Ethical considerations in design of a study to evaluate a US Food and Drug Administration-approved indication: antivenom versus placebo for copperhead envenomation.

PubMed

Gerardo, Charles J; Lavonas, Eric J; McKinney, Ross E

2014-10-01

In 2000, the US Food and Drug Administration approved CroFab(®) Crotalidae Polyvalent Immune Fab, ovine (FabAV), which had received orphan drug designation, for use in patients with minimal to moderate North American crotaline envenomations including copperhead snakes. As existing evidence on the effectiveness of FabAV for this indication is limited, wide practice variation in its use exists. In order to provide more definitive clinical evidence as to the role of this treatment, a new randomized, placebo-controlled trial of FabAV specifically for copperhead bites was initiated. In light of the existing US Food and Drug Administration approval, ethical considerations of participation in this trial have been raised. We discuss the ethical principles pertinent to this randomized, placebo-controlled trial with placebo arm. We apply an accepted framework for ethical research to this trial. Due to the evidence gap in the literature, wide-ranging treatment recommendations by medical experts, and broad practice variation, clinical equipoise exists in the treatment of copperhead envenomation with FabAV. The impact of this clinical equipoise on the value and scientific validity of the trial is discussed. The trial's risk-benefit ratio is also considered. Potential risks to the patients are minimized as the protocol includes a plan for rescue therapy in the event that patients progress to severe envenomation symptoms. Overall, risks are further minimized by the inclusion of an interim analysis with stopping rules based on demonstrated efficacy should the therapy clearly prove to be beneficial. Although a post-marketing clinical study of this nature is unusual for an approved indication, this trial adheres to all ethical preconditions found in existing guidelines for clinical research involving human subjects. © The Author(s) 2014.

Cumulative watershed effects: Can they be measured? What have we learned from the Caspar Creek studies in northern California?

Treesearch

R. M. Rice

1991-01-01

Cumulative Watershed Effects (CWEs) may be additive or synergistic. Additive CWEs are the accumulation downstream of the effects of various activities. Their existence is inevitable. However, their magnitude is often difficult to measure. The amount of sediment, for example, has considerable natural variation which may mask the CWEs caused by road construction or...

Application of Variational Methods to the Thermal Entrance Region of Ducts

NASA Technical Reports Server (NTRS)

Sparrow, E. M.; Siegel. R.

1960-01-01

A variational method is presented for solving eigenvalue problems which arise in connection with the analysis of convective heat transfer in the thermal entrance region of ducts. Consideration is given, to both situations where the temperature profile depends upon one cross-sectional coordinate (e.g. circular tube) or upon two cross-sectional coordinates (e.g. rectangular duct). The variational method is illustrated and verified by application to laminar heat transfer in a circular tube and a parallel-plate channel, and good agreement with existing numerical solutions is attained. Then, application is made to laminar heat transfer in a square duct as a check, an alternate computation for the square duct is made using a method indicated by Misaps and Pohihausen. The variational method can, in principle, also be applied to problems in turbulent heat transfer.

Serological Relationships Among Feline Caliciviruses

PubMed Central

Povey, R. C.

1974-01-01

A total of 46 strains of feline calicivirus isolates from the United Kingdom, United States, Australia, and New Zealand were used in an investigation of their serological relationships based on the serum neutralization test. Although demonstrable antigenic variation exists between these isolates, it is shown that significant in vitro cross-activity exists between all these isolates to greater or lesser extent. All isolates tested may be regarded as serological variants of a single serotype of feline calicivirus. It is postulated that this relationship would provide for considerable cross-protection during successive exposures of cats to various feline caliciviruses. PMID:4435957

Inter- and intraspecific variation in leaf economic traits in wheat and maize

PubMed Central

Hale, Christine E; Cerabolini, Bruno E L; Cornelissen, Johannes H C; Craine, Joseph; Gough, William A; Kattge, Jens; Tirona, Cairan K F

2018-01-01

Abstract Leaf Economics Spectrum (LES) trait variation underpins multiple agroecological processes and many prominent crop yield models. While there are numerous independent studies assessing trait variation in crops, to date there have been no comprehensive assessments of intraspecific trait variation (ITV) in LES traits for wheat and maize: the world’s most widespread crops. Using trait databases and peer-reviewed literature, we compiled over 700 records of specific leaf area (SLA), maximum photosynthetic rates (Amax) and leaf nitrogen (N) concentrations, for wheat and maize. We evaluated intraspecific LES trait variation, and intraspecific trait–environment relationships. While wheat and maize occupy the upper 90th percentile of LES trait values observed across a global species pool, ITV ranged widely across the LES in wheat and maize. Fertilization treatments had strong impacts on leaf N, while plant developmental stage (here standardized as the number of days since planting) had strong impacts on Amax; days since planting, N fertilization and irrigation all influenced SLA. When controlling for these factors, intraspecific responses to temperature and precipitation explained 39.4 and 43.7 % of the variation in Amax and SLA, respectively, but only 5.4 % of the variation in leaf N. Despite a long history of domestication in these species, ITV in wheat and maize among and within cultivars remains large. Intraspecific trait variation is a critical consideration to refine regional to global models of agroecosystem structure, function and food security. Considerable opportunities and benefits exist for consolidating a crop trait database for a wider range of domesticated plant species. PMID:29484152

Inter- and intraspecific variation in leaf economic traits in wheat and maize.

PubMed

Martin, Adam R; Hale, Christine E; Cerabolini, Bruno E L; Cornelissen, Johannes H C; Craine, Joseph; Gough, William A; Kattge, Jens; Tirona, Cairan K F

2018-02-01

Leaf Economics Spectrum (LES) trait variation underpins multiple agroecological processes and many prominent crop yield models. While there are numerous independent studies assessing trait variation in crops, to date there have been no comprehensive assessments of intraspecific trait variation (ITV) in LES traits for wheat and maize: the world's most widespread crops. Using trait databases and peer-reviewed literature, we compiled over 700 records of specific leaf area (SLA), maximum photosynthetic rates ( A max ) and leaf nitrogen (N) concentrations, for wheat and maize. We evaluated intraspecific LES trait variation, and intraspecific trait-environment relationships. While wheat and maize occupy the upper 90th percentile of LES trait values observed across a global species pool, ITV ranged widely across the LES in wheat and maize. Fertilization treatments had strong impacts on leaf N, while plant developmental stage (here standardized as the number of days since planting) had strong impacts on A max ; days since planting, N fertilization and irrigation all influenced SLA. When controlling for these factors, intraspecific responses to temperature and precipitation explained 39.4 and 43.7 % of the variation in A max and SLA, respectively, but only 5.4 % of the variation in leaf N. Despite a long history of domestication in these species, ITV in wheat and maize among and within cultivars remains large. Intraspecific trait variation is a critical consideration to refine regional to global models of agroecosystem structure, function and food security. Considerable opportunities and benefits exist for consolidating a crop trait database for a wider range of domesticated plant species.

Mercury content of the Springfield coal, Indiana and Kentucky

USGS Publications Warehouse

Hower, J.C.; Mastalerz, Maria; Drobniak, A.; Quick, J.C.; Eble, C.F.; Zimmerer, M.J.

2005-01-01

With pending regulation of mercury emissions in United States power plants, its control at every step of the combustion process is important. An understanding of the amount of mercury in coal at the mine is the first step in this process. The Springfield coal (Middle Pennsylvanian) is one of the most important coal resources in the Illinois Basin. In Indiana and western Kentucky, Hg contents range from 0.02 to 0.55 ppm. The variation within small areas is comparable to the variation on a basin basis. Considerable variation also exists within the coal column, ranging from 0.04 to 0.224 ppm at one Kentucky site. Larger variations likely exist, since that site does not represent the highest whole-seam Hg nor was the collection of samples done with optimization of trace element variations in mind. Estimates of Hg capture by currently installed pollution control equipment range from 9-53% capture by cold-side electrostatic precipitators (ESP) and 47-81% Hg capture for ESP + flue-gas desulfurization (FGD). The high Cl content of many Illinois basin coals and the installation of Selective Catalytic Reduction of NOx enhances the oxidation of Hg species, improving the ability of ESPs and FGDs to capture Hg. ?? 2005 Elsevier B.V. All rights reserved.

AK-cut crystal resonators

NASA Technical Reports Server (NTRS)

Kahan, A.; Euler, F. K.

1983-01-01

Calculations have predicted the existence of crystallographically doubly rotated quartz orientations with turnover temperatures which are considerably less sensitive to angular misorientation then comparable AT- or BT-cuts. These crystals are arbitrarily designated as the AK-cut. Experimental data is given for seven orientations, phi-angle variations between 30-46 deg and theta-angle variations between 21-28 deg measured on 3.3-3.4 MHz fundamental mode resonators vibrating in the thickness shear c-mode. The experimental turnover temperatures of these resonators are between 80 C and 150 C, in general agreement with calculated values. The normalized frequency change as a function of temperature has been fitted with a cubic equation.

Ontogenetic and diel variation in stream habitat use by brook trout (Salvelinus fontinalis) in a headwater stream

USGS Publications Warehouse

Johnson, J. H.; Ross, R.M.; Dropkin, D.S.; Redell, L.A.

2011-01-01

Although considerable information exists on habitat use by stream salmonids, only a small portion has quantitatively examined diurnal and nocturnal habitat variation. We examined diel variation in habitat use by age-0 and age-1+ brook trout (Salvelinus fontinalis) during summer and autumn in a headwater stream in northern Pennsylvania. Habitat variables measured included cover, depth, substrate, and velocity. The most pronounced diel variation occurred in the use of cover during both seasons. Both age-0 brook trout and age-1+ trout were associated with less cover at night. Age-0 brook trout occupied swifter water during the day than at night during both seasons, but the difference was not significant. Increased cover, depth, and substrate size governed the habitat of age-1+ brook trout. Our findings support the need for a better understanding of diel differences in habitat use of stream salmonids when considering habitat enhancement and protection.

The impact of environmental and climatic variation on the spatiotemporal trends of hospitalized pediatric diarrhea in Ho Chi Minh City, Vietnam.

PubMed

Thompson, Corinne N; Zelner, Jonathan L; Nhu, Tran Do Hoang; Phan, My Vt; Hoang Le, Phuc; Nguyen Thanh, Hung; Vu Thuy, Duong; Minh Nguyen, Ngoc; Ha Manh, Tuan; Van Hoang Minh, Tu; Lu Lan, Vi; Nguyen Van Vinh, Chau; Tran Tinh, Hien; von Clemm, Emmiliese; Storch, Harry; Thwaites, Guy; Grenfell, Bryan T; Baker, Stephen

2015-09-01

It is predicted that the integration of climate-based early warning systems into existing action plans will facilitate the timely provision of interventions to diarrheal disease epidemics in resource-poor settings. Diarrhea remains a considerable public health problem in Ho Chi Minh City (HCMC), Vietnam and we aimed to quantify variation in the impact of environmental conditions on diarrheal disease risk across the city. Using all inpatient diarrheal admissions data from three large hospitals within HCMC, we developed a mixed effects regression model to differentiate district-level variation in risk due to environmental conditions from the overarching seasonality of diarrheal disease hospitalization in HCMC. We identified considerable spatial heterogeneity in the risk of all-cause diarrhea across districts of HCMC with low elevation and differential responses to flooding, air temperature, and humidity driving further spatial heterogeneity in diarrheal disease risk. The incorporation of these results into predictive forecasting algorithms will provide a powerful resource to aid diarrheal disease prevention and control practices in HCMC and other similar settings. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Consideration of measurement error when using commercial indoor radon determinations for selecting radon action levels

USGS Publications Warehouse

Reimer, G.M.; Szarzi, S.L.; Dolan, Michael P.

1998-01-01

An examination of year-long, in-home radon measurement in Colorado from commercial companies applying typical methods indicates that considerable variation in precision exists. This variation can have a substantial impact on any mitigation decisions, either voluntary or mandated by law, especially regarding property sale or exchange. Both long-term exposure (nuclear track greater than 90 days), and short-term (charcoal adsorption 4-7 days) exposure methods were used. In addition, periods of continuous monitoring with a highly calibrated alpha-scintillometer took place for accuracy calibration. The results of duplicate commercial analysis show that typical results are no better than ??25 percent with occasional outliers (up to 5 percent of all analyses) well beyond that limit. Differential seasonal measurements (winter/summer) by short-term methods provide equivalent information to single long-term measurements. Action levels in the U.S. for possible mitigation decisions should be selected so that they consider the measurement variability; specifically, they should reflect a concentration range similar to that adopted by the European Community.

Cultural group selection follows Darwin's classic syllogism for the operation of selection.

PubMed

Richerson, Peter; Baldini, Ryan; Bell, Adrian V; Demps, Kathryn; Frost, Karl; Hillis, Vicken; Mathew, Sarah; Newton, Emily K; Naar, Nicole; Newson, Lesley; Ross, Cody; Smaldino, Paul E; Waring, Timothy M; Zefferman, Matthew

2016-01-01

The main objective of our target article was to sketch the empirical case for the importance of selection at the level of groups on cultural variation. Such variation is massive in humans, but modest or absent in other species. Group selection processes acting on this variation is a framework for developing explanations of the unusual level of cooperation between non-relatives found in our species. Our case for cultural group selection (CGS) followed Darwin's classic syllogism regarding natural selection: If variation exists at the level of groups, if this variation is heritable, and if it plays a role in the success or failure of competing groups, then selection will operate at the level of groups. We outlined the relevant domains where such evidence can be sought and characterized the main conclusions of work in those domains. Most commentators agree that CGS plays some role in human evolution, although some were considerably more skeptical. Some contributed additional empirical cases. Some raised issues of the scope of CGS explanations versus competing ones.

Sizing ocean giants: patterns of intraspecific size variation in marine megafauna

PubMed Central

Balk, Meghan A.; Benfield, Mark C.; Branch, Trevor A.; Chen, Catherine; Cosgrove, James; Dove, Alistair D.M.; Gaskins, Lindsay C.; Helm, Rebecca R.; Hochberg, Frederick G.; Lee, Frank B.; Marshall, Andrea; McMurray, Steven E.; Schanche, Caroline; Stone, Shane N.; Thaler, Andrew D.

2015-01-01

What are the greatest sizes that the largest marine megafauna obtain? This is a simple question with a difficult and complex answer. Many of the largest-sized species occur in the world’s oceans. For many of these, rarity, remoteness, and quite simply the logistics of measuring these giants has made obtaining accurate size measurements difficult. Inaccurate reports of maximum sizes run rampant through the scientific literature and popular media. Moreover, how intraspecific variation in the body sizes of these animals relates to sex, population structure, the environment, and interactions with humans remains underappreciated. Here, we review and analyze body size for 25 ocean giants ranging across the animal kingdom. For each taxon we document body size for the largest known marine species of several clades. We also analyze intraspecific variation and identify the largest known individuals for each species. Where data allows, we analyze spatial and temporal intraspecific size variation. We also provide allometric scaling equations between different size measurements as resources to other researchers. In some cases, the lack of data prevents us from fully examining these topics and instead we specifically highlight these deficiencies and the barriers that exist for data collection. Overall, we found considerable variability in intraspecific size distributions from strongly left- to strongly right-skewed. We provide several allometric equations that allow for estimation of total lengths and weights from more easily obtained measurements. In several cases, we also quantify considerable geographic variation and decreases in size likely attributed to humans. PMID:25649000

Estimates of annual survival, growth, and recruitment of a white-tailed ptarmigan population in Colorado over 43 years

USGS Publications Warehouse

Wann, Greg; Aldridge, Cameron L.; Braun, Clait E.

2014-01-01

Long-term datasets for high-elevation species are rare, and considerable uncertainty exists in understanding how high-elevation populations have responded to recent climate warming. We present estimates of demographic vital rates from a 43-year population study of white-tailed ptarmigan (Lagopus leucura), a species endemic to alpine habitats in western North America. We used capture-recapture models to estimate annual rates of apparent survival, population growth, and recruitment for breeding-age ptarmigan, and we fit winter weather covariates to models in an attempt to explain annual variation. There were no trends in survival over the study period but there was strong support for age and sex effects. The average rate of annual growth suggests a relatively stable breeding-age population ( λ ¯ = 1.036), but there was considerable variation between years for both population growth and recruitment rates. Winter weather covariates only explained a small amount of variation in female survival and were not an important predictor of male survival. Cumulative winter precipitation was found to have a quadratic effect on female survival, with survival being highest during years of average precipitation. Cumulative winter precipitation was positively correlated with population growth and recruitment rates, although this covariate only explained a small amount of annual variation in these rates and there was considerable uncertainty among the models tested. Our results provide evidence for an alpine-endemic population that has not experienced extirpation or drastic declines. However, more information is needed to understand risks and vulnerabilities of warming effects on juveniles as our analysis was confined to determination of vital rates for breeding-age birds.

Discrete diffraction managed solitons: Threshold phenomena and rapid decay for general nonlinearities

NASA Astrophysics Data System (ADS)

Choi, Mi-Ran; Hundertmark, Dirk; Lee, Young-Ran

2017-10-01

We prove a threshold phenomenon for the existence/non-existence of energy minimizing solitary solutions of the diffraction management equation for strictly positive and zero average diffraction. Our methods allow for a large class of nonlinearities; they are, for example, allowed to change sign, and the weakest possible condition, it only has to be locally integrable, on the local diffraction profile. The solutions are found as minimizers of a nonlinear and nonlocal variational problem which is translation invariant. There exists a critical threshold λcr such that minimizers for this variational problem exist if their power is bigger than λcr and no minimizers exist with power less than the critical threshold. We also give simple criteria for the finiteness and strict positivity of the critical threshold. Our proof of existence of minimizers is rather direct and avoids the use of Lions' concentration compactness argument. Furthermore, we give precise quantitative lower bounds on the exponential decay rate of the diffraction management solitons, which confirm the physical heuristic prediction for the asymptotic decay rate. Moreover, for ground state solutions, these bounds give a quantitative lower bound for the divergence of the exponential decay rate in the limit of vanishing average diffraction. For zero average diffraction, we prove quantitative bounds which show that the solitons decay much faster than exponentially. Our results considerably extend and strengthen the results of Hundertmark and Lee [J. Nonlinear Sci. 22, 1-38 (2012) and Commun. Math. Phys. 309(1), 1-21 (2012)].

Smear correction of highly variable, frame-transfer CCD images with application to polarimetry.

PubMed

Iglesias, Francisco A; Feller, Alex; Nagaraju, Krishnappa

2015-07-01

Image smear, produced by the shutterless operation of frame-transfer CCD detectors, can be detrimental for many imaging applications. Existing algorithms used to numerically remove smear do not contemplate cases where intensity levels change considerably between consecutive frame exposures. In this report, we reformulate the smearing model to include specific variations of the sensor illumination. The corresponding desmearing expression and its noise properties are also presented and demonstrated in the context of fast imaging polarimetry.

Spatiotemporal variation in local adaptation of a specialist insect herbivore to its long-lived host plant.

PubMed

Kalske, Aino; Leimu, Roosa; Scheepens, J F; Mutikainen, Pia

2016-09-01

Local adaptation of interacting species to one another indicates geographically variable reciprocal selection. This process of adaptation is central in the organization and maintenance of genetic variation across populations. Given that the strength of selection and responses to it often vary in time and space, the strength of local adaptation should in theory vary between generations and among populations. However, such spatiotemporal variation has rarely been explicitly demonstrated in nature and local adaptation is commonly considered to be relatively static. We report persistent local adaptation of the short-lived herbivore Abrostola asclepiadis to its long-lived host plant Vincetoxicum hirundinaria over three successive generations in two studied populations and considerable temporal variation in local adaptation in six populations supporting the geographic mosaic theory. The observed variation in local adaptation among populations was best explained by geographic distance and population isolation, suggesting that gene flow reduces local adaptation. Changes in herbivore population size did not conclusively explain temporal variation in local adaptation. Our results also imply that short-term studies are likely to capture only a part of the existing variation in local adaptation. © 2016 The Author(s). Evolution © 2016 The Society for the Study of Evolution.

Natural genetic variation of root system architecture from Arabidopsis to Brachypodium: towards adaptive value.

PubMed

Pacheco-Villalobos, David; Hardtke, Christian S

2012-06-05

Root system architecture is a trait that displays considerable plasticity because of its sensitivity to environmental stimuli. Nevertheless, to a significant degree it is genetically constrained as suggested by surveys of its natural genetic variation. A few regulators of root system architecture have been isolated as quantitative trait loci through the natural variation approach in the dicotyledon model, Arabidopsis. This provides proof of principle that allelic variation for root system architecture traits exists, is genetically tractable, and might be exploited for crop breeding. Beyond Arabidopsis, Brachypodium could serve as both a credible and experimentally accessible model for root system architecture variation in monocotyledons, as suggested by first glimpses of the different root morphologies of Brachypodium accessions. Whether a direct knowledge transfer gained from molecular model system studies will work in practice remains unclear however, because of a lack of comprehensive understanding of root system physiology in the native context. For instance, apart from a few notable exceptions, the adaptive value of genetic variation in root system modulators is unknown. Future studies should thus aim at comprehensive characterization of the role of genetic players in root system architecture variation by taking into account the native environmental conditions, in particular soil characteristics.

Morphological Variation in the Adult Hard Palate and Posterior Pharyngeal Wall

PubMed Central

Lammert, Adam; Proctor, Michael; Narayanan, Shrikanth

2013-01-01

Purpose Adult human vocal tracts display considerable morphological variation across individuals, but the nature and extent of this variation has not been extensively studied for many vocal tract structures. There exists a need to analyze morphological variation and, even more basically, to develop a methodology for morphological analysis of the vocal tract. Such analysis will facilitate fundamental characterization of the speech production system, with broad implications from modeling to explaining inter-speaker variability. Method A data-driven methodology to automatically analyze the extent and variety of morphological variation is proposed and applied to a diverse subject pool of 36 adults. Analysis is focused on two key aspects of vocal tract structure: the midsagittal shape of the hard palate and the posterior pharyngeal wall. Result Palatal morphology varies widely in its degree of concavity, but also in anteriority and sharpness. Pharyngeal wall morphology, by contrast, varies mostly in terms of concavity alone. The distribution of morphological characteristics is complex, and analysis suggests that certain variations may be categorical in nature. Conclusion Major modes of morphological variation are identified, including their relative magnitude, distribution and categorical nature. Implications of these findings for speech articulation strategies and speech acoustics are discussed. PMID:23690566

Seasonal and geothermal production variations in concentrations of He and CO2 in soil gases, Roosevelt Hot Springs Known Geothermal Resource Area, Utah, U.S.A.

USGS Publications Warehouse

Hinkle, M.E.

1991-01-01

To increase understanding of natural variations in soil gas concentrations, CO2, He, O2 and N2 were measured in soil gases collected regularly for several months from four sites at the Roosevelt Hot Springs Known Geothermal Resource Area, Utah. Soil temperature, air temperature, per cent relative humidity, barometric pressure and amounts of rain and snowfall were also monitored to determine the effect of meteorological parameters on concentrations of the measured gases. Considerable seasonal variation existed in concentrations of CO2 and He. The parameters that most affected the soil-gas concentrations were soil and air temperatures. Moisture from rain and snow probably affected the soil-gas concentrations also. However, annual variations in meteorological parameters did not appear to affect measurements of anomalous concentrations in samples collected within a time period of a few days. Production from some of the geothermal wells probably affected the soil-gas concentrations. ?? 1990.

Variation of the shower lateral spread with air temperature at the ground

NASA Astrophysics Data System (ADS)

Wilczyńska, B.; Engel, R.; Homola, P.; Keilhauer, B.; Klages, H.; Pękala, J.; Wilczyński, H.

The vertical profile of air density at a given site varies considerably with time. Well understood seasonal differences are present, but sizeable effects on shorter time scales, like day to night or day to day variations, are also observed. In consequence, the Moliere radius changes, influencing the lateral distribution of particles in the air showers and therefore may influence the shower detection in surface detector arrays. In air shower reconstruction, usually seasonal average profiles of the atmosphere are used, because local daily measurements of the profile are rarely available. Therefore, the daily fluctuations of the atmosphere are not accounted for. This simplification increases the inaccuracies of shower reconstruction. We show that a universal correlation exists between the ground temperature and the shape of the atmospheric profile, up to altitudes of several kilometers, hence providing a method to reduce inaccuracies in shower reconstruction due to weather variation.

Calling for an ecological approach to studying climate change and infectious diseases

USGS Publications Warehouse

Lafferty, Kevin D.

2009-01-01

My Concepts and Synthesis paper (Lafferty 2009),which inspired this Forum, echoed the premise that earlyreviews about climate change exaggerated claims thatinfectious diseases will increase in the future (Randolph2009). The paper sparked five well-reasoned commen-taries from ecologists with considerable expertise ininfectious diseases (Dobson 2009, Harvell et al. 2009,Ostfeld 2009, Pascual and Bouma 2009, Randolph2009). These reviews illustrate several examples andcase studies which corr elate i ncreases in infectiousdisease with existing climate variation, though alterna-tive explanations exist for many of these patterns(Dobson 2009, Harvell et al. 2009, Ostfeld 2009, Pascualand Bouma 2009, Randolph 2009). A common messageis that an ecological approach is increasingly relevant tothe challenging topic of infectious disease.

Worldwide Mycotoxins Exposure in Pig and Poultry Feed Formulations

PubMed Central

Guerre, Philippe

2016-01-01

The purpose of this review is to present information about raw materials that can be used in pig and poultry diets and the factors responsible for variations in their mycotoxin contents. The levels of mycotoxins in pig and poultry feeds are calculated based on mycotoxin contamination levels of the raw materials with different diet formulations, to highlight the important role the stage of production and the raw materials used can have on mycotoxins levels in diets. Our analysis focuses on mycotoxins for which maximum tolerated levels or regulatory guidelines exist, and for which sufficient contamination data are available. Raw materials used in feed formulation vary considerably depending on the species of animal, and the stage of production. Mycotoxins are secondary fungal metabolites whose frequency and levels also vary considerably depending on the raw materials used and on the geographic location where they were produced. Although several reviews of existing data and of the literature on worldwide mycotoxin contamination of food and feed are available, the impact of the different raw materials used on feed formulation has not been widely studied. PMID:27886128

Determination of the Characteristic Values and Variation Ratio for Sensitive Soils

NASA Astrophysics Data System (ADS)

Milutinovici, Emilia; Mihailescu, Daniel

2017-12-01

In 2008, Romania adopted Eurocode 7, part II, regarding the geotechnical investigations - called SR EN1997-2/2008. However a previous standard already existed in Romania, by using the mathematical statistics in determination of the calculation values, the requirements of Eurocode can be taken into consideration. The setting of characteristics and calculations values of the geotechnical parameters was finally issued in Romania at the end of 2010 at standard NP122-2010 - “Norm regarding determination of the characteristic and calculation values of the geotechnical parameters”. This standard allows using of data already known from analysed area and setting the calculation values of geotechnical parameters. However, this possibility exist, it is not performed easy in Romania, considering that there isn’t any centralized system of information coming from the geotechnical studies performed for various objectives of private or national interests. Every company performing geotechnical studies tries to organize its own data base, but unfortunately none of them use existing centralized data. When determining the values of calculation, an important role is played by the variation ratio of the characteristic values of a geotechnical parameter. There are recommendations in the mentioned Norm, that could be taken into account, regarding the limits of the variation ratio, but these values are mentioned for Quaternary age soils only, normally consolidated, with a content of organic material < 5%. All of the difficult soils are excluded from the Norm even if they exist and affect the construction foundations on more than a half of the Romania’s surface. A type of difficult soil, extremely widespread on the Romania’s territory, is the contractile soil (with high swelling and contractions, very sensitive to the seasonal moisture variations). This type of material covers and influences the construction foundations in one over third of Romania’s territory. This work is proposing to be a step in determination of limits of the variation ratios for the contractile soils category, for the most used geotechnical parameters in the Romanian engineering practice, namely: the index of consistency and the cohesion.

Smooth interface effects on the confinement properties of GaSb/Al xGa 1- xSb quantum wells

NASA Astrophysics Data System (ADS)

Adib, Artur B.; de Sousa, Jeanlex S.; Farias, Gil A.; Freire, Valder N.

2000-10-01

A theoretical investigation on the confinement properties of GaSb/Al xGa 1- xSb single quantum wells (QWs) with smooth interfaces is performed. Error function ( erf)-like interfacial aluminum molar fraction variations in the QWs, from which it is possible to obtain the carriers effective masses and confinement potential profiles, are assumed. It is shown that the existence of smooth interfaces blue shifts considerably the confined carriers and exciton energies, an effect which is stronger in thin QWs.

Rural hospital wages

PubMed Central

Hendricks, Ann M.

1989-01-01

Average fiscal year 1982 wages from 2,302 rural American hospitals were used to test for a gradient descending from hospitals in counties adjacent to metropolitan areas to those not adjacent. Considerable variation in the ratios of adjacent to nonadjacent averages existed. No statistically significant difference was found, however. Of greater importance in explaining relative wages within States were occupational mix, mix of part-time and full-time workers, case mix, presence of medical residencies, and location in a high-rent county within the State. Medicare already adjusts payments for only two of these variables. PMID:10313454

Determination of the hypersonic-continuum/rarefied-flow drag coefficient of the Viking lander capsule 1 aeroshell from flight data

NASA Technical Reports Server (NTRS)

Blanchard, R. C.; Walberg, G. D.

1980-01-01

Results of an investigation to determine the full scale drag coefficient in the high speed, low density regime of the Viking lander capsule 1 entry vehicle are presented. The principal flight data used in the study were from onboard pressure, mass spectrometer, and accelerometer instrumentation. The hypersonic continuum flow drag coefficient was unambiguously obtained from pressure and accelerometer data; the free molecule flow drag coefficient was indirectly estimated from accelerometer and mass spectrometer data; the slip flow drag coefficient variation was obtained from an appropriate scaling of existing experimental sphere data. Comparison of the flight derived drag hypersonic continuum flow regime except for Reynolds numbers from 1000 to 100,000, for which an unaccountable difference between flight and ground test data of about 8% existed. The flight derived drag coefficients in the free molecule flow regime were considerably larger than those previously calculated with classical theory. The general character of the previously determined temperature profile was not changed appreciably by the results of this investigation; however, a slightly more symmetrical temperature variation at the highest altitudes was obtained.

Statistical Considerations Concerning Dissimilar Regulatory Requirements for Dissolution Similarity Assessment. The Example of Immediate-Release Dosage Forms.

PubMed

Jasińska-Stroschein, Magdalena; Kurczewska, Urszula; Orszulak-Michalak, Daria

2017-05-01

When performing in vitro dissolution testing, especially in the area of biowaivers, it is necessary to follow regulatory guidelines to minimize the risk of an unsafe or ineffective product being approved. The present study examines model-independent and model-dependent methods of comparing dissolution profiles based on various compared and contrasted international guidelines. Dissolution profiles for immediate release solid oral dosage forms were generated. The test material comprised tablets containing several substances, with at least 85% of the labeled amount dissolved within 15 min, 20-30 min, or 45 min. Dissolution profile similarity can vary with regard to the following criteria: time point selection (including the last time point), coefficient of variation, and statistical method selection. Variation between regulatory guidance and statistical methods can raise methodological questions and result potentially in a different outcome when reporting dissolution profile testing. The harmonization of existing guidelines would address existing problems concerning the interpretation of regulatory recommendations and research findings. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

An analysis of Australian graduate critical care nurse education.

PubMed

Gill, Fenella J; Leslie, Gavin D; Grech, Carol; Latour, Jos M

2015-01-01

Preparation of specialist critical care nurses in Australia is at graduate level, although there remains considerable variation in courses offered in relation to qualification, content, assessment and outcomes. As higher education providers must now comply with the Australian Qualifications Framework (AQF) a study was conducted to examine existing critical care courses and graduate practice outcomes. Twenty-two critical care courses were reviewed. Data sources included course provider, websites, course curricula and telephone interviews with course coordinators. A framework approach, was used consisting of five key stages: preliminary immersion of raw data, conceptualising a thematic framework, indexing, charting, mapping and interpretation of data. Analysis revealed considerable variations in course delivery and graduate practice outcomes. Most courses used professional competency standards as a framework for course curricula and clinical assessment, with inconsistency in their translation to graduate practice outcomes. Twenty-one courses included clinical assessment at graduate certificate level with no clinical assessment conducted at master level. The expected practice outcome for fifteen courses was safe practice with graduates not expected to practice at a specialist or team leadership level. Minimum graduate practice standards were not included in three courses as an expected outcome. The AQF requires graduate nurse education to be compliant with academic outcome standards. The findings of our study indicate variations between courses and subsequent graduate practice outcomes. It is therefore timely to establish national critical care education graduate practice standards.

Variations in the Prevalence of Obesity Among European Countries, and a Consideration of Possible Causes

PubMed Central

Blundell, John E.; Baker, Jennifer Lyn; Boyland, Emma; Blaak, Ellen; Charzewska, Jadwiga; de Henauw, Stefaan; Frühbeck, Gema; Gonzalez-Gross, Marcela; Hebebrand, Johannes; Holm, Lotte; Kriaucioniene, Vilma; Lissner, Lauren; Oppert, Jean-Michel; Schindler, Karin; Silva, Analiza Mónica; Woodward, Euan

2017-01-01

Over the last 10 years the prevalence of obesity across the European continent has in general been rising. With the exception of a few countries where a levelling-off can be perceived, albeit at a high level, this upward trend seems likely to continue. However, considerable country to country variation is noticeable, with the proportion of people with obesity varying by 10% or more. This variation is intriguing and suggests the existence of different profiles of risk or protection factors operating in different countries. The identification of such protection factors could indicate suitable targets for interventions to help manage the obesity epidemic in Europe. This report is the output of a 2-day workshop on the ‘Diversity of Obesity in Europe’. The workshop included 14 delegates from 12 different European countries. This report contains the contributions and discussions of the materials and viewpoints provided by these 14 experts; it is not the output of a single mind. However, such is the nature of scientific analysis regarding obesity that it is possible that a different set of 14 experts may have come to a different set of conclusions. Therefore the report should not be seen as a definitive statement of a stable situation. Rather it is a focus for discussion and comment, and a vehicle to drive forward further understanding and management of obesity in Europe. PMID:28190010

Quantifying heterogeneity in human tumours using MRI and PET.

PubMed

Asselin, Marie-Claude; O'Connor, James P B; Boellaard, Ronald; Thacker, Neil A; Jackson, Alan

2012-03-01

Most tumours, even those of the same histological type and grade, demonstrate considerable biological heterogeneity. Variations in genomic subtype, growth factor expression and local microenvironmental factors can result in regional variations within individual tumours. For example, localised variations in tumour cell proliferation, cell death, metabolic activity and vascular structure will be accompanied by variations in oxygenation status, pH and drug delivery that may directly affect therapeutic response. Documenting and quantifying regional heterogeneity within the tumour requires histological or imaging techniques. There is increasing evidence that quantitative imaging biomarkers can be used in vivo to provide important, reproducible and repeatable estimates of tumoural heterogeneity. In this article we review the imaging methods available to provide appropriate biomarkers of tumour structure and function. We also discuss the significant technical issues involved in the quantitative estimation of heterogeneity and the range of descriptive metrics that can be derived. Finally, we have reviewed the existing clinical evidence that heterogeneity metrics provide additional useful information in drug discovery and development and in clinical practice. Copyright © 2012 Elsevier Ltd. All rights reserved.

Genetic influence on athletic performance.

PubMed

Guth, Lisa M; Roth, Stephen M

2013-12-01

To summarize the existing literature on the genetics of athletic performance, with particular consideration for the relevance to young athletes. Two gene variants, ACE I/D and ACTN3 R577X, have been consistently associated with endurance (ACE I/I) and power-related (ACTN3 R/R) performance, though neither can be considered predictive. The role of genetic variation in injury risk and outcomes is more sparsely studied, but genetic testing for injury susceptibility could be beneficial in protecting young athletes from serious injury. Little information on the association of genetic variation with athletic performance in young athletes is available; however, genetic testing is becoming more popular as a means of talent identification. Despite this increase in the use of such testing, evidence is lacking for the usefulness of genetic testing over traditional talent selection techniques in predicting athletic ability, and careful consideration should be given to the ethical issues surrounding such testing in children. A favorable genetic profile, when combined with an optimal training environment, is important for elite athletic performance; however, few genes are consistently associated with elite athletic performance, and none are linked strongly enough to warrant their use in predicting athletic success.

Quality variations in black musli (curculigo orchioides gaertn.).

PubMed

Mathew, P P Joy Samuel; Savithri, K E; Skaria, Baby P; Kurien, Kochurani

2004-07-01

Black musli (Curculigo orchioides Gaertn.) one of the ayurvedic dasapushpa and a rejuvenating and aphrodisiac drug. Is on the verge of extinction and needs to be conserved and cultivated. Large variations are also observed in the quality of the crude drug available in the market. Study on the quality of C. orchioides in natural habitat, under cultivation and in trade in south India showed that there was considerable variation with biotypes and habitats. Drugs collected form the natural habitat was superior in quality to that produced by cultivation. Among the market samples collected from the various Zones of kerala, those from the High Ranges were superior in most of the quality parameters, which indicated its superiority for high quality drug formulation. Among the southern states, Tamil Nadu samples ranked next to High Range samples in this respect. There exists large variability in the market samples and there is felt-need for proper standardization of the crude drug for ensuring quality in the drug formulations.

Consensus training: an effective tool to minimize variations in periodontal diagnosis and treatment planning among dental faculty and students.

PubMed

John, Vanchit; Lee, Seung-Jun; Prakasam, Sivaraman; Eckert, George J; Maupome, Gerardo

2013-08-01

Considerable disagreements and variations exist in diagnosis and treatment planning of periodontal disease. Achieving high interrater periodontal diagnosis can prove challenging. The objectives of this study were to measure variations in periodontal diagnosis and treatment planning among predoctoral periodontics faculty members after consensus training and to compare such variation with those identified in third- and fourth-year dental students. Nine electronically stored case vignettes and survey instruments were made available to eighteen faculty members and twenty dental students under standardized conditions. A chi-square test was used to compare responses between groups, and multirater kappa tests were used to evaluate interrater agreement/reliability. Of the nine cases, only one differed between groups significantly in terms of treatment. Also, third-year students differed from fourth-year students on the diagnosis of aggressive periodontitis versus chronic periodontitis. Most respondents were able to distinguish clearly among diagnoses of chronic periodontitis, aggressive periodontitis, and gingivitis. This study established a baseline assessment of the current status of consensus after training. We will reassess variations after addressing the specific challenges identified. Programs designed and implemented to help decrease the variation in periodontal diagnosis and treatment planning among faculty members may ultimately translate into better agreement and better standardization of dental instruction.

The stress response and exploratory behaviour in Yucatan minipigs (Sus scrofa): Relations to sex and social rank.

PubMed

Adcock, Sarah J J; Martin, Gerard M; Walsh, Carolyn J

2015-12-01

According to the coping styles hypothesis, an individual demonstrates an integrated behavioural and physiological response to environmental challenge that is consistent over time and across situations. Individual consistency in behavioural responses to challenge has been documented across the animal kingdom. Comparatively few studies, however, have examined inter-individual variation in the physiological response, namely glucocorticoid and catecholamine levels, the stress hormones secreted by the hypothalamic-pituitary-adrenal axis and the sympathetic nervous system, respectively. Variation in coping styles between individuals may be explained in part by differences in social rank and sex. Using 20 Yucatan minipigs (Sus scrofa) we: (1) investigated the existence of consistent inter-individual variation in exploratory behaviour and the hormonal stress response, and tested for correlations as predicted by the coping styles hypothesis; and (2) evaluated whether inter-individual behavioural and hormonal variation is related to social rank and sex. Salivary stress biomarkers (cortisol, alpha-amylase, chromogranin A) were assessed in the presence and absence of a stressor consisting of social isolation in a crate for 10 min. Principal components analysis on a set of behavioural variables revealed two traits, which we labelled exploratory tendency and neophobia. Neither exploratory tendency nor neophobia predicted the physiological stress response. Subordinate pigs exhibited higher catecholamine levels compared to dominant conspecifics. We observed sex differences in the repeatability of salivary stress markers and reactivity of the stress systems. The results do not provide support for the existence of behavioural-physiological coping styles in pigs. Sex is an important determinant of the physiological stress response and warrants consideration in research addressing behavioural and hormonal variation. Copyright © 2015 Elsevier Inc. All rights reserved.

Regulation of circadian blood pressure: from mice to astronauts.

PubMed

Agarwal, Rajiv

2010-01-01

Circadian variation is commonly seen in healthy people; aberration in these biological rhythms is an early sign of disease. Impaired circadian variation of blood pressure (BP) has been shown to be associated with greater target organ damage and with an elevated risk of cardiovascular events independent of the BP load. The purpose of this review is to examine the physiology of circadian BP variation and propose a tripartite model that explains the regulation of circadian BP. The time-keeper in mammals resides centrally in the suprachiasmatic nucleus. Apart from this central clock, molecular clocks exist in most peripheral tissues including vascular tissue and the kidney. These molecular clocks regulate sodium balance, sympathetic function and vascular tone. A physiological model is proposed that integrates our understanding of molecular clocks in mice with the circadian BP variation among humans. The master regulator in this proposed model is the sleep-activity cycle. The equivalents of peripheral clocks are endothelial and adrenergic functions. Thus, in the proposed model, the variation in circadian BP is dependent upon three major factors: physical activity, autonomic function, and sodium sensitivity. The integrated consideration of physical activity, autonomic function, and sodium sensitivity appears to explain the physiology of circadian BP variation and the pathophysiology of disrupted BP rhythms in various conditions and disease states. Our understanding of molecular clocks in mice may help to explain the provenance of blunted circadian BP variation even among astronauts.

What it means to "spoil" a baby: parents' perception.

PubMed

Wilson, A L; Witzke, D B; Volin, A

1981-12-01

Discussion concerning spoiling a baby frequently takes place in pediatric-care settings and may occur without a clear understanding of how parents define the word "spoil" when baby care is discussed. This study presents data from 531 parents asked to respond to a questionnaire on spoiling babies. The majority of mothers and fathers believe a baby can be spoiled, but considerable variation exists in perceptions of how this takes place, what a spoiled baby is like, and the present and future effects of spoiling. The younger and less educated parents have more rigid and negative views about the effects of spoiling babies.

NREL Software Aids Offshore Wind Turbine Designs (Fact Sheet)

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

Not Available

2013-10-01

NREL researchers are supporting offshore wind power development with computer models that allow detailed analyses of both fixed and floating offshore wind turbines. While existing computer-aided engineering (CAE) models can simulate the conditions and stresses that a land-based wind turbine experiences over its lifetime, offshore turbines require the additional considerations of variations in water depth, soil type, and wind and wave severity, which also necessitate the use of a variety of support-structure types. NREL's core wind CAE tool, FAST, models the additional effects of incident waves, sea currents, and the foundation dynamics of the support structures.

Project IMPACT: a report on barriers and facilitators to sustainability.

PubMed

Blasinsky, Margaret; Goldman, Howard H; Unützer, Jürgen

2006-11-01

Project IMPACT is a collaborative care intervention to assist older adults suffering from major depressive disorder or dysthymia. Qualitative research methods were used to determine the barriers and facilitators to sustaining IMPACT in a primary care setting. Strong evidence supports the program's sustainability, but considerable variation exists in continuation strategies and operationalization across sites. Sustainability depended on the organizations' support of collaborative care models, the availability of staff trained in the intervention, and funding. The intervention's success was the most important sustainability factor, as documented by outcome data and through the "real world" experience of treating patients with this intervention.

Electrocardiogram transmission - The state of the art.

NASA Technical Reports Server (NTRS)

Firstenberg, A.; Huston, S. W.; Olsen, D. E.; Hahn, P. M.

1971-01-01

A comparative analysis of available clinical EKG telemetry systems was conducted. Although present day electrocardiogram diagnosis requires a high degree of measurement accuracy, there exists wide variations in the performance characteristics of the various telemeters marketed today necessitating careful consideration of specifications prior to procurement. The authors have endeavored to provide the physicians with a clear understanding, in terms of the effects on the electrocardiogram, of the factors he must evaluate in order to ensure high fidelity EKG reproduction. A tabulation of comparative parameter values for each unit obtained from manufacturers' specifications and substantiated by standardized performance tests conducted in our laboratory is presented.

Carbide fuel pin and capsule design for irradiations at thermionic temperatures

NASA Technical Reports Server (NTRS)

Siegel, B. L.; Slaby, J. G.; Mattson, W. F.; Dilanni, D. C.

1973-01-01

The design of a capsule assembly to evaluate tungsten-emitter - carbide-fuel combinations for thermionic fuel elements is presented. An inpile fuel pin evaluation program concerned with clad temperture, neutron spectrum, carbide fuel composition, fuel geometry,fuel density, and clad thickness is discussed. The capsule design was a compromise involving considerations between heat transfer, instrumentation, materials compatibility, and test location. Heat-transfer calculations were instrumental in determining the method of support of the fuel pin to minimize axial temperature variations. The capsule design was easily fabricable and utilized existing state-of-the-art experience from previous programs.

Contributions of Human Enzymes in Carcinogen Metabolism

PubMed Central

Rendic, Slobodan; Guengerich, F. Peter

2012-01-01

Considerable support exists for roles of metabolism in modulating the carcinogenic properties of chemicals. In particular, many of these compounds are procarcinogens that require activation to electrophilic forms to exert genotoxic effects. We systematically analyzed the existing literature on metabolism of carcinogens by human enzymes, which has been developed largely in the past 25 years. The metabolism and especially bioactivation of carcinogens are dominated by cytochrome P450 enzymes (66% of bioactivations). Within this group, six P450s—1A1, 1A2, 1B1, 2A6, 2E1, and 3A4—accounted for 77% of the P450 activation reactions. The roles of these P450s can be compared with those estimated for drug metabolism and should be considered in issues involving enzyme induction, chemoprevention, molecular epidemiology, inter-individual variations, and risk assessment. PMID:22531028

A comparison of policies on nurse faculty workload in the United States.

PubMed

Ellis, Peggy A

2013-01-01

This article describes nurse faculty workload policies from across the nation in order to assess current practice. There is a well-documented shortage of nursing faculty leading to an increase in workload demands. Increases in faculty workload results in difficulties with work-life balance and dissatisfaction threatening to make nursing education less attractive to young faculty. In order to begin an examination of faculty workload in nursing, existing workloads must be known. Faculty workload data were solicited from nursing programs nationwide and analyzed to determine the current workloads. The most common faculty teaching workload reported overall for nursing is 12 credit hours per semester; however, some variations exist. Consideration should be given to the multiple components of the faculty workload. Research is needed to address the most effective and efficient workload allocation for nursing faculty.

Frequency allocations for a new satellite service - Digital audio broadcasting

NASA Technical Reports Server (NTRS)

Reinhart, Edward E.

1992-01-01

The allocation in the range 500-3000 MHz for digital audio broadcasting (DAB) is described in terms of key issues such as the transmission-system architectures. Attention is given to the optimal amount of spectrum for allocation and the technological considerations relevant to downlink bands for satellite and terrestrial transmissions. Proposals for DAB allocations are compared, and reference is made to factors impinging on the provision of ground/satellite feeder links. The allocation proposals describe the implementation of 50-60-MHz bandwidths for broadcasting in the ranges near 800 MHz, below 1525 MHz, near 2350 MHz, and near 2600 MHz. Three specific proposals are examined in terms of characteristics such as service areas, coverage/beam, channels/satellite beam, and FCC license status. Several existing problems are identified including existing services crowded with systems, the need for new bands in the 1000-3000-MHz range, and variations in the nature and intensity of implementations of existing allocations that vary from country to country.

Sensitivity Analysis of earth and environmental models: a systematic review to guide scientific advancement

NASA Astrophysics Data System (ADS)

Wagener, Thorsten; Pianosi, Francesca

2016-04-01

Sensitivity Analysis (SA) investigates how the variation in the output of a numerical model can be attributed to variations of its input factors. SA is increasingly being used in earth and environmental modelling for a variety of purposes, including uncertainty assessment, model calibration and diagnostic evaluation, dominant control analysis and robust decision-making. Here we provide some practical advice regarding best practice in SA and discuss important open questions based on a detailed recent review of the existing body of work in SA. Open questions relate to the consideration of input factor interactions, methods for factor mapping and the formal inclusion of discrete factors in SA (for example for model structure comparison). We will analyse these questions using relevant examples and discuss possible ways forward. We aim at stimulating the discussion within the community of SA developers and users regarding the setting of good practices and on defining priorities for future research.

Simultaneous stochastic inversion for geomagnetic main field and secular variation. II - 1820-1980

NASA Technical Reports Server (NTRS)

Bloxham, Jeremy; Jackson, Andrew

1989-01-01

With the aim of producing readable time-dependent maps of the geomagnetic field at the core-mantle boundary, the method of simultaneous stochastic inversion for the geomagnetic main field and secular variation, described by Bloxham (1987), was applied to survey data from the period 1820-1980 to yield two time-dependent geomagnetic-field models, one for the period 1900-1980 and the other for 1820-1900. Particular consideration was given to the effect of crustal fields on observations. It was found that the existing methods of accounting for these fields as sources of random noise are inadequate in two circumstances: (1) when sequences of measurements are made at one particular site, and (2) for measurements made at satellite altitude. The present model shows many of the features in the earth's magnetic field at the core-mantle boundary described by Bloxham and Gubbins (1985) and supports many of their earlier conclusions.

Extreme isotopic variations in the upper mantle: evidence from Ronda

NASA Astrophysics Data System (ADS)

Reisberg, Laurie; Zindler, Alan

1986-12-01

The Ronda Ultramafic Complex in southern Spain represents a piece of the Earth's mantle which has been tectonically emplaced into the crust. Nd and Sr isotopic analyses are presented for leached, hand-picked Cr-diopside separates prepared from 15 rock and 18 river sediment samples from Ronda. These results demonstrate that within this small, contiguous body there exists the entire range of Nd isotopic compositions, and much of the range of Sr compositions, found in rocks derived from the sub-oceanic mantle. The sediment cpx samples show that the average isotopic composition of the massif becomes progressively less "depleted" moving from SW to NE along the long axis of the massif. The rock cpx samples document 143Nd/ 144Nd variations from 0.5129 to 0.5126 and 87Sr/ 86Sr variations from 0.7031 to 0.7039 within a uniform outcrop less than 10 m in extent. Thus, extreme isotopic fluctuations exist over a wide range of wavelengths. Sr and Nd isotopes are generally inversely correlated, forming a trend on a Nd-Sr diagram that sharply crosscuts that of the "mantle array". Many of the 143Nd/ 144Nd values, and all of the Sm/Nd values, from one section of the massif are lower than that SCV015SCV0 of the bulk earth, implying that this region existed, or was influenced by a component which existed, in a LREE-enriched environment for a significant period of time. Among the sediment cpxs there is a positive correlation between 143Nd/ 144Nd and 147Sm/ 144Nd. The rock cpx separates display considerably more scatter. A simple, single-stage differentiation event starting with a uniform mantle source cannot explain these results. At least one episode of mixing with a LREE-enriched component is required. If these results from Ronda are typical of the upper mantle, basalts with different isotopic compositions need not derive from spatially separated mantle sources.

Genetic influence on athletic performance

PubMed Central

Guth, Lisa M.; Roth, Stephen M.

2014-01-01

Purpose of review The purpose of this review is to summarize the existing literature on the genetics of athletic performance, with particular consideration for the relevance to young athletes. Recent findings Two gene variants, ACE I/D and ACTN3 R577X, have been consistently associated with endurance (ACE I/I) and power-related (ACTN3 R/R) performance, though neither can be considered predictive. The role of genetic variation in injury risk and outcomes is more sparsely studied, but genetic testing for injury susceptibility could be beneficial in protecting young athletes from serious injury. Little information on the association of genetic variation with athletic performance in young athletes is available; however, genetic testing is becoming more popular as a means of talent identification. Despite this increase in the use of such testing, evidence is lacking for the usefulness of genetic testing over traditional talent selection techniques in predicting athletic ability, and careful consideration should be given to the ethical issues surrounding such testing in children. Summary A favorable genetic profile, when combined with an optimal training environment, is important for elite athletic performance; however, few genes are consistently associated with elite athletic performance, and none are linked strongly enough to warrant their use in predicting athletic success. PMID:24240283

Influence of precipitation and crop germination on resource selection by mule deer (Odocoileus hemionus) in southwest Colorado

USGS Publications Warehouse

Carrollo, Emily M.; Johnson, Heather E.; Fischer, Justin W.; Hammond, Matthew; Dorsey, Patricia D.; Anderson, Charles; Vercauteren, Kurt C.; Walter, W. David

2017-01-01

Mule deer (Odocoileus hemionus) populations in the western United States provide many benefits to local economies but can also cause considerable damage to agriculture, particularly damage to lucrative crops. Limited information exists to understand resource selection of mule deer in response to annual variation in crop rotation and climatic conditions. We tested the hypothesis that mule deer select certain crops, and in particular sunflower, based on annual climatic variability. Our objective was to use movements, estimates of home range, and resource selection analysis to identify resources selected by mule deer. We used annually-derived crop-specific datasets along with Global Positioning System collars to monitor 14 mule deer in an agricultural area near public lands in southwestern Colorado, USA. We estimated home ranges for two winter seasons that ranged between 7.68 and 9.88 km2, and for two summer seasons that ranged between 5.51 and 6.24 km2. Mule deer selected areas closer to forest and alfalfa for most periods during 2012, but selected areas closer to sunflower in a majority of periods during 2013. Considerable annual variation in climate patterns and precipitation levels appeared to influence selection by mule deer because of variability in crop rotation and success of germination of specific crops.

How do Danish community pharmacies vary in engaging customers in medicine dialogues at the counter - an observational study.

PubMed

Kaae, Susanne; Saleem, Sahdia; Kristiansen, Maria

2014-07-01

Counter counseling is an important part of community pharmacies service delivery. Difficulties arise because customers appear less interested than the staff in discussing their medicine. It is unclear how individual pharmacies differ with regard to overcoming these obstacles. This study explores differences in the communication practices of pharmacies with regard to engaging customers in medicine dialogues. The work of Stevenson et al. describing five types of interaction scenarios at the counter was used for structured overt non-participant observations of 100 encounters in each of five Danish pharmacies. Variation in pharmacies success in engaging customers in medicine dialogues were calculated using descriptive statistics, and the statistical significance of observed differences across pharmacies was analyzed using odds ratios (OR). Considerable differences between the pharmacies were identified. Differences exist in how often pharmacy staff attempts to encourage customers to participate in medication dialogues and how often they succeed. The pharmacies serving the most customers per day were the most successful. A possible link between a low number of refill customers offered counseling and 'success rate' was identified. The pharmacies showed considerable variation in attempts to engage customers in medication dialogues at the counter and success in doing so. The reasons for the identified patterns are unclear.

How do Danish community pharmacies vary in engaging customers in medicine dialogues at the counter – an observational study

PubMed Central

Kaae, Susanne; Saleem, Sahdia; Kristiansen, Maria

2014-01-01

Background Counter counseling is an important part of community pharmacies service delivery. Difficulties arise because customers appear less interested than the staff in discussing their medicine. It is unclear how individual pharmacies differ with regard to overcoming these obstacles. Objective This study explores differences in the communication practices of pharmacies with regard to engaging customers in medicine dialogues. Methods The work of Stevenson et al. describing five types of interaction scenarios at the counter was used for structured overt non-participant observations of 100 encounters in each of five Danish pharmacies. Variation in pharmacies success in engaging customers in medicine dialogues were calculated using descriptive statistics, and the statistical significance of observed differences across pharmacies was analyzed using odds ratios (OR). Results Considerable differences between the pharmacies were identified. Differences exist in how often pharmacy staff attempts to encourage customers to participate in medication dialogues and how often they succeed. The pharmacies serving the most customers per day were the most successful. A possible link between a low number of refill customers offered counseling and ‘success rate’ was identified. Conclusions The pharmacies showed considerable variation in attempts to engage customers in medication dialogues at the counter and success in doing so. The reasons for the identified patterns are unclear. PMID:25243031

Influence of Precipitation and Crop Germination on Resource Selection by Mule Deer (Odocoileus hemionus) in Southwest Colorado.

PubMed

Carrollo, Emily M; Johnson, Heather E; Fischer, Justin W; Hammond, Matthew; Dorsey, Patricia D; Anderson, Charles; Vercauteren, Kurt C; Walter, W David

2017-11-09

Mule deer (Odocoileus hemionus) populations in the western United States provide many benefits to local economies but can also cause considerable damage to agriculture, particularly damage to lucrative crops. Limited information exists to understand resource selection of mule deer in response to annual variation in crop rotation and climatic conditions. We tested the hypothesis that mule deer select certain crops, and in particular sunflower, based on annual climatic variability. Our objective was to use movements, estimates of home range, and resource selection analysis to identify resources selected by mule deer. We used annually-derived crop-specific datasets along with Global Positioning System collars to monitor 14 mule deer in an agricultural area near public lands in southwestern Colorado, USA. We estimated home ranges for two winter seasons that ranged between 7.68 and 9.88 km 2 , and for two summer seasons that ranged between 5.51 and 6.24 km 2 . Mule deer selected areas closer to forest and alfalfa for most periods during 2012, but selected areas closer to sunflower in a majority of periods during 2013. Considerable annual variation in climate patterns and precipitation levels appeared to influence selection by mule deer because of variability in crop rotation and success of germination of specific crops.

Parallel Geographic Variation in Drosophila melanogaster

PubMed Central

Reinhardt, Josie A.; Kolaczkowski, Bryan; Jones, Corbin D.; Begun, David J.; Kern, Andrew D.

2014-01-01

Drosophila melanogaster, an ancestrally African species, has recently spread throughout the world, associated with human activity. The species has served as the focus of many studies investigating local adaptation relating to latitudinal variation in non-African populations, especially those from the United States and Australia. These studies have documented the existence of shared, genetically determined phenotypic clines for several life history and morphological traits. However, there are no studies designed to formally address the degree of shared latitudinal differentiation at the genomic level. Here we present our comparative analysis of such differentiation. Not surprisingly, we find evidence of substantial, shared selection responses on the two continents, probably resulting from selection on standing ancestral variation. The polymorphic inversion In(3R)P has an important effect on this pattern, but considerable parallelism is also observed across the genome in regions not associated with inversion polymorphism. Interestingly, parallel latitudinal differentiation is observed even for variants that are not particularly strongly differentiated, which suggests that very large numbers of polymorphisms are targets of spatially varying selection in this species. PMID:24610860

D/H Ratios of Marine Lipids from Santa Barbara Basin Sediments

NASA Astrophysics Data System (ADS)

Li, C.; Sessions, A.; Kinnaman, F.; Valentine, D.

2006-12-01

With the early successful application of compound-specific D/H analyses to reconstructing paleoclimate records, most subsequent research has focused on understanding organic D/H fractionations in terrestrial environments. Thus we still know very little about natural D/H variations in lipids derived from marine organisms, or indeed if any such variations exist. We have therefore conducted an extensive survey of lipid δD values in two sediment cores collected in the Santa Barbara Basin. These data allow us to examine 1) variations between the lipid products of different organisms, 2) down-core variations due to diagenesis, and 3) differences between sediments deposited under oxic or anoxic bottom-water conditions. Our results show that considerable D/H variability between different marine products does exist. δD values of n-alkanes (except n-C35) ranged from -94 to -175 ‰, and exhibit a systematic offset between odd and even carbon numbers. The δD value of n-C35 is anomalous at -220‰. Isotopic compositions of n-alkanols range from -126 to -221 , with a pattern of progressive D depletion with chain length observed for free alcohols. δD values of sterols range from -215 to -309‰, and show no systematic variation with carbon number. However, offsets do exist between the saturated, monounsaturated, and diunsaturated sterols. Sterols as a group are strongly depleted in D relative to the bacterial-derived hopanols (-166 to -232‰), suggesting possible differences in biosynthetic fractionations by bacteria and eukaryotes. Phytol and phytane δD values roughly ranged from -360 to -410‰, while phytanol was systematically enriched at -300 to -340‰. Fatty acids encompassed much greater variability, with dD values ranging from -55 to -270‰. In general, saturated fatty acids are enriched in D relative to their unsaturated analogs, and long-chain (>C24) acids are enriched in D relative to short-chain (

70,489 primary care encounters: retrospective analysis of morbidity at a primary care centre in Ireland.

PubMed

Molony, D; Beame, C; Behan, W; Crowley, J; Dennehy, T; Quinlan, M; Cullen, W

2016-11-01

While considerable changes are happening in primary care in Ireland and considerable potential exists in intelligence derived from practice-based data to inform these changes, relatively few large-scale general morbidity surveys have been published. To examine the most common reasons why people attend primary care, specifically 'reasons for encounter' (RFEs) among the general practice population and among specific demographic groups (i.e., young children and older adults). We retrospectively examined clinical encounters (which had a diagnostic code) over a 4-year time period. Descriptive analyses were conducted on anonymised data. 70,489 RFEs consultations were recorded (mean 13.53 recorded RFEs per person per annum) and consultations involving multiple RFEs were common. RFE categories for which codes were most commonly recorded were: 'general/unspecified' (31.6 %), 'respiratory' (15.4 %) and 'musculoskeletal' (12.6 %). Most commonly recorded codes were: 'medication renewal' (6.8 %), 'cough' (6.6 %), and 'health maintenance/prevention' (5.8 %). There was considerable variation in the number of RFEs recorded per age group. 6239 RFEs (8.9 %) were recorded by children under 6 years and 15,295 RFEs (21.7 %) were recorded by adults aged over 70. RFEs recorded per calendar month increased consistently through the study period and there was a marked seasonal and temporal variation in the number of RFEs recorded. Practice databases can generate intelligence on morbidity and health service utilisation in the community. Future research to optimise diagnostic coding at a practice level and to promote this activity in a more representative sample of practices is a priority.

Alternative Considerations for Surgical Training and Funding.

PubMed

Martin, Ronald F

2016-02-01

Since the late 1880s surgical residency programs have existed in forms that are similar to our current models. Many important variations have been introduced over time. On aggregate this system has worked remarkably well; though as economic, demographic, and cultural changes continue to evolve, one must wonder if we were to change our models how might we do that and what reasoning could we use. This article's focus is to take a stratospheric view of what could be done, particularly in the United States, rather than characterize what happens in other countries with other health economic systems. Copyright © 2016 Elsevier Inc. All rights reserved.

Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. Report 1. Baseline Studies. Volume II. The Fish, Mammals, and Waterfowl of Lake Conway, Florida.

DTIC Science & Technology

1979-12-01

and Culicidae. 99. In addition to the sporadic occurrence of minor food items, considerable seasonal variations existed in food habits. Overall, the...included Copepoda, Amphipoda, Hydracarina, and eggs. The remaining 16 food groups were of minor importance in the diet (f bluefin killifish and were...Widgeon 1 Empty Ring-necked duck 8 Seed N.A. 3 American coot 17 Fish 1 1 Hydrilla N.A. 15 Lemna N.A. I Seed N.A. 3 Eleocharis N.A. I Chironomidae 1 1

Phylogenomics and comparative genomics of Lactobacillus salivarius, a mammalian gut commensal.

PubMed

Harris, Hugh M B; Bourin, Maxence J B; Claesson, Marcus J; O'Toole, Paul W

2017-08-01

The genus Lactobacillus is a diverse group with a combined species count of over 200. They are the largest group within the lactic acid bacteria and one of the most important bacterial groups involved in food microbiology and human nutrition because of their fermentative and probiotic properties. Lactobacillus salivarius , a species commonly isolated from the gastrointestinal tract of humans and animals, has been described as having potential probiotic properties and results of previous studies have revealed considerable functional diversity existing on both the chromosomes and plasmids. Our study consists of comparative genomic analyses of the functional and phylogenomic diversity of 42 genomes of strains of L . salivarius using bioinformatic techniques. The main aim of the study was to describe intra-species diversity and to determine how this diversity is spread across the replicons. We found that multiple phylogenomic and non-phylogenomic methods used for reconstructing trees all converge on similar tree topologies, showing that different metrics largely agree on the evolutionary history of the species. The greatest genomic variation lies on the small plasmids, followed by the repA -type circular megaplasmid, with the chromosome varying least of all. Additionally, the presence of extra linear and circular megaplasmids is noted in several strains, while small plasmids are not always present. Glycosyl hydrolases, bacteriocins and proteases vary considerably on all replicons while two exopolysaccharide clusters and several clustered regularly interspaced short palindromic repeats-associated systems show a lot of variation on the chromosome. Overall, despite its reputation as a mammalian gastrointestinal tract specialist, the intra-specific variation of L. salivarius reveals potential strain-dependant effects on human health.

Estimating the Medical Care Costs of Obesity in the United States: Systematic Review, Meta-Analysis, and Empirical Analysis.

PubMed

Kim, David D; Basu, Anirban

2016-01-01

The prevalence of adult obesity exceeds 30% in the United States, posing a significant public health concern as well as a substantial financial burden. Although the impact of obesity on medical spending is undeniably significant, the estimated magnitude of the cost of obesity has varied considerably, perhaps driven by different study methodologies. To document variations in study design and methodology in existing literature and to understand the impact of those variations on the estimated costs of obesity. We conducted a systematic review of the twelve recently published articles that reported costs of obesity and performed a meta-analysis to generate a pooled estimate across those studies. Also, we performed an original analysis to understand the impact of different age groups, statistical models, and confounder adjustment on the magnitude of estimated costs using the nationally representative Medical Expenditure Panel Surveys from 2008-2010. We found significant variations among cost estimates in the existing literature. The meta-analysis found that the annual medical spending attributable to an obese individual was $1901 ($1239-$2582) in 2014 USD, accounting for $149.4 billion at the national level. The two most significant drivers of variability in the cost estimates were age groups and adjustment for obesity-related comorbid conditions. It would be important to acknowledge variations in the magnitude of the medical cost of obesity driven by different study design and methodology. Researchers and policy-makers need to be cautious on determining appropriate cost estimates according to their scientific and political questions. Copyright © 2016 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

Arbitrary amplitude nucleus-acoustic solitons in multi-ion quantum plasmas with relativistically degenerate electrons

NASA Astrophysics Data System (ADS)

Sultana, S.; Schlickeiser, R.

2018-02-01

A three component degenerate relativistic quantum plasma (consisting of relativistically degenerate electrons, nondegenerate inertial light nuclei, and stationary heavy nuclei) is considered to model the linear wave and also the electrostatic solitary waves in the light nuclei-scale length. A well-known normal mode analysis is employed to investigate the linear wave properties. A mechanical-motion analog (Sagdeev-type) pseudo-potential approach, which reveals the existence of large amplitude solitary excitations, is adopted to study the nonlinear wave properties. Only the positive potential solitary excitations are found to exist in the plasma medium under consideration. The basic properties of the arbitrary amplitude electrostatic acoustic modes in the light nuclei-scale length and their existence domain in terms of soliton speed (Mach number) are examined. The modifications of solitary wave characteristics and their existence domain with the variation of different key plasma configuration parameters (e.g., electrons degeneracy parameter, inertial light nuclei number density, and degenerate electron number density) are also analyzed. Our results, which may be helpful to explain the basic features of the nonlinear wave propagation in multi-component degenerate quantum plasmas, in connection with astrophysical compact objects (e.g., white dwarfs) are briefly discussed.

Current UK practices in the management of subacromial impingement.

PubMed

Bryceland, James K; Drury, Colin; Tait, Gavin R

2015-07-01

Controversy presently exists surrounding the management of patients with subacromial impingement. This study aims to highlight current UK practices in the management of these patients. BESS members were invited to complete a questionnaire and responses were received from 157 consultant shoulder surgeons. Physiotherapy is an integral part of management for 93% of surgeons with a minimum period of 12 weeks being most popular prior to consideration of arthroscopic subacromial decompression. Subacromial steroid injection is used by 95% and 86% repeat this if the patient has failed to respond to a previous injection by the general practioner. From initial presentation, 77% felt there should be at least 3 months of conservative management before proceeding to surgery. Good but transient response to subacromial injection was considered the best predictor of good surgical outcome by 77%. The coracoacromial ligament is fully released by 78%, although there was greater variation in how aggressive surgeons were with acromioplasty. Most (59%) do not include the nontender acromioclavicular joint to any extent in routine acromioplasty. Hospital physiotherapy protocols are used by 63% for postoperative rehabilitation. Variation exists in the management regimes offered to patients with subacromial impingement, but most employ a minimum period of 12 weeks of conservative management incorporating physiotherapy and at least 2 subacromial steriod injections.

Current UK practices in the management of subacromial impingement

PubMed Central

Drury, Colin; Tait, Gavin R

2015-01-01

Background Controversy presently exists surrounding the management of patients with subacromial impingement. This study aims to highlight current UK practices in the management of these patients. Methods BESS members were invited to complete a questionnaire and responses were received from 157 consultant shoulder surgeons. Results Physiotherapy is an integral part of management for 93% of surgeons with a minimum period of 12 weeks being most popular prior to consideration of arthroscopic subacromial decompression. Subacromial steroid injection is used by 95% and 86% repeat this if the patient has failed to respond to a previous injection by the general practioner. From initial presentation, 77% felt there should be at least 3 months of conservative management before proceeding to surgery. Good but transient response to subacromial injection was considered the best predictor of good surgical outcome by 77%. The coracoacromial ligament is fully released by 78%, although there was greater variation in how aggressive surgeons were with acromioplasty. Most (59%) do not include the nontender acromioclavicular joint to any extent in routine acromioplasty. Hospital physiotherapy protocols are used by 63% for postoperative rehabilitation. Conclusions Variation exists in the management regimes offered to patients with subacromial impingement, but most employ a minimum period of 12 weeks of conservative management incorporating physiotherapy and at least 2 subacromial steriod injections. PMID:27582972

Analytical and between-subject variation of thrombin generation measured by calibrated automated thrombography on plasma samples.

PubMed

Kristensen, Anne F; Kristensen, Søren R; Falkmer, Ursula; Münster, Anna-Marie B; Pedersen, Shona

2018-05-01

The Calibrated Automated Thrombography (CAT) is an in vitro thrombin generation (TG) assay that holds promise as a valuable tool within clinical diagnostics. However, the technique has a considerable analytical variation, and we therefore, investigated the analytical and between-subject variation of CAT systematically. Moreover, we assess the application of an internal standard for normalization to diminish variation. 20 healthy volunteers donated one blood sample which was subsequently centrifuged, aliquoted and stored at -80 °C prior to analysis. The analytical variation was determined on eight runs, where plasma from the same seven volunteers was processed in triplicates, and for the between-subject variation, TG analysis was performed on plasma from all 20 volunteers. The trigger reagents used for the TG assays included both PPP reagent containing 5 pM tissue factor (TF) and PPPlow with 1 pM TF. Plasma, drawn from a single donor, was applied to all plates as an internal standard for each TG analysis, which subsequently was used for normalization. The total analytical variation for TG analysis performed with PPPlow reagent is 3-14% and 9-13% for PPP reagent. This variation can be minimally reduced by using an internal standard but mainly for ETP (endogenous thrombin potential). The between-subject variation is higher when using PPPlow than PPP and this variation is considerable higher than the analytical variation. TG has a rather high inherent analytical variation but considerable lower than the between-subject variation when using PPPlow as reagent.

Ecological and methodological drivers of species' distribution and phenology responses to climate change.

PubMed

Brown, Christopher J; O'Connor, Mary I; Poloczanska, Elvira S; Schoeman, David S; Buckley, Lauren B; Burrows, Michael T; Duarte, Carlos M; Halpern, Benjamin S; Pandolfi, John M; Parmesan, Camille; Richardson, Anthony J

2016-04-01

Climate change is shifting species' distribution and phenology. Ecological traits, such as mobility or reproductive mode, explain variation in observed rates of shift for some taxa. However, estimates of relationships between traits and climate responses could be influenced by how responses are measured. We compiled a global data set of 651 published marine species' responses to climate change, from 47 papers on distribution shifts and 32 papers on phenology change. We assessed the relative importance of two classes of predictors of the rate of change, ecological traits of the responding taxa and methodological approaches for quantifying biological responses. Methodological differences explained 22% of the variation in range shifts, more than the 7.8% of the variation explained by ecological traits. For phenology change, methodological approaches accounted for 4% of the variation in measurements, whereas 8% of the variation was explained by ecological traits. Our ability to predict responses from traits was hindered by poor representation of species from the tropics, where temperature isotherms are moving most rapidly. Thus, the mean rate of distribution change may be underestimated by this and other global syntheses. Our analyses indicate that methodological approaches should be explicitly considered when designing, analysing and comparing results among studies. To improve climate impact studies, we recommend that (1) reanalyses of existing time series state how the existing data sets may limit the inferences about possible climate responses; (2) qualitative comparisons of species' responses across different studies be limited to studies with similar methodological approaches; (3) meta-analyses of climate responses include methodological attributes as covariates; and (4) that new time series be designed to include the detection of early warnings of change or ecologically relevant change. Greater consideration of methodological attributes will improve the accuracy of analyses that seek to quantify the role of climate change in species' distribution and phenology changes. © 2015 John Wiley & Sons Ltd.

Valley plugs, land use, and phytogeomorphic response: Chapter 14

USGS Publications Warehouse

Pierce, Aaron R.; King, Sammy L.; Shroder, John F.

2013-01-01

Anthropogenic alteration of fluvial systems can disrupt functional processes that provide valuable ecosystem services. Channelization alters fluvial parameters and the connectivity of river channels to their floodplains which is critical for productivity, nutrient cycling, flood control, and biodiversity. The effects of channelization can be exacerbated by local geology and land-use activities, resulting in dramatic geomorphic readjustments including the formation of valley plugs. Considerable variation in the response of abiotic processes, including surface hydrology, subsurface hydrology, and sedimentation dynamics, to channelization and the formation of valley plugs. Altered abiotic processes associated with these geomorphic features and readjustments influence biotic processes including species composition, abundance, and successional processes. Considerable interest exists for restoring altered fluvial systems and their floodplains because of their social and ecological importance. Understanding abiotic and biotic responses of channelization and valley-plug formation within the context of the watershed is essential to successful restoration. This chapter focuses on the primary causes of valley-plug formation, resulting fluvial-geomorphic responses, vegetation responses, and restoration and research needs for these systems.

Plans for a new rio-imager experiment in Northern Scandinavia

NASA Astrophysics Data System (ADS)

Nielsen, E.; Hagfors, T.

1997-05-01

To observe the spatial variations and dynamics of charged particle precipitation in the high latitude ionosphere, a riometer experiment is planned, which from the ground will image the precipitation regions over an area of 300 × 300 km with a spatial resolution of 6 km in the zenith, increasing to 12 km at 60° zenith angle. The time resolution is one second. The spatial resolution represents a considerable improvement over existing imaging systems. The experiment employs a Mill's Cross technique not used before in riometer work: two 32 element rows of antennas form the antenna array, two 32 element Butler Matrices achieve directionality, and cross-correlation yield the directional intensities.

Monitoring blood flow responses during topical ALA-PDT

PubMed Central

Becker, Theresa L.; Paquette, Anne D.; Keymel, Kenneth R.; Henderson, Barbara W.; Sunar, Ulas

2011-01-01

Photodynamic therapy (PDT) using topical 5-aminolevulinic acid (ALA) is currently used as a clinical treatment for nonmelanoma skin cancers. In order to optimize PDT treatment, vascular disruption early in treatment must be identified and prevented. We present blood flow responses to topical ALA-PDT in a preclinical model and basal cell carcinoma patients assessed by diffuse correlation spectroscopy (DCS). Our results show that ALA-PDT induced early blood flow changes and these changes were irradiance dependent. It is clear that there exists considerable variation in the blood flow responses in patients from lesion to lesion. Monitoring blood flow parameter may be useful for assessing ALA-PDT response and planning. PMID:21326642

Realized heritability of personalities in the great tit (Parus major).

PubMed

Drent, Pieter J; van Oers, Kees; van Noordwijk, Arie J

2003-01-07

Behaviour under conditions of mild stress shows consistent patterns in all vertebrates: exploratory behaviour, boldness, aggressiveness covary in the same way. The existence of highly consistent individual variation in these behavioural strategies, also referred to as personalities or coping styles, allows us to measure the behaviour under standardized conditions on birds bred in captivity, link the standardized measurements to the behaviour under natural conditions and measure natural selection in the field. We have bred the great tit (Parus major), a classical model species for the study of behaviour under natural conditions, in captivity. Here, we report a realized heritability of 54 +/- 5% for early exploratory behaviour, based on four generations of bi-directional artificial selection. In addition to this, we measured hand-reared juveniles and their wild-caught parents in the laboratory. The heritability found in the mid-offspring-mid-parent regression was significantly different from zero. We have thus established the presence of considerable amounts of genetic variation for personality types in a wild bird.

Start-up Characteristics of Swallow-tailed Axial-grooved Heat Pipe under the conditions of Multiple Heat Sources

NASA Astrophysics Data System (ADS)

Zhang, Renping

2017-12-01

A mathematical model was developed for predicting start-up characteristics of Swallow-tailed Axial-grooved Heat Pipe under the conditions of Multiple Heat Sources. The effects of heat capacitance of heat source, liquid-vapour interfacial evaporation-condensation heat transfer, shear stress at the interface was considered in current model. The interfacial evaporating mass flow rate is based on the kinetic analysis. Time variations of evaporating mass rate, wall temperature and liquid velocity are studied from the start-up to steady state. The calculated results show that wall temperature demonstrates step transition at the junction between the heat source and non-existent heat source on the evaporator. The liquid velocity changes drastically at the evaporator section, however, it has slight variation at the evaporator section without heat source. When the effect of heat source is ignored, the numerical temperature demonstrates a quicker response. With the consideration of capacitance of the heat source, the data obtained from the proposed model agree well with the experimental results.

Personalising exercise recommendations for brain health: considerations and future directions.

PubMed

Barha, Cindy K; Galea, Liisa A; Nagamatsu, Lindsay S; Erickson, Kirk I; Liu-Ambrose, Teresa

2017-04-01

The societal value of strategies that delay the onset and progression of dementia cannot be overstated. Physical activity-unstructured and structured-is a promising, cost-effective strategy for the promotion of brain health. However, a large degree of variation exists in its efficacy. Therefore, to increase its utility as 'medication' for healthy cognitive ageing, it is imperative to identify key moderators and mediators of the positive effects of targeted exercise training on brain health. In this commentary, we focus on the type of targeted exercise training, the determinants of individual variation, including biological sex and genotypic factors, and the mechanisms by which exercise exerts its influence on the brain. We argue that a better understanding of these factors will allow for evidence-based, personalised, tailored exercise recommendations that go beyond the one-size-fits-all approach to successfully combat dementia. 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/.

Efficient identification of context dependent subgroups of risk from genome wide association studies

PubMed Central

Dyson, Greg; Sing, Charles F.

2014-01-01

We have developed a modified Patient Rule-Induction Method (PRIM) as an alternative strategy for analyzing representative samples of non-experimental human data to estimate and test the role of genomic variations as predictors of disease risk in etiologically heterogeneous sub-samples. A computational limit of the proposed strategy is encountered when the number of genomic variations (predictor variables) under study is large (> 500) because permutations are used to generate a null distribution to test the significance of a term (defined by values of particular variables) that characterizes a sub-sample of individuals through the peeling and pasting processes. As an alternative, in this paper we introduce a theoretical strategy that facilitates the quick calculation of Type I and Type II errors in the evaluation of terms in the peeling and pasting processes carried out in the execution of a PRIM analysis that are underestimated and non-existent, respectively, when a permutation-based hypothesis test is employed. The resultant savings in computational time makes possible the consideration of larger numbers of genomic variations (an example genome wide association study is given) in the selection of statistically significant terms in the formulation of PRIM prediction models. PMID:24570412

Genetical Analysis of Chromosomal Interaction Effects on the Activities of the Glucose 6-Phosphate and 6-Phosphogluconate Dehydrogenases in DROSOPHILA MELANOGASTER

PubMed Central

Miyashita, Naohiko; Laurie-Ahlberg, C. C.

1984-01-01

By combining ten second and ten third chromosomes, we investigated chromosomal interaction with respect to the action of the modifier factors on G6PD and 6PGD activities in Drosophila melanogaster. Analysis of variance revealed that highly significant chromosomal interaction exists for both enzyme activities. From the estimated variance components, it was concluded that the variation in enzyme activity attributed to the interaction is as great as the variation attributed to the second chromosome but less than attributed to the third chromosome. The interaction is not explained by the variation of body size (live weight). The interaction is generated from both the lack of correlation of second chromosomes for third chromosome backgrounds and the heterogeneous variance of second chromosomes for different third chromosome backgrounds. Large and constant correlation between G6PD and 6PGD activities were found for third chromosomes with any second chromosome background, whereas the correlations for second chromosomes were much smaller and varied considerably with the third chromosome background. This result suggests that the activity modifiers on the second chromosome are under the influence of third chromosome factors. PMID:6425115

Seasonal variation in the Dutch bovine raw milk composition.

PubMed

Heck, J M L; van Valenberg, H J F; Dijkstra, J; van Hooijdonk, A C M

2009-10-01

In this study, we determined the detailed composition of and seasonal variation in Dutch dairy milk. Raw milk samples representative of the complete Dutch milk supply were collected weekly from February 2005 until February 2006. Large seasonal variation exists in the concentrations of the main components and milk fatty acid composition. Milk lactose concentration was rather constant throughout the season. Milk true protein content was somewhat more responsive to season, with the lowest content in June (3.21 g/100 g) and the highest content in December (3.38 g/100 g). Milk fat concentration increased from a minimum of 4.10 g/100 g in June to a maximum of 4.57 g/100 g in January. The largest (up to 2-fold) seasonal changes in the fatty acid composition were found for trans fatty acids, including conjugated linoleic acid. Milk protein composition was rather constant throughout the season. Milk unsaturation indices, which were used as an indication of desaturase activity, were lowest in spring and highest in autumn. Compared with a previous investigation of Dutch dairy milk in 1992, the fatty acid composition of Dutch raw milk has changed considerably, in particular with a higher content of saturated fatty acids in 2005 milk.

X-autosome incompatibilities in Drosophila melanogaster: tests of Haldane’s rule and geographic patterns within species

PubMed Central

Lachance, Joseph; True, John R.

2010-01-01

Substantial genetic variation exists in natural populations of Drosophila melanogaster. This segregating variation includes alleles at different loci that interact to cause lethality or sterility (synthetic incompatibilities). Fitness epistasis in natural populations has important implications for speciation and the rate of adaptive evolution. To assess the prevalence of epistatic fitness interactions, we placed naturally occurring X chromosomes into genetic backgrounds derived from different geographic locations. Considerable amounts of synthetic incompatibilities were observed between X chromosomes and autosomes: greater than 44% of all combinations were either lethal or sterile. Sex-specific lethality and sterility were also tested to determine whether Haldane's rule holds for within-species variation. Surprisingly, we observed an excess of female sterility in genotypes that were homozygous, but not heterozygous, for the X chromosome. The recessive nature of these incompatibilities is similar to that predicted for incompatibilities underlying Haldane’s rule. Our study also found higher levels of sterility and lethality for genomes that contain chromosomes from different geographical regions. These findings are consistent with the view that genomes are co-adapted gene complexes and that geography affects the likelihood of epistatic fitness interactions. PMID:20455929

Natural mode of horizontal transmission of bovine leukemia virus (BLV): the potential role of tabanids (Tabanus spp.).

PubMed

Manet, G; Guilbert, X; Roux, A; Vuillaume, A; Parodi, A L

1989-10-01

In order to evaluate the potential role of hematophagous insects in the natural spreading of bovine leukemia virus (BLV) infection in cattle, a 2-year survey was carried out involving sequential serological tests on 3328 cattle in three different areas. A parallel entomological study was run over the same period, using continuous trapping, in order to determine both the density and variations of horsefly (Tabanus spp.) populations in the close vicinity of the herds. After statistical analysis, this space-time study showed that: (1) There is a significant positive geographical correlation between the rate of incidence of BLV infection and the density of the horsefly population. (2) Seasonal variations in the incidence rate exist; the highest rates are generally observed during summer (from July of September), and the lowest during winter, spring and early summer (from November to mid-July). (3) There is a time link between the rate of sero-conversion and the variations in activity of the horsefly population. All these data combined would appear to indicate that tabanids play a considerable role in the spread of BLV under natural conditions.

Lidar observed seasonal variation of vertical canopy structure in the Amazon evergreen forests

NASA Astrophysics Data System (ADS)

Tang, H.; Dubayah, R.

2017-12-01

Both light and water are important environmental factors governing tree growth. Responses of tropical forests to their changes are complicated and can vary substantially across different spatial and temporal scales. Of particular interest is the dry-season greening-up of Amazon forests, a phenomenon undergoing considerable debates whether it is real or a "light illusion" caused by artifacts of passive optical remote sensing techniques. Here we analyze seasonal dynamic patterns of vertical canopy structure in the Amazon forests using lidar observations from NASA's Ice, Cloud, and and land Elevation Satellite (ICESat). We found that the net greening of canopy layer coincides with the wet-to-dry transition period, and its net browning occurs mostly at the late dry season. The understory also shows a seasonal cycle, but with an opposite variation to canopy and minimal correlation to seasonal variations in rainfall or radiation. Our results further suggest a potential interaction between canopy layers in the light regime that can optimize the growth of Amazon forests during the dry season. This light regime variability that exists in both spatial and temporal domains can better reveal the dry-season greening-up phenomenon, which appears less obvious when treating the Amazon forests as a whole.

Revised Atmospheric Angular Momentum Series Related to Earth's Variable Rotation under Consideration of Surface Topography

NASA Technical Reports Server (NTRS)

Zhou, Y. H.; Salstein, D. A.; Chen, J. L.

2006-01-01

The atmospheric angular momentum is closely related to variations in the Earth rotation. The atmospheric excitation function (AEF), or namely atmospheric effective angular momentum function, is introduced in studying the atmospheric excitation of the Earth's variable rotation. It may be separated into two portions, i.e, the "wind" terms due to the atmospheric motion relative to the mantle and the "pressure" terms due to the variations of atmospheric mass distribution evident through surface pressure changes. The AEF wind terms during the period of 1948-2004 are re-processed from the NCEP/NCAR (National Centers for Environmental Prediction-National Center for Atmospheric Research) reanalysis 6-hourly wind and pressure fields. Some previous calculations were approximate, in that the wind terms were integrated from an isobaric lower boundary of 1000 hPa. To consider the surface topography effect, however, the AEF is computed by integration using the winds from the Earth's surface to 10 hPa, the top atmospheric model level, instead of from 1000 hPa. For these two cases, only a minor difference, equivalent to approx. 0.004 milliseconds in length-of-day variation, exists with respect to the axial wind term. However, considerable differences, equivalent to 5-6 milliarcseconds in polar motion, are found regarding equatorial wind terms. We further compare the total equatorial AEF (with and without the topographic effect) with the polar motion excitation function (PMEF) during the period of 1980-2003. The equatorial AEF gets generally closer to the PMEF, and improved coherences are found between them when the topography effect is included. Keywords: Atmospheric angular momentum, Atmospheric excitation function, Earth rotation, Topography, Wind, Pressure.

Acute management and outcomes of patients with diabetes mellitus presenting to Canadian emergency departments with hypoglycemia.

PubMed

Rowe, Brian H; Singh, Mira; Villa-Roel, Cristina; Leiter, Lawrence A; Hramiak, Irene; Edmonds, Marcia L; Lang, Eddy; Sivilotti, Marco; Scheuermeyer, Frank; Worster, Andrew; Riley, Jennifer; Afilalo, Marc; Stiell, Ian; Yale, Jean-Francois; Woo, Vincent C; Campbell, Samuel

2015-02-01

This retrospective chart audit examined the demographics, investigations, management and outcomes of adult patients with diabetes mellitus presenting to Canadian emergency departments (EDs). All sites conducted a search of their electronic medical records using International Classification of Diseases, Tenth Revision, codes to identify ED visits for hypoglycemia between 2008 and 2010. Patient characteristics, demographics, ED management, ED resources and outcome are reported. A total of 1039 patients over the age of 17 years were included in the study; 347 (33.4%) were classified as type 1 diabetes and 692 (66.6%) were classified as type 2 diabetes. Type 2 diabetes patients were significantly older (73 vs. 49 years; p<0.0001) and had more chronic conditions recorded on their chart (all p<0.001). Most subjects arrived by ambulance, and triage scores revealed severe presentations in 39% of cases. Treatments for hypoglycemia were common (75.7%) during prehospital transport; 38.5% received intravenous glucose and 40.1% received glucagon. Hypoglycemia treatments in the ED included oral (76.8%), intravenous (29.6%) and continuous infusion (27.7%) of glucose. Diagnostic testing (81.9%) commonly included electrocardiograms (51.9%), chest radiography (37.5%) and head computed tomography scans (14.5%). Most patients (73.5%) were discharged; however, more subjects with type 2 diabetes required admission (30.3 vs. 8.8%). Discharge instructions were documented in only 55.5% of patients, and referral to diabetes services occurred in fewer than 20% of cases. Considerable variation existed in the management of hypoglycemia across EDs. Patients with diabetes presenting to an ED with hypoglycemia consume considerable healthcare resources, and practice variation exists. Emergency departments should develop protocols for the management of hypoglycemia, with attention to discharge planning to reduce recurrence. Copyright © 2015 Canadian Diabetes Association. Published by Elsevier Inc. All rights reserved.

Biological variations in depression and anxiety between East and West.

PubMed

Chen, Po-Yu; Wang, Sheng-Chang; Poland, Russell E; Lin, Keh-Ming

2009-01-01

Ethnicity and culture represent important factors in shaping psychopathology as well as pharmacotherapeutic responses in psychiatric patients. A large body of literature, accumulated over the past several decades, demonstrates that these factors not only determine the metabolism and disposition of medications (pharmacokinetics), but also their interactions with therapeutic targets (pharmacodynamics). This article focuses on the impact of such variations on the diagnosis and treatment of depression and anxiety disorders between East and West. Genes controlling the expression of drug metabolizing enzymes as well as the function of the brain are highly polymorphic, and the patterns and distribution of these polymorphisms are typically divergent across ethnic groups. To the extent that these genetic patterns determine drug response, ethnic variations in these genetic dispositions will lead to differential responses in clinical settings. In addition, the expression of these genes is significantly influenced by environmental factors including diet as well as exposure to other natural products. Superimposed on these biological influences, culturally determined beliefs and behavioral patterns also profoundly influence patients' expectations of treatment response, adherence, and interactions with clinicians. In addition to pharmacotherapeutic responses, emerging data also indicate that significant ethnic variations exist in genetic polymorphisms and neurobiologic correlates (biomarkers) that may be associated with the vulnerability to psychiatric disorders. These considerations argue for the importance of examining biological variations across ethnic groups, especially in the clinical context, in terms of the assessment and treatment of psychiatric patients, and in our understanding of psychiatric phenomenology and nosology.

Genetic studies at the receptor level: investigations in human twins and experimental animals.

PubMed

Propping, P; Friedl, W; Hebebrand, J; Lentes, K U

1986-01-01

In receptors, as in enzymes, quantitative as well as qualitative genetic variation may exist. Studies in inbred strains of mice have shown for various receptors that the receptor density as determined by Bmax values is under genetic control. In healthy adult twins we have shown that the density of alpha-adrenoceptors on platelets is also influenced by genetic factors, since monozygotic twins were much more similar to one another than dizygotic twins. However, Bmax values are up-regulated and down-regulated by endogenous neurotransmitters and pharmacologically active agents. Thus, receptor densities are under considerable regulatory influences. Bmax values therefore reflect regulatory mechanisms rather than innate characteristics of the receptor protein. In another twin study we failed to find evidence for a genetic influence on the density of imipramine-binding sites on platelets. Since qualitative variation (polymorphism) is well known in enzymes, it may also apply to receptors. Qualitative differences in the receptor protein within one species would be of particular interest because of possible functional implications. As a first approach we examined central benzodiazepine receptors by photoaffinity labelling and sodium dodecyl sulphate-polyacrylamide gel electrophoresis. A comparison of fish, frog, chicken, mouse, rat and calf led to the detection of variation between species. Investigations in five inbred mouse and rat strains have not so far revealed genetic variation in benzodiazepine receptors. Nevertheless variation may be detectable by more sensitive methods such as peptide mapping after limited proteolysis or two-dimensional electrophoresis.

High sensitivity capacitive MEMS microphone with spring supported diaphragm

NASA Astrophysics Data System (ADS)

Mohamad, Norizan; Iovenitti, Pio; Vinay, Thurai

2007-12-01

Capacitive microphones (condenser microphones) work on a principle of variable capacitance and voltage by the movement of its electrically charged diaphragm and back plate in response to sound pressure. There has been considerable research carried out to increase the sensing performance of microphones while reducing their size to cater for various modern applications such as mobile communication and hearing aid devices. This paper reviews the development and current performance of several condenser MEMS microphone designs, and introduces a microphone with spring supported diaphragm to further improve condenser microphone performance. The numerical analysis using Coventor FEM software shows that this new microphone design has a higher mechanical sensitivity compared to the existing edge clamped flat diaphragm condenser MEMS microphone. The spring supported diaphragm is shown to have a flat frequency response up to 7 kHz and more stable under the variations of the diaphragm residual stress. The microphone is designed to be easily fabricated using the existing silicon fabrication technology and the stability against the residual stress increases its reproducibility.

Geologic interpretation of gravity data from the Date Creek basin and adjacent areas, west-central Arizona

USGS Publications Warehouse

Otton, James K.; Wynn, Jeffrey C.

1978-01-01

A gravity survey of the Date Creek Basin and adjacent areas was conducted in June 1977 to provide information for the interpretation of basin geology. A comparison of facies relations in the locally uraniferous Chapin Wash Formation and the position of the Anderson mine gravity anomaly in the Date Creek Basin suggested that a relationship between gravity lows and the development of thick lacustrine sections in the region might exist. A second-order residual gravity map derived from the complete Bouguer gravity map for the survey area (derived from survey data and pre-existing U.S. Department of Defense data) shows an excellent correspondence between gravity lows and sediment-filled basins and suggests considerable variation in basin-fill thickness. Using the Anderson mine anomaly as a model, gravity data and facies relations suggest that the southeastern flank of the Aguila Valley gravity low and the gravity low at the western end of the Hassayampa Plain are likely areas for finding thick sections of tuffaceous lacustrine rocks.

Case-mix analysis and variation in rates of non-surgical treatment of older women with operable breast cancer.

PubMed

Morgan, J; Richards, P; Ward, S; Francis, M; Lawrence, G; Collins, K; Reed, M; Wyld, L

2015-08-01

Non-surgical management of older women with oestrogen receptor (ER)-positive operable breast cancer is common in the UK, with up to 40 per cent of women aged over 70 years receiving primary endocrine therapy. Although this may be appropriate for frailer patients, for some it may result in treatment failure, contributing to the poor outcomes seen in this age group. Wide variation in the rates of non-operative management of breast cancer in older women exists across the UK. Case mix may explain some of this variation in practice. Data from two UK regional cancer registries were analysed to determine whether variation in treatment observed between 2002 and 2010 at hospital and clinician level persisted after adjustment for case mix. Expected case mix-adjusted surgery rates were derived by logistic regression using the variables age, proxy Charlson co-morbidity score, deprivation quintile, method of cancer detection, tumour size, stage, grade and node status. Data on 17,129 women aged 70 years or more with ER-positive operable breast cancer were analysed. There was considerable variation in rates of surgery at both hospital and clinician level. Despite adjusting for case mix, this variation persisted at hospital level, although not at clinician level. This study demonstrates variation in selection criteria for older women for operative treatment of early breast cancer, indicating that some older women may be undertreated or overtreated, and may partly explain the inferior disease outcomes in this age group. It emphasizes the urgent need for evidence-based guidelines for treatment selection criteria in older women with breast cancer. © 2015 BJS Society Ltd Published by John Wiley & Sons Ltd.

Assessing response of sediment load variation to climate change and human activities with six different approaches.

PubMed

Zhao, Guangju; Mu, Xingmin; Jiao, Juying; Gao, Peng; Sun, Wenyi; Li, Erhui; Wei, Yanhong; Huang, Jiacong

2018-05-23

Understanding the relative contributions of climate change and human activities to variations in sediment load is of great importance for regional soil, and river basin management. Considerable studies have investigated spatial-temporal variation of sediment load within the Loess Plateau; however, contradictory findings exist among methods used. This study systematically reviewed six quantitative methods: simple linear regression, double mass curve, sediment identity factor analysis, dam-sedimentation based method, the Sediment Delivery Distributed (SEDD) model, and the Soil Water Assessment Tool (SWAT) model. The calculation procedures and merits for each method were systematically explained. A case study in the Huangfuchuan watershed on the northern Loess Plateau has been undertaken. The results showed that sediment load had been reduced by 70.5% during the changing period from 1990 to 2012 compared to that of the baseline period from 1955 to 1989. Human activities accounted for an average of 93.6 ± 4.1% of the total decline in sediment load, whereas climate change contributed 6.4 ± 4.1%. Five methods produced similar estimates, but the linear regression yielded relatively different results. The results of this study provide a good reference for assessing the effects of climate change and human activities on sediment load variation by using different methods. Copyright © 2018. Published by Elsevier B.V.

Establishing Quantitative Within-Subject Confidence Limits For Clinical Stereoroentgenographs

NASA Astrophysics Data System (ADS)

Korn, Edward L.; Baumrind, Sheldon; Chafetz, Neil; Curry, Sean; Moffitt, Francis

1983-07-01

It is now quite clear that under ideal conditions, discrete points can be located on x-ray films with standard deviations of less than 50 i. However, under routine clinical conditions, such considerations as individual variation in anatomy, movement of the subject between exposures, and variations in image quality combine to produce considerable reductions in the confidence which can be placed in quantitative assessments made from stereoroentgenographic films. This paper discusses some considerations involved in designing mathematical models in such a way as to optimize the use of imperfect data in answering specific clinical questions.

Species conservation and natural variation among populations [Chapter 5

Treesearch

Leonard F. Ruggiero; Michael K. Schwartz; Keith B. Aubry; Charles J. Krebs; Amanda Stanley; Steven W. Buskirk

2000-01-01

In conservation planning, the importance of natural variation is often given inadequate consideration. However, ignoring the implications of variation within species may result in conservation strategies that jeopardize, rather than conserve, target species (see Grieg 1979; Turcek 1951; Storfer 1999). Natural variation in the traits of individuals and populations is...

Consideration Sets and Their Role in Modelling Doctor Recommendations About Contraceptives.

PubMed

Fiebig, Denzil G; Viney, Rosalie; Knox, Stephanie; Haas, Marion; Street, Deborah J; Hole, Arne R; Weisberg, Edith; Bateson, Deborah

2017-01-01

Decisions about prescribed contraception are typically the result of a consultation between a woman and her doctor. In order to better understand contraceptive choice within this environment, stated preference methods are utilized to ask doctors about what contraceptive options they would discuss with different types of women. The role of doctors is to confine their discussion to a subset of products that best match their patient. This subset of options forms the consideration set from which the ultimate recommendation is made. Given the existence of consideration sets we address the issue of how to model appropriately the ultimate recommendations. The estimated models enable us to characterize doctor recommendations and how they vary with patient attributes and to highlight where recommendations are clear and when they are uncertain. The results also indicate systematic variation in recommendations across different types of doctors, and in particular we observe that some doctors are reluctant to embrace new products and instead recommend those that are more familiar. Such effects are one possible explanation for the relatively low uptake of more cost effective longer acting reversible contraceptives and indicate that further education and training of doctors may be warranted. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Studies of silicon pn junction solar cells

NASA Technical Reports Server (NTRS)

Lindholm, F. A.; Neugroschel, A.

1977-01-01

Modifications of the basic Shockley equations that result from the random and nonrandom spatial variations of the chemical composition of a semiconductor were developed. These modifications underlie the existence of the extensive emitter recombination current that limits the voltage over the open circuit of solar cells. The measurement of parameters, series resistance and the base diffusion length is discussed. Two methods are presented for establishing the energy bandgap narrowing in the heavily-doped emitter region. Corrections that can be important in the application of one of these methods to small test cells are examined. Oxide-charge-induced high-low-junction emitter (OCI-HLE) test cells which exhibit considerably higher voltage over the open circuit than was previously seen in n-on-p solar cells are described.

Generic Drug Cost Containment in Medicaid: Lessons from Five State MAC Programs

PubMed Central

Abramson, Richard G.; Harrington, Catherine A.; Missmar, Raad; Li, Susan P.; Mendelson, Daniel N.

2004-01-01

In Medicaid, generic drug cost containment revolves around two programs: the Federal upper limit (FUL) program and State maximum allowable cost (MAC) programs. This article analyzes MAC programs in five States and finds considerable variation between these programs and the FUL program in both size and pricing aggressiveness. We conclude that expansion of existing MAC programs and creation of new ones could contribute to cost containment efforts nationwide. Options for States seeking to optimize their efforts include focusing on pricing for drugs with high sales volumes, ensuring that MAC lists include prices for all forms and dosages of listed drug entities, and collaborating with other States or the Federal Government on MAC list operations. PMID:15229994

Extent and character of early tertiary penetrative deformation, Sonora, Northwest Mexico

NASA Technical Reports Server (NTRS)

Anderson, T. H.

1985-01-01

Reconnaissance field work has led to the recognition of extensive Early Tertiary gneiss and schist which are distinguished by weakly developed to highly conspicous northeast to east-trending stretching lineation commonly accompanied by low-dipping foliation. This structural fabric has been imposed on Precambrian to Paleogene rocks. Regionally, minimum ages of deformation are based upon interpreted U-Pb isotopic ages from suites of cogenetic zircon from the Paleogene orthogneiss. Locally, the interpreted ages indicate that ductile deformation continued as late as Oligocene (Anderson and others, 1980; Silver and Anderson, 1984). The consistency of the deformational style is such that, although considerable variation in intensity exists, the fabric can be recognized and correlated in rocks away from the Paleogene orthogneiss.

Sexual Cannibalism as a Manifestation of Sexual Conflict

PubMed Central

Schneider, Jutta M.

2014-01-01

Sexual cannibalism is a well-known example for sexual conflict and has many facets that determine the costs and benefits for the cannibal and the victim. Here, I focus on species in which sexual cannibalism is a general component of a mating system in which males invest maximally in mating with a single (monogyny) or two (bigyny) females. Sexual cannibalism can be a male strategy to maximize paternity and a female strategy to prevent paternity monopolization by any or a particular male. Considerable variation exists between species (1) in the potential of males to monopolize females, and (2) in the success of females in preventing monopolization by males. This opens up exciting future possibilities to investigate sexually antagonistic coevolution in a largely unstudied mating system. PMID:25213095

Methodologic European external quality assurance for DNA sequencing: the EQUALseq program.

PubMed

Ahmad-Nejad, Parviz; Dorn-Beineke, Alexandra; Pfeiffer, Ulrike; Brade, Joachim; Geilenkeuser, Wolf-Jochen; Ramsden, Simon; Pazzagli, Mario; Neumaier, Michael

2006-04-01

DNA sequencing is a key technique in molecular diagnostics, but to date no comprehensive methodologic external quality assessment (EQA) programs have been instituted. Between 2003 and 2005, the European Union funded, as specific support actions, the EQUAL initiative to develop methodologic EQA schemes for genotyping (EQUALqual), quantitative PCR (EQUALquant), and sequencing (EQUALseq). Here we report on the results of the EQUALseq program. The participating laboratories received a 4-sample set comprising 2 DNA plasmids, a PCR product, and a finished sequencing reaction to be analyzed. Data and information from detailed questionnaires were uploaded online and evaluated by use of a scoring system for technical skills and proficiency of data interpretation. Sixty laboratories from 21 European countries registered, and 43 participants (72%) returned data and samples. Capillary electrophoresis was the predominant platform (n = 39; 91%). The median contiguous correct sequence stretch was 527 nucleotides with considerable variation in quality of both primary data and data evaluation. The association between laboratory performance and the number of sequencing assays/year was statistically significant (P <0.05). Interestingly, more than 30% of participants neither added comments to their data nor made efforts to identify the gene sequences or mutational positions. Considerable variations exist even in a highly standardized methodology such as DNA sequencing. Methodologic EQAs are appropriate tools to uncover strengths and weaknesses in both technique and proficiency, and our results emphasize the need for mandatory EQAs. The results of EQUALseq should help improve the overall quality of molecular genetics findings obtained by DNA sequencing.

Spinal surgery: variations in health care costs and implications for episode-based bundled payments.

PubMed

Ugiliweneza, Beatrice; Kong, Maiying; Nosova, Kristin; Huang, Kevin T; Babu, Ranjith; Lad, Shivanand P; Boakye, Maxwell

2014-07-01

Retrospective, observational. To simulate what episodes of care in spinal surgery might look like in a bundled payment system and to evaluate the associated costs and characteristics. Episode-based payment bundling has received considerable attention as a potential method to help curb the rise in health care spending and is being investigated as a new payment model as part of the Affordable Care Act. Although earlier studies investigated bundled payments in a number of surgical settings, very few focused on spine surgery, specifically. We analyzed data from MarketScan. Patients were included in the study if they underwent cervical or lumbar spinal surgery during 2000-2009, had at least 2-year preoperative and 90-day postoperative follow-up data. Patients were grouped on the basis of their diagnosis-related group (DRG) and then tracked in simulated episodes-of-care/payment bundles that lasted for the duration of 30, 60, and 90 days after the discharge from the index-surgical hospitalization. The total cost associated with each episode-of-care duration was measured and characterized. A total of 196,918 patients met our inclusion criteria. Significant variation existed between DRGs, ranging from $11,180 (30-day bundle, DRG 491) to $107,642 (30-day bundle, DRG 456). There were significant cost variations within each individual DRG. Postdischarge care accounted for a relatively small portion of overall bundle costs (range, 4%-8% in 90-day bundles). Total bundle costs remained relatively flat as bundle-length increased (total average cost of 30-day bundle: $33,522 vs. $35,165 for 90-day bundle). Payments to hospitals accounted for the largest portion of bundle costs (76%). There exists significant variation in total health care costs for patients who undergo spinal surgery, even within a given DRG. Better characterization of impacts of a bundled payment system in spine surgery is important for understanding the costs of index procedure hospital, physician services, and postoperative care on potential future health care policy decision making. N/A.

When is rational to order a diagnostic test, or prescribe treatment: the threshold model as an explanation of practice variation.

PubMed

Djulbegovic, Benjamin; van den Ende, Jef; Hamm, Robert M; Mayrhofer, Thomas; Hozo, Iztok; Pauker, Stephen G

2015-05-01

The threshold model represents an important advance in the field of medical decision-making. It is a linchpin between evidence (which exists on the continuum of credibility) and decision-making (which is a categorical exercise - we decide to act or not act). The threshold concept is closely related to the question of rational decision-making. When should the physician act, that is order a diagnostic test, or prescribe treatment? The threshold model embodies the decision theoretic rationality that says the most rational decision is to prescribe treatment when the expected treatment benefit outweighs its expected harms. However, the well-documented large variation in the way physicians order diagnostic tests or decide to administer treatments is consistent with a notion that physicians' individual action thresholds vary. We present a narrative review summarizing the existing literature on physicians' use of a threshold strategy for decision-making. We found that the observed variation in decision action thresholds is partially due to the way people integrate benefits and harms. That is, explanation of variation in clinical practice can be reduced to a consideration of thresholds. Limited evidence suggests that non-expected utility threshold (non-EUT) models, such as regret-based and dual-processing models, may explain current medical practice better. However, inclusion of costs and recognition of risk attitudes towards uncertain treatment effects and comorbidities may improve the explanatory and predictive value of the EUT-based threshold models. The decision when to act is closely related to the question of rational choice. We conclude that the medical community has not yet fully defined criteria for rational clinical decision-making. The traditional notion of rationality rooted in EUT may need to be supplemented by reflective rationality, which strives to integrate all aspects of medical practice - medical, humanistic and socio-economic - within a coherent reasoning system. © 2015 Stichting European Society for Clinical Investigation Journal Foundation.

Sex Bias Exists in Human Surgical Clinical Research

PubMed Central

Mansukhani, Neel A.; Yoon, Dustin Y.; Teter, Katherine A.; Stubbs, Vanessa C.; Helenowski, Irene B.; Woodruff, Teresa K.; Kibbe, Melina R.

2016-01-01

Importance Sex is a variable that is poorly controlled for in clinical research. Objective Determine if sex bias exists in human surgical clinical research, determine if data are reported and analyzed using sex as an independent variable, and identify specialties where the greatest and least sex biases exist. Design Review and data abstraction from published peer-reviewed manuscripts. Setting All original peer-reviewed manuscripts published in 2011 and 2012 in Annals of Surgery, American Journal of Surgery, JAMA Surgery, Journal of Surgical Research, and Surgery. Main Outcome Measures Study type, location, number and sex of subjects, sex matching, and inclusion of sex-based reporting, statistical analysis, and discussion of data. Results Of 2,347 articles reviewed, 1,668 included human subjects. After excluding 365 articles, 1,303 manuscripts remained: 17 (1%) included only males, 41 (3%) included only females, 1,020 (78%) included males and females, and 225 (17%) did not document the sex of the subjects. While females represent over 50% of the total number of subjects included, considerable variability existed with the number of male, female, and unspecified subjects included among the journals, between US domestic and international studies, and between single versus multi-center studies. For manuscripts included in the study, only 38% reported these data by sex, 33% analyzed these data by sex, and 23% included a discussion of sex-based results. Sex matching of the subjects included in the research was poor, with only 18% of the studies matching the inclusion of both sexes by 80%. Upon analysis of the different surgical specialties, a wide variation in sex-based inclusion, matching, and data reporting existed, with colorectal surgery having the best matching of males and females and cardiac surgery having the worst. Conclusion Our data show that sex bias exists in human surgical clinical research. Few studies included men and women equally, less than one-third performed data analysis by sex, and there was wide variation in inclusion and matching of the sexes among the specialties and the journals reviewed. Because clinical research serves as the foundation for evidence-based medicine, it is imperative that this disparity be addressed so that therapies benefit both sexes. PMID:27551816

Causes of the mid-latitudinal daytime NmF2 semi-annual anomaly at solar minimum

NASA Astrophysics Data System (ADS)

Pavlov, A. V.

2018-04-01

Ionospheric ionosonde and radar observations and theoretical calculations of the F2-layer peak altitude, hmF2, and number density, NmF2, over Millstone Hill during winter, spring, summer, and autumn geomagnetically quiet time periods at low solar activity are used to study the causes of the observed daytime NmF2 semi-annual anomaly. It follows from the model simulations that this anomalous phenomenon arises in the ionosphere mainly as a result of seasonal variations of the following atmospheric parameters: (1) the plasma drift along geomagnetic field lines due to corresponding changes in neutral wind components, (2) temperature and number densities of the neutral atmosphere, and (3) an optical thickness of the atmosphere caused by the dependence of the solar zenith angle on the day of the year for the same solar local time. Seasonal variations of the production rate unexcited O+ ions due to chemical reactions involving electronically excited O+ ions contribute to the formation of the NmF2 semi-annual anomaly during the predominant part of the existence time of this anomalous phenomenon. However, these seasonal variations are not significant, and this mechanism should be considered only as an additional source of the NmF2 semi-annual anomaly during its time of existence. The reactions of unexcited O+ ions with vibrationally excited N2 and O2 cause only weak changes of NmF2 and these changes are close in magnitude at a given solar local time during the winter, spring, summer, and autumn daytime conditions under consideration. Ignoring these reactions cannot produce a significant impact on the formation of the NmF2 semi-annual anomaly.

Postmarket policy considerations for biosimilar oncology drugs.

PubMed

Renwick, Matthew J; Smolina, Kate; Gladstone, Emilie J; Weymann, Deirdre; Morgan, Steven G

2016-01-01

Oncology biological products are some of the most expensive drugs on the market and are a growing financial burden on patients and health-care systems. By 2020, numerous major biological cancer drugs will lose their patent protection allowing follow-on competitors, known as biosimilars, to enter the market. Clinical and regulatory considerations for biosimilars have begun to harmonise in Europe and the USA to help to define and streamline the pathway for biosimilar market authorisation. Yet, substantial international variation still exists in the pricing and market uptake of approved biosimilar oncology drugs. Differences in national postmarket policies for biosimilars might explain these disparities in pricing and uptake. In this Policy Review, policy approaches to competition between biosimilars and originators used by seven European countries--Belgium, France, Germany, Italy, the Netherlands, Norway, and the UK--and the USA are discussed, chosen because these countries represent a variety of postmarket policies and build on conclusions from previous work. We discuss these policies within the context of interchangeability, physician prescribing, substitutability, pharmacist dispensing, hospital financing and tendering, and pricing. Copyright © 2016 Elsevier Ltd. All rights reserved.

Assessment of Service Life for Regenerative ECLSS Resin Beds

NASA Technical Reports Server (NTRS)

Cloud, Dale L.; Keilich, Maria C.; Polis, Peter C.; Yanczura, Stephen J.

2013-01-01

The International Space Station (ISS) Water Processor Assembly (WPA) and Oxygen Generation Assembly (OGA) manage and process water at various levels of cleanliness for multiple purposes. The effluent of theWPA and the influent of the OGA require water at very high levels of purity. The bulk of the water purification that occurs in both systems is performed by consumable activated carbon and ion exchange resin beds. Replacement beds must be available on orbit in order to continue the ISS critical processes of water purification and oxygen generation. Various hurdles exist in order to ensure viable spare resin beds. These include the characteristics of resin beds such as: storage environment, shelf life requirements, microbial growth, and variations in the levels and species of contaminants the beds are required to remove. Careful consideration has been given to match water models, bed capacities and spares traffic models to ensure that spares are always viable. The results of these studies and considerations, in particular, how shelf life requirements affect resin bed life management, are documented in this paper.

Scheduling terminology for oral and maxillofacial surgery. Are we speaking a universal language?

PubMed

Howe, T E; Varley, I; Allen, J E; Glossop, A; McKechnie, A

2017-05-01

Use of a universal vocabulary to assist with the scheduling of operations has been shown to considerably reduce delays and improve the use of theatre resources. Within the UK the National Confidential Enquiry into Patient Outcome and Death (NCEPOD) has established a classification to assist with the triage of both emergency and non-emergency operating lists. We completed a survey to assess the uptake and understanding of this classification when scheduling maxillofacial operations. From a list of eight scheduling terms, respondents had to choose one each for 20 different clinical situations (that represented equally) immediate, urgent, expedited, and elective operations as defined by them. A total of 50 surveys were collated. Only 65% of answers selected represented NCPOD terms. 25% of answers represented a term higher and 18% a term lower, on the scale of intervention for the same category of situation. Current NCEPOD terms do not seem to be used universally and are poorly understood. Considerable variation in terminology exists when scheduling maxillofacial operations. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Light-driven growth in Amazon evergreen forests explained by seasonal variations of vertical canopy structure.

PubMed

Tang, Hao; Dubayah, Ralph

2017-03-07

Light-regime variability is an important limiting factor constraining tree growth in tropical forests. However, there is considerable debate about whether radiation-induced green-up during the dry season is real, or an apparent artifact of the remote-sensing techniques used to infer seasonal changes in canopy leaf area. Direct and widespread observations of vertical canopy structures that drive radiation regimes have been largely absent. Here we analyze seasonal dynamic patterns between the canopy and understory layers in Amazon evergreen forests using observations of vertical canopy structure from a spaceborne lidar. We discovered that net leaf flushing of the canopy layer mainly occurs in early dry season, and is followed by net abscission in late dry season that coincides with increasing leaf area of the understory layer. Our observations of understory development from lidar either weakly respond to or are not correlated to seasonal variations in precipitation or insolation, but are strongly related to the seasonal structural dynamics of the canopy layer. We hypothesize that understory growth is driven by increased light gaps caused by seasonal variations of the canopy. This light-regime variability that exists in both spatial and temporal domains can better reveal the drought-induced green-up phenomenon, which appears less obvious when treating the Amazon forests as a whole.

Drivers of protogynous sex change differ across spatial scales.

PubMed

Taylor, Brett M

2014-01-22

The influence of social demography on sex change schedules in protogynous reef fishes is well established, yet effects across spatial scales (in particular, the magnitude of natural variation relative to size-selective fishing effects) are poorly understood. Here, I examine variation in timing of sex change for exploited parrotfishes across a range of environmental, anthropogenic and geographical factors. Results were highly dependent on spatial scale. Fishing pressure was the most influential factor determining length at sex change at the within-island scale where a wide range of anthropogenic pressure existed. Sex transition occurred at smaller sizes where fishing pressure was high. Among islands, however, differences were overwhelmingly predicted by reefal-scale structural features, a pattern evident for all species examined. For the most abundant species, Chlorurus spilurus, length at sex change increased at higher overall densities and greater female-to-male sex ratios at all islands except where targeted by fishermen; here the trend was reversed. This implies differing selective pressures on adult individuals can significantly alter sex change dynamics, highlighting the importance of social structure, demography and the selective forces structuring populations. Considerable life-history responses to exploitation were observed, but results suggest potential fishing effects on demography may be obscured by natural variation at biogeographic scales.

Biological and analytical variations of 16 parameters related to coagulation screening tests and the activity of coagulation factors.

PubMed

Chen, Qian; Shou, Weiling; Wu, Wei; Guo, Ye; Zhang, Yujuan; Huang, Chunmei; Cui, Wei

2015-04-01

To accurately estimate longitudinal changes in individuals, it is important to take into consideration the biological variability of the measurement. The few studies available on the biological variations of coagulation parameters are mostly outdated. We confirmed the published results using modern, fully automated methods. Furthermore, we added data for additional coagulation parameters. At 8:00 am, 12:00 pm, and 4:00 pm on days 1, 3, and 5, venous blood was collected from 31 healthy volunteers. A total of 16 parameters related to coagulation screening tests as well as the activity of coagulation factors were analyzed; these included prothrombin time, fibrinogen (Fbg), activated partial thromboplastin time, thrombin time, international normalized ratio, prothrombin time activity, activated partial thromboplastin time ratio, fibrin(-ogen) degradation products, as well as the activity of factor II, factor V, factor VII, factor VIII, factor IX, and factor X. All intraindividual coefficients of variation (CVI) values for the parameters of the screening tests (except Fbg) were less than 5%. Conversely, the CVI values for the activity of coagulation factors were all greater than 5%. In addition, we calculated the reference change value to determine whether a significant difference exists between two test results from the same individual. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Long-term monitoring of airborne pollen in Alaska and the Yukon: Possible implications for global change

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

Anderson, J.H.

Airborne pollen and spores have been sampled since 1978 in Fairbanks and 1982 Anchorage and other Alaska-Yukon locations for medical and ecological purposes. Comparative analyses of pre- and post-1986 data subsets reveal that after 1986 (1) pollen is in the air earlier, (2) the multiyear average of degree-days promoting pollen onset is little changed while (3) annual variation in degree-days at onset is greater, (4) pollen and spore annual productions are considerably higher, and (5) there is more year-to-year variation in pollen production. These changes probably reflect directional changes in certain weather variables, and there is some indication that theymore » are of global change significance, i.e., related to increasing atmospheric greenhouse gases. Correlations with pollen data suggest that weather variables of high influence are temperatures during specific periods following pollen dispersal in the preceding year and the average temperature in April of the current year. Annual variations in pollen dispersal might be roughly linked to the 11 year sunspot cycle through air temperature mediators. Weather in 1990, apparent pollen production cycles under endogenous control, and the impending sunspot maximum portend a very severe pollen season in 199 existing but unfunded sampling projects.« less

Analyzing the non-stationary space relationship of a city's degree of vegetation and social economic conditions in Shanghai, China using OLS and GWR models

NASA Astrophysics Data System (ADS)

Wang, Kejing; Zhang, Yuan; An, Youzhi; Jing, Zhuoxin; Wang, Chao

2013-09-01

With the fast urbanization process, how does the vegetation environment change in one of the most economically developed metropolis, Shanghai in East China? To answer this question, there is a pressing demand to explore the non-stationary relationship between socio-economic conditions and vegetation across Shanghai. In this study, environmental data on vegetation cover, the Normalized Difference Vegetation Index (NDVI) derived from MODIS imagery in 2003 were integrated with socio-economic data to reflect the city's vegetative conditions at the census block group level. To explore regional variations in the relationship of vegetation and socio-economic conditions, Ordinary Least Squares (OLS) and Geographically Weighted Regression (GWR) models were applied to characterize mean NDVI against three independent socio-economic variables, an urban land use ratio, Gross Domestic Product (GDP) and population density. The study results show that a considerable distinctive spatial variation exists in the relationship for each model. The GWR model has superior effects and higher precision than the OLS model at the census block group scale. So, it is more suitable to account for local effects and geographical variations. This study also indicates that unreasonable excessive urbanization, together with non-sustainable economic development, has a negative influence of vegetation vigor for some neighborhoods in Shanghai.

Survey Shows Variation in Ph.D. Methods Training.

ERIC Educational Resources Information Center

Steeves, Leslie; And Others

1983-01-01

Reports on a 1982 survey of journalism graduate studies indicating considerable variation in research methods requirements and emphases in 23 universities offering doctoral degrees in mass communication. (HOD)

Morphological comparison of five species of poison dart frogs of the genus Ranitomeya (Anura: Dendrobatidae) including the skeleton, the muscle system and inner organs.

PubMed

Krings, Markus; Klein, Benjamin; Heneka, Markus J; Rödder, Dennis

2017-01-01

The morphology of larvae stages of most amphibians are often completely different than in adults. Tadpole descriptions have historically been based on external characters like morphometrics, color pattern and oral disc structure. Other papers described anatomical details by the use of dissections. The increase in micro-CT scanning technology provides an opportunity to quantify and describe in detail internal characters like skeleton, musculature and organs. To date, no such tadpole descriptions exist for the well-studied Neotropical poison dart frog genus Ranitomeya (Anura: Dendrobatidae). Here we provide descriptions of the internal skeletal, musculature and organ structures of five Ranitomeya species and then provide morphological comparisons. Contrary to previous observations, closely related species display several morphological differences. For example, we observed considerable variation in chondrocranial characters, the extent of cranial ossifications, the appearance of some cranial muscles and the arrangement of inner organs. Further studies on the tadpole morphology of more species of Ranitomeya and other dendrobatid genera are needed to enable us to understand the complete morphological variation in this group.

Morphological comparison of five species of poison dart frogs of the genus Ranitomeya (Anura: Dendrobatidae) including the skeleton, the muscle system and inner organs

PubMed Central

Krings, Markus; Klein, Benjamin; Heneka, Markus J.

2017-01-01

The morphology of larvae stages of most amphibians are often completely different than in adults. Tadpole descriptions have historically been based on external characters like morphometrics, color pattern and oral disc structure. Other papers described anatomical details by the use of dissections. The increase in micro-CT scanning technology provides an opportunity to quantify and describe in detail internal characters like skeleton, musculature and organs. To date, no such tadpole descriptions exist for the well-studied Neotropical poison dart frog genus Ranitomeya (Anura: Dendrobatidae). Here we provide descriptions of the internal skeletal, musculature and organ structures of five Ranitomeya species and then provide morphological comparisons. Contrary to previous observations, closely related species display several morphological differences. For example, we observed considerable variation in chondrocranial characters, the extent of cranial ossifications, the appearance of some cranial muscles and the arrangement of inner organs. Further studies on the tadpole morphology of more species of Ranitomeya and other dendrobatid genera are needed to enable us to understand the complete morphological variation in this group. PMID:28235032

A Complementary Note to 'A Lag-1 Smoother Approach to System-Error Estimation': The Intrinsic Limitations of Residual Diagnostics

NASA Technical Reports Server (NTRS)

Todling, Ricardo

2015-01-01

Recently, this author studied an approach to the estimation of system error based on combining observation residuals derived from a sequential filter and fixed lag-1 smoother. While extending the methodology to a variational formulation, experimenting with simple models and making sure consistency was found between the sequential and variational formulations, the limitations of the residual-based approach came clearly to the surface. This note uses the sequential assimilation application to simple nonlinear dynamics to highlight the issue. Only when some of the underlying error statistics are assumed known is it possible to estimate the unknown component. In general, when considerable uncertainties exist in the underlying statistics as a whole, attempts to obtain separate estimates of the various error covariances are bound to lead to misrepresentation of errors. The conclusions are particularly relevant to present-day attempts to estimate observation-error correlations from observation residual statistics. A brief illustration of the issue is also provided by comparing estimates of error correlations derived from a quasi-operational assimilation system and a corresponding Observing System Simulation Experiments framework.

The temperature size rule in arthropods: independent of macro-environmental variables but size dependent.

PubMed

Klok, C Jaco; Harrison, Jon F

2013-10-01

Temperature is a key factor that affects the rates of growth and development in animals, which ultimately determine body size. Although not universal, a widely documented and poorly understood pattern is the inverse relationship between the temperature at which an ectothermic animal is reared and its body size (temperature size rule [TSR]). The proximate and ultimate mechanisms for the TSR remain unclear. To explore possible explanations for the TSR, we tested for correlations between the magnitude/direction of the TSR and latitude, temperature, elevation, habitat, availability of oxygen, capacity for flight, and taxonomic grouping in 98 species/populations of arthropods. The magnitude and direction of the TSR was not correlated with any of the macro-environmental variables we examined, supporting the generality of the TSR. However, body size affected the magnitude and direction of the TSR, with smaller arthropods more likely to demonstrate a classic TSR. Considerable variation among species exists in the TSR, suggesting either strong interactions with nutrition, or selection based on microclimatic or seasonal variation not captured in classic macro-environmental variables.

Rumor spreading model with noise interference in complex social networks

NASA Astrophysics Data System (ADS)

Zhu, Liang; Wang, Youguo

2017-03-01

In this paper, a modified susceptible-infected-removed (SIR) model has been proposed to explore rumor diffusion on complex social networks. We take variation of connectivity into consideration and assume the variation as noise. On the basis of related literature on virus networks, the noise is described as standard Brownian motion while stochastic differential equations (SDE) have been derived to characterize dynamics of rumor diffusion both on homogeneous networks and heterogeneous networks. Then, theoretical analysis on homogeneous networks has been demonstrated to investigate the solution of SDE model and the steady state of rumor diffusion. Simulations both on Barabási-Albert (BA) network and Watts-Strogatz (WS) network display that the addition of noise accelerates rumor diffusion and expands diffusion size, meanwhile, the spreading speed on BA network is much faster than on WS network under the same noise intensity. In addition, there exists a rumor diffusion threshold in statistical average meaning on homogeneous network which is absent on heterogeneous network. Finally, we find a positive correlation between peak value of infected individuals and noise intensity while a negative correlation between rumor lifecycle and noise intensity overall.

Neonatal extravasation injury: prevention and management in Australia and New Zealand-a survey of current practice.

PubMed

Restieaux, Matthew; Maw, Andrew; Broadbent, Roland; Jackson, Pam; Barker, David; Wheeler, Ben

2013-03-11

Extravasation injury remains an important cause of iatrogenic injury in neonatal intensive care. This study aims to describe the current approach to extravasation injury (EI) prevention and management in Neonatal Intensive Care Units (NICUs) in Australia and New Zealand. A literature review regarding extravasation injury in the newborn was carried out to inform questionnaire design. An internet-based survey was then conducted with the clinical directors of the 27 tertiary NICUs in Australia and New Zealand. The survey received a 96% response rate. Approximately two thirds of Australian and New Zealand NICUs have written protocols for prevention and management of extravasation injury. Considerable practice variation was seen for both prevention and treatment of EI. 92% of units had experienced cases of significant EI. Australian and New Zealand tertiary neonatal units clearly recognise EI as an important cause of iatrogenic morbidity and mortality. Significant variation still exists among units with regards to guidelines for both prevention and management of EI. We recommend that neonatal staff should remain vigilant, ensuring that guidelines for the prevention and treatment of EI are available, and rigorously followed.

Estimating geocenter motion and barystatic sea-level variability from GRACE observations with explicit consideration of self-attraction and loading effects

NASA Astrophysics Data System (ADS)

Bergmann-Wolf, I.; Dobslaw, H.

2015-12-01

Estimating global barystatic sea-level variations from monthly mean gravity fields delivered by the Gravity Recovery and Climate Experiment (GRACE) satellite mission requires additional information about geocenter motion. These variations are not available directly due to the mission implementation in the CM-frame and are represented by the degree-1 terms of the spherical harmonics expansion. Global degree-1 estimates can be determined with the method of Swenson et al. (2008) from ocean mass variability, the geometry of the global land-sea distribution, and GRACE data of higher degrees and orders. Consequently, a recursive relation between the derivation of ocean mass variations from GRACE data and the introduction of geocenter motion into GRACE data exists.In this contribution, we will present a recent improvement to the processing strategy described in Bergmann-Wolf et al. (2014) by introducing a non-homogeneous distribution of global ocean mass variations in the geocenter motion determination strategy, which is due to the effects of loading and self-attraction induced by mass redistributions at the surface. A comparison of different GRACE-based oceanographic products (barystatic signal for both the global oceans and individual basins; barotropic transport variations of major ocean currents) with degree-1 terms estimated with a homogeneous and non-homogeneous ocean mass representation will be discussed, and differences in noise levels in most recent GRACE solutions from GFZ (RL05a), CSR, and JPL (both RL05) and their consequences for the application of this method will be discussed.

Equivalent Indels – Ambiguous Functional Classes and Redundancy in Databases

PubMed Central

Assmus, Jens; Kleffe, Jürgen; Schmitt, Armin O.; Brockmann, Gudrun A.

2013-01-01

There is considerable interest in studying sequenced variations. However, while the positions of substitutions are uniquely identifiable by sequence alignment, the location of insertions and deletions still poses problems. Each insertion and deletion causes a change of sequence. Yet, due to low complexity or repetitive sequence structures, the same indel can sometimes be annotated in different ways. Two indels which differ in allele sequence and position can be one and the same, i.e. the alternative sequence of the whole chromosome is identical in both cases and, therefore, the two deletions are biologically equivalent. In such a case, it is impossible to identify the exact position of an indel merely based on sequence alignment. Thus, variation entries in a mutation database are not necessarily uniquely defined. We prove the existence of a contiguous region around an indel in which all deletions of the same length are biologically identical. Databases often show only one of several possible locations for a given variation. Furthermore, different data base entries can represent equivalent variation events. We identified 1,045,590 such problematic entries of insertions and deletions out of 5,860,408 indel entries in the current human database of Ensembl. Equivalent indels are found in sequence regions of different functions like exons, introns or 5' and 3' UTRs. One and the same variation can be assigned to several different functional classifications of which only one is correct. We implemented an algorithm that determines for each indel database entry its complete set of equivalent indels which is uniquely characterized by the indel itself and a given interval of the reference sequence. PMID:23658777

Facial Cosmetics and Attractiveness: Comparing the Effect Sizes of Professionally-Applied Cosmetics and Identity.

PubMed

Jones, Alex L; Kramer, Robin S S

2016-01-01

Forms of body decoration exist in all human cultures. However, in Western societies, women are more likely to engage in appearance modification, especially through the use of facial cosmetics. How effective are cosmetics at altering attractiveness? Previous research has hinted that the effect is not large, especially when compared to the variation in attractiveness observed between individuals due to differences in identity. In order to build a fuller understanding of how cosmetics and identity affect attractiveness, here we examine how professionally-applied cosmetics alter attractiveness and compare this effect with the variation in attractiveness observed between individuals. In Study 1, 33 YouTube models were rated for attractiveness before and after the application of professionally-applied cosmetics. Cosmetics explained a larger proportion of the variation in attractiveness compared with previous studies, but this effect remained smaller than variation caused by differences in attractiveness between individuals. Study 2 replicated the results of the first study with a sample of 45 supermodels, with the aim of examining the effect of cosmetics in a sample of faces with low variation in attractiveness between individuals. While the effect size of cosmetics was generally large, between-person variability due to identity remained larger. Both studies also found interactions between cosmetics and identity-more attractive models received smaller increases when cosmetics were worn. Overall, we show that professionally-applied cosmetics produce a larger effect than self-applied cosmetics, an important theoretical consideration for the field. However, the effect of individual differences in facial appearance is ultimately more important in perceptions of attractiveness.

Facial Cosmetics and Attractiveness: Comparing the Effect Sizes of Professionally-Applied Cosmetics and Identity

PubMed Central

Kramer, Robin S. S.

2016-01-01

Forms of body decoration exist in all human cultures. However, in Western societies, women are more likely to engage in appearance modification, especially through the use of facial cosmetics. How effective are cosmetics at altering attractiveness? Previous research has hinted that the effect is not large, especially when compared to the variation in attractiveness observed between individuals due to differences in identity. In order to build a fuller understanding of how cosmetics and identity affect attractiveness, here we examine how professionally-applied cosmetics alter attractiveness and compare this effect with the variation in attractiveness observed between individuals. In Study 1, 33 YouTube models were rated for attractiveness before and after the application of professionally-applied cosmetics. Cosmetics explained a larger proportion of the variation in attractiveness compared with previous studies, but this effect remained smaller than variation caused by differences in attractiveness between individuals. Study 2 replicated the results of the first study with a sample of 45 supermodels, with the aim of examining the effect of cosmetics in a sample of faces with low variation in attractiveness between individuals. While the effect size of cosmetics was generally large, between-person variability due to identity remained larger. Both studies also found interactions between cosmetics and identity–more attractive models received smaller increases when cosmetics were worn. Overall, we show that professionally-applied cosmetics produce a larger effect than self-applied cosmetics, an important theoretical consideration for the field. However, the effect of individual differences in facial appearance is ultimately more important in perceptions of attractiveness. PMID:27727311

Phylogeny of Fomitopsis pinicola: A species complex

Treesearch

John Haight; Gary A. Laursen; Jessie A. Glaeser; D. Lee Taylor

2016-01-01

Fungal species with a broad distribution may exhibit considerable genetic variation over their geographic ranges. Variation may develop among populations based on geographic isolation, lack of migration, and genetic drift, though this genetic variation may not always be evident when examining phenotypic characters. Fomitopsis pinicola is an...

Variation in the molecular clock of primates.

PubMed

Moorjani, Priya; Amorim, Carlos Eduardo G; Arndt, Peter F; Przeworski, Molly

2016-09-20

Events in primate evolution are often dated by assuming a constant rate of substitution per unit time, but the validity of this assumption remains unclear. Among mammals, it is well known that there exists substantial variation in yearly substitution rates. Such variation is to be expected from differences in life history traits, suggesting it should also be found among primates. Motivated by these considerations, we analyze whole genomes from 10 primate species, including Old World Monkeys (OWMs), New World Monkeys (NWMs), and apes, focusing on putatively neutral autosomal sites and controlling for possible effects of biased gene conversion and methylation at CpG sites. We find that substitution rates are up to 64% higher in lineages leading from the hominoid-NWM ancestor to NWMs than to apes. Within apes, rates are ∼2% higher in chimpanzees and ∼7% higher in the gorilla than in humans. Substitution types subject to biased gene conversion show no more variation among species than those not subject to it. Not all mutation types behave similarly, however; in particular, transitions at CpG sites exhibit a more clocklike behavior than do other types, presumably because of their nonreplicative origin. Thus, not only the total rate, but also the mutational spectrum, varies among primates. This finding suggests that events in primate evolution are most reliably dated using CpG transitions. Taking this approach, we estimate the human and chimpanzee divergence time is 12.1 million years,​ and the human and gorilla divergence time is 15.1 million years​.

Menopause and the influence of culture: another gap for Indigenous Australian women?

PubMed Central

2012-01-01

Background There is great variation in experience of menopause in women around the world. The purpose of this study was to review current understanding of Australian Aboriginal and Torres Strait Islander (Indigenous) women’s experiences of menopause. The literature pertaining to the perception, significance and experience of menopause from a number of cultural groups around the world has been included to provide context for why Indigenous women’s experience might be important for their health and differ from that reported in other studies of Australian women and menopause. Methods A search of databases including Ovid Medline, Pubmed, Web of Science, AUSThealth, AMED, EMBASE, Global Health and PsychINFO was undertaken from January 2011 to April 2011 using the search terms menopause, Indigenous, Aboriginal, attitudes, and perceptions and repeated in September 2012. Results Considerable research shows significant variation across cultures in the menopausal experience. Biological, psychological, social and cultural factors are associated with either positive or negative attitudes, perceptions or experiences of menopause in various cultures. Comparative international literature shows that neither biological nor social factors alone are sufficient to explain the variation in experiences of the menopausal transition. However, a strong influence of culture on the menopause experience can be found. The variation in women’s experience of menopause indicates that different cultural groups of women may have different understandings and needs during the menopausal transition. While considerable literature exists for Australian women as a whole, there has been little investigation of Australian Indigenous women, with only two research studies related to Indigenous women’s experiences of menopause identified. Conclusions Differences in biocultural experience of menopause around the world suggest the importance of biocultural research. For the Indigenous women of Australia, the relative contribution of culture, social disadvantage and poor general health compared with non-Indigenous women to the experience of menopause is unknown. As such, further research and understanding of the experience of Indigenous women around Australia is needed. This information could assist individuals, families, cultural groups and healthcare providers to enhance management and support for Indigenous Australian women. PMID:23234340

Menopause and the influence of culture: another gap for Indigenous Australian women?

PubMed

Jones, Emma K; Jurgenson, Janelle R; Katzenellenbogen, Judith M; Thompson, Sandra C

2012-12-12

There is great variation in experience of menopause in women around the world. The purpose of this study was to review current understanding of Australian Aboriginal and Torres Strait Islander (Indigenous) women's experiences of menopause. The literature pertaining to the perception, significance and experience of menopause from a number of cultural groups around the world has been included to provide context for why Indigenous women's experience might be important for their health and differ from that reported in other studies of Australian women and menopause. A search of databases including Ovid Medline, Pubmed, Web of Science, AUSThealth, AMED, EMBASE, Global Health and PsychINFO was undertaken from January 2011 to April 2011 using the search terms menopause, Indigenous, Aboriginal, attitudes, and perceptions and repeated in September 2012. Considerable research shows significant variation across cultures in the menopausal experience. Biological, psychological, social and cultural factors are associated with either positive or negative attitudes, perceptions or experiences of menopause in various cultures. Comparative international literature shows that neither biological nor social factors alone are sufficient to explain the variation in experiences of the menopausal transition. However, a strong influence of culture on the menopause experience can be found. The variation in women's experience of menopause indicates that different cultural groups of women may have different understandings and needs during the menopausal transition. While considerable literature exists for Australian women as a whole, there has been little investigation of Australian Indigenous women, with only two research studies related to Indigenous women's experiences of menopause identified. Differences in biocultural experience of menopause around the world suggest the importance of biocultural research. For the Indigenous women of Australia, the relative contribution of culture, social disadvantage and poor general health compared with non-Indigenous women to the experience of menopause is unknown. As such, further research and understanding of the experience of Indigenous women around Australia is needed. This information could assist individuals, families, cultural groups and healthcare providers to enhance management and support for Indigenous Australian women.

Population-Based Resequencing of Experimentally Evolved Populations Reveals the Genetic Basis of Body Size Variation in Drosophila melanogaster

PubMed Central

Turner, Thomas L.; Stewart, Andrew D.; Fields, Andrew T.; Rice, William R.; Tarone, Aaron M.

2011-01-01

Body size is a classic quantitative trait with evolutionarily significant variation within many species. Locating the alleles responsible for this variation would help understand the maintenance of variation in body size in particular, as well as quantitative traits in general. However, successful genome-wide association of genotype and phenotype may require very large sample sizes if alleles have low population frequencies or modest effects. As a complementary approach, we propose that population-based resequencing of experimentally evolved populations allows for considerable power to map functional variation. Here, we use this technique to investigate the genetic basis of natural variation in body size in Drosophila melanogaster. Significant differentiation of hundreds of loci in replicate selection populations supports the hypothesis that the genetic basis of body size variation is very polygenic in D. melanogaster. Significantly differentiated variants are limited to single genes at some loci, allowing precise hypotheses to be formed regarding causal polymorphisms, while other significant regions are large and contain many genes. By using significantly associated polymorphisms as a priori candidates in follow-up studies, these data are expected to provide considerable power to determine the genetic basis of natural variation in body size. PMID:21437274

Naturally occurring variation in tadpole morphology and performance linked to predator regime

Treesearch

James B. Johnson; Daniel Saenz; Cory K. Adams; Toby J. Hibbitts

2015-01-01

Divergent natural selection drives a considerable amount of the phenotypic and genetic variation observed in natural populations. For example, variation in the predator community can generate conflicting selection on behavioral, life-history, morphological, and performance traits. Differences in predator regime can subsequently increase phenotypic and genetic...

Study on Analysis of Variance on the indigenous wild and cultivated rice species of Manipur Valley

NASA Astrophysics Data System (ADS)

Medhabati, K.; Rohinikumar, M.; Rajiv Das, K.; Henary, Ch.; Dikash, Th.

2012-10-01

The analysis of variance revealed considerable variation among the cultivars and the wild species for yield and other quantitative characters in both the years of investigation. The highly significant differences among the cultivars in year wise and pooled analysis of variance for all the 12 characters reveal that there are enough genetic variabilities for all the characters studied. The existence of genetic variability is of paramount importance for starting a judicious plant breeding programme. Since introduced high yielding rice cultivars usually do not perform well. Improvement of indigenous cultivars is a clear choice for increase of rice production. The genetic variability of 37 rice germplasms in 12 agronomic characters estimated in the present study can be used in breeding programme

Unnecessary surgery.

PubMed Central

Leape, L L

1989-01-01

The extent of unnecessary surgery has been the object of considerable speculation and occasional wild accusation in recent years. Most evidence of the existence of unnecessary surgery, such as information from studies of geographic variations and the results of second surgical opinion programs, is circumstantial. However, results from the few studies that have measured unnecessary surgery directly indicate that for some highly controversial operations the fraction that are unwarranted could be as high as 30 percent. Most unnecessary surgery results from physician uncertainty about the effectiveness of an operation. Elimination of this uncertainty requires more efficient production and dissemination of scientific information about clinical effectiveness. In the absence of adequate data from scientific studies, the use of a consensus of expert opinion, disseminated by means of comprehensive practice guidelines, offers the best opportunity to identify and eliminate unnecessary surgery. PMID:2668237

Flocking and invariance of velocity angles.

PubMed

Liu, Le; Huang, Lihong; Wu, Jianhong

2016-04-01

Motsch and Tadmor considered an extended Cucker-Smale model to investigate the flocking behavior of self-organized systems of interacting species. In this extended model, a cone of the vision was introduced so that outside the cone the influence of one agent on the other is lost and hence the corresponding influence function takes the value zero. This creates a problem to apply the Motsch-Tadmor and Cucker-Smale method to prove the flocking property of the system. Here, we examine the variation of the velocity angles between two arbitrary agents, and obtain a monotonicity property for the maximum cone of velocity angles. This monotonicity permits us to utilize existing arguments to show the flocking property of the system under consideration, when the initial velocity angles satisfy some minor technical constraints.

Effects of climate change on saltwater intrusion at Hilton Head Island, SC. U.S.A.

USGS Publications Warehouse

Payne, Dorothy F.

2010-01-01

Sea‐level rise and changes in precipitation patterns may contribute to the occurrence and affect the rate of saltwater contamination in the Hilton Head Island, South Carolina area. To address the effects of climate change on saltwater intrusion, a threedimensional, finite‐element, variable‐density, solute‐transport model was developed to simulate different rates of sea‐level rise and variation in onshore freshwater recharge. Model simulation showed that the greatest effect on the existing saltwater plume occurred from reducing recharge, suggesting recharge may be a more important consideration in saltwater intrusion management than estimated rates of sea‐level rise. Saltwater intrusion management would benefit from improved constraints on recharge rates by using model‐independent, local precipitation and evapotranspiration data, and improving estimates of confining unit hydraulic properties.

Discovering and understanding the vector field using simulation in android app

NASA Astrophysics Data System (ADS)

Budi, A.; Muliyati, D.

2018-05-01

An understanding of vector field’s concepts are fundamental parts of the electrodynamics course. In this paper, we use a simple simulation that can be used to show qualitative imaging results as a variation of the vector field. Android application packages the simulation with consideration of the efficiency of use during the lecture. In addition, this simulation also trying to cover the divergences and curl concepts from the same conditions that students have a complete understanding and can distinguish concepts that have been described only mathematically. This simulation is designed to show the relationship between the field magnitude and its potential. This application can show vector field simulations in various conditions that help to improve students’ understanding of vector field concepts and their relation to particle existence around the field vector.

Avionics Integrity Program (AVIP). Volume 4. Force Management - Economic Life Considerations.

DTIC Science & Technology

1984-03-01

often used to refer to the period of time during which financial considerations justify the continued use of an existing system. The study addresses...rejporLs incl-ude contractor ei forts between September 1983 and Marih 1984. Each report represents a completed study in a specific area and stands alone...during which financial considerations justify the selection or continued use of a system. A variety of definitions currently exist for economic life. One

Variation in tooth morphology of Gorilla gorilla.

PubMed

Uchida, A

1998-01-01

Gorilla gorilla exemplifies a species that shows considerable variation in habitat, behaviour, genetic structure and morphology. This study examines variation of dental morphology in gorillas. Despite the marked size dimorphism, there are no significant shape differences between the sexes within subspecies. Differences in dental morphology, including tooth cusp proportions between the western G. g. gorilla and the eastern G. g. beringei are considerable. Although more similar to G. g. beringei than to the western G. g. gorilla, G. g. graueri also shows distinct morphological features. This indicates that the morphology of G. g. graueri is not merely intermediate, and genetic isolation between the two eastern subspecies could have had a substantial influence. Such extensive variation in dental morphology in Gorilla gorilla can be considered to be the result of an interesting combination of factors, including local dietary adaptations.

A current profile and assessment of north american cholecystectomy: results from the american college of surgeons national surgical quality improvement program.

PubMed

Ingraham, Angela M; Cohen, Mark E; Ko, Clifford Y; Hall, Bruce Lee

2010-08-01

Cholecystectomy is among the most common surgical procedures performed in the United States. The current state of cholecystectomy outcomes, including variations in hospital performance, is unclear. The objective of this study is to compare the risk factors, indications, and 30-day outcomes, as well as variations in hospital performance associated with laparoscopic (LC) versus open cholecystectomy (OC) at 221 hospitals during a 4-year period. Using the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database (2005-2008), patients were identified who underwent cholecystectomy and related procedures (cholangiogram and/or common bile duct exploration). Four outcomes were studied, ie, 30-day overall morbidity, serious morbidity, surgical site infections, and mortality. Forward stepwise logistic regressions yielded patient-level predicted probabilities, and hospital-level observed-to-expected ratios were determined. Of 65,511 patients, 58,659 (89.5%) underwent LC; 6,852 (10.5%) underwent OC. OC patients were considerably older with a higher comorbidity burden. LC patients were less likely to experience any morbidity (3.1% versus 17.8%; p < 0.0001), a serious morbidity (1.4% versus 11.1%; p < 0.0001), or a surgical site infection (1.3% versus 8.4%; p < 0.0001), and less likely to die (0.3% versus 2.8%; p < 0.0001). Observed-to-expected ratios for overall morbidity ranged from 0 to 3.55; for serious morbidity, 0 to 3.23; for surgical site infection, 0 to 7.02; for mortality, 0 to 13.05. Although overall incidence of adverse events is low after LC, substantial morbidity and mortality are associated with OC. Additionally, controlling for patient- and operation-related factors, considerable variations exist in hospital performance when evaluating 30-day outcomes after cholecystectomy. Copyright 2010 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

Refugia revisited: individualistic responses of species in space and time

PubMed Central

Stewart, John R.; Lister, Adrian M.; Barnes, Ian; Dalén, Love

2010-01-01

Climate change in the past has led to significant changes in species' distributions. However, how individual species respond to climate change depends largely on their adaptations and environmental tolerances. In the Quaternary, temperate-adapted taxa are in general confined to refugia during glacials while cold-adapted taxa are in refugia during interglacials. In the Northern Hemisphere, evidence appears to be mounting that in addition to traditional southern refugia for temperate species, cryptic refugia existed in the North during glacials. Equivalent cryptic southern refugia, to the south of the more conventional high-latitude polar refugia, exist in montane areas during periods of warm climate, such as the current interglacial. There is also a continental/oceanic longitudinal gradient, which should be included in a more complete consideration of the interaction between species ranges and climates. Overall, it seems clear that there is large variation in both the size of refugia and the duration during which species are confined to them. This has implications for the role of refugia in the evolution of species and their genetic diversity. PMID:19864280

Environmental Assessment. Moanalua Shopping Center Redevelopment Oahu, Hawaii

DTIC Science & Technology

2004-08-01

redevelop the approximately 15-acre MSC site as in-kind consideration for the fair market rent which would be due under a 40-year lease of the...the existing approximately 15-acre (6-hectare) MSC site as in-kind consideration for the fair market rent which would be due under a 40-year lease of...would redevelop the existing MSC site as in-kind consideration for the fair market rent which would be due under a 40-year lease of the properties

Interpreting species-specific variation in tree-ring oxygen isotope ratios among three temperate forest trees

Treesearch

Xin Song; Kenneth S. Clark; Brent R. Helliker

2014-01-01

Although considerable variation has been documented in tree-ring cellulose oxygen isotope ratios (δ18Ocell) among co-occurring species, the underlying causes are unknown. Here, we used a combination of field measurements and modelling to investigate the mechanisms behind variations in late-wood δ

Temporal-spatial variation and partitioning of dissolved and particulate heavy metal(loid)s in a river affected by mining activities in Southern China.

PubMed

Wang, Juan; Liu, Guannan; Wu, Hao; Zhang, Tao; Liu, Xinhui; Li, Wuqing

2018-04-01

The physicochemical properties and heavy metal(loid) concentrations of the river water both fluctuate greatly along the river affected by mining activities, and the transportation of heavy metal(loid)s is therefore more complicated than unpolluted river. Dissolved and particulate heavy metal(loid)s in a river polluted by mining activities were measured to study their temporal-spatial variation and partitioning. The concentrations of dissolved arsenic (As), cadmium (Cd), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) were considerably high at the sites near the mine area. Notably, dissolved As at most sites were higher than the Chinese quality criterion of class II for surface water indicating high environmental risk. Mn and Pb at most sites and Ni at a part of the sites mainly existed in the particulate phase. For other heavy metal(loid)s, i.e., As, Cd, chromium (Cr), and Zn, the particulate phase was extremely high at the sites near the mine area and responsible for heavy metal(loid) transport. Significant correlations between particulate heavy metal(loid)s and temperature and electrical conductivity (EC) were found. However, the partitioning of heavy metal(loid)s did not significantly relate to the river water properties, due to most heavy metal(loid)s in suspended particulate matter (SPM) are stable and affected less by water properties. Except for Cr and Ni, other heavy metal(loid)s showed high concentrations in sediments, and considerable Cd, Mn, and Zn existed in exchangeable and carbonate fraction indicating high environmental risk. The environmental assessment of SPM showed that Cd, Zn, and As, as the main pollutants in SPM, all reached extremely polluted level at the sites near the mine area, and the environmental risk of heavy metal(loid)s in SPM was higher during dry season than that during wet season. The results can contribute to understanding the partitioning and transportation of heavy metal(loid)s in the river affected by mining activities.

Magnetic field variation caused by rotational speed change in a magnetohydrodynamic dynamo.

PubMed

Miyagoshi, Takehiro; Hamano, Yozo

2013-09-20

We have performed numerical magnetohydrodynamic dynamo simulations in a spherical shell with rotational speed or length-of-day (LOD) variation, which is motivated by correlations between geomagnetic field and climatic variations with ice and non-ice ages. The results show that LOD variation leads to magnetic field variation whose amplitude is considerably larger than that of LOD variation. The heat flux at the outer sphere and the zonal flow also change. The mechanism of the magnetic field variation due to LOD variation is also found. The keys are changes of dynamo activity and Joule heating.

Estimating geocenter motion and barystatic sea-level variability from GRACE observations with explicit consideration of self-attraction and loading effects

NASA Astrophysics Data System (ADS)

Bergmann-Wolf, Inga; Dobslaw, Henryk

2016-04-01

Estimating global barystatic sea-level variations from monthly mean gravity fields delivered by the Gravity Recovery and Climate Experiment (GRACE) satellite mission requires additional information about geocenter motion. These variations are not available directly due to the mission implementation in the CM-frame and are represented by the degree-1 terms of the spherical harmonics expansion. Global degree-1 estimates can be determined with the method of Swenson et al. (2008) from ocean mass variability, the geometry of the global land-sea distribution, and GRACE data of higher degrees and orders. Consequently, a recursive relation between the derivation of ocean mass variations from GRACE data and the introduction of geocenter motion into GRACE data exists. In this contribution, we will present a recent improvement to the processing strategy described in Bergmann-Wolf et al. (2014) by introducing a non-homogeneous distribution of global ocean mass variations in the geocenter motion determination strategy, which is due to the effects of loading and self-attraction induced by mass redistributions at the surface. A comparison of different GRACE-based oceanographic products (barystatic signal for both the global oceans and individual basins; barotropic transport variations of major ocean currents) with degree-1 terms estimated with a homogeneous and non-homogeneous ocean mass representation will be discussed, and differences in noise levels in most recent GRACE solutions from GFZ (RL05a), CSR, and JPL (both RL05) and their consequences for the application of this method will be discussed. Swenson, S., D. Chambers and J. Wahr (2008), Estimating geocenter variations from a combination of GRACE and ocean model output, J. Geophys. Res., 113, B08410 Bergmann-Wolf, I., L. Zhang and H. Dobslaw (2014), Global Eustatic Sea-Level Variations for the Approximation of Geocenter Motion from GRACE, J. Geod. Sci., 4, 37-48

Explaining variance of avian malaria infection in the wild: the importance of host density, habitat, individual life-history and oxidative stress.

PubMed

Isaksson, Caroline; Sepil, Irem; Baramidze, Vladimer; Sheldon, Ben C

2013-04-08

Avian malaria (Plasmodium sp.) is globally widespread, but considerable variation exists in infection (presence/absence) patterns at small spatial scales. This variation can be driven by variation in ecology, demography, and phenotypic characters, in particular those that influence the host's resistance. Generation of reactive oxygen species (ROS) is one of the host's initial immune responses to combat parasitic invasion. However, long-term ROS exposure can harm the host and the redox response therefore needs to be adjusted according to infection stage and host phenotype. Here we use experimental and correlational approaches to assess the relative importance of host density, habitat composition, individual level variation and redox physiology for Plasmodium infection in a wild population of great tits, Parus major. We found that 36% of the great tit population was infected with Plasmodium (22% P. relictum and 15% P. circumflexum prevalence) and that patterns of infection were Plasmodium species-specific. First, the infection of P. circumflexum was significantly higher in areas with experimental increased host density, whereas variation in P. relictum infection was mainly attributed to age, sex and reproduction. Second, great tit antioxidant responses - total and oxidizied glutathione - showed age- , sex- and Plasmodium species-specific patterns between infected and uninfected individuals, but reactive oxygen metabolites (ROM) showed only a weak explanatory power for patterns of P. relictum infection. Instead ROM significantly increased with Plasmodium parasitaemia. These results identify some key factors that influence Plasmodium infection in wild birds, and provide a potential explanation for the underlying physiological basis of recently documented negative effects of chronic avian malaria on survival and reproductive success.

To pair or not to pair: Sources of social variability with white-faced saki monkeys (Pithecia pithecia) as a case study.

PubMed

Thompson, Cynthia L

2016-05-01

Intraspecific variability in social systems is gaining increased recognition in primatology. Many primate species display variability in pair-living social organizations through incorporating extra adults into the group. While numerous models exist to explain primate pair-living, our tools to assess how and why variation in this trait occurs are currently limited. Here I outline an approach which: (i) utilizes conceptual models to identify the selective forces driving pair-living; (ii) outlines novel possible causes for variability in social organization; and (iii) conducts a holistic species-level analysis of social behavior to determine the factors contributing to variation in pair-living. A case study on white-faced sakis (Pithecia pithecia) is used to exemplify this approach. This species lives in either male-female pairs or groups incorporating "extra" adult males and/or females. Various conceptual models of pair-living suggest that high same-sex aggression toward extra-group individuals is a key component of the white-faced saki social system. Variable pair-living in white-faced sakis likely represents alternative strategies to achieve competency in this competition, in which animals experience conflicting selection pressures between achieving successful group defense and maintaining sole reproductive access to mates. Additionally, independent decisions by individuals may generate social variation by preventing other animals from adopting a social organization that maximizes fitness. White-faced saki inter-individual relationships and demographic patterns also lend conciliatory support to this conclusion. By utilizing both model-level and species-level approaches, with a consideration for potential sources of variation, researchers can gain insight into the factors generating variation in pair-living social organizations. © 2014 The Authors. American Journal of Primatology published by Wiley Periodicals, Inc.

The evolution of transcriptional regulation in eukaryotes

NASA Technical Reports Server (NTRS)

Wray, Gregory A.; Hahn, Matthew W.; Abouheif, Ehab; Balhoff, James P.; Pizer, Margaret; Rockman, Matthew V.; Romano, Laura A.

2003-01-01

Gene expression is central to the genotype-phenotype relationship in all organisms, and it is an important component of the genetic basis for evolutionary change in diverse aspects of phenotype. However, the evolution of transcriptional regulation remains understudied and poorly understood. Here we review the evolutionary dynamics of promoter, or cis-regulatory, sequences and the evolutionary mechanisms that shape them. Existing evidence indicates that populations harbor extensive genetic variation in promoter sequences, that a substantial fraction of this variation has consequences for both biochemical and organismal phenotype, and that some of this functional variation is sorted by selection. As with protein-coding sequences, rates and patterns of promoter sequence evolution differ considerably among loci and among clades for reasons that are not well understood. Studying the evolution of transcriptional regulation poses empirical and conceptual challenges beyond those typically encountered in analyses of coding sequence evolution: promoter organization is much less regular than that of coding sequences, and sequences required for the transcription of each locus reside at multiple other loci in the genome. Because of the strong context-dependence of transcriptional regulation, sequence inspection alone provides limited information about promoter function. Understanding the functional consequences of sequence differences among promoters generally requires biochemical and in vivo functional assays. Despite these challenges, important insights have already been gained into the evolution of transcriptional regulation, and the pace of discovery is accelerating.

Genetic variation in the endangered Southwestern Willow Flycatcher

USGS Publications Warehouse

Busch, Joseph; Miller, Mark P.; Paxton, E.H.; Sogge, M.K.; Keim, Paul

2000-01-01

The Southwestern Willow Flycatcher (Empidonax traillii extimus) is an endangered Neotropical migrant that breeds in isolated remnants of dense riparian habitat in the southwestern United States. We estimated genetic variation at 20 breeding sites of the Southwestern Willow Flycatcher (290 individuals) using 38 amplified fragment length polymorphisms (AFLPs). Our results suggest that considerable genetic diversity exists within the subspecies and within local breeding sites. Statistical analyses of genetic variation revealed only slight, although significant, differentiation among breeding sites (Mantel's r = 0.0705, P < 0.0005; θ = 0.0816, 95% CI = 0.0608 to 0.1034; ΦST = 0.0458, P < 0.001). UPGMA cluster analysis of the AFLP markers indicates that extensive gene flow has occurred among breeding sites. No one site stood out as being genetically unique or isolated. Therefore, the small level of genetic structure that we detected may not be biologically significant. Ongoing field studies are consistent with this conclusion. Of the banded birds that were resighted or recaptured in Arizona during the 1996 to 1998 breeding seasons, one-third moved between breeding sites and two-thirds were philopatric. Low differentiation may be the result of historically high rangewide diversity followed by recent geographic isolation of breeding sites, although observational data indicate that gene flow is a current phenomenon. Our data suggest that breeding groups of E. t. extimus act as a metapopulation.

3D mechanical stratigraphy of a deformed multi-layer: Linking sedimentary architecture and strain partitioning

NASA Astrophysics Data System (ADS)

Cawood, Adam J.; Bond, Clare E.

2018-01-01

Stratigraphic influence on structural style and strain distribution in deformed sedimentary sequences is well established, in models of 2D mechanical stratigraphy. In this study we attempt to refine existing models of stratigraphic-structure interaction by examining outcrop scale 3D variations in sedimentary architecture and the effects on subsequent deformation. At Monkstone Point, Pembrokeshire, SW Wales, digital mapping and virtual scanline data from a high resolution virtual outcrop have been combined with field observations, sedimentary logs and thin section analysis. Results show that significant variation in strain partitioning is controlled by changes, at a scale of tens of metres, in sedimentary architecture within Upper Carboniferous fluvio-deltaic deposits. Coupled vs uncoupled deformation of the sequence is defined by the composition and lateral continuity of mechanical units and unit interfaces. Where the sedimentary sequence is characterized by gradational changes in composition and grain size, we find that deformation structures are best characterized by patterns of distributed strain. In contrast, distinct compositional changes vertically and in laterally equivalent deposits results in highly partitioned deformation and strain. The mechanical stratigraphy of the study area is inherently 3D in nature, due to lateral and vertical compositional variability. Consideration should be given to 3D variations in mechanical stratigraphy, such as those outlined here, when predicting subsurface deformation in multi-layers.

Takeoff certification considerations for large subsonic and supersonic transport airplanes using the Ames flight simulator for advanced aircraft

NASA Technical Reports Server (NTRS)

Snyder, C. T.; Drinkwater, F. J., III; Fry, E. B.; Forrest, R. D.

1973-01-01

Data for use in development of takeoff airworthiness standards for new aircraft designs such as the supersonic transport (SST) and the large wide-body subsonic jet transport are provided. An advanced motion simulator was used to compare the performance and handling characteristics of three representative large jet transports during specific flight certification tasks. Existing regulatory constraints and methods for determining rotation speed were reviewed, and the effects on takeoff performance of variations in rotation speed, pitch attitude, and pitch attitude rate during the rotation maneuver were analyzed. A limited quantity of refused takeoff information was obtained. The aerodynamics, wing loading, and thrust-to-weight ratio of the subject SST resulted in takeoff speeds limited by climb (rather than lift-off) considerations. Take-off speeds based on U.S. subsonic transport requirements were found unacceptable because of the criticality of rotation-abuse effects on one-engine-inoperative climb performance. Adequate safety margin was provided by takeoff speeds based on proposed Anglo-French supersonic transport (TSS) criteria, with the limiting criterion being that takeoff safety speed be at least 1.15 times the one-engine-inoperative zero-rate-of-climb speed. Various observations related to SST certification are presented.

A Systematic Review of Quantitative Resilience Measures for Water Infrastructure Systems

DOE PAGES

Shin, Sangmin; Lee, Seungyub; Judi, David; ...

2018-02-07

Over the past few decades, the concept of resilience has emerged as an important consideration in the planning and management of water infrastructure systems. Accordingly, various resilience measures have been developed for the quantitative evaluation and decision-making of systems. There are, however, numerous considerations and no clear choice of which measure, if any, provides the most appropriate representation of resilience for a given application. This study provides a critical review of quantitative approaches to measure the resilience of water infrastructure systems, with a focus on water resources and distribution systems. A compilation of 11 criteria evaluating 21 selected resilience measuresmore » addressing major features of resilience is developed using the Axiomatic Design process. Existing gaps of resilience measures are identified based on the review criteria. The results show that resilience measures have generally paid less attention to cascading damage to interrelated systems, rapid identification of failure, physical damage of system components, and time variation of resilience. Concluding the paper, improvements to resilience measures are recommended. The findings contribute to our understanding of gaps and provide information to help further improve resilience measures of water infrastructure systems.« less

A Systematic Review of Quantitative Resilience Measures for Water Infrastructure Systems

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

Shin, Sangmin; Lee, Seungyub; Judi, David

Over the past few decades, the concept of resilience has emerged as an important consideration in the planning and management of water infrastructure systems. Accordingly, various resilience measures have been developed for the quantitative evaluation and decision-making of systems. There are, however, numerous considerations and no clear choice of which measure, if any, provides the most appropriate representation of resilience for a given application. This study provides a critical review of quantitative approaches to measure the resilience of water infrastructure systems, with a focus on water resources and distribution systems. A compilation of 11 criteria evaluating 21 selected resilience measuresmore » addressing major features of resilience is developed using the Axiomatic Design process. Existing gaps of resilience measures are identified based on the review criteria. The results show that resilience measures have generally paid less attention to cascading damage to interrelated systems, rapid identification of failure, physical damage of system components, and time variation of resilience. Concluding the paper, improvements to resilience measures are recommended. The findings contribute to our understanding of gaps and provide information to help further improve resilience measures of water infrastructure systems.« less

Considerations of viscosity in the preliminaries to mammalian fertilisation.

PubMed

Hunter, Ronald H F; Coy, P; Gadea, J; Rath, D

2011-03-01

Migration of spermatozoa in the female genital tract will be strongly influenced by the viscosity of the fluids encountered, yet little systematic analysis has been given to such a consideration. This essay reviews the series of milieux confronting a fertilising sperm during its progression to the oviduct ampulla. Two groups are discussed, first those in which ejaculation is into the vagina, second those in which semen enters the uterus during a protracted mating. Viscous glycoprotein secretions that accumulate in the oviduct isthmus of both groups before ovulation are highlighted, as is the environment generated in the ampulla by the post-ovulatory suspension of oocyte(s), cumulus cells and spermatozoa; follicular and peritoneal fluids may also be present. The viscosity of all female tract fluids responds to cyclical variations in temperature, and these exist within the oviduct near the time of ovulation. Gradations in viscosity influence the pattern and strength of sperm flagellar activity and the rate of forward movement. Measurements of sperm motility are currently made in a physiological medium of constant viscosity and temperature, thereby overlooking changes in the female genital tract. A more sophisticated approach might reveal an adequate fertilising potential in a proportion of putatively poor semen samples.

The role of population monitoring in the management of North American waterfowl

USGS Publications Warehouse

Nichols, J.D.; Williams, B.K.; Johnson, F.A.

2000-01-01

Despite the effort and expense devoted to large-scale monitoring programs, few existing programs have been designed with specific objectives in mind and few permit strong inferences about the dynamics of monitored systems. The waterfowl population monitoring programs of the U.S. Fish and Wildlife Service, Canadian Wildlife Service and state and provincial agencies provide a nice example with respect to program objectives, design and implementation. The May Breeding Grounds Survey provides an estimate of system state (population size) that serves two primary purposes in the adaptive management process: identifying the appropriate time-specific management actions and updating the information state (model weights) by providing a basis for evaluating predictions of competing models. Other waterfowl monitoring programs (e.g., banding program, hunter questionnaire survey, parts collection survey, winter survey) provide estimates of vital rates (rates of survival, reproduction and movement) associated with system dynamics and variables associated with management objectives (e.g., harvest). The reliability of estimates resulting from monitoring programs depends strongly on whether considerations about spatial variation and detection probability have been adequately incorporated into program design and implementation. Certain waterfowl surveys again provide nice examples of monitoring programs that incorporate these considerations.

Radiation effects on moisture variation in ponderosa pine litter

Treesearch

Clive M. Countryman

1977-01-01

This exploratory study indicated that considerable variation in the moisture content of litter can occur within short horizontal distances. The variations ere found to be caused primarily by differences in the amount of solar radiation received by the litter and in the degree of cooling by radiation at night. Because actual fuel moisture lags behind equilibrium...

Mimetic Theory and Scapegoating in the Age of Cyberbullying: The Case of Phoebe Prince

ERIC Educational Resources Information Center

Norman, James O'Higgins; Connolly, Justin

2011-01-01

Whilst traditional forms of bullying have and continue to receive considerable attention in the literature, research on technology-enabled bullying remains in an embryonic stage and considerable deficits exist in our understanding of the nature, extent, dynamics and consequents of this new form of bullying. Of the limited studies that exist on…

Existence of evolutionary variational solutions via the calculus of variations

NASA Astrophysics Data System (ADS)

Bögelein, Verena; Duzaar, Frank; Marcellini, Paolo

In this paper we introduce a purely variational approach to time dependent problems, yielding the existence of global parabolic minimizers, that is ∫0T ∫Ω [uṡ∂tφ+f(x,Du)] dx dt⩽∫0T ∫Ω f(x,Du+Dφ) dx dt, whenever T>0 and φ∈C0∞(Ω×(0,T),RN). For the integrand f:Ω×R→[0,∞] we merely assume convexity with respect to the gradient variable and coercivity. These evolutionary variational solutions are obtained as limits of maps depending on space and time minimizing certain convex variational functionals. In the simplest situation, with some growth conditions on f, the method provides the existence of global weak solutions to Cauchy-Dirichlet problems of parabolic systems of the type ∂tu-divDξf(x,Du)=0 in Ω×(0,∞).

Electrochemical measurements and thermodynamic calculations of redox equilibria in pallasite meteorites - Implications for the eucrite parent body

NASA Technical Reports Server (NTRS)

Righter, Kevin; Arculus, Richard J.; Paslick, Cassi; Delano, John W.

1990-01-01

The intrinsic oxygen fugacity (IOF) of olivine separates from the Salta, Springwater, and Eagle Station pallasites was measured between 850 and 1150 C using oxygen-specific solid zirconia electrolytes at 100,000 Pa. Thermodynamic calculations of redox equilibria involving equalibrium pallasite assemblages are in good agreement with the experimental results and provide a lower limit to pallasite redox stability; others involving disequilibrium assemblages, suggest that pallasites experienced localized, late-stage oxidation and reduction effects. Consideration of the redox buffer metal-olivine-orthopyroxene utilizing calculated Eucrite Parent Body (EPB) mantle phase compositions indicates that small redox gradients may have existed in the EPB. Such gradients may have produced strong compositional variation within the EPB. In addition, there is apparently significant redox heterogeneity in the source area of Eagle Station Trio pallasites and Bocaiuva iron meteorites.

The link between middle school mathematics course placement and achievement.

PubMed

Domina, Thurston

2014-01-01

The proportion of eighth graders in United States public schools enrolled in algebra or a more advanced mathematics course doubled between 1990 and 2011. This article uses Early Childhood Longitudinal Study's Kindergarten Cohort data to consider the selection process into advanced middle school mathematics courses and estimate the effects of advanced courses on students' mathematics achievement (n = 6,425; mean age at eighth grade = 13.7). Eighth-grade algebra and geometry course placements are academically selective, but considerable between-school variation exists in students' odds of taking these advanced courses. While analyses indicate that advanced middle school mathematics courses boost student achievement, these effects are most pronounced in content areas closely related to class content and may be contingent on student academic readiness. © 2014 The Author. Child Development © 2014 Society for Research in Child Development, Inc.

Use of big data in drug development for precision medicine

PubMed Central

Kim, Rosa S.; Goossens, Nicolas; Hoshida, Yujin

2016-01-01

Summary Drug development has been a costly and lengthy process with an extremely low success rate and lack of consideration of individual diversity in drug response and toxicity. Over the past decade, an alternative “big data” approach has been expanding at an unprecedented pace based on the development of electronic databases of chemical substances, disease gene/protein targets, functional readouts, and clinical information covering inter-individual genetic variations and toxicities. This paradigm shift has enabled systematic, high-throughput, and accelerated identification of novel drugs or repurposed indications of existing drugs for pathogenic molecular aberrations specifically present in each individual patient. The exploding interest from the information technology and direct-to-consumer genetic testing industries has been further facilitating the use of big data to achieve personalized Precision Medicine. Here we overview currently available resources and discuss future prospects. PMID:27430024

Methoxyflurane and Nitrous Oxide as Obstetric Analgesics. II.—A Comparison by Self-administered Intermittent Inhalation

PubMed Central

Jones, Peter L.; Rosen, M.; Mushin, W. W.; Jones, E. V.

1969-01-01

Methoxyflurane (0·35%) in air and nitrous oxide/oxygen (50%/50%) self-administered intermittently in the usual way have been compared as analgesics for labour. There were 25 patients in each group. Objective assessment by an anaesthetist showed that methoxyflurane is the more effective analgesic, and this was supported by the opinion of the multiparae. Nausea and vomiting were significantly less with methoxyflurane. Fifty per cent. nitrous oxide in oxygen given intermittently does not appear to be the best analgesic concentration. Nevertheless, since a considerable variation in sensitivity exists, it would probably be unwise to consider the introduction of higher concentrations for use by unsupervised midwives. This trial confirms the predictions made by us using a method for screening inhalational analgesics, in which methoxyflurane and nitrous oxide were given continuously. PMID:4895339

Methoxyflurane and nitrous oxide as obstetric analgesics. II. A comparison by self-administered intermittent inhalation.

PubMed

Jones, P L; Rosen, M; Mushin, W W; Jones, E V

1969-08-02

Methoxyflurane (0.35%) in air and nitrous oxide/oxygen (50%/50%) self-administered intermittently in the usual way have been compared as analgesics for labour. There were 25 patients in each group. Objective assessment by an anaesthetist showed that methoxyflurane is the more effective analgesic, and this was supported by the opinion of the multiparae. Nausea and vomiting were significantly less with methoxyflurane. Fifty per cent. nitrous oxide in oxygen given intermittently does not appear to be the best analgesic concentration. Nevertheless, since a considerable variation in sensitivity exists, it would probably be unwise to consider the introduction of higher concentrations for use by unsupervised midwives.This trial confirms the predictions made by us using a method for screening inhalational analgesics, in which methoxyflurane and nitrous oxide were given continuously.

Sexual cannibalism as a manifestation of sexual conflict.

PubMed

Schneider, Jutta M

2014-09-11

Sexual cannibalism is a well-known example for sexual conflict and has many facets that determine the costs and benefits for the cannibal and the victim. Here, I focus on species in which sexual cannibalism is a general component of a mating system in which males invest maximally in mating with a single (monogyny) or two (bigyny) females. Sexual cannibalism can be a male strategy to maximize paternity and a female strategy to prevent paternity monopolization by any or a particular male. Considerable variation exists between species (1) in the potential of males to monopolize females, and (2) in the success of females in preventing monopolization by males. This opens up exciting future possibilities to investigate sexually antagonistic coevolution in a largely unstudied mating system. Copyright © 2014 Cold Spring Harbor Laboratory Press; all rights reserved.

Timescales alter the inferred strength and temporal consistency of intraspecific diet specialization

USGS Publications Warehouse

Novak, Mark; Tinker, M. Tim

2015-01-01

Many populations consist of individuals that differ substantially in their diets. Quantification of the magnitude and temporal consistency of such intraspecific diet variation is needed to understand its importance, but the extent to which different approaches for doing so reflect instantaneous vs. time-aggregated measures of individual diets may bias inferences. We used direct observations of sea otter individuals (Enhydra lutris nereis) to assess how: (1) the timescale of sampling, (2) under-sampling, and (3) the incidence- vs. frequency-based consideration of prey species affect the inferred strength and consistency of intraspecific diet variation. Analyses of feeding observations aggregated over hourly to annual intervals revealed a substantial bias associated with time aggregation that decreases the inferred magnitude of specialization and increases the inferred consistency of individuals’ diets. Time aggregation also made estimates of specialization more sensitive to the consideration of prey frequency, which decreased estimates relative to the use of prey incidence; time aggregation did not affect the extent to which under-sampling contributed to its overestimation. Our analyses demonstrate the importance of studying intraspecific diet variation with an explicit consideration of time and thereby suggest guidelines for future empirical efforts. Failure to consider time will likely produce inconsistent predictions regarding the effects of intraspecific variation on predator–prey interactions.

On the dynamic forcing of short-term climate fluctuations by feedback mechanisms

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

Reiter, E.R.

1979-09-01

The energies involved in the general circulation of the atmosphere, especially the zonal available potential energy, show considerable interannual variability, suggesting the presence of various internal feedback mechanisms in the ocean-atmosphere system. Sea-surface temperature (SST) variations appear to have some effect on the hydrological cycle. The possible existence of feedback mechanisms between ocean and atmosphere seem to be evident in some of the data from the North Pacific and North Atlantic. One of these proposed mechanisms involves the variation in the convergence between the North and South Pacific trade-wind systems and is strongly reflected in rainfall variability within the drymore » region of the equatorial Pacific. Similar variations appear in low-latitude SST anomalies. The convergence between the two trade-wind systems in the Atlantic region also undergoes marked interannual variations. This quasi-biennial oscillation (QBO) in trade-wind convergence over the Atlantic appears to be tied to the global QBO of equatorial stratospheric winds and to regional rainfall regimes in the dry region of northeastern Brazil. A variability pattern of SST's with a QBO has been detected off the coast of Senegal, in the Gulf of Guinea and even in the Gulf Stream as it leaves the North American continental shelf. Possible physical connections between some of these QBO's are pointed out by a hypothetical feedback model. It is also suggested that interaction of a QBO with the annual cycle may lead to beating frequencies resembling climatic trends of a duration of several years.« less

Variation of surface water spectral response as a function of in situ sampling technique

NASA Technical Reports Server (NTRS)

Davis, Bruce A.; Hodgson, Michael E.

1988-01-01

Tests were carried out to determine the spectral variation contributed by a particular sampling technique. A portable radiometer was used to measure the surface water spectral response. Variation due to the reflectance of objects near the radiometer (i.e., the boat side) during data acquisition was studied. Consideration was also given to the variation due to the temporal nature of the phenomena (i.e., wave activity).

Suicide Prevention Training: Policies for Health Care Professionals Across the United States as of October 2017.

PubMed

Graves, Janessa M; Mackelprang, Jessica L; Van Natta, Sara E; Holliday, Carrie

2018-06-01

To identify and compare state policies for suicide prevention training among health care professionals across the United States and benchmark state plan updates against national recommendations set by the surgeon general and the National Action Alliance for Suicide Prevention in 2012. We searched state legislation databases to identify policies, which we described and characterized by date of adoption, target audience, and duration and frequency of the training. We used descriptive statistics to summarize state-by-state variation in suicide education policies. In the United States, as of October 9, 2017, 10 (20%) states had passed legislation mandating health care professionals complete suicide prevention training, and 7 (14%) had policies encouraging training. The content and scope of policies varied substantially. Most states (n = 43) had a state suicide prevention plan that had been revised since 2012, but 7 lacked an updated plan. Considerable variation in suicide prevention training for health care professionals exists across the United States. There is a need for consistent polices in suicide prevention training across the nation to better equip health care providers to address the needs of patients who may be at risk for suicide.

Allelopathic interference of alfalfa (Medicago sativa L.) genotypes to annual ryegrass (Lolium rigidum).

PubMed

Zubair, Hasan Muhammad; Pratley, James E; Sandral, G A; Humphries, A

2017-07-01

Alfalfa (Medicago sativa L.) genotypes at varying densities were investigated for allelopathic impact using annual ryegrass (Lolium rigidum) as the target species in a laboratory bioassay. Three densities (15, 30, and 50 seedlings/beaker) and 40 alfalfa genotypes were evaluated by the equal compartment agar method (ECAM). Alfalfa genotypes displayed a range of allelopathic interference in ryegrass seedlings, reducing root length from 5 to 65%. The growth of ryegrass decreased in response to increasing density of alfalfa seedlings. At the lowest density, Q75 and Titan9 were the least allelopathic genotypes. An overall inhibition index was calculated to rank each alfalfa genotype. Reduction in seed germination of annual ryegrass occurred in the presence of several alfalfa genotypes including Force 10, Haymaster7 and SARDI Five. A comprehensive metabolomic analysis using Quadruple Time of Flight (Q-TOF), was conducted to compare six alfalfa genotypes. Variation in chemical compounds was found between alfalfa root extracts and exudates and also between genotypes. Further individual compound assessments and quantitative study at greater chemical concentrations are needed to clarify the allelopathic activity. Considerable genetic variation exists among alfalfa genotypes for allelopathic activity creating the opportunity for its use in weed suppression through selection.

Machine Learning and Network Analysis of Molecular Dynamics Trajectories Reveal Two Chains of Red/Ox-specific Residue Interactions in Human Protein Disulfide Isomerase.

PubMed

Karamzadeh, Razieh; Karimi-Jafari, Mohammad Hossein; Sharifi-Zarchi, Ali; Chitsaz, Hamidreza; Salekdeh, Ghasem Hosseini; Moosavi-Movahedi, Ali Akbar

2017-06-16

The human protein disulfide isomerase (hPDI), is an essential four-domain multifunctional enzyme. As a result of disulfide shuffling in its terminal domains, hPDI exists in two oxidation states with different conformational preferences which are important for substrate binding and functional activities. Here, we address the redox-dependent conformational dynamics of hPDI through molecular dynamics (MD) simulations. Collective domain motions are identified by the principal component analysis of MD trajectories and redox-dependent opening-closing structure variations are highlighted on projected free energy landscapes. Then, important structural features that exhibit considerable differences in dynamics of redox states are extracted by statistical machine learning methods. Mapping the structural variations to time series of residue interaction networks also provides a holistic representation of the dynamical redox differences. With emphasizing on persistent long-lasting interactions, an approach is proposed that compiled these time series networks to a single dynamic residue interaction network (DRIN). Differential comparison of DRIN in oxidized and reduced states reveals chains of residue interactions that represent potential allosteric paths between catalytic and ligand binding sites of hPDI.

Impact of host cell variation on the neutralization of HIV-1 in vitro.

PubMed

Polonis, Victoria R; Schuitemaker, Hanneke; Bunnik, Evelien M; Brown, Bruce K; Scarlatti, Gabriella

2009-09-01

In this review we present current advances in our understanding of HIV-1 neutralization assays that employ primary cell types, as compared with those that utilize cell lines and the newer, more standardized pseudovirus assays. A commentary on the challenges of standardizing in-vitro neutralization assays using primary cells is included. The data from reporter cell line neutralization assays may agree with results observed in primary cells; however, exceptions have recently been reported. Multiple variables exist in primary cell assays using peripheral blood mononuclear cells from HIV-seronegative donors; in-vitro neutralization titers can vary significantly based on the donor cells used for assay targets and for virus propagation. Thus, more research is required to achieve validated primary cell neutralization assays. HIV-vaccine-induced antibody performance in the current neutralization assays may function as a 'gatekeeper' for HIV-1 subunit vaccine advancement. Development of standardized platforms for reproducible measurement of in-vitro neutralization is therefore a high priority. Given the considerable variation in results obtained from some widely applied HIV neutralization platforms, parallel evaluation of new antibodies using different host cells for assay targets, as well as virus propagation, is recommended until immune correlates of protection are identified.

Neonatal extravasation injury: prevention and management in Australia and New Zealand-a survey of current practice

PubMed Central

2013-01-01

Background Extravasation injury remains an important cause of iatrogenic injury in neonatal intensive care. This study aims to describe the current approach to extravasation injury (EI) prevention and management in Neonatal Intensive Care Units (NICUs) in Australia and New Zealand. Methods A literature review regarding extravasation injury in the newborn was carried out to inform questionnaire design. An internet-based survey was then conducted with the clinical directors of the 27 tertiary NICUs in Australia and New Zealand. Results The survey received a 96% response rate. Approximately two thirds of Australian and New Zealand NICUs have written protocols for prevention and management of extravasation injury. Considerable practice variation was seen for both prevention and treatment of EI. 92% of units had experienced cases of significant EI. Conclusions Australian and New Zealand tertiary neonatal units clearly recognise EI as an important cause of iatrogenic morbidity and mortality. Significant variation still exists among units with regards to guidelines for both prevention and management of EI. We recommend that neonatal staff should remain vigilant, ensuring that guidelines for the prevention and treatment of EI are available, and rigorously followed. PMID:23497004

Untangling the neurobiology of coping styles in rodents: Towards neural mechanisms underlying individual differences in disease susceptibility.

PubMed

de Boer, Sietse F; Buwalda, Bauke; Koolhaas, Jaap M

2017-03-01

Considerable individual differences exist in trait-like patterns of behavioral and physiological responses to salient environmental challenges. This individual variation in stress coping styles has an important functional role in terms of health and fitness. Hence, understanding the neural embedding of coping style variation is fundamental for biobehavioral neurosciences in probing individual disease susceptibility. This review outlines individual differences in trait-aggressiveness as an adaptive component of the natural sociobiology of rats and mice, and highlights that these reflect the general style of coping that varies from proactive (aggressive) to reactive (docile). We propose that this qualitative coping style can be disentangled into multiple quantitative behavioral domains, e.g., flexibility/impulse control, emotional reactivity and harm avoidance/reward processing, that each are encoded into selective neural circuitries. Since functioning of all these brain circuitries rely on fine-tuned serotonin signaling, autoinhibitory control mechanisms of serotonergic neuron (re)activity are crucial in orchestrating general coping style. Untangling the precise neuromolecular mechanisms of different coping styles will provide a roadmap for developing better therapeutic strategies of stress-related diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Assessment of ecosystem in giant panda distribution area based on entropy method and coefficient of variation].

PubMed

Yan, Zhi Gang; Li, Jun Qing

2017-12-01

The areas of the habitat and bamboo forest, and the size of the giant panda wild population have greatly increased, while habitat fragmentation and local population isolation have also intensified in recent years. Accurate evaluation of ecosystem status of the panda in the giant panda distribution area is important for giant panda conservation. The ecosystems of the distribution area and six mountain ranges were subdivided into habitat and population subsystems based on the hie-rarchical system theory. Using the panda distribution area as the study area and the three national surveys as the time node, the evolution laws of ecosystems were studied using the entropy method, coefficient of variation, and correlation analysis. We found that with continuous improvement, some differences existed in the evolution and present situation of the ecosystems of six mountain ranges could be divided into three groups. Ecosystems classified into the same group showed many commonalities, and difference between the groups was considerable. Problems of habitat fragmentation and local population isolation became more serious, resulting in ecosystem degradation. Individuali-zed ecological protection measures should be formulated and implemented in accordance with the conditions in each mountain system to achieve the best results.

Chemical evolution in spiral and irregular galaxies

NASA Technical Reports Server (NTRS)

Torres-Peimbert, S.

1986-01-01

A brief review of models of chemical evolution of the interstellar medium in our galaxy and other galaxies is presented. These models predict the time variation and radial dependence of chemical composition in the gas as function of the input parameters; initial mass function, stellar birth rate, chemical composition of mass lost by stars during their evolution (yields), and the existence of large scale mass flows, like infall from the halo, outflow to the intergalactic medium or radial flows within a galaxy. At present there is a considerable wealth of observational data on the composition of HII regions in spiral and irregular galaxies to constrain the models. Comparisons are made between theory and the observed physical conditions. In particular, studies of helium, carbon, nitrogen and oxygen abundances are reviewed. In many molecular clouds the information we have on the amount of H2 is derived from the observed CO column density, and a standard CO/H2 ratio derived for the solar neighborhood. Chemical evolution models and the observed variations in O/H and N/O values, point out the need to include these results in a CO/H2 relation that should be, at least, a function of the O/H ratio. This aspect is also discussed.

Time-varying BRDFs.

PubMed

Sun, Bo; Sunkavalli, Kalyan; Ramamoorthi, Ravi; Belhumeur, Peter N; Nayar, Shree K

2007-01-01

The properties of virtually all real-world materials change with time, causing their bidirectional reflectance distribution functions (BRDFs) to be time varying. However, none of the existing BRDF models and databases take time variation into consideration; they represent the appearance of a material at a single time instance. In this paper, we address the acquisition, analysis, modeling, and rendering of a wide range of time-varying BRDFs (TVBRDFs). We have developed an acquisition system that is capable of sampling a material's BRDF at multiple time instances, with each time sample acquired within 36 sec. We have used this acquisition system to measure the BRDFs of a wide range of time-varying phenomena, which include the drying of various types of paints (watercolor, spray, and oil), the drying of wet rough surfaces (cement, plaster, and fabrics), the accumulation of dusts (household and joint compound) on surfaces, and the melting of materials (chocolate). Analytic BRDF functions are fit to these measurements and the model parameters' variations with time are analyzed. Each category exhibits interesting and sometimes nonintuitive parameter trends. These parameter trends are then used to develop analytic TVBRDF models. The analytic TVBRDF models enable us to apply effects such as paint drying and dust accumulation to arbitrary surfaces and novel materials.

Examining variations in health within rural Canada.

PubMed

Lavergne, M Ruth; Kephart, George

2012-01-01

Differences in health between urban and rural areas of Canada are well documented. Canadian rural communities are remarkably heterogeneous in terms of social, economic, and geographic characteristics. There is reason to believe that there is also considerable heterogeneity in health within rural Canada but existing literature has not given this adequate consideration. This article describes heterogeneity in health along the urban-rural continuum, both between and within categories of rural areas. Factors that may explain observed variations are then examined. The study population included all adult (>18 years) respondents on the Canadian Community Health Survey Cycle 1.1, linked to census subdivision-level data from the corresponding Canadian Census. Study areas were classified according to Metropolitan Influenced Zones (MIZ), which group rural areas based on their degree of connectivity with nearby urban areas. Dichotomized Health Utilities Index (HUI) scores were the outcome variable. Random-intercept logistic regression models investigated the associations of HUI with individual and area characteristics. To describe between-area variation in health, the proportion of the total variation accounted for by the area random effect (the intra-class correlation coefficient [ICC]) was estimated. To aid interpretation of the magnitude of the effect of area relative to other variables in the models, the ICC was also expressed as a median odds ratio (MOR), or the median amount by which the probability of disability will change for an individual who moves from one area to another. On a descriptive level, poorer health was observed in more remote rural areas, but the size of estimated effects for categories of rural areas was generally small compared with effects of other individual and area variables, and with the degree of heterogeneity between areas. The composition of rural areas is important in order to understand patterns in health. Individual income, education, and employment, and area characteristics such as Francophone or Aboriginal populations, and migration patterns help explain the gradient in health by MIZ, but considerable heterogeneity in health within categories of MIZ remains. In models stratified by MIZ, significant between-area heterogeneity was observed in all models, with MORs ranging from 1.18 to 1.53. It was observed that heterogeneity in health among rural areas is substantial, and generally larger than the effect of rurality, itself, on health. More attention is needed to understand the characteristics of Canada's heterogeneous rural communities, and the different processes by which disparities in health emerge and persist. The findings suggest that a focus on rurality alone, emphasizing urban versus rural disparities, or even continuum-based approaches like MIZ, may be less informative than finding ways to classify and examine different types of rural areas according to factors relevant to health.

Environmental variation is directly responsible for short- but not long-term variation in forest-atmosphere carbon exchange

Treesearch

Andrew D. Richardson; David Y. Hollinger; John D. Aber; Scott V. Ollinger; Bobby H. Braswell

2007-01-01

Tower-based eddy covariance measurements of forest-atmosphere carbon dioxide (CO2) exchange from many sites around the world indicate that there is considerable year-to-year variation in net ecosystem exchange (NEE). Here, we use a statistical modeling approach to partition the interannual variability in NEE (and its component fluxes, ecosystem...

Genetic variation in tree structure and its relation to size in Douglas-fir: II. crown form, branch characters, and foliage characters.

Treesearch

J.B. St. Clair

1994-01-01

Genetic variation and covariation among traits of tree size and structure were assessed in an 18-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) genetic test in the Coast Range of Oregon. Considerable genetic variation was found for relative crown width; stem increment per crown projection area; leaf...

Adolescent medicine training in pediatric residency programs.

PubMed

Fox, Harriette B; McManus, Margaret A; Klein, Jonathan D; Diaz, Angela; Elster, Arthur B; Felice, Marianne E; Kaplan, David W; Wibbelsman, Charles J; Wilson, Jane E

2010-01-01

The aim of this study was to provide an assessment of pediatric residency training in adolescent medicine. We conducted 2 national surveys: 1 of pediatric residency program directors and the other of faculty who are responsible for the adolescent medicine block rotation for pediatric residents to elicit descriptive and qualitative information concerning the nature of residents' ambulatory care training experience in adolescent medicine and the workforce issues that affect the experience. Required adolescent medicine topics that are well covered pertain to normal development, interviewing, and sexual issues. Those least well covered concern the effects of violence, motor vehicle safety, sports medicine, and chronic illness. Shortages of adolescent medicine specialists, addictions counselors, psychiatrists, and other health professionals who are knowledgeable about adolescents frequently limit pediatric residency training in adolescent medicine. Considerable variation exists in the timing of the mandatory adolescent medicine block rotation, the clinic sites used for ambulatory care training, and the range of services offered at the predominant training sites. In addition, residents' continuity clinic experience often does not include adolescent patients; thus, pediatric residents do not have opportunities to establish ongoing therapeutic relationships with adolescents over time. Both program and rotation directors had similar opinions about adolescent medicine training. Significant variation and gaps exist in adolescent medicine ambulatory care training in pediatric residency programs throughout the United States. For addressing the shortcomings in many programs, the quality of the block rotation should be improved and efforts should be made to teach adolescent medicine in continuity, general pediatric, and specialty clinics. In addition, renewed attention should be given to articulating the core competencies needed to care for adolescents.

DXA in the assessment of subchondral bone mineral density in knee osteoarthritis--A semi-standardized protocol after systematic review.

PubMed

Sepriano, Alexandre; Roman-Blas, Jorge A; Little, Robert D; Pimentel-Santos, Fernando; Arribas, Jose María; Largo, Raquel; Branco, Jaime C; Herrero-Beaumont, Gabriel

2015-12-01

Subchondral bone mineral density (sBMD) contributes to the initiation and progression of knee osteoarthritis (OA). Reliable methods to assess sBMD status may predict the response of specific OA phenotypes to targeted therapies. While dual-energy X-ray absorptiometry (DXA) of the knee can determine sBMD, no consensus exists regarding its methodology. Construct a semi-standardized protocol for knee DXA to measure sBMD in patients with OA of the knee by evaluating the varying methodologies present in existing literature. We performed a systematic review of original papers published in PubMed and Web of Science from their inception to July 2014 using the following search terms: subchondral bone, osteoarthritis, and bone mineral density. DXA of the knee can be performed with similar reproducibility values to those proposed by the International Society for Clinical Densitometry for the hip and spine. We identified acquisition view, hip rotation, knee positioning and stabilization, ROI location and definition, and the type of analysis software as important sources of variation. A proposed knee DXA protocol was constructed taking into consideration the results of the review. DXA of the knee can be reliably performed in patients with knee OA. Nevertheless, we found substantial methodological variation across previous studies. Methodological standardization may provide a foundation from which to establish DXA of the knee as a valid tool for identification of SB changes and as an outcome measure in clinical trials of disease modifying osteoarthritic drugs. Copyright © 2015 Elsevier Inc. All rights reserved.

Verification of Gyrokinetic codes: theoretical background and applications

NASA Astrophysics Data System (ADS)

Tronko, Natalia

2016-10-01

In fusion plasmas the strong magnetic field allows the fast gyro motion to be systematically removed from the description of the dynamics, resulting in a considerable model simplification and gain of computational time. Nowadays, the gyrokinetic (GK) codes play a major role in the understanding of the development and the saturation of turbulence and in the prediction of the consequent transport. We present a new and generic theoretical framework and specific numerical applications to test the validity and the domain of applicability of existing GK codes. For a sound verification process, the underlying theoretical GK model and the numerical scheme must be considered at the same time, which makes this approach pioneering. At the analytical level, the main novelty consists in using advanced mathematical tools such as variational formulation of dynamics for systematization of basic GK code's equations to access the limits of their applicability. The indirect verification of numerical scheme is proposed via the Benchmark process. In this work, specific examples of code verification are presented for two GK codes: the multi-species electromagnetic ORB5 (PIC), and the radially global version of GENE (Eulerian). The proposed methodology can be applied to any existing GK code. We establish a hierarchy of reduced GK Vlasov-Maxwell equations using the generic variational formulation. Then, we derive and include the models implemented in ORB5 and GENE inside this hierarchy. At the computational level, detailed verification of global electromagnetic test cases based on the CYCLONE are considered, including a parametric β-scan covering the transition between the ITG to KBM and the spectral properties at the nominal β value.

CFD simulation of blood flow inside the corkscrew collaterals of the Buerger's disease.

PubMed

Sharifi, Alireza; Charjouei Moghadam, Mohammad

2016-01-01

Buerger's disease is an occlusive arterial disease that occurs mainly in medium and small vessels. This disease is associated with Tobacco usage. The existence of corkscrew collateral is one of the established characteristics of the Buerger's disease. In this study, the computational fluid dynamics (CFD) simulation of blood flow within the corkscrew artery of the Buerger's disease is conducted. The geometry of the artery is constructed based on the actual corkscrew artery of a patient diagnosed with the Buerger's disease. The blood properties are the same as the actual blood properties of the patient. The blood flow rate is taken from the available experimental data in the literature. The local velocity patterns, pressure and kinematic viscosity distributions in different segments of the corkscrew collateral artery was demonstrated and discussed for the first time for this kind of artery. The effects of non-Newtonian consideration for the blood viscosity behavior were investigated in different segments of the artery. Moreover, the variations of the blood flow patterns along the artery were investigated in details for each segment. It was found that the flow patterns were affected by the complex geometry of this artery in such a way that it could lead to the presence of sites that were prone to the accumulation of the flowing particles in blood like nicotine. Furthermore, due to the existence of many successive bends in this artery, the variations of kinematic viscosity along this artery were significant, therefore the non-Newtonian behavior of the blood viscosity must be considered.

CFD simulation of blood flow inside the corkscrew collaterals of the Buerger’s disease

PubMed Central

Sharifi, Alireza; Charjouei Moghadam, Mohammad

2016-01-01

Introduction: Buerger’s disease is an occlusive arterial disease that occurs mainly in medium and small vessels. This disease is associated with Tobacco usage. The existence of corkscrew collateral is one of the established characteristics of the Buerger’s disease. Methods: In this study, the computational fluid dynamics (CFD) simulation of blood flow within the corkscrew artery of the Buerger’s disease is conducted. The geometry of the artery is constructed based on the actual corkscrew artery of a patient diagnosed with the Buerger’s disease. The blood properties are the same as the actual blood properties of the patient. The blood flow rate is taken from the available experimental data in the literature. Results: The local velocity patterns, pressure and kinematic viscosity distributions in different segments of the corkscrew collateral artery was demonstrated and discussed for the first time for this kind of artery. The effects of non-Newtonian consideration for the blood viscosity behavior were investigated in different segments of the artery. Moreover, the variations of the blood flow patterns along the artery were investigated in details for each segment. Conclusion: It was found that the flow patterns were affected by the complex geometry of this artery in such a way that it could lead to the presence of sites that were prone to the accumulation of the flowing particles in blood like nicotine. Furthermore, due to the existence of many successive bends in this artery, the variations of kinematic viscosity along this artery were significant, therefore the non-Newtonian behavior of the blood viscosity must be considered. PMID:27340623

Model of the Human Eye Based on ABCD Matrix

NASA Astrophysics Data System (ADS)

González, G. Díaz; Castillo, M. David Iturbe

2008-04-01

At the moment several models of the human eye exist, nevertheless the gradient index models of the human lens (crystalline) have received little attention in optometry and vision sciences, although they consider how the refractive index and the refracting power can change with the accommodation. On the other hand, in study fields like ophthalmology and optometry, exist cases where there is a lack of information about the factors that influence the change of refractive power and therefore the focal length of the eye. By such reason, in this paper we present a model of the human eye based on the ABCD matrix in order to describe the propagation of light rays, that can be understood by professional people in optics, ophthalmology and optometry, and the dispersions of the different ocular mediums are taken into account,. The aim of the model is to obtain data about the refractive power of the eye under different considerations, such as: changes in wavelength, radius of curvature and thicknesses of the ocular mediums. We present results of simulations in Matlab of our model, assuming that the object is punctual and is placed to a certain distance of the eye, and considering at the beginning to the crystalline like a medium with fixed refractive index, and after like a gradient lens. By means of graphs, we show the total refractive power of the eye and its form and type of dependence with respect to variations in radius of curvature and thicknesses of the cornea and crystalline, as well as variations in the thickness of the previous and later cameras.

Mini-review: Strategies for Variation and Evolution of Bacterial Antigens

PubMed Central

Foley, Janet

2015-01-01

Across the eubacteria, antigenic variation has emerged as a strategy to evade host immunity. However, phenotypic variation in some of these antigens also allows the bacteria to exploit variable host niches as well. The specific mechanisms are not shared-derived characters although there is considerable convergent evolution and numerous commonalities reflecting considerations of natural selection and biochemical restraints. Unlike in viruses, mechanisms of antigenic variation in most bacteria involve larger DNA movement such as gene conversion or DNA rearrangement, although some antigens vary due to point mutations or modified transcriptional regulation. The convergent evolution that promotes antigenic variation integrates various evolutionary forces: these include mutations underlying variant production; drift which could remove alleles especially early in infection or during life history phases in arthropod vectors (when the bacterial population size goes through a bottleneck); selection not only for any particular variant but also for the mechanism for the production of variants (i.e., selection for mutability); and overcoming negative selection against variant production. This review highlights the complexities of drivers of antigenic variation, in particular extending evaluation beyond the commonly cited theory of immune evasion. A deeper understanding of the diversity of purpose and mechanisms of antigenic variation in bacteria will contribute to greater insight into bacterial pathogenesis, ecology and coevolution with hosts. PMID:26288700

Sex, race, and consideration of bariatric surgery among primary care patients with moderate to severe obesity.

PubMed

Wee, Christina C; Huskey, Karen W; Bolcic-Jankovic, Dragana; Colten, Mary Ellen; Davis, Roger B; Hamel, Marybeth

2014-01-01

Bariatric surgery is one of few obesity treatments to produce substantial weight loss but only a small proportion of medically-eligible patients, especially men and racial minorities, undergo bariatric surgery. To describe primary care patients' consideration of bariatric surgery, potential variation by sex and race, and factors that underlie any variation. Telephone interview of 337 patients with a body mass index or BMI > 35 kg/m(2) seen at four diverse primary care practices in Greater-Boston. Patients' consideration of bariatric surgery. Of 325 patients who had heard of bariatric surgery, 34 % had seriously considered surgery. Men were less likely than women and African Americans were less likely than Caucasian patients to have considered surgery after adjustment for sociodemographics and BMI. Comorbid conditions did not explain sex and racial differences but racial differences dissipated after adjustment for quality of life (QOL), which tended to be higher among African American than Caucasian patients. Physician recommendation of bariatric surgery was independently associated with serious consideration for surgery [OR 4.95 (95 % CI 2.81-8.70)], but did not explain variation in consideration of surgery across sex and race. However, if recommended by their doctor, men were as willing and African American and Hispanic patients were more willing to consider bariatric surgery than their respective counterparts after adjustment. Nevertheless, only 20 % of patients reported being recommended bariatric surgery by their doctor and African Americans and men were less likely to receive this recommendation; racial differences in being recommended surgery were also largely explained by differences in QOL. High perceived risk to bariatric surgery was the most commonly cited barrier; financial concerns were uncommonly cited. Single geographic region; examined consideration and not who eventually proceeded with bariatric surgery. African Americans and men were less likely to have considered bariatric surgery and were less likely to have been recommended surgery by their doctors. Differences in how obesity affects QOL appear to account for some of these variations. High perceived risk rather than financial barrier was the major deterrent for patients.

Wave impedance selection for passivity-based bilateral teleoperation

NASA Astrophysics Data System (ADS)

D'Amore, Nicholas John

When a task must be executed in a remote or dangerous environment, teleoperation systems may be employed to extend the influence of the human operator. In the case of manipulation tasks, haptic feedback of the forces experienced by the remote (slave) system is often highly useful in improving an operator's ability to perform effectively. In many of these cases (especially teleoperation over the internet and ground-to-space teleoperation), substantial communication latency exists in the control loop and has the strong tendency to cause instability of the system. The first viable solution to this problem in the literature was based on a scattering/wave transformation from transmission line theory. This wave transformation requires the designer to select a wave impedance parameter appropriate to the teleoperation system. It is widely recognized that a small value of wave impedance is well suited to free motion and a large value is preferable for contact tasks. Beyond this basic observation, however, very little guidance exists in the literature regarding the selection of an appropriate value. Moreover, prior research on impedance selection generally fails to account for the fact that in any realistic contact task there will simultaneously exist contact considerations (perpendicular to the surface of contact) and quasi-free-motion considerations (parallel to the surface of contact). The primary contribution of the present work is to introduce an approximate linearized optimum for the choice of wave impedance and to apply this quasi-optimal choice to the Cartesian reality of such a contact task, in which it cannot be expected that a given joint will be either perfectly normal to or perfectly parallel to the motion constraint. The proposed scheme selects a wave impedance matrix that is appropriate to the conditions encountered by the manipulator. This choice may be implemented as a static wave impedance value or as a time-varying choice updated according to the instantaneous conditions encountered. A Lyapunov-like analysis is presented demonstrating that time variation in wave impedance will not violate the passivity of the system. Experimental trials, both in simulation and on a haptic feedback device, are presented validating the technique. Consideration is also given to the case of an uncertain environment, in which an a priori impedance choice may not be possible.

Underlying role of mechanical rigidity and topological constraints in physical sputtering and reactive ion etching of amorphous materials

NASA Astrophysics Data System (ADS)

Bhattarai, Gyanendra; Dhungana, Shailesh; Nordell, Bradley J.; Caruso, Anthony N.; Paquette, Michelle M.; Lanford, William A.; King, Sean W.

2018-05-01

Analytical expressions describing ion-induced sputter or etch processes generally relate the sputter yield to the surface atomic binding energy (Usb) for the target material. While straightforward to measure for the crystalline elemental solids, Usb is more complicated to establish for amorphous and multielement materials due to composition-driven variations and incongruent sublimation. In this regard, we show that for amorphous multielement materials, the ion-driven yield can instead be better understood via a consideration of mechanical rigidity and network topology. We first demonstrate a direct relationship between Usb, bulk modulus, and ion sputter yield for the elements, and then subsequently prove our hypothesis for amorphous multielement compounds by demonstrating that the same relationships exist between the reactive ion etch (RIE) rate and nanoindentation Young's modulus for a series of a -Si Nx :H and a -Si OxCy :H thin films. The impact of network topology is further revealed via application of the Phillips-Thorpe theory of topological constraints, which directly relates the Young's modulus to the mean atomic coordination () for an amorphous solid. The combined analysis allows the trends and plateaus in the RIE rate to be ultimately reinterpreted in terms of the atomic structure of the target material through a consideration of . These findings establish the important underlying role of mechanical rigidity and network topology in ion-solid interactions and provide additional considerations for the design and optimization of radiation-hard materials in nuclear and outer space environments.

Controversies and considerations regarding the termination of pregnancy for Foetal Anomalies in Islam

PubMed Central

2014-01-01

Background Approximately one-fourth of all the inhabitants on earth are Muslims. Due to unprecedented migration, physicians are often confronted with cultures other than their own that adhere to different pdigms. Discussion In Islam, and most religions, abortion is forbidden. Islam is considerably liberal concerning abortion, which is dependent on (i) the threat of harm to mothers, (ii) the status of the pregnancy before or after ensoulment (on the 120th day of gestation), and (iii) the presence of foetal anomalies that are incompatible with life. Considerable variation in religious edicts exists, but most Islamic scholars agree that the termination of a pregnancy for foetal anomalies is allowed before ensoulment, after which abortion becomes totally forbidden, even in the presence of foetal abnormalities; the exception being a risk to the mother’s life or confirmed intrauterine death. Summary The authors urge Muslim law makers to also consider abortion post ensoulment if it is certain that the malformed foetus will decease soon after birth or will be severely malformed and physically and mentally incapacitated after birth to avoid substantial hardship that may continue for years for mothers and family members. The authors recommend that an institutional committee governed and monitored by a national committee make decisions pertaining to abortion to ensure that ethics are preserved and mistakes are prevented. Anomalous foetuses must be detected at the earliest possible time to enable an appropriate medical intervention prior to the 120th day. PMID:24499356

Controversies and considerations regarding the termination of pregnancy for foetal anomalies in Islam.

PubMed

Al-Matary, Abdulrahman; Ali, Jaffar

2014-02-05

Approximately one-fourth of all the inhabitants on earth are Muslims. Due to unprecedented migration, physicians are often confronted with cultures other than their own that adhere to different paradigms. In Islam, and most religions, abortion is forbidden. Islam is considerably liberal concerning abortion, which is dependent on (i) the threat of harm to mothers, (ii) the status of the pregnancy before or after ensoulment (on the 120th day of gestation), and (iii) the presence of foetal anomalies that are incompatible with life. Considerable variation in religious edicts exists, but most Islamic scholars agree that the termination of a pregnancy for foetal anomalies is allowed before ensoulment, after which abortion becomes totally forbidden, even in the presence of foetal abnormalities; the exception being a risk to the mother's life or confirmed intrauterine death. The authors urge Muslim law makers to also consider abortion post ensoulment if it is certain that the malformed foetus will decease soon after birth or will be severely malformed and physically and mentally incapacitated after birth to avoid substantial hardship that may continue for years for mothers and family members. The authors recommend that an institutional committee governed and monitored by a national committee make decisions pertaining to abortion to ensure that ethics are preserved and mistakes are prevented. Anomalous foetuses must be detected at the earliest possible time to enable an appropriate medical intervention prior to the 120th day.

Variations in achievement of evidence-based, high-impact quality indicators in general practice: An observational study

PubMed Central

West, Robert; Rushforth, Bruno; Stokes, Tim; Glidewell, Liz; Carder, Paul; Faulkner, Simon; Foy, Robbie

2017-01-01

Background There are widely recognised variations in the delivery and outcomes of healthcare but an incomplete understanding of their causes. There is a growing interest in using routinely collected ‘big data’ in the evaluation of healthcare. We developed a set of evidence-based ‘high impact’ quality indicators (QIs) for primary care and examined variations in achievement of these indicators using routinely collected data in the United Kingdom (UK). Methods Cross-sectional analysis of routinely collected, electronic primary care data from a sample of general practices in West Yorkshire, UK (n = 89). The QIs covered aspects of care (including processes and intermediate clinical outcomes) in relation to diabetes, hypertension, atrial fibrillation, myocardial infarction, chronic kidney disease (CKD) and ‘risky’ prescribing combinations. Regression models explored the impact of practice and patient characteristics. Clustering within practice was accounted for by including a random intercept for practice. Results Median practice achievement of the QIs ranged from 43.2% (diabetes control) to 72.2% (blood pressure control in CKD). Considerable between-practice variation existed for all indicators: the difference between the highest and lowest performing practices was 26.3 percentage points for risky prescribing and 100 percentage points for anticoagulation in atrial fibrillation. Odds ratios associated with the random effects for practices emphasised this; there was a greater than ten-fold difference in the likelihood of achieving the hypertension indicator between the lowest and highest performing practices. Patient characteristics, in particular age, gender and comorbidity, were consistently but modestly associated with indicator achievement. Statistically significant practice characteristics were identified less frequently in adjusted models. Conclusions Despite various policy and improvement initiatives, there are enduring inappropriate variations in the delivery of evidence-based care. Much of this variation is not explained by routinely collected patient or practice variables, and is likely to be attributable to differences in clinical and organisational behaviour. PMID:28704407

Parabolic Systems with p, q-Growth: A Variational Approach

NASA Astrophysics Data System (ADS)

Bögelein, Verena; Duzaar, Frank; Marcellini, Paolo

2013-10-01

We consider the evolution problem associated with a convex integrand {f : {R}^{Nn}to [0,infty)} satisfying a non-standard p, q-growth assumption. To establish the existence of solutions we introduce the concept of variational solutions. In contrast to weak solutions, that is, mappings {u\\colon Ω_T to {R}^n} which solve partial_tu-div Df(Du)=0 weakly in {Ω_T}, variational solutions exist under a much weaker assumption on the gap q - p. Here, we prove the existence of variational solutions provided the integrand f is strictly convex and 2n/n+2 < p le q < p+1. These variational solutions turn out to be unique under certain mild additional assumptions on the data. Moreover, if the gap satisfies the natural stronger assumption 2le p le q < p+ minbig \\{1,4/n big \\}, we show that variational solutions are actually weak solutions. This means that solutions u admit the necessary higher integrability of the spatial derivative Du to satisfy the parabolic system in the weak sense, that is, we prove that uin L^q_locbig(0,T; W^{1,q}_loc(Ω,{R}^N)big).

The existence results and Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces

NASA Astrophysics Data System (ADS)

Wang, Min

2017-06-01

This paper aims to establish the Tikhonov regularization method for generalized mixed variational inequalities in Banach spaces. For this purpose, we firstly prove a very general existence result for generalized mixed variational inequalities, provided that the mapping involved has the so-called mixed variational inequality property and satisfies a rather weak coercivity condition. Finally, we establish the Tikhonov regularization method for generalized mixed variational inequalities. Our findings extended the results for the generalized variational inequality problem (for short, GVIP( F, K)) in R^n spaces (He in Abstr Appl Anal, 2012) to the generalized mixed variational inequality problem (for short, GMVIP(F,φ , K)) in reflexive Banach spaces. On the other hand, we generalized the corresponding results for the generalized mixed variational inequality problem (for short, GMVIP(F,φ ,K)) in R^n spaces (Fu and He in J Sichuan Norm Univ (Nat Sci) 37:12-17, 2014) to reflexive Banach spaces.

Some design considerations for solar-powered aircraft

NASA Technical Reports Server (NTRS)

Phillips, W. H.

1980-01-01

Performance and operating characteristics are presented for a solar powered aircraft intended to remain aloft for long periods. The critical technologies which limit the performance are identified. By using the techniques presented, the effects of variation in the system parameters are studied. Practical design consideration are discussed.

Assessing Conformity to Standards for Treatment Foster Care.

ERIC Educational Resources Information Center

Farmer, Elizabeth M. Z.; Burns, Barbara J.; Dubs, Melanie S.; Thompson, Shealy

2002-01-01

This study examined conformity to the Program Standards for Treatment Foster Care among 42 statewide programs. Findings suggest fair to good overall conformity, with considerable variation among programs. A discussion of methodological and substantive considerations for future research and evaluation using this approach is included. (Contains…

Fourwing saltbush (Atriplex canescens) seed transfer zones

Treesearch

Stewart C. Sanderson; Durant E. McArthur

2004-01-01

Atriplex canescens (Pursh.) Nutt. is the most widespread species of perennial Atriplex in North America. Throughout its distributional range, A. canescens shows considerable between-population variation. Some of this variation may be due to phenotypic plasticity but most of it appears to be genetic. Mutations,...

Genetic variation in tree structure and its relation to size in Douglas-fir: I. Biomass partitioning, foliage efficiency, stem form, and wood density.

Treesearch

J.B. St. Clair

1994-01-01

Genetic variation and covariation among traits of tree size and structure were assessed in an 18-year-old Douglas-fir (Pseudotsuga menziesii var. menziesii (Mirb.) Franco) genetic test in the Coast Range of Oregon. Considerable genetic variation was found in size, biomass partitioning, and wood density, and genetic gains may be...

Apprenticeship Programme Requirements and Apprenticeship Completion Rates in Canada

ERIC Educational Resources Information Center

Coe, Patrick J.

2013-01-01

The past two decades have seen considerable growth in new apprenticeship registrations in Canada. However, this has not been matched by a corresponding increase in completions. Across provinces, trades and time, there is considerable variation in apprenticeship completion rates. In Canada, apprenticeship programmes are provincially regulated and…

Physiological constraints on deceleration during the aerocapture of manned vehicles

NASA Technical Reports Server (NTRS)

Lyne, J. E.

1992-01-01

The peak deceleration load allowed for aerobraking of manned vehicles is a critical parameter in planning future excursions to Mars. However, considerable variation exists in the limits used by various investigators. The goal of this study was to determine the most appropriate level for this limit. Methods: Since previous U.S. space flights have been limited to 84 days duration, Soviet flight results were examined. Published details of Soviet entry trajectories were not available. However, personal communication with Soviet cosmonauts suggested that peak entry loads of 5-6 G had been encountered upon return from 8 months in orbit. Soyuz entry capsule's characteristics were established and the capsule's entry trajectory was numerically calculated. The results confirm a peak load of 5 to 6 G. Results: Although the Soviet flights were of shorter duration than expected Mars missions, evidence exists that the deceleration experience is applicable. G tolerance has been shown to stabilize after 1 to 3 months in space if adequate countermeasures are used. The calculated Soyuz deceleration histories are graphically compared with those expected for Mars aerobraking. Conclusions: Previous spaceflight experience supports the use of a 5 G limit for the aerocapture of a manned vehicle at Mars.

Feed efficiency and the microbiota of the alimentary tract

USDA-ARS?s Scientific Manuscript database

There is considerable variation in the efficiency that cattle convert feed for maintenance and product (body weight gain, milk, and conceptus). Both intake and gain are polygenic traits and to better understand factors that contribute to variation in feed efficiency more defined phenotypes are need...

Size and burden of mental disorders in Europe--a critical review and appraisal of 27 studies.

PubMed

Wittchen, Hans-Ulrich; Jacobi, Frank

2005-08-01

Epidemiological data on a wide range of mental disorders from community studies conducted in European countries are presented to determine the availability and consistency of prevalence, disability and treatment findings for the EU. Using a stepwise multimethod approach, 27 eligible studies with quite variable designs and methods including over 150,000 subjects from 16 European countries were identified. Prevalence: On the basis of meta-analytic techniques as well as on reanalyses of selected data sets, it is estimated that about 27% (equals 82.7 million; 95% CI: 78.5-87.1) of the adult EU population, 18-65 of age, is or has been affected by at least one mental disorder in the past 12 months. Taking into account the considerable degree of comorbidity (about one third had more than one disorder), the most frequent disorders are anxiety disorders, depressive, somatoform and substance dependence disorders. When taking into account design, sampling and other methodological differences between studies, little evidence seems to exist for considerable cultural or country variation. Disability and treatment: despite very divergent and fairly crude assessment strategies, the available data consistently demonstrate (a) an association of all mental disorders with a considerable disability burden in terms of number of work days lost (WLD) and (b) generally low utilization and treatment rates. Only 26% of all cases had any consultation with professional health care services, a finding suggesting a considerable degree of unmet need. The paper highlights considerable future research needs for coordinated EU studies across all disorders and age groups. As prevalence estimates could not simply be equated with defined treatment needs, such studies should determine the degree of met and unmet needs for services by taking into account severity, disability and comorbidity. These needs are most pronounced for the new EU member states as well as more generally for adolescent and older populations.

An efficient transmission power control scheme for temperature variation in wireless sensor networks.

PubMed

Lee, Jungwook; Chung, Kwangsue

2011-01-01

Wireless sensor networks collect data from several nodes dispersed at remote sites. Sensor nodes can be installed in harsh environments such as deserts, cities, and indoors, where the link quality changes considerably over time. Particularly, changes in transmission power may be caused by temperature, humidity, and other factors. In order to compensate for link quality changes, existing schemes detect the link quality changes between nodes and control transmission power through a series of feedback processes, but these approaches can cause heavy overhead with the additional control packets needed. In this paper, the change of the link quality according to temperature is examined through empirical experimentation. A new power control scheme combining both temperature-aware link quality compensation and a closed-loop feedback process to adapt to link quality changes is proposed. We prove that the proposed scheme effectively adapts the transmission power to the changing link quality with less control overhead and energy consumption.

Numerical Studies into Flow Profiles in Confined Lubricant

NASA Astrophysics Data System (ADS)

di Mare, Luca; Ponjavic, Aleks; Wong, Janet

2013-03-01

This paper documents a computational study of flow profiles in confined fluids. The study is motivated by experimental evidence for deviation from Couette flow found by one of the authors (JSW). The computational study examines several possible stress-strain relations. Since a linear profile is the only possible solution for a constant stress layer even in presence of a power law, the study introduces a functional dependence of the fluid viscosity on the distance from the wall. Based on this dependence, a family of scaling laws for the velocity profile near the wall is derived which matches the measured profiles. The existence of this scaling law requires the viscosity of the fluid to increase at least linearly away from the wall. This behaviour is explained at a microscopic level by considerations on the mobility of long molecules near a wall. This behaviour is reminiscent of the variation of eddy length scales in near-wall turbulence.

Trends in total column ozone measurements

NASA Technical Reports Server (NTRS)

Rowland, F. S.; Angell, J.; Attmannspacher, W.; Bloomfield, P.; Bojkov, R. D.; Harris, N.; Komhyr, W.; Mcfarland, M.; Mcpeters, R.; Stolarski, R. S.

1989-01-01

It is important to ensure the best available data are used in any determination of possible trends in total ozone in order to have the most accurate estimates of any trends and the associated uncertainties. Accordingly, the existing total ozone records were examined in considerable detail. Once the best data set has been produced, the statistical analysis must examine the data for any effects that might indicate changes in the behavior of global total ozone. The changes at any individual measuring station could be local in nature, and herein, particular attention was paid to the seasonal and latitudinal variations of total ozone, because two dimensional photochemical models indicate that any changes in total ozone would be most pronounced at high latitudes during the winter months. The conclusions derived from this detailed examination of available total ozone can be split into two categories, one concerning the quality and the other the statistical analysis of the total ozone record.

Missing variables: how exclusion of human resources policy information confounds research connecting health and business outcomes.

PubMed

Lynch, Wendy D; Sherman, Bruce W

2014-01-01

When corporate health researchers examine the effects of health on business outcomes or the effect of health interventions on health and business outcomes, results will necessarily be confounded by the corporate environment(s) in which they are studied. In this research setting, most studies control for factors traditionally identified in public health, such as demographics and health status. Nevertheless, often overlooked is the extent to which company policies can also independently impact health care cost, work attendance, and productivity outcomes. With changes in employment and benefits practices resulting from health care reform, including incentives and plan design options, consideration of these largely neglected variables in research design has become increasingly important. This commentary summarizes existing knowledge regarding the implications of policy variations in research outcomes and provides a framework for incorporating them into future employer-based research.

Metagenomic analysis reveals significant changes of microbial compositions and protective functions during drinking water treatment.

PubMed

Chao, Yuanqing; Ma, Liping; Yang, Ying; Ju, Feng; Zhang, Xu-Xiang; Wu, Wei-Min; Zhang, Tong

2013-12-19

The metagenomic approach was applied to characterize variations of microbial structure and functions in raw (RW) and treated water (TW) in a drinking water treatment plant (DWTP) at Pearl River Delta, China. Microbial structure was significantly influenced by the treatment processes, shifting from Gammaproteobacteria and Betaproteobacteria in RW to Alphaproteobacteria in TW. Further functional analysis indicated the basic metabolic functions of microorganisms in TW did not vary considerably. However, protective functions, i.e. glutathione synthesis genes in 'oxidative stress' and 'detoxification' subsystems, significantly increased, revealing the surviving bacteria may have higher chlorine resistance. Similar results were also found in glutathione metabolism pathway, which identified the major reaction for glutathione synthesis and supported more genes for glutathione metabolism existed in TW. This metagenomic study largely enhanced our knowledge about the influences of treatment processes, especially chlorination, on bacterial community structure and protective functions (e.g. glutathione metabolism) in ecosystems of DWTPs.

Computation of the properties of liquid neon, methane, and gas helium at low temperature by the Feynman-Hibbs approach.

PubMed

Tchouar, N; Ould-Kaddour, F; Levesque, D

2004-10-15

The properties of liquid methane, liquid neon, and gas helium are calculated at low temperatures over a large range of pressure from the classical molecular-dynamics simulations. The molecular interactions are represented by the Lennard-Jones pair potentials supplemented by quantum corrections following the Feynman-Hibbs approach. The equations of state, diffusion, and shear viscosity coefficients are determined for neon at 45 K, helium at 80 K, and methane at 110 K. A comparison is made with the existing experimental data and for thermodynamical quantities, with results computed from quantum numerical simulations when they are available. The theoretical variation of the viscosity coefficient with pressure is in good agreement with the experimental data when the quantum corrections are taken into account, thus reducing considerably the 60% discrepancy between the simulations and experiments in the absence of these corrections.

Technological advances for improving adenoma detection rates: The changing face of colonoscopy.

PubMed

Ishaq, Sauid; Siau, Keith; Harrison, Elizabeth; Tontini, Gian Eugenio; Hoffman, Arthur; Gross, Seth; Kiesslich, Ralf; Neumann, Helmut

2017-07-01

Worldwide, colorectal cancer is the third commonest cancer. Over 90% follow an adenoma-to-cancer sequence over many years. Colonoscopy is the gold standard method for cancer screening and early adenoma detection. However, considerable variation exists between endoscopists' detection rates. This review considers the effects of different endoscopic techniques on adenoma detection. Two areas of technological interest were considered: (1) optical technologies and (2) mechanical technologies. Optical solutions, including FICE, NBI, i-SCAN and high definition colonoscopy showed mixed results. In contrast, mechanical advances, such as cap-assisted colonoscopy, FUSE, EndoCuff and G-EYE™, showed promise, with reported detections rates of up to 69%. However, before definitive recommendations can be made for their incorporation into daily practice, further studies and comparison trials are required. Copyright © 2017 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

Communications network design and costing model technical manual

NASA Technical Reports Server (NTRS)

Logan, K. P.; Somes, S. S.; Clark, C. A.

1983-01-01

This computer model provides the capability for analyzing long-haul trunking networks comprising a set of user-defined cities, traffic conditions, and tariff rates. Networks may consist of all terrestrial connectivity, all satellite connectivity, or a combination of terrestrial and satellite connectivity. Network solutions provide the least-cost routes between all cities, the least-cost network routing configuration, and terrestrial and satellite service cost totals. The CNDC model allows analyses involving three specific FCC-approved tariffs, which are uniquely structured and representative of most existing service connectivity and pricing philosophies. User-defined tariffs that can be variations of these three tariffs are accepted as input to the model and allow considerable flexibility in network problem specification. The resulting model extends the domain of network analysis from traditional fixed link cost (distance-sensitive) problems to more complex problems involving combinations of distance and traffic-sensitive tariffs.

Mapping telemedicine efforts: surveying regional initiatives in Denmark.

PubMed

Kierkegaard, Patrick

2015-05-01

The aim of this study is to survey telemedicine services currently in operation across Denmark. The study specifically seeks to answer the following questions: What initiatives are deployed within the different regions? What are the motivations behind the projects? What technologies are being utilized? What medical disciplines are being supported using telemedicine systems? All data were surveyed from the Telemedicinsk Landkort, a newly created database designed to provide a comprehensive and systematic overview of all telemedicine technologies in Denmark. The results of this study suggest that a growing numbers of telemedicine initiatives are currently in operation across Denmark but that considerable variations exist in terms of regional efforts as the number of operational telemedicine projects varied from region to region. The results of this study provide a timely picture of the factors that are shaping the telemedicine landscape of Denmark and suggest potential strategies to help policymakers increase and improve national telemedicine deployment.

What attitudes and beliefs underlie patients' decisions about participating in chemotherapy trials?

PubMed

Sutherland, H J; da Cunha, R; Lockwood, G A; Till, J E

1998-01-01

The theory of reasoned action, which postulates that personal attitudes and external social influences predict intentions to undertake a behavior, was used as a conceptual framework for developing a questionnaire to elicit beliefs and attitudes associated with the decision to participate in a hypothetical cancer chemotherapy trial. After completing the questionnaire, two-thirds of the 150 respondents indicated they would enroll in such a trial if it were available. Considerable variation existed in both "universal" and "trial-specific" beliefs and attitudes underpinning their intentions. A substantial amount of the variance in "intention" to participate was explained by "attitude" alone (75%). Social influences, although statistically significant, made a mere 1% additional contribution. One interpretation is that subjective expected-utility theory, which essentially predicts beliefs or "attitude," is a better model. The authors conclude that both theories may be criticized regarding how well they capture the rationality and nuances of decision behavior.

Landform degradation on Mercury, the moon, and Mars - Evidence from crater depth/diameter relationships

NASA Technical Reports Server (NTRS)

Malin, M. C.; Dzurisin, D.

1977-01-01

Craters on Mercury, the moon, and Mars were classified into two groups, namely, fresh and degraded craters, on the basis of qualitative visual degradation as revealed by degree of rim crispness, terraced interior walls, slumping from crater walls, etc., and the depth/diameter relationship of craters was studied. Lunar and Mercurian crater populations indicate the existence of terrain-correlated degradational phenomena. The depth/diameter relations for Mercury and the moon display remarkably similar forms, suggesting similar degrees of landform degradation. Depth/diameter curves display a break in slope, dividing two distinct crater populations. Mars craters show few of the trends of those of Mercury and the moon. The depth/diameter curve has no definite break in slope, though there is considerable depth variation. The role of nonballistic degradation in connection with the early formation of large expanses of intercrater plains is discussed.

Health- and Disease-Related Biomarkers in Aging Research

PubMed Central

Thompson, Hilaire J.; Voss, Joachim G.

2011-01-01

This article focuses on a synthesis of knowledge about healthy aging research in human beings and then synthesized nurse-led research in gerontology and geriatrics that use biomarkers. Healthy aging research has attracted considerable attention in the biomedical and basic sciences within the context of four major areas: (a) genetic variations as an expression of successful or unsuccessful aging; (b) caloric restriction as an intervention to slow the progression of aging; (c) immunological aging; (d) neurobiology of the aging brain. A systematic review of the literature was performed to identify nurse-led geriatric-related biomarker research. Nurse researchers who have chosen to integrate biomarkers as part of their research studies have been working in six focal areas, which are reviewed: health promotion within risk populations, cancer, vascular disease, Alzheimer’s disease, caregiving, and complementary therapies. The article provides a discussion of contributions to date, identifying existing gaps and future research opportunities. PMID:20077975

Achievable flatness in a large microwave power transmitting antenna

NASA Technical Reports Server (NTRS)

Ried, R. C.

1980-01-01

A dual reference SPS system with pseudoisotropic graphite composite as a representative dimensionally stable composite was studied. The loads, accelerations, thermal environments, temperatures and distortions were calculated for a variety of operational SPS conditions along with statistical considerations of material properties, manufacturing tolerances, measurement accuracy and the resulting loss of sight (LOS) and local slope distributions. A LOS error and a subarray rms slope error of two arc minutes can be achieved with a passive system. Results show that existing materials measurement, manufacturing, assembly and alignment techniques can be used to build the microwave power transmission system antenna structure. Manufacturing tolerance can be critical to rms slope error. The slope error budget can be met with a passive system. Structural joints without free play are essential in the assembly of the large truss structure. Variations in material properties, particularly for coefficient of thermal expansion from part to part, is more significant than actual value.

Development of Teleological Explanations in Peruvian Quechua-Speaking and U.S. English-Speaking Preschoolers and Adults.

PubMed

Sánchez Tapia, Ingrid; Gelman, Susan A; Hollander, Michelle A; Manczak, Erika M; Mannheim, Bruce; Escalante, Carmen

2016-05-01

Teleological reasoning involves the assumption that entities exist for a purpose (giraffes have long necks for reaching leaves). This study examines how teleological reasoning relates to cultural context, by studying teleological reasoning in 61 Quechua-speaking Peruvian preschoolers (Mage  = 5.3 years) and adults in an indigenous community, compared to 72 English-speaking U.S. preschoolers (Mage  = 4.9 years) and university students. Data were responses to open-ended "why" questions ("Why is that mountain tall?"). Teleological explanations about nonliving natural kinds were more frequent for children than adults, and for Quechua than U.S. However, changes with age were importantly distinct from differences corresponding to cultural variation. Developmental and cultural differences in teleological explanations may reflect causal analysis of the features under consideration. © 2016 The Authors. Child Development © 2016 Society for Research in Child Development, Inc.

Assessment of the Average Price and Ethanol Content of Alcoholic Beverages by Brand – United States, 2011

PubMed Central

DiLoreto, Joanna T.; Siegel, Michael; Hinchey, Danielle; Valerio, Heather; Kinzel, Kathryn; Lee, Stephanie; Chen, Kelsey; Shoaff, Jessica Ruhlman; Kenney, Jessica; Jernigan, David H.; DeJong, William

2011-01-01

Background There are no existing data on alcoholic beverage prices and ethanol content at the level of alcohol brand. A comprehensive understanding of alcohol prices and ethanol content at the brand level is essential for the development of effective public policy to reduce alcohol use among underage youth. The purpose of this study was to comprehensively assess alcoholic beverage prices and ethanol content at the brand level. Methods Using online alcohol price data from 15 control states and 164 online alcohol stores, we estimated the average alcohol price and percentage alcohol by volume for 900 brands of alcohol, across 17 different alcoholic beverage types, in the United States in 2011. Results There is considerable variation in both brand-specific alcohol prices and ethanol content within most alcoholic beverage types. For many types of alcohol, the within-category variation between brands exceeds the variation in average price and ethanol content among the several alcoholic beverage types. Despite differences in average prices between alcoholic beverage types, in 12 of the 16 alcoholic beverage types, customers can purchase at least one brand of alcohol that is under one dollar per ounce of ethanol. Conclusions Relying on data or assumptions about alcohol prices and ethanol content at the level of alcoholic beverage type is insufficient for understanding and influencing youth drinking behavior. Surveillance of alcohol prices and ethanol content at the brand level should become a standard part of alcohol research. PMID:22316218

Temporal variability of foliar nutrients: responses to nitrogen deposition and prescribed fire in a temperate steppe

USGS Publications Warehouse

Lü, Xiao-Tao; Reed, Sasha C.; Hou, Shuang-Li; Hu, Yan-Yu; Wei, Hai-Wei; Lü, Fu-Mei; Cui, Qiang; Han, Xing Guo

2017-01-01

Plant nutrient concentrations and stoichiometry drive fundamental ecosystem processes, with important implications for primary production, diversity, and ecosystem sustainability. While a range of evidence exists regarding how plant nutrients vary across spatial scales, our understanding of their temporal variation remains less well understood. Nevertheless, we know nutrients regulate plant function across time, and that important temporal controls could strongly interact with environmental change. Here, we report results from a 3-year assessment of inter-annual changes of foliar nitrogen (N) and phosphorus (P) concentrations and stoichiometry in three dominant grasses in response to N deposition and prescribed fire in a temperate steppe of northern China. Foliar N and P concentrations and their ratios varied greatly among years, with this temporal variation strongly related to inter-annual variation in precipitation. Nitrogen deposition significantly increased foliar N concentrations and N:P ratios in all species, while fire significantly altered foliar N and P concentrations but had no significant impacts on N:P ratios. Generally, N addition enhanced the temporal stability of foliar N and decreased that of foliar P and of N:P ratios. Our results indicate that plant nutrient status and response to environmental change are temporally dynamic and that there are differential effects on the interactions between environmental change drivers and timing for different nutrients. These responses have important implications for consideration of global change effects on plant community structure and function, management strategies, and the modeling of biogeochemical cycles under global change scenarios.

Collagen Fiber Orientation in Primate Long Bones.

PubMed

Warshaw, Johanna; Bromage, Timothy G; Terranova, Carl J; Enlow, Donald H

2017-07-01

Studies of variation in orientation of collagen fibers within bone have lead to the proposition that these are preferentially aligned to accommodate different kinds of load, with tension best resisted by fibers aligned longitudinally relative to the load, and compression best resisted by transversely aligned fibers. However, previous studies have often neglected to consider the effect of developmental processes, including constraints on collagen fiber orientation (CFO), particularly in primary bone. Here we use circularly polarized light microscopy to examine patterns of CFO in cross-sections from the midshaft femur, humerus, tibia, radius, and ulna in a range of living primate taxa with varied body sizes, phylogenetic relationships and positional behaviors. We find that a preponderance of longitudinally oriented collagen is characteristic of both periosteal primary and intracortically remodeled bone. Where variation does occur among groups, it is not simply understood via interpretations of mechanical loads, although prioritized adaptations to tension and/or shear are considered. While there is some suggestion that CFO may correlate with body size, this relationship is neither consistent nor easily explicable through consideration of size-related changes in mechanical adaptation. The results of our study indicate that there is no clear relationship between CFO and phylogenetic status. One of the principle factors accounting for the range of variation that does exist is primary tissue type, where slower depositing bone is more likely to comprise a larger proportion of oblique to transverse collagen fibers. Anat Rec, 300:1189-1207, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Quantitative contrast-enhanced ultrasound imaging: a review of sources of variability

PubMed Central

Tang, M.-X.; Mulvana, H.; Gauthier, T.; Lim, A. K. P.; Cosgrove, D. O.; Eckersley, R. J.; Stride, E.

2011-01-01

Ultrasound provides a valuable tool for medical diagnosis offering real-time imaging with excellent spatial resolution and low cost. The advent of microbubble contrast agents has provided the additional ability to obtain essential quantitative information relating to tissue vascularity, tissue perfusion and even endothelial wall function. This technique has shown great promise for diagnosis and monitoring in a wide range of clinical conditions such as cardiovascular diseases and cancer, with considerable potential benefits in terms of patient care. A key challenge of this technique, however, is the existence of significant variations in the imaging results, and the lack of understanding regarding their origin. The aim of this paper is to review the potential sources of variability in the quantification of tissue perfusion based on microbubble contrast-enhanced ultrasound images. These are divided into the following three categories: (i) factors relating to the scanner setting, which include transmission power, transmission focal depth, dynamic range, signal gain and transmission frequency, (ii) factors relating to the patient, which include body physical differences, physiological interaction of body with bubbles, propagation and attenuation through tissue, and tissue motion, and (iii) factors relating to the microbubbles, which include the type of bubbles and their stability, preparation and injection and dosage. It has been shown that the factors in all the three categories can significantly affect the imaging results and contribute to the variations observed. How these factors influence quantitative imaging is explained and possible methods for reducing such variations are discussed. PMID:22866229

[Variations among Spanish regions in the use of three cardiovascular technologies].

PubMed

Fitch-Warner, Kathryn; García de Yébenes, María J; Lázaro y de Mercado, Pablo; Belaza-Santurde, Javier

2006-12-01

There is evidence that some geographic variations in the use of medical technologies are not explained by differences in disease burden. The objectives of this study were to quantify variability in the use of percutaneous coronary intervention (PCI), implantable cardioverter-defibrillators (ICDs), and cardiac resynchronization therapy (CRT) in Spanish autonomous regions and to try to explain the variability found for the first two technologies. Linear regression models were developed in which the number of procedures performed per million population (pmp) in 2003 in each autonomous region was the dependent variable. Independent variables used included indices of technology provision, regional wealth, and disease burden. For PCI, the mean utilization rate for the whole of Spain was 1038 procedures pmp, with a high-low ratio of 1.95. Differences in gross domestic product explained 21% of the variability, but there was no relationship between the number of procedures performed and disease burden. For ICDs, the mean number of procedures performed in the whole of Spain was 46 pmp, with a high-low ratio of 3.04. As for PCI, differences in regional wealth explained 40% of the variability, with disease burden making no contribution. For CRT, the mean number of procedures performed in Spain in 2003 was 15 pmp, with a high-low ratio of 15.7. The considerable regional variation that exists in the use of these three medical technologies is principally explained by differences in regional wealth and not in disease burden.

Qualitative variation of photolabelled benzodiazepine receptors in different species.

PubMed

Hebebrand, J; Friedl, W; Lentes, K U; Propping, P

1986-01-01

In order to examine whether species differences of benzodiazepine receptor subunits exist, we compared the fluorographic pattern of photoaffinity labelled subunits after SDS-PAGE in five species: fish, frog, chicken, mouse and calf. Each species showed a distinct pattern of specifically labelled proteins. We conclude that species variation of benzodiazepine receptor does indeed exist.

Metabolomic profiling of the nectars of Aquilegia pubescens and A. canadensis

USDA-ARS?s Scientific Manuscript database

To date, variation in nectar chemistry of flowering plants has not been studied in detail. Such variation exerts considerable influence on pollinator–plant interactions, as well as on flower traits that play important roles in the selection of a plant for visitation by specific pollinators. Over the...

Secondary stroke prevention services in Canada: a cross-sectional survey and geospatial analysis of resources, capacity and geographic access

PubMed Central

Jewett, Lauren; Harroud, Adil; Hill, Michael D.; Côté, Robert; Wein, Theodore; Smith, Eric E.; Gubitz, Gord; Demchuk, Andrew M.; Sahlas, Demetrios J.; Gladstone, David J.; Lindsay, M. Patrice

2018-01-01

Background: Rapid assessment and management of transient ischemic attacks and nondisabling strokes by specialized stroke prevention services reduces the risk of recurrent stroke and improves outcomes. In Canada, with its vast geography and with 16.8% of the population living in rural areas, access to these services is challenging, and considerable variation in access to care exists. The purpose of this multiphase study was to identify sites across Canada providing stroke prevention services, evaluate resource capacity and determine geographic access for Canadians. Methods: We developed a Stroke Prevention Services Resource Inventory that contained 22 questions on the organization and delivery of stroke prevention services and quality monitoring. The inventory ran from November 2015 to January 2016 and was administered online. We conducted a geospatial analysis to estimate access by drive times. Considerations were made for hours of operation and access within and across provincial borders. Results: A total of 123 stroke prevention sites were identified, of which 119 (96.7%) completed the inventory. Most (95) are designated stroke prevention or rapid assessment clinics. Of the 119 sites, 68 operate full time, and 39 operate less than 2.5 days per week. A total of 87.3% of the Canadian population has access to a stroke prevention service within a 1-hour drive; however, only 69.2% has access to a service that operates 5-7 days a week. Allowing provincial border crossing improves access (< 6-h drive) for those who are beyond a 6-hour drive within their home province (3.4%). Interpretation: Most Canadians have reasonable geographic access to stroke prevention services. Allowing patients to cross borders improves the existing access for many, particularly some remote communities along the Ontario-Quebec and British Columbia-Alberta borders. PMID:29472251

Genetic variation in domestic reindeer and wild caribou in Alaska

USGS Publications Warehouse

Cronin, M.; Renecker, L.; Pierson, Barbara J.; Patton, J.C.

1995-01-01

Reindeer were introduced into Alaska 100 years ago and have been maintained as semidomestic livestock. They have had contact with wild caribou herds, including deliberate cross-breeding and mixing in the wild. Reindeer have considerable potential as a domestic animal for meat or velvet antler production, and wild caribou are important to subsistence and sport hunters. Our objective was to quantify the genetic relationships of reindeer and caribou in Alaska. We identified allelic variation among five herds of wild caribou and three herds of reindeer with DNA sequencing and restriction enzymes for three loci: a DQA locus of the major histocompatibility complex (Rata-DQA1), k-casein and the D-loop of mitochondrial DNA. These loci are of interest because of their potential influence on domestic animal performance and the fitness of wild populations. There is considerable genetic variation in reindeer and caribou for all three loci, including five, three and six alleles for DQA, k-casein and D-loop respectively. Most alleles occur in both reindeer and caribou, which may be the result of recent common ancestry or genetic introgression in either direction. However, allele frequencies differ considerably between reindeer and caribou, which suggests that gene flow has been limited.

Dust Records in Ice Cores from the Tibetan Plateau

NASA Astrophysics Data System (ADS)

Wang, N.; Yao, T.; Thompson, L. G.

2014-12-01

Dust plays an important role in the Earth system, and it usually displays largely spatial and temporal variations. It is necessary for us to reconstruct the past variations of dust in different regions to better understand the interactions between dust and environments. Ice core records can reveal the history of dust variations. In this paper, we used the Guliya, Dunde, Malan and Dasuopu ice cores from the Tibetan Plateau to study the spatial distribution, the seasonal variations and the secular trends of dust. It was found that the mean dust concentration was higher by one or two order of magnitudes in the Guliya and Dunde ice cores from the northern Tibetan Plateau than in the Dasuopu ice core from the southern Tibetan Plateau. During the year, the highest dust concentration occurs in the springtime in the northern Tibetan Plateau while in the non-monsoon season in the southern Tibetan Plateau. Over the last millennium, the Dasuopu ice core record shows that the 1270s~1380s and 1870s~1990s were the two epochs with high dust concentration. However, the Malan ice core from the northern Tibetan Plateau indicates that high dust concentration occurred in the 1130s~1550s and 1770s~1940s. Interestingly, climatic and environmental records of the ice cores from the Tibetan Plateau reflected that the correlation between dust concentration and air temperature was strongly positive in the southern Plateau while negative in the northern Plateau over the last millennium. This implies that climatic and environmental changes existed considerable differences in the different parts of the Plateau. Moreover, four Asian megadroughts occurred in 1638~1641, 1756~1758, 1790~1796 and 1876~1878, which caused more than tens millions people died, were revealed clearly by dust record in the Dasuopu ice core.

A population genomics approach shows widespread geographical distribution of cryptic genomic forms of the symbiotic fungus Rhizophagus irregularis.

PubMed

Savary, Romain; Masclaux, Frédéric G; Wyss, Tania; Droh, Germain; Cruz Corella, Joaquim; Machado, Ana Paula; Morton, Joseph B; Sanders, Ian R

2018-01-01

Arbuscular mycorrhizal fungi (AMF; phylum Gomeromycota) associate with plants forming one of the most successful microbe-plant associations. The fungi promote plant diversity and have a potentially important role in global agriculture. Plant growth depends on both inter- and intra-specific variation in AMF. It was recently reported that an unusually large number of AMF taxa have an intercontinental distribution, suggesting long-distance gene flow for many AMF species, facilitated by either long-distance natural dispersal mechanisms or human-assisted dispersal. However, the intercontinental distribution of AMF species has been questioned because the use of very low-resolution markers may be unsuitable to detect genetic differences among geographically separated AMF, as seen with some other fungi. This has been untestable because of the lack of population genomic data, with high resolution, for any AMF taxa. Here we use phylogenetics and population genomics to test for intra-specific variation in Rhizophagus irregularis, an AMF species for which genome sequence information already exists. We used ddRAD sequencing to obtain thousands of markers distributed across the genomes of 81 R. irregularis isolates and related species. Based on 6 888 variable positions, we observed significant genetic divergence into four main genetic groups within R. irregularis, highlighting that previous studies have not captured underlying genetic variation. Despite considerable genetic divergence, surprisingly, the variation could not be explained by geographical origin, thus also supporting the hypothesis for at least one AMF species of widely dispersed AMF genotypes at an intercontinental scale. Such information is crucial for understanding AMF ecology, and how these fungi can be used in an environmentally safe way in distant locations.

Editor's Choice - Carotid Stenosis Treatment: Variation in International Practice Patterns.

PubMed

Venermo, M; Wang, G; Sedrakyan, A; Mao, J; Eldrup, N; DeMartino, R; Mani, K; Altreuther, M; Beiles, B; Menyhei, G; Danielsson, G; Thomson, I; Heller, G; Setacci, C; Björck, M; Cronenwett, J

2017-04-01

The aim was to determine current practice for the treatment of carotid stenosis among 12 countries participating in the International Consortium of Vascular Registries (ICVR). Data from the United States Vascular Quality Initiative (VQI) and the Vascunet registry collaboration (including 10 registries in Europe and Australasia) were used. Variation in treatment modality of asymptomatic versus symptomatic patients was analysed between countries and among centres within each country. Among 58,607 procedures, octogenarians represented 18% of all patients, ranging from 8% (Hungary) to 22% (New Zealand and Australia). Women represented 36%, ranging from 29% (Switzerland) to 40% (USA). The proportion of carotid artery stenting (CAS) among asymptomatic patients ranged from 0% (Finland) to 26% (Sweden) and among symptomatic patients from 0% (Denmark) to 19% (USA). Variation among centres within countries for CAS was highest in the United States and Australia (from 0% to 80%). The overall proportion of asymptomatic patients was 48%, but varied from 0% (Denmark) to 73% (Italy). There was also substantial centre level variation within each country in the proportion of asymptomatic patients, most pronounced in Australia (0-72%), Hungary (5-55%), and the United States (0-100%). Countries with fee for service reimbursement had higher rates of treatment in asymptomatic patients than countries with population based reimbursement (OR 5.8, 95% CI 4.4-7.7). Despite evidence about treatment options for carotid artery disease, the proportion of asymptomatic patients, treatment modality, and the proportion of women and octogenarians vary considerably among and within countries. There was a significant association of treating more asymptomatic patients in countries with fee for service reimbursement. The findings reflect the inconsistency of the existing guidelines and a need for cooperation among guideline committees all over the world. Copyright © 2017 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.

Patterns of DNA barcode variation in Canadian marine molluscs.

PubMed

Layton, Kara K S; Martel, André L; Hebert, Paul D N

2014-01-01

Molluscs are the most diverse marine phylum and this high diversity has resulted in considerable taxonomic problems. Because the number of species in Canadian oceans remains uncertain, there is a need to incorporate molecular methods into species identifications. A 648 base pair segment of the cytochrome c oxidase subunit I gene has proven useful for the identification and discovery of species in many animal lineages. While the utility of DNA barcoding in molluscs has been demonstrated in other studies, this is the first effort to construct a DNA barcode registry for marine molluscs across such a large geographic area. This study examines patterns of DNA barcode variation in 227 species of Canadian marine molluscs. Intraspecific sequence divergences ranged from 0-26.4% and a barcode gap existed for most taxa. Eleven cases of relatively deep (>2%) intraspecific divergence were detected, suggesting the possible presence of overlooked species. Structural variation was detected in COI with indels found in 37 species, mostly bivalves. Some indels were present in divergent lineages, primarily in the region of the first external loop, suggesting certain areas are hotspots for change. Lastly, mean GC content varied substantially among orders (24.5%-46.5%), and showed a significant positive correlation with nearest neighbour distances. DNA barcoding is an effective tool for the identification of Canadian marine molluscs and for revealing possible cases of overlooked species. Some species with deep intraspecific divergence showed a biogeographic partition between lineages on the Atlantic, Arctic and Pacific coasts, suggesting the role of Pleistocene glaciations in the subdivision of their populations. Indels were prevalent in the barcode region of the COI gene in bivalves and gastropods. This study highlights the efficacy of DNA barcoding for providing insights into sequence variation across a broad taxonomic group on a large geographic scale.

Breeding progress, environmental variation and correlation of winter wheat yield and quality traits in German official variety trials and on-farm during 1983-2014.

PubMed

Laidig, Friedrich; Piepho, Hans-Peter; Rentel, Dirk; Drobek, Thomas; Meyer, Uwe; Huesken, Alexandra

2017-01-01

Over the last 32 years, a large gain in grain yield (24 %) was achieved in official German variety trials, and despite considerable loss in protein concentration (-7.9 %), winter wheat baking quality was partially improved over the last 32 years. On-farm gain in grain yield (32 %) exceeded gain in trials, but at yield level about 25 dt ha -1 lower. Breeding progress was very successfully transferred into both progress in grain yield and on-farm baking quality. Long-term gains in grain yield and baking quality of 316 winter wheat varieties from German official trials were evaluated. We dissected progress into a genetic and a non-genetic part to quantify the contribution of genetic improvement. We further investigated the influence of genotype and environment on total variation by estimating variance components. We also estimated genetic and phenotypic correlation between quality traits. For trial data, we found a large gain in grain yield (24%), but a strong decline in protein concentration (-8.0%) and loaf volume (-8.5%) relative to 1983. Improvement of baking quality could be achieved for falling number (5.8%), sedimentation value (7.9%), hardness (13.4%), water absorption (1.2%) and milling yield (2.4%). Grain yield, falling number and protein concentration were highly influenced by environment, whereas for sedimentation value, hardness, water absorption and loaf volume genotypes accounted for more than 60% of total variation. Strong to very strong relations exist among protein concentration, sedimentation value, and loaf volume. On-farm yields were obtained from national statistics, and grain quality data from samples collected by national harvest survey. These on-farm data were compared with trial results. On-farm gain in grain yield was 31.6%, but at a mean level about 25 dt ha -1  lower. Improvement of on-farm quality exceeded trial results considerably. A shift to varieties with improved baking quality can be considered as the main reason for this remarkable improvement of on-farm baking quality.

A Variational Reduction and the Existence of a Fully Localised Solitary Wave for the Three-Dimensional Water-Wave Problem with Weak Surface Tension

NASA Astrophysics Data System (ADS)

Buffoni, Boris; Groves, Mark D.; Wahlén, Erik

2017-12-01

Fully localised solitary waves are travelling-wave solutions of the three- dimensional gravity-capillary water wave problem which decay to zero in every horizontal spatial direction. Their existence has been predicted on the basis of numerical simulations and model equations (in which context they are usually referred to as `lumps'), and a mathematically rigorous existence theory for strong surface tension (Bond number {β} greater than {1/3} ) has recently been given. In this article we present an existence theory for the physically more realistic case {0 < β < 1/3} . A classical variational principle for fully localised solitary waves is reduced to a locally equivalent variational principle featuring a perturbation of the functional associated with the Davey-Stewartson equation. A nontrivial critical point of the reduced functional is found by minimising it over its natural constraint set.

A Variational Reduction and the Existence of a Fully Localised Solitary Wave for the Three-Dimensional Water-Wave Problem with Weak Surface Tension

NASA Astrophysics Data System (ADS)

Buffoni, Boris; Groves, Mark D.; Wahlén, Erik

2018-06-01

Fully localised solitary waves are travelling-wave solutions of the three- dimensional gravity-capillary water wave problem which decay to zero in every horizontal spatial direction. Their existence has been predicted on the basis of numerical simulations and model equations (in which context they are usually referred to as `lumps'), and a mathematically rigorous existence theory for strong surface tension (Bond number {β} greater than {1/3}) has recently been given. In this article we present an existence theory for the physically more realistic case {0 < β < 1/3}. A classical variational principle for fully localised solitary waves is reduced to a locally equivalent variational principle featuring a perturbation of the functional associated with the Davey-Stewartson equation. A nontrivial critical point of the reduced functional is found by minimising it over its natural constraint set.

Similarity solutions for unsteady flow behind an exponential shock in a self-gravitating non-ideal gas with azimuthal magnetic field

NASA Astrophysics Data System (ADS)

Nath, G.; Pathak, R. P.; Dutta, Mrityunjoy

2018-01-01

Similarity solutions for the flow of a non-ideal gas behind a strong exponential shock driven out by a piston (cylindrical or spherical) moving with time according to an exponential law is obtained. Solutions are obtained, in both the cases, when the flow between the shock and the piston is isothermal or adiabatic. The shock wave is driven by a piston moving with time according to an exponential law. Similarity solutions exist only when the surrounding medium is of constant density. The effects of variation of ambient magnetic field, non-idealness of the gas, adiabatic exponent and gravitational parameter are worked out in detail. It is shown that the increase in the non-idealness of the gas or the adiabatic exponent of the gas or presence of magnetic field have decaying effect on the shock wave. Consideration of the isothermal flow and the self-gravitational field increase the shock strength. Also, the consideration of isothermal flow or the presence of magnetic field removes the singularity in the density distribution, which arises in the case of adiabatic flow. The result of our study may be used to interpret measurements carried out by space craft in the solar wind and in neighborhood of the Earth's magnetosphere.

Exploring the Gaps in Practical Ethical Guidance for Animal Welfare Considerations of Field Interventions and Innovations Targeting Dogs and Cats.

PubMed

Tasker, Louisa; Getty, Susan F; Briggs, Joyce R; Benka, Valerie A W

2018-01-27

Domestic dogs ( Canis lupus familiaris ) and cats ( Felis silvestris catus ) are common species targeted by nongovernmental or intergovernmental organizations, veterinarians and government agencies worldwide, for field interventions (e.g., population management, rabies vaccination programs) or innovations (e.g., development of technologies or pharmaceuticals to improve animal welfare). We have a moral responsibility to ensure that the conduct of this work is humane for dogs or cats, and to consider the human communities in which the animals live. Ethical review is widely accepted as being integral to responsible practice, and it is fundamental to good science that underpins innovation. Despite the necessity of field interventions or innovations to advance the welfare of individuals or populations of animals, we found a lack of specific guidance and review processes to help navigate ethical dilemmas surrounding the conduct of such work. This can be detrimental to the wellbeing of animals and their human communities. Here we identify the gaps in existing ethical frameworks (specifically application of Reduction and Refinement principles, challenges of obtaining meaningful informed consent with variations in the quality of human-animal relationships, and limited resources regarding considerations of local stakeholders), and outline the need for additional tools to promote ethical conduct in the field.

Periprocedural Management of Non-Vitamin K Oral Anticoagulants in Chronic Kidney Disease: A Review of Existing Heterogeneity and Contemporary Evidence.

PubMed

Gunasekaran, Prasad; Parashara, Deepak K

2015-12-01

Non vitamin-K oral anticoagulants (NOAC) have considerably enhanced anticoagulation practice for non-valvular atrial fibrillation with specific advantages of fixed dosing, non-fluctuant therapeutic levels and obviation of therapeutic level monitoring. NOAC pharmacology is remarkable for considerable renal excretion. Heterogeneity in the precise time cut-offs for discontinuation of NOACs prior to elective surgical or percutaneous procedures arise from the non-linear variations of drug excretion with different levels of creatinine clearances as in chronic kidney disease. Multiple authors have suggested cut-offs leading to ambiguity among practicing clinicians. Recent data pertaining to systemic thromboembolism, stroke and major bleeding derived from randomized controlled clinical trials have simplified the periprocedural management of NOACs. This review focusses on heterogeneity in the management of NOACs in patients with CKD in this peculiar scenario and highlights the contemporary evidence to support a unified approach towards perioperative management of NOACs. Multiple antidotes targeted towards binding of specific NOACs have been developed and are in the testing phase, thereby offering immense potential for rapid and complete reversal of NOAC activity in emergent procedures and major bleeding episodes. Targeted research on thromboembolism, stroke and major bleeding following temporary periprocedural interruption of NOACs using multicentric registries could further expand the clinical utility of these agents.

Long‐term follow‐up of children treated for cancer: why is it necessary, by whom, where and how?

PubMed Central

Skinner, Roderick; Wallace, W Hamish B; Levitt, Gillian

2007-01-01

About 1 in 715 young adults is a survivor of childhood malignancy, but these individuals are at increased risk of considerable treatment‐related morbidity or even mortality. A recent study suggests that at least 60% have one or more chronic health problems, whilst about 20% have three or more. The principle goal of long‐term follow‐up (LTFU) of survivors is to decrease the severity of late treatment complications by performing appropriate surveillance to detect incipient toxicity, and by facilitating timely diagnosis and management of emerging or established late adverse effects. The content of LTFU is dictated by the type and amount of treatment for the malignancy, and has been defined in recent clinical guidelines. Moreover, LTFU allows provision of survivor education, psychosocial support and health promotion advice. However, considerable variation exists in how LTFU is performed, with several alternative models involving a range of professionals in a variety of locations, depending on numerous clinical and organisational factors. There is increasing utilisation of multidisciplinary teams, and recognition of the importance of effective transition strategies whereby care is transferred to more age‐appropriate providers, usually after a period of joint care in adolescence. It is of paramount importance to ascertain and meet the needs of survivors themselves. PMID:17337686

40 CFR 230.91 - Purpose and general considerations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... done after taking into consideration cost, existing technology, and logistics in light of overall... national or regional level. No modifications to the basic application, meaning, or intent of this subpart...

Genetic improvement of disease resistance in salmonid fish using selective breeding: Overview of concepts, considerations and limitations

USDA-ARS?s Scientific Manuscript database

In aquaculture, endemic infectious diseases constitute a considerable economic burden due to direct losses as well as indirect impacts on growth and animal welfare. In response to infectious disease, it is well documented that host genetic variation is present in most animal populations, especially ...

Determinants of Awareness, Consideration, and Choice Set Size in University Choice.

ERIC Educational Resources Information Center

Dawes, Philip L.; Brown, Jennifer

2002-01-01

Developed and tested a model of students' university "brand" choice using five individual-level variables (ethnic group, age, gender, number of parents going to university, and academic ability) and one situational variable (duration of search) to explain variation in the sizes of awareness, consideration, and choice decision sets. (EV)

A cancer survival model that takes sociodemographic variations in "normal" mortality into account: comparison with other models

PubMed Central

Kravdal, O

2002-01-01

Study objectives: Sociodemographic differentials in cancer survival have occasionally been studied by using a relative survival approach, where all cause mortality among persons with a cancer diagnosis is compared with that among similar persons without such a diagnosis ("normal" mortality). One should ideally take into account that this "normal" mortality not only depends on age, sex, and period, but also various other sociodemographic variables. However, this has very rarely been done. A method that permits such variations to be considered is presented here, as an alternative to an existing technique, and is compared with a relative survival model where these variations are disregarded and two other methods that have often been used. Design, setting, and participants: The focus is on how education and marital status affect the survival from 12 common cancer types among men and women aged 40–80. Four different types of hazard models are estimated, and differences between effects are compared. The data are from registers and censuses and cover the entire Norwegian population for the years 1960–1991. There are more than 100 000 deaths to cancer patients in this material. Main results and conclusions: A model for registered cancer mortality among cancer patients gives results that for most, but not all, sites are very similar to those from a relative survival approach where educational or marital variations in "normal" mortality are taken into account. A relative survival approach without consideration of these sociodemographic variations in "normal" mortality gives more different results, the most extreme example being the doubling of the marital differentials in survival from prostate cancer. When neither sufficient data on cause of death nor on variations in "normal" mortality are available, one may well choose the simplest method, which is to model all cause mortality among cancer patients. There is little reason to bother with the estimation of a relative-survival model that does not allow sociodemographic variations in "normal" mortality beyond those related to age, sex, and period. Fortunately, both these less data demanding models perform well for the most aggressive cancers. PMID:11896140

Patient Handoffs between Emergency Department and Inpatient Physicians: A Qualitative Study to Inform Standardization of Practice and Organization Theory

ERIC Educational Resources Information Center

Hilligoss, Phillip Brian

2011-01-01

This dissertation is motivated by two problems. First, existing literature characterizes patient handoff as an information transfer activity in which safety and quality are compromised by practice variation. This has prompted a movement to standardize practice. However, existing research has not closely examined how practice variations may be…

An Application of Variational Theory to an Integrated Walrasian Model of Exchange, Consumption and Production

NASA Astrophysics Data System (ADS)

Donato, M. B.; Milasi, M.; Vitanza, C.

2010-09-01

An existence result of a Walrasian equilibrium for an integrated model of exchange, consumption and production is obtained. The equilibrium model is characterized in terms of a suitable generalized quasi-variational inequality; so the existence result comes from an original technique which takes into account tools of convex and set-valued analysis.

Geographical variation in the periodicity of gypsy moth outbreaks

Treesearch

Derek M. Johnson; Andrew M. Liebhold; Ottar N. Bj& #248rnstad

2006-01-01

The existence of periodic oscillations in populations of forest Lepidoptera is well known. While information exists on how the periods of oscillations vary among different species, there is little prior evidence of variation in periodicity within the range of a single Lepidopteran species. The exotic gypsy moth is an introduced foliage-feeding insect in North America....

33 CFR 332.1 - Purpose and general considerations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... available and capable of being done after taking into consideration cost, existing technology, and logistics... and the Corps at the national or regional level. No modifications to the basic application, meaning...

The multiple meanings of global health governance: a call for conceptual clarity.

PubMed

Lee, Kelley; Kamradt-Scott, Adam

2014-04-28

The term global health governance (GHG) is now widely used, with over one thousand works published in the scholarly literature, almost all since 2002. Amid this rapid growth there is considerable variation in how the term is defined and applied, generating confusion as to the boundaries of the subject, the perceived problems in practice, and the goals to be achieved through institutional reform. This paper is based on the results of a separate scoping study of peer reviewed GHG research from 1990 onwards which undertook keyword searches of public health and social science databases. Additional works, notably books, book chapters and scholarly articles, not currently indexed, were identified through Web of Science citation searches. After removing duplicates, book reviews, commentaries and editorials, we reviewed the remaining 250 scholarly works in terms of how the concept of GHG is applied. More specifically, we identify what is claimed as constituting GHG, how it is problematised, the institutional features of GHG, and what forms and functions are deemed ideal. After examining the broader notion of global governance and increasingly ubiquitous term "global health", the paper identifies three ontological variations in GHG scholarship - the scope of institutional arrangements, strengths and weaknesses of existing institutions, and the ideal form and function of GHG. This has produced three common, yet distinct, meanings of GHG that have emerged - globalisation and health governance, global governance and health, and governance for global health. There is a need to clarify ontological and definitional distinctions in GHG scholarship and practice, and be critically reflexive of their normative underpinnings. This will enable greater precision in describing existing institutional arrangements, as well as serve as a prerequisite for a fuller debate about the desired nature of GHG.

Verification of Gyrokinetic codes: Theoretical background and applications

NASA Astrophysics Data System (ADS)

Tronko, Natalia; Bottino, Alberto; Görler, Tobias; Sonnendrücker, Eric; Told, Daniel; Villard, Laurent

2017-05-01

In fusion plasmas, the strong magnetic field allows the fast gyro-motion to be systematically removed from the description of the dynamics, resulting in a considerable model simplification and gain of computational time. Nowadays, the gyrokinetic (GK) codes play a major role in the understanding of the development and the saturation of turbulence and in the prediction of the subsequent transport. Naturally, these codes require thorough verification and validation. Here, we present a new and generic theoretical framework and specific numerical applications to test the faithfulness of the implemented models to theory and to verify the domain of applicability of existing GK codes. For a sound verification process, the underlying theoretical GK model and the numerical scheme must be considered at the same time, which has rarely been done and therefore makes this approach pioneering. At the analytical level, the main novelty consists in using advanced mathematical tools such as variational formulation of dynamics for systematization of basic GK code's equations to access the limits of their applicability. The verification of the numerical scheme is proposed via the benchmark effort. In this work, specific examples of code verification are presented for two GK codes: the multi-species electromagnetic ORB5 (PIC) and the radially global version of GENE (Eulerian). The proposed methodology can be applied to any existing GK code. We establish a hierarchy of reduced GK Vlasov-Maxwell equations implemented in the ORB5 and GENE codes using the Lagrangian variational formulation. At the computational level, detailed verifications of global electromagnetic test cases developed from the CYCLONE Base Case are considered, including a parametric β-scan covering the transition from ITG to KBM and the spectral properties at the nominal β value.

Aberrant Gene Expression in Humans

PubMed Central

Yang, Ence; Ji, Guoli; Brinkmeyer-Langford, Candice L.; Cai, James J.

2015-01-01

Gene expression as an intermediate molecular phenotype has been a focus of research interest. In particular, studies of expression quantitative trait loci (eQTL) have offered promise for understanding gene regulation through the discovery of genetic variants that explain variation in gene expression levels. Existing eQTL methods are designed for assessing the effects of common variants, but not rare variants. Here, we address the problem by establishing a novel analytical framework for evaluating the effects of rare or private variants on gene expression. Our method starts from the identification of outlier individuals that show markedly different gene expression from the majority of a population, and then reveals the contributions of private SNPs to the aberrant gene expression in these outliers. Using population-scale mRNA sequencing data, we identify outlier individuals using a multivariate approach. We find that outlier individuals are more readily detected with respect to gene sets that include genes involved in cellular regulation and signal transduction, and less likely to be detected with respect to the gene sets with genes involved in metabolic pathways and other fundamental molecular functions. Analysis of polymorphic data suggests that private SNPs of outlier individuals are enriched in the enhancer and promoter regions of corresponding aberrantly-expressed genes, suggesting a specific regulatory role of private SNPs, while the commonly-occurring regulatory genetic variants (i.e., eQTL SNPs) show little evidence of involvement. Additional data suggest that non-genetic factors may also underlie aberrant gene expression. Taken together, our findings advance a novel viewpoint relevant to situations wherein common eQTLs fail to predict gene expression when heritable, rare inter-individual variation exists. The analytical framework we describe, taking into consideration the reality of differential phenotypic robustness, may be valuable for investigating complex traits and conditions. PMID:25617623

Density contrast across the Moho beneath the Indian shield: Implications for isostasy

NASA Astrophysics Data System (ADS)

Paul, Himangshu; Mangalampally, Ravi Kumar; Tiwari, Virendra Mani; Singh, Arun; Chadha, Rajender Kumar; Davuluri, Srinagesh

2018-04-01

Knowledge of isostasy provides insights into how excess (or deficit) of mass on and within the lithosphere is maintained over different time scales, and also helps decipher the vertical dynamics. In continental regions, isostasy is primarily manifested as a crustal root, the extent of which is defined by the lithospheric strength and the density contrast at the Moho. In this study, we briefly review the methodology for extracting the density contrast across the Moho using the amplitudes of the P-to-s converted and free-surface reverberating phases in a receiver function (RF). We test the efficacy of this technique by applying it on synthetic and real data from 10 broadband seismic stations sited on diverse tectonic provinces in the Indian shield. We determine the density contrast after parameterizing the shear-wave velocity structure beneath the stations using the nearest neighbourhood algorithm. We find considerable variation in the density contrast across the Moho beneath the stations (0.4-0.65 gm/cc). This is explained in terms of isostatic compensation, incorporating the existing estimates of lithospheric strength (Te). Crustal roots computed using the estimated Te and the deduced density contrast substantiate the crustal thickness values inferred through RF analysis, and vice versa. This illustrates isostasy as a combination of variation in density contrast and Te. The density contrasts and crustal thicknesses inferred from RF analysis explain well the isostatic compensation mechanism in different regions. However, unusually large density contrasts (∼0.6 gm/cc) corresponding to elevated regions are intriguing and warrant further investigations. Our observation of varied density contrasts at the Moho in a Precambrian continental setting is interesting and raises a question about the existence of such situations in other parts of the world.

The multiple meanings of global health governance: a call for conceptual clarity

PubMed Central

2014-01-01

Background The term global health governance (GHG) is now widely used, with over one thousand works published in the scholarly literature, almost all since 2002. Amid this rapid growth there is considerable variation in how the term is defined and applied, generating confusion as to the boundaries of the subject, the perceived problems in practice, and the goals to be achieved through institutional reform. Methodology This paper is based on the results of a separate scoping study of peer reviewed GHG research from 1990 onwards which undertook keyword searches of public health and social science databases. Additional works, notably books, book chapters and scholarly articles, not currently indexed, were identified through Web of Science citation searches. After removing duplicates, book reviews, commentaries and editorials, we reviewed the remaining 250 scholarly works in terms of how the concept of GHG is applied. More specifically, we identify what is claimed as constituting GHG, how it is problematised, the institutional features of GHG, and what forms and functions are deemed ideal. Results After examining the broader notion of global governance and increasingly ubiquitous term “global health”, the paper identifies three ontological variations in GHG scholarship - the scope of institutional arrangements, strengths and weaknesses of existing institutions, and the ideal form and function of GHG. This has produced three common, yet distinct, meanings of GHG that have emerged – globalisation and health governance, global governance and health, and governance for global health. Conclusions There is a need to clarify ontological and definitional distinctions in GHG scholarship and practice, and be critically reflexive of their normative underpinnings. This will enable greater precision in describing existing institutional arrangements, as well as serve as a prerequisite for a fuller debate about the desired nature of GHG. PMID:24775919

Effects of body condition on buoyancy in endangered North Atlantic right whales.

PubMed

Nousek-McGregor, Anna E; Miller, Carolyn A; Moore, Michael J; Nowacek, Douglas P

2014-01-01

Buoyancy is an important consideration for diving marine animals, resulting in specific ecologically relevant adaptations. Marine mammals use blubber as an energy reserve, but because this tissue is also positively buoyant, nutritional demands have the potential to cause considerable variation in buoyancy. North Atlantic right whales Eubalaena glacialis are known to be positively buoyant as a result of their blubber, and the thickness of this layer varies considerably, but the effect of this variation on buoyancy has not been explored. This study compared the duration and rate of ascending and descending glides, recorded with an archival tag, with blubber thickness, measured with an ultrasound device, in free-swimming right whales. Ascending whales with thicker blubber had shorter portions of active propulsion and longer passive glides than whales with thinner blubber, suggesting that blubber thickness influences buoyancy because the buoyant force is acting in the same direction as the animal's movement during this phase. Whales with thinner layers also used similar body angles and velocities when traveling to and from depth, while those with thicker layers used shallower ascent angles but achieved higher ascent velocities. Such alterations in body angle may help to reduce the cost of transport when swimming against the force of buoyancy in a state of augmented positive buoyancy, which represents a dynamic response to reduce the energetic consequences of physiological changes. These results have considerable implications for any diving marine animal during periods of nutritional stress, such as during seasonal migrations and annual variations in prey availability.

A study of vertebra number in pigs confirms the association of vertnin and reveals additional QTL

USDA-ARS?s Scientific Manuscript database

Background: Formation of the vertebral column is a critical developmental stage in mammals. The strict control of this process has resulted in little variation in number of vertebrae across mammalian species and no variation within most mammalian species. The pig is quite unique as considerable vari...

Variations in Pedagogical Design of Massive Open Online Courses (MOOCs) across Disciplines

ERIC Educational Resources Information Center

Najafi, Hadieh; Rolheiser, Carol; Håklev, Stian; Harrison, Laurie

2017-01-01

Given that few studies have formally examined pedagogical design considerations of Massive Online Open Courses (MOOCs), this study explored variations in the pedagogical design of six MOOCs offered at the University of Toronto, while considering disciplinary characteristics and expectations of each MOOC. Using a framework (Neumann et al., 2002)…

Self-Study and Evaluation Guide; Section C-2; Financial Accounting and Service Reporting.

ERIC Educational Resources Information Center

National Accreditation Council for Agencies Serving the Blind and Visually Handicapped, New York, NY.

In determining standards to judge an agency's performance in meeting its responsibilities to the public, two fundamental factors must be taken into consideration: (1) standards for financial accounting and service reporting must be formulated in the knowledge that variations among agencies will necessarily give rise to variations in applicability…

Adjustment of relative humidity and temperature for differences in elevation.

Treesearch

Owen P. Cramer

1961-01-01

The variation of fire-weather elements in mountainous terrain is complex at any one time, and the patterns vary considerably with time. During periods of serious fire weather, this variation becomes important. Much information is obtainable by local interpretation of available forecasts and observations. Optimum use of available information requires some understanding...

Nuclear genetic variation across the range of ponderosa pine (Pinus ponderosa): Phylogeographic, taxonomic and conservation implications

Treesearch

Kevin M. Potter; Valerie D. Hipkins; Mary F. Mahalovich; Robert E. Means

2015-01-01

Ponderosa pine (Pinus ponderosa) is among the most broadly distributed conifer species of western North America, where it possesses considerable ecological, esthetic, and commercial value. It exhibits complicated patterns of morphological and genetic variation, suggesting that it may be in the process of differentiating into distinct regional...

Height growth of ponderosa pine progenies

Treesearch

R. Z. Callaham; A. A. Hasel

1957-01-01

Research at the Institute of Forest Genetics at Plaeerville, California since its inception in 1925, has been concerned with the variation in individual trees of a speices. We are interested in this variation as a guide to selection of outstanding individuals. Western forests have considerable diversity in soils, topography, species composition, and distribution of age...

Family losses following truncation selection in populations of half-sib families

Treesearch

J. H. Roberds; G. Namkoong; H. Kang

1980-01-01

Family losses during truncation selection may be sizable in populations of half-sib families. Substantial losses may occur even in populations containing little or no variation among families. Heavier losses will occur, however, under conditions of high heritability where there is considerable family variation. Standard deviations and therefore variances of family loss...

Laboratory Needs for Interstellar Ice Studies

NASA Astrophysics Data System (ADS)

Boogert, Abraham C. A.

2012-05-01

A large fraction of the molecules in dense interstellar and circumstellar environments is stored in icy grain mantles. The mantles are formed by a complex interplay between chemical and physical processes. Key questions on the accretion and desorption processes and the chemistry on the grain surfaces and within the icy mantles can only be answered by laboratory experiments. Recent infrared (2-30 micron) spectroscopic surveys of large samples of Young Stellar Objects (YSOs) and background stars tracing quiescent cloud material have shown that the ice band profiles and depths vary considerably as a function of environment. Using laboratory spectra in the identification process, it is clear that a rather complex mixture of simple species (CH3OH, CO2, H2O, CO) exists even in the quiescent cloud phase. Variations of the local physical conditions (CO freeze out) and time scales (CH3OH formation) appear to be key factors in the observed variations. Sublimation and thermal processing dominate as YSOs heat their environments. The identification of several ice absorption features is still disputed. I will outline laboratory work (e.g., on salts, PAHs, and aliphatic hydrocarbons) needed to further constrain the ice band identification as well as the thermal and chemical history of the carriers. Such experiments will also be essential to interpret future high spectral resolution SOFIA and JWST observations.

Investigation of Multi-Input Multi-Output Robust Control Methods to Handle Parametric Uncertainties in Autopilot Design.

PubMed

Kasnakoğlu, Coşku

2016-01-01

Some level of uncertainty is unavoidable in acquiring the mass, geometry parameters and stability derivatives of an aerial vehicle. In certain instances tiny perturbations of these could potentially cause considerable variations in flight characteristics. This research considers the impact of varying these parameters altogether. This is a generalization of examining the effects of particular parameters on selected modes present in existing literature. Conventional autopilot designs commonly assume that each flight channel is independent and develop single-input single-output (SISO) controllers for every one, that are utilized in parallel for actual flight. It is demonstrated that an attitude controller built like this can function flawlessly on separate nominal cases, but can become unstable with a perturbation no more than 2%. Two robust multi-input multi-output (MIMO) design strategies, specifically loop-shaping and μ-synthesis are outlined as potential substitutes and are observed to handle large parametric changes of 30% while preserving decent performance. Duplicating the loop-shaping procedure for the outer loop, a complete flight control system is formed. It is confirmed through software-in-the-loop (SIL) verifications utilizing blade element theory (BET) that the autopilot is capable of navigation and landing exposed to high parametric variations and powerful winds.

A three-dimensional meso-macroscopic model for Li-Ion intercalation batteries

DOE PAGES

Allu, S.; Kalnaus, S.; Simunovic, S.; ...

2016-06-09

Through this study, we present a three-dimensional computational formulation for electrode-electrolyte-electrode system of Li-Ion batteries. The physical consistency between electrical, thermal and chemical equations is enforced at each time increment by driving the residual of the resulting coupled system of nonlinear equations to zero. The formulation utilizes a rigorous volume averaging approach typical of multiphase formulations used in other fields and recently extended to modeling of supercapacitors [1]. Unlike existing battery modeling methods which use segregated solution of conservation equations and idealized geometries, our unified approach can model arbitrary battery and electrode configurations. The consistency of multi-physics solution also allowsmore » for consideration of a wide array of initial conditions and load cases. The formulation accounts for spatio-temporal variations of material and state properties such as electrode/void volume fractions and anisotropic conductivities. The governing differential equations are discretized using the finite element method and solved using a nonlinearly consistent approach that provides robust stability and convergence. The new formulation was validated for standard Li-ion cells and compared against experiments. Finally, its scope and ability to capture spatio-temporal variations of potential and lithium distribution is demonstrated on a prototypical three-dimensional electrode problem.« less

Investigation of Multi-Input Multi-Output Robust Control Methods to Handle Parametric Uncertainties in Autopilot Design

PubMed Central

Kasnakoğlu, Coşku

2016-01-01

Some level of uncertainty is unavoidable in acquiring the mass, geometry parameters and stability derivatives of an aerial vehicle. In certain instances tiny perturbations of these could potentially cause considerable variations in flight characteristics. This research considers the impact of varying these parameters altogether. This is a generalization of examining the effects of particular parameters on selected modes present in existing literature. Conventional autopilot designs commonly assume that each flight channel is independent and develop single-input single-output (SISO) controllers for every one, that are utilized in parallel for actual flight. It is demonstrated that an attitude controller built like this can function flawlessly on separate nominal cases, but can become unstable with a perturbation no more than 2%. Two robust multi-input multi-output (MIMO) design strategies, specifically loop-shaping and μ-synthesis are outlined as potential substitutes and are observed to handle large parametric changes of 30% while preserving decent performance. Duplicating the loop-shaping procedure for the outer loop, a complete flight control system is formed. It is confirmed through software-in-the-loop (SIL) verifications utilizing blade element theory (BET) that the autopilot is capable of navigation and landing exposed to high parametric variations and powerful winds. PMID:27783706

Mini-Mental State Exam performance of older African Americans: effect of age, gender, education, hypertension, diabetes, and the inclusion of serial 7s subtraction versus "world" backward on score.

PubMed

Hawkins, Keith A; Cromer, Jennifer R; Piotrowski, Andrea S; Pearlson, Godfrey D

2011-11-01

The Mini-Mental State Exam (MMSE) is a clinically ubiquitous yet incompletely standardized instrument. Though the test offers considerable examiner leeway, little data exist on the normative consequences of common administration variations. We sought to: (a) determine the effects of education, age, gender, health status, and a common administration variation (serial 7s subtraction vs. "world" spelled backward) on MMSE score within a minority sample, (b) provide normative data stratified on the most empirically relevant bases, and (c) briefly address item failure rates. African American citizens (N = 298) aged 55-87 living independently in the community were recruited by advertisement, community recruitment, and word of mouth. Total score with "world" spelled backward exceeded total score with serial 7s subtraction across all levels of education, replicating findings in Caucasian samples. Education is the primary source of variance on MMSE score, followed by age. In this cohort, women out-performed men when "world" spelled backward was included, but there was no gender effect when serial 7s subtraction was included in MMSE total score. To ensure an appropriate interpretation of MMSE scores, reports, whether clinical or in publications of research findings, should be explicit regarding the administration method. Stratified normative data are provided.

Early Autumn Senescence in Red Maple (Acer rubrum L.) Is Associated with High Leaf Anthocyanin Content

PubMed Central

Anderson, Rachel; Ryser, Peter

2015-01-01

Several theories exist about the role of anthocyanins in senescing leaves. To elucidate factors contributing to variation in autumn leaf anthocyanin contents among individual trees, we analysed anthocyanins and other leaf traits in 27 individuals of red maple (Acer rubrum L.) over two growing seasons in the context of timing of leaf senescence. Red maple usually turns bright red in the autumn, but there is considerable variation among the trees. Leaf autumn anthocyanin contents were consistent between the two years of investigation. Autumn anthocyanin content strongly correlated with degree of chlorophyll degradation mid to late September, early senescing leaves having the highest concentrations of anthocyanins. It also correlated positively with leaf summer chlorophyll content and dry matter content, and negatively with specific leaf area. Time of leaf senescence and anthocyanin contents correlated with soil pH and with canopy openness. We conclude that the importance of anthocyanins in protection of leaf processes during senescence depends on the time of senescence. Rather than prolonging the growing season by enabling a delayed senescence, autumn anthocyanins in red maple in Ontario are important when senescence happens early, possibly due to the higher irradiance and greater danger of oxidative damage early in the season. PMID:27135339

Early Autumn Senescence in Red Maple (Acer rubrum L.) Is Associated with High Leaf Anthocyanin Content.

PubMed

Anderson, Rachel; Ryser, Peter

2015-08-05

Several theories exist about the role of anthocyanins in senescing leaves. To elucidate factors contributing to variation in autumn leaf anthocyanin contents among individual trees, we analysed anthocyanins and other leaf traits in 27 individuals of red maple (Acer rubrum L.) over two growing seasons in the context of timing of leaf senescence. Red maple usually turns bright red in the autumn, but there is considerable variation among the trees. Leaf autumn anthocyanin contents were consistent between the two years of investigation. Autumn anthocyanin content strongly correlated with degree of chlorophyll degradation mid to late September, early senescing leaves having the highest concentrations of anthocyanins. It also correlated positively with leaf summer chlorophyll content and dry matter content, and negatively with specific leaf area. Time of leaf senescence and anthocyanin contents correlated with soil pH and with canopy openness. We conclude that the importance of anthocyanins in protection of leaf processes during senescence depends on the time of senescence. Rather than prolonging the growing season by enabling a delayed senescence, autumn anthocyanins in red maple in Ontario are important when senescence happens early, possibly due to the higher irradiance and greater danger of oxidative damage early in the season.

Genetic modulation of oxytocin sensitivity: a pharmacogenetic approach.

PubMed

Chen, F S; Kumsta, R; Dvorak, F; Domes, G; Yim, O S; Ebstein, R P; Heinrichs, M

2015-10-27

Intranasal administration of the neuropeptide oxytocin has been shown to influence a range of complex social cognitions and social behaviors, and it holds therapeutic potential for the treatment of mental disorders characterized by social functioning deficits such as autism, social phobia and borderline personality disorder. However, considerable variability exists in individual responses to oxytocin administration. Here, we undertook a study to investigate the role of genetic variation in sensitivity to exogenous oxytocin using a socioemotional task. In a randomized, double-blind, placebo-controlled experiment with a repeated-measures (crossover) design, we assessed the performance of 203 men on an emotion recognition task under oxytocin and placebo. We took a haplotype-based approach to investigate the association between oxytocin receptor gene variation and oxytocin sensitivity. We identified a six-marker haplotype block spanning the promoter region and intron 3 that was significantly associated with our measure of oxytocin sensitivity. Specifically, the TTCGGG haplotype comprising single-nucleotide polymorphisms rs237917-rs2268498-rs4564970-rs237897-rs2268495-rs53576 is associated with increased emotion recognition performance under oxytocin versus placebo, and the CCGAGA haplotype with the opposite pattern. These results on the genetic modulation of sensitivity to oxytocin document a significant source of individual differences with implications for personalized treatment approaches using oxytocin administration.

Investigation of optimization-based reconstruction with an image-total-variation constraint in PET

NASA Astrophysics Data System (ADS)

Zhang, Zheng; Ye, Jinghan; Chen, Buxin; Perkins, Amy E.; Rose, Sean; Sidky, Emil Y.; Kao, Chien-Min; Xia, Dan; Tung, Chi-Hua; Pan, Xiaochuan

2016-08-01

Interest remains in reconstruction-algorithm research and development for possible improvement of image quality in current PET imaging and for enabling innovative PET systems to enhance existing, and facilitate new, preclinical and clinical applications. Optimization-based image reconstruction has been demonstrated in recent years of potential utility for CT imaging applications. In this work, we investigate tailoring the optimization-based techniques to image reconstruction for PET systems with standard and non-standard scan configurations. Specifically, given an image-total-variation (TV) constraint, we investigated how the selection of different data divergences and associated parameters impacts the optimization-based reconstruction of PET images. The reconstruction robustness was explored also with respect to different data conditions and activity up-takes of practical relevance. A study was conducted particularly for image reconstruction from data collected by use of a PET configuration with sparsely populated detectors. Overall, the study demonstrates the robustness of the TV-constrained, optimization-based reconstruction for considerably different data conditions in PET imaging, as well as its potential to enable PET configurations with reduced numbers of detectors. Insights gained in the study may be exploited for developing algorithms for PET-image reconstruction and for enabling PET-configuration design of practical usefulness in preclinical and clinical applications.

Genetic Diversity and Geographical Gene Flow Patterns of Spawning Broadcast Coral Lobophyllia corymbosa in The Sulawesi Waters as A Coral Triangle Area

NASA Astrophysics Data System (ADS)

Umar, Widyastuti; Jompa, Jamaluddin; Tassakka, Asmi Citra Malina A. R.

2018-02-01

The existence of hard coral is one of the keys to maintain the suistainability of ecosystem in the waters. Currently, the hard coral keeps declining over time due to various disturbances. In addition, hard coral where fish and other organisms live in will directly affect the ecosystem sustainability if the damage still happens. Molecular approach, such as knowing the genetic variation information of coral population can be an informative study to estimate the condition of waters, so that, conservation efforts can be easily done. In this study, we use Lobophyllia corymbosa as a spawning broadcast coral to be the sample which is collected from Sinjai and Luwuk Banggai. The study areas are selected based on geographical patterns which are in the South and East of Sulawesi waters. Since they have a considerable distance, it is likely for them to produce high genetic variations. Genome DNA uses mitochondrial genome that is extracted from coral tissue. The result shows that the genetic diversity is high. From the two major groups provided, there have been 8 haplotypes for all locations. In addition, the L.corymbosa distribution between Sinjai and Luwuk banggai has a high genetic connectivity with 0.6 fixation index.

Sequence variation in SORL1 and Dementia risk in Swedes

PubMed Central

Reynolds, Chandra A.; Hong, Mun-Gwan; Eriksson, Ulrika K.; Blennow, Kaj; Johansson, Boo; Malmberg, Bo; Berg, Stig; Gatz, Margaret; Pedersen, Nancy L.; Bennet, Anna M.; Prince, Jonathan A.

2010-01-01

The gene encoding the neuronal sortilin-related receptor SORL1 has been claimed to be associated with Alzheimer Disease by independent groups and across various human populations. We evaluated six genetic markers in SORL1 in a sample of 1558 Swedish dementia cases (including 1270 Alzheimer disease cases) and 2179 controls. For both single marker and haplotype-based analyses we found no strong support for SORL1 as a dementia- or AD-risk modifying gene in our sample in isolation, nor did we observe association with AD/dementia-related traits, including CSF β-amyloid1–42, tau levels, or age-at-onset. However, meta-analyses of markers in this study together with previously published studies on SORL1 encompassing in excess of 13,000 individuals does suggest significant association with AD (best OR 1.097; 95% CI 1.038–1.158, p = 0.001). All six markers were significant in meta-analyses and it is notable that they occur in two distinct LD blocks. These data are consistent with either allelic heterogeneity or the existence of as yet untested functional variants and these will be important considerations in further attempts to evaluate the importance of sequence variation in SORL1 with AD risk. PMID:19653016

Cloning and restriction enzyme mapping of ribosomal DNA of Giardia duodenalis, Giardia ardeae and Giardia muris.

PubMed

van Keulen, H; Campbell, S R; Erlandsen, S L; Jarroll, E L

1991-06-01

In an attempt to study Giardia at the DNA sequence level, the rRNA genes of three species, Giardia duodenalis, Giardia ardeae and Giardia muris were cloned and restriction enzyme maps were constructed. The rDNA repeats of these Giardia show completely different restriction enzyme recognition patterns. The size of the rDNA repeat ranges from approximately 5.6 kb in G. duodenalis to 7.6 kb in both G. muris and G. ardeae. These size differences are mainly attributable to the variation in length of the spacer. Minor differences exist among these Giardia in the sizes of their small subunit rRNA and the internal transcribed spacer between small and large subunit rRNA. The genetic maps were constructed by sequence analysis of the DNA around the 5' and 3' ends of the mature rRNA genes and between the rRNA covering the 5.8S rRNA gene and internal transcribed spacer. Comparison of the 5.8S rDNA and 3' end of large subunit rDNA from these three Giardia species showed considerable sequence variation, but the rDNA sequences of G. duodenalis and G. ardeae appear more closely related to each other than to G. muris.

Cannibals in space: the coevolution of cannibalism and dispersal in spatially structured populations.

PubMed

Rudolf, Volker H W; Kamo, Masashi; Boots, Mike

2010-05-01

The propensity for cannibalism varies considerably both within and between species. Currently we have little understanding of both the causes of this variation and its evolutionary consequences for other life-history traits. We examine how different levels of spatial structure affect the evolution of cannibalism and how cannibalism in turn drives the evolution of dispersal. Using pair approximations and simulations, we show that cannibalism can easily evolve in spatially structured populations as long as some dispersal exists. Furthermore, for a wide range of intermediate levels of spatial structure, we find the possibility of evolutionary branching leading to polymorphism in cannibalism. We also show that cannibalism itself can have important evolutionary consequences and select for increased dispersal rates, thus helping to determine the spatial structure of populations. The coevolution of cannibalism and dispersal results in the evolution of various alternative life-history strategies with different dispersal and cannibalism regimes. Which strategy evolves depends on the environmental conditions that determine initial cannibalism rates. Our results therefore suggest that differences in spatial structure could explain variation in the propensity for cannibalism and cannibalistic polyphenism. Furthermore, results emphasize that cannibalism can drive the evolution of other life-history traits and determine the spatial structure of natural populations.

Genetic modulation of oxytocin sensitivity: a pharmacogenetic approach

PubMed Central

Chen, F S; Kumsta, R; Dvorak, F; Domes, G; Yim, O S; Ebstein, R P; Heinrichs, M

2015-01-01

Intranasal administration of the neuropeptide oxytocin has been shown to influence a range of complex social cognitions and social behaviors, and it holds therapeutic potential for the treatment of mental disorders characterized by social functioning deficits such as autism, social phobia and borderline personality disorder. However, considerable variability exists in individual responses to oxytocin administration. Here, we undertook a study to investigate the role of genetic variation in sensitivity to exogenous oxytocin using a socioemotional task. In a randomized, double-blind, placebo-controlled experiment with a repeated-measures (crossover) design, we assessed the performance of 203 men on an emotion recognition task under oxytocin and placebo. We took a haplotype-based approach to investigate the association between oxytocin receptor gene variation and oxytocin sensitivity. We identified a six-marker haplotype block spanning the promoter region and intron 3 that was significantly associated with our measure of oxytocin sensitivity. Specifically, the TTCGGG haplotype comprising single-nucleotide polymorphisms rs237917–rs2268498–rs4564970–rs237897–rs2268495–rs53576 is associated with increased emotion recognition performance under oxytocin versus placebo, and the CCGAGA haplotype with the opposite pattern. These results on the genetic modulation of sensitivity to oxytocin document a significant source of individual differences with implications for personalized treatment approaches using oxytocin administration. PMID:26506050

Identification of species and genetic variation in Taenia isolates from human and swine of North India.

PubMed

Singh, Satyendra K; Prasad, Kashi N; Singh, Aloukick K; Gupta, Kamlesh K; Chauhan, Ranjeet S; Singh, Amrita; Singh, Avinash; Rai, Ravi P; Pati, Binod K

2016-10-01

Taenia solium is the major cause of taeniasis and cysticercosis/neurocysticercosis (NCC) in the developing countries including India, but the existence of other Taenia species and genetic variation have not been studied in India. So, we studied the existence of different Taenia species, and sequence variation in Taenia isolates from human (proglottids and cysticerci) and swine (cysticerci) in North India. Amplification of cytochrome c oxidase subunit 1 gene (cox1) was done by polymerase chain reaction (PCR) followed by sequencing and phylogenetic analysis. We identified two species of Taenia i.e. T. solium and Taenia asiatica in our isolates. T. solium isolates showed similarity with Asian genotype and nucleotide variations from 0.25 to 1.01 %, whereas T. asiatica displayed nucleotide variations ranged from 0.25 to 0.5 %. These findings displayed the minimal genetic variations in North Indian isolates of T. solium and T. asiatica.

What doesn't kill you might make you stronger: functional basis for variation in body armour.

PubMed

Broeckhoven, Chris; Diedericks, Genevieve; Mouton, P le Fras N

2015-09-01

1. Predation has been proposed to be a selective agent in the evolution of morphological antipredator strategies in prey. Among vertebrates, one of the morphological traits that evolved multiple times is body armour, including carapaces, thickened keratinized scales and plates of dermal bone. 2. It has been generally assumed that body armour provides protection against a predatory attack; yet, few explicit tests of the hypothesis exist. Cordylidae, a relatively small family of southern African lizards, show considerable variation in the degree of body armour. Hence, this family provides an opportunity to test the hypothesis that body armour serves as protection against predators. 3. Experiments were conducted to test whether the bite forces of four species of mammalian predators were high enough to penetrate the skins of Karusasaurus polyzonus, Namazonurus peersi, Cordylus cordylus and Cordylus macropholis, as well as those of Ouroborus cataphractus individuals originating from three localities that differed in their predator diversity. Furthermore, histological techniques were used to test whether variation in skin toughness was associated with concomitant changes in the degree of epidermal (i.e. β-keratin) and dermal (i.e. osteoderm) armour. 4. The skin toughness values for four out of five cordylid lizards tested in this study were well below the bite forces of the mammalian predators. In contrast, the thick osteoderms in the dermis of O. cataphractus can withstand bites from several mongoose species. However, the significant variation in body armour that is present between the three populations of O. cataphractus does not seem to be related to predator diversity. 5. It is concluded that body armour can serve as protection against predation in O. cataphractus, but that alternative selection pressures, such as thermoregulation or predation by snakes, presumably underlie variation in defensive morphology in the other cordylid lizards. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Pulsation in the presence of a strong magnetic field: the roAp star HD166473

NASA Astrophysics Data System (ADS)

Mathys, G.; Kurtz, D. W.; Elkin, V. G.

2007-09-01

Phase-resolved high-resolution, high signal-to-noise ratio (S/N) observations of the strongly magnetic roAp star HD166473 are analysed. HD166473 was selected as the target of this study because it has one of the strongest magnetic fields of all the roAp stars known with resolved magnetically split lines. Indeed, we show that enhanced pulsation diagnosis can be achieved from consideration of the different pulsation behaviour of the π and σ Zeeman components of the resolved spectral lines. This study is based on a time-series of high spectral resolution observations obtained with the Ultraviolet and Visual Echelle Spectrograph of the Very Large Telescope of the European Southern Observatory. Radial velocity variations due to pulsation are observed in rare earth lines, with amplitudes up to 110ms-1. The variations occur with three frequencies, already detected in photometry, but which can in this work be determined with better precision: 1.833, 1.886 and 1.928mHz. The pulsation amplitudes and phases observed in the rare earth element lines vary with atmospheric height, as is the case in other roAp stars studied in detail. Lines of Fe and of other (mostly non-rare earth) elements do not show any variation to very high precision (1.5ms-1 in the case of Fe). The low amplitudes of the observed variations do not allow the original goal of studying differences between the behaviour of the resolved Zeeman line components to be reached; the S/N achieved in the radial velocity determinations is insufficient to establish definitely the possible existence of such differences. Yet the analysis provides a tantalizing hint at the occurrence of variations of the mean magnetic field modulus with the pulsation frequency, with an amplitude of 21 +/- 5G. Based on observations collected at the European Southern Observatory, Paranal, Chile, as part of programme 067.D-0272. E-mail: gmathys@eso.org

EEG sensorimotor rhythms' variation and functional connectivity measures during motor imagery: linear relations and classification approaches.

PubMed

Stefano Filho, Carlos A; Attux, Romis; Castellano, Gabriela

2017-01-01

Hands motor imagery (MI) has been reported to alter synchronization patterns amongst neurons, yielding variations in the mu and beta bands' power spectral density (PSD) of the electroencephalography (EEG) signal. These alterations have been used in the field of brain-computer interfaces (BCI), in an attempt to assign distinct MI tasks to commands of such a system. Recent studies have highlighted that information may be missing if knowledge about brain functional connectivity is not considered. In this work, we modeled the brain as a graph in which each EEG electrode represents a node. Our goal was to understand if there exists any linear correlation between variations in the synchronization patterns-that is, variations in the PSD of mu and beta bands-induced by MI and alterations in the corresponding functional networks. Moreover, we (1) explored the feasibility of using functional connectivity parameters as features for a classifier in the context of an MI-BCI; (2) investigated three different types of feature selection (FS) techniques; and (3) compared our approach to a more traditional method using the signal PSD as classifier inputs. Ten healthy subjects participated in this study. We observed significant correlations ( p  < 0.05) with values ranging from 0.4 to 0.9 between PSD variations and functional network alterations for some electrodes, prominently in the beta band. The PSD method performed better for data classification, with mean accuracies of (90 ± 8)% and (87 ± 7)% for the mu and beta band, respectively, versus (83 ± 8)% and (83 ± 7)% for the same bands for the graph method. Moreover, the number of features for the graph method was considerably larger. However, results for both methods were relatively close, and even overlapped when the uncertainties of the accuracy rates were considered. Further investigation regarding a careful exploration of other graph metrics may provide better alternatives.

Legal approaches regarding health-care decisions involving minors: implications for next-generation sequencing

PubMed Central

Sénécal, Karine; Thys, Kristof; Vears, Danya F; Van Assche, Kristof; Knoppers, Bartha M; Borry, Pascal

2016-01-01

The development of next-generation sequencing (NGS) technologies are revolutionizing medical practice, facilitating more accurate, sophisticated and cost-effective genetic testing. NGS is already being implemented in the clinic assisting diagnosis and management of disorders with a strong heritable component. Although considerable attention has been paid to issues regarding return of incidental or secondary findings, matters of consent are less well explored. This is particularly important for the use of NGS in minors. Recent guidelines addressing genomic testing and screening of children and adolescents have suggested that as ‘young children' lack decision-making capacity, decisions about testing must be conducted by a surrogate, namely their parents. This prompts consideration of the age at which minors can provide lawful consent to health-care interventions, and consequently NGS performed for diagnostic purposes. Here, we describe the existing legal approaches regarding the rights of minors to consent to health-care interventions, including how laws in the 28 Member States of the European Union and in Canada consider competent minors, and then apply this to the context of NGS. There is considerable variation in the rights afforded to minors across countries. Many legal systems determine that minors would be allowed, or may even be required, to make decisions about interventions such as NGS. However, minors are often considered as one single homogeneous population who always require parental consent, rather than recognizing there are different categories of ‘minors' and that capacity to consent or to be involved in discussions and decision-making process is a spectrum rather than a hurdle. PMID:27302841

Legal approaches regarding health-care decisions involving minors: implications for next-generation sequencing.

PubMed

Sénécal, Karine; Thys, Kristof; Vears, Danya F; Van Assche, Kristof; Knoppers, Bartha M; Borry, Pascal

2016-11-01

The development of next-generation sequencing (NGS) technologies are revolutionizing medical practice, facilitating more accurate, sophisticated and cost-effective genetic testing. NGS is already being implemented in the clinic assisting diagnosis and management of disorders with a strong heritable component. Although considerable attention has been paid to issues regarding return of incidental or secondary findings, matters of consent are less well explored. This is particularly important for the use of NGS in minors. Recent guidelines addressing genomic testing and screening of children and adolescents have suggested that as 'young children' lack decision-making capacity, decisions about testing must be conducted by a surrogate, namely their parents. This prompts consideration of the age at which minors can provide lawful consent to health-care interventions, and consequently NGS performed for diagnostic purposes. Here, we describe the existing legal approaches regarding the rights of minors to consent to health-care interventions, including how laws in the 28 Member States of the European Union and in Canada consider competent minors, and then apply this to the context of NGS. There is considerable variation in the rights afforded to minors across countries. Many legal systems determine that minors would be allowed, or may even be required, to make decisions about interventions such as NGS. However, minors are often considered as one single homogeneous population who always require parental consent, rather than recognizing there are different categories of 'minors' and that capacity to consent or to be involved in discussions and decision-making process is a spectrum rather than a hurdle.

Endodontic and Clinical Considerations in the Management of Variable Anatomy in Mandibular Premolars: A Literature Review

PubMed Central

Hammo, Mohammad

2014-01-01

Mandibular premolars are known to have numerous anatomic variations of their roots and root canals, which are a challenge to treat endodontically. The paper reviews literature to detail the various clinically relevant anatomic considerations with detailed techniques and methods to successfully manage these anomalies. An emphasis and detailed description of every step of treatment including preoperative diagnosis, intraoperative identification and management, and surgical endodontic considerations for the successful management of these complex cases have been included. PMID:24895584

Identification of structural variation in mouse genomes.

PubMed

Keane, Thomas M; Wong, Kim; Adams, David J; Flint, Jonathan; Reymond, Alexandre; Yalcin, Binnaz

2014-01-01

Structural variation is variation in structure of DNA regions affecting DNA sequence length and/or orientation. It generally includes deletions, insertions, copy-number gains, inversions, and transposable elements. Traditionally, the identification of structural variation in genomes has been challenging. However, with the recent advances in high-throughput DNA sequencing and paired-end mapping (PEM) methods, the ability to identify structural variation and their respective association to human diseases has improved considerably. In this review, we describe our current knowledge of structural variation in the mouse, one of the prime model systems for studying human diseases and mammalian biology. We further present the evolutionary implications of structural variation on transposable elements. We conclude with future directions on the study of structural variation in mouse genomes that will increase our understanding of molecular architecture and functional consequences of structural variation.

Concept considerations for a small orbital transfer vehicle

NASA Technical Reports Server (NTRS)

Green, M.; Sibila, A. I.

1979-01-01

This paper summarizes a study of small orbital transfer vehicles to place payloads in orbits with altitudes above those of the standard Shuttle operations. The overall objective of the study is to examine the role of the small orbital transfer vehicle (SOTV) in Shuttle operations and to identify typical propulsion concepts for accomplishing the mission. Consideration is given to existing and planned systems and upper stages, along with new propulsion stages. The new propulsion concept development examines tandem and clustered solids, controlled solids, monopropellant and bipropellant liquids, and staged solid/liquid combinations. The paper presents considerations of the mission requirements, tradeoffs of the various configurations, and candidate selections. For the selected candidate concepts the performance, support equipment, operational considerations and program costs were determined. The results show that a new modular liquid stage system is cost effective in handling the majority of the payloads considered. The remainder of the payloads can be accomodated by existing systems.

Genetic variation in the USDA Chamaecrista fasciculata collection

USDA-ARS?s Scientific Manuscript database

Germplasm collections serve as critical repositories of genetic variation. Characterizing genetic diversity in existing collections is necessary to maximize their utility and to guide future collecting efforts. We have used AFLP markers to characterize genetic variation in the USDA germplasm collect...

Positive Relationship between Abdominal Coloration and Dermal Melanin Density in Phrynosomatid Lizards

Treesearch

Vanessa S. Quinn; Diana K. Hews

2003-01-01

Phrynosomatid lizards show considerable variation among species in the occurrence of a secondary sexual trait, blue abdominal coloration. The production of blue skin may be controlled by at least two cellular components, melanin in melanophores, and guanine in iridophores. To examine the hypothesis that a mechanism producing variation in abdominal coloration is...

The Adoption of Variation Theory in the Classroom: Effect on Students' Algebraic Achievement and Motivation to Learn

ERIC Educational Resources Information Center

Ting, Jing Jing; Tarmizi, Rohani Tarmizi; Bakar, Kamariah Abu; Aralas, Dalia

2017-01-01

Introduction: Analysis of lessons held in East Asia regions that perform well in Trends in International Mathematics and Science Studies such as; South Korea, Hong Kong and Japan, demonstrated teachers in mathematics classroom enacted features of the content systematically with consideration of variation within students' capabilities. Recent…

Geographical variation in camper expenditures

Treesearch

Wilbur F. LaPage; Edward G. Fisher

1971-01-01

Daily expenditures by families camping in New Hampshire State parks in 1967 averaged $11.81. Considerable variation was found between the northern, central, and southern regions of the State in both the average amount of money spent and the way in which the money was spent. Daily expenditures in the north were higher, but average visit lengths were shorter, resulting...

NASA Integrated Network Monitor and Control Software Architecture

NASA Technical Reports Server (NTRS)

Shames, Peter; Anderson, Michael; Kowal, Steve; Levesque, Michael; Sindiy, Oleg; Donahue, Kenneth; Barnes, Patrick

2012-01-01

The National Aeronautics and Space Administration (NASA) Space Communications and Navigation office (SCaN) has commissioned a series of trade studies to define a new architecture intended to integrate the three existing networks that it operates, the Deep Space Network (DSN), Space Network (SN), and Near Earth Network (NEN), into one integrated network that offers users a set of common, standardized, services and interfaces. The integrated monitor and control architecture utilizes common software and common operator interfaces that can be deployed at all three network elements. This software uses state-of-the-art concepts such as a pool of re-programmable equipment that acts like a configurable software radio, distributed hierarchical control, and centralized management of the whole SCaN integrated network. For this trade space study a model-based approach using SysML was adopted to describe and analyze several possible options for the integrated network monitor and control architecture. This model was used to refine the design and to drive the costing of the four different software options. This trade study modeled the three existing self standing network elements at point of departure, and then described how to integrate them using variations of new and existing monitor and control system components for the different proposed deployments under consideration. This paper will describe the trade space explored, the selected system architecture, the modeling and trade study methods, and some observations on useful approaches to implementing such model based trade space representation and analysis.

Intraspecific variation in egg size and egg composition in birds: effects on offspring fitness.

PubMed

Williams, T D

1994-02-01

1. There is little unequivocal evidence to date in support of a positive relationship between egg size and offspring fitness in birds. Although 40 studies (of 34 species) have considered the effect of variation in egg size on chick growth and/or survival up to fledgling only 12 studies have controlled for other characters potentially correlated both with egg size and offspring fitness. Of these only two have reported a significant residual effect of egg size on chick growth (in the roseate tern and European blackbird) and three a residual effect on chick survival (all in seabirds: common tern, lesser black-backed gull and kittiwake). 2. More consistent evidence exists, though from fewer studies, for a positive relationship between egg size and offspring fitness early in the chick-rearing period; chick growth and chick survival being dependent on egg size in 8 of 10 studies and 4 of 5 studies respectively. It is suggested that the most important effect of variation in egg size might be in determining the probability of offspring survival in the first few days after hatching. 3. Egg size explains on average 66% of the variation in chick mass at hatching (n = 35 studies) but only 30% of the variation in chick body size (n = 18). When effects of hatching body size are controlled for chick mass remains significantly correlated with egg size, though the reverse is not true. This supports the hypothesis that large eggs give rise to heavier chicks at hatching, i.e., chicks with more nutrient (yolk) reserves, rather than structurally larger chicks. 4. Egg composition increased isometrically with increasing egg size in about half the studies so far reported (n equals approximately 20). However, in seabirds, and some passerines, larger eggs contain disproportionately more albumen, whilst in some waterfowl percentage yolk content increases with increasing egg size. Changes in albumen content largely reflect variation in the water content of eggs, but changes in yolk content involve variation in lipid content, and therefore in egg 'quality.' The adaptive significance of variation in egg composition is considered; females may adjust egg composition facultatively to maximise the benefits to their offspring of increased reproductive investment. 5. Considerations for future research are discussed with particular emphasis on experimental studies and the application of new techniques.

The radiated electromagnetic field from collimated gamma rays and electron beams in air

NASA Astrophysics Data System (ADS)

Tumolillo, T. A.; Wondra, J. P.; Hobbs, W. E.; Smith, K.

1980-12-01

Nuclear weapons effects computer codes are used to study the electromagnetic field produced by gamma rays or by highly relativistic electron beams moving through the air. Consideration is given to large-area electron and gamma beams, small-area electron beams, variation of total beam current, variation of pressure in the beam channel, variation of the beam rise time, variation of beam radius, far-field radiated signals, and induced current on a system from a charged-particle beam. The work has application to system EMP coupling from nuclear weapons or charged-particle-beam weapons.

Two unusual anatomic variations create a diagnostic dilemma in distal ulnar nerve compression.

PubMed

Kiehn, Mark W; Derrick, Allison J; Iskandar, Bermans J

2008-09-01

Diagnosis of peripheral neuropathies is based upon patterns of functional deficits and electrodiagnostic testing. However, anatomic variations can lead to confounding patterns of physical and electrodiagnostic findings. Authors present a case of ulnar nerve compression due to a rare combination of anatomic variations, aberrant branching pattern, and FCU insertion at the wrist, which posed a diagnostic and therapeutic dilemma. The literature related to isolated distal ulnar motor neuropathy and anatomic variations of the ulnar nerve and adjacent structures is also reviewed. This case demonstrates how anatomic variations can complicate the interpretation of clinical and electrodiagnostic findings and underscores the importance of thorough exploration of the nerve in consideration for possible variations. (c) 2008 Wiley-Liss, Inc.

Influences of meteorological parameters on indoor radon concentrations (222Rn) excluding the effects of forced ventilation and radon exhalation from soil and building materials.

PubMed

Schubert, Michael; Musolff, Andreas; Weiss, Holger

2018-06-13

Elevated indoor radon concentrations ( 222 Rn) in dwellings pose generally a potential health risk to the inhabitants. During the last decades a considerable number of studies discussed both the different sources of indoor radon and the drivers for diurnal and multi day variations of its concentration. While the potential sources are undisputed, controversial opinions exist regarding their individual relevance and regarding the driving influences that control varying radon indoor concentrations. These drivers include (i) cyclic forced ventilation of dwellings, (ii) the temporal variance of the radon exhalation from soil and building materials due to e.g. a varying moisture content and (iii) diurnal and multi day temperature and pressure patterns. The presented study discusses the influences of last-mentioned temporal meteorological parameters by effectively excluding the influences of forced ventilation and undefined radon exhalation. The results reveal the continuous variation of the indoor/outdoor pressure gradient as key driver for a constant "breathing" of any interior space, which affects the indoor radon concentration with both diurnal and multi day patterns. The diurnally recurring variation of the pressure gradient is predominantly triggered by the day/night cycle of the indoor temperature that is associated with an expansion/contraction of the indoor air volume. Multi day patterns, on the other hand, are mainly due to periods of negative air pressure indoors that is triggered by periods of elevated wind speeds as a result of Bernoulli's principle. Copyright © 2018 Elsevier Ltd. All rights reserved.

Prevalence of dementia and major dementia subtypes in Spanish populations: A reanalysis of dementia prevalence surveys, 1990-2008

PubMed Central

de Pedro-Cuesta, Jesús; Virués-Ortega, Javier; Vega, Saturio; Seijo-Martínez, Manuel; Saz, Pedro; Rodríguez, Fernanda; Rodríguez-Laso, Angel; Reñé, Ramón; de las Heras, Susana Pérez; Mateos, Raimundo; Martínez-Martín, Pablo; Manubens, José María; Mahillo-Fernandez, Ignacio; López-Pousa, Secundino; Lobo, Antonio; Reglà, Jordi Llinàs; Gascón, Jordi; García, Francisco José; Fernández-Martínez, Manuel; Boix, Raquel; Bermejo-Pareja, Félix; Bergareche, Alberto; Benito-León, Julián; de Arce, Ana; del Barrio, José Luis

2009-01-01

Background This study describes the prevalence of dementia and major dementia subtypes in Spanish elderly. Methods We identified screening surveys, both published and unpublished, in Spanish populations, which fulfilled specific quality criteria and targeted prevalence of dementia in populations aged 70 years and above. Surveys covering 13 geographically different populations were selected (prevalence period: 1990-2008). Authors of original surveys provided methodological details of their studies through a systematic questionnaire and also raw age-specific data. Prevalence data were compared using direct adjustment and logistic regression. Results The reanalyzed study population (aged 70 year and above) was composed of Central and North-Eastern Spanish sub-populations obtained from 9 surveys and totaled 12,232 persons and 1,194 cases of dementia (707 of Alzheimer's disease, 238 of vascular dementia). Results showed high variation in age- and sex-specific prevalence across studies. The reanalyzed prevalence of dementia was significantly higher in women; increased with age, particularly for Alzheimer's disease; and displayed a significant geographical variation among men. Prevalence was lowest in surveys reporting participation below 85%, studies referred to urban-mixed populations and populations diagnosed by psychiatrists. Conclusion Prevalence of dementia and Alzheimer's disease in Central and North-Eastern Spain is higher in females, increases with age, and displays considerable geographic variation that may be method-related. People suffering from dementia and Alzheimer's disease in Spain may approach 600,000 and 400,000 respectively. However, existing studies may not be completely appropriate to infer prevalence of dementia and its subtypes in Spain until surveys in Southern Spain are conducted. PMID:19840375

Assessment of the average price and ethanol content of alcoholic beverages by brand--United States, 2011.

PubMed

DiLoreto, Joanna T; Siegel, Michael; Hinchey, Danielle; Valerio, Heather; Kinzel, Kathryn; Lee, Stephanie; Chen, Kelsey; Shoaff, Jessica R; Kenney, Jessica; Jernigan, David H; DeJong, William

2012-07-01

There are no existing data on alcoholic beverage prices and ethanol (EtOH) content at the level of alcohol brand. A comprehensive understanding of alcohol prices and EtOH content at the brand level is essential for the development of effective public policy to reduce alcohol use among underage youth. The purpose of this study was to comprehensively assess alcoholic beverage prices and EtOH content at the brand level. Using online alcohol price data from 15 control states and 164 online alcohol stores, we estimated the average alcohol price and percent alcohol by volume for 900 brands of alcohol, across 17 different alcoholic beverage types, in the United States in 2011. There is considerable variation in both brand-specific alcohol prices and EtOH content within most alcoholic beverage types. For many types of alcohol, the within-category variation between brands exceeds the variation in average price and EtOH content among the several alcoholic beverage types. Despite differences in average prices between alcoholic beverage types, in 12 of the 16 alcoholic beverage types, customers can purchase at least 1 brand of alcohol that is under $1 per ounce of EtOH. Relying on data or assumptions about alcohol prices and EtOH content at the level of alcoholic beverage type is insufficient for understanding and influencing youth drinking behavior. Surveillance of alcohol prices and EtOH content at the brand level should become a standard part of alcohol research. Copyright © 2012 by the Research Society on Alcoholism.

Genetic diversity of wild germplasm of "yerba mate" (Ilex paraguariensis St. Hil.) from Uruguay.

PubMed

Cascales, Jimena; Bracco, Mariana; Poggio, Lidia; Gottlieb, Alexandra Marina

2014-12-01

The "yerba mate" tree, Ilex paraguariensis St. Hil., is a crop native to subtropical South America, marketed for the elaboration of the highly popular "mate" beverage. The Uruguayan germplasm occupies the southernmost area of the species distribution range and carries adaptations to environments that considerably differ from the current production area. We characterized the genetic variability of the germplasm from this unexplored area by jointly analyzing individuals from the diversification center (ABP, Argentina, Brazil and Paraguay) with 19 nuclear and 11 plastidic microsatellite markers. For the Uruguayan germplasm, we registered 55 alleles (18 % private), and 80 genotypes (44 % exclusive), whereas 63 alleles (28.6 % private) and 81 genotypes (42 % exclusive) were recorded for individuals from ABP. Only two plastidic haplotypes were detected. Distance-based and multilocus genotype analyses showed that individuals from ABP intermingle and that the Uruguayan germplasm is differentiated in three gene-pools. Significant positive correlations between genetic and geographic distances were detected. Our results concur in that ABP individuals harbor greater genetic variation than those from the tail of the distribution, as to the number of alleles (1.15-fold), He (1.19-fold), Rs (1.39-fold), and the between-group genetic distances (1.16-fold). Also the shape of the genetic landscape interpolation analysis suggests that the genetic variation decays southward towards the Uruguayan territory. We showed that Uruguayan germplasm hosts a combination of nuclear alleles not present in the central region, constituting a valuable breeding resource. Future conservation efforts should concentrate in collecting numerous individuals of "yerba mate" per site to gather the existent variation.

Application of variational and Galerkin equations to linear and nonlinear finite element analysis

NASA Technical Reports Server (NTRS)

Yu, Y.-Y.

1974-01-01

The paper discusses the application of the variational equation to nonlinear finite element analysis. The problem of beam vibration with large deflection is considered. The variational equation is shown to be flexible in both the solution of a general problem and in the finite element formulation. Difficulties are shown to arise when Galerkin's equations are used in the consideration of the finite element formulation of two-dimensional linear elasticity and of the linear classical beam.

Relative Radiation Density and Temperature Distribution of Rocket Flames

DTIC Science & Technology

1951-07-10

traversed along the axis of the flame image to determine the flame length and the position of the Mach nodes. Other traverses were made across the...variation is due to different stages of flame growth. Other variations especially those of 2 6• flame length , can be accounted for by dif- U L L ference...The temperature gradient is considerably less at the tip of the flame and by similar reasoning would give greater variation in flame length . The problem

Magnetic resonance cholangiographic evaluation of intrahepatic and extrahepatic bile duct variations

PubMed Central

Sureka, Binit; Bansal, Kalpana; Patidar, Yashwant; Arora, Ankur

2016-01-01

Biliary anatomy and its common and uncommon variations are of considerable clinical significance when performing living donor transplantation, radiological interventions in hepatobiliary system, laparoscopic cholecystectomy, and liver resection (hepatectomy, segmentectomy). Because of increasing trend found in the number of liver transplant surgeries being performed, magnetic resonance cholangiopancreatography (MRCP) has become the modality of choice for noninvasive evaluation of abnormalities of the biliary tract. The purpose of this study is to describe the anatomic variations of the intrahepatic and extrahepatic biliary tree. PMID:27081220

SU-F-T-394: Impact of PTV Margins With Taking Into Account Shape Variation On IMRT Plans For Prostate Cancer

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

Hirose, T; Arimura, H; Oga, S

2016-06-15

Purpose: The purpose of this study was to investigate the impact of planning target volume (PTV) margins with taking into consideration clinical target volume (CTV) shape variations on treatment plans of intensity modulated radiation therapy (IMRT) for prostate cancer. Methods: The systematic errors and the random errors for patient setup errors in right-left (RL), anterior-posterior (AP), and superior-inferior (SI) directions were obtained from data of 20 patients, and those for CTV shape variations were calculated from 10 patients, who were weekly scanned using cone beam computed tomography (CBCT). The setup error was defined as the difference in prostate centers betweenmore » planning CT and CBCT images after bone-based registrations. CTV shape variations of high, intermediate and low risk CTVs were calculated for each patient from variances of interfractional shape variations on each vertex of three-dimensional CTV point distributions, which were manually obtained from CTV contours on the CBCT images. PTV margins were calculated using the setup errors with and without CTV shape variations for each risk CTV. Six treatment plans were retrospectively made by using the PTV margins with and without CTV shape variations for the three risk CTVs of 5 test patients. Furthermore, the treatment plans were applied to CBCT images for investigating the impact of shape variations on PTV margins. Results: The percentages of population to cover with the PTV, which satisfies the CTV D98 of 95%, with and without the shape variations were 89.7% and 74.4% for high risk, 89.7% and 76.9% for intermediate risk, 84.6% and 76.9% for low risk, respectively. Conclusion: PTV margins taking into account CTV shape variation provide significant improvement of applicable percentage of population (P < 0.05). This study suggested that CTV shape variation should be taken consideration into determination of the PTV margins.« less

Consideration of Materials for Aircraft Brakes

NASA Technical Reports Server (NTRS)

Peterson, M. B.; Ho, T.

1972-01-01

An exploratory investigation was conducted concerning materials and their properties for use in aircraft brakes. Primary consideration was given to the heat dissipation and the frictional behavior of materials. Used brake pads and rotors were analyzed as part of the investigation. A simple analysis was conducted in order to determine the most significant factors which affect surface temperatures. It was found that where size and weight restrictions are necessary, the specific heat of the material, and maintaining uniform contact area are the most important factors. A criterion was suggested for optimum sizing of the brake disks. Bench friction tests were run with brake materials. It was found that there is considerable friction variation due to the formation and removal of surface oxide films. Other causes of friction variations are surface softening and melting. The friction behavior at high temperature was found to be more characteristic of the steel surface rather than the copper brake material. It is concluded that improved brake materials are feasible.

Study of Integration Considerations for Wireless Emergency Alerts

DTIC Science & Technology

2014-02-01

affect adoption. Section 4 presents a list of overall considerations for integrating a WEA messaging solution into an existing emergency management...in a product may negatively affect another de- sired quality. This section offers considerations for balancing an organization’s priorities con... affect what emergency management agencies can, should, and must do with respect to conducting exercises and issuing alerts. More information about

Contending With Preplanned Death: Questions for Clinicians.

PubMed

Yager, Joel

2017-09-01

The goal of this column is to assist readers in reflecting on their attitudes and responses toward clinical and nonclinical situations involving preplanned deaths by decisionally capable individuals. Such circumstances range from encountering individuals in one's personal and professional lives who desire and intend to end their lives under their own terms, to having such individuals request assistance with predeath and postdeath arrangements. Attending to pertinent literature, this essay uses Socratic inquiry to question conventional assumptions and attitudes, push readers' thoughts beyond typical comfort zones, and consider alternative modes of responding to challenges posed by preplanned death. Studies indicate that, for their own end-of-life circumstances, physicians would prefer a briefer, higher quality life to prolonged low-quality life, dignity in infirmity and death, and avoidance of terminal suffering. Lay people generally endorse similar preferences. Although contemporary society generally shuns contemplating preplanned death, cultural attitudes regarding preplanned death are rapidly evolving, and variations of "Death with Dignity" legislation have gained traction in increasing numbers of US states as well as internationally. As yet, no broad consensus exists as to how clinicians should manage circumstances involving preplanned death. Considerations regarding preplanned deaths merit greater professional and public discussion. Many options exist for improving how professionals address the quality of human experiences surrounding death.

Aging and compressibility of municipal solid wastes.

PubMed

Chen, Y M; Zhan, Tony L T; Wei, H Y; Ke, H

2009-01-01

The expansion of a municipal solid waste (MSW) landfill requires the ability to predict settlement behavior of the existing landfill. The practice of using a single compressibility value when performing a settlement analysis may lead to inaccurate predictions. This paper gives consideration to changes in the mechanical compressibility of MSW as a function of the fill age of MSW as well as the embedding depth of MSW. Borehole samples representative of various fill ages were obtained from five boreholes drilled to the bottom of the Qizhishan landfill in Suzhou, China. Thirty-one borehole samples were used to perform confined compression tests. Waste composition and volume-mass properties (i.e., unit weight, void ratio, and water content) were measured on all the samples. The test results showed that the compressible components of the MSW (i.e., organics, plastics, paper, wood and textiles) decreased with an increase in the fill age. The in situ void ratio of the MSW was shown to decrease with depth into the landfill. The compression index, Cc, was observed to decrease from 1.0 to 0.3 with depth into the landfill. Settlement analyses were performed on the existing landfill, demonstrating that the variation of MSW compressibility with fill age or depth should be taken into account in the settlement prediction.

He nui na ala e hiki aku ai: Factors Influencing Phonetic Variation in the Hawaiian Word "keia"

ERIC Educational Resources Information Center

Drager, Katie; Comstock, Bethany Kaleialohapau'ole Chun; Kneubuhl, Hina Puamohala

2017-01-01

Apart from a handful of studies (e.g., Kinney 1956), linguists know little about what variation exists in Hawaiian and what factors constrain the variation. In this paper, we present an analysis of phonetic variation in the word "keia," meaning "this," examining the social, linguistic, and probabilistic factors that constrain…

Local, national, and service component cost variations in the management of low back pain: Considerations for the clinician.

PubMed

Babu, Ashwin N; McCormick, Zachary; Kennedy, David J; Press, Joel

2016-11-21

In the past two decades, the cost associated with managing low back pain has increased significantly. Improved consciousness of how clinicians utilize resources when managing low back pain is necessary in the current economic climate. The goal of this review is to examine the component costs associated with managing low back pain and provide practical solutions for reducing healthcare costs. This is accomplished by utilizing examples from a major metropolitan area with several major academic institutions and private health care centers. It is clear that there is considerable local and national variation in the component costs of managing low back pain, including physician visits, imaging studies, medications, and therapy services. By being well informed about these variations in one's environment, clinicians and patients alike can make strides towards reducing the financial impact of low back pain. Investigation of the cost discrepancies for services within one's community of practice is important. Improved public access to both cost and outcomes data is needed.

Manufacture of threads with variable pitch by using noncircular gears

NASA Astrophysics Data System (ADS)

Slătineanu, L.; Dodun, O.; Coteață, M.; Coman, I.; Nagîț, G.; Beșliu, I.

2016-08-01

There are mechanical equipments in which shafts threaded with variable pitch are included. Such a shaft could be met in the case of worm specific to the double enveloping worm gearing. Over the years, the researchers investigated some possibilities to geometrically define and manufacture the shaft zones characterized by a variable pitch. One of the methods able to facilitate the manufacture of threads with variable pitch is based on the use of noncircular gears in the threading kinematic chain for threading by cutting. In order to design the noncircular gears, the mathematical law of pitch variation has to be known. An analysis of pitch variation based on geometrical considerations was developed in the case of a double enveloping globoid worm. Subsequently, on the bases of a proper situation, a numerical model was determined. In this way, an approximately law of pitch variation was determined and it could be taken into consideration when designing the noncircular gears included in the kinematic chain of the cutting machine tool.

Towards a Global Unified Model of Europa's Tenuous Atmosphere

NASA Astrophysics Data System (ADS)

Plainaki, Christina; Cassidy, Tim A.; Shematovich, Valery I.; Milillo, Anna; Wurz, Peter; Vorburger, Audrey; Roth, Lorenz; Galli, André; Rubin, Martin; Blöcker, Aljona; Brandt, Pontus C.; Crary, Frank; Dandouras, Iannis; Jia, Xianzhe; Grassi, Davide; Hartogh, Paul; Lucchetti, Alice; McGrath, Melissa; Mangano, Valeria; Mura, Alessandro; Orsini, Stefano; Paranicas, Chris; Radioti, Aikaterini; Retherford, Kurt D.; Saur, Joachim; Teolis, Ben

2018-02-01

Despite the numerous modeling efforts of the past, our knowledge on the radiation-induced physical and chemical processes in Europa's tenuous atmosphere and on the exchange of material between the moon's surface and Jupiter's magnetosphere remains limited. In lack of an adequate number of in situ observations, the existence of a wide variety of models based on different scenarios and considerations has resulted in a fragmentary understanding of the interactions of the magnetospheric ion population with both the moon's icy surface and neutral gas envelope. Models show large discrepancy in the source and loss rates of the different constituents as well as in the determination of the spatial distribution of the atmosphere and its variation with time. The existence of several models based on very different approaches highlights the need of a detailed comparison among them with the final goal of developing a unified model of Europa's tenuous atmosphere. The availability to the science community of such a model could be of particular interest in view of the planning of the future mission observations (e.g., ESA's JUpiter ICy moons Explorer (JUICE) mission, and NASA's Europa Clipper mission). We review the existing models of Europa's tenuous atmosphere and discuss each of their derived characteristics of the neutral environment. We also discuss discrepancies among different models and the assumptions of the plasma environment in the vicinity of Europa. A summary of the existing observations of both the neutral and the plasma environments at Europa is also presented. The characteristics of a global unified model of the tenuous atmosphere are, then, discussed. Finally, we identify needed future experimental work in laboratories and propose some suitable observation strategies for upcoming missions.

Joint correction of Nyquist artifact and minuscule motion-induced aliasing artifact in interleaved diffusion weighted EPI data using a composite two-dimensional phase correction procedure

PubMed Central

Chang, Hing-Chiu; Chen, Nan-kuei

2016-01-01

Diffusion-weighted imaging (DWI) obtained with interleaved echo-planar imaging (EPI) pulse sequence has great potential of characterizing brain tissue properties at high spatial-resolution. However, interleaved EPI based DWI data may be corrupted by various types of aliasing artifacts. First, inconsistencies in k-space data obtained with opposite readout gradient polarities result in Nyquist artifact, which is usually reduced with 1D phase correction in post-processing. When there exist eddy current cross terms (e.g., in oblique-plane EPI), 2D phase correction is needed to effectively reduce Nyquist artifact. Second, minuscule motion induced phase inconsistencies in interleaved DWI scans result in image-domain aliasing artifact, which can be removed with reconstruction procedures that take shot-to-shot phase variations into consideration. In existing interleaved DWI reconstruction procedures, Nyquist artifact and minuscule motion-induced aliasing artifact are typically removed subsequently in two stages. Although the two-stage phase correction generally performs well for non-oblique plane EPI data obtained from well-calibrated system, the residual artifacts may still be pronounced in oblique-plane EPI data or when there exist eddy current cross terms. To address this challenge, here we report a new composite 2D phase correction procedure, which effective removes Nyquist artifact and minuscule motion induced aliasing artifact jointly in a single step. Our experimental results demonstrate that the new 2D phase correction method can much more effectively reduce artifacts in interleaved EPI based DWI data as compared with the existing two-stage artifact correction procedures. The new method robustly enables high-resolution DWI, and should prove highly valuable for clinical uses and research studies of DWI. PMID:27114342

Variation in nutrient characteristics of surface soils from the Luquillo Experimental Forest of Puerto Rico: A multivariate perspective.

Treesearch

S. B. Cox; M. R. Willig; F. N. Scatena

2002-01-01

We assessed the effects of landscape features (vegetation type and topography), season, and spatial hierarchy on the nutrient content of surface soils in the Luquillo Experimental Forest (LEF) of Puerto Rico. Considerable spatial variation characterized the soils of the LEF, and differences between replicate sites within each combination of vegetation type (tabonuco vs...

"It All Comes down to the Leadership": The Role of the School Principal in Fostering Parent-School Engagement

ERIC Educational Resources Information Center

Barr, Jenny; Saltmarsh, Sue

2014-01-01

Parent-school engagement is widely understood to be an important factor in children's school experience and educational outcomes. However, there is considerable variation in the ways that schools manage their relationships with parents, as well as variation in what parents themselves view as important for engagement with their children's…

Theoretical studies for the rates and kinetic isotope effects of the excited-state double proton transfer in the 1:1 7-azaindole:H2O complex using variational transition state theory including multidimensional tunneling.

PubMed

Duong, My Phu Thi; Kim, Yongho

2010-03-18

Variational transition state theory calculations including multidimensional tunneling (VTST/MT) for excited-state tautomerization in the 1:1 7-azaindole:H(2)O complex were performed. Electronic structures and energies for reactant, product, transition state, and potential energy curves along the reaction coordinate were computed at the CASSCF(10,9)/6-31G(d,p) level of theory. The potential energies were corrected by second-order multireference perturbation theory to take the dynamic electron correlation into consideration. The final potential energy curves along the reaction coordinate were generated at the MRPT2//CASSCF(10,9)/6-31G(d,p) level. Two protons in the excited-state tautomerization are transferred concertedly, albeit asynchronously. The position of the variational transition state is very different from the conventional transition state, and is highly dependent on isotopic substitution. Rate constants were calculated using VTST/MT, and were on the order of 10(-6) s(-1) at room temperature. The HH/DD kinetic isotope effects are consistent with experimental observations; consideration of both tunneling and variational effects was essential to predict the experimental values correctly.

mHealth text and voice communication for monitoring people with chronic diseases in low-resource settings: a realist review

PubMed Central

Goudge, Jane; Gómez-Olivé, Francesc Xavier; Huxley, Caroline; Dodd, Katherine; Griffiths, Frances

2018-01-01

Background Routine monitoring by patients and healthcare providers to manage chronic disease is vital, though this can be challenging in low-resourced health systems. Mobile health (mHealth) has been proposed as one way to improve management of chronic diseases. Past mHealth reviews have proposed the need for a greater understanding around how the theoretical constructs in mHealth interventions actually work. In response, we synthesised evidence from primary studies on monitoring of chronic diseases using two-way digital text or voice communication between a patient and health worker. We did this in order to understand the important considerations for the design of mHealth interventions. Method Articles retrieved were systematically screened and analysed to elicit explanations of mHealth monitoring interventions. These explanations were consolidated into programme theory and compared with existing theory and frameworks. We identified variation in outcomes to understand how context moderates the outcome. Results Four articles were identified—monitoring of hypertension and HIV/AIDS from: Kenya, Pakistan, Honduras and Mexico and South Africa. Six components were found in all four interventions: reminders, patient observation of health state, motivational education/advice, provision of support communication, targeted actions and praise and encouragement. Intervention components were mapped to existing frameworks and theory. Variation in outcome identified in subgroup analysis suggests greater impact is achieved with certain patient groups, such as those with low literacy, those with stressful life events or those early in the disease trajectory. There was no other evidence in the included studies of the effect of context on the intervention and outcome. Conclusion mHealth interventions for monitoring chronic disease in low-resource settings, based on existing frameworks and theory, can be effective. A match between what the intervention provides and the needs or social factors relevant to specific patient group increases the effect. It was not possible to understand the impact of context on intervention and outcome beyond these patient-level measures as no evidence was provided in the study reports. PMID:29527356

Potential Moderating Effects of Selenium on Mercury Uptake and Selenium:Mercury Molar Ratios in Fish From Oak Ridge and Savannah River Site - 12086

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

Burger, Joanna; Gochfeld, Michael; Donio, Mark

2012-07-01

Mercury contamination is an important remediation issue at the U.S. Department of Energy's (DOE) Oak Ridge Reservation and to a lesser extent at other DOE sites because of the hazard it presents, potential consequences to humans and eco-receptors, and completed pathways, to offsite receptors. Recent work has emphasized that selenium might ameliorate the toxicity of mercury, and we examine the selenium:mercury (Se:Hg) molar ratios in fish from Oak Ridge, and compare them to Se:Hg molar ratios in fish from the Savannah River. Selenium/mercury molar ratios varied considerably among and within fish species. There was considerable variation in the molar ratiosmore » for individual fish (as opposed to mean ratios by species) for freshwater fish from both sites. The inter-individual variation in molar ratios indicates that such that the molar ratios of mean Se and Hg concentrations may not be representative. Even for fish species with relatively low mercury levels, some individual fish have molar ratios less than unity, the value sometime thought to be protective. Selenium levels varied narrowly regardless of fish size, consistent with homeostatic regulation of this essential trace element. The data indicate that considerable attention will need to be directed toward variations and variances, as well as the mechanisms of the interaction of selenium and mercury, before risk assessment and risk management policies can use this information to manage mercury pollution and risk. Even so, if there are high levels of selenium in the fish from Poplar Creek on Oak Ridge, then the potential exists for some amelioration of adverse health effects, on the fish themselves, predators that eat them, and people who consume them. This work will aid DOE because it will allow managers and scientists to understand another aspect that affects fate and transport of mercury, as well as the potential effects of methylmercury in fish for human and ecological receptors. The variability within fish species, however, suggests that the relative Se:Hg molar ratios in fish are not stable enough to be used in risk assessment at this time. Nor is it known how much excess selenium is required to confer any degree of protectiveness. That is, in conducting risk assessments, it is not possible to determine the spread of ratios, which would be needed for probabilistic risk assessment. Significantly more fish samples per species are required to begin to generate data that would allow it use in risk assessment. Adding Se:Hg molar ratios seems to complicate risk assessment for the potential adverse effects of mercury exposure, and using mercury levels at this time remains the most viable option. (authors)« less

Extending Data Worth Analyses to Select Multiple Observations Targeting Multiple Forecasts.

PubMed

Vilhelmsen, Troels N; Ferré, Ty P A

2018-05-01

Hydrological models are often set up to provide specific forecasts of interest. Owing to the inherent uncertainty in data used to derive model structure and used to constrain parameter variations, the model forecasts will be uncertain. Additional data collection is often performed to minimize this forecast uncertainty. Given our common financial restrictions, it is critical that we identify data with maximal information content with respect to forecast of interest. In practice, this often devolves to qualitative decisions based on expert opinion. However, there is no assurance that this will lead to optimal design, especially for complex hydrogeological problems. Specifically, these complexities include considerations of multiple forecasts, shared information among potential observations, information content of existing data, and the assumptions and simplifications underlying model construction. In the present study, we extend previous data worth analyses to include: simultaneous selection of multiple new measurements and consideration of multiple forecasts of interest. We show how the suggested approach can be used to optimize data collection. This can be used in a manner that suggests specific measurement sets or that produces probability maps indicating areas likely to be informative for specific forecasts. Moreover, we provide examples documenting that sequential measurement election approaches often lead to suboptimal designs and that estimates of data covariance should be included when selecting future measurement sets. © 2017, National Ground Water Association.

State experiences implementing youth sports concussion laws: challenges, successes, and lessons for evaluating impact.

PubMed

Lowrey, Kerri McGowan; Morain, Stephanie R

2014-01-01

While provisions of youth sports concussion laws are very similar, little is known as to how they are being implemented, factors that promote or impede implementation, or the level of compliance in each jurisdiction. We aimed to describe state experiences with implementation in order to inform ongoing efforts to reduce the harm of sports-related traumatic brain injury and to guide future evaluations of the laws' impacts and the development of future public health laws. We conducted key-informant interviews in 35 states with recently enacted concussion legislation. States varied considerably in their readiness and capacity for implementation. Factors facilitating implementation included existing partnerships, procedures, and resources; centralized implementation authority; prior related efforts; and involvement in the policymaking process by those now charged with implementation. Inhibitors included ambiguous statutory language, unclear delegation of authority, and compliance difficulties. Ongoing challenges persist, including primary prevention; determining which providers are qualified to make return-to-play assessments and contents of those assessments; compliance difficulties in rural and under-served areas; and unclear responsibility for enforcement. Despite the similarity of youth sports concussion laws, early evidence suggests there is considerable variation in their implementation. These findings are critical for ongoing empirical investigations to accurately evaluate the laws' provisions and to identify successful legal approaches to protecting young athletes. © 2014 American Society of Law, Medicine & Ethics, Inc.

Efficient Segmentation of a Breast in B-Mode Ultrasound Tomography Using Three-Dimensional GrabCut (GC3D)

PubMed Central

Wu, Shibin; Zhuang, Ling; Wei, Xinhua; Sak, Mark; Neb, Duric; Hu, Jiani; Xie, Yaoqin

2017-01-01

As an emerging modality for whole breast imaging, ultrasound tomography (UST), has been adopted for diagnostic purposes. Efficient segmentation of an entire breast in UST images plays an important role in quantitative tissue analysis and cancer diagnosis, while major existing methods suffer from considerable time consumption and intensive user interaction. This paper explores three-dimensional GrabCut (GC3D) for breast isolation in thirty reflection (B-mode) UST volumetric images. The algorithm can be conveniently initialized by localizing points to form a polygon, which covers the potential breast region. Moreover, two other variations of GrabCut and an active contour method were compared. Algorithm performance was evaluated from volume overlap ratios (TO, target overlap; MO, mean overlap; FP, false positive; FN, false negative) and time consumption. Experimental results indicate that GC3D considerably reduced the work load and achieved good performance (TO = 0.84; MO = 0.91; FP = 0.006; FN = 0.16) within an average of 1.2 min per volume. Furthermore, GC3D is not only user friendly, but also robust to various inputs, suggesting its great potential to facilitate clinical applications during whole-breast UST imaging. In the near future, the implemented GC3D can be easily automated to tackle B-mode UST volumetric images acquired from the updated imaging system. PMID:28786946

Demographic implications of socioeconomic transition among the tribal populations of Manipur, India.

PubMed

Hemam, N S; Reddy, B M

1998-06-01

The demographic implications of socioeconomic transition are studied among the three subsistence categories of the Gangte, a little known tribe from northeast India. Reproductive histories of 444 ever-married women and other data on the 343 households from which these women were drawn were collected from 11 villages representing the 3 transitional groups. A trend of increasing household income and literacy of couples was observed from shifting cultivators to settled agriculturists to the town-dwelling Gangte. The effect of socioeconomic transition is also seen in the constriction at the base of the age-sex pyramid of the town dwellers compared with the other subsistence categories, suggesting a relatively lower proportion of children in the 0-5-year-old age group. Although exogamy is practiced among all the subsistence categories, a considerably higher percentage of admixture with non-Gangte is observed among the town dwellers compared with the others. Overall infant and child mortality among the Gangte is low. However, variation exists among the three subsistence groups in the sense that a considerable reduction is seen from the traditional shifting cultivators to the urbanized town dwellers, reflecting better socioeconomic conditions and greater awareness and accessibility of the town dwellers to public health amenities. No consistent or perceptible trend is evident in mean number of live births. The genetic implications of this demographic transition are reflected in Crow's indexes of selection.

Stratospheric ozone - Impact of human activity

NASA Technical Reports Server (NTRS)

Mcelroy, Michael B.; Salawitch, Ross J.

1989-01-01

The current knowledge of the chemistry of the stratosphere is reviewed, with particular consideration given to the measurements from the Atmospheric Trace Molecule Spectroscopy (ATMOS) experiment and from the Airborne Antarctic Ozone Experiment. Analysis of the ATMOS data at 30 deg N suggests that the current understanding of the contemporary-stratosphere chemistry at mid-latitudes is relatively complete, except for possible problems with the diurnal variations of N2O5 at low altitudes, and with ClNO3 at higher altitudes. Except for some difficulties with these two compounds, the data from ATMOS agree well with the gas phase models for nitrogen and chlorine species at 30 deg N in spring. It is emphasized that, in addition to the HOCl mechanism proposed by Solomon et al. (1986), the ClO-BrO scheme proposed by McElroy et al. (1986), and the ClO dimer mechanism introduced by Molina and Molina (1987), other processes exist that are responsible for ozone removal.

Illiquidity premium and expected stock returns in the UK: A new approach

NASA Astrophysics Data System (ADS)

Chen, Jiaqi; Sherif, Mohamed

2016-09-01

This study examines the relative importance of liquidity risk for the time-series and cross-section of stock returns in the UK. We propose a simple way to capture the multidimensionality of illiquidity. Our analysis indicates that existing illiquidity measures have considerable asset specific components, which justifies our new approach. Further, we use an alternative test of the Amihud (2002) measure and parametric and non-parametric methods to investigate whether liquidity risk is priced in the UK. We find that the inclusion of the illiquidity factor in the capital asset pricing model plays a significant role in explaining the cross-sectional variation in stock returns, in particular with the Fama-French three-factor model. Further, using Hansen-Jagannathan non-parametric bounds, we find that the illiquidity-augmented capital asset pricing models yield a small distance error, other non-liquidity based models fail to yield economically plausible distance values. Our findings have important implications for managing the liquidity risk of equity portfolios.

Peer assessment of aviation performance: inconsistent for good reasons.

PubMed

Roth, Wolff-Michael; Mavin, Timothy J

2015-03-01

Research into expertise is relatively common in cognitive science concerning expertise existing across many domains. However, much less research has examined how experts within the same domain assess the performance of their peer experts. We report the results of a modified think-aloud study conducted with 18 pilots (6 first officers, 6 captains, and 6 flight examiners). Pairs of same-ranked pilots were asked to rate the performance of a captain flying in a critical pre-recorded simulator scenario. Findings reveal (a) considerable variance within performance categories, (b) differences in the process used as evidence in support of a performance rating, (c) different numbers and types of facts (cues) identified, and (d) differences in how specific performance events affect choice of performance category and gravity of performance assessment. Such variance is consistent with low inter-rater reliability. Because raters exhibited good, albeit imprecise, reasons and facts, a fuzzy mathematical model of performance rating was developed. The model provides good agreement with observed variations. Copyright © 2014 Cognitive Science Society, Inc.

Study on the Key Factor Parameters to Increase Productivity in Construction and Manufacturing Industries.

NASA Astrophysics Data System (ADS)

Almazyed, K.; Alaswad, A.; Olabi, A. G.

2016-02-01

Proper management of human and non-human resources in construction and manufacturing projects can give-in considerable savings in time and cost. Construction and Manufacturing industry faces issues in connection with problems related with productivity and the problems are usually connected with performance of employees. The performance of employees is affected by many factors. In this paper a survey was made on respondents who are employed various projects of Saudi Arabia. The researcher developed a theoretical framework from the existing research which was used as a Model to collect and analyze the field data to test the hypothesis. In this research activity three predictors (commitment, job satisfaction and job performance) for determining the change in productivity. The results highlight that commitment and job performance (respectively) are the two predictors which are explaining 37% of variation in the productivity of the companies. The results also show that Job Satisfaction has no role in the prediction of productivity.

Enhanced Condensation Heat Transfer On Patterned Surfaces

NASA Astrophysics Data System (ADS)

Alizadeh-Birjandi, Elaheh; Kavehpour, H. Pirouz

2017-11-01

Transition from film to drop wise condensation can improve the efficiency of thermal management applications and result in considerable savings in investments and operating costs by millions of dollars every year. The current methods available are either hydrophobic coating or nanostructured surfaces. The former has little adhesion to the structure which tends to detach easily under working conditions, the fabrication techniques of the latter are neither cost-effective nor scalable, and both are made with low thermal conductivity materials that would negate the heat transfer enhancement by drop wise condensation. Therefore, the existing technologies have limitations in enhancing vapor-to-liquid condensation. This work focuses on development of surfaces with wettability contrast to boost drop wise condensation, which its overall heat transfer efficiency is 2-3 times film wise condensation, while maintaining high conduction rate through the surface at low manufacturing costs. The variation in interfacial energy is achieved through crafting hydrophobic patterns to the surface of the metal via scalable fabrication techniques. The results of experimental and surface optimization studies are also presented.

Smoking intensity among male factory workers in Kunming, China.

PubMed

Cheng, Kai-Wen; Tsoh, Janice Y; Cui, Wenlong; Li, Xiaoliang; Kohrman, Matthew

2015-03-01

This study investigated the intensity of cigarette consumption and its correlates in China among urban male factory workers, a cohort especially vulnerable to tobacco exposure, one that appears to have benefitted little from recent public health efforts to reduce smoking rates. Data were collected from men working in factories of Kunming city, Yunnan, China, who are current daily smokers (N = 490). A multinomial logistic regression was conducted to examine the factors in association with smoking intensity in light, moderate, and heavy levels. Light smoking correlated with social smoking, smoking the first cigarette later in the day, self-reported health condition, and quit intention. Heavy smoking was associated with purchase of lower priced cigarettes, difficulty refraining from smoking, and prehypertensive blood pressure. Even in regions where smoking is highly prevalent, even among cohorts who smoke heavily, variation exists in how cigarettes are consumed. Analyses of this consumption, with special consideration given to smoking intensity and its correlates, can help guide tobacco-control strategists in developing more effective interventions. © 2013 APJPH.

Development of spray guns for the application of rigid foam insulation

NASA Technical Reports Server (NTRS)

Allen, Peter B.

1993-01-01

The paper describes the activities initiated to improve the existing spray gun system used for spraying insulating foam on the External Tank of the Space Shuttle, due to the quality variations of the applied foam noted in the past. Consideration is given to the two tasks of the project: (1) investigations of possible improvements, as an interim measure, to the spray gun currently used to apply the large acreage spray-on-foam insulation and the evaluation of other commercial equipment; and (2) the design and fabrication of a new automatic spray gun. The design and operation of the currently used Binks 43 PA spray gun are described together with several new breadboard spray guns designed and fabricated and the testing procedures developed. These new guns include the Modular Automatic Foam spray gun, the Ball Valve spray gun, and the Tapered Plug Valve (TPV) gun. As a result of tests, the TPV spray gun is recommended to replace the currently used automatic spray gun.

Applications of molecular markers in the discrimination of Panax species and Korean ginseng cultivars (Panax ginseng).

PubMed

Jo, Ick Hyun; Kim, Young Chang; Kim, Dong Hwi; Kim, Kee Hong; Hyun, Tae Kyung; Ryu, Hojin; Bang, Kyong Hwan

2017-10-01

The development of molecular markers is one of the most useful methods for molecular breeding and marker-based molecular associated selections. Even though there is less information on the reference genome, molecular markers are indispensable tools for determination of genetic variation and identification of species with high levels of accuracy and reproducibility. The demand for molecular approaches for marker-based breeding and genetic discriminations in Panax species has greatly increased in recent times and has been successfully applied for various purposes. However, owing to the existence of diverse molecular techniques and differences in their principles and applications, there should be careful consideration while selecting appropriate marker types. In this review, we outline the recent status of different molecular marker applications in ginseng research and industrial fields. In addition, we discuss the basic principles, requirements, and advantages and disadvantages of the most widely used molecular markers, including restriction fragment length polymorphism, random amplified polymorphic DNA, sequence tag sites, simple sequence repeats, and single nucleotide polymorphisms.

Effects of plasma drag on low Earth orbiting satellites due to solar forcing induced perturbations and heating

NASA Astrophysics Data System (ADS)

Nwankwo, Victor U. J.; Chakrabarti, Sandip K.; Weigel, Robert S.

2015-07-01

The upper atmosphere changes significantly in temperature, density and composition as a result of solar cycle variations, which causes severe storms and flares, and increases in the amount of absorbed solar radiation from solar energetic events. Satellite orbits are consequently affected by this process, especially those in low Earth orbit (LEO). In this paper, we present a model of atmospheric drag effects on the trajectory of two hypothetical LEO satellites of different ballistic coefficients, initially injected at h = 450 km. We investigate long-term trends of atmospheric drag on LEO satellites due to solar forcing induced atmospheric perturbations and heating at different phases of the solar cycle, and during short intervals of strong geomagnetic disturbances or magnetic storms. We show dependence of orbital decay on the severity of both solar cycle and phase and the extent of geomagnetic perturbations. The result of the model compares well with observed decay profile of some existing LEO satellites and provide a justification of the theoretical considerations used here.

Heat Transfer Study for HTS Power Transfer Cables

NASA Technical Reports Server (NTRS)

Augustynowicz, S.; Fesmire, J.

2002-01-01

Thermal losses are a key factor in the successful application of high temperature superconducting (HTS) power cables. Existing concepts and prototypes rely on the use of multilayer insulation (MLI) systems that are subject to large variations in actual performance. The small space available for the thermal insulation materials makes the application even more difficult because of bending considerations, mechanical loading, and the arrangement between the inner and outer piping. Each of these mechanical variables affects the heat leak rate. These factors of bending and spacing are examined in this study. Furthermore, a maintenance-free insulation system (high vacuum level for 20 years or longer) is a practical requirement. A thermal insulation system simulating a section of a flexible FITS power cable was constructed for test and evaluation on a research cryostat. This paper gives experimental data for the comparison of ideal MLI, MLI on rigid piping, and MLI between flexible piping. A section of insulated flexible piping was tested under cryogenic vacuum conditions including simulated bending and spacers.

Theoretical Current-Voltage Curve in Low-Pressure Cesium Diode for Electron-Rich Emission

NASA Technical Reports Server (NTRS)

Coldstein, C. M.

1964-01-01

Although considerable interest has been shown in the space-charge analysis of low-pressure (collisionless case) thermionic diodes, there is a conspicuous lack in the presentation of results in a way that allows direct comparison with experiment. The current-voltage curve of this report was, therefore, computed for a typical case within the realm of experimental interest. The model employed in this computation is shown in Fig. 1 and is defined by the limiting potential distributions [curves (a) and (b)]. Curve (a) represents the potential V as a monotonic function of position with a slope of zero at the anode; curve (b) is similarly monotonic with a slope of zero at the cathode. It is assumed that by a continuous variation of the anode voltage, the potential distributions vary continuously from one limiting form to the other. Although solutions for infinitely spaced electrodes show that spatically oscillatory potential distributions may exist, they have been neglected in this computation.

Variation in nitrogen use efficiencies on Dutch dairy farms.

PubMed

Daatselaar, Co Hg; Reijs, Joan R; Oenema, Jouke; Doornewaard, Gerben J; Aarts, H Frans M

2015-12-01

On dairy farms, the input of nutrients including nitrogen is higher than the output in products such as milk and meat. This causes losses of nitrogen to the environment. One of the indicators for the losses of nitrogen is the nitrogen use efficiency. In the Dutch Minerals Policy Monitoring Program (LMM), many data on nutrients of a few hundred farms are collected which can be processed by the instrument Annual Nutrient Cycle Assessment (ANCA, in Dutch: Kringloopwijzer) in order to provide nitrogen use efficiencies. After dividing the dairy farms (available in the LMM program) according to soil type and in different classes for milk production ha(-1) , it is shown that considerable differences in nitrogen use efficiency exist between farms on the same soil type and with the same level of milk production ha(-1) . This offers opportunities for improvement of the nitrogen use efficiency on many dairy farms. Benchmarking will be a useful first step in this process. © 2015 Society of Chemical Industry.

Social media analysis during political turbulence

PubMed Central

Spiliotopoulos, Dimitris; V. Samaras, Christos; Pratikakis, Polyvios; Ioannidis, Sotiris; Fragopoulou, Paraskevi

2017-01-01

Today, a considerable proportion of the public political discourse on nationwide elections proceeds in Online Social Networks. Through analyzing this content, we can discover the major themes that prevailed during the discussion, investigate the temporal variation of positive and negative sentiment and examine the semantic proximity of these themes. According to existing studies, the results of similar tasks are heavily dependent on the quality and completeness of dictionaries for linguistic preprocessing, entity discovery and sentiment analysis. Additionally, noise reduction is achieved with methods for sarcasm detection and correction. Here we report on the application of these methods on the complete corpus of tweets regarding two local electoral events of worldwide impact: the Greek referendum of 2015 and the subsequent legislative elections. To this end, we compiled novel dictionaries for sentiment and entity detection for the Greek language tailored to these events. We subsequently performed volume analysis, sentiment analysis, sarcasm correction and topic modeling. Results showed that there was a strong anti-austerity sentiment accompanied with a critical view on European and Greek political actions. PMID:29088263

Spatial-temporal population dynamics across species range: from center to margin

USGS Publications Warehouse

Guo, Q.; Taper, M.L.; Schoenberger, M.; Brandl, J.

2005-01-01

Understanding the boundaries of species' ranges and the variations in population dynamics from the centre to margin of a species' range is critical. This study simulated spatial-temporal patterns of birth and death rates and migration across a species' range in different seasons. Our results demonstrated the importance of dispersal and migration in altering birth and death rates, balancing source and sink habitats, and governing expansion or contraction of species' ranges in changing environments. We also showed that the multiple equilibria of metapopulations across a species' range could be easily broken following climatic changes or physical disturbances either or local or regional. Although we refer to our models as describing the population dynamics across whole species' range, they should also apply to small-scale habitats (metapopulations) in which species abundance follows a humped pattern or to any ecosystem or landscape where strong central-marginal (C-M) environmental gradients exist. Conservation of both central and marginal populations would therefore be equally important considerations in making management decisions.

Spatial-temporal population dynamics across species range: From centre to margin

USGS Publications Warehouse

Guo, Q.; Taper, M.; Schoenberger, M.; Brandle, J.

2005-01-01

Understanding the boundaries of species' ranges and the variations in population dynamics from the centre to margin of a species' range is critical. This study simulated spatial-temporal patterns of birth and death rates and migration across a species' range in different seasons. Our results demonstrated the importance of dispersal and migration in altering birth and death rates, balancing source and sink habitats, and governing expansion or contraction of species' ranges in changing environments. We also showed that the multiple equilibria of metapopulations across a species' range could be easily broken following climatic changes or physical disturbances either local or regional. Although we refer to our models as describing the population dynamics across whole species' range, they should also apply to small-scale habitats (metapopulations) in which species abundance follows a humped pattern or to any ecosystem or landscape where strong central-marginal (C-M) environmental gradients exist. Conservation of both central and marginal populations would therefore be equally important considerations in making management decisions.

Ocular toxoplasmosis I: parasitology, epidemiology and public health.

PubMed

Furtado, João M; Winthrop, Kevin L; Butler, Nicholas J; Smith, Justine R

2013-01-01

Ocular toxoplasmosis results from retinal infection with the protozoan, Toxoplasma gondii. This parasite, which exists as multiple clonal subpopulations and in three stages, is capable of replication in any nucleated cell of its primary feline or multiple paratenic hosts. Human seroprevalence of toxoplasmosis is high across the globe, but with geographic variation. While prevalence of ocular toxoplasmosis is not well documented, toxoplasmic retinochoroiditis is the commonest form of posterior uveitis in many countries. Correlation of parasite genotype with disease is an important area of new research. Ocular infection with T. gondii often follows ingestion of bradyzoites in undercooked infected meat. Oocysts may survive for an extended period in the environment, and water contaminated with oocysts is an important source in toxoplasmosis epidemics. Ocular toxoplasmosis is preventable by a combination of community activities and personal measures. Public health action is well justified by the considerable burden of congenital and postnatal infections. © 2012 The Authors. Clinical and Experimental Ophthalmology © 2012 Royal Australian and New Zealand College of Ophthalmologists.

Patient Blood Management: An International Perspective.

PubMed

Eichbaum, Quentin; Murphy, Michael; Liu, Yu; Kajja, Isaac; Hajjar, Ludhmila Abrahao; Smit Sibinga, Cees Th; Shan, Hua

2016-12-01

This article describes practices in patient blood management (PBM) in 4 countries on different continents that may provide insights for anesthesiologists and other physicians working in global settings. The article has its foundation in the proceedings of a session at the 2014 AABB annual meeting during which international experts from England, Uganda, China, and Brazil presented the programs and implementation strategies in PBM developed in their respective countries. To systematize the review and enhance the comparability between these countries on different continents, authors were requested to respond to the same set of 6 key questions with respect to their country's PBM program(s). Considerable variation exists between these country regions that is driven both by differences in health contexts and by disparities in resources. Comparing PBM strategies from low-, middle-, and high-income countries, as described in this article, allows them to learn bidirectionally from one another and to work toward implementing innovative and preferably evidence-based strategies for improvement. Sharing and distributing knowledge from such programs will ultimately also improve transfusion outcomes and patient safety.

Social media analysis during political turbulence.

PubMed

Antonakaki, Despoina; Spiliotopoulos, Dimitris; V Samaras, Christos; Pratikakis, Polyvios; Ioannidis, Sotiris; Fragopoulou, Paraskevi

2017-01-01

Today, a considerable proportion of the public political discourse on nationwide elections proceeds in Online Social Networks. Through analyzing this content, we can discover the major themes that prevailed during the discussion, investigate the temporal variation of positive and negative sentiment and examine the semantic proximity of these themes. According to existing studies, the results of similar tasks are heavily dependent on the quality and completeness of dictionaries for linguistic preprocessing, entity discovery and sentiment analysis. Additionally, noise reduction is achieved with methods for sarcasm detection and correction. Here we report on the application of these methods on the complete corpus of tweets regarding two local electoral events of worldwide impact: the Greek referendum of 2015 and the subsequent legislative elections. To this end, we compiled novel dictionaries for sentiment and entity detection for the Greek language tailored to these events. We subsequently performed volume analysis, sentiment analysis, sarcasm correction and topic modeling. Results showed that there was a strong anti-austerity sentiment accompanied with a critical view on European and Greek political actions.

A Tricky Trait: Applying the Fruits of the "Function Debate" in the Philosophy of Biology to the "Venom Debate" in the Science of Toxinology.

PubMed

Jackson, Timothy N W; Fry, Bryan G

2016-09-07

The "function debate" in the philosophy of biology and the "venom debate" in the science of toxinology are conceptually related. Venom systems are complex multifunctional traits that have evolved independently numerous times throughout the animal kingdom. No single concept of function, amongst those popularly defended, appears adequate to describe these systems in all their evolutionary contexts and extant variations. As such, a pluralistic view of function, previously defended by some philosophers of biology, is most appropriate. Venom systems, like many other functional traits, exist in nature as points on a continuum and the boundaries between "venomous" and "non-venomous" species may not always be clearly defined. This paper includes a brief overview of the concept of function, followed by in-depth discussion of its application to venom systems. A sound understanding of function may aid in moving the venom debate forward. Similarly, consideration of a complex functional trait such as venom may be of interest to philosophers of biology.

Density estimates of monarch butterflies overwintering in central Mexico

PubMed Central

Diffendorfer, Jay E.; López-Hoffman, Laura; Oberhauser, Karen; Pleasants, John; Semmens, Brice X.; Semmens, Darius; Taylor, Orley R.; Wiederholt, Ruscena

2017-01-01

Given the rapid population decline and recent petition for listing of the monarch butterfly (Danaus plexippus L.) under the Endangered Species Act, an accurate estimate of the Eastern, migratory population size is needed. Because of difficulty in counting individual monarchs, the number of hectares occupied by monarchs in the overwintering area is commonly used as a proxy for population size, which is then multiplied by the density of individuals per hectare to estimate population size. There is, however, considerable variation in published estimates of overwintering density, ranging from 6.9–60.9 million ha−1. We develop a probability distribution for overwinter density of monarch butterflies from six published density estimates. The mean density among the mixture of the six published estimates was ∼27.9 million butterflies ha−1 (95% CI [2.4–80.7] million ha−1); the mixture distribution is approximately log-normal, and as such is better represented by the median (21.1 million butterflies ha−1). Based upon assumptions regarding the number of milkweed needed to support monarchs, the amount of milkweed (Asclepias spp.) lost (0.86 billion stems) in the northern US plus the amount of milkweed remaining (1.34 billion stems), we estimate >1.8 billion stems is needed to return monarchs to an average population size of 6 ha. Considerable uncertainty exists in this required amount of milkweed because of the considerable uncertainty occurring in overwinter density estimates. Nevertheless, the estimate is on the same order as other published estimates. The studies included in our synthesis differ substantially by year, location, method, and measures of precision. A better understanding of the factors influencing overwintering density across space and time would be valuable for increasing the precision of conservation recommendations. PMID:28462031

Density estimates of monarch butterflies overwintering in central Mexico

USGS Publications Warehouse

Thogmartin, Wayne E.; Diffendorfer, James E.; Lopez-Hoffman, Laura; Oberhauser, Karen; Pleasants, John M.; Semmens, Brice X.; Semmens, Darius J.; Taylor, Orley R.; Wiederholt, Ruscena

2017-01-01

Given the rapid population decline and recent petition for listing of the monarch butterfly (Danaus plexippus L.) under the Endangered Species Act, an accurate estimate of the Eastern, migratory population size is needed. Because of difficulty in counting individual monarchs, the number of hectares occupied by monarchs in the overwintering area is commonly used as a proxy for population size, which is then multiplied by the density of individuals per hectare to estimate population size. There is, however, considerable variation in published estimates of overwintering density, ranging from 6.9–60.9 million ha−1. We develop a probability distribution for overwinter density of monarch butterflies from six published density estimates. The mean density among the mixture of the six published estimates was ∼27.9 million butterflies ha−1 (95% CI [2.4–80.7] million ha−1); the mixture distribution is approximately log-normal, and as such is better represented by the median (21.1 million butterflies ha−1). Based upon assumptions regarding the number of milkweed needed to support monarchs, the amount of milkweed (Asclepias spp.) lost (0.86 billion stems) in the northern US plus the amount of milkweed remaining (1.34 billion stems), we estimate >1.8 billion stems is needed to return monarchs to an average population size of 6 ha. Considerable uncertainty exists in this required amount of milkweed because of the considerable uncertainty occurring in overwinter density estimates. Nevertheless, the estimate is on the same order as other published estimates. The studies included in our synthesis differ substantially by year, location, method, and measures of precision. A better understanding of the factors influencing overwintering density across space and time would be valuable for increasing the precision of conservation recommendations.

Genome Variation Within Triticale in Comparison to its Wheat and Rye Progenitors

USDA-ARS?s Scientific Manuscript database

Genome variation in the intergeneric wheat-rye hybrid triticale (X Triticosecale Wittmack) has been a puzzle to scientists and plant breeders since the first triticale was synthesized. The existence of unexplained genetic variation in triticale as compared to the parents has been a hindrance to bre...

METHODS FOR INTEGRATING ENVIRONMENTAL CONSIDERATIONS INTO CHEMICAL PROCESS DESIGN DECISIONS

EPA Science Inventory

The objective of this cooperative agreement was to postulate a means by which an engineer could routinely include environmental considerations in day-to-day conceptual design problems; a means that could easily integrate with existing design processes, and thus avoid massive retr...

A Study of Poisson's Ratio in the Yield Region

NASA Technical Reports Server (NTRS)

Gerard, George; Wildhorn, Sorrel

1952-01-01

In the yield region of the stress-strain curve the variation in Poisson's ratio from the elastic to the plastic value is most pronounced. This variation was studied experimentally by a systematic series of tests on several aluminum alloys. The tests were conducted under simple tensile and compressive loading along three orthogonal axes. A theoretical variation of Poisson's ratio for an orthotropic solid was obtained from dilatational considerations. The assumptions used in deriving the theory were examined by use of the test data and were found to be in reasonable agreement with experimental evidence.

Analysis of magnetic fields using variational principles and CELAS2 elements

NASA Technical Reports Server (NTRS)

Frye, J. W.; Kasper, R. G.

1977-01-01

Prospective techniques for analyzing magnetic fields using NASTRAN are reviewed. A variational principle utilizing a vector potential function is presented which has as its Euler equations, the required field equations and boundary conditions for static magnetic fields including current sources. The need for an addition to this variational principle of a constraint condition is discussed. Some results using the Lagrange multiplier method to apply the constraint and CELAS2 elements to simulate the matrices are given. Practical considerations of using large numbers of CELAS2 elements are discussed.

Combining a generic process-based productivity model classification method to predict the presence and absence species in the Pacific Northwest, U.S.A

Treesearch

Nicholas C. Coops; Richard H. Waring; Todd A. Schroeder

2009-01-01

Although long-lived tree species experience considerable environmental variation over their life spans, their geographical distributions reflect sensitivity mainly to mean monthly climatic conditions.We introduce an approach that incorporates a physiologically based growth model to illustrate how a half-dozen tree species differ in their responses to monthly variation...

Computer methods for sampling from the gamma distribution

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

Johnson, M.E.; Tadikamalla, P.R.

1978-01-01

Considerable attention has recently been directed at developing ever faster algorithms for generating gamma random variates on digital computers. This paper surveys the current state of the art including the leading algorithms of Ahrens and Dieter, Atkinson, Cheng, Fishman, Marsaglia, Tadikamalla, and Wallace. General random variate generation techniques are explained with reference to these gamma algorithms. Computer simulation experiments on IBM and CDC computers are reported.

A semi-inverse variational method for generating the bound state energy eigenvalues in a quantum system: the Dirac Coulomb type-equation

NASA Astrophysics Data System (ADS)

Libarir, K.; Zerarka, A.

2018-05-01

Exact eigenspectra and eigenfunctions of the Dirac quantum equation are established using the semi-inverse variational method. This method improves of a considerable manner the efficiency and accuracy of results compared with the other usual methods much argued in the literature. Some applications for different state configurations are proposed to concretize the method.

Plasticity of Lateralization: Schooling Predicts Hand Preference but not Hand Skill Asymmetry in a Non-Industrial Society

ERIC Educational Resources Information Center

Geuze, Reint H.; Schaafsma, Sara M.; Lust, Jessica M.; Bouma, Anke; Schiefenhovel, Wulf; Groothuis, Ton G. G.

2012-01-01

Considerable variation in the frequency of left-handedness between cultures has been reported, ranging from 0.5 to 24%. This variation in hand preference may have evolved under natural or cultural selection. It has been suggested that schooling affects handedness but as in most human societies only a selected and minor part of the population does…

The influence of soil properties and nutrients on conifer forest growth in Sweden, and the first steps in developing a nutrient availability metric

NASA Astrophysics Data System (ADS)

Van Sundert, Kevin; Horemans, Joanna A.; Stendahl, Johan; Vicca, Sara

2018-06-01

The availability of nutrients is one of the factors that regulate terrestrial carbon cycling and modify ecosystem responses to environmental changes. Nonetheless, nutrient availability is often overlooked in climate-carbon cycle studies because it depends on the interplay of various soil factors that would ideally be comprised into metrics applicable at large spatial scales. Such metrics do not currently exist. Here, we use a Swedish forest inventory database that contains soil data and tree growth data for > 2500 forests across Sweden to (i) test which combination of soil factors best explains variation in tree growth, (ii) evaluate an existing metric of constraints on nutrient availability, and (iii) adjust this metric for boreal forest data. With (iii), we thus aimed to provide an adjustable nutrient metric, applicable for Sweden and with potential for elaboration to other regions. While taking into account confounding factors such as climate, N deposition, and soil oxygen availability, our analyses revealed that the soil organic carbon concentration (SOC) and the ratio of soil carbon to nitrogen (C : N) were the most important factors explaining variation in normalized (climate-independent) productivity (mean annual volume increment - m3 ha-1 yr-1) across Sweden. Normalized forest productivity was significantly negatively related to the soil C : N ratio (R2 = 0.02-0.13), while SOC exhibited an empirical optimum (R2 = 0.05-0.15). For the metric, we started from a (yet unvalidated) metric for constraints on nutrient availability that was previously developed by the International Institute for Applied Systems Analysis (IIASA - Laxenburg, Austria) for evaluating potential productivity of arable land. This IIASA metric requires information on soil properties that are indicative of nutrient availability (SOC, soil texture, total exchangeable bases - TEB, and pH) and is based on theoretical considerations that are also generally valid for nonagricultural ecosystems. However, the IIASA metric was unrelated to normalized forest productivity across Sweden (R2 = 0.00-0.01) because the soil factors under consideration were not optimally implemented according to the Swedish data, and because the soil C : N ratio was not included. Using two methods (each one based on a different way of normalizing productivity for climate), we adjusted this metric by incorporating soil C : N and modifying the relationship between SOC and nutrient availability in view of the observed relationships across our database. In contrast to the IIASA metric, the adjusted metrics explained some variation in normalized productivity in the database (R2 = 0.03-0.21; depending on the applied method). A test for five manually selected local fertility gradients in our database revealed a significant and stronger relationship between the adjusted metrics and productivity for each of the gradients (R2 = 0.09-0.38). This study thus shows for the first time how nutrient availability metrics can be evaluated and adjusted for a particular ecosystem type, using a large-scale database.

Regional isolation in the Balkan region: an analysis of craniofacial variation.

PubMed

Ross, Ann H

2004-05-01

Biological variation is investigated among contemporary Croatians, Bosnians, American whites, and other multitemporal Balkan populations (World War II Croatians, Macedonians, and Greeks) via multivariate statistics and distance measures of the craniofacial complex. This study demonstrates that there is considerable variation among groups of European ancestry. Bosnians and Croatians who are thought to be relatively homogenous and historically to originate from the same Slav ancestry show local variations. While environmental plasticity has been used to explain cranial changes among human groups, it does not adequately explain the variation observed between Bosnians and Croatians. It is an oversimplification to exclusively attribute the vast range of variability observed among local as well as geographic populations to environmental adaptations. Copyright 2003 Wiley-Liss, Inc.

Premaxillary crest variation within the Wukongopteridae (Reptilia, Pterosauria) and comments on cranial structures in pterosaurs.

PubMed

Cheng, Xin; Jiang, Shunxing; Wang, Xiaolin; Kellner, Alexander W A

2017-01-01

Cranial crests show considerable variation within the Pterosauria, a group of flying reptiles that developed powered flight. This includes the Wukongopteridae, a clade of non-pterodactyloids, where the presence or absence of such head structures, allied with variation in the pelvic canal, have been regarded as evidence for sexual dimorphism. Here we discuss the cranial crest variation within wukongopterids and briefly report on a new specimen (IVPP V 17957). We also show that there is no significant variation in the anatomy of the pelvis of crested and crestless specimens. We further revisit the discussion regarding the function of cranial structures in pterosaurs and argue that they cannot be dismissed a priori as a valuable tool for species recognition.

Probabilistic Micromechanics and Macromechanics for Ceramic Matrix Composites

NASA Technical Reports Server (NTRS)

Murthy, Pappu L. N.; Mital, Subodh K.; Shah, Ashwin R.

1997-01-01

The properties of ceramic matrix composites (CMC's) are known to display a considerable amount of scatter due to variations in fiber/matrix properties, interphase properties, interphase bonding, amount of matrix voids, and many geometry- or fabrication-related parameters, such as ply thickness and ply orientation. This paper summarizes preliminary studies in which formal probabilistic descriptions of the material-behavior- and fabrication-related parameters were incorporated into micromechanics and macromechanics for CMC'S. In this process two existing methodologies, namely CMC micromechanics and macromechanics analysis and a fast probability integration (FPI) technique are synergistically coupled to obtain the probabilistic composite behavior or response. Preliminary results in the form of cumulative probability distributions and information on the probability sensitivities of the response to primitive variables for a unidirectional silicon carbide/reaction-bonded silicon nitride (SiC/RBSN) CMC are presented. The cumulative distribution functions are computed for composite moduli, thermal expansion coefficients, thermal conductivities, and longitudinal tensile strength at room temperature. The variations in the constituent properties that directly affect these composite properties are accounted for via assumed probabilistic distributions. Collectively, the results show that the present technique provides valuable information about the composite properties and sensitivity factors, which is useful to design or test engineers. Furthermore, the present methodology is computationally more efficient than a standard Monte-Carlo simulation technique; and the agreement between the two solutions is excellent, as shown via select examples.

Complete Mitochondrial Genome Sequence of Acrida cinerea (Acrididae: Orthoptera) and Comparative Analysis of Mitochondrial Genomes in Orthoptera

PubMed Central

Liu, Nian; Huang, Yuan

2010-01-01

The complete 15,599-bp mitogenome of Acrida cinerea was determined and compared with that of the other 20 orthopterans. It displays characteristic gene content, genome organization, nucleotide composition, and codon usage found in other Caelifera mitogenomes. Comparison of 21 orthopteran sequences revealed that the tRNAs encoded by the H-strand appear more conserved than those by the L-stand. All tRNAs form the typical clover-leaf structure except trnS (agn), and most of the size variation among tRNAs stemmed from the length variation in the arm and loop of TΨC and the loop of DHU. The derived secondary structure models of the rrnS and rrnL from 21 orthoptera species closely resemble those from other insects on CRW except a considerably enlarged loop of helix 1399 of rrnS in Caelifera, which is a potentially autapomorphy of Caelifera. In the A+T-rich region, tandem repeats are not only conserved in the closely related mitogenome but also share some conserved motifs in the same subfamily. A stem-loop structure, 16 bp or longer, is likely to be involved in replication initiation in Caelifera and Grylloidea. A long T-stretch (>17 bp) with conserved stem-loop structure next to rrnS on the H-strand, bounded by a purine at either end, exists in the three species from Tettigoniidae. PMID:21197069

Improving AFLP analysis of large-scale patterns of genetic variation--a case study with the Central African lianas Haumania spp (Marantaceae) showing interspecific gene flow.

PubMed

Ley, A C; Hardy, O J

2013-04-01

AFLP markers are often used to study patterns of population genetic variation and gene flow because they offer a good coverage of the nuclear genome, but the reliability of AFLP scoring is critical. To assess interspecific gene flow in two African rainforest liana species (Haumania danckelmaniana, H. liebrechtsiana) where previous evidence of chloroplast captures questioned the importance of hybridization and species boundaries, we developed new AFLP markers and a novel approach to select reliable bands from their degree of reproducibility. The latter is based on the estimation of the broad-sense heritability of AFLP phenotypes, an improvement over classical scoring error rates, which showed that the polymorphism of most AFLP bands was affected by a substantial nongenetic component. Therefore, using a quantitative genetics framework, we also modified an existing estimator of pairwise kinship coefficient between individuals correcting for the limited heritability of markers. Bayesian clustering confirms the recognition of the two Haumania species. Nevertheless, the decay of the relatedness between individuals of distinct species with geographic distance demonstrates that hybridization affects the nuclear genome. In conclusion, although we showed that AFLP markers might be substantially affected by nongenetic factors, their analysis using the new methods developed considerably advanced our understanding of the pattern of gene flow in our model species. © 2013 Blackwell Publishing Ltd.

Rapid Response Team composition, resourcing and calling criteria in Australia.

PubMed

Jones, Daryl; Drennan, Kelly; Hart, Graeme K; Bellomo, Rinaldo; Web, Steven A R

2012-05-01

Rapid Response Teams (RRTs) have been introduced into at least 60% of Intensive Care Unit (ICU) - equipped Australian hospitals to review deteriorating ward patients. Most studies have assessed their impact on patient outcome and less information exists on team composition or aspects of their calling criteria. We obtained information on team composition, resourcing and details of activation criteria from 39 of 108 (36.1%) RRT-equipped Australian hospitals. We found that all 39 teams operated 24/7 (h/days), but only 10 (25.6%) had received additional funding for the service. Although 38/39 teams, were physician-led medical emergency teams, in 7 (17.9%) sites the most senior member would be unlikely to have advanced airway skills. Three quarters of calling criteria were structured into "ABCD", and approximately 40% included cardiac and/or respiratory arrest as a calling criterion. Thresholds for calling criteria varied widely (particularly for respiratory rate and heart rate), as did the wording of the worried/concerned criterion. There was also wide variation in the number and nature of additional activation criteria. Our findings imply the likelihood of significant practice variation in relation to RRT composition, staff skill set and activation criteria between hospitals. We recommend improved resourcing of RRTs, training of the team members, and consideration for improved standardisation of calling criteria across institutions. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Many-to-one form-to-function mapping weakens parallel morphological evolution.

PubMed

Thompson, Cole J; Ahmed, Newaz I; Veen, Thor; Peichel, Catherine L; Hendry, Andrew P; Bolnick, Daniel I; Stuart, Yoel E

2017-11-01

Evolutionary ecologists aim to explain and predict evolutionary change under different selective regimes. Theory suggests that such evolutionary prediction should be more difficult for biomechanical systems in which different trait combinations generate the same functional output: "many-to-one mapping." Many-to-one mapping of phenotype to function enables multiple morphological solutions to meet the same adaptive challenges. Therefore, many-to-one mapping should undermine parallel morphological evolution, and hence evolutionary predictability, even when selection pressures are shared among populations. Studying 16 replicate pairs of lake- and stream-adapted threespine stickleback (Gasterosteus aculeatus), we quantified three parts of the teleost feeding apparatus and used biomechanical models to calculate their expected functional outputs. The three feeding structures differed in their form-to-function relationship from one-to-one (lower jaw lever ratio) to increasingly many-to-one (buccal suction index, opercular 4-bar linkage). We tested for (1) weaker linear correlations between phenotype and calculated function, and (2) less parallel evolution across lake-stream pairs, in the many-to-one systems relative to the one-to-one system. We confirm both predictions, thus supporting the theoretical expectation that increasing many-to-one mapping undermines parallel evolution. Therefore, sole consideration of morphological variation within and among populations might not serve as a proxy for functional variation when multiple adaptive trait combinations exist. © 2017 The Author(s). Evolution © 2017 The Society for the Study of Evolution.

Post-Formation Sodium Loss on the Moon: A Bulk Estimate

NASA Technical Reports Server (NTRS)

Saxena, P.; Killen, R. M.; Airapetian, V.; Petro, N. E.; Mandell, A. M.

2018-01-01

The Moon and Earth are generally similar in terms of composition, but there exist variations in the abundance of certain elements among the two bodies. These differences are a likely consequence of differing physical evolution of the two bodies over the solar system's history. While previous works have assumed this may be due to conditions during the Moonâ€"TM"s formation, we explore the likelihood that the observed depletion in Sodium in lunar samples may be partially due to post-formation mechanisms. Solar effects, loss from a primordial atmosphere and impacts are some of the dominant post-formation mechanisms that we examine. We describe how our past and current modeling efforts indicate that a significant fraction of the observed depletion of sodium in lunar samples relative to a bulk silicate earth composition may have been due to solar activity, atmospheric loss and impacts. Using profiles of sodium abundances from lunar crustal samples may thus serve as a powerful tool towards exploring conditions on the Moon's surface throughout solar system history. Conditions on the Moon immediately after formation may still be recorded in the lunar crust and may provide a window towards interpreting observations from some of the first rocky exoplanets that will be most amenable to characterization. Potential spatial variation of sodium in the lunar crust may be a relevant consideration for future sample return efforts. Sodium Depletion in the Lunar Crust: Lunar

Extremely low frequency (ELF) stray magnetic fields of laboratory equipment: a possible co-exposure conducting experiments on cell cultures.

PubMed

Gresits, Iván; Necz, Péter Pál; Jánossy, Gábor; Thuróczy, György

2015-09-01

Measurements of extremely low frequency (ELF) magnetic fields were conducted in the environment of commercial laboratory equipment in order to evaluate the possible co-exposure during the experimental processes on cell cultures. Three types of device were evaluated: a cell culture CO2 incubator, a thermostatic water bath and a laboratory shaker table. These devices usually have electric motors, heating wires and electronic control systems, therefore may expose the cell cultures to undesirable ELF stray magnetic fields. Spatial distributions of magnetic field time domain signal waveform and frequency spectral analysis (FFT) were processed. Long- and short-term variation of stray magnetic field was also evaluated under normal use of investigated laboratory devices. The results show that the equipment under test may add a considerable ELF magnetic field to the ambient environmental magnetic field or to the intentional exposure to ELF, RF or other physical/chemical agents. The maximum stray magnetic fields were higher than 3 µT, 20 µT and 75 µT in the CO2 incubator, in water bath and on the laboratory shaker table, respectively, with high variation of spatial distribution and time domain. Our investigation emphasizes possible confounding factors conducting cell culture studies related to low-level ELF-EMF exposure due to the existing stray magnetic fields in the ambient environment of laboratory equipment.

Comparison of storm-time changes of geomagnetic field at ground and at MAGSAT altitudes, part 3

NASA Technical Reports Server (NTRS)

Dejesusparada, N. (Principal Investigator); Kane, R. P.; Trivedi, N. B.

1982-01-01

The latitudinal distributions of delta H, delta X, delta Y, and delta Z were studied for quiet and disturbed periods. For quiet periods, the average patterns showed some variations common to dusk and dawn, thus indicating probable ground anomaly. However, there were significant differences too between dusk and dawn, indicating considerable diurnal variation effects. Particularly in delta Y, these effects were large and were symmetric about the dip equator. For disturbed day passes, the quiet day patterns were considered as base levels and the latter were subtracted from the former. The resulting residual latitudinal patterns were, on the average, symmetric about the geographical equator. However, individual passes showed considerable north-south asymmetries, probably indicating meanderings of the central plane of the magnetospheric ring current.

Educational Attainment by Age, Sex, and Race, for the United States: 1970. 1970 Census of Population, Supplementary Report.

ERIC Educational Resources Information Center

Bureau of the Census (DOC), Suitland, MD. Population Div.

The 1960's witnessed considerable change in educational attainment levels. Of Americans 25 years old and over in 1970, 52 percent were at least high school graduates, as compared with 41 percent in 1960 and 34 percent in 1950. There was considerable variation in educational attainment levels in 1970 among the various age groups in the population.…

Efficient genotype compression and analysis of large genetic variation datasets

PubMed Central

Layer, Ryan M.; Kindlon, Neil; Karczewski, Konrad J.; Quinlan, Aaron R.

2015-01-01

Genotype Query Tools (GQT) is a new indexing strategy that expedites analyses of genome variation datasets in VCF format based on sample genotypes, phenotypes and relationships. GQT’s compressed genotype index minimizes decompression for analysis, and performance relative to existing methods improves with cohort size. We show substantial (up to 443 fold) performance gains over existing methods and demonstrate GQT’s utility for exploring massive datasets involving thousands to millions of genomes. PMID:26550772

Frequency of use of the International Classification of Diseases ICD-10 diagnostic categories for mental and behavioural disorders across world regions.

PubMed

Faiad, Y; Khoury, B; Daouk, S; Maj, M; Keeley, J; Gureje, O; Reed, G

2017-11-09

The study aimed to examine variations in the use of International Classification of Diseases, Tenth Edition (ICD-10) diagnostic categories for mental and behavioural disorders across countries, regions and income levels using data from the online World Psychiatric Association (WPA)-World Health Organization (WHO) Global Survey that examined the attitudes of psychiatrists towards the classification of mental disorders. A survey was sent to 46 psychiatric societies which are members of WPA. A total of 4887 psychiatrists participated in the survey, which asked about their use of classification, their preferred system and the categories that were used most frequently. The majority (70.1%) of participating psychiatrists (out of 4887 psychiatrists) reported using the ICD-10 the most and using at least one diagnostic category once a week. Nine out of 44 diagnostic categories were considerably variable in terms of frequency of use across countries. These were: emotionally unstable personality disorder, borderline type; dissociative (conversion) disorder; somatoform disorders; obsessive-compulsive disorder (OCD); mental and behavioural disorders due to the use of alcohol; adjustment disorder; mental and behavioural disorders due to the use of cannabinoids; dementia in Alzheimer's disease; and acute and transient psychotic disorder. The frequency of use for these nine categories was examined across WHO regions and income levels. The most striking differences across WHO regions were found for five out of these nine categories. For dissociative (conversion) disorder, use was highest for the WHO Eastern Mediterranean Region (EMRO) and non-existent for the WHO African Region. For mental and behavioural disorders due to the use of alcohol, use was lowest for EMRO. For mental and behavioural disorders due to the use of cannabinoids, use was lowest for the WHO European Region and the WHO Western Pacific Region. For OCD and somatoform disorders, use was lowest for EMRO and the WHO Southeast Asian Region. Differences in the frequency of use across income levels were statistically significant for all categories except for mental and behavioural disorders due to the use of alcohol. The most striking variations were found for acute and transient psychotic disorder, which was reported to be more commonly used among psychiatrists from countries with lower income levels. The differences in frequency of use reported in the current study show that cross-cultural variations in psychiatric practice exist. However, whether these differences are due to the variations in prevalence, treatment-seeking behaviour and other factors, such as psychiatrist and patient characteristics as a result of culture, cannot be determined based on the findings of the study. Further research is needed to examine whether these variations are culturally determined and how that would affect the cross-cultural applicability of ICD-10 diagnostic categories.

Study of weak solutions for parabolic variational inequalities with nonstandard growth conditions.

PubMed

Dong, Yan

2018-01-01

In this paper, we study the degenerate parabolic variational inequality problem in a bounded domain. First, the weak solutions of the variational inequality are defined. Second, the existence and uniqueness of the solutions in the weak sense are proved by using the penalty method and the reduction method.

Variational formulation for Black-Scholes equations in stochastic volatility models

NASA Astrophysics Data System (ADS)

Gyulov, Tihomir B.; Valkov, Radoslav L.

2012-11-01

In this note we prove existence and uniqueness of weak solutions to a boundary value problem arising from stochastic volatility models in financial mathematics. Our settings are variational in weighted Sobolev spaces. Nevertheless, as it will become apparent our variational formulation agrees well with the stochastic part of the problem.

Parents or predators: Examining intraseasonal variation in nest survival for migratory passerine

Treesearch

Robin Hirsch-Jacobson; W. Andrew Cox; Emily E. Tewes; Frank R., III Thompson; John Faaborg

2012-01-01

For birds, risk of nest predation can vary within a breeding season, but few data exist that explain why such variation occurs. We investigated intraseasonal variation of nest survival of the Acadian Flycatcher (Empidonax virescens) in Midwestern forests and tested whether four of the adults' reproductive strategies (clutch size, nest...

Identification and ranking of environmental threats with ecosystem vulnerability distributions.

PubMed

Zijp, Michiel C; Huijbregts, Mark A J; Schipper, Aafke M; Mulder, Christian; Posthuma, Leo

2017-08-24

Responses of ecosystems to human-induced stress vary in space and time, because both stressors and ecosystem vulnerabilities vary in space and time. Presently, ecosystem impact assessments mainly take into account variation in stressors, without considering variation in ecosystem vulnerability. We developed a method to address ecosystem vulnerability variation by quantifying ecosystem vulnerability distributions (EVDs) based on monitoring data of local species compositions and environmental conditions. The method incorporates spatial variation of both abiotic and biotic variables to quantify variation in responses among species and ecosystems. We show that EVDs can be derived based on a selection of locations, existing monitoring data and a selected impact boundary, and can be used in stressor identification and ranking for a region. A case study on Ohio's freshwater ecosystems, with freshwater fish as target species group, showed that physical habitat impairment and nutrient loads ranked highest as current stressors, with species losses higher than 5% for at least 6% of the locations. EVDs complement existing approaches of stressor assessment and management, which typically account only for variability in stressors, by accounting for variation in the vulnerability of the responding ecosystems.

Quantifying Geographic Variation in Health Care Outcomes in the United States before and after Risk-Adjustment.

PubMed

Rosenberg, Barry L; Kellar, Joshua A; Labno, Anna; Matheson, David H M; Ringel, Michael; VonAchen, Paige; Lesser, Richard I; Li, Yue; Dimick, Justin B; Gawande, Atul A; Larsson, Stefan H; Moses, Hamilton

2016-01-01

Despite numerous studies of geographic variation in healthcare cost and utilization at the local, regional, and state levels across the U.S., a comprehensive characterization of geographic variation in outcomes has not been published. Our objective was to quantify variation in US health outcomes in an all-payer population before and after risk-adjustment. We used information from 16 independent data sources, including 22 million all-payer inpatient admissions from the Healthcare Cost and Utilization Project (which covers regions where 50% of the U.S. population lives) to analyze 24 inpatient mortality, inpatient safety, and prevention outcomes. We compared outcome variation at state, hospital referral region, hospital service area, county, and hospital levels. Risk-adjusted outcomes were calculated after adjusting for population factors, co-morbidities, and health system factors. Even after risk-adjustment, there exists large geographical variation in outcomes. The variation in healthcare outcomes exceeds the well publicized variation in US healthcare costs. On average, we observed a 2.1-fold difference in risk-adjusted mortality outcomes between top- and bottom-decile hospitals. For example, we observed a 2.3-fold difference for risk-adjusted acute myocardial infarction inpatient mortality. On average a 10.2-fold difference in risk-adjusted patient safety outcomes exists between top and bottom-decile hospitals, including an 18.3-fold difference for risk-adjusted Central Venous Catheter Bloodstream Infection rates. A 3.0-fold difference in prevention outcomes exists between top- and bottom-decile counties on average; including a 2.2-fold difference for risk-adjusted congestive heart failure admission rates. The population, co-morbidity, and health system factors accounted for a range of R2 between 18-64% of variability in mortality outcomes, 3-39% of variability in patient safety outcomes, and 22-70% of variability in prevention outcomes. The amount of variability in health outcomes in the U.S. is large even after accounting for differences in population, co-morbidities, and health system factors. These findings suggest that: 1) additional examination of regional and local variation in risk-adjusted outcomes should be a priority; 2) assumptions of uniform hospital quality that underpin rationale for policy choices (such as narrow insurance networks or antitrust enforcement) should be challenged; and 3) there exists substantial opportunity for outcomes improvement in the US healthcare system.

Vertical gradients and seasonal variation in stem CO2 efflux within a Norway spruce stand.

PubMed

Tarvainen, Lasse; Räntfors, Mats; Wallin, Göran

2014-05-01

Stem CO2 efflux is known to vary seasonally and vertically along tree stems. However, annual tree- and stand-scale efflux estimates are commonly based on measurements made only a few times a year, during daytime and at breast height. In this study, the effect of these simplifying assumptions on annual efflux estimates and their influence on the estimates of the importance of stems in stand-scale carbon cycling are evaluated. In order to assess the strength of seasonal, diurnal and along-stem variability in CO2 efflux, half-hourly measurements were carried out at three heights on three mature Norway spruce (Picea abies (L.) Karst.) trees over a period of 3 years. Making the common assumption of breast height efflux rates being representative of the entire stem was found to result in underestimations of 10-17% in the annual tree-scale CO2 efflux. Upscaling using only daytime measurements from breast height increased the underestimation to 15-20%. Furthermore, the results show that the strength of the vertical gradient varies seasonally, being strongest in the early summer and non-existent during the cool months. The observed seasonality in the vertical CO2 efflux gradient could not be explained by variation in stem temperature, temperature response of the CO2 efflux (Q10), outer-bark permeability, CO2 transport in the xylem or CO2 release from the phloem. However, the estimated CO2 concentration immediately beneath the bark was considerably higher in the upper stem during the main period of diameter growth, coinciding with the strongest vertical efflux gradient. These results suggest that higher growth rates in the upper stem are the main cause for the observed vertical variation in the stem CO2 effluxes. Furthermore, the results indicate that accounting for the vertical efflux variation is essential for assessments of the importance of stems in stand-scale carbon cycling. © The Author 2014. Published by Oxford University Press. All rights reserved.

Ecological and sampling constraints on defining landscape fire severity

USGS Publications Warehouse

Key, C.H.

2006-01-01

Ecological definition and detection of fire severity are influenced by factors of spatial resolution and timing. Resolution determines the aggregation of effects within a sampling unit or pixel (alpha variation), hence limiting the discernible ecological responses, and controlling the spatial patchiness of responses distributed throughout a burn (beta variation). As resolution decreases, alpha variation increases, extracting beta variation and complexity from the spatial model of the whole burn. Seasonal timing impacts the quality of radiometric data in terms of transmittance, sun angle, and potential contrast between responses within burns. Detection sensitivity candegrade toward the end of many fire seasons when low sun angles, vegetation senescence, incomplete burning, hazy conditions, or snow are common. Thus, a need exists to supersede many rapid response applications when remote sensing conditions improve. Lag timing, or timesince fire, notably shapes the ecological character of severity through first-order effects that only emerge with time after fire, including delayed survivorship and mortality. Survivorship diminishes the detected magnitude of severity, as burned vegetation remains viable and resprouts, though at first it may appear completely charred or consumed above ground. Conversely, delayed mortality increases the severity estimate when apparently healthy vegetation is in fact damaged by heat to the extent that it dies over time. Both responses dependon fire behavior and various species-specific adaptations to fire that are unique to the pre-firecomposition of each burned area. Both responses can lead initially to either over- or underestimating severity. Based on such implications, three sampling intervals for short-term burn severity are identified; rapid, initial, and extended assessment, sampled within about two weeks, two months, and depending on the ecotype, from three months to one year after fire, respectively. Spatial and temporal conditions of sampling strategies constrain data quality and ecological information obtained about fire severity. Though commonly overlooked, such considerations determine the objectives and hypotheses that are appropriate for each application, and are especially important when building comparative studies or long-term reference databases on fire severity.

Exploring the workforce implications of a decade of medical school expansion: variations in medical school growth and changes in student characteristics and career plans.

PubMed

Shipman, Scott A; Jones, Karen C; Erikson, Clese E; Sandberg, Shana F

2013-12-01

To explore whether medical school enrollment growth may help address workforce priorities, including diversity, primary care, care for underserved populations, and academic faculty. The authors compared U.S. MD-granting medical schools, applicants, and matriculants immediately before expansion (1999-2001) and 10 years later (2009-2011). Using data from the American Medical Association Physician Masterfile and the Association of American Medical Colleges, they examined medical schools' past production of physicians and changes in matriculant characteristics and practice intentions. Among the 124 schools existing in 1999-2001, growth varied substantially. Additionally, 11 new schools enrolled students by 2009-2011. Aggregate enrollment increased by 16.6%. Increases in applicants led to a lower likelihood of matriculation for all but those with rural backgrounds, racial/ethnic minorities, applicants >24 years old, and those with Medical College Admission Test scores > 33. The existing schools that expanded most had a history of producing the highest percentages of physicians practicing in primary care and in underserved and rural areas; those that expanded least had produced the greatest percentage of faculty. Compared with existing schools, new schools enrolled higher percentages of racial/ethnic minorities and of students with limited parental education or lower income. Matriculants' interest in primary care careers showed no decline; interest in practicing with underserved populations increased, while interest in rural practice declined. Despite expansion, the characteristics of matriculating medical students changed little, except at new schools. Further expansion may benefit from targeted consideration of workforce needs.

Educational inequalities in self-rated health across US states and European countries.

PubMed

Präg, Patrick; Subramanian, S V

2017-07-01

The US shows a distinct health disadvantage when compared to other high-income nations. A potential lever to reduce this disadvantage is to improve the health situation of lower socioeconomic groups. Our objective is to explore how the considerable within-US variation in health inequalities compares to the health inequalities across other Western countries. Representative survey data from 44 European countries and the US federal states were obtained from the fourth wave of the European Values Study (EVS) and the 2008 wave of the Behavioral Risk Factor Surveillance System. Using binary logistic regression, we analyze different forms of educational inequalities in self-rated health (SRH), adjusted for age and sex. The extent of educational inequalities in SRH varies considerably over European countries and US states; with US states in general showing greater inequality, however, differences between US states and European countries are less clear than commonly assumed. The US has considerable differences in educational inequalities in SRH across geographic locations. To understand the reasons for the US health disadvantage, comparative research has to take into account the vast variation in health inequalities within the US.

Alternative Aviation Jet Fuel Sustainability Evaluation Report Task 1 : Report Evaluating Existing Sustainability Evaluation Programs

DOT National Transportation Integrated Search

2011-10-25

This report describes how existing biofuel sustainability evaluation programs meet requirements that are under consideration or are in early phases of adoption and implementation in various US and international contexts. Biofuel sustainability evalua...

Simulating the Stability of Colloidal Amorphous Iron Oxide in Natural Water

EPA Science Inventory

Considerable uncertainty exists as to whether existing thermodynamic equilibrium solid/water partitioning paradigms can be used to assess the mobility of insoluble manufactured nanomaterials in the aquatic environment. In this work, the traditional Derjaguin–Landau–Verwey–Overbee...

Feasibility study of an aerospace museum in the western United States. Volume 1: Summary, conclusions, and recommendations

NASA Technical Reports Server (NTRS)

1972-01-01

A survey of existing aerospace museums in the U.S. and a study of the feasibility of establishing an aerospace museum in the western U.S. are summarized. It is recommended that prime consideration be given to carefully considered support of development of existing aerospace exhibits rather than establishment of a new major museum. In the event that the decision is made to pursue the establishment of a new museum, Los Angeles is considered to be the most favorable location. In particular, because of the large attendance and existing building space at the California Museum of Science and Industry at Los Angeles, it is recommended that this museum's proposal be given first consideration. Supporting surveys of aerospace museums, funding, and related studies are also summarized.

Diffuse nitrogen loss simulation and impact assessment of stereoscopic agriculture pattern by integrated water system model and consideration of multiple existence forms

NASA Astrophysics Data System (ADS)

Zhang, Yongyong; Gao, Yang; Yu, Qiang

2017-09-01

Agricultural nitrogen loss becomes an increasingly important source of water quality deterioration and eutrophication, even threatens water safety for humanity. Nitrogen dynamic mechanism is still too complicated to be well captured at watershed scale due to its multiple existence forms and instability, disturbance of agricultural management practices. Stereoscopic agriculture is a novel agricultural planting pattern to efficiently use local natural resources (e.g., water, land, sunshine, heat and fertilizer). It is widely promoted as a high yield system and can obtain considerable economic benefits, particularly in China. However, its environmental quality implication is not clear. In our study, Qianyanzhou station is famous for its stereoscopic agriculture pattern of Southern China, and an experimental watershed was selected as our study area. Regional characteristics of runoff and nitrogen losses were simulated by an integrated water system model (HEQM) with multi-objective calibration, and multiple agriculture practices were assessed to find the effective approach for the reduction of diffuse nitrogen losses. Results showed that daily variations of runoff and nitrogen forms were well reproduced throughout watershed, i.e., satisfactory performances for ammonium and nitrate nitrogen (NH4-N and NO3-N) loads, good performances for runoff and organic nitrogen (ON) load, and very good performance for total nitrogen (TN) load. The average loss coefficient was 62.74 kg/ha for NH4-N, 0.98 kg/ha for NO3-N, 0.0004 kg/ha for ON and 63.80 kg/ha for TN. The dominating form of nitrogen losses was NH4-N due to the applied fertilizers, and the most dramatic zones aggregated in the middle and downstream regions covered by paddy and orange orchard. In order to control diffuse nitrogen losses, the most effective practices for Qianyanzhou stereoscopic agriculture pattern were to reduce farmland planting scale in the valley by afforestation, particularly for orchard in the downstream regions, followed by fertilizer application optimization.

Morphology, sedimentary features and evolution of a large palaeo submarine canyon in Qiongdongnan basin, Northern South China Sea

NASA Astrophysics Data System (ADS)

Li, Xiangquan; Fairweather, Luke; Wu, Shiguo; Ren, Jianye; Zhang, Hongjie; Quan, Xiayun; Jiang, Tao; Zhang, Cheng; Su, Ming; He, Yunlong; Wang, Dawei

2013-01-01

The large Miocene-aged palaeo canyon that extents through the Qiongdongnan basin (QDNB) and Yinggehai basin (YGHB) of Northern South China Sea has been of considerable interest both economically and scientifically over the past decade. Stemmed from this, significant research has been employed into understanding the mechanism for its existence, incision, and sedimentary fill, yet debate remains. In the first case the canyon itself is actually quite anomalous. Alone from the size (over 570 km in length and more than 8 km in width (Yuan et al., 2009)), which is considerably more than most ancient deep-water channels (REFS), the canyon's sedimentary fill is also distinctly different. Some explanations have been given to explain the canyon's origin and existence, these include increased sediment supply from the Red River which is genetically linked to uplift of the Tibetan Plateau, lowstand turbidite and mass-transport activity, reactivation and dextral displacement of the Red River Fault zone inducing erosive gravity-flows, regional tilt of the QDNB and YGHB, paleo-seafloor morphology and seal-level fluctuations. With the application of new data obtained from interpretations of a large number of 2D seismic profiles, core and well log data, and tectonic and sedimentary analysis this contribution aims to: (1) Present models to explain the Canyon's sedimentary fill and basin plain deposits, which provided significant understanding of processes pre-, syn- and post-incision and; (2) review the plausibility and likelihood of each of the controlling mechanisms, hoping to shed light on this controversial aspect. We conclude that the final erosive event that shaped the canyon is dated at 5.5 Ma. The Canyon's unusual fill is a product of variation in the interaction between turbidity currents and MTD that blocked the canyon's axis, and the reduction in gravity flow energy through time; and therefore the complete succession represents one major erosive and cut event at 5.5 Ma and thereafter multi-gravity currents fills unlike in most slope channel-fills.

Prevalence, outcome, and women's experiences of external cephalic version in a low-risk population.

PubMed

Rijnders, Marlies; Offerhaus, Pien; van Dommelen, Paula; Wiegers, Therese; Buitendijk, Simone

2010-06-01

Until recently, external cephalic version to prevent breech presentation at birth was not widely accepted. The objective of our study was to assess the prevalence, outcomes, and women's experiences of external cephalic version to improve the implementation of the procedure in the Netherlands. A prospective cohort study was conducted of 167 women under the care of a midwife with confirmed breech presentation at a gestational age of 33 completed weeks or more. Between June 2007 and January 2008, 167 women with a confirmed breech presentation were offered an external cephalic version. Of this group, 123 women (73.7%, 95% CI: 65.5-80.5) subsequently received the version. These women had about a ninefold increased probability of a cephalic presentation at birth compared with women who did not undergo a version (relative risk [RR]: 8.8, 95% CI: 2.2-34.8). The chance of a vaginal birth after an external cephalic version was almost threefold (RR: 2.7, 95% CI: 1.5-5.0). The success rate was 39 percent, although considerable differences existed associated with region and parity. Ninety-four percent of women with a successful version rated it as a good experience compared with 71 percent of women who had a failed version (p = 0.015). Significant pain during the version was experienced by 34 percent of women, of whom 18 percent also experienced fear during the version, compared with no women who reported little or no pain (p = 0.006). Women who reported significant pain or fear during the version experienced the version more negatively (OR: 6.0, 95% CI: 3.3-12.2 and OR: 2.7, 95% CI: 1.1-6.0, respectively). One in every four women with a breech presentation in independent midwifery care did not receive an external cephalic version. Of the women who received a version one third experienced significant pain during the procedure. Considerable regional variation in success rate existed.

High diversity of tropical peatland ecosystem types in the Pastaza-Marañón basin, Peruvian Amazonia

NASA Astrophysics Data System (ADS)

LäHteenoja, Outi; Page, Susan

2011-06-01

Very little information exists on Amazonian peatlands with most studies on tropical peatlands concentrating on Southeast Asia. Here we describe diversity of Amazonian peatland ecosystems and consider its implications for the global diversity of tropical peatland ecosystems. Nine study sites were selected from within the most extensive wetland area of Peruvian Amazonia: the 120,000 km2 Pastaza-Marañón basin. Peat thickness was determined every 500 m from the edge toward the center of each site, and peat samples were collected from two cores per site. Samples from the entire central core and surface samples from the other core were analyzed for nutrient content. Topography of four peat deposits was measured. In order to study differences in vegetation, pixel values were extracted from a satellite image. The surface peat nutrient content of the peatlands varied from very nutrient-rich to nutrient-poor. Two of the peatlands measured for their topography were domed (5.4 and 5.8 m above the stream), one was gently sloping (1.4 m above the stream), and one was flat and occurred behind a 7 m high levee. Five different peatland vegetation types were detected on the basis of pixel values derived from the satellite image. The peat cores had considerable variation in nutrient content and showed different developmental pathways. In summary, the Pastaza-Marañón basin harbors a considerable diversity of previously undescribed peatland ecosystems, representing a gradient from atmosphere-influenced, nutrient-poor ombrotrophic bogs through to river-influenced, nutrient-rich swamps. Their existence affects the habitat diversity, carbon dynamics, and hydrology of the Amazonian lowlands, and they also provide an undisturbed analog for the heavily disturbed peatlands of Southeast Asia. Considering the factors threatening the Amazonian lowlands, there is an urgent need to investigate and conserve these peatland ecosystems, which may in the near future be among the very few undisturbed tropical ombrotrophic bogs remaining in the world.

Public Drug Plan Coverage for Children Across Canada: A Portrait of Too Many Colours

PubMed Central

Ungar, Wendy J; Witkos, Maciej

2005-01-01

Background: As debate continues regarding pharmacare in Canada, little discussion has addressed appropriate drug plan coverage for vulnerable populations, such as children. The primary objective of this study was to determine the extent of medication coverage for children in publicly administered programs in each province across Canada. Methods: Data were collected on provincial, territorial and federal government drug plans, and 2003 formulary updates were obtained. A simulation model was constructed to demonstrate costs to a low-income family with an asthmatic child in each province. Programs were compared descriptively. The extent of interprovincial variation in 2003 formulary approvals was summarized statistically. Results: There was 39% variation between provinces with respect to 2003 formulary approvals (chi-square p < 0.0001) and 48% variation for 2003 paediatric-labelled products (chi-square p < 0.0001). Across Canada, only 8% of 2003 formulary approvals were indicated primarily for paediatric conditions. In the simulation model, costs were less than or equal to 3% of household income in provinces with plans for low-income families, catastrophic costs (Ontario) or for the population. Families who failed to qualify for low income plans or who resided in New Brunswick or Newfoundland faced costs up to 7% of household income. Interpretation: With regard to pharmaceutical benefits for children, provincial drug programs vary considerably in terms of whom they cover, what drugs are covered and how much subscribers must pay out of pocket. Unlike seniors and social assistance recipients, the provinces do not agree on the importance of providing comprehensive coverage for all children. For many Canadian children, significant financial barriers exist to medication access. PMID:19308106

Gene network polymorphism is the raw material of natural selection: the selfish gene network hypothesis.

PubMed

Boldogköi, Zsolt

2004-09-01

Population genetics, the mathematical theory of modern evolutionary biology, defines evolution as the alteration of the frequency of distinct gene variants (alleles) differing in fitness over the time. The major problem with this view is that in gene and protein sequences we can find little evidence concerning the molecular basis of phenotypic variance, especially those that would confer adaptive benefit to the bearers. Some novel data, however, suggest that a large amount of genetic variation exists in the regulatory region of genes within populations. In addition, comparison of homologous DNA sequences of various species shows that evolution appears to depend more strongly on gene expression than on the genes themselves. Furthermore, it has been demonstrated in several systems that genes form functional networks, whose products exhibit interrelated expression profiles. Finally, it has been found that regulatory circuits of development behave as evolutionary units. These data demonstrate that our view of evolution calls for a new synthesis. In this article I propose a novel concept, termed the selfish gene network hypothesis, which is based on an overall consideration of the above findings. The major statements of this hypothesis are as follows. (1) Instead of individual genes, gene networks (GNs) are responsible for the determination of traits and behaviors. (2) The primary source of microevolution is the intraspecific polymorphism in GNs and not the allelic variation in either the coding or the regulatory sequences of individual genes. (3) GN polymorphism is generated by the variation in the regulatory regions of the component genes and not by the variance in their coding sequences. (4) Evolution proceeds through continuous restructuring of the composition of GNs rather than fixing of specific alleles or GN variants.

Time-dependent inversions of slow slip at the Hikurangi subduction zone, New Zealand, using numerical Green's functions

NASA Astrophysics Data System (ADS)

Williams, C. A.; Wallace, L. M.; Bartlow, N. M.

2017-12-01

Slow slip events (SSEs) have been observed throughout the world, and the existence of these events has fundamentally altered our understanding of the possible ranges of slip behavior at subduction plate boundaries. In New Zealand, SSEs occur along the Hikurangi Margin, with shallower events in the north and deeper events to the south. In a recent study, Williams and Wallace (2015) found that static SSE inversions that consider elastic property variations provided significantly different results than those based on an elastic half-space. For deeper events, the heterogeneous models predicted smaller amounts of slip, while for shallower events the heterogeneous model predicted larger amounts of slip. In this study, we extend our initial work to examine the temporal variations in slip. We generate Green's functions using the PyLith finite element code (Aagaard et al., 2013) to allow consideration of elastic property variations provided by the New Zealand-wide seismic velocity model (Eberhart-Phillips et al., 2010). These Green's functions are then integrated to provide Green's functions compatible with the Network Inversion Filter (NIF, Segall and Matthews,1997; McGuire and Segall, 2003; Miyazaki et al.,2006). We examine 12 SSEs occurring along the Hikurangi Margin during 2010 and 2011, and compare the results using heterogeneous Green's functions with those of Bartlow et al. (2014), who examined the same set of SSEs with the NIF using a uniform elastic half-space model. The use of heterogeneous Green's functions should provide a more accurate picture of the slip distribution and evolution of the SSEs. This will aid in understanding the correlations between SSEs and seismicity and/or tremor and the role of SSEs in the accommodation of plate motion budgets in New Zealand.

A Cross-Sectional Review of Reporting Variation in Postoperative Bowel Dysfunction After Rectal Cancer Surgery.

PubMed

Chapman, Stephen J; Bolton, William S; Corrigan, Neil; Young, Neville; Jayne, David G

2017-02-01

Postoperative bowel dysfunction affects quality of life after sphincter-preserving rectal cancer surgery, but the extent of the problem is not clearly defined because of inconsistent outcome measures used to characterize the condition. The purpose of this study was to assess variation in the reporting of postoperative bowel dysfunction and to make recommendations for standardization in future studies. If possible, a quantitative synthesis of bowel dysfunction symptoms was planned. MEDLINE and EMBASE databases, as well as the Cochrane Library, were queried systematically between 2004 and 2015. The studies selected reported at least 1 component of bowel dysfunction after resection of rectal cancer. The main outcome measures were reporting, measurement, and definition of postoperative bowel dysfunction. Of 5428 studies identified, 234 met inclusion criteria. Widely reported components of bowel dysfunction were incontinence to stool (227/234 (97.0%)), frequency (168/234 (71.8%)), and incontinence to flatus (158/234 (67.5%)). Urgency and stool clustering were reported less commonly, with rates of 106 (45.3%) of 234 and 61 (26.1%) of 234. Bowel dysfunction measured as a primary outcome was associated with better reporting (OR = 3.49 (95% CI, 1.99-6.23); p < 0.001). Less than half of the outcomes were assessed using a dedicated research tool (337/720 (46.8%)), and the remaining descriptive measures were infrequently defined (56/383 (14.6%)). Heterogeneity in the reporting, measurement, and definition of postoperative bowel dysfunction precluded pooling of results and limited interpretation. Considerable variation exists in the reporting, measurement, and definition of postoperative bowel dysfunction. These inconsistencies preclude reliable estimates of incidence and meta-analysis. A broadly accepted outcome measure may address this deficit in future studies.

Morphological and Genetic Variation along a North-to-South Transect in Stipa purpurea, a Dominant Grass on the Qinghai-Tibetan Plateau: Implications for Response to Climate Change

PubMed Central

You, Jianling; Qi, Danhui; Zhou, Yin; Chen, Jiakuan; Song, Zhiping

2016-01-01

Estimating the potential of species to cope with rapid environmental climatic modifications is of vital importance for determining their future viability and conservation. The variation between existing populations along a climatic gradient may predict how a species will respond to future climate change. Stipa purpurea is a dominant grass species in the alpine steppe and meadow of the Qinghai-Tibetan Plateau (QTP). Ecological niche modelling was applied to S. purpurea, and its distribution was found to be most strongly correlated with the annual precipitation and the mean temperature of the warmest quarter. We established a north-to-south transect over 2000 km long on the QTP reflecting the gradients of temperature and precipitation, and then we estimated the morphological by sampling fruited tussocks and genetic divergence by using 11 microsatellite markers between 20 populations along the transect. Reproductive traits (the number of seeds and reproductive shoots), the reproductive-vegetative growth ratio and the length of roots in the S. purpurea populations varied significantly with climate variables. S. purpurea has high genetic diversity (He = 0.585), a large effective population size (Ne >1,000), and a considerable level of gene flow between populations. The S. purpurea populations have a mosaic genetic structure: some distant populations (over 1000 km apart) clustered genetically, whereas closer populations (< 100 km apart) had diverged significantly, suggesting local adaptation. Asymmetrical long-distance inter-population gene flow occurs along the sampling transect and might be mediated by seed dispersal via migratory herbivores, such as the chiru (Pantholops hodgsonii). These findings suggest that population performance variation and gene flow both facilitate the response of S. purpurea to climate change. PMID:27580056

Morphological and Genetic Variation along a North-to-South Transect in Stipa purpurea, a Dominant Grass on the Qinghai-Tibetan Plateau: Implications for Response to Climate Change.

PubMed

Liu, Wensheng; Zhao, Yao; You, Jianling; Qi, Danhui; Zhou, Yin; Chen, Jiakuan; Song, Zhiping

2016-01-01

Estimating the potential of species to cope with rapid environmental climatic modifications is of vital importance for determining their future viability and conservation. The variation between existing populations along a climatic gradient may predict how a species will respond to future climate change. Stipa purpurea is a dominant grass species in the alpine steppe and meadow of the Qinghai-Tibetan Plateau (QTP). Ecological niche modelling was applied to S. purpurea, and its distribution was found to be most strongly correlated with the annual precipitation and the mean temperature of the warmest quarter. We established a north-to-south transect over 2000 km long on the QTP reflecting the gradients of temperature and precipitation, and then we estimated the morphological by sampling fruited tussocks and genetic divergence by using 11 microsatellite markers between 20 populations along the transect. Reproductive traits (the number of seeds and reproductive shoots), the reproductive-vegetative growth ratio and the length of roots in the S. purpurea populations varied significantly with climate variables. S. purpurea has high genetic diversity (He = 0.585), a large effective population size (Ne >1,000), and a considerable level of gene flow between populations. The S. purpurea populations have a mosaic genetic structure: some distant populations (over 1000 km apart) clustered genetically, whereas closer populations (< 100 km apart) had diverged significantly, suggesting local adaptation. Asymmetrical long-distance inter-population gene flow occurs along the sampling transect and might be mediated by seed dispersal via migratory herbivores, such as the chiru (Pantholops hodgsonii). These findings suggest that population performance variation and gene flow both facilitate the response of S. purpurea to climate change.

The Costs of Delivering Integrated HIV and Sexual Reproductive Health Services in Limited Resource Settings.

PubMed

Obure, Carol Dayo; Sweeney, Sedona; Darsamo, Vanessa; Michaels-Igbokwe, Christine; Guinness, Lorna; Terris-Prestholt, Fern; Muketo, Esther; Nhlabatsi, Zelda; Warren, Charlotte E; Mayhew, Susannah; Watts, Charlotte; Vassall, Anna

2015-01-01

To present evidence on the total costs and unit costs of delivering six integrated sexual reproductive health and HIV services in a high and medium HIV prevalence setting, in order to support policy makers and planners scaling up these essential services. A retrospective facility based costing study conducted in 40 non-government organization and public health facilities in Kenya and Swaziland. Economic and financial costs were collected retrospectively for the year 2010/11, from each study site with an aim to estimate the cost per visit of six integrated HIV and SRH services. A full cost analysis using a combination of bottom-up and step-down costing methods was conducted from the health provider's perspective. The main unit of analysis is the economic unit cost per visit for each service. Costs are converted to 2013 International dollars. The mean cost per visit for the HIV/SRH services ranged from $Int 14.23 (PNC visit) to $Int 74.21 (HIV treatment visit). We found considerable variation in the unit costs per visit across settings with family planning services exhibiting the least variation ($Int 6.71-52.24) and STI treatment and HIV treatment visits exhibiting the highest variation in unit cost ranging from ($Int 5.44-281.85) and ($Int 0.83-314.95), respectively. Unit costs of visits were driven by fixed costs while variability in visit costs across facilities was explained mainly by technology used and service maturity. For all services, variability in unit costs and cost components suggest that potential exists to reduce costs through better use of both human and capital resources, despite the high proportion of expenditure on drugs and medical supplies. Further work is required to explore the key drivers of efficiency and interventions that may facilitate efficiency improvements.

Object Classification With Joint Projection and Low-Rank Dictionary Learning.

PubMed

Foroughi, Homa; Ray, Nilanjan; Hong Zhang

2018-02-01

For an object classification system, the most critical obstacles toward real-world applications are often caused by large intra-class variability, arising from different lightings, occlusion, and corruption, in limited sample sets. Most methods in the literature would fail when the training samples are heavily occluded, corrupted or have significant illumination or viewpoint variations. Besides, most of the existing methods and especially deep learning-based methods, need large training sets to achieve a satisfactory recognition performance. Although using the pre-trained network on a generic large-scale data set and fine-tune it to the small-sized target data set is a widely used technique, this would not help when the content of base and target data sets are very different. To address these issues simultaneously, we propose a joint projection and low-rank dictionary learning method using dual graph constraints. Specifically, a structured class-specific dictionary is learned in the low-dimensional space, and the discrimination is further improved by imposing a graph constraint on the coding coefficients, that maximizes the intra-class compactness and inter-class separability. We enforce structural incoherence and low-rank constraints on sub-dictionaries to reduce the redundancy among them, and also make them robust to variations and outliers. To preserve the intrinsic structure of data, we introduce a supervised neighborhood graph into the framework to make the proposed method robust to small-sized and high-dimensional data sets. Experimental results on several benchmark data sets verify the superior performance of our method for object classification of small-sized data sets, which include a considerable amount of different kinds of variation, and may have high-dimensional feature vectors.

Variation in Management of Fever and Neutropenia Among Pediatric Patients with Cancer: A Survey of Providers in Michigan

PubMed Central

Mueller, Emily L.; Walkovich, Kelly J.; Yanik, Gregory A.; Clark, Sarah J.

2016-01-01

Considerable variation in the management of fever and neutropenia (FN) exists, with factors associated with treatment variation not well described. An on-line survey of 90 pediatric cancer providers in Michigan was performed in Spring 2014. The survey frame was pediatric patients with cancer receiving treatment, with a Port-a-cath, who were clinically stable. Criteria for “Decreased” and “Increased” risk groups were defined by respondents. Survey questions addressed FN definitions, risk groups conceptualization, routine clinical practice, and management guidelines, in the context of risk groups and distance to treating institution. Fifty providers responded (56%), the majority defined a febrile event as temperature >38.3°C and/or two events > 38.0°C within a 24-hour period. Neutropenia was defined as current or anticipated absolute neutrophil count (ANC) <500/μL. Majority of respondents recommended “Decreased” and “Increased” patients present to a local emergency department (ED) if they live >2 hours away. Respondents were significantly more likely to have a “Decreased Risk” patient travel over 2 hours if they rated the local ED as “Poor to Fair” on ability to access Port-a-caths (p 0.048). Most respondents would discharge patients who are afebrile for 24 hours, blood cultures negative for 48 hours, and neutrophil count of greater than 200/μL. 40% preferred discharge on oral antibiotics when the ANC<500/μL. Triaging for febrile pediatric patients with cancer is significantly influenced by the providers’ perceptions of local EDs. Future investigation of local hospitals’ ability to provide urgent evaluation, combined with parental perspectives could lead to improvements in timely and effective management. PMID:26086779

Variation in Management of Fever and Neutropenia Among Pediatric Patients With Cancer: A Survey of Providers in Michigan.

PubMed

Mueller, Emily L; Walkovich, Kelly J; Yanik, Gregory A; Clark, Sarah J

2015-01-01

Considerable variation in the management of fever and neutropenia (FN) exists, with factors associated with treatment variation not well described. An online survey of 90 pediatric cancer providers in Michigan was performed in Spring 2014. The survey frame was pediatric patients with cancer receiving treatment, with a Port-a-cath, who were clinically stable. Criteria for "Decreased" and "Increased" risk groups were defined by respondents. Survey questions addressed FN definitions, risk groups conceptualization, routine clinical practice, and management guidelines, in the context of risk groups and distance to treating institution. Fifty providers responded (56%); the majority defined a febrile event as temperature >38.3°C and/or 2 events >38.0°C within a 24-hour period. Neutropenia was defined as current or anticipated absolute neutrophil count (ANC) <500/μL. Majority of respondents recommended "Decreased" and "Increased" patients present to a local emergency department (ED) if they live >2 hours away. Respondents were significantly more likely to have a "Decreased Risk" patient travel over 2 hours if they rated the local ED as "Poor to Fair" on ability to access Port-a-caths (P = .048). Most respondents would discharge patients who are afebrile for 24 hours, blood cultures negative for 48 hours, and neutrophil count of greater than 200/μL; 40% preferred discharge on oral antibiotics when the ANC <500/μL. Triaging for febrile pediatric patients with cancer is significantly influenced by the providers' perceptions of local EDs. Future investigation of local hospitals' ability to provide urgent evaluation, combined with parental perspectives, could lead to improvements in timely and effective management.

Solutions to variational inequalities of parabolic type

NASA Astrophysics Data System (ADS)

Zhu, Yuanguo

2006-09-01

The existence of strong solutions to a kind of variational inequality of parabolic type is investigated by the theory of semigroups of linear operators. As an application, an abstract semi permeable media problem is studied.

Characterization of Relatively Large Track Geometry Variations

DOT National Transportation Integrated Search

1982-03-01

An analysis of existing track geometry data is described from which the signatures of key track geometry variations related to severe track-train dynamic interaction are identified and quantified. Mathematical representations of these signatures are ...

Instructional Design Considerations in Converting Non-CBT Materials into CBT Courses.

ERIC Educational Resources Information Center

Ng, Raymond

Instructional designers who are asked to convert existing training materials into computer-based training (CBT) must take special precautions to avoid making the product into a sophisticated page turner. Although conversion may save considerable time on subject research and analysis, courses to be delivered through microcomputers may require…

32 CFR Enclosure 1 to Part 187 - Requirements for Environmental Considerations-Global Commons

Code of Federal Regulations, 2014 CFR

2014-07-01

... environment of the global commons, an environmental impact statement, as described below, will be prepared to... duplication. If an environmental impact statement for a particular action already exists, regardless of what... implementation, or subject matter. 6. Tiering. Consideration should be given to tiering of environmental impact...

32 CFR Enclosure 1 to Part 187 - Requirements for Environmental Considerations-Global Commons

Code of Federal Regulations, 2013 CFR

2013-07-01

... environment of the global commons, an environmental impact statement, as described below, will be prepared to... duplication. If an environmental impact statement for a particular action already exists, regardless of what... implementation, or subject matter. 6. Tiering. Consideration should be given to tiering of environmental impact...

Considerations Before Writing a Public Library Building Program in Children's Services.

ERIC Educational Resources Information Center

Hektoen, Faith

Designed to be useful for the assessment of existing collections and facilities as well as for planning new libraries, these guidelines detail specific needs, considerations and possibilities, and specifications for both materials and area planning. The materials section includes separate treatment for various types of books and other…

Education as Experimentation: A Planned Variation Model. Volume IV-E. Supplementary Analyses: Reanalysis of Selected Data Sets. Volume IV-F. Supplementary Analyses: Appendix.

ERIC Educational Resources Information Center

Proper, Elizabeth C.; And Others

This segment of the national evaluation study of the Follow Through Planned Variation Model discusses findings of analyses of achievement test data which have been adjusted to take into consideration the preschool experience of children in three Follow Through cohorts. These analyses serve as a supplement to analyses presented in Volume IV-A of…

Socio-demographic diversity and unexplained variation in death rates among the most deprived parliamentary constituencies in Britain.

PubMed

Tunstall, H; Mitchell, R; Gibbs, J; Platt, S; Dorling, D

2012-06-01

There is considerable unexplained variation in death rates between deprived areas of Britain. This analysis assesses the degree of variation in socio-demographic factors among deprivation deciles and how variables associated with deaths differ among the most deprived areas. Death rates 1996-2001, Carstairs' 2001 deprivation score and indicators, population density, black and minority ethnic group (BME) and population change 1971-2001 were calculated for 641 parliamentary constituencies in Britain. Constituencies were grouped into Carstairs' deciles. We assessed standard errors of all variables by decile and the relationship between death rates and socio-demographic variables with Pearson's correlations and linear regression by decile and for all constituencies combined. Standard errors in death rates and most socio-demographic variables were greatest for the most deprived decile. Death rates among all constituencies were positively correlated with Carstairs' score and indicators, density and BME, but for the most deprived decile, there was no association with Carstairs and a negative correlation with overcrowding, density and BME. For the most deprived decile multivariate models containing population density, BME and change had substantially higher R(2). Understanding variations in death rates between deprived areas requires greater consideration of their socio-demographic diversity including their population density, ethnicity and migration.

Molecular and morphological variation of Paragonimus westermani in Vietnam with records of new second intermediate crab hosts and a new locality in a northern province.

PubMed

Doanh, N Pham; Tu, A Luu; Bui, T Dung; Loan, T Ho; Nonaka, Nariaki; Horii, Yoichiro; Blair, David; Nawa, Yukifumi

2016-10-01

Paragonimus westermani is one of the most medically important lung flukes and is widely distributed in Asia. It exhibits considerable variation in morphological, genetic and biological features. In central provinces of Vietnam, a high prevalence of metacercariae of this species has been reported from the crab intermediate host, Vietopotamon aluoiense. In this study, we detected P. westermani metacercariae in two additional crab hosts, Donopotamon haii in Quang Tri Province, central Vietnam and Indochinamon tannanti in Yen Bai Province in the north. The latter is a new locality for P. westermani in a northern region of Vietnam where P. heterotremus is the only species currently known to cause human paragonimiasis. Paragonimus westermani metacercariae found in Vietnam showed considerable morphological variation but slight genetic variation based on DNA sequences from the nuclear ribosomal ITS2 region and the mitochondrial 16S gene. Co-infection of the same individual crabs with P. westermani and P. heterotremus and/or some other Paragonimus species was found frequently, suggesting potential for co-infection in humans. The findings of the present study emphasize the need for highly specific molecular and immunodiagnostic methods to differentially diagnose between P. westermani and P. heterotremus infections.

Yellowstone bison genetics: let us move forward

USGS Publications Warehouse

Halbert, Natalie D.; Gogan, Peter J.P.; Hedrick, Philip W.; Wahl, Jacquelyn M.; Derr, James N.

2012-01-01

White and Wallen (2012) disagree with the conclusions and suggestions made in our recent assessment of population structure among Yellowstone National Park (YNP) bison based on 46 autosomal microsatellite loci in 661 animals (Halbert et al. 2012). First, they suggest that "the existing genetic substructure (that we observed) was artificially created." Specifically, they suggest that the substructure observed between the northern and central populations is the result of human activities, both historical and recent. In fact, the genetic composition of all known existing bison herds was created by, or has been influenced by, anthropogenic activities, although this obviously does not reduce the value of these herds for genetic conservation (Dratch and Gogan 2010). As perspective, many, if not most, species of conservation concern have been influenced by human actions and as a result currently exist as isolated populations. However, it is quite difficult to distinguish between genetic differences caused by human actions and important ancestral variation contained in separate populations without data from early time periods. Therefore, to not lose genetic variation that may be significant or indicative of important genetic variation, the generally acceptable management approach is to attempt to retain this variation based on the observed population genetic subdivision (Hedrick et al. 1986).

The behavioral ecology of cultural psychological variation.

PubMed

Sng, Oliver; Neuberg, Steven L; Varnum, Michael E W; Kenrick, Douglas T

2018-04-23

Recent work has documented a wide range of important psychological differences across societies. Multiple explanations have been offered for why such differences exist, including historical philosophies, subsistence methods, social mobility, social class, climactic stresses, and religion. With the growing body of theory and data, there is an emerging need for an organizing framework. We propose here that a behavioral ecological perspective, particularly the idea of adaptive phenotypic plasticity, can provide an overarching framework for thinking about psychological variation across cultures and societies. We focus on how societies vary as a function of six important ecological dimensions: density, relatedness, sex ratio, mortality likelihood, resources, and disease. This framework can: (a) highlight new areas of research, (b) integrate and ground existing cultural psychological explanations, (c) integrate research on variation across human societies with research on parallel variations in other animal species, (d) provide a way for thinking about multiple levels of culture and cultural change, and (e) facilitate the creation of an ecological taxonomy of societies, from which one can derive specific predictions about cultural differences and similarities. Finally, we discuss the relationships between the current framework and existing perspectives. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

The Improved Hydrological Gravity Model for Moxa Observatory, Germany

NASA Astrophysics Data System (ADS)

Weise, A.; Jahr, Th.

2017-04-01

The gravity variations observed by the superconducting gravimeter (SG) CD-034 at Moxa Geodynamic Observatory/Germany were compared with the GRACE results some years ago. The combination of a local hydrological model of a catchment area with a 3D-gravimetric model had been applied successfully for correcting the SG record of Moxa which is especially necessary due to the strong topography nearest to the SG location. Now, the models have been corrected and improved considerably by inserting several details in the very near surrounding. Mainly these are: the observatory building is inserted with the roof covered by a soil layer above the gravity sensor where humidity is varying, snow is placed on top of the roof and on topography (steep slope), and ground water is taken into account, additionally. The result is that the comparison of the corrected gravity residuals with gravity variations of the satellite mission GRACE, now using RL5 data, shows higher agreement, not only in amplitude but also the formerly apparent phase shift is obviously not realistic. The agreement between terrestrial gravity variations (SG) and the GRACE data is improved considerably which is discussed widely.

The Improved Hydrological Gravity Model for Moxa Observatory, Germany

NASA Astrophysics Data System (ADS)

Weise, A.; Jahr, Th.

2018-05-01

The gravity variations observed by the superconducting gravimeter (SG) CD-034 at Moxa Geodynamic Observatory/Germany were compared with the GRACE results some years ago. The combination of a local hydrological model of a catchment area with a 3D-gravimetric model had been applied successfully for correcting the SG record of Moxa which is especially necessary due to the strong topography nearest to the SG location. Now, the models have been corrected and improved considerably by inserting several details in the very near surrounding. Mainly these are: the observatory building is inserted with the roof covered by a soil layer above the gravity sensor where humidity is varying, snow is placed on top of the roof and on topography (steep slope), and ground water is taken into account, additionally. The result is that the comparison of the corrected gravity residuals with gravity variations of the satellite mission GRACE, now using RL5 data, shows higher agreement, not only in amplitude but also the formerly apparent phase shift is obviously not realistic. The agreement between terrestrial gravity variations (SG) and the GRACE data is improved considerably which is discussed widely.

Electrochemical kinetics and dimensional considerations, at the nanoscale

NASA Astrophysics Data System (ADS)

Yamada, H.; Bandaru, P. R.

2016-06-01

It is shown that the consideration of the density of states variation in nanoscale electrochemical systems yields modulations in the rate constant and concomitant electrical currents. The proposed models extend the utility of Marcus-Hush-Chidsey (MHC) kinetics to a larger class of materials and could be used as a test of dimensional character. The implications of the study are of much significance to an understanding and modulation of charge transfer nanostructured electrodes.

Strongly nonlinear parabolic variational inequalities.

PubMed

Browder, F E; Brézis, H

1980-02-01

An existence and uniqueness result is established for a general class of variational inequalities for parabolic partial differential equations of the form partial differentialu/ partial differentialt + A(u) + g(u) = f with g nondecreasing but satisfying no growth condition. The proof is based upon a type of compactness result for solutions of variational inequalities that should find a variety of other applications.

Test Format and the Variation of Gender Achievement Gaps within the United States

ERIC Educational Resources Information Center

Reardon, Sean; Fahle, Erin; Kalogrides, Demetra; Podolsky, Anne; Zarate, Rosalia

2016-01-01

Prior research demonstrates the existence of gender achievement gaps and the variation in the magnitude of these gaps across states. This paper characterizes the extent to which the variation of gender achievement gaps on standardized tests across the United States can be explained by differing state accountability test formats. A comprehensive…

Algal-bacterial co-variation in streams: a cross-stream comparison

Treesearch

Xueqing Gao; Ola A. Olapade; Mark W. Kershner; Laura G. Leff

2004-01-01

Algal-bacterial co-variation has been frequently observed in lentic and marine environments, but the existence of such relationships in lotic ecosystems is not well established. To examine possible co-variation, bacterial number and chlorophyll-a concentration in water and sediments of nine streams from different regions in the USA were examined. In the water, a strong...

Associations between dopamine D4 receptor gene variation with both infidelity and sexual promiscuity.

PubMed

Garcia, Justin R; MacKillop, James; Aller, Edward L; Merriwether, Ann M; Wilson, David Sloan; Lum, J Koji

2010-11-30

Human sexual behavior is highly variable both within and between populations. While sex-related characteristics and sexual behavior are central to evolutionary theory (sexual selection), little is known about the genetic bases of individual variation in sexual behavior. The variable number tandem repeats (VNTR) polymorphism in exon III of the human dopamine D4 receptor gene (DRD4) has been correlated with an array of behavioral phenotypes and may be predicatively responsible for variation in motivating some sexual behaviors, particularly promiscuity and infidelity. We administered an anonymous survey on personal history of sexual behavior and intimate relationships to 181 young adults. We also collected buccal wash samples and genotyped the DRD4 VNTR. Here we show that individuals with at least one 7-repeat allele (7R+) report a greater categorical rate of promiscuous sexual behavior (i.e., having ever had a "one-night stand") and report a more than 50% increase in instances of sexual infidelity. DRD4 VNTR genotype varies considerably within and among populations and has been subject to relatively recent, local selective pressures. Individual differences in sexual behavior are likely partially mediated by individual genetic variation in genes coding for motivation and reward in the brain. Conceptualizing these findings in terms of r/K selection theory suggests a mechanism for selective pressure for and against the 7R+ genotype that may explain the considerable global allelic variation for this polymorphism.

Associations between Dopamine D4 Receptor Gene Variation with Both Infidelity and Sexual Promiscuity

PubMed Central

Garcia, Justin R.; MacKillop, James; Aller, Edward L.; Merriwether, Ann M.; Wilson, David Sloan; Lum, J. Koji

2010-01-01

Background Human sexual behavior is highly variable both within and between populations. While sex-related characteristics and sexual behavior are central to evolutionary theory (sexual selection), little is known about the genetic bases of individual variation in sexual behavior. The variable number tandem repeats (VNTR) polymorphism in exon III of the human dopamine D4 receptor gene (DRD4) has been correlated with an array of behavioral phenotypes and may be predicatively responsible for variation in motivating some sexual behaviors, particularly promiscuity and infidelity. Methodology/Principal Findings We administered an anonymous survey on personal history of sexual behavior and intimate relationships to 181 young adults. We also collected buccal wash samples and genotyped the DRD4 VNTR. Here we show that individuals with at least one 7-repeat allele (7R+) report a greater categorical rate of promiscuous sexual behavior (i.e., having ever had a “one-night stand”) and report a more than 50% increase in instances of sexual infidelity. Conclusions/Significance DRD4 VNTR genotype varies considerably within and among populations and has been subject to relatively recent, local selective pressures. Individual differences in sexual behavior are likely partially mediated by individual genetic variation in genes coding for motivation and reward in the brain. Conceptualizing these findings in terms of r/K selection theory suggests a mechanism for selective pressure for and against the 7R+ genotype that may explain the considerable global allelic variation for this polymorphism. PMID:21152404

Construction Costs and Physico-chemical Properties of the Assimilatory Organs of Nepenthes Species in Northern Borneo

PubMed Central

Osunkoya, Olusegun O.; Daud, Siti Dayanawati; Di-Giusto, Bruno; Wimmer, Franz L.; Holige, Thippeswamy M.

2007-01-01

Background and Aims Species of the Nepenthaceae family are under-represented in studies of leaf traits and the consequent view of mineral nutrition and limitation in carnivorous plants. This study is aimed to complement existing data on leaf traits of carnivorous plants. Methods Physico-chemical properties, including construction costs (CC), of the assimilatory organs (leaf and pitcher) of a guild of lowland Nepenthes species inhabiting heath and/or peat swamp forests of Brunei, Northern Borneo were determined. Key Results Stoichiometry analyses indicate that Nepenthes species are nitrogen limited. Most traits vary appreciably across species, but greater variations exist between the assimilatory organs. Organ mass per unit area, dry matter tissue concentration (density), nitrogen (N), phosphorus (P), carbon, heat of combustion (Hc) and CC values were higher in the leaf relative to the pitcher, while organ thickness, potassium (K) and ash showed the opposite trend. Cross-species correlations indicate that joint rather than individual consideration of the leaf and the pitcher give better predictive relationships between variables, signalling tight coupling and functional interdependence of the two assimilatory organs. Across species, mass-based CC did not vary with N or P, but increases significantly with tissue density, carbon and Hc, and decreases with K and ash contents. Area-based CC gave the same trends (though weaker in strength) in addition to a significant positive correlation with tissue mass per unit area. Conclusions The lower CC value for the pitcher is in agreement with the concept of low marginal cost for carnivory relative to conventional autotrophy. The poor explanatory power of N, P or N : P ratio with CC suggests that factors other than production of expensive photosynthetic machinery (which calls for a high N input), including concentrations of lignin, wax/lipids or osmoregulatory ions like K+, may give a better explanation of the CC variation across Nepenthes species. PMID:17452380

Energy compensation after sprint- and high-intensity interval training.

PubMed

Schubert, Matthew M; Palumbo, Elyse; Seay, Rebekah F; Spain, Katie K; Clarke, Holly E

2017-01-01

Many individuals lose less weight than expected in response to exercise interventions when considering the increased energy expenditure of exercise (ExEE). This is due to energy compensation in response to ExEE, which may include increases in energy intake (EI) and decreases in non-exercise physical activity (NEPA). We examined the degree of energy compensation in healthy young men and women in response to interval training. Data were examined from a prior study in which 24 participants (mean age, BMI, & VO2max = 28 yrs, 27.7 kg•m-2, and 32 mL∙kg-1∙min-1) completed either 4 weeks of sprint-interval training or high-intensity interval training. Energy compensation was calculated from changes in body composition (air displacement plethysmography) and exercise energy expenditure was calculated from mean heart rate based on the heart rate-VO2 relationship. Differences between high (≥ 100%) and low (< 100%) levels of energy compensation were assessed. Linear regressions were utilized to determine associations between energy compensation and ΔVO2max, ΔEI, ΔNEPA, and Δresting metabolic rate. Very large individual differences in energy compensation were noted. In comparison to individuals with low levels of compensation, individuals with high levels of energy compensation gained fat mass, lost fat-free mass, and had lower change scores for VO2max and NEPA. Linear regression results indicated that lower levels of energy compensation were associated with increases in ΔVO2max (p < 0.001) and ΔNEPA (p < 0.001). Considerable variation exists in response to short-term, low dose interval training. In agreement with prior work, increases in ΔVO2max and ΔNEPA were associated with lower energy compensation. Future studies should focus on identifying if a dose-response relationship for energy compensation exists in response to interval training, and what underlying mechanisms and participant traits contribute to the large variation between individuals.

Mapping medical marijuana: state laws regulating patients, product safety, supply chains and dispensaries, 2017.

PubMed

Klieger, Sarah B; Gutman, Abraham; Allen, Leslie; Pacula, Rosalie Liccardo; Ibrahim, Jennifer K; Burris, Scott

2017-12-01

(1) To describe open source legal data sets, created for research use, that capture the key provisions of US state medical marijuana laws. The data document how state lawmakers have regulated a medicine that remains, under federal law, a Schedule I illegal drug with no legitimate medical use. (2) To demonstrate the variability that exists across states in rules governing patient access, product safety and dispensary practice. Two legal researchers collected and coded state laws governing marijuana patients, product safety and dispensaries in effect on 1 February 2017, creating three empirical legal data sets. We used summary tables to identify the variation in specific statutory provisions specified in each state's medical marijuana law as it existed on 1 February 2017. We compared aspects of these laws to the traditional Federal approach to regulating medicine. Full data sets, codebooks and protocols are available through the Prescription Drug Abuse Policy System (http://www.pdaps.org/; Archived at http://www.webcitation.org/6qv5CZNaZ on 2 June 2017). Twenty-eight states (including the District of Columbia) have authorized medical marijuana. Twenty-seven specify qualifying diseases, which differ across states. All states protect patient privacy; only 14 protect patients against discrimination. Eighteen states have mandatory product safety testing before any sale. While the majority have package/label regulations, states have a wide range of specific requirements. Most regulate dispensaries (25 states), with considerable variation in specific provisions such as permitted product supply sources number of dispensaries per state and restricting proximity to various types of location. The federal ban in the United States on marijuana has resulted in a patchwork of regulatory strategies that are not uniformly consistent with the approach usually taken by the Federal government and whose effectiveness remains unknown. © 2017 Society for the Study of Addiction.

Novel Methods for Measuring LiDAR

NASA Astrophysics Data System (ADS)

Ayrey, E.; Hayes, D. J.; Fraver, S.; Weiskittel, A.; Cook, B.; Kershaw, J.

2017-12-01

The estimation of forest biometrics from airborne LiDAR data has become invaluable for quantifying forest carbon stocks, forest and wildlife ecology research, and sustainable forest management. The area-based approach is arguably the most common method for developing enhanced forest inventories from LiDAR. It involves taking a series of vertical height measurements of the point cloud, then using those measurements with field measured data to develop predictive models. Unfortunately, there is considerable variation in methodology for collecting point cloud data, which can vary in pulse density, seasonality, canopy penetrability, and instrument specifications. Today there exists a wealth of public LiDAR data, however the variation in acquisition parameters makes forest inventory prediction by traditional means unreliable across the different datasets. The goal of this project is to test a series of novel point cloud measurements developed along a conceptual spectrum of human interpretability, and then to use the best measurements to develop regional enhanced forest inventories on Northern New England's and Atlantic Canada's public LiDAR. Similarly to a field-based inventory, individual tree crowns are being segmented, and summary statistics are being used as covariates. Established competition and structural indices are being generated using each tree's relationship to one another, whilst existing allometric equations are being used to estimate diameter and biomass of each tree measured in the LiDAR. Novel metrics measuring light interception, clusteredness, and rugosity are also being measured as predictors. On the other end of the human interpretability spectrum, convolutional neural networks are being employed to directly measure both the canopy height model, and the point clouds by scanning each using two and three dimensional kernals trained to identify features useful for predicting biological attributes such as biomass. Predictive models will be trained and tested against one another using 28 different sites and over 42 different LiDAR acquisitions. The optimal model will then be used to generate regional wall-to-wall forest inventories at a 10 m resolution.

Analysis of infant isolates of Bifidobacterium breve by comparative genome hybridization indicates the existence of new subspecies with marked infant specificity.

PubMed

Boesten, Rolf; Schuren, Frank; Wind, Richèle D; Knol, Jan; de Vos, Willem M

2011-09-01

A total of 20 Bifidobacterium strains were isolated from fecal samples of 4 breast- and bottle-fed infants and all were characterized as Bifidobacterium breve based on 16S rRNA gene sequence and metabolic analysis. These isolates were further characterized and compared to the type strains of B. breve and 7 other Bifidobacterium spp. by comparative genome hybridization. For this purpose, we constructed and used a DNA-based microarray containing over 2000 randomly cloned DNA fragments from B. breve type strain LMG13208. This molecular analysis revealed a high degree of genomic variation between the isolated strains and allowed the vast majority to be grouped into 4 clusters. One cluster contained a single isolate that was virtually indistinguishable from the B. breve type strain. The 3 other clusters included 19 B. breve strains that differed considerably from all type strains. Remarkably, each of the 4 clusters included strains that were isolated from a single infant, indicating that a niche adaptation may contribute to variation within the B. breve species. Based on genomic hybridization data, the new B. breve isolates were estimated to contain approximately 60-90% of the genes of the B. breve type strain, attesting to the existence of various subspecies within the species B. breve. Further bioinformatic analysis identified several hundred diagnostic clones specific to the genomic clustering of the B. breve isolates. Molecular analysis of representatives of these revealed that annotated genes from the conserved B. breve core encoded mainly housekeeping functions, while the strain-specific genes were predicted to code for functions related to life style, such as carbohydrate metabolism and transport. This is compatible with genetic adaptation of the strains to their niche, a combination of infants and diet. Copyright © 2011 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

Variational method of determining effective moduli of polycrystals: (A) hexagonal symmetry, (B) trigonal symmetry

USGS Publications Warehouse

Peselnick, L.; Meister, R.

1965-01-01

Variational principles of anisotropic elasticity have been applied to aggregates of randomly oriented pure-phase polycrystals having hexagonal symmetry and trigonal symmetry. The bounds of the effective elastic moduli obtained in this way show a considerable improvement over the bounds obtained by means of the Voigt and Reuss assumptions. The Hill average is found to be in most cases a good approximation when compared to the bounds found from the variational method. The new bounds reduce in their limits to the Voigt and Reuss values. ?? 1965 The American Institute of Physics.

Environmental control implications of generating electric power from coal. 1977 technology status report. Appendix D. Assessment of NO/sub x/ control technology for coal fired utility boilers. [Low-excess-air, staged combustion, flu gas recirculation and burner design

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

Not Available

1977-12-01

An NOx control technology assessment study was conducted to examine the effectiveness of low-excess-air firing, staged combustion, flue gas recirculation, and current burner/boiler designs as applied to coal-fired utility boilers. Significant variations in NOx emissions exist with boiler type, firing method, and coal type, but a relative comparison of emissions control performance, cost, and operational considerations is presented for each method. The study emphasized the numerous operational factors that are of major importance to the user in selecting and implementing a combustion modification technique. Staged combustion and low-excess-air operation were identified as the most cost-effective methods for existing units. Closemore » control of local air/fuel ratios and rigorous combustion equipment maintenance are essential to the success of both methods. Flue gas recirculation is relatively ineffective and has the added concern of tube erosion. More research is needed to resolve potential corrosion concerns with low-NOx operating modes. Low-NOx burners in conjunction with a compartmentalized windbox are capable of meeting a 0.6-lb/million Btu emission level on new units. Advanced burner designs are being developed to meet research emission goals of approximately 0.25 lb/MBtu.« less

Holocene climate variability in Texas, USA: An integration of existing paleoclimate data and modeling with a new, high-resolution speleothem record

NASA Astrophysics Data System (ADS)

Wong, Corinne I.; Banner, Jay L.; Musgrove, MaryLynn

2015-11-01

Delineating the climate processes governing precipitation variability in drought-prone Texas is critical for predicting and mitigating climate change effects, and requires the reconstruction of past climate beyond the instrumental record. We synthesize existing paleoclimate proxy data and climate simulations to provide an overview of climate variability in Texas during the Holocene. Conditions became progressively warmer and drier transitioning from the early to mid Holocene, culminating between 7 and 3 ka (thousand years ago), and were more variable during the late Holocene. The timing and relative magnitude of Holocene climate variability, however, is poorly constrained owing to considerable variability among the different records. To help address this, we present a new speleothem (NBJ) reconstruction from a central Texas cave that comprises the highest resolution proxy record to date, spanning the mid to late Holocene. NBJ trace-element concentrations indicate variable moisture conditions with no clear temporal trend. There is a decoupling between NBJ growth rate, trace-element concentrations, and δ18O values, which indicate that (i) the often direct relation between speleothem growth rate and moisture availability is likely complicated by changes in the overlying ecosystem that affect subsurface CO2 production, and (ii) speleothem δ18O variations likely reflect changes in moisture source (i.e., proportion of Pacific-vs. Gulf of Mexico-derived moisture) that appear not to be linked to moisture amount.

Systematic review of tonsil surgery quality registers and introduction of the Nordic Tonsil Surgery Register Collaboration.

PubMed

Ruohoalho, Johanna; Østvoll, Eirik; Bratt, Mette; Bugten, Vegard; Bäck, Leif; Mäkitie, Antti; Ovesen, Therese; Stalfors, Joacim

2018-06-01

Surgical quality registers provide tools to measure and improve the outcome of surgery. International register collaboration creates an opportunity to assess and critically evaluate national practices, and increases the size of available datasets. Even though millions of yearly tonsillectomies and tonsillotomies are performed worldwide, clinical practices are variable and inconsistency of evidence regarding the best clinical practice exists. The need for quality improvement actions is evident. We aimed to systematically investigate the existing tonsil surgery quality registers found in the literature, and to provide a thorough presentation of the planned Nordic Tonsil Surgery Register Collaboration. A systematic literature search of MEDLINE and EMBASE databases (from January 1990 to December 2016) was conducted to identify registers, databases, quality improvement programs or comprehensive audit programs addressing tonsil surgery. We identified two active registers and three completed audit programs focusing on tonsil surgery quality registration. Recorded variables were fairly similar, but considerable variation in coverage, number of operations included and length of time period for inclusion was discovered. Considering tonsillectomies and tonsillotomies being among the most commonly performed surgical procedures in otorhinolaryngology, it is surprising that only two active registers could be identified. We present a Nordic Tonsil Surgery Register Collaboration-an international tonsil surgery quality register project aiming to provide accurate benchmarks and enhance the quality of tonsil surgery in Denmark, Finland, Norway and Sweden.

Learning Robust and Discriminative Subspace With Low-Rank Constraints.

PubMed

Li, Sheng; Fu, Yun

2016-11-01

In this paper, we aim at learning robust and discriminative subspaces from noisy data. Subspace learning is widely used in extracting discriminative features for classification. However, when data are contaminated with severe noise, the performance of most existing subspace learning methods would be limited. Recent advances in low-rank modeling provide effective solutions for removing noise or outliers contained in sample sets, which motivates us to take advantage of low-rank constraints in order to exploit robust and discriminative subspace for classification. In particular, we present a discriminative subspace learning method called the supervised regularization-based robust subspace (SRRS) approach, by incorporating the low-rank constraint. SRRS seeks low-rank representations from the noisy data, and learns a discriminative subspace from the recovered clean data jointly. A supervised regularization function is designed to make use of the class label information, and therefore to enhance the discriminability of subspace. Our approach is formulated as a constrained rank-minimization problem. We design an inexact augmented Lagrange multiplier optimization algorithm to solve it. Unlike the existing sparse representation and low-rank learning methods, our approach learns a low-dimensional subspace from recovered data, and explicitly incorporates the supervised information. Our approach and some baselines are evaluated on the COIL-100, ALOI, Extended YaleB, FERET, AR, and KinFace databases. The experimental results demonstrate the effectiveness of our approach, especially when the data contain considerable noise or variations.

Information Fusion Issues in the UK Environmental Science Community

NASA Astrophysics Data System (ADS)

Giles, J. R.

2010-12-01

The Earth is a complex, interacting system which cannot be neatly divided by discipline boundaries. To gain an holistic understanding of even a component of an Earth System requires researchers to draw information from multiple disciplines and integrate these to develop a broader understanding. But the barriers to achieving this are formidable. Research funders attempting to encourage the integration of information across disciplines need to take into account culture issues, the impact of intrusion of projects on existing information systems, ontologies and semantics, scale issues, heterogeneity and the uncertainties associated with combining information from diverse sources. Culture - There is a cultural dualism in the environmental sciences were information sharing is both rewarded and discouraged. Researchers who share information both gain new opportunities and risk reducing their chances of being first author in an high-impact journal. The culture of the environmental science community has to be managed to ensure that information fusion activities are encouraged. Intrusion - Existing information systems have an inertia of there own because of the intellectual and financial capital invested within them. Information fusion activities must recognise and seek to minimise the potential impact of their projects on existing systems. Low intrusion information fusions systems such as OGC web-service and the OpenMI Standard are to be preferred to whole-sale replacement of existing systems. Ontology and Semantics - Linking information across disciplines requires a clear understanding of the concepts deployed in the vocabulary used to describe them. Such work is a critical first step to creating routine information fusion. It is essential that national bodies, such as geological surveys organisations, document and publish their ontologies, semantics, etc. Scale - Environmental processes operate at scales ranging from microns to the scale of the Solar System and potentially beyond. The many different scales involved provide serious challenges to information fusion which need to be researched. Heterogeneity - Natural systems are heterogeneous, that is a system consisting of multiple components each of which may have considerable internal variation. Modelling Earth Systems requires recognition of the inherent complexity. Uncertainty - Understanding the uncertainties within a single information source can be difficult. Understanding the uncertainties across a system of linked models, each drawn from multiple information resources, represents a considerable challenge that must be addressed. The challenges to overcome appear insurmountable to individual research groups; but the potential rewards, in terms of a fuller scientific understanding of Earth Systems, are significant. A major international effort must be mounted to tackle these barriers and enable routine information fusion.

Variation in mineral content of red maple sap across an atmospheric deposition gradient

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

McCormick, L.H.

1997-11-01

Xylem sap was collected from red maple (Acer rubrum L.) trees during the spring of 1988 and 1989 at seven forest sites along an atmospheric deposition gradient in north central Pennsylvania and analyzed for pH and twelve mineral constituents. The objectives of the study were to examine the sources and patterns of variation in red maple sap chemistry across an atmospheric deposition gradient and to assess the feasibility of using sap analysis as an indicator of nutrient bioavailability. For most sap constituents, there was considerable spatial and temporal variation in concentration. Sources of variation included within and between site variation,more » date, and year of collection. The nature and extent of variation varied for different constituents. Site differences were similar in 1988 and 1989 for most sap constituents and for some constituents corresponded with differences in soil levels.« less

A Quarter Century of Variation in Color and Allometric Characteristics of Eggs from a Rain Forest Population of the Pearly-eyed Thrasher (Margarops fuscatus).

Treesearch

WAYNE J. ARENDT

2004-01-01

Egg color, size, and shape vary considerably within and among female Pearly-eyed Thrashers (Margarops fuscatus). Results of a 25-yr study (1979-2004) are presented to provide comparative data. In a sample of 4,128 eggs, typical shape was prolate spheroid; but several variations were observed, depending on the age, stature, and physiological condition of the female, as...

VLSI Architectures and CAD

DTIC Science & Technology

1989-11-01

considerable promise is a variation of the familiar Lempel - Ziv adaptive data compression scheme that permits a straightforward mapping to hardware...types of data . The UNIX " compress " implementation is based upon Terry Welch’s 1984 variation of the Lempel - Ziv method (LZW). One flaw lies in the fact...or more; it must effec- tively compress all types of data (i.e. the algorithm must be universal); the implementation must be contained within a small

Patterns of trust in sources of health information.

PubMed

Lawson, Rob; Forbes, Sarah; Williams, John

2011-01-21

To understand the different patterns of trust that exist regarding different sources of information about health issues. Data from a large national health lifestyles survey of New Zealanders was examined using a factor analysis of trust toward 24 health information sources (HIS). Differences in trust are compared across a range of demographic variables. Factor analysis identified six different groupings of health information. Variations in trust in sources for health information are identified by age, employment status, level of education, income, sex and ethnic group. Systematic variations exist in the trust that people report with respect to different sources of health information. Understanding these variations may assist policymakers and other agencies which are responsible for planning the dissemination of health information.

A Consideration of the Ethics of Teaching English

ERIC Educational Resources Information Center

Christenbury, Leila

2008-01-01

The consideration of questions of morality and ethics, of right and wrong is not confined to churches and mosques and synagogues; it also exists outside religious frameworks, notably in the schools and in teaching. In this article, the author extends the exploration of ethics into the classroom where virtually all acts of writing, language, and…

Design considerations for community mental health management information systems.

PubMed

Lowe, B H; Sugarman, B

1978-01-01

Many community mental health centers are presently faced with the necessity of implementing a management information system. This article offers guidelines for centers dealing with this situation. Whether a center chooses to adapt an existing system or develop one of its own, careful planning prior to the implementation of the system can help ensure that it will meet the needs of the center and operate successfully. The guidelines are organized into the categories of data considerations, people considerations, and system considerations. The first two categories are of general interest, whereas the last category is more technical in nature.

Withdrawing Versus Withholding Freedoms: Nudging and the Case of Tobacco Control.

PubMed

Schmidt, Andreas T

2016-07-01

Is it a stronger interference with people's freedom to withdraw options they currently have than to withhold similar options they do not have? Drawing on recent theorizing about sociopolitical freedom, this article identifies considerations that often make this the case for public policy. However, when applied to tobacco control, these considerations are shown to give us at best only very weak freedom-based reason to prioritize the status quo. This supports a popular argument for so-called "endgame" tobacco control measures: If we believe that cigarettes would and should be withheld from entering markets in hypothetical scenarios in which they do not yet exist, then we also have reason to seek their abolition in situations, such as ours, in which cigarettes do exist-if necessary by banning their sale. The same considerations are then used to disarm objections that have recently been raised to using nudges in public policy.

Trend and variability of atmospheric ozone over middle Indo-Gangetic Plain: impacts of seasonality and precursor gases.

PubMed

Shukla, K; Srivastava, Prashant K; Banerjee, T; Aneja, Viney P

2017-01-01

Ozone dynamics in two urban background atmospheres over middle Indo-Gangetic Plain (IGP) were studied in two contexts: total columnar and ground-level ozone. In terms of total columnar ozone (TCO), emphases were made to compare satellite-based retrieval with ground-based observation and existing trend in decadal and seasonal variation was also identified. Both satellite-retrieved (Aura Ozone Monitoring Instrument-Differential Optical Absorption Spectroscopy (OMI-DOAS)) and ground-based observations (IMD-O 3 ) revealed satisfying agreement with OMI-DOAS observation over predicting TCO with a positive bias of 7.24 % under all-sky conditions. Minor variation between daily daytime (r = 0.54; R 2  = 29 %; n = 275) and satellite overpass time-averaged TCO (r = 0.58; R 2  = 34 %; n = 208) was also recognized. A consistent and clear seasonal trend in columnar ozone (2005-2015) was noted with summertime (March-June) maxima (Varanasi, 290.9 ± 8.8; Lucknow, 295.6 ± 9.5 DU) and wintertime (December-February) minima (Varanasi, 257.4 ± 10.1; Lucknow, 258.8 ± 8.8 DU). Seasonal trend decomposition based on locally weighted regression smoothing technique identified marginally decreasing trend (Varanasi, 0.0084; Lucknow, 0.0096 DU year -1 ) especially due to reduction in monsoon time minima and summertime maxima. In continuation to TCO, variation in ground-level ozone in terms of seasonality and precursor gases were also analysed from September 2014 to August 2015. Both stations registered similar pattern of variation with Lucknow representing slightly higher annual mean (44.3 ± 30.6; range, 1.5-309.1 μg/m 3 ) over Varanasi (38.5 ± 17.7; range, 4.9-104.2 μg/m 3 ). Variation in ground-level ozone was further explained in terms water vapour, atmospheric boundary layer height and solar radiation. Ambient water vapour content was found to associate negatively (r = -0.28, n = 284) with ground-level ozone with considerable seasonal variation in Varanasi. Implication of solar radiation on formation of ground-level ozone was overall positive (Varanasi, 0.60; Lucknow, 0.26), while season-specific association was recorded in case of atmospheric boundary layer.

Variations in the water vapor distribution and the associated effects on fog and haze events over Xi'an based on Raman lidar data and back trajectories.

PubMed

Wang, Yufeng; Zhang, Jing; Fu, Qiang; Song, Yuehui; Di, Huige; Li, Bo; Hua, Dengxin

2017-10-01

A combination of more than two years of water vapor lidar data with back trajectory analysis using the hybrid single-particle Lagrangian integrated trajectory (HYSPLIT) model was used to study the long-range transport of air masses and the water vapor distribution characteristics and variations over Xi'an, China (34.233° N, 108.911° E), which is a typical city in Northwest China. High-quality profiles of the water vapor density were derived from a multifunction Raman lidar system built in Xi'an, and more than 2000 sets of profiles with >400 nighttime observations from October 2013 to July 2016 were collected and used for statistical and quantitative analyses. The vertical variations in the water vapor content were discussed. A mutation height of the water vapor exists at 2-4 km with a high occurrence rate of ∼60% during the autumn and winter seasons. This height reflects a distinct stratification in the water vapor content. Additionally, the atmospheric water vapor content was mainly concentrated in the lower troposphere, and the proportion of the water vapor content at 0.5-5 km accounted for 80%-90% of the total water vapor below 10 km. Obvious seasonal variations were observed, including large water vapor content during the spring and summer and small content during the autumn and winter. Combined with back trajectory analysis, the results showed that markedly different water vapor transport pathways contribute to seasonal variations in the water vapor content. South and southeast airflows dominated during the summer, with 30% of the 84 trajectories originating from these areas; however, the air masses during the winter originated from the north and local regions (64.3%) and from the northwest (27%). In addition, we discussed variations in the water vapor during fog and haze weather conditions during the winter. A considerable enhancement in the mean water vapor density at 0.5-3 km exhibited a clear positive correlation (correlation coefficient >0.8) with the PM2.5 and PM10 concentrations. The results indicate that local airflow trajectories mainly affect water vapor transport below the boundary layer, and that these flows are closely related to the formation of fog and haze events in the Xi'an area.

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

Rode, J.R.; Brzezeina, P.; Strach, F.

This paper discusses the engineering considerations related to the design of a new 110 MWe atmospheric fluidized bed boiler (CFB) and boiler island auxiliaries for installation at the CEZ, a.s. (Czech Republic Utility) Ledvice Power Station. The plant is located in the northwest Bohemia area of the Czech Republic in the foothills of the Krusne Hory Mountains, between the towns of Bilina and Teplice. The type of fuel to be burned in the CFB is brown coal which requires unique design considerations in as well as the particular boiler operational parameters. The impetus behind the addition of this new CFBmore » at the plant is that the existing pulverized coal fired steam generator which was put in service in 1969 is unable to meet new regulations and laws regarding compliance with the protection of the environment and will be replaced once the new CFB unit is brought into service. A technical-economic study conducted by CEZ, a.s. evaluated CFB technology as the most advantageous from a long-term standpoint. The following variations were considered in the study: boiler retrofit and construction of new ash handling equipment; implementation of the combined cycle based upon natural gas; and reconstruction of the boiler equipment with transition to atmospheric fluid-bed combustion. The selection of the supplier of fluid-bed boiler was performed with an emphasis of the bidders` references as for the construction and operation of fluid-bed boilers with the outputs of min. 300 t/hr.« less

An approach toward incorporation of global warming effects into Intensity-Duration-Frequency values

NASA Astrophysics Data System (ADS)

Kunkel, K.; Easterling, D. R.

2017-12-01

Rising global temperatures from increasing greenhouse gas concentrations will increase overall atmospheric water vapor concentrations. There is a high level of scientific confidence that this will increase the future intensity and frequency of extreme precipitation events, even in regions where overall precipitation may decrease. For control of runoff from extreme rainfall, infrastructure engineering utilizes design values of rainfall known as Intensity-Duration-Frequency (IDF) values. Use of the existing IDF values, which are based solely on historical climate records, is likely to lead to under-design of runoff control structures, and associated increased flood damages. However, future changes in IDF values are uncertain and probably regionally variable. Our paradigm is that changes in IDF values will result from changes in atmospheric capacity (water vapor concentrations) and opportunity (the number and intensity of heavy precipitation-producing storm systems). Relevant storm systems being investigated include extratropical cyclones and their associated fronts, tropical cyclones, and the North American Monsoon system. The overall approach involves developing IDF adjustment factors for changes in these components of the climate system. The adjustment factors have associated uncertainties, primarily from (1) uncertainties in the future pathway of greenhouse gas emissions and (2) variations among climate models in the sensitivity of the climate system to greenhouse gas concentration changes. In addition to meteorological considerations, the lifetime of projects designed using IDF values is an essential consideration because the IDF values may change substantially during that time. The initial results of this project will be discussed.

Local-search based prediction of medical image registration error

NASA Astrophysics Data System (ADS)

Saygili, Görkem

2018-03-01

Medical image registration is a crucial task in many different medical imaging applications. Hence, considerable amount of work has been published recently that aim to predict the error in a registration without any human effort. If provided, these error predictions can be used as a feedback to the registration algorithm to further improve its performance. Recent methods generally start with extracting image-based and deformation-based features, then apply feature pooling and finally train a Random Forest (RF) regressor to predict the real registration error. Image-based features can be calculated after applying a single registration but provide limited accuracy whereas deformation-based features such as variation of deformation vector field may require up to 20 registrations which is a considerably high time-consuming task. This paper proposes to use extracted features from a local search algorithm as image-based features to estimate the error of a registration. The proposed method comprises a local search algorithm to find corresponding voxels between registered image pairs and based on the amount of shifts and stereo confidence measures, it predicts the amount of registration error in millimetres densely using a RF regressor. Compared to other algorithms in the literature, the proposed algorithm does not require multiple registrations, can be efficiently implemented on a Graphical Processing Unit (GPU) and can still provide highly accurate error predictions in existence of large registration error. Experimental results with real registrations on a public dataset indicate a substantially high accuracy achieved by using features from the local search algorithm.

Bifidobacterium longum and Bifidobacterium breve isolates from preterm and full term neonates: comparison of cell surface properties.

PubMed

Andriantsoanirina, Valérie; Teolis, Anne-Claire; Xin, Liu Xin; Butel, Marie Jose; Aires, Julio

2014-08-01

We compared autoaggregation, surface hydrophobicity and Caco-2 cells adhesion capabilities of independent Bifidobacterium breve (n = 22) and Bifidobacterium longum (n = 25) strains isolated from preterm (n = 20) and full term neonates (n = 27). Concerning strains properties, a correlation between autoaggregation and surface hydrophobicity was found for B. longum (r = 0.40, p = 0.048), B. breve (r = 0.57, p = 0.005), and all strains independently of the species consideration (r = 0.46, p = 0.001). The absence of difference in adhesion capabilities between preterm and full term neonate strains suggests a strain-dependent property. However, B. longum strains from preterm neonates (n = 10) showed higher autoaggregation ability (p = 0.044). Additionally, independently of species consideration, preterm neonates strains showed lower surface hydrophobicity (p = 0.027). As far as species are considered, preterm neonate B. breve strains (n = 10) showed significantly lower surface hydrophobicity percentages (p = 0.043). Our results suggest the existence of variations in bifidobacteria membrane structure and/or composition that may reflect adaptation of these bacteria to the intestinal environment of either preterm or full term neonates. Such information is of interest when considering the use of bifidobacteria probiotic strains for modulation of preterm neonates gut microbiota. Copyright © 2014 Elsevier Ltd. All rights reserved.

Trend and disease burden of bacillary dysentery in China (1991-2000).

PubMed Central

Wang, Xuan-yi; Tao, Fangbiao; Xiao, Donglou; Lee, Hyejon; Deen, Jacqueline; Gong, Jian; Zhao, Yuliang; Zhou, Weizhong; Li, Weiming; Shen, Bing; Song, Yang; Ma, Jianming; Li, Zheng-mao; Wang, Zijun; Su, Pu-yu; Chang, Nayoon; Xu, Jun-hong; Ouyang, Pei-ying; von Seidlein, Lorenz; Xu, Zhi-yi; Clemens, John D.

2006-01-01

OBJECTIVE: We aimed to determine the burden of bacillary dysentery in China, its cross-regional variations, trends in morbidity and mortality, the causative bacterial species and antimicrobial resistance patterns. METHODS: We extracted and integrated governmental statistics and relevant medical literature published from 1991 to 2000. Data were also collected from one general hospital each for the six provinces and Jin-an district, Shanghai, representative of six geographical regions and a modern city. FINDINGS: In 2000, 0.8-1.7 million episodes of bacillary dysentery occurred of which 0.5 to 0.7 million were treated at health-care facilities and 0.15-0.20 million patients were hospitalized. The highest morbidity and mortality rates were among the youngest and oldest age groups. Bacillary dysentery peaked during the summer months. The major causative species was Shigella flexneri (86%) and the predominant S. flexneri serotype was 2a (80%). About 74-80% of Shigella isolates remained susceptible to fluorinated quinolones. CONCLUSION: We conclude that while morbidity and mortality due to bacillary dysentery has decreased considerably in China in the past decade due to increasing access to affordable health care and antibiotics, a considerable burden exists among the youngest and oldest age groups and in regions with low economic development. We suggest that while a vaccine would be effective for short- and medium-term control of bacillary dysentery, improved water supply, sanitation, and hygiene are likely to be required for long-term control. PMID:16878230

Educational needs of health professionals working in rheumatology in Europe.

PubMed

Vliet Vlieland, Theodora P M; van den Ende, Cornelia H M; Alliot-Launois, Francoise; Beauvais, Catherine; Gobbo, Milena; Iagnocco, Annamaria; Lundberg, Ingrid E; Munuera-Martínez, Pedro V; Opava, Christina H; Prior, Yeliz; Redmond, Anthony; Smucrova, Hana; Wiek, Dieter

2016-01-01

To explore the availability of postgraduate education for health professionals (HPs) working in rheumatology in Europe, and their perceived educational needs and barriers for participation in current educational offerings. Structured interviews were conducted with national representatives of rheumatology HPs' organisations and an online survey among individual HPs was disseminated through existing European League Against Rheumatism (EULAR) networks (10 languages including English). These comprised questions on: availability of postgraduate education, familiarity with EULAR and its educational offerings, unmet needs regarding the contents and mode of delivery and potential barriers to participate in education (0-10 scales). According to 17 national representatives, postgraduate rheumatology education was most common for nurses, physical and occupational therapists. There were 1041 individuals responding to the survey, of whom 48% completed all questions. More than half (56%) were familiar with EULAR as an organisation, whereas <25% had attended the EULAR congress or were familiar with EULAR online courses. Educational needs regarding contents were highest for 'inflammatory arthritis' and 'connective tissue diseases' and regarding modes of delivery for 'courses organised in own country' and 'online courses'. Important barriers to participation included lack of 'resources', 'time' and 'English language skills'. Overall, there was considerable variation in needs and barriers among countries. There is a lack of postgraduate rheumatology education for HPs in most countries. There are opportunities to raise awareness regarding EULAR educational offerings and to develop courses provided in HPs' own country, tailored to national needs and barriers and taking language barriers into consideration.

Recent Advances and Perspectives in Liposomes for Cutaneous Drug Delivery.

PubMed

Carita, Amanda C; Eloy, Josimar O; Chorilli, Marlus; Lee, Robert J; Leonardi, Gislaine Ricci

2018-02-13

The cutaneous route is attractive for the delivery of drugs in the treatment of a wide variety of diseases. However the stratum corneum (SC) is an effective barrier that hampers skin penetration. Within this context, liposomes emerge as a potential carrier for improving topical delivery of therapeutic agents. In this review, we aimed to discuss key aspects for the topical delivery by drug-loaded liposomes. Phospholipid type and phase transition temperature have been shown to affect liposomal topical delivery. The effect of surface charge is subject to considerable variation depending on drug and composition. In addition, modified vesicles with the presence of components for permeation enhancement, such as surfactants and solvents, have been shown to have a considerable effect. These liposomes include: Transfersomes, Niosomes, Ethosomes, Transethosomes, Invasomes, coated liposomes, penetration enhancer containing vesicles (PEVs), fatty acids vesicles, Archaeosomes and Marinosomes. Furthermore, adding polymeric coating onto liposome surface could influence cutaneous delivery. Mechanisms of delivery include intact vesicular skin penetration, free drug diffusion, permeation enhancement, vesicle adsorption to and/or fusion with the SC, trans-appendageal penetration, among others. Finally, several skin conditions, including acne, melasma, skin aging, fungal infections and skin cancer, have benefited from liposomal topical delivery of drugs, with promising in vitro and in vivo results. However, despite the existence of some clinical trials, more studies are needed to be conducted in order to explore the potential of liposomes in the dermatological field. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Strongly nonlinear parabolic variational inequalities

PubMed Central

Browder, Felix E.; Brézis, Haim

1980-01-01

An existence and uniqueness result is established for a general class of variational inequalities for parabolic partial differential equations of the form ∂u/∂t + A(u) + g(u) = f with g nondecreasing but satisfying no growth condition. The proof is based upon a type of compactness result for solutions of variational inequalities that should find a variety of other applications. PMID:16592776

Evaluating the Policies that Lead to Substantial Tuition Variation at Public Land-Grant Universities

ERIC Educational Resources Information Center

Burgess, Brent

2011-01-01

The aim of this study is to evaluate the current state of, and the causes for, the substantial variation in the tuition rates of America's land-grant universities. This aim was pursued with the objective of trying to identify consistent and revealing policies and external characteristics related to the high level of variation that exists among…

Predictive models for radial sap flux variation in coniferous, diffuse-porous and ring-porous temperate trees

Treesearch

Aaron B. Berdanier; Chelcy F. Miniat; James S. Clark

2016-01-01

Accurately scaling sap flux observations to tree or stand levels requires accounting for variation in sap flux between wood types and by depth into the tree. However, existing models for radial variation in axial sap flux are rarely used because they are difficult to implement, there is uncertainty about their predictive ability and calibration measurements...

Prisoners as Living Donors: A Vulnerabilities Analysis.

PubMed

Ross, Lainie Friedman; Thistlethwaite, J Richard

2018-01-01

Although national guidelines exist for evaluating the eligibility of potential living donors and for procuring their informed consent, no special protections or considerations exist for potential living donors who are incarcerated. Human research subject protections in the United States are codified in the Federal Regulations, 45 CFR 46, and special protections are given to prisoners. Living donor transplantation has parallels with human subject research in that both activities are performed with the primary goal of benefiting third parties. In this article, we describe what special considerations should be provided to prisoners as potential living donors using a vulnerabilities approach adapted from the human research subject protection literature.

Wisconsin's approach to variation in traffic data

DOT National Transportation Integrated Search

2000-08-01

Traffic data exhibits considerable variability, both spatially and temporally. Given limited resources and the large geographic coverage required for data collection efforts, short period (24-hours to 7-day) traffic data collection must often serve t...

Variational submanifolds of Euclidean spaces

NASA Astrophysics Data System (ADS)

Krupka, D.; Urban, Z.; Volná, J.

2018-03-01

Systems of ordinary differential equations (or dynamical forms in Lagrangian mechanics), induced by embeddings of smooth fibered manifolds over one-dimensional basis, are considered in the class of variational equations. For a given non-variational system, conditions assuring variationality (the Helmholtz conditions) of the induced system with respect to a submanifold of a Euclidean space are studied, and the problem of existence of these "variational submanifolds" is formulated in general and solved for second-order systems. The variational sequence theory on sheaves of differential forms is employed as a main tool for the analysis of local and global aspects (variationality and variational triviality). The theory is illustrated by examples of holonomic constraints (submanifolds of a configuration Euclidean space) which are variational submanifolds in geometry and mechanics.

Intra- and Inter-Fractional Variation Prediction of Lung Tumors Using Fuzzy Deep Learning

PubMed Central

Park, Seonyeong; Lee, Suk Jin; Weiss, Elisabeth

2016-01-01

Tumor movements should be accurately predicted to improve delivery accuracy and reduce unnecessary radiation exposure to healthy tissue during radiotherapy. The tumor movements pertaining to respiration are divided into intra-fractional variation occurring in a single treatment session and inter-fractional variation arising between different sessions. Most studies of patients’ respiration movements deal with intra-fractional variation. Previous studies on inter-fractional variation are hardly mathematized and cannot predict movements well due to inconstant variation. Moreover, the computation time of the prediction should be reduced. To overcome these limitations, we propose a new predictor for intra- and inter-fractional data variation, called intra- and inter-fraction fuzzy deep learning (IIFDL), where FDL, equipped with breathing clustering, predicts the movement accurately and decreases the computation time. Through the experimental results, we validated that the IIFDL improved root-mean-square error (RMSE) by 29.98% and prediction overshoot by 70.93%, compared with existing methods. The results also showed that the IIFDL enhanced the average RMSE and overshoot by 59.73% and 83.27%, respectively. In addition, the average computation time of IIFDL was 1.54 ms for both intra- and inter-fractional variation, which was much smaller than the existing methods. Therefore, the proposed IIFDL might achieve real-time estimation as well as better tracking techniques in radiotherapy. PMID:27170914

To Remodel or To Build?

ERIC Educational Resources Information Center

Rosenblum, Todd

2009-01-01

The question of remodeling an existing house to make it wheelchair accessible or building a new barrier-free house is a difficult decision. This article presents some initial questions and considerations followed by a list of pros and cons for remodeling an existing house vs. building a new house.

Computer aided modeling of soil mix designs to predict characteristics and properties of stabilized road bases.

DOT National Transportation Integrated Search

2009-07-01

"Considerable data exists for soils that were tested and documented, both for native properties and : properties with pozzolan stabilization. While the data exists there was no database for the Nebraska : Department of Roads to retrieve this data for...

Subjective Probabilities in Household Surveys

PubMed Central

Hurd, Michael D.

2011-01-01

Subjective probabilities are now collected on a number of large household surveys with the objective of providing data to better understand inter-temporal decision making. Comparison of subjective probabilities with actual outcomes shows that the probabilities have considerable predictive power in situations where individuals have considerable private information such as survival and retirement. In contrast the subjective probability of a stock market gain varies greatly across individuals even though no one has private information and the outcome is the same for everyone. An explanation is that there is considerable variation in accessing and processing information. Further, the subjective probability of a stock market gain is considerably lower than historical averages, providing an explanation for the relatively low frequency of stock holding. An important research objective will be to understand how individuals form their subjective probabilities. PMID:21643535

Deviation diagnosis and analysis of hull flat block assembly based on a state space model

NASA Astrophysics Data System (ADS)

Zhang, Zhiying; Dai, Yinfang; Li, Zhen

2012-09-01

Dimensional control is one of the most important challenges in the shipbuilding industry. In order to predict assembly dimensional variation in hull flat block construction, a variation stream model based on state space was presented in this paper which can be further applied to accuracy control in shipbuilding. Part accumulative error, locating error, and welding deformation were taken into consideration in this model, and variation propagation mechanisms and the accumulative rule in the assembly process were analyzed. Then, a model was developed to describe the variation propagation throughout the assembly process. Finally, an example of flat block construction from an actual shipyard was given. The result shows that this method is effective and useful.

Soil Moisture Memory in Climate Models

NASA Technical Reports Server (NTRS)

Koster, Randal D.; Suarez, Max J.; Zukor, Dorothy J. (Technical Monitor)

2000-01-01

Water balance considerations at the soil surface lead to an equation that relates the autocorrelation of soil moisture in climate models to (1) seasonality in the statistics of the atmospheric forcing, (2) the variation of evaporation with soil moisture, (3) the variation of runoff with soil moisture, and (4) persistence in the atmospheric forcing, as perhaps induced by land atmosphere feedback. Geographical variations in the relative strengths of these factors, which can be established through analysis of model diagnostics and which can be validated to a certain extent against observations, lead to geographical variations in simulated soil moisture memory and thus, in effect, to geographical variations in seasonal precipitation predictability associated with soil moisture. The use of the equation to characterize controls on soil moisture memory is demonstrated with data from the modeling system of the NASA Seasonal-to-Interannual Prediction Project.

An Estimate of Changes in the Sun's Total Irradiance Caused by UV Irradiance Variations from 1874 to 1988

NASA Technical Reports Server (NTRS)

Lean, J.

1990-01-01

Enhanced emission from bright solar faculae is a source of significant variation in the sun's total irradiance. Relative to the emission from the quiet sun, facular emission is known to be considerably greater at UV wavelengths than at visible wavelengths. Determining the spectral dependence of facular emission is of interest for the physical insight this may provide to the origin of the sun's irradiance variations. It is also of interest because solar radiation at lambda less than 300 nm is almost totally absorbed in the Earth's atmosphere. Depending on the magnitude of the UV irradiance variations, changes in the sun's irradiance that penetrates to the Earth's surface may not be equivalent to total irradiance variations measured above the Earth's atmosphere. Using an empirical model of total irradiance variations which accounts separately for changes caused by bright faculae from those associated with dark sunspots, the contribution of UV irradiance variations to changes in the sun's total irradiance is estimated during solar cycles 12 to 21.

Evaluation of simulation motion fidelity criteria in the vertical and directional axes

NASA Technical Reports Server (NTRS)

Schroeder, Jeffery A.

1993-01-01

An evaluation of existing motion fidelity criteria was conducted on the NASA Ames Vertical Motion Simulator. Experienced test pilots flew single-axis repositioning tasks in both the vertical and the directional axes. Using a first-order approximation of a hovering helicopter, tasks were flown with variations only in the filters that attenuate the commands to the simulator motion system. These filters had second-order high-pass characteristics, and the variations were made in the filter gain and natural frequency. The variations spanned motion response characteristics from nearly full math-model motion to fixed-base. Between configurations, pilots recalibrated their motion response perception by flying the task with full motion. Pilots subjectively rated the motion fidelity of subsequent configurations relative to this full motion case, which was considered the standard for comparison. The results suggested that the existing vertical-axis criterion was accurate for combinations of gain and natural frequency changes. However, if only the gain or the natural frequency was changed, the rated motion fidelity was better than the criterion predicted. In the vertical axis, the objective and subjective results indicated that a larger gain reduction was tolerated than the existing criterion allowed. The limited data collected in the yaw axis revealed that pilots had difficulty in distinguishing among the variations in the pure yaw motion cues.

From Existence to Essence: A Conceptual Model for an Appalachian Studies Curriculum.

ERIC Educational Resources Information Center

Best, Billy F.

Comprised of 4 chapters, this dissertation explores the existential premise "existence precedes essence" as applicable to development of a conceptual model for an Appalachian studies curriculum. Entitled "Personal Considerations: Pedagogy of a Hillbilly", the 1st chapter details the conflicts between the Appalachian institution…

Consideration of extinction risks for salmonids

Treesearch

Bruce Rieman; Danny Lee; Jack McIntyre; Kerry Overton; Russ Thurow

1993-01-01

Under the National Forest Management Act of 1979, the USDA Forest Service is charged with maintaining viable populations of all existing native vertebrate species on lands they administer. Accomplishment of this responsibility requires complete assessment of all federally authorized, funded, or implemented projects that may jeopardize the continued existence of a...

Antiterrorism Measures For Historic Properties

DTIC Science & Technology

2006-09-01

steel jacket on an existing concrete column (Morley Builders 1997...of the material. Figure 17. Seismic application of a steel jacket on an existing concrete column (Morley Builders 1997). Columns — Reinforced...from a previously unreinforced structure, so future irreversibility of the technique need not disqualify it from consideration by project teams. ERDC

Steps toward a Technology for the Diffusion of Innovations.

ERIC Educational Resources Information Center

Stolz, Stephanie B.

Research-based technologies for solving problems currently exist but are not being widely implemented. Although user variables, program effectiveness, and political considerations have been documented as correlates of implementation, general non-implementation of the technology still exists, due to a lack of methods. A technology of dissemination…

Optimizing chirped laser pulse parameters for electron acceleration in vacuum

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

Akhyani, Mina; Jahangiri, Fazel; Niknam, Ali Reza

2015-11-14

Electron dynamics in the field of a chirped linearly polarized laser pulse is investigated. Variations of electron energy gain versus chirp parameter, time duration, and initial phase of laser pulse are studied. Based on maximizing laser pulse asymmetry, a numerical optimization procedure is presented, which leads to the elimination of rapid fluctuations of gain versus the chirp parameter. Instead, a smooth variation is observed that considerably reduces the accuracy required for experimentally adjusting the chirp parameter.

Cloud Feedback in Atmospheric General Circulation Models: An Update

NASA Technical Reports Server (NTRS)

Cess, R. D.; Zhang, M. H.; Ingram, W. J.; Potter, G. L.; Alekseev, V.; Barker, H. W.; Cohen-Solal, E.; Colman, R. A.; Dazlich, D. A.; DelGenio, A. D.;

Well, what about intraspecific variation? Taxonomic and phylogenetic characters in the genus Synoeca de Saussure (Hymenoptera, Vespidae).

PubMed

Carpenter, James M; Andena, Sergio R; Noll, Fernando B; Wenzel, John W

2013-01-01

Cely and Sarmiento (2011) took issue with the cladistic analysis of relationships among species of the genus Synoeca by Andena et al. (2009a), and presented a reanalysis. They claimed that intraspecific variation in the genus is meaningful, and proper consideration yields a conclusion different from that of Andena et al. Both their critique and reanalysis are vitiated by numerous errors, as is shown in the present paper.

Interactive effects of genotype and food quality on consumer growth rate and elemental content.

PubMed

Prater, Clay; Wagner, Nicole D; Frost, Paul C

2017-05-01

Consumer body stoichiometry is a key trait that links organismal physiology to population and ecosystem-level dynamics. However, as elemental composition has traditionally been considered to be constrained within a species, the ecological and evolutionary factors shaping consumer elemental composition have not been clearly resolved. To this end, we examined the causes and extent of variation in the body phosphorus (P) content and the expression of P-linked traits, mass specific growth rate (MSGR), and P use efficiency (PUE) of the keystone aquatic consumer Daphnia using lake surveys and common garden experiments. While daphnid body %P was relatively constrained in field assemblages sampled across an environmental P gradient, unique genotypes isolated from these lakes showed highly variable phenotypic responses when raised across dietary P gradients in the laboratory. Specifically, we observed substantial inter- and intra-specific variation and differences in daphnid responses within and among our study lakes. While variation in Daphnia body %P was mostly due to plastic phenotypic changes, we documented considerable genetic differences in daphnid MSGR and PUE, and relationships between MSGR and body P content were highly variable among genotypes. Overall, our study found that consumer responses to food quality may differ considerably among genotypes and that relationships between organismal life-history traits and body stoichiometry may be strongly influenced by genetic and environmental variation in natural assemblages. © 2017 by the Ecological Society of America.

Genome-wide investigation of genetic changes during modern breeding of Brassica napus.

PubMed

Wang, Nian; Li, Feng; Chen, Biyun; Xu, Kun; Yan, Guixin; Qiao, Jiangwei; Li, Jun; Gao, Guizhen; Bancroft, Ian; Meng, Jingling; King, Graham J; Wu, Xiaoming

2014-08-01

Considerable genome variation had been incorporated within rapeseed breeding programs over past decades. In past decades, there have been substantial changes in phenotypic properties of rapeseed as a result of extensive breeding effort. Uncovering the underlying patterns of allelic variation in the context of genome organisation would provide knowledge to guide future genetic improvement. We assessed genome-wide genetic changes, including population structure, genetic relatedness, the extent of linkage disequilibrium, nucleotide diversity and genetic differentiation based on F ST outlier detection, for a panel of 472 Brassica napus inbred accessions using a 60 k Brassica Infinium® SNP array. We found genetic diversity varied in different sub-groups. Moreover, the genetic diversity increased from 1950 to 1980 and then remained at a similar level in China and Europe. We also found ~6-10 % genomic regions revealed high F ST values. Some QTLs previously associated with important agronomic traits overlapped with these regions. Overall, the B. napus C genome was found to have more high F ST signals than the A genome, and we concluded that the C genome may contribute more valuable alleles to generate elite traits. The results of this study indicate that considerable genome variation had been incorporated within rapeseed breeding programs over past decades. These results also contribute to understanding the impact of rapeseed improvement on available genome variation and the potential for dissecting complex agronomic traits.

Sexual Grooming of Children: Review of Literature and Theoretical Considerations

ERIC Educational Resources Information Center

Craven, Samantha; Brown, Sarah; Gilchrist, Elizabeth

2006-01-01

The current review aims to outline the existing understanding of sexual grooming. Issues of poor definition, the adoption of the term "grooming" and the prevalence of sexual grooming will be discussed. Consideration will be given to how prominent theories of child sexual abuse often neglect sexual grooming. This will be followed by a detailed…

Topical treatment of psoriasis: questionnaire results on topical therapy accessibility and influence of body surface area on usage.

PubMed

Iversen, L; Lange, M M; Bissonette, R; Carvalho, A V E; van de Kerkhof, P C; Kirby, B; Kleyn, C E; Lynde, C W; van der Walt, J M; Wu, J J

2017-07-01

Topical treatment of mild to moderate psoriasis is first-line treatment and exhibits varying degrees of success across patient groups. Key factors influencing treatment success are physician topical treatment choice (high efficacy, low adverse events) and strict patient adherence. Currently, no formalized, international consensus guidelines exist to direct optimal topical treatment, although many countries have national guidelines. To describe and analyse cross-regional variations in the use and access of psoriasis topical therapies. The study was conducted as an observational cross-sectional study. A survey was distributed to dermatologists from the International Psoriasis Council (IPC) to assess topical therapy accessibility in 26 countries and to understand how body surface area (BSA) categories guide clinical decisions on topical use. Variation in the availability of tars, topical retinoids, dithranol and balneotherapy was reported. The vast majority of respondents (100% and 88.4%) used topical therapy as first-line monotherapy in situations with BSA < 3% and BSA between 3% and 10%, respectively. However, with disease severity increasing to BSA > 10%, the number of respondents who prescribe topical therapy decreased considerably. In addition, combination therapy of a topical drug and a systemic drug was frequently reported when BSA measured >10%. This physician survey provides new evidence on topical access and the influence of disease severity on topical usage in an effort to improve treatment strategies on a global level. © 2017 European Academy of Dermatology and Venereology.

Purification of Keratan Sulfate-endogalactosidase and its action on keratan sulfates of different origin.

PubMed

Nakazawa, K; Suzuki, S

1975-02-10

A glycosidase which attacks corneal keratan sulfate was purified from extracts of Pseudomonas sp. IFO-13309. When corneal keratan sulfate was degraded by the purified enzyme, Sephadex G-50 chromatography indicated the presence of a number of oligosaccharides differing in size and sulfate content. The characterization of two major fractions of the oligosaccharides indicated that the point of enzyme attack is limited to the endo-beta-D-galactoside bonds in which nonsulfated D-galactose residues participate. The enzyme, unlike ordinary exo-beta-D-galactosidases, did not catalyze the hydrolysis of phenyl beta-D-galactoside. Moreover, beta-D-galactosyl-(1 leads to 3)-2-acetamido-2-deoxy-beta-D-glucosyl-(1 leads to 3)-beta-D-galactosyl-(1 leads to 4)-D-glucose ("lacto-N-tetraose") was completely refractory to the action of this enzyme, suggesting that a structure of the type, X-(1 leads to 3)-beta-D-galactosyl-(1 leads to 4)-Y, is not the only specificity-determining factor, i.e. neighboring sugars, X and Y, or even larger portions of substrate molecule must have an important effect. Compared with corneal keratan sulfate, keratan sulfates from human nucleus pulposus and shark cartilage were attacked at lower rates with a resultant production of oligosaccharides of relatively large size. The result is in agreement with the view that considerable variations exist in the structure of keratan sulfates of different origin, and further suggests that the enzyme may serve as a useful reagent in studying these variations.

Psychiatric reactions to continuous traumatic stress: A Latent Profile Analysis of two Israeli samples.

PubMed

Itzhaky, Liat; Gelkopf, Mark; Levin, Yafit; Stein, Jacob Y; Solomon, Zahava

2017-10-01

Many individuals worldwide are exposed to continuous traumatic stress (CTS). However, the psychiatric sequela of CTS and the relevance of posttraumatic stress disorder (PTSD) diagnostic criteria in this situation have yet to be determined. Filling this gap, the present study assessed psychiatric reactions to CTS and the relationship between such reactions and functional impairment among two representative samples of adults exposed to ongoing shelling over 6 (n=387) and 9 years (n=468). Assessment included PTSD symptomatology (i.e., intrusion, avoidance, hyperarousal), anxiety, somatization, and depression. Profile categorization aimed to underscore variations in symptom clustering and severity, and determine whether or not a profile is dominated by PTSD symptoms. Latent Profile analyses (LPA) of sample I revealed four distinct symptoms profiles: (1) 'symptomatically resilient'; (2) 'symptomatically low-moderate'; (3) 'symptomatically moderate-high'; and (4) 'symptomatically overall high'. LPA of sample II revealed three distinct symptoms profiles: (1) 'symptomatically resilient'; (2) 'symptomatically low-moderate'; (3) "symptomatically moderate-high". Moreover, profile variation was implicated in dysfunction. Consistent with studies focusing on single trauma exposure, the findings revealed that the most prevalent profile was the symptomatically resilient, indicating that most people exposed to CTS seem to evince a scarce number of psychiatric symptoms. Moreover, reactions to CTS proved broader than the existing PTSD symptomatology. Examining symptom dominance and severity in relation to impairment and dysfunction, and clinical considerations are discussed. Copyright © 2017 Elsevier Ltd. All rights reserved.

Genetic Polymorphisms Associated with Rubella Virus-Specific Cellular Immunity Following MMR Vaccination

PubMed Central

Kennedy, Richard B.; Ovsyannikova, Inna G.; Haralambieva, Iana H.; Lambert, Nathaniel D.; Pankratz, V. Shane; Poland, Gregory A.

2014-01-01

Rubella virus causes a relatively benign disease in most cases, although infection during pregnancy can result in serious birth defects. An effective vaccine has been available since the early 1970s and outbreaks typically do not occur among highly vaccinated (≥2 doses) populations. Nevertheless, considerable inter-individual variation in immune response to rubella immunization does exist, with single dose seroconversion rates ~95%. Understanding the mechanisms behind this variability may provide important insights into rubella immunity. In the current study, we examined associations between single nucleotide polymorphisms (SNPs) in selected cytokine, cytokine receptor, and innate/antiviral genes and immune responses following rubella vaccination in order to understand genetic influences on vaccine response. Our approach consisted of a discovery cohort of 887 subjects ages 11–22 at the time of enrollment and a replication cohort of 542 older adolescents and young adults (ages 18–40). Our data indicate that SNPs near the butyrophilin genes (BTN3A3/BTN2A1) and cytokine receptors (IL10RB/IFNAR1) are associated with variations in IFNγ secretion and that multiple SNPs in the PVR gene, as well as SNPs located in the ADAR gene, exhibit significant associations with rubella virus-specific IL-6 secretion. This information may be useful, not only in furthering our understanding immune responses to rubella vaccine, but also in identifying key pathways for targeted adjuvant use to boost immunity in those with weak or absent immunity following vaccination. PMID:25098560

Investigation of different simulation approaches on a high-head Francis turbine and comparison with model test data: Francis-99

NASA Astrophysics Data System (ADS)

Mössinger, Peter; Jester-Zürker, Roland; Jung, Alexander

2015-01-01

Numerical investigations of hydraulic turbo machines under steady-state conditions are state of the art in current product development processes. Nevertheless allow increasing computational resources refined discretization methods, more sophisticated turbulence models and therefore better predictions of results as well as the quantification of existing uncertainties. Single stage investigations are done using in-house tools for meshing and set-up procedure. Beside different model domains and a mesh study to reduce mesh dependencies, the variation of several eddy viscosity and Reynolds stress turbulence models are investigated. All obtained results are compared with available model test data. In addition to global values, measured magnitudes in the vaneless space, at runner blade and draft tube positions in term of pressure and velocity are considered. From there it is possible to estimate the influence and relevance of various model domains depending on different operating points and numerical variations. Good agreement can be found for pressure and velocity measurements with all model configurations and, except the BSL-RSM model, all turbulence models. At part load, deviations in hydraulic efficiency are at a large magnitude, whereas at best efficiency and high load operating point efficiencies are close to the measurement. A consideration of the runner side gap geometry as well as a refined mesh is able to improve the results either in relation to hydraulic efficiency or velocity distribution with the drawbacks of less stable numerics and increasing computational time.

Electronic cigarettes: product characterisation and design considerations.

PubMed

Brown, Christopher J; Cheng, James M

2014-05-01

To review the available evidence regarding electronic cigarette (e-cigarette) product characterisation and design features in order to understand their potential impact on individual users and on public health. Systematic literature searches in 10 reference databases were conducted through October 2013. A total of 14 articles and documents and 16 patents were included in this analysis. Numerous disposable and reusable e-cigarette product options exist, representing wide variation in product configuration and component functionality. Common e-cigarette components include an aerosol generator, a flow sensor, a battery and a nicotine-containing solution storage area. e-cigarettes currently include many interchangeable parts, enabling users to modify the character of the delivered aerosol and, therefore, the product's 'effectiveness' as a nicotine delivery product. Materials in e-cigarettes may include metals, rubber and ceramics. Some materials may be aerosolised and have adverse health effects. Several studies have described significant performance variability across and within e-cigarette brands. Patent applications include novel product features designed to influence aerosol properties and e-cigarette efficiency at delivering nicotine. Although e-cigarettes share a basic design, engineering variations and user modifications result in differences in nicotine delivery and potential product risks. e-cigarette aerosols may include harmful and potentially harmful constituents. Battery explosions and the risks of exposure to the e-liquid (especially for children) are also concerns. Additional research will enhance the current understanding of basic e-cigarette design and operation, aerosol production and processing, and functionality. A standardised e-cigarette testing regime should be developed to allow product comparisons.

Genetic polymorphisms associated with rubella virus-specific cellular immunity following MMR vaccination.

PubMed

Kennedy, Richard B; Ovsyannikova, Inna G; Haralambieva, Iana H; Lambert, Nathaniel D; Pankratz, V Shane; Poland, Gregory A

2014-11-01

Rubella virus causes a relatively benign disease in most cases, although infection during pregnancy can result in serious birth defects. An effective vaccine has been available since the early 1970s and outbreaks typically do not occur among highly vaccinated (≥2 doses) populations. Nevertheless, considerable inter-individual variation in immune response to rubella immunization does exist, with single-dose seroconversion rates ~95 %. Understanding the mechanisms behind this variability may provide important insights into rubella immunity. In the current study, we examined associations between single nucleotide polymorphisms (SNPs) in selected cytokine, cytokine receptor, and innate/antiviral genes and immune responses following rubella vaccination in order to understand genetic influences on vaccine response. Our approach consisted of a discovery cohort of 887 subjects aged 11-22 at the time of enrollment and a replication cohort of 542 older adolescents and young adults (age 18-40). Our data indicate that SNPs near the butyrophilin genes (BTN3A3/BTN2A1) and cytokine receptors (IL10RB/IFNAR1) are associated with variations in IFNγ secretion and that multiple SNPs in the PVR gene, as well as SNPs located in the ADAR gene, exhibit significant associations with rubella virus-specific IL-6 secretion. This information may be useful, not only in furthering our understanding immune responses to rubella vaccine, but also in identifying key pathways for targeted adjuvant use to boost immunity in those with weak or absent immunity following vaccination.

Deposition parameterizations for the Industrial Source Complex (ISC3) model

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

Wesely, Marvin L.; Doskey, Paul V.; Shannon, J. D.

2002-06-01

Improved algorithms have been developed to simulate the dry and wet deposition of hazardous air pollutants (HAPs) with the Industrial Source Complex version 3 (ISC3) model system. The dry deposition velocities (concentrations divided by downward flux at a specified height) of the gaseous HAPs are modeled with algorithms adapted from existing dry deposition modules. The dry deposition velocities are described in a conventional resistance scheme, for which micrometeorological formulas are applied to describe the aerodynamic resistances above the surface. Pathways to uptake at the ground and in vegetative canopies are depicted with several resistances that are affected by variations inmore » air temperature, humidity, solar irradiance, and soil moisture. The role of soil moisture variations in affecting the uptake of gases through vegetative plant leaf stomata is assessed with the relative available soil moisture, which is estimated with a rudimentary budget of soil moisture content. Some of the procedures and equations are simplified to be commensurate with the type and extent of information on atmospheric and surface conditions available to the ISC3 model system user. For example, standardized land use types and seasonal categories provide sets of resistances to uptake by various components of the surface. To describe the dry deposition of the large number of gaseous organic HAPS, a new technique based on laboratory study results and theoretical considerations has been developed providing a means of evaluating the role of lipid solubility in uptake by the waxy outer cuticle of vegetative plant leaves.« less

A cocaine context renews drug seeking preferentially in a subset of individuals.

PubMed

Saunders, Benjamin T; O'Donnell, Elizabeth G; Aurbach, Elyse L; Robinson, Terry E

2014-11-01

Addiction is characterized by a high propensity for relapse, in part because cues associated with drugs can acquire Pavlovian incentive motivational properties, and acting as incentive stimuli, such cues can instigate and invigorate drug-seeking behavior. There is, however, considerable individual variation in the propensity to attribute incentive salience to reward cues. Discrete and localizable reward cues act as much more effective incentive stimuli in some rats ('sign-trackers', STs), than others ('goal-trackers', GTs). We asked whether similar individual variation exists for contextual cues associated with cocaine. Cocaine context conditioned motivation was quantified in two ways: (1) the ability of a cocaine context to evoke conditioned hyperactivity and (2) the ability of a context in which cocaine was previously self-administered to renew cocaine-seeking behavior. Finally, we assessed the effects of intra-accumbens core flupenthixol, a nonselective dopamine receptor antagonist, on context renewal. In contrast to studies using discrete cues, a cocaine context spurred greater conditioned hyperactivity, and more robustly renewed extinguished cocaine seeking in GTs than STs. In addition, cocaine context renewal was blocked by antagonism of dopamine receptors in the accumbens core. Thus, contextual cues associated with cocaine preferentially acquire motivational control over behavior in different individuals than do discrete cues, and in these individuals the ability of a cocaine context to create conditioned motivation for cocaine requires dopamine in the core of the nucleus accumbens. We speculate that different individuals may be preferentially sensitive to different 'triggers' of relapse.

Questionnaire-based survey on the distribution and incidence of canine babesiosis in countries of Western Europe

PubMed Central

Halos, Lénaïg; Lebert, Isabelle; Abrial, David; Danlois, Fabien; Garzik, Karin; Rodes, Daniel; Schillmeier, Monika; Ducrot, Christian; Guillot, Jacques

2014-01-01

The incidence of canine babesiosis may vary considerably from one country to another depending on the distribution of the causative parasite species and their specific vectors. The aim of the present study was to evaluate the clinical occurrence of canine babesiosis diagnosed in European veterinary clinics and propose an updated map of the disease distribution in Western Europe. Questionnaires were sent to companion animal veterinary clinics in Spain, France, Benelux, Germany and Austria. The annual number of babesiosis cases in 2010, the number of practitioners in the clinic and the location of the clinic were recorded. The total numbers of dogs and practitioners in each country were used for definition of the reference populations and the annual incidence of canine babesiosis was calculated by dividing the total number of reported babesiosis cases by the total number of dogs in the veterinary practices involved in the study. Data were georeferenced for distribution map construction. The overall annual incidence of clinical babesiosis amongst the investigated dog population was 0.7%, with significant variations amongst countries and regions. Three epidemiological situations were described: (i) Spain, with co-existence of several species of piroplasms and patchy distribution of babesiosis, (ii) France, with overall presence of babesiosis due to Babesia canis and local variations and (iii) Benelux, Germany and Austria, with overall low prevalence of the disease associated with localised description related either to imported cases or to small autochthonous foci of B. canis infection. PMID:24626325

A biophysical model of kiwifruit (Actinidia deliciosa) berry development

PubMed Central

Hall, Alistair J.

2013-01-01

A model of kiwifruit berry development is presented, building on the model of Fishman and Génard used for peach fruit. That model has been extended to incorporate a number of important features of kiwifruit growth. First, the kiwifruit berry is attached to the stem through a pedicel/receptacle complex which contributes significantly to the hydraulic resistance between the stem and the fruit, and this resistance changes considerably during the season. Second, much of the carbohydrate in kiwifruit berries is stored as starch until the fruit matures late in the season, when the starch hydrolyses to soluble sugars. This starch storage has a major effect on the osmotic potential of the fruit, so an existing model of kiwifruit starch dynamics was included in the model. Using previously published approaches, we also included elasticity and extended the modelling period to cover both the cell division and cell expansion phases of growth. The resulting model showed close simulation of field observations of fresh weight, dry matter, starch, and soluble solids in kiwifruit. Comparison with continuous measurements of fruit diameter confirmed that elasticity was needed to adequately simulate observed diurnal variation in fruit size. Sensitivity analyses suggested that the model is particularly sensitive to variation in inputs relating to water (stem water potential and the humidity of the air), and to parameters controlling cell expansion (cell wall extensibility). Some limitations in the model structure were identified, suggesting that a revised model including current apoplastic/symplastic concepts needs to be developed. PMID:24123250

A biophysical model of kiwifruit (Actinidia deliciosa) berry development.

PubMed

Hall, Alistair J; Minchin, Peter E H; Clearwater, Michael J; Génard, Michel

2013-12-01

A model of kiwifruit berry development is presented, building on the model of Fishman and Génard used for peach fruit. That model has been extended to incorporate a number of important features of kiwifruit growth. First, the kiwifruit berry is attached to the stem through a pedicel/receptacle complex which contributes significantly to the hydraulic resistance between the stem and the fruit, and this resistance changes considerably during the season. Second, much of the carbohydrate in kiwifruit berries is stored as starch until the fruit matures late in the season, when the starch hydrolyses to soluble sugars. This starch storage has a major effect on the osmotic potential of the fruit, so an existing model of kiwifruit starch dynamics was included in the model. Using previously published approaches, we also included elasticity and extended the modelling period to cover both the cell division and cell expansion phases of growth. The resulting model showed close simulation of field observations of fresh weight, dry matter, starch, and soluble solids in kiwifruit. Comparison with continuous measurements of fruit diameter confirmed that elasticity was needed to adequately simulate observed diurnal variation in fruit size. Sensitivity analyses suggested that the model is particularly sensitive to variation in inputs relating to water (stem water potential and the humidity of the air), and to parameters controlling cell expansion (cell wall extensibility). Some limitations in the model structure were identified, suggesting that a revised model including current apoplastic/symplastic concepts needs to be developed.

Hydraulic tests in highly permeable aquifers

NASA Astrophysics Data System (ADS)

Butler, James J.; Zhan, Xiaoyong

2004-12-01

A semianalytical solution is presented for a mathematical model describing the flow of groundwater in response to a slug or pumping test in a highly permeable, confined aquifer. This solution, which is appropriate for wells of any degree of penetration and incorporates inertial mechanisms at both the test and observation wells, can be used to gain new insights into hydraulic tests in highly permeable settings. The oscillatory character of slug- and pumping-induced responses will vary considerably across a site, even in an essentially homogeneous formation, when wells of different radii, depths, and screen lengths are used. Thus variations in the oscillatory character of responses do not necessarily indicate variations in hydraulic conductivity (K). Existing models for slug tests in partially penetrating wells in high-K aquifers neglect the storage properties of the media. That assumption, however, appears reasonable for a wide range of common conditions. Unlike in less permeable formations, drawdown at an observation well in a high-K aquifer will be affected by head losses in the pumping well. Those losses, which affect the form of the pumping-induced oscillations, can be difficult to characterize. Thus analyses of observation-well drawdown should utilize data from the period after the oscillations have dissipated whenever possible. Although inertial mechanisms can have a large impact on early-time drawdown, that impact decreases rapidly with duration of pumping and distance to the observation well. Conventional methods that do not consider inertial mechanisms should therefore be viable options for the analysis of drawdown data at moderate to large times.

Hydraulic tests in highly permeable aquifers

USGS Publications Warehouse

Butler, James J.; Zhan, Xiaoyong

2004-01-01

A semianalytical solution is presented for a mathematical model describing the flow of groundwater in response to a slug or pumping test in a highly permeable, confined aquifer. This solution, which is appropriate for wells of any degree of penetration and incorporates inertial mechanisms at both the test and observation wells, can be used to gain new insights into hydraulic tests in highly permeable settings. The oscillatory character of slug‐ and pumping‐induced responses will vary considerably across a site, even in an essentially homogeneous formation, when wells of different radii, depths, and screen lengths are used. Thus variations in the oscillatory character of responses do not necessarily indicate variations in hydraulic conductivity (K). Existing models for slug tests in partially penetrating wells in high‐K aquifers neglect the storage properties of the media. That assumption, however, appears reasonable for a wide range of common conditions. Unlike in less permeable formations, drawdown at an observation well in a high‐K aquifer will be affected by head losses in the pumping well. Those losses, which affect the form of the pumping‐induced oscillations, can be difficult to characterize. Thus analyses of observation‐well drawdown should utilize data from the period after the oscillations have dissipated whenever possible. Although inertial mechanisms can have a large impact on early‐time drawdown, that impact decreases rapidly with duration of pumping and distance to the observation well. Conventional methods that do not consider inertial mechanisms should therefore be viable options for the analysis of drawdown data at moderate to large times.

American lookback option with fixed strike price—2-D parabolic variational inequality

NASA Astrophysics Data System (ADS)

Chen, Xiaoshan; Yi, Fahuai; Wang, Lihe

In this paper we study a 2-dimensional parabolic variational inequality with financial background. We define a suitable weak formula and obtain existence and uniqueness of the problem. Moreover we analyze the behaviors of the free boundary surface.

Intragenomic variation in the ITS rDNA region obscures phylogenetic relationships and inflates estimates of operational taxonomic units in genus Laetiporus

Treesearch

Daniel L. Lindner; Mark T. Banik

2011-01-01

Regions of rDNA are commonly used to infer phylogenetic relationships among fungal species and as DNA barcodes for identification. These regions occur in large tandem arrays, and concerted evolution is believed to reduce intragenomic variation among copies within these arrays, although some variation still might exist. Phylogenetic studies typically use consensus...

Variation in psychotropic drug use in nursing homes.

PubMed

Castle, N G

1998-01-01

Numerous studies of health service use reveal considerable variation in the degree of services provided. In this article the variation in psychotropic drug use in nursing homes is examined. First, a descriptive analysis of nursing homes with and without high levels of psychotropic drug use is provided. Second, an analysis of the determinants of high levels of psychotropic drug use in nursing homes is provided. Factors such as ownership, staffing levels, having special care units, case-mix intensity, competitiveness of the nursing home market, and the state Medicaid reimbursement rate structure are examined. The results of these analyses are discussed in terms of their policy issues.

Rationale and methods for an epidemiologic study of cancer among Seventh-Day Adventists.

PubMed

Phillips, R L; Kuzma, J W

1977-12-01

Considerable evidence was found that Adventists are a low-risk population to develop cancer of many sites. Adventists have numerous unique life-style and dietary habits with great variability within the population in adherence to these practices as well as considerable variation in duration of exposure to these characteristics. Thus this study population will likely be extremely productive in identifying dietary habits or other life-style characteristics that are etiologically related to various cancer sites.

Multiscale 3D Shape Analysis using Spherical Wavelets

PubMed Central

Nain, Delphine; Haker, Steven; Bobick, Aaron; Tannenbaum, Allen

2013-01-01

Shape priors attempt to represent biological variations within a population. When variations are global, Principal Component Analysis (PCA) can be used to learn major modes of variation, even from a limited training set. However, when significant local variations exist, PCA typically cannot represent such variations from a small training set. To address this issue, we present a novel algorithm that learns shape variations from data at multiple scales and locations using spherical wavelets and spectral graph partitioning. Our results show that when the training set is small, our algorithm significantly improves the approximation of shapes in a testing set over PCA, which tends to oversmooth data. PMID:16685992

Multiscale 3D shape analysis using spherical wavelets.

PubMed

Nain, Delphine; Haker, Steven; Bobick, Aaron; Tannenbaum, Allen R

2005-01-01

Shape priors attempt to represent biological variations within a population. When variations are global, Principal Component Analysis (PCA) can be used to learn major modes of variation, even from a limited training set. However, when significant local variations exist, PCA typically cannot represent such variations from a small training set. To address this issue, we present a novel algorithm that learns shape variations from data at multiple scales and locations using spherical wavelets and spectral graph partitioning. Our results show that when the training set is small, our algorithm significantly improves the approximation of shapes in a testing set over PCA, which tends to oversmooth data.

Regulatory Approaches for Adding Capacity to Existing Hydropower Facilities

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

Levine, Aaron L.; Curtis, Taylor L.; Kazerooni, Borna

In 2015, hydroelectric generation accounted for more than 6 percent of total net electricity generation in the United States and 46 percent of electricity generation from all renewables. The United States has considerable hydroelectric potential beyond what is already being developed. Nearly 7 GW of this potential is found by adding capacity to existing hydropower facilities. To optimize the value of hydroelectric generation, the U.S. Department of Energy's Hydropower Vision Study highlights the importance of adding capacity to existing facilities. This report provides strategic approaches and considerations for Federal Energy Regulatory Commission licensed and exempt hydropower facilities seeking to increasemore » generation capacity, which may include increases from efficiency upgrades. The regulatory approaches reviewed for this report include capacity and non-capacity amendments, adding capacity during relicensing, and adding capacity when converting a license to a 10-MW exemption.« less

Schizoaffective disorder: a review of current research themes and pharmacological management.

PubMed

Kantrowitz, Joshua T; Citrome, Leslie

2011-04-01

Despite a clear recognition of the existence of patients with co-morbid psychotic and mood symptoms, many studies conclude that schizoaffective disorder as a distinct diagnosis does not exist. Regardless of one's opinion on schizoaffective disorder, psychiatrists remain dependent on phenomenological descriptions for diagnosing psychiatric disorders, and these phenomenological criteria are also used for clinical trial entry. On the other hand, many psychiatrists prescribe for specific target symptoms and do not always rigidly follow diagnostic systems and, moreover, there have been very few trials that have specifically studied schizoaffective disorder. Despite recent intriguing work in epidemiology, genetics, neurocognition and electrophysiology, the diagnosis of schizoaffective disorder remains controversial. Taken together, these studies suggest that even if schizoaffective disorder exists as a separate diagnosis, it may not be useful clinically due to considerable variation in the general use of this term. It is possible that diagnostic criteria in the future will include genetic, imaging and electrophysiological components, and that this will allow for better differentiation of disease states among the heterogeneous pool of patients currently believed to have schizophrenia, schizoaffective disorder or bipolar disorder. Although it is likely that most, if not all, antipsychotics are effective for schizoaffective disorder, given recent regulatory approval of a specific antipsychotic agent for the acute treatment of schizoaffective disorder, greater attention is now being focused on the entity of schizoaffective disorder and potential treatment decisions. However, based on the limited extant evidence, it is not yet possible to make definitive treatment recommendations for schizoaffective disorder. Additional clinical trials that include other antipsychotics, mood stabilizers and antidepressants are desirable and necessary before clear and comprehensive evidence-based treatment recommendations can be made.

Measuring Stress Before and During Pregnancy: A Review of Population-Based Studies of Obstetric Outcomes

PubMed Central

Witt, Whitney; Litzelman, Kristin; Cheng, Erika R; Wakeel, Fathima; Barker, Emily S.

2013-01-01

Objectives Mounting evidence from clinic and convenience samples suggests that stress is an important predictor of adverse obstetric outcomes. Using a proposed theoretical framework, this review identified and synthesized the population-based literature on the measurement of stress prior to and during pregnancy in relation to obstetric outcomes. Methods Population-based, peer-reviewed empirical articles that examined stress prior to or during pregnancy in relation to obstetric outcomes were identified in the PubMed and PsycInfo databases. Articles were evaluated to determine the domain(s) of stress (environmental, psychological, and/or biological), period(s) of stress (preconception and/or pregnancy), and strength of the association between stress and obstetric outcomes. Results Thirteen studies were evaluated. The identified studies were all conducted in developed countries. The majority of studies examined stress only during pregnancy (n=10); three examined stress during both the preconception and pregnancy periods (n=3). Most studies examined the environmental domain (e.g., life events) only (n=9), two studies examined the psychological domain only, and two studies examined both. No study incorporated a biological measure of stress. Environmental stressors before and during pregnancy were associated with worse obstetric outcomes, although some conflicting findings exist. Conclusions Few population-based studies have examined stress before or during pregnancy in relation to obstetric outcomes. Although considerable variation exists in the measurement of stress across studies, environmental stress increased the risk for poor obstetric outcomes. Additional work using a lifecourse approach is needed to fill the existing gaps in the literature and to develop a more comprehensive understanding of the mechanisms by which stress impacts obstetric outcomes. PMID:23447085

Modelling approaches: the case of schizophrenia.

PubMed

Heeg, Bart M S; Damen, Joep; Buskens, Erik; Caleo, Sue; de Charro, Frank; van Hout, Ben A

2008-01-01

Schizophrenia is a chronic disease characterized by periods of relative stability interrupted by acute episodes (or relapses). The course of the disease may vary considerably between patients. Patient histories show considerable inter- and even intra-individual variability. We provide a critical assessment of the advantages and disadvantages of three modelling techniques that have been used in schizophrenia: decision trees, (cohort and micro-simulation) Markov models and discrete event simulation models. These modelling techniques are compared in terms of building time, data requirements, medico-scientific experience, simulation time, clinical representation, and their ability to deal with patient heterogeneity, the timing of events, prior events, patient interaction, interaction between co-variates and variability (first-order uncertainty). We note that, depending on the research question, the optimal modelling approach should be selected based on the expected differences between the comparators, the number of co-variates, the number of patient subgroups, the interactions between co-variates, and simulation time. Finally, it is argued that in case micro-simulation is required for the cost-effectiveness analysis of schizophrenia treatments, a discrete event simulation model is best suited to accurately capture all of the relevant interdependencies in this chronic, highly heterogeneous disease with limited long-term follow-up data.

Analysis of growth of tetraploid nuclei in roots of Vicia faba.

PubMed

Bansal, J; Davidson, D

1978-03-01

Growth of nuclei of a marked population of cells was determined from G1 to prophase in roots of Vicia faba. The cells were marked by inducing them to become tetraploid by treatment with 0.002% colchicine for 1 hr. Variation in nuclear volume is large; it is established in early G1 and maintained through interphase and into prophase. One consequence of this variation is that there is considerable overlap between volumes of nuclei of different ages in the cell cycle; nuclear volume, we suggest, cannot be used as an accurate indicator of the age of the cell in its growth cycle. Nuclei exhibit considerable variation in their growth rate through the cell cycle. Of the marked population of cells, about 65% had completed a cell cycle 14--15 hr after they were formed. These tetraploid nuclei have a cell cycle duration similar to that of fast cycling diploid cells of the same roots. Since they do complete a cell cycle, at least 65% of the nuclei studied must come from rapidly proliferating cells, showing that variability in nuclear volumes must be present in growing cells and cannot be attributed solely to the presence, in our samples, of non-cycling cells.

Physiotherapy for cystic fibrosis in Australia and New Zealand: A clinical practice guideline*

PubMed Central

Wilson, Christine; Dentice, Ruth; Cox, Narelle S.; Middleton, Anna; Tannenbaum, Esta; Bishop, Jennifer; Cobb, Robyn; Burton, Kate; Wood, Michelle; Moran, Fiona; Black, Ryan; Bowen, Summar; Day, Rosemary; Depiazzi, Julie; Doiron, Katherine; Doumit, Michael; Dwyer, Tiffany; Elliot, Alison; Fuller, Louise; Hall, Kathleen; Hutchins, Matthew; Kerr, Melinda; Lee, Annemarie L.; Mans, Christina; O'Connor, Lauren; Steward, Ranjana; Potter, Angela; Rasekaba, Tshepo; Scoones, Rebecca; Tarrant, Ben; Ward, Nathan; West, Samantha; White, Dianne; Wilson, Lisa; Wood, Jamie; Holland, Anne E.

2016-01-01

Abstract Physiotherapy management is a key element of care for people with cystic fibrosis (CF) throughout the lifespan. Although considerable evidence exists to support physiotherapy management of CF, there is documented variation in practice. The aim of this guideline is to optimize the physiotherapy management of people with CF in Australia and New Zealand. A systematic review of the literature in key areas of physiotherapy practice for CF was undertaken. Recommendations were formulated based on National Health and Medical Research Council (Australia) guidelines and considered the quality, quantity and level of the evidence; the consistency of the body of evidence; the likely clinical impact; and applicability to physiotherapy practice in Australia and New Zealand. A total of 30 recommendations were made for airway clearance therapy, inhalation therapy, exercise assessment and training, musculoskeletal management, management of urinary incontinence, managing the newly diagnosed patient with CF, delivery of non‐invasive ventilation, and physiotherapy management before and after lung transplantation. These recommendations can be used to underpin the provision of evidence‐based physiotherapy care to people with CF in Australia and New Zealand. PMID:27086904

Using Animal Models to Determine the Role of Gustatory Neural Input in the Control of Ingestive Behavior and the Maintenance of Body Weight

PubMed Central

Ciullo, Dana L.

2015-01-01

Introduction Decades of research have suggested that nutritional intake contributes to the development of human disease, mainly by influencing the development of obesity and obesity-related conditions. A relatively large body of research indicates that functional variation in human taste perception can influence nutritional intake as well as body mass accumulation. However, there are a considerable number of studies that suggest that no link between these variables actually exists. These discrepancies in the literature likely result from the confounding influence of a variety of other, uncontrolled, factors that can influence ingestive behavior. Strategy In this review, the use of controlled animal experimentation to alleviate at least some of these issues related to the lack of control of experimental variables is discussed. Specific examples of the use of some of these techniques are examined. Discussion and conclusions The review will close with some specific suggestions aimed at strengthening the link between gustatory neural input and its putative influence on ingestive behaviors and the maintenance of body weight. PMID:26557212

Multiple solutions and numerical analysis to the dynamic and stationary models coupling a delayed energy balance model involving latent heat and discontinuous albedo with a deep ocean.

PubMed

Díaz, J I; Hidalgo, A; Tello, L

2014-10-08

We study a climatologically important interaction of two of the main components of the geophysical system by adding an energy balance model for the averaged atmospheric temperature as dynamic boundary condition to a diagnostic ocean model having an additional spatial dimension. In this work, we give deeper insight than previous papers in the literature, mainly with respect to the 1990 pioneering model by Watts and Morantine. We are taking into consideration the latent heat for the two phase ocean as well as a possible delayed term. Non-uniqueness for the initial boundary value problem, uniqueness under a non-degeneracy condition and the existence of multiple stationary solutions are proved here. These multiplicity results suggest that an S-shaped bifurcation diagram should be expected to occur in this class of models generalizing previous energy balance models. The numerical method applied to the model is based on a finite volume scheme with nonlinear weighted essentially non-oscillatory reconstruction and Runge-Kutta total variation diminishing for time integration.

Chronic Subdural Hematoma: A Questionnaire Survey of Management Practice in India and Review of Literature.

PubMed

Avanali, Raghunath; Bhadran, Biju; Krishna Kumar, P; Vijayan, Abhishek; Arun, S; Musthafa, Aneeze M; Panchal, Sunil; Gopal, Vinu V

2016-12-01

To identify the current management modalities practiced by neurosurgeons in India for chronic subdural hematoma. A questionnaire was prepared for the survey and sent via e-mail to neurosurgeons. It covered the following aspects of managing chronic subdural hematoma: 1) demographic and institutional details; 2) choice of surgical procedure; 3) surgical adjutants such as placing a subdural drain; 4) pre- and postoperative care; and 5) recurrences and management. Responses obtained were entered in a SPSS data sheet and analyzed. Response rate of the survey was 9.3%. The majority of neurosurgeons (75%) preferred to do burr whole drainage for primary chronic subdural hematoma and also for recurrences. Only one third of routinely placed a subdural drain. Considerable practice variations exist for medical and perioperative management. Bedside twist drill drainage, which is effective and less costly than operative room procedures, has not gained popularity in practice. The present survey points towards the importance of making management guidelines for this common neurosurgical entity. Copyright © 2016 Elsevier Inc. All rights reserved.

Scrutinizing MHC-I binding peptides and their limits of variation.

PubMed

Koch, Christian P; Perna, Anna M; Pillong, Max; Todoroff, Nickolay K; Wrede, Paul; Folkers, Gerd; Hiss, Jan A; Schneider, Gisbert

2013-01-01

Designed peptides that bind to major histocompatibility protein I (MHC-I) allomorphs bear the promise of representing epitopes that stimulate a desired immune response. A rigorous bioinformatical exploration of sequence patterns hidden in peptides that bind to the mouse MHC-I allomorph H-2K(b) is presented. We exemplify and validate these motif findings by systematically dissecting the epitope SIINFEKL and analyzing the resulting fragments for their binding potential to H-2K(b) in a thermal denaturation assay. The results demonstrate that only fragments exclusively retaining the carboxy- or amino-terminus of the reference peptide exhibit significant binding potential, with the N-terminal pentapeptide SIINF as shortest ligand. This study demonstrates that sophisticated machine-learning algorithms excel at extracting fine-grained patterns from peptide sequence data and predicting MHC-I binding peptides, thereby considerably extending existing linear prediction models and providing a fresh view on the computer-based molecular design of future synthetic vaccines. The server for prediction is available at http://modlab-cadd.ethz.ch (SLiDER tool, MHC-I version 2012).

The impact of the tax system on health insurance coverage.

PubMed

Gruber, J

2001-01-01

A central question in health economics is the extent to which this tax subsidization matters for the health insurance coverage of the U.S. population. I assess the impact of taxes on health insurance by using the considerable existing variation in tax subsidies, both at a point in time and across time. I do so by putting together data from more than a decade of Current Population Survey (CPS) data sets, and matching to workers in those data sets their tax subsidies to health insurance coverage. I find that the elasticity of insurance eligibility of workers is at least -0.6, and that the elasticity of own insurance coverage is roughly similar; the results imply that most of the impact of taxes on insurance coverage arise through firm offering and eligibility decisions. I also find that higher tax rates induce more private coverage through other sources, but less public coverage, so that overall there is a reduction in the rate of uninsurance that is comparable to the change in own employer-provided insurance coverage.

Distribution of human waste samples in relation to sizing waste processing in space

NASA Technical Reports Server (NTRS)

Parker, Dick; Gallagher, S. K.

1992-01-01

Human waste processing for closed ecological life support systems (CELSS) in space requires that there be an accurate knowledge of the quantity of wastes produced. Because initial CELSS will be handling relatively few individuals, it is important to know the variation that exists in the production of wastes rather than relying upon mean values that could result in undersizing equipment for a specific crew. On the other hand, because of the costs of orbiting equipment, it is important to design the equipment with a minimum of excess capacity because of the weight that extra capacity represents. A considerable quantity of information that had been independently gathered on waste production was examined in order to obtain estimates of equipment sizing requirements for handling waste loads from crews of 2 to 20 individuals. The recommended design for a crew of 8 should hold 34.5 liters per day (4315 ml/person/day) for urine and stool water and a little more than 1.25 kg per day (154 g/person/day) of human waste solids and sanitary supplies.

Learning may need only a few bits of synaptic precision

NASA Astrophysics Data System (ADS)

Baldassi, Carlo; Gerace, Federica; Lucibello, Carlo; Saglietti, Luca; Zecchina, Riccardo

2016-05-01

Learning in neural networks poses peculiar challenges when using discretized rather then continuous synaptic states. The choice of discrete synapses is motivated by biological reasoning and experiments, and possibly by hardware implementation considerations as well. In this paper we extend a previous large deviations analysis which unveiled the existence of peculiar dense regions in the space of synaptic states which accounts for the possibility of learning efficiently in networks with binary synapses. We extend the analysis to synapses with multiple states and generally more plausible biological features. The results clearly indicate that the overall qualitative picture is unchanged with respect to the binary case, and very robust to variation of the details of the model. We also provide quantitative results which suggest that the advantages of increasing the synaptic precision (i.e., the number of internal synaptic states) rapidly vanish after the first few bits, and therefore that, for practical applications, only few bits may be needed for near-optimal performance, consistent with recent biological findings. Finally, we demonstrate how the theoretical analysis can be exploited to design efficient algorithmic search strategies.

Teaching This Class Drives Me Nuts! - Examining the Person and Context Specificity of Teacher Emotions

PubMed Central

Pekrun, Reinhard; Goetz, Thomas

2015-01-01

Teachers’ emotions are critically important for the quality of classroom instruction, and they are key components of teachers’ psychological well-being. Past research has focused on individual differences between teachers, whereas within-teacher variation across contexts has rarely been considered. As such, the present research addresses the long-standing yet unresolved person-situation debate pertaining to the emotional experiences of teachers. In two diary studies (N = 135, 70% female, and N = 85, 28% female), we examined the role of person, academic subject, and group of students for teacher emotions; focusing on three of the most salient emotions found in teachers: enjoyment, anger, and anxiety. Findings from multi-level analysis confirmed the person specificity of enjoyment, anger, and, in particular, anxiety. In addition, underscoring the existence of within-teacher variability, findings supported that teachers’ emotions considerably varied depending on the subject and group of students taught, particularly so for enjoyment and anger. Implications of the person and context specificity of teacher emotions are discussed in relation to assessments and intervention programs aiming to improve teachers’ emotional lives in the classroom. PMID:26053623

A special protection scheme utilizing trajectory sensitivity analysis in power transmission

NASA Astrophysics Data System (ADS)

Suriyamongkol, Dan

In recent years, new measurement techniques have provided opportunities to improve the North American Power System observability, control and protection. This dissertation discusses the formulation and design of a special protection scheme based on a novel utilization of trajectory sensitivity techniques with inputs consisting of system state variables and parameters. Trajectory sensitivity analysis (TSA) has been used in previous publications as a method for power system security and stability assessment, and the mathematical formulation of TSA lends itself well to some of the time domain power system simulation techniques. Existing special protection schemes often have limited sets of goals and control actions. The proposed scheme aims to maintain stability while using as many control actions as possible. The approach here will use the TSA in a novel way by using the sensitivities of system state variables with respect to state parameter variations to determine the state parameter controls required to achieve the desired state variable movements. The initial application will operate based on the assumption that the modeled power system has full system observability, and practical considerations will be discussed.

Damage assessment of composite plate structures with material and measurement uncertainty

NASA Astrophysics Data System (ADS)

Chandrashekhar, M.; Ganguli, Ranjan

2016-06-01

Composite materials are very useful in structural engineering particularly in weight sensitive applications. Two different test models of the same structure made from composite materials can display very different dynamic behavior due to large uncertainties associated with composite material properties. Also, composite structures can suffer from pre-existing imperfections like delaminations, voids or cracks during fabrication. In this paper, we show that modeling and material uncertainties in composite structures can cause considerable problem in damage assessment. A recently developed C0 shear deformable locking free refined composite plate element is employed in the numerical simulations to alleviate modeling uncertainty. A qualitative estimate of the impact of modeling uncertainty on the damage detection problem is made. A robust Fuzzy Logic System (FLS) with sliding window defuzzifier is used for delamination damage detection in composite plate type structures. The FLS is designed using variations in modal frequencies due to randomness in material properties. Probabilistic analysis is performed using Monte Carlo Simulation (MCS) on a composite plate finite element model. It is demonstrated that the FLS shows excellent robustness in delamination detection at very high levels of randomness in input data.

Odor-Sensing System to Support Social Participation of People Suffering from Incontinence

PubMed Central

Ortiz Pérez, Alvaro; Kallfaß-de Frenes, Vera; Filbert, Alexander; Kneer, Janosch; Bierer, Benedikt; Held, Pirmin; Klein, Philipp; Wöllenstein, Jürgen; Benyoucef, Dirk; Kallfaß, Sigrid; Mescheder, Ulrich; Palzer, Stefan

2016-01-01

This manuscript describes the design considerations, implementation, and laboratory validation of an odor sensing module whose purpose is to support people that suffer from incontinence. Because of the requirements expressed by the affected end-users the odor sensing unit is realized as a portable accessory that may be connected to any pre-existing smart device. We have opted for a low-cost, low-power consuming metal oxide based gas detection approach to highlight the viability of developing an inexpensive yet helpful odor recognition technology. The system consists of a hotplate employing, inkjet-printed p-type semiconducting layers of copper(II) oxide, and chromium titanium oxide. Both functional layers are characterized with respect to their gas-sensitive behavior towards humidity, ammonia, methylmercaptan, and dimethylsulfide and we demonstrate detection limits in the parts-per-billion range for the two latter gases. Employing a temperature variation scheme that reads out the layer’s resistivity in a steady-state, we use each sensor chip as a virtual array. With this setup, we demonstrate the feasibility of detecting odors associated with incontinence. PMID:28036081