarks were analyzed by multivariate regressions of shape on size in samples from 121 humans, 48 chimpanzees, and 50 gorillas (all recent specimens), eight fossil hominids from Atapuerca, Sima de los Huesos (AT-SH), and 17 Neandertals. The findings show that in all of the examined species, there was significantly greater allometric variation in the supra-nerve unit than in the infra-nerve unit. The formation of the retromolar space exhibited an allometric relationship with the supra-nerve unit in all of the species studied. The formation of the chin-like morphology is an "apodynamic" feature of the infra-nerve unit in the AT-SH hominids. The results of this study support the hypothesis that allometry contributes to the organization of variation in complex morphological structures. Copyright 2004 Wiley-Liss, Inc.

24 CFR 886.125 - Overcrowded and underoccupied units.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Sanitary by reason of increase in Family size or that a Contract unit is larger than appropriate for the size of the Family in occupancy, housing assistance payments with respect to such unit will not be abated, unless the Owner fails to offer the Family a suitable unit as soon as one becomes vacant and...

Incorporating GIS and remote sensing for census population disaggregation

NASA Astrophysics Data System (ADS)

Wu, Shuo-Sheng'derek'

Census data are the primary source of demographic data for a variety of researches and applications. For confidentiality issues and administrative purposes, census data are usually released to the public by aggregated areal units. In the United States, the smallest census unit is census blocks. Due to data aggregation, users of census data may have problems in visualizing population distribution within census blocks and estimating population counts for areas not coinciding with census block boundaries. The main purpose of this study is to develop methodology for estimating sub-block areal populations and assessing the estimation errors. The City of Austin, Texas was used as a case study area. Based on tax parcel boundaries and parcel attributes derived from ancillary GIS and remote sensing data, detailed urban land use classes were first classified using a per-field approach. After that, statistical models by land use classes were built to infer population density from other predictor variables, including four census demographic statistics (the Hispanic percentage, the married percentage, the unemployment rate, and per capita income) and three physical variables derived from remote sensing images and building footprints vector data (a landscape heterogeneity statistics, a building pattern statistics, and a building volume statistics). In addition to statistical models, deterministic models were proposed to directly infer populations from building volumes and three housing statistics, including the average space per housing unit, the housing unit occupancy rate, and the average household size. After population models were derived or proposed, how well the models predict populations for another set of sample blocks was assessed. The results show that deterministic models were more accurate than statistical models. Further, by simulating the base unit for modeling from aggregating blocks, I assessed how well the deterministic models estimate sub-unit-level populations. I also assessed the aggregation effects and the resealing effects on sub-unit estimates. Lastly, from another set of mixed-land-use sample blocks, a mixed-land-use model was derived and compared with a residential-land-use model. The results of per-field land use classification are satisfactory with a Kappa accuracy statistics of 0.747. Model Assessments by land use show that population estimates for multi-family land use areas have higher errors than those for single-family land use areas, and population estimates for mixed land use areas have higher errors than those for residential land use areas. The assessments of sub-unit estimates using a simulation approach indicate that smaller areas show higher estimation errors, estimation errors do not relate to the base unit size, and resealing improves all levels of sub-unit estimates.

History of water-column anoxia in the Black Sea indicated by pyrite framboid size distributions

USGS Publications Warehouse

Wilkin, R.T.; Arthur, M.A.; Dean, W.E.

1997-01-01

A detailed study of size distributions of framboidal pyrite in Holocene Black Sea sediments establishes the timing of a change from deposition under an oxic water column to deposition under an anoxic and sulfidic water column. In the most recent carbonate-rich sediments (Unit I) and in the organic carbon-rich sapropel (Unit II), framboid size distributions are remarkably uniform (mean diameter= 5 ??m); over 95% of the framboids in Unit I and Unit II are < 7 ??m in diameter. These properties of framboidal pyrite are consistent with framboid nucleation and growth within an anoxic and sulfidic water column, followed by transport to the sediment-water interface, cessation of pyrite growth due to the exhaustion of reactive iron, and subsequent burial. In contrast, the organic carbon-poor sediments of lacustrine Unit III contain pyrite framboids that are generally much larger in size (mean diameter = 10 ??m). In Unit III, over 95% of the framboids are < 25 ??m in diameter, 40% of framboids are between 7 ??m and 25 ??m, and framboids up to 50 ??m in diameter are present. This distribution of sizes suggests framboid nucleation and growth within anoxic sediment porewaters. These new data on size distributions of framboidal pyrite confirm that the development of water-column anoxia in the Black Sea coincided with the initiation of deposition of laminated Unit II sapropels.

Analysis of area level and unit level models for small area estimation in forest inventories assisted with LiDAR auxiliary information.

PubMed

Mauro, Francisco; Monleon, Vicente J; Temesgen, Hailemariam; Ford, Kevin R

2017-01-01

Forest inventories require estimates and measures of uncertainty for subpopulations such as management units. These units often times hold a small sample size, so they should be regarded as small areas. When auxiliary information is available, different small area estimation methods have been proposed to obtain reliable estimates for small areas. Unit level empirical best linear unbiased predictors (EBLUP) based on plot or grid unit level models have been studied more thoroughly than area level EBLUPs, where the modelling occurs at the management unit scale. Area level EBLUPs do not require a precise plot positioning and allow the use of variable radius plots, thus reducing fieldwork costs. However, their performance has not been examined thoroughly. We compared unit level and area level EBLUPs, using LiDAR auxiliary information collected for inventorying 98,104 ha coastal coniferous forest. Unit level models were consistently more accurate than area level EBLUPs, and area level EBLUPs were consistently more accurate than field estimates except for large management units that held a large sample. For stand density, volume, basal area, quadratic mean diameter, mean height and Lorey's height, root mean squared errors (rmses) of estimates obtained using area level EBLUPs were, on average, 1.43, 2.83, 2.09, 1.40, 1.32 and 1.64 times larger than those based on unit level estimates, respectively. Similarly, direct field estimates had rmses that were, on average, 1.37, 1.45, 1.17, 1.17, 1.26, and 1.38 times larger than rmses of area level EBLUPs. Therefore, area level models can lead to substantial gains in accuracy compared to direct estimates, and unit level models lead to very important gains in accuracy compared to area level models, potentially justifying the additional costs of obtaining accurate field plot coordinates.

Analysis of area level and unit level models for small area estimation in forest inventories assisted with LiDAR auxiliary information

PubMed Central

Monleon, Vicente J.; Temesgen, Hailemariam; Ford, Kevin R.

2017-01-01

Forest inventories require estimates and measures of uncertainty for subpopulations such as management units. These units often times hold a small sample size, so they should be regarded as small areas. When auxiliary information is available, different small area estimation methods have been proposed to obtain reliable estimates for small areas. Unit level empirical best linear unbiased predictors (EBLUP) based on plot or grid unit level models have been studied more thoroughly than area level EBLUPs, where the modelling occurs at the management unit scale. Area level EBLUPs do not require a precise plot positioning and allow the use of variable radius plots, thus reducing fieldwork costs. However, their performance has not been examined thoroughly. We compared unit level and area level EBLUPs, using LiDAR auxiliary information collected for inventorying 98,104 ha coastal coniferous forest. Unit level models were consistently more accurate than area level EBLUPs, and area level EBLUPs were consistently more accurate than field estimates except for large management units that held a large sample. For stand density, volume, basal area, quadratic mean diameter, mean height and Lorey’s height, root mean squared errors (rmses) of estimates obtained using area level EBLUPs were, on average, 1.43, 2.83, 2.09, 1.40, 1.32 and 1.64 times larger than those based on unit level estimates, respectively. Similarly, direct field estimates had rmses that were, on average, 1.37, 1.45, 1.17, 1.17, 1.26, and 1.38 times larger than rmses of area level EBLUPs. Therefore, area level models can lead to substantial gains in accuracy compared to direct estimates, and unit level models lead to very important gains in accuracy compared to area level models, potentially justifying the additional costs of obtaining accurate field plot coordinates. PMID:29216290

Magnetic properties of the upper mantle beneath the continental United States

NASA Astrophysics Data System (ADS)

Friedman, S. A.; Ferre, E. C.; Demory, F.; Rochette, P.; Martin Hernandez, F.; Conder, J. A.

2012-12-01

The interpretation of long wavelength satellite magnetic data (Magsat, Oersted, CHAMP, SWARM) requires an understanding of magnetic mineralogy in the lithospheric mantle and reliable models of induced and remanent magnetic sources in the lithospheric mantle and the crust. Blakely et al. (2005) proposed the hypothesis of a magnetic lithospheric mantle in subduction zones. This prompted us to reexamine magnetic sources in the lithospheric mantle in different tectonic settings where unaltered mantle xenolith have been reported since the 1990s. Xenoliths from the upper mantle beneath the continental United States show different magnetic properties depending on the tectonic setting in which they equilibrated. Three localities in the South Central United States (San Carlos, AZ; Kilbourne Hole, NM; Knippa, TX) produced lherzolite and harzburgite xenoliths, while the Bearpaw Mountains in Montana (subduction zone) produced dunite and phlogopite-rich dunite xenoliths. Paleomagnetic data on these samples shows the lack of secondary alteration which is commonly caused by post-eruption serpentinization and the lack of basalt contamination. The main magnetic carrier is pure magnetite. The ascent of mantle xenoliths to the surface of the Earth generally takes only a few hours. Numerical modelling shows that nucleation of magnetite during ascent would form superparamagnetic grains and therefore cannot explain the observed magnetic grain sizes. This implies that the ferromagnetic phases present in the studied samples formed at mantle depth. The samples from the South Central United States exhibit a small range in low-field magnetic susceptibility (+/- 0.00003 [SI]), and Natural Remanent Magnetization (NRM) between 0.001 - 0.100 A/m. To the contrary samples from the Bearpaw Mountains exhibit a wider range of low-field susceptibilities (0.00001 to 0.0015 [SI]) and NRM (0.01 and 9.00 A/m). These samples have been serpentinized in-situ by metasomatic fluids related to the Farallon plate (Facer et al., 2009). Hence, the magnetic properties of the lithospheric mantle beneath the continental United States differ significantly depending on tectonic setting. The combination of the low geotherm observed in the Bearpaw Mountains with the stronger induced and remanent magnetization of mantle rocks in this area may produce a detectable LWMA.

Do fixed-dose combination pills or unit-of-use packaging improve adherence? A systematic review.

PubMed Central

Connor, Jennie; Rafter, Natasha; Rodgers, Anthony

2004-01-01

Adequate adherence to medication regimens is central to the successful treatment of communicable and noncommunicable disease. Fixed-dose combination pills and unit-of-use packaging are therapy-related interventions that are designed to simplify medication regimens and so potentially improve adherence. We conducted a systematic review of relevant randomized trials in order to quantify the effects of fixed-dose combination pills and unit-of-use packaging, compared with medications as usually presented, in terms of adherence to treatment and improved outcomes. Only 15 trials met the inclusion criteria; fixed-dose combination pills were investigated in three of these, while unit-of-use packaging was studied in 12 trials. The trials involved treatments for communicable diseases (n = 5), blood pressure lowering medications (n = 3), diabetic patients (n = 1), vitamin supplementation (n = 1) and management of multiple medications by the elderly (n = 5). The results of the trials suggested that there were trends towards improved adherence and/or clinical outcomes in all but three of the trials; this reached statistical significance in four out of seven trials reporting a clinically relevant or intermediate end-point, and in seven out of thirteen trials reporting medication adherence. Measures of outcome were, however, heterogeneous, and interpretation was further limited by methodological issues, particularly small sample size, short duration and loss to follow-up. Overall, the evidence suggests that fixed-dose combination pills and unit-of-use packaging are likely to improve adherence in a range of settings, but the limitations of the available evidence means that uncertainty remains about the size of these benefits. PMID:15654408

Online alcohol interventions: a systematic review.

PubMed

White, Angela; Kavanagh, David; Stallman, Helen; Klein, Britt; Kay-Lambkin, Frances; Proudfoot, Judy; Drennan, Judy; Connor, Jason; Baker, Amanda; Hines, Emily; Young, Ross

2010-12-19

There has been a significant increase in the availability of online programs for alcohol problems. A systematic review of the research evidence underpinning these programs is timely. Our objective was to review the efficacy of online interventions for alcohol misuse. Systematic searches of Medline, PsycINFO, Web of Science, and Scopus were conducted for English abstracts (excluding dissertations) published from 1998 onward. Search terms were: (1) Internet, Web*; (2) online, computer*; (3) alcohol*; and (4) E\\effect*, trial*, random* (where * denotes a wildcard). Forward and backward searches from identified papers were also conducted. Articles were included if (1) the primary intervention was delivered and accessed via the Internet, (2) the intervention focused on moderating or stopping alcohol consumption, and (3) the study was a randomized controlled trial of an alcohol-related screen, assessment, or intervention. The literature search initially yielded 31 randomized controlled trials (RCTs), 17 of which met inclusion criteria. Of these 17 studies, 12 (70.6%) were conducted with university students, and 11 (64.7%) specifically focused on at-risk, heavy, or binge drinkers. Sample sizes ranged from 40 to 3216 (median 261), with 12 (70.6%) studies predominantly involving brief personalized feedback interventions. Using published data, effect sizes could be extracted from 8 of the 17 studies. In relation to alcohol units per week or month and based on 5 RCTs where a measure of alcohol units per week or month could be extracted, differential effect sizes to posttreatment ranged from 0.02 to 0.81 (mean 0.42, median 0.54). Pre-post effect sizes for brief personalized feedback interventions ranged from 0.02 to 0.81, and in 2 multi-session modularized interventions, a pre-post effect size of 0.56 was obtained in both. Pre-post differential effect sizes for peak blood alcohol concentrations (BAC) ranged from 0.22 to 0.88, with a mean effect size of 0.66. The available evidence suggests that users can benefit from online alcohol interventions and that this approach could be particularly useful for groups less likely to access traditional alcohol-related services, such as women, young people, and at-risk users. However, caution should be exercised given the limited number of studies allowing extraction of effect sizes, the heterogeneity of outcome measures and follow-up periods, and the large proportion of student-based studies. More extensive RCTs in community samples are required to better understand the efficacy of specific online alcohol approaches, program dosage, the additive effect of telephone or face-to-face interventions, and effective strategies for their dissemination and marketing.

Online Alcohol Interventions: A Systematic Review

PubMed Central

Kavanagh, David; Stallman, Helen; Klein, Britt; Kay-Lambkin, Frances; Proudfoot, Judy; Drennan, Judy; Connor, Jason; Baker, Amanda; Hines, Emily; Young, Ross

2010-01-01

Background There has been a significant increase in the availability of online programs for alcohol problems. A systematic review of the research evidence underpinning these programs is timely. Objectives Our objective was to review the efficacy of online interventions for alcohol misuse. Systematic searches of Medline, PsycINFO, Web of Science, and Scopus were conducted for English abstracts (excluding dissertations) published from 1998 onward. Search terms were: (1) Internet, Web*; (2) online, computer*; (3) alcohol*; and (4) E\\effect*, trial*, random* (where * denotes a wildcard). Forward and backward searches from identified papers were also conducted. Articles were included if (1) the primary intervention was delivered and accessed via the Internet, (2) the intervention focused on moderating or stopping alcohol consumption, and (3) the study was a randomized controlled trial of an alcohol-related screen, assessment, or intervention. Results The literature search initially yielded 31 randomized controlled trials (RCTs), 17 of which met inclusion criteria. Of these 17 studies, 12 (70.6%) were conducted with university students, and 11 (64.7%) specifically focused on at-risk, heavy, or binge drinkers. Sample sizes ranged from 40 to 3216 (median 261), with 12 (70.6%) studies predominantly involving brief personalized feedback interventions. Using published data, effect sizes could be extracted from 8 of the 17 studies. In relation to alcohol units per week or month and based on 5 RCTs where a measure of alcohol units per week or month could be extracted, differential effect sizes to posttreatment ranged from 0.02 to 0.81 (mean 0.42, median 0.54). Pre-post effect sizes for brief personalized feedback interventions ranged from 0.02 to 0.81, and in 2 multi-session modularized interventions, a pre-post effect size of 0.56 was obtained in both. Pre-post differential effect sizes for peak blood alcohol concentrations (BAC) ranged from 0.22 to 0.88, with a mean effect size of 0.66. Conclusions The available evidence suggests that users can benefit from online alcohol interventions and that this approach could be particularly useful for groups less likely to access traditional alcohol-related services, such as women, young people, and at-risk users. However, caution should be exercised given the limited number of studies allowing extraction of effect sizes, the heterogeneity of outcome measures and follow-up periods, and the large proportion of student-based studies. More extensive RCTs in community samples are required to better understand the efficacy of specific online alcohol approaches, program dosage, the additive effect of telephone or face-to-face interventions, and effective strategies for their dissemination and marketing. PMID:21169175

Density, aggregation, and body size of northern pikeminnow preying on juvenile salmonids in a large river

USGS Publications Warehouse

Petersen, J.H.

2001-01-01

Predation by northern pikeminnow Ptychocheilus oregonensis on juvenile salmonids Oncorhynchus spp. occurred probably during brief feeding bouts since diets were either dominated by salmonids (>80% by weight), or contained other prey types and few salmonids (<5%). In samples where salmonids had been consumed, large rather than small predators were more likely to have captured salmonids. Transects with higher catch-per-unit of effort of predators also had higher incidences of salmonids in predator guts. Predators in two of three reservoir areas were distributed more contagiously if they had preyed recently on salmonids. Spatial and temporal patchiness of salmonid prey may be generating differences in local density, aggregation, and body size of their predators in this large river.

Sex differences and similarities in job attribute preferences: a meta-analysis.

PubMed

Konrad, A M; Ritchie, J E; Lieb, P; Corrigall, E

2000-07-01

Many researchers have studied sex differences in job attribute preferences. The authors meta-analyzed 242 samples collected from 321,672 men and boys and 316,842 women and girls in the United States between 1970 and 1998. Findings indicated significant (p < .05) sex differences on 33 of 40 job attribute preferences examined. The effect sizes were small. Of the 33 significant differences, 26 had average effect sizes of magnitude .20 or less. The directions of the differences were generally consistent with gender roles and stereotypes. Many job attributes became relatively more important to women and girls in the 1980s and 1990s compared with the 1970s, indicating that women's aspirations to obtain job attributes rose as gender barriers to opportunity declined.

Estimates of long-term mean-annual nutrient loads considered for use in SPARROW models of the Midcontinental region of Canada and the United States, 2002 base year

USGS Publications Warehouse

Saad, David A.; Benoy, Glenn A.; Robertson, Dale M.

2018-05-11

Streamflow and nutrient concentration data needed to compute nitrogen and phosphorus loads were compiled from Federal, State, Provincial, and local agency databases and also from selected university databases. The nitrogen and phosphorus loads are necessary inputs to Spatially Referenced Regressions on Watershed Attributes (SPARROW) models. SPARROW models are a way to estimate the distribution, sources, and transport of nutrients in streams throughout the Midcontinental region of Canada and the United States. After screening the data, approximately 1,500 sites sampled by 34 agencies were identified as having suitable data for calculating the long-term mean-annual nutrient loads required for SPARROW model calibration. These final sites represent a wide range in watershed sizes, types of nutrient sources, and land-use and watershed characteristics in the Midcontinental region of Canada and the United States.

Use of a miniature diamond-anvil cell in high-pressure single-crystal neutron Laue diffraction

PubMed Central

Binns, Jack; Kamenev, Konstantin V.; McIntyre, Garry J.; Moggach, Stephen A.; Parsons, Simon

2016-01-01

The first high-pressure neutron diffraction study in a miniature diamond-anvil cell of a single crystal of size typical for X-ray diffraction is reported. This is made possible by modern Laue diffraction using a large solid-angle image-plate detector. An unexpected finding is that even reflections whose diffracted beams pass through the cell body are reliably observed, albeit with some attenuation. The cell body does limit the range of usable incident angles, but the crystallographic completeness for a high-symmetry unit cell is only slightly less than for a data collection without the cell. Data collections for two sizes of hexamine single crystals, with and without the pressure cell, and at 300 and 150 K, show that sample size and temperature are the most important factors that influence data quality. Despite the smaller crystal size and dominant parasitic scattering from the diamond-anvil cell, the data collected allow a full anisotropic refinement of hexamine with bond lengths and angles that agree with literature data within experimental error. This technique is shown to be suitable for low-symmetry crystals, and in these cases the transmission of diffracted beams through the cell body results in much higher completeness values than are possible with X-rays. The way is now open for joint X-ray and neutron studies on the same sample under identical conditions. PMID:27158503

Geochemistry of sediments in the Northern and Central Adriatic Sea

NASA Astrophysics Data System (ADS)

De Lazzari, A.; Rampazzo, G.; Pavoni, B.

2004-03-01

Major, minor and trace elements, loss of ignition, specific surface area, quantities of calcite and dolomite, qualitative mineralogical composition, grain-size distribution and organic micropollutants (PAH, PCB, DDT) were determined on surficial marine sediments sampled during the 1990 ASCOP (Adriatic Scientific Cooperative Program) cruise. Mineralogical composition and carbonate content of the samples were found to be comparable with data previously reported in the literature, whereas geochemical composition and distribution of major, minor and trace elements for samples in international waters and in the central basin have never been reported before. The large amount of information contained in the variables of different origin has been processed by means of a comprehensive approach which establishes the relations among the components through the mathematical-statistical calculation of principal components (factors). These account for the major part of data variance loosing only marginal parts of information and are independent from the units of measure. The sample descriptors concerning natural components and contamination load are discussed by means of a statistical model based on an R-mode Factor analysis calculating four significant factors which explain 86.8% of the total variance, and represent important relationships between grain size, mineralogy, geochemistry and organic micropollutants. A description and an interpretation of factor composition is discussed on the basis of pollution inputs, basin geology and hydrodynamics. The areal distribution of the factors showed that it is the fine grain-size fraction, with oxides and hydroxides of colloidal origin, which are the main means of transport and thus the principal link between chemical, physical and granulometric elements in the Adriatic.

Temporal analysis of genetic structure to assess population dynamics of reintroduced swift foxes.

PubMed

Cullingham, Catherine I; Moehrenschlager, Axel

2013-12-01

Reintroductions are increasingly used to reestablish species, but a paucity of long-term postrelease monitoring has limited understanding of whether and when viable populations subsequently persist. We conducted temporal genetic analyses of reintroduced populations of swift foxes (Vulpes velox) in Canada (Alberta and Saskatchewan) and the United States (Montana). We used samples collected 4 years apart, 17 years from the initiation of the reintroduction, and 3 years after the conclusion of releases. To assess program success, we genotyped 304 hair samples, subsampled from the known range in 2000 and 2001, and 2005 and 2006, at 7 microsatellite loci. We compared diversity, effective population size, and genetic connectivity over time in each population. Diversity remained stable over time and there was evidence of increasing effective population size. We determined population structure in both periods after correcting for differences in sample sizes. The geographic distribution of these populations roughly corresponded with the original release locations, which suggests the release sites had residual effects on the population structure. However, given that both reintroduction sites had similar source populations, habitat fragmentation, due to cropland, may be associated with the population structure we found. Although our results indicate growing, stable populations, future connectivity analyses are warranted to ensure both populations are not subject to negative small-population effects. Our results demonstrate the importance of multiple sampling years to fully capture population dynamics of reintroduced populations. Análisis Temporal de la Estructura Genética para Evaluar la Dinámica Poblacional de Zorros (Vulpes velox) Reintroducidos. © 2013 Society for Conservation Biology.

The Role of Body Size in Mate Selection among African American Young Adults

PubMed Central

Simons, Leslie G.; Simons, Ronald L.

2016-01-01

A profusion of studies have demonstrated that body size is a major factor in mate selection for both men and women. The particular role played by weight, however, has been subject to some debate, particularly with respect to the types of body sizes deemed most attractive, and scholars have questioned the degree to which body size preferences are constant across groups. In this paper, we drew from two perspectives on this issue, Sexual Strategies Theory and what we termed the cultural variability perspective, and used survey data to examine how body size was associated with both casual dating and serious romantic relationships. We used a United States sample of 386 African American adolescents and young adults between ages 16 and 21, living in the Midwest and Southeast, and who were enrolled in either high school or college. Results showed that overweight women were more likely to report casually dating than women in the thinnest weight category. Body size was not related to dating status among men. Among women, the results suggest stronger support for the cultural variability argument than for Sexual Strategies Theory. Potential explanations for these findings are discussed. PMID:26973377

The Power of Low Back Pain Trials: A Systematic Review of Power, Sample Size, and Reporting of Sample Size Calculations Over Time, in Trials Published Between 1980 and 2012.

PubMed

Froud, Robert; Rajendran, Dévan; Patel, Shilpa; Bright, Philip; Bjørkli, Tom; Eldridge, Sandra; Buchbinder, Rachelle; Underwood, Martin

2017-06-01

A systematic review of nonspecific low back pain trials published between 1980 and 2012. To explore what proportion of trials have been powered to detect different bands of effect size; whether there is evidence that sample size in low back pain trials has been increasing; what proportion of trial reports include a sample size calculation; and whether likelihood of reporting sample size calculations has increased. Clinical trials should have a sample size sufficient to detect a minimally important difference for a given power and type I error rate. An underpowered trial is one within which probability of type II error is too high. Meta-analyses do not mitigate underpowered trials. Reviewers independently abstracted data on sample size at point of analysis, whether a sample size calculation was reported, and year of publication. Descriptive analyses were used to explore ability to detect effect sizes, and regression analyses to explore the relationship between sample size, or reporting sample size calculations, and time. We included 383 trials. One-third were powered to detect a standardized mean difference of less than 0.5, and 5% were powered to detect less than 0.3. The average sample size was 153 people, which increased only slightly (∼4 people/yr) from 1980 to 2000, and declined slightly (∼4.5 people/yr) from 2005 to 2011 (P < 0.00005). Sample size calculations were reported in 41% of trials. The odds of reporting a sample size calculation (compared to not reporting one) increased until 2005 and then declined (Equation is included in full-text article.). Sample sizes in back pain trials and the reporting of sample size calculations may need to be increased. It may be justifiable to power a trial to detect only large effects in the case of novel interventions. 3.

Heavy metal contents of road-deposited sediment along the urban-rural gradient around Beijing and its potential contribution to runoff pollution.

PubMed

Zhao, Hongtao; Li, Xuyong; Wang, Xiaomei

2011-09-01

Understanding the contribution of road-deposited sediment (RDS) and its washoff process is essential for controlling urban runoff pollution. Ninety-seven RDS samples were collected along the urban-suburban-rural gradient from areas of five administrative units in the Beijing metropolitan region, including central urban (UCA), urban village (UVA), central suburban county (CSA), rural town (RTA), and rural village (RVA) areas. RDS washoff was evaluated with different particle sizes using a rainfall simulator. Heavy metal elements (i.e., Cr, Cu, Ni, Pb, and Zn) were estimated in both RDS and runoff samples. The RDS mass per unit area increased in the order UCA (21 ± 24 g/m(2)) ≈ CSA (20 ± 16 g/m(2)) < RTA (59 ± 63 g/m(2)) < RVA (147 ± 112 g/m(2)) ≈ UVA (147 ± 198 g/m(2)). Compared to RDS from the other administrative units, RDS from the UCA and CSA had higher metal concentrations and higher proportions of smaller particles, whereas that from the RVA and UVA had larger quantities of metals per unit area. UCA and CSA had lower potential runoff pollution contributions per unit area. Our findings imply that controlling the first flush in the UCA and CSA, and improving existing street cleaning methods and road surface conditions in the TRA, UVA, and RVA will be appropriate strategies for controlling runoff pollution from RDS.

Lot quality assurance sampling (LQAS) for monitoring a leprosy elimination program.

PubMed

Gupte, M D; Narasimhamurthy, B

1999-06-01

In a statistical sense, prevalences of leprosy in different geographical areas can be called very low or rare. Conventional survey methods to monitor leprosy control programs, therefore, need large sample sizes, are expensive, and are time-consuming. Further, with the lowering of prevalence to the near-desired target level, 1 case per 10,000 population at national or subnational levels, the program administrator's concern will be shifted to smaller areas, e.g., districts, for assessment and, if needed, for necessary interventions. In this paper, Lot Quality Assurance Sampling (LQAS), a quality control tool in industry, is proposed to identify districts/regions having a prevalence of leprosy at or above a certain target level, e.g., 1 in 10,000. This technique can also be considered for identifying districts/regions at or below the target level of 1 per 10,000, i.e., areas where the elimination level is attained. For simulating various situations and strategies, a hypothetical computerized population of 10 million persons was created. This population mimics the actual population in terms of the empirical information on rural/urban distributions and the distribution of households by size for the state of Tamil Nadu, India. Various levels with respect to leprosy prevalence are created using this population. The distribution of the number of cases in the population was expected to follow the Poisson process, and this was also confirmed by examination. Sample sizes and corresponding critical values were computed using Poisson approximation. Initially, villages/towns are selected from the population and from each selected village/town households are selected using systematic sampling. Households instead of individuals are used as sampling units. This sampling procedure was simulated 1000 times in the computer from the base population. The results in four different prevalence situations meet the required limits of Type I error of 5% and 90% Power. It is concluded that after validation under field conditions, this method can be considered for a rapid assessment of the leprosy situation.

Optimizing and Validating a Brief Assessment for Identifying Children of Service Members at Risk for Psychological Health Problems Following Parent Deployment

DTIC Science & Technology

2017-09-01

these groups . In the 2014/2015 year, efforts focused on securing a commitment from the United States Marine Corps to host the study. In Winter 2014...we can reach an adjusted sample size target in the 2017/2018 project year by expanding our recruitment to incorporate deploying infantry groups ...Vocabulary Test Revised. Circle Pines, MN: American Guidance Service. George, C. & Solomon , J. (2008). The caregving system: A behavioral systems approach

Some effects of sex, age, and household structure on family drawings of Barbadian children.

PubMed

Payne, M A

1996-10-01

An analysis of the family drawings of a nonclinical sample of 502 Barbadian children aged 7-11 years is reported. The inclusion or omission of figures and the size and positioning of the figures of parents and self were examined with reference to sex, age, and household structure. The view that cultural values about the structure of the family unit and parental roles are reflected in children's representations of their parents in family drawings was supported.

Pavement Maintenance Management for Roads and Parking Lots.

DTIC Science & Technology

1981-10-01

PAVEMENT INSPECTION SHEET aRANCH SECT ION DA TE SAMPLE UNIT SURVEYED BY SLAB SIZE * 0 0 0 Distress Types !0 2f Blow- Up 3’ Polished Buckling/Shattering...10 21 Blow- up 31 Poisnec Buckling/Shatternrg Aggregate 0 1 22. Corner Break 32 Porouis 23. D’viOea SIcD 33 Ptmo,nq 9 24 Durability . " 34 Pancnout...Load Durability Drainage Other Factors Corner Break Blow- up Corner Break Faulting Divided Slab Ŕ" Cracking Divided Slab Lane/Shoulder Dropoff

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

Whitledge, T.E.; Malloy, S.C.; Patton, C.J.

This manual was assembled for use as a guide for analyzing the nutrient content of seawater samples collected in the marine coastal zone of the Northeast United States and the Bering Sea. Some modifications (changes in dilution or sample pump tube sizes) may be necessary to achieve optimum measurements in very pronounced oligotrophic, eutrophic or brackish areas. Information is presented under the following section headings: theory and mechanics of automated analysis; continuous flow system description; operation of autoanalyzer system; cookbook of current nutrient methods; automated analyzer and data analysis software; computer interfacing and hardware modifications; and trouble shooting. The threemore » appendixes are entitled: references and additional reading; manifold components and chemicals; and software listings. (JGB)« less

24 CFR 882.509 - Overcrowded and under occupied units.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Family size, or that a Contract unit is larger than appropriate for the size of the Family in occupancy... Family a suitable alternative unit should one be available and the Family will be required to move. If the Owner does not have a suitable available unit, the PHA must assist the Family in locating other...

The effect of environmental factors on technical and scale efficiency of primary health care providers in Greece.

PubMed

Kontodimopoulos, Nick; Moschovakis, Giorgos; Aletras, Vassilis H; Niakas, Dimitris

2007-11-17

The purpose of this study was to compare technical and scale efficiency of primary care centers from the two largest Greek providers, the National Health System (NHS) and the Social Security Foundation (IKA) and to determine if, and how, efficiency is affected by various exogenous factors such as catchment population and location. The sample comprised of 194 units (103 NHS and 91 IKA). Efficiency was measured with Data Envelopment Analysis (DEA) using three inputs, -medical staff, nursing/paramedical staff, administrative/other staff- and two outputs, which were the aggregated numbers of scheduled/emergency patient visits and imaging/laboratory diagnostic tests. Facilities were categorized as small, medium and large (<15,000, 15,000-30,000 and >30,000 respectively) to reflect catchment population and as urban/semi-urban or remote/island to reflect location. In a second stage analysis, technical and scale efficiency scores were regressed against facility type (NHS or IKA), size and location using multivariate Tobit regression. Regarding technical efficiency, IKA performed better than the NHS (84.9% vs. 70.1%, Mann-Whitney P < 0.001), smaller units better than medium-sized and larger ones (84.2% vs. 72.4% vs. 74.3%, Kruskal-Wallis P < 0.01) and remote/island units better than urban centers (81.1% vs. 75.7%, Mann-Whitney P = 0.103). As for scale efficiency, IKA again outperformed the NHS (89.7% vs. 85.9%, Mann-Whitney P = 0.080), but results were reversed in respect to facility size and location. Specifically, larger units performed better (96.3% vs. 90.9% vs. 75.9%, Kruskal-Wallis P < 0.001), and urban units showed higher scale efficiency than remote ones (91.9% vs. 75.3%, Mann-Whitney P < 0.001). Interestingly 75% of facilities appeared to be functioning under increasing returns to scale. Within-group comparisons revealed significant efficiency differences between the two primary care providers. Tobit regression models showed that facility type, size and location were significant explanatory variables of technical and scale efficiency. Variations appeared to exist in the productive performance of the NHS and IKA as the two main primary care providers in Greece. These variations reflect differences in primary care organization, economical incentives, financial constraints, sociodemographic and local peculiarities. In all technical efficiency comparisons, IKA facilities appeared to outperform NHS ones irrespective of facility size or location. In respect to scale efficiency, the results were to some extent inconclusive and observed differences were mostly insignificant, although again IKA appeared to perform better.

Crystal-Chemical Correlations in Chromites from Kimberlitic and Non-Kimberlitic Sources.

NASA Astrophysics Data System (ADS)

Freckelton, C. N.; Flemming, R. L.

2009-05-01

This study explores the utility of micro X-ray diffraction (μXRD) as a tool for diamond exploration, as a compliment to current industry-standard techniques such as electron probe microanalysis (EPMA). Here we examine chromite. As one of the first phases to crystallize in mantle rocks, it is a useful indicator of upper mantle magmatic conditions in rocks that have been sampled by kimberlites. In addition, chromite does not alter easily from chemical and physical weathering processes. As such, chromite is a useful kimberlite indicator mineral in diamond exploration. We present correlations between crystal structure (unit cell) and chemical composition of chromite, (Fe,Mg)[Cr, Al]2O4, using correlated μXRD and EPMA data for 133 chromites from a three source locations: Two kimberlite sources and one non-kimberlitic source from an Archean granite/greenstone terrain. Quantitative analysis was performed using Electron Probe Microanalysis (EPMA) at Mineral Services, South Africa, prior to the loan of the samples. Randomly-oriented chromite grains, approximately 500 μm in diameter, were analyzed as previously mounted for EPMA. Micro X-ray-diffraction was performed using a Bruker D8-Discover Diffractometer, with θ-θ geometry, with CuKα radiation, operating at 40 kV and 40 mA, with nominal beam diameter of 500 μm. The data were collected in omega scan mode. Two dimensional General Area Detector Diffraction System (GADDS) images were collected for 20 minutes per image, and integrated to produce one-dimensional plots of intensity versus 2θ, for subsequent unit cell refinement using CELREF. Although all samples in this study were considered to be 'chromite', a plot of Cr/(Cr+Al) versus Fe2+/(Fe2++Mg) shows extensive substitution among four dominant members: chromite (FeCr2O4), magnesio-chromite (MgCr2O4), spinel (MgAl2O4), and hercynite (FeAl2O4), where Mg and Fe2+ substitute for one another on the tetrahedral site, and Cr and Al substitute for one another on the octahedral site. Our data are widely variable as compared to the field occupied by chromite inclusions in diamonds (high Cr and Mg (˜60 wt %) and very low Ti (˜0.40 wt %). Plots of the unit cell parameter, ao, versus composition demonstrate a decrease in unit cell size with increasing Al content (and corresponding decrease in Cr content), consistent with a smaller cation radius for Al versus Cr (Al=0.675 Å and Cr=0.905 Å). The trend in unit cell size is unlikely to be effected by Mg-Fe substitution because of the very small difference in their tetrahedral cation radii (Fe2+=0.835 Å and Mg=0.86 Å). Initial plots of composition versus unit cell parameter were clearly able to distinguish a difference between unit cell of kimberlitic chromites and non-kimberlitic chromites. The significantly higher Cr content in kimberlitic chromites (radius=0.905 Å), and correspondingly higher Al content in non-kimberlitic chromites (radius=0.675 Å), results in a striking bimodal distribution in unit cell parameter, ao, where kimberlitic chromites have a larger unit cell (> 8.3 Å) than non-kimberlitic chromites (< 8.3 Å). This preliminary data provides a useful starting point for screening minerals from naturally relevant chromite solid solutions using their corresponding unit cell parameters. Future work will examine which site substitutions (octahedral versus tetrahedral) are affecting the unit cell as well as the effect of cation order-disorder on unit cell parameters.

Analysis of spatial distribution of land cover maps accuracy

NASA Astrophysics Data System (ADS)

Khatami, R.; Mountrakis, G.; Stehman, S. V.

2017-12-01

Land cover maps have become one of the most important products of remote sensing science. However, classification errors will exist in any classified map and affect the reliability of subsequent map usage. Moreover, classification accuracy often varies over different regions of a classified map. These variations of accuracy will affect the reliability of subsequent analyses of different regions based on the classified maps. The traditional approach of map accuracy assessment based on an error matrix does not capture the spatial variation in classification accuracy. Here, per-pixel accuracy prediction methods are proposed based on interpolating accuracy values from a test sample to produce wall-to-wall accuracy maps. Different accuracy prediction methods were developed based on four factors: predictive domain (spatial versus spectral), interpolation function (constant, linear, Gaussian, and logistic), incorporation of class information (interpolating each class separately versus grouping them together), and sample size. Incorporation of spectral domain as explanatory feature spaces of classification accuracy interpolation was done for the first time in this research. Performance of the prediction methods was evaluated using 26 test blocks, with 10 km × 10 km dimensions, dispersed throughout the United States. The performance of the predictions was evaluated using the area under the curve (AUC) of the receiver operating characteristic. Relative to existing accuracy prediction methods, our proposed methods resulted in improvements of AUC of 0.15 or greater. Evaluation of the four factors comprising the accuracy prediction methods demonstrated that: i) interpolations should be done separately for each class instead of grouping all classes together; ii) if an all-classes approach is used, the spectral domain will result in substantially greater AUC than the spatial domain; iii) for the smaller sample size and per-class predictions, the spectral and spatial domain yielded similar AUC; iv) for the larger sample size (i.e., very dense spatial sample) and per-class predictions, the spatial domain yielded larger AUC; v) increasing the sample size improved accuracy predictions with a greater benefit accruing to the spatial domain; and vi) the function used for interpolation had the smallest effect on AUC.

Publication Bias in Psychology: A Diagnosis Based on the Correlation between Effect Size and Sample Size

PubMed Central

Kühberger, Anton; Fritz, Astrid; Scherndl, Thomas

2014-01-01

Background The p value obtained from a significance test provides no information about the magnitude or importance of the underlying phenomenon. Therefore, additional reporting of effect size is often recommended. Effect sizes are theoretically independent from sample size. Yet this may not hold true empirically: non-independence could indicate publication bias. Methods We investigate whether effect size is independent from sample size in psychological research. We randomly sampled 1,000 psychological articles from all areas of psychological research. We extracted p values, effect sizes, and sample sizes of all empirical papers, and calculated the correlation between effect size and sample size, and investigated the distribution of p values. Results We found a negative correlation of r = −.45 [95% CI: −.53; −.35] between effect size and sample size. In addition, we found an inordinately high number of p values just passing the boundary of significance. Additional data showed that neither implicit nor explicit power analysis could account for this pattern of findings. Conclusion The negative correlation between effect size and samples size, and the biased distribution of p values indicate pervasive publication bias in the entire field of psychology. PMID:25192357

Publication bias in psychology: a diagnosis based on the correlation between effect size and sample size.

PubMed

Kühberger, Anton; Fritz, Astrid; Scherndl, Thomas

2014-01-01

The p value obtained from a significance test provides no information about the magnitude or importance of the underlying phenomenon. Therefore, additional reporting of effect size is often recommended. Effect sizes are theoretically independent from sample size. Yet this may not hold true empirically: non-independence could indicate publication bias. We investigate whether effect size is independent from sample size in psychological research. We randomly sampled 1,000 psychological articles from all areas of psychological research. We extracted p values, effect sizes, and sample sizes of all empirical papers, and calculated the correlation between effect size and sample size, and investigated the distribution of p values. We found a negative correlation of r = -.45 [95% CI: -.53; -.35] between effect size and sample size. In addition, we found an inordinately high number of p values just passing the boundary of significance. Additional data showed that neither implicit nor explicit power analysis could account for this pattern of findings. The negative correlation between effect size and samples size, and the biased distribution of p values indicate pervasive publication bias in the entire field of psychology.

Larger is not necessarily better! Impact of HIV care unit characteristics on virological success: results from the French national representative ANRS-VESPA2 study.

PubMed

Sagaon-Teyssier, Luis; Fressard, Lisa; Mora, Marion; Maradan, Gwenaëlle; Guagliardo, Valérie; Suzan-Monti, Marie; Dray-Spira, Rosemary; Spire, Bruno

2016-08-01

To determine the impact of hospital caseload size on HIV virological success when taking into account individual patient characteristics. Data from the ANRS-VESPA2 survey representative of people living with HIV in France was used. Analyses were carried out on the 2612 (86.4% out of 3022) individuals receiving antiretroviral (ARV) treatment for at least one year. Outcomes correspond to two definitions of virological success (VS1 and VS2 respectively) and were analyzed under a multi-level modeling framework with a special focus on the effect of the caseload size on VS. Structures with caseloads <1700 patients were more likely to have increased the proportion of patients achieving virological success (59% and 81% for VS1 and VS2, respectively) than structures whose caseloads numbered ≥1700 patients. Our results highlight that patients in the 11 largest care units in the sample were exposed to a context where their VS was potentially compromised by care unit characteristics, independently of both their individual characteristics and their own HIV treatment adherence behavior. Our results suggest that - at least in the case of HIV care - in France large care units are not necessarily better. This result serves as an evidence-based warning to public authorities to ensure that health outcomes are guaranteed in an era when the French hospital sector is being substantially restructured. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

75 FR 11080 - Endangered and Threatened Wildlife and Plants; Designation of Critical Habitat for Carex lutea

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-10

... time the species was listed. The occurrence at Watkins Savannah (O'Berry Tract C) (EO 5.19) was found... are: (1) Unit 1: Watkins Savanna, (2) Unit 2: Haws Run Mitigation Site, (3) Unit 3: Maple Hill School... Type Size of Unit Acres Size of Unit Hectares 1 A Watkins Savanna, NCDPR 1.2 0.5 O'Berry, Tract A 1 B...

A flexible system to capture sample vials in a storage box - the box vial scanner.

PubMed

Nowakowski, Steven E; Kressin, Kenneth R; Deick, Steven D

2009-01-01

Tracking sample vials in a research environment is a critical task and doing so efficiently can have a large impact on productivity, especially in high volume laboratories. There are several challenges to automating the capture process, including the variety of containers used to store samples. We developed a fast and robust system to capture the location of sample vials being placed in storage that allows the laboratories the flexibility to use sample containers of varying dimensions. With a single scan, this device captures the box identifier, the vial identifier and the location of each vial within a freezer storage box. The sample vials are tracked through a barcode label affixed to the cap while the boxes are tracked by a barcode label on the side of the box. Scanning units are placed at the point of use and forward data to a sever application for processing the scanned data. Scanning units consist of an industrial barcode reader mounted in a fixture positioning the box for scanning and providing lighting during the scan. The server application transforms the scan data into a list of storage locations holding vial identifiers. The list is then transferred to the laboratory database. The box vial scanner captures the IDs and location information for an entire box of sample vials into the laboratory database in a single scan. The system accommodates a wide variety of vials sizes by inserting risers under the sample box and a variety of storage box layouts are supported via the processing algorithm on the server.

All plastic ultra-small size imaging lens unit fabrication and evaluation for endoscope

NASA Astrophysics Data System (ADS)

Ishii, Kenta; Okamoto, Dai; Ushio, Makoto; Tai, Hidetoshi; Nishihara, Atsuhiko; Tokuda, Kimio; Kawai, Shinsuke; Kitagawa, Seiichiro

2017-02-01

There is demand for small-size lens units for endoscope and industrial applications. Polished glass lenses with a diameter of 1 - 2mm exist, however plastic lenses similar in size are not commonplace. For low-cost, light-weight, and mass production, plastic lens fabrication is extremely beneficial. Especially, in the medical field, there is strong demand for disposable lens unit for endoscopes which prevent contamination due to reuse of the lens. Therefore, high mass producible and low cost becomes increasingly important. This paper reports our findings on injection-molded ultra-small size plastic lens units with a diameter of 1.3mm and total thickness of 1.4mm. We performed optical design, injection molding, and lens unit assembly for injection moldable, high imaging performance ultra-small sized lens units. We prioritize a robust product design, considering injection molding properties and lens unit assembly, with feedback from molding simulations reflected into the optical design. A mold capable of high precision lens positioning is used to fabricate the lenses and decrease the variability of the assembly. The geometric dimensions of the resulting lenses, are measured and used in the optical simulation to validate the optical performance, and a high agreement is reported. The injection molding of the lens and the assembly of the lens unit is performed with high precision, and results in high optical performance.

Optimum sample size allocation to minimize cost or maximize power for the two-sample trimmed mean test.

PubMed

Guo, Jiin-Huarng; Luh, Wei-Ming

2009-05-01

When planning a study, sample size determination is one of the most important tasks facing the researcher. The size will depend on the purpose of the study, the cost limitations, and the nature of the data. By specifying the standard deviation ratio and/or the sample size ratio, the present study considers the problem of heterogeneous variances and non-normality for Yuen's two-group test and develops sample size formulas to minimize the total cost or maximize the power of the test. For a given power, the sample size allocation ratio can be manipulated so that the proposed formulas can minimize the total cost, the total sample size, or the sum of total sample size and total cost. On the other hand, for a given total cost, the optimum sample size allocation ratio can maximize the statistical power of the test. After the sample size is determined, the present simulation applies Yuen's test to the sample generated, and then the procedure is validated in terms of Type I errors and power. Simulation results show that the proposed formulas can control Type I errors and achieve the desired power under the various conditions specified. Finally, the implications for determining sample sizes in experimental studies and future research are discussed.

Apollo rocks, fines and soil cores

NASA Astrophysics Data System (ADS)

Allton, J.; Bevill, T.

Apollo rocks and soils not only established basic lunar properties and ground truth for global remote sensing, they also provided important lessons for planetary protection (Adv. Space Res ., 1998, v. 22, no. 3 pp. 373-382). The six Apollo missions returned 2196 samples weighing 381.7 kg, comprised of rocks, fines, soil cores and 2 gas samples. By examining which samples were allocated for scientific investigations, information was obtained on usefulness of sampling strategy, sampling devices and containers, sample types and diversity, and on size of sample needed by various disciplines. Diversity was increased by using rakes to gather small rocks on the Moon and by removing fragments >1 mm from soils by sieving in the laboratory. Breccias and soil cores are diverse internally. Per unit weight these samples were more often allocated for research. Apollo investigators became adept at wringing information from very small sample sizes. By pushing the analytical limits, the main concern was adequate size for representative sampling. Typical allocations for trace element analyses were 750 mg for rocks, 300 mg for fines and 70 mg for core subsamples. Age-dating and isotope systematics allocations were typically 1 g for rocks and fines, but only 10% of that amount for core depth subsamples. Historically, allocations for organics and microbiology were 4 g (10% for cores). Modern allocations for biomarker detection are 100mg. Other disciplines supported have been cosmogenic nuclides, rock and soil petrology, sedimentary volatiles, reflectance, magnetics, and biohazard studies . Highly applicable to future sample return missions was the Apollo experience with organic contamination, estimated to be from 1 to 5 ng/g sample for Apollo 11 (Simonheit &Flory, 1970; Apollo 11, 12 &13 Organic contamination Monitoring History, U.C. Berkeley; Burlingame et al., 1970, Apollo 11 LSC , pp. 1779-1792). Eleven sources of contaminants, of which 7 are applicable to robotic missions, were identified and reduced; thus, improving Apollo 12 samples to 0.1 ng/g. Apollo sample documentation preserves the parentage, orientation, and location, packaging, handling and environmental histories of each of the 90,000 subsamples currently curated. Active research on Apollo samples continues today, and because 80% by weight of the Apollo collection remains pristine, researchers have a reservoir of material to support studies well into the future.

Importance of Unit Cells in Accurate Evaluation of the Characteristics of Graphene

NASA Astrophysics Data System (ADS)

Sabzyan, Hassan; Sadeghpour, Narges

2016-04-01

Effects of the size of the unit cell on energy, atomic charges, and phonon frequencies of graphene at the Γ point of the Brillouin zone are studied in the absence and presence of an electric field using density functional theory (DFT) methods (LDA and DFT-PBE functionals with Goedecker-Teter-Hutter (GTH) and Troullier-Martins (TM) norm-conserving pseudopotentials). Two types of unit cells containing nC=4-28 carbon atoms are considered. Results show that stability of graphene increases with increasing size of the unit cell. Energy, atomic charges, and phonon frequencies all converge above nC=24 for all functional-pseudopotentials used. Except for the LDA-GTH calculations, application of an electric field of 0.4 and 0.9 V/nm strengths does not change the trends with the size of the unit cell but instead slightly decreases the binding energy of graphene. Results of this study show that the choice of unit cell size and type is critical for calculation of reliable characteristics of graphene.

Firefighter Hand Anthropometry and Structural Glove Sizing: A New Perspective

PubMed Central

Hsiao, Hongwei; Whitestone, Jennifer; Kau, Tsui-Ying; Hildreth, Brooke

2015-01-01

Objective We evaluated the current use and fit of structural firefighting gloves and developed an improved sizing scheme that better accommodates the U.S. firefighter population. Background Among surveys, 24% to 30% of men and 31% to 62% of women reported experiencing problems with the fit or bulkiness of their structural firefighting gloves. Method An age-, race/ethnicity-, and gender-stratified sample of 863 male and 88 female firefighters across the United States participated in the study. Fourteen hand dimensions relevant to glove design were measured. A cluster analysis of the hand dimensions was performed to explore options for an improved sizing scheme. Results The current national standard structural firefighting glove-sizing scheme underrepresents firefighter hand size range and shape variation. In addition, mismatch between existing sizing specifications and hand characteristics, such as hand dimensions, user selection of glove size, and the existing glove sizing specifications, is significant. An improved glove-sizing plan based on clusters of overall hand size and hand/finger breadth-to-length contrast has been developed. Conclusion This study presents the most up-to-date firefighter hand anthropometry and a new perspective on glove accommodation. The new seven-size system contains narrower variations (standard deviations) for almost all dimensions for each glove size than the current sizing practices. Application The proposed science-based sizing plan for structural firefighting gloves provides a step-forward perspective (i.e., including two women hand model–based sizes and two wide-palm sizes for men) for glove manufacturers to advance firefighter hand protection. PMID:26169309

12 CFR 1282.17 - Affordability-Income level definitions-family size and income known (owner-occupied units, actual...

Code of Federal Regulations, 2010 CFR

2010-01-01

... GOALS AND MISSION Housing Goals § 1282.17 Affordability—Income level definitions—family size and income..., for rental housing, family size and income information for the dwelling unit is known to the... sizes: Number of persons in family Percentageof area median income 1 70 2 80 3 90 4 100 5 or more...

Microbiological evaluation of groups of beef carcasses: heifers and steers.

PubMed Central

Jericho, K W; Bradley, J A; Kozub, G C

1994-01-01

Numbers of mesophilic bacteria were estimated on carcasses of 25 heifers and 25 steers of beef breeds in a modern, high-line-speed abattoir. One side of each carcass from each sex was sampled at the end of the kill-floor, before the carcass wash, on each of 25 visits. Two adjacent excision samples (5 x 5 x 0.5 cm) were taken from each of ten sites and processed for automatic enumeration of aerobic bacteria on hydrophobic grid membrane filters. The effects of sex and carcass weight on bacterial counts were examined. Groups of carcasses were examined to determine the sample size required for future assessments of kill-floor hygiene. The log10 of the most probable number of growth units (MPNGU)/cm2 did not differ significantly between heifers and steers (average over the ten sites of 2.2) and there was no effect of carcass weight on bacterial counts for nine of the ten sites. There were, however, highly significant (p < 0.001) differences in the counts between sites and the counts from the ten sites clustered into five homogenous groups. The between-carcass component of variation at a site was generally larger than the within-carcass component. We conclude that, to estimate the mean log10 MPNGU/cm2 at a site to within +/- 0.5 units, future group-carcass evaluations require about 200 samples from 10 (two adjacent samples/site) or 20 carcasses (one sample/site). PMID:7954120

Aerosol sampling system for collection of Capstone depleted uranium particles in a high-energy environment.

PubMed

Holmes, Thomas D; Guilmette, Raymond A; Cheng, Yung Sung; Parkhurst, Mary Ann; Hoover, Mark D

2009-03-01

The Capstone Depleted Uranium (DU) Aerosol Study was undertaken to obtain aerosol samples resulting from a large-caliber DU penetrator striking an Abrams or Bradley test vehicle. The sampling strategy was designed to (1) optimize the performance of the samplers and maintain their integrity in the extreme environment created during perforation of an armored vehicle by a DU penetrator, (2) collect aerosols as a function of time post perforation, and (3) obtain size-classified samples for analysis of chemical composition, particle morphology, and solubility in lung fluid. This paper describes the experimental setup and sampling methodologies used to achieve these objectives. Custom-designed arrays of sampling heads were secured to the inside of the target in locations approximating the breathing zones of the crew locations in the test vehicles. Each array was designed to support nine filter cassettes and nine cascade impactors mounted with quick-disconnect fittings. Shielding and sampler placement strategies were used to minimize sampler loss caused by the penetrator impact and the resulting fragments of eroded penetrator and perforated armor. A cyclone train was used to collect larger quantities of DU aerosol for measurement of chemical composition and solubility. A moving filter sample was used to obtain semicontinuous samples for DU concentration determination. Control for the air samplers was provided by five remotely located valve control and pressure monitoring units located inside and around the test vehicle. These units were connected to a computer interface chassis and controlled using a customized LabVIEW engineering computer control program. The aerosol sampling arrays and control systems for the Capstone study provided the needed aerosol samples for physicochemical analysis, and the resultant data were used for risk assessment of exposure to DU aerosol.

Aerosol Sampling System for Collection of Capstone Depleted Uranium Particles in a High-Energy Environment

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

Holmes, Thomas D.; Guilmette, Raymond A.; Cheng, Yung-Sung

2009-03-01

The Capstone Depleted Uranium Aerosol Study was undertaken to obtain aerosol samples resulting from a kinetic-energy cartridge with a large-caliber depleted uranium (DU) penetrator striking an Abrams or Bradley test vehicle. The sampling strategy was designed to (1) optimize the performance of the samplers and maintain their integrity in the extreme environment created during perforation of an armored vehicle by a DU penetrator, (2) collect aerosols as a function of time post-impact, and (3) obtain size-classified samples for analysis of chemical composition, particle morphology, and solubility in lung fluid. This paper describes the experimental setup and sampling methodologies used tomore » achieve these objectives. Custom-designed arrays of sampling heads were secured to the inside of the target in locations approximating the breathing zones of the vehicle commander, loader, gunner, and driver. Each array was designed to support nine filter cassettes and nine cascade impactors mounted with quick-disconnect fittings. Shielding and sampler placement strategies were used to minimize sampler loss caused by the penetrator impact and the resulting fragments of eroded penetrator and perforated armor. A cyclone train was used to collect larger quantities of DU aerosol for chemical composition and solubility. A moving filter sample was used to obtain semicontinuous samples for depleted uranium concentration determination. Control for the air samplers was provided by five remotely located valve control and pressure monitoring units located inside and around the test vehicle. These units were connected to a computer interface chassis and controlled using a customized LabVIEW engineering computer control program. The aerosol sampling arrays and control systems for the Capstone study provided the needed aerosol samples for physicochemical analysis, and the resultant data were used for risk assessment of exposure to DU aerosol.« less

The Violent Early Solar System, as Told by Lunar Sample Geochronology

NASA Technical Reports Server (NTRS)

Cohen, Barbara

2012-01-01

One of the legacies of the samples collected by the Apollo and Luna missions is the link forged between radiometric ages of rocks and relative ages according to stratigraphic relationships and impact crater size-frequency distributions. Our current understanding of the history of the inner solar system is based on the relative chronology of individual planets, tied to the absolute geochronology of the Moon via these important samples. Samples from these nearside locations reveal a preponderance of impact-disturbed or recrystallized ages between 3.75 and 3.95 billion years. Argon and lead loss (and correlated disturbances in the Rb-Sr system) have been attributed to metamorphism of the lunar crust by an enormous number of impacts in a brief pulse of time, called the Lunar Cataclysm or Late Heavy Bombardment. Subsequent high-precision geochronometric analyses of Apollo samples and lunar highlands meteorites show a wider range of ages, but very few older than 4 Ga. The paucity of ancient impact melt rocks has been interpreted to mean that either that most impact basins formed at this time, or that ejecta from the large, near-side, young basins dominates the Apollo samples. Selenochronology is getting more complicated: new results question meaning of sample ages, crater counts, crater production functions, and the solar system itself. Improved geological mapping of lunar geologic units and boundaries using multiple remote sensing datasets. High-resolution image-based crater counting of discrete geologic units and relating them to location. Improved understanding of the regolith thickness and its global variation (GRAIL). Tying the sampling of impact-melt rocks to the lunar impact flux. Using improved techniques (magnetic fields, diffusion studies, isotopic analysis) on existing samples. New sample return from benchmark craters, particularly SPA, which appears in 2013 Decadal Survey.

[History of pharmaceutical packaging in modern Japan. II--Package size of pharmaceuticals].

PubMed

Hattori, Akira

2014-01-01

When planning pharmaceutical packaging, the package size for the product is important for determining the basic package concept. Initially, the sales unit for herbal medicines was the weight; however in 1868, around the early part of the Meiji era, Japanese and Western units were being used and the sales unit was confusing. Since the Edo era, the packing size for OTC medicines was adopted using weight, numbers, dosage or treatment period. These were devised in various ways in consideration of convenience for the consumer, but the concept was not simple. In 1887, from the time that the first edition of the Japanese Pharmacopoeia came out, use of the metric system began to spread in Japan. Its use spread gradually for use in the package size of pharmaceutical products. At the time, the number of pharmaceutical units (i.e., tablets), became the sales unit, which is easy to understand by the purchaser.

Genetic diversity and population structure of the tsetse fly Glossina fuscipes fuscipes (Diptera: Glossinidae) in Northern Uganda: Implications for vector control

PubMed Central

Echodu, Richard; Opiyo, Elizabeth A.; Dion, Kirstin; Halyard, Alexis; Dunn, Augustine W.; Aksoy, Serap; Caccone, Adalgisa

2017-01-01

Uganda is the only country where the chronic and acute forms of human African Trypanosomiasis (HAT) or sleeping sickness both occur and are separated by < 100 km in areas north of Lake Kyoga. In Uganda, Glossina fuscipes fuscipes is the main vector of the Trypanosoma parasites responsible for these diseases as well for the animal African Trypanosomiasis (AAT), or Nagana. We used highly polymorphic microsatellite loci and a mitochondrial DNA (mtDNA) marker to provide fine scale spatial resolution of genetic structure of G. f. fuscipes from 42 sampling sites from the northern region of Uganda where a merger of the two disease belts is feared. Based on microsatellite analyses, we found that G. f. fuscipes in northern Uganda are structured into three distinct genetic clusters with varying degrees of interconnectivity among them. Based on genetic assignment and spatial location, we grouped the sampling sites into four genetic units corresponding to northwestern Uganda in the Albert Nile drainage, northeastern Uganda in the Lake Kyoga drainage, western Uganda in the Victoria Nile drainage, and a transition zone between the two northern genetic clusters characterized by high level of genetic admixture. An analysis using HYBRIDLAB supported a hybrid swarm model as most consistent with tsetse genotypes in these admixed samples. Results of mtDNA analyses revealed the presence of 30 haplotypes representing three main haplogroups, whose location broadly overlaps with the microsatellite defined clusters. Migration analyses based on microsatellites point to moderate migration among the northern units located in the Albert Nile, Achwa River, Okole River, and Lake Kyoga drainages, but not between the northern units and the Victoria Nile drainage in the west. Effective population size estimates were variable with low to moderate sizes in most populations and with evidence of recent population bottlenecks, especially in the northeast unit of the Lake Kyoga drainage. Our microsatellite and mtDNA based analyses indicate that G. f. fuscipes movement along the Achwa and Okole rivers may facilitate northwest expansion of the Rhodesiense disease belt in Uganda. We identified tsetse migration corridors and recommend a rolling carpet approach from south of Lake Kyoga northward to minimize disease dispersal and prevent vector re-colonization. Additionally, our findings highlight the need for continuing tsetse monitoring efforts during and after control. PMID:28453513

Segmentation of the mouse fourth deep lumbrical muscle connectome reveals concentric organisation of motor units

PubMed Central

Hirst, Theodore C; Ribchester, Richard R

2013-01-01

Connectomic analysis of the nervous system aims to discover and establish principles that underpin normal and abnormal neural connectivity and function. Here we performed image analysis of motor unit connectivity in the fourth deep lumbrical muscle (4DL) of mice, using transgenic expression of fluorescent protein in motor neurones as a morphological reporter. We developed a method that accelerated segmentation of confocal image projections of 4DL motor units, by applying high resolution (63×, 1.4 NA objective) imaging or deconvolution only where either proved necessary, in order to resolve axon crossings that produced ambiguities in the correct assignment of axon terminals to identified motor units imaged at lower optical resolution (40×, 1.3 NA). The 4DL muscles contained between 4 and 9 motor units and motor unit sizes ranged in distribution from 3 to 111 motor nerve terminals per unit. Several structural properties of the motor units were consistent with those reported in other muscles, including suboptimal wiring length and distribution of motor unit size. Surprisingly, however, small motor units were confined to a region of the muscle near the nerve entry point, whereas their larger counterparts were progressively more widely dispersed, suggesting a previously unrecognised form of segregated motor innervation in this muscle. We also found small but significant differences in variance of motor endplate length in motor units, which correlated weakly with their motor unit size. Thus, our connectomic analysis has revealed a pattern of concentric innervation that may perhaps also exist in other, cylindrical muscles that have not previously been thought to show segregated motor unit organisation. This organisation may be the outcome of competition during postnatal development based on intrinsic neuronal differences in synaptic size or synaptic strength that generates a territorial hierarchy in motor unit size and disposition. PMID:23940381

A systematic approach to designing statistically powerful heteroscedastic 2 × 2 factorial studies while minimizing financial costs.

PubMed

Jan, Show-Li; Shieh, Gwowen

2016-08-31

The 2 × 2 factorial design is widely used for assessing the existence of interaction and the extent of generalizability of two factors where each factor had only two levels. Accordingly, research problems associated with the main effects and interaction effects can be analyzed with the selected linear contrasts. To correct for the potential heterogeneity of variance structure, the Welch-Satterthwaite test is commonly used as an alternative to the t test for detecting the substantive significance of a linear combination of mean effects. This study concerns the optimal allocation of group sizes for the Welch-Satterthwaite test in order to minimize the total cost while maintaining adequate power. The existing method suggests that the optimal ratio of sample sizes is proportional to the ratio of the population standard deviations divided by the square root of the ratio of the unit sampling costs. Instead, a systematic approach using optimization technique and screening search is presented to find the optimal solution. Numerical assessments revealed that the current allocation scheme generally does not give the optimal solution. Alternatively, the suggested approaches to power and sample size calculations give accurate and superior results under various treatment and cost configurations. The proposed approach improves upon the current method in both its methodological soundness and overall performance. Supplementary algorithms are also developed to aid the usefulness and implementation of the recommended technique in planning 2 × 2 factorial designs.

Public Acceptability in the UK and USA of Nudging to Reduce Obesity: The Example of Reducing Sugar-Sweetened Beverages Consumption.

PubMed

Petrescu, Dragos C; Hollands, Gareth J; Couturier, Dominique-Laurent; Ng, Yin-Lam; Marteau, Theresa M

2016-01-01

"Nudging"-modifying environments to change people's behavior, often without their conscious awareness-can improve health, but public acceptability of nudging is largely unknown. We compared acceptability, in the United Kingdom (UK) and the United States of America (USA), of government interventions to reduce consumption of sugar-sweetened beverages. Three nudge interventions were assessed: i. reducing portion Size, ii. changing the Shape of the drink containers, iii. changing their shelf Location; alongside two traditional interventions: iv. Taxation and v. Education. We also tested the hypothesis that describing interventions as working through non-conscious processes decreases their acceptability. Predictors of acceptability, including perceived intervention effectiveness, were also assessed. Participants (n = 1093 UK and n = 1082 USA) received a description of each of the five interventions which varied, by randomisation, in how the interventions were said to affect behaviour: (a) via conscious processes; (b) via non-conscious processes; or (c) no process stated. Acceptability was derived from responses to three items. Levels of acceptability for four of the five interventions did not differ significantly between the UK and US samples; reducing portion size was less accepted by the US sample. Within each country, Education was rated as most acceptable and Taxation the least, with the three nudge-type interventions rated between these. There was no evidence to support the study hypothesis: i.e. stating that interventions worked via non-conscious processes did not decrease their acceptability in either the UK or US samples. Perceived effectiveness was the strongest predictor of acceptability for all interventions across the two samples. In conclusion, nudge interventions to reduce consumption of sugar-sweetened beverages seem similarly acceptable in the UK and USA, being more acceptable than taxation, but less acceptable than education. Contrary to prediction, we found no evidence that highlighting the non-conscious processes by which nudge interventions may work decreases their acceptability. However, highlighting the effectiveness of all interventions has the potential to increase their acceptability.

Size principle and information theory.

PubMed

Senn, W; Wyler, K; Clamann, H P; Kleinle, J; Lüscher, H R; Müller, L

1997-01-01

The motor units of a skeletal muscle may be recruited according to different strategies. From all possible recruitment strategies nature selected the simplest one: in most actions of vertebrate skeletal muscles the recruitment of its motor units is by increasing size. This so-called size principle permits a high precision in muscle force generation since small muscle forces are produced exclusively by small motor units. Larger motor units are activated only if the total muscle force has already reached certain critical levels. We show that this recruitment by size is not only optimal in precision but also optimal in an information theoretical sense. We consider the motoneuron pool as an encoder generating a parallel binary code from a common input to that pool. The generated motoneuron code is sent down through the motoneuron axons to the muscle. We establish that an optimization of this motoneuron code with respect to its information content is equivalent to the recruitment of motor units by size. Moreover, maximal information content of the motoneuron code is equivalent to a minimal expected error in muscle force generation.

Habitat fragmentation causes bottlenecks and inbreeding in the European tree frog (Hyla arborea).

PubMed Central

Andersen, Liselotte W.; Fog, Kåre; Damgaard, Christian

2004-01-01

A genetic study of the European tree frog, Hyla arborea, in Denmark was undertaken to examine the population structure on mainland Jutland and the island of Lolland after a period of reduction in suitable habitat and population sizes. The two regions have experienced the same rate of habitat loss but fragmentation has been more severe on Lolland. Genetic variation based on 12 polymorphic DNA microsatellites was analysed in 494 tree frogs sampled from two ponds in Jutland and 10 ponds on Lolland. A significant overall deviation from Hardy-Weinberg expectations could be attributed to three ponds, all on Lolland. This was most probably caused by an inbreeding effect reducing fitness, which was supported by the observed significant negative correlation between larva survival and mean F(IS) value and mean individual inbreeding coefficient. A significant reduction in genetic variation (bottleneck) was detected in most of the ponds on Lolland. Population-structure analysis suggested the existence of at least 11 genetically different populations, corresponding to most of the sampled population units. The results indicated that the populations were unique genetic units and could be used to illustrate the migration pattern between newly established ponds arisen either by natural colonization of tree frogs or by artificial introduction. A high degree of pond fidelity in the tree frogs was suggested. A severe fragmentation process reducing population size and fitness within some of the populations probably caused the significant reduction in genetic variation of tree frog populations on Lolland. PMID:15306354

Controlling of dielectrical properties of hydroxyapatite by ethylenediamine tetraacetic acid (EDTA) for bone healing applications

NASA Astrophysics Data System (ADS)

Kaygili, Omer; Ates, Tankut; Keser, Serhat; Al-Ghamdi, Ahmed A.; Yakuphanoglu, Fahrettin

2014-08-01

The hydroxyapatite (HAp) samples in the presence of various amounts of ethylenediamine tetraacetic acid (EDTA) were prepared by sol-gel method. The effects of EDTA on the crystallinity, phase structure, chemical, micro-structural and dielectric properties of HAp samples were investigated. With the addition of EDTA, the average crystallite size of the HAp samples is gradually decreased from 30 to 22 nm and the crystallinity is in the range of 65-71%. The values of the lattice parameters (a and c) and volume of the unit cell are decreased by stages with the addition of EDTA. The dielectric parameters such as relative permittivity, dielectric loss and relaxation time are affected by the adding of EDTA. The alternating current conductivity of the as-synthesized hydroxyapatites increases with the increasing frequency and obeys the universal power law behavior. The HAp samples exhibit a non-Debye relaxation mechanism. The obtained results that the dielectrical parameters of the HAp sample can be controlled by EDTA.

Optimal flexible sample size design with robust power.

PubMed

Zhang, Lanju; Cui, Lu; Yang, Bo

2016-08-30

It is well recognized that sample size determination is challenging because of the uncertainty on the treatment effect size. Several remedies are available in the literature. Group sequential designs start with a sample size based on a conservative (smaller) effect size and allow early stop at interim looks. Sample size re-estimation designs start with a sample size based on an optimistic (larger) effect size and allow sample size increase if the observed effect size is smaller than planned. Different opinions favoring one type over the other exist. We propose an optimal approach using an appropriate optimality criterion to select the best design among all the candidate designs. Our results show that (1) for the same type of designs, for example, group sequential designs, there is room for significant improvement through our optimization approach; (2) optimal promising zone designs appear to have no advantages over optimal group sequential designs; and (3) optimal designs with sample size re-estimation deliver the best adaptive performance. We conclude that to deal with the challenge of sample size determination due to effect size uncertainty, an optimal approach can help to select the best design that provides most robust power across the effect size range of interest. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

A Systematic Review of the Relationship between Familism and Mental Health Outcomes in Latino Population

PubMed Central

Valdivieso-Mora, Esmeralda; Peet, Casie L.; Garnier-Villarreal, Mauricio; Salazar-Villanea, Monica; Johnson, David K.

2016-01-01

Background: Familismo or familism is a cultural value frequently seen in Hispanic cultures, in which a higher emphasis is placed on the family unit in terms of respect, support, obligation, and reference. Familism has been implicated as a protective factor against mental health problems and may foster the growth and development of children. This study aims at measuring the size of the relationship between familism and mental health outcomes of depression, suicide, substance abuse, internalizing, and externalizing behaviors. Methods: Thirty-nine studies were systematically reviewed to assess the relationship between familism and mental health outcomes. Data from the studies were comprised and organized into five categories: depression, suicide, internalizing symptoms, externalizing symptoms, and substance use. The Cohen's d of each value (dependent variable in comparison to familism) was calculated. Results were weighted based on sample sizes (n) and total effect sizes were then calculated. It was hypothesized that there would be a large effect size in the relationship between familism and depression, suicide, internalizing, and externalizing symptoms and substance use in Hispanics. Results: The meta-analysis showed small effect sizes in the relationship between familism and depression, suicide and internalizing behaviors. And no significant effects for substance abuse and externalizing behaviors. Discussion: The small effects found in this study may be explained by the presence of moderator variables between familism and mental health outcomes (e.g., communication within the family). In addition, variability in the Latino samples and in the measurements used might explain the small and non-significant effects found. PMID:27826269

The SOLID (Signs Of LIfe Detector) instrument concept: an antibody microarray-based biosensor for life detection in astrobiology

NASA Astrophysics Data System (ADS)

Parro, V.; Rivas, L. A.; Rodríguez-Manfredi, J. A.; Blanco, Y.; de Diego-Castilla, G.; Cruz-Gil, P.; Moreno-Paz, M.; García-Villadangos, M.; Compostizo, C.; Herrero, P. L.

2009-04-01

Immunosensors have been extensively used since many years for environmental monitoring. Different technological platforms allow new biosensor designs and implementations. We have reported (Rivas et al., 2008) a shotgun approach for antibody production for biomarker detection in astrobiology and environmental monitoring, the production of 150 new polyclonal antibodies against microbial strains and environmental extracts, and the construction and validation of an antibody microarray (LDCHIP200, for "Life Detector Chip") containing 200 different antibodies. We have successfully used the LDCHIP200 for the detection of biological polymers in extreme environments in different parts of the world (e.g., a deep South African mine, Antarctica's Dry valleys, Yellowstone, Iceland, and Rio Tinto). Clustering analysis associated similar immunopatterns to samples from apparently very different environments, indicating that they indeed share similar universal biomarkers. A redundancy in the number of antibodies against different target biomarkers apart of revealing the presence of certain biomolecules, it renders a sample-specific immuno-profile, an "immnuno-fingerprint", which may constitute by itself an indirect biosignature. We will present a case study of immunoprofiling different iron-sulfur as well as phylosilicates rich samples along the Rio Tinto river banks. Based on protein microarray technology, we designed and built the concept instrument called SOLID (for "Signs Of LIfe Detector"; Parro et al., 2005; 2008a, b; http://cab.inta.es/solid) for automatic in situ analysis of soil samples and molecular biomarkers detection. A field prototype, SOLID2, was successfully tested for the analysis of grinded core samples during the 2005 "MARTE" campaign of a Mars drilling simulation experiment by a sandwich microarray immunoassay (Parro et al., 2008b). We will show the new version of the instrument (SOLID3) which is able to perform both sandwich and competitive immunoassays. SOLID3 consists of two separate functional units: a Sample Preparation Unit (SPU), for ten different extractions by ultrasonication, and a Sample Analysis Unit (SAU), for fluorescent immunoassays. The SAU consists of ten different flow cells each of one allocate one antibody microarray (up to 2000 spots), and is equipped with an unique designed optical package for fluorescent detection. We demonstrate the performance of SOLID3 for the detection of a broad range of molecular size compounds, from the amino acid size, peptides, proteins, to whole cells and spores, with sensitivities at the ppb level. References Parro, V., et al., 2005. Planetary and Space Science 53: 729-737. Parro, V., et al., 2008a. Space Science Reviews 135: 293-311 Parro, V., et al., 2008b. Astrobiology 8:987-99 Rivas, L. A., et al., 2008. Analytical Chemistry 80: 7970-7979

[Effect sizes, statistical power and sample sizes in "the Japanese Journal of Psychology"].

PubMed

Suzukawa, Yumi; Toyoda, Hideki

2012-04-01

This study analyzed the statistical power of research studies published in the "Japanese Journal of Psychology" in 2008 and 2009. Sample effect sizes and sample statistical powers were calculated for each statistical test and analyzed with respect to the analytical methods and the fields of the studies. The results show that in the fields like perception, cognition or learning, the effect sizes were relatively large, although the sample sizes were small. At the same time, because of the small sample sizes, some meaningful effects could not be detected. In the other fields, because of the large sample sizes, meaningless effects could be detected. This implies that researchers who could not get large enough effect sizes would use larger samples to obtain significant results.

Sample Size Estimation: The Easy Way

ERIC Educational Resources Information Center

Weller, Susan C.

2015-01-01

This article presents a simple approach to making quick sample size estimates for basic hypothesis tests. Although there are many sources available for estimating sample sizes, methods are not often integrated across statistical tests, levels of measurement of variables, or effect sizes. A few parameters are required to estimate sample sizes and…

Hygroscopic and Chemical Properties of Aerosols collected near a Copper Smelter: Implications for Public and Environmental Health

PubMed Central

Sorooshian, Armin; Csavina, Janae; Shingler, Taylor; Dey, Stephen; Brechtel, Fred J.; Sáez, A. Eduardo; Betterton, Eric A.

2012-01-01

Particulate matter emissions near active copper smelters and mine tailings in the southwestern United States pose a potential threat to nearby environments owing to toxic species that can be inhaled and deposited in various regions of the body depending on the composition and size of the particles, which are linked by particle hygroscopic properties. This study reports the first simultaneous measurements of size-resolved chemical and hygroscopic properties of particles next to an active copper smelter and mine tailings by the towns of Hayden and Winkelman in southern Arizona. Size-resolved particulate matter samples collected near an active copper smelter were examined with inductively coupled plasma mass spectrometry, ion chromatography, and a humidified tandem differential mobility analyzer. Aerosol particles collected at the measurement site are enriched in metals and metalloids (e.g. arsenic, lead, and cadmium) and water-uptake measurements of aqueous extracts of collected samples indicate that the particle diameter range of particles most enriched with these species (0.18–0.55 µm) overlaps with the most hygroscopic mode at a relative humidity of 90% (0.10–0.32 µm). These measurements have implications for public health, microphysical effects of aerosols, and regional impacts owing to the transport and deposition of contaminated aerosol particles. PMID:22852879

The Relationship between Sample Sizes and Effect Sizes in Systematic Reviews in Education

ERIC Educational Resources Information Center

Slavin, Robert; Smith, Dewi

2009-01-01

Research in fields other than education has found that studies with small sample sizes tend to have larger effect sizes than those with large samples. This article examines the relationship between sample size and effect size in education. It analyzes data from 185 studies of elementary and secondary mathematics programs that met the standards of…

Status and trends of the rainbow trout population in the Lees Ferry reach of the Colorado River downstream from Glen Canyon Dam, Arizona, 1991–2009

USGS Publications Warehouse

Makinster, Andrew S.; Persons, William R.; Avery, Luke A.

2011-01-01

The Lees Ferry reach of the Colorado River, a 25-kilometer segment of river located immediately downstream from Glen Canyon Dam, has contained a nonnative rainbow trout (Oncorhynchus mykiss) sport fishery since it was first stocked in 1964. The fishery has evolved over time in response to changes in dam operations and fish management. Long-term monitoring of the rainbow trout population downstream of Glen Canyon Dam is an essential component of the Glen Canyon Dam Adaptive Management Program. A standardized sampling design was implemented in 1991 and has changed several times in response to independent, external scientific-review recommendations and budget constraints. Population metrics (catch per unit effort, proportional stock density, and relative condition) were estimated from 1991 to 2009 by combining data collected at fixed sampling sites during this time period and at random sampling sites from 2002 to 2009. The validity of combining population metrics for data collected at fixed and random sites was confirmed by a one-way analysis of variance by fish-length class size. Analysis of the rainbow trout population metrics from 1991 to 2009 showed that the abundance of rainbow trout increased from 1991 to 1997, following implementation of a more steady flow regime, but declined from about 2000 to 2007. Abundance in 2008 and 2009 was high compared to previous years, which was likely the result of increased early survival caused by improved habitat conditions following the 2008 high-flow experiment at Glen Canyon Dam. Proportional stock density declined between 1991 and 2006, reflecting increased natural reproduction and large numbers of small fish in samples. Since 2001, the proportional stock density has been relatively stable. Relative condition varied with size class of rainbow trout but has been relatively stable since 1991 for fish smaller than 152 millimeters (mm), except for a substantial decrease in 2009. Relative condition was more variable for larger size classes, and substantial decreases were observed for the 152-304-mm size class in 2009 and 305-405-mm size class in 2008 that persisted into 2009.

Miniaturized technology for DNA typing: cassette PCR.

PubMed

Manage, Dammika P; Pilarski, Linda M

2015-01-01

With the smaller size, low cost, and rapid testing capabilities, miniaturized lab-on-a-chip devices can change the way medical diagnostics are currently performed in the health-care system. We have demonstrated such a device that is self-contained, simple, disposable, and inexpensive. It is capable of performing DNA amplification on an inexpensive instrument suitable for near point of care settings. This technology will enable on the spot evaluation of patients in the clinic for faster medical decision-making and more informed therapeutic choices. Our device, a gel capillary cassette, termed cassette PCR, contains capillary reaction units each holding a defined primer set, with arrays of capillary reaction units for simultaneously detecting multiple targets. With the exception of the sample to be tested, each capillary reaction unit holds all the reagents needed for PCR in a desiccated form that can be stored at room temperature for up to 3 months and even longer in colder conditions. It relies on capillary forces for sample delivery of microliter volumes through capillaries, hence avoiding the need for pumps or valves. In the assembled cassette, the wax architecture supporting the capillaries melts during the PCR and acts as a vapor barrier as well as segregating capillaries with different primer sets. No other chip sealing techniques are required. Cassette PCR accepts raw samples such as urine, genital swabs, and blood. The cassette is made with off-the-shelf components and contains integrated positive and negative controls.

Organochlorine compounds and trace elements in fish tissue and ancillary data for the Connecticut, Housatonic, and Thames river basins study unit, 1992-94

USGS Publications Warehouse

Coles, J.F.

1996-01-01

Concentrations of organochlorine compounds and trace elements were assayed in fish tissue collected from the Connecticut, Housatonic, and Thames River Basins Study Unit, 1992-94. These data were collected to determine the occurrence and distribution of organochlorine compounds and trace elements in the study unit. Ancillary data included are land-use categories by percentage of the sampling-site basins and the size, gender, and age of the individual fish collected for this study. Concentrations of 28 organochlorine compounds in composited whole fish samples were measured at 32 sites, and concentrations of 22 trace elements in composited fish liver samples were measured at 14 of the 32 sites. Most frequently detected organochlorines were DDT related compounds at 31 sites, total PCBs at 28 sites, and chlordane related compounds at 25 sites. Concentrations of total PCBs in fish tissue were generally higher at the large river sites than at the smaller tributary sites. Concentrations of chlordane-related compounds in fish tissue were higher at sites from more urbanized basins than at sites from predominately agriculture and forested basins. Concentrations of the DDT related compounds were undifferentiated among sites comprising different land uses. Trace elements detected at all 14 sites included boron, copper, iron, manganese, molybdenum, selenium, and zinc. Trace elements detected at 10 or more sites included arsenic, mercury, silver, strontium, and vanadium. Antimony, beryllium, and uranium were not detected at any site.

Spectral analysis of tissues from patients with cancer using a portable spectroscopic diagnostic ratiometer unit

NASA Astrophysics Data System (ADS)

Sordillo, Laura A.; Pu, Yang; Sordillo, Peter P.; Budansky, Yury; Alfano, R. R.

2014-05-01

Spectral profiles of tissues from patients with breast carcinoma, malignant carcinoid and non-small cell lung carcinoma were acquired using native fluorescence spectroscopy. A novel spectroscopic ratiometer device (S3-LED) with selective excitation wavelengths at 280 nm and 335 nm was used to produce the emission spectra of the key biomolecules, tryptophan and NADH, in the tissue samples. In each of the samples, analysis of emission intensity peaks from biomolecules showed increased 340 nm/440 nm and 340 nm/460 nm ratios in the malignant samples compared to their paired normal samples. This most likely represented increased tryptophan to NADH ratios in the malignant tissue samples compared to their paired normal samples. Among the non-small cell lung carcinoma and breast carcinomas, it appeared that tumors of very large size or poor differentiation had an even greater increase in the 340 nm/440 nm and 340 nm/460 nm ratios. In the samples of malignant carcinoid, which is known to be a highly metabolically active tumor, a marked increase in these ratios was also seen.

Phylogenetic effective sample size.

PubMed

Bartoszek, Krzysztof

2016-10-21

In this paper I address the question-how large is a phylogenetic sample? I propose a definition of a phylogenetic effective sample size for Brownian motion and Ornstein-Uhlenbeck processes-the regression effective sample size. I discuss how mutual information can be used to define an effective sample size in the non-normal process case and compare these two definitions to an already present concept of effective sample size (the mean effective sample size). Through a simulation study I find that the AICc is robust if one corrects for the number of species or effective number of species. Lastly I discuss how the concept of the phylogenetic effective sample size can be useful for biodiversity quantification, identification of interesting clades and deciding on the importance of phylogenetic correlations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Structural, compositional, and sensorial properties of United States commercial ice cream products.

PubMed

Warren, Maya M; Hartel, Richard W

2014-10-01

Commercial vanilla ice cream products from the United States (full fat, low fat, and nonfat) were analyzed for their structural, behavioral (i.e., melt rate and drip-through), compositional, and sensorial attributes. Mean size distributions of ice crystals and air cells, drip-through rates, percent partially coalesced fat, percent overrun and total fat, and density were determined. A trained panel carried out sensory analyses in order to determine correlations between ice cream microstructure attributes and sensory properties using a Spectrum(TM) descriptive analysis. Analyses included melt rate, breakdown, size of ice particulates (iciness), denseness, greasiness, and overall creaminess. To determine relationships and interactions, principle component analysis and multivariate pairwise correlation were performed within and between the instrumental and sensorial data. Greasiness and creaminess negatively correlated with drip-through rate and creaminess correlated with percent total fat and percent fat destabilization. Percent fat did not determine the melt rate on a sensorial level. However, drip-through rate at ambient temperatures was predicted by total fat content of the samples. Based on sensory analysis, high-fat products were noted to be creamier than low and nonfat products. Iciness did not correlate with mean ice crystal size and drip-through rate did not predict sensory melt rate. Furthermore, on a sensorial level, greasiness positively correlated with total percent fat destabilization and mean air cell size positively correlated with denseness. These results indicate that commercial ice cream products vary widely in composition, structure, behavior, and sensory properties. There is a wide range of commercial ice creams in the United States market, ranging from full fat to nonfat. In this research we showed that these ice creams vary greatly in their microstructures, behaviors (the melt/drip-though, collapse, and/or stand up properties of ice cream products at ambient temperatures), and sensory properties. © 2014 Institute of Food Technologists®

Free-ranging farm cats: home range size and predation on a livestock unit in Northwest Georgia.

PubMed

Kitts-Morgan, Susanna E; Caires, Kyle C; Bohannon, Lisa A; Parsons, Elizabeth I; Hilburn, Katharine A

2015-01-01

This study's objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05) on overall (95% KDE and 90% KDE) or core home range size (50% KDE). Male cats tended (P = 0.08) to have larger diurnal and nocturnal core home ranges (1.09 ha) compared to female cats (0.64 ha). Reproductively intact cats (n = 2) had larger (P < 0.0001) diurnal and nocturnal home ranges as compared to altered cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus) was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife.

Free-Ranging Farm Cats: Home Range Size and Predation on a Livestock Unit In Northwest Georgia

PubMed Central

Kitts-Morgan, Susanna E.; Caires, Kyle C.; Bohannon, Lisa A.; Parsons, Elizabeth I.; Hilburn, Katharine A.

2015-01-01

This study’s objective was to determine seasonal and diurnal vs. nocturnal home range size, as well as predation for free-ranging farm cats at a livestock unit in Northwest Georgia. Seven adult cats were tracked with attached GPS units for up to two weeks for one spring and two summer seasons from May 2010 through August 2011. Three and five cats were tracked for up to two weeks during the fall and winter seasons, respectively. Feline scat was collected during this entire period. Cats were fed a commercial cat food daily. There was no seasonal effect (P > 0.05) on overall (95% KDE and 90% KDE) or core home range size (50% KDE). Male cats tended (P = 0.08) to have larger diurnal and nocturnal core home ranges (1.09 ha) compared to female cats (0.64 ha). Reproductively intact cats (n = 2) had larger (P < 0.0001) diurnal and nocturnal home ranges as compared to altered cats. Feline scat processing separated scat into prey parts, and of the 210 feline scats collected during the study, 75.24% contained hair. Of these 158 scat samples, 86 contained non-cat hair and 72 contained only cat hair. Other prey components included fragments of bone in 21.43% of scat and teeth in 12.86% of scat. Teeth were used to identify mammalian prey hunted by these cats, of which the Hispid cotton rat (Sigmodon hispidus) was the primary rodent. Other targeted mammals were Peromyscus sp., Sylvilagus sp. and Microtus sp. Invertebrates and birds were less important as prey, but all mammalian prey identified in this study consisted of native animals. While the free-ranging farm cats in this study did not adjust their home range seasonally, sex and reproductive status did increase diurnal and nocturnal home range size. Ultimately, larger home ranges of free-ranging cats could negatively impact native wildlife. PMID:25894078

Choice of Stimulus Range and Size Can Reduce Test-Retest Variability in Glaucomatous Visual Field Defects

PubMed Central

Swanson, William H.; Horner, Douglas G.; Dul, Mitchell W.; Malinovsky, Victor E.

2014-01-01

Purpose To develop guidelines for engineering perimetric stimuli to reduce test-retest variability in glaucomatous defects. Methods Perimetric testing was performed on one eye for 62 patients with glaucoma and 41 age-similar controls on size III and frequency-doubling perimetry and three custom tests with Gaussian blob and Gabor sinusoid stimuli. Stimulus range was controlled by values for ceiling (maximum sensitivity) and floor (minimum sensitivity). Bland-Altman analysis was used to derive 95% limits of agreement on test and retest, and bootstrap analysis was used to test the hypotheses about peak variability. Results Limits of agreement for the three custom stimuli were similar in width (0.72 to 0.79 log units) and peak variability (0.22 to 0.29 log units) for a stimulus range of 1.7 log units. The width of the limits of agreement for size III decreased from 1.78 to 1.37 to 0.99 log units for stimulus ranges of 3.9, 2.7, and 1.7 log units, respectively (F = 3.23, P < 0.001); peak variability was 0.99, 0.54, and 0.34 log units, respectively (P < 0.01). For a stimulus range of 1.3 log units, limits of agreement were narrowest with Gabor and widest with size III stimuli, and peak variability was lower (P < 0.01) with Gabor (0.18 log units) and frequency-doubling perimetry (0.24 log units) than with size III stimuli (0.38 log units). Conclusions Test-retest variability in glaucomatous visual field defects was substantially reduced by engineering the stimuli. Translational Relevance The guidelines should allow developers to choose from a wide range of stimuli. PMID:25371855

Choice of Stimulus Range and Size Can Reduce Test-Retest Variability in Glaucomatous Visual Field Defects.

PubMed

Swanson, William H; Horner, Douglas G; Dul, Mitchell W; Malinovsky, Victor E

2014-09-01

To develop guidelines for engineering perimetric stimuli to reduce test-retest variability in glaucomatous defects. Perimetric testing was performed on one eye for 62 patients with glaucoma and 41 age-similar controls on size III and frequency-doubling perimetry and three custom tests with Gaussian blob and Gabor sinusoid stimuli. Stimulus range was controlled by values for ceiling (maximum sensitivity) and floor (minimum sensitivity). Bland-Altman analysis was used to derive 95% limits of agreement on test and retest, and bootstrap analysis was used to test the hypotheses about peak variability. Limits of agreement for the three custom stimuli were similar in width (0.72 to 0.79 log units) and peak variability (0.22 to 0.29 log units) for a stimulus range of 1.7 log units. The width of the limits of agreement for size III decreased from 1.78 to 1.37 to 0.99 log units for stimulus ranges of 3.9, 2.7, and 1.7 log units, respectively ( F = 3.23, P < 0.001); peak variability was 0.99, 0.54, and 0.34 log units, respectively ( P < 0.01). For a stimulus range of 1.3 log units, limits of agreement were narrowest with Gabor and widest with size III stimuli, and peak variability was lower ( P < 0.01) with Gabor (0.18 log units) and frequency-doubling perimetry (0.24 log units) than with size III stimuli (0.38 log units). Test-retest variability in glaucomatous visual field defects was substantially reduced by engineering the stimuli. The guidelines should allow developers to choose from a wide range of stimuli.

The endothelial sample size analysis in corneal specular microscopy clinical examinations.

PubMed

Abib, Fernando C; Holzchuh, Ricardo; Schaefer, Artur; Schaefer, Tania; Godois, Ronialci

2012-05-01

To evaluate endothelial cell sample size and statistical error in corneal specular microscopy (CSM) examinations. One hundred twenty examinations were conducted with 4 types of corneal specular microscopes: 30 with each BioOptics, CSO, Konan, and Topcon corneal specular microscopes. All endothelial image data were analyzed by respective instrument software and also by the Cells Analyzer software with a method developed in our lab. A reliability degree (RD) of 95% and a relative error (RE) of 0.05 were used as cut-off values to analyze images of the counted endothelial cells called samples. The sample size mean was the number of cells evaluated on the images obtained with each device. Only examinations with RE < 0.05 were considered statistically correct and suitable for comparisons with future examinations. The Cells Analyzer software was used to calculate the RE and customized sample size for all examinations. Bio-Optics: sample size, 97 ± 22 cells; RE, 6.52 ± 0.86; only 10% of the examinations had sufficient endothelial cell quantity (RE < 0.05); customized sample size, 162 ± 34 cells. CSO: sample size, 110 ± 20 cells; RE, 5.98 ± 0.98; only 16.6% of the examinations had sufficient endothelial cell quantity (RE < 0.05); customized sample size, 157 ± 45 cells. Konan: sample size, 80 ± 27 cells; RE, 10.6 ± 3.67; none of the examinations had sufficient endothelial cell quantity (RE > 0.05); customized sample size, 336 ± 131 cells. Topcon: sample size, 87 ± 17 cells; RE, 10.1 ± 2.52; none of the examinations had sufficient endothelial cell quantity (RE > 0.05); customized sample size, 382 ± 159 cells. A very high number of CSM examinations had sample errors based on Cells Analyzer software. The endothelial sample size (examinations) needs to include more cells to be reliable and reproducible. The Cells Analyzer tutorial routine will be useful for CSM examination reliability and reproducibility.

Improving understanding of mixed-land-use watershed suspended sediment regimes: Mechanistic progress through high-frequency sampling.

PubMed

Kellner, Elliott; Hubbart, Jason A

2017-11-15

Given the importance of suspended sediment to biogeochemical functioning of aquatic ecosystems, and the increasing concern of mixed-land-use effects on pollutant loading, there is an urgent need for research that quantitatively characterizes spatiotemporal variation of suspended sediment dynamics in contemporary watersheds. A study was conducted in a representative watershed of the central United States utilizing a nested-scale experimental watershed design, including five gauging sites (n=5) partitioning the catchment into five sub-watersheds. Hydroclimate stations at gauging sites were used to monitor air temperature, precipitation, and stream stage at 30-min intervals during the study (Oct. 2009-Feb. 2014). Streamwater grab samples were collected four times per week, at each site, for the duration of the study (Oct. 2009-Feb. 2014). Water samples were analyzed for suspended sediment using laser particle diffraction. Results showed significant differences (p<0.05) between monitoring sites for total suspended sediment concentration, mean particle size, and silt volume. Total concentration and silt volume showed a decreasing trend from the primarily agricultural upper watershed to the urban mid-watershed, and a subsequent increasing trend to the more suburban lower watershed. Conversely, mean particle size showed an opposite spatial trend. Results are explained by a combination of land use (e.g. urban stormwater dilution) and surficial geology (e.g. supply-controlled spatial variation of particle size). Correlation analyses indicated weak relationships with both hydroclimate and land use, indicating non-linear sediment dynamics. Suspended sediment parameters displayed consistent seasonality during the study, with total concentration decreasing through the growing season and mean particle size inversely tracking air temperature. Likely explanations include vegetation influences and climate-driven weathering cycles. Results reflect unique observations of spatiotemporal variation of suspended sediment particle size class. Such information is crucial for land and water resource managers working to mitigate aquatic ecosystem degradation and improve water resource sustainability in mixed-land-use watersheds globally. Copyright © 2017 Elsevier B.V. All rights reserved.

The effect of size, orientation and alloying on the deformation of AZ31 nanopillars

NASA Astrophysics Data System (ADS)

Aitken, Zachary H.; Fan, Haidong; El-Awady, Jaafar A.; Greer, Julia R.

2015-03-01

We conducted uniaxial compression of single crystalline Mg alloy, AZ31 (Al 3 wt% and Zn 1 wt%) nanopillars with diameters between 300 and 5000 nm with two distinct crystallographic orientations: (1) along the [0001] c-axis and (2) at an acute angle away from the c-axis, nominally oriented for basal slip. We observe single slip deformation for sub-micron samples nominally oriented for basal slip with the deformation commencing via a single set of parallel shear offsets. Samples compressed along the c-axis display an increase in yield strength compared to basal samples as well as significant hardening with the deformation being mostly homogeneous. We find that the "smaller is stronger" size effect in single crystals dominates any improvement in strength that may have arisen from solid solution strengthening. We employ 3D-discrete dislocation dynamics (DDD) to simulate compression along the [0001] and [ 11 2 bar 2 ] directions to elucidate the mechanisms of slip and evolution of dislocation microstructure. These simulations show qualitatively similar stress-strain signatures to the experimentally obtained stress-strain data. Simulations of compression parallel to the [ 11 2 bar 2 ] direction reveal the activation and motion of only -type dislocations and virtually no dislocation junction formation. Computations of compression along [0001] show the activation and motion of both and dislocations along with a significant increase in the formation of junctions corresponding to the interaction of intersecting pyramidal planes. Both experiments and simulation show a size effect, with a differing exponent for basal and pyramidal slip. We postulate that this anisotropy in size effect is a result of the underlying anisotropic material properties only. We discuss these findings in the context of the effective resolved shear stress relative to the unit Burgers vector for each type of slip, which reveal that the mechanism that governs size effect in this Mg-alloy is equivalent in both orientations.

Accounting for twin births in sample size calculations for randomised trials.

PubMed

Yelland, Lisa N; Sullivan, Thomas R; Collins, Carmel T; Price, David J; McPhee, Andrew J; Lee, Katherine J

2018-05-04

Including twins in randomised trials leads to non-independence or clustering in the data. Clustering has important implications for sample size calculations, yet few trials take this into account. Estimates of the intracluster correlation coefficient (ICC), or the correlation between outcomes of twins, are needed to assist with sample size planning. Our aims were to provide ICC estimates for infant outcomes, describe the information that must be specified in order to account for clustering due to twins in sample size calculations, and develop a simple tool for performing sample size calculations for trials including twins. ICCs were estimated for infant outcomes collected in four randomised trials that included twins. The information required to account for clustering due to twins in sample size calculations is described. A tool that calculates the sample size based on this information was developed in Microsoft Excel and in R as a Shiny web app. ICC estimates ranged between -0.12, indicating a weak negative relationship, and 0.98, indicating a strong positive relationship between outcomes of twins. Example calculations illustrate how the ICC estimates and sample size calculator can be used to determine the target sample size for trials including twins. Clustering among outcomes measured on twins should be taken into account in sample size calculations to obtain the desired power. Our ICC estimates and sample size calculator will be useful for designing future trials that include twins. Publication of additional ICCs is needed to further assist with sample size planning for future trials. © 2018 John Wiley & Sons Ltd.

SIproc: an open-source biomedical data processing platform for large hyperspectral images.

PubMed

Berisha, Sebastian; Chang, Shengyuan; Saki, Sam; Daeinejad, Davar; He, Ziqi; Mankar, Rupali; Mayerich, David

2017-04-10

There has recently been significant interest within the vibrational spectroscopy community to apply quantitative spectroscopic imaging techniques to histology and clinical diagnosis. However, many of the proposed methods require collecting spectroscopic images that have a similar region size and resolution to the corresponding histological images. Since spectroscopic images contain significantly more spectral samples than traditional histology, the resulting data sets can approach hundreds of gigabytes to terabytes in size. This makes them difficult to store and process, and the tools available to researchers for handling large spectroscopic data sets are limited. Fundamental mathematical tools, such as MATLAB, Octave, and SciPy, are extremely powerful but require that the data be stored in fast memory. This memory limitation becomes impractical for even modestly sized histological images, which can be hundreds of gigabytes in size. In this paper, we propose an open-source toolkit designed to perform out-of-core processing of hyperspectral images. By taking advantage of graphical processing unit (GPU) computing combined with adaptive data streaming, our software alleviates common workstation memory limitations while achieving better performance than existing applications.

Measurement of surface water runoff from plots of two different sizes

NASA Astrophysics Data System (ADS)

Joel, Abraham; Messing, Ingmar; Seguel, Oscar; Casanova, Manuel

2002-05-01

Intensities and amounts of water infiltration and runoff on sloping land are governed by the rainfall pattern and soil hydraulic conductivity, as well as by the microtopography and soil surface conditions. These components are closely interrelated and occur simultaneously, and their particular contribution may change during a rainfall event, or their effects may vary at different field scales. The scale effect on the process of infiltration/runoff was studied under natural field and rainfall conditions for two plot sizes: small plots of 0·25 m2 and large plots of 50 m2. The measurements were carried out in the central region of Chile in a piedmont most recently used as natural pastureland. Three blocks, each having one large plot and five small plots, were established. Cumulative rainfall and runoff quantities were sampled every 5 min. Significant variations in runoff responses to rainfall rates were found for the two plot sizes. On average, large plots yielded only 40% of runoff quantities produced on small plots per unit area. This difference between plot sizes was observed even during periods of continuous runoff.

Unit bias. A new heuristic that helps explain the effect of portion size on food intake.

PubMed

Geier, Andrew B; Rozin, Paul; Doros, Gheorghe

2006-06-01

People seem to think that a unit of some entity (with certain constraints) is the appropriate and optimal amount. We refer to this heuristic as unit bias. We illustrate unit bias by demonstrating large effects of unit segmentation, a form of portion control, on food intake. Thus, people choose, and presumably eat, much greater weights of Tootsie Rolls and pretzels when offered a large as opposed to a small unit size (and given the option of taking as many units as they choose at no monetary cost). Additionally, they consume substantially more M&M's when the candies are offered with a large as opposed to a small spoon (again with no limits as to the number of spoonfuls to be taken). We propose that unit bias explains why small portion sizes are effective in controlling consumption; in some cases, people served small portions would simply eat additional portions if it were not for unit bias. We argue that unit bias is a general feature in human choice and discuss possible origins of this bias, including consumption norms.

Sample size determination for mediation analysis of longitudinal data.

PubMed

Pan, Haitao; Liu, Suyu; Miao, Danmin; Yuan, Ying

2018-03-27

Sample size planning for longitudinal data is crucial when designing mediation studies because sufficient statistical power is not only required in grant applications and peer-reviewed publications, but is essential to reliable research results. However, sample size determination is not straightforward for mediation analysis of longitudinal design. To facilitate planning the sample size for longitudinal mediation studies with a multilevel mediation model, this article provides the sample size required to achieve 80% power by simulations under various sizes of the mediation effect, within-subject correlations and numbers of repeated measures. The sample size calculation is based on three commonly used mediation tests: Sobel's method, distribution of product method and the bootstrap method. Among the three methods of testing the mediation effects, Sobel's method required the largest sample size to achieve 80% power. Bootstrapping and the distribution of the product method performed similarly and were more powerful than Sobel's method, as reflected by the relatively smaller sample sizes. For all three methods, the sample size required to achieve 80% power depended on the value of the ICC (i.e., within-subject correlation). A larger value of ICC typically required a larger sample size to achieve 80% power. Simulation results also illustrated the advantage of the longitudinal study design. The sample size tables for most encountered scenarios in practice have also been published for convenient use. Extensive simulations study showed that the distribution of the product method and bootstrapping method have superior performance to the Sobel's method, but the product method was recommended to use in practice in terms of less computation time load compared to the bootstrapping method. A R package has been developed for the product method of sample size determination in mediation longitudinal study design.

Tunable separations based on a molecular size effect for biomolecules by poly(ethylene glycol) gel-based capillary electrophoresis.

PubMed

Kubo, Takuya; Nishimura, Naoki; Furuta, Hayato; Kubota, Kei; Naito, Toyohiro; Otsuka, Koji

2017-11-10

We report novel capillary gel electrophoresis (CGE) with poly(ethylene glycol) (PEG)-based hydrogels for the effective separations of biomolecules containing sugars and DNAs based on a molecular size effect. The gel capillaries were prepared in a fused silica capillary modified with 3-(trimethoxysilyl)propylmethacrylate using a variety of the PEG-based hydrogels. After the fundamental evaluations in CGE regarding the separation based on the molecular size effect depending on the crosslinking density, the optimized capillary provided the efficient separation of glucose ladder (G1 to G20). In addition, another capillary showed the successful separation of DNA ladder in the range of 10-1100 base pair, which is superior to an authentic acrylamide-based gel capillary. For both glucose and DNA ladders, the separation ranges against the molecular size were simply controllable by alteration of the concentration and/or units of ethylene oxide in the PEG-based crosslinker. Finally, we demonstrated the separations of real samples, which included sugars carved out from monoclonal antibodies, mAbs, and then the efficient separations based on the molecular size effect were achieved. Copyright © 2017 Elsevier B.V. All rights reserved.

Public Opinion Polls, Chicken Soup and Sample Size

ERIC Educational Resources Information Center

Nguyen, Phung

2005-01-01

Cooking and tasting chicken soup in three different pots of very different size serves to demonstrate that it is the absolute sample size that matters the most in determining the accuracy of the findings of the poll, not the relative sample size, i.e. the size of the sample in relation to its population.

24 CFR 982.555 - Informal hearing for participant.

Code of Federal Regulations, 2010 CFR

2010-04-01

... allowance schedule. (iii) A determination of the family unit size under the PHA subsidy standards. (iv) A... appropriate for the family unit size under the PHA subsidy standards, or the PHA determination to deny the... with HQS because of the family size. (8) A determination by the PHA to exercise or not to exercise any...

Examining the influence of heterogeneous porosity fields on conservative solute transport

USGS Publications Warehouse

Hu, B.X.; Meerschaert, M.M.; Barrash, W.; Hyndman, D.W.; He, C.; Li, X.; Guo, Laodong

2009-01-01

It is widely recognized that groundwater flow and solute transport in natural media are largely controlled by heterogeneities. In the last three decades, many studies have examined the effects of heterogeneous hydraulic conductivity fields on flow and transport processes, but there has been much less attention to the influence of heterogeneous porosity fields. In this study, we use porosity and particle size measurements from boreholes at the Boise Hydrogeophysical Research Site (BHRS) to evaluate the importance of characterizing the spatial structure of porosity and grain size data for solute transport modeling. Then we develop synthetic hydraulic conductivity fields based on relatively simple measurements of porosity from borehole logs and grain size distributions from core samples to examine and compare the characteristics of tracer transport through these fields with and without inclusion of porosity heterogeneity. In particular, we develop horizontal 2D realizations based on data from one of the less heterogeneous units at the BHRS to examine effects where spatial variations in hydraulic parameters are not large. The results indicate that the distributions of porosity and the derived hydraulic conductivity in the study unit resemble fractal normal and lognormal fields respectively. We numerically simulate solute transport in stochastic fields and find that spatial variations in porosity have significant effects on the spread of an injected tracer plume including a significant delay in simulated tracer concentration histories.

Sample size in studies on diagnostic accuracy in ophthalmology: a literature survey.

PubMed

Bochmann, Frank; Johnson, Zoe; Azuara-Blanco, Augusto

2007-07-01

To assess the sample sizes used in studies on diagnostic accuracy in ophthalmology. Design and sources: A survey literature published in 2005. The frequency of reporting calculations of sample sizes and the samples' sizes were extracted from the published literature. A manual search of five leading clinical journals in ophthalmology with the highest impact (Investigative Ophthalmology and Visual Science, Ophthalmology, Archives of Ophthalmology, American Journal of Ophthalmology and British Journal of Ophthalmology) was conducted by two independent investigators. A total of 1698 articles were identified, of which 40 studies were on diagnostic accuracy. One study reported that sample size was calculated before initiating the study. Another study reported consideration of sample size without calculation. The mean (SD) sample size of all diagnostic studies was 172.6 (218.9). The median prevalence of the target condition was 50.5%. Only a few studies consider sample size in their methods. Inadequate sample sizes in diagnostic accuracy studies may result in misleading estimates of test accuracy. An improvement over the current standards on the design and reporting of diagnostic studies is warranted.

Grain-size variations on a longitudinal dune and a barchan dune

NASA Astrophysics Data System (ADS)

Watson, Andrew

1986-01-01

The grain-size characteristics of the sand upon two dunes—a 40 m high longitudinal dune in the central Namib Desert and a 6.0 m high barchan in the Jafurah sand sea of Saudi Arabia—vary with position on the dunes. On the longitudinal dune, median grain size decreases, sorting improves and the grain-size distributions are less skewed and more normalized toward the crest. Though sand at the windward toe is distinct, elsewhere on the dune the changes in grain-size characteristics are gradual. An abrupt change in grain size and sorting near the crest—as described by Bagnold (1941, pp. 226-229)—is not well represented on this dune. Coarse grains remain as a lag on concave slope units and small particles are winnowed from the sand on the steepest windward slopes near the crest. Avalanching down slipfaces at the crest acts only as a supplementary grading mechanism. On the barchan dune median grain size also decreases near the crest, but sorting becomes poorer, though the grain-size distributions are more symmetric and more normalized. The dune profile is a Gaussian curve with a broad convex zone at the apex upon which topset beds had accreted prior to sampling. Grain size increases and sorting improves down the dune's slipface. However, this grading mechanism does not influence sand on the whole dune because variations in wind regime bring about different modes of dune accretion. On both dunes, height and morphology appear to influence significantly the grain-size characteristics.

Surface-water-quality assessment of the lower Kansas River basin, Kansas and Nebraska; selected metals, arsenic, and phosphorus in streambed sediments of first- and second-order streams, 1987

USGS Publications Warehouse

Tanner, D.Q.; Ryder, J.L.

1996-01-01

Concentrations of metals and nonmetallic elements were measured in the less than 63-micrometer-sized fraction of streambed-sediment samples from 422 sites on first- and second-order streams in the lower Kansas River Basin of Kansas and Nebraska. Median concentrations were of the same order of magnitude as the geometric mean concentrations in soils of the western United States. Either threshold concentrations (based on normal-probability plots) or upper percentile classes (greater than 50 percent) of concentrations were determined for 14 metals, arsenic, and phosphorus. Samples with a concentration greater than the threshold concentration indicated possible enrichment with respect to that particular element. Concentrations of the transition metals, which included chromium, cobalt, copper, manganese, nickel, and vanadium, generally were larger in the southeastern part of the study unit where Permian and Pennsylvanian shale and limestone predominate. The largest concen- trations of alakali metals, potassium and sodium, mainly were in the northwestern part of the study unit, which is an area of Quaternary loess deposits irrigated with ground water. Larger concentrations of the alkaline-earth metal, barium, also were in the northwestern part of the study unit. Concentrations of the other alkaline-earth metals, calcium, magnesium, and strontium, were larger in the southern part of the basin, which is underlain by Permian and Pennsylvanian shale and limestone. The largest concentrations of arsenic and lead and were mainly in the southeastern part of the study unit. Large concentrations of phosphorus occurred in the northwestern part of the study unit and were associated with irrigated agriculture.

Caution regarding the choice of standard deviations to guide sample size calculations in clinical trials.

PubMed

Chen, Henian; Zhang, Nanhua; Lu, Xiaosun; Chen, Sophie

2013-08-01

The method used to determine choice of standard deviation (SD) is inadequately reported in clinical trials. Underestimations of the population SD may result in underpowered clinical trials. This study demonstrates how using the wrong method to determine population SD can lead to inaccurate sample sizes and underpowered studies, and offers recommendations to maximize the likelihood of achieving adequate statistical power. We review the practice of reporting sample size and its effect on the power of trials published in major journals. Simulated clinical trials were used to compare the effects of different methods of determining SD on power and sample size calculations. Prior to 1996, sample size calculations were reported in just 1%-42% of clinical trials. This proportion increased from 38% to 54% after the initial Consolidated Standards of Reporting Trials (CONSORT) was published in 1996, and from 64% to 95% after the revised CONSORT was published in 2001. Nevertheless, underpowered clinical trials are still common. Our simulated data showed that all minimal and 25th-percentile SDs fell below 44 (the population SD), regardless of sample size (from 5 to 50). For sample sizes 5 and 50, the minimum sample SDs underestimated the population SD by 90.7% and 29.3%, respectively. If only one sample was available, there was less than 50% chance that the actual power equaled or exceeded the planned power of 80% for detecting a median effect size (Cohen's d = 0.5) when using the sample SD to calculate the sample size. The proportions of studies with actual power of at least 80% were about 95%, 90%, 85%, and 80% when we used the larger SD, 80% upper confidence limit (UCL) of SD, 70% UCL of SD, and 60% UCL of SD to calculate the sample size, respectively. When more than one sample was available, the weighted average SD resulted in about 50% of trials being underpowered; the proportion of trials with power of 80% increased from 90% to 100% when the 75th percentile and the maximum SD from 10 samples were used. Greater sample size is needed to achieve a higher proportion of studies having actual power of 80%. This study only addressed sample size calculation for continuous outcome variables. We recommend using the 60% UCL of SD, maximum SD, 80th-percentile SD, and 75th-percentile SD to calculate sample size when 1 or 2 samples, 3 samples, 4-5 samples, and more than 5 samples of data are available, respectively. Using the sample SD or average SD to calculate sample size should be avoided.

Mobilization of ventilated patients in the intensive care unit: An elicitation study using the theory of planned behavior.

PubMed

Holdsworth, Clare; Haines, Kimberley J; Francis, Jill J; Marshall, Andrea; O'Connor, Denise; Skinner, Elizabeth H

2015-12-01

Early mobilization in intensive care unit (ICU) is safe, feasible, and beneficial. However, mobilization frequently does not occur in practice. The study objective was to elicit attitudinal, normative, and control beliefs (barriers and enablers) toward the mobilization of ventilated patients, to inform development of targeted implementation interventions. A 9-item elicitation questionnaire was administered electronically to a convenience sample of multidisciplinary staff in a tertiary ICU. A snowball recruitment approach was used to target a sample size of 20 to 25. Two investigators performed word count and thematic analyses independently. Themes were cross-checked by a third investigator. Twenty-two questionnaires were completed. Respondents wrote the most text about disadvantages. Positive attitudinal beliefs included better respiratory function, reduced functional decline, and reduced muscle wasting/weakness. The main negative attitudinal beliefs were that mobilization is perceived as time consuming and poses a risk of line dislodgement/disconnection. Positive control beliefs (enablers) included increased staff availability, positive staff attitudes, engagement, and teamwork. Negative control beliefs (barriers) included unstable patient physiology and negative workplace culture. Intensive care unit staff expressed positive and negative attitudinal, normative, and control beliefs across the spectrum, and disadvantages were most frequently reported. Identified beliefs can be used to inform development of future interventions. Copyright © 2015 Elsevier Inc. All rights reserved.

24 CFR 884.219 - Overcrowded and underoccupied units.

Code of Federal Regulations, 2010 CFR

2010-04-01

... assisted under this part is not Decent, Safe, and Sanitary by reason of increase in Family size, or that a Contract unit is larger than appropriate for the size of the Family in occupancy, housing assistance payments with respect to such unit will not be abated, unless the Owner fails to offer the Family a...

Size of households and income disparities.

PubMed

Kuznets, S

1981-01-01

The author examines "the relation between differentials in size of households, (preponderantly family households including one-person units) and disparities in income per household, per person, or per some version of consuming unit." The analysis is based on data for the United States, the Federal Republic of Germany, Israel, Taiwan, the Philippines, and Thailand. excerpt

Moist-soil seed abundance in managed wetlands in the Mississippi Alluvial Valley

USGS Publications Warehouse

Kross, J.; Kaminski, R.M.; Reinecke, K.J.; Penny, E.J.; Pearse, A.T.

2008-01-01

Managed moist-soil units support early succession herbaceous vegetation that produces seeds, tubers, and other plant parts used by waterfowl in the Mississippi Alluvial Valley (MAV), USA. We conducted a stratified multi-stage sample survey on state and federal lands in the MAV of Arkansas, Louisiana, Mississippi, and Missouri during autumns 2002?2004 to generate a contemporary estimate of combined dry mass of seeds and tubers (herein seed abundance) in managed moist-soil units for use by the Lower Mississippi Valley Joint Venture (LMVJV) of the North American Waterfowl Management Plan. We also examined variation in mean seed abundance among moist-soil units in 2003 and 2004 in relation to management intensity (active or passive), soil pH and nutrient levels, proportional occurrence of plant life-forms (e.g., grass, flatsedge, and forb; vine; woody plants), and unit area. Estimates of mean seed abundance were similar in 2002 (X over bar = 537.1 kg/ha, SE = 100.1) and 2004 (X over bar = 555.2 kg/ha, SE = 105.2) but 35?40% less in 2003 (X over bar = 396.8 kg/ha, SE = 116.1). Averaged over years, seed abundance was 496.3 kg/ha (SE = 62.0; CV = 12.5%). Multiple regression analysis indicated seed abundance varied among moist-soil units inversely with proportional occurrence of woody vegetation and unit area and was greater in actively than passively managed units (R2adj = 0.37). Species of early succession grasses occurred more frequently in actively than passively managed units (P < 0.09), whereas mid- and late-succession plants occurred more often in passively managed units (P < 0.02). We recommend the LMVJV consider 556 kg/ha as a measure of seed abundance for use in estimating carrying capacity in managed moist-soil units on public lands in the MAV. We recommend active management of moist-soil units to achieve maximum potential seed production and further research to determine recovery rates of seeds of various sizes from core samples and the relationship between seed abundance and unit area.

Threshold responses of Blackside Dace (Chrosomus cumberlandensis) and Kentucky Arrow Darter (Etheostoma spilotum) to stream conductivity

USGS Publications Warehouse

Hitt, Nathaniel P.; Floyd, Michael; Compton, Michael; McDonald, Kenneth

2016-01-01

Chrosomus cumberlandensis (Blackside Dace [BSD]) and Etheostoma spilotum (Kentucky Arrow Darter [KAD]) are fish species of conservation concern due to their fragmented distributions, their low population sizes, and threats from anthropogenic stressors in the southeastern United States. We evaluated the relationship between fish abundance and stream conductivity, an index of environmental quality and potential physiological stressor. We modeled occurrence and abundance of KAD in the upper Kentucky River basin (208 samples) and BSD in the upper Cumberland River basin (294 samples) for sites sampled between 2003 and 2013. Segmented regression indicated a conductivity change-point for BSD abundance at 343 μS/cm (95% CI: 123–563 μS/cm) and for KAD abundance at 261 μS/cm (95% CI: 151–370 μS/cm). In both cases, abundances were negligible above estimated conductivity change-points. Post-hoc randomizations accounted for variance in estimated change points due to unequal sample sizes across the conductivity gradients. Boosted regression-tree analysis indicated stronger effects of conductivity than other natural and anthropogenic factors known to influence stream fishes. Boosted regression trees further indicated threshold responses of BSD and KAD occurrence to conductivity gradients in support of segmented regression results. We suggest that the observed conductivity relationship may indicate energetic limitations for insectivorous fishes due to changes in benthic macroinvertebrate community composition.

Red blood cells for transfusion in patients with sepsis: respective roles of unit age and exposure to recipient plasma.

PubMed

Chadebech, Philippe; Bodivit, Gwellaouen; Razazi, Keyvan; de Vassoigne, Christophe; Pellé, Laurence; Burin-des-Roziers, Nicolas; Bocquet, Thibault; Bierling, Philippe; Djoudi, Rachid; Mekontso-Dessap, Armand; Pirenne, France

2017-08-01

Red blood cell (RBC) storage in blood banks is not exempt from cellular injury. Alterations not observed on RBCs freshly isolated from units can rapidly appear in circulation. The transfusion of old blood units, even if this is a controversial issue, could therefore have adverse effects on the recipient. We wanted to determine the respective effects of storage duration and recipient plasma on RBCs for transfusion into patients with severe sepsis. Eleven stored RBC units were sampled at various time points, approximately Days 3 to 8 (referred to as fresh RBCs) and Days 38 to 42 (old RBCs) and tested in coincubation experiments with plasma obtained from 13 patients with severe sepsis and 17 healthy donors as controls. RBCs were tested after 24 or 48 hours at 37°C for the detection of senescence markers (phosphatidylserine exposure, calcium influx, and reactive oxygen species detection and decrease in size) with or without exposure to plasma. We confirmed that a 42-day refrigerated storage of RBCs alone (without any incubation in plasma) had no significant effect on RBCs and no senescence marker detected. By contrast, ex vivo exposure to plasma samples altered both fresh and old RBCs, with a much larger effect for old RBCs, regardless of the plasma used (sepsis vs. control). We show that the main factor affecting the senescence of RBCs for transfusion into patients with severe sepsis is the age of the stored units rather than the clinical status of the recipient. © 2017 AABB.

Autumnal Biomass and Potential Productivity of Salt Marsh Fungi from 29° to 43° North Latitude along the United States Atlantic Coast†

PubMed Central

Newell, Steven Y.; Blum, Linda K.; Crawford, Richard E.; Dai, Ting; Dionne, Michele

2000-01-01

It has been established that substantial amounts of fungal mass accumulate in standing decaying smooth cordgrass (Spartina alterniflora) marshes in the southeastern United States (e.g., in standing decaying leaf blades with a total fungal organic mass that accounts for about 20% of the decay system organic mass), but it has been hypothesized that in marshes farther north this is not true. We obtained samples of autumnal standing decaying smooth cordgrass from sites in Florida to Maine over a 3-year period. The variation in latitude could not explain any of the variation in the living fungal standing crop (as determined by ergosterol content) or in the instantaneous rates of fungal growth (as determined by acetate incorporation into ergosterol at a standard temperature, 20°C), which led to the conclusion that the potential levels of fungal production per unit of naturally decaying grass are not different in northern and southern marshes. Twenty-one percent of the variation in the size of the living fungal standing crop could be explained by variation in the C/N ratio (the higher the C/N ratio the smaller the fungal crop), but the C/P ratio was not related to the size of the fungal crop. Instantaneous rates of fungal growth were negatively related to the size of the living fungal crop (r = −0.35), but these rates were not correlated with C/nutrient ratios. The same two predominant species of ascomycetes (one Phaeosphaeria species and one Mycosphaerella species) were found ejecting ascospores from standing decaying smooth cordgrass blades at all of the sites examined from Florida to Maine. PMID:10618221

Development of a model to simulate infection dynamics of Mycobacterium bovis in cattle herds in the United States

PubMed Central

Smith, Rebecca L.; Schukken, Ynte H.; Lu, Zhao; Mitchell, Rebecca M.; Grohn, Yrjo T.

2013-01-01

Objective To develop a mathematical model to simulate infection dynamics of Mycobacterium bovis in cattle herds in the United States and predict efficacy of the current national control strategy for tuberculosis in cattle. Design Stochastic simulation model. Sample Theoretical cattle herds in the United States. Procedures A model of within-herd M bovis transmission dynamics following introduction of 1 latently infected cow was developed. Frequency- and density-dependent transmission modes and 3 tuberculin-test based culling strategies (no test-based culling, constant (annual) testing with test-based culling, and the current strategy of slaughterhouse detection-based testing and culling) were investigated. Results were evaluated for 3 herd sizes over a 10-year period and validated via simulation of known outbreaks of M bovis infection. Results On the basis of 1,000 simulations (1000 herds each) at replacement rates typical for dairy cattle (0.33/y), median time to detection of M bovis infection in medium-sized herds (276 adult cattle) via slaughterhouse surveillance was 27 months after introduction, and 58% of these herds would spontaneously clear the infection prior to that time. Sixty-two percent of medium-sized herds without intervention and 99% of those managed with constant test-based culling were predicted to clear infection < 10 years after introduction. The model predicted observed outbreaks best for frequency-dependent transmission, and probability of clearance was most sensitive to replacement rate. Conclusions and Clinical Relevance Although modeling indicated the current national control strategy was sufficient for elimination of M bovis infection from dairy herds after detection, slaughterhouse surveillance was not sufficient to detect M bovis infection in all herds and resulted in subjectively delayed detection, compared with the constant testing method. Further research is required to economically optimize this strategy. PMID:23865885

Encephalitozoon cuniculi antibodies in a specific-pathogen-free rabbit unit.

PubMed Central

Bywater, J E; Kellett, B S

1978-01-01

We describe our discovery of Encephalitozoon cuniculi antibodies in a specific-pathogen-free rabbit colony. Small-sized samples had failed to reveal the presence of infection with a prevalence of about 5%. Using an India ink immunoreaction test by which we were able to visualize both negative and positive reactions, we were able to undertake a 100% screen of the colony of more than 700 rabbits and to repeat this 4 weeks later when we had culled the positive reactors. By collating the results of those tests with the results of tests on previously collected samples, we have been able to discuss and observe age and sex susceptibilities and the mode of transmission of the naturally occurring disease. PMID:151081

Size-fractionated diversity of eukaryotic microbial communities in the Eastern Tropical North Pacific oxygen minimum zone.

PubMed

Duret, Manon T; Pachiadaki, Maria G; Stewart, Frank J; Sarode, Neha; Christaki, Urania; Monchy, Sébastien; Srivastava, Ankita; Edgcomb, Virginia P

2015-05-01

Oxygen minimum zones (OMZs) caused by water column stratification appear to expand in parts of the world's ocean, with consequences for marine biogeochemical cycles. OMZ formation is often fueled by high surface primary production, and sinking organic particles can be hotspots of interactions and activity within microbial communities. This study investigated the diversity of OMZ protist communities in two biomass size fractions (>30 and 30-1.6 μm filters) from the world's largest permanent OMZ in the Eastern Tropical North Pacific. Diversity was quantified via Illumina MiSeq sequencing of V4 region of 18S SSU rRNA genes in samples spanning oxygen gradients at two stations. Alveolata and Rhizaria dominated the two size fractions at both sites along the oxygen gradient. Community composition at finer taxonomic levels was partially shaped by oxygen concentration, as communities associated with versus anoxic waters shared only ∼32% of operational taxonomic unit (OTU) (97% sequence identity) composition. Overall, only 9.7% of total OTUs were recovered at both stations and under all oxygen conditions sampled, implying structuring of the eukaryotic community in this area. Size-fractionated communities exhibited different taxonomical features (e.g. Syndiniales Group I in the 1.6-30 μm fraction) that could be explained by the microniches created on the surface-originated sinking particles. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Effect of Cu2+ substitution on the structural, optical and magnetic behaviour ofchemically derived manganese ferrite nanoparticles

NASA Astrophysics Data System (ADS)

Vasuki, G.; Balu, T.

2018-06-01

Mixed spinel copper manganese ferrite (CuXMn1‑XFe2O4, X = 0, 0.25, 0.5, 0.75, 1) nanoparticles were synthesized by chemical co-precipitation technique. From the powder x-ray diffraction analysis the lattice constant, volume of unit cell, x-ray density, hopping lengths, crystallite size, surface area, dislocation density and microstrain were calculated. The substitution of Cu2+ ions shows a considerable reduction in the crystallite size of manganese ferrite from 34 nm to 22 nm. Further a linear fit of Williamson-Hall plot has been drawn to determine the microstrain and crystallite size. The crystallite size and morphology were further observed through high resolution transmission electron microscope and scanning electron microscope. The diffraction rings observed from selected area electron diffraction pattern exhibits the crystalline nature of all the samples. The energy dispersive x-ray analysis shows the composition of all the elements incorporated in the synthesized nanomaterials. FTIR studies reveal the absorption peaks that correspond to the metal-oxygen vibrations in the tetrahedral and octahedral sites. From the UV–vis absorption spectra the band gap energy, refractive index and optical dielectric constant were determined. Magnetic studies carried out using vibrating sample magnetometer shows interesting behaviour in the variation of magnetisation and coercivity. Peculiar magnetic behaviour is observed when Cu2+ ions are substituted in manganese ferrites. All the synthesized materials have very low value of squareness ratio which attributes to the superparamagnetic behaviour.

Mercury in fishes from Wrangell-St. Elias National Park and Preserve, Alaska

USGS Publications Warehouse

Kowalski, Brandon M.; Willacker, James J.; Zimmerman, Christian E.; Eagles-Smith, Collin A.

2014-01-01

In this study, mercury (Hg) concentrations were examined in fishes from Wrangell-St. Elias National Park and Preserve, Alaska, the largest and one of the most remote units in the national park system. The goals of the study were to (1) examine the distribution of Hg in select lakes of Wrangell-St. Elias National Park and Preserve; (2) evaluate the differences in Hg concentrations among fish species and with fish age and size; and (3) assess the potential ecological risks of Hg to park fishes, wildlife, and human consumers by comparing Hg concentrations to a series of risk benchmarks. Total Hg concentrations ranged from 17.9 to 616.4 nanograms per gram wet weight (ng/g ww), with a mean (± standard error) of 180.0 ±17.9 across the 83 individuals sampled. Without accounting for the effects of size, Hg concentrations varied by a factor of 10.9 across sites and species. After accounting for the effects of size, Hg concentrations were even more variable, differing by a factor of as much as 13.2 within a single species sampled from two lakes. Such inter-site variation suggests that site characteristics play an important role in determining fish Hg concentrations and that more intensive sampling may be necessary to adequately characterize Hg contamination in the park. Size-normalized Hg concentrations also differed among three species sampled from Tanada Lake, and Hg concentrations were strongly correlated with age. Furthermore, potential risks to park fish, wildlife, and human users were variable across lakes and species. Although no fish from two of the lakes studied (Grizzly Lake and Summit Lake) had Hg concentrations exceeding any of the benchmarks used, concentrations in Copper Lake and Tanada Lake exceeded conservative benchmarks for bird (90 ng/g ww in whole-body) and human (150 ng/g ww in muscle) consumption. In Tanada Lake, concentrations in most fishes also exceeded benchmarks for risk to moderate- and low-sensitivity avian consumers (180 and 270 ng/g ww in whole-body, respectively), as well as the concentration at which Alaska State guidelines suggest at-risk groups limit fish consumption to 3 meals per week (320 ng/g). However, the relationship between Hg concentrations and fish size in Tanada Lake suggests that consumption of smaller-sized fishes could reduce Hg exposure in human consumers.

Measurement of pH in whole blood by near-infrared spectroscopy

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

Alam, M. Kathleen; Maynard, John D.; Robinson, M. Ries

1999-03-01

Whole blood pH has been determined {ital in vitro} by using near-infrared spectroscopy over the wavelength range of 1500 to 1785 nm with multivariate calibration modeling of the spectral data obtained from two different sample sets. In the first sample set, the pH of whole blood was varied without controlling cell size and oxygen saturation (O{sub 2} Sat) variation. The result was that the red blood cell (RBC) size and O{sub 2} Sat correlated with pH. Although the partial least-squares (PLS) multivariate calibration of these data produced a good pH prediction cross-validation standard error of prediction (CVSEP)=0.046, R{sup 2}=0.982, themore » spectral data were dominated by scattering changes due to changing RBC size that correlated with the pH changes. A second experiment was carried out where the RBC size and O{sub 2} Sat were varied orthogonally to the pH variation. A PLS calibration of the spectral data obtained from these samples produced a pH prediction with an R{sup 2} of 0.954 and a cross-validated standard error of prediction of 0.064 pH units. The robustness of the PLS calibration models was tested by predicting the data obtained from the other sets. The predicted pH values obtained from both data sets yielded R{sup 2} values greater than 0.9 once the data were corrected for differences in hemoglobin concentration. For example, with the use of the calibration produced from the second sample set, the pH values from the first sample set were predicted with an R{sup 2} of 0.92 after the predictions were corrected for bias and slope. It is shown that spectral information specific to pH-induced chemical changes in the hemoglobin molecule is contained within the PLS loading vectors developed for both the first and second data sets. It is this pH specific information that allows the spectra dominated by pH-correlated scattering changes to provide robust pH predictive ability in the uncorrelated data, and visa versa. {copyright} {ital 1999} {ital Society for Applied Spectroscopy}« less

Simple, Defensible Sample Sizes Based on Cost Efficiency

PubMed Central

Bacchetti, Peter; McCulloch, Charles E.; Segal, Mark R.

2009-01-01

Summary The conventional approach of choosing sample size to provide 80% or greater power ignores the cost implications of different sample size choices. Costs, however, are often impossible for investigators and funders to ignore in actual practice. Here, we propose and justify a new approach for choosing sample size based on cost efficiency, the ratio of a study’s projected scientific and/or practical value to its total cost. By showing that a study’s projected value exhibits diminishing marginal returns as a function of increasing sample size for a wide variety of definitions of study value, we are able to develop two simple choices that can be defended as more cost efficient than any larger sample size. The first is to choose the sample size that minimizes the average cost per subject. The second is to choose sample size to minimize total cost divided by the square root of sample size. This latter method is theoretically more justifiable for innovative studies, but also performs reasonably well and has some justification in other cases. For example, if projected study value is assumed to be proportional to power at a specific alternative and total cost is a linear function of sample size, then this approach is guaranteed either to produce more than 90% power or to be more cost efficient than any sample size that does. These methods are easy to implement, based on reliable inputs, and well justified, so they should be regarded as acceptable alternatives to current conventional approaches. PMID:18482055

RnaSeqSampleSize: real data based sample size estimation for RNA sequencing.

PubMed

Zhao, Shilin; Li, Chung-I; Guo, Yan; Sheng, Quanhu; Shyr, Yu

2018-05-30

One of the most important and often neglected components of a successful RNA sequencing (RNA-Seq) experiment is sample size estimation. A few negative binomial model-based methods have been developed to estimate sample size based on the parameters of a single gene. However, thousands of genes are quantified and tested for differential expression simultaneously in RNA-Seq experiments. Thus, additional issues should be carefully addressed, including the false discovery rate for multiple statistic tests, widely distributed read counts and dispersions for different genes. To solve these issues, we developed a sample size and power estimation method named RnaSeqSampleSize, based on the distributions of gene average read counts and dispersions estimated from real RNA-seq data. Datasets from previous, similar experiments such as the Cancer Genome Atlas (TCGA) can be used as a point of reference. Read counts and their dispersions were estimated from the reference's distribution; using that information, we estimated and summarized the power and sample size. RnaSeqSampleSize is implemented in R language and can be installed from Bioconductor website. A user friendly web graphic interface is provided at http://cqs.mc.vanderbilt.edu/shiny/RnaSeqSampleSize/ . RnaSeqSampleSize provides a convenient and powerful way for power and sample size estimation for an RNAseq experiment. It is also equipped with several unique features, including estimation for interested genes or pathway, power curve visualization, and parameter optimization.

Empirical Bayes method for reducing false discovery rates of correlation matrices with block diagonal structure.

PubMed

Pacini, Clare; Ajioka, James W; Micklem, Gos

2017-04-12

Correlation matrices are important in inferring relationships and networks between regulatory or signalling elements in biological systems. With currently available technology sample sizes for experiments are typically small, meaning that these correlations can be difficult to estimate. At a genome-wide scale estimation of correlation matrices can also be computationally demanding. We develop an empirical Bayes approach to improve covariance estimates for gene expression, where we assume the covariance matrix takes a block diagonal form. Our method shows lower false discovery rates than existing methods on simulated data. Applied to a real data set from Bacillus subtilis we demonstrate it's ability to detecting known regulatory units and interactions between them. We demonstrate that, compared to existing methods, our method is able to find significant covariances and also to control false discovery rates, even when the sample size is small (n=10). The method can be used to find potential regulatory networks, and it may also be used as a pre-processing step for methods that calculate, for example, partial correlations, so enabling the inference of the causal and hierarchical structure of the networks.

The special case of the 2 × 2 table: asymptotic unconditional McNemar test can be used to estimate sample size even for analysis based on GEE.

PubMed

Borkhoff, Cornelia M; Johnston, Patrick R; Stephens, Derek; Atenafu, Eshetu

2015-07-01

Aligning the method used to estimate sample size with the planned analytic method ensures the sample size needed to achieve the planned power. When using generalized estimating equations (GEE) to analyze a paired binary primary outcome with no covariates, many use an exact McNemar test to calculate sample size. We reviewed the approaches to sample size estimation for paired binary data and compared the sample size estimates on the same numerical examples. We used the hypothesized sample proportions for the 2 × 2 table to calculate the correlation between the marginal proportions to estimate sample size based on GEE. We solved the inside proportions based on the correlation and the marginal proportions to estimate sample size based on exact McNemar, asymptotic unconditional McNemar, and asymptotic conditional McNemar. The asymptotic unconditional McNemar test is a good approximation of GEE method by Pan. The exact McNemar is too conservative and yields unnecessarily large sample size estimates than all other methods. In the special case of a 2 × 2 table, even when a GEE approach to binary logistic regression is the planned analytic method, the asymptotic unconditional McNemar test can be used to estimate sample size. We do not recommend using an exact McNemar test. Copyright © 2015 Elsevier Inc. All rights reserved.

Priority-pollutant trace elements in streambed sediments of the Cook Inlet basin, Alaska, 1998-2000

USGS Publications Warehouse

Frenzel, Steven A.

2002-01-01

Trace element concentrations in 48 streambed sediment samples collected at 47 sites in the Cook Inlet Basin, Alaska, were compared to concentrations from studies in the conterminous United States using identical methods and to Probable Effect Concentrations. Concentrations of arsenic, chromium, mercury, and nickel in the 0.063-mm size fraction of streambed sediments from the Cook Inlet Basin were elevated relative to reference sites in the conterminous United States. Concentrations of cadmium, lead, and zinc were highest at the most urbanized site in Anchorage and at two sites downstream from an ore body in Lake Clark National Park and Preserve. At least 35 percent of the 48 samples collected in the Cook Inlet Basin exceeded the Probable Effect Concentration for arsenic, chromium, or nickel. More than 50 percent of the samples were considered to have low potential toxicity for cadmium, lead, mercury, nickel, selenium, and zinc. A Probable Effect Concentration quotient that reflects the combined toxicity of arsenic, cadmium, chromium, copper, lead, mercury, nickel, and zinc was exceeded in 44 percent of the samples from the Cook Inlet Basin. The potential toxicity was high in the Denali and Lake Clark National Parks and Preserves where organic carbon concentrations in streambed sediments were low. However, potential toxicity results should be considered in context with the very small amounts of fine-grained sediment present in the streambed sediments of the Cook Inlet Basin.

Survey methods for assessing land cover map accuracy

USGS Publications Warehouse

Nusser, S.M.; Klaas, E.E.

2003-01-01

The increasing availability of digital photographic materials has fueled efforts by agencies and organizations to generate land cover maps for states, regions, and the United States as a whole. Regardless of the information sources and classification methods used, land cover maps are subject to numerous sources of error. In order to understand the quality of the information contained in these maps, it is desirable to generate statistically valid estimates of accuracy rates describing misclassification errors. We explored a full sample survey framework for creating accuracy assessment study designs that balance statistical and operational considerations in relation to study objectives for a regional assessment of GAP land cover maps. We focused not only on appropriate sample designs and estimation approaches, but on aspects of the data collection process, such as gaining cooperation of land owners and using pixel clusters as an observation unit. The approach was tested in a pilot study to assess the accuracy of Iowa GAP land cover maps. A stratified two-stage cluster sampling design addressed sample size requirements for land covers and the need for geographic spread while minimizing operational effort. Recruitment methods used for private land owners yielded high response rates, minimizing a source of nonresponse error. Collecting data for a 9-pixel cluster centered on the sampled pixel was simple to implement, and provided better information on rarer vegetation classes as well as substantial gains in precision relative to observing data at a single-pixel.

Reporting of sample size calculations in analgesic clinical trials: ACTTION systematic review.

PubMed

McKeown, Andrew; Gewandter, Jennifer S; McDermott, Michael P; Pawlowski, Joseph R; Poli, Joseph J; Rothstein, Daniel; Farrar, John T; Gilron, Ian; Katz, Nathaniel P; Lin, Allison H; Rappaport, Bob A; Rowbotham, Michael C; Turk, Dennis C; Dworkin, Robert H; Smith, Shannon M

2015-03-01

Sample size calculations determine the number of participants required to have sufficiently high power to detect a given treatment effect. In this review, we examined the reporting quality of sample size calculations in 172 publications of double-blind randomized controlled trials of noninvasive pharmacologic or interventional (ie, invasive) pain treatments published in European Journal of Pain, Journal of Pain, and Pain from January 2006 through June 2013. Sixty-five percent of publications reported a sample size calculation but only 38% provided all elements required to replicate the calculated sample size. In publications reporting at least 1 element, 54% provided a justification for the treatment effect used to calculate sample size, and 24% of studies with continuous outcome variables justified the variability estimate. Publications of clinical pain condition trials reported a sample size calculation more frequently than experimental pain model trials (77% vs 33%, P < .001) but did not differ in the frequency of reporting all required elements. No significant differences in reporting of any or all elements were detected between publications of trials with industry and nonindustry sponsorship. Twenty-eight percent included a discrepancy between the reported number of planned and randomized participants. This study suggests that sample size calculation reporting in analgesic trial publications is usually incomplete. Investigators should provide detailed accounts of sample size calculations in publications of clinical trials of pain treatments, which is necessary for reporting transparency and communication of pre-trial design decisions. In this systematic review of analgesic clinical trials, sample size calculations and the required elements (eg, treatment effect to be detected; power level) were incompletely reported. A lack of transparency regarding sample size calculations may raise questions about the appropriateness of the calculated sample size. Copyright © 2015 American Pain Society. All rights reserved.

High resolution MRI imaging at 9.4 Tesla of the osteochondral unit in a translational model of articular cartilage repair.

PubMed

Goebel, Lars; Müller, Andreas; Bücker, Arno; Madry, Henning

2015-04-16

Non-destructive structural evaluation of the osteochondral unit is challenging. Here, the capability of high-field magnetic resonance imaging (μMRI) at 9.4 Tesla (T) was explored to examine osteochondral repair ex vivo in a preclinical large animal model. A specific aim of this study was to detect recently described alterations of the subchondral bone associated with cartilage repair. Osteochondral samples of medial femoral condyles from adult ewes containing full-thickness articular cartilage defects treated with marrow stimulation were obtained after 6 month in vivo and scanned in a 9.4 T μMRI. Ex vivo imaging of small osteochondral samples (typical volume: 1-2 cm(3)) at μMRI was optimised by variation of repetition time (TR), time echo (TE), flip angle (FA), spatial resolution and number of excitations (NEX) from standard MultiSliceMultiEcho (MSME) and three-dimensional (3D) spoiled GradientEcho (SGE) sequences. A 3D SGE sequence with the parameters: TR = 10 ms, TE = 3 ms, FA = 10°, voxel size = 120 × 120 × 120 μm(3) and NEX = 10 resulted in the best fitting for sample size, image quality, scanning time and artifacts. An isovolumetric voxel shape allowed for multiplanar reconstructions. Within the osteochondral unit articular cartilage, cartilaginous repair tissue and bone marrow could clearly be distinguished from the subchondral bone plate and subarticular spongiosa. Specific alterations of the osteochondral unit associated with cartilage repair such as persistent drill holes, subchondral bone cysts, sclerosis of the subchondral bone plate and of the subarticular spongiosa and intralesional osteophytes were precisely detected. High resolution, non-destructive ex vivo analysis of the entire osteochondral unit in a preclinical large animal model that is sufficient for further analyses is possible using μMRI at 9.4 T. In particular, 9.4 T is capable of accurately depicting alterations of the subchondral bone that are associated with osteochondral repair.

Use of a single-bowl continuous-flow centrifuge for dewatering suspended sediments: effect on sediment physical and chemical characteristics

USGS Publications Warehouse

Rees, T.F.; Leenheer, J.A.; Ranville, J.F.

1991-01-01

Sediment-recovery efficiency of 86-91% is comparable to that of other types of CFC units. The recovery efficiency is limited by the particle-size distribution of the feed water and by the limiting particle diameter that is retained in the centrifuge bowl. Contamination by trace metals and organics is minimized by coating all surfaces that come in contact with the sample with either FEP or PFA Teflon and using a removable FEP Teflon liner in the centrifuge bowl. -from Authors

Geomorphic Controls on Floodplain Soil Organic Carbon in the Yukon Flats, Interior Alaska, From Reach to River Basin Scales

NASA Astrophysics Data System (ADS)

Lininger, K. B.; Wohl, E.; Rose, J. R.

2018-03-01

Floodplains accumulate and store organic carbon (OC) and release OC to rivers, but studies of floodplain soil OC come from small rivers or small spatial extents on larger rivers in temperate latitudes. Warming climate is causing substantial change in geomorphic process and OC fluxes in high latitude rivers. We investigate geomorphic controls on floodplain soil OC concentrations in active-layer mineral sediment in the Yukon Flats, interior Alaska. We characterize OC along the Yukon River and four tributaries in relation to geomorphic controls at the river basin, segment, and reach scales. Average OC concentration within floodplain soil is 2.8% (median = 2.2%). Statistical analyses indicate that OC varies among river basins, among planform types along a river depending on the geomorphic unit, and among geomorphic units. OC decreases with sample depth, suggesting that most OC accumulates via autochthonous inputs from floodplain vegetation. Floodplain and river characteristics, such as grain size, soil moisture, planform, migration rate, and riverine DOC concentrations, likely influence differences among rivers. Grain size, soil moisture, and age of surface likely influence differences among geomorphic units. Mean OC concentrations vary more among geomorphic units (wetlands = 5.1% versus bars = 2.0%) than among study rivers (Dall River = 3.8% versus Teedrinjik River = 2.3%), suggesting that reach-scale geomorphic processes more strongly control the spatial distribution of OC than basin-scale processes. Investigating differences at the basin and reach scale is necessary to accurately assess the amount and distribution of floodplain soil OC, as well as the geomorphic controls on OC.

The effect of nurse manager turnover on patient fall and pressure ulcer rates.

PubMed

Warshawsky, Nora; Rayens, Mary Kay; Stefaniak, Karen; Rahman, Rana

2013-07-01

The purpose of this study was to explore the effects of nurse manager turnover on the occurrence of adverse events. Nurse managers create professional nurse practice environments to support the provision of quality patient outcomes. Inconsistent findings were reported in the literature testing the relationship between nurse managers and patient outcomes. All prior studies assumed stable nursing management. A longitudinal quasi-experimental study of 23 nursing units in two hospitals was used to determine whether unit characteristics, including nurse manager turnover, have an effect on patient falls or pressure ulcers. Statistical analyses included repeated measures and hierarchical modelling. Patients in medical/surgical units experienced more falls than in intensive care units (F1,11 = 15.9, P = 0.002). Patients in units with a nurse manager turnover [odds ratio: 3.16; 95% confidence interval: 1.49-6.70] and intensive care units (odds ratio: 2.70; 95% confidence interval: 1.33-5.49) were more likely to develop pressure ulcers. Nurse manager turnover and intensive care unit status were associated with more pressure ulcers. Medical/surgical unit status was associated with more falls. The study was limited by a small sample size. Nurse manager turnover may negatively impact patient outcomes. Stable nursing management, strategic interim management and long-term succession planning may reduce adverse patient events. © 2013 John Wiley & Sons Ltd.

Use of remote-sensing techniques to survey the physical habitat of large rivers

USGS Publications Warehouse

Edsall, Thomas A.; Behrendt, Thomas E.; Cholwek, Gary; Frey, Jeffery W.; Kennedy, Gregory W.; Smith, Stephen B.; Edsall, Thomas A.; Behrendt, Thomas E.; Cholwek, Gary; Frey, Jeffrey W.; Kennedy, Gregory W.; Smith, Stephen B.

1997-01-01

Remote-sensing techniques that can be used to quantitatively characterize the physical habitat in large rivers in the United States where traditional survey approaches typically used in small- and medium-sized streams and rivers would be ineffective or impossible to apply. The state-of-the-art remote-sensing technologies that we discuss here include side-scan sonar, RoxAnn, acoustic Doppler current profiler, remotely operated vehicles and camera systems, global positioning systems, and laser level survey systems. The use of these technologies will permit the collection of information needed to create computer visualizations and hard copy maps and generate quantitative databases that can be used in real-time mode in the field to characterize the physical habitat at a study location of interest and to guide the distribution of sampling effort needed to address other habitat-related study objectives. This report augments habitat sampling and characterization guidance provided by Meador et al. (1993) and is intended for use primarily by U.S. Geological Survey National Water Quality Assessment program managers and scientists who are documenting water quality in streams and rivers of the United States.

Smaller Cigarette Pack as a Commitment to Smoke Less? Insights from Behavioral Economics

PubMed Central

Marti, Joachim; Sindelar, Jody

2015-01-01

Cigarettes are commonly sold in packs of 20 units and therefore little is known about the potential impact of pack size on consumption. Using insights from behavioral economics, we suggest that cigarette packs smaller than the standard size may help some smokers cut back and/or quit, consistent with their long-term goals. Results from an online hypothetical purchase experiment conducted in a sample of US smokers reveal that over a third of smokers are willing to pay a price premium to purchase in smaller quantities. Further, a desire to quit smoking and high self-control is associated with preference for a smaller pack. While we provide some preliminary evidence that smaller packs may be beneficial to certain types of smokers, further research should be conducted to assess whether the smaller pack size should be considered in the arsenal of tobacco control policies to help current smokers quit (JEL: I18; I12; D12) PMID:26356844

Effects of sintering atmosphere and temperature on structural and magnetic properties of Ni-Cu-Zn ferrite nano-particles: Magnetic enhancement by a reducing atmosphere

NASA Astrophysics Data System (ADS)

Gholizadeh, Ahmad; Jafari, Elahe

2017-01-01

In this work, effects of sintering atmosphere and temperature on structural and magnetic properties of Ni0.3Cu0.2Zn0.5Fe2O4 nanoparticles prepared by citrate precursor method have been studied. The structural characterization of the samples by X-ray powder diffraction and FT-IR spectroscopy is evidence for formation of a cubic structure with no presence of impurity phase. Calculated values of crystallite size and unit cell parameter show an increase with sintering temperature under different atmospheres. Variation of saturation magnetization with sintering temperature and atmosphere can be attributed to change of three factors: magnetic core size, inversion parameter and the change of Fe3+-ion concentration due to the presence of Fe4+ and Fe2+ ions. The saturation magnetization gradually grows with sintering temperature due to increase of magnetic core size and a maximum 63 emu/g was achieved at 600 °C under carbon monoxide-ambient atmosphere.

Accuracy of burn size estimation in patients transferred to adult Burn Units in Sydney, Australia: an audit of 698 patients.

PubMed

Harish, Varun; Raymond, Andrew P; Issler, Andrea C; Lajevardi, Sepehr S; Chang, Ling-Yun; Maitz, Peter K M; Kennedy, Peter

2015-02-01

The purpose of this study was to compare burn size estimation between referring centres and Burn Units in adult patients transferred to Burn Units in Sydney, Australia. A review of all adults transferred to Burn Units in Sydney, Australia between January 2009 and August 2013 was performed. The TBSA estimated by the referring institution was compared with the TBSA measured at the Burns Unit. There were 698 adults transferred to a Burns Unit. Equivalent TBSA estimation between the referring hospital and Burns Unit occurred in 30% of patients. Overestimation occurred at a ratio exceeding 3:1 with respect to underestimation, with the difference between the referring institutions and Burns Unit estimation being statistically significant (P<0.001). Significant overestimation occurs in the early transfer of burn-injured patients as well as in patients transferred more than 48h after the burn (P<0.005). Underestimation occurs with less frequency but rises with increasing time after the burn (P<0.005) and with increasing TBSA. Throughout the temporal spectrum of transferred patients, severe burns (≥20% TBSA) were found to have more satisfactory burn size estimations compared with less severe injuries (<20% TBSA; P<0.005). There are significant inaccuracies in burn size assessment by referring centres. The systemic tendency for overestimation occurs throughout the entire TBSA spectrum, and persists with increasing time after the burn. Underestimation occurs less frequently but rises with increasing time after the burn and with increasing TBSA. Severe burns (≥20% TBSA) are more accurately estimated by the referring hospital. The inaccuracies in burn size assessment have the potential to result in suboptimal treatment and inappropriate referral to specialised Burn Units. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

Lithological properties of sedimentary environments in the shallow subsurface of the Northern Netherlands

NASA Astrophysics Data System (ADS)

Harting, Ronald; Bosch, Aleid; Gunnink, Jan

2014-05-01

Society has an increasing demand from the subsurface, which in the Dutch shallow subsurface (upper 30 to 40 meters) mainly focuses on natural aggregate resources, groundwater, infrastructure and dike safety. This stimulates the demand for knowledge about the composition and heterogeneity of the subsurface and its physical and chemical properties, including the uncertainties involved. Physical and chemical properties of sediments in the subsurface have been under investigation for decades; however, the usefulness of this data for applied research and the understanding of these properties is limited. This is due to several factors: studies consist mainly of separately collected datasets, targeted at a limited amount of parameters, focused on a small number of geological units, distributed unevenly with depth and usually collected from clustered drillings with limited spatial extent or are analysed with different techniques and methods, often on disturbed samples. These factors result in a heterogeneous and biased dataset not suitable to function as a reference dataset or to statistically determine regional characteristics of geological units. To overcome these shortcomings, the Geological Survey of the Netherlands is establishing a nation-wide reference dataset for physical and chemical properties. In 2006, a drilling campaign was started using cone penetration tests, cored drillings and geophysical well logs, choosing the sites for a good geographical distribution. The lithological properties of the undisturbed cores are visually described and interpreted for lithostratigraphy and inferred sedimentary environment based on lithofacies. The location of the samples in the cores are chosen based on this description and interpretation, resulting in an evenly distributed dataset of in situ samples with respect to geological units as well as an adequate number of samples suitable for statistical analysis. Analyses are uniformly performed for grain size distribution, permeability (both high and low permeable lithologies) and geochemical methods (X-Ray Fluorescence, Thermo-Gravimetric Analysis, Total Carbon, Total Sulphur and Total Organic Carbon). These analyses result in a large number of lithological, hydrological and geochemical parameters, i.e. clay content, sand median, vertical and horizontal permeability and CaCO3-content. We present the results from the analysis of lithological properties for the Northern Netherlands. Besides geology, these properties can be applied directly in studies concerning (amongst others) groundwater, natural aggregates and dike safety. We demonstrate the use of sedimentary environments based on lithofacies as a useful tool for comparison between lithostratigraphic units and lithofacies. These lithofacies match distinct parts of the marine, fluvial, glacial, eolian or organogenic environment, i.e. tidal channel sand, floodbasin clay and subglacial till. This results in lithological properties illustrating the heterogeneity within a geological unit and between equal depositional environments in different lithostratigraphic units. The acquired data have so far been used in several applied studies, i.e. improving parameterisation of 3D models leading to increased accuracy in groundwater models and dike safety studies concerning dike failure due to undermining. Recently, grain size distributions measured with different methods were recalibrated into a homogeneous dataset using this reference set, which greatly enlarged the dataset to be incorporated in the parameterisation of a 3D voxel model.

Determination of the optimal sample size for a clinical trial accounting for the population size.

PubMed

Stallard, Nigel; Miller, Frank; Day, Simon; Hee, Siew Wan; Madan, Jason; Zohar, Sarah; Posch, Martin

2017-07-01

The problem of choosing a sample size for a clinical trial is a very common one. In some settings, such as rare diseases or other small populations, the large sample sizes usually associated with the standard frequentist approach may be infeasible, suggesting that the sample size chosen should reflect the size of the population under consideration. Incorporation of the population size is possible in a decision-theoretic approach either explicitly by assuming that the population size is fixed and known, or implicitly through geometric discounting of the gain from future patients reflecting the expected population size. This paper develops such approaches. Building on previous work, an asymptotic expression is derived for the sample size for single and two-arm clinical trials in the general case of a clinical trial with a primary endpoint with a distribution of one parameter exponential family form that optimizes a utility function that quantifies the cost and gain per patient as a continuous function of this parameter. It is shown that as the size of the population, N, or expected size, N∗ in the case of geometric discounting, becomes large, the optimal trial size is O(N1/2) or O(N∗1/2). The sample size obtained from the asymptotic expression is also compared with the exact optimal sample size in examples with responses with Bernoulli and Poisson distributions, showing that the asymptotic approximations can also be reasonable in relatively small sample sizes. © 2016 The Author. Biometrical Journal published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Variability in the relative abundance, size structure and sex ratio of the dolphinfish Coryphaena hippurus (Pisces: Coryphaenidae) in the Gulf of Tehuantepec, México].

PubMed

Alejo-Plata, Carmen; Gómez, José Luis; Serrano-Guzmán, Saúl J

2014-06-01

Variability in the relative abundance, size structure and sex ratio of the dolphinfish Coryphaena hippurus (Pisces: Coryphaenidae) in the Gulf of Tehuantepec, México. The dolphinfish (Coryphaena hippurus), is an oceanic epipelagic fish found worldwide in tropical and subtropical waters, with a high dispersal capability via large-scale migrations. This fast-swimming top-level predator is abundant in the Gulf of Tehuantepec, where it is caught incidentally by artisanal fisheries, and represents a target species for both recreational and commercial fisheries in Mexico, Ecuador, Peru and Central America. Nowadays, local fishery information on this species is scarce, thus our objective was to analyze the size structure by sex and the catch-per-unit-effort (CPUE) tendency of dolphinfish caught in the Gulf of Tehuantepec, from 2000 to 2007. For this, fishery catches information was obtained from the artisanal fleet, at six landing sites in the Gulf, and the sex ratio, fork length (FL) and the catch per unit effort (CPUE) were estimated. From all sampling sites, a total of 3 494 females, and 3 877 males were obtained, and dolphinfish size as fork length (FL) ranged from 20.5 to 152cm. Fish size ranged from 25.5 to 148cm furcal length (FL) in males, and 20.5 to 129cm FL in females. The sex ratio (males:females) was 1:1, except in April-May (1:1.5, p < 0.05) and November (1:0.5, p < 0.05). The sex ratio at different size classes showed a significant bias towards females at smaller sizes (< 75cm FL), whereas the males were predominant in larger size classes (> 100cm FL). The size structure was bimodal, with a variation in the size average; the modes were defined as the small group (FL = 50-55cm) and the large size group (FL = 100-110cm). The CPUE showed seasonal changes: values were high for the November-December period, and values were lower for July-August. The seasonal and inter annual variation in the abundance of dolphinfish is probably related to a pre-spawning migration in close relation to the rain-drought regime characteristic of the region, and the associated wind upwelling season of "Tehuanos" in the Gulf of Tehuantepec.

Bacterial diversity of soil aggregates of different sizes in various land use conditions

NASA Astrophysics Data System (ADS)

Ivanova, Ekaterina; Azida, Thakahova; Olga, Kutovaya

2014-05-01

The patterns of soil microbiome structure may be a universal and very sensitive indicator of soil quality (soil "health") used for optimization and biologization of agricultural systems. The understanding of how microbial diversity influenses, and is influenced by, the environment can only be attained by analyses at scales relevant to those at which processes influencing microbial diversity actually operate. The basic structural and functional unit of the soil is a soil aggregate, which is actually a microcosm of the associative co-existing groups of microorganisms that form characteristic ecological food chains. It is known that many important microbial processes occur in spatially segregated microenvironments in soil leading to a microscale biogeography. The Metagenomic library of typical chernozem in conditions of different land use systems was created. Total genomic DNA was extracted from 0.5 g of the frozen soil after mechanical destruction. Sample preparation and sequencing was performed on a GS Junior ("Roche»", Switzerland) according to manufacturer's recommendations, using the universal primers to the variable regions V4 gene 16S - rRNA - F515 (GTGCCAGCMGCCGCGGTAA) and R806 (GGACT-ACVSGGGTATCTAAT). It is shown that the system of land use is a stronger determinant of the taxonomic composition of the soil microbial community, rather than the size of the structural units. In soil samples from different land use systems the presence of accessory components was revealed. They may be used as indicators of processes of soil recovery, soil degradation or soil exhaustion processes occuring in the agroecosystems. The comparative analysis of microbial communities of chernozem aggregates investigated demonstrates the statistically valuable differences in the amount of bacterial phyla and Archean domain content as well as the species richness in aggregates of various size fractions. The occurrence of specific components in the taxonomic structure of micro-and macro-aggregates may indicate the presence of a certain size fraction in the structure of the investigated soil. The study of soils' metagenome is promising for the development of both soil microbiology, and for the soil processes trends in soils of anthropogenic origin.

Predicting the proportion of full-thickness involvement for any given burn size based on burn resuscitation volumes.

PubMed

Liu, Nehemiah T; Salinas, José; Fenrich, Craig A; Serio-Melvin, Maria L; Kramer, George C; Driscoll, Ian R; Schreiber, Martin A; Cancio, Leopoldo C; Chung, Kevin K

2016-11-01

The depth of burn has been an important factor often overlooked when estimating the total resuscitation fluid needed for early burn care. The goal of this study was to determine the degree to which full-thickness (FT) involvement affected overall 24-hour burn resuscitation volumes. We performed a retrospective review of patients admitted to our burn intensive care unit from December 2007 to April 2013, with significant burns that required resuscitation using our computerized decision support system for burn fluid resuscitation. We defined the degree of FT involvement as FT Index (FTI; percentage of FT injury/percentage of total body surface area (TBSA) burned [%FT / %TBSA]) and compared variables on actual 24-hour fluid resuscitation volumes overall as well as for any given burn size. A total of 203 patients admitted to our burn center during the study period were included in the analysis. Mean age and weight were 47 ± 19 years and 87 ± 18 kg, respectively. Mean %TBSA was 41 ± 20 with a mean %FT of 18 ± 24. As %TBSA, %FT, and FTI increased, so did actual 24-hour fluid resuscitation volumes (mL/kg). However, increase in FTI did not result in increased volume indexed to burn size (mL/kg per %TBSA). This was true even when patients with inhalation injury were excluded. Further investigation revealed that as %TBSA increased, %FT increased nonlinearly (quadratic polynomial) (R = 0.994). Total burn size and FT burn size were both highly correlated with increased 24-hour fluid resuscitation volumes. However, FTI did not correlate with a corresponding increase in resuscitation volumes for any given burn size, even when patients with inhalation injury were excluded. Thus, there are insufficient data to presume that those who receive more volume at any given burn size are likely to be mostly full thickness or vice versa. This was influenced by a relatively low sample size at each 10%TBSA increment and larger burn sizes disproportionately having more FT burns. A more robust sample size may elucidate this relationship better. Therapeutic/care management study, level IV.

M551 metals melting experiment. [space manufacturing of aluminum alloys, tantalum alloys, stainless steels

NASA Technical Reports Server (NTRS)

Li, C. H.; Busch, G.; Creter, C.

1976-01-01

The Metals Melting Skylab Experiment consisted of selectively melting, in sequence, three rotating discs made of aluminum alloy, stainless steel, and tantalum alloy. For comparison, three other discs of the same three materials were similarly melted or welded on the ground. The power source of the melting was an electron beam unit. Results are presented which support the concept that the major difference between ground base and Skylab samples (i.e., large elongated grains in ground base samples versus nearly equiaxed and equal sized grains in Skylab samples) can be explained on the basis of constitutional supercooling, and not on the basis of surface phenomena. Microstructural observations on the weld samples and present explanations for some of these observations are examined. In particular, ripples and their implications to weld solidification were studied. Evidence of pronounced copper segregation in the Skylab A1 weld samples, and the tantalum samples studied, indicates a weld microhardness (and hence strength) that is uniformly higher than the ground base results, which is in agreement with previous predictions. Photographs are shown of the microstructure of the various alloys.

Some physical properties of naturally irradiated fluorite

USGS Publications Warehouse

Berman, Robert

1955-01-01

Five samples of purple fluorite found in association with radioactive, materials, and a synthetic colorless control sample were studied and compared.  Before and after heating, observations were made on specific gravity, index of refraction, unit-cell size, breadth of X-ray diffraction lines, and fluorescence.  The purple samples became colorless on heating above 175° C.  During the process, observations were made on color, thermoluminescence, and differential thermal analysis curves.  There were strong correlations between the various physical properties, and it was found possible to arrange the samples in order of increasing difference in their physical properties from the control sample. This order apparently represents increasing structural damage by radiation; if so, it correlates with decreasing specific gravity, increasing index of refraction, broadening of X-ray lines, and increasingly strong exothermic reactions on annealing. The differences between the samples in index of refraction and X-ray pattern are largely eliminated on annealing.  Annealing begins at 1750 C; thermoluminescence at lower temperatures is due to electrons escaping from the metastable potential traps, not the destruction of those traps which takes place on annealing.

Requirements for Minimum Sample Size for Sensitivity and Specificity Analysis

PubMed Central

Adnan, Tassha Hilda

2016-01-01

Sensitivity and specificity analysis is commonly used for screening and diagnostic tests. The main issue researchers face is to determine the sufficient sample sizes that are related with screening and diagnostic studies. Although the formula for sample size calculation is available but concerning majority of the researchers are not mathematicians or statisticians, hence, sample size calculation might not be easy for them. This review paper provides sample size tables with regards to sensitivity and specificity analysis. These tables were derived from formulation of sensitivity and specificity test using Power Analysis and Sample Size (PASS) software based on desired type I error, power and effect size. The approaches on how to use the tables were also discussed. PMID:27891446

Italy of censuses.

PubMed

Rey, G M

1983-06-01

To supplement census data on Italy's economy, Istat conducted a sample survey of 2% of households. This paper reports survey findings in 3 areas: age structure of the population, employment and unemployment patterns by region, and structure of the productive system. Those over age 65 years have increased from 11% of the population in 1971 to 13% in 1981 and are forecast to constitute 14.5% in 1991. Women accounted for 51.3% of the total population in 1981 but 58.5% of those over age 65. 12% of households have a member over age 75. The 0-14 year age group has declined from 24.4% of the population in 1971 to 21.5% in 1981 and is projected to comprise 17.4% in 1991. The labor force activity rate was 39.8% in 1981. Unemployment was set at 14.7% in the census sample compared with 9.1% in Istat's quarterly survey of the labor force. 60% of the difference between these 2 figures was accounted for by Campania, Sicily, Puglia, Calabria, and Latium. These 5 regions, which account for only 30% of total employment, are the areas with the most acute employment problems and highest proportions of casual employment in agriculture and traditional services. Agriculture accounted for 22% of total unemployment, construction for 18.5%, and traditional industry for 14%--percentages that are higher than the share of total employment represented by these sectors. In the South, 20.4% of employment is in agriculture, 18.1% in industry, 12.6% in construction, and 48.9% in services. The average worker in the South supports 3.3 persons compared with 2.5 persons in the North. Survey results indicate a substantial shift in the sectoral composition of employment as well as a change in the size of productive units. There has been an increase in the highly specialized components of the economy, including services to firms. The average size of factories has declined, with a proliferation of small and medium sized units. These findings suggest a need to broaden and deepen Italy's industrial base. Also needed is a consistent plan for labor and capital accumulation. The growth of medium sized firms should be supported until they reach a size compatible with investment and technical progress, thereby permitting greater employment and productivity.

Qualitative exploration of nurses' decisions to activate rapid response teams.

PubMed

Astroth, Kim S; Woith, Wendy M; Stapleton, Stephen J; Degitz, R Joseph; Jenkins, Sheryl H

2013-10-01

To identify barriers and facilitators to nurses' decisions regarding activation of rapid response teams (RRTs) in hospitals. Hospitalised patients in the United States who experience cardiopulmonary arrest seldom recover. Most of these patients show signs of clinical deterioration prior to cardiopulmonary arrest. RRTs have been shown to decrease the incidence of cardiopulmonary arrest by bringing needed resources to unstable patients. Despite the evidence in support of the activation of RRTs, nurses do not always use this resource. Nurses' decisions to activate or not to activate the RRT are not clearly understood. We used a qualitative design for this study. A purposive sample of 15 medical/surgical nurses was recruited from a small medical centre in the Midwest. Researchers used semistructured, open-ended questions to elicit subject responses regarding facilitators and barriers to activating RRTs. Themes emerged and were categorised as facilitators and barriers to calling the RRT. Facilitators and barriers were then subdivided into distinct subthemes: RRT characteristics and unit culture. The expertise of the RRT members and support and encouragement from nursing unit colleagues and leaders emerged as two potential facilitators. Communication of the RRT members and calling the physician first emerged as two potential barriers. We also identified educational factors that were not clearly facilitators or barriers to calling the RRT. Further study is needed using quantitative designs with larger sample sizes. Nurses can build upon knowledge of facilitators and barriers related to RRT characteristics and nursing unit culture. © 2013 Blackwell Publishing Ltd.

Quality control of next-generation sequencing library through an integrative digital microfluidic platform.

PubMed

Thaitrong, Numrin; Kim, Hanyoup; Renzi, Ronald F; Bartsch, Michael S; Meagher, Robert J; Patel, Kamlesh D

2012-12-01

We have developed an automated quality control (QC) platform for next-generation sequencing (NGS) library characterization by integrating a droplet-based digital microfluidic (DMF) system with a capillary-based reagent delivery unit and a quantitative CE module. Using an in-plane capillary-DMF interface, a prepared sample droplet was actuated into position between the ground electrode and the inlet of the separation capillary to complete the circuit for an electrokinetic injection. Using a DNA ladder as an internal standard, the CE module with a compact LIF detector was capable of detecting dsDNA in the range of 5-100 pg/μL, suitable for the amount of DNA required by the Illumina Genome Analyzer sequencing platform. This DMF-CE platform consumes tenfold less sample volume than the current Agilent BioAnalyzer QC technique, preserving precious sample while providing necessary sensitivity and accuracy for optimal sequencing performance. The ability of this microfluidic system to validate NGS library preparation was demonstrated by examining the effects of limited-cycle PCR amplification on the size distribution and the yield of Illumina-compatible libraries, demonstrating that as few as ten cycles of PCR bias the size distribution of the library toward undesirable larger fragments. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Factors affecting plant growth in membrane nutrient delivery

NASA Technical Reports Server (NTRS)

Dreschel, T. W.; Wheeler, R. M.; Sager, J. C.; Knott, W. M.

1990-01-01

The development of the tubular membrane plant growth unit for the delivery of water and nutrients to roots in microgravity has recently focused on measuring the effects of changes in physical variables controlling solution availability to the plants. Significant effects of membrane pore size and the negative pressure used to contain the solution were demonstrated. Generally, wheat grew better in units with a larger pore size but equal negative pressure and in units with the same pore size but less negative pressure. Lettuce also exhibited better plant growth at less negative pressure.

Transport behavior of groundwater protozoa and protozoan-sized microspheres in sandy aquifer sediments

USGS Publications Warehouse

Harvey, R.W.; Kinner, N.E.; Bunn, A.; MacDonald, D.; Metge, D.

1995-01-01

Transport behaviors of unidentified flagellated protozoa (flagellates) and flagellate-sized carboxylated microspheres in sandy, organically contaminated aquifer sediments were investigated in a small-scale (1 to 4-m travel distance) natural-gradient tracer test on Cape Cod and in flow-through columns packed with sieved (0.5-to 1.0-mm grain size) aquifer sediments. The minute (average in situ cell size, 2 to 3 ??m) flagellates, which are relatively abundant in the Cape Cod aquifer, were isolated from core samples, grown in a grass extract medium, labeled with hydroethidine (a vital eukaryotic stain), and coinjected into aquifer sediments along with bromide, a conservative tracer. The 2-??m flagellates appeared to be near the optimal size for transport, judging from flowthrough column experiments involving a polydispersed (0.7 to 6.2 ??m in diameter) suspension of carboxylated microspheres. However, immobilization within the aquifer sediments accounted for a log unit reduction over the first meter of travel compared with a log unit reduction over the first 10 m of travel for indigenous, free-living groundwater bacteria in earlier tests. High rates of flagellate immobilization in the presence of aquifer sediments also was observed in the laboratory. However, immobilization rates for the laboratory-grown flagellates (initially 4 to 5 ??m) injected into the aquifer were not constant and decreased noticeably with increasing time and distance of travel. The decrease in propensity for grain surfaces was accompanied by a decrease in cell size, as the flagellates presumably readapted to aquifer conditions. Retardation and apparent dispersion were generally at least twofold greater than those observed earlier for indigenous groundwater bacteria but were much closer to those observed for highly surface active carboxylated latex microspheres. Field and laboratory results suggest that 2- ??m carboxylated microspheres may be useful as analogs in investigating several abiotic aspects of flagellate transport behavior in groundwater.

Sample size calculations for randomized clinical trials published in anesthesiology journals: a comparison of 2010 versus 2016.

PubMed

Chow, Jeffrey T Y; Turkstra, Timothy P; Yim, Edmund; Jones, Philip M

2018-06-01

Although every randomized clinical trial (RCT) needs participants, determining the ideal number of participants that balances limited resources and the ability to detect a real effect is difficult. Focussing on two-arm, parallel group, superiority RCTs published in six general anesthesiology journals, the objective of this study was to compare the quality of sample size calculations for RCTs published in 2010 vs 2016. Each RCT's full text was searched for the presence of a sample size calculation, and the assumptions made by the investigators were compared with the actual values observed in the results. Analyses were only performed for sample size calculations that were amenable to replication, defined as using a clearly identified outcome that was continuous or binary in a standard sample size calculation procedure. The percentage of RCTs reporting all sample size calculation assumptions increased from 51% in 2010 to 84% in 2016. The difference between the values observed in the study and the expected values used for the sample size calculation for most RCTs was usually > 10% of the expected value, with negligible improvement from 2010 to 2016. While the reporting of sample size calculations improved from 2010 to 2016, the expected values in these sample size calculations often assumed effect sizes larger than those actually observed in the study. Since overly optimistic assumptions may systematically lead to underpowered RCTs, improvements in how to calculate and report sample sizes in anesthesiology research are needed.

Multiscale sampling of plant diversity: Effects of minimum mapping unit size

USGS Publications Warehouse

Stohlgren, T.J.; Chong, G.W.; Kalkhan, M.A.; Schell, L.D.

1997-01-01

Only a small portion of any landscape can be sampled for vascular plant diversity because of constraints of cost (salaries, travel time between sites, etc.). Often, the investigator decides to reduce the cost of creating a vegetation map by increasing the minimum mapping unit (MMU), and/or by reducing the number of vegetation classes to be considered. Questions arise about what information is sacrificed when map resolution is decreased. We compared plant diversity patterns from vegetation maps made with 100-ha, 50-ha, 2-ha, and 0.02-ha MMUs in a 754-ha study area in Rocky Mountain National Park, Colorado, United States, using four 0.025-ha and 21 0.1-ha multiscale vegetation plots. We developed and tested species-log(area) curves, correcting the curves for within-vegetation type heterogeneity with Jaccard's coefficients. Total species richness in the study area was estimated from vegetation maps at each resolution (MMU), based on the corrected species-area curves, total area of the vegetation type, and species overlap among vegetation types. With the 0.02-ha MMU, six vegetation types were recovered, resulting in an estimated 552 species (95% CI = 520-583 species) in the 754-ha study area (330 plant species were observed in the 25 plots). With the 2-ha MMU, five vegetation types were recognized, resulting in an estimated 473 species for the study area. With the 50-ha MMU, 439 plant species were estimated for the four vegetation types recognized in the study area. With the 100-ha MMU, only three vegetation types were recognized, resulting in an estimated 341 plant species for the study area. Locally rare species and keystone ecosystems (areas of high or unique plant diversity) were missed at the 2-ha, 50-ha, and 100-ha scales. To evaluate the effects of minimum mapping unit size requires: (1) an initial stratification of homogeneous, heterogeneous, and rare habitat types; and (2) an evaluation of within-type and between-type heterogeneity generated by environmental gradients and other factors. We suggest that at least some portions of vegetation maps created at a coarser level of resolution be validated at a higher level of resolution.

Glove Changing When Handling Money: Observational and Microbiological Analysis.

PubMed

Basch, Corey H; Wahrman, Miryam Z; Shah, Jay; Guerra, Laura A; MacDonald, Zerlina; Marte, Myladys; Basch, Charles E

2016-04-01

The purpose of this study was to determine the rate of glove changing by mobile food vendors after monetary transactions, and the presence of bacterial contamination on a sample of dollar bills obtained from 25 food vendors near five hospitals in Manhattan, New York City. During 495 monetary transactions observed there were only seven glove changes performed by the workers. Eleven of 34 food workers wore no gloves at all while handling money and food. Nineteen of 25 one-dollar bills collected (76 %) had 400 to 42,000 total bacterial colony-forming units. Colonies were of varied morphology and size. Of these 19 samples, 13 were selected (based on level of growth), and tested for the presence of coliform bacteria, which was found in 10 of the 13 samples. Effective strategies to monitor and increase glove wearing and changing habits of mobile food vendors are needed to reduce risk of foodborne illness.

Diversity and prevalence of hemoparasites of wading birds in southern Florida, USA.

PubMed

Coker, Sarah M; Hernandez, Sonia M; Kistler, Whitney M; Curry, Shannon E; Welch, Catharine N; Barron, Heather W; Harsch, Stefan; Murray, Maureen H; Yabsley, Michael J

2017-12-01

Relatively few studies on hemoparasites have been conducted on wading birds in the families Ardeidae and Threskiornithidae (order Pelecaniformes), especially in the United States. In this study, we obtained baseline data on the prevalence and genetic diversity of haemosporidian parasites in wading birds opportunistically sampled from southern Florida, USA. We detected blood parasites in White Ibis ( Eudocimus albus ), Glossy Ibis ( Plegadis falcinellus ), Green Heron ( Butorides virescens ), and Roseate Spoonbill ( Platalea ajaja ) with several novel host-parasite relationships. Infected birds had low parasitemias (average 0.77%, range 0-4%) suggesting that infections were chronic. Despite the low sample sizes for several of our sampled species, these data highlight the diversity of parasites in this understudied group of birds and suggest that additional studies are needed to investigate the potential impacts of these parasites on their health, especially since southern Florida is becoming increasingly urbanized which can alter parasite transmission or host susceptibility.

Environmental quality of Korean coasts as determined by modified Shannon-Wiener evenness proportion.

PubMed

Yoo, Jae-Won; Lee, Yong-Woo; Ruesink, Jennifer L; Lee, Chang-Gun; Kim, Chang-Soo; Park, Mi-Ra; Yoon, Kon-Tak; Hwang, In-Seo; Maeng, Jun-Ho; Rosenberg, Rutger; Hong, Jae-Sang

2010-11-01

The coast of the Korean peninsula experiences a range of human impacts, including pollution, shipping, reclamation, and aquaculture, that have motivated numerous local studies of macrobenthic organisms. In this paper, 1,492 subtidal stations were compiled from 23 studies (areas) to evaluate environmental quality on a broader scale. A common index in biomonitoring, Shannon-Wiener evenness proportion (SEP), could not incorporate azoic or single-species samples. This shortcoming was overcome by developing an inverse function of SEP (ISEP), which was positively correlated with independent measures of water quality available for nine sites and was not biased by the size of the sampling unit. Additionally, at Shihwa Dike, where samples were collected before and after reinstating a tidal connection with the ocean, ISEP values improved over time, as expected. Thus, it is now possible to assign Korean subtidal sites to seven ISEP "grades" and to use their values and trends to guide coastal management.

Thermoelectric technique to precisely control hyperthermic exposures of human whole blood.

PubMed

DuBose, D A; Langevin, R C; Morehouse, D H

1996-12-01

The need in military research to avoid exposing humans to harsh environments and reduce animal use requires the development of in vitro models for the study of hyperthermic injury. A thermoelectric module (TEM) system was employed to heat human whole blood (HWB) in a manner similar to that experienced by heat-stroked rats. This system precisely and accurately replicated mild, moderate, and extreme heat-stress exposures. Temperature changes could be monitored without the introduction of a test sample thermistor, which reduced contamination problems. HWB with hematocrits of 45 or 50% had similar heating curves, indicating that the system compensated for differences in sample character. The unit's size permitted its containment within a standard carbon dioxide incubator to further control sample environment. These results indicate that the TEM system can precisely control temperature change in this heat stress in vitro model employing HWB. Information obtained from such a model could contribute to military preparedness.

Cache-Aware Asymptotically-Optimal Sampling-Based Motion Planning

PubMed Central

Ichnowski, Jeffrey; Prins, Jan F.; Alterovitz, Ron

2014-01-01

We present CARRT* (Cache-Aware Rapidly Exploring Random Tree*), an asymptotically optimal sampling-based motion planner that significantly reduces motion planning computation time by effectively utilizing the cache memory hierarchy of modern central processing units (CPUs). CARRT* can account for the CPU’s cache size in a manner that keeps its working dataset in the cache. The motion planner progressively subdivides the robot’s configuration space into smaller regions as the number of configuration samples rises. By focusing configuration exploration in a region for periods of time, nearest neighbor searching is accelerated since the working dataset is small enough to fit in the cache. CARRT* also rewires the motion planning graph in a manner that complements the cache-aware subdivision strategy to more quickly refine the motion planning graph toward optimality. We demonstrate the performance benefit of our cache-aware motion planning approach for scenarios involving a point robot as well as the Rethink Robotics Baxter robot. PMID:25419474

Cache-Aware Asymptotically-Optimal Sampling-Based Motion Planning.

PubMed

Ichnowski, Jeffrey; Prins, Jan F; Alterovitz, Ron

2014-05-01

We present CARRT* (Cache-Aware Rapidly Exploring Random Tree*), an asymptotically optimal sampling-based motion planner that significantly reduces motion planning computation time by effectively utilizing the cache memory hierarchy of modern central processing units (CPUs). CARRT* can account for the CPU's cache size in a manner that keeps its working dataset in the cache. The motion planner progressively subdivides the robot's configuration space into smaller regions as the number of configuration samples rises. By focusing configuration exploration in a region for periods of time, nearest neighbor searching is accelerated since the working dataset is small enough to fit in the cache. CARRT* also rewires the motion planning graph in a manner that complements the cache-aware subdivision strategy to more quickly refine the motion planning graph toward optimality. We demonstrate the performance benefit of our cache-aware motion planning approach for scenarios involving a point robot as well as the Rethink Robotics Baxter robot.

Size-induced variations in bulk/surface structures and their impact on photoluminescence properties of GdVO4:Eu3+ nanoparticles.

PubMed

Yang, Liusai; Li, Liping; Zhao, Minglei; Li, Guangshe

2012-07-28

This work explores the size-induced lattice modification and its relevance to photoluminescence properties of tetragonal zircon-type GdVO(4):Eu(3+) nanostructures. GdVO(4):Eu(3+) nanoparticles with crystallite sizes ranging from 14.4 to 24.7 nm were synthesized by a hydrothermal method using sodium citrate as a capping agent. Regardless of the reaction temperatures, all samples retained an ellipsoidal-like morphology. Nevertheless, as the crystallite size reduces, there appears a tensile strain and lattice distortion, which is accompanied by a lattice expansion and a decreased symmetry of structural units. These lattice modifications could be associated with the changes in the interior chemical bonding due to the interactions of surface defect dipoles that have imposed an increased negative pressure with crystallite size reduction. Furthermore, crystallite size reduction also led to a significant increase in the amounts of surface hydroxyl groups and citric species, as well as the concentration of the surface Eu(3+) ions. When Eu(3+) was taken as a structural probe, it was found that the asymmetric ratio (I(02)/I(01)) of Eu(3+) gradually declined to show a remarkable decrease in color chromaticity as crystallite size reduces, which could be interpreted as due to the change of local environments of Eu(3+) ions from the interior to the surface of the nanoparticles.

Accounting for body size deviations when reporting bone mineral density variables in children.

PubMed

Webber, C E; Sala, A; Barr, R D

2009-01-01

In a child, bone mineral density (BMD) may differ from an age-expected normal value, not only because of the presence of disease, but also because of deviations of height or weight from population averages. Appropriate adjustment for body size deviations simplifies interpretation of BMD measurements. For children, a bone mineral density (BMD) measurement is normally expressed as a Z score. Interpretation is complicated when weight or height distinctly differ from age-matched children. We develop a procedure to allow for the influence of body size deviations upon measured BMD. We examined the relation between body size deviation and spine, hip and whole body BMD deviation in 179 normal children (91 girls). Expressions were developed that allowed derivation of an expected BMD based on age, gender and body size deviation. The difference between measured and expected BMD was expressed as a HAW score (Height-, Age-, Weight-adjusted score). In a second independent sample of 26 normal children (14 girls), measured spine, total femur and whole body BMD all fell within the same single normal range after accounting for age, gender and body size deviations. When traditional Z scores and HAW scores were compared in 154 children, 17.5% showed differences of more than 1 unit and such differences were associated with height and weight deviations. For almost 1 in 5 children, body size deviations influence BMD to an extent that could alter clinical management.

On the error in crop acreage estimation using satellite (LANDSAT) data

NASA Technical Reports Server (NTRS)

Chhikara, R. (Principal Investigator)

1983-01-01

The problem of crop acreage estimation using satellite data is discussed. Bias and variance of a crop proportion estimate in an area segment obtained from the classification of its multispectral sensor data are derived as functions of the means, variances, and covariance of error rates. The linear discriminant analysis and the class proportion estimation for the two class case are extended to include a third class of measurement units, where these units are mixed on ground. Special attention is given to the investigation of mislabeling in training samples and its effect on crop proportion estimation. It is shown that the bias and variance of the estimate of a specific crop acreage proportion increase as the disparity in mislabeling rates between two classes increases. Some interaction is shown to take place, causing the bias and the variance to decrease at first and then to increase, as the mixed unit class varies in size from 0 to 50 percent of the total area segment.

The Technical Efficiency of Specialised Milk Farms: A Regional View

PubMed Central

Špička, Jindřich; Smutka, Luboš

2014-01-01

The aim of the article is to evaluate production efficiency and its determinants of specialised dairy farming among the EU regions. In the most of European regions, there is a relatively high significance of small specialised farms including dairy farms. The DEAVRS method (data envelopment analysis with variable returns to scale) reveals efficient and inefficient regions including the scale efficiency. In the next step, the two-sample t-test determines differences of economic and structural indicators between efficient and inefficient regions. The research reveals that substitution of labour by capital/contract work explains the variability of the farm net value added per AWU (annual work unit) income indicator by more than 30%. The significant economic determinants of production efficiency in specialised dairy farming are farm size, herd size, crop output per hectare, productivity of energy, and capital (at α = 0.01). Specialised dairy farms in efficient regions have significantly higher farm net value added per AWU than inefficient regions. Agricultural enterprises in inefficient regions have a more extensive structure and produce more noncommodity output (public goods). Specialised dairy farms in efficient regions have a slightly higher milk yield, specific livestock costs of feed, bedding, and veterinary services per livestock unit. PMID:25050408

Effect of Sand Bed Depth and Medium Age on Escherichia coli and Turbidity Removal in Biosand Filters.

PubMed

Napotnik, Julie A; Baker, Derek; Jellison, Kristen L

2017-03-21

The main objective of this study was to build several full-scale biosand filters (BSFs) and assess the long-term (9 month) efficacy for particulate and Escherichia coli removal under simulated real-world usage. Four replicates of three different filter designs were built: the traditional concrete BSF and two scaled-down versions that use a 5 or 2 gal bucket as the casing material. The smaller sand bed depths in the bucket-sized filters did not impact filter performance with respect to (i) turbidity and E. coli removal or (ii) effluent levels of turbidity and E. coli. All filters produced effluents with a mean turbidity of <0.6 nephelometric turbidity unit. In addition, 78, 74, and 72% of effluent samples for the concrete, 5 gal, and 2 gal filters, respectively, had E. coli concentrations of <1 colony-forming unit/100 mL. The bucket-sized filters were found to be a potential alternative to the concrete BSFs for the removal of E. coli and turbidity from drinking water. Because smaller BSFs must be filled more frequently than larger BSFs to produce comparable water volumes, the effect of shorter pause periods on BSF performance should be investigated.

Sample Size and Statistical Conclusions from Tests of Fit to the Rasch Model According to the Rasch Unidimensional Measurement Model (Rumm) Program in Health Outcome Measurement.

PubMed

Hagell, Peter; Westergren, Albert

Sample size is a major factor in statistical null hypothesis testing, which is the basis for many approaches to testing Rasch model fit. Few sample size recommendations for testing fit to the Rasch model concern the Rasch Unidimensional Measurement Models (RUMM) software, which features chi-square and ANOVA/F-ratio based fit statistics, including Bonferroni and algebraic sample size adjustments. This paper explores the occurrence of Type I errors with RUMM fit statistics, and the effects of algebraic sample size adjustments. Data with simulated Rasch model fitting 25-item dichotomous scales and sample sizes ranging from N = 50 to N = 2500 were analysed with and without algebraically adjusted sample sizes. Results suggest the occurrence of Type I errors with N less then or equal to 500, and that Bonferroni correction as well as downward algebraic sample size adjustment are useful to avoid such errors, whereas upward adjustment of smaller samples falsely signal misfit. Our observations suggest that sample sizes around N = 250 to N = 500 may provide a good balance for the statistical interpretation of the RUMM fit statistics studied here with respect to Type I errors and under the assumption of Rasch model fit within the examined frame of reference (i.e., about 25 item parameters well targeted to the sample).

A noninvasive technique for real-time detection of bruises in apple surface based on machine vision

NASA Astrophysics Data System (ADS)

Zhao, Juan; Peng, Yankun; Dhakal, Sagar; Zhang, Leilei; Sasao, Akira

2013-05-01

Apple is one of the highly consumed fruit item in daily life. However, due to its high damage potential and massive influence on taste and export, the quality of apple has to be detected before it reaches the consumer's hand. This study was aimed to develop a hardware and software unit for real-time detection of apple bruises based on machine vision technology. The hardware unit consisted of a light shield installed two monochrome cameras at different angles, LED light source to illuminate the sample, and sensors at the entrance of box to signal the positioning of sample. Graphical Users Interface (GUI) was developed in VS2010 platform to control the overall hardware and display the image processing result. The hardware-software system was developed to acquire the images of 3 samples from each camera and display the image processing result in real time basis. An image processing algorithm was developed in Opencv and C++ platform. The software is able to control the hardware system to classify the apple into two grades based on presence/absence of surface bruises with the size of 5mm. The experimental result is promising and the system with further modification can be applicable for industrial production in near future.

Letter Report: Stable Hydrogen and Oxygen Isotope Analysis of B-Complex Perched Water Samples

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

Lee, Brady D.; Moran, James J.; Nims, Megan K.

Fine-grained sediments associated with the Cold Creek Unit at Hanford have caused the formation of a perched water aquifer in the deep vadose zone at the B Complex area, which includes waste sites in the 200-DV-1 Operable Unit and the single-shell tank farms in Waste Management Area B-BX-BY. High levels of contaminants, such as uranium, technetium-99, and nitrate, make this aquifer a continuing source of contamination for the groundwater located a few meters below the perched zone. Analysis of deuterium ( 2H) and 18-oxygen ( 18O) of nine perched water samples from three different wells was performed. Samples represent timemore » points from hydraulic tests performed on the perched aquifer using the three wells. The isotope analyses showed that the perched water had δ 2H and δ 18O ratios consistent with the regional meteoric water line, indicating that local precipitation events at the Hanford site likely account for recharge of the perched water aquifer. Data from the isotope analysis can be used along with pumping and recovery data to help understand the perched water dynamics related to aquifer size and hydraulic control of the aquifer in the future.« less

Analysis of methods commonly used in biomedicine for treatment versus control comparison of very small samples.

PubMed

Ristić-Djurović, Jasna L; Ćirković, Saša; Mladenović, Pavle; Romčević, Nebojša; Trbovich, Alexander M

2018-04-01

A rough estimate indicated that use of samples of size not larger than ten is not uncommon in biomedical research and that many of such studies are limited to strong effects due to sample sizes smaller than six. For data collected from biomedical experiments it is also often unknown if mathematical requirements incorporated in the sample comparison methods are satisfied. Computer simulated experiments were used to examine performance of methods for qualitative sample comparison and its dependence on the effectiveness of exposure, effect intensity, distribution of studied parameter values in the population, and sample size. The Type I and Type II errors, their average, as well as the maximal errors were considered. The sample size 9 and the t-test method with p = 5% ensured error smaller than 5% even for weak effects. For sample sizes 6-8 the same method enabled detection of weak effects with errors smaller than 20%. If the sample sizes were 3-5, weak effects could not be detected with an acceptable error; however, the smallest maximal error in the most general case that includes weak effects is granted by the standard error of the mean method. The increase of sample size from 5 to 9 led to seven times more accurate detection of weak effects. Strong effects were detected regardless of the sample size and method used. The minimal recommended sample size for biomedical experiments is 9. Use of smaller sizes and the method of their comparison should be justified by the objective of the experiment. Copyright © 2018 Elsevier B.V. All rights reserved.

High dependency units in the UK: variable size, variable character, few in number.

PubMed Central

Thompson, F. J.; Singer, M.

1995-01-01

An exploratory descriptive survey was conducted to determine the size and character of high dependency units (HDUs) in the UK. A telephone survey and subsequent postal questionnaire was sent to the 39 general HDUs in the UK determined by a recent survey from the Royal College of Anaesthetists; replies were received from 28. Most HDUs (82%, n = 23) were geographically distinct from the intensive care unit and varied in size from three to 13 beds, although only 64% (n = 18) reported that all beds were currently open. Nurse: patient ratios were at least 1:3. Fifty per cent of units had one or more designated consultants in charge, although only 11% (n = 3) had specifically designated consultant sessions. Junior medical cover was provided mainly by the on-call speciality term. Twenty units acted as a step-down facility for discharged intensive care unit patients and 21 offered a step-up facility for patients from general wards. Provision of facilities and levels of monitoring varied between these units. Few HDUs exist in the UK and they are variable in size and in the facilities and monitoring procedures which they provide. Future studies are urgently required to determine cost-effectiveness and outcome benefit of this intermediate care facility. Images p221-a PMID:7784281

High dependency units in the UK: variable size, variable character, few in number.

PubMed

Thompson, F J; Singer, M

1995-04-01

An exploratory descriptive survey was conducted to determine the size and character of high dependency units (HDUs) in the UK. A telephone survey and subsequent postal questionnaire was sent to the 39 general HDUs in the UK determined by a recent survey from the Royal College of Anaesthetists; replies were received from 28. Most HDUs (82%, n = 23) were geographically distinct from the intensive care unit and varied in size from three to 13 beds, although only 64% (n = 18) reported that all beds were currently open. Nurse: patient ratios were at least 1:3. Fifty per cent of units had one or more designated consultants in charge, although only 11% (n = 3) had specifically designated consultant sessions. Junior medical cover was provided mainly by the on-call speciality term. Twenty units acted as a step-down facility for discharged intensive care unit patients and 21 offered a step-up facility for patients from general wards. Provision of facilities and levels of monitoring varied between these units. Few HDUs exist in the UK and they are variable in size and in the facilities and monitoring procedures which they provide. Future studies are urgently required to determine cost-effectiveness and outcome benefit of this intermediate care facility.

The Emergence of a Phoneme-Sized Unit in L2 Speech Production: Evidence from Japanese–English Bilinguals

PubMed Central

Nakayama, Mariko; Kinoshita, Sachiko; Verdonschot, Rinus G.

2016-01-01

Recent research has revealed that the way phonology is constructed during word production differs across languages. Dutch and English native speakers are suggested to incrementally insert phonemes into a metrical frame, whereas Mandarin Chinese speakers use syllables and Japanese speakers use a unit called the mora (often a CV cluster such as “ka” or “ki”). The present study is concerned with the question how bilinguals construct phonology in their L2 when the phonological unit size differs from the unit in their L1. Japanese–English bilinguals of varying proficiency read aloud English words preceded by masked primes that overlapped in just the onset (e.g., bark-BENCH) or the onset plus vowel corresponding to the mora-sized unit (e.g., bell-BENCH). Low-proficient Japanese–English bilinguals showed CV priming but did not show onset priming, indicating that they use their L1 phonological unit when reading L2 English words. In contrast, high-proficient Japanese–English bilinguals showed significant onset priming. The size of the onset priming effect was correlated with the length of time spent in English-speaking countries, which suggests that extensive exposure to L2 phonology may play a key role in the emergence of a language-specific phonological unit in L2 word production. PMID:26941669

Scanning Electron Microscopy with Samples in an Electric Field

PubMed Central

Frank, Ludĕk; Hovorka, Miloš; Mikmeková, Šárka; Mikmeková, Eliška; Müllerová, Ilona; Pokorná, Zuzana

2012-01-01

The high negative bias of a sample in a scanning electron microscope constitutes the “cathode lens” with a strong electric field just above the sample surface. This mode offers a convenient tool for controlling the landing energy of electrons down to units or even fractions of electronvolts with only slight readjustments of the column. Moreover, the field accelerates and collimates the signal electrons to earthed detectors above and below the sample, thereby assuring high collection efficiency and high amplification of the image signal. One important feature is the ability to acquire the complete emission of the backscattered electrons, including those emitted at high angles with respect to the surface normal. The cathode lens aberrations are proportional to the landing energy of electrons so the spot size becomes nearly constant throughout the full energy scale. At low energies and with their complete angular distribution acquired, the backscattered electron images offer enhanced information about crystalline and electronic structures thanks to contrast mechanisms that are otherwise unavailable. Examples from various areas of materials science are presented.

Performance analysis of the toroidal field ITER production conductors

NASA Astrophysics Data System (ADS)

Breschi, M.; Macioce, D.; Devred, A.

2017-05-01

The production of the superconducting cables for the toroidal field (TF) magnets of the ITER machine has recently been completed at the manufacturing companies selected during the previous qualification phase. The quality assurance/quality control programs that have been implemented to ensure production uniformity across numerous suppliers include performance tests of several conductor samples from selected unit lengths. The short full-size samples (4 m long) were subjected to DC and AC tests in the SULTAN facility at CRPP in Villigen, Switzerland. In a previous work the results of the tests of the conductor performance qualification samples were reported. This work reports the analyses of the results of the tests of the production conductor samples. The results reported here concern the values of current sharing temperature, critical current, effective strain and n-value from the DC tests and the energy dissipated per cycle from the AC loss tests. A detailed comparison is also presented between the performance of the conductors and that of their constituting strands.

Influence of Zn doping on structural, optical and dielectric properties of LaFeO3

NASA Astrophysics Data System (ADS)

Manzoor, Samiya; Husain, Shahid

2018-05-01

The effect of Zn doping on structural, optical and dielectric properties of nano-crystalline LaFe1‑xZnxO3 (0.0 ≤ x ≤ 0.3) samples have been investigated. These samples are synthesized using conventional solid state reaction route. X-ray diffraction patterns with Rietveld analysis confirm the single phase nature of samples. Further, the sample formation has been confirmed by FTIR spectroscopy. All the samples are formed in orthorhombic crystal symmetry with Pbnm space group. The average crystallite sizes, calculated from the Scherer’s formula, lie in the range below 50 nm. Rietveld refinement technique is used to determine lattice parameters, bond lengths and unit cell volume. Williamson-Hall analysis has been performed to calculate the crystallite size and lattice strain. Crystallite sizes are found to be of nanometer range while the strain is of the order of 10‑3. Zn doping leads to the expansion of volume due to the tensile strain. Optical bandgap has been determined from Kubelka-Munk function using Tauc’s relation. Zinc doping in LaFeO3 leads to decrease in optical bandgap. Dielectric constant as a function of frequency is measured in the frequency range of 75 kHz–5 MHz. The dielectric behavior has been investigated by analyzing ‘universal dielectric response’ (UDR) model. The dielectric constant (ε‧) shows colossal value with Zn doping in the whole frequency range. However, the imaginary part (ε″) shows relaxational behavior which may be attributed to the strong correlation that exists between conduction mechanism and dielectric behavior in ferrites. Cole-Cole analysis has been done that confirms the dielectric material does not follow the ideal Debye theory but shows distribution of relaxation times. The a.c conductivity increases with frequency and with Zn doping due to the increased polaron hopping.

Size really does matter: effects of filter fractionation on microbial community structure in a model oxygen minimum zone.

NASA Astrophysics Data System (ADS)

Torres Beltran, M.

2016-02-01

The Scientific Committee on Oceanographic Research (SCOR) Working Group 144 "Microbial Community Responses to Ocean Deoxygenation" workshop held in Vancouver, British Columbia in July 2014 had the primary objective of kick-starting the establishment of a minimal core of technologies, techniques and standard operating procedures (SOPs) to enable compatible process rate and multi-molecular data (DNA, RNA and protein) collection in marine oxygen minimum zones (OMZs) and other oxygen starved waters. Experimental activities conducted in Saanich Inlet, a seasonally anoxic fjord on Vancouver Island British Columbia, were designed to compare and cross-calibrate in situ sampling devices (McLane PPS system) with conventional bottle sampling and incubation methods. Bottle effects on microbial community composition, and activity were tested using different filter combinations and sample volumes to compare PPS/IPS (0.4 µm) versus Sterivex (0.22 µm) filtration methods with and without prefilters (2.7 µm). Resulting biomass was processed for small subunit ribosomal RNA gene sequencing across all three domains of life on the 454 platform followed by downstream community structure analyses. Significant community shifts occurred within and between filter fractions for in situ versus on-ship processed samples. For instance, the relative abundance of several bacterial phyla including Bacteroidetes, Delta and Gammaproteobacteria decreased five-fold on-ship when compared to in situ filtration. Similarly, experimental mesocosms showed similar community structure and activity to in situ filtered samples indicating the need to cross-calibrate incubations to constrain bottle effects. In addition, alpha and beta diversity significantly changed as function of filter size and volume, as well as the operational taxonomic units identified using indicator species analysis for each filter size. Our results provide statistical support that microbial community structure is systematically biased by filter fraction methods and highlight the need for establishing compatible techniques among researchers that facilitate comparative and reproducible science for the whole community.

A knowledge-based T2-statistic to perform pathway analysis for quantitative proteomic data

PubMed Central

Chen, Yi-Hau

2017-01-01

Approaches to identify significant pathways from high-throughput quantitative data have been developed in recent years. Still, the analysis of proteomic data stays difficult because of limited sample size. This limitation also leads to the practice of using a competitive null as common approach; which fundamentally implies genes or proteins as independent units. The independent assumption ignores the associations among biomolecules with similar functions or cellular localization, as well as the interactions among them manifested as changes in expression ratios. Consequently, these methods often underestimate the associations among biomolecules and cause false positives in practice. Some studies incorporate the sample covariance matrix into the calculation to address this issue. However, sample covariance may not be a precise estimation if the sample size is very limited, which is usually the case for the data produced by mass spectrometry. In this study, we introduce a multivariate test under a self-contained null to perform pathway analysis for quantitative proteomic data. The covariance matrix used in the test statistic is constructed by the confidence scores retrieved from the STRING database or the HitPredict database. We also design an integrating procedure to retain pathways of sufficient evidence as a pathway group. The performance of the proposed T2-statistic is demonstrated using five published experimental datasets: the T-cell activation, the cAMP/PKA signaling, the myoblast differentiation, and the effect of dasatinib on the BCR-ABL pathway are proteomic datasets produced by mass spectrometry; and the protective effect of myocilin via the MAPK signaling pathway is a gene expression dataset of limited sample size. Compared with other popular statistics, the proposed T2-statistic yields more accurate descriptions in agreement with the discussion of the original publication. We implemented the T2-statistic into an R package T2GA, which is available at https://github.com/roqe/T2GA. PMID:28622336

A knowledge-based T2-statistic to perform pathway analysis for quantitative proteomic data.

PubMed

Lai, En-Yu; Chen, Yi-Hau; Wu, Kun-Pin

2017-06-01

Approaches to identify significant pathways from high-throughput quantitative data have been developed in recent years. Still, the analysis of proteomic data stays difficult because of limited sample size. This limitation also leads to the practice of using a competitive null as common approach; which fundamentally implies genes or proteins as independent units. The independent assumption ignores the associations among biomolecules with similar functions or cellular localization, as well as the interactions among them manifested as changes in expression ratios. Consequently, these methods often underestimate the associations among biomolecules and cause false positives in practice. Some studies incorporate the sample covariance matrix into the calculation to address this issue. However, sample covariance may not be a precise estimation if the sample size is very limited, which is usually the case for the data produced by mass spectrometry. In this study, we introduce a multivariate test under a self-contained null to perform pathway analysis for quantitative proteomic data. The covariance matrix used in the test statistic is constructed by the confidence scores retrieved from the STRING database or the HitPredict database. We also design an integrating procedure to retain pathways of sufficient evidence as a pathway group. The performance of the proposed T2-statistic is demonstrated using five published experimental datasets: the T-cell activation, the cAMP/PKA signaling, the myoblast differentiation, and the effect of dasatinib on the BCR-ABL pathway are proteomic datasets produced by mass spectrometry; and the protective effect of myocilin via the MAPK signaling pathway is a gene expression dataset of limited sample size. Compared with other popular statistics, the proposed T2-statistic yields more accurate descriptions in agreement with the discussion of the original publication. We implemented the T2-statistic into an R package T2GA, which is available at https://github.com/roqe/T2GA.

Evaluation of the spatial variability of soil water content at the spatial resolution of SMAP data products : case studies in Italy and Morocco

NASA Astrophysics Data System (ADS)

Menenti, Massimo; Akdim, Nadia; Alfieri, Silvia Maria; Labbassi, Kamal; De Lorenzi, Francesca; Bonfante, Antonello; Basile, Angelo

2014-05-01

Frequent and contiguous observations of soil water content such as the ones to be provided by SMAP are potentially useful to improve distributed models of soil water balance. This requires matching of observations and model estimates provided both sample spatial patterns consistently. The spatial resolution of SMAP soil water content data products ranges from 3 km X 3 km to 40 km X 40 km. Even the highest spatial resolution may not be sufficient to capture the spatial variability due to terrain, soil properties and precipitation. We have evaluated the SMAP spatial resolution against spatial variability of soil water content in two Mediterranean landscapes: a hilly area dominated by vineyards and olive orchards in Central Italy and a large irrigation schemes (Doukkala) in Morocco. The "Valle Telesina" is a 20,000 ha complex landscape located in South Italy in the Campania region, which has a complex geology and geomorphology and it is characterised by an E-W elongated graben where the Calore river flows. The main crops are grapevine (6,448 ha) and olive (3,390 ha). Soil information was mainly derived from an existing soil map at 1:50 000 scale (Terribile et al., 1996). The area includes 47 SMUs (Soil Mapping Units) and about 60 soil typological units (STUs). (Bonfante et al., 2011). In Doukkala, the soil water retention and unsaturated capillary conductivity were estimated from grain size distribution of a number of samples (22 pilot points, each one sampled in 3 horizons of 20cm), and combined with a soil map. The land use classification was carried out using a NDVI time series at high spatial resolution (Landsat TM and SPOT HRV). We have calculated soil water content for each soil unit in each area in response to several climate cases generating daily maps of soil water content at different depths. To reproduce spatial sampling by SMAP we have filtered these spatial patterns by calculating box averages with grid sizes of 1 km X 1 km and 5 km X 5 km. We have repeated this procedure for soil water content in the 0 to 5 cm and 0 to 10 cm depths. For each case we have compared the variance of filtered soil water content with the expected accuracy of SMAP soil water content. The two areas are very different as regards morphology and soil formation. The Valle Telesina is characterized by a very significant variability of soil hydrological properties leading to complex patterns in soil water content. Contrariwise, the soil properties estimated for all soil mapping units in the Dhoukkala collapse into just two pairs of water retention and hydraulic conductivity characteristics, leading to smoother patterns of soil water content.

A comparison of sample unit designs in the national inventory of the U.S.

Treesearch

B. E. Borders; G. H. Brister; N. Grahl; B. D. Shiver; C. J. Cieszewski

2000-01-01

The Forest Inventory and Analysis (FIA) program of the USDA Forest Service has adopted a new sampling unit for the national forest inventory of the U.S. We compared this new sampling unit with five other sampling units. Data from natural loblolly pine (Pinus taeda L.) stands in the Georgia piedmont show that all sample units produce reasonable...

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

Núñez-Coavas, H.

As cast Cu{sub 90}Co{sub 10} ribbons rapidly solidified by twin-roller melt spinning, exhibit special microstructure features. This processing method provides scenarios where a different phase selection takes place; coherent Co precipitates form directly from solidification, with neither a spinodal-like composition oscillation nor a discontinuously precipitated laminar phase. Samples are processed at tangential wheel speeds of 10 m/s (V10), 15 m/s (V15), 20 m/s (V20) and 30 m/s (V30). Microstructures resulting from this single step process are characterized and the hysteresis properties and the magnetoresistance effects evaluated. Samples V30 have a quite uniform density of coherent precipitates, with a narrow sizemore » distribution around 4 nm. On contrary, non-uniform precipitate distributions are found in samples cooled at lower rates; zones with a high density of coherent Co-rich precipitates are found forming colonies. These colonies are consistent with the extended compositional fluctuations occurring during very early stages in the cooling process. Samples may exhibit wide (V10) and even bimodal (V15) size distributions. Only samples V30 behave close to the ideal superparamagnetism. Samples V20 present relatively large coercivity and relative remanence and behave as an interacting superparamagnet, while the hysteresis loops of ribbons cooled at lower rates exhibit a ferromagnetic contribution in addition to the superparamagnetic-like one. This ferromagnetic component arises from blocked precipitates, larger than the upper bound size for superparamagnetic behavior at 300 K (12 nm). Room temperature magnetoresistance values associated to granular scattering units decrease as the mean precipitate size increases, but they remain below 2%, which is lower than that measured in samples annealed after rapid solidification, indicating that in this latter case contributions from the spinodally segregated matrix take place in addition to that of Co granules. - Highlights: •Microstructures of twin-rolled Cu{sub 90}Cu{sub 10} alloys are for the first time characterized. •Coherent Co-rich precipitates distribute forming dense colonies inside the grains. •No coexisting multilayer-like structures (spinodal or laminar phases) are detected. •Magnetic hysteresis arises from inter-particle interaction in these dense colonies. •Magnetoresistance level in these purely granular systems is low (1.6% at 300 K).« less

Failure to expand the motor unit size to compensate for declining motor unit numbers distinguishes sarcopenic from non-sarcopenic older men.

PubMed

Piasecki, M; Ireland, A; Piasecki, J; Stashuk, D W; Swiecicka, A; Rutter, M K; Jones, D A; McPhee, J S

2018-05-01

The age-related loss of muscle mass is related to the loss of innervating motor neurons and denervation of muscle fibres. Not all denervated muscle fibres are degraded; some may be reinnervated by an adjacent surviving neuron, which expands the innervating motor unit proportional to the numbers of fibres rescued. Enlarged motor units have larger motor unit potentials when measured using electrophysiological techniques. We recorded much larger motor unit potentials in relatively healthy older men compared to young men, but the older men with the smallest muscles (sarcopenia) had smaller motor unit potentials than healthy older men. These findings suggest that healthy older men reinnervate large numbers of muscle fibres to compensate for declining motor neuron numbers, but a failure to do so contributes to muscle loss in sarcopenic men. Sarcopenia results from the progressive loss of skeletal muscle mass and reduced function in older age. It is likely to be associated with the well-documented reduction of motor unit numbers innervating limb muscles and the increase in size of surviving motor units via reinnervation of denervated fibres. However, no evidence exists to confirm the extent of motor unit remodelling in sarcopenic individuals. The aim of the present study was to compare motor unit size and number between young (n = 48), non-sarcopenic old (n = 13), pre-sarcopenic (n = 53) and sarcopenic (n = 29) men. Motor unit potentials (MUPs) were isolated from intramuscular and surface EMG recordings. The motor unit numbers were reduced in all groups of old compared with young men (all P < 0.001). MUPs were higher in non-sarcopenic and pre-sarcopenic men compared with young men (P = 0.039 and 0.001 respectively), but not in the vastus lateralis of sarcopenic old (P = 0.485). The results suggest that extensive motor unit remodelling occurs relatively early during ageing, exceeds the loss of muscle mass and precedes sarcopenia. Reinnervation of denervated muscle fibres probably expands the motor unit size in the non-sarcopenic and pre-sarcopenic old, but not in the sarcopenic old. These findings suggest that a failure to expand the motor unit size distinguishes sarcopenic from pre-sarcopenic muscles. © 2018 The Authors. The Journal of Physiology published by John Wiley & Sons Ltd on behalf of The Physiological Society.

Sample size determination for estimating antibody seroconversion rate under stable malaria transmission intensity.

PubMed

Sepúlveda, Nuno; Drakeley, Chris

2015-04-03

In the last decade, several epidemiological studies have demonstrated the potential of using seroprevalence (SP) and seroconversion rate (SCR) as informative indicators of malaria burden in low transmission settings or in populations on the cusp of elimination. However, most of studies are designed to control ensuing statistical inference over parasite rates and not on these alternative malaria burden measures. SP is in essence a proportion and, thus, many methods exist for the respective sample size determination. In contrast, designing a study where SCR is the primary endpoint, is not an easy task because precision and statistical power are affected by the age distribution of a given population. Two sample size calculators for SCR estimation are proposed. The first one consists of transforming the confidence interval for SP into the corresponding one for SCR given a known seroreversion rate (SRR). The second calculator extends the previous one to the most common situation where SRR is unknown. In this situation, data simulation was used together with linear regression in order to study the expected relationship between sample size and precision. The performance of the first sample size calculator was studied in terms of the coverage of the confidence intervals for SCR. The results pointed out to eventual problems of under or over coverage for sample sizes ≤250 in very low and high malaria transmission settings (SCR ≤ 0.0036 and SCR ≥ 0.29, respectively). The correct coverage was obtained for the remaining transmission intensities with sample sizes ≥ 50. Sample size determination was then carried out for cross-sectional surveys using realistic SCRs from past sero-epidemiological studies and typical age distributions from African and non-African populations. For SCR < 0.058, African studies require a larger sample size than their non-African counterparts in order to obtain the same precision. The opposite happens for the remaining transmission intensities. With respect to the second sample size calculator, simulation unravelled the likelihood of not having enough information to estimate SRR in low transmission settings (SCR ≤ 0.0108). In that case, the respective estimates tend to underestimate the true SCR. This problem is minimized by sample sizes of no less than 500 individuals. The sample sizes determined by this second method highlighted the prior expectation that, when SRR is not known, sample sizes are increased in relation to the situation of a known SRR. In contrast to the first sample size calculation, African studies would now require lesser individuals than their counterparts conducted elsewhere, irrespective of the transmission intensity. Although the proposed sample size calculators can be instrumental to design future cross-sectional surveys, the choice of a particular sample size must be seen as a much broader exercise that involves weighting statistical precision with ethical issues, available human and economic resources, and possible time constraints. Moreover, if the sample size determination is carried out on varying transmission intensities, as done here, the respective sample sizes can also be used in studies comparing sites with different malaria transmission intensities. In conclusion, the proposed sample size calculators are a step towards the design of better sero-epidemiological studies. Their basic ideas show promise to be applied to the planning of alternative sampling schemes that may target or oversample specific age groups.

Utility of the AAMC’s Graduation Questionnaire to Study Behavioral and Social Sciences Domains in Undergraduate Medical Education

PubMed Central

Carney, Patricia A.; Rdesinski, Rebecca; Blank, Arthur E.; Graham, Mark; Wimmers, Paul; Chen, H. Carrie; Thompson, Britta; Jackson, Stacey A.; Foertsch, Julie; Hollar, David

2010-01-01

Purpose The Institute of Medicine (IOM) report on social and behavioral sciences (SBS) indicated that 50% of morbidity and mortality in the United States is associated with SBS factors, which the report also found were inadequately taught in medical school. A multischool collaborative explored whether the Association of American Medical Colleges Graduation Questionnaire (GQ) could be used to study changes in the six SBS domains identified in the IOM report. Method A content analysis conducted with the GQ identified 30 SBS variables, which were narrowed to 24 using a modified Delphi approach. Summary data were pooled from nine medical schools for 2006 and 2007, representing 1,126 students. Data were generated on students’ perceptions of curricular experiences, attitudes related to SBS curricula, and confidence with relevant clinical knowledge and skills. The authors determined the sample sizes required for various effect sizes to assess the utility of the GQ. Results The 24 variables were classified into five of six IOM domains representing a total of nine analytic categories with cumulative scale means ranging from 60.8 to 93.4. Taking into account the correlations among measures over time, and assuming a two-sided test, 80% power, alpha at .05, and standard deviation of 4.1, the authors found that 34 medical schools would be required for inclusion to attain an estimated effect size of 0.50 (50%). With a sample size of nine schools, the ability to detect changes would require a very high effect size of 107%. Conclusions Detecting SBS changes associated with curricular innovations would require a large collaborative of medical schools. Using a national measure (the GQ) to assess curricular innovations in most areas of SBS is possible if enough medical schools were involved in such an effort. PMID:20042845

Alterations in Neural Control of Constant Isometric Contraction with the Size of Error Feedback

PubMed Central

Hwang, Ing-Shiou; Lin, Yen-Ting; Huang, Wei-Min; Yang, Zong-Ru; Hu, Chia-Ling; Chen, Yi-Ching

2017-01-01

Discharge patterns from a population of motor units (MUs) were estimated with multi-channel surface electromyogram and signal processing techniques to investigate parametric differences in low-frequency force fluctuations, MU discharges, and force-discharge relation during static force-tracking with varying sizes of execution error presented via visual feedback. Fourteen healthy adults produced isometric force at 10% of maximal voluntary contraction through index abduction under three visual conditions that scaled execution errors with different amplification factors. Error-augmentation feedback that used a high amplification factor (HAF) to potentiate visualized error size resulted in higher sample entropy, mean frequency, ratio of high-frequency components, and spectral dispersion of force fluctuations than those of error-reducing feedback using a low amplification factor (LAF). In the HAF condition, MUs with relatively high recruitment thresholds in the dorsal interosseous muscle exhibited a larger coefficient of variation for inter-spike intervals and a greater spectral peak of the pooled MU coherence at 13–35 Hz than did those in the LAF condition. Manipulation of the size of error feedback altered the force-discharge relation, which was characterized with non-linear approaches such as mutual information and cross sample entropy. The association of force fluctuations and global discharge trace decreased with increasing error amplification factor. Our findings provide direct neurophysiological evidence that favors motor training using error-augmentation feedback. Amplification of the visualized error size of visual feedback could enrich force gradation strategies during static force-tracking, pertaining to selective increases in the discharge variability of higher-threshold MUs that receive greater common oscillatory inputs in the β-band. PMID:28125658

Cross-seasonal effects on waterfowl productivity: Implications under climate change

USGS Publications Warehouse

Osnas, Erik; Zhao, Qing; Runge, Michael C.; Boomer, G Scott

2016-01-01

Previous efforts to relate winter-ground precipitation to subsequent reproductive success as measured by the ratio of juveniles to adults in the autumn failed to account for increased vulnerability of juvenile ducks to hunting and uncertainty in the estimated age ratio. Neglecting increased juvenile vulnerability will positively bias the mean productivity estimate, and neglecting increased vulnerability and estimation uncertainty will positively bias the year-to-year variance in productivity because raw age ratios are the product of sampling variation, the year-specific vulnerability, and year-specific reproductive success. Therefore, we estimated the effects of cumulative winter precipitation in the California Central Valley and the Mississippi Alluvial Valley on pintail (Anas acuta) and mallard (Anas platyrhnchos) reproduction, respectively, using hierarchical Bayesian methods to correct for sampling bias in productivity estimates and observation error in covariates. We applied the model to a hunter-collected parts survey implemented by the United States Fish and Wildlife Service and band recoveries reported to the United States Geological Survey Bird Banding Laboratory using data from 1961 to 2013. We compared our results to previous estimates that used simple linear regression on uncorrected age ratios from a smaller subset of years in pintail (1961–1985). Like previous analyses, we found large and consistent effects of population size and wetland conditions in prairie Canada on mallard productivity, and large effects of population size and mean latitude of the observed breeding population on pintail productivity. Unlike previous analyses, we report a large amount of uncertainty in the estimated effects of wintering-ground precipitation on pintail and mallard productivity, with considerable uncertainty in the sign of the estimated main effect, although the posterior medians of precipitation effects were consistent with past studies. We found more consistent estimates in the sign of an interaction effect between population size and precipitation, suggesting that wintering-ground precipitation has a larger effect in years of high population size, especially for pintail. When we used the estimated effects in a population model to derive a sustainable harvest and population size projection (i.e., a yield curve), there was considerable uncertainty in the effect of increased or decreased wintering-ground precipitation on sustainable harvest potential and population size. These results suggest that the mechanism of cross-seasonal effects between winter habitat and reproduction in ducks occurs through a reduction in the strength of density dependence in years of above-average wintering-ground precipitation. We suggest additional investigation of the underlying mechanisms and that habitat managers and decision-makers consider the level of uncertainty in these estimates when attempting to integrate habitat management and harvest management decisions. Collection of annual data on the status of wintering-ground habitat in a rigorous sampling framework would likely be the most direct way to improve understanding of mechanisms and inform management.

Sample Size Calculations for Population Size Estimation Studies Using Multiplier Methods With Respondent-Driven Sampling Surveys.

PubMed

Fearon, Elizabeth; Chabata, Sungai T; Thompson, Jennifer A; Cowan, Frances M; Hargreaves, James R

2017-09-14

While guidance exists for obtaining population size estimates using multiplier methods with respondent-driven sampling surveys, we lack specific guidance for making sample size decisions. To guide the design of multiplier method population size estimation studies using respondent-driven sampling surveys to reduce the random error around the estimate obtained. The population size estimate is obtained by dividing the number of individuals receiving a service or the number of unique objects distributed (M) by the proportion of individuals in a representative survey who report receipt of the service or object (P). We have developed an approach to sample size calculation, interpreting methods to estimate the variance around estimates obtained using multiplier methods in conjunction with research into design effects and respondent-driven sampling. We describe an application to estimate the number of female sex workers in Harare, Zimbabwe. There is high variance in estimates. Random error around the size estimate reflects uncertainty from M and P, particularly when the estimate of P in the respondent-driven sampling survey is low. As expected, sample size requirements are higher when the design effect of the survey is assumed to be greater. We suggest a method for investigating the effects of sample size on the precision of a population size estimate obtained using multipler methods and respondent-driven sampling. Uncertainty in the size estimate is high, particularly when P is small, so balancing against other potential sources of bias, we advise researchers to consider longer service attendance reference periods and to distribute more unique objects, which is likely to result in a higher estimate of P in the respondent-driven sampling survey. ©Elizabeth Fearon, Sungai T Chabata, Jennifer A Thompson, Frances M Cowan, James R Hargreaves. Originally published in JMIR Public Health and Surveillance (http://publichealth.jmir.org), 14.09.2017.

[Renal biopsy practice in Piedmont and Valle d'Aosta].

PubMed

Manganaro, Marco; Nebiolo, Pier Eugenio; Rollino, Cristiana; Giacchino, Franca; Savoldi, Silvana; Besso, Luca; Colla, Loredana; Amore, Alessandro; Ferro, Michela; Marazzi, Federico; Chiarinotti, Doriana; Guarnieri, Andrea; Quaglia, Marco; Manes, Massimo; Vaccaro, Valentina; Marcuccio, Cristina; Licata, Carolina; Patti, Rosaria; Mariano, Filippo; Bongi, Anna Maria; Biamino, Ercole; Boschetti, Maria Antonietta; Della Volpe, Mario; Malcangi, Ugo; Baroni, Adriana; Vagelli, Giuseppe; Costantini, Luigia; Salomone, Mario; Formica, Marco; Caramello, Elisa; Campo, Andrea; Pignone, Eugenia; Messuerotti, Alessandra; Roccatello, Dario; Stratta, Piero; Segoloni, Giuseppe; Coppo, Rosanna

2012-01-01

In 2010 a questionnaire was administered to the renal units of Piedmont and Valle d'Aosta to analyze their procedures for renal biopsy (RB). Seventy-eight percent of units performed RBs, 57% for more than 20 years, but only 43% performed at least 20 BRs per year. 20/21 units performed RB in an inpatient setting and 1/21 in day hospital with the patient remaining under observation the night after. Thirty-two percent did not consider a single kidney as a contraindication to RB, 59% considered it a relative contraindication and 9% considered it an absolute contraindication. In 90.5% of units there was a specific protocol for patient preparation for RB and 86% used a specific informed consent form. Ninety-five percent of units performed ultrasound-guided RB, 60% of them using needle guides attached to the probe. In 81% of units the left side was preferred; 71% put a pillow under the patient's abdomen. All units used disposable, automated or semi-automated needles. Needle size was 16G in 29%, 18G in 58%, and both 16G and 18G in 14% of units; 1 to 3 samples were drawn. One third of units had a microscope available for immediate evaluation of specimen adequacy. After RB, 86% of units kept patients in the prone position for 2-6 hours and all prescribed a period of bed rest (at least 24 hours in 90.5%). 90.5% of units followed a specific postbiopsy observation protocol consisting of blood pressure, heart rate and red blood cell measurements at different times, and urine monitoring and ultrasound control within 12-24 hours (only half of them also employing color Doppler). One third of all units discharged patients after 1 day and two thirds after 2-3 days; all prescribed abstention from effort and from antiplatelet drugs for 7-15 days. In 9 units both RB and tissue processing and examination were done in the same hospital, while 12 units sent the samples elsewhere. 76% obtained results in 2-4 days, 19% in 6-7 days, and 5% in 10-15 days. Less than 20% of the interviewed operators were fully familiar with the clauses of hospital insurance securing their activity. Use of RB is widespread in Piedmont and Valle d'Aosta but its practice shows variation between centers.

Relative efficiency and sample size for cluster randomized trials with variable cluster sizes.

PubMed

You, Zhiying; Williams, O Dale; Aban, Inmaculada; Kabagambe, Edmond Kato; Tiwari, Hemant K; Cutter, Gary

2011-02-01

The statistical power of cluster randomized trials depends on two sample size components, the number of clusters per group and the numbers of individuals within clusters (cluster size). Variable cluster sizes are common and this variation alone may have significant impact on study power. Previous approaches have taken this into account by either adjusting total sample size using a designated design effect or adjusting the number of clusters according to an assessment of the relative efficiency of unequal versus equal cluster sizes. This article defines a relative efficiency of unequal versus equal cluster sizes using noncentrality parameters, investigates properties of this measure, and proposes an approach for adjusting the required sample size accordingly. We focus on comparing two groups with normally distributed outcomes using t-test, and use the noncentrality parameter to define the relative efficiency of unequal versus equal cluster sizes and show that statistical power depends only on this parameter for a given number of clusters. We calculate the sample size required for an unequal cluster sizes trial to have the same power as one with equal cluster sizes. Relative efficiency based on the noncentrality parameter is straightforward to calculate and easy to interpret. It connects the required mean cluster size directly to the required sample size with equal cluster sizes. Consequently, our approach first determines the sample size requirements with equal cluster sizes for a pre-specified study power and then calculates the required mean cluster size while keeping the number of clusters unchanged. Our approach allows adjustment in mean cluster size alone or simultaneous adjustment in mean cluster size and number of clusters, and is a flexible alternative to and a useful complement to existing methods. Comparison indicated that we have defined a relative efficiency that is greater than the relative efficiency in the literature under some conditions. Our measure of relative efficiency might be less than the measure in the literature under some conditions, underestimating the relative efficiency. The relative efficiency of unequal versus equal cluster sizes defined using the noncentrality parameter suggests a sample size approach that is a flexible alternative and a useful complement to existing methods.

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

Pawellek, Nicole; Krivov, Alexander V.; Marshall, Jonathan P.

The radii of debris disks and the sizes of their dust grains are important tracers of the planetesimal formation mechanisms and physical processes operating in these systems. Here we use a representative sample of 34 debris disks resolved in various Herschel Space Observatory (Herschel is an ESA space observatory with science instruments provided by European-led Principal Investigator consortia and with important participation from NASA) programs to constrain the disk radii and the size distribution of their dust. While we modeled disks with both warm and cold components, and identified warm inner disks around about two-thirds of the stars, we focusmore » our analysis only on the cold outer disks, i.e., Kuiper-belt analogs. We derive the disk radii from the resolved images and find a large dispersion for host stars of any spectral class, but no significant trend with the stellar luminosity. This argues against ice lines as a dominant player in setting the debris disk sizes, since the ice line location varies with the luminosity of the central star. Fixing the disk radii to those inferred from the resolved images, we model the spectral energy distribution to determine the dust temperature and the grain size distribution for each target. While the dust temperature systematically increases toward earlier spectral types, the ratio of the dust temperature to the blackbody temperature at the disk radius decreases with the stellar luminosity. This is explained by a clear trend of typical sizes increasing toward more luminous stars. The typical grain sizes are compared to the radiation pressure blowout limit s {sub blow} that is proportional to the stellar luminosity-to-mass ratio and thus also increases toward earlier spectral classes. The grain sizes in the disks of G- to A-stars are inferred to be several times s {sub blow} at all stellar luminosities, in agreement with collisional models of debris disks. The sizes, measured in the units of s {sub blow}, appear to decrease with the luminosity, which may be suggestive of the disk's stirring level increasing toward earlier-type stars. The dust opacity index β ranges between zero and two, and the size distribution index q varies between three and five for all the disks in the sample.« less

Influence of human papillomavirus on the clinical presentation of oropharyngeal carcinoma in the United States.

PubMed

Stenmark, Matthew H; Shumway, Dean; Guo, Cui; Vainshtein, Jeffrey; Mierzwa, Michelle; Jagsi, Reshma; Griggs, Jennifer J; Banerjee, Mousumi

2017-10-01

Much of what is known about the significance of human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma is derived from single-institution retrospective studies, post hoc analyses of tissue specimens from clinical trials, and tissue bank studies with a small sample size. The objective of this study is to investigate the impact of HPV on the frequency and clinical presentation of oropharyngeal carcinoma in a large, national sample with information from patients who underwent HPV testing. Retrospective, cross-sectional study. We identified a comprehensive national sample of 8,359 patients with oropharyngeal carcinoma and known HPV status diagnosed between 2010 and 2011 within the National Cancer Database. Multivariable logistic regression was used to assess correlates of patient and tumor characteristics on HPV status. Among patients with oropharyngeal carcinoma, the frequency of HPV-related squamous cell carcinoma in the United States was 65.4%. HPV-related oropharyngeal carcinoma was associated with younger age, male sex, and white race (P < 0.001). Advanced primary tumor stage was associated with HPV-negative disease (P < 0.001), whereas increasing nodal burden was associated with HPV-positive disease (P < 0.001). Despite less-advanced nodal disease, HPV-negative tumors were associated with a higher likelihood of metastasis at presentation (P < 0.001). HPV now accounts for the majority of newly diagnosed oropharyngeal carcinoma in the United States and is associated with a distinct clinical profile, supporting efforts to re-evaluate the staging and treatment paradigm for HPV-associated oropharyngeal cancer. 4. Laryngoscope, 127:2270-2278, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

Concentrations of selected constituents in surface-water and streambed-sediment samples collected from streams in and near an area of oil and natural-gas development, south-central Texas, 2011-13

USGS Publications Warehouse

Opsahl, Stephen P.; Crow, Cassi L.

2014-01-01

During collection of streambed-sediment samples, additional samples from a subset of three sites (the SAR Elmendorf, SAR 72, and SAR McFaddin sites) were processed by using a 63-µm sieve on one aliquot and a 2-mm sieve on a second aliquot for PAH and n-alkane analyses. The purpose of analyzing PAHs and n-alkanes on a sample containing sand, silt, and clay versus a sample containing only silt and clay was to provide data that could be used to determine if these organic constituents had a greater affinity for silt- and clay-sized particles relative to sand-sized particles. The greater concentrations of PAHs in the <63-μm size-fraction samples at all three of these sites are consistent with a greater percentage of binding sites associated with fine-grained (<63 μm) sediment versus coarse-grained (<2 mm) sediment. The larger difference in total PAHs between the <2-mm and <63-μm size-fraction samples at the SAR Elmendorf site might be related to the large percentage of sand in the <2-mm size-fraction sample which was absent in the <63-μm size-fraction sample. In contrast, the <2-mm size-fraction sample collected from the SAR McFaddin site contained very little sand and was similar in particle-size composition to the <63-μm size-fraction sample.

Demographics of the gay and lesbian population in the United States: evidence from available systematic data sources.

PubMed

Black, D; Gates, G; Sanders, S; Taylor, L

2000-05-01

This work provides an overview of standard social science data sources that now allow some systematic study of the gay and lesbian population in the United States. For each data source, we consider how sexual orientation can be defined, and we note the potential sample sizes. We give special attention to the important problem of measurement error, especially the extent to which individuals recorded as gay and lesbian are indeed recorded correctly. Our concern is that because gays and lesbians constitute a relatively small fraction of the population, modest measurement problems could lead to serious errors in inference. In examining gays and lesbians in multiple data sets we also achieve a second objective: We provide a set of statistics about this population that is relevant to several current policy debates.

Geology and assessment of undiscovered oil and gas resources of the Chukchi Borderland Province, 2008

USGS Publications Warehouse

Bird, Kenneth J.; Houseknecht, David W.; Moore, Thomas E.; Gautier, Donald L.

2017-12-22

The Chukchi Borderland is both a stand-alone petroleum province and assessment unit (AU) that lies north of the Chukchi Sea. It is a bathymetrically high-standing block of continental crust that was probably rifted from the Canadian continental margin. The sum of our knowledge of this province is based upon geophysical data (seismic, gravity, and magnetic) and a limited number of seafloor core and dredge samples. As expected from the limited data set, the basin’s petroleum potential is poorly known. A single assessment unit, the Chukchi Borderland AU, was defined and assigned an overall probability of about a 5 percent chance of at least one petroleum accumulation >50 million barrels of oil equivalent (MMBOE). No quantitative assessment of sizes and numbers of petroleum accumulations was conducted for this AU.

Collecting Research-Grade Data With Volunteers: A Case Study from Montana's Wilderness to the Sea

NASA Astrophysics Data System (ADS)

Kautz, M.

2016-12-01

Collecting Research-Grade Data With Volunteers: A Case Study from Montana's Wilderness Waterways to the SeaKautz, M (1), Barrows, A (2)(1) Adventurers and Scientists for Conservation. Bozeman, Montana, United States - mike@adventureandscience.org(2) College of the Atlantic. Bar Harbor, Maine, United States - abby.barrows@coa.eduSince World War II, global plastic production and consumption has increased dramatically. Plastics released into the environment may break down into smaller pieces through physical, biological and chemical processes. These small particles, referred to as microplastics, are less than 5mm in size and are a pollutant of emerging concern in both marine and freshwater environments. Since 2013, researcher Abigail Barrows and ASC have been conducting a global survey of microplastic distribution by utilizing the outdoor skills of adventurers. ASC recruits, trains and manages volunteers with specialized skills (surfers, long-distance open-ocean rowers, sailors, hikers, mountaineers, kayakers and others) to collect marine and freshwater samples from remote environments. Of the nearly 1500 samples collected worldwide to date (from areas as remote as the edge of Antarctica and the wilderness of Alaska) 90% contain microplastic, with an average of 8 pieces/1L of water. Samples are also in preparation for micro-Raman spectroscopy to determine source materials. In 2016 and 2017 the survey is focusing on freshwater around the globe. In the United States samples are being collected from the length of the 4th longest river system in the world, the Missouri-Mississippi. ASC has adventurous citizen scientists sampling in the mountain headwaters near Yellowstone National Park to the delta of the Mississippi River near New Orleans. This citizen-driven observation allows research at a geographic scale simply not possible through traditional methods. ASC works closely with Barrows and other researchers to develop water sampling protocols that allow volunteers to collect research grade data. This includes the use of POV cameras to review volunteers' sample collection methods, incorporating self-assessment into data collection, online training and refreshers, and app-based field data recording.

Study samples are too small to produce sufficiently precise reliability coefficients.

PubMed

Charter, Richard A

2003-04-01

In a survey of journal articles, test manuals, and test critique books, the author found that a mean sample size (N) of 260 participants had been used for reliability studies on 742 tests. The distribution was skewed because the median sample size for the total sample was only 90. The median sample sizes for the internal consistency, retest, and interjudge reliabilities were 182, 64, and 36, respectively. The author presented sample size statistics for the various internal consistency methods and types of tests. In general, the author found that the sample sizes that were used in the internal consistency studies were too small to produce sufficiently precise reliability coefficients, which in turn could cause imprecise estimates of examinee true-score confidence intervals. The results also suggest that larger sample sizes have been used in the last decade compared with those that were used in earlier decades.

Analysis of Sample Size, Counting Time, and Plot Size from an Avian Point Count Survey on Hoosier National Forest, Indiana

Treesearch

Frank R. Thompson; Monica J. Schwalbach

1995-01-01

We report results of a point count survey of breeding birds on Hoosier National Forest in Indiana. We determined sample size requirements to detect differences in means and the effects of count duration and plot size on individual detection rates. Sample size requirements ranged from 100 to >1000 points with Type I and II error rates of <0.1 and 0.2. Sample...

24 CFR 982.613 - Group home: Rent and voucher housing assistance payment.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT SECTION 8 TENANT BASED ASSISTANCE: HOUSING CHOICE VOUCHER PROGRAM... standard—(1) Family unit size. (i) Unless there is a live-in aide, the family unit size is zero or one...

Physical Volcanology and Geochemistry of the Brown's Creek Rhyolite Lava in the Western Snake River Plain, Idaho.

NASA Astrophysics Data System (ADS)

Steenberg, L.; Gruber, B.; Boroughs, S.; Wolff, J.

2015-12-01

The Brown's Creek rhyolite (BCR), ~70 km south of Boise, Idaho, erupted during a period of widespread rhyolitic volcanism in southwestern Idaho during the middle Miocene. However, the Brown's Creek unit has several characteristics that are unusual relative to near contemporaneous units in the Central Snake Rive Plain (CSRP) and units in the Western Snake River Plain (WSRP). The BCR can contain up to 40% phenocrysts, with some feldspar and quartz crystals in excess of 2 cm in diameter. A proximal vent location is particularly well exposed in the BCR, and appears as an elongated topographic "dome" with pervasive, chaotic and steep flow banding, ramp structures, and breccias. Evidence of dome building activity is also represented by a matrix supported deposit of ash and poorly sorted, angular, rhyolite clasts up to boulder size; which crops out in a small area near the vent. The BCR is among numerous units in the CSRP and WSRP that show evidence of interaction with ancient Lake Idaho (e.g. silicification, opalized zones, pepperites, etc), but the unconformity with the sedimentary rocks of the lake and its feeder streams, is extremely well preserved in the Brown's Creek rhyolite. Geochemically, the Brown's Creek rhyolite shows greater compositional variation in comparison to other individual units in the region. This variation (e.g. Ba/Sr and Zr/Nb) may be a result of variable crystal cargo in hand samples, but could potentially represent a zoned magma body, which is also extremely rare in the CSRP or WSRP. A limited number of samples have trace element concentrations/ratios (e.g. Rb, U, and Th) that may indicate the presence of a second unit underlying the dominant outcrops of BCR, but Nb/Ta ratios are relatively invariant across the entire BCR suite; if there are two units in the BCR, their sources are the same or very similar.

A double Fe-Ti oxide and Fe-sulphide liquid immiscibility in the Itsindro Gabbro Complex, Madagascar

NASA Astrophysics Data System (ADS)

Augé, Thierry; Bailly, Laurent; Roig, Jean-Yves

2017-11-01

The petrology and mineralogy of the Itsindro complex in south-central Madagascar has been investigated through samples obtained from the 320.7 m-deep Lanjanina borehole. The section consists of a 254 m-thick pyroxenite unit with interbedded gabbro layers that overlies a gabbro unit and is itself overlain by a 19 m-thick granite unit. Most of the structures are sub-horizontal. A weak magmatic layering is locally observed but at the scale of the core, the intrusion does not appear to be a layered complex. Pyroxenite and gabbro show a systematic disseminated mineralization consisting of Fe-Ti-P oxides and Fe-(Cu-Ni) sulphides that takes the form of ilmenite-titanomagnetite ± apatite and pyrrhotite ± chalcopyrite ± pentlandite. In the upper zone, from 90 to 72 m, sub-massive centimetre-to decimetre-sized layers of oxides and sulphides comprise a total of 16 m of sub-massive sulphide (the main mineralized zone). In this mineralized zone the oxide/sulphide ratio is close to 1/1. The sulphide is strongly dominated by pyrrhotite, which may locally contain inclusions of molybdenite crystals with the Re sulphide rheniite (ReS2). Oxides are generally euhedral, included in or attached to the Fe-sulphide, and also locally form sub-massive centimetre-sized bands. Apatite as a cumulus phase is ubiquitous. Locally it may account for 30% of the ore-rich samples and some samples consist of apatite-Fe-Ti oxides-Fe-Cu-Ni sulphides with virtually no silicate. Apatite is the main REE carrier but the total REE content remains low (<90 ppm). Mineral compositions and whole rock geochemistry indicate that the rocks are highly differentiated, and in spite of a relatively limited thickness, the differentiation process is observed. Two zones can be distinguished: from the bottom to 162.8 m we see a decrease in the Mg number of olivine and pyroxene, and a drop in TiO2 and Al2O3 for the latter. A reverse trend is then observed within the pyroxenite unit from the 162.8 m level upwards. The main mineralized zone is located in the upper part of this unit, about 70 m above this discontinuity. The highly differentiated Fe-Ti-P facies of the Lanjanina series in the Itsindro Gabbro Complex have been interpreted as corresponding to the Fe-Ti-P rich, Si-poor member remaining after an immiscible segregation of an evolved mafic magma. The granite dykes and the overlying granite unit represent the second, Si-rich member of the immiscibility process. The presence of large amounts of sulphide is attributed to sulphur contamination of the Fe-Ti-rich liquid. Fe-Ti oxides will tend to crystallize on the sulphide droplets and the accumulation of dense Fe-sulphides (liquid) and associated Fe-Ti oxides (solid) will result in this complex and unusual association taking the form of a net texture.

Immunochemical quantitation, size distribution, and cross-reactivity of lepidoptera (moth) aeroallergens in southeastern Minnesota

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

Wynn, S.R.; Swanson, M.C.; Reed, C.E.

1988-07-01

With an immunochemical method, we analyzed outdoor air samples during a 3-year period for concentrations of the predominant local species of moth, Pseudaletia unipuncta (Haworth). Airborne particulates were collected on fiberglass filter sheets with an Accu-Vol sampler located 1.5 m above ground on the southeastern Minnesota prairie. Filter eluates analyzed by RIA inhibition contained concentrations of moth protein peaking in June and August to September of each year, with levels comparable to reported immunochemically measured levels of pollen and mold allergens. These peaks also corresponded with total numbers of moths captured in light traps. Moth-allergen activity was distributed in particlemore » sizes ranging from 0.8 to greater than 4.1 micron when sized samples were obtained by use of an Andersen cascade impaction head. By RIA inhibition, there was cross-reactivity between P. unipuncta and insects of different genera, families, and orders, but not with pollens or molds. Forty-five percent of 257 patients with immediate positive skin tests to common aeroallergens had positive skin tests to one or more commercially available whole body insect extracts. Of 120 patients with allergic rhinitis believed to be primarily caused by ragweed sensitivity, 5% also had elevated specific IgE to moths. We conclude that airborne concentrations of Lepidoptera can be measured immunochemically and that moths may be a seasonal allergen in the United States.« less

Integration of bed characteristics, geochemical tracers, current measurements, and numerical modeling for assessing the provenance of beach sand in the San Francisco Bay Coastal System

USGS Publications Warehouse

Barnard, Patrick L.; Foxgrover, Amy C.; Elias, Edwin P.L.; Erikson, Li H.; Hein, James; McGann, Mary; Mizell, Kira; Rosenbauer, Robert J.; Swarzenski, Peter W.; Takesue, Renee K.; Wong, Florence L.; Woodrow, Don

2013-01-01

Over 150 million m3 of sand-sized sediment has disappeared from the central region of the San Francisco Bay Coastal System during the last half century. This enormous loss may reflect numerous anthropogenic influences, such as watershed damming, bay-fill development, aggregate mining, and dredging. The reduction in Bay sediment also appears to be linked to a reduction in sediment supply and recent widespread erosion of adjacent beaches, wetlands, and submarine environments. A unique, multi-faceted provenance study was performed to definitively establish the primary sources, sinks, and transport pathways of beach-sized sand in the region, thereby identifying the activities and processes that directly limit supply to the outer coast. This integrative program is based on comprehensive surficial sediment sampling of the San Francisco Bay Coastal System, including the seabed, Bay floor, area beaches, adjacent rock units, and major drainages. Analyses of sample morphometrics and biological composition (e.g., Foraminifera) were then integrated with a suite of tracers including 87Sr/86Sr and 143Nd/144Nd isotopes, rare earth elements, semi-quantitative X-ray diffraction mineralogy, and heavy minerals, and with process-based numerical modeling, in situ current measurements, and bedform asymmetry to robustly determine the provenance of beach-sized sand in the region.

Comprehensive characterisation of atmospheric aerosols in Budapest, Hungary: physicochemical properties of inorganic species

NASA Astrophysics Data System (ADS)

Salma, Imre; Maenhaut, Willy; Zemplén-Papp, Éva; Záray, Gyula

As part of an air pollution project in Budapest, aerosol samples were collected by stacked filter units and cascade impactors at an urban background site, two downtown sites, and within a road tunnel in field campaigns conducted in 1996, 1998 and 1999. Some criteria pollutants were also measured at one of the downtown sites. The aerosol samples were analysed by one or more of the following methods: instrumental neutron activation analysis, particle-induced X-ray emission analysis, a light reflection technique, gravimetry, thermal profiling carbon analysis and capillary electrophoresis. The quantities measured or derived include atmospheric concentrations of elements (from Na to U), of particulate matter, of black and elemental carbon, and total carbonaceous fraction, of some ionic species (e.g., nitrate and sulphate) in the fine ( <2 μm equivalent aerodynamic diameter, EAD) or in both coarse (10- 2 μm EAD) and fine size fractions, atmospheric concentrations of NO, NO 2, SO 2, CO and total suspended particulate matter, and meteorological parameters. The analytical results were used for characterisation of the concentration levels, elemental composition, time trends, enrichment of and relationships among the aerosol species in coarse and fine size fractions, for studying their fine-to-coarse concentration ratios, spatial and temporal variability, for determining detailed elemental mass size distributions, and for examining the extent of chemical mass closure.

Habitat use by elk (cervus elaphus) within structural stages of a managed forest of the northcentral United States

Treesearch

Mark A. Rumble; R. Scott Gamo

2011-01-01

Timber management is the most prominent land management activity in the Black Hills National Forest in the northcentral United States. Management units are stands 4-32 ha in size and are described using a hierarchal vegetative description including vegetation type, size class (age), and overstory canopy cover. For the most part, these stands are relatively homogeneous...

Estimating Most Productive Scale Size in Data Envelopment Analysis with Integer Value Data

NASA Astrophysics Data System (ADS)

Dwi Sari, Yunita; Angria S, Layla; Efendi, Syahril; Zarlis, Muhammad

2018-01-01

The most productive scale size (MPSS) is a measurement that states how resources should be organized and utilized to achieve optimal results. The most productive scale size (MPSS) can be used as a benchmark for the success of an industry or company in producing goods or services. To estimate the most productive scale size (MPSS), each decision making unit (DMU) should pay attention the level of input-output efficiency, by data envelopment analysis (DEA) method decision making unit (DMU) can identify units used as references that can help to find the cause and solution from inefficiencies can optimize productivity that main advantage in managerial applications. Therefore, data envelopment analysis (DEA) is chosen to estimating most productive scale size (MPSS) that will focus on the input of integer value data with the CCR model and the BCC model. The purpose of this research is to find the best solution for estimating most productive scale size (MPSS) with input of integer value data in data envelopment analysis (DEA) method.

Controlling of dielectrical properties of hydroxyapatite by ethylenediamine tetraacetic acid (EDTA) for bone healing applications.

PubMed

Kaygili, Omer; Ates, Tankut; Keser, Serhat; Al-Ghamdi, Ahmed A; Yakuphanoglu, Fahrettin

2014-08-14

The hydroxyapatite (HAp) samples in the presence of various amounts of ethylenediamine tetraacetic acid (EDTA) were prepared by sol-gel method. The effects of EDTA on the crystallinity, phase structure, chemical, micro-structural and dielectric properties of HAp samples were investigated. With the addition of EDTA, the average crystallite size of the HAp samples is gradually decreased from 30 to 22 nm and the crystallinity is in the range of 65-71%. The values of the lattice parameters (a and c) and volume of the unit cell are decreased by stages with the addition of EDTA. The dielectric parameters such as relative permittivity, dielectric loss and relaxation time are affected by the adding of EDTA. The alternating current conductivity of the as-synthesized hydroxyapatites increases with the increasing frequency and obeys the universal power law behavior. The HAp samples exhibit a non-Debye relaxation mechanism. The obtained results that the dielectrical parameters of the HAp sample can be controlled by EDTA. Copyright © 2014 Elsevier B.V. All rights reserved.

The quality of the reported sample size calculations in randomized controlled trials indexed in PubMed.

PubMed

Lee, Paul H; Tse, Andy C Y

2017-05-01

There are limited data on the quality of reporting of information essential for replication of the calculation as well as the accuracy of the sample size calculation. We examine the current quality of reporting of the sample size calculation in randomized controlled trials (RCTs) published in PubMed and to examine the variation in reporting across study design, study characteristics, and journal impact factor. We also reviewed the targeted sample size reported in trial registries. We reviewed and analyzed all RCTs published in December 2014 with journals indexed in PubMed. The 2014 Impact Factors for the journals were used as proxies for their quality. Of the 451 analyzed papers, 58.1% reported an a priori sample size calculation. Nearly all papers provided the level of significance (97.7%) and desired power (96.6%), and most of the papers reported the minimum clinically important effect size (73.3%). The median (inter-quartile range) of the percentage difference of the reported and calculated sample size calculation was 0.0% (IQR -4.6%;3.0%). The accuracy of the reported sample size was better for studies published in journals that endorsed the CONSORT statement and journals with an impact factor. A total of 98 papers had provided targeted sample size on trial registries and about two-third of these papers (n=62) reported sample size calculation, but only 25 (40.3%) had no discrepancy with the reported number in the trial registries. The reporting of the sample size calculation in RCTs published in PubMed-indexed journals and trial registries were poor. The CONSORT statement should be more widely endorsed. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Distribution of the two-sample t-test statistic following blinded sample size re-estimation.

PubMed

Lu, Kaifeng

2016-05-01

We consider the blinded sample size re-estimation based on the simple one-sample variance estimator at an interim analysis. We characterize the exact distribution of the standard two-sample t-test statistic at the final analysis. We describe a simulation algorithm for the evaluation of the probability of rejecting the null hypothesis at given treatment effect. We compare the blinded sample size re-estimation method with two unblinded methods with respect to the empirical type I error, the empirical power, and the empirical distribution of the standard deviation estimator and final sample size. We characterize the type I error inflation across the range of standardized non-inferiority margin for non-inferiority trials, and derive the adjusted significance level to ensure type I error control for given sample size of the internal pilot study. We show that the adjusted significance level increases as the sample size of the internal pilot study increases. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

ENHANCEMENT OF LEARNING ON SAMPLE SIZE CALCULATION WITH A SMARTPHONE APPLICATION: A CLUSTER-RANDOMIZED CONTROLLED TRIAL.

PubMed

Ngamjarus, Chetta; Chongsuvivatwong, Virasakdi; McNeil, Edward; Holling, Heinz

2017-01-01

Sample size determination usually is taught based on theory and is difficult to understand. Using a smartphone application to teach sample size calculation ought to be more attractive to students than using lectures only. This study compared levels of understanding of sample size calculations for research studies between participants attending a lecture only versus lecture combined with using a smartphone application to calculate sample sizes, to explore factors affecting level of post-test score after training sample size calculation, and to investigate participants’ attitude toward a sample size application. A cluster-randomized controlled trial involving a number of health institutes in Thailand was carried out from October 2014 to March 2015. A total of 673 professional participants were enrolled and randomly allocated to one of two groups, namely, 341 participants in 10 workshops to control group and 332 participants in 9 workshops to intervention group. Lectures on sample size calculation were given in the control group, while lectures using a smartphone application were supplied to the test group. Participants in the intervention group had better learning of sample size calculation (2.7 points out of maximnum 10 points, 95% CI: 24 - 2.9) than the participants in the control group (1.6 points, 95% CI: 1.4 - 1.8). Participants doing research projects had a higher post-test score than those who did not have a plan to conduct research projects (0.9 point, 95% CI: 0.5 - 1.4). The majority of the participants had a positive attitude towards the use of smartphone application for learning sample size calculation.

Size- and pressure-controlled ferromagnetism in LaCoO3 nanoparticles

NASA Astrophysics Data System (ADS)

Fita, I.; Markovich, V.; Mogilyansky, D.; Puzniak, R.; Wisniewski, A.; Titelman, L.; Vradman, L.; Herskowitz, M.; Varyukhin, V. N.; Gorodetsky, G.

2008-06-01

Magnetic properties of nanocrystalline LaCoO3 with particle size of 25, 30, 32, and 38 nm, prepared by the citrate method, were investigated in temperature range 2-320 K, magnetic field up to 50 kOe, and under hydrostatic pressure up to 11 kbar. All nanoparticles exhibit weak ferromagnetism below TC≈85K , in agreement with recent observation on LaCoO3 particles and tensile thin films. It was found that with decreasing particle size, i.e., with increasing the surface to volume ratio, the unit-cell volume increases monotonically due to the surface effect. The ferromagnetic moment increases as well, simultaneously with lattice expansion, whereas TC remains nearly unchanged. On the other hand, an applied hydrostatic pressure suppresses strongly the ferromagnetic phase leading to its full disappearance at 10 kbar, while the TC does not change visibly under pressure. It appears that the ferromagnetism in LaCoO3 nanoparticles is controlled by the unit-cell volume. This clear correlation suggests that the nature of ferromagnetic ground state of LaCoO3 is likely related to orbitally ordered Jahn-Teller active Co3+ ions with intermediate-spin (IS) state, which may persist in the expanded lattice at low temperatures. A robust orbital order presumed among the IS Co3+ species can explain the very stable TC observed for LaCoO3 samples prepared under different conditions: single crystal powders, nanoparticles, and thin films.

Estimation method for serial dilution experiments.

PubMed

Ben-David, Avishai; Davidson, Charles E

2014-12-01

Titration of microorganisms in infectious or environmental samples is a corner stone of quantitative microbiology. A simple method is presented to estimate the microbial counts obtained with the serial dilution technique for microorganisms that can grow on bacteriological media and develop into a colony. The number (concentration) of viable microbial organisms is estimated from a single dilution plate (assay) without a need for replicate plates. Our method selects the best agar plate with which to estimate the microbial counts, and takes into account the colony size and plate area that both contribute to the likelihood of miscounting the number of colonies on a plate. The estimate of the optimal count given by our method can be used to narrow the search for the best (optimal) dilution plate and saves time. The required inputs are the plate size, the microbial colony size, and the serial dilution factors. The proposed approach shows relative accuracy well within ±0.1log10 from data produced by computer simulations. The method maintains this accuracy even in the presence of dilution errors of up to 10% (for both the aliquot and diluent volumes), microbial counts between 10(4) and 10(12) colony-forming units, dilution ratios from 2 to 100, and plate size to colony size ratios between 6.25 to 200. Published by Elsevier B.V.

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico and Texas; organic compounds and trace elements in bed sediment and fish tissue, 1992-93

USGS Publications Warehouse

Carter, L.F.; Anderholm, S.K.

1997-01-01

The occurrence and distribution of contaminants in aquatic systems are major components of the National Water-Quality Assessment (NAWQA) Program. Bed-sediment samples were collected at 18 sites in the Rio Grande Valley study unit between September 1992 and March 1993 to characterize the geographic distribution of organic compounds, including chlorinated insecticides, polychlorinated biphenyls (PCB's), and other chlorinated hydrocarbons, and also trace elements. Two-millimeter-size- fraction sediment was analyzed for organic compounds and less than 63-micron-size-fraction sediment was analyzed for trace elements. Concentrations of p,p'-DDE were detected in 33 percent of the bed-sediment samples. With the exception of DDT-related compounds, no other organochlorine insecticides or polychlorinated biphenyls were detected in samples of bed sediment. Whole-body fish samples were collected at 11 of the bed- sediment sites and analyzed for organic compounds. Organic compounds were reported more frequently in samples of fish, and more types of organic compounds were found in whole-body fish samples than in bed-sediment samples. Concentrations of p,p'-DDE were detected in 91 percent of whole-body fish samples. Polychlorinated biphenyls, cis-chlordane, trans-chlordane, trans- nonachlor, and hexachlorobenzene were other organic compounds detected in whole-body samples of fish from at least one site. Because of the extent of mineralized areas in the Rio Grande Basin arsenic, cadmium, copper, lead, mercury, selenium, and zinc concentrations in bed-sediment samples could represent natural conditions at most sites. However, a combination of natural conditions and human activities appears to be associated with elevated trace-element concentrations in the bed-sediment sample from the site Rio Grande near Creede, Colorado, because this sample exceeded the background trace-element concentrations calculated for this study. Fish-liver samples were collected at 12 of the bed-sediment sites and analyzed for trace elements. Certain trace elements were detected at higher concentrations in fish-liver samples than in bed-sediment samples from the same site. Both bed-sediment and fish-tissue samples are necessary for a complete environmental assessment of the occurrence and distribution of trace elements.

Developing the Noncentrality Parameter for Calculating Group Sample Sizes in Heterogeneous Analysis of Variance

ERIC Educational Resources Information Center

Luh, Wei-Ming; Guo, Jiin-Huarng

2011-01-01

Sample size determination is an important issue in planning research. In the context of one-way fixed-effect analysis of variance, the conventional sample size formula cannot be applied for the heterogeneous variance cases. This study discusses the sample size requirement for the Welch test in the one-way fixed-effect analysis of variance with…

Sample Size Determination for Regression Models Using Monte Carlo Methods in R

ERIC Educational Resources Information Center

Beaujean, A. Alexander

2014-01-01

A common question asked by researchers using regression models is, What sample size is needed for my study? While there are formulae to estimate sample sizes, their assumptions are often not met in the collected data. A more realistic approach to sample size determination requires more information such as the model of interest, strength of the…

Nomogram for sample size calculation on a straightforward basis for the kappa statistic.

PubMed

Hong, Hyunsook; Choi, Yunhee; Hahn, Seokyung; Park, Sue Kyung; Park, Byung-Joo

2014-09-01

Kappa is a widely used measure of agreement. However, it may not be straightforward in some situation such as sample size calculation due to the kappa paradox: high agreement but low kappa. Hence, it seems reasonable in sample size calculation that the level of agreement under a certain marginal prevalence is considered in terms of a simple proportion of agreement rather than a kappa value. Therefore, sample size formulae and nomograms using a simple proportion of agreement rather than a kappa under certain marginal prevalences are proposed. A sample size formula was derived using the kappa statistic under the common correlation model and goodness-of-fit statistic. The nomogram for the sample size formula was developed using SAS 9.3. The sample size formulae using a simple proportion of agreement instead of a kappa statistic and nomograms to eliminate the inconvenience of using a mathematical formula were produced. A nomogram for sample size calculation with a simple proportion of agreement should be useful in the planning stages when the focus of interest is on testing the hypothesis of interobserver agreement involving two raters and nominal outcome measures. Copyright © 2014 Elsevier Inc. All rights reserved.

30 CFR 70.207 - Bimonthly sampling; mechanized mining units.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Bimonthly sampling; mechanized mining units. 70... Bimonthly sampling; mechanized mining units. (a) Each operator shall take five valid respirable dust samples from the designated occupation in each mechanized mining unit during each bimonthly period beginning...

Sample size calculation in cost-effectiveness cluster randomized trials: optimal and maximin approaches.

PubMed

Manju, Md Abu; Candel, Math J J M; Berger, Martijn P F

2014-07-10

In this paper, the optimal sample sizes at the cluster and person levels for each of two treatment arms are obtained for cluster randomized trials where the cost-effectiveness of treatments on a continuous scale is studied. The optimal sample sizes maximize the efficiency or power for a given budget or minimize the budget for a given efficiency or power. Optimal sample sizes require information on the intra-cluster correlations (ICCs) for effects and costs, the correlations between costs and effects at individual and cluster levels, the ratio of the variance of effects translated into costs to the variance of the costs (the variance ratio), sampling and measuring costs, and the budget. When planning, a study information on the model parameters usually is not available. To overcome this local optimality problem, the current paper also presents maximin sample sizes. The maximin sample sizes turn out to be rather robust against misspecifying the correlation between costs and effects at the cluster and individual levels but may lose much efficiency when misspecifying the variance ratio. The robustness of the maximin sample sizes against misspecifying the ICCs depends on the variance ratio. The maximin sample sizes are robust under misspecification of the ICC for costs for realistic values of the variance ratio greater than one but not robust under misspecification of the ICC for effects. Finally, we show how to calculate optimal or maximin sample sizes that yield sufficient power for a test on the cost-effectiveness of an intervention.

Quantification of the resist dissolution process: an in situ analysis using high speed atomic force microscopy

NASA Astrophysics Data System (ADS)

Santillan, Julius Joseph; Shichiri, Motoharu; Itani, Toshiro

2016-03-01

This work focuses on the application of a high speed atomic force microscope (HS-AFM) for the in situ visualization / quantification of the resist dissolution process. This technique, as reported in the past, has provided useful pointers on the formation of resist patterns during dissolution. This paper discusses about an investigation made on the quantification of what we refer to as "dissolution unit size" or the basic units of patterning material dissolution. This was done through the establishment of an originally developed analysis method which extracts the difference between two succeeding temporal states of the material film surface (images) to indicate the amount of change occurring in the material film at a specific span of time. Preliminary experiments with actual patterning materials were done using a positive-tone EUV model resist composed only of polyhydroxystyrene (PHS)-based polymer with a molecular weight of 2,500 and a polydispersity index of 1.2. In the absence of a protecting group, the material was utilized at a 50nm film thickness with post application bake of 90°C/60s. The resulting film is soluble in the alkali-based developer even without exposure. Results have shown that the dissolution components (dissolution unit size) of the PHS-based material are not of fixed size. Instead, it was found that aside from one constantly dissolving unit size, another, much larger dissolution unit size trend also occurs during material dissolution. The presence of this larger dissolution unit size suggests an occurrence of "polymer clustering". Such polymer clustering was not significantly present during the initial stages of dissolution (near the original film surface) but becomes more persistently obvious after the dissolution process reaches a certain film thickness below the initial surface.

Sample size determination in group-sequential clinical trials with two co-primary endpoints

PubMed Central

Asakura, Koko; Hamasaki, Toshimitsu; Sugimoto, Tomoyuki; Hayashi, Kenichi; Evans, Scott R; Sozu, Takashi

2014-01-01

We discuss sample size determination in group-sequential designs with two endpoints as co-primary. We derive the power and sample size within two decision-making frameworks. One is to claim the test intervention’s benefit relative to control when superiority is achieved for the two endpoints at the same interim timepoint of the trial. The other is when the superiority is achieved for the two endpoints at any interim timepoint, not necessarily simultaneously. We evaluate the behaviors of sample size and power with varying design elements and provide a real example to illustrate the proposed sample size methods. In addition, we discuss sample size recalculation based on observed data and evaluate the impact on the power and Type I error rate. PMID:24676799

7 CFR 51.1438 - Size classifications for pieces.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS) United States Standards for Grades of Shelled Pecans Size Classifications § 51.1438 Size classifications for pieces. The size of pecan pieces in a lot may be specified in accordance with one of the size...

Improvement of sampling plans for Salmonella detection in pooled table eggs by use of real-time PCR.

PubMed

Pasquali, Frédérique; De Cesare, Alessandra; Valero, Antonio; Olsen, John Emerdhal; Manfreda, Gerardo

2014-08-01

Eggs and egg products have been described as the most critical food vehicles of salmonellosis. The prevalence and level of contamination of Salmonella on table eggs are low, which severely affects the sensitivity of sampling plans applied voluntarily in some European countries, where one to five pools of 10 eggs are tested by the culture based reference method ISO 6579:2004. In the current study we have compared the testing-sensitivity of the reference culture method ISO 6579:2004 and an alternative real-time PCR method on Salmonella contaminated egg-pool of different sizes (4-9 uninfected eggs mixed with one contaminated egg) and contamination levels (10°-10(1), 10(1)-10(2), 10(2)-10(3)CFU/eggshell). Two hundred and seventy samples corresponding to 15 replicates per pool size and inoculum level were tested. At the lowest contamination level real-time PCR detected Salmonella in 40% of contaminated pools vs 12% using ISO 6579. The results were used to estimate the lowest number of sample units needed to be tested in order to have a 95% certainty not falsely to accept a contaminated lot by Monte Carlo simulation. According to this simulation, at least 16 pools of 10 eggs each are needed to be tested by ISO 6579 in order to obtain this confidence level, while the minimum number of pools to be tested was reduced to 8 pools of 9 eggs each, when real-time PCR was applied as analytical method. This result underlines the importance of including analytical methods with higher sensitivity in order to improve the efficiency of sampling and reduce the number of samples to be tested. Copyright © 2013 Elsevier B.V. All rights reserved.

Method and apparatus for measuring spatial uniformity of radiation

DOEpatents

Field, Halden

2002-01-01

A method and apparatus for measuring the spatial uniformity of the intensity of a radiation beam from a radiation source based on a single sampling time and/or a single pulse of radiation. The measuring apparatus includes a plurality of radiation detectors positioned on planar mounting plate to form a radiation receiving area that has a shape and size approximating the size and shape of the cross section of the radiation beam. The detectors concurrently receive portions of the radiation beam and transmit electrical signals representative of the intensity of impinging radiation to a signal processor circuit connected to each of the detectors and adapted to concurrently receive the electrical signals from the detectors and process with a central processing unit (CPU) the signals to determine intensities of the radiation impinging at each detector location. The CPU displays the determined intensities and relative intensity values corresponding to each detector location to an operator of the measuring apparatus on an included data display device. Concurrent sampling of each detector is achieved by connecting to each detector a sample and hold circuit that is configured to track the signal and store it upon receipt of a "capture" signal. A switching device then selectively retrieves the signals and transmits the signals to the CPU through a single analog to digital (A/D) converter. The "capture" signal. is then removed from the sample-and-hold circuits. Alternatively, concurrent sampling is achieved by providing an A/D converter for each detector, each of which transmits a corresponding digital signal to the CPU. The sampling or reading of the detector signals can be controlled by the CPU or level-detection and timing circuit.

Approximate sample size formulas for the two-sample trimmed mean test with unequal variances.

PubMed

Luh, Wei-Ming; Guo, Jiin-Huarng

2007-05-01

Yuen's two-sample trimmed mean test statistic is one of the most robust methods to apply when variances are heterogeneous. The present study develops formulas for the sample size required for the test. The formulas are applicable for the cases of unequal variances, non-normality and unequal sample sizes. Given the specified alpha and the power (1-beta), the minimum sample size needed by the proposed formulas under various conditions is less than is given by the conventional formulas. Moreover, given a specified size of sample calculated by the proposed formulas, simulation results show that Yuen's test can achieve statistical power which is generally superior to that of the approximate t test. A numerical example is provided.

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

Jomekian, A.; Faculty of Chemical Engineering, Iran University of Science and Technology; Behbahani, R.M., E-mail: behbahani@put.ac.ir

Ultra porous ZIF-8 particles synthesized using PEO/PA6 based poly(ether-block-amide) (Pebax 1657) as structure directing agent. Structural properties of ZIF-8 samples prepared under different synthesis parameters were investigated by laser particle size analysis, XRD, N{sub 2} adsorption analysis, BJH and BET tests. The overall results showed that: (1) The mean pore size of all ZIF-8 samples increased remarkably (from 0.34 nm to 1.1–2.5 nm) compared to conventionally synthesized ZIF-8 samples. (2) Exceptional BET surface area of 1869 m{sup 2}/g was obtained for a ZIF-8 sample with mean pore size of 2.5 nm. (3) Applying high concentrations of Pebax 1657 to themore » synthesis solution lead to higher surface area, larger pore size and smaller particle size for ZIF-8 samples. (4) Both, Increase in temperature and decrease in molar ratio of MeIM/Zn{sup 2+} had increasing effect on ZIF-8 particle size, pore size, pore volume, crystallinity and BET surface area of all investigated samples. - Highlights: • The pore size of ZIF-8 samples synthesized with Pebax 1657 increased remarkably. • The BET surface area of 1869 m{sup 2}/gr obtained for a ZIF-8 synthesized sample with Pebax. • Increase in temperature had increasing effect on textural properties of ZIF-8 samples. • Decrease in MeIM/Zn{sup 2+} had increasing effect on textural properties of ZIF-8 samples.« less