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Sample records for sward density affect

  1. Linking Management, Environment and Morphogenetic and Structural Components of a Sward for Simulating Tiller Density Dynamics in Bahiagrass (Paspalum notatum

    Directory of Open Access Journals (Sweden)

    Masahiko Hirata

    2015-06-01

    Full Text Available A model which describes tiller density dynamics in bahiagrass (Paspalum notatum Flügge swards has been developed. The model incorporates interrelationships between various morphogenetic and structural components of the sward and uses the inverse of the self-thinning rule as the standard relationship between tiller density and tiller weight (a density-size equilibrium toward which tiller density progressively changes over time under varying nitrogen (N rates, air temperature and season. Water and nutrient limitations were not considered except partial consideration of N. The model was calibrated against data from swards subjected to different N rates and cutting intensities, and further validated against data from a grazed sward and swards under different cutting intensities. As the calibration and validation results were satisfactory, the model was used as a tool to investigate the responses of tiller density to various combinations of defoliation frequencies and intensities. Simulations identified defoliation regimes required for stabilizing tiller density at an arbitrary target level, i.e., sustainable use of the sward. For example, the model predicted that tiller density can be maintained at a medium level of about 4000 m−2 under conditions ranging from weekly cuttings to an 8 cm height to 8-weekly cuttings to 4 cm. More intense defoliation is needed for higher target tiller density and vice versa.

  2. Pasture intake and milk production of dairy cows rotationally grazing on multi-species swards.

    Science.gov (United States)

    Roca-Fernández, A I; Peyraud, J L; Delaby, L; Delagarde, R

    2016-09-01

    Increasing plant species diversity has been proposed as a means for enhancing annual pasture productivity and decreasing seasonal variability of pasture production facing more frequent drought scenarios due to climate change. Few studies have examined how botanical complexity of sown swards affects cow performance. A 2-year experiment was conducted to determine how sward botanical complexity, from a monoculture of ryegrass to multi-species swards (MSS) (grasses-legumes-forb), affect pasture chemical composition and nutritive value, pasture dry matter (DM) intake, milk production and milk solids production of grazing dairy cows. Five sward species: perennial ryegrass (L as Lolium), white clover and red clover (both referred to as T as Trifolium because they were always sown together), chicory (C as Cichorium) and tall fescue (F as Festuca) were assigned to four grazing treatments by combining one (L), three (LT), four (LTC) or five (LTCF) species. Hereafter, the LT swards are called mixed swards as a single combination of ryegrass and clovers, whereas LTC and LTCF swards are called MSS as a combination of at least four species from three botanical families. The experimental area (8.7 ha) was divided into four block replicates with a mineral nitrogen fertilisation of 75 kg N/ha per year for each treatment. In total, 13 grazing rotations were carried out by applying the same grazing calendar and the same pasture allowance of 19 kg DM/cow per day above 4 cm for all treatments. Clover represented 20% of DM for mixed and MSS swards; chicory represented 30% of DM for MSS and tall fescue represented 10% of DM for LTCF swards. Higher milk production (+1.1 kg/day) and milk solids production (+0.08 kg/day) were observed for mixed swards than for ryegrass swards. Pasture nutritive value and pasture DM intake were unaffected by the inclusion of clover. Pasture DM, organic matter and NDF concentrations were lower for MSS than for mixed swards. Higher milk production (+0.8 kg

  3. Monitoring grass swards using imaging spectroscopy

    NARCIS (Netherlands)

    Schut, A.G.T.; Ketelaars, J.J.M.H.

    2003-01-01

    The potential of an imaging spectroscopy system with high spatial (0.16-1.45 mm2) and spectral resolution (5-13 nm) was explored for monitoring light interception and biomass of grass swards. Thirty-six Lolium perenne L. mini-swards were studied for a total of eleven consecutive growth periods.

  4. Imaging spectroscopy for characterisation of grass swards

    NARCIS (Netherlands)

    Schut, A.G.T.

    2003-01-01

    Keywords: Imaging spectroscopy, imaging spectrometry, remote sensing, reflection, reflectance, grass sward, white clover, recognition, characterisation, ground cover, growth monitoring, stress detection, heterogeneity quantificationThe potential of imaging spectroscopy as a tool for characterisation

  5. Novel Imaging Spectroscopy for Grass Sward Characterization

    NARCIS (Netherlands)

    Schut, A.G.T.; Ketelaars, J.J.M.H.; Meuleman, J.; Kornet, J.G.; Lokhorst, C.

    2002-01-01

    Attempts to improve grassland management may benefit from the use of new sensing techniques, such as imaging spectroscopy. In order to explore the potential of hyperspectral imaging spectroscopy for rapid and objective characterization of grass swards an experimental prototype has been developed.

  6. Hydrologic properties of grazed perennial swards in semiarid ...

    African Journals Online (AJOL)

    The hypothesis was tested that grazed perennial swards have similar hydrologic properties and threshold removal levels below which runoff increases markedly. Infiltration capacity for the perennial swards increased with increasing stubble height before leveling off towards the highest stubble height. A 50% removal of ...

  7. Hydrologic properties of grazed perennial swards in semiarid ...

    African Journals Online (AJOL)

    hope&shola

    2009-02-07

    Feb 7, 2009 ... The results support the existence of a threshold level of sward stubble height for minimizing runoff. Key words: Perennial swards, water infiltration capacity, runoff thresholds. INTRODUCTION. The trade-offs .... include different drought tolerant varieties of maize, sorghum, millet, pigeon peas and beans.

  8. Influence of sward characteristics on grazing behaviour and short ...

    African Journals Online (AJOL)

    The review showed that cattle prefer short dense leafy swards compared to senescent plant materials. This is based on research results suggesting that short dense sward possess high quantity of green materials which is relished by ruminants during grazing. The feasibility of intensifying grazing studies in the tropics, ...

  9. SWARD STRUCTURE AND NUTRITIVE VALUE OF UROCHLOA RUZIZIENSIS UNDER NITROGEN AND POTASSIUM FERTILISATION

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    KARLA RODRIGUES DE LIMA

    2017-01-01

    Full Text Available This study aimed to assess the effect of nitrogen (N and potassium (K fertilisation on the forage accumulation and nutritive value of Urochloa ruziziensis during the summer of 2010/2011 and autumn, winter, spring and summer of 2011/2012. A complete randomised block design with four treatments (0, 120, 240 and 360 kg ha-1 year-1 N and K2O and five replicates were used. The data were analysed under the PROC MIXED of SAS®. The following variables were evaluated: sward height; forage mass; forage bulk density; percentages of leaf blade dry matter, stem dry matter, and dead material dry matter; leaf blade:stem ratio; contents of dry matter and crude protein; in vitro digestibility of dry matter; neutral detergent fibre content; and lignin content of Urochloa ruziziensis. There was an interaction between the N and K levels of fertilisation and the season for all variables. In addition, there was a positive linear effect of the N and K levels of fertilisation on the forage accumulation rate, the crude protein content and the in vitro digestibility of dry matter and a negative linear effect these levels on the neutral detergent fibre and lignin contents during the spring and summer of 2011/2012. N and K fertilisation and the climate changes characteristic of each season jointly affected the accumulation and nutritive value of Urochloa ruziziensis. N and K fertilisation up to 360 kg ha-1 year-1 improved the forage accumulation and nutritive value of Urochloa ruziziensis.

  10. Grazing behavior and performance of beef cattle as a function of sward structure and herbage quality under rotational and continuous stocking on species-rich upland pasture.

    Science.gov (United States)

    Stejskalová, Michaela; Hejcmanová, Pavla; Pavlů, Vilém; Hejcman, Michal

    2013-08-01

    An experiment to reveal functional response and heifers' performance to sward characteristics and forage chemical composition was conducted for 5 years in rotational (RSS) and continuous (CSS) stocking systems on native species-rich upland grassland. We measured sward characteristics, forage chemical composition, heifers' grazing behavior and live-weight gains from July to September. Mean sward surface height was lower on CSS than on RSS; grass and forb density, and white clover stolon length, were similar. Herbage on CSS had higher crude protein content and lower crude fiber content than on RSS. No difference existed in time budgets of grazing, ruminating and resting between stocking systems and season, while grazing rates were higher on CSS. Stocking rate was 1671 and 1332 kg per ha on CSS and RSS, individual daily live-weight gain 683 and 652 g on CSS and RSS. Gain per ha was 20 kg higher on CSS. Results suggested stocking systems on native species-rich grassland had no effect on activity time budgets or animal performance. Both RSS and CSS allow similar outputs for stocking rates in terms of individual daily live-weight gain. Key parameters determining heifers' behavior and performance were sward height, grass and forb density in the sward, and content of crude fiber and protein in forage. © 2013 Japanese Society of Animal Science.

  11. Sward and milk production response to early turnout of dairy cows to pasture in Finland

    OpenAIRE

    Virkajärvi, Perttu; Sairanen, Auvo; Nousiainen, Jouni I.; Khalili, Hannele

    2003-01-01

    The timing of turnout is an important factor affecting the grazing management of dairy cows. However, its consequences are not well known in the short grazing season of northern Europe. Thus, the effect of the turnout date of dairy cows to pasture on sward regrowth, herbage mass production and milk production was studied in two experiments, 1) a grazing trial with 16 Holstein-Friesian dairy cows and 2) a plot trial where the treatments simulated the grazing trial. The treatments were early tu...

  12. Forage intake processes by goats on a massai grass pasture with different sward heights

    Directory of Open Access Journals (Sweden)

    Marcônio Martins Rodrigues

    2016-12-01

    Full Text Available The objective of this study was to evaluate the forage-intake process of goats feeding on Massai grass pastures with different heights (40, 50, 60, and 70 cm. The experimental design was completely randomized, with treatments corresponding to four sward heights with two replicates over time and space. Collected data were related to the forage-intake process and the chemical and morphological composition of the pasture. Grazing trials (45 min were performed with four Anglo-Nubian crossbred goats. Total forage mass intake, bite mass, and intake rate were expressed in relation to animal weight. Pasture density, forage mass, and leaf blade increased as forage height increased. The chemical composition of forage at the evaluated heights was similar, except for reduced crude protein content at 70-cm height. Bite rate, intake rate, and time per bite had a quadratic relationship with increasing sward height. The greatest intake rate was observed at 54.7 cm of height, with 0.136 g DM min-1 kg-1 LW. Bite rate exhibited a linear and positive correlation with increase in intake. At the 50-cm height, goats harvested a mass of 3.65 g DM bite-1 kg-1 LW, when they performed 34.5 bites per minute. Adult goats had a greater forage intake on 50-cm high Massai grass pastures because they could obtain a greater bite mass in a shorter time per bite.

  13. Sward and milk production response to early turnout of dairy cows to pasture in Finland

    Directory of Open Access Journals (Sweden)

    P. VIRKAJÄRVI

    2008-12-01

    Full Text Available The timing of turnout is an important factor affecting the grazing management of dairy cows. However,its consequences are not well known in the short grazing season of northern Europe. Thus, the effect of the turnout date of dairy cows to pasture on sward regrowth, herbage mass production and milk production was studied in two experiments,1a grazing trial with 16 Holstein-Friesian dairy cows and 2a plot trial where the treatments simulated the grazing trial.The treatments were early turnout (1 Juneand normal turnout (6 June.Early turnout decreased the annual herbage mass (HM production in the plot trial (P =0.005,but due to a higher average organic matter (OMdigestibility (P 0.05. Although early turnout had no effect on milk yields it meant easier management of pastures.;

  14. Tillering affected by sowing density and growth regulators in wheat

    Directory of Open Access Journals (Sweden)

    Samuel Luiz Fioreze

    2014-02-01

    Full Text Available Tillering capacity of wheat is highly influenced by environmental conditions and management practices. This research had as objective to evaluate tiller emission, survival and contribution to grain final yield affected by increasing sowing densities and growth regulators application in wheat. The experiment was conducted under completely randomized block design, with subdivided plots and four replications. Treatments consisted of four plant densities (30, 50, 70 and 90 plants m-1 combined with the application of growth regulators [control, (IBA+GA+KT, Trinexapac-Ethyl and (IBA+GA+KT + Trinexapac- Ethyl]. Tiller emission, contribution to dry matter accumulation and grain yield, survival and yield potential in relation to the main stem were evaluated, as well as yield components and grain final yield. The application plant growth regulators did not affect tiller emission or any other yield parameters related to the main stem. Increasing plant densities reduced tiller emission and dry matter accumulation, which led to lower tiller contribution and yield potential. Reduced plant densities increased grain yield due to higher grain number and mass per ear, making up for lower number of ears per area.

  15. Factors affecting bone mineral density in adults with cerebral palsy.

    Science.gov (United States)

    Yoon, Young Kwon; Kim, Ae Ryoung; Kim, On Yoo; Lee, Kilchan; Suh, Young Joo; Cho, Sung-Rae

    2012-12-01

    To clarify factors affecting bone mineral density (BMD) in adults with cerebral palsy (CP). Thirty-five patients with CP participated in this study. Demographic data including gender, age, body mass index (BMI), subtype according to neuromotor type and topographical distribution, ambulatory function, and functional independence measure (FIM) were investigated. The BMD of the lumbar spine and femur were measured using Dual-energy X-ray absorptiometry, and the factors affecting BMD were analyzed. The BMD had no significant association with factors such as gender, age, and subtype in adults with CP. However, BMI was significantly correlated with the BMD of lumbar spine and femur (pbasic data, suggesting the importance of treatment including weight bearing exercise and gait training in adults with CP.

  16. Stochasticity and determinism: how density-independent and density-dependent processes affect population variability.

    Science.gov (United States)

    Ohlberger, Jan; Rogers, Lauren A; Stenseth, Nils Chr

    2014-01-01

    A persistent debate in population ecology concerns the relative importance of environmental stochasticity and density dependence in determining variability in adult year-class strength, which contributes to future reproduction as well as potential yield in exploited populations. Apart from the strength of the processes, the timing of density regulation may affect how stochastic variation, for instance through climate, translates into changes in adult abundance. In this study, we develop a life-cycle model for the population dynamics of a large marine fish population, Northeast Arctic cod, to disentangle the effects of density-independent and density-dependent processes on early life-stages, and to quantify the strength of compensatory density dependence in the population. The model incorporates information from scientific surveys and commercial harvest, and dynamically links multiple effects of intrinsic and extrinsic factors on all life-stages, from eggs to spawners. Using a state-space approach we account for observation error and stochasticity in the population dynamics. Our findings highlight the importance of density-dependent survival in juveniles, indicating that this period of the life cycle largely determines the compensatory capacity of the population. Density regulation at the juvenile life-stage dampens the impact of stochastic processes operating earlier in life such as environmental impacts on the production of eggs and climate-dependent survival of larvae. The timing of stochastic versus regulatory processes thus plays a crucial role in determining variability in adult abundance. Quantifying the contribution of environmental stochasticity and compensatory mechanisms in determining population abundance is essential for assessing population responses to climate change and exploitation by humans.

  17. Intranuclear DNA density affects chromosome condensation in metazoans.

    Science.gov (United States)

    Hara, Yuki; Iwabuchi, Mari; Ohsumi, Keita; Kimura, Akatsuki

    2013-08-01

    Chromosome condensation is critical for accurate inheritance of genetic information. The degree of condensation, which is reflected in the size of the condensed chromosomes during mitosis, is not constant. It is differentially regulated in embryonic and somatic cells. In addition to the developmentally programmed regulation of chromosome condensation, there may be adaptive regulation based on spatial parameters such as genomic length or cell size. We propose that chromosome condensation is affected by a spatial parameter called the chromosome amount per nuclear space, or "intranuclear DNA density." Using Caenorhabditis elegans embryos, we show that condensed chromosome sizes vary during early embryogenesis. Of importance, changing DNA content to haploid or polyploid changes the condensed chromosome size, even at the same developmental stage. Condensed chromosome size correlates with interphase nuclear size. Finally, a reduction in nuclear size in a cell-free system from Xenopus laevis eggs resulted in reduced condensed chromosome sizes. These data support the hypothesis that intranuclear DNA density regulates chromosome condensation. This suggests an adaptive mode of chromosome condensation regulation in metazoans.

  18. Impact of combined management on the newly established pasture sward

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    Pavlína Hakrová

    2012-01-01

    Full Text Available The effect of the combined grazing and cutting management on the phytocenological characteristics was examined at the submountain paddock in the South Bohemia. The botanical scans were sampled during the five-years study (2006–2010 starting after the sowing the pasture sward in the originally arable field and 0–2 years after the beginning of the grazing (paddock A and paddock B, respectively. The paddock A was grazed all year round, whereas the paddock B was grazed in spring and autumn and cut in summer for hay. At both paddocks, Lolium perenne, Trifolium repens and Taraxacum sect. Ruderalia dominated the community of total 43 and 47 species (paddock A and B, respectively. Among the sowing species, Lolium perenne, Festuca pratensis, Poa pratensis, Festuca rubra and Trifolium repens increased its cover on both paddocks, while Phleum pratense increased its cover only at paddock B. Lolium multiflorum decreased it cover at both paddocks. Most of arable field weeds disappeared (paddock A or decreased its cover (paddock B. The cover of herb layer was higher at paddock A than at paddock B, whereas the number of species (N, the diversity (H and the equitability (J was higher at paddock B than at paddock A. The cover of herb layer increased during the study at both the paddocks, while the number of species declined at paddock A and increased at paddock B.

  19. Factors affecting the density of Brassica napus seeds

    NARCIS (Netherlands)

    Young, L.; Jalink, H.; Denkert, R.; Reaney, M.

    2006-01-01

    Brassica napus seed is composed of low density oil (0.92 g.cm(-3)) and higher density solids (1.3-1.45 g.cm(-3)). Seed buoyant density may potentially be used to determine seed oil content and to separate seeds with different oil contents, however, we have found that seeds with the lowest buoyant

  20. Shifts of community composition and population density substantially affect ecosystem function despite invariant richness

    NARCIS (Netherlands)

    Spaak, Jurg W.; Baert, Jan M.; Baird, Donald J.; Eisenhauer, Nico; Maltby, Lorraine; Pomati, Francesco; Radchuk, Viktoriia; Rohr, Jason R.; Brink, van den Paul J.; Laender, De Frederik

    2017-01-01

    There has been considerable focus on the impacts of environmental change on ecosystem function arising from changes in species richness. However, environmental change may affect ecosystem function without affecting richness, most notably by affecting population densities and community

  1. How are mortality rates affected by population density?

    CERN Document Server

    Wang, Lei; Di, Zengru; Roehner, Bertrand M

    2013-01-01

    Biologists have found that the death rate of cells in culture depends upon their spatial density. Permanent "Stay alive" signals from their neighbours seem to prevent them from dying. In a previous paper (Wang et al. 2013) we gave evidence for a density effect for ants. In this paper we examine whether there is a similar effect in human demography. We find that although there is no observable relationship between population density and overall death rates, there is a clear relationship between density and the death rates of young age-groups. Basically their death rates decrease with increasing density. However, this relationship breaks down around 300 inhabitants per square kilometre. Above this threshold the death rates remains fairly constant. The same density effect is observed in Canada, France, Japan and the United States. We also observe a striking parallel between the density effect and the so-called marital status effect in the sense that they both lead to higher suicide rates and are both enhanced fo...

  2. The effect of sward type, cutting frequency and fertilizer-N ...

    African Journals Online (AJOL)

    use

    2011-11-23

    Nov 23, 2011 ... grass/legume mixed swards), three cutting regimes (4, 8 and 12 weeks) and two nitrogen fertilizer rates. (0 and 300 kg N ... however, increased (P < 0.05) from 11 to 14% with fertilizer application compared with the control in. 2006. Type of ... The required quantity of nitrogen as Urea (46%N) was divided ...

  3. Effect of owersowing on yields and botanical composition of pasture sward

    Directory of Open Access Journals (Sweden)

    Martin Müller

    2008-01-01

    Full Text Available There are several metods of permanent pasture renovation. Different technologies were investigated on a pasture sward. Three seeders (Einböck seeder with the tine harrow, no-till Sulky disc seeder and SPP 8 strip seeder and two fertilization regimes (with no fertilization and with mineral fertilization N90P30K60 kg.ha−1 were used to determine optimum methods of establishment and the use of oversowed pasture swards. In the first year, renovated plots had a higher DM production than control plots. The pasture oversowing had no effect on herbage production in the second production year. The fertilization had no effect in the first production year with a higher clover content in the sward. The share of clovers was higher in plots oversown with the Einböck and Sulky seeders but only in the second and third cuts of the first production year and in the third cut of the second production year. The highest content of clovers was observed in the second and third cuts. There was a positive correlation between the clover content in DM yield and herbage DM production. The oversowing did not show any effect on the grass content in the pasture sward.

  4. Seasonal selection of soil types and grass swards by roan antelope in a South African savanna.

    NARCIS (Netherlands)

    Heitkönig, I.M.A.; Owen-Smith, N.

    1997-01-01

    Roan antelope are distributed mainly in regions characterized by infertile soils, offering food of low quality. We hypothesized that roan may select localities with higher soil nutrient levels and/or grass swards with more favourable properties in terms of food abundance or quality than generally

  5. Complementary effects of red clover inclusion in ryegrass-white clover swards for grazing and cutting

    DEFF Research Database (Denmark)

    Eriksen, Jørgen; Askegaard, Margrethe; Søegaard, Karen

    2014-01-01

    Increasing plant species diversity in grasslands may improve productivity and stability of yields. In a field experiment, we investigated the herbage dry-matter (DM) yield and crude protein content of two-species swards of perennial ryegrass–white clover (Lolium perenne L.–Trifolium repens L...

  6. Nitrogen fertilization of grass/clover swards under cutting or grazing by dairy cows

    DEFF Research Database (Denmark)

    Søegaard, Karen

    2009-01-01

    Intensively managed perennial ryegrass/white clover (Lolium perenne L. and Trifolium repens L.) swards receive relatively high levels of fertilizer N, and high N surpluses can subsequently be found. The N-fertilization effects on growth, yield, and herbage quality were therefore examined on three...

  7. Ski areas affect Pacific marten movement, habitat use, and density

    Science.gov (United States)

    Keith M. Slauson; William J. Zielinski; Michael K. Schwartz

    2017-01-01

    Alpine ski recreation is one of the most popular outdoor winter sports globally but often involves habitat modification and dense human activity, both of which can harm wildlife. We investigated the effects of ski area development and winter recreation activities on movement, occupancy, and density of Pacific martens (Martes caurina) in the Lake...

  8. Maximizing plant density affects broccoli yield and quality

    Science.gov (United States)

    Increased demand for fresh market bunch broccoli (Brassica oleracea L. var. italica) has led to increased production along the United States east coast. Maximizing broccoli yields is a primary concern for quickly expanding southeastern commercial markets. This broccoli plant density study was carr...

  9. Rhythmic Density Affects Listeners' Emotional Response to Microtiming

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    Olivier Senn

    2017-10-01

    – Study A investigates the effect of fixed time displacements within and between the parts played by different musicians. Listeners (n = 160 reacted negatively to irregularities within the drum track, but the mutual displacement of bass vs. drums did not have an effect.– Study B develops three metrics to calculate the average microtiming magnitude in a musical excerpt. The experiment showed that listeners' (n = 160 emotional responses to expert performance microtiming aligned with each other across styles, when microtiming magnitude was adjusted for rhythmic density. This indicates that rhythmic density is a unifying moderator for listeners' emotional response to microtiming in swing and funk.– Study C used the data from both experiments in order to compare the effect of fixed microtiming displacements (from Study A with scaled versions of the originally performed microtiming patterns (from Study B. It showed that fixed snare drum displacements irritated expert listeners more than the more flexible deviations occurring in the original performances. This provides some evidence that listeners' emotional response to microtiming deviations not only depends on the magnitude of the deviations, but also on the kind and origin of the microtiming patterns (fixed lab displacements vs. flexible performance microtiming.

  10. The effect of sward type, cutting frequency and fertilizer-N ...

    African Journals Online (AJOL)

    Tiller number per m-2 was higher (P < 0.05) in pure grass sward compared with where grass was in mixture with legume in 2007. Increasing cutting interval from 4 to 12 weeks reduced (P < 0.05) the proportion of leaf fraction from 55 to 40% in 2006. The stem fraction was increased (P < 0.05) from 32 to 42%, while the ...

  11. Assessment of Hyperspectral Remote Sensing for Analyzing the Impact of Human Trampling on Alpine Swards

    Directory of Open Access Journals (Sweden)

    Marlena Kycko

    2017-02-01

    Full Text Available Tourist traffic has been observed to cause changes in vegetation cover, particularly in alpine areas. These changes can be monitored using remote-sensing methods. This paper presents an analysis of the condition of the dominant sward species surrounding the most frequented alpine tourist trails in the Tatra National Park, one of the most visited natural mountain parks in Poland and a UNESCO Man and the Biosphere Reserve. Hyperspectral measurements of interactions between the electromagnetic spectrum and the morphology and physiology of plants were presented. The spectral properties of plants and remote-sensing vegetation indices could be used at a later date for monitoring, for example from the air. The results identified the species' sensitivity and resistance to trampling and allowed an assessment of their physiological condition. Differences were observed in the conditions of trampled and control plants. The alpine swards in the Tatra National Park were assessed as being in good condition, with only small areas located close to the most popular trails showing damage. The proposed method for analyzing the condition of alpine swards could be a useful tool for the future management of protected areas.

  12. Steers production in integrated crop-livestock systems: pasture management under different sward heights

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    Cristiane de Lima Wesp

    Full Text Available ABSTRACT The aim of this study was to evaluate the effects of different grazing intensities on forage production and animal performance of yearling steers kept under permanent grazing in an integrated crop-livestock system. The treatments consisted of areas with sward heights of 10; 20; 30 and 40 cm, and one treatment with no grazing. The pastures were of bristle oat (Avena strigosa Schreb. and annual ryegrass (Lolium multiflorum Lam. following soybean (Glycine max (L. Merr.. The variables forage mass, forage allowance and residual straw showed a positive and linear fit to the increasing sward height (P≤0.0001. Average daily gain of steers displayed a quadratic response (P = 0.0017, being optimal with increases in grazing height up to values of near 30 cm, showing a weight gain per animal of approximately 1.0 kg day-1. A similar response was seen for live weight at slaughter and carcass characteristics (P≤0.0305. The results suggest that sward heights close to 30 cm provide greater individual gains, due to the increase in forage available to each animal and the better quality of the consumed forage without compromising the residual straw destined for the following crop.

  13. Increased density of cutaneous nerve fibres in the affected dermatomes after herpes zoster therapy

    National Research Council Canada - National Science Library

    Zografakis, Charalampos; Tiniakos, Dina G; Palaiologou, Marina; Kouloukoussa, Mirsini; Kittas, Christos; Staurianeas, Nikos

    2014-01-01

    Herpes zoster neural injury was assessed by determining cutaneous nerve density in skin biopsies from the affected dermatomes of 35 adult patients with herpes zoster in the acute phase and 3 months...

  14. Initial density affects biomass – density and allometric relationships in self-thinning populations of Fagopyrum esculentum

    DEFF Research Database (Denmark)

    Li, Lei; Weiner, Jacob; Zhou, Daowei

    2013-01-01

    and the biomass–density trajectory, we grew Fagopyrum esculentum populations at three high densities and measured shoot biomass, density and the height and diameter of individual plants at six harvests. * Initial density did not affect the slope of the log biomass–log density relationship, but there was a clear...... by the biomass density: the relationship between mass and volume. Initial density could affect this by altering allometric growth in a way that influences architectural compactness. An alternative hypothesis is that competition at higher initial density is more size symmetric, which has been shown to reduce...

  15. How do visitor density and anthropogenic change in frontcountry wilderness settings affect recreation benefits?

    Science.gov (United States)

    Jeffrey R. Behan; Merton T. Richards; Martha E. Lee

    2000-01-01

    Effects on recreation benefits were assessed using questionnaires and image sets depicting visitor density ranges and anthropogenic setting changes at two heavily-visited wilderness sites. Visitor benefits were less affected by high visitor densities at the more accessible of the two sites. New age medicine wheels had a positive effect on visitor benefits, as did trail...

  16. The Comparison Between Affected and Non-Affected Side of the Calcaneal Bone Density in Chronic Hemiparetic Patients

    Directory of Open Access Journals (Sweden)

    Demet Ofluoğlu

    2005-06-01

    Full Text Available Stroke is a non-traumatic brain injury caused by occlusion or rupture of cerebral blood vessels that results in sudden neurological deficit characterized by loss of motor control, altered sensation, cognitive or language impairment, disequilibrium, or coma. Immobilization is an important risk factor for osteoporosis. The aim of this study was to compare between affected and non-affected side’s calcaneal bone mineral density in chronic hemiparetic patients. Thirty-tree unilateral and independently mobile hemiparetic patients due to stroke were included in the study. The exclusion criteria were to have poor general health status, bilateral involvement, congenital dislocation of hip and past calcaneal fracture history. Motor functional level, spasticity and daily living activities of the patients were assessed by using Brunstrom, Ashworth and Barthel scales, respectively. The calcaneal bone mineral density was evaluated with DXL-Calscan in both affected and non-affected side of all patients. Patients’ mean age and duration of disease were 58.9±11.9 years and 20±19.4 months, respectively. 48.5% of patients were male and 60.6% has right side hemiparesis. Their mean spasticity level was 1.6±1.2 according to Ashworth Scale. Mean motor functional level and activity of daily living score were 4.5±1 and 87.4±22.2, respectively. The calcaneal mean T score was –2.1±0.9 and –1.7±0.7 in affected and non-affected side, respectively. In the pearson correlation analysis, there were positive correlation between age and non-affected Z score (r=0.42, p=0.01; Brunstrom score and affected side T score (r=0.48, p=0.005; Brunstrom score and affected side BMD (r=0.51, p=0.002. On the other hand, there were negative correlation between age and disease duration (r=-0.36, p=0.03; Ashworth score and Brunstrom (r=-0.66, p=0.0001, affected side T score (r=-0.41, p=0.01, affected side Z score (r=-0.35, p=0.04, affected BMD (r=-0.46, p=0.01. However, there was no

  17. Sistema de integração lavoura-pecuária: efeito do manejo da altura em pastagem de aveia preta e azevém anual sobre o rendimento da cultura da soja Crop-livestock integration system: effect of oat and italian ryegrass sward height management on soybean yield

    Directory of Open Access Journals (Sweden)

    Marília Lazzarotto Terra Lopes

    2009-08-01

    management. Forage accumulation rate was not influenced by treatments. Stocking rate decreased linearly with increasing sward height. Post grazing herbage mass increased with increasing sward height. Treatments had effect on initial soybean stand, but soybean yield was not affected. Results suggest grazing animals do not damage succeeding crop, allowing farmers profitability enhancement by using those areas during soybean intercropping.

  18. Effects of chicory/perennial ryegrass swards compared with perennial ryegrass swards on the performance and carcass quality of grazing beef steers.

    Directory of Open Access Journals (Sweden)

    Christina L Marley

    Full Text Available An experiment investigated whether the inclusion of chicory (Cichorium intybus in swards grazed by beef steers altered their performance, carcass characteristics or parasitism when compared to steers grazing perennial ryegrass (Lolium perenne. Triplicate 2-ha plots were established with a chicory/ryegrass mix or ryegrass control. Forty-eight Belgian Blue-cross steers were used in the first grazing season and a core group (n = 36 were retained for finishing in the second grazing season. The experiment comprised of a standardisation and measurement period. During standardisation, steers grazed a ryegrass/white clover pasture as one group. Animals were allocated to treatment on the basis of liveweight, body condition and faecal egg counts (FEC determined 7 days prior to the measurement period. The measurement period ran from 25 May until 28 September 2010 and 12 April until 11 October 2011 in the first and second grazing year. Steers were weighed every 14 days at pasture or 28 days during housing. In the first grazing year, faecal samples were collected for FEC and parasite cultures. At the end of the first grazing year, individual blood samples were taken to determine O. ostertagi antibody and plasma pepsinogen levels. During winter, animals were housed as one group and fed silage. In the second grazing year, steers were slaughtered when deemed to reach fat class 3. Data on steer performance showed no differences in daily live-weight gain which averaged 1.04 kg/day. The conformation, fat grade and killing out proportion of beef steers grazing chicory/ryegrass or ryegrass were not found to differ. No differences in FEC, O. ostertagi antibody or plasma pepsinogen levels of beef steers grazing either chicory/ryegrass or ryegrass were observed. Overall, there were no detrimental effects of including chicory in swards grazed by beef cattle on their performance, carcass characteristics or helminth parasitism, when compared with steers grazing ryegrass.

  19. Effects of sward structure on herbivore foraging behaviour in a South-African savanna: an investigation of the forage maturation hypothesis

    NARCIS (Netherlands)

    Drescher, M.F.; Heitkönig, I.M.A.; Brink, van den P.; Prins, H.H.T.

    2006-01-01

    The grass layer of savannas is characterized by strong temporal and spatial heterogeneity in the quantity and quality of forage. Besides this, there is strong variation in other aspects of sward structure, here defined as sward chemistry, morphology, architecture and species composition. The forage

  20. Performance of 'Rocha' and 'Santa Maria' pears as affected by planting density

    Directory of Open Access Journals (Sweden)

    Mateus da Silveira Pasa

    2015-02-01

    Full Text Available The objective of this work was to evaluate the performance of 'Rocha' and 'Santa Maria' pears at two planting densities. The experiment was carried out during the 2011/2012, 2012/2013, and 2013/2014 growing seasons, in one-year-old orchards (2011/2012 of 'Rocha' and 'Santa Maria' pears, trained in a central-leader system and planted in two densities (2,000 and 4,000 trees per hectare. The assessed parameters were: production per hectare, production per tree, yield efficiency, number of fruit per tree, average fruit weight, trunk diameter increment, fruit firmness, and soluble solid contents. The cumulative yield of 'Rocha' is greater at the higher planting density, whereas the yield efficiency of 'Santa Maria' increases at the lower planting density, as the trees get more mature. Trunk diameter of 'Rocha' also increases at the lower planting density. However, fruit quality parameters in both cultivars are little affected by planting density.

  1. Do Phytomer Turnover Models of Plant Morphology Describe Perennial Ryegrass Root Data from Field Swards?

    Directory of Open Access Journals (Sweden)

    Cory Matthew

    2016-07-01

    Full Text Available This study aimed to elucidate seasonal dynamics of ryegrass root systems in field swards. Established field swards of perennial ryegrass with white clover removed by herbicide and fertilised with nitrogen (N to replace clover N fixation were subjected to lax and hard grazing management and root biomass deposition monitored using a root ingrowth core technique over a 13 month period. A previously published phytomer-based model of plant morphology that assumes continuous turnover of the root system was used to estimate mean individual root weight (mg not previously available for field swards. The predicted root weights compared credibly with root data from hydroponic culture and the model output explained much of the seasonal variation in the field data. In particular, root deposition showed a seasonality consistent with influence of an architectural signal (AS determined by plant morphology. This AS arises because it is theoretically expected that with rising temperatures and decreasing phyllochron in early summer, more than one leaf on average would feed each root bearing node. Conversely, in autumn the reverse would apply and root deposition is expected to be suppressed. The phytomer-based model was also able to explain deeper root penetration in summer dry conditions, as seen in the field data. A prediction of the model is that even though total root deposition is reduced by less than 10% under hard grazing, individual root weight is reduced proportionately more because the available substrate is being shared between a higher population of tillers. Two features of the field data not explained by the phytomer based model, and therefore suggestive of hormonal signaling, were peaks of root production after summer drought and in late winter that preceded associated herbage mass rises by about one month. In summary, this research supports a view that the root system of ryegrass is turning over on a continuous basis, like the leaves above ground

  2. Estimated metabolizable energy yields of perennial and annual grass swards compared with those of spring barley and oat

    Directory of Open Access Journals (Sweden)

    O. NIEMELÄINEN

    2008-12-01

    Full Text Available The dry matter yields of cultivar trials (from 1976 to 1998 at 15 sites in Finland of perennial grass sward (meadow fescue (Festuca pratensis cv. Boris, annual grass sward (Italian ryegrass (Lolium multiflorum, cv. Barmultra and Mitos, spring barley (Hordeum vulgare cv. Otra, Arra, Arve and oat (Avena sativa cv. Veli were used to estimate metabolisable energy yields (MEY by using the feeds metabolisable energy concentration values (MJ/kg DM from ruminant feed tables. Harvest index (HI of barley and oat was set to 50%, and straw yields and whole crop cereal silage (WCCS yields were generated from grain yields accordingly. The MEY in the third year of perennial grass (81.4 GJ/ha was significantly lower than that in the first (90.0 GJ/ha and second years (90.7 GJ/ha. However, on average, the one to three year old perennial grass-swards had significantly higher MEY than the annual grass swards (87.7 vs. 83.3 GJ/ha, respectively. The MEYs of perennial and annual grass swards were substantially higher than the MEY of barley grain (52.7 GJ/ha and oat grain (47. 8 GJ/ha. When the total herbage of cereals, i.e. straw and grain, was used in the calculations, at a ME value of 6.0 MJ/ kg dry matter (DM for straw, the MEY of barley rose to 75.8 GJ/ha and that of oat to 72.6 GJ/ha. Additionally, the MEY of barley was estimated in the WCCS production situation by converting total herbage to MEY by using ME value 9.9 MJ/kg DM. The MEY of barley in the WCCS calculations was 77.4 GJ/ha, which was significantly lower than the MEY of annual and perennial grass swards. The MEY of barley was a 60%, b 86%, and c 88% of the average MEY of one to three year old perennial grass sward when the MEY of barley was calculated according to a grain, b grain + straw, and c whole crop cereal silage. Perennial grass sward was the most productive of the studied crops in metabolisable energy production for ruminants.

  3. Predator density and timing of arrival affect reef fish community assembly.

    Science.gov (United States)

    Stier, Adrian C; Geange, Shane W; Hanson, Kate M; Bolker, Benjamin M

    2013-05-01

    Most empirical studies of predation use simple experimental approaches to quantify the effects of predators on prey (e.g., using constant densities of predators, such as ambient vs. zero). However, predator densities vary in time, and these effects may not be well represented by studies that use constant predator densities. Although studies have independently examined the importance of predator density, temporal variability, and timing of arrival (i.e., early or late relative to prey), the relative contribution of these different predator regimes on prey abundance, diversity, and composition remains poorly understood. The hawkfish (Paracirrhites arcatus), a carnivorous coral reef fish, exhibits substantial variability in patch occupancy, density, and timing of arrival to natural reefs. Our field experiments demonstrated that effects of hawkfish on prey abundance depended on both hawkfish density and the timing of their arrival, but not on variability in hawkfish density. Relative to treatments without hawkfish, hawkfish presence reduced prey abundance by 50%. This effect increased with a doubling of hawkfish density (an additional 33% reduction), and when hawkfish arrived later during community development (a 34% reduction). Hawkfish did not affect within-patch diversity (species richness), but they increased between-patch diversity (beta) based on species incidence (22%), and caused shifts in species composition. Our results suggest that the timing of predator arrival can be as important as predator density in modifying prey abundance and community composition.

  4. Increased density of cutaneous nerve fibres in the affected dermatomes after herpes zoster therapy.

    Science.gov (United States)

    Zografakis, Charalampos; Tiniakos, Dina G; Palaiologou, Marina; Kouloukoussa, Mirsini; Kittas, Christos; Staurianeas, Nikos

    2014-03-01

    Herpes zoster neural injury was assessed by determining cutaneous nerve density in skin biopsies from the affected dermatomes of 35 adult patients with herpes zoster in the acute phase and 3 months post-treatment, using protein gene product 9.5 immunohistochemistry. In contrast to the significant increase in subepidermal nerve fibre density (11.77 ± 4.88/mm vs. 13.29 ± 5.74/mm, p = 0.045) after 3 months, no differences were found in epidermal free nerve endings (2.43 ± 2.35/mm and 2.8 ± 2.86/mm, p = 0.168). Patients with post-herpetic neuralgia had significantly lower subepidermal nerve fibre densities (9.7 ± 2.05/mm vs. 14.72 ± 6.13/mm, p = 0.011) compared with non-post-herpetic neuralgia patients. No differences in cutaneous nerve density were found in relation to antiviral therapy. In conclusion, 3 months after acute infection, no sign of epidermal innervation recovery is observed, while the increased subepidermal nerve fibre density in the affected dermatomes probably reflects nerve regeneration that is not affected by antiviral agent type. Subepidermal nerve fibre density is decreased in patients with post-herpetic neuralgia 3-months post-acute herpes zoster infection.

  5. Sward structure and livestock performance in guinea grass cv: Tanzania pastures managed by rotational stocking strategies

    Directory of Open Access Journals (Sweden)

    Valéria Pacheco Batista Euclides

    2014-12-01

    Full Text Available Grazing strategy is a key element in the determination of sward structure, herbage nutritive value and animal performance. We aimed to compare the herbage characteristics and performance of livestock in pastures of Panicum maximum cv. Tanzania managed, using two rotational stocking strategies, which provided either a fixed-length rest period (FRP of 35 days in the spring and fall and 30 days in the summer, or a variable-length rest period (VRP, determined by the time required for the canopy to achieve 70 cm in height. The pastures were evaluated in the pregrazing condition for forage mass (FM; leaf (LP, stem (SP and dead matter (DP percentages; and nutritive value (NV. The animals were weighed every 28 days. Pastures managed with the FRPs exhibited greater FMs, SPs and DPs and lower LPs and NVs than those managed with the VRPs. The average daily livestock weight gain was greater during the spring and summer for the VRP than for the FRP pastures, resulting in an average animal weight gain per area of 990 and 860 kg ha−¹ wet period−¹ for the pastures managed with the VRPs and FRPs, respectively. Thus, pasture rest periods that were maintained after the sward reached 70 cm in height reduced the animal performance on Tanzania guinea grass.

  6. Dairy cow excreta patches change the boreal grass swards from sink to source of methane

    Directory of Open Access Journals (Sweden)

    Marja Elisa Maljanen

    2012-06-01

    Full Text Available We studied methane (CH4 flux rates from experimental excreta patches on a dairy pasture with a chamber technique during snow free seasons and with a gas gradient technique during winter from timothy-meadow fescue sward with mineral N fertilization (220 kg ha-1 and from grass-white clover mixture without fertilization. The dung and urine patches were applied in June or August two consecutive grazing seasons and the measurements were carried out for a year following each application. There were no significant differences in CH4 fluxes between plant species and emissions originated mainly from the fresh dung pats. The average annual CH4 fluxes from the control sites without excreta were -0.60±0.1 and with the excreta 0.47±0.3 kg CH4 ha-1. Thus, excreta originating from dairy cows can turn boreal swards from weak sinks to small sources of CH4. However, these emissions are only 0.2% of the total CH4 emissions from a dairy cow.

  7. Evaluation of Quality Traits of Forage Maize Cultivars as Affected by Different Plant Densities

    Directory of Open Access Journals (Sweden)

    Hamdollah Eskandari

    2017-04-01

    Full Text Available Maize has an important role in livestock nutrition. Thus, improving its forage quality through agronomical managements seems to be of high importance. To evaluate quality traits of forage maize cultivars in response to plant densities, a factorial experiment based on RCBD with three replications was carried out at the Research Station of Faculty of Agriculture, University of Maragheh during 2013-2014 growing season. The first factor was plant density with three levels (93000, 105000 and 119000 plant.ha-1 and the second factor was maize cultivars with five levels (Zola, Simon, NS, 540 and 370. Results of the experiment indicated that dry matter production was affected by the interaction of plant density and cultivar, where cultivar 540 produced the highest dry forage (980 g.m-2 by density of 119000 plant.h-1 and cultivar NS the lowest (933 g.m-2 dry forage by density of 93000 plant.m-2. However, all cultivars under study produced higher dry matter under higher plant densities. It was also observed that Zola cultivar, with 638 g.kg-1 of hemicellulose, had the lowest forage quality. Other cultivars were in the same statistical group. Phosphorous content of forage was in its highest value in 93000 plant density, while calcium content was not affected by plant density. Lower plant densities resulted in higher crude protein content. Cultivar no. 540 produced the highest crude protein yield (kg.ha-1 suggesting its superiority to the other cultivar. This cultivar can be recommended for growing in this region and other regions with same climatic conditions for producing high quality and quantity of maize forage production.

  8. Pasture management effects on diet composition and cattle performance on continuously stocked rhizoma peanut-mixed grass swards.

    Science.gov (United States)

    Valencia, E; Williams, M J; Chase, C C; Sollenberger, L E; Hammond, A C; Kalmbacher, R S; Kunkle, W E

    2001-09-01

    In Florida, rhizoma peanut (RP; Arachis glabrata Benth.), a tropical legume, combines the attributes of excellent nutritive value, competitive ability with tropical grasses, and high animal performance. The objective of this study was to determine the effects of spring N fertilization (0 vs 35 kg/ha) and summer stocking rate (1.5 and 2.5 bulls/ha) on herbage mass, nutritive value, herbage allowance, and diet botanical composition of grazed RP-grass swards and their interaction with growth and development of bulls (Senepol, and Brahman or Angus). The study was conducted in 1995 and 1996 at the USDA, ARS, Subtropical Agriculture Research Station in Brooksville, FL. Nitrogen was applied in April of each year, and all pastures were stocked with 1.5 bulls/ha until approximately July of each year, when stocking rate was increased on half the pastures to 2.5 bulls/ha. Herbage mass (HM, kg/ha), herbage allowance (HA, kg/kg BW), nutritive value (CP and in vitro organic matter digestibility [IVOMD]), and diet botanical composition (fecal microhistological) readings were determined. Animal measurements included total and seasonal (spring vs summer), ADG, hip height (cm), scrotal circumference (SC, cm), and plasma urea nitrogen (PUN, mg/dL). Herbage mass (3.0 +/- 0.12 Mg/ha and 3.4 +/- 0.13 Mg/ha in 1995 and 1996, respectively) was not affected by nitrogen fertilization or stocking rate but was affected by season (P Senepol or Brahman. There were no differences in final BW, SC, BCS, hip height, or PUN due to treatments, but breed differences were noted (P < 0.05) for all measures except BCS.

  9. Productivity affects the density-body mass relationship of soil fauna communities

    NARCIS (Netherlands)

    Comor, V.N.R.; Thakur, M.P.; Berg, M.P.; Bie, de S.; Prins, H.H.T.; Langevelde, van F.

    2014-01-01

    The productivity of ecosystems and their disturbance regime affect the structure of animal communities. However, it is not clear which trophic levels benefit the most from higher productivity or are the most impacted by disturbance. The density-body mass (DBM) relationship has been shown to reflect

  10. Herbage and animal production responses to fertilizer nitrogen in perennial ryegrass swards. II. rotational grazing and cutting

    NARCIS (Netherlands)

    Lantinga, E.A.; Deenen, P.J.A.G.; Keulen, van H.

    1999-01-01

    The yield response of grass swards to fertilizer nitrogen (N) differs under cutting and grazing, as grazing cattle exert positive and negative effects on pasture production, with varying negative effects on different soil types. Nevertheless, current N fertilization recommendations in the

  11. Effects of cultivar and cutting frequency on dynamics of stolon growth and leaf appearance in white clover in mixed swards

    NARCIS (Netherlands)

    Elgersma, A.; Li Fengrui,

    1997-01-01

    The hypothesis that dynamics of growth, branching of stolons and appearance of leaves are important for the persistence of white clover (Trifolium repens) in mixed swards was tested. The effect of cutting frequency and white clover cultivar on stolon and leaf dynamics was studied throughout the

  12. Effects of white clover cultivar and companion grass on winter survival of seedlings in autumn-sown swards

    NARCIS (Netherlands)

    Elgersma, A.; Schlepers, H.

    2003-01-01

    The aim was to study the effects of white clover cultivar and combinations with perennial ryegrass cultivars on seedling establishment in autumn-sown swards and on winter survival of seedlings. Large-leaved white clover cv. Alice and small-leaved white clover cv. Gwenda, and an erect and a prostrate

  13. Individual differences in local gray matter density are associated with differences in affective and cognitive empathy.

    Science.gov (United States)

    Eres, Robert; Decety, Jean; Louis, Winnifred R; Molenberghs, Pascal

    2015-08-15

    The understanding of empathy from a neuroscientific perspective has recently developed quickly, with numerous functional MRI studies associating different brain regions with different components of empathy. A recent meta-analysis across 40 fMRI studies revealed that affective empathy is most often associated with increased activity in the insula, whereas cognitive empathy is most often associated with activity in the midcingulate cortex and adjacent dorsomedial prefrontal cortex (MCC/dmPFC). To date, however, it remains unclear whether individual differences in brain morphometry in these regions underlie different dispositions in affective and cognitive empathy. In order to test this hypothesis, voxel-based morphometry (VBM) was used to examine the extent to which gray matter density predicts scores from an established empathy measure (Questionnaire of Cognitive and Affective Empathy; QCAE). One hundred and seventy-six participants completed the QCAE and underwent MRI in order to acquire a high-resolution, three-dimensional T1-weighted structural scans. A factor analysis of the questionnaire scores revealed two distinct factors of empathy, affective and cognitive, which confirmed the validity of the QCAE. VBM results revealed gray matter density differences associated with the distinct components of empathy. Higher scores on affective empathy were associated with greater gray matter density in the insula cortex and higher scores of cognitive empathy were associated with greater gray matter density in the MCC/dmPFC. Taken together, these results provide validation for empathy being a multi-component construct, suggesting that affective and cognitive empathy are differentially represented in brain morphometry as well as providing convergent evidence for empathy being represented by different neural and structural correlates. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Operational sex ratio and density do not affect directional selection on male sexual ornaments and behavior.

    Science.gov (United States)

    Head, Megan L; Lindholm, Anna K; Brooks, Robert

    2008-01-01

    Demographic parameters including operational sex ratio (OSR) and population density may influence the opportunity for, and strength of sexual selection. Traditionally, male-biased OSRs and high population densities have been thought to increase the opportunity for sexual selection on male sexual traits due to increased male competition for mates. Recent experimental evidence, however, suggests that male-biased OSRs might reduce the opportunity for sexual selection due to increased sexual coercion experienced by females. How OSR, density, and any resultant changes in the opportunity for sexual selection actually affect selection on male sexual traits is unclear. In this study, we independently manipulated OSR and density in the guppy (Poecilia reticulata) without altering the number of males present. We recorded male and female behavior and used DNA microsatellite data to assign paternity to offspring and estimate male reproductive success. We then used linear selection analyses to examine the effects of OSR and density on directional sexual selection on male behavioral and morphological traits. We found that females were pursued more by males in male-biased treatments, despite no change in individual male behavior. There were no differences in sexual behavior experienced by females or performed by males in relation to density. Neither OSR nor density significantly altered the opportunity for sexual selection. Also, Although there was significant multivariate linear selection operating on males, neither OSR nor density altered the pattern of sexual selection on male traits. Our results suggest that differences in either OSR or density (independent of the number of males present) are unlikely to alter directional evolutionary change in male sexual traits.

  15. Grazing intensity affects insect diversity via sward structure and heterogeneity in a long‐term experiment

    National Research Council Canada - National Science Library

    Jerrentrup, Jana Sabrina; Wrage‐Mönnig, Nicole; Röver, Klaus‐Ulrich; Isselstein, Johannes; McKenzie, Ailsa

    2014-01-01

    .... In this study, we investigate the long‐term influence of grazing and the potential for spatial patterns created by different grazing intensities to enhance insect diversity. In a long‐term experiment (2002–2011...

  16. Vapor-like liquid coexistence densities affect the extension of the critical point's influence zone

    CERN Document Server

    Rivera, Jose Luis; Guerra-Gonzalez, Roberto

    2015-01-01

    The critical point affects the coexistence behavior of the vapor-liquid equilibrium densities. The length of the critical influence zone is under debate because for some properties, like shear viscosity, the extension is only a few degrees, while for others, such as the density order parameter, the critical influence zone range covers up to hundreds of degrees below the critical temperature. Here we show that for a simple molecular potential of ethane, the critical influence zone covers a wide zone of tens of degrees (below the critical temperature) down to a transition temperature, at which the apparent critical influence zone vanishes and the transition temperature can be predicted through a pressure analysis of the coexisting bulk liquid phase. The liquid phases within the apparent critical influence zone show low densities, making them behave internally like their corresponding vapor phases. Therefore, the experimentally observed wide extension of the critical influence zone is due to a vapor-like effect ...

  17. THE INFLUENCE OF NITROGEN FERTILIZATION APPLIED IN DIFFERENT DOSES ON FODDER QUALITY OF MEADOW SWARD

    Directory of Open Access Journals (Sweden)

    Kazimierz Jankowski

    2013-07-01

    Full Text Available The experiment was organized in four replicants in arrangement split-plot with plots having a surface equal 9 m2. The basic fertilization was applied under the first regrowth. It was a mixture of unary fertilizers (ammonium nitrate, superphosphate, potassic salt or polifoska. One form of supplementary fertilization was applied under the second and third regrowth. It was the stable form of fertilizer applied to soil. This form of supplemented nitrogen gave respectively: 50 kg N·ha-l; 80 kg N·ha-l; 110 kg N·ha-1 per each moving. During the vegetation season three movings were harvested. From each movings the sampIes of green matter were taken for chemical analyses, i.e. total protein content, soluble carbohydrates and net energy (NEL. The obtained results showed large differences in fodder quality of the meadow sward fertilized with three doses of nitrogen.

  18. The share of roots, sward and stubble biomass in biological yield of selected grass species

    Directory of Open Access Journals (Sweden)

    Piotr Kacorzyk

    2013-04-01

    Full Text Available In this study assessed the share of harvested yield and share of root stem bases and stolon biomass in biological yield of 6 grass species grown in pure sowing. The biological yield included harvested yield from 3 regrowth and biomass of RSS (roots, sward and stubble, which was taken after 3 th cut. The highest biological yield was observed in Festuca rubra, next in Arrhenatherum elatiusand Poa pratensis, and the smallest in Holcus lanatus and Agropyron repens. In F. rubra harvested yield held 13.8% of biological yield, and RSS biomass held 86.2%. In contrast, in H. lanatusharvested yield was 44.7% and RSS biomass was 55.3% of biological yield.

  19. Wing wear affects wing use and choice of floral density in foraging bumble bees

    OpenAIRE

    Danusha J. Foster; Ralph V. Cartar

    2011-01-01

    Damage to structures that enable mobility can potentially influence foraging behavior. Bumble bees vary in extent of individual wing wear, a trait predicted to affect mechanical performance during foraging. This study asks 1) do bumble bees distribute themselves across different floral densities in accordance with their concurrent wing wear? and 2) does wing use in foraging bumble bees depend on concurrent wing wear? We observed individually identifiable bumble bees foraging in 1-m-super-2 pa...

  20. Yield components in wheat affected by sowing density and growth regulators

    Directory of Open Access Journals (Sweden)

    Samuel Luiz Fioreze

    2014-02-01

    Full Text Available Improvement on yield potential of plants by crop management is the main research challenge due to the growing of food demand worldwide. The objective of this work was to study physiological and morphological traits and its relationship with yield components and yield of wheat as affected by sowing densities and plant growth regulators. The experimental design was a split-plot design with four replications. The plots were consisted by four sowing densities (30, 50 70 and 90 plants m-1 and the subplots were consisted by plant growth regulators [control, (IBA+GA+KT, Trinexapac-Ethyl e (IBA+GA+KT + Trinexapac-Ethyl]. Dry matter accumulation, plant height, source-sink distance, gas exchange and yield were determined. Trinexapac-Ethyl application resulted in decreasing of plant height, source-sink distance and flag leaf length; however, the grain yield was not affected. The number of plants per unit area affected dry matter accumulation. Higher dry matter accumulation showed direct relationship with yield and yield components in lower plant densities.

  1. Expansion of adipose mesenchymal stromal cells is affected by human platelet lysate and plating density.

    Science.gov (United States)

    Cholewa, Dominik; Stiehl, Thomas; Schellenberg, Anne; Bokermann, Gudrun; Joussen, Sylvia; Koch, Carmen; Walenda, Thomas; Pallua, Norbert; Marciniak-Czochra, Anna; Suschek, Christoph V; Wagner, Wolfgang

    2011-01-01

    The composition of mesenchymal stromal cells (MSCs) changes in the course of in vitro culture expansion. Little is known how these cell preparations are influenced by culture media, plating density, or passaging. In this study, we have isolated MSCs from human adipose tissue in culture medium supplemented with either fetal calf serum (FCS) or human platelet lysate (HPL). In addition, culture expansion was simultaneously performed at plating densities of 10 or 10,000 cells/cm(2). The use of FCS resulted in larger cells, whereas HPL significantly enhanced proliferation. Notably, HPL also facilitated expansion for more population doublings than FCS (43 ± 3 vs. 22 ± 4 population doubling; p < 0.001), while plating density did not have a significant effect on long-term growth curves. To gain further insight into population dynamics, we conceived a cellular automaton model to simulate expansion of MSCS. It is based on the assumptions that the number of cell divisions is limited and that due to contact inhibition proliferation occurs only at the rim of colonies. The model predicts that low plating densities result in more heterogeneity with regard to cell division history, and favor subpopulations of higher migratory activity. In summary, HPL is a suitable serum supplement for isolation of MSC from adipose tissue and facilitates more population doublings than FCS. Cellular automaton computer simulations provided additional insights into how complex population dynamics during long-term expansion are affected by plating density and migration.

  2. Density of founder cells affects spatial pattern formation and cooperation in Bacillus subtilis biofilms

    Science.gov (United States)

    van Gestel, Jordi; Weissing, Franz J; Kuipers, Oscar P; Kovács, Ákos T

    2014-01-01

    In nature, most bacteria live in surface-attached sedentary communities known as biofilms. Biofilms are often studied with respect to bacterial interactions. Many cells inhabiting biofilms are assumed to express ‘cooperative traits', like the secretion of extracellular polysaccharides (EPS). These traits can enhance biofilm-related properties, such as stress resilience or colony expansion, while being costly to the cells that express them. In well-mixed populations cooperation is difficult to achieve, because non-cooperative individuals can reap the benefits of cooperation without having to pay the costs. The physical process of biofilm growth can, however, result in the spatial segregation of cooperative from non-cooperative individuals. This segregation can prevent non-cooperative cells from exploiting cooperative neighbors. Here we examine the interaction between spatial pattern formation and cooperation in Bacillus subtilis biofilms. We show, experimentally and by mathematical modeling, that the density of cells at the onset of biofilm growth affects pattern formation during biofilm growth. At low initial cell densities, co-cultured strains strongly segregate in space, whereas spatial segregation does not occur at high initial cell densities. As a consequence, EPS-producing cells have a competitive advantage over non-cooperative mutants when biofilms are initiated at a low density of founder cells, whereas EPS-deficient cells have an advantage at high cell densities. These results underline the importance of spatial pattern formation for competition among bacterial strains and the evolution of microbial cooperation. PMID:24694715

  3. Children's Access to Dental Care Affected by Reimbursement Rates, Dentist Density, and Dentist Participation in Medicaid.

    Science.gov (United States)

    Chalmers, Natalia I; Compton, Robert D

    2017-10-01

    To assess the relation between Medicaid reimbursement rates and access to dental care services in the context of dentist density and dentist participation in Medicaid in each state. Data were from Early and Periodic Screening, Diagnostic, and Treatment reports for 2014, Medicaid reimbursement rate in 2013, dentist density in 2014, and dentist participation in Medicaid in 2014. We assessed patterns of mediation or moderation. Reimbursement rates and access to dental care were directly related at the state level, but no evidence indicated that higher reimbursement rates resulted in overuse of dental services for those who had access. The relation between reimbursement rates and access to care was moderated by dentist density and dentist participation in Medicaid. We estimate that more than 1.8 million additional children would have had access to dental care if reimbursement rates were higher in states with low rates. Children who access the dental care system receive care, but reimbursement may significantly affect access. States with low dentist density and low dentist participation in Medicaid may be able to improve access to dental services significantly by increasing reimbursement rates.

  4. Cell culture density affects the proliferation activity of human adipose tissue stem cells.

    Science.gov (United States)

    Kim, Dae Seong; Lee, Myoung Woo; Ko, Young Jong; Chun, Yong Hoon; Kim, Hyung Joon; Sung, Ki Woong; Koo, Hong Hoe; Yoo, Keon Hee

    2016-01-01

    In this study, we investigated the effect of cell density on the proliferation activity of human mesenchymal stem cells (MSCs) derived from adipose tissue (AT-MSCs) over time in culture. Passage #4 (P4) and #12 (P12) AT-MSCs from two donors were plated at a density of 200 (culture condition 1, CC1) or 5000 (culture condition 2, CC2) cells cm(-2) . After 7 days of incubation, P4 and P12 AT-MSCs cultured in CC1 were thin and spindle-shaped, whereas those cultured in CC2 had extensive cell-to-cell contacts and an expanded cell volume. In addition, P4 and P12 AT-MSCs in CC1 divided more than three times, while those in CC2 divided less than once on average. Flow cytometric analysis using 5(6)-carboxyfluorescein diacetate N-succinimidyl ester dye showed that the fluorescence intensity of AT-MSCs was lower in CC1 than in CC2. Furthermore, expression of proliferation-associated genes, such as CDC45L, CDC20A and KIF20A, in P4 AT-MSCs was higher in CC1 than in CC2, and this difference was also observed in P12 AT-MSCs. These data demonstrated that cell culture density affects the proliferation activity of MSCs, suggesting that it is feasible to design a strategy to prepare suitable MSCs using specific culture conditions. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

    Science.gov (United States)

    Lehner, Adam; Kaszas, Zita; Murber, Akos; Rigo, Janos; Urbancsek, Janos; Fancsovits, Peter

    2017-08-01

    Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 μl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 μl/embryo), Group 2 with 5-6 (4.2-5.0 μl/embryo), and Group 3 with 7-9 (2.8-3.6 μl/embryo) embryos. Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p Culturing 5-6 embryos together in a culture volume of 25 μl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

  6. Características do pasto e acúmulo de forragem em capim-tanzânia submetido a alturas de manejo do pasto Sward characteristics and herbage accumulation of Tanzania grass submitted to sward heights

    Directory of Open Access Journals (Sweden)

    Marcos Weber do Canto

    2008-03-01

    Full Text Available O objetivo deste experimento foi avaliar alturas de manejo do pasto (20, 40, 60 e 80 cm em capim-tanzânia (Panicum maximum Jacq., em regime de lotação contínua, nas características do dossel e acúmulo de matéria seca. Os animais utilizados foram novilhos Nelore (Bos indicus, e a taxa de lotação foi variável. Foram avaliados: a massa de forragem, a massa de lâmina de folha verde, a razão folha:colmo, a composição morfológica e a taxa de acúmulo de matéria seca. O delineamento experimental foi inteiramente casualizado, com duas repetições. A massa de forragem aumentou linearmente com o aumento da altura do pasto. As médias de massa de forragem foram 2.767, 3.105, 3.657 e 4.436 kg ha-1, respectivamente, para as alturas de 20, 40, 60 e 80 cm. As taxas de acúmulo de matéria seca, a 20, 40, 60 e 80 cm, foram, respectivamente, 104, 108, 90 e 81 kg ha-1 por dia, o que indica que houve redução dessas taxas com a elevação da altura do pasto. A razão folha:colmo decresceu linearmente com o aumento da altura do pasto. Pastagens de capim-tanzânia, sob lotação contínua ao final da primavera e durante o verão, devem ser utilizadas entre 40 e 60 cm de altura.The objective of this experiment was to evaluate different sward height (20, 40, 60 e 80 cm in Tanzania grass (Panicum maximum Jacq. pastures managed under continuous stocking. The animals used were Nellore steers, and the control of sward height was done with put-and-take techniques. Evaluations were made for: forage mass, green leaf mass, leaf:stem ratio, morphological composition and dry matter accumulation rate. The experimental design was completely randomized with two replications. Forage mass increased linearly with sward height with overall mean of 2,767, 3,105, 3,657 and 4,436 kg ha-1 at sward heights 20, 40, 60 and 80 cm, respectively. Rates of dry matter accumulation decreased with increasing sward heights and were 104, 108, 90 and 81 kg ha-1 per day for sward

  7. Seed Filling Trend of Faba bean (Vicia faba L. as Affected by Planting Date and Density

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    Ali Rahemi Karizaki

    2016-03-01

    Full Text Available To investigate the effect of planting date and plant density on phenology, seed yield, its components, seed filling rate and grain filling period of faba bean, a factorial experiment based on randomized complete block design with four replications was conducted at Research Farm of Agricultural Sciences and Natural Resources of Gonbad University, Iran, during growing season of 2012-2013. The factors were three planting dates (4th of November, 4th of December 2013 and 3th of January 2014 and four planting densities (8, 12, 16 and 18 plant/m2. The results showed that planting dates significantly affected on phenology, yield and its components, seed filling rate and periods while the effect of plant density on seed filling period was not significant. Comparison of sigmoid equation coefficients showed that seed filling rates in three planting dates were different. The highest seed filling rate was obtained in 3th of January and the lowest at November 4, planting dates. The effect of planting date on seed filling duration was also significant, but it was not on plant density. Regression analysis showed that increasing 0.01g seed growth rate in seed unit, resulted in seed weight increase by 45.11, 32.43 and 26.66 g for November 4, December 4 and January 3 planting dates respectively. Delaying planting dates decreased seed filling period by 8.53 days and seed weight by 0.27 g. due to its effect on day length and temperature changes. Delayed planting dates were more effective on the rate and period of seed filling and phenology of faba bean. Delaying in planting date increased time to emergence, while decreased seed filling period and seed yield because of coincidence of this period with high temperatures.

  8. Estimating bulk density of compacted grains in storage bins and modifications of Janssen's load equations as affected by bulk density.

    Science.gov (United States)

    Haque, Ekramul

    2013-03-01

    Janssen created a classical theory based on calculus to estimate static vertical and horizontal pressures within beds of bulk corn. Even today, his equations are widely used to calculate static loadings imposed by granular materials stored in bins. Many standards such as American Concrete Institute (ACI) 313, American Society of Agricultural and Biological Engineers EP 433, German DIN 1055, Canadian Farm Building Code (CFBC), European Code (ENV 1991-4), and Australian Code AS 3774 incorporated Janssen's equations as the standards for static load calculations on bins. One of the main drawbacks of Janssen's equations is the assumption that the bulk density of the stored product remains constant throughout the entire bin. While for all practical purposes, this is true for small bins; in modern commercial-size bins, bulk density of grains substantially increases due to compressive and hoop stresses. Over pressure factors are applied to Janssen loadings to satisfy practical situations such as dynamic loads due to bin filling and emptying, but there are limited theoretical methods available that include the effects of increased bulk density on the loadings of grain transmitted to the storage structures. This article develops a mathematical equation relating the specific weight as a function of location and other variables of materials and storage. It was found that the bulk density of stored granular materials increased with the depth according to a mathematical equation relating the two variables, and applying this bulk-density function, Janssen's equations for vertical and horizontal pressures were modified as presented in this article. The validity of this specific weight function was tested by using the principles of mathematics. As expected, calculations of loads based on the modified equations were consistently higher than the Janssen loadings based on noncompacted bulk densities for all grain depths and types accounting for the effects of increased bulk densities

  9. Evaluation of fecal contamination indicators (fecal coliforms, somatic phages, and helminth eggs) in ryegrass sward farming.

    Science.gov (United States)

    Cárdenas, Martha; Moreno, Gerardo; Campos, Claudia

    2009-02-15

    The effect of soil supplementation with biosolids at various ratios on fecal-origin microorganism activity was evaluated in a ryegrass sward farm. Fifteen plots with 3 different soil and biosolid mixture ratios were assessed. Soil and grass were sampled over a period of 4 months (days 0, 30, 45, 60, 75, and 120) for soil and on days 75 and 120 for grass, corresponding to first and second grass harvest periods. We analyzed fecal coliforms, somatic phages, helminth eggs, and environmental factors, such as rainfall, temperature, and moisture. The fecal coliforms decreased by 2 logarithmic units (LU) in all soils containing biosolids and by 1 LU in the soil alone and in biosolid control plots alone. The concentration of somatic phages decreased to 2 to 3 LU in the soil containing biosolids and to 1 to 2 LU in the control plots. In contrast, however, there was a noticeable increase in helminth eggs on days 75 ad 120, but not in the soil control alone. Maximum concentrations (10(2) CFU/g TS; colony forming units per gram total solids) of fecal coliforms were found on the grass and in other samples, but the concentrations of phages and helminth eggs were below detection limits. Environmental factors did not significantly influence the results, and grass production increased from 35 to 50 Ton/Ha (tons per hectare) with biosolid supplementation, as compared with controls (14 Ton/Ha).

  10. The Impact of Tourist Traffic on the Condition and Cell Structures of Alpine Swards

    Directory of Open Access Journals (Sweden)

    Marlena Kycko

    2018-02-01

    Full Text Available This research focuses on the effect of trampling on vegetation in high-mountain ecosystems through the electromagnetic spectrum’s interaction with plant pigments, cell structure, water content and other substances that have a direct impact on leaf properties. The aim of the study was to confirm with the use of fluorescence methods of variability in the state of high-mountain vegetation previously measured spectrometrically. The most heavily visited part of the High Tatras in Poland was divided into polygons and, after selecting the dominant species within alpine swards, a detailed analysis of trampled and reference patterns was performed. The Analytical Spectral Devices (ASD FieldSpec 3/4 were used to acquire high-resolution spectral properties of plants, their fluorescence and the leaf chlorophyll content with the difference between the plant surface temperature (ts, and the air temperature (ta as well as fraction of Absorbed Photosynthetically Active Radiation (fAPAR used as reference data. The results show that, along tourist trails, vegetation adapts to trampling with the impact depending on the species. A lower chlorophyll value was confirmed by a decrease in fluorescence, and the cellular structures were degraded in trampled compared to reference species, with a lower leaf reflectance. In addition, at the extreme, trampling can eliminate certain species such as Luzula alpino-pilosa, for which significant changes were noted due to trampling.

  11. Wolbachia-Host Interactions: Host Mating Patterns Affect Wolbachia Density Dynamics.

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    Dong-Xiao Zhao

    Full Text Available Wolbachia are maternally inherited intracellular bacteria that infect a wide range of arthropods and cause an array of effects on host reproduction, fitness and mating behavior. Although our understanding of the Wolbachia-associated effects on hosts is rapidly expanding, our knowledge of the host factors that mediate Wolbachia dynamics is rudimentary. Here, we explore the interactions between Wolbachia and its host, the two-spotted spider mite Tetranychus urticae Koch. Our results indicate that Wolbachia induces strong cytoplasmic incompatibility (CI, increases host fecundity, but has no effects on the longevity of females and the mating competitiveness of males in T. urticae. Most importantly, host mating pattern was found to affect Wolbachia density dynamics during host aging. Mating of an uninfected mite of either sex with an infected mite attenuates the Wolbachia density in the infected mite. According to the results of Wolbachia localization, this finding may be associated with the tropism of Wolbachia for the reproductive tissue in adult spider mites. Our findings describe a new interaction between Wolbachia and their hosts.

  12. Tillage and planting density affect the performance of maize hybrids in Chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Tika Baladur Karki

    2015-12-01

    Full Text Available To find out whether the different tillage methods at different planting densities affect the performance of maize hybrids, an experiment was carried out at National Maize Research Program, Rampur during spring season of 2013 and 2014. The experiment was laid out in strip plot design with three replications having 12 treatments. The vertical factor was tillage with conservation tillage (No Tillage + residue=NT and conventional tillage (CT and the horizontal factor were genotypes (Rampur Hybrid-2 and RML-32/RML-17 and in split planting geometries (75cm × 25cm =53333 plants/ha, 70cm × 25cm=57142 plant/ha and 60cm ×25cm= 66666 plants/ha. In both the years, the highest number of cobs (73,177 and 67638/ha was recorded at planting density of 66666/ha. NT had the highest no of kernel rows/cob (14.01 as against 12.12 in CT in 2014. The highest number of kernels (27.3 and 29.29 per row was recorded in NT during 2013 and 2014 respectively. Similarly, in 2014, the highest number of kernels were found in RML-32/RMl-17 (29.17/row and planting density of 53333/ha (28.46/row. In 2013, RML-32/RML-17 produced the highest test weight of 363.94g over the Rampur hybrid-2 with 362.17g. Significantly the highest grain yield of 9240.00 kg/ha in 2013 and 7459.80 kg/ha in 2014 at planting geometry of 65cm ×25cm were recorded. No effects was found by tillage methods for grain yields of maize in 2013, but was found in 2014 (7012.18 kg in NT compared to 6037.59 kg/ha in CT. NT and wider spaced crop matured earlier in both the years; however Rampur hybrid-2 matured earlier to RML-32/RML-17 in 2013. In 2014, harvest index of 47.85 % was recorded in planting geometry of 66666/ha, the highest benefit cost ratio of 1.36 was worked out in NT and 1.46 at the density of 66666/ha. The highest value of 2.46% of soil organic matter was recorded in NT as compared to 2.43% in CT.

  13. Distribuição horizontal e taxas de crescimento, senescência e desfolhação de azevém perene e festuca, puros e em associação Horizontal distribution and growth, senescence and defoliation fluxes of perennial ryegrass and tall fescue pure and mixed swards

    Directory of Open Access Journals (Sweden)

    Andréa Machado Groff

    2002-09-01

    Full Text Available O experimento foi realizado no INRA (Institut National de la Recherche Agronomique em Theix, França. Duas gramíneas (azevém perene e festucaforam semeadas em caixas (0,13 m² usando-se três distribuições horizontais do pasto (pura, linhas alternadas e faixas alternadas e três intervalos de desfolhações (3,5, 7 e 14 dias, com quatro repetições por tratamento. Quatro meses após a semeadura, a cada data de desfolhação, as caixas foram oferecidas, individualmente, a quatro ovelhas secas e retiradas após a realização de 340 bocados.m-2. Para cada gramínea estudaram-se a densidade populacional e a massa de perfilhos, a altura e a produção de matéria seca, a profundidade e a massa do bocado e as taxas de crescimento, senescência e desfolhação. A maior altura do pasto, gerada por desfolhações menos freqüentes, promoveu a realização de bocados mais profundos e de maior massa. Por outro lado, em desfolhações mais freqüentes a altura do pasto foi mantida mais baixa, e a profundidade e massa do bocado foram menores. A distribuição horizontal das plantas promoveu respostas diferenciadas em relação as taxas de crescimento, senescência e desfolhação. Quando em linhas alternadas a festuca teve a taxa de crescimento limitada, provavelmente desfavorecida pela competição.The experiment was carried in INRA (Institut National de la Recherche Agronomique at Theix, France. Two grasses (perennial ryegrass and tall fescue were grown in sward boxes (0,13 m², using three different sward horizontal distribution (pure, alternate rows and alternate strips and three defoliation intervals (3,5, 7 and 14 days between two successive defoliation with four replications. Four months after sowing, at defoliation date, sward boxes were offered to four individual dry ewes and removed after 340 bites.m-2 had been taken. For each grass species, the population density and the tiller mass, sward height, herbage production, bite depth and bite mass

  14. Location of symbionts in the whitefly Bemisia tabaci affects their densities during host development and environmental stress.

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    Qi Su

    Full Text Available Bacterial symbionts often enhance the physiological capabilities of their arthropod hosts and enable their hosts to expand into formerly unavailable niches, thus leading to biological diversification. Many arthropods, including the worldwide invasive whitefly Bemisia tabaci, have individuals simultaneously infected with symbionts of multiple genera that occur in different locations in the host. This study examined the population dynamics of symbionts that are located in different areas within B. tabaci. While densities of Portiera and Hamiltonella (which are located in bacteriocytes appeared to be well-regulated during host development, densities of Rickettsia (which are not located in bacteriocytes were highly variable among individual hosts during host development. Host mating did not significantly affect symbiont densities. Infection by Tomato yellow leaf curl virus did not affect Portiera and Hamiltonella densities in either sex, but increased Rickettsia densities in females. High and low temperatures did not affect Portiera and Hamiltonella densities, but low temperature (15 °C significantly suppressed Rickettsia densities whereas high temperature (35 °C had little effect on Rickettsia densities. The results are consistent with the view that the population dynamics of bacterial symbionts in B. tabaci are regulated by symbiont location within the host and that the regulation reflects adaptation between the bacteria and insect.

  15. Light response of sunflower and canola as affected by plant density, plant genotype and N fertilization.

    Science.gov (United States)

    Soleymani, A

    2017-08-01

    Crop response to light is an important parameter determining crop growth. Three field (split plots) experiments were conducted to investigate the effects of plant density, plant genotype and N fertilization on the light absorption and light extinction of sunflower (Helianthus annuus L.) and canola (Brassica napus L.). A detailed set of plant growth, light absorption and crop yield and oil related parameters were determined. Light was measured at noon during the sunny days with clear sky. In experiment I, although the plant density (PD) of 14 resulted in the highest rate of sunflower light absorption (31.37%) and light extinction (0.756), the highest rate of grain yield and grain oil yield was resulted at PD12 at 3639 and 1457.9kg/ha, respectively; as well as by genotype SUP.A. In experiment II (canola), PD80 resulted in the highest rate of light absorption (13.13%), light extinction (0.63), grain yield (2189.4kg/ha) and grain oil yield (556.54kg/ha). This was also the case for Genotype H. In experiment III (canola), although N150 resulted in the highest rate of light absorption (10.74%) and light extinction (0.48), the highest rate of grain yield (3413.6kg/ha) and grain oil yield (891.86kg/ha) was resulted at N100 as well as by Genotype H401. Results indicate how light properties, crop growth and yield of sunflower and canola can be affected by plant and environmental parameters, which are also of practical use by farmers. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. High-Density Lipoprotein Binds to Mycobacterium avium and Affects the Infection of THP-1 Macrophages

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    Naoya Ichimura

    2016-01-01

    Full Text Available High-density lipoprotein (HDL is involved in innate immunity toward various infectious diseases. Concerning bacteria, HDL is known to bind to lipopolysaccharide (LPS and to neutralize its physiological activity. On the other hand, cholesterol is known to play an important role in mycobacterial entry into host cells and in survival in the intracellular environment. However, the pathogenicity of Mycobacterium avium (M. avium infection, which tends to increase worldwide, remains poorly studied. Here we report that HDL indicated a stronger interaction with M. avium than that with other Gram-negative bacteria containing abundant LPS. A binding of apolipoprotein (apo A-I, the main protein component of HDL, with a specific lipid of M. avium might participate in this interaction. HDL did not have a direct bactericidal activity toward M. avium but attenuated the engulfment of M. avium by THP-1 macrophages. HDL also did not affect bacterial killing after ingestion of live M. avium by THP-1 macrophage. Furthermore, HDL strongly promoted the formation of lipid droplets in M. avium-infected THP-1 macrophages. These observations provide new insights into the relationship between M. avium infection and host lipoproteins, especially HDL. Thus, HDL may help M. avium to escape from host innate immunity.

  17. Sonoran Desert winter annuals affected by density of red brome and soil nitrogen

    Science.gov (United States)

    Salo, L.F.; McPherson, G.R.; Williams, D.G.

    2005-01-01

    Red brome [Bromus madritensis subsp. rubens (L.) Husn.] is a Mediterranean winter annual grass that has invaded Southwestern USA deserts. This study evaluated interactions among 13 Sonoran Desert annual species at four densities of red brome from 0 to the equivalent of 1200 plants ma??2. We examined these interactions at low (3 I?g) and high (537 I?g NO3a?? g soila??1) nitrogen (N) to evaluate the relative effects of soil N level on survival and growth of native annuals and red brome. Red brome did not affect emergence or survival of native annuals, but significantly reduced growth of natives, raising concerns about effects of this exotic grass on the fecundity of these species. Differences in growth of red brome and of the three dominant non nitrogen-fixing native annuals at the two levels of soil N were similar. Total species biomass of red brome was reduced by 83% at low, compared to high, N levels, whereas that of the three native species was reduced by from 42 to 95%. Mean individual biomass of red brome was reduced by 87% at low, compared to high, N levels, whereas that of the three native species was reduced by from 72 to 89%.

  18. Wildlife Habitat Quality (Sward Structure and Ground Cover Response of Mixed Native Warm-Season Grasses to Harvesting

    Directory of Open Access Journals (Sweden)

    Vitalis W. Temu

    2014-08-01

    Full Text Available Agricultural intensification in America has replaced native warm-season grasses (NWSG with introduced forages causing wildlife habitat loss and population declines for the northern bobwhite (Colinus virginianus and similar ground-nesting birds. Reintroducing NWSGs onto managed grasslands to reverse grassland bird population declines lacks information about appropriate multi-purpose management. Post-season nesting habitat quality of mixed NWSGs (indiangrass (IG, Sorghastrum nutans, big bluestem (BB, Andropogon gerardii and little bluestem (LB, Schizachyrium scoparium responding to previous-year(s harvest intervals (treatments, 30-, 40-, 60-, 90 or 120-d and duration (years in production, were assessed on late-spring-early-summer re-growths. Yearly phased harvestings were initiated in May on sets of randomized plots, ≥90-cm apart, in five replications (blocks to produce one-, two-, and three-year old stands by the third year. Sward heights and canopy closure were recorded a day before harvest, followed a week after by visual estimates of ground cover of plant species and litter. Harvesting increased post-season grass cover and reduced forbs following a high rainfall year. Harvested plot swards showed no treatment differences, but were shorter and intercepted more sunlight. Similarly, harvest duration increased grass cover with no year effect but reduced forbs following a high rainfall year. One- or two-year full-season harvesting of similar stands may not compromise subsequent bobwhite nesting-cover provided post-season harvesting starts after the breeding cycle is completed.

  19. Sowing Density: A Neglected Factor Fundamentally Affecting Root Distribution and Biomass Allocation of Field Grown Spring Barley (Hordeum Vulgare L.).

    Science.gov (United States)

    Hecht, Vera L; Temperton, Vicky M; Nagel, Kerstin A; Rascher, Uwe; Postma, Johannes A

    2016-01-01

    Studies on the function of root traits and the genetic variation in these traits are often conducted under controlled conditions using individual potted plants. Little is known about root growth under field conditions and how root traits are affected by agronomic practices in particular sowing density. We hypothesized that with increasing sowing density, root length density (root length per soil volume, cm cm(-3)) increases in the topsoil as well as specific root length (root length per root dry weight, cm g(-1)) due to greater investment in fine roots. Therefore, we studied two spring barley cultivars at ten different sowing densities (24-340 seeds m(-2)) in 2 consecutive years in a clay loam field in Germany and established sowing density dose-response curves for several root and shoot traits. We took soil cores for measuring roots up to a depth of 60 cm in and between plant rows (inter-row distance 21 cm). Root length density increased with increasing sowing density and was greatest in the plant row in the topsoil (0-10 cm). Greater sowing density increased specific root length partly through greater production of fine roots in the topsoil. Rooting depth (D50) of the major root axes (root diameter class 0.4-1.0 mm) was not affected. Root mass fraction decreased, while stem mass fraction increased with sowing density and over time. Leaf mass fraction was constant over sowing density but greater leaf area was realized through increased specific leaf area. Considering fertilization, we assume that light competition caused plants to grow more shoot mass at the cost of investment into roots, which is partly compensated by increased specific root length and shallow rooting. Increased biomass per area with greater densities suggest that density increases the efficiency of the cropping system, however, declines in harvest index at densities over 230 plants m(-2) suggest that this efficiency did not translate into greater yield. We conclude that plant density is a

  20. Intravenous contrast injection significantly affects bone mineral density measured on CT

    Energy Technology Data Exchange (ETDEWEB)

    Pompe, Esther; Willemink, Martin J.; Dijkhuis, Gawein R.; Verhaar, Harald J.J.; Hoesein, Firdaus A.A.M.; Jong, Pim A. de [University Medical Center Utrecht, Department of Radiology and Internal Medicine-Geriatrics, Postbus 85500, Postbox: E.03.511, GA, Utrecht (Netherlands)

    2014-09-05

    The objective is to evaluate the effect of intravenous contrast media on bone mineral density (BMD) assessment by comparing unenhanced and contrast-enhanced computed tomography (CT) examinations performed for other indications. One hundred and fifty-two patients (99 without and 53 with malignant neoplasm) who underwent both unenhanced and two contrast-enhanced (arterial and portal venous phase) abdominal CT examinations in a single session between June 2011 and July 2013 were included. BMD was evaluated on the three examinations as CT-attenuation values in Hounsfield Units (HU) in the first lumbar vertebra (L1). CT-attenuation values were significantly higher in both contrast-enhanced phases, compared to the unenhanced phase (p < 0.01). In patients without malignancies, mean ± standard deviation (SD) HU-values increased from 128.8 ± 48.6 HU for the unenhanced phase to 142.3 ± 47.2 HU for the arterial phase and 147.0 ± 47.4 HU for the portal phase (p < 0.01). In patients with malignancies, HU-values increased from 112.1 ± 38.1 HU to 126.2 ± 38.4 HU and 130.1 ± 37.3 HU (p < 0.02), respectively. With different thresholds to define osteoporosis, measurements in the arterial and portal phase resulted in 7-25 % false negatives. Our study showed that intravenous contrast injection substantially affects BMD-assessment on CT and taking this into account may improve routine assessment of low BMD in nonquantitative CT. (orig.)

  1. Predator density and dissolved oxygen affect body condition of Stenonema tripunctatum (Ephemeroptera, Heptageniidae) from intermittent streams

    Science.gov (United States)

    Joseph W. Love; Christopher M. Taylor; Melvin L. Warren

    2005-01-01

    The effects of population density, fish density, and dissolved oxygen on body condition of late-instar nymphs of Stenonema tripunctatum (Ephemeroptera, Heptageniidae) were investigated using nymphs sampled from isolated, upland stream pools over summer in central Arkansas, USA. All three factors exhibited high variation among pools. Body condition...

  2. Sowing density and harvest time affect fibre content in hemp (Cannabis sativa) through their effects on stem weight

    NARCIS (Netherlands)

    Westerhuis, W.; Amaducci, S.; Struik, P.C.; Zatta, A.; Dam, van J.E.G.; Stomph, T.J.

    2009-01-01

    Sowing density and harvest time are considered important crop management factors influencing fibre quantity and quality in hemp (Cannabis sativa). We investigated whether the effects of these factors are essentially different or that both factors affect stem weight and thereby total and long-fibre

  3. How do stocking density and straw provision affect fouling in conventionally housed slaughter pigs?

    DEFF Research Database (Denmark)

    Larsen, Mona Lilian Vestbjerg; Bertelsen, Maja; Pedersen, Lene Juul

    2017-01-01

    The aim of the study was to investigate when fouling appears in conventionally housed slaughter pigs and whether stocking density and straw provision are risk factors to fouling. During four batches of a total of 112 pens with slaughter pigs, pens were randomly assigned to one level of each of two....... First event of fouling was mostly seen during the first week after insertion and in the last 3 weeks prior to slaughter (10 week study period). Pens with high stocking density had a 90% higher hazard of fouling compared to pens with low stocking density (P = 0.016), meaning that pens with a high...... was a significant risk factor of fouling, whereas straw provision only indicated this numerically within the used experimental setup and chosen sample size. The results suggest that lowering the stocking density to a level of around 1.21 m2/pig could reduce the risk of fouling in slaughter pigs. The relationship...

  4. Dietary boron does not affect tooth strength, micro-hardness, and density, but affects tooth mineral composition and alveolar bone mineral density in rabbits fed a high-energy diet.

    Science.gov (United States)

    Hakki, Sema S; SiddikMalkoc; Dundar, Niyazi; Kayis, Seyit Ali; Hakki, Erdogan E; Hamurcu, Mehmet; Baspinar, Nuri; Basoglu, Abdullah; Nielsen, Forrest H; Götz, Werner

    2015-01-01

    The objective of this study was to determine whether dietary boron (B) affects the strength, density and mineral composition of teeth and mineral density of alveolar bone in rabbits with apparent obesity induced by a high-energy diet. Sixty female, 8-month-old, New Zealand rabbits were randomly assigned for 7 months into five groups as follows: (1) control 1, fed alfalfa hay only (5.91 MJ/kg and 57.5 mg B/kg); (2) control 2, high energy diet (11.76 MJ and 3.88 mg B/kg); (3) B10, high energy diet + 10 mg B gavage/kg body weight/96 h; (4) B30, high energy diet + 30 mg B gavage/kg body weight/96 h; (5) B50, high energy diet + 50 mg B gavage/kg body weight/96 h. Maxillary incisor teeth of the rabbits were evaluated for compression strength, mineral composition, and micro-hardness. Enamel, dentin, cementum and pulp tissue were examined histologically. Mineral densities of the incisor teeth and surrounding alveolar bone were determined by using micro-CT. When compared to controls, the different boron treatments did not significantly affect compression strength, and micro-hardness of the teeth, although the B content of teeth increased in a dose-dependent manner. Compared to control 1, B50 teeth had decreased phosphorus (P) concentrations. Histological examination revealed that teeth structure (shape and thickness of the enamel, dentin, cementum and pulp) was similar in the B-treated and control rabbits. Micro CT evaluation revealed greater alveolar bone mineral density in B10 and B30 groups than in controls. Alveolar bone density of the B50 group was not different than the controls. Although the B treatments did not affect teeth structure, strength, mineral density and micro-hardness, increasing B intake altered the mineral composition of teeth, and, in moderate amounts, had beneficial effects on surrounding alveolar bone.

  5. Stocking density affects the growth performance of broilers in a sex-dependent fashion.

    Science.gov (United States)

    Zuowei, S; Yan, L; Yuan, L; Jiao, H; Song, Z; Guo, Y; Lin, H

    2011-07-01

    The effects of stocking density, sex, and dietary ME concentration on live performance, footpad burns, and leg weakness of broilers were investigated. A total of 876 male and 1,020 female 1-d-old chicks were placed in 24 pens to simulate final stocking density treatments of 26 kg (LSD; 10 males or 12 females/m(2)) and 42 kg (HSD; 16 males or 18 females/m(2)) of BW/m(2) floor space. Two series of experimental diets with a 150 kcal/kg difference in ME concentration (2,800, 2,900, and 3,000 or 2,950, 3,050, and 3,150 kcal of ME/kg) were compared in a 3-phase feeding program. The HSD treatment significantly decreased BW gain and feed conversion ratio (FCR). The HSD chickens consumed less feed by 35 d of age; thereafter, the reverse was true. Male chickens had significantly higher feed intake (FI), BW gain, and FCR compared with females. A significant interaction was found of stocking density and age for FI, BW gain, and FCR. Compared with LSD treatment, HSD broilers had a higher FI and a lower FCR from 36 to 42 d of age. Stocking density, sex, and age had a significant interaction for BW gain and FCR. Female broilers had worse BW gain and FCR when stocked at high density from 36 to 42 d of age. Stocking density had no significant influence on breast, thigh, or abdominal fat yield. Female broilers had significantly higher breast yield and abdominal fat. Male broilers and HSD treatment had high footpad burn and gait scores. A low ME diet increased footpad burn score but had no effect on gait score. The result indicated that stocking density had a more severe effect on the growth of male broilers before 35 d of age. Female broilers need more space than males at similar BW per square meter near marketing age. The incidence and severity of leg weakness are associated with sex, diet, and stocking density. This result suggests that the deteriorated effect of high stocking density is sex and age dependent.

  6. An evaluation of calculation procedures affecting the constituent factors of equivalent circulating density for drilling hydraulics

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, William J.

    1996-12-31

    This Dr. ing. thesis covers a study of drilling hydraulics offshore. The purpose of drilling hydraulics is to provide information about downhole pressure, suitable surface pump rates, the quality of hole cleaning and optimum tripping speeds during drilling operations. Main fields covered are drilling hydraulics, fluid characterisation, pressure losses, and equivalent circulating density. 197 refs., 23 figs., 22 tabs.

  7. Internal fixation for displaced fractures of the femoral neck - Does bone density affect clinical outcome?

    NARCIS (Netherlands)

    Heetveld, M. J.; Raaymakers, E. L. F. B.; van Eck-Smit, B. L.; van Walsum, A. D. P.; Luitse, J. S. K.

    2005-01-01

    The results of meta-analysis show a revision rate of 33% for internal fixation of displaced fractures of the femoral neck, mostly because of nonunion. Osteopenia and osteoporosis are highly prevalent in elderly patients. Bone density has been shown to correlate with the intrinsic stability of the

  8. Do sex-specific densities affect local survival of free-ranging great tits?

    NARCIS (Netherlands)

    Michler, Stephanie P. M.; Nicolaus, Marion; Ubels, Richard; van der Velde, Marco; Both, Christiaan; Tinbergen, Joost M.; Komdeur, Jan

    2011-01-01

    Competition within sexes is expected when resources are sex specific, whereas competition between sexes can occur when similar resources are exploited. Local population density and sex ratio will determine the amount of sex-specific interactions and thus the potential degree of sex-specific

  9. Local offspring density and sex ratio affect sex allocation in the great tit

    NARCIS (Netherlands)

    Michler, Stephanie P. M.; Nicolaus, Marion; van der Velde, Marco; Radersma, Reinder; Ubels, Richard; Both, Christiaan; Komdeur, Jan; Tinbergen, Joost M.

    2013-01-01

    The expected fitness gain for offspring of a given sex may depend on local population sex ratio and density. Knowing the influence of such social factors on brood sex ratios may contribute considerably to the understanding of sex allocation in higher vertebrates. For 3 consecutive years, we

  10. Does high-density stocking affect perennial forbs in mesic grassland ...

    African Journals Online (AJOL)

    Livestock production is an appropriate land use for mainstreaming biodiversity conservation, but little is known about the impact of grazing strategies on forbs that contribute most species, in grasslands. This study compared the effects of high-density, short-duration stocking (HDG) with no grazing (control) on vegetation ...

  11. Country roads, take me home… to my friends: How intelligence, population density, and friendship affect modern happiness.

    Science.gov (United States)

    Li, Norman P; Kanazawa, Satoshi

    2016-11-01

    We propose the savanna theory of happiness, which suggests that it is not only the current consequences of a given situation but also its ancestral consequences that affect individuals' life satisfaction and explains why such influences of ancestral consequences might interact with intelligence. We choose two varied factors that characterize basic differences between ancestral and modern life - population density and frequency of socialization with friends - as empirical test cases. As predicted by the theory, population density is negatively, and frequency of socialization with friends is positively, associated with life satisfaction. More importantly, the main associations of life satisfaction with population density and socialization with friends significantly interact with intelligence, and, in the latter case, the main association is reversed among the extremely intelligent. More intelligent individuals experience lower life satisfaction with more frequent socialization with friends. This study highlights the utility of incorporating evolutionary perspectives in the study of subjective well-being. © 2016 The British Psychological Society.

  12. How much intravenous contrast media affect bone mineral density (BMD assessed by routine computed tomogr

    Directory of Open Access Journals (Sweden)

    Jalil Pirayesh Islamian

    2016-06-01

    Conclusions: BMD values derived from the routine abdominal MDCT can be affected by intravenous contrast media in enhanced abdominal CT scanning. The impact of contrast media on the BMD decreases with increasing age of patients.

  13. MDCT appearance of the appendix: how does the low-density barium sulfate oral contrast agent affect it?

    Science.gov (United States)

    Yaghmai, Vahid; Aghaei-Lasboo, Anahita; Brandwein, Warren M; Tochetto, Sandra; Mafi, John N; Miller, Frank H; Nikolaidis, Paul

    2011-01-01

    We compared the effect of low-density barium sulfate neutral oral contrast agent on the diameter of normal appendix and its luminal content versus that of water on multidetector-row CT. CT scans of 24 patients who had been imaged on two separate occasions for the evaluation of pancreatic pathology, once with water and subsequently with low-density barium sulfate as the neutral oral contrast agent were evaluated (total of 48 scans). Studies were randomized and reviewed in consensus on a workstation in the stack mode by two radiologists blinded to the type of oral contrast. The appendix was measured at baseline and 10 days later to obtain an average diameter. Results of the water and low-density barium sulfate groups were compared using paired t test. Contents of the appendiceal lumen were also noted (gas, fluid, mixed, and collapsed appendix). The average diameter of the appendix for scans obtained with water and low-density barium sulfate was 4.09 ± 0.87 mm (median, 4.22 mm; range, 2.50-5.65 mm) and 4.13 ± 0.93 mm (median, 4 mm, range, 2.2-5.65 mm), respectively. This difference was not statistically significant (P = 0.69). There was no statistically significant difference in the appendiceal content when water or low-density barium sulfate were used as oral contrast (χ (2) = 4.25, P = 0.89). Low-density barium sulfate does not affect appendiceal content or diameter and, therefore, should not adversely affect evaluation of the appendix on multidetector row CT.

  14. Understanding how Supernova Light Curves are Affected by the Density Profiles of Extended Material

    Science.gov (United States)

    Mühleisen, Marc; Piro, Anthony

    2017-01-01

    The light curve of a supernova can provide important clues about the structure of the exploding progenitor. When extended material is present, shock cooling of this material can lead to a prominent early peak distinct from the main radioactive nickel peak, as seen in some Type IIb supernovae. We explore whether the density profile of the extended material plays a role in shaping these light curves. We perform a series of numerical supernova simulations with a range of extended mass configurations. We find that steeper density profiles for the extended material shrink the width and decrease the luminosity of the early peak of the light curve. We conclude that light curves with a distinct, early peak do not imply a particular structure, but rather may arise from several distinct mass configurations. This places limits on how much can be inferred about the progenitor's structure from its light curve.

  15. Bulk density and soil resistance to penetration as affected by commercial thinning in northeastern Washington.

    Science.gov (United States)

    Johanna D. Landsberg; Richard E. Miller; Harry W. Anderson; Jeffrey S. Tepp

    2003-01-01

    Bulk density and soil resistance to penetration were measured in ten, 3- to 11-ha operational units in overstocked, mixed-conifer stands in northeast Washington. Resistance was measured with a recording penetrometer to the 33-cm depth (13 in) at 10 stations on each of 8 to 17, 30.5-m-long, randomly located transects in each unit. Subsequently, different combinations of...

  16. A methodology based on spatial distribution of parameters for understanding affect of rainfall and vegetation density on groundwater recharge

    OpenAIRE

    Vijai Singhal; Rohit Goyal

    2012-01-01

    Accurate estimation of groundwater recharge is extremely important for propermanagement of groundwater systems. Attempts have been made by various researchers torelate impact of various parameters on groundwater recharge. In the present study, amethodology based on spatial distribution of parameters has been developed forunderstanding affect of rainfall and vegetation density on groundwater recharge.Normalized Difference Vegetation Index (NDVI) has been used as an indicative parameterfor vege...

  17. Autoantibodies Affect Brain Density Reduction in Nonneuropsychiatric Systemic Lupus Erythematosus Patients

    Directory of Open Access Journals (Sweden)

    Jian Xu

    2015-01-01

    Full Text Available This study explores the relationship between autoantibodies and brain density reduction in SLE patients without major neuropsychiatric manifestation (NPSLE. Ninety-five NPSLE patients without obvious cerebral deficits, as determined by conventional MRI, as well as 89 control subjects, underwent high-resolution structural MRI. Whole-brain density of grey matter (GMD and white matter (WMD were calculated for each individual, and correlations between the brain density, symptom severity, immunosuppressive agent (ISA, and autoantibody levels were assessed. The GMD and WMD of the SLE group decreased compared to controls. GMD was negatively associated with SLE activity. The WMD of patients who received ISA treatment were higher than that in the patients who did not. The WMD of patients with anticardiolipin (ACL or anti-SSB/La antibodies was lower than in patients without these antibodies, while the GMD was lower in patients with anti-SM or anti-U1RNP antibodies. Thus, obvious brain atrophy can occur very early even before the development of significant symptoms and specific autoantibodies might contribute to the reduction of GMD or WMD in NPSLE patients. However, ISAs showed protective effects in minimizing GMD and WMD reduction. The presence of these specific autoantibodies might help identify early brain damage in NPSLE patients.

  18. Warming and nitrogen affect size structuring and density dependence in a host–parasitoid food web

    Science.gov (United States)

    de Sassi, Claudio; Staniczenko, Phillip P. A.; Tylianakis, Jason M.

    2012-01-01

    Body size is a major factor constraining the trophic structure and functioning of ecological communities. Food webs are known to respond to changes in basal resource abundance, and climate change can initiate compounding bottom-up effects on food-web structure through altered resource availability and quality. However, the effects of climate and co-occurring global changes, such as nitrogen deposition, on the density and size relationships between resources and consumers are unknown, particularly in host–parasitoid food webs, where size structuring is less apparent. We use a Bayesian modelling approach to explore the role of consumer and resource density and body size on host–parasitoid food webs assembled from a field experiment with factorial warming and nitrogen treatments. We show that the treatments increased resource (host) availability and quality (size), leading to measureable changes in parasitoid feeding behaviour. Parasitoids interacted less evenly within their host range and increasingly focused on abundant and high-quality (i.e. larger) hosts. In summary, we present evidence that climate-mediated bottom-up effects can significantly alter food-web structure through both density- and trait-mediated effects. PMID:23007092

  19. Soil nutrients affect spatial patterns of aboveground biomass and emergent tree density in southwestern Borneo.

    Science.gov (United States)

    Paoli, Gary D; Curran, Lisa M; Slik, J W F

    2008-03-01

    Studies on the relationship between soil fertility and aboveground biomass in lowland tropical forests have yielded conflicting results, reporting positive, negative and no effect of soil nutrients on aboveground biomass. Here, we quantify the impact of soil variation on the stand structure of mature Bornean forest throughout a lowland watershed (8-196 m a.s.l.) with uniform climate and heterogeneous soils. Categorical and bivariate methods were used to quantify the effects of (1) parent material differing in nutrient content (alluvium > sedimentary > granite) and (2) 27 soil parameters on tree density, size distribution, basal area and aboveground biomass. Trees > or =10 cm (diameter at breast height, dbh) were enumerated in 30 (0.16 ha) plots (sample area = 4.8 ha). Six soil samples (0-20 cm) per plot were analyzed for physiochemical properties. Aboveground biomass was estimated using allometric equations. Across all plots, stem density averaged 521 +/- 13 stems ha(-1), basal area 39.6 +/- 1.4 m(2) ha(-1) and aboveground biomass 518 +/- 28 Mg ha(-1) (mean +/- SE). Adjusted forest-wide aboveground biomass to account for apparent overestimation of large tree density (based on 69 0.3-ha transects; sample area = 20.7 ha) was 430 +/- 25 Mg ha(-1). Stand structure did not vary significantly among substrates, but it did show a clear trend toward larger stature on nutrient-rich alluvium, with a higher density and larger maximum size of emergent trees. Across all plots, surface soil phosphorus (P), potassium, magnesium and percentage sand content were significantly related to stem density and/or aboveground biomass (R (Pearson) = 0.368-0.416). In multiple linear regression, extractable P and percentage sand combined explained 31% of the aboveground biomass variance. Regression analyses on size classes showed that the abundance of emergent trees >120 cm dbh was positively related to soil P and exchangeable bases, whereas trees 60-90 cm dbh were negatively related to these

  20. Does nitrogen gas bubbled through a low density polymer gel dosimeter solution affect the polymerization process?

    Directory of Open Access Journals (Sweden)

    Daryoush Shahbazi-Gahrouei

    2015-01-01

    Conclusion: It appeared that reactions between gelatin-free radicals and monomers, due to an increase in the gel temperature during rotation in the household mixer, led to a higher R 2 -background response. In the second type of gel, it seemed that the collapse of the nitrogen bubbles was the main factor that affected the R 2 -responses.

  1. Maize production as affected by sowing date, plant density and row spacing in the Bolivian Amazon

    Directory of Open Access Journals (Sweden)

    Paolo Casini

    2012-12-01

    Full Text Available The traditional cropping system widespread in the Department of Pando (Bolivian Amazon is the slash and burn methodology. The main crops sowed soon after the slash are maize, rice, cassava and common beans. Two separate field experiments (carried out in 2008-2009 were carried out to determine the agronomic responses of maize to sowing date, plant population and row width. For the first experiment a split-plot design was used. Maize cultivar (Bayo Blando and Perla Pandino was considered as main plots and the date of sowing as subplots. For the second experiment a split-split-plot design was used. Row spacing (0.5, 0.7 and 0.9 m was considered as main plot, maize cultivar (Cubano Amrarillo and Perla Pandino as subplots, and plant density (5.0, 7.5 and 10 plant m-2 as sub-subplots. A significant reduction of grain yield was observed as the date of sowing (DS delayied. Yield reduction of the second DS compared to the first, was 85 and 45% for Perla Pandino and Bayo Blando. The importance of plant density as a function of the correct row spacing is clearly shown. With the row spacing in use in the considered area (0.9 m and with the narrowest (0.5 m, the best yields were obtained with 10 plants m-2 (5.5 t ha-1. The following conclusions can be drawn from the present study: 1. A delay in the sowing date for maize by 15-20 days (compared to sowing ??immediately after the cutting of the virgin forest or the secondary forest strongly reduces grain production. The cultivar Perla Pandino was the most susceptible with a reduction of 85%. Late sowing of maize (mais de socorro, is suitable only if intercropped with other crops in order to protect the soil from erosion. Traditionally, rice and cassava are intercropped with maize, even if common beans or a legume cover crop would be more advisable. 2. The density of maize may be increased up until 10 m-2 in order to achieve the most productive results by using row spacings of 0.5 e 0.9 m, respectively

  2. Fatty acid, tocopherol and carotenoid content in herbage and milk affected by sward composition and season of grazing

    DEFF Research Database (Denmark)

    Larsen, Mette Krogh; Fretté, Xavier; Kristensen, Troels

    2012-01-01

    BACKGROUND: The aim of the present work was to study to what extent grazing large amounts ofwhite clover (WCL), red clover (RCL), lucerne (LUC) or chicory (CHI) was suitable for production of bovine milk with a high milk fat content of tocopherols, carotenoids, α-linolenic acid and conjugated...

  3. Dietary energy density affects fat mass in early adolescence and is not modified by FTO variants.

    Science.gov (United States)

    Johnson, Laura; van Jaarsveld, Cornelia H M; Emmett, Pauline M; Rogers, Imogen S; Ness, Andy R; Hattersley, Andrew T; Timpson, Nicholas J; Smith, George Davey; Jebb, Susan A

    2009-01-01

    Dietary energy density (DED) does not have a simple linear relationship to fat mass in children, which suggests that some children are more susceptible than others to the effects of DED. Children with the FTO (rs9939609) variant that increases the risk of obesity may have a higher susceptibility to the effects of DED because their internal appetite control system is compromised. We tested the relationship between DED and fat mass in early adolescence and its interaction with FTO variants. We carried out a prospective analysis on 2,275 children enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC). Diet was assessed at age 10 y using 3-day diet diaries. DED (kJ/g) was calculated excluding drinks. Children were genotyped for the FTO (rs9939609) variant. Fat mass was estimated at age 13 y using the Lunar Prodigy Dual-energy X-ray Absorptiometry scanner. There was no evidence of interaction between DED at age 10 y and the high risk A allele of the FTO gene in relation to fat mass at age 13 y (beta = 0.005, p = 0.51), suggesting that the FTO gene has no effect on the relation between DED at 10 y and fat mass at 13 y. When DED at 10 y and the A allele of FTO were in the same model they were independently related to fat mass at 13 y. Each A allele of FTO was associated with 0.35+/-0.13 kg more fat mass at 13 y and each 1 kJ/g DED at 10 y was associated with 0.16+/-0.06 kg more fat mass at age 13 y, after controlling for misreporting of energy intake, gender, puberty, overweight status at 10 y, maternal education, TV watching, and physical activity. This study reveals the multi-factorial origin of obesity and indicates that although FTO may put some children at greater risk of obesity, encouraging a low dietary energy density may be an effective strategy to help all children avoid excessive fat gain.

  4. Dietary energy density affects fat mass in early adolescence and is not modified by FTO variants.

    Directory of Open Access Journals (Sweden)

    Laura Johnson

    Full Text Available Dietary energy density (DED does not have a simple linear relationship to fat mass in children, which suggests that some children are more susceptible than others to the effects of DED. Children with the FTO (rs9939609 variant that increases the risk of obesity may have a higher susceptibility to the effects of DED because their internal appetite control system is compromised. We tested the relationship between DED and fat mass in early adolescence and its interaction with FTO variants.We carried out a prospective analysis on 2,275 children enrolled in the Avon Longitudinal Study of Parents and Children (ALSPAC. Diet was assessed at age 10 y using 3-day diet diaries. DED (kJ/g was calculated excluding drinks. Children were genotyped for the FTO (rs9939609 variant. Fat mass was estimated at age 13 y using the Lunar Prodigy Dual-energy X-ray Absorptiometry scanner. There was no evidence of interaction between DED at age 10 y and the high risk A allele of the FTO gene in relation to fat mass at age 13 y (beta = 0.005, p = 0.51, suggesting that the FTO gene has no effect on the relation between DED at 10 y and fat mass at 13 y. When DED at 10 y and the A allele of FTO were in the same model they were independently related to fat mass at 13 y. Each A allele of FTO was associated with 0.35+/-0.13 kg more fat mass at 13 y and each 1 kJ/g DED at 10 y was associated with 0.16+/-0.06 kg more fat mass at age 13 y, after controlling for misreporting of energy intake, gender, puberty, overweight status at 10 y, maternal education, TV watching, and physical activity.This study reveals the multi-factorial origin of obesity and indicates that although FTO may put some children at greater risk of obesity, encouraging a low dietary energy density may be an effective strategy to help all children avoid excessive fat gain.

  5. Characterization of osteopenia/osteoporosis in adult scoliosis: does bone density affect surgical outcome?

    Science.gov (United States)

    Yagi, Mitsuru; King, Akilah B; Boachie-Adjei, Oheneba

    2011-09-15

    Retrospective study. The aim of this study is to validate the prevalence of low bone mineral density (BMD) in woman patients with adult scoliosis and to relate that to surgical treatment outcome. Despite reports of the high prevalence of low BMD among female with adolescent idiopathic, these findings have not been substantiated in any comprehensive review of adult scoliosis patients undergoing surgical treatment. It has been suggested that scoliosis may predispose to osteoporosis and that degenerative scoliosis could falsely elevate spinal BMD measurements with dual energy radiograph absorptiometry (DXA). The discordance between hip and spine BMD measurement using DXA has also been shown in previous cross-sectional study for adult population. A retrospective review of 176 women treated surgically for scoliosis. BMD of the lumbar spine and femoral neck were determined by DXA. Patients were categorized as follows: concordance (osteoporosis, osteopenia, or normal BMD on both sites), minor discordance (osteoporosis in one site and osteopenia in the other site), and major discordance (osteoporosis in one site and normal the other site). Body mass index (BMI), preoperative Cobb angle, fusion ratio, and complication were recorded. Statistical analysis included the Student t test, χ(2) test, regression coefficient test, and simple linear regression. P value was set at P spine was -0.52 ± 1.57. Major discordance in BMD 7 (4%) points, minor discordance 68 (39%) points, and concordance was 101 (57%) points. There was moderate correlation between T score of hip and spine (R = 0.55P spine showed 10.8% and 10.2% of the patients were osteoporotic. The mean Z score of the hip and of the spine showed comparable age and sex matched values. No correlation was observed between BMD and Cobb angle (R = 0.05, P = 0.464). The fusion rate was 93% and surgical complication rate was 14.9%. No significant correlation was observed between BMD and fusion (P = 0.80) complication (P = 0

  6. Oxygen tension and oocyte density during in vitro maturation affect the in vitro fertilization of bovine oocytes

    Directory of Open Access Journals (Sweden)

    Angelo Bertani Giotto

    2015-12-01

    Full Text Available Oocyte maturation is the key factor affecting the fertilization and embryonic development. Factors such as oocyte density and oxygen tension can directly influence the IMV. Thus, the objective of this study was to evaluate the effect of the association of oxygen tensions (5% or 20% with different oocyte densities (1:10?l or 1:20?l in the in vitro maturation (IVM of bovine oocytes on maturation and fertilization rates, ROS production and antioxidant activity. Three experiments were performed with bovine oocytes that were obtained from slaughterhouse ovaries. After selection, the oocytes were randomly distributed in four treatments: 1:10/5%; 1:10/20%; 1:20/5%and 1:20/20% for each experiment. In experiment I, nuclear maturation status and cytoplasmic maturation were evaluated through detection of the first polar body by immunofluorescence and the mitochondrial reorganization assay. In experiment II, ROS production and antioxidant activity were analyzed in oocytes and IVM medium after 24 h of maturation through detection of ROS, reduced glutathione (GSH and Superoxide dismutase activity by spectrofluorimetric methods. In experiment III, fertilization was evaluated through pronucleus formation, sperm penetration with or without decondensation and polyspermy rates by immunofluorescence. In experiment I, the nuclear maturation and cytoplasmic maturation were similar among treatments (P>0.05. In experiment II, reactive oxygen species in oocytes were elevated in treatments with low oxygen tension which was independent of oocyte density (P<0.05. Additionally, ROS levels in IVM medium were higher in treatments with high oocyte density by volume of medium, which was independent of oxygen tension (P<0.05. In Experiment III, the fertilization and penetration rates were higher in the treatment with 20% oxygen tension and high oocyte density (P<0.05. Furthermore, a high incidence of polyspermy was observed in groups with high oxygen tension and low oocyte

  7. THE FERTILIZATION EFFECT OF PERMANENT MEADOWS WITH SPENT MUSHROM SUBSTRATE ON THE UPTAKING OF MANGANESE, COPPER AND ZINC BY THE MEADOW SWARD

    Directory of Open Access Journals (Sweden)

    Beata Wiśniewska-Kadżajan

    2013-04-01

    Full Text Available The study was conducted in the years 1999–2001 in a meadow with the following fertilizer combinations: control object (without fertilizer, NPK mineral fertilization, fertilizing with manure, manure with NPK fertilization, fertilizing with spent mushroom substrate; spent mushroom substrate with NPK fertilization. The aim of the study was to determine the effect of permanent grassland fertilization both with spent mushroom substrate and the one supplemented with NPK on the uptaking of manganese, copper and zinc by the meadow sward. After the cultivation of mushrooms, in comparison to the standard manure, the substrate used in the experiment was characterized by more than twice higher amount of manganese and zinc. However, the amount of copper in the organic materials was similar. In spite of having supplied lager amount of manganese, zinc and similar amount of copper to the mushrooms substrate, it caused the reduction of the uptake of the elements in the meadow sward. In spite of supplying larger amounts of manganese, zinc and copper the reduction of their uptaking by meadow sward was observed in comparison to manure mushroom substrate. This may be connected with a slightly alkaline reaction of the soil environment, thus limiting the uptake of the studied micronutrients.

  8. Positioner and clothing artifact can affect one-third radius bone mineral density measurement.

    Science.gov (United States)

    Krueger, Diane; Vallarta-Ast, Nellie; Libber, Jessie; Checovich, Mary; Gangnon, Ronald; Binkley, Neil

    2013-01-01

    This report identifies a radius dual-energy X-ray absorptiometry (DXA) confounder and technical approach to avoid this inaccuracy. Initially, a precision study revealed substantial differences (pradius bone mineral density (BMD) least significant change ranging from 0.038 to 0.073g/cm(2) between 3 technologists that each performed assessments in 30 men and 30 women. Subsequently, visual examination of all 360 forearm DXA images, including bone, soft tissue, neutral, and air point-typing was performed. Errors in automated "soft tissue" identification were observed; compared with the manufacturer's ideal depiction, suboptimal soft tissue point-typing was present in 30/360 scans (8.3%) involving 27 individuals. These point-typing deviations appeared to result from inclusion of forearm positioner slots at the scan field edges or clothing covering the forearm. Twenty-four individuals had a paired scan appropriately point-typed, thus allowing evaluation of the effect on BMD measurement. In those with incorrect point-typing associated with positioner slots, the mean one-third radius BMD was ∼7% higher. In conclusion, positioner slots at the edges of the distal scan field can lead to automated soft tissue identification inaccuracies and consequent erroneous one-third radius BMD measurement. DXA technologists should avoid slot inclusion in forearm scans and evaluate point-typing as part of routine analysis. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  9. High hydrostatic pressure specifically affects molecular dynamics and shape of low-density lipoprotein particles

    Science.gov (United States)

    Golub, M.; Lehofer, B.; Martinez, N.; Ollivier, J.; Kohlbrecher, J.; Prassl, R.; Peters, J.

    2017-04-01

    Lipid composition of human low-density lipoprotein (LDL) and its physicochemical characteristics are relevant for proper functioning of lipid transport in the blood circulation. To explore dynamical and structural features of LDL particles with either a normal or a triglyceride-rich lipid composition we combined coherent and incoherent neutron scattering methods. The investigations were carried out under high hydrostatic pressure (HHP), which is a versatile tool to study the physicochemical behavior of biomolecules in solution at a molecular level. Within both neutron techniques we applied HHP to probe the shape and degree of freedom of the possible motions (within the time windows of 15 and 100 ps) and consequently the flexibility of LDL particles. We found that HHP does not change the types of motion in LDL, but influences the portion of motions participating. Contrary to our assumption that lipoprotein particles, like membranes, are highly sensitive to pressure we determined that LDL copes surprisingly well with high pressure conditions, although the lipid composition, particularly the triglyceride content of the particles, impacts the molecular dynamics and shape arrangement of LDL under pressure.

  10. Small bowel bacterial overgrowth may not affect bone mineral density in older people.

    Science.gov (United States)

    Mitsui, Takahiro; Shimaoka, Kiyoshi; Takagi, Chihiro; Goto, Yumi; Kagami, Hideo; Ito, Akira

    2005-12-01

    Small bowel bacterial overgrowth (SBBO) may be associated with malnutrition, diarrhea, and weight loss. Recently, bone mineral density (BMD) in patients with SBBO was reported to be lower, and SBBO may be an important factor in the development of metabolic bone disease. However, the subjects in these studies were relatively young patients with intestinal diseases. There is no information on the effect of SBBO on BMD in older people. Seventeen relatively active and 33 disabled older people participated in this study. SBBO was determined by a breath hydrogen (H2) test after ingestion of a glucose solution. BMD of the lumbar spine and femur were measured using a dual energy X-ray absorptiometry scan (DEXA). One healthy control and 11 disabled subjects were SBBO-positive. The Z-scores of the lumbar spine were not statistically different between groups, and a high incidence of disorders, >70%, was seen in all groups. On the other hand, there were significant differences in the femoral BMD between the healthy controls and the SBBO-negative (Pinstitutionalized people. SBBO seems to have little effect on BMD in people approximately 80 years old.

  11. Intraguild predation by shore crabs affects mortality, behavior, growth, and densities of California horn snails

    Science.gov (United States)

    Lorda, J.; Hechinger, R.F.; Cooper, S. D.; Kuris, A. M.; Lafferty, Kevin D.

    2016-01-01

    The California horn snail, Cerithideopsis californica, and the shore crabs, Pachygrapsus crassipesand Hemigrapsus oregonensis, compete for epibenthic microalgae, but the crabs also eat snails. Such intraguild predation is common in nature, despite models predicting instability. Using a series of manipulations and field surveys, we examined intraguild predation from several angles, including the effects of stage-dependent predation along with direct consumptive and nonconsumptive predator effects on intraguild prey. In the laboratory, we found that crabs fed on macroalgae, snail eggs, and snails, and the size of consumed snails increased with predator crab size. In field experiments, snails grew less in the presence of crabs partially because snails behaved differently and were buried in the sediment (nonconsumptive effects). Consistent with these results, crab and snail abundances were negatively correlated in three field surveys conducted at three different spatial scales in estuaries of California, Baja California, and Baja California Sur: (1) among 61 sites spanning multiple habitat types in three estuaries, (2) among the habitats of 13 estuaries, and (3) among 34 tidal creek sites in one estuary. These results indicate that shore crabs are intraguild predators on California horn snails that affect snail populations via predation and by influencing snail behavior and performance.

  12. Biogenic gradients in algal density affect the emergent properties of spatially self-organized mussel beds.

    Science.gov (United States)

    Liu, Quan-Xing; Weerman, Ellen J; Gupta, Rohit; Herman, Peter M J; Olff, Han; van de Koppel, Johan

    2014-07-06

    Theoretical models highlight that spatially self-organized patterns can have important emergent effects on the functioning of ecosystems, for instance by increasing productivity and affecting the vulnerability to catastrophic shifts. However, most theoretical studies presume idealized homogeneous conditions, which are rarely met in real ecosystems. Using self-organized mussel beds as a case study, we reveal that spatial heterogeneity, resulting from the large-scale effects of mussel beds on their environment, significantly alters the emergent properties predicted by idealized self-organization models that assume homogeneous conditions. The proposed model explicitly considers that the suspended algae, the prime food for the mussels, are supplied by water flow from the seaward boundary of the bed, which causes in combination with consumption a gradual depletion of algae over the simulated domain. Predictions of the model are consistent with properties of natural mussel patterns observed in the field, featuring a decline in mussel biomass and a change in patterning. Model analyses reveal a fundamental change in ecosystem functioning when this self-induced algal depletion gradient is included in the model. First, no enhancement of secondary productivity of the mussels comparing with non-patterns states is predicted, irrespective of parameter setting; the equilibrium amount of mussels is entirely set by the input of algae. Second, alternate stable states, potentially present in the original (no algal gradient) model, are absent when gradual depletion of algae in the overflowing water layer is allowed. Our findings stress the importance of including sufficiently realistic environmental conditions when assessing the emergent properties of self-organized ecosystems.

  13. Does subclinical hypercortisolism adversely affect the bone mineral density of patients with adrenal incidentalomas?

    Science.gov (United States)

    Hadjidakis, D; Tsagarakis, S; Roboti, C; Sfakianakis, M; Iconomidou, V; Raptis, S A; Thalassinos, N

    2003-01-01

    Subclinical hypercortisolism (SH) is detected increasingly in a substantial proportion of patients with incidentally discovered adrenal adenomas. The clinical implications of SH are currently unclear. Osteoporosis is a well-known complication of glucocorticoid excess. So far, the impact of SH on bone mineral density (BMD) has been studied in a limited number of reports with discordant results. In the present study we evaluated the BMD in a large cohort of post-menopausal women with adrenal incidentalomas. : patients and measurements Forty-two post-menopausal women with incidentally discovered adrenal masses and radiological features highly suggestive of benign adrenal adenomas were investigated. All patients underwent a standard low-dose dexamethasone suppression test (LDDST; 0.5 mg 6-hourly for 2 days). The diagnosis of subclinical hypercortisolism (SH) was based on post-LDDST cortisol concentrations of > 70 nmol/l. According to this criterion patients were subdivided into two groups: with (n = 18; group A) or without (n = 24; group B) SH. There was no significant difference in age, years since menopause and body mass index between these groups. BMD was measured at L2-L4 vertebrae and three sites of the proximal femur by the dual energy X-ray absorptiometry (DEXA) method. Post-menopausal women with SH (group A) exhibited slightly but significantly lower absolute and age-adjusted BMD values compared to group B patients in the femoral neck (BMD g/cm2: 0.72 +/- 0.08 vs. 0.79 +/- 0.09; Z-score: -0.20 +/- 0.82 vs. +0.43 +/- 0.94, P < 0.05) and trochanter (BMD g/cm2: 0.60 +/- 0.09 vs. 0.69 +/- 0.10; Z-score: -0.32 +/- 1.0 vs. +0.30 +/- 1.05, P < 0.01). BMD measurements of the Ward's triangle were also lower in group A patients but the difference did not reach statistical significance (BMD g/cm2: 0.60 +/- 0.10 vs. 0.68 +/- 0.13, P = 0.06). There was no difference in the lumbar vertebrae between the two groups (BMD g/cm2: 0.888 +/- 0.13 vs. 0.90 +/- 0.16, P = 0.78; z

  14. Tree Species Composition and Harvest Intensity Affect Herbivore Density and Leaf Damage on Beech, Fagus sylvatica, in Different Landscape Contexts.

    Science.gov (United States)

    Mangels, Jule; Blüthgen, Nico; Frank, Kevin; Grassein, Fabrice; Hilpert, Andrea; Mody, Karsten

    2015-01-01

    Most forests are exposed to anthropogenic management activities that affect tree species composition and natural ecosystem processes. Changes in ecosystem processes such as herbivory depend on management intensity, and on regional environmental conditions and species pools. Whereas influences of specific forest management measures have already been addressed for different herbivore taxa on a local scale, studies considering effects of different aspects of forest management across different regions are rare. We assessed the influence of tree species composition and intensity of harvesting activities on arthropod herbivores and herbivore-related damage to beech trees, Fagus sylvatica, in 48 forest plots in three regions of Germany. We found that herbivore abundance and damage to beech trees differed between regions and that - despite the regional differences - density of tree-associated arthropod taxa and herbivore damage were consistently affected by tree species composition and harvest intensity. Specifically, overall herbivore damage to beech trees increased with increasing dominance of beech trees - suggesting the action of associational resistance processes - and decreased with harvest intensity. The density of leaf chewers and mines was positively related to leaf damage, and several arthropod groups responded to beech dominance and harvest intensity. The distribution of damage patterns was consistent with a vertical shift of herbivores to higher crown layers during the season and with higher beech dominance. By linking quantitative data on arthropod herbivore abundance and herbivory with tree species composition and harvesting activity in a wide variety of beech forests, our study helps to better understand the influence of forest management on interactions between a naturally dominant deciduous forest tree and arthropod herbivores.

  15. The response of sward-dwelling arthropod communities to reduced grassland management intensity in pastures

    Directory of Open Access Journals (Sweden)

    Helden Alvin J.

    2015-12-01

    Full Text Available We compared arthropod taxon richness, diversity and community structure of two replicated grassland husbandry experiments to investigate effects of reduced management intensity, as measured by nutrient input levels (390, 224 and 0 kg/ha per year N in one experiment, and 225 and 88 kg/ha per year N in another. Suction sampling was used to collect Araneae, Coleoptera, Hemiptera and Hymenoptera, with Araneae and Coleoptera also sampled with pitfall trapping. Univariate analyses found no significant differences in abundance and species density between treatments. However, with multivariate analysis, there were significant differences in arthropod community structure between treatments in both experiments.

  16. Performance of beef cattle on pasture of Brachiaria brizantha cv. Xaraés maintained at different sward heights

    Directory of Open Access Journals (Sweden)

    Marco Aurélio Alves de Freitas Barbosa

    2014-02-01

    Full Text Available The production of grazing cattle has been very interesting, due to the low cost to produce fodder, compared to other sources of forage used to feed these animals, but the adequate management pasture has high influence on the success and profitability of cattle production systems. Thus, the objective of this study was to determine the optimum grazing height of Brachiaria brizantha cv. Xaraés, which provides the highest individual weight gain and gain per area. The stocking rate was continuous, with variable stocking rate. The experimental period was from January to December 2010. Three Nellore males were used in each experimental plot, and, when needed, additional animals were used for adjusting the desired heights. Monthly sampling was obtained to estimate forage mass (kg.ha-1 of DM and the structural characteristics of the pastures, such as, leaf: stem ratio. The animals were weighed at the beginning of the experiment and every 28 days, after 12 hours of fasting, to measure the average daily gain (ADG After weighings were performed adjustments stocking rate to desired heights. Throughout the experimental period the animals received mineral supplementation. The desired sward heights were 15, 30, 45 and 60 cm, with three replicates each. The experimental design was completely randomized with four treatments and three replications. To body weight gain (BWG and average daily gain (ADG, each animal was considered an experimental unit. To gain per area and stocking rate, the paddock was considered the experimental unit. The leaf: stem ratio showed a linear increasing behavior in the spring and summer seasons. The smaller grazing heights provided higher gain per unit area (812.15 kg ha-1, while the highest grazing heights promoted high individual weight gain (0.790 kg.dia-1. The results suggest that Xaraés grass pastures should be grazed between 30 and 45 cm to allow reasonable performances by area and individual performances.

  17. Avaliação do desempenho animal e do pasto na mistura aveia IAPAR 61 (Avena strigosa Schreb e ervilha forrageira (Pisum arvense L. manejada em diferentes alturas Evaluation of animal performance and of the pasture in a mixture of oat (Avena strigosa Schreb Cv. IAPAR 61 and field pea (Pisum arvense L. managed in different sward heights

    Directory of Open Access Journals (Sweden)

    Marcia Maria Grise

    2002-06-01

    accomplished through the use of the disk meter, with agreement for animal load, weekly. DLG ranged from .497 to 1.017 kg/ animal/ day, at the heights of 8.9 and 18.3 cm, respectively, presenting linear effect with the increase of the sward height. WGP/ha oscillated between 127 and 356 kg/ha to 8,9 and 18,3 cm of sward height respectively, the stocking rate having varied of 184 to 424 animals.day/ha at heights of 14.7 and 10.0 cm respectively, although the sward height did not affect GPV/ha and in the pasture stocking rate. The plants of field pea marked were not grazing by the animals. The DISK methodology showed that the level of dry matter residue/ha was linearly influenced as sward height increased. The oat remained dominant in the botanical composition of the pasture representing 99.69% of it, and the field pea contributing with 0.31%. The percentage of discovered soil decreased as the sward height increased. These results showed that the residue of DM was higher than 18 cm is important on animal performance and pasture response.

  18. Fruit production and branching density affect shoot and whole-tree wood to leaf biomass ratio in olive.

    Science.gov (United States)

    Rosati, Adolfo; Paoletti, Andrea; Al Hariri, Raeed; Famiani, Franco

    2018-02-14

    The amount of shoot stem (i.e., woody part of the shoot) dry matter per unit shoot leaf dry matter (i.e., the shoot wood to leaf biomass ratio) has been reported to be lower in short shoots than in long ones, and this is related to the greater and earlier ability of short shoots to export carbon. This is important in fruit trees, since the greater and earlier carbon export ability of shoots with a lower wood to leaf biomass ratio improves fruit production. This ratio may vary with cultivars, training systems or plant age, but no study has previously investigated the possible effect of fruit production. In this study on two olive cultivars (i.e., Arbequina, with low growth rate, and Frantoio, with high growth rate) subject to different fruit production treatments, we found that at increasing fruit production, shoot length and shoot wood to leaf biomass ratio were proportionally reduced in the new shoots growing at the same time as the fruit. Specifically, fruit production proportionally reduced total new-shoot biomass, length, leaf area and average shoot length. With decreasing shoot length, shoot diameter, stem mass, internode length, individual leaf area and shoot wood to leaf biomass ratio also decreased. This may be viewed as a plant strategy to better support fruit growth in the current year, given the greater and earlier ability of short shoots to export carbon. Moreover, at the whole-tree level, the percentage of total tree biomass production invested in leaves was closely correlated with branching density, which differed significantly across cultivars. By branching more, Arbequina concentrates more shoots (thus leaves) per unit of wood (trunk, branches and root) mass, decreasing wood to leaf biomass ratio at the whole-tree level. Therefore, while, at the shoot level, shoot length determines shoot wood to leaf biomass ratio, at the canopy level branching density is also an important determinant of whole-tree wood to leaf biomass ratio. Whole-tree wood to leaf

  19. Effect of planting density and cutting frequency on forage and grain yields of kochia (Kochia scoparia under saline water irrigation

    Directory of Open Access Journals (Sweden)

    mseou ziyaeii

    2009-06-01

    Full Text Available AField experiment was conducted at Research Farms of Center of Excellence for Special Crops, Ferdowsi University of Mashhad, Mashhad, Iran, in 2006 to evaluate the effect of planting density on forage and grain yield of kochia (Kochia scoparia. Experimental design was a randomized complete block with split-plot arrangement of treatments,with three replications, where different planting densities (10, 20, 30 and 40 plant m-2 were assigned to main plots and number of cutting (including a single cutting, two cutting and no cutting i.e. allowing the crop to grow until maturity allocated to sub-plots. At each harvest date (cutting the biological yield, leaf and stem dry weight, plant height, number of branches and the individual plant biomass were measured. Grain yield and thousand seed weight were also determined at the end of growing season. Result showed the highest biological yield and leaf and stem dry weights for kochia obtaind at 30 plant m-2. The total biomass, leaf and stem dry weights, plant height, number of branches were greater for the first cutting as compared to the second cutting. Planting density and cutting number interacted to affect the leaf dry weight. At physiological maturity stage there were no significant differences among planting densities for plant height and number of branches. The best planting density, in terms of biomass production and leaf and stem dry weight, was found as 30 plant m-2, while for grain production a planting density of 20 plant m-2 could be recommended. Key words: Kochia, planting density, sward, biological yield, grain production.

  20. Conjugated linoleic acid is related to bone mineral density but does not affect parathyroid hormone in men.

    Science.gov (United States)

    Deguire, Jason R; Makarem, Nour; Vanstone, Catherine A; Morin, Suzanne; Duque, Gustavo; Weiler, Hope A

    2012-12-01

    The relationships between conjugated linoleic acid (CLA) status, bone, body composition, and the effect of CLA on calciotropic hormones are unclear. A cross-sectional study was designed to examine the association between c9, t11 CLA status in erythrocyte membranes (RBC) and body composition. This preceded a dose-response trial investigating if c9, t11 CLA affected parathyroid hormone (PTH). It was hypothesized that (1) higher c9, t11 CLA status in RBC will be associated with a lower fat and higher bone mass and that (2) PTH will be reduced by 30% after supplementation of c9, t11 CLA. Fifty-four men (age, 19-53 years) were included in the cross-sectional analysis, of which 31 were studied in the dose-response trial and randomized to 1 of 3 groups: placebo (n = 10), 1.5 g/d (n = 11), or 3.0 g/d (n = 10) of c9, t11 CLA for 16 weeks. Men with RBC c9, t11 CLA status above the median had higher whole body bone mineral density (BMD) (1.359 ± 0.024 vs 1.287 ± 0.023 g/cm(2); P = .04) and whole body lean mass (WBL) percentage (78.8% ± 0.9% vs 75.3% ± 1.0%; P = .01), whereas body mass index (24.8 ± 0.5 kg/m(2) vs 27.3 ± 0.9 kg/m(2); P = .01) and whole body fat mass percentage (17.3% ± 0.9% vs 21.3% ± 1.1%; P = .007) were lower. In regression analysis, RBC c9, t11 CLA status accounted for a significant proportion (r(2) = 0.10) of the variation in whole body BMD (P = .03). There were no time or treatment differences among any bone or biomarkers of bone metabolism including PTH. These findings indicate that RBC c9, t11 CLA status, a reflection of long-term (~4 months) dietary CLA intake, positively relates to BMD. However, c9, t11 CLA supplementation does not appear to affect PTH in healthy men. Copyright © 2012 Elsevier Inc. All rights reserved.

  1. Ghrelin receptor deficiency does not affect diet-induced atherosclerosis in low-density lipoprotein receptor-null mice

    Directory of Open Access Journals (Sweden)

    Kirk M. Habegger

    2011-11-01

    Full Text Available Objective: Ghrelin, a stomach-derived, secreted peptide, and its receptor (growth hormone secretagogue receptor, GHSR are known to modulate food intake and energy homeostasis. The ghrelin system is also expressed broadly in cardiovascular tissues. Since ghrelin has been associated with anti-inflammatory and anti-atherogenic properties, but is also well known to promote obesity and impair glucose metabolism, we investigated whether ghrelin has any impact on the development of atherosclerosis. The hypothesis that endogenous ghrelin signaling may be involved in atherosclerosis has not been tested previously Methods and Results: We crossed ghrelin receptor knockout mice (GHSr-/- into a low-density lipoprotein receptor-null (Ldlr-/- mouse line. In this model, atherosclerotic lesions were promoted by feeding a high-fat, high-cholesterol Western-type diet for 13 months, following a standard protocol. Body composition and glucose homeostasis were similar between Ldlr-/- and Ldlr/GHSR -/- ko mice throughout the study. Absence or presence of GHSr did not alter the apolipoprotein profile changes in response to diet exposure on an LDLRko background. Atherosclerotic plaque volume in the aortic arch and thoracic aorta were also not affected differentially in mice without ghrelin signaling due to GHSR gene disruption as compared to control LDLRko littermates. In light of the associations reported for ghrelin with cardiovascular disease in humans, the lack of a phenotype in these loss-of- function studies in mice suggests no directly functional role for endogenous ghrelin in either the inhibition or the promotion of diet-induced atherosclerosis.Conclusions: These data indicate that, surprisingly, the complex and multifaceted actions of endogenous ghrelin signaling on the cardiovascular system have minimal direct impact on atherosclerotic plaque progression as based on loss-of-function in a mouse model of the disease.

  2. Crop growth, light utilization and yield of relay intercropped cotton as affected by plant density and a plant growth regulator

    NARCIS (Netherlands)

    Mao, L.; Zhang, L.; Zhao, X.; Liu, S.; Werf, van der W.; Zhang, S.; Spiertz, J.H.J.; Li, Z.

    2014-01-01

    Modern cotton cultivation requires high plant densities and compact plants. Here we study planting density and growth regulator effects on plant structure and production of cotton when the cotton is grown in a relay intercrop with wheat, a cultivation system that is widespread in China. Field

  3. Using post-grazing sward height to impose dietary restrictions of varying duration in early lactation: its effects on spring-calving dairy cow production.

    Science.gov (United States)

    Crosse, M; O'Donovan, M; Boland, T M; Delaby, L; Ganche, E; Kennedy, E

    2015-04-01

    The objective of this study was to investigate the immediate and carryover effects of imposing two post-grazing sward heights (PGSH) for varying duration during early lactation on sward characteristics and dairy cow production. The experiment was a randomised block design with a 2×2 factorial arrangement of treatments. A total of 80 spring-calving (mean calving date - 6 February) dairy cows were randomly assigned, pre-calving, to one of the two (n=40) PGSH treatments - S (2.7 cm) and M (3.5 cm) - from 13 February to 18 March, 2012 (P1). For the subsequent 5-week period (P2: 19 March to 22 April, 2012), half the animals from each P1 treatment remained on their treatment, whereas the other half of the animals switched to the opposing treatment. Following P2, all cows were managed similarly for the remainder of the lactation (P3: 23 April to 4 November, 2012) to measure the carryover effect. Milk production, BW and body condition score were measured weekly, and grass dry matter intake (GDMI) was measured on four occasions - approximately weeks 5, 10, 15 and 20 of lactation. Sward utilisation (above 2.7 cm; P1 and P2) was significantly improved by reducing the PGSH from 3.5 (0.83) to 2.7 cm (0.96). There was no effect of PGSH on cumulative annual grass dry matter (DM) production (15.3 t DM/ha). Grazing to 2.7 cm reduced GDMI by 1.7 and 0.8 kg DM/cow in P1 and P2, respectively, when compared with 3.5 cm (13.3 and 14.0 kg/cow per day, respectively). Cows grazing to 2.7 cm for both P1 and P2 (SS) tended to have reduced cumulative 10-week milk yield (-105 kg) and milk solids yield (-9 kg) when compared with cows grazing to 3.5 cm for both periods (MM; 1608 and 128 kg/cow, respectively). Treatments that alternated PGSH at the end of P1, SM and MS had intermediate results. There was no interaction between P1 and P2 treatments. There was also no carryover effect of early lactation grazing regime on milk and milk solids production in P3, given the reduction in early lactation

  4. Density Affects the Nature of the Hexatic-Liquid Transition in Two-Dimensional Melting of Soft-Core Systems.

    Science.gov (United States)

    Zu, Mengjie; Liu, Jun; Tong, Hua; Xu, Ning

    2016-08-19

    We find that both continuous and discontinuous hexatic-liquid transitions can happen in the melting of two-dimensional solids of soft-core disks. For three typical model systems, Hertzian, harmonic, and Gaussian-core models, we observe the same scenarios. These systems exhibit reentrant crystallization (melting) with a maximum melting temperature T_{m} happening at a crossover density ρ_{m}. The hexatic-liquid transition at a density smaller than ρ_{m} is discontinuous. Liquid and hexatic phases coexist in a density interval, which becomes narrower with increasing temperature and tends to vanish approximately at T_{m}. Above ρ_{m}, the transition is continuous, in agreement with the Kosterlitz-Thouless-Halperin-Nelson-Young theory. For these soft-core systems, the nature of the hexatic-liquid transition depends on density (pressure), with the melting at ρ_{m} being a plausible transition point from discontinuous to continuous hexatic-liquid transition.

  5. Sward structure and nutritive value of tanzania guineagrass subjected to rotational stocking managements Estrutura do pasto e valor nutritivo do capim-tanzânia submetido a estratégias de pastejo rotativo

    Directory of Open Access Journals (Sweden)

    Gelson dos Santos Difante

    2009-01-01

    Full Text Available The objective of this work was to evaluate the sward structure and nutritive value of Panicum maximum Jacq. cv. Tanzânia subjected to rotational stocking managements characterised by a common pre-grazing condition of 95% canopy light interception (LI and two post-grazing residues, 25 and 50 cm. Treatments (95/25, 95/50 - LI/residue were assigned to experimental units (groups of six 2500 m² paddocks per treatment according to a complete randomised block design, with two replications. The variables measured corresponded to: canopy light interception, pre and post-grazing sward height, herbage mass and pre and post-grazing morphological composition, herbage bulk density, herbage accumulation and nutritive value (including to IVOMD of the morphological components. Pre-grazing herbage mass did not differ between residues, although the herbage accumulation rate was higher for the 50 than the 25 cm (164.9 and 90.6 kg/ha.day DM, respectively. Post-grazing herbage mass values were higher for the 50 cm residue and were characterised by a higher proportion of leaf blade in relation to the 25 cm treatment, which presented a higher proportion of dead material. On average, the contents of crude protein (CP, neutral detergent fibre (NDF and lignin in acid detergent (LAD as well as the values of the "in vitro" organic matter digestibility (IVOMD were similar for both treatments. Crude protein and IVOMD decreased and NDF and LAD increased from top to the bottom of the sward, indicating grazing intensity as an important variable for promoting adjustments in the grazing efficiency and nutritive value of the consumed herbage by the grazing animals.Este trabalho foi realizado com o objetivo de avaliar a estrutura e o valor nutritivo de pastos de Panicum maximum Jacq. cv. Tanzânia sob regime de desfolhação intermitente submetido a duas intensidades de desfolhação e a duas alturas de resíduo (25 e 50 cm associadas à condição pré-pastejo definida por 95% de

  6. Axo-somatic synapses in the normal and X-irradiated dendate gyrus; factors affecting the density of afferent innervation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, K.S. (Max-Planck-Institut fuer Psychiatrie, Muenchen (Germany, F.R.)); Gerbrandt, L. (Neuroscience Research Program, Boston, MA (USA)); Lynch, G. (California Univ., Irvine (USA))

    1982-10-07

    The density of synaptic input to the somata of dentate gyrus granule cells was examined utilizing quantitative electron microscopic techniques. In control (non-irradiated) material, greater numbers of axo-somatic synapses were observed in the superficial, earlier-generated cells as compared to the deep, later-generated cells. We further studied the X-irradiated dentate gyrus, in which the majority of granule cells were destroyed during postnatal genesis. The surviving cells displayed a density of innervation on their somata which exceeded that observed in either layer of the control material. These data are discussed in terms of the possible contribution of afferent-target cell interactions to the regulation of the density of synaptic innervation.

  7. Revisiting QTL Affecting Clinical Mastitis by High-Density GWAS and Resequencing in the Finnish Ayrshire Dairy Cattle

    DEFF Research Database (Denmark)

    Vilkki, Johanna; Iso-Touru, Terhi; Schulman, Nina F

    -genotyped with the BovineHD chip, and the remaining bulls imputed to high density genotypes using Beagle software. GWAS was repeated with the imputed HD-data with GRAMMAS (GenABEL in R). Thereby 17 peaks on 12 chromosomes were identified. Eight high priority peaks were defined based on both 50K and imputed HD results...

  8. WHEAT LEAF RUST SEVERITY AS AFFECTED BY PLANT DENSITY AND SPECIES PROPORTION IN SIMPLE COMMUNITIES OF WHEAT AND WILD OATS

    Science.gov (United States)

    While it is generally accepted that dense stands of plants exacerbate epidemics caused by foliar pathogens, there is little experimental evidence to support this view. We grew model plant communities consisting of wheat and wild oats at different densities and proportions and exp...

  9. Exenatide treatment did not affect bone mineral density despite body weight reduction in patients with type 2 diabetes

    NARCIS (Netherlands)

    Bunck, M.C.M.; Eliasson, B.; Corner, A.; Heine, R.J.; Shaginian, R.M.; Taskinen, M.R.; Yki-Jarvinen, H.; Smith, U.; Diamant, M.

    2011-01-01

    Preclinical studies suggest that incretin-based therapies may be beneficial for the bone; however, clinical data are largely lacking. We assessed whether the differential effects of these therapies on body weight differed with respect to their effect on bone mineral density (BMD) and markers of

  10. Bond Strength of High-Viscosity Glass Ionomer Cements is Affected by Tubular Density and Location in Dentin?

    Science.gov (United States)

    Tedesco, Tamara K; Calvo, Ana Flávia B; Domingues, Gabrielle G; Mendes, Fausto M; Raggio, Daniela P

    2015-08-01

    This study evaluated the influence of tubular density of different dentin depths and location on the bond strength of high-viscosity glass ionomer cements (GIC). A total of 20 molars were selected and assigned into six experimental groups, considering two different high-viscosity GICs-Fuji IX (FIX) or Ketac Molar (KM), and dentin location-proximal, occlusal superficial, or occlusal deep dentin (n=10). Teeth were cut and a topographical analysis of four sections per group was performed to obtain data about the tubular density of each different dentin location and depths by laser scanning confocal microscopy (100×). Polyethylene tubes were placed over the pretreated surfaces and filled with one of the GICs. Microshear bond strength (µSBS) test was performed after storage in distilled water (24 h at 37°C). Failure modes were evaluated using a stereomicroscope (400×). Multilevel regression analysis was performed to compare the results at a significance level set at 5%. The tubule density was inversely proportional to the bond strength for both GICs (p<0.05). Adhesive/mixed failure prevailed in all experimental groups. Proximal (30036.5±3433.3) and occlusal superficial 29665.3±1434.04 dentin shows lower tubule density, resulting in a better GIC bonding performance (proximal: FIX-3.61±1.05; KM-3.40±1.62; occlusal superficial: FIX-4.70±1.85; KM-4.97±1.25). Thus, we can concluded that the lowest tubule density in proximal and occlusal superficial dentin results in a better GIC bond strength performance.

  11. Factors affecting the population density of weeds and yield loss of them in wheat: a case study in Golestan province – Bandargaz

    Directory of Open Access Journals (Sweden)

    Mohamad Zaman Nekahi

    2016-05-01

    Full Text Available To investigate the factors affecting the population density of weeds and yield loss of them in wheat, a non systematic survey experiment was conducted in 45 fields in the township of Bandar-gaz (Sarmahaleh village in 2012. Sampling of wheat and weeds were taken in two stages (Heading and Harvest maturity by randomized to the five points of each field using quadrate size 1m*1m. In this study all information about crop management including Land area , farmers experience , the seed bed preparation, sowing date , cultivar and site preparation of them, sowing ways , seed rate , weeds control ways , kind , amount and time of herbicide , fungicide use and wheat harvest time were collected during a growing season by preparing questionnaire and complete them with farmers. At the end of the growing season, the actual yield harvested by farmers’ ‬ recorded. Among the various parameters, Wheat plant and raceme density, farmer experience, Kind of variety and use of Tapic+Geranestar herbicide had significant effects on weed population. With increased wheat plant density, weed density decreased. Also there was less weed density in field of high experience farmer. Weed density was lesser in N8118 variety than N8019 variety and not use Tapic+granestar herbicide due to increased of weeds density. Among weed different species, Avena sp, Phalaris minor and Sinapis arvense had highest negative effect on wheat yield. Model study showed if wheat plant density was optimum and there were weeds, yield will be 2713kg/ha and if weeds remove yield will increase to 2877kg/ha (yield gap equal164kg/ha. Amaong weed, Phalaris minor (12 plant per m-2, Sinapis arvensis (3plant per m-2 and Avena sp (2 plant per m-2 with 65, 18 and 17% yield loss respectively, were the strongest competitor with wheat.

  12. Leptin deficiency-induced obesity affects the density of mast cells in abdominal fat depots and lymph nodes in mice

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    Altintas Mehmet M

    2012-02-01

    Full Text Available Abstract Background Mast cells are implicated in the pathogenesis of obesity and insulin resistance. Here, we explored the effects of leptin deficiency-induced obesity on the density of mast cells in metabolic (abdominal fat depots, skeletal muscle, and liver and lymphatic (abdominal lymph nodes, spleen, and thymus organs. Fourteen-week-old male leptin-deficient ob/ob mice and their controls fed a standard chow were studied. Tissue sections were stained with toluidine blue to determine the density of mast cells. CD117/c-kit protein expression analysis was also carried out. Furthermore, mast cells containing immunoreactive tumor necrosis factor-α (TNF-α, a proinflammatory cytokine involved in obesity-linked insulin resistance, were identified by immunostaining. Results ob/ob mice demonstrated adiposity and insulin resistance. In abdominal fat depots, mast cells were distributed differentially. While most prevalent in subcutaneous fat in controls, mast cells were most abundant in epididymal fat in ob/ob mice. Leptin deficiency-induced obesity was accompanied by a 20-fold increase in the density of mast cells in epididymal fat, but a 13-fold decrease in subcutaneous fat. This finding was confirmed by CD117/c-kit protein expression analysis. Furthermore, we found that a subset of mast cells in epididymal and subcutaneous fat were immunoreactive for TNF-α. The proportion of mast cells immunoreactive for TNF-α was higher in epididymal than in subcutaneous fat in both ob/ob and control mice. Mast cells were also distributed differentially in retroperitoneal, mesenteric, and inguinal lymph nodes. In both ob/ob mice and lean controls, mast cells were more prevalent in retroperitoneal than in mesenteric and inguinal lymph nodes. Leptin deficiency-induced obesity was accompanied by increased mast cell density in all lymph node stations examined. No significant difference in the density of mast cells in skeletal muscle, liver, spleen, and thymus was

  13. Irrigation dose and plant density affect the volatile composition and sensory quality of dill (Anethum graveolens L.).

    Science.gov (United States)

    El-Zaeddi, Hussein; Martínez-Tomé, Juan; Calín-Sánchez, Ángel; Burló, Francisco; Carbonell-Barrachina, Ángel A

    2017-01-01

    Two independent field experiments were carried out to investigate the influence of (i) three irrigation treatments (ID0 = 1585 m(3) ha(-1) , considered as a control; ID1 = 1015 m(3) ha(-1) ; and ID2 = 2180 m(3) ha(-1) ) and (ii) three plant density treatments (PD0 = 5.56 plants m(-2) , considered as a control; PD1 = 4.44 plants m(-2) ; and PD2 = 7.41 plants m(-2) ) on the production, volatile composition of essential oil, and sensory quality of dill. The highest plant yield was obtained with intermediate conditions of both irrigation dose (ID0) and plant density (PD0). The main compounds of the essential oil were α-phellandrene, dill ether and β-phellandrene. The highest irrigation dose (ID2) produced the highest concentrations of most of the main compounds: α-phellandrene (49.5 mg per 100 g), β-phellandrene (6.89 mg per 100 g) and limonene (2.49 mg per 100 g). A similar pattern was found for the highest plant density (PD2): α-phellandrene (71.0 mg per 100 g), dill ether (16.7 mg per 100 g) and β-phellandrene (9.70 mg per 100 g). The use of descriptive sensory analysis helped in reaching a final decision, and the dill plants with the highest sensory quality were those of the ID2 and PD0 treatments. The final recommendation is to use the irrigation dose ID2 and the plant density PD2 if the objective is to produce dill samples with the highest aromatic and sensory quality; however, if the only objective is to produce high amounts of dill, the best options are ID0 and PD0. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  14. Factors affecting outbreaks of high-density Cochlodinium polykrikoides red tides in the coastal seawaters around Yeosu and Tongyeong, Korea.

    Science.gov (United States)

    Lee, Young Sik

    2006-10-01

    Red tides caused by the dinoflagellate Cochlodinium polykrikoides occur annually in coastal waters of Korea, causing significant damage. A distinguishing characteristic of C. polykrikoides red tides is that they develop and persist in the open sea, where the water is comparatively clean with little contamination from the shore. We examined the causes of and key nutrients involved in high-density C. polykrikoides red tide outbreaks in the coastal seawaters around Yeosu and Tongyeong, Korea. High-density C. polykrikoides red tides occur in the coastal areas of Geomo Island, where freshwater flows into the sea after heavy rainfall events. Red tides are widespread in years when rainfall is heavy. The maximum concentration of C. polykrikoides and the duration of the red tides increase with increasing rainfall. Adding nitrogen and Seomjin River water to cultures of C. polykrikoides also increases biomass production and cell density of C. polykrikoides remarkably increased after heavy rainfall events. The occurrence of high concentrations of C. polykrikoides along the shores of Yeosu and Tongyeong seems to result from rainfall-initiated inflows of high concentrations of nitrate secondarily, after a conducive physical and chemical open-water environment has been established for C. polykrikoides to spread initially.

  15. Protein-enriched meal replacements do not adversely affect liver, kidney or bone density: an outpatient randomized controlled trial

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    Yan Eric

    2010-12-01

    Full Text Available Abstract Background There is concern that recommending protein-enriched meal replacements as part of a weight management program could lead to changes in biomarkers of liver or renal function and reductions in bone density. This study was designed as a placebo-controlled clinical trial utilizing two isocaloric meal plans utilizing either a high protein-enriched (HP or a standard protein (SP meal replacement in an outpatient weight loss program. Subjects/methods 100 obese men and women over 30 years of age with a body mass index (BMI between 27 to 40 kg/m2 were randomized to one of two isocaloric weight loss meal plans 1. HP group: providing 2.2 g protein/kg of lean body mass (LBM/day or 2. SP group: providing 1.1 g protein/kg LBM/day. Meal replacement (MR was used twice daily (one meal, one snack for 3 months and then once a day for 9 months. Body weight, lipid profiles, liver function, renal function and bone density were measured at baseline and 12 months. Results Seventy subjects completed the study. Both groups lost weight (HP -4.29 ± 5.90 kg vs. SP -4.66 ± 6.91 kg, p 2, p = 0.210; SP -0.03 ± 0.17 g/cm2, p = 0.320 in either group over one year. Conclusions These studies demonstrate that protein-enriched meals replacements as compared to standard meal replacements recommended for weight management do not have adverse effects on routine measures of liver function, renal function or bone density at one year. Clinicaltrial.gov: NCT01030354.

  16. Diet and density dependent competition affect larval performance and oviposition site selection in the mosquito species Aedes albopictus (Diptera: Culicidae

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    Yoshioka Miho

    2012-10-01

    Full Text Available Abstract Background Oviposition-site choice is an essential component of the life history of all mosquito species. According to the oviposition-preference offspring-performance (P-P hypothesis, if optimizing offspring performance and fitness ensures high overall reproductive fitness for a given species, the female should accurately assess details of the heterogeneous environment and lay her eggs preferentially in sites with conditions more suitable to offspring. Methods We empirically tested the P-P hypothesis using the mosquito species Aedes albopictus by artificially manipulating two habitat conditions: diet (measured as mg of food added to a container and conspecific density (CD; number of pre-existing larvae of the same species. Immature development (larval mortality, development time to pupation and time to emergence and fitness (measured as wing length were monitored from first instar through adult emergence using a factorial experimental design over two ascending gradients of diet (2.0, 3.6, 7.2 and 20 mg food/300 ml water and CD (0, 20, 40 and 80 larvae/300 ml water. Treatments that exerted the most contrasting values of larval performance were recreated in a second experiment consisting of single-female oviposition site selection assay. Results Development time decreased as food concentration increased, except from 7.2 mg to 20.0 mg (Two-Way CR ANOVA Post-Hoc test, P > 0.1. Development time decreased also as conspecific density increased from zero to 80 larvae (Two-Way CR ANOVA Post-Hoc test, P . Combined, these results support the role of density-dependent competition for resources as a limiting factor for mosquito larval performance. Oviposition assays indicated that female mosquitoes select for larval habitats with conspecifics and that larval density was more important than diet in driving selection for oviposition sites. Conclusions This study supports predictions of the P-P hypothesis and provides a mechanistic understanding

  17. Survey of SSC12 regions affecting fatty acid composition of intramuscular fat using high density SNP data

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    María eMuñoz

    2012-01-01

    Full Text Available Fatty acid composition is a critical aspect of pork because it affects sensorial and technological aspects of meat quality and it is relevant for human health. Previous studies identified significant QTLs in porcine chromosome 12 for fatty acid profile of backfat and intramuscular fat. In the present study, 374 SNPs mapped in SSC12 from the 60K Porcine SNP Beadchip were used. We have combined linkage and association analyses with expression data analysis in order to identify regions of SSC12 that could affect fatty acid composition of intramuscular fat in longissimus muscle. The QTL scan showed a region around the 60 cM position that significantly affects palmitic fatty acid and two related fatty acid indexes. The Iberian QTL allele increased the palmitic content (+2.6% of mean trait. This QTL does not match any of those reported in the previous study on fatty acid composition of backfat, suggesting different genetic control acting at both tissues. The SNP association analyses showed significant associations with linolenic and palmitic acids besides several indexes. Among the polymorphisms that affect palmitic fatty acid and match the QTL region at 60 cM, there were three that mapped in the Phosphatidylcholine Transfer Protein (PCTP gene and one in the Acetyl-CoA Carboxylase  gene (ACACA. Interestingly one of the PCTP SNPs also affected significantly unsaturated and double bound indexes and the ratio between polyunsaturated/monounsaturated fatty acids. Differential expression was assessed on longissimus muscle conditional on the genotype of the QTL and on the most significant SNPs, according to the results obtained in the former analyses. Results from the microarray expression analyses, validated by RT-qPCR, showed that PCTP expression levels significantly vary depending on the QTL as well as on the own PCTP genotype. The results obtained with the different approaches point out the PCTP gene as a powerful candidate underlying the QTL for

  18. Water, Nitrogen and Plant Density Affect the Response of Leaf Appearance of Direct Seeded Rice to Thermal Time

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    Maite MARTÍNEZ-EIXARCH

    2013-01-01

    Full Text Available Field experiments were conducted in the Ebro Delta area (Spain, from 2007 to 2009 with two rice varieties: Gleva and Tebre. The experimental treatments included a series of seed rates, two different water management systems and two different nitrogen fertilization times. The number of leaves on the main stems and their emergence time were periodically tagged. The results indicated that the final leaf number on the main stems in the two rice varieties was quite stable over a three-year period despite of the differences in their respective growth cycles. Interaction between nitrogen fertilization and water management influenced the final leaf number on the main stems. Plant density also had a significant influence on the rate of leaf appearance by extending the phyllochron and postponing the onset of intraspecific competition after the emergence of the 7th leaf on the main stems. Final leaf number on the main stems was negatively related to plant density. A relationship between leaf appearance and thermal time was established with a strong nonlinear function. In direct-seeded rice, the length of the phyllochron increases exponentially in line with the advance of plant development. A general model, derived from 2-year experimental data, was developed and satisfactorily validated; it had a root mean square error of 0.3 leaf. An exponential model can be used to predict leaf emergence in direct-seeded rice.

  19. Storage affects the phenolic profiles and antioxidant activities of cherries (Prunus avium L) on human low-density lipoproteins

    DEFF Research Database (Denmark)

    Goncalves, B.; Landbo, Anne-Katrine Regel; Let, Mette Bruni

    2004-01-01

    levels in the cvs Burlat and Saco. Phenolic cherry extracts inhibited low-density lipoprotein oxidation in vitro in a dose-dependent manner. Extracts of freshly harvested cherries exhibited significantly higher antioxidant activities than extracts of stored samples. The cv Summit samples had the highest...... antioxidant activity. Differences in the antioxidant effects of the cherry samples were positively correlated with their levels of p-coumaroylquinic acid (p ...Four sweet cherry cultivars (cvs), Burlat, Saco, Summit and Van, were analysed at harvest and after storage at 2 and 15degreesC for 30 and 6 days respectively. Phenolic profiles in methanolic extracts of freeze-dried samples of the fresh and differently stored cherries were quantified by high...

  20. Caged Gammarus as biomonitors identifying thresholds of toxic metal bioavailability that affect gammarid densities at the French national scale.

    Science.gov (United States)

    Ciliberti, Alexandre; Chaumot, Arnaud; Recoura-Massaquant, Rémi; Chandesris, André; François, Adeline; Coquery, Marina; Ferréol, Martial; Geffard, Olivier

    2017-07-01

    Bioaccumulated concentrations of toxic elements in biomonitor invertebrate species have already been used to successfully link metal bioavailability and impairments of stream macroinvertebrate communities at the scale of the watershed. However, implementing this empirical comparative approach at a greater spatial scale remains a challenge due to the diversity of biogeographical contexts encompassed by regional and national scales. We showed in previous studies that the use of standard organisms caged permits the use of a common biomonitor over a far greater geographical range, while limiting the influence of confounding factors on levels of bioavailable contamination. In this study, levels of Cd, Hg, Ni and Pb contamination assessed by active biomonitoring with caged Gammarus fossarum were compared to abundances of on-site gammarids on 94 sites in France. Based on this national dataset of in situ bioassays, we first re-determined bioavailable background assessment concentrations (BBACs), i.e. concentrations measured in caged G. fossarum indicating a significant bioavailable contamination, which we had previously defined at a regional scale for these four metallic elements. On-site gammarid abundances were retrieved from monitoring programs implemented by French water agencies for the evaluation of ecological status for the European Water Framework Directive. These abundances were corrected for the influence of stream physico-chemical typology in order to permit a reliable comparison of gammarid densities between sites at the national scale. Clear trends of degradation of gammarid densities with increasing levels of bioaccumulated concentrations were identified for three of the four elements (Cd, Ni and Pb). Threshold concentrations in caged organisms above which the numbers of free-ranging gammarids were abnormally low - namely bioavailable ecological assessment concentrations (BEACs) - were determined. The reliability and validity of the BEACs, their comparison

  1. Genome-wide association study using extreme truncate selection identifies novel genes affecting bone mineral density and fracture risk.

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    Emma L Duncan

    2011-04-01

    Full Text Available Osteoporotic fracture is a major cause of morbidity and mortality worldwide. Low bone mineral density (BMD is a major predisposing factor to fracture and is known to be highly heritable. Site-, gender-, and age-specific genetic effects on BMD are thought to be significant, but have largely not been considered in the design of genome-wide association studies (GWAS of BMD to date. We report here a GWAS using a novel study design focusing on women of a specific age (postmenopausal women, age 55-85 years, with either extreme high or low hip BMD (age- and gender-adjusted BMD z-scores of +1.5 to +4.0, n = 1055, or -4.0 to -1.5, n = 900, with replication in cohorts of women drawn from the general population (n = 20,898. The study replicates 21 of 26 known BMD-associated genes. Additionally, we report suggestive association of a further six new genetic associations in or around the genes CLCN7, GALNT3, IBSP, LTBP3, RSPO3, and SOX4, with replication in two independent datasets. A novel mouse model with a loss-of-function mutation in GALNT3 is also reported, which has high bone mass, supporting the involvement of this gene in BMD determination. In addition to identifying further genes associated with BMD, this study confirms the efficiency of extreme-truncate selection designs for quantitative trait association studies.

  2. Single nucleotide polymorphisms in the apolipoprotein B and low density lipoprotein receptor genes affect response to antihypertensive treatment

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    Kahan Thomas

    2004-09-01

    Full Text Available Abstract Background Dyslipidemia has been associated with hypertension. The present study explored if polymorphisms in genes encoding proteins in lipid metabolism could be used as predictors for the individual response to antihypertensive treatment. Methods Ten single nucleotide polymorphisms (SNP in genes related to lipid metabolism were analysed by a microarray based minisequencing system in DNA samples from ninety-seven hypertensive subjects randomised to treatment with either 150 mg of the angiotensin II type 1 receptor blocker irbesartan or 50 mg of the β1-adrenergic receptor blocker atenolol for twelve weeks. Results The reduction in blood pressure was similar in both treatment groups. The SNP C711T in the apolipoprotein B gene was associated with the blood pressure response to irbesartan with an average reduction of 19 mmHg in the individuals carrying the C-allele, but not to atenolol. The C16730T polymorphism in the low density lipoprotein receptor gene predicted the change in systolic blood pressure in the atenolol group with an average reduction of 14 mmHg in the individuals carrying the C-allele. Conclusions Polymorphisms in genes encoding proteins in the lipid metabolism are associated with the response to antihypertensive treatment in a drug specific pattern. These results highlight the potential use of pharmacogenetics as a guide for individualised antihypertensive treatment, and also the role of lipids in blood pressure control.

  3. Does Subjective Sleep Affect Bone Mineral Density in Older People with Minimal Health Disorders? The PROOF Cohort.

    Science.gov (United States)

    Saint Martin, Magali; Labeix, Pierre; Garet, Martin; Thomas, Thierry; Barthélémy, Jean-Claude; Collet, Philippe; Roche, Frédéric; Sforza, Emilia

    2016-11-15

    Clinical and epidemiological studies suggest a relation between bone mineral density (BMD) and self-assessment of sleep with an effect on bone formation and osteoporosis (OS) risk in short and long sleepers. This study explores this association in a large sample of older subjects. We examined 500 participants without insomnia complaints aged 65.7 ± 0.8 y. Each participant had a full evaluation including anthropometric measurement, clinical examination and measurements of BMD at the lumbar spine and femoral sites by dual-energy X-ray absorptiometry. The daily energy expenditure (DEE) was measured by the Population Physical Activity Questionnaire. Sleep duration and quality were evaluated by the Pittsburgh Sleep Quality Index. The subjects were stratified into three groups according to sleep duration, i.e., short (sleep was the best predictor of OS risk at the femoral level. This finding suggests an association between OS and self-reported sleep duration in older subjects. NCT 00759304 and NCT 00766584.

  4. Is bone mineral density measurement using dual-energy X-ray absorptiometry affected by gamma rays?

    Science.gov (United States)

    Xie, Liang-Jun; Li, Jian-Fang; Zeng, Feng-Wei; Jiang, Hang; Cheng, Mu-Hua; Chen, Yi

    2013-01-01

    The objective of this study was to determine whether the gamma rays emitted from the radionuclide effect bone mineral density (BMD) measurement. Nine subjects (mean age: 56 ± 17.96 yr) scheduled for bone scanning underwent BMD measurement using dual-energy X-ray absorptiometry (DXA) (Hologic/Discovery A) before and 1, 2, and 4 h after injection of technetium-99m-methylene diphosphonate (99mTc-MDP). Ten subjects (mean age: 41 ± 15.47 yr) scheduled for therapy of differentiated thyroid carcinoma with iodine-131 underwent BMD measurement before and 2 h after therapeutic radionuclide administration. All patients were given whole body BMD measurement, including head, arm, ribs, lumbar spine, pelvis, and leg sites. Besides, patients who referred to radioiodine therapy were given total hip and femoral neck BMD measurement as well. No statistically significant changes in BMD values were detected after 99mTc-MDP and iodine-131 administration for all measurement sites (p > 0.05), and individual difference of BMD before and after radionuclide imaging or therapy was less than the least significant change in lumbar spine, total hip, and femoral neck. In conclusion, BMD measurements are not influenced by the gamma rays emitted from technetium-99m and iodine-131. DXA bone densitometry may be performed simultaneously with bone scanning and radioiodine therapy. Copyright © 2013 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

  5. Bottom trawling affects fish condition through changes in the ratio of prey availability to density of competitors

    DEFF Research Database (Denmark)

    Hiddink, Jan Geert; Moranta, Joan; Balestrini, Stephen

    2016-01-01

    and applications. Our study indicates that fish production may be maximized by keeping bottom-trawling intensities relatively low, although this may negatively ffect the economically more important Nephrops fishery. The effects of bottom trawls may be mitigated by switching to gears, which affect prey availability......1. Bottom-trawl fisheries are widespread and cause mortality of benthic invertebrates, which in turn may lead to a decrease in the availability of prey for target fish species. Exploitation also reduces the abundance of the fish species themselves. Modelling studies have shown that bottom trawling...... could lead to both increases and decreases in fish production, but so far empirical evidence to test these ideas has been very limited. We hypothesize that the effect of bottom trawling on the food intake and condition of fish depends on how the ratio of prey to consumers changes with increasing fishing...

  6. Stocking density affects the growth performance and metabolism of Amur sturgeon by regulating expression of genes in the GH/IGF axis

    Science.gov (United States)

    Ren, Yuanyuan; Wen, Haishen; Li, Yun; Li, Jifang

    2017-07-01

    The effects of stocking density on the growth and metabolism of Amur sturgeon were assessed. Amur sturgeon were grown for 70 days at three different stocking densities (low stocking density, LSD: 5.5 kg/m3; medium stocking density, MSD: 8.0 kg/m3; and high stocking density, HSD: 11.0 kg/m3), and the biometric index, muscle composition, and serum biochemical parameters were evaluated. In addition, pituitary, liver, and muscle samples were collected for gene cloning and expression analyses. After 70 days of growth, the fish maintained at HSD had significantly lower final body weight and specific growth rate, and a higher feed conversion ratio than those of the fish in the MSD and LSD groups. The HSD group had the lowest lipid and protein concentrations in serum and muscle. The serum cortisol concentration increased significantly in the HSD group, indicating that the stress-response system was activated in these fish. There was no change in the concentration of serum insulin-like growth factor 2 (IGF-2), while the concentrations of serum growth hormone (GH) and insulin-like growth factor 1 (IGF-1) decreased in the HSD group. The full-length cDNAs of GH and IGF-2 genes (995-bp and 1 207-bp long, respectively), were cloned and analyzed. In the HSD group, the expressions of GH in the pituitary and growth hormone receptor (GHR) and IGF-1 in the liver were down-regulated at the end of the 70-day experiment. In the HSD group, the transcript level of IGF-2 significantly decreased in the liver, but did not change in muscle. Overall, our results indicated that a HSD negatively affects the growth performance and leads to changes in lipid and protein metabolism in Amur sturgeon. The down-regulated expression of genes related to the GH/IGF axis may be responsible for the poor growth performance of Amur sturgeon under crowding stress.

  7. Corticosteroids and low bone mineral density affect hip cartilage in systemic lupus erythematosus patients: Quantitative T2 mapping.

    Science.gov (United States)

    Hagiwara, Shigeo; Nakamura, Junichi; Watanabe, Atsuya; Kishida, Shunji; Ohtori, Seiji; Omae, Takanori; Miyamoto, Shuichi; Orita, Sumihisa; Takahashi, Kazuhisa

    2015-12-01

    The purpose of this diagnostic study was to quantify the effect of high-dose corticosteroid treatment on hip joint cartilage degeneration in patients with systemic lupus erythematosus (SLE), with and without osteonecrosis, using magnetic resonance imaging (MRI). T2 mapping, with a 3.0 Tesla Discovery MR750 (GE Healthcare) MRI scanner, was performed in 12 volunteers without hip pathology (control group, 12 hips), in 11 patients with SLE without osteonecrosis, who were receiving corticosteroid therapy (corticosteroid-ON group, 17 hips), and in 15 patients with SLE receiving corticosteroids, who had noncollapsed and asymptomatic osteonecrosis (corticosteroid+ON group, 26 hips). The distribution of T2 values in the femoral head and acetabular cartilage were compared among the three groups. Step-wise multiple regression analysis was performed to determine the prognostic factors for T2 values indicative of femoral head cartilage degeneration. Mean T2 values of femoral head cartilage were significantly higher in the corticosteroid-ON (40.3 ms) and corticosteroid+ON (35.2 ms) groups than in the control group (30.1 ms, P = 0.001). T2 values of acetabular cartilage were significantly higher in the corticosteroid-ON group (41.8 ms) versus the control (33.4 ms) and the corticosteroid+ON groups (37.0 ms; P = 0.001). Low bone mineral density was a significant prognostic factor for high T2 values of cartilage at the femoral head in patients treated with corticosteroids, regardless of whether they had osteonecrosis. T2 mapping suggests that corticosteroid therapy and osteoporosis are independent risk factors for cartilage degeneration at the femoral head in patients with SLE. © 2015 Wiley Periodicals, Inc.

  8. Factors affecting high-density lipoprotein cholesterol in HIV-infected patients on nevirapine-based antiretroviral therapy

    Science.gov (United States)

    Padmapriyadarsini, C.; Ramesh, K.; Sekar, L.; Ramachandran, Geetha; Reddy, Devaraj; Narendran, G.; Sekar, S.; Chandrasekar, C.; Anbarasu, D.; Wanke, Christine; Swaminathan, Soumya

    2017-01-01

    Background & objectives: Cardiovascular disease (CVD) risk with low high-density lipoprotein cholesterol (HDL-C) and high triglycerides is common in the general population in India. As nevirapine (NVP)-based antiretroviral therapy (ART) tends to increase HDL-C, gene polymorphisms associated with HDL-C metabolism in HIV-infected adults on stable NVP-based ART were studied. Methods: A cross-sectional study was conducted between January 2013 and July 2014 among adults receiving NVP-based ART for 12-15 months. Blood lipids were estimated and gene polymorphisms in apolipoprotein C3 (APOC3), cholesteryl ester transfer protein (CETP) and lipoprotein lipase (LPL) genes were analyzed by real-time polymerase chain reaction. Framingham's 10-yr CVD risk score was estimated. Logistic regression was done to show factors related to low HDL-C levels. Results: Of the 300 patients included (mean age: 38.6±8.7 yr; mean CD4 count 449±210 cell/μl), total cholesterol (TC) >200 mg/dl was observed in 116 (39%) patients. Thirty nine per cent males and 47 per cent females had HDL-C levels below normal while 32 per cent males and 37 per cent females had TC/HDL ratio of 4.5 and 4.0, respectively. Body mass index [adjusted odds ratio (aOR)=1.70, 95% confidence interval (CI) 1.01-2.84, P=0.04] and viral load (aOR=3.39, 95% CI: 1.52-7.52, P=0.003) were negatively associated with serum HDL-C levels. The 10-yr risk score of developing CVD was 11-20 per cent in 3 per cent patients. Allelic variants of APOC3 showed a trend towards low HDL-C. Interpretation & conclusions: High-risk lipid profiles for atherosclerosis and cardiovascular disease were common among HIV-infected individuals, even after 12 months of NVP-based ART. Targeted interventions to address these factors should be recommended in the national ART programmes. PMID:28948955

  9. Low-density lipoprotein receptor genetic polymorphism in chronic hepatitis C virus Egyptian patients affects treatment response.

    Science.gov (United States)

    Naga, Mazen; Amin, Mona; Algendy, Dina; Elbadry, Ahmed; Fawzi, May; Foda, Ayman; Esmat, Serag; Sabry, Dina; Rashed, Laila; Gabal, Samia; Kamal, Manal

    2015-10-21

    To correlate a genetic polymorphism of the low-density lipoprotein (LDL) receptor with antiviral responses in Egyptian chronic hepatitis C virus (HCV) patients. Our study included 657 HCV-infected patients with genotype 4 who received interferon-based combination therapy. Patients were divided into two groups based on their response to therapy: 356 were responders, and 301 were non-responders. Patients were compared to 160 healthy controls. All patients and controls underwent a thorough physical examination, measurement of body mass index (BMI) and the following laboratory tests: serum alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, albumin, total bilirubin, direct bilirubin, prothrombin time, prothrombin concentration, INR, complete blood count, serum creatinine, fasting blood sugar, HCV antibody, and hepatitis B surface antigen. All HCV patients were further subjected to the following laboratory tests: HCV-RNA using quantitative polymerase chain reaction (PCR), antinuclear antibodies, thyroid-stimulating hormone, an LDL receptor (LDLR) genotype study of LDLR exon8c.1171G>A and exon10c.1413G>A using real-time PCR-based assays, abdominal ultrasonography, ultrasonographic-guided liver biopsy, and histopathological examination of liver biopsies. Correlations of LDL receptor polymorphisms with HAI, METAVIR score, presence of steatosis, and BMI were performed in all cases. There were no statistically significant differences in response rates between the different types of interferon used or LDLR exon10c.1413G>A. However, there was a significant difference in the frequency of the LDL receptor exon8c.1171G>A genotype between cases (AA: 25.9%, GA: 22.2%, GG: 51.9%) and controls (AA: 3.8%, GA: 53.1% and GG: 43.1%) (P A polymorphism between responders (AA: 3.6%, GA: 15.2%, GG: 81.2%) and non-responders (AA: 52.2%, GA: 30.6%, GG: 17.2%) (P A predominated in cases and controls over the A allele, and a statistically significant association with

  10. Structural characteristics of marandu palisadegrass swards subjected to continuous stocking and contrasting rhythms of growth Características estruturais de pastos de capim-marandu submetidos à lotação contínua e ritmos de crescimento contrastantes

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    Priscila de Mesquita

    2010-02-01

    Full Text Available The concept of sward target has been used recently to characterise grazing management practices, but its efficiency to monitor and control sward structure questioned since it corresponds to a single sward structural feature, usually sward surface height. The objective of this experiment was to evaluate sward structure and its patterns of variation throughout the year on continuously stocked marandu palisadegrass swards maintained at 30 cm and subjected to contrasting rhythms of growth from January 2007 to April 2008. Treatments corresponded to three nitrogen application rates (150, 300 and 450 kg ha-1 of N plus the control (no N fertilisation, and were allocated to experimental units according to a complete randomised block design, with four replications. Sward herbage mass, morphological composition, leaf area index (LAI, foliage angle and light interception were evaluated. The increase in nitrogen application rates resulted in increased sward herbage mass, proportion of leaf and stem, and reduction in the proportion of dead material. These modifications were in line with the increase in LAI and reduction in foliage angle, although they did not modify sward light interception. Despite the wide range of nitrogen application rates used, there was a common pattern of variation in sward structure. Overall, changes in sward structural characteristics generated by the range of growth rhythms studied were small, indicating that sward height corresponded to an efficient way to monitor and control the grazing process and sward structure, and can be used to define targets of grazing management.O conceito de alvo de manejo tem sido utilizado recentemente para caracterizar estratégias de manejo do pastejo, mas sua eficiência em permitir controle e monitoramento da estrutura do dossel forrageiro questionada desde que corresponde a uma única característica estrutural, geralmente a altura do pasto. O objetivo deste experimento foi avaliar a estrutura do

  11. Estrutura da pastagem e padrões de desfolhação em capim-mombaça em diferentes alturas do dossel forrageiro Sward structure and defoliation patterns in mombaçagrass according to different canopy heights

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    Ana Luisa Palhano

    2005-12-01

    Full Text Available Com o objetivo de avaliar o padrão de desfolhação em pastagens de capim-mombaça (Panicum maximum, Jacq., novilhas leiteiras da raça HPB foram submetidas, em testes de pastejo, a cinco alturas de dossel (60, 80, 100, 120 e 140 cm, em um delineamento completamente casualizado, com duas repetições. Caracterizou-se a estrutura do dossel por meio de: altura; oferta de forragem, massa de forragem e de lâminas foliares; densidade volumétrica da forragem, de colmos mais bainhas e de lâminas foliares; densidade populacional de perfilhos; número e comprimento de lâminas foliares expandidas e em expansão. Com o aumento da altura do dossel, observou-se redução linear (Y= 0,369606 + 0,001555 x, R² = 0,5560, P = 0,008 na probabilidade de desfolhação das plantas, como resultado da maior massa de forragem. Com o incremento em altura do dossel, notadamente à altura de 85 cm, os animais passaram a ingerir maior proporção de lâminas foliares expandidas à medida que as mesmas apresentaram-se mais acessíveis, apesar da maior preferência por lâminas foliares em expansão. A intensidade de desfolhação das folhas expandidas diminuiu linearmente (Y= 80,866791 – 0,370979 x, R² = 0,6076, P = 0,004, refletindo o aumento em seu comprimento (Y= -104,311106 + 2,877570 x – 0,012035 x², R² = 0,9271, P = 0,002 e também a maior resistência à apreensão, imposta pela idade das folhas. Com o aumento em altura do dossel, o padrão de desfolhação foi alterado, de maneira que os animais passaram a executar um pastejo mais periférico nas touceiras e com acesso reduzido às folhas em expansão, de melhor valor nutritivo.To evaluate the pattern of defoliation in a Mombaça (Panicum maximum grass pasture, experimental paddocks were grazed by Holstein heifers to maintain canopy height of: 60, 80, 100, 120 and 140 cm height. The experimental design was completely randomized, with two replications. The assessed sward structures were: canopy height

  12. Características fermentativas da silagem do capim Marandu manejado em diferentes alturas de dossel Marandu grass silage fermentative characteristic managed under different sward heights

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    Virgílio Jamir Gonçalves Mota

    2011-06-01

    Full Text Available Objetivou-se avaliar as características fermentativas da silagem de Brachiaria brizantha (Hochst ex. Rich Stapf cv. Marandu manejada em diferentes alturas de dossel. Utilizou-se o delineamento em blocos ao acaso, com quatro alturas de dossel (30; 45; 60 e 75cm em cinco blocos, totalizando 20 unidades experimentais. A gramínea foi ensilada em silos experimentais de PVC, com peso conhecido. A abertura dos silos foi realizada aos 56 dias após a ensilagem. Momentos antes da abertura, os silos foram pesados para avaliar as perdas por gases, e em seguida, abertos para retirada da silagem e quantificação das perdas por efluentes. Foram determinados os valores de pH, nitrogênio amoniacal, teores de ácidos orgânicos (lático, acético e butírico e matéria seca. Os dados coletados foram submetidos à análise de variância, e quando significativa, as médias de tratamentos foram submetidas ao estudo de regressão. A gramínea manejada a 30 e a 45cm de dossel resultou em silagens com melhores características fermentativas, com maior conteúdo de ácido lático, menores conteúdos de ácido butírico e nitrogênio amoniacal, e menores perdas durante a fermentação. A gramínea manejada a 60 e a 75cm apresentou processo fermentativo totalmente inadequado à conservação da forragem, portanto classificada como de péssima qualidade. Conclui-se que a altura de dossel de 30 e de 45cm do capim Marandu resultou em silagem com melhores características fermentativas, quando comparada com as silagens das demais alturas avaliadas, porém não atingiu um nível de qualidade desejada.The objective of this study was to evaluate the fermentation characteristics of Brachiaria brizantha Hochst ex. Rich Stapf cv. Marandu managed under different sward heights. We used a complete randomized block delimitation layout, with four sward heights (30; 45; 60 and 75cm in 5 blocks totaling 20 experimental units. The grass was packed and weighted in PVC silos. The silos

  13. Comparação de três métodos para estimativa do índice de área foliar em pastos de capim-marandu sob lotação contínua Comparison of three methods for estimating leaf area index of marandu palisadegrass swards under continuous stocking

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    André Fischer Sbrissia

    2008-02-01

    , destructive (LAI DM; (2 Indirect, destructive, based on the use of tiller population density and mean leaf area per tiller (LAI TPD; and (3 Indirect, non-destructive, based on the use of a LAI-2000 canopy analyser equipment (LAI LICOR. LAI DM was estimated on herbage samples harvested using four 0.30 × 0.37 m metallic frames per paddock. Measurements were carried out in a monthly basis and results grouped into five seasons of the year: summer, autumn, winter, early and late spring. The experiment was carried out according to a complete randomised block design, with four replications and a split-plot arrangement, where sward heights were allocated to plots and LAI estimation methods to sub-plots. The results showed that the canopy analyser overestimated LAI values in relation to the other two methods. This overestimation is mainly due to the excessive accumulation of dead material at the base of swards, particularly on those kept taller (30 and 40 cm. The LAI DM was the method that better detected variations in sward height and seasons of the year, and the LAI TPD showed intermediate values, with a pattern of variation in absolute values similar to that obtained for the LAI DM. The canopy analyser should not be used when LAI estimates are being generated for simulation and mathematical modelling purposes and to estimate the efficiency of incident radiation use.

  14. Perdas de forragem em capim-Tanzânia (Panicum maximum Jacq cv. Tanzania-1 manejado sob diferentes alturas sob pastejo Forage losses in Tanzania grass (Panicum maximum Jacq cv. Tanzania-1 managed in different sward height under grazing

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    Ulysses Cecato

    2001-04-01

    Full Text Available RESUMO - O experimento foi conduzido com objetivo de avaliar as perdas de forragem e a acumulação de liteira em uma pastagem de capim-Tanzânia (Panicum maximum Jacq cv. Tanzania-1 manejada sob diferentes alturas. Os níveis de altura (tratamentos estudados foram: 29,8; 32,0; 47,1; 51,5; 57,9; 62,7; 72,6 e 80,0 cm, em um delineamento completamente casualizado e com duas repetições. As taxas de acúmulo e acumulação de liteira e as perdas de forragem foram iguais em todas as alturas. A porcentagem de forragem senescente foi influenciada de forma quadrática pelos níveis de altura. Os resultados indicam que foram altos os níveis de acumulação de liteira e as perdas de forragem, em média, 38,9 kg/ha/dia de MS e 2179 kg/ha de MS, respectivamente. Devido à possibilidade de se reduzirem a persistência da pastagem e a modificação da estrutura das plantas, recomenda-se não utilizar pastagens de capim-Tanzânia em alturas próximas ou iguais a 20 e 80 cm, sob lotações contínuas.The experiment was conducted to evaluate, the forage losses and litter accumulation, in a pasture of Tanzania grass (Panicum maximun Jacq cv. Tanzania managed in different sward height levels. The studied levels of sward heights (treatments were: 29.8, 32.0, 47.1, 51.5, 57.9, 62.7, 72.6 and 80.0 cm, in a completely randomized design and two replications. The litter accumulation rate, litter accumulation and forage losses were similar in all heights. The percentage of senescent forage in the plant canopy was influenced on a quadratic way by the sward height levels. The results show that the litter accumulation and forage losses were high, with average DM of 38.9 kg/ha.day and 2179 kg/ha of DM, respectively. Due to the possibility to reduce the pasture persistence and plant structure deteriorate, it is not recommended to utilize Tanzania grass pastures, in levels sward height near or equal of 20 and 80 cm, under continuous stocking rate.

  15. Growth and Accumulation of Secondary Metabolites in Perilla as Affected by Photosynthetic Photon Flux Density and Electrical Conductivity of the Nutrient Solution

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    Na Lu

    2017-05-01

    Full Text Available The global demand for medicinal plants is increasing. The quality of plants grown outdoors, however, is difficult to control. Myriad environmental factors influence plant growth and directly impact biosynthetic pathways, thus affecting the secondary metabolism of bioactive compounds. Plant factories use artificial lighting to increase the quality of medicinal plants and stabilize production. Photosynthetic photon flux density (PPFD and electrical conductivity (EC of nutrient solutions are two important factors that substantially influence perilla (Perilla frutescens, Labiatae plant growth and quality. To identify suitable levels of PPFD and EC for perilla plants grown in a plant factory, the growth, photosynthesis, and accumulation of secondary metabolites in red and green perilla plants were measured at PPFD values of 100, 200, and 300 μmol m-2 s-1 in nutrient solutions with EC values of 1.0, 2.0, and 3.0 dS m-1. The results showed significant interactive effects between PPFD and EC for both the fresh and dry weights of green perilla, but not for red perilla. The fresh and dry weights of shoots and leafy areas were affected more by EC than by PPFD in green perilla, whereas they were affected more by PPFD than by EC in red perilla. Leaf net photosynthetic rates were increased as PPFD increased in both perilla varieties, regardless of EC. The perillaldehyde concentration (mg g-1 in red perilla was unaffected by the treatments, but accumulation in plants (mg per plant was significantly enhanced as the weight of dry leaves increased. Perillaldehyde concentrations in green perilla showed significant differences between combinations of the highest PPFD with the highest EC and the lowest PPFD with the lowest EC. Rosmarinic acid concentration (mg g-1 was increased in a combination of low EC and high PPFD conditions. Optimal cultivation conditions of red and green perilla in plant factory will be discussed in terms of plant growth and contents of

  16. Boron fertilisation of organically managed grass-clover swards on coarse-textured soils: effects on botanical and element composition

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    Lisbeth Linse

    2015-12-01

    Full Text Available Three trials were performed on two organic farms with dairy and suckler cows and using home-produced forage and feed crops, predominantly grass-clover ley, in order to determine whether boron (B is a limiting factor for legumes on coarse-textured soils in an area predisposed to low B soil concentrations. The effects of B fertilisation (applied as sprayed liquid on biomass yield, botanical composition and plant macro- and micronutrient concentrations relative to soil concentrations and livestock requirements were investigated. Boron fertilisation (i did not affect any yield, (ii increased the white clover percentage significantly in forage on one farm and (iii increased B concentrations in plants and soil on both farms, and (iv did not affect concentrations of other nutrients in forage on either farm. Thus, B was not an obvious limiting factor on these farms. Effects of management practices on interactions and ratios between B, calcium (Ca, potassium (K, magnesium (Mg and sodium (Na and their implications are discussed.

  17. Acute central neuropeptide Y administration increases food intake but does not affect hepatic very low-density lipoprotein (VLDL) production in mice.

    Science.gov (United States)

    Geerling, Janine J; Wang, Yanan; Havekes, Louis M; Romijn, Johannes A; Rensen, Patrick C N

    2013-01-01

    Central neuropeptide Y (NPY) administration stimulates food intake in rodents. In addition, acute modulation of central NPY signaling increases hepatic production of very low-density lipoprotein (VLDL)-triglyceride (TG) in rats. As hypertriglyceridemia is an important risk factor for atherosclerosis, for which well-established mouse models are available, we set out to validate the effect of NPY on hepatic VLDL-TG production in mice, to ultimately investigate whether NPY, by increasing VLDL production, contributes to the development of atherosclerosis. Male C57Bl/6J mice received an intracerebroventricular (i.c.v.) cannula into the lateral (LV) or third (3V) ventricle of the brain. One week later, after a 4 h fast, the animals received an intravenous (i.v.) injection of Tran(35)S (100 µCi) followed by tyloxapol (500 mg/kg body weight; BW), enabling the study of hepatic VLDL-apoB and VLDL-TG production, respectively. Immediately after the i.v. injection of tyloxapol, the animals received either an i.c.v. injection of NPY (0.2 mg/kg BW in artificial cerebrospinal fluid; aCSF), synthetic Y1 receptor antagonist GR231118 (0.5 mg/kg BW in aCSF) or vehicle (aCSF), or an i.v. injection of PYY3-36 (0.5 mg/kg BW in PBS) or vehicle (PBS). Administration of NPY into both the LV and 3V increased food intake within one hour after injection (+164%, pproduction. Likewise, antagonizing central NPY signaling by either PYY3-36 or GR231118 administration did not affect hepatic VLDL production. In mice, as opposed to rats, acute central administration of NPY increases food intake without affecting hepatic VLDL production. These results are of great significance when extrapolating findings on the central regulation of hepatic VLDL production between species.

  18. High-Density Lipoprotein Subfractions and Cholesterol Efflux Capacity Are Not Affected by Supervised Exercise but Are Associated with Baseline Interleukin-6 in Patients with Peripheral Artery Disease.

    Science.gov (United States)

    Albaghdadi, Mazen S; Wang, Zheng; Gao, Ying; Mutharasan, R Kannan; Wilkins, John

    2017-01-01

    To quantify the association between high-density lipoprotein (HDL) subfractions, efflux capacity, and inflammatory markers at baseline and the effect of supervised exercise on these HDL parameters in patients with peripheral artery disease (PAD). The study to improve leg circulation (SILC) was a randomized trial of supervised treadmill exercise, leg resistance training, or control in individuals with PAD. In a post hoc cross-sectional analysis, we quantified the associations between baseline HDL subfraction concentrations (HDL2 and HDL3), HDL-C efflux capacity, and inflammatory markers [C-reactive protein (CRP) and interleukin-6 (IL-6)]. We then examined the effect of supervised exercise on changes in these lipoprotein parameters and inflammatory markers in 88 patients from SILC. Baseline HDL-C efflux capacity was associated with baseline concentrations of HDL2 (β = 0.008, p = 0.0106), HDL3 (β = 0.013, p capacity, CRP, or IL-6 were not significantly different at 6 months following the structured exercise intervention. HDL efflux and HDL3 were inversely associated with IL-6 in PAD patients. Structured exercise was not associated with changes in HDL subfractions, HDL-C efflux capacity, CRP, and IL-6 in PAD patients. Our preliminary findings support the theory that inflammation may adversely affect HDL structure and function; however, further studies are needed to evaluate these findings.

  19. Monocyte proliferation and differentiation to osteoclasts is affected by density of collagen covalently bound to a poly(dimethyl siloxane) culture surface.

    Science.gov (United States)

    Shafieyan, Yousef; Tiedemann, Kerstin; Goulet, Andrew; Komarova, Svetlana; Quinn, Thomas M

    2012-06-01

    Osteoclast differentiation is affected by substrate characteristics and environmental conditions; these parameters are therefore of interest for understanding bone remodeling. As a step toward osteoclast mechanotransduction experiments, we aimed to optimize conditions for osteoclast differentiation on extendable poly(dimethylsiloxane) (PDMS) substrates. Because cells attach poorly on PDMS alone, chemical modification by covalent attachment of collagen type I was performed. Effects of collagen surface concentrations on monocyte fusion and osteoclast differentiation were examined. Osteoclasts differentiated on modified PDMS were fewer in number (by ∼50%) than controls on polystyrene physically modified by nonspecific attachment of collagen, and exhibited somewhat different morphologies. Nevertheless, for certain choices of the chemical modification procedures, appropriate differentiation on PDMS was still evident by qRT-PCR analysis for tartrate-resistant acid phosphate (TRAP) and cathepsin K (CTSK) gene expression, positive TRAP staining, fluorescent phalloidin staining showing actin ring formation and bone resorption assays. At relatively high collagen surface densities, monocyte clumps appeared on PDMS suggesting substrate-induced alterations to monocyte fusion. Covalently bound collagen can therefore be used to promote osteoclast differentiation on extendable PDMS substrates. Under appropriate conditions osteoclasts retain similar functionality as on polystyrene, which will enable future studies of osteoclast interactions with microstructured surfaces and mechanostimulation. Copyright © 2012 Wiley Periodicals, Inc.

  20. Acute central neuropeptide Y administration increases food intake but does not affect hepatic very low-density lipoprotein (VLDL production in mice.

    Directory of Open Access Journals (Sweden)

    Janine J Geerling

    Full Text Available OBJECTIVE: Central neuropeptide Y (NPY administration stimulates food intake in rodents. In addition, acute modulation of central NPY signaling increases hepatic production of very low-density lipoprotein (VLDL-triglyceride (TG in rats. As hypertriglyceridemia is an important risk factor for atherosclerosis, for which well-established mouse models are available, we set out to validate the effect of NPY on hepatic VLDL-TG production in mice, to ultimately investigate whether NPY, by increasing VLDL production, contributes to the development of atherosclerosis. RESEARCH DESIGN AND METHODS: Male C57Bl/6J mice received an intracerebroventricular (i.c.v. cannula into the lateral (LV or third (3V ventricle of the brain. One week later, after a 4 h fast, the animals received an intravenous (i.v. injection of Tran(35S (100 µCi followed by tyloxapol (500 mg/kg body weight; BW, enabling the study of hepatic VLDL-apoB and VLDL-TG production, respectively. Immediately after the i.v. injection of tyloxapol, the animals received either an i.c.v. injection of NPY (0.2 mg/kg BW in artificial cerebrospinal fluid; aCSF, synthetic Y1 receptor antagonist GR231118 (0.5 mg/kg BW in aCSF or vehicle (aCSF, or an i.v. injection of PYY3-36 (0.5 mg/kg BW in PBS or vehicle (PBS. RESULTS: Administration of NPY into both the LV and 3V increased food intake within one hour after injection (+164%, p<0.001 and +367%, p<0.001, respectively. NPY administration neither in the LV nor in the 3V affected hepatic VLDL-TG or VLDL-apoB production. Likewise, antagonizing central NPY signaling by either PYY3-36 or GR231118 administration did not affect hepatic VLDL production. CONCLUSION: In mice, as opposed to rats, acute central administration of NPY increases food intake without affecting hepatic VLDL production. These results are of great significance when extrapolating findings on the central regulation of hepatic VLDL production between species.

  1. Nutrient density of prestarter diets from one to ten days of age affects intestinal morphometry, enzyme activity, serum indices and performance of broiler chickens

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    Ficinine V. Ivanovich

    2017-09-01

    Full Text Available A total of 480 day-old Cobb 500 broilers were used to investigate the effects of different levels of digestible amino acids (DAA; 100%, 107% and 114% of Cobb recommendations and ME (3,000 or 2,900 kcal/kg of prestarter diet on mixed sex broilers performance, enzyme activity, small intestine morphology, and serum metabolites. Broilers were randomly allotted to 6 treatments, where each treatment applied to 4 pens with 20 birds in each. The birds were subjected to their respective treatment diets from 1 to 10 days of age. This was followed by feeding common starter and finisher diets for the last 29 days. The enzyme activity of the pancreas was measured at 10 days of age. Morphometric indexes of jejunum were measured at 10 days of age and the end of the feeding period. Our results showed that the body weight (BW increased as the DAA density of the prestarter diet increased from 100% to 114% over the first 10 days and the entire period of the study. Birds fed 114% DAA presented a better feed conversion ratio on day 10 (P  0.05; however, the activity of pancreatic protease increased as the DAA level increased from 100% to 114% (P < 0.05. The villus width and villus surface area (VSA increased as the DAA level increased from 100% to 114% on day 10 (P < 0.05. At 10 days of age, crypt depth was the lowest in the birds fed plenty DAA prestarter diets (P < 0.05. It was found that dietary treatments at 39 days of age did not affect intestinal morphology. The results of the present work indicate that DAA level of 114% of Cobb recommendations and energy level of 2,900 kcal/kg diet may be recommended for starting broiler chicks.

  2. Apolipoprotein E-low density lipoprotein receptor interaction affects spatial memory retention and brain ApoE levels in an isoform-dependent manner.

    Science.gov (United States)

    Johnson, Lance A; Olsen, Reid H J; Merkens, Louise S; DeBarber, Andrea; Steiner, Robert D; Sullivan, Patrick M; Maeda, Nobuyo; Raber, Jacob

    2014-04-01

    Human apolipoprotein E (apoE) exists in three isoforms: apoE2, apoE3 and apoE4. APOE ε4 is a major genetic risk factor for cardiovascular disease (CVD) and Alzheimer's disease (AD). ApoE mediates cholesterol metabolism by binding various receptors. The low-density lipoprotein receptor (LDLR) has a high affinity for apoE, and is the only member of its receptor family to demonstrate an apoE isoform specific binding affinity (E4>E3>E2). Evidence suggests that a functional interaction between apoE and LDLR influences the risk of CVD and AD. We hypothesize that the differential cognitive effects of the apoE isoforms are a direct result of their varying interactions with LDLR. To test this hypothesis, we have employed transgenic mice that express human apoE2, apoE3, or apoE4, and either human LDLR (hLDLR) or no LDLR (LDLR(-/-)). Our results show that plasma and brain apoE levels, cortical cholesterol, and spatial memory are all regulated by isoform-dependent interactions between apoE and LDLR. Conversely, both anxiety-like behavior and cued associative memory are strongly influenced by APOE genotype, but these processes appear to occur via an LDLR-independent mechanism. Both the lack of LDLR and the interaction between E4 and the LDLR were associated with significant impairments in the retention of long term spatial memory. Finally, levels of hippocampal apoE correlate with long term spatial memory retention in mice with human LDLR. In summary, we demonstrate that the apoE-LDLR interaction affects regional brain apoE levels, brain cholesterol, and cognitive function in an apoE isoform-dependent manner. Copyright © 2014 Elsevier Inc. All rights reserved.

  3. Effect of particle size of limestone on Ca, Mg and K contents in soil and in sward plants Efeito do tamanho das partículas de calcário nos teores de Ca, Mg e K no solo e em plantas forrageiras

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    Ana Viadé

    2011-04-01

    Full Text Available Liming increases crop production through improved soil conditions in acidic soils. Among the effects of liming, increased availabilities of alkaline and alkaline-earth cations are worth mention. These availabilities may be affected by the particle size of applied limestone, which influences lime reactivity. The effects of particle size and application schedule of magnesium limestone were investigated on extractable Ca, Mg and K in soil, their concentrations in sward plants and dry-matter yield. Magnesium limestone of various particle sizes was applied to experimental plots at a rate of 3 t ha-1, a grass-clover sward was sown, and the plots were monitored during three years. The finest limestone (A aplicação de calcário em solos ácidos promove aumento da produção agrícola por meio da melhoria das condições do solo. Entre os efeitos da calagem, o aumento da disponibilidade de cátions alcalinos e alcalino-terrosos são dignos de menção. Essas disponibilidades podem ser afetadas pelo tamanho das partículas do calcário aplicado, que influencia a solubilidade do mesmo. Investigaram-se os efeitos da granulometria e épocas de aplicação de calcário magnesiano nos cátions trocáveis Ca, Mg e K extraidos no solo, nas suas concentrações em plantas crescidas cultivadas nesse solo e no rendimento das suas matérias secas. Vários tamanhos de partículas de calcário magnesiano foram aplicadas às parcelas experimentais, a uma taxa de 3 t ha-1, gramíneas e trevo foram plantados e as parcelas foram monitoradas durante três anos. O calcário mais fino (< 0,25 mm em uma única aplicação proporcionou os maiores teores de Ca e Mg extraídos por Mehlich-3 e por NH4Cl. Este mesmo calcário quando aplicado parcelado em três doses anuais foi menos eficaz. Parcelas tratadas com o clacário mais grosseiro (2-4 mm não diferiram da testemunha. A calagem não teve efeito sobre o potássio, quer seja no solo ou nas plantas. As concentrações no

  4. Acute central neuropeptide Y administration increases food intake but does not affect hepatic very low-density lipoprotein (VLDL) production in mice

    NARCIS (Netherlands)

    Geerling, Janine J.; Wang, Yanan; Havekes, Louis M.; Romijn, Johannes A.; Rensen, Patrick C. N.

    2013-01-01

    Central neuropeptide Y (NPY) administration stimulates food intake in rodents. In addition, acute modulation of central NPY signaling increases hepatic production of very low-density lipoprotein (VLDL)-triglyceride (TG) in rats. As hypertriglyceridemia is an important risk factor for

  5. Acute Central Neuropeptide Y Administration Increases Food Intake but Does Not Affect Hepatic Very Low-Density Lipoprotein (Vldl) Production in Mice

    NARCIS (Netherlands)

    Geerling, J.J.; Wang, Y.; Havekes, L.M.; Romijn, J.A.; Rensen, P.C.N.

    2013-01-01

    Objective: Central neuropeptide Y (NPY) administration stimulates food intake in rodents. In addition, acute modulation of central NPY signaling increases hepatic production of very low-density lipoprotein (VLDL)-triglyceride (TG) in rats. As hypertriglyceridemia is an important risk factor for

  6. Silent exonic mutations in the low-density lipoprotein receptor gene that cause familial hypercholesterolemia by affecting mRNA splicing

    NARCIS (Netherlands)

    Defesche, J. C.; Schuurman, E. J. M.; Klaaijsen, L. N.; Khoo, K. L.; Wiegman, A.; Stalenhoef, A. F. H.

    2008-01-01

    In a large group of patients with the clinical phenotype of familial hypercholesterolemia, such as elevated low-density lipoprotein (LDL) cholesterol and premature atherosclerosis, but without functional mutations in the genes coding for the LDL receptor and apolipoprotein B, we examined the effect

  7. Population age and initial density in a patchy environment affect the occurrence of abrupt transitions in a birth-and-death model of Taylor's law

    Science.gov (United States)

    Jiang, Jiang; DeAngelis, Donald L.; Zhang, B.; Cohen, J.E.

    2014-01-01

    Taylor's power law describes an empirical relationship between the mean and variance of population densities in field data, in which the variance varies as a power, b, of the mean. Most studies report values of b varying between 1 and 2. However, Cohen (2014a) showed recently that smooth changes in environmental conditions in a model can lead to an abrupt, infinite change in b. To understand what factors can influence the occurrence of an abrupt change in b, we used both mathematical analysis and Monte Carlo samples from a model in which populations of the same species settled on patches, and each population followed independently a stochastic linear birth-and-death process. We investigated how the power relationship responds to a smooth change of population growth rate, under different sampling strategies, initial population density, and population age. We showed analytically that, if the initial populations differ only in density, and samples are taken from all patches after the same time period following a major invasion event, Taylor's law holds with exponent b=1, regardless of the population growth rate. If samples are taken at different times from patches that have the same initial population densities, we calculate an abrupt shift of b, as predicted by Cohen (2014a). The loss of linearity between log variance and log mean is a leading indicator of the abrupt shift. If both initial population densities and population ages vary among patches, estimates of b lie between 1 and 2, as in most empirical studies. But the value of b declines to ~1 as the system approaches a critical point. Our results can inform empirical studies that might be designed to demonstrate an abrupt shift in Taylor's law.

  8. High-density native-range species affects the invasive plant Chromolaena odorata more strongly than species from its invasive range.

    Science.gov (United States)

    Zheng, Yulong; Liao, Zhiyong

    2017-11-22

    Invasive plant species often form dense mono-dominant stands in areas they have invaded, while having only sparse distribution in their native ranges, and the reasons behind this phenomenon are a key point of research in invasive species biology. Differences in species composition between native and invasive ranges may contribute to the difference in distribution status. In this study, we found that the high-density condition had a more negative effect on C. odorata than the low-density condition when co-grown with neighbor plants from its native range in Mexico, while this pattern was not in evidence when it was grown with neighbors from its invasive range in China. Different competitive ability and coevolutionary history with C. odorata between native-range neighbors and invasive-range neighbors may lead to the inconsistent patterns.

  9. Testosterone increases the muscle protein synthesis rate but does not affect very-low-density lipoprotein metabolism in obese premenopausal women.

    Science.gov (United States)

    Wang, Xuewen; Smith, Gordon I; Patterson, Bruce W; Reeds, Dominic N; Kampelman, Janine; Magkos, Faidon; Mittendorfer, Bettina

    2012-03-15

    Men and women with hyperandrogenemia have a more proatherogenic plasma lipid profile [e.g., greater triglyceride (TG) and total and low-density lipoprotein-cholesterol and lower high-density lipoprotein-cholesterol concentrations] than healthy premenopausal women. Furthermore, castration of male rats markedly reduces testosterone availability below normal and decreases plasma TG concentration, and testosterone replacement reverses this effect. Testosterone is, therefore, thought to be an important regulator of plasma lipid homeostasis. However, little is known about the effect of testosterone on plasma TG concentration and kinetics. Furthermore, testosterone is a potent skeletal muscle protein anabolic agent in men, but its effect on muscle protein turnover in women is unknown. We measured plasma lipid concentrations, hepatic very low density lipoprotein (VLDL)-TG and VLDL-apolipoprotein B-100 secretion rates, and the muscle protein fractional synthesis rate in 10 obese women before and after trandermal testosterone (1.25 g of 1% AndroGel daily) treatment for 3 wk. Serum total and free testosterone concentrations increased (P testosterone treatment, reaching concentrations that are comparable to those in women with hyperandrogenemia, but lower than the normal range for eugonadal men. Except for a small (∼10%) decrease in plasma high-density lipoprotein particle and cholesterol concentrations (P testosterone therapy had no effect on plasma lipid concentrations, lipoprotein particle sizes, and hepatic VLDL-TG and VLDL-apolipoprotein B-100 secretion rates (all P > 0.05); the muscle protein fractional synthesis rate, however, increased by ∼45% (P testosterone is a potent skeletal muscle protein anabolic agent, but not an important regulator of plasma lipid homeostasis in obese women.

  10. Risk Factors for Neck Shortening in Patients with Valgus Impacted Femoral Neck Fractures Treated with Three Parallel Screws: Is Bone Density an Affecting Factor?

    Science.gov (United States)

    Sung, Yerl-Bo; Jung, Eui-Yub; Kim, Kyung-Il; Kim, Soo-Yeon

    2017-12-01

    The purpose of this study is to analyze the relationship between significant femoral neck shortening (SFNS) and bone density after three parallel screw fixation in valgus impacted femoral neck fracture, and to analyze the risk factors for SFNS. This is retrospective study of 83 patients. We performed univariate analysis for patient information, bone density, fracture configuration and screw position divided into SFNS group (n=13) and non-SFNS group (n=70) and performed multivariate analysis using logistic regression model. We also analyzed the relationship between SFNS and complications such as osteonecrosis of femoral head and nonunion. There was a significant difference in age, screw non-parallelism and bone mineral density of intertrochanteric and total hip area in the univariate analysis between the two groups ( P femoral neck fractures treated with three parallel screws. The risk factors of SFNS were old age and screw non-parallelism. Therefore, we recommend using other fixation method to prevent SFNS in older ages and making the screw position as parallel as possible when performing screw fixation in valgus impacted femoral neck fracture.

  11. Dinâmica do acúmulo de matéria seca em pastagens de Tifton 85 sob pastejo Dry matter accumulation dynamics in grazed Tifton 85 bermudagrass swards

    Directory of Open Access Journals (Sweden)

    Luiz Felipe de Moura Pinto

    2001-09-01

    Full Text Available O acúmulo de forragem é o resultado líquido de dois processos concomitantes e antagônicos: o crescimento e a senescência e morte de tecidos. O presente trabalho teve por objetivo avaliar o processo de produção de forragem através do estudo de seus componentes; crescimento e senescência. Os tratamentos corresponderam a quatro condições de pasto caracterizadas pelas alturas de 5, 10, 15 e 20 cm, mantidas constante através do pastejo por ovinos em regime de lotação contínua e taxa de lotação variável. O delineamento experimental utilizado foi o de blocos completos casualizados, com quatro repetições. Foram avaliadas as seguintes respostas: alongamento de hastes, alongamento de folhas, senescência, filocrono e o número de folhas por perfilho. Os resultados revelaram um padrão estacional de produção de forragem, com as maiores taxas de crescimento e senescência sendo observadas nas alturas de pasto mais altas (15 e 20 cm. O filocrono variou com a época do ano e com a altura de pasto, revelando uma alta associação com variações em temperatura do ar, disponibilidade de água no solo e índice de área foliar do pasto. As alturas de 15 e 20 cm resultaram na maior produção de matéria seca. Os mesmos princípios e relações originalmente descritos para plantas forrageiras de clima temperado são válidos para plantas tropicais dentro do contexto das limitações fisiológicas e de ambiente inerentes para cada condição.Herbage dry matter accumulation from forage plants results from the balance between growth and senescence. Agronomic practices may influence both processes in different ways and, therefore, alter the quantitative and qualitative patterns of dry matter production. This study aimed at evaluating the process of dry matter accumulation through measurements of growth and senescence. Experimental treatments corresponded to four sward state conditions (5, 10, 15 and 20 cm of sward surface height - SSH generated

  12. Importance of individual analysis of environmental and climatic factors affecting the density of Leishmania vectors living in the same geographical area: the example of Phlebotomus ariasi and P. perniciosus in northeast Spain

    Directory of Open Access Journals (Sweden)

    Cristina Ballart

    2014-05-01

    Full Text Available The aim of the present study was to determine the role of specific environmental and climatic factors affecting the distribution and density of Phlebotomus ariasi and P. perniciosus, the proven vectors for Leishmania infantum in Spain. An entomological study was carried out in July 2006 in the province of Lleida with sticky traps set in their diurnal resting places at altitudes ranging from 86 to 1,755 m above the mean sea level (339 sites were sampled. Bivariate analysis revealed that factors such as altitude, bioclimatic zone, temperature, precipitation, sampling site (site relative to settlement, site situation, site category, wall vegetation, particular environment (in this case a natural park, general environment, adjacent natural vegetation and land cover were significantly associated with sand fly densities. The multivariate model for P. perniciosus revealed that its density was affected by site and land cover. Specifically, paved driveways correlated negatively with vector density (Incidence Risk Ratio (IRR: 0.41 and arable land cover correlated positively (IRR: 4.59. In the case of P. ariasi, a significant correlation was observed with the altitude and bioclimatic zone, with density increasing at >800 m above the mean sea level (IRR: 3.40 and decreasing in the meso-Mediterranean bioclimatic zone (IRR: 0.08. Both species were mostly found in agricultural and forest areas far from domestic environments. However, the two species correlated differently with altitude, bio-climate, vegetation, temperature and precipitation, which emphasises the importance of their individual analysis in studies regarding risk of leishmaniasis transmission.

  13. Pregnancy Followed by Delivery May Affect Circulating Soluble Lectin-Like Oxidized Low-Density Lipoprotein Receptor-1 Levels in Women of Reproductive Age

    Directory of Open Access Journals (Sweden)

    Mehmet Balin

    2012-01-01

    Full Text Available Background/Objective. It is known that menopause or lack of endogenous estrogen is a risk factor for endothelial dysfunction and CAD. Lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1 is involved inmultiple phases of vascular dysfunction.The purpose of the current study was to determine the association between soluble LOX-1 (sLOX-1 and pregnancy followed by delivery in women of reproductive age. Materials/Methods. Sixty-eight subjects with pregnancy followed by delivery (group 1 and 57 subjects with nongravidity (group 2 were included in this study. Levels of sLOX-1 were measured in serum by EL SA. Results. Plasma levels of sLOX-1 were significantly lower in Group 1 than Group 2 in women of reproductive age (0.52±0.18 ng/mL and 0.78±0.13, resp., <0.001. There were strong correlations between sLOX-1 levels and the number of gravida (=−0.645, <0.001. The levels of sLOX-1 highly correlated with the number of parous (=−0.683, <0.001. Conclusion. Our study demonstrated that serum sLOX-1 levels were associated with pregnancy followed by delivery that might predict endothelial dysfunction. We conclude that pregnancy followed by delivery may delay the beginning and progress of arteriosclerosis and its clinical manifestations in women of reproductive age.

  14. Preparation method of Ni@Pt/C nanocatalyst affects the performance of direct borohydride-hydrogen peroxide fuel cell: Improved power density and increased catalytic oxidation of borohydride.

    Science.gov (United States)

    Hosseini, Mir Ghasem; Mahmoodi, Raana

    2017-08-15

    The Ni@Pt/C electrocatalysts were synthesized using two different methods: with sodium dodecyl sulfate (SDS) and without SDS. The metal loading in synthesized nanocatalysts was 20wt% and the molar ratio of Ni: Pt was 1:1. The structural characterizations of Ni@Pt/C electrocatalysts were investigated by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM). The electrocatalytic activity of Ni@Pt/C electrocatalysts toward BH4- oxidation in alkaline medium was studied by means of cyclic voltammetry (CV), chronopotentiometry (CP), chronoamperometry (CA) and electrochemical impedance spectroscopy (EIS). The results showed that Ni@Pt/C electrocatalyst synthesized without SDS has superior catalytic activity toward borohydride oxidation (22016.92AgPt-1) in comparison with a catalyst prepared in the presence of SDS (17766.15AgPt-1) in NaBH4 0.1M at 25°C. The Membrane Electrode Assembly (MEA) used in fuel cell set-up was fabricated with catalyst-coated membrane (CCM) technique. The effect of Ni@Pt/C catalysts prepared with two methods as anode catalyst on the performance of direct borohydride-hydrogen peroxide fuel cell was studied. The maximum power density was obtained using Ni@Pt/C catalyst synthesized without SDS at 60°C, 1M NaBH4 and 2M H2O2 (133.38mWcm-2). Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Lifestyle factors and duration of androgen deprivation affect bone mineral density of patients with prostate cancer during first year of therapy.

    Science.gov (United States)

    Ryan, Christopher W; Huo, Dezheng; Stallings, James W; Davis, Ronald L; Beer, Tomasz M; McWhorter, Laura T

    2007-07-01

    Androgen deprivation therapy (ADT) is associated with loss of bone mineral density (BMD) and increased fracture risk. We sought to examine the impact of ADT and lifestyle variables on BMD in 120 patients with prostate cancer without bone metastases entering a randomized clinical trial. A total of 120 patients with prostate cancer and without bone metastases who had been treated with ADT for less than 12 months were enrolled in a clinical trial of zoledronic acid versus placebo. BMD measurements of the femoral neck, total hip, and lumbar spine were obtained before starting the study treatment by dual energy x-ray absorptiometry. The subjects answered a questionnaire regarding possible osteoporosis risk factors, including dairy product use, caffeinated beverage use, smoking history, alcohol intake, calcium/vitamin D supplementation, thyroid medication, and exercise. The median duration of ADT was 3 months (range 0 to 12). Osteopenia or osteoporosis (T score of less than -1) was detected in two thirds of the subjects at one or more measured sites. The mean baseline BMD Z scores were femoral neck -0.091 +/- 0.959, total hip 0.122 +/- 1.005, and lumbar spine 0.657 +/- 1.789. On multiple linear regression analysis, the duration of ADT was negatively associated with the Z score at all three sites and the body mass index, calcium/vitamin D supplementation, and alcohol use were positively associated with the Z score. BMD loss is a function of the duration of ADT during the first year of therapy. The body mass index, calcium/vitamin D supplementation, and alcohol use were associated with greater BMD, even after controlling for ADT exposure.

  16. Posterior Cruciate Ligament Retention or Substitution During Total Knee Arthroplasty Does Not Affect Long-Term Bone Mineral Density or Quality.

    Science.gov (United States)

    Ishii, Yoshinori; Noguchi, Hideo; Sato, Junko; Todoroki, Koji; Toyabe, Shin-Ichi

    2017-04-01

    Physical activity is recognized as one of the factors that influence bone mineral density (BMD) and bone quality after total knee arthroplasty (TKA). According to biomechanical analyses after posterior cruciate ligament (PCL) retaining (PCLR) and substituting (PCLS) TKA, each implant design has different kinematics and kinetics. The purposes of this study were: (1) to perform within-patient comparisons of the midterm and long-term effects of PCL retention in mobile-bearing TKA on proximal femur and tibia BMD and calcaneus bone quality measured using ultrasound and (2) to identify correlations between them. A prospective, quasi-randomized design was used. Thirty-seven patients (74 knees) who underwent bilateral TKA (PCLR on one side and PCLS on the other) were evaluated. Mean follow-up periods were 118 months (standard deviation 40) and 117 months (standard deviation 36) in knees with PCLR and PCLS implants, respectively. The BMDs of the total hip and proximal tibia and broadband ultrasound attenuation (BUA; dB/MHz) through the calcaneus were measured. The mean BMD of PCLR and PCLS were equivalent at the proximal hip and tibia. The BUA of the calcaneus was also the same between implants. There were significant correlations between the 3 anatomic sites. When measured approximately 10 years after TKA, PCL retention had no substantial effect on the BMD of the proximal femur and tibia, or on the bone quality of the calcaneus. The measurement of noninvasive BUA may predict BMD, although further analysis is required. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Road density

    Data.gov (United States)

    U.S. Environmental Protection Agency — Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More...

  18. Grazing management strategies for massaigrass-forage peanut pastures: 1. dynamics of sward condition and botanical composition Estratégias de manejo do pastejo para pastos consorciados de capim-massai e amendoim forrageiro: 1. dinâmica da condição do pasto e da composição botânica

    Directory of Open Access Journals (Sweden)

    Carlos Mauricio Soares de Andrade

    2006-04-01

    Full Text Available This study was carried out from October 2002 to December 2003 to evaluate the dynamics of sward condition and botanical composition of a mixed massaigrass (Panicum maximum x P. infestum, cv. Massai and forage peanut (Arachis pintoi Ac 01 pasture, intermittently stocked at three daily herbage allowance levels (9.0, 14.5 and 18.4% live weight. Sward condition was characterized in each grazing cycle in terms of the pre and post-grazing sward height, forage mass and percentage of bare ground. Botanical composition (grass, legume and weeds was evaluated before each grazing period. Sward height and forage mass increased linearly with increasing herbage allowance (HA levels, and higher values were observed during the rainy season. Percentage of bare ground increased primarily at the lowest HA level. Percentage of forage peanut increased throughout the experimental period, primarily in the barest and shortest swards, under the lowest HA level. In the last quarter of 2003 the legume constituted 23.5, 10.6 and 6.4% of the pasture forage mass, respectively, from the lowest to the highest HA level. These results suggest that forage peanut can be successfully associated with massaigrass, as long as the pre-grazing sward height is maintained shorter than 65-70 cm, which will prevent excessive shading to the legume.Este estudo foi realizado com o objetivo de avaliar a dinâmica e a composição botânica de uma pastagem consorciada de capim-massai (Panicum maximum x P. infestum, cv. Massai e amendoim forrageiro (Arachis pintoi Ac 01, manejada sob lotação rotacionada em três níveis de oferta diária de forragem (9,0; 14,5 e 18,4% do peso vivo. A condição da pastagem foi caracterizada em cada ciclo de pastejo, em termos de altura, massa de forragem e porcentagem de solo descoberto (pré e pós-pastejo. A composição botânica da pastagem (gramínea, leguminosa e invasoras foi monitorada antes de cada período de ocupação. Houve aumento linear da altura

  19. Description of Microbacterium foliorum sp. nov. and Microbacterium phyllosphaerae sp. nov., isolated from the phyllosphere of grasses and the surface litter after mulching the sward, and reclassification of Aureobacterium resistens (Funke et al. 1998) as Microbacterium resistens comb. nov..

    Science.gov (United States)

    Behrendt, U; Ulrich, A; Schumann, P

    2001-07-01

    The taxonomic position of a group of coryneform bacteria isolated from the phyllosphere of grasses and the surface litter after sward mulching was investigated. On the basis of restriction analyses of 16S rDNA, the isolates were divided into two genotypes. According to the 16S rDNA sequence analysis, representatives of both genotypes were related at a level of 99.2% similarity and clustered within the genus Microbacterium. Chemotaxonomic features (major menaquinones MK-12, MK-11 and MK-10; predominating iso- and anteiso-branched cellular fatty acids; G+C content 64-67 mol%; peptidoglycan-type B2beta with glycolyl residues) corresponded to this genus as well. DNA-DNA hybridization studies showed a reassociation value of less than 70% between representative strains of both subgroups, suggesting that two different species are represented. Although the extensive morphological and physiological analyses did not reveal any differentiating feature for the genotypes, differences in the presence of the cell-wall sugar mannose enabled the subgroups to be distinguished from one another. DNA-DNA hybridization with type strains of closely related Microbacterium spp. indicated that the isolates represent two individual species, which can also be differentiated from previously described species of Microbacterium on the basis of biochemical features. As a result of phenotypic and phylogenetic analyses, the species Microbacterium foliorum sp. nov., type strain P 333/02T (= DSM 12966T = LMG 19580T), and Microbacterium phyllosphaerae sp. nov., type strain P 369/06T (= DSM 13468T = LMG 19581T), are proposed. Furthermore, the reclassification of Aureobacterium resistens (Funke et al. 1998) as Microbacterium resistens (Funke et al. 1998) comb. nov. is proposed.

  20. Lung density

    DEFF Research Database (Denmark)

    Garnett, E S; Webber, C E; Coates, G

    1977-01-01

    The density of a defined volume of the human lung can be measured in vivo by a new noninvasive technique. A beam of gamma-rays is directed at the lung and, by measuring the scattered gamma-rays, lung density is calculated. The density in the lower lobe of the right lung in normal man during quiet...... breathing in the sitting position ranged from 0.25 to 0.37 g.cm-3. Subnormal values were found in patients with emphsema. In patients with pulmonary congestion and edema, lung density values ranged from 0.33 to 0.93 g.cm-3. The lung density measurement correlated well with the findings in chest radiographs...... but the lung density values were more sensitive indices. This was particularly evident in serial observations of individual patients....

  1. Qualidade nutricional de cenoura e alface cultivadas em Mossoró-RN em função da densidade populacional Nutritional quality of carrot and lettuce grown in Mossoró-RN, Brazil, as affected by plant densities

    Directory of Open Access Journals (Sweden)

    Francisco Bezerra Neto

    2006-12-01

    out from June to September of 2003, in the experimental area of "Universidade Federal Rural do Semi-Árido" (UFERSA, in Mossoró, Rio Grande do Norte state, Brazil, in order to evaluate the effect of carrot and lettuce populational densities in a second growing period on their nutritional quality in a strip-intercropping system. A randomized complete block design was used with the treatments arranged in a 4 x 4 factorial scheme with three replications. The treatments consisted of the combination of four carrot-plant densities (40%, 60%, 80% and 100% of the recommended sole crop density - RSCD with four lettuce-plant densities (40%, 60%, 80% and 100% of the RSCD. The reference populations for carrot and lettuce in sole crop, corresponding to 100%, were of 500,000 plants.ha-1 and 250,000 plants.ha-1, respectively. Carrot cv. Brasília and lettuce cv. Tainá were planted. Quality characteristics evaluated were firmness and content of vitamin C, total carotenoids and beta-carotene for carrot roots and firmness, contents of vitamin C, total carotenoids and total chlorophyll for lettuce leaves. The associations of plant densities of carrot and lettuce did not affect any of the assessed characteristics in both crops. However, both carrot and lettuce plant densities affected the traits evaluated in both crops. The firmness, contents of vitamin C and beta-carotene in carrot roots decreased as the plant densities of carrot increased, while the content of total carotenoids increased as carrot population increased. The same decreasing behavior was observed in contents of vitamin C, total carotenoids and chlorophyll in the lettuce leaves with an increase in the plant densities of lettuce.

  2. Low Bone Density

    Science.gov (United States)

    ... Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone density ... people with normal bone density. Detecting Low Bone Density A bone density test will determine whether you ...

  3. Isolated olecranon fractures in children affected by osteogenesis imperfecta type I treated with single screw or tension band wiring system: Outcomes and pitfalls in relation to bone mineral density.

    Science.gov (United States)

    Persiani, Pietro; Ranaldi, Filippo M; Graci, Jole; De Cristo, Claudia; Zambrano, Anna; D'Eufemia, Patrizia; Martini, Lorena; Villani, Ciro

    2017-05-01

    The purpose of this study is to compare the results of 2 techniques, tension band wiring (TBW) and fixation with screws, in olecranon fractures in children affected with osteogenesis imperfecta (OI) type I. Between 2010 and 2014, 21 olecranon fractures in 18 children with OI (average age: 12 years old) were treated surgically. Ten patients were treated with the screw fixation and 11 with TBW. A total of 65% of olecranon fractures occurred as a result of a spontaneous avulsion of the olecranon during the contraction of the triceps muscle. The average follow-up was 36 months. Among the children treated with 1 screw, 5 patients needed a surgical revision with TBW due to a mobilization of the screw. In this group, the satisfactory results were 50%. In patients treated with TBW, the satisfactory results were 100% of the cases. The average Z-score, the last one recorded in the patients before the trauma, was -2.53 in patients treated with screw fixation and -2.04 in those treated with TBW. TBW represents the safest surgical treatment for patients suffering from OI type I, as it helps to prevent the rigidity of the elbow through an earlier recovery of the range of motion, and there was no loosening of the implant. In analyzing the average Z-score before any fracture, the fixation with screws has an increased risk of failure in combination with low bone mineral density.

  4. Exercise frequency and bone mineral density development in exercising postmenopausal osteopenic women. Is there a critical dose of exercise for affecting bone? Results of the Erlangen Fitness and Osteoporosis Prevention Study.

    Science.gov (United States)

    Kemmler, Wolfgang; von Stengel, Simon; Kohl, Matthias

    2016-08-01

    Due to older people's low sports participation rates, exercise frequency may be the most critical component for designing exercise protocols that address bone. The aims of the present article were to determine the independent effect of exercise frequency (ExFreq) and its corresponding changes on bone mineral density (BMD) and to identify the minimum effective dose that just relevantly affects bone. Based on the 16-year follow-up of the intense, consistently supervised Erlangen Fitness and Osteoporosis Prevention-Study, ExFreq was retrospectively determined in the exercise-group of 55 initially early-postmenopausal females with osteopenia. Linear mixed-effect regression analysis was conducted to determine the independent effect of ExFreq on BMD changes at lumbar spine and total hip. Minimum effective dose of ExFreq based on BMD changes less than the 90% quantile of the sedentary control-group (n=43). Cut-offs were determined after 4, 8, 12 and 16years using bootstrap with 5000 replications. After 16years, average ExFreq ranged between 1.02 and 2.96sessions/week (2.28±0.40sessions/week). ExFreq has an independent effect on LS-BMD (pexercise frequency that relevantly addresses BMD is quite high, at least compared with the low sport participation rate of older adults. This result might not be generalizable across all exercise types, protocols and cohorts, but it does indicate at least that even when applying high impact/high intensity programs, exercise frequency and its maintenance play a key role in bone adaptation. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Components of the leaf area index of marandu palisadegrass swards subjected to strategies of intermittent stocking Componentes do índice de área foliar de pastos de capim-marandu submetidos a estratégias de lotação intermitente

    Directory of Open Access Journals (Sweden)

    Alessandra Aparecida Giacomini

    2009-12-01

    Full Text Available Leaf area index is the main sward characteristic related to the processes of light interception and competition in plant communities. The objective of this experiment was to quantify and evaluate the composition of the leaf area on tillers of marandu palisadegrass (Brachiaria brizantha cv. Marandu subjected to strategies of intermittent stocking. The experiment was carried out in Piracicaba, state of São Paulo, Brazil, from October/2004 to December/2005. Swards were grazed at 95 and 100% canopy light interception (LI to post-grazing heights of 10 and 15 cm, following a 2 ' 2 factorial arrangement with four replications in a randomised complete block design. Estimates were made of sward leaf area index, site filling, specific leaf area and the dimensionless ratio between tiller leaf area and volume (R, as well as the relative contribution of basal and aerial tillers to these variables. In early spring, values of leaf area index and specific leaf area were low when compared to the other seasons, and swards grazed at 95% LI presented higher site filling and specific leaf area than those grazed at 100% LI. This resulted in higher tillering activity and increase in leaf area index in late spring, indicating quick recovery and early return of swards grazed at 95% LI to growing conditions. Aerial tillers corresponded to an important morphological adaptation of marandu palisadegrass to increase its competitive ability. Treatment 100/10 resulted in the highest and 95/15 in the lowest R values throughout the experiment, suggesting an allometric pattern of growth of tillers during regrowth in order to compensate low tiller population and optimise the leaf area index. Grazing management practices can benefit from this knowledge by promoting ideal sward conditions to maximise and accelerate growth.O índice de área foliar é a principal característica do dossel relacionada com os processos de interceptação e competição por luz em comunidades de

  6. Avaliação da composição química e da digestibilidade in vitro da mistura aveia IAPAR 61 (Avena strigosa Schreb + ervilha forrageira (Pisum arvense L. em diferentes alturas sob pastejo Evaluation of chemical composition and in vitro digestibility of mixture of oat IAPAR 61 (Avena strigosa Schreb cv IAPAR 61 + field pea (Pisum arvense L. under grazing in different sward heights

    Directory of Open Access Journals (Sweden)

    Márcia Mascarenhas Grise

    2001-06-01

    Full Text Available O objetivo do trabalho foi avaliar o efeito das alturas (8,9; 10,0; 11,2; 11,8; 13,3; 13,6; 14,6; 18,2 cm de pastos consorciados de aveia IAPAR 61 (Avena strigosa Schreb cv IAPAR 61 com ervilha forrageira (Pisum arvense L. sob pastejo sobre a relação folha/colmo (F/C, os teores de proteína bruta (PB, fibra em detergente neutro (FDN e fibra em detergente ácido (FDA e a digestibilidade in vitro da matéria seca (DIVMS e da matéria orgânica (DIVMO. O delineamento experimental usado foi o inteiramente casualizado, com duas repetições. A relação F/C não foi influenciada pela altura do pasto, porém apresentou comportamento quadrático com o avanço na maturidade do pasto. Os teores de PB apresentaram comportamento quadrático ao longo do período experimental, devido à interação entre altura do pasto e o tempo. Os teores de FDN e FDA mostraram um comportamento quadrático ao longo do período experimental, ocorrendo uma diminuição dos mesmos quando as plantas se apresentavam mais baixas e, uma elevação, quando as plantas estavam mais altas, isto ocorreu em função da interação das variáveis tempo e altura. A DIVMS e a DIVMO tiveram incrementos lineares em função do aumento da altura do pasto, porém com comportamento quadrático no tempo (dias em todas as alturas, sendo mais elevadas nas alturas intermediárias do pasto.The objective of this work was to evaluate the effect of different sward heights (8.9, 10.0, 11.2, 11.8; 13.3; 13.6; 14.6; 18.2 cm in the mixture of black oat IAPAR 61 (Avena strigosa Schreb cv IAPAR 61 + field pea (Pisum arvense L., under grazing, on leaf/stem ratio (L/S, crude protein (CP, neutral detergent fiber (NDF and acid detergent fiber (ADF contents and dry matter (DMIVD and of organic matter (OMIVD in vitro digestibility. A completely randomized experimental design with two replicates was used. L/S ratio was not influenced by sward height, although it presented quadratic behavior with the progress of

  7. Qualidade de crisântemo (Dendranthema grandiflora Tzevelev. cv. Snowdon em diferentes populações e épocas de plantio Quality of chrysanthemum (Dendranthema grandiflora Tzevelev. cv. Snowdon affected by plant density and plant date

    Directory of Open Access Journals (Sweden)

    Claudia Nardi

    2001-12-01

    Full Text Available Para avaliar a qualidade das hastes florais, a cultivar de crisântemo Snowdon foi conduzida em estufa plástica em oito populações de plantas e duas épocas de plantio. O experimento bifatorial (2 x 8, com parcela subdividida, foi conduzido na Universidade Federal de Santa Maria (Santa Maria, RS e teve época como parcela principal, sendo a primeira época outono/inverno no período de 05/03/98 à 29/06/98 e a segunda época inverno/primavera no período de 22/07/98 à 11/11/98 e as populações de 40, 48, 56, 64, 72, 80, 88 e 104pl/m², na subparcela para as duas épocas de plantio. As plantas foram conduzidas em haste unifloral. Determinaram-se a altura da planta, o diâmetro da inflorescência e da haste e a massa da matéria fresca. Para obtenção de maiores rendimentos de hastes de classe A (comprimento da haste > ou = 90 cm, diâmetro da inflorescência > ou = 13,5cm, diâmetro da haste > ou = 0,73cm e massa da matéria fresca > ou = 113g a população indicada está entre 40 e 56plantas/m². Não há diferenças de rendimento qualitativo de classe A entre as épocas de plantio. Para obtenção de maiores rendimentos qualitativos, as populações de plantas não devem ser superiores a 72 plantas/m².To evaluate the quality of the flowers of chrysanthemums, were cultivated the cv. Snowdon in greenhouse in eight plant densities and two planting dates. The experimental design was factorial, (2 planting dates x 8 plants densities. The two planting dates were: 05 March 1998 (Fall/Winter growing season and 22 July 1998 (Winter/Spring growing season. Plant densities were: 48, 56, 64, 72, 80, 88 and 104plants/m². Plant height, diameter of the flower and stem, fresh weight were determinated. For obtaining of larger revenues of class stems A, the suitable plant density is between 40 and 56plants/m². There are not differences of qualitative revenue of class A (stem lenght > or = 90cm, flower diameter > or = 13,5cm, stem diameter > or = 0,73cm

  8. Density Distribution Sunflower Plots

    Directory of Open Access Journals (Sweden)

    William D. Dupont

    2003-01-01

    Full Text Available Density distribution sunflower plots are used to display high-density bivariate data. They are useful for data where a conventional scatter plot is difficult to read due to overstriking of the plot symbol. The x-y plane is subdivided into a lattice of regular hexagonal bins of width w specified by the user. The user also specifies the values of l, d, and k that affect the plot as follows. Individual observations are plotted when there are less than l observations per bin as in a conventional scatter plot. Each bin with from l to d observations contains a light sunflower. Other bins contain a dark sunflower. In a light sunflower each petal represents one observation. In a dark sunflower, each petal represents k observations. (A dark sunflower with p petals represents between /2-pk k and /2+pk k observations. The user can control the sizes and colors of the sunflowers. By selecting appropriate colors and sizes for the light and dark sunflowers, plots can be obtained that give both the overall sense of the data density distribution as well as the number of data points in any given region. The use of this graphic is illustrated with data from the Framingham Heart Study. A documented Stata program, called sunflower, is available to draw these graphs. It can be downloaded from the Statistical Software Components archive at http://ideas.repec.org/c/boc/bocode/s430201.html . (Journal of Statistical Software 2003; 8 (3: 1-5. Posted at http://www.jstatsoft.org/index.php?vol=8 .

  9. Affect Regulation

    DEFF Research Database (Denmark)

    Pedersen, Signe Holm; Poulsen, Stig Bernt; Lunn, Susanne

    2014-01-01

    Gergely and colleagues’ state that their Social Biofeedback Theory of Parental Affect Mirroring” can be seen as a kind of operationalization of the classical psychoanalytic concepts of holding, containing and mirroring. This article examines to what extent the social biofeedback theory of parental...... affect mirroring may be understood as a specification of these concepts. It is argued that despite similarities at a descriptive level the concepts are embedded in theories with different ideas of subjectivity. Hence an understanding of the concept of affect regulation as a concretizisation...... and specification of the classical concepts dilutes the complexity of both the concept of affect regulation and of the classical concepts....

  10. DOSES DE NITROGÊNIO E DENSIDADES DE PLANTAS COM E SEM UM REGULADOR DE CRESCIMENTO AFETANDO O TRIGO, CULTIVAR OR-1 NITROGEN DOSES AND PLANT DENSITIES WITH AND WITHOUT A GROWTH REGULATOR AFFECTING WHEAT, CULTIVAR OR-1

    Directory of Open Access Journals (Sweden)

    Jeferson Zagonel

    2002-02-01

    established at the UEPG "Capão da Onça" School Farm in Ponta Grossa, PR, in 1999. The experimental design was complete randomized blocks in a factorial design 2 x 3 x 4 with four replications. The twenty four treatments consisted in the application of 125g a.i./ha of trinexapac-ethyl and control; plant densities of 55, 75 and 112 plants/m in the row spacing of 0.17m and rates of 0, 45, 90, and 135kg/ha of surface broadcasted nitrogen. The application of trinexapac-ethyl resulted in short internodes of plants, increase of the number of spikes/m and of the productivity. As the nitrogen rate increased, it also happered to plant height, number of spikes/m and yield. With the increase of plant density the stem diameter, the dry matter of plants and the number of grains/spike decreased; however, the number of spikes/m and the weight of 1000 grains increased with no effect on productivity. No lodging was observed in any of the treatments.

  11. Laboratory Density Functionals

    OpenAIRE

    Giraud, B. G.

    2007-01-01

    We compare several definitions of the density of a self-bound system, such as a nucleus, in relation with its center-of-mass zero-point motion. A trivial deconvolution relates the internal density to the density defined in the laboratory frame. This result is useful for the practical definition of density functionals.

  12. The dynamics of variable-density turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, D.L.

    1995-11-01

    The dynamics of variable-density turbulent fluids are studied by direct numerical simulation. The flow is incompressible so that acoustic waves are decoupled from the problem, and implying that density is not a thermodynamic variable. Changes in density occur due to molecular mixing. The velocity field, is in general, divergent. A pseudo-spectral numerical technique is used to solve the equations of motion. Three-dimensional simulations are performed using a grid size of 128{sup 3} grid points. Two types of problems are studied: (1) the decay of isotropic, variable-density turbulence, and (2) buoyancy-generated turbulence in a fluid with large density fluctuations. In the case of isotropic, variable-density turbulence, the overall statistical decay behavior, for the cases studied, is relatively unaffected by the presence of density variations when the initial density and velocity fields are statistically independent. The results for this case are in quantitative agreement with previous numerical and laboratory results. In this case, the initial density field has a bimodal probability density function (pdf) which evolves in time towards a Gaussian distribution. The pdf of the density field is symmetric about its mean value throughout its evolution. If the initial velocity and density fields are statistically dependent, however, the decay process is significantly affected by the density fluctuations. For the case of buoyancy-generated turbulence, variable-density departures from the Boussinesq approximation are studied. The results of the buoyancy-generated turbulence are compared with variable-density model predictions. Both a one-point (engineering) model and a two-point (spectral) model are tested against the numerical data. Some deficiencies in these variable-density models are discussed and modifications are suggested.

  13. Future Road Density

    Data.gov (United States)

    U.S. Environmental Protection Agency — Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More...

  14. Atomic vapor density monitor

    Energy Technology Data Exchange (ETDEWEB)

    Sewall, N.; Harris, W.; Beeler, R.; Wooldridge, J.; Chen, H.L.

    1986-09-01

    This report presents information on the Atomic Vapor Density Monitor (AVDM) system that measures the density of a vapor by measuring the absorption of light from a swept-wavelength laser that passes through an atomic vapor stream.

  15. The dynamics of variable-density turbulence

    Energy Technology Data Exchange (ETDEWEB)

    Sandoval, Donald L. [Univ. of California, Berkeley, CA (United States)

    1995-11-01

    The dynamics of variable-density turbulent fluids are studied by direct numerical simulation. The flow is incompressible so that acoustic waves are decoupled from the problem, and implying that density is not a thermodynamic variable. Changes in density occur due to molecular mixing. The velocity field is, in general, divergent. A pseudo-spectral numerical technique is used to solve the equations of motion. Three-dimensional simulations are performed using a grid size of 1283 grid points. Two types of problems are studied: (1) the decay of isotropic, variable-density turbulence, and (2) buoyancy-generated turbulence in a fluid with large density fluctuations (such that the Boussinesq approximation is not valid). In the case of isotropic, variable-density turbulence, the overall statistical decay behavior, for the cases studied, is relatively unaffected by the presence of density variations when the initial density and velocity fields are statistically independent. The results for this case are in quantitative agreement with previous numerical and laboratory results. In this case, the initial density field has a bimodal probability density function (pdf) which evolves in time towards a Gaussian distribution. The pdf of the density field is symmetric about its mean value throughout its evolution. If the initial velocity and density fields are statistically dependent, however, the decay process is significantly affected by the density fluctuations. For this case, the pdf of the density becomes asymmetric about its mean value during the early stages of its evolution. It is argued that these asymmetries in the pdf of the density field are due to different entrainment rates, into the mixing region, that favor the high speed fluid.

  16. Affective Networks

    OpenAIRE

    Jodi Dean

    2010-01-01

    This article sets out the idea of affective networks as a constitutive feature of communicative capitalism. It explores the circulation of intensities in contemporary information and communication networks, arguing that this circulation should be theorized in terms of the psychoanalytic notion of the drive. The article includes critical engagements with theorists such as Guy Debord, Jacques Lacan, Tiziana Terranova, and Slavoj Zizek.

  17. Affective Urbanism

    DEFF Research Database (Denmark)

    Samson, Kristine

    Urban design and architecture are increasingly used as material and affective strategies for setting the scene, for manipulation and the production of urban life: The orchestration of atmospheres, the framing and staging of urban actions, the programming for contemplation, involvement, play...

  18. Crowding and Density

    Science.gov (United States)

    Design and Environment, 1972

    1972-01-01

    Three-part report pinpointing problems and uncovering solutions for the dual concepts of density (ratio of people to space) and crowding (psychological response to density). Section one, A Primer on Crowding,'' reviews new psychological and social findings; section two, Density in the Suburbs,'' shows conflict between status quo and increased…

  19. Affective Networks

    Directory of Open Access Journals (Sweden)

    Jodi Dean

    2010-02-01

    Full Text Available This article sets out the idea of affective networks as a constitutive feature of communicative capitalism. It explores the circulation of intensities in contemporary information and communication networks, arguing that this circulation should be theorized in terms of the psychoanalytic notion of the drive. The article includes critical engagements with theorists such as Guy Debord, Jacques Lacan, Tiziana Terranova, and Slavoj Zizek.

  20. Does Vowel Inventory Density Affect Vowel-to-Vowel Coarticulation?

    Science.gov (United States)

    Mok, Peggy P. K.

    2013-01-01

    This study tests the output constraints hypothesis that languages with a crowded phonemic vowel space would allow less vowel-to-vowel coarticulation than languages with a sparser vowel space to avoid perceptual confusion. Mandarin has fewer vowel phonemes than Cantonese, but their allophonic vowel spaces are similarly crowded. The hypothesis…

  1. Natural regeneration of whitebark pine: Factors affecting seedling density

    Science.gov (United States)

    S. Goeking; D. Izlar

    2014-01-01

    Whitebark pine (Pinus albicaulis) is an ecologically important species in high-altitude areas of the western United States and Canada due to the habitat and food source it provides for Clark’s nutcrackers, red squirrels, grizzly bears, and other animals. Whitebark pine stands have recently experienced high mortality due to wildfire, white pine blister rust, and a...

  2. Rhythmic Density Affects Listeners' Emotional Response to Microtiming

    National Research Council Canada - National Science Library

    Olivier Senn; Claudia Bullerjahn; Lorenz Kilchenmann; Richard von Georgi

    2017-01-01

    ... under which microtiming has no negative impact on groove. The three studies in this paper aim at explaining some of these discrepancies by clarifying to what extent listeners' emotional responses to microtiming depend on the distribution of microtiming...

  3. Probability densities and Lévy densities

    DEFF Research Database (Denmark)

    Barndorff-Nielsen, Ole Eiler

    For positive Lévy processes (i.e. subordinators) formulae are derived that express the probability density or the distribution function in terms of power series in time t. The applicability of the results to finance and to turbulence is briefly indicated.......For positive Lévy processes (i.e. subordinators) formulae are derived that express the probability density or the distribution function in terms of power series in time t. The applicability of the results to finance and to turbulence is briefly indicated....

  4. A Survey of Coronal Cavity Density Profiles

    Science.gov (United States)

    Fuller, J.; Gibson, S. E.

    2009-08-01

    Coronal cavities are common features of the solar corona that appear as darkened regions at the base of coronal helmet streamers in coronagraph images. Their darkened appearance indicates that they are regions of lowered density embedded within the comparatively higher density helmet streamer. Despite interfering projection effects of the surrounding helmet streamer (which we refer to as the cavity rim), Fuller et al. have shown that under certain conditions it is possible to use a Van de Hulst inversion of white-light polarized brightness (pB) data to calculate the electron density of both the cavity and cavity rim plasma. In this article, we apply minor modifications to the methods of Fuller et al. in order to improve the accuracy and versatility of the inversion process, and use the new methods to calculate density profiles for both the cavity and cavity rim in 24 cavity systems. We also examine trends in cavity morphology and how departures from the model geometry affect our density calculations. The density calculations reveal that in all 24 cases the cavity plasma has a flatter density profile than the plasma of the cavity rim, meaning that the cavity has a larger density depletion at low altitudes than it does at high altitudes. We find that the mean cavity density is over four times greater than that of a coronal hole at an altitude of 1.2 R sun and that every cavity in the sample is over twice as dense as a coronal hole at this altitude. Furthermore, we find that different cavity systems near solar maximum span a greater range in density at 1.2 R sun than do cavity systems near solar minimum, with a slight trend toward higher densities for systems nearer to solar maximum. Finally, we found no significant correlation of cavity density properties with cavity height—indeed, cavities show remarkably similar density depletions—except for the two smallest cavities that show significantly greater depletion.

  5. Modeling thermospheric neutral density

    Science.gov (United States)

    Qian, Liying

    Satellite drag prediction requires determination of thermospheric neutral density. The NCAR Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIEGCM) and the global-mean Thermosphere-Ionosphere-Mesosphere-Electrodynamics General Circulation Model (TIMEGCM) were used to quantify thermospheric neutral density and its variations, focusing on annual/semiannual variation, the effect of using measured solar irradiance on model calculations of solar-cycle variation, and global change in the thermosphere. Satellite drag data and the MSIS00 empirical model were utilized to compare to the TIEGCM simulations. The TIEGCM simulations indicated that eddy diffusion and its annual/semiannual variation is a mechanism for annual/semiannual density variation in the thermosphere. It was found that eddy diffusion near the turbopause can effectively influence thermospheric neutral density. Eddy diffusion, together with annual insolation variation and large-scale circulation, generated global annual/semiannual density variation observed by satellite drag. Using measured solar irradiance as solar input for the TIEGCM improved the solar-cycle dependency of the density calculation shown in F10.7 -based thermospheric empirical models. It has been found that the empirical models overestimate density at low solar activity. The TIEGCM simulations did not show such solar-cycle dependency. Using historic measurements of CO2 and F 10.7, simulations of the global-mean TIMEGCM showed that thermospheric neutral density at 400 km had an average long-term decrease of 1.7% per decade from 1970 to 2000. A forecast of density decrease for solar cycle 24 suggested that thermospheric density will decrease at 400 km from present to the end of solar cycle 24 at a rate of 2.7% per decade. Reduction in thermospheric density causes less atmospheric drag on earth-orbiting space objects. The implication of this long-term decrease of thermospheric neutral density is that it will increase the

  6. Why Density Dependent Propulsion?

    Science.gov (United States)

    Robertson, Glen A.

    2011-01-01

    In 2004 Khoury and Weltman produced a density dependent cosmology theory they call the Chameleon, as at its nature, it is hidden within known physics. The Chameleon theory has implications to dark matter/energy with universe acceleration properties, which implies a new force mechanism with ties to the far and local density environment. In this paper, the Chameleon Density Model is discussed in terms of propulsion toward new propellant-less engineering methods.

  7. [Affective dependency].

    Science.gov (United States)

    Scantamburlo, G; Pitchot, W; Ansseau, M

    2013-01-01

    Affective dependency is characterized by emotional distress (insecure attachment) and dependency to another person with a low self-esteem and reassurance need. The paper proposes a reflection on the definition of emotional dependency and the confusion caused by various denominations. Overprotective and authoritarian parenting, cultural and socio-environmental factors may contribute to the development of dependent personality. Psychological epigenetic factors, such as early socio-emotional trauma could on neuronal circuits in prefronto-limbic regions that are essential for emotional behaviour.We also focus on the interrelations between dependent personality, domestic violence and addictions. The objective for the clinician is to propose a restoration of self-esteem and therapeutic strategies focused on autonomy.

  8. Density dependent neurodynamics.

    Science.gov (United States)

    Halnes, Geir; Liljenström, Hans; Arhem, Peter

    2007-01-01

    The dynamics of a neural network depends on density parameters at (at least) two different levels: the subcellular density of ion channels in single neurons, and the density of cells and synapses at a network level. For the Frankenhaeuser-Huxley (FH) neural model, the density of sodium (Na) and potassium (K) channels determines the behaviour of a single neuron when exposed to an external stimulus. The features of the onset of single neuron oscillations vary qualitatively among different regions in the channel density plane. At a network level, the density of neurons is reflected in the global connectivity. We study the relation between the two density levels in a network of oscillatory FH neurons, by qualitatively distinguishing between three regions, where the mean network activity is (1) spiking, (2) oscillating with enveloped frequencies, and (3) bursting, respectively. We demonstrate that the global activity can be shifted between regions by changing either the density of ion channels at the subcellular level, or the connectivity at the network level, suggesting that different underlying mechanisms can explain similar global phenomena. Finally, we model a possible effect of anaesthesia by blocking specific inhibitory ion channels.

  9. On density forecast evaluation

    NARCIS (Netherlands)

    Diks, C.

    2008-01-01

    Traditionally, probability integral transforms (PITs) have been popular means for evaluating density forecasts. For an ideal density forecast, the PITs should be uniformly distributed on the unit interval and independent. However, this is only a necessary condition, and not a sufficient one, as

  10. Future Road Density

    Science.gov (United States)

    Road density is generally highly correlated with amount of developed land cover. High road densities usually indicate high levels of ecological disturbance. More information about these resources, including the variables used in this study, may be found here: https://edg.epa.gov/data/Public/ORD/NERL/ReVA/ReVA_Data.zip.

  11. Learning Grasp Affordance Densities

    DEFF Research Database (Denmark)

    Detry, Renaud; Kraft, Dirk; Kroemer, Oliver

    2011-01-01

    these and records their outcomes. When a satisfactory number of grasp data is available, an importance-sampling algorithm turns these into a grasp density. We evaluate our method in a largely autonomous learning experiment run on three objects of distinct shapes. The experiment shows how learning increases success......We address the issue of learning and representing object grasp affordance models. We model grasp affordances with continuous probability density functions (grasp densities) which link object-relative grasp poses to their success probability. The underlying function representation is nonparametric...... and relies on kernel density estimation to provide a continuous model. Grasp densities are learned and refined from exploration, by letting a robot “play” with an object in a sequence of graspand-drop actions: The robot uses visual cues to generate a set of grasp hypotheses; it then executes...

  12. The affection of the disturbance of the hydrodynamics of blood in case of stress on pathological increase of level of low density lipoproteins in blood. The formation of cylindrical plaques, and their participation in the development of acute ischemic disorders of heart and brain.

    Science.gov (United States)

    Rusanov, S E

    2017-09-01

    In this article is given the new insight about the affection of stress on the increase of level of low density lipoproteins (LDL) in the blood, which is connected with the disturbance of hydrodynamics in the bloodstream, the attention was paid to the cylindrical cholesterol plaque, and it's classification. The disturbance of hydrodynamics of blood under the stress leads to the formation of a cylindrical cholesterol plaque, which repeats the contour of the vessel, and leads to the ischemic disorders of the heart and brain. The cylindrical cholesterol plaque goes through several stages of development: friable, yielding, dense, old. In the case of destruction of friable, fresh cholesterol plaque, releases a big quantity of low-density lipoproteins. This leads to the pathological increase of level of LDL in the blood. In the case of long disturbance of hydrodynamics, occurs the formation of strong links between low-density lipoproteins. Yielding cholesterol plaque is formed. Further maturation of cylindrical cholesterol plaque, leads to it's densifying and damage. We may emphasize, that short periods of strong contraction and expansion of vessels lead to the increase of level of LDL in the blood. Self-dependent restoration of normal level of LDL in blood occurs in the case of restoration of pressure in the limits of numbers, which are specific for particular person, and which don't exceed the physiological standard. Among patients with long duration of stress, the duration of vasospasm increases. LDL, without having a possibility to crumble, begin to stick together and form the yielding cylindrical plaque. It is characterized by having of not so strong connection with the vascular wall, and maintains only at the expanse of iteration of the vascular wall, it has cylindrical shape, is elastic and yellow. The thickness and length of walls depends on the degree of cross-clamping during the time of formation of yielding cylindrical plaque. In the case of stopping of spasm

  13. Denitrification and N2O emission from urine-affected grassland soil

    NARCIS (Netherlands)

    Klein, M.C.A.; van Logtestijn, R. S P

    Denitrification and N2O emission rates were measured following two applications of artificial urine (40 g urine-N m-2) to a perennial rye-grass sward on sandy soil. To distinguish between N2O emission from denitrification or nitrification, urine was also applied with a nitrification inhibitor

  14. On the Origin of the High Column Density Turnover in the H I Column Density Distribution

    Science.gov (United States)

    Erkal, Denis; Gnedin, Nickolay Y.; Kravtsov, Andrey V.

    2012-12-01

    We study the high column density regime of the H I column density distribution function and argue that there are two distinct features: a turnover at N H I ≈ 1021 cm-2, which is present at both z = 0 and z ≈ 3, and a lack of systems above N H I ≈ 1022 cm-2 at z = 0. Using observations of the column density distribution, we argue that the H I-H2 transition does not cause the turnover at N H I ≈ 1021 cm-2 but can plausibly explain the turnover at N H I >~ 1022 cm-2. We compute the H I column density distribution of individual galaxies in the THINGS sample and show that the turnover column density depends only weakly on metallicity. Furthermore, we show that the column density distribution of galaxies, corrected for inclination, is insensitive to the resolution of the H I map or to averaging in radial shells. Our results indicate that the similarity of H I column density distributions at z = 3 and 0 is due to the similarity of the maximum H I surface densities of high-z and low-z disks, set presumably by universal processes that shape properties of the gaseous disks of galaxies. Using fully cosmological simulations, we explore other candidate physical mechanisms that could produce a turnover in the column density distribution. We show that while turbulence within giant molecular clouds cannot affect the damped Lyα column density distribution, stellar feedback can affect it significantly if the feedback is sufficiently effective in removing gas from the central 2-3 kpc of high-redshift galaxies. Finally, we argue that it is meaningful to compare column densities averaged over ~ kpc scales with those estimated from quasar spectra that probe sub-pc scales due to the steep power spectrum of H I column density fluctuations observed in nearby galaxies.

  15. Bone mineral density test

    Science.gov (United States)

    BMD test; Bone density test; Bone densitometry; DEXA scan; DXA; Dual-energy x-ray absorptiometry; p-DEXA; Osteoporosis - BMD ... need to undress. This scan is the best test to predict your risk of fractures, especially of ...

  16. Negative Ion Density Fronts

    Energy Technology Data Exchange (ETDEWEB)

    Igor Kaganovich

    2000-12-18

    Negative ions tend to stratify in electronegative plasmas with hot electrons (electron temperature Te much larger than ion temperature Ti, Te > Ti ). The boundary separating a plasma containing negative ions, and a plasma, without negative ions, is usually thin, so that the negative ion density falls rapidly to zero-forming a negative ion density front. We review theoretical, experimental and numerical results giving the spatio-temporal evolution of negative ion density fronts during plasma ignition, the steady state, and extinction (afterglow). During plasma ignition, negative ion fronts are the result of the break of smooth plasma density profiles during nonlinear convection. In a steady-state plasma, the fronts are boundary layers with steepening of ion density profiles due to nonlinear convection also. But during plasma extinction, the ion fronts are of a completely different nature. Negative ions diffuse freely in the plasma core (no convection), whereas the negative ion front propagates towards the chamber walls with a nearly constant velocity. The concept of fronts turns out to be very effective in analysis of plasma density profile evolution in strongly non-isothermal plasmas.

  17. The influence of sward competition on shoot growth and ...

    African Journals Online (AJOL)

    In each of two seasons the growth form of Senecio retrorsus plants in Natal Tall Grassveld differed in accordance with the degree of utilization of the grasses and thus the degree of competition offered. In rested veld the main stems of seedlings and mature plants were long and spindly while those in frequently clipped veld ...

  18. Influence of sward defoliation and soil disturbance on seedling ...

    African Journals Online (AJOL)

    Development of vegetation from seed requires a seed bank, germination, emergence and subsequent seedling survival. Reports on the influence of a number of practicably feasible treatments to the vegetation and soil on emergence and survival of grass seedlings in the Southern Tall Grassveld of Natal. Illustrates with ...

  19. Matgrass sward plant species benefit from soil organisms

    NARCIS (Netherlands)

    Brinkman, E.P.; Raaijmakers, C.E.; Bakx-Schotman, J.M.T.; Hannula, S.E.; Kemmers, R.H.; Boer, de W.; Putten, van der W.H.

    2012-01-01

    Soil organisms are important in the structuring of plant communities. However, little is known about how to apply this knowledge to vegetation management. Here, we examined if soil organisms may promote plant species of characteristic habitats, and suppress plant species of disturbed habitats. We

  20. Gap and density theorems

    CERN Document Server

    Levinson, N

    1940-01-01

    A typical gap theorem of the type discussed in the book deals with a set of exponential functions { \\{e^{{{i\\lambda}_n} x}\\} } on an interval of the real line and explores the conditions under which this set generates the entire L_2 space on this interval. A typical gap theorem deals with functions f on the real line such that many Fourier coefficients of f vanish. The main goal of this book is to investigate relations between density and gap theorems and to study various cases where these theorems hold. The author also shows that density- and gap-type theorems are related to various propertie

  1. Polarizable Density Embedding

    DEFF Research Database (Denmark)

    Olsen, Jógvan Magnus Haugaard; Steinmann, Casper; Ruud, Kenneth

    2015-01-01

    We present a new QM/QM/MM-based model for calculating molecular properties and excited states of solute-solvent systems. We denote this new approach the polarizable density embedding (PDE) model and it represents an extension of our previously developed polarizable embedding (PE) strategy. The PDE...... model is a focused computational approach in which a core region of the system studied is represented by a quantum-chemical method, whereas the environment is divided into two other regions: an inner and an outer region. Molecules belonging to the inner region are described by their exact densities...

  2. Holographic magnetisation density waves

    Energy Technology Data Exchange (ETDEWEB)

    Donos, Aristomenis [Centre for Particle Theory and Department of Mathematical Sciences, Durham University,Stockton Road, Durham, DH1 3LE (United Kingdom); Pantelidou, Christiana [Departament de Fisica Quantica i Astrofisica & Institut de Ciencies del Cosmos (ICC),Universitat de Barcelona,Marti i Franques 1, 08028 Barcelona (Spain)

    2016-10-10

    We numerically construct asymptotically AdS black brane solutions of D=4 Einstein theory coupled to a scalar and two U(1) gauge fields. The solutions are holographically dual to d=3 CFTs in a constant external magnetic field along one of the U(1)’s. Below a critical temperature the system’s magnetisation density becomes inhomogeneous, leading to spontaneous formation of current density waves. We find that the transition can be of second order and that the solutions which minimise the free energy locally in the parameter space of solutions have averaged stressed tensor of a perfect fluid.

  3. Choice of grazed herbage or maize silage by lactating dairy cows: influence of sward height and concentrate level Preferência por pastagem ou silagem de milho por vacas leiteiras em lactação: influência da altura do pasto e do nível de concentrado

    Directory of Open Access Journals (Sweden)

    O. Hernandez-Mendo

    2010-10-01

    Full Text Available The preference of lactating dairy cows for grazed herbage or maize silage (MS, simultaneously offered ad libitum in the field, was examined at two sward heights (SH 4-6 and 8-10cm and two concentrate levels (CL 0 and 6kg day-1 in a 2x2 factorial arrangement within a completely randomised experimental design. The experiment lasted 35 days and was carried out in spring using 24 multiparous Holstein Friesian cows. On average, the cows proportionately spent more time grazing than eating MS (0.85:0.15 and even though the higher rate of intake (RI of dry matter (DM of MS compared with grazed herbage (76 versus 26g DM min-1, the proportion of total DM intake as herbage was higher compared to that of MS (0.56:0.44. The higher crude protein and low fibre content of grazed herbage appeared to have a higher priority of choice than RI, as the cows chose to graze for longer (grazing time 385 min, MS feeding time 67min despite the lower RI of herbage. The low proportion MS intake indicated that RI was a secondary factor of choice. Concentrate supplementation had a greater depressing effect on herbage intake than on MS intake. These results suggest that the animals reduce the intake of feed with lower RI when the labor associated to eat is decreased. The factors influencing the choice for herbage over maize silage remain unclear.A preferência de vacas leiteiras em lactação por pasto ou silagem de milho (SM oferecidas ad libitum simultaneamente no pasto foi avaliada quanto a duas alturas de pastagem (4-6 e 8-10cm e dois níveis de concentrado (0 e 6kg dia-1, em um arranjo fatorial 2x2 dentro de um delineamento inteiramente ao acaso. O experimento, com duração de 35 dias, foi executado na primavera utilizando 24 vacas multíparas da raça Holandesa. As vacas passaram, em média, proporcionalmente mais tempo pastando do que comendo SM (0,85:0,15 e, mesmo considerando a maior taxa de consumo (TC de matéria seca (MS de SM comparada com a da pastagem (76

  4. A Tryst With Density

    Indian Academy of Sciences (India)

    Walter Kohn transformed theoretical chemistry and solid statephysics with his development of density functional theory, forwhich he was awarded the Nobel Prize. This article tries toexplain, in simple terms, why this was an important advancein the field, and to describe precisely what it was that he (togetherwith his ...

  5. Density in Liquids.

    Science.gov (United States)

    Nesin, Gert; Barrow, Lloyd H.

    1984-01-01

    Describes a fourth-grade unit on density which introduces a concept useful in the study of chemistry and procedures appropriate to the chemistry laboratory. The hands-on activities, which use simple equipment and household substances, are at the level of thinking Piaget describes as concrete operational. (BC)

  6. Multiple density layered insulator

    Science.gov (United States)

    Alger, Terry W.

    1994-01-01

    A multiple density layered insulator for use with a laser is disclosed wh provides at least two different insulation materials for a laser discharge tube, where the two insulation materials have different thermoconductivities. The multiple layer insulation materials provide for improved thermoconductivity capability for improved laser operation.

  7. Polarizable Density Embedding

    DEFF Research Database (Denmark)

    Reinholdt, Peter; Kongsted, Jacob; Olsen, Jógvan Magnus Haugaard

    2017-01-01

    We analyze the performance of the polarizable density embedding (PDE) model-a new multiscale computational approach designed for prediction and rationalization of general molecular properties of large and complex systems. We showcase how the PDE model very effectively handles the use of large...

  8. A Tryst With Density

    Indian Academy of Sciences (India)

    related to gender and science. Walter Kohn transformed theoretical chemistry and solid state physics with his development of density functional theory, for which he was awarded the Nobel Prize. This article tries to explain, in simple terms, why this was an important advance in the field, and to describe precisely what it was ...

  9. Quantal density functional theory

    CERN Document Server

    Sahni, Viraht

    2016-01-01

    This book deals with quantal density functional theory (QDFT) which is a time-dependent local effective potential theory of the electronic structure of matter. The treated time-independent QDFT constitutes a special case. In the 2nd edition, the theory is extended to include the presence of external magnetostatic fields. The theory is a description of matter based on the ‘quantal Newtonian’ first and second laws which is in terms of “classical” fields that pervade all space, and their quantal sources. The fields, which are explicitly defined, are separately representative of electron correlations due to the Pauli exclusion principle, Coulomb repulsion, correlation-kinetic, correlation-current-density, and correlation-magnetic effects. The book further describes Schrödinger theory from the new physical perspective of fields and quantal sources. It also describes traditional Hohenberg-Kohn-Sham DFT, and explains via QDFT the physics underlying the various energy functionals and functional derivatives o...

  10. Airborne Crowd Density Estimation

    Science.gov (United States)

    Meynberg, O.; Kuschk, G.

    2013-10-01

    This paper proposes a new method for estimating human crowd densities from aerial imagery. Applications benefiting from an accurate crowd monitoring system are mainly found in the security sector. Normally crowd density estimation is done through in-situ camera systems mounted on high locations although this is not appropriate in case of very large crowds with thousands of people. Using airborne camera systems in these scenarios is a new research topic. Our method uses a preliminary filtering of the whole image space by suitable and fast interest point detection resulting in a number of image regions, possibly containing human crowds. Validation of these candidates is done by transforming the corresponding image patches into a low-dimensional and discriminative feature space and classifying the results using a support vector machine (SVM). The feature space is spanned by texture features computed by applying a Gabor filter bank with varying scale and orientation to the image patches. For evaluation, we use 5 different image datasets acquired by the 3K+ aerial camera system of the German Aerospace Center during real mass events like concerts or football games. To evaluate the robustness and generality of our method, these datasets are taken from different flight heights between 800 m and 1500 m above ground (keeping a fixed focal length) and varying daylight and shadow conditions. The results of our crowd density estimation are evaluated against a reference data set obtained by manually labeling tens of thousands individual persons in the corresponding datasets and show that our method is able to estimate human crowd densities in challenging realistic scenarios.

  11. The relationship between breast density and bone mineral density in never users of postmenopausal hormone therapy.

    Science.gov (United States)

    Seckin, Berna; Pekcan, Meryem Kuru; Inal, Hasan Ali; Gulerman, Cavidan

    2017-06-01

    Estrogen is known to affect both mammographic breast density and bone mineral density (BMD), but there are inconsistent results about the association of these density measurements in postmenopausal women. Furthermore, there are scarce data on the relationship between breast density and BMD in never users of postmenopausal hormone therapy. In this study, we examined the relationship between mammographic breast density and BMD in postmenopausal women who were never hormone replacement therapy users. A total of 293 postmenopausal women were enrolled in this cross-sectional study. Mammograms and BMD measurements for screening purposes were obtained. Assessment of mammographic breast density was performed by using breast imaging reporting and data system classification. The BMD was measured using dual-energy X-ray absorptiometry of the lumbar spine and femoral neck. Grade 1 breast density was observed in 64 women (21.8 %), grade 2 in 113 women (38.6 %) and grades 3 and 4 in 116 (39.6 %) women. Breast density decreased with increasing age and body mass index (BMI). Meanwhile, no significant differences were detected in BMD measures of the hip (p = 0.14) and lumbar spine (p = 0.29) among the breast density categories. After adjusting for age and BMI, the differences in the mean BMD at the hip and lumbar spine across the breast density categories remained insignificant (p = 0.26 and 0.11, respectively). There is no evidence of a relationship between mammographic breast density and BMD in postmenopausal women who had never used hormone replacement therapy.

  12. Nonuniform distribution of collagen density in human knee ligaments

    NARCIS (Netherlands)

    Mommersteeg, T. J.; Blankevoort, L.; Kooloos, J. G.; Hendriks, J. C.; Kauer, J. M.; Huiskes, R.

    1994-01-01

    It is generally recognized that the mechanical properties of soft connective tissues are affected by their structural components. We documented collagen density distributions in human knee ligaments to quantify differences in density within and between these ligaments. In order to explain the

  13. Contingent kernel density estimation.

    Directory of Open Access Journals (Sweden)

    Scott Fortmann-Roe

    Full Text Available Kernel density estimation is a widely used method for estimating a distribution based on a sample of points drawn from that distribution. Generally, in practice some form of error contaminates the sample of observed points. Such error can be the result of imprecise measurements or observation bias. Often this error is negligible and may be disregarded in analysis. In cases where the error is non-negligible, estimation methods should be adjusted to reduce resulting bias. Several modifications of kernel density estimation have been developed to address specific forms of errors. One form of error that has not yet been addressed is the case where observations are nominally placed at the centers of areas from which the points are assumed to have been drawn, where these areas are of varying sizes. In this scenario, the bias arises because the size of the error can vary among points and some subset of points can be known to have smaller error than another subset or the form of the error may change among points. This paper proposes a "contingent kernel density estimation" technique to address this form of error. This new technique adjusts the standard kernel on a point-by-point basis in an adaptive response to changing structure and magnitude of error. In this paper, equations for our contingent kernel technique are derived, the technique is validated using numerical simulations, and an example using the geographic locations of social networking users is worked to demonstrate the utility of the method.

  14. Density measures and additive property

    OpenAIRE

    Kunisada, Ryoichi

    2015-01-01

    We deal with finitely additive measures defined on all subsets of natural numbers which extend the asymptotic density (density measures). We consider a class of density measures which are constructed from free ultrafilters on natural numbers and study a certain additivity property of such density measures.

  15. Toward a Redefinition of Density

    Science.gov (United States)

    Rapoport, Amos

    1975-01-01

    This paper suggests that in addition to the recent work indicating that crowding is a subjective phenomenon, an adequate definition of density must also include a subjective component since density is a complex phenomenon in itself. Included is a discussion of both physical density and perceived density. (Author/MA)

  16. Method and timing of grassland renovation affects herbage yield, nitrate leaching, and nitrous oxide emission in intensively managed grasslands

    NARCIS (Netherlands)

    Velthof, G.L.; Hoving, I.E.; Dolfing, J.; Smit, A.; Kuikman, P.J.; Oenema, O.

    2010-01-01

    Managed grasslands are occasionally ploughed up and reseeded in order to maintain or increase the sward productivity. It has been reported that this renovation of grassland is associated with a flush of soil organic nitrogen (N) mineralization and with a temporary increase in soil mineral N

  17. Relation between Spongy Bone Density in the Maxilla and Skeletal Bone Density.

    Science.gov (United States)

    Merheb, Joe; Temmerman, Andy; Coucke, Wim; Rasmusson, Lars; Kübler, Alexander; Thor, Andreas; Quirynen, Marc

    2015-12-01

    Osteoporosis is a disease affecting more than 300 million people worldwide and is responsible for numerous medical complications. This study aimed to investigate the relation between skeletal and maxillary bone density. Seventy-three patients were recruited and divided between group A (osteoporosis), group B (healthy, control), and group C (osteopenia) on the basis of a dual-energy x-ray absorptiomery (DXA) scan. These patients also received a CT scan on which bone density measurements were performed at five sites: maxilla midline, retromolar tuberosities, incisor, premolars, and molar regions. The bone density was lower in osteoporotic patients compared with the control patients. The bone mineral density (BMD) of the tuberosities showed the strongest correlations with the BMD of the hip and the spine (respectively, r = 0.50 and r = 0.61). The midline region showed moderate correlations with the hip (r = 0.47) and the spine (r = 0.46). For potential implant sites, the correlations with the BMD of the hip and spine were, however, small to insignificant. Based on measurements of bone density of the maxilla, it was possible to predict if the patient was osteoporotic or not with a sensitivity of 65% and a specificity of 83%. The maxillary bone density of subjects with osteoporosis is significantly lower than that of healthy patients. Moreover, there is a direct correlation between the density of the skeleton and the density of some sites of the maxilla. Using measurements of maxillary bone density in order to predict skeletal bone density might be a useful tool for the screening of osteoporosis. © 2014 Wiley Periodicals, Inc.

  18. Gluon density in nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Ayala, A.L. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica][Pelotas Univ., RS (Brazil). Inst. de Fisica e Matematica; Ducati, M.B.G. [Rio Grande do Sul Univ., Porto Alegre, RS (Brazil). Inst. de Fisica; Levin, E.M. [Fermi National Accelerator Lab., Batavia, IL (United States)][Nuclear Physics Inst., St. Petersburg (Russian Federation)

    1996-10-01

    In this talk we present our detailed study (theory and numbers) on the shadowing corrections to the gluon structure functions for nuclei. Starting from rather controversial information on the nucleon structure function which is originated by the recent HERA data, we develop the Glauber approach for the gluon density in a nucleus based on Mueller formula and estimate the value of the shadowing corrections in this case. Then we calculate the first corrections to the Glauber approach and show that these corrections are big. Based on this practical observation we suggest the new evolution equation which takes into account the shadowing corrections and solve it. We hope to convince you that the new evolution equation gives a good theoretical tool to treat the shadowing corrections for the gluons density in a nucleus and, therefore, it is able to provide the theoretically reliable initial conditions for the time evolution of the nucleus-nucleus cascade. The initial conditions should be fixed both theoretically and phenomenologically before to attack such complicated problems as the mixture of hard and soft processes in nucleus-nucleus interactions at high energy or the theoretically reliable approach to hadron or/and parton cascades for high energy nucleus-nucleus interaction. 35 refs., 24 figs., 1 tab.

  19. On holographic entanglement density

    Science.gov (United States)

    Gushterov, Nikola I.; O'Bannon, Andy; Rodgers, Ronnie

    2017-10-01

    We use holographic duality to study the entanglement entropy (EE) of Conformal Field Theories (CFTs) in various spacetime dimensions d, in the presence of various deformations: a relevant Lorentz scalar operator with constant source, a temperature T , a chemical potential μ, a marginal Lorentz scalar operator with source linear in a spatial coordinate, and a circle-compactified spatial direction. We consider EE between a strip or sphere sub-region and the rest of the system, and define the "entanglement density" (ED) as the change in EE due to the deformation, divided by the sub-region's volume. Using the deformed CFTs above, we show how the ED's dependence on the strip width or sphere radius, L, is useful for characterizing states of matter. For example, the ED's small- L behavior is determined either by the dimension of the perturbing operator or by the first law of EE. For Lorentz-invariant renormalization group (RG) flows between CFTs, the "area theorem" states that the coefficient of the EE's area law term must be larger in the UV than in the IR. In these cases the ED must therefore approach zero from below as L→∞. However, when Lorentz symmetry is broken and the IR fixed point has different scaling from the UV, we find that the ED often approaches the thermal entropy density from above, indicating area theorem violation.

  20. How does real affect affect affect recognition in speech?

    NARCIS (Netherlands)

    Truong, Khiet Phuong

    2009-01-01

    The automatic analysis of affect is a relatively new and challenging multidisciplinary research area that has gained a lot of interest over the past few years. The research and development of affect recognition systems has opened many opportunities for improving the interaction between man and

  1. Densidade e qualidade dos estratos de forragem do capim Tanzânia (Panicum maximum Jacq. Cv. Tanzânia-1 manejado em diferentes alturas, sob pastejo Density bulk and quality of Tanzania grass layers (Panicum maximum Jacq.cv. Tanzania-1, at different heights in grazing

    Directory of Open Access Journals (Sweden)

    Geraldo Tadeu dos Santos

    2001-05-01

    Full Text Available O objetivo do trabalho foi avaliar o efeito de diferentes alturas (24; 26; 43; 45; 52; 62; 73 e 78 cm do pasto sobre a qualidade de forragem e estrutura do perfil do capim-Tanzânia, (Panicum maximum Jacq. cv. Tanzânia – 1 (Poaceae. Foram utilizados novilhos da raça Nelore sob pastejo com carga animal variável, por meio da técnica put and take. O delineamento experimental utilizado foi inteiramente casualizado, com duas repetições. A densidade de matéria seca total (DMT aumentou com o avanço no período experimental, enquanto a densidade de matéria seca de lâminas (DML não foi influenciada pelo período e pela altura do pasto. O estrato superior da pastagem foi a porção de maior qualidade, apresentando maior DML e maior teor de PB. Os estratos inferiores apresentaram menor qualidade, devido à maior DMT e menor DML, acarretando em maiores valores de FDA e FDN e menores teores de PB. O conteúdo de minerais das lâminas foi superior aos colmos, mantendo-se inalterado com relação aos estratos da pastagem.The effect of different sward heights (24; 26; 43; 45; 52; 62; 73 and 78 cm on forage quality and profile structure Tanzania grass, Panicum maximum Jacq. cv. Tanzania – 1 (Poaceae is provided. Nelore steers were used in grazing at variable stocking rates with put and take technique. The experimental design was completely randomized, with two replications. Total dry matter bulk densitity (TDMD increased during experimental period, while the leaf blade dry matter bulk density (LDMD was not influenced by period on by sward height. The upper layers had the best quality with higher LDMD and CP levels. Lower layers had the worst quality, due the higher TDMD and lower LDMD. This fact caused higher ADF and NDF levels and lower CP levels. Leaf blade mineral content was higher than that of stem, and remained unaltered in relation to the different layers.

  2. Can host density attenuate parasitism?

    National Research Council Canada - National Science Library

    Magalhães, L; Freitas, R; Dairain, A; De Montaudouin, X

    .... Considering that these parasites infect cockles through filtration activity, our first hypothesis was that high host density will have a dilution effect so that infection intensity decreases with host density...

  3. Experiencing affective interactive art

    NARCIS (Netherlands)

    Bialoskorski, Leticia S.S.; Westerink, Joyce H.D.M.; van den Broek, Egon

    2010-01-01

    The progress in the field of affective computing enables the realization of affective art. This paper describes the affective interactive art system Mood Swings, which interprets and visualizes affect expressed by a person. Mood Swings is founded on the integration of a framework for affective

  4. Density-orbital embedding theory

    NARCIS (Netherlands)

    Visscher, L.; Gritsenko, O.

    2010-01-01

    In the article density-orbital embedding (DOE) theory is proposed. DOE is based on the concept of density orbital (DO), which is a generalization of the square root of the density for real functions and fractional electron numbers. The basic feature of DOE is the representation of the total

  5. GPS, GNSS, and Ionospheric Density Gradients

    Science.gov (United States)

    Kintner, P. M.; O'Hanlon, B.; Humphreys, T. E.

    2009-12-01

    Ionospheric density and density gradients affect GNSS signals in two ways. They can introduce ranging errors or irregularities that form on the density gradients producing scintillation. Here we focus on the issue of ranging errors. There are two approaches to mitigating ranging errors produced by ionospheric density gradients which can be 20-30 m during major magnetic storms. The first approach is to use a reference receiver(s) to determine the ionospheric contribution to ranging errors. The ranging error is then transmitted to the user for correction within the mobile receiver. This approach is frequently referred to as differential GPS and, when multiple reference receivers are used, the system is referred to as an augmentation system. This approach is vulnerable to ionospheric gradients depending on the reference receiver spacing(s) and latency in applying the correction within the mobile receiver. The second approach is to transmit navigation signals at two frequencies and then use the relative delay between the two signals to both estimate the ranging error and calculate the correct range. Currently the dual frequency technique is used by US military receivers with an encryption key and some civilian receivers which must be stationary and average over times long compared to those required for navigation. However, the technology of space based radio navigation is changing. GPS will soon be a system with three frequencies and multiple codes. Furthermore Europe, Russia, and China are developing independent systems to complement and compete with GPS while India and Japan are developing local systems to enhance GPS performance in their regions. In this talk we address two questions. How do density gradients affect augmentation systems including the social consequences and will the new GPS/GNSS systems with multiple civilian frequencies be able to remove ionospheric errors. The answers are not at all clear.

  6. Density regulation in Northeast Atlantic fish populations: Density dependence is stronger in recruitment than in somatic growth.

    Science.gov (United States)

    Zimmermann, Fabian; Ricard, Daniel; Heino, Mikko

    2018-01-30

    Population regulation is a central concept in ecology, yet in many cases its presence and the underlying mechanisms are difficult to demonstrate. The current paradigm maintains that marine fish populations are predominantly regulated by density-dependent recruitment. While it is known that density-dependent somatic growth can be present too, its general importance remains unknown and most practical applications neglect it. This study aimed to close this gap by for the first time quantifying and comparing density dependence in growth and recruitment over a large set of fish populations. We fitted density-dependent models to time-series data on population size, recruitment and age-specific weight from commercially exploited fish populations in the Northeast Atlantic Ocean and the Baltic Sea. Data were standardized to enable a direct comparison within and among populations, and estimated parameters were used to quantify the impact of density regulation on population biomass. Statistically significant density dependence in recruitment was detected in a large proportion of populations (70%), whereas for density dependence in somatic growth the prevalence of density dependence depended heavily on the method (26% and 69%). Despite age-dependent variability, the density dependence in recruitment was consistently stronger among age groups and between alternative approaches that use weight-at-age or weight increments to assess growth. Estimates of density-dependent reduction in biomass underlined these results: 97% of populations with statistically significant parameters for growth and recruitment showed a larger impact of density-dependent recruitment on population biomass. The results reaffirm the importance of density-dependent recruitment in marine fishes, yet they also show that density dependence in somatic growth is not uncommon. Furthermore, the results are important from an applied perspective because density dependence in somatic growth affects productivity and

  7. Spatial Density Maps from a Debris Cloud

    Science.gov (United States)

    Healy, L.; Kindl, S.; Binz, C.

    2016-09-01

    A debris cloud from a fragmentation on orbit may be modeled by transformation of variables from the instantaneous velocity distribution at the fragmentation time to the spatial distribution at some elapsed time later. There are no Gaussian distributions assumed and the evolution map is quite nonlinear, being derived from the solution of the Lambert, two-point boundary value, problem and the state transition matrix for unperturbed propagation, so the traditional tools of analysis that assume these qualities fail dramatically. The transformation of variables technique does not suffer from any such assumptions, and unlike the Monte Carlo method, is not subject to sampling errors or approximations. Structures and features are evident in the density maps, and these structures show promise for simplified approximation of the density map. Most prominent of the structures is the well-known pinch point at the fragmentation location in inertial space. The anti-pinch line, or wedge, is also observed. Bands on the opposite side of the fragmentation are very noticeable, and their existence may be motivated from simple orbit dynamics. These bands make the anti-pinch line actually more of a set of anti-pinch line segments. By computing these density maps over time, the evolution may be studied. There is a density generator, a density band at roughly the same altitude as the pinch point, that cycles around the earth and appears a source of the bands, with newly created bands moving radially outward and diminishing in density. Although the initial velocity distribution affects the final spatial distribution, the Lambert solutions, which are the most time consuming to compute, need only be computed once. Therefore, different initial distributions may be changed and the results recomputed with relative speed. A comparison of the effects of initial distributions is shown in this paper.

  8. Density sensitive hashing.

    Science.gov (United States)

    Jin, Zhongming; Li, Cheng; Lin, Yue; Cai, Deng

    2014-08-01

    Nearest neighbor search is a fundamental problem in various research fields like machine learning, data mining and pattern recognition. Recently, hashing-based approaches, for example, locality sensitive hashing (LSH), are proved to be effective for scalable high dimensional nearest neighbor search. Many hashing algorithms found their theoretic root in random projection. Since these algorithms generate the hash tables (projections) randomly, a large number of hash tables (i.e., long codewords) are required in order to achieve both high precision and recall. To address this limitation, we propose a novel hashing algorithm called density sensitive hashing (DSH) in this paper. DSH can be regarded as an extension of LSH. By exploring the geometric structure of the data, DSH avoids the purely random projections selection and uses those projective functions which best agree with the distribution of the data. Extensive experimental results on real-world data sets have shown that the proposed method achieves better performance compared to the state-of-the-art hashing approaches.

  9. Density dependence in demography and dispersal generates fluctuating invasion speeds.

    Science.gov (United States)

    Sullivan, Lauren L; Li, Bingtuan; Miller, Tom E X; Neubert, Michael G; Shaw, Allison K

    2017-05-09

    Density dependence plays an important role in population regulation and is known to generate temporal fluctuations in population density. However, the ways in which density dependence affects spatial population processes, such as species invasions, are less understood. Although classical ecological theory suggests that invasions should advance at a constant speed, empirical work is illuminating the highly variable nature of biological invasions, which often exhibit nonconstant spreading speeds, even in simple, controlled settings. Here, we explore endogenous density dependence as a mechanism for inducing variability in biological invasions with a set of population models that incorporate density dependence in demographic and dispersal parameters. We show that density dependence in demography at low population densities-i.e., an Allee effect-combined with spatiotemporal variability in population density behind the invasion front can produce fluctuations in spreading speed. The density fluctuations behind the front can arise from either overcompensatory population growth or density-dependent dispersal, both of which are common in nature. Our results show that simple rules can generate complex spread dynamics and highlight a source of variability in biological invasions that may aid in ecological forecasting.

  10. Physical activity and bone mineral density

    Directory of Open Access Journals (Sweden)

    Međedović Bojan

    2015-01-01

    Full Text Available The bones play an important structural role in the organism. They provide mobility, support, and protect the body, and the place where the storage essential minerals. Healthy bones have a crucial impact on the overall health of a person, and activities that promote health and preventive influence on the formation of bone disease are crucial in maintaining a strong and healthy skeletal system. Physical inactivity affects the decrease in function of bone, and the most common disease of bone osteoporosis. Osteoporosis is a systemic skeletal disorder that results in low bone density and micro-architectural deterioration of bone tissue, that results in less bone density, and may lead to fracture. Physical activity is essential for bone health and prevention of osteoporosis. Based on available information, the best effect to maintain and stimulate the formation of bone mineral density is a combination of dynamic exercises with resistance training that engage multiple joints, large muscle groups, and have influence on the spine and hips. The results suggest that exercises with axial loading, such as running, jumping, and power exercise, promote the positive gains in bone mineral density. Therefore, training should focus on the adaptation of specific parts of the body that is most susceptible to injury, and should be sufficiently intense that exceeds the normal loads.

  11. Decreasing seagrass density negatively influences associated fauna.

    Science.gov (United States)

    McCloskey, Rosemary M; Unsworth, Richard K F

    2015-01-01

    Seagrass meadows globally are disappearing at a rapid rate with physical disturbances being one of the major drivers of this habitat loss. Disturbance of seagrass can lead to fragmentation, a reduction in shoot density, canopy height and coverage, and potentially permanent loss of habitat. Despite being such a widespread issue, knowledge of how such small scale change affects the spatial distribution and abundances of motile fauna remains limited. The present study investigated fish and macro faunal community response patterns to a range of habitat variables (shoot length, cover and density), including individual species habitat preferences within a disturbed and patchy intertidal seagrass meadow. Multivariate analysis showed a measurable effect of variable seagrass cover on the abundance and distribution of the fauna, with species specific preferences to both high and low seagrass cover seagrass. The faunal community composition varied significantly with increasing/decreasing cover. The faunal species composition of low cover seagrass was more similar to sandy control plots than to higher cover seagrass. Shannon Wiener Diversity (H') and species richness was significantly higher in high cover seagrass than in low cover seagrass, indicating increasing habitat value as density increases. The results of this study underline how the impacts of small scale disturbances from factors such as anchor damage, boat moorings and intertidal vehicle use on seagrass meadows that reduce shoot density and cover can impact upon associated fauna. These impacts have negative consequences for the delivery of ecosystem services such as the provision of nursery habitat.

  12. Ion density deviations in semipermeable ionic microcapsules.

    Science.gov (United States)

    Tang, Qiyun; Denton, Alan R

    2015-04-28

    By implementing the nonlinear Poisson-Boltzmann theory in a cell model, we theoretically investigate the influence of polyelectrolye gel permeability on ion densities and pH deviations inside the cavities of ionic microcapsules. Our calculations show that variations in permeability of a charged capsule shell cause a redistribution of ion densities within the capsule, which ultimately affects the pH deviation and Donnan potential induced by the electric field of the shell. We find that semipermeable capsules can induce larger pH deviations inside their cavities that can permeable capsules. Furthermore, with increasing capsule charge, the influence of permeability on pH deviations progressively increases. Our theory, while providing a self-consistent method for modeling the influence of permeability on fundamental properties of ionic microgels, makes predictions of practical significance for the design of microcapsules loaded with fluorescent dyes, which can serve as biosensors for diagnostic purposes.

  13. Shampoo, Soy Sauce, and the Prince's Pendant: Density for Middle-Level Students

    Science.gov (United States)

    Chandrasekhar, Meera; Litherland, Rebecca

    2006-01-01

    In this article, the authors describe a series of activities they have used with middle-level students. The first set of lessons explores density through the layering of liquids. In the second set, they use some of the same liquids to explore the density of solids. The third set investigates how temperature affects the density of…

  14. Effects of shelterbelt on soil bulk density, particle density, total ...

    African Journals Online (AJOL)

    The effect of shelterbelt at measurement position (60,120 and 180) on bulk density, particle density, total porosity and moisture contents of semi-arid soils in the extreme part of northwestern, Nigeria was studied. The effect of shelterbelt on the three measurement positions was compared with the unsheltered area. Changes ...

  15. Bulk density and relationship air/water of horticultural substrate

    OpenAIRE

    Fernandes,Carolina; Corá, José Eduardo

    2004-01-01

    Change on substrate bulk density during the growing period may negatively affect other substrate physical properties and, consequently, plant growth. The objectives of this research were 1) to characterize physical properties of two horticultural substrates (S1 and S2), 2) to evaluate the effect of different bulk densities values of those substrates on their air/water relationship, and 3) to develop mathematical functions to estimate the air/water relationship by increasing substrates bulk de...

  16. Mammography density estimation with automated volumetic breast density measurement

    Energy Technology Data Exchange (ETDEWEB)

    Ko, Su Yeon; Kim, Eun Kyung; Kim, Min Jung; Moon, Hee Jung [Dept. of Radiology, Severance Hospital, Research Institute of Radiological Science, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-06-15

    To compare automated volumetric breast density measurement (VBDM) with radiologists' evaluations based on the Breast Imaging Reporting and Data System (BI-RADS), and to identify the factors associated with technical failure of VBDM. In this study, 1129 women aged 19-82 years who underwent mammography from December 2011 to January 2012 were included. Breast density evaluations by radiologists based on BI-RADS and by VBDM (Volpara Version 1.5.1) were compared. The agreement in interpreting breast density between radiologists and VBDM was determined based on four density grades (D1, D2, D3, and D4) and a binary classification of fatty (D1-2) vs. dense (D3-4) breast using kappa statistics. The association between technical failure of VBDM and patient age, total breast volume, fibroglandular tissue volume, history of partial mastectomy, the frequency of mass > 3 cm, and breast density was analyzed. The agreement between breast density evaluations by radiologists and VBDM was fair (k value = 0.26) when the four density grades (D1/D2/D3/D4) were used and moderate (k value = 0.47) for the binary classification (D1-2/D3-4). Twenty-seven women (2.4%) showed failure of VBDM. Small total breast volume, history of partial mastectomy, and high breast density were significantly associated with technical failure of VBDM (p 0.001 to 0.015). There is fair or moderate agreement in breast density evaluation between radiologists and VBDM. Technical failure of VBDM may be related to small total breast volume, a history of partial mastectomy, and high breast density.

  17. Density of organic thin films in organic photovoltaics

    Science.gov (United States)

    Zhao, Cindy X.; Xiao, Steven; Xu, Gu

    2015-07-01

    A practical parameter, the volume density of organic thin films, found to affect the electronic properties and in turn the performance of organic photovoltaics (OPVs), is investigated in order to benefit the polymer synthesis and thin film preparation in OPVs. To establish the correlation between film density and device performance, the density of organic thin films with various treatments was obtained, by two-dimensional X-ray diffraction measurement using the density mapping with respect to the crystallinity of thin films. Our results suggest that the OPV of higher performance has a denser photoactive layer, which may hopefully provide a solution to the question of whether the film density matters in organic electronics, and help to benefit the OPV industry in terms of better polymer design, standardized production, and quality control with less expenditure.

  18. All Road Density (18km)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Density (km / km^2) of all roads in the western United States. Dataset was developed to generalize the 2000 US Census TIGER/Line Roads layer to a density within 18km...

  19. Population Density and Group Size

    Science.gov (United States)

    Tucker, James; Friedman, S. Thomas

    1972-01-01

    This study looks at the relationship between the size of the small interacting group (in numbers of persons) and its environment; in this case, the density of its immediate population. Results indicated a significant inverse relationship between population density and the size of small interacting groups. (Author)

  20. The Density of Sustainable Settlements

    DEFF Research Database (Denmark)

    Lauring, Michael; Silva, Victor; Jensen, Ole B.

    2010-01-01

    This paper is the initial result of a cross-disciplinary attempt to encircle an answer to the question of optimal densities of sustainable settlements. Urban density is an important component in the framework of sustainable development and influences not only the character and design of cities...

  1. Space, Density and Urban Form

    NARCIS (Netherlands)

    Berghauser Pont, M.Y.; Haupt, P.A.

    2009-01-01

    The concentration of humans – in some cases judged as too high, in others not high enough – and the problems connected to this, have resulted in discussions on density. Prior to the 20th century, density in European cities was merely an outcome of complex circumstances. During the second half of the

  2. Thermospheric neutral densities derived from Swarm accelerometer and GPS data

    DEFF Research Database (Denmark)

    Doornbos, Eelco; Encarnacao, Joao; van den IJss, Jose

    approach, affects the possibility of determining densities from the accelerometer measurements of the Swarm A and B satellites. We also investigate the possibility of determining crosswind speeds from Swarm data.In the meantime, we have investigated the possibility of deriving thermosphere neutral density...... data from the Swarm GPS observations only, with a much lower temporal resolution. We analyse the differences in the data between the three Swarm satellites as well as between the accelerometer-derived and GPS-only-derived densities for Swarm C....

  3. Mediatised affective activism

    DEFF Research Database (Denmark)

    Reestorff, Camilla Møhring

    2014-01-01

    bodies by addressing affective registers. The mediatised ‘affective environment’ (Massumi, 2009) cues bodies and generates spreadability, yet it also produces disconnections. These disconnections might redistribute the ‘economy of recognizability’ (Butler and Athanasiou, 2013); however, the Femen...

  4. Effects of density profile of MDF on stiffness and strength of nailed joints

    OpenAIRE

    Sawata, Kei; Shibusawa, Tatsuya; Ohashi, Kazuo; Sotomayor Castellanos, Javier Ramon; Hatano, Yasunori

    2008-01-01

    Nail-head pull-through, lateral nail resistance, and single shear nailed joint tests were conducted on medium density fiberboard (MDF) with different density profiles, and the relations between the results of these tests and the density profiles of MDF were investigated. The maximum load of nail-head pull-through and the maximum load of nailed joints were little affected by the density profile. However, the ultimate strength of lateral nail resistance, the stiffness, and the yield strength of...

  5. Feed intake as explanation for density related growth differences of common sole Solea solea

    DEFF Research Database (Denmark)

    Lund, Ivar; Steenfeldt, Svend Jørgen; Herrmann, Bent

    2013-01-01

    Growth of common sole Solea solea is negatively correlated to density, which affects productivity in culture and hence commercial success. Studies of individual feed intake were performed to examine growth and population dynamics at different densities. Three initial stocking densities: 1.0, 2.......1 and 3.9 kg m−2 of individually tagged sole, referred to as low density (LD), medium density and high density HD), were examined during 145 days. Despite that tank productivity (g m−2 day−1), was highest for the HD group, the specific growth rate (SGR) decreased significantly with increase in stocking...

  6. Affect and Cognition.

    Science.gov (United States)

    Forgas, Joseph P

    2008-03-01

    One of the greatest puzzles of human nature concerns the poorly understood interplay between affect and cognition-the rational and emotional ways of dealing with the social world around us. Affect is a ubiquitous and powerful phenomenon in our lives, yet research on human affectivity has been neglected until quite recently. This article reviews traditional and contemporary approaches to this issue, and recent theoretical and empirical work exploring the links between affect and cognition is considered. The major achievements and shortcomings of this now-thriving research area are discussed, and the future prospects of psychological research on human affectivity are considered. © 2008 Association for Psychological Science.

  7. Affectivity in the Liminal

    DEFF Research Database (Denmark)

    Thomassen, Bjørn

    In this paper I propose a return to the work of Arnold van Gennep, in order to briefly discuss how the terms of liminality and affectivity were always already connected. By linking the concept of liminality that van Gennep made famous to affectivity, we are actually not proposing new...... at the threshold. The paper contains three sections: a) liminality and affectivity in van Gennep’s life; b) liminality and affectivity as a theme in his work; c) liminality and affectivity as developed in the early reception of his work....

  8. Engaging in Affective Practices

    DEFF Research Database (Denmark)

    Galløe, Lotte Rannveig

    The paper presents how the merging of the theoretical concepts ‘Affect’ and ‘Power’ faces methodological and ethical challenges when entangled in teachers’ and pupils’ practice. Based on a study of pedagogical methods aiming to shape certain affective relations and avoid conflicts in Danish primary....... Witnessing tense conflict situations taking place I as a researcher get affected as well, and in turn affect the practice myself. Because, both the teacher, pupil, and I are well aware of my research focus on power and affect, being observed in conflictual situations contributes to pervasive shame...... schools, the paper develops an affective-power approach drawing on Foucault’s notion of power and Whetherell’s conceptualisation of affect. The approach captures the affective dimension of governing and resistance in interactional practice that engages teachers and pupils. This enables a research focus...

  9. Obesity and Regional Immigrant Density.

    Science.gov (United States)

    Emerson, Scott D; Carbert, Nicole S

    2017-11-24

    Canada has an increasingly large immigrant population. Areas of higher immigrant density, may relate to immigrants' health through reduced acculturation to Western foods, greater access to cultural foods, and/or promotion of salubrious values/practices. It is unclear, however, whether an association exists between Canada-wide regional immigrant density and obesity among immigrants. Thus, we examined whether regional immigrant density was related to obesity, among immigrants. Adult immigrant respondents (n = 15,595) to a national population-level health survey were merged with region-level immigrant density data. Multi-level logistic regression was used to model the odds of obesity associated with increased immigrant density. The prevalence of obesity among the analytic sample was 16%. Increasing regional immigrant density was associated with lower odds of obesity among minority immigrants and long-term white immigrants. Immigrant density at the region-level in Canada may be an important contextual factor to consider when examining obesity among immigrants.

  10. Density fluctuations in traffic flow

    CERN Document Server

    Yukawa, S

    1996-01-01

    Density fluctuations in traffic current are studied by computer simulations using the deterministic coupled map lattice model on a closed single-lane circuit. By calculating a power spectral density of temporal density fluctuations at a local section, we find a power-law behavior, \\sim 1/f^{1.8}, on the frequency f, in non-congested flow phase. The distribution of the headway distance h also shows the power law like \\sim 1/h^{3.0} at the same time. The power law fluctuations are destroyed by the occurence of the traffic jam.

  11. FOREWORD: Special issue on density

    Science.gov (United States)

    Fujii, Kenichi

    2004-04-01

    This special issue on density was undertaken to provide readers with an overview of the present state of the density standards for solids, liquids and gases, as well as the technologies developed for measuring density. This issue also includes topics on the refractive index of gases and on techniques used for calibrating hydrometers so that almost all areas concerned with density standards are covered in four review articles and seven original articles, most of which describe current research being conducted at national metrology institutes (NMIs). A review article was invited from the Ruhr-Universität Bochum to highlight research on the magnetic suspension densimeters. In metrology, the determinations of the volume of a weight and the density of air are of primary importance in establishing a mass standard because the effect of the buoyancy force of air acting on the weight must be known accurately to determine the mass of the weight. A density standard has therefore been developed at many NMIs with a close relation to the mass standard. Hydrostatic weighing is widely used to measure the volume of a solid. The most conventional hydrostatic weighing method uses water as a primary density standard for measuring the volume of a solid. A brief history of the determination of the density of water is therefore given in a review article, as well as a recommended value for the density of water with a specified isotopic abundance. The most modern technique for hydrostatic weighing uses a solid density standard instead of water. For this purpose, optical interferometers for measuring the diameters of silicon spheres have been developed to convert the length standard into the volume standard with a small uncertainty. A review article is therefore dedicated to describing the state-of-the-art optical interferometers developed for silicon spheres. Relative combined standard uncertainties of several parts in 108 have been achieved today for measuring the volume and density of

  12. High Energy Density Capacitors Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA?s future space science missions cannot be realized without the state of the art energy storage devices which require high energy density, high reliability, and...

  13. Affectivity and Race

    DEFF Research Database (Denmark)

    of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...... into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection sheds light...... on the role of feelings in the formation of subjectivities, how race and whiteness are affectively circulated in public life and the ways in which emotions contribute to regimes of inclusion and exclusion. As such it will appeal to scholars across the social sciences, with interests in sociology, anthropology...

  14. Affectivity and race

    DEFF Research Database (Denmark)

    of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...... into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection sheds light...... on the role of feelings in the formation of subjectivities, how race and whiteness are affectively circulated in public life and the ways in which emotions contribute to regimes of inclusion and exclusion. As such it will appeal to scholars across the social sciences, with interests in sociology, anthropology...

  15. Bulk density of small meteoroids

    Science.gov (United States)

    Kikwaya, J.-B.; Campbell-Brown, M.; Brown, P. G.

    2011-06-01

    Aims: Here we report on precise metric and photometric observations of 107 optical meteors, which were simultaneously recorded at multiple stations using three different intensified video camera systems. The purpose is to estimate bulk meteoroid density, link small meteoroids to their parent bodies based on dynamical and physical density values expected for different small body populations, to better understand and explain the dynamical evolution of meteoroids after release from their parent bodies. Methods: The video systems used had image sizes ranging from 640 × 480 to 1360 × 1036 pixels, with pixel scales from 0.01° per pixel to 0.05° per pixel, and limiting meteor magnitudes ranging from Mv = +2.5 to +6.0. We find that 78% of our sample show noticeable deceleration, allowing more robust constraints to be placed on density estimates. The density of each meteoroid is estimated by simultaneously fitting the observed deceleration and lightcurve using a model based on thermal fragmentation, conservation of energy and momentum. The entire phase space of the model free parameters is explored for each event to find ranges of parameters which fit the observations within the measurement uncertainty. Results: (a) We have analysed our data by first associating each of our events with one of the five meteoroid classes. The average density of meteoroids whose orbits are asteroidal and chondritic (AC) is 4200 kg m-3 suggesting an asteroidal parentage, possibly related to the high-iron content population. Meteoroids with orbits belonging to Jupiter family comets (JFCs) have an average density of 3100 ± 300 kg m-3. This high density is found for all meteoroids with JFC-like orbits and supports the notion that the refractory material reported from the Stardust measurements of 81P/Wild 2 dust is common among the broader JFC population. This high density is also the average bulk density for the 4 meteoroids with orbits belonging to the Ecliptic shower-type class (ES) also

  16. Effective size of density-dependent two-sex populations: the effect of mating systems.

    Science.gov (United States)

    Myhre, A M; Engen, S; SAEther, B-E

    2017-08-01

    Density dependence in vital rates is a key feature affecting temporal fluctuations of natural populations. This has important implications for the rate of random genetic drift. Mating systems also greatly affect effective population sizes, but knowledge of how mating system and density regulation interact to affect random genetic drift is poor. Using theoretical models and simulations, we compare N e in short-lived, density-dependent animal populations with different mating systems. We study the impact of a fluctuating, density-dependent sex ratio and consider both a stable and a fluctuating environment. We find a negative relationship between annual N e /N and adult population size N due to density dependence, suggesting that loss of genetic variation is reduced at small densities. The magnitude of this decrease was affected by mating system and life history. A male-biased, density-dependent sex ratio reduces the rate of genetic drift compared to an equal, density-independent sex ratio, but a stochastic change towards male bias reduces the N e /N ratio. Environmental stochasticity amplifies temporal fluctuations in population size and is thus vital to consider in estimation of effective population sizes over longer time periods. Our results on the reduced loss of genetic variation at small densities, particularly in polygamous populations, indicate that density regulation may facilitate adaptive evolution at small population sizes. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

  17. Organic carbon organic matter and bulk density relationships in arid ...

    African Journals Online (AJOL)

    Evaluation of their stocks requires knowledge about BD. BD is affected by factors such as water, aeration status, root penetrate, clay content, texture, land use and management, therefore it is a very important soil parameter. Key words: Soil organic carbon, soil organic matter, soil bulk density, arid-semi arid soils.

  18. Effect of plant density on the characteristics of photosynthetic ...

    African Journals Online (AJOL)

    ajl yemi

    2011-11-14

    Nov 14, 2011 ... of stand density on the photosynthetic apparatus of the garlic plant. These effects were found to ... correlation between crop growth rate (CGR) and the leaf area index ..... and Quantity of garlic as Affected by Different Farming Systems and. Garlic Clones. Pak. ... light and carbon dioxide? Bioscience, 47(11): ...

  19. Mendelian Disorders of High-Density Lipoprotein Metabolism

    NARCIS (Netherlands)

    Oldoni, Federico; Sinke, Richard J.; Kuivenhoven, Jan Albert

    2014-01-01

    High-density lipoproteins (HDLs) are a highly heterogeneous and dynamic group of the smallest and densest lipoproteins present in the circulation. This review provides the current molecular insight into HDL metabolism led by articles describing mutations in genes that have a large affect on HDL

  20. Nitrogen dose and plant density effects on popcorn grain yield ...

    African Journals Online (AJOL)

    Popcorn (Zea mays everta Sturt.) is a popular and nutritious snack food. Environmental factors affecting grain yield and yield-related components of popcorn are needed to compensate increasing demand. This research was conducted to determine the effects of nitrogen fertilizer application rates and plant densities on grain ...

  1. Redundancy and reduction: Speakers manage syntactic information density

    Science.gov (United States)

    Florian Jaeger, T.

    2010-01-01

    A principle of efficient language production based on information theoretic considerations is proposed: Uniform Information Density predicts that language production is affected by a preference to distribute information uniformly across the linguistic signal. This prediction is tested against data from syntactic reduction. A single multilevel logit model analysis of naturally distributed data from a corpus of spontaneous speech is used to assess the effect of information density on complementizer that-mentioning, while simultaneously evaluating the predictions of several influential alternative accounts: availability, ambiguity avoidance, and dependency processing accounts. Information density emerges as an important predictor of speakers’ preferences during production. As information is defined in terms of probabilities, it follows that production is probability-sensitive, in that speakers’ preferences are affected by the contextual probability of syntactic structures. The merits of a corpus-based approach to the study of language production are discussed as well. PMID:20434141

  2. Symposium: Unveiling Affective Signals

    NARCIS (Netherlands)

    van den Broek, Egon; Nijholt, Antinus; Westerink, J.H.D.M.; Spink, A.J.; Grieco, F; Krips, O.E.; Loijens, L.W.S.; Noldus, L.P.J.J.; Zimmerman, P.H.

    2010-01-01

    The ability to process and, subsequently, understand affective signals is the core of emotional intelligence and empathy. However, more than a decade of research in affective computing has shown that it is hard to develop computational models of this process. We pose that the solution for this

  3. Unveiling Affective Signals

    NARCIS (Netherlands)

    van den Broek, Egon; Nijholt, Antinus; Westerink, J.H.D.M.; Barakova, E.; de Ruyter, B.; Spink, A

    2010-01-01

    The ability to process and, subsequently, understand affective signals is the core of emotional intelligence and empathy. However, more than a decade of research in affective computing has shown that it is hard to develop computational models of this process. We pose that the solution for this

  4. Structure and Dynamics of Low-Density and High-Density Liquid Water at High Pressure.

    Science.gov (United States)

    Fanetti, Samuele; Lapini, Andrea; Pagliai, Marco; Citroni, Margherita; Di Donato, Mariangela; Scandolo, Sandro; Righini, Roberto; Bini, Roberto

    2014-01-02

    Liquid water has a primary role in ruling life on Earth in a wide temperature and pressure range as well as a plethora of chemical, physical, geological, and environmental processes. Nevertheless, a full understanding of its dynamical and structural properties is still lacking. Water molecules are associated through hydrogen bonds, with the resulting extended network characterized by a local tetrahedral arrangement. Two different local structures of the liquid, called low-density (LDW) and high-density (HDW) water, have been identified to potentially affect many different chemical, biological, and physical processes. By combining diamond anvil cell technology, ultrafast pump-probe infrared spectroscopy, and classical molecular dynamics simulations, we show that the liquid structure and orientational dynamics are intimately connected, identifying the P-T range of the LDW and HDW regimes. The latter are defined in terms of the speeding up of the orientational dynamics, caused by the increasing probability of breaking and reforming the hydrogen bonds.

  5. Affects and assemblages

    DEFF Research Database (Denmark)

    Samson, Kristine

    Affects and assemblages are Deleuzian Guattarian notions related to aesthetics and spatial territories. In recent urban geography and urban studies these notions are increasingly gaining more impact (Amin & Thrift 2002, Pile 2008, Farías & Bender 2010, Andersen & Harrison 2010, Thrift 2008). What...... happens to aesthetics and how does it change the existing social and geographical understanding of urban space? The paper sets out to reintroduce aesthetical aspects of affects and assemblages in relation to urban space and urban planning. It presupposes urban space as a continuous state of becoming where...... affects and assemblages produce subjective feelings and emotions (Pile 2009) Recently, urban experience designs and events aim at evoking affects through affects and assemblages. A Danish example is the Carlsberg city in Copenhagen another is The High line in Chelsea, New York (Samson 2011). Thus...

  6. Affectivity and race

    DEFF Research Database (Denmark)

    This book presents new empirical studies of social difference in the Nordic welfare states, in order to advance novel theoretical perspectives on the everyday practices and macro-politics of race and gender in multi-ethnic societies. With attention to the specific political and cultural landscapes...... of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...... into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection sheds light...

  7. Affectivity and Race

    DEFF Research Database (Denmark)

    This book presents new empirical studies of social difference in the Nordic welfare states, in order to advance novel theoretical perspectives on the everyday practices and macro-politics of race and gender in multi-ethnic societies. With attention to the specific political and cultural landscapes...... of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...... into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection sheds light...

  8. Affectivity and race

    DEFF Research Database (Denmark)

    This book presents new empirical studies of social difference in the Nordic welfare states, in order to advance novel theoretical perspectives on the everyday practices and macro-politics of race and gender in multi-ethnic societies. With attention to the specific political and cultural landscapes...... into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection sheds light...... of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...

  9. Numerical studies of density transition injection in laser wakefield acceleration

    Science.gov (United States)

    Massimo, F.; Lifschitz, A. F.; Thaury, C.; Malka, V.

    2017-08-01

    The quality of laser wakefield accelerated electrons beams is strongly determined by the physical mechanism exploited to inject electrons in the wakefield. One of the techniques used to improve the beam quality is the density transition injection, where the electron trapping occurs as the laser pulse passes a sharp density transition created in the plasma. Although this technique has been widely demonstrated experimentally, the literature lacks theoretical and numerical studies on the effects of all the transition parameters. We thus report and discuss the results of a series of particle in cell (PIC) simulations where the density transition height and downramp length are systematically varied, to show how the electron beam parameters and the injection mechanism are affected by the density transition parameters.

  10. Determining the Limiting Current Density of Vanadium Redox Flow Batteries

    Directory of Open Access Journals (Sweden)

    Jen-Yu Chen

    2014-09-01

    Full Text Available All-vanadium redox flow batteries (VRFBs are used as energy storage systems for intermittent renewable power sources. The performance of VRFBs depends on materials of key components and operating conditions, such as current density, electrolyte flow rate and electrolyte composition. Mass transfer overpotential is affected by the electrolyte flow rate and electrolyte composition, which is related to the limiting current density. In order to investigate the effect of operating conditions on mass transport overpotential, this study established a relationship between the limiting current density and operating conditions. First, electrolyte solutions with different states of charge were prepared and used for a single cell to obtain discharging polarization curves under various operating conditions. The experimental results were then analyzed and are discussed in this paper. Finally, this paper proposes a limiting current density as a function of operating conditions. The result helps predict the effect of operating condition on the cell performance in a mathematical model.

  11. Reported mammographic density: film-screen versus digital acquisition.

    Science.gov (United States)

    Harvey, Jennifer A; Gard, Charlotte C; Miglioretti, Diana L; Yankaskas, Bonnie C; Kerlikowske, Karla; Buist, Diana S M; Geller, Berta A; Onega, Tracy L

    2013-03-01

    To test the hypothesis that American College of Radiology Breast Imaging Reporting and Data System (BI-RADS) categories for breast density reported by radiologists are lower when digital mammography is used than those reported when film-screen (FS) mammography is used. This study was institutional review board approved and HIPAA compliant. Demographic data, risk factors, and BI-RADS breast density categories were collected from five mammography registries that were part of the Breast Cancer Surveillance Consortium. Active, passive, or waiver of consent was obtained for all participants. Women aged 40 years and older who underwent at least two screening mammographic examinations less than 36 months apart between January 1, 2000, and December 31, 2009, were included. Women with prior breast cancer, augmentation, or use of agents known to affect density were excluded. The main sample included 89 639 women with both FS and digital mammograms. The comparison group included 259 046 women with two FS mammograms and 87 066 women with two digital mammograms. BI-RADS density was cross-tabulated according to the order in which the two types of mammogram were acquired and by the first versus second interpretation. Regardless of acquisition method, the percentage of women with a change in density from one reading to the next was similar. Breast density was lower in 19.8% of the women who underwent FS before digital mammography and 17.1% of those who underwent digital before FS mammography. Similarly, lower density classifications were reported on the basis of the second mammographic examination regardless of acquisition method (15.8%-19.8%). The percentage of agreement between density readings was similar regardless of mammographic types paired (67.3%-71.0%). The study results showed no difference in reported BI-RADS breast density categories according to acquisition method. Reported BI-RADS density categories may be useful in the development of breast cancer risk models in

  12. Properties of Refrigerant Affect Compressor Design

    OpenAIRE

    Bukac, Hubert

    2012-01-01

    The paper examines selected thermodynamic properties of commonly used refrigerants and how they may affect design of a compressor. Among those properties are volumetric capacity, system pressure difference, system compression ratio, isentropic coefficient of performance, gas density, temperature of discharge gas, velocity of sound etc. The is made on the scale of evaporating temperatures from –40 oC to 30 oC, and condensing temperature 40.5 oC. The temperature of gas entering suction port is ...

  13. Can Supersaturation Affect Protein Crystal Quality?

    Science.gov (United States)

    Gorti, Sridhar

    2013-01-01

    In quiescent environments (microgravity, capillary tubes, gels) formation of a depletion zone is to be expected, due either to limited sedimentation, density driven convection or a combination of both. The formation of a depletion zone can: Modify solution supersaturation near crystal; Give rise to impurity partitioning. It is conjectured that both supersaturation and impurity partitioning affect protein crystal quality and size. Further detailed investigations on various proteins are needed to assess above hypothesis.

  14. Affect and criminal responsibility

    Directory of Open Access Journals (Sweden)

    Drakić Dragiša S.

    2017-01-01

    Full Text Available In this article the author deals with an issue of relationship between the affect and criminal responsibility. In order to provide a multi-angle approach to analysis of this issue the author resorted to multidisciplinary - criminal law and psychiatric-psychological approach. Although the topic covered by this article is significant and complex, it appears to be of virtually no interest in the literature. For that reason the author's endeavor to research this topic should not go unmentioned. In the first part of the article the author tried to provide answers to some preliminary questions without which it would be impossible to understand the relationship between the affect and criminal responsibility. Those are the following questions: what are affects, what is their nature and intensity, how long they last and how they influence psychological functions of a person acting in affect? Central part of the article is dedicated to examining the importance of the affect as a phenomenon in criminal law dogma and in judicial rulings, as well as its effect on criminal responsibility. The author finds that acting in affect may be considered as a mitigating circumstance in the sentencing, but can also be a basis for mitigation of the sentence or even suspension of the sentence, as part of some general criminal law norms. Also, for certain offenses it may be considered as a favorable condition that renders that offence to be less grave. Finally, the affect may be considered as a psychological basis diminished, or even lack of, mental capacity. The last above mentioned issue receives special attention of the author, and claims that only the affect that is 'of extreme proportions' may lead to mental incapacity. Such affect is the one that 'demolishes restrains and removes reasonable and target-oriented actions'. In further analysis the author proposes criteria and methodology for assessment of person's sanity in criminal law and criminal procedure. Further

  15. Automatic breast tissue density estimation scheme in digital mammography images

    Science.gov (United States)

    Menechelli, Renan C.; Pacheco, Ana Luisa V.; Schiabel, Homero

    2017-03-01

    Cases of breast cancer have increased substantially each year. However, radiologists are subject to subjectivity and failures of interpretation which may affect the final diagnosis in this examination. The high density features in breast tissue are important factors related to these failures. Thus, among many functions some CADx (Computer-Aided Diagnosis) schemes are classifying breasts according to the predominant density. In order to aid in such a procedure, this work attempts to describe automated software for classification and statistical information on the percentage change in breast tissue density, through analysis of sub regions (ROIs) from the whole mammography image. Once the breast is segmented, the image is divided into regions from which texture features are extracted. Then an artificial neural network MLP was used to categorize ROIs. Experienced radiologists have previously determined the ROIs density classification, which was the reference to the software evaluation. From tests results its average accuracy was 88.7% in ROIs classification, and 83.25% in the classification of the whole breast density in the 4 BI-RADS density classes - taking into account a set of 400 images. Furthermore, when considering only a simplified two classes division (high and low densities) the classifier accuracy reached 93.5%, with AUC = 0.95.

  16. Annual Screening Mammogram and its Relation to Breast Density

    Directory of Open Access Journals (Sweden)

    Sabek EAS

    2017-11-01

    Full Text Available Background: Current national screening programs totally depend on mammographic evaluation. After increased incidence of breast cancer in women under the age of 35, mammography sensitivity in now a question. Several factors added to decrease sensitivity of mammography, such as increased density in older age groups and increased aggressiveness of tumour biology. All these factors will change the reliability of the screening program. The study is a retrospective study conducted at Ain Shams University. Method: 138 patients diagnosed with cancer breast underwent both mammography and sonography to determine percentage of patient with more than one focus, age and density distribution breast cancer in the affected patient and accuracy of both mammography and US. Results: By studying this population, we found that around 61,44% have areas of density ranging from dense breast, heterogenous density or scattered density. These areas of density render the mammography a less sensitive tool as its sensitivity fall to 34.09%, while that of US was 77.27%. Conclusion: As breast cancer is prevalent in younger population, also with increased density in older population who are relatively insensitive to mammography, we recommended the use of Automated Breast Ultrasound (ABUS in the national screening program.

  17. Sleep spindle density in narcolepsy

    DEFF Research Database (Denmark)

    Christensen, Julie Anja Engelhard; Nikolic, Miki; Hvidtfelt, Mathias

    2017-01-01

    BACKGROUND: Patients with narcolepsy type 1 (NT1) show alterations in sleep stage transitions, rapid-eye-movement (REM) and non-REM sleep due to the loss of hypocretinergic signaling. However, the sleep microstructure has not yet been evaluated in these patients. We aimed to evaluate whether...... the sleep spindle (SS) density is altered in patients with NT1 compared to controls and patients with narcolepsy type 2 (NT2). METHODS: All-night polysomnographic recordings from 28 NT1 patients, 19 NT2 patients, 20 controls (C) with narcolepsy-like symptoms, but with normal cerebrospinal fluid hypocretin...... levels and multiple sleep latency tests, and 18 healthy controls (HC) were included. Unspecified, slow, and fast SS were automatically detected, and SS densities were defined as number per minute and were computed across sleep stages and sleep cycles. The between-cycle trends of SS densities in N2...

  18. High Energy Density Electrolytic Capacitor

    Science.gov (United States)

    Evans, David A.

    1996-01-01

    A new type of electrolytic capacitor which combines an electrolytic capacitor anode with an electrochemical capacitor cathode was developed. The resulting capacitor has a four time higher energy density than standard electrolytic capacitors, with comparable electric performance. The prototype, a 480 microFarad, 200 V device, has an energy density exceeding 4 J/cc. Now a 680 microFarad 50 V, MIL-style all tantalum device has been constructed and is undergoing qualification testing. Pending a favorable outcome, work will begin on other ratings. The potential for commercially significant development exists in applying this technology to aluminum-based electrolytic capacitors. It is possible to at least double the energy density of aluminum electrolytics, while using existing manufacturing methods, and without adding material expense. Data presented include electrical characteristics and performance measurements of the 200 V and 50 V hybrid capacitors and results from ongoing qualification testing of the MIL-style tantalum capacitors.

  19. High Energy Density Laboratory Astrophysics

    CERN Document Server

    Lebedev, Sergey V

    2007-01-01

    During the past decade, research teams around the world have developed astrophysics-relevant research utilizing high energy-density facilities such as intense lasers and z-pinches. Every two years, at the International conference on High Energy Density Laboratory Astrophysics, scientists interested in this emerging field discuss the progress in topics covering: - Stellar evolution, stellar envelopes, opacities, radiation transport - Planetary Interiors, high-pressure EOS, dense plasma atomic physics - Supernovae, gamma-ray bursts, exploding systems, strong shocks, turbulent mixing - Supernova remnants, shock processing, radiative shocks - Astrophysical jets, high-Mach-number flows, magnetized radiative jets, magnetic reconnection - Compact object accretion disks, x-ray photoionized plasmas - Ultrastrong fields, particle acceleration, collisionless shocks. These proceedings cover many of the invited and contributed papers presented at the 6th International Conference on High Energy Density Laboratory Astrophys...

  20. Union Density and Hospital Outcomes.

    Science.gov (United States)

    Koys, Daniel J; Martin, Wm Marty; LaVan, Helen; Katz, Marsha

    2015-01-01

    The authors address the hospital outcomes of patient satisfaction, healthcare quality, and net income per bed. They define union density as the percentage of a hospital's employees who are in unions, healthcare quality as its 30-day acute myocardial infraction (AMI; heart attack) mortality rate, and patient satisfaction as its overall Hospital Consumer Assessment of Healthcare Providers and Systems score. Using a random sample of 84 union and 84 nonunion hospitals from across the United States, multiple regression analyses show that union density is negatively related to patient satisfaction. Union density is not related to healthcare quality as measured by the AMI mortality rate or to net income per bed. This implies that unions per se are not good or bad for hospitals. The authors suggest that it is better for hospital administrators to take a Balanced Scorecard approach and be concerned about employee satisfaction, patient satisfaction, healthcare quality, and net income.

  1. Simulating QCD at finite density

    CERN Document Server

    de Forcrand, Philippe

    2009-01-01

    In this review, I recall the nature and the inevitability of the "sign problem" which plagues attempts to simulate lattice QCD at finite baryon density. I present the main approaches used to circumvent the sign problem at small chemical potential. I sketch how one can predict analytically the severity of the sign problem, as well as the numerically accessible range of baryon densities. I review progress towards the determination of the pseudo-critical temperature T_c(mu), and towards the identification of a possible QCD critical point. Some promising advances with non-standard approaches are reviewed.

  2. High-density multicore fibers

    DEFF Research Database (Denmark)

    Takenaga, K.; Matsuo, S.; Saitoh, K.

    2016-01-01

    High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber.......High-density single-mode multicore fibers were designed and fabricated. A heterogeneous 30-core fiber realized a low crosstalk of −55 dB. A quasi-single-mode homogeneous 31-core fiber attained the highest core count as a single-mode multicore fiber....

  3. Sorting cells by their density.

    Directory of Open Access Journals (Sweden)

    Nazila Norouzi

    Full Text Available Sorting cells by their type is an important capability in biological research and medical diagnostics. However, most cell sorting techniques rely on labels or tags, which may have limited availability and specificity. Sorting different cell types by their different physical properties is an attractive alternative to labels because all cells intrinsically have these physical properties. But some physical properties, like cell size, vary significantly from cell to cell within a cell type; this makes it difficult to identify and sort cells based on their sizes alone. In this work we continuously sort different cells types by their density, a physical property with much lower cell-to-cell variation within a cell type (and therefore greater potential to discriminate different cell types than other physical properties. We accomplish this using a 3D-printed microfluidic chip containing a horizontal flowing micron-scale density gradient. As cells flow through the chip, Earth's gravity makes each cell move vertically to the point where the cell's density matches the surrounding fluid's density. When the horizontal channel then splits, cells with different densities are routed to different outlets. As a proof of concept, we use our density sorter chip to sort polymer microbeads by their material (polyethylene and polystyrene and blood cells by their type (white blood cells and red blood cells. The chip enriches the fraction of white blood cells in a blood sample from 0.1% (in whole blood to nearly 98% (in the output of the chip, a 1000x enrichment. Any researcher with access to a 3D printer can easily replicate our density sorter chip and use it in their own research using the design files provided as online Supporting Information. Additionally, researchers can simulate the performance of a density sorter chip in their own applications using the Python-based simulation software that accompanies this work. The simplicity, resolution, and throughput of this

  4. Sorting cells by their density.

    Science.gov (United States)

    Norouzi, Nazila; Bhakta, Heran C; Grover, William H

    2017-01-01

    Sorting cells by their type is an important capability in biological research and medical diagnostics. However, most cell sorting techniques rely on labels or tags, which may have limited availability and specificity. Sorting different cell types by their different physical properties is an attractive alternative to labels because all cells intrinsically have these physical properties. But some physical properties, like cell size, vary significantly from cell to cell within a cell type; this makes it difficult to identify and sort cells based on their sizes alone. In this work we continuously sort different cells types by their density, a physical property with much lower cell-to-cell variation within a cell type (and therefore greater potential to discriminate different cell types) than other physical properties. We accomplish this using a 3D-printed microfluidic chip containing a horizontal flowing micron-scale density gradient. As cells flow through the chip, Earth's gravity makes each cell move vertically to the point where the cell's density matches the surrounding fluid's density. When the horizontal channel then splits, cells with different densities are routed to different outlets. As a proof of concept, we use our density sorter chip to sort polymer microbeads by their material (polyethylene and polystyrene) and blood cells by their type (white blood cells and red blood cells). The chip enriches the fraction of white blood cells in a blood sample from 0.1% (in whole blood) to nearly 98% (in the output of the chip), a 1000x enrichment. Any researcher with access to a 3D printer can easily replicate our density sorter chip and use it in their own research using the design files provided as online Supporting Information. Additionally, researchers can simulate the performance of a density sorter chip in their own applications using the Python-based simulation software that accompanies this work. The simplicity, resolution, and throughput of this technique make

  5. The Affective Turn

    DEFF Research Database (Denmark)

    Carnera, Alexander

    2012-01-01

    -management that human individuation ties together modes of productions with affects and emotions. Introducing Spinoza's concept of ‘affect’, and Gilles Deleuze's reading of Spinoza's ethics focusing on the ‘affective turn’ in relation to the new economy and society, the paper argues for a more positive notion...... of biopolitics that surpasses that of governmentality. The affective self-relation is used as a research tool to analyse the creation of social and economic values in our new modes of productions, for instance, within free labour of the cultural industry. The movie The Five Obstructions is used to show how...... organizing good affective encounters based on limitations enhance and facilitate the performative dimension of self-management. Finally, the paper addresses the problem of critique confronting self-relation with Spinoza's ethics as an ethical difference of powe...

  6. Seasonal Affective Disorder

    Science.gov (United States)

    ... look different in women, men, seniors, and children. Depression and College Students : This booklet describes what depression is, how it affects college students, and treatment options. Teen Depression : This flier for ...

  7. Affectivity and Race

    DEFF Research Database (Denmark)

    This book presents new empirical studies of social difference in the Nordic welfare states, in order to advance novel theoretical perspectives on the everyday practices and macro-politics of race and gender in multi-ethnic societies. With attention to the specific political and cultural landscapes...... into the experience of racial difference and the unfolding of political discourses on race in various social spheres. Organised around the themes of the politicisation of race through affect, the way that race produces affect and the affective experience of race, this interdisciplinary collection sheds light...... on the role of feelings in the formation of subjectivities, how race and whiteness are affectively circulated in public life and the ways in which emotions contribute to regimes of inclusion and exclusion. As such it will appeal to scholars across the social sciences, with interests in sociology, anthropology...

  8. Pain, Affect, and Attachment

    Directory of Open Access Journals (Sweden)

    Carl Eduard Scheidt

    2015-05-01

    Full Text Available Various psychodynamic processes may underlie the development of psychogenic pain disorder such as conversion, the displacement of affect, or narcissistic defenses. However, many of the processes suggested are related to a disorder of affect regulation. The term affect regulation in psychoanalytic literature refers to phenomena which are often described by the concept of alexithymia. Empirical observations suggest that alexithymia is correlated to insecure attachment, especially an insecure dismissing representation of attachment. Psychodynamic psychotherapy in psychogenic pain disorder should focus on the reintegration of split-off affects which may provoke intensive counter-transference and which in order to be used therapeutically must be linked to attachment experiences within and outside of the therapeutic relationship.

  9. Cancers Affecting the Retina

    Science.gov (United States)

    ... Degeneration Additional Content Medical News Cancers Affecting the Retina By Sonia Mehta, MD, Assistant Professor of Ophthalmology, ... Retinopathy Epiretinal Membrane Hypertensive Retinopathy Retinitis Pigmentosa The retina is the transparent, light-sensitive structure at the ...

  10. Forward Affect Bridge.

    Science.gov (United States)

    Bonshtein, Udi; Torem, Moshe

    2017-01-01

    This article presents a modification of the affect bridge technique. The Forward Affect Bridge enables practitioners to create and maintain hope when it is missing. Hope is relevant for diminishing avoidance and being involved with necessary activities. The main idea is to build up a positive atmosphere in the here and now (relying on rapport), to amplify it, and to project it forward. By using clinical vignettes, the authors illustrate these techniques.

  11. Breeding territory size affects fitness : an experimental study on competition at the individual level

    NARCIS (Netherlands)

    Both, C; Visser, ME

    2000-01-01

    1. Descriptive studies have shown that the annual mean fecundity and survival in bird populations decline as density increases. Experimental studies in which breeding density has been manipulated show that density causally affects reproduction in some but not other species. 2. In a 3-year study on

  12. Fire danger rating network density

    Science.gov (United States)

    Rudy M. King; R. William Furman

    1976-01-01

    Conventional statistical techniques are used to answer the question, "What is the necessary station density for a fire danger network?" The Burning Index of the National Fire-Danger Rating System is used as an indicator of fire danger. Results are presented as station spacing in tabular form for each of six regions in the western United States.

  13. Bounded Densities and Their Derivatives

    DEFF Research Database (Denmark)

    Kozine, Igor; Krymsky, V.

    2009-01-01

    This paper describes how one can compute interval-valued statistical measures given limited information about the underlying distribution. The particular focus is on a bounded derivative of a probability density function and its combination with other available statistical evidence for computing ...

  14. SYNTHESIS, CHARACTERIZATION AND DENSITY FUNCTIONAL ...

    African Journals Online (AJOL)

    Preferred Customer

    ABSTRACT. We synthesized a number of aniline derivatives containing acyl groups to compare their barriers of rotation around the N-CO groups. Geometry optimization for all the rotamers have been performed using density functional theory (DFT) at the B3LYP/6-31G** level of theory. For each stationary point we carried ...

  15. High density matter at RHIC

    Indian Academy of Sciences (India)

    Keywords. Quark-gluon plasma; relativistic heavy ion physics; relativistic heavy ion collider ... matter and a quark-gluon plasma at high energy density. The relativistic heavy ion collider (RHIC) at Brookhaven National Laboratory is a new facility dedicated to the experimental study of matter under extreme conditions. Already ...

  16. Density estimation from local structure

    CSIR Research Space (South Africa)

    Van der Walt, Christiaan M

    2009-11-01

    Full Text Available Mixture Model (GMM) density function of the data and the log-likelihood scores are compared to the scores of a GMM trained with the expectation maximization (EM) algorithm on 5 real-world classification datasets (from the UCI collection). They show...

  17. Crown management and stand density

    Science.gov (United States)

    Thomas J. Dean; V. Clark Baldwin

    1996-01-01

    Determination of optimal stand-density continues to be a difficult problem. A trial cannot be established on every combination of soils, topography, and climate possible across the range of a widely distributed species such as loblolly pine, and continual advancements in nutrition and vegetation management, breeding, and utilization make established trials obsolete....

  18. An experimental electron density investigation

    Indian Academy of Sciences (India)

    Unknown

    based on X-ray diffraction measurements at 130 K. The electron density and its associated properties have been evaluated at the bond and the ring critical points for the naphthalene residues as well as for the central ring. The variation of the Laplacian along the axis, above and below the ring plane, is found to be symmetric ...

  19. Nonlinear effects of consumer density on multiple ecosystem processes.

    Science.gov (United States)

    Klemmer, Amanda J; Wissinger, Scott A; Greig, Hamish S; Ostrofsky, Milton L

    2012-07-01

    1. In the face of human-induced declines in the abundance of common species, ecologists have become interested in quantifying how changes in density affect rates of biophysical processes, hence ecosystem function. We manipulated the density of a dominant detritivore (the cased caddisfly, Limnephilus externus) in subalpine ponds to measure effects on the release of detritus-bound nutrients and energy. 2. Detritus decay rates (k, mass loss) increased threefold, and the loss of nitrogen (N) and phosphorus (P) from detrital substrates doubled across a range of historically observed caddisfly densities. Ammonium and total soluble phosphorus concentrations in the water column also increased with caddisfly density on some dates. Decay rates, nutrient release and the change in total detritivore biomass all exhibited threshold or declining responses at the highest densities. 3. We attributed these threshold responses in biophysical processes to intraspecific competition for limiting resources manifested at the population level, as density-dependent per-capita consumption, growth, development and case : body size in caddisflies was observed. Moreover, caddisflies increasingly grazed on algae at high densities, presumably in response to limiting detrital resources. 4. These results provide evidence that changes in population size of a common species will have nonlinear, threshold effects on the rates of biophysical processes at the ecosystem level. Given the ubiquity of negative density dependence in nature, nonlinear consumer density-ecosystem function relationships should be common across species and ecosystems. © 2012 The Authors. Journal of Animal Ecology © 2012 British Ecological Society.

  20. The topology of the Coulomb potential density. A comparison with the electron density, the virial energy density, and the Ehrenfest force density.

    Science.gov (United States)

    Ferreira, Lizé-Mari; Eaby, Alan; Dillen, Jan

    2017-12-15

    The topology of the Coulomb potential density has been studied within the context of the theory of Atoms in Molecules and has been compared with the topologies of the electron density, the virial energy density and the Ehrenfest force density. The Coulomb potential density is found to be mainly structurally homeomorphic with the electron density. The Coulomb potential density reproduces the non-nuclear attractor which is observed experimentally in the molecular graph of the electron density of a Mg dimer, thus, for the first time ever providing an alternative and energetic foundation for the existence of this critical point. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  1. Dual Cryogenic Capacitive Density Sensor

    Science.gov (United States)

    Youngquist, Robert; Mata, Carlos; Vokrot, Peter; Cox, Robert

    2009-01-01

    A dual cryogenic capacitive density sensor has been developed. The device contains capacitive sensors that monitor two-phase cryogenic flow density to within 1% accuracy, which, if temperature were known, could be used to determine the ratio of liquid to gas in the line. Two of these density sensors, located a known distance apart, comprise the sensor, providing some information on the velocity of the flow. This sensor was constructed as a proposed mass flowmeter with high data acquisition rates. Without moving parts, this device is capable of detecting the density change within a two-phase cryogenic flow more than 100 times a second. Detection is enabled by a series of two sets of five parallel plates with stainless steel, cryogenically rated tubing. The parallel plates form the two capacitive sensors, which are measured by electrically isolated digital electronics. These capacitors monitor the dielectric of the flow essentially the density of the flow and can be used to determine (along with temperature) the ratio of cryogenic liquid to gas. Combining this information with the velocity of the flow can, with care, be used to approximate the total two-phase mass flow. The sensor can be operated at moderately high pressures and can be lowered into a cryogenic bath. The electronics have been substantially improved over the older sensors, incorporating a better microprocessor, elaborate ground loop protection and noise limiting circuitry, and reduced temperature sensitivity. At the time of this writing, this design has been bench tested at room temperature, but actual cryogenic tests are pending

  2. Affective responses to dance.

    Science.gov (United States)

    Christensen, Julia F; Pollick, Frank E; Lambrechts, Anna; Gomila, Antoni

    2016-07-01

    The objective of the present work was the characterization of mechanisms by which affective experiences are elicited in observers when watching dance movements. A total of 203 dance stimuli from a normed stimuli library were used in a series of independent experiments. The following measures were obtained: (i) subjective measures of 97 dance-naïve participants' affective responses (Likert scale ratings, interviews); and (ii) objective measures of the physical parameters of the stimuli (motion energy, luminance), and of the movements represented in the stimuli (roundedness, impressiveness). Results showed that (i) participants' ratings of felt and perceived affect differed, (ii) felt and perceived valence but not arousal ratings correlated with physical parameters of the stimuli (motion energy and luminance), (iii) roundedness in posture shape was related to the experience of more positive emotion than edgy shapes (1 of 3 assessed rounded shapes showed a clear effect on positiveness ratings while a second reached trend level significance), (iv) more impressive movements resulted in more positive affective responses, (v) dance triggered affective experiences through the imagery and autobiographical memories it elicited in some people, and (vi) the physical parameters of the video stimuli correlated only weakly and negatively with the aesthetics ratings of beauty, liking and interest. The novelty of the present approach was twofold; (i) the assessment of multiple affect-inducing mechanisms, and (ii) the use of one single normed stimulus set. The results from this approach lend support to both previous and present findings. Results are discussed with regards to current literature in the field of empirical aesthetics and affective neuroscience. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Importing low-density ideas to high-density revitalisation

    DEFF Research Database (Denmark)

    Arnholtz, Jens; Ibsen, Christian Lyhne; Ibsen, Flemming

    2016-01-01

    Why did union officials from a high-union-density country like Denmark choose to import an organising strategy from low-density countries such as the US and the UK? Drawing on in-depth interviews with key union officials and internal documents, the authors of this article argue two key points....... First, rather than unions settling for a semi-automatic response to membership decline, the ‘organising model’ was actively imported as a strategic tool for challenging alternative responses to membership decline. Second, the organising model was actively translated into a Danish context and most unions...... cherry-pick some elements while leaving fundamental aspects out. The study nevertheless indicates that a lack of coherency and model-fit to Danish industrial relations might hamper the positive effects of the organising strategy....

  4. Density can be misleading for low-density species: benefits of passive acoustic monitoring.

    Directory of Open Access Journals (Sweden)

    Tracey L Rogers

    Full Text Available Climate-induced changes may be more substantial within the marine environment, where following ecological change is logistically difficult, and typically expensive. As marine animals tend to produce stereotyped, long-range signals, they are ideal for repeatable surveying. In this study we illustrate the potential for calling rates to be used as a tool for determining habitat quality by using an Antarctic pack-ice seal, the leopard seal, as a model.With an understanding of the vocal behavior of a species, their seasonal and diurnal patterns, sex and age-related differences, an underwater passive-acoustic survey conducted alongside a visual survey in an arc of 4,225 km across the Davis Sea, Eastern Antarctica, showed that while acoustic and visual surveys identified similar regions as having high densities, the acoustic surveys surprisingly identified the opposite regions as being 'critical' habitats. Density surveys of species that cannot be differentiated into population classes may be misleading because overall density can be a negative indicator of habitat quality.Under special circumstances acoustics can offer enormous advantage over traditional techniques and open up monitoring to regions that are remote, difficult and expensive to work within, no longer restricting long-term community assessment to resource-wealthy communities. As climatic change affects a broad range of organisms across geographic boundaries we propose that capitalizing on the significant advances in passive acoustic technology, alongside physical acoustics and population modeling, can help in addressing ecological questions more broadly.

  5. Density can be misleading for low-density species: benefits of passive acoustic monitoring.

    Science.gov (United States)

    Rogers, Tracey L; Ciaglia, Michaela B; Klinck, Holger; Southwell, Colin

    2013-01-01

    Climate-induced changes may be more substantial within the marine environment, where following ecological change is logistically difficult, and typically expensive. As marine animals tend to produce stereotyped, long-range signals, they are ideal for repeatable surveying. In this study we illustrate the potential for calling rates to be used as a tool for determining habitat quality by using an Antarctic pack-ice seal, the leopard seal, as a model.With an understanding of the vocal behavior of a species, their seasonal and diurnal patterns, sex and age-related differences, an underwater passive-acoustic survey conducted alongside a visual survey in an arc of 4,225 km across the Davis Sea, Eastern Antarctica, showed that while acoustic and visual surveys identified similar regions as having high densities, the acoustic surveys surprisingly identified the opposite regions as being 'critical' habitats. Density surveys of species that cannot be differentiated into population classes may be misleading because overall density can be a negative indicator of habitat quality.Under special circumstances acoustics can offer enormous advantage over traditional techniques and open up monitoring to regions that are remote, difficult and expensive to work within, no longer restricting long-term community assessment to resource-wealthy communities. As climatic change affects a broad range of organisms across geographic boundaries we propose that capitalizing on the significant advances in passive acoustic technology, alongside physical acoustics and population modeling, can help in addressing ecological questions more broadly.

  6. The Affective Turn

    Directory of Open Access Journals (Sweden)

    Alí Lara

    2013-11-01

    Full Text Available In the last decade studies on affect and emotions have become relevant in the social sciences. This is not just a fad guideline, but instead a simultaneous reader of public life changes and subjective experience, from which it is also being transformed the knowledge production. Such a trend has been known as ‘The Affective Turn’ within the Anglophone Academy. Here we will translate it as ‘El Giro Afectivo’. This turn, so far, has not dabbled in the social science literature that is written in Spanish. This paper draws on a singular panorama of discussions about contemporary social studies of affect and emotion, and it’s vertebrate by some of its expressions in the contemporary academy.

  7. Spontaneous mutation rate is a plastic trait associated with population density across domains of life

    National Research Council Canada - National Science Library

    Rok Krašovec; Huw Richards; Danna R Gifford; Charlie Hatcher; Katy J Faulkner; Roman V Belavkin; Alastair Channon; Elizabeth Aston; Andrew J McBain; Christopher G Knight

    2017-01-01

    .... Such plasticity affects evolutionary trajectories and may be adaptive. We recently identified an inverse plastic association between mutation rate and population density at 1 locus in 1 species of bacterium...

  8. Stability of high cell density brewery fermentations during serial repitching.

    Science.gov (United States)

    Verbelen, Pieter J; Dekoninck, Tinne M L; Van Mulders, Sebastiaan E; Saerens, Sofie M G; Delvaux, Filip; Delvaux, Freddy R

    2009-11-01

    The volumetric productivity of the beer fermentation process can be increased by using a higher pitching rate (i.e. higher inoculum size). However, the decreased yeast net growth observed in these high cell density brewery fermentations can adversely affect the physiological stability throughout subsequent yeast generations. Therefore, different O(2) conditions (wort aeration and yeast preoxygenation) were applied to high cell density fermentation and eight generations of fermentations were evaluated together with conventional fermentations. Freshly propagated high cell density populations adapted faster to the fermentative conditions than normal cell density populations. Preoxygenating the yeast was essential for the yeast physiological and beer flavor compound stability of high cell density fermentations during serial repitching. In contrast, the use of non-preoxygenated yeast resulted in inadequate growth which caused (1) insufficient yield of biomass to repitch all eight generations, (2) a 10% decrease in viability, (3) a moderate increase of yeast age, (4) and a dramatic increase of the unwanted flavor compounds acetaldehyde and total diacetyl during the sequence of fermentations. Therefore, to achieve sustainable high cell density fermentations throughout the economical valuable process of serial repitching, adequate yeast growth is essential.

  9. Affectivity and race

    DEFF Research Database (Denmark)

    This book presents new empirical studies of social difference in the Nordic welfare states, in order to advance novel theoretical perspectives on the everyday practices and macro-politics of race and gender in multi-ethnic societies. With attention to the specific political and cultural landscapes...... of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...

  10. Affectivity and Race

    DEFF Research Database (Denmark)

    This book presents new empirical studies of social difference in the Nordic welfare states, in order to advance novel theoretical perspectives on the everyday practices and macro-politics of race and gender in multi-ethnic societies. With attention to the specific political and cultural landscapes...... of the Nordic countries, Affectivity and Race draws on a variety of sources, including television programmes, news media, fictional literature, interviews, ethnographic observations, teaching curricula and policy documents, to explore the ways in which ideas about affectivity and emotion afford new insights...

  11. Effective spatial scales for evaluating environmental determinants of population density in Yakushima macaques

    OpenAIRE

    Agetsuma, Naoki; Koda, Ryosuke; Tsujino, Riyou; Agetsuma-Yanagihara, Yoshimi

    2015-01-01

    Population densities of wildlife species tend to be correlated with resource productivity of habitats. However, wildlife density has been greatly modified by increasing human influences. For effective conservation, we must first identify the significant factors that affect wildlife density, and then determine the extent of the areas in which the factors should be managed. Here, we propose a protocol that accomplishes these two tasks. The main threats to wildlife are thought to be habitat alte...

  12. Fractionation of plant protoplast types by iso-osmotic density gradient centrifugation.

    Science.gov (United States)

    Harms, C T; Potrykus, I

    1978-09-01

    A simple effective technique for the fractionation of protoplast populations is described. Protoplasts are separated by low-speed centrifugation in an iso-osmotic, discontinuous density gradient system on the basis of differences in their buoyant densities. At a constant osmolality of 660±20 mOs/kg H2O, the gradients provide a density range from 1.017 to 1.069 g/cm(3) at 20 °C which corresponds to the buoyant densities of most protoplast types studied. Characteristics of the KMC/S-density gradient system and factors affecting the fractionation were investigated. Protoplasts were isolated from various tissues and cultivars of tobacco, barley, wheat, rye, oat and maize. Their density-dependent distribution profiles in KMC/S-gradients and their average buoyant densities were determined under standardized conditions. Great differences in the buoyant densities were found between protoplasts of different tissues. Mixed populations of two types of protoplasts, differing in buoyant density by about 15-20 mg/cm(3), were separated to give highly purified fractions. Factors affecting the buoyant densities of protoplasts have been investigated. Ploidy level and species differences did not significantly affect the fractionation profiles. However, an age-dependent variation in the average buoyant density of tobacco mesophyll protoplasts was observed. Fractionation of tobacco mesophyll protoplasts and their subsequent regeneration to plants demonstrates the practicability and physiological compatibility of the KMC/S-density gradient system under sterile conditions. The morphogenetic potential of protoplasts was not affected by the separation procedure or the gradient components.

  13. Profound Effects of Population Density on Fitness-Related Traits in an Invasive Freshwater Snail

    OpenAIRE

    Nicholas Zachar; Maurine Neiman

    2013-01-01

    Population density can profoundly influence fitness-related traits and population dynamics, and density dependence plays a key role in many prominent ecological and evolutionary hypotheses. Here, we evaluated how individual-level changes in population density affect growth rate and embryo production early in reproductive maturity in two different asexual lineages of Potamopyrgus antipodarum, a New Zealand freshwater snail that is an important model system for ecotoxicology and the evolution o...

  14. Effects of Population Density on Smallholder Agricultural Production and Commercialization in Rural Kenya

    OpenAIRE

    Muyanga, Milu; Jayne, Thomas S.

    2012-01-01

    This study analyzes the implications of increasing population density in Kenya’s rural areas on smallholder production and commercialization. Using data from five panel surveys on 1,146 small-scale farms over the 1997-2010 period, we use econometric techniques to determine how increasing rural population density is affecting farm household behavior and its implication to smallholder commercialization. We find that farm productivity and incomes tend to rise with population density up to 600-65...

  15. Automated analysis of mammographic densities.

    Science.gov (United States)

    Byng, J W; Boyd, N F; Fishell, E; Jong, R A; Yaffe, M J

    1996-05-01

    Information derived from mammographic parenchymal patterns provides one of the strongest indicators of the risk of developing breast cancer. To address several limitations of subjective classification of mammographic parenchyma into coarse density categories, we have been investigating more quantitative, objective methods of analysing the film-screen mammogram. These include measures of the skewness of the image brightness histogram, and of image texture characterized by the fractal dimension. Both measures were found to be strongly correlated with radiologists' subjective classifications of mammographic parenchyma (Spearman correlation coefficients, Rs = -0.88 and -0.76 for skewness and fractal dimension measurements, respectively). Further, neither measure was strongly dependent on simulated changes in mammographic technique. Correlation with subjective classification of mammographic density was better when both the skewness and fractal measures were used in combination than when either was used alone. This suggests that each feature provides some independent information.

  16. Network reconstruction via density sampling

    CERN Document Server

    Squartini, Tiziano; Gabrielli, Andrea; Garlaschelli, Diego

    2016-01-01

    Reconstructing weighted networks from partial information is necessary in many important circumstances, e.g. for a correct estimation of systemic risk. It has been shown that, in order to achieve an accurate reconstruction, it is crucial to reliably replicate the empirical degree sequence, which is however unknown in many realistic situations. More recently, it has been found that the knowledge of the degree sequence can be replaced by the knowledge of the strength sequence, which is typically accessible, complemented by that of the total number of links, thus considerably relaxing the observational requirements. Here we further relax these requirements and devise a procedure valid when even the the total number of links is unavailable. We assume that, apart from the heterogeneity induced by the degree sequence itself, the network is homogeneous, so that its link density can be estimated by sampling subsets of nodes with representative density. We show that the best way of sampling nodes is the random selecti...

  17. Density Deconvolution With EPI Splines

    Science.gov (United States)

    2015-09-01

    MATLAB [31], a Gaussian kernel, and the default bandwidth calculation. 2.5 Procedures We describe procedures for obtaining density estimates. Given an...combination of written methods and software such as the MATLAB Symbolic Toolbox [31] we find the closed form solutions of each addend in Equation (A.2). The...Robinson, “Predictive decomposition of time series with application to seismic exploration,” Geophysics, vol. 32, no. 3, 1967, pp. 418–484. [3] E. A

  18. High energy density aluminum battery

    Science.gov (United States)

    Brown, Gilbert M.; Paranthaman, Mariappan Parans; Dai, Sheng; Dudney, Nancy J.; Manthiram, Arumugan; McIntyre, Timothy J.; Sun, Xiao-Guang; Liu, Hansan

    2016-10-11

    Compositions and methods of making are provided for a high energy density aluminum battery. The battery comprises an anode comprising aluminum metal. The battery further comprises a cathode comprising a material capable of intercalating aluminum or lithium ions during a discharge cycle and deintercalating the aluminum or lithium ions during a charge cycle. The battery further comprises an electrolyte capable of supporting reversible deposition and stripping of aluminum at the anode, and reversible intercalation and deintercalation of aluminum or lithium at the cathode.

  19. Directed seed dispersal towards areas with low conspecific tree density by a scatter-hoarding rodent

    NARCIS (Netherlands)

    Hirsch, Ben T.; Kays, Roland; Pereira, Veronica E.; Jansen, Patrick A.

    2012-01-01

    Scatter-hoarding animals spread out cached seeds to reduce density-dependent theft of their food reserves. This behaviour could lead to directed dispersal into areas with lower densities of conspecific trees, where seed and seedling survival are higher, and could profoundly affect the spatial

  20. Density functionals from deep learning

    Science.gov (United States)

    McMahon, Jeffrey

    Density-functional theory is a formally exact description of a many-body quantum system in terms of its density; in practice, however, approximations to the universal density functional (DF) are necessary. Machine learning has recently been proposed as a novel approach to discover such a DF (or components of it). Conventional machine learning algorithms, however, are limited in their ability to process data in their raw form, leading to invariance and/or sensitivity issues. In this presentation, an alternative approach based on deep learning will be demonstrated. Deep learning allows computational models that are capable of discovering intricate structure in large and/or high-dimensional data sets with multiple levels of abstraction, and do not suffer from the aforementioned issues. Results from the application of this approach to the prediction of the kinetic-energy DF of noninteracting electrons will be presented. Using theoretical results from computer science, a connection between the underlying model and the theorems of Hohenberg and Kohn will also be suggested.

  1. On VC-density over indiscernible sequences

    OpenAIRE

    Guingona, Vincent; Hill, Cameron Donnay

    2011-01-01

    In this paper, we study VC-density over indiscernible sequences (denoted VC_ind-density). We answer an open question in [1], showing that VC_ind-density is always integer valued. We also show that VC_ind-density and dp-rank coincide in the natural way.

  2. Density heterogeneity of the cratonic lithosphere

    DEFF Research Database (Denmark)

    Cherepanova, Yulia; Artemieva, Irina

    2015-01-01

    correlation between mantle density variations and the tectonic setting. Three types of cratonic mantle are recognized from mantle density anomalies. 'Pristine' cratonic regions not sampled by kimberlites have the strongest depletion with density deficit of 1.8-3.0% (and SPT density of 3.29-3.33 t/m3...

  3. Design Difficulties in Stand Density Studies

    Science.gov (United States)

    Frank A. Bennett

    1969-01-01

    Designing unbiased stand density studies is difficult. An acceptable sample requires stratification of the plots of age, site, and density. When basal area, percent stocking, or Reineke's stand density index is used as the density measure, this stratification forces a high negative correlation between site and number of trees per acre. Mortality in trees per acre...

  4. Material and Affective Movements

    DEFF Research Database (Denmark)

    Rasmussen, Lisa Rosén

    2014-01-01

    . The chapter traces the former pupil’s memories of physical and affective movements within the larger context of school and discovers surprisingly diverse modes of knowing, relating, and attending to things, teachers and classmates among and between the three generations. It thus taps into the rich realms...

  5. Factors affecting soil cohesion

    Science.gov (United States)

    Soil erodibility is a measure of a soil’s resistance against erosive forces and is affected by both intrinsic (or inherent) soil property and the extrinsic condition at the time erodibility measurement is made. Since soil erodibility is usually calculated from results obtained from erosion experimen...

  6. What Variables Affect Solubility?

    Science.gov (United States)

    Baker, William P.; Leyva, Kathryn

    2003-01-01

    Helps middle school students understand the concept of solubility through hands-on experience with a variety of liquids and solids. As they explore factors that affect solubility and saturation, students gain content mastery and an understanding of the inquiry process. Also enables teachers to authentically assess student performance on several…

  7. Personalized affective music player

    NARCIS (Netherlands)

    Janssen, Joris H.; van den Broek, Egon; Westerink, Joyce H.D.M.; Cohn, J.; Nijholt, Antinus; Pantic, Maja

    2009-01-01

    We introduce and test an affective music player (AMP) that selects music for mood enhancement. Through a concise overview of content, construct, and ecological validity, we elaborate five considerations that form the foundation of the AMP. Based on these considerations, computational models are

  8. Examining the occupancy–density relationship for a low-density carnivore

    Science.gov (United States)

    Linden, Daniel W.; Fuller, Angela K.; Royle, J. Andrew; Hare, Matthew P.

    2017-01-01

    -mixed forest and negatively associated with road density. As a result, spatially explicit management recommendations for fisher were similar across models, though relative variation was dampened for the detection–non-detection data.Synthesis and applications. Our work provides empirical evidence that models using detection–non-detection data can make similar inferences regarding relative spatial variation of the focal population to models using more expensive individual encounters when the selected spatial grain approximates or is marginally smaller than home range size. When occupancy alone is chosen as a cost-effective state variable for monitoring, simulation and sensitivity analyses should be used to understand how inferences from detection–non-detection data will be affected by aspects of study design and species ecology.

  9. Dynamic Synchronization of Teacher-Students Affection in Affective Instruction

    Science.gov (United States)

    Zhang, Wenhai; Lu, Jiamei

    2011-01-01

    Based on Bower's affective network theory, the article links the dynamic analysis of affective factors in affective instruction, and presents affective instruction strategic of dynamic synchronization between teacher and students to implement the best ideal mood that promotes students' cognition and affection together. In the process of teaching,…

  10. Low larval densities in northern populations reinforce range expansion by a Mediterranean damselfly

    DEFF Research Database (Denmark)

    Therry, Lieven; Swaegers, Janne; Dinh, Khuong Van

    2016-01-01

    towards the very edge of the expansion front has been neglected. Density effects may, however, have a profound direct impact on traits involved in range expansion and influence range dynamics. 2. In this study, we contrast the effects of high conspecific larval density typical for established populations...... and low larval density typical for newly founded populations at the edge of the expansion front on a set of larval traits that may affect the range dynamics in the poleward moving damselfly Coenagrion scitulum. We therefore ran an outdoor mesocosm experiment with a low- and high-density treatment close...... in voltinism) at low conspecific density will translate in increased population growth rates. Furthermore, nutritional advantages at low conspecific density may increase investment in dispersal ability. Together, these direct and delayed density-dependent effects that gradually increase towards the expansion...

  11. Beyond the local density approximation : improving density functional theory for high energy density physics applications.

    Energy Technology Data Exchange (ETDEWEB)

    Mattsson, Ann Elisabet; Modine, Normand Arthur; Desjarlais, Michael Paul; Muller, Richard Partain; Sears, Mark P.; Wright, Alan Francis

    2006-11-01

    A finite temperature version of 'exact-exchange' density functional theory (EXX) has been implemented in Sandia's Socorro code. The method uses the optimized effective potential (OEP) formalism and an efficient gradient-based iterative minimization of the energy. The derivation of the gradient is based on the density matrix, simplifying the extension to finite temperatures. A stand-alone all-electron exact-exchange capability has been developed for testing exact exchange and compatible correlation functionals on small systems. Calculations of eigenvalues for the helium atom, beryllium atom, and the hydrogen molecule are reported, showing excellent agreement with highly converged quantumMonte Carlo calculations. Several approaches to the generation of pseudopotentials for use in EXX calculations have been examined and are discussed. The difficult problem of finding a correlation functional compatible with EXX has been studied and some initial findings are reported.

  12. The Influence of Flame Retardant Treated Timber Density on Combustibility

    Directory of Open Access Journals (Sweden)

    Zbignev Karpovič

    2011-04-01

    Full Text Available Timber is widely used as a construction material in the majority of countries. In most cases, timber is the main structural material. Timber and timber fabrics used in building structure elements have to fulfill the requirements of fire safety. This article presents factors affecting the combustibility of timber, mainly the influence of flame retardants on the combustion phase, timber density and moisture. The influence of flame retardant treated timber density on combustibility is analyzed in this paper. Research was performed according to the requirements of the standard LST ISO 5657:1999 “Reaction to fire tests – ignitibility of building products using a radiant heat source”. The influence of flame retardant treated timber density on combustibility is assessed according to duration up to the combustion of the specimen. Article in Lithuanian

  13. Simulation of density measurements in plasma wakefields using photo acceleration

    CERN Document Server

    Kasim, Muhammad Firmansyah; Ceurvorst, Luke; Sadler, James; Burrows, Philip N; Trines, Raoul; Holloway, James; Wing, Matthew; Bingham, Robert; Norreys, Peter

    2015-01-01

    One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  14. Simulation of density measurements in plasma wakefields using photon acceleration

    Directory of Open Access Journals (Sweden)

    Muhammad Firmansyah Kasim

    2015-03-01

    Full Text Available One obstacle in plasma accelerator development is the limitation of techniques to diagnose and measure plasma wakefield parameters. In this paper, we present a novel concept for the density measurement of a plasma wakefield using photon acceleration, supported by extensive particle in cell simulations of a laser pulse that copropagates with a wakefield. The technique can provide the perturbed electron density profile in the laser’s reference frame, averaged over the propagation length, to be accurate within 10%. We discuss the limitations that affect the measurement: small frequency changes, photon trapping, laser displacement, stimulated Raman scattering, and laser beam divergence. By considering these processes, one can determine the optimal parameters of the laser pulse and its propagation length. This new technique allows a characterization of the density perturbation within a plasma wakefield accelerator.

  15. Laser Propagation in Nanostructured Ultra-Low-Density Materials

    Energy Technology Data Exchange (ETDEWEB)

    Fournier, K. B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Colvin, J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Yogo, A [Osaka Univ. (Japan). Inst. of Laser Engineering; Kemp, G. E. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Matsukuma, H. [Osaka Univ. (Japan). Inst. of Laser Engineering; Tanaka, N. [Osaka Univ. (Japan). Inst. of Laser Engineering; Zhang, Z. [Osaka Univ. (Japan). Inst. of Laser Engineering; Koga, K. [Osaka Univ. (Japan). Inst. of Laser Engineering; Tosaki, S. [Osaka Univ. (Japan). Inst. of Laser Engineering; Nishimura, H. [Osaka Univ. (Japan). Inst. of Laser Engineering

    2016-03-15

    The nanostructure of very-low-density aerogels (< 10 mg/cm3) affects the laser heating and propagation of the subsequent heat front. Simulations treat these materials as an atomistic medium without any structure differentiating between near-solid-density material and voids. Thus, simulations fail to predict the effects of the aerogel’s physical micro or nanostructure on the laser-matter interaction. We have designed an experiment using the GEKKO XII laser and ILE diagnostics to characterize the ionization-wave propagation and x-ray yield from aerogel and mass-matched gaseous targets as the laser passes through each. By design, the gas and aerogel targets will have identical densities and identical effective ionization states.

  16. Automated Volumetric Mammographic Breast Density Measurements May Underestimate Percent Breast Density for High-density Breasts.

    Science.gov (United States)

    Rahbar, Kareem; Gubern-Merida, Albert; Patrie, James T; Harvey, Jennifer A

    2017-12-01

    The purpose of this study was to evaluate discrepancy in breast composition measurements obtained from mammograms using two commercially available software methods for systematic trends in overestimation or underestimation compared to magnetic resonance-derived measurements. An institutional review board-approved, Health Insurance Portability and Accountability Act-compliant retrospective study was performed to calculate percent breast density (PBD) by quantifying fibroglandular volume and total breast volume derived from magnetic resonance imaging (MRI) segmentation and mammograms using two commercially available software programs (Volpara and Quantra). Consecutive screening MRI exams from a 6-month period with negative or benign findings were used. The most recent mammogram within 9 months was used to derive mean density values from "for processing" images at the per breast level. Bland-Altman statistical analyses were performed to determine the mean discrepancy and the limits of agreement. A total of 110 women with 220 breasts met the study criteria. Overall, PBD was not different between MRI (mean 10%, range 1%-41%) and Volpara (mean 10%, range 3%-29%); a small but significant difference was present in the discrepancy between MRI and Quantra (4.0%, 95% CI: 2.9 to 5.0, P breast densities, with Volpara slightly underestimating and Quantra slightly overestimating PBD compared to MRI. The mean discrepancy for both Volpara and Quantra for total breast volume was not significantly different from MRI (p = 0.89, 0.35, respectively). Volpara tended to underestimate, whereas Quantra tended to overestimate fibroglandular volume, with the highest discrepancy at higher breast volumes. Both Volpara and Quantra tend to underestimate PBD, which is most pronounced at higher densities. PBD can be accurately measured using automated volumetric software programs, but values should not be used interchangeably between vendors. Copyright © 2017. Published by Elsevier Inc.

  17. A two-population sporadic meteoroid bulk density distribution and its implications for environment models

    Science.gov (United States)

    Moorhead, Althea V.; Blaauw, Rhiannon C.; Moser, Danielle E.; Campbell-Brown, Margaret D.; Brown, Peter G.; Cooke, William J.

    2017-12-01

    The bulk density of a meteoroid affects its dynamics in space, its ablation in the atmosphere, and the damage it does to spacecraft and lunar or planetary surfaces. Meteoroid bulk densities are also notoriously difficult to measure, and we are typically forced to assume a density or attempt to measure it via a proxy. In this paper, we construct a density distribution for sporadic meteoroids based on existing density measurements. We considered two possible proxies for density: the KB parameter introduced by Ceplecha and Tisserand parameter, TJ. Although KB is frequently cited as a proxy for meteoroid material properties, we find that it is poorly correlated with ablation-model-derived densities. We therefore follow the example of Kikwaya et al. in associating density with the Tisserand parameter. We fit two density distributions to meteoroids originating from Halley-type comets (TJ 2); the resulting two-population density distribution is the most detailed sporadic meteoroid density distribution justified by the available data. Finally, we discuss the implications for meteoroid environment models and spacecraft risk assessments. We find that correcting for density increases the fraction of meteoroid-induced spacecraft damage produced by the helion/antihelion source.

  18. Density-dependent benefits in ant-hemipteran mutualism? The case of the ghost ant Tapinoma melanocephalum (Hymenoptera: Formicidae) and the invasive mealybug Phenacoccus solenopsis (Hemiptera: Pseudococcidae).

    Science.gov (United States)

    Zhou, Aiming; Kuang, Beiqing; Gao, Yingrui; Liang, Guangwen

    2015-01-01

    Although density-dependent benefits to hemipterans from ant tending have been measured many times, few studies have focused on integrated effects such as interactions between ant tending, natural enemy density, and hemipteran density. In this study, we tested whether the invasive mealybug Phenacoccus solenopsis is affected by tending by ghost ants (Tapinoma melanocephalum), the presence of parasitoids, mealybug density, parasitoid density and interactions among these factors. Our results showed that mealybug colony growth rate and percentage parasitism were significantly affected by ant tending, parasitoid presence, and initial mealybug density separately. However, there were no interactions among the independent factors. There were also no significant interactions between ant tending and parasitoid density on either mealybug colony growth rate or percentage parasitism. Mealybug colony growth rate showed a negative linear relationship with initial mealybug density but a positive linear relationship with the level of ant tending. These results suggest that benefits to mealybugs are density-independent and are affected by ant tending level.

  19. Affect in electoral politics.

    Science.gov (United States)

    Glaser, J; Salovey, P

    1998-01-01

    Recent U.S. history provides vivid illustrations of the importance of politicians' emotional displays in subsequent judgments of them. Yet, a review of empirical research on the role of affect (emotion, mood, and evaluation) in electoral politics reveals little work that has focused on the impact of candidates' emotional expression on voters' preferences for them. A theoretical framework is proposed to identify psychological mechanisms by which a target's displays of emotion influence judgments of that target. Findings from the emerging literature on emotions and politics challenge the traditional assumption of political science that voters make decisions based solely on the cold consideration of nonaffectively charged information. The affect and politics literature, although somewhat unfocused and broad, represents an interdisciplinary domain of study that contributes to the understanding of both electoral politics and social interaction more generally.

  20. TRACTOGRAPHY DENSITY AND NETWORK MEASURES IN ALZHEIMER'S DISEASE.

    Science.gov (United States)

    Prasad, Gautam; Nir, Talia M; Toga, Arthur W; Thompson, Paul M

    2013-04-01

    Brain connectivity declines in Alzheimer's disease (AD), both functionally and structurally. Connectivity maps and networks derived from diffusion-based tractography offer new ways to track disease progression and to understand how AD affects the brain. Here we set out to identify (1) which fiber network measures show greatest differences between AD patients and controls, and (2) how these effects depend on the density of fibers extracted by the tractography algorithm. We computed brain networks from diffusion-weighted images (DWI) of the brain, in 110 subjects (28 normal elderly, 56 with early and 11 with late mild cognitive impairment, and 15 with AD). We derived connectivity matrices and network topology measures, for each subject, from whole-brain tractography and cortical parcellations. We used an ODF lookup table to speed up fiber extraction, and to exploit the full information in the orientation distribution function (ODF). This made it feasible to compute high density connectivity maps. We used accelerated tractography to compute a large number of fibers to understand what effect fiber density has on network measures and in distinguishing different disease groups in our data. We focused on global efficiency, transitivity, path length, mean degree, density, modularity, small world, and assortativity measures computed from weighted and binary undirected connectivity matrices. Of all these measures, the mean nodal degree best distinguished diagnostic groups. High-density fiber matrices were most helpful for picking up the more subtle clinical differences, e.g. between mild cognitively impaired (MCI) and normals, or for distinguishing subtypes of MCI (early versus late). Care is needed in clinical analyses of brain connectivity, as the density of extracted fibers may affect how well a network measure can pick up differences between patients and controls.

  1. Offsetting the Affective Filter

    Directory of Open Access Journals (Sweden)

    Barry Chametzky, PhD

    2017-06-01

    Full Text Available When forced to deal with a stressful, unfamiliar situation, how do people react? People are familiar, in a traditional setting, with sensory overload. But in an online environment, when learners are anxious, they exhibit different behaviors to help mediate their anxiety. Additionally, in an online environment, since visual clues are often lacking, how do these behaviors manifest themselves? People navigate stressful and/or unfamiliar situations by offsetting their affective filter.

  2. Density estimation in wildlife surveys

    Science.gov (United States)

    Bart, Jonathan; Droege, Sam; Geissler, Paul E.; Peterjohn, Bruce G.; Ralph, C. John

    2004-01-01

    Several authors have recently discussed the problems with using index methods to estimate trends in population size. Some have expressed the view that index methods should virtually never be used. Others have responded by defending index methods and questioning whether better alternatives exist. We suggest that index methods are often a cost-effective component of valid wildlife monitoring but that double-sampling or another procedure that corrects for bias or establishes bounds on bias is essential. The common assertion that index methods require constant detection rates for trend estimation is mathematically incorrect; the requirement is no long-term trend in detection "ratios" (index result/parameter of interest), a requirement that is probably approximately met by many well-designed index surveys. We urge that more attention be given to defining bird density rigorously and in ways useful to managers. Once this is done, 4 sources of bias in density estimates may be distinguished: coverage, closure, surplus birds, and detection rates. Distance, double-observer, and removal methods do not reduce bias due to coverage, closure, or surplus birds. These methods may yield unbiased estimates of the number of birds present at the time of the survey, but only if their required assumptions are met, which we doubt occurs very often in practice. Double-sampling, in contrast, produces unbiased density estimates if the plots are randomly selected and estimates on the intensive surveys are unbiased. More work is needed, however, to determine the feasibility of double-sampling in different populations and habitats. We believe the tension that has developed over appropriate survey methods can best be resolved through increased appreciation of the mathematical aspects of indices, especially the effects of bias, and through studies in which candidate methods are evaluated against known numbers determined through intensive surveys.

  3. Leptin and bone mineral density

    DEFF Research Database (Denmark)

    Morberg, Cathrine M.; Tetens, Inge; Black, Eva

    2003-01-01

    Leptin has been suggested to decrease bone mineral density (BMD). This observational analysis explored the relationship between serum leptin and BMD in 327 nonobese men (controls) (body mass index 26.1 +/- 3.7 kg/m(2), age 49.9 +/- 6.0 yr) and 285 juvenile obese men (body mass index 35.9 +/- 5.9 kg...... with BMD in the control group, whereas in the juvenile obese, only lean body mass was positively associated with BMD and smoking negatively associated with BMD. Our study supports that leptin is inversely associated with BMD and may play a direct role in the bone metabolism in nonobese and obese Danish...

  4. Variable Density Turbulence Tunnel Facility

    OpenAIRE

    Bodenschatz, Eberhard; Bewley, Gregory P.; Nobach, Holger; Sinhuber, Michael; Xu, Haitao

    2014-01-01

    The Variable Density Turbulence Tunnel (VDTT) at the Max Planck Institute for Dynamics and Self-Organization in G\\"ottingen, Germany produces very high turbulence levels at moderate flow velocities, low power consumption and adjustable kinematic viscosity between $10^{-4} m^2/s$ and $10^{-7} m^2/s$. The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. The highest kinematic viscosities, and hence lowest Reyn...

  5. Bone Density in Peripubertal Boys with Autism Spectrum Disorders

    Science.gov (United States)

    Neumeyer, Ann M.; Gates, Amy; Ferrone, Christine; Lee, Hang; Misra, Madhusmita

    2013-01-01

    We determined whether bone mineral density (BMD) is lower in boys with autism spectrum disorders (ASD) than controls, and also assessed variables that may affect BMD in ASD. BMD was measured using dual energy X-ray absorptiometry (DXA) in 18 boys with ASD and 19 controls 8-14 years old. Boys with ASD had lower BMD Z-scores at the spine, hip and…

  6. Proton and neutron density distributions at supranormal density in low- and medium-energy heavy-ion collisions

    Science.gov (United States)

    Stone, J. R.; Danielewicz, P.; Iwata, Y.

    2017-07-01

    energies was ˜0.17 . Conclusions: We find that the initial state, beam energy, system size, and a symmetry energy model affect very little the maximum proton and neutron densities, but have a subtle impact on the proton-neutron asymmetry. Most importantly, the variations in the proton-neutron asymmetry at maximum densities are related at most at 50% level to the details in the symmetry energy at supranormal density. The reminder is due to the details in the symmetry energy at subnormal densities and proton and neutron distributions in the initial state. This result brings to the forefront the need for a proper initialization of the nuclei in the simulation, but also brings up the question of microscopy, such as shell effects, that affect initial proton and neutron densities, but cannot be consistently incorporated into semiclassical transport models.

  7. Affective monitoring: A generic mechanism for affect elicitation

    National Research Council Canada - National Science Library

    Phaf, R.H; Rotteveel, M

    2012-01-01

    .... Negative affect is raised instantly by mismatches, incongruency, disfluency, novelty, incoherence, and dissonance, whereas positive affect follows from matches, congruency, fluency, familiarity...

  8. Graduate density, gender, and employment.

    Science.gov (United States)

    Brynin, Malcolm

    2002-09-01

    The expansion of higher education is often viewed as reflecting increased demand for skills, whether related to technological change or the growing complexity of the economy. It is also linked to widening pay differentials between the poorly and highly educated. There are reasons, however, to question these associations. Even if demand for graduates is growing the supply of graduates might as a result of the status derived from having a degree still exceed this. The demand for graduates itself need not be wholly tied in with upgrading of the labour force. Graduates could be part of a more flexible workforce who increasingly undertake non-graduate work, thus downgrading their labour-market position. LFS (Labour Force Survey) and BHPS (British Household Panel Study) data are used to show that there has been no major shift in the distribution of graduates in the British labour market, that career starts are increasingly at a lower status point, and that there is a negative effect of graduate density on wages. There are also redistributional effects. There has been a large increase in the social demand for higher education by women, and they have gained from this expansion while men have lost out. In addition, graduate density is positive for non-graduates, who gain from the reduced rewards accruing to graduates. The results call into question the simple idea of a trend towards a demand for increasing levels of skills and qualifications. More attention should be paid to the distribution of skills and to complex interactions within this.

  9. Density functional theory: Foundations reviewed

    Energy Technology Data Exchange (ETDEWEB)

    Kryachko, Eugene S., E-mail: eugene.kryachko@ulg.ac.be [Bogolyubov Institute for Theoretical Physics, Kiev, 03680 (Ukraine); Ludeña, Eduardo V., E-mail: popluabe@yahoo.es [Centro de Química, Instituto Venezolano de Investigaciones Científicas, IVIC, Apartado 21827, Caracas 1020-A (Venezuela, Bolivarian Republic of); Prometheus Program, Senescyt (Ecuador); Grupo Ecuatoriano para el Estudio Experimental y Teórico de Nanosistemas, GETNano, USFQ, N104-E, Quito (Ecuador); Escuela Politécnica Superior del Litoral, ESPOL, Guayaquil (Ecuador)

    2014-11-10

    Guided by the above motto (quotation), we review a broad range of issues lying at the foundations of Density Functional Theory, DFT, a theory which is currently omnipresent in our everyday computational study of atoms and molecules, solids and nano-materials, and which lies at the heart of modern many-body computational technologies. The key goal is to demonstrate that there are definitely the ways to improve DFT. We start by considering DFT in the larger context provided by reduced density matrix theory (RDMT) and natural orbital functional theory (NOFT), and examine the implications that N-representability conditions on the second-order reduced density matrix (2-RDM) have not only on RDMT and NOFT but, also, by extension, on the functionals of DFT. This examination is timely in view of the fact that necessary and sufficient N-representability conditions on the 2-RDM have recently been attained. In the second place, we review some problems appearing in the original formulation of the first Hohenberg–Kohn theorem which is still a subject of some controversy. In this vein we recall Lieb’s comment on this proof and the extension to this proof given by Pino et al. (2009), and in this context examine the conditions that must be met in order that the one-to-one correspondence between ground-state densities and external potentials remains valid for finite subspaces (namely, the subspaces where all Kohn–Sham solutions are obtained in practical applications). We also consider the issue of whether the Kohn–Sham equations can be derived from basic principles or whether they are postulated. We examine this problem in relation to ab initio DFT. The possibility of postulating arbitrary Kohn–Sham-type equations, where the effective potential is by definition some arbitrary mixture of local and non-local terms, is discussed. We also deal with the issue of whether there exists a universal functional, or whether one should advocate instead the construction of problem

  10. The Nutrient Density of Snacks

    Directory of Open Access Journals (Sweden)

    Julie Hess BA

    2017-03-01

    Full Text Available Background: Although Americans receive almost a quarter of their daily energy from snacks, snacking remains a poorly defined and understood eating occasion. However, there is little dietary guidance about choosing snacks. Families, clinicians, and researchers need a comprehensive approach to assessing their nutritional value. Objective: To quantify and compare the nutrient density of commonly consumed snacks by their overall nutrient profiles using the Nutrient-Rich Foods (NRF Index 10.3. Methods: NRF Index scores were calculated for the top 3 selling products (based on 2014 market research data in different snack categories. These NRF scores were averaged to provide an overall nutrient-density score for each category. Results: Based on NRF scores, yogurt (55.3, milk (52.5, and fruit (30.1 emerged as the most nutrient-dense snacks. Ice cream (−4.4, pies and cakes (−11.1, and carbonated soft drinks (−17.2 emerged as the most nutrient-poor snacks. Conclusions: The NRF Index is a useful tool for assessing the overall nutritional value of snacks based on nutrients to limit and nutrients to encourage.

  11. Communication: Quasi-robust local density fitting.

    Science.gov (United States)

    Tew, David P

    2018-01-07

    The requirement that the linear density fitting error in the integral exactly vanishes introduces unphysical long range contributions to the approximate density when the auxiliary basis is incomplete. A quasi-robust density fitting formulation is presented where spatial locality is recovered at the expense of permitting a linear error that is made small by the fitting procedure, which involves optimising the Coulomb potential of the approximate charge density. The method is shown to be stable and almost as accurate as standard robust density fitting without local approximations in practical calculations using standard density fitting basis sets.

  12. Social and Affective Robotics Tutorial

    NARCIS (Netherlands)

    Pantic, Maja; Evers, Vanessa; Deisenroth, Marc; Merino, Luis; Schuller, Björn

    2016-01-01

    Social and Affective Robotics is a growing multidisciplinary field encompassing computer science, engineering, psychology, education, and many other disciplines. It explores how social and affective factors influence interactions between humans and robots, and how affect and social signals can be

  13. Reducing the graphene grain density in three steps

    Science.gov (United States)

    Hsieh, Ya-Ping; Chu, Yi-Hung; Tsai, He-Guang; Hofmann, Mario

    2016-03-01

    The production of large-scale, single crystalline graphene is a requirement for enhancing its electronic, mechanical, and chemical properties. Chemical vapor deposition (CVD) has shown the potential to grow high quality graphene but the simultaneous nucleation of many grains limits their achievable domain size. We report here that ultralow nucleation densities can be achieved through multi-step optimization of the catalyst morphology. First, annealing in a hydrogen-free environment is required to retain a surface copper oxide which decreases the nucleation density. Second, CuO was found to be the relevant copper species for this process and air oxidation of the copper foil at 200 °C maximizes its concentration. Both pre-treatment steps were found to affect the morphology of the catalyst and a direct correlation between nucleation density and surface roughness was found which indicates that the primary role of the oxidation step is the decrease in catalyst roughness. To further enhance this determining parameter, confined CVD was carried out after sample oxidation and hydrogen-free annealing. Each of these three steps reduces the grain density by approximately one order of magnitude resulting in ultralow nucleation densities of 1.23 grains/mm2 and high quality, single-crystalline graphene grains of several millimeter sizes were grown using this method.

  14. Role of turbulence regime on determining the local density gradient

    Science.gov (United States)

    Wang, X.; Mordijck, S.; Doyle, E. J.; Zeng, L.; Staebler, G. M.; Meneghini, O.; Smith, S. P.

    2018-01-01

    In this paper we show that the local density gradient in the plasma core depends on the calculated mode-frequency of the most unstable linear mode and reaches a maximum when this frequency is close to zero. Previous theoretical and experimental work on AUG has shown that the ratio of electron to ion temperature, and as such the frequency of the dominant linear gyrokinetic mode, affects the local density gradient close to ρ = 0.3 (Fable et al 2010 Plasma Phys. Control. Fusion 52 015007, Angioni et al 2011 Nucl. Fusion 51 023006). On DIII-D we find that by adding electron cyclotron heating, we modify the dominant unstable linear gyrokinetic mode from an ion temperature gradient (ITG) mode to a trapped electron mode (TEM), which means that the frequency of the dominant mode changes sign (from the ion to the electron direction). Local density peaking around mid-radius increases by 50% right around the cross-over between the ITG and TEM regimes. By comparing how the particle flux changes, through the derivative of the electron density, n e , with respect to time, \\partial n_e/\\partial t , we find that the particle flux also exhibits the same trend versus mode frequency. As a result, we find that the changes in local particle transport are inversely proportional to the changes in electron density, indicating that the changes are driven by a change in thermo-diffusive pinch.

  15. Ionospheric topside models compared with experimental electron density profiles

    Directory of Open Access Journals (Sweden)

    S. M. Radicella

    2005-06-01

    Full Text Available Recently an increasing number of topside electron density profiles has been made available to the scientific community on the Internet. These data are important for ionospheric modeling purposes, since the experimental information on the electron density above the ionosphere maximum of ionization is very scarce. The present work compares NeQuick and IRI models with the topside electron density profiles available in the databases of the ISIS2, IK19 and Cosmos 1809 satellites. Experimental electron content from the F2 peak up to satellite height and electron densities at fixed heights above the peak have been compared under a wide range of different conditions. The analysis performed points out the behavior of the models and the improvements needed to be assessed to have a better reproduction of the experimental results. NeQuick topside is a modified Epstein layer, with thickness parameter determined by an empirical relation. It appears that its performance is strongly affected by this parameter, indicating the need for improvements of its formulation. IRI topside is based on Booker's approach to consider two parts with constant height gradients. It appears that this formulation leads to an overestimation of the electron density in the upper part of the profiles, and overestimation of TEC.

  16. Seeding density in wheat: the more, the merrier?

    Directory of Open Access Journals (Sweden)

    Igor Pirez Valério

    2013-06-01

    Full Text Available Adjustment of seeding schemes is one of the crop management techniques that most influences grain yield components. This work aimed to characterize the potential grain yield and its components in wheat (Triticum aestivum L. genotypes with contrasting tillering ability under different seeding densities and environments. Five experiments were conducted in split-plot design, each with ten cultivars (main plot, sown in five distinct seeding densities (subplots. Experiments were sown in three locations in southern Brazil in the years 2005, 2006 and 2007. The grain yield per plot and its yield components: number of fertile tillers, weight of 1,000 grains, ear weight and number of grains per ear were evaluated. Genotypes with reduced tillering ability expressed an increase in grain yield with an increase in seeding densities, however showing a reduction in ear weight. The number of grains per ear did not affect grain yield but was highly influenced by seeding densities. The compensatory effect was expressed by the weight of a thousand grains as a function of the experimental conditions in which the genotypes were evaluated, regardless of seeding densities used. Results pointed to differences among cultivars tested in specific locations and years.

  17. Influence of stocking density on growth, body composition and energy budget of Atlantic salmon Salmo salar L. in recirculating aquaculture systems

    Science.gov (United States)

    Liu, Baoliang; Liu, Ying; Liu, Ziyi; Qiu, Denggao; Sun, Guoxiang; Li, Xian

    2014-09-01

    Atlantic salmon Salmo salar were reared at four stocking densities—high density D 1 (final density ˜39 kg/m3), medium densities D 2 (˜29 kg/m3) and D 3 (˜19 kg/m3), and low density D 4 (˜12 kg/m3)—for 40 days to investigate the effect of stocking density on their growth performance, body composition and energy budgets. Stocking density did not significantly affect specific growth rate in terms of weight (SGRw) but did affect specific growth rate in terms of energy (SGRe). Stocking density significantly influenced the ration level (RLw and RLe), feed conversion ratio (FCRw and FCRe) and apparent digestibility rate (ADR). Ration level and FCRw tended to increase with increasing density. Fish at the highest density D 1 and lowest density D 4 showed lower FCRe and higher ADR than at medium densities. Stocking density significantly affected protein and energy contents of the body but did not affect its moisture, lipid, or ash contents. The expenditure of energy for metabolism in the low-density and high-density groups was lower than that in the medium-density groups. Stocking density affected energy utilization from the feces but had no effect on excretion rate. The greater energy allocation to growth at high density and low density may be attributed to reduced metabolic rate and increased apparent digestibility rate. These findings provide information that will assist selection of suitable stocking densities in the Atlantic-salmon-farming industry.

  18. Density modulation-induced absolute laser-plasma-instabilities: simulations and theory

    CERN Document Server

    Li, J; Ren, C

    2016-01-01

    Fluid simulations show that when a sinusoidal density modulation is superimposed on a linear density profile, convective instabilities can become absolutely unstable. This conversion can occur for two-plasmon-decay and stimulated Raman Scattering instabilities under realistic direct-drive inertial confinement fusion conditions and can affect hot electron generation and laser energy deposition. Analysis of the three-wave model shows that a sufficiently large change of the density gradient in a linear density profile can turn convective instabilities into absolute ones. An analytical expression is given for the threshold of the gradient change, which depends on the convective gain only.

  19. The relation between food price, energy density and diet quality

    Directory of Open Access Journals (Sweden)

    Margareta Bolarić

    2013-01-01

    Full Text Available Low energy density diet, high in fruits and vegetables, is related to lower obesity risk and to better health status, but is more expensive. High energy density diet, high in added sugar and fats, is more affordable, but is related to higher obesity and chronic diseases risk. The aim of this study was to report prices according to energy density (low vs. high of food items and to show how food affordability could affect food choice and consumers’ health. Data was collected for 137 raw and processed foods from three purchase sites in Zagreb (one representative for supermarket, one smaller shop and green market. Results showed that low energy density food is more expensive than high energy density food (for example, the price of 1000 kcal from green zucchini (15 kcal/100 g is 124.20 kn while the price of 1000 kcal from sour cream (138 kcal/100 g is 13.99 kn. Food energy price was significantly different (p<0.05 between food groups with highest price for vegetable products (159.04 ± 36.18 kn/1000 kcal and raw vegetables (97.90 ± 50.13 kn/1000 kcal and lowest for fats (8.49 ± 1.22 kn/1000 kcal and cereals and products (5.66 ± 0.76 kn/1000 kcal. Negative correlation (Spearman r=-0.72, p<0.0001 was observed for energy density (kcal/100 g and price of 1000 kcal. Therefore, it is advisable to develop strategies in order to reduce price of low energy density food and encourage its intake since it would improve diet quality, which could lead to better costumers’ health.

  20. Risk, Affect and Emotion

    Directory of Open Access Journals (Sweden)

    Jens O. Zinn

    2006-01-01

    Full Text Available For a long time theorising has underestimated the importance of affect and emotion in decision making and the management of risk and uncertainty. In relatively one-sided interpretations emotions were often interpreted as threats for rational decision making, and could be triggered by uncertainties, which would go along with social change. Recent interdisciplinary research has shown the importance to acknowledge the more complex link between reasoning and emotions. The article outlines different perspectives on emotion in risk research of economics, psychology and sociology and argues for further research. URN: urn:nbn:de:0114-fqs0601293

  1. Assistive Technology and Affective Mediation

    OpenAIRE

    Nestor Garay; Idoia Cearreta; Juan Miguel López; Inmaculada Fajardo

    2006-01-01

    The lack of attention towards affective communication in assistive technology and disability research can be potentially overcome thanks to the development of affective computing and affective mediation areas. This document describes the main impairments and disorders that may involve affective communication deficits. We also present several affective mediation technologies that are being applied or may be integrated in assistive technologies in order to improve affective communication for a ...

  2. Imaging Breast Density: Established and Emerging Modalities

    Directory of Open Access Journals (Sweden)

    Jeon-Hor Chen

    2015-12-01

    Full Text Available Mammographic density has been proven as an independent risk factor for breast cancer. Women with dense breast tissue visible on a mammogram have a much higher cancer risk than women with little density. A great research effort has been devoted to incorporate breast density into risk prediction models to better estimate each individual’s cancer risk. In recent years, the passage of breast density notification legislation in many states in USA requires that every mammography report should provide information regarding the patient’s breast density. Accurate definition and measurement of breast density are thus important, which may allow all the potential clinical applications of breast density to be implemented. Because the two-dimensional mammography-based measurement is subject to tissue overlapping and thus not able to provide volumetric information, there is an urgent need to develop reliable quantitative measurements of breast density. Various new imaging technologies are being developed. Among these new modalities, volumetric mammographic density methods and three-dimensional magnetic resonance imaging are the most well studied. Besides, emerging modalities, including different x-ray–based, optical imaging, and ultrasound-based methods, have also been investigated. All these modalities may either overcome some fundamental problems related to mammographic density or provide additional density and/or compositional information. The present review article aimed to summarize the current established and emerging imaging techniques for the measurement of breast density and the evidence of the clinical use of these density methods from the literature.

  3. How do humans affect wildlife nematodes?

    Science.gov (United States)

    Weinstein, Sara B; Lafferty, Kevin D

    2015-05-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host-parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. How do humans affect wildlife nematodes?

    Science.gov (United States)

    Weinstein, Sara B.; Lafferty, Kevin D.

    2015-01-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host–parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

  5. Review of non-nuclear density gauges as possible replacements for ITD's nuclear density gauges.

    Science.gov (United States)

    2015-01-01

    This report examines the possibility of replacing nuclear density gauges (NDGs) with non-nuclear density gauges (NNDGs) to : measure density of hot mix asphalt (HMA) and unbound pavement layers in the field. The research team evaluated the : effectiv...

  6. Sleep affects cortical source modularity in temporal lobe epilepsy: A high-density EEG study.

    Science.gov (United States)

    Del Felice, Alessandra; Storti, Silvia Francesca; Manganotti, Paolo

    2015-09-01

    Interictal epileptiform discharges (IEDs) constitute a perturbation of ongoing cerebral rhythms, usually more frequent during sleep. The aim of the study was to determine whether sleep influences the spread of IEDs over the scalp and whether their distribution depends on vigilance-related modifications in cortical interactions. Wake and sleep 256-channel electroencephalography (EEG) data were recorded in 12 subjects with right temporal lobe epilepsy (TLE) differentiated by whether they had mesial or neocortical TLE. Spikes were selected during wake and sleep. The averaged waking signal was subtracted from the sleep signal and projected on a bidimensional scalp map; sleep and wake spike distributions were compared by using a t-test. The superimposed signal of sleep and wake traces was obtained; the rising phase of the spike, the peak, and the deflections following the spike were identified, and their cortical generator was calculated using low-resolution brain electromagnetic tomography (LORETA) for each group. A mean of 21 IEDs in wake and 39 in sleep per subject were selected. As compared to wake, a larger IED scalp projection was detected during sleep in both mesial and neocortical TLE (pEEG deflections followed the spike, the cortical sources of which displayed alternating activations of different cortical areas in wake, substituted by isolated, stationary activations in sleep in mesial TLE and a silencing in neocortical TLE. During sleep, the IED scalp region increases, while cortical interaction decreases. The interaction of cortical modules in sleep and wake in TLE may influence the appearance of IEDs on scalp EEG; in addition, IEDs could be proxies for cerebral oscillation perturbation. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  7. Density of founder cells affects spatial pattern formation and cooperation in Bacillus subtilis biofilms

    NARCIS (Netherlands)

    van Gestel, Jordi; Weissing, Franz J.; Kuipers, Oscar P.; Kovacs, Akos T.

    2014-01-01

    In nature, most bacteria live in surface-attached sedentary communities known as biofilms. Biofilms are often studied with respect to bacterial interactions. Many cells inhabiting biofilms are assumed to express 'cooperative traits', like the secretion of extracellular polysaccharides (EPS). These

  8. Tri-trophic interactions affect density dependence of seed fate in a tropical forest palm

    NARCIS (Netherlands)

    Visser, M.D.; Muller-Landau, H.C.; Wright, J.; Rutten, G.; Jansen, P.A.

    2011-01-01

    Natural enemies, especially host-specific enemies, are hypothesised to facilitate the coexistence of plant species by disproportionately inflicting more damage at increasing host abundance. However, few studies have assessed such Janzen–Connell mechanisms on a scale relevant for coexistence and no

  9. Tri-trophic interactions affect density dependence of seed fate in a tropical forest palm

    NARCIS (Netherlands)

    Visser, Marco D.; Muller-Landau, Helene C.; Wright, S. Joseph; Rutten, Gemma; Jansen, Patrick A.

    2011-01-01

    Natural enemies, especially host-specific enemies, are hypothesised to facilitate the coexistence of plant species by disproportionately inflicting more damage at increasing host abundance. However, few studies have assessed such Janzen-Connell mechanisms on a scale relevant for coexistence and no

  10. Timing and rate of Chaparral treatment affects tall fescue seedhead development and pasture plant densities

    Science.gov (United States)

    The herbicide Chaparral™ has been shown to suppress seedhead development in tall fescue (Neotyphodium coenophialum) pastures and reduce the symptoms of tall fescue toxicosis in cattle. However, little is known about the logistics of herbicide treatment on tall fescue pastures. The objective of thi...

  11. How Does Tree Density Affect Water Loss of Peatlands? A Mesocosm Experiment

    NARCIS (Netherlands)

    Limpens, J.; Holmgren, M.; Jacobs, C.M.J.; Zee, van der S.E.A.T.M.; Karofeld, E.; Berendse, F.

    2014-01-01

    Raised bogs have accumulated more atmospheric carbon than any other terrestrial ecosystem on Earth. Climate-induced expansion of trees and shrubs may turn these ecosystems from net carbon sinks into sources when associated with reduced water tables. Increasing water loss through tree

  12. Dual herbivore attack and herbivore density affect metabolic profiles of Brassica nigra leaves

    NARCIS (Netherlands)

    Ponzio, Camille; Papazian, Stefano; Albrectsen, Benedicte R.; Dicke, Marcel; Gols, Rieta

    2017-01-01

    Plant responses to dual herbivore attack are increasingly studied, but effects on the metabolome have largely been restricted to volatile metabolites and defence-related non-volatile metabolites. However, plants subjected to stress, such as herbivory, undergo major changes in both primary and

  13. Level of threshold weed density does not affect the long-term frequency of weed control.

    NARCIS (Netherlands)

    Wallinga, J.; Oijen, van M.

    1997-01-01

    Weed control thresholds are often presented as a means to reduce unnecessary control measures, thereby increasing the effectiveness of weed management. While the threshold is a useful tool for cost-effective application of control on a single-year base, its role over the longer term is more

  14. Profound effects of population density on fitness-related traits in an invasive freshwater snail.

    Directory of Open Access Journals (Sweden)

    Nicholas Zachar

    Full Text Available Population density can profoundly influence fitness-related traits and population dynamics, and density dependence plays a key role in many prominent ecological and evolutionary hypotheses. Here, we evaluated how individual-level changes in population density affect growth rate and embryo production early in reproductive maturity in two different asexual lineages of Potamopyrgus antipodarum, a New Zealand freshwater snail that is an important model system for ecotoxicology and the evolution of sexual reproduction as well as a potentially destructive worldwide invader. We showed that population density had a major influence on individual growth rate and early-maturity embryo production, effects that were often apparent even when comparing treatments that differed in population density by only one individual. While individual growth rate generally decreased as population density increased, we detected a hump-shaped relationship between embryo production and density, with females from intermediate-density treatments producing the most embryos and females from low- and high-density treatments producing the fewest embryos. The two lineages responded similarly to the treatments, indicating that these effects of population density might apply more broadly across P. antipodarum. These results indicate that there are profound and complex relationships between population density, growth rate, and early-maturity embryo production in at least two lineages of this important model system, with potential implications for the study of invasive populations, research on the maintenance of sex, and approaches used in ecotoxicology.

  15. Density structures inside the plasmasphere: Cluster observations

    Directory of Open Access Journals (Sweden)

    F. Darrouzet

    2004-07-01

    Full Text Available The electron density profiles derived from the EFW and WHISPER instruments on board the four Cluster spacecraft reveal density structures inside the plasmasphere and at its outer boundary, the plasmapause. We have conducted a statistical study to characterize these density structures. We focus on the plasmasphere crossing on 11 April 2002, during which Cluster observed several density irregularities inside the plasmasphere, as well as a plasmaspheric plume. We derive the density gradient vectors from simultaneous density measurements by the four spacecraft. We also determine the normal velocity of the boundaries of the plume and of the irregularities from the time delays between those boundaries in the four individual density profiles, assuming they are planar. These new observations yield novel insights about the occurrence of density irregularities, their geometry and their dynamics. These in-situ measurements are compared with global images of the plasmasphere from the EUV imager on board the IMAGE satellite.

  16. VT Building Density - from E911 ESITE

    Data.gov (United States)

    Vermont Center for Geographic Information — (Link to Metadata) The FacilitiesBuildings_DENSITY data set depicts density for defined types of structures in Vermont. The vector source used to generate the...

  17. Global Population Density Grid Time Series Estimates

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Population Density Grid Time Series Estimates provide a back-cast time series of population density grids based on the year 2000 population grid from SEDAC's...

  18. On thermodynamic limits of entropy densities

    NARCIS (Netherlands)

    Moriya, H; Van Enter, A

    We give some sufficient conditions which guarantee that the entropy density in the thermodynamic limit is equal to the thermodynamic limit of the entropy densities of finite-volume (local) Gibbs states.

  19. Density structures inside the plasmasphere: Cluster observations

    DEFF Research Database (Denmark)

    Darrouzet, F.; Decreau, P.M.E.; De Keyser, J.

    2004-01-01

    The electron density profiles derived from the EFW and WHISPER instruments on board the four Cluster spacecraft reveal density structures inside the plasmasphere and at its outer boundary, the plasmapause. We have conducted a statistical study to characterize these density structures. We focus...... on the plasmasphere crossing on I I April 2002, during which Cluster observed several density irregularities inside the plasmasphere, as well as a plasmaspheric plume. We derive the density gradient vectors from simultaneous density measurements by the four spacecraft. We also determine the normal velocity...... of the boundaries of the plume and of the irregularities from the time delays between those boundaries in the four individual density profiles, assuming they are planar. These new observations yield novel insights about the occurrence of density irregularities, their geometry and their dynamics. These in...

  20. HIV and bone mineral density.

    Science.gov (United States)

    Mallon, Patrick W G

    2010-02-01

    This review details the clinical aspects and pathogenesis of low bone mineral density (BMD) in HIV, discusses broad management issues and outlines areas in which our understanding of this condition is incomplete. Low BMD is prevalent in HIV-infected patients, with traditional risk factors, HIV infection and exposure to antiretroviral therapy all contributing. The role of specific antiretrovirals in the development of low BMD remains controversial, but most changes arise at either antiretroviral therapy initiation or switch. Further research is needed to clarify mechanisms underlying low BMD in HIV, whether low BMD will translate to increased fractures and to determine the correct therapeutic approach to low BMD in HIV, particularly in younger HIV-infected patients.

  1. On the origin of plasma density blobs

    Energy Technology Data Exchange (ETDEWEB)

    Krasheninnikov, S.I., E-mail: skrash@mae.ucsd.edu

    2016-12-01

    By keeping nonlinear Boltzmann factor in electron density dependence on electrostatic potential it is demonstrated that large plasma density blobs, often seen in experiment inside separatrix, can exist within the framework of drift wave dynamics. The estimates show that plasma density in a blob can be ∼3 times higher that average plasma density, but hardly exceeds this limit, which in a ball park is in agreement with experimental observations.

  2. 36 CFR 910.12 - Development density.

    Science.gov (United States)

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Development density. 910.12... DEVELOPMENT AREA Urban Planning and Design Concerns § 910.12 Development density. (a) Land would be developed... density within the building envelope delineated by specific height restrictions, but shall also establish...

  3. Ultimate Energy Densities for Electromagnetic Pulses

    OpenAIRE

    Tsang, Mankei

    2008-01-01

    The ultimate electric and magnetic energy densities that can be attained by bandlimited electromagnetic pulses in free space are calculated using an ab initio quantized treatment, and the quantum states of electromagnetic fields that achieve the ultimate energy densities are derived. The ultimate energy densities also provide an experimentally accessible metric for the degree of localization of polychromatic photons.

  4. Generalized density-functional theory: Conquering the ...

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Chemical Sciences; Volume 117; Issue 5. Generalized density-functional theory: Conquering the -representability problem with exact functionals for the electron pair density and the second-order reduced density matrix. Paul W Ayers Mel Levy. Volume 117 Issue 5 September 2005 pp 507-514 ...

  5. Multisensory Perception of Affect

    Directory of Open Access Journals (Sweden)

    Beatrice de Gelder

    2011-10-01

    Full Text Available Multisensory integration must stand out among the fields of research that have witnessed a most impressive explosion of interest this last decade. One of these new areas of multisensory research concerns emotion. Since our first exploration of this phenomenon (de Gelder et al., 1999 a number of studies have appeared and they have used a wide variety of behavioral, neuropsychological and neuroscientifc methods. The goal of this presentation is threefold. First, we review the research on audiovisual perception of emotional signals from the face and the voice followed by a report or more recent studies on integrating emotional information provided by the voice and whole body expressions. We will also include some recent work on multisensory music perception. In the next section we discuss some methodological and theoretical issues. Finally, we will discuss findings about abnormal affective audiovisual integration in schizophrenia and in autism.

  6. Affective World Literature

    DEFF Research Database (Denmark)

    Vilslev, Annette Thorsen

    The PhD dissertation compares the literary theory and novels of modern Japanese writer Natsume Sōseki. It reads Sōseki’s Theory of Literature (2009, Bungakuron, 1907) as an inherently comparative and interdisciplinary approach to theorizing feelings in world literature. More broadly......, the dissertation investigates the critical negotiation of the novel as a travelling genre in Japan in the beginning of the 20th century, and, more specifically, Sōseki’s work in relation to world literature and affect theory. Sōseki’s work is highly influential in Japan and East Asia, and his novels widely...... circulated beyond Japan. Using Sōseki’s theory as an example, and by comparing it to other theories, the dissertation argues that comparative literature needs to include not only more non-Western literature but also more non-Western literary theories in the ongoing debate of world literature. Close...

  7. Factors Affecting Wound Healing

    Science.gov (United States)

    Guo, S.; DiPietro, L.A.

    2010-01-01

    Wound healing, as a normal biological process in the human body, is achieved through four precisely and highly programmed phases: hemostasis, inflammation, proliferation, and remodeling. For a wound to heal successfully, all four phases must occur in the proper sequence and time frame. Many factors can interfere with one or more phases of this process, thus causing improper or impaired wound healing. This article reviews the recent literature on the most significant factors that affect cutaneous wound healing and the potential cellular and/or molecular mechanisms involved. The factors discussed include oxygenation, infection, age and sex hormones, stress, diabetes, obesity, medications, alcoholism, smoking, and nutrition. A better understanding of the influence of these factors on repair may lead to therapeutics that improve wound healing and resolve impaired wounds. PMID:20139336

  8. [Etiology of affective disorders].

    Science.gov (United States)

    Shinohara, M; Kariya, T

    1994-05-01

    We discussed mainly neurochemical etiology of affective disorders (A.D.). Neurochemically, decreased 5-HT uptake in the platelet, increased 5-HT2 receptor in the platelet and cortex of suicides, increased beta receptor in the brains of suicide, functional abnormality of alpha 2 receptor in clonidine, DMI test, GABAB receptor up-regulation after chronic administration of antidepressants and mood stabilizers, participation of neuropeptide Y, and abnormality of HPA axis were recognized. Moreover, we referred to the importance of psychosocial and genetic factors. As for the etiology of A.D., while predisposition and environment participate, the method of participation will be different in subtypes. Frailty to stress in a broad sense, however is commonly seen in A.D. Though psychosocial factors are important, the physical condition, which involves fatigue, cannot be ignored. And, it is the most important that the biological and genetical factors which cause A.D., in the face of stimuli, must first be elucidated.

  9. Anticipated affect and behavioral choice

    NARCIS (Netherlands)

    Richard, R.; van der Pligt, J.; de Vries, N.K.

    1996-01-01

    Most research on the impact of affect on attitudes and behavior emphasizes the effect of past and present affective reactions. In this article we focus on anticipated, postbehavioral, affective reactions. The influence of anticipated affective reactions on a number of behaviors was investigated in

  10. Neurophysiological Assessment of Affective Experience

    NARCIS (Netherlands)

    Mühl, C.

    2009-01-01

    In the field of Affective Computing the affective experience (AX) of the user during the interaction with computers is of great interest. The automatic recognition of the affective state, or emotion, of the user is one of the big challenges. In this proposal I focus on the affect recognition via

  11. Lianas escape self-thinning: Experimental evidence of positive density dependence in temperate lianas Celastrus orbiculatus and C. scandens

    Science.gov (United States)

    Leicht-Young, S. A.; Latimer, A.M.; Silander, J.A.

    2011-01-01

    The neighborhood density of plants strongly affects their growth, reproduction, and survival. In most cases, high density increases competition and negatively affects a focal plant in predictable ways, leading to the self-thinning law. There are, however, situations in which high densities of plants facilitate focal plant performance, resulting in positive density dependence. Despite their importance in forest gap dynamics and distinctive growth form, there have been very few studies of the effect of density on lianas or vines. We grew an invasive (Celastrus orbiculatus) and a native (Celastrus scandens) liana species together in three different density treatments, while also manipulating the light and support availability. We found that across treatment conditions, C. orbiculatus always out-performed C. scandens, showing greater relative growth rate in height and diameter, greater biomass and higher survival. Both species responded similarly to the density treatments: with plants in high density not showing a decrease in relative height growth rate compared to medium density. Aboveground biomass for C. scandens was not affected by density, while for C. orbiculatus, the most massive plants were growing in medium density without support. More surprisingly, survival analysis indicated that the two species both had significantly lower mortality rates in the highest density treatment; this trend held true across the other treatments of light and supports. More generally, this study demonstrates that these lianas can escape the consequences of high density and thus the self-thinning law that affects self-supporting plants. This suggests a broader hypothesis about lianas in general: their greater flexibility in allocating growth resources allows them to grow taller and thinner without collapsing and thereby potentially escape shading and mortality even at high densities.

  12. The effect of turbidity and prey fish density on consumption rates of piscivorous Eurasian perch Perca fluviatilis

    DEFF Research Database (Denmark)

    Jacobsen, Lene; Berg, Søren; Baktoft, Henrik

    2014-01-01

    piscivorous Eurasian perch Perca fluviatilis L. This was done in outdoor mesocosm (16 m2) experiments with clear water and two levels of turbidity (25 and 105 NTU) and two prey fish densities [3.1 and 12.5 roach Rutilus rutilus (L.) individuals m–2]. Perch consumption rates were affected by visibility less...... than expected, while they were highly affected by increased prey fish density. Perch responded to high prey density in all visibility conditions, indicating that prey density is more crucial for consumption than visibility in turbid lakes...

  13. Relationships between human population density and burned area at continental and global scales.

    Science.gov (United States)

    Bistinas, Ioannis; Oom, Duarte; Sá, Ana C L; Harrison, Sandy P; Prentice, I Colin; Pereira, José M C

    2013-01-01

    We explore the large spatial variation in the relationship between population density and burned area, using continental-scale Geographically Weighted Regression (GWR) based on 13 years of satellite-derived burned area maps from the global fire emissions database (GFED) and the human population density from the gridded population of the world (GPW 2005). Significant relationships are observed over 51.5% of the global land area, and the area affected varies from continent to continent: population density has a significant impact on fire over most of Asia and Africa but is important in explaining fire over area in croplands. Overall, the relationship between population density and burned area is non-monotonic: burned area initially increases with population density and then decreases when population density exceeds a threshold. These thresholds vary regionally. Our study contributes to improved understanding of how human activities relate to burned area, and should contribute to a better estimate of atmospheric emissions from biomass burning.

  14. Dynamic through-silicon-via filling process using copper electrochemical deposition at different current densities

    Science.gov (United States)

    Wang, Fuliang; Zhao, Zhipeng; Nie, Nantian; Wang, Feng; Zhu, Wenhui

    2017-01-01

    This work demonstrates the dynamic through-silicon-via (TSV) filling process through staged electrodeposition experiments at different current densities. Different morphologies corresponding to TSV filling results can be obtained by controlling the applied current density. Specifically, a low current density (4 mA/cm2) induces seam defect filling, a medium current density (7 mA/cm2) induces defect-free filling, and a high current density (10 mA/cm2) induces void defect filling. Analysis of the filling coefficient indicates that the effect of current density on the TSV filling models is triggered by the coupling effect of consumption and diffusion of additives and copper ions. Further, the morphological evolution of plating reveals that the local deposition rate is affected by the geometrical characteristics of the plating. PMID:28422170

  15. Does the exclusion of meiofauna affect the estimation of biotic ...

    African Journals Online (AJOL)

    Biomonitoring of rivers is usually undertaken using information based on macroinvertebrate assemblages. However, exclusion of meiofauna (i.e. invertebrates less than 0.5 mm in size) when sorting benthic invertebrates can affect the estimation of densities and other biotic indices. In the present study, the effect of excluding ...

  16. Ecological factors affecting the foraging behaviour of Xerus rutilus ...

    African Journals Online (AJOL)

    The African unstriped ground squirrel (Xerus rutilus) is widely dispersed across various habitats in East Africa and hence encounters a diverse suite of predators and plant communities. It is not known how different habitats and plant characteristics affect the foraging behaviour of X. rutilus. We used giving-up densities ...

  17. factors affecting particle retention in thermal field-flow fractionation

    African Journals Online (AJOL)

    In this paper, we report a range of factors which affect the retention of colloidal particles in thermal field-flow fractionation (ThFFF). These results are observed among different sizes of polystyrene (PS) latex particles suspended in both aqueous and nonaqueous liquid carriers and very low density lipoproteins in a phosphate ...

  18. Conditional Density Approximations with Mixtures of Polynomials

    DEFF Research Database (Denmark)

    Varando, Gherardo; López-Cruz, Pedro L.; Nielsen, Thomas Dyhre

    2015-01-01

    Mixtures of polynomials (MoPs) are a non-parametric density estimation technique especially designed for hybrid Bayesian networks with continuous and discrete variables. Algorithms to learn one- and multi-dimensional (marginal) MoPs from data have recently been proposed. In this paper we introduce...... two methods for learning MoP approximations of conditional densities from data. Both approaches are based on learning MoP approximations of the joint density and the marginal density of the conditioning variables, but they differ as to how the MoP approximation of the quotient of the two densities...

  19. Local breast density assessment using reacquired mammographic images.

    Science.gov (United States)

    García, Eloy; Diaz, Oliver; Martí, Robert; Diez, Yago; Gubern-Mérida, Albert; Sentís, Melcior; Martí, Joan; Oliver, Arnau

    2017-08-01

    The aim of this paper is to evaluate the spatial glandular volumetric tissue distribution as well as the density measures provided by Volpara™ using a dataset composed of repeated pairs of mammograms, where each pair was acquired in a short time frame and in a slightly changed position of the breast. We conducted a retrospective analysis of 99 pairs of repeatedly acquired full-field digital mammograms from 99 different patients. The commercial software Volpara™ Density Maps (Volpara Solutions, Wellington, New Zealand) is used to estimate both the global and the local glandular tissue distribution in each image. The global measures provided by Volpara™, such as breast volume, volume of glandular tissue, and volumetric breast density are compared between the two acquisitions. The evaluation of the local glandular information is performed using histogram similarity metrics, such as intersection and correlation, and local measures, such as statistics from the difference image and local gradient correlation measures. Global measures showed a high correlation (breast volume R=0.99, volume of glandular tissue R=0.94, and volumetric breast density R=0.96) regardless the anode/filter material. Similarly, histogram intersection and correlation metric showed that, for each pair, the images share a high degree of information. Regarding the local distribution of glandular tissue, small changes in the angle of view do not yield significant differences in the glandular pattern, whilst changes in the breast thickness between both acquisition affect the spatial parenchymal distribution. This study indicates that Volpara™ Density Maps is reliable in estimating the local glandular tissue distribution and can be used for its assessment and follow-up. Volpara™ Density Maps is robust to small variations of the acquisition angle and to the beam energy, although divergences arise due to different breast compression conditions. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The effects of sex-ratio and density on locomotor activity in the house fly, Musca domestica

    DEFF Research Database (Denmark)

    Bahrndorff, Simon; Kjaersgaard, Anders; Pertoldi, Cino

    2012-01-01

    Although locomotor activity is involved in almost all behavioral traits, there is a lack of knowledge on what factors affect it. This study examined the effects of sex-ratio and density on the circadian rhythm of locomotor activity of adult Musca domestica L. (Diptera: Muscidae) using an infra...... with and without the presence of females. Overall, this study demonstrates that locomotor activity in M. domestica is affected by sex-ratio and density. Furthermore, the predictability of locomotor activity is affected by both sex-ratio, density, and circadian rhythm. These results add to our understanding...

  1. Microvessels Density in Uterine Leiomyosarcoma

    Directory of Open Access Journals (Sweden)

    Marcin Bobiński

    2015-01-01

    Full Text Available Uterine leiomyosarcomas (LMS are rare tumors typically presenting rapid growth and unfavorable outcome. Nowadays the results of uterine LMS treatment do not meet expectations. Angiogenesis is one of processes investigated to be target for future treatment. The aim of the research was to assess microvessels density (MVD in tumor samples collected from 50 patients with histological confirmed uterine leiomyosarcoma and to investigate statistical relations between MVD, patients survival, and FIGO stage of tumor. The assessment was carried out using immunohistochemistry methods with anti-CD34 antibody. No significant difference in MVD between FIGO stages was observed. Furthermore, contrary to many other malignancies, we found no significant relation between MVD and patients overall and 2-year survival. Results obtained in the study suggest that processes on vascular mimicry and mesenchymal to epithelial transition (MET may play important role in development of LMS. No statistical relation between MVD and survival leads to conclusion that not only angiogenesis but other mechanisms as well should be taken into consideration in planning future research.

  2. Hyperon matter at low densities

    Energy Technology Data Exchange (ETDEWEB)

    Sulaksono, A., E-mail: anto.sulaksono@sci.ui.ac.id [Department Fisika, FMIPA, Universitas Indonesia, Depok 16424 (Indonesia)

    2014-09-25

    It was reported recently that hyperons can be present inside PSRJ1614-2230 compact star. This can be realized only if the strength of the ω-hyperons and φ-hyperons coupling of conventional hyperons coupling constant on the extended relativistic mean field (ERMF) model increase by a factor of 1.5 to 3. In the present work, the mass and radius relation of the neutron star that is calculated by using BSR28 parameter set of ERMF model augmented with maximal coupling strength of the ω-hyperons and φ-hyperons (X=1), is compared to the mass and radius relation of the neutron star that is predicted by the same RMF parameter set but by assuming that hyperons do not exist in the matter (No. Hyp) as well as those by assuming the hyperons coupling constant fulfilled the conventional SU(6) and SU(3) symmetry. The consequences of implementing X=1 prescription are also discussed. The potential depths of hyperons in symmetric nuclear matter (SNM), pure neutron matter (PNM) and pure lambda matter (PLM) based on this parameter set are also calculated by using the X=1, SU (6) and SU (3) prescriptions. The results are compared to those obtained from microscopic models, quark meson coupling model (χ QMM) and the QCD sum rule for finite density (QCD SM) result.

  3. Overcoming Seasonal Affective Disorder.

    Science.gov (United States)

    Leahy, Laura G

    2017-11-01

    Seasonal affective disorder (SAD) significantly impacts the lives of individuals around the world. The mood fluctuations that occur are not only exhibited during the winter months but also during the spring and summer. The key to identifying SAD is the distinct seasonal onset and spontaneous remission of symptoms over the course of a season. Nurses are in a unique position to identify the symptoms of SAD and offer treatment recommendations to reduce the negative impact of these seasonal mood fluctuations. As holistic health care practitioners, nurses provide patient education regarding healthy lifestyle interventions, which can aid in minimizing the disruptive symptoms of SAD. Advanced practice nurses can offer pharmacotherapy interventions to address symptoms contributing to the individual's inability to function across domains-individual, family, and social. Finally, after reading the article, nurses of all disciplines will have a better understanding of the evidence-based bright light therapy (also known as light box therapy) and how to incorporate this treatment when caring for patients with SAD. [Journal of Psychosocial Nursing and Mental Health Services, 55(11), 10-14.]. Copyright 2017, SLACK Incorporated.

  4. Does Deafness Affect Resilience?

    Directory of Open Access Journals (Sweden)

    Ahmadi

    2015-10-01

    Full Text Available Background Resilience is a positive psychological characteristic that contributes to mental health and adjustment under challenging conditions, such as deafness. Deafness is a traumatic experience and causes communication disorders; it may also affect resilience. Objectives We compared the resilience of deaf signers to that of a matched group of hearing individuals. Materials and Methods This comparative study was performed to assess self-evaluated resilience in 45 deaf signers and in 76 matched hearing subjects from Hamadan, Iran. Resilience scores were measured using a modified connor-davidson resilience scale. Results The average resilience score was 61.20 in deaf signers and 62.8 in hearing subjects; however, this difference was not statistically significant. The resilience score was different in female and male deaf participants. It was 65.22 for male deaf participants (SD = 10.4 and 55.17 for female deaf participants (SD = 16.1, and this difference was statistically significant (P = 0.014. The gender difference between the resilience scores of hearing participants (male, 66.24 [SD = 16.7] and female, 59.36 [SD = 13.9] was not significant (P = 0.057. Discussion Similar resilience scores in deaf and hearing participants may be due to appropriate interaction of deaf signers with family members and society. Male deaf subjects were more resilient than female ones; studies should be done to examine the effects of cultural characteristics that may provide females with less communication opportunities than males.

  5. How Obesity Affects Tendons?

    Science.gov (United States)

    Abate, Michele; Salini, Vincenzo; Andia, Isabel

    Several epidemiological and clinical observations have definitely demonstrated that obesity has harmful effects on tendons. The pathogenesis of tendon damage is multi-factorial. In addition to overload, attributable to the increased body weight, which significantly affects load-bearing tendons, systemic factors play a relevant role. Several bioactive peptides (chemerin, leptin, adiponectin and others) are released by adipocytes, and influence tendon structure by means of negative activities on mesenchymal cells. The ensuing systemic state of chronic, sub-clinic, low-grade inflammation can damage tendon structure. Metabolic disorders (diabetes, impaired glucose tolerance, and dislipidemia), frequently associated with visceral adiposity, are concurrent pathogenetic factors. Indeed, high glucose levels increase the formation of Advanced Glycation End-products, which in turn form stable covalent cross-links within collagen fibers, modifying their structure and functionality.Sport activities, so useful for preventing important cardiovascular complications, may be detrimental for tendons if they are submitted to intense acute or chronic overload. Therefore, two caution rules are mandatory: first, to engage in personalized soft training program, and secondly to follow regular check-up for tendon pathology.

  6. Security affects us all!

    CERN Multimedia

    SMB Department

    2016-01-01

    In the hope of minimising the number of thefts of the Organization’s property, which can lead to months of work going to waste on certain projects, you are reminded of the importance that CERN attaches to the rules concerning the protection of equipment for which we are responsible. If you see any unusual behaviour or if you are the victim of a theft, don’t hesitate to report it by submitting a ticket through the CERN Portal or calling the CSA. Security affects us all!   CERN is attractive in more ways than one, and it remains as attractive as ever to thieves. With the nice weather and with the holiday season in full swing, the number of thefts recorded at CERN is on the rise. Items stolen include money, computers, electronic equipment, cable drums and copper antennae.   There are a few basic precautions that you should take to protect both your own and the Organization’s property: lock your door, don’t leave valuable items in your office, st...

  7. Factors affecting aspartase activity.

    Science.gov (United States)

    DEPUE, R H; MOAT, A G

    1961-09-01

    Depue, Robert H. (Hahnemann Medical College, Philadelphia), and Albert G. Moat. Factors affecting aspartase activity. J. Bacteriol. 82:383-386. 1961.-Cells of Escherichia coli grown in a glucose-mineral salts medium contain about one-fifth the amount of aspartase activity observed in cells grown in a yeast extract-peptone medium. The aspartase activity of the cells grown in glucose-salts medium would appear to be too low to provide a mechanism for synthesis of amino groups. Aspartase was purified approximately eightfold by ammonium sulfate precipitation and column chromatography of cell-free extracts. The purified preparation was specific for l-aspartic acid and contained no fumarase activity. A divalent metal ion requirement was demonstrated, this requirement being satisfied by cobaltous or manganous ions. The enzyme activity was found to be dependent upon free sulfhydryl groups. Biotin did not appear to be directly involved in the aspartase reaction since high concentrations of avidin did not alter the reaction rate. The Michaelis constant for aspartase with aspartic acid as substrate was determined to be 0.033 m.

  8. [Effects of temperature and density on the mortality and reproduction of cotton aphid Aphis gossypii].

    Science.gov (United States)

    Gao, Gui-Zhen; Lü, Zhao-Zhi; Xia, De-Ping; Sun, Ping; Ma, Ji-Hong; Xu, Yang-Cheng

    2013-05-01

    A laboratory cotton leaf disc experiment was conducted to study the effects of different temperature (32, 34, 36, 38, and 40 degrees C) and density (5, 25, 50, and 75 individuals per dish) on the mortality and reproduction of Aphis gossypii. With the increase of temperature, density, and culture duration, the cumulative mortality of A. gossypii presented an increasing trend. The parameters estimated by complementary log-log (CLL) model showed that the beta value decreased with the increase of density, indicating that the effects of temperature weakened with increasing density. The gamma value, a parameter for the time effect of temperature, changed with culture duration, indicating that the morality of A. gossypii was co-affected by the temperature and culture duration. The two-way ANOVA analysis of variance showed that temperature and density had significant effects on the fecundity of A. gossypii, and there existed interactive effect. At 32-36 degrees C, the reproduction rate of A. gossypii decreased with the increase of density, but at 40 degrees C, no significant difference was observed in the reproduction rate under different densities, suggesting that the density effect was weakened with increasing temperature, i. e., the contribution of temperature and density to the survival and reproduction of individual varied with the ranges of the temperature and density. This study could provide reference for the monitoring and forecasting of A. gossypii population and for the improvement of pests control.

  9. Coffee farm diversity and landscape features influence density of colonies of Atta cephalotes (Hymenoptera: Formicidae).

    Science.gov (United States)

    Varón, Edgar; Eigenbrode, Sanford D; Bosque-Pérez, Nilsa A; Hilje, Luko; Jones, Jeffrey

    2011-02-01

    The density of colonies of leaf-cutting ants, Atta cephalotes L. (Hymenoptera: Formicidae), was measured and compared among coffee (Coffea arabica L.) plantations in five management categories: monoculture conventional, diversified conventional, diversified organic, highly diversified conventional, and highly diversified organic. Twenty-four small farms (farm and off-farm (landscape) variables were measured and tested for their relationship with A. cephalotes colony density. Total ant colony density (colonies per ha) and density of new colonies shortly after a nuptial flight were significantly greater in the coffee monoculture conventional system, compared with all other systems. Total ant colony density and density of new colonies were inversely related to percentage of shade within the farms. Within farms, colony density was greater near edges adjacent to riparian forest than those adjacent to nonforested land. Regardless of edge type, plots closer to the edge (0-30 m) had greater colony density than those furthest from the edge. At the landscape scale, density of new colonies was positively related to fallow land use coverage within a 2,000-m buffer radius and to forest coverage within a 500-m radius. Results indicate that coffee farm management practices and landscape level factors can affect A. cephalotes colony densities. Understanding such practices and factors could assist in the development of better management methods of these injurious insects in coffee farms. Increased diversification in coffee farms, possibly due to the greater shade associated with it, may reduce colonization by the ants, which are considered forest gap specialists.

  10. Affective match: Leader emotions, follower positive affect, and follower performance

    NARCIS (Netherlands)

    Damen, F.; van Knippenberg, B.M.; van Knippenberg, D.

    2008-01-01

    Leader emotions may play an important role in leadership effectiveness. Extending earlier research on leader emotional displays and leadership effectiveness, we propose that the affective match between follower positive affect (PA) and leaders' emotional displays moderates the effectiveness of

  11. Affective Monitoring: A Generic Mechanism for Affect Elicitation

    OpenAIRE

    Hans ePhaf; Mark eRotteveel

    2012-01-01

    In this paper we sketch a new framework for affect elicitation, which is based on previous evolutionary and connectionist modeling and experimental work from our group. Affective monitoring is considered a local match–mismatch process within a module of the neural network. Negative affect is raised instantly by mismatches, incongruency, disfluency, novelty, incoherence, and dissonance, whereas positive affect follows from matches, congruency, fluency, familiarity, coherence, and resonance, at...

  12. Dispersal patterns of red foxes relative to population density

    Science.gov (United States)

    Allen, Stephen H.; Sargeant, Alan B.

    1993-01-01

    Factors affecting red fox (Vulpes vulpes) dispersal patterns are poorly understood but warranted investigation because of the role of dispersal in rebuilding depleted populations and transmission of diseases. We examined dispersal patterns of red foxes in North Dakota based on recoveries of 363 of 854 foxes tagged as pups and relative to fox density. Foxes were recovered up to 8.6 years after tagging; 79% were trapped or shot. Straight-line distances between tagging and recovery locations ranged from 0 to 302 km. Mean recovery distances increased with age and were greater for males than females, but longest individual recovery distances were by females. Dispersal distances were not related to population density for males (P = 0.36) or females (P = 0.96). The proportion of males recovered that dispersed was inversely related to population density (r = -0.94; n = 5; P = 0.02), but not the proportion of females (r = -0.49; n = 5; P = 0.40). Dispersal directions were not uniform for either males (P = 0.003) or females (P = 0.006); littermates tended to disperse in similar directions (P = 0.09). A 4-lane interstate highway altered dispersal directions (P = 0.001). Dispersal is a strong innate behavior of red foxes (especially males) that results in many individuals of both sexes traveling far from natal areas. Because dispersal distance was unaffected by fox density, populations can be rebuilt and diseases transmitted long distances regardless of fox abundance.

  13. Do plasma proteins distinguish between liposomes of varying charge density?

    KAUST Repository

    Capriotti, Anna Laura

    2012-03-01

    Cationic liposomes (CLs) are one of the most employed nonviral nanovector systems in gene therapy. However, their transfection efficiency is strongly affected by interactions with plasma components, that lead to the formation of a "protein corona" onto CL surface. The interactions between nanoparticles entering the body and biomolecules have an essential role for their biodistribution. Because the knowledge of proteins adsorbed onto vector surface could be useful in the screening of new, more efficient and more biocompatible liposomal formulations, the behavior of three CLs with different membrane charge densities was investigated. The proteins of the three coronas were identified by nano-liquid chromatography-tandem mass spectrometry, and quantified with label-free spectral counting strategy. Fibrinogen displayed higher association with CLs with high membrane charge density, while apolipoproteins and C4b-binding protein with CLs with low membrane charge density. These results are discussed in terms of the different lipid compositions of CLs and may have a deep biological impact for in vivo applications. Surface charge of nanoparticles is emerging as a relevant factor determining the corona composition after interaction with plasma proteins. Remarkably, it is also shown that the charge of the protein corona formed around CLs is strongly related to their membrane charge density. © 2012 Elsevier B.V.

  14. Citrus rootstocks influence the population densities of pest mites

    Directory of Open Access Journals (Sweden)

    Rafael Rocha da Silva

    2016-01-01

    Full Text Available Citrus are attacked by pest mites such as the citrus rust mite Phyllocoptruta oleivora (Ashmead (Acari: Eriophyidae and the spider mite Tetranychus mexicanus (McGregor (Acari: Tetranychidae. However, little is known on citrus rootstocks influencing pest mites. We aimed to evaluate the influence of rootstocks on population densities of pest mites on the sweet oranges 'Pera CNPMF D-6' and 'Valencia Tuxpan' throughout time. Adults of both mite species were monthly counted during 19 months from June 2011 to February 2013. Rootstocks influenced the populations of pest mites, since lower densities of P. oleivora were found on 'Pera CNPMF D-6' sweet orange grafted on the hybrid TSKC × CTTR - 002 and on 'Swingle' citrumelo in comparison with the hybrid LVK × LCR - 010, 'Red' rough lime and 'Santa Cruz' rangpur lime as rootstocks. Similarly, lower densities of T. mexicanus were found on 'Valencia Tuxpan' sweet orange grafted on the hybrid HTR-051 in comparison to 'Indio' citrandarin, 'Sunki Tropical' mandarin and LVK × LCR - 010 as rootstocks. We concluded that densities of the mites P. oleivora and T. mexicanus on the sweet oranges 'Pera CNPMF D-6' and 'Valencia Tuxpan' were affected in some periods of the year by some rootstocks, suggesting influence of some genotypes on these pests.

  15. Analysis of the IMAGE RPI electron density data and CHAMP plasmasphere electron density reconstructions with focus on plasmasphere modelling

    Science.gov (United States)

    Gerzen, T.; Feltens, J.; Jakowski, N.; Galkin, I.; Reinisch, B.; Zandbergen, R.

    2016-09-01

    The electron density of the topside ionosphere and the plasmasphere contributes essentially to the overall Total Electron Content (TEC) budget affecting Global Navigation Satellite Systems (GNSS) signals. The plasmasphere can cause half or even more of the GNSS range error budget due to ionospheric propagation errors. This paper presents a comparative study of different plasmasphere and topside ionosphere data aiming at establishing an appropriate database for plasmasphere modelling. We analyze electron density profiles along the geomagnetic field lines derived from the Imager for Magnetopause-to-Aurora Global Exploration (IMAGE) satellite/Radio Plasma Imager (RPI) records of remote plasma sounding with radio waves. We compare these RPI profiles with 2D reconstructions of the topside ionosphere and plasmasphere electron density derived from GNSS based TEC measurements onboard the Challenging Minisatellite Payload (CHAMP) satellite. Most of the coincidences between IMAGE profiles and CHAMP reconstructions are detected in the region with L-shell between 2 and 5. In general the CHAMP reconstructed electron densities are below the IMAGE profile densities, with median of the CHAMP minus IMAGE residuals around -588 cm-3. Additionally, a comparison is made with electron densities derived from passive radio wave RPI measurements onboard the IMAGE satellite. Over the available 2001-2005 period of IMAGE measurements, the considered combined data from the active and passive RPI operations cover the region within a latitude range of ±60°N, all longitudes, and an L-shell ranging from 1.2 to 15. In the coincidence regions (mainly 2 ⩽ L ⩽ 4), we check the agreement between available active and passive RPI data. The comparison shows that the measurements are well correlated, with a median residual of ∼52 cm-3. The RMS and STD values of the relative residuals are around 22% and 21% respectively. In summary, the results encourage the application of IMAGE RPI data for

  16. Affective monitoring: A generic mechanism for affect elicitation

    NARCIS (Netherlands)

    Phaf, R.H.; Rotteveel, M.

    2012-01-01

    In this paper we sketch a new framework for affect elicitation, which is based on previous evolutionary and connectionist modeling and experimental work from our group. Affective monitoring is considered a local match-mismatch process within a module of the neural network. Negative affect is raised

  17. Encountering Science Education's Capacity to Affect and Be Affected

    Science.gov (United States)

    Alsop, Steve

    2016-01-01

    What might science education learn from the recent affective turn in the humanities and social sciences? Framed as a response to Michalinos Zembylas's article, this essay draws from selected theorizing in affect theory, science education and science and technology studies, in pursuit of diverse and productive ways to talk of affect within science…

  18. The Fourier transform of tubular densities

    KAUST Repository

    Prior, C B

    2012-05-18

    We consider the Fourier transform of tubular volume densities, with arbitrary axial geometry and (possibly) twisted internal structure. This density can be used to represent, among others, magnetic flux or the electron density of biopolymer molecules. We consider tubes of both finite radii and unrestricted radius. When there is overlap of the tube structure the net density is calculated using the super-position principle. The Fourier transform of this density is composed of two expressions, one for which the radius of the tube is less than the curvature of the axis and one for which the radius is greater (which must have density overlap). This expression can accommodate an asymmetric density distribution and a tube structure which has non-uniform twisting. In addition we give several simpler expressions for isotropic densities, densities of finite radius, densities which decay at a rate sufficient to minimize local overlap and finally individual surfaces of the tube manifold. These simplified cases can often be expressed as arclength integrals and can be evaluated using a system of first-order ODEs. © 2012 IOP Publishing Ltd.

  19. Wood density variation and tree ring distinctness in Gmelina arborea trees by x-ray densitometry

    Directory of Open Access Journals (Sweden)

    Roger Moya

    2009-03-01

    Full Text Available Due to its relationship with other properties, wood density is the main wood quality parameter. Modern, accuratemethods such as X-ray densitometry - are applied to determine the spatial distribution of density in wood sections and to evaluatewood quality. The objectives of this study were to determinate the influence of growing conditions on wood density variation andtree ring demarcation of gmelina trees from fast growing plantations in Costa Rica. The wood density was determined by X-raydensitometry method. Wood samples were cut from gmelina trees and were exposed to low X-rays. The radiographic films weredeveloped and scanned using a 256 gray scale with 1000 dpi resolution and the wood density was determined by CRAD and CERDsoftware. The results showed tree-ring boundaries were distinctly delimited in trees growing in site with rainfall lower than 2510 mm/year. It was demonstrated that tree age, climatic conditions and management of plantation affects wood density and its variability. Thespecific effect of variables on wood density was quantified by for multiple regression method. It was determined that tree yearexplained 25.8% of the total variation of density and 19.9% were caused by climatic condition where the tree growing. Wood densitywas less affected by the intensity of forest management with 5.9% of total variation.

  20. Variable density turbulence tunnel facility

    Science.gov (United States)

    Bodenschatz, E.; Bewley, G. P.; Nobach, H.; Sinhuber, M.; Xu, H.

    2014-09-01

    The Variable Density Turbulence Tunnel at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany, produces very high turbulence levels at moderate flow velocities, low power consumption, and adjustable kinematic viscosity between 10-4 m2/s and 10-7 m2/s. The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. The highest kinematic viscosities, and hence lowest Reynolds numbers, are reached with air or nitrogen at 0.1 bar. To reach the highest Reynolds numbers the tunnel is pressurized to 15 bars with the dense gas sulfur hexafluoride (SF6). Turbulence is generated at the upstream ends of two measurement sections with grids, and the evolution of this turbulence is observed as it moves down the length of the sections. We describe the instrumentation presently in operation, which consists of the tunnel itself, classical grid turbulence generators, and state-of-the-art nano-fabricated hot-wire anemometers provided by Princeton University [M. Vallikivi, M. Hultmark, S. C. C. Bailey, and A. J. Smits, Exp. Fluids 51, 1521 (2011)]. We report measurements of the characteristic scales of the flow and of turbulent spectra up to Taylor Reynolds number Rλ ≈ 1600, higher than any other grid-turbulence experiment. We also describe instrumentation under development, which includes an active grid and a Lagrangian particle tracking system that moves down the length of the tunnel with the mean flow. In this configuration, the properties of the turbulence are adjustable and its structure is resolvable up to Rλ ≈ 8000.

  1. Variable density turbulence tunnel facility.

    Science.gov (United States)

    Bodenschatz, E; Bewley, G P; Nobach, H; Sinhuber, M; Xu, H

    2014-09-01

    The Variable Density Turbulence Tunnel at the Max Planck Institute for Dynamics and Self-Organization in Göttingen, Germany, produces very high turbulence levels at moderate flow velocities, low power consumption, and adjustable kinematic viscosity between 10(-4) m(2)/s and 10(-7) m(2)/s. The Reynolds number can be varied by changing the pressure or flow rate of the gas or by using different non-flammable gases including air. The highest kinematic viscosities, and hence lowest Reynolds numbers, are reached with air or nitrogen at 0.1 bar. To reach the highest Reynolds numbers the tunnel is pressurized to 15 bars with the dense gas sulfur hexafluoride (SF6). Turbulence is generated at the upstream ends of two measurement sections with grids, and the evolution of this turbulence is observed as it moves down the length of the sections. We describe the instrumentation presently in operation, which consists of the tunnel itself, classical grid turbulence generators, and state-of-the-art nano-fabricated hot-wire anemometers provided by Princeton University [M. Vallikivi, M. Hultmark, S. C. C. Bailey, and A. J. Smits, Exp. Fluids 51, 1521 (2011)]. We report measurements of the characteristic scales of the flow and of turbulent spectra up to Taylor Reynolds number R(λ) ≈ 1600, higher than any other grid-turbulence experiment. We also describe instrumentation under development, which includes an active grid and a Lagrangian particle tracking system that moves down the length of the tunnel with the mean flow. In this configuration, the properties of the turbulence are adjustable and its structure is resolvable up to R(λ) ≈ 8000.

  2. Reineke’s stand density index: a quantitative and non-unitless measure of stand density

    Science.gov (United States)

    Curtis L. VanderSchaaf

    2013-01-01

    When used as a measure of relative density, Reineke’s stand density index (SDI) can be made unitless by relating the current SDI to a standard density but when used as a quantitative measure of stand density SDI is not unitless. Reineke’s SDI relates the current stand density to an equivalent number of trees per unit area in a stand with a quadratic mean diameter (Dq)...

  3. BLOOD GROUPS AND AFFECTIVE DISORDERS

    OpenAIRE

    Reddy, P. Lakshmi; Puttaram, Sowbhagya; Rao, B.S. Sridhara Rama; Khanna, Sumant; Channabasavanna, S.M.

    1988-01-01

    SUMMARY An analysis was made of the distribution of various blood groups in subjects with affective disorders. A group of healthy subjects served as controls. The distribution showed lack of association of affective disorder and any blood groups.

  4. Formaldehyde adsorption on carbon nanotubes fragment by density functional theory

    Science.gov (United States)

    Chen, D.; Yuan, Yong J.

    2017-07-01

    The interaction between formaldehyde (HCOH) and pristine single-walled carbon nanotube (SWCNT) fragment was investigated by density functional theory (DFT) to evaluate the detection of HCOH. The simulation results demonstrated less adsorption on surface of SWCNT and doped CNTs, while a HCOH molecule tended to be chemisorbed to the C atom located on SWCNT’s edge positions with larger binding energy of 1.742 eV and smaller binding distance of 1.351 Å. Furthermore, charge transfer and density of states study indicated that the electronic properties changed evidently in the most stable HCOH-SWCNT system, and were mainly around the Fermi level. More importantly, the adsorption of HCOH affected the electronic conductance of SWCNT. It is expected that the results could provide a useful theoretical guidance for the investigation of molecular films interface bonding and design of HCOH sensing devices.

  5. High Density Fuel Development for Research Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Daniel Wachs; Dennis Keiser; Mitchell Meyer; Douglas Burkes; Curtis Clark; Glenn Moore; Jan-Fong Jue; Totju Totev; Gerard Hofman; Tom Wiencek; Yeon So Kim; Jim Snelgrove

    2007-09-01

    An international effort to develop, qualify, and license high and very high density fuels has been underway for several years within the framework of multi-national RERTR programs. The current development status is the result of significant contributions from many laboratories, specifically CNEA in Argentina, AECL in Canada, CEA in France, TUM in Germany, KAERI in Korea, VNIIM, RDIPE, IPPE, NCCP and RIARR in Russia, INL, ANL and Y-12 in USA. These programs are mainly engaged with UMo dispersion fuels with densities from 6 to 8 gU/cm3 (high density fuel) and UMo monolithic fuel with density as high as 16 gU/cm3 (very high density fuel). This paper, mainly focused on the French & US programs, gives the status of high density UMo fuel development and perspectives on their qualification.

  6. Quartz resonator fluid density and viscosity monitor

    Science.gov (United States)

    Martin, Stephen J.; Wiczer, James J.; Cernosek, Richard W.; Frye, Gregory C.; Gebert, Charles T.; Casaus, Leonard; Mitchell, Mary A.

    1998-01-01

    A pair of thickness-shear mode resonators, one smooth and one with a textured surface, allows fluid density and viscosity to be independently resolved. A textured surface, either randomly rough or regularly patterned, leads to trapping of liquid at the device surface. The synchronous motion of this trapped liquid with the oscillating device surface allows the device to weigh the liquid; this leads to an additional response that depends on liquid density. This additional response enables a pair of devices, one smooth and one textured, to independently resolve liquid density and viscosity; the difference in responses determines the density while the smooth device determines the density-viscosity product, and thus, the pair determines both density and viscosity.

  7. Affective monitoring: a generic mechanism for affect elicitation.

    Science.gov (United States)

    Phaf, R Hans; Rotteveel, Mark

    2012-01-01

    In this paper we sketch a new framework for affect elicitation, which is based on previous evolutionary and connectionist modeling and experimental work from our group. Affective monitoring is considered a local match-mismatch process within a module of the neural network. Negative affect is raised instantly by mismatches, incongruency, disfluency, novelty, incoherence, and dissonance, whereas positive affect follows from matches, congruency, fluency, familiarity, coherence, and resonance, at least when an initial mismatch can be solved quickly. Affective monitoring is considered an evolutionary-early conflict and change detection process operating at the same level as, for instance, attentional selection. It runs in parallel and imparts affective flavor to emotional behavior systems, which involve evolutionary-prepared stimuli and action tendencies related to for instance defensive, exploratory, attachment, or appetitive behavior. Positive affect is represented in the networks by high-frequency oscillations, presumably in the gamma band. Negative affect corresponds to more incoherent lower-frequency oscillations, presumably in the theta band. For affect to become conscious, large-scale synchronization of the oscillations over the network and the construction of emotional experiences are required. These constructions involve perceptions of bodily states and action tendencies, but also appraisals as well as efforts to regulate the emotion. Importantly, affective monitoring accompanies every kind of information processing, but conscious emotions, which result from the later integration of affect in a cognitive context, are much rarer events.

  8. Affective monitoring: A generic mechanism for affect elicitation

    Directory of Open Access Journals (Sweden)

    Hans ePhaf

    2012-03-01

    Full Text Available In this paper we sketch a new framework for affect elicitation, which is based on previous evolutionary and connectionist modeling and experimental work from our group. Affective monitoring is considered a local match-mismatch process within a module of the neural network. Negative affect is raised instantly by mismatches, incongruency, disfluency, novelty, incoherence, and dissonance, whereas positive affect follows from matches, congruency, fluency, familiarity, coherence, and resonance, at least when an initial mismatch can be solved quickly. Affective monitoring is considered an evolutionary-early conflict and change detection process operating at the same level as, for instance, attentional selection. It runs in parallel and imparts affective flavour to emotional behavior systems, which involve evolutionary-prepared stimuli and action tendencies related to for instance defensive, exploratory, attachment, or appetitive behavior. Positive affect is represented in the networks by high-frequency oscillations, presumably in the gamma band. Negative affect corresponds to more incoherent lower-frequency oscillations, presumably in the theta band. For affect to become conscious, large-scale synchronization of the oscillations over the network and the construction of emotional experiences are required. These constructions involve perceptions of bodily states and action tendencies, but also appraisals as well as efforts to regulate the emotion. Importantly, affective monitoring accompanies every kind of information processing, but conscious emotions, which result from the later integration of affect in a cognitive context, are much rarer events.

  9. Insect herbivores, density dependence, and the performance of the perennial herb Solanum carolinense.

    Science.gov (United States)

    Underwood, Nora; Halpern, Stacey L

    2012-05-01

    How insect herbivores affect plant performance is of central importance to basic and applied ecology. A full understanding of herbivore effects on plant performance requires understanding interactions (if any) of herbivore effects with plant density and size because these interactions will be critical for determining how herbivores influence plant population size. However, few studies have considered these interactions, particularly over a wide enough range of densities to detect nonlinear effects. Here we ask whether plant density and herbivores influence plant performance linearly or nonlinearly, how plant density affects herbivore damage, and how herbivores alter density dependence in transitions between plant size classes. In a large field experiment, we manipulated the density of the herbaceous perennial plant Solanum carolinense and herbivore presence in a fully crossed design. We measured plant size, sexual reproduction, and damage to plants in two consecutive years, and asexual reproduction of new stems in the second year, allowing us to characterize both plant performance and rates of transition between plant size classes across years. We found nonlinear effects of plant density on damage. Damage by herbivores and plant density both influenced sexual and asexual reproduction of S. carolinense; these effects were mostly mediated via effects on plant size. Importantly, we found that herbivores altered the pattern of linear density dependence in some transition rates (including survival and asexual reproduction) between plant size classes. These results suggest that understanding the ecological or evolutionary effects of herbivores on plant populations requires consideration of plant density and plant size, because feedbacks between density, herbivores, and plant size may complicate longer-term dynamics.

  10. Upper Atmosphere Neutral and Plasma Density Modeling

    Science.gov (United States)

    1993-03-31

    Semidiurnal density amplitude vs. height and latitude at 429N. 15 Figure 2. Percent density variation vs. height and local time over the equator during...March. 16 Figure 3. Semidiurnal (top) and diurnal (bottom) density variations as a function of height near the equator , for the 1979 Kwajalein...M.W., Klobuchar , J.A. and Doherty, P.H. Evaluation of six iono- spheric models as predictors of total electron content, Radio Science, 26, p. 1007, 1991

  11. Affective Productions of Mathematical Experience

    Science.gov (United States)

    Walshaw, Margaret; Brown, Tony

    2012-01-01

    In underscoring the affective elements of mathematics experience, we work with contemporary readings of the work of Spinoza on the politics of affect, to understand what is included in the cognitive repertoire of the Subject. We draw on those resources to tell a pedagogical tale about the relation between cognition and affect in settings of…

  12. A Density Functional Theory Study

    KAUST Repository

    Lim, XiaoZhi

    2011-12-11

    Complexes with pincer ligand moieties have garnered much attention in the past few decades. They have been shown to be highly active catalysts in several known transition metal-catalyzed organic reactions as well as some unprecedented organic transformations. At the same time, the use of computational organometallic chemistry to aid in the understanding of the mechanisms in organometallic catalysis for the development of improved catalysts is on the rise. While it was common in earlier studies to reduce computational cost by truncating donor group substituents on complexes such as tertbutyl or isopropyl groups to hydrogen or methyl groups, recent advancements in the processing capabilities of computer clusters and codes have streamlined the time required for calculations. As the full modeling of complexes become increasingly popular, a commonly overlooked aspect, especially in the case of complexes bearing isopropyl substituents, is the conformational analysis of complexes. Isopropyl groups generate a different conformer with each 120 ° rotation (rotamer), and it has been found that each rotamer typically resides in its own potential energy well in density functional theory studies. As a result, it can be challenging to select the most appropriate structure for a theoretical study, as the adjustment of isopropyl substituents from a higher-energy rotamer to the lowest-energy rotamer usually does not occur during structure optimization. In this report, the influence of the arrangement of isopropyl substituents in pincer complexes on calculated complex structure energies as well as a case study on the mechanism of the isomerization of an iPrPCP-Fe complex is covered. It was found that as many as 324 rotamers can be generated for a single complex, as in the case of an iPrPCP-Ni formato complex, with the energy difference between the global minimum and the highest local minimum being as large as 16.5 kcalmol-1. In the isomerization of a iPrPCP-Fe complex, it was found

  13. Concrete density estimation by rebound hammer method

    Energy Technology Data Exchange (ETDEWEB)

    Ismail, Mohamad Pauzi bin, E-mail: pauzi@nm.gov.my; Masenwat, Noor Azreen bin; Sani, Suhairy bin; Mohd, Shukri [NDT Group, Nuclear Malaysia, Bangi, Kajang, Selangor (Malaysia); Jefri, Muhamad Hafizie Bin; Abdullah, Mahadzir Bin [Material Technology Program, Faculty of Applied Sciences, UiTM, Shah Alam, Selangor (Malaysia); Isa, Nasharuddin bin; Mahmud, Mohamad Haniza bin [Pusat Penyelidikan Mineral, Jabatan Mineral dan Geosains, Ipoh, Perak (Malaysia)

    2016-01-22

    Concrete is the most common and cheap material for radiation shielding. Compressive strength is the main parameter checked for determining concrete quality. However, for shielding purposes density is the parameter that needs to be considered. X- and -gamma radiations are effectively absorbed by a material with high atomic number and high density such as concrete. The high strength normally implies to higher density in concrete but this is not always true. This paper explains and discusses the correlation between rebound hammer testing and density for concrete containing hematite aggregates. A comparison is also made with normal concrete i.e. concrete containing crushed granite.

  14. Irradiation test of high density Si material

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Man Soon; Choo, Kee Nam; Lee, Chul Yong; Yang, Seong Woo; Shim, Kyue Taek; Park, Sang Jun [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2012-10-15

    The feasibility of irradiation test for the high-density Si material entrusted by Guju Inc. was reviewed. The high density Si material is used for a sealing of the penetration holes of piping at the nuclear power plants. The irradiation test was performed and the density changes between before and after irradiation test were measured. The irradiation tests were performed 2 times for 1 day and 20 days at IP 4 hole of HANARO. The 3 Si specimens irradiated were without flaws and the density changes after irradiation were successfully measured. The result satisfies the requirement of the design specification.

  15. Spatial mapping of humeral head bone density.

    Science.gov (United States)

    Alidousti, Hamidreza; Giles, Joshua W; Emery, Roger J H; Jeffers, Jonathan

    2017-09-01

    Short-stem humeral replacements achieve fixation by anchoring to the metaphyseal trabecular bone. Fixing the implant in high-density bone can provide strong fixation and reduce the risk of loosening. However, there is a lack of data mapping the bone density distribution in the proximal humerus. The aim of the study was to investigate the bone density in proximal humerus. Eight computed tomography scans of healthy cadaveric humeri were used to map bone density distribution in the humeral head. The proximal humeral head was divided into 12 slices parallel to the humeral anatomic neck. Each slice was then divided into 4 concentric circles. The slices below the anatomic neck, where short-stem implants have their fixation features, were further divided into radial sectors. The average bone density for each of these regions was calculated, and regions of interest were compared using a repeated-measures analysis of variance with significance set at P density was found to decrease from proximal to distal regions, with the majority of higher bone density proximal to the anatomic neck of the humerus (P density increases from central to peripheral regions, where cortical bone eventually occupies the space (P density distribution in the medial calcar region was also observed. This study indicates that it is advantageous with respect to implant fixation to preserve some bone above the anatomic neck and epiphyseal plate and to use the denser bone at the periphery. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Density Dependence and Growth Rate: Evolutionary Effects on Resistance Development to Bt (Bacillus thuringiensis).

    Science.gov (United States)

    Martinez, Jeannette C; Caprio, Michael A; Friedenberg, Nicholas A

    2018-02-09

    It has long been recognized that pest population dynamics can affect the durability of a pesticide, but dose remains the primary component of insect resistance management (IRM). For transgenic pesticidal traits such as Bt (Bacillus thuringiensis Berliner (Bacillales: Bacillaceae)), dose (measured as the mortality of susceptibles caused by a toxin) is a relatively fixed characteristic and often falls below the standard definition of high dose. Hence, it is important to understand how pest population dynamics modify durability and what targets they present for IRM. We used a deterministic model of a generic arthropod pest to examine how timing and strength of density dependence interacted with population growth rate and Bt mortality to affect time to resistance. As in previous studies, durability typically reached a minimum at intermediate doses. However, high population growth rates could eliminate benefits of high dose. The timing of density dependence had a more subtle effect. If density dependence operated simultaneously with Bt mortality, durability was insensitive to its strengths. However, if density dependence was driven by postselection densities, decreasing its strength could increase durability. The strength of density dependence could affect durability of both single traits and pyramids, but its influence depended on the timing of density dependence and size of the refuge. Our findings suggest the utility of a broader definition of high dose, one that incorporates population-dynamic context. That maximum growth rates and timing and strength of interactions causing density dependent mortality can all affect durability, also highlights the need for ecologically integrated approaches to IRM research. © The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Assistive Technology and Affective Mediation

    Directory of Open Access Journals (Sweden)

    Nestor Garay

    2006-01-01

    Full Text Available The lack of attention towards affective communication in assistive technology and disability research can be potentially overcome thanks to the development of affective computing and affective mediation areas. This document describes the main impairments and disorders that may involve affective communication deficits. We also present several affective mediation technologies that are being applied or may be integrated in assistive technologies in order to improve affective communication for a range of disabilities. Finally, we describe our experience with Gestele, an application that incorporates multimodal elements of affective mediation for people with mobility impairments, as well as the results of an empirical study conducted to evaluate the application’s validity in communication via telephone.

  18. Density Stress has Minimal Impacts on the Barley or Maize Seedling Transcriptome

    Directory of Open Access Journals (Sweden)

    Summer St. Pierre

    2011-03-01

    Full Text Available High planting density affects the morphology and productivity of many crop species. Our objectives were to examine the phenotypic and transcriptomic changes that occur during plant density stress in barley ( L. and maize ( L. seedlings. In maize and barley seedlings, density stress impacted several morphological traits. Gene expression profiles were examined in four barley and five maize genotypes grown at low and high plant densities. Only 221 barley and 35 maize genes exhibited differential expression in response to plant density stress. The majority of the gene expression changes were observed in a subset of the genotypes and reflected minor changes in the level of expression, indicating that the plant density stress imposed in this study did not result in major changes in gene expression. Also, little overlap was observed within barley or maize genotypes in gene expression during density stress, indicating that genotypic differences play a major role in the response to density stress. While it is clear that gene expression differences are involved in morphological changes induced by high plant densities, it is likely that many of these gene expression differences are subtle and restricted to particular tissues and developmental time.

  19. Physical and Microbiological Qualities of Kampong-Broiler Crossbred Chickens Meat Raised in Different Stocking Densities

    Directory of Open Access Journals (Sweden)

    C. A. Patria

    2016-12-01

    Full Text Available The crossbreeding between broiler and kampong chickens has been performed to develop a kampong-broiler strain chicken. The chicken stocking condition needs more attention as a part of animal welfare. This study was performed to identify the relationship between the stocking density and the stress based on Temperature Humidity Index (THI and the effect of stocking density on meat quality, i.e., physical, microbiological, and organoleptic. Ninety DOCs of Kampong-Broiler (KB were assigned into a completely randomized design with 3 treatments of stocking density  i.e., 8, 10, and 12 birds m-2. Each treatment was replicated 3 times. The experimental chickens were housed in 9 blocks of housing each with 1 x 1 m2 size. Data on physical and microbiology of meat qualities were analyzed with analysis of variance and continued with Duncan’s multiple range test. The organoleptic data were analyzed by using Kruskal-Wallis test. The result showed that the stocking density did not significantly affect the physical and hedonic quality of KB chicken’s breast. The stocking densities significantly affected (P<0.05 the microbiological variables of breast meat. The average value of THI during maintenance reached 28.98±1.25–29.33±1.32oC. The higher the animal density the higher the THI value that correlated to the stress condition. However, high stocking density did not affect the physical and hedonic quality of breast meat,  thus it can be accepted by the consumers. The higher the stocking density the higher the total plate count, Escherichia coli, and Staphylococcus aureus, without the presence of Salmonella sp. The meat quality of KB chickens raised in the stocking density of 10 birds m-2 meets the requirement of SNI 01-3924-2009.

  20. Electron-density topology in molecular systems: Paired and unpaired densities

    Science.gov (United States)

    Lobayan, Rosana M.; Bochicchio, Roberto C.; Lain, Luis; Torre, Alicia

    2005-10-01

    This work studies the partitioning of the electron density into two contributions which are interpreted as the paired and the effectively unpaired electron densities. The topological features of each density field as well as of the total density are described localizing the corresponding critical points in simple selected molecules (local formalism). The results show that unpaired electron-density concentrations occur out of the topological bonding regions whereas the paired electron densities present accumulations inside those regions. A comparison of these results with those arising from population analysis techniques (nonlocal or integrated formalisms) is reported.

  1. Mg doping affects dislocation core structures in GaN.

    Science.gov (United States)

    Rhode, S K; Horton, M K; Kappers, M J; Zhang, S; Humphreys, C J; Dusane, R O; Sahonta, S -L; Moram, M A

    2013-07-12

    Aberration-corrected scanning transmission electron microscopy was used to investigate the core structures of threading dislocations in undoped GaN films with both high and low dislocation densities, and in a comparable high dislocation density Mg-doped GaN film. All a-type dislocations in all samples have a 5/7-atom core structure. In contrast, most (a+c)-type dislocations in undoped GaN dissociate due to local strain variations from nearby dislocations. In contrast, Mg doping prevents (a+c)-type dislocation dissociation. Our data indicate that Mg affects dislocation cores in GaN significantly.

  2. Temperature and Population Density Effects on Locomotor Activity of Musca domestica (Diptera: Muscidae)

    DEFF Research Database (Denmark)

    Schou, T. M.; Faurby, S.; Kjærsgaard, A.

    2013-01-01

    The behavior of ectotherm organisms is affected by both abiotic and biotic factors. However, a limited number of studies have investigated the synergistic effects on behavioral traits. This study examined the effect of temperature and density on locomotor activity of Musca domestica (L.). Locomotor...... activity was measured for both sexes and at four densities (with mixed sexes) during a full light and dark (L:D) cycle at temperatures ranging from 10 to 40°C. Locomotor activity during daytime increased with temperature at all densities until reaching 30°C and then decreased. High-density treatments...... activity than females. During nighttime, locomotor activity was considerably lower for all treatments. Altogether the results of the current study show that there is a significant interaction of temperature and density on daytime locomotor activity of M. domestica and that houseflies are likely to show...

  3. Graph Bundling by Kernel Density Estimation

    NARCIS (Netherlands)

    Hurter, C.; Ersoy, O.; Telea, A.

    We present a fast and simple method to compute bundled layouts of general graphs. For this, we first transform a given graph drawing into a density map using kernel density estimation. Next, we apply an image sharpening technique which progressively merges local height maxima by moving the convolved

  4. Isogeometric shape optimization of magnetic density separators

    NARCIS (Netherlands)

    Dang Manh, N.; Evgrafov, A.; Gravesen, J.; Lahaye, D.

    2013-01-01

    Purpose: The waste recycling industry increasingly relies on magnetic density separators. These devices generate an upward magnetic force in ferro-fluids allowing to separate the immersed particles according to their mass density. Recently a new separator design that significantly reduces the

  5. Energy density of marine pelagic fish eggs

    DEFF Research Database (Denmark)

    Riis-Vestergaard, J.

    2002-01-01

    Analysis of the literature on pelagic fish eggs enabled generalizations to be made of their energy densities, because the property of being buoyant in sea water appears to constrain the proximate composition of the eggs and thus to minimize interspecific variation. An energy density of 1.34 J mul...

  6. Trabecular bone density in premenopausal rheumatoid arthritis ...

    African Journals Online (AJOL)

    Trabecular bone density in premenopausal rheumatoid arthritis patients. ... Objective. This study was undertaken to compare trabecular bone mineral density (BMD) in premenopausal rheumatoid arthritis. (RA) patients and normal ... Using Bayes' theorem, the prevalence of osteopenia in RA was found to be6%. Conclusion.

  7. Electronic DC transformer with high power density

    NARCIS (Netherlands)

    Pavlovský, M.

    2006-01-01

    This thesis is concerned with the possibilities of increasing the power density of high-power dc-dc converters with galvanic isolation. Three cornerstones for reaching high power densities are identified as: size reduction of passive components, reduction of losses particularly in active components

  8. Fast response densitometer for measuring liquid density

    Science.gov (United States)

    1972-01-01

    Densitometer was developed which produces linear voltage proportional to changes in density of flowing liquid hydrogen. Unit has fast response time and good system stability, statistical variation, and thermal equilibrium. System accuracy is 2 percent of total density span. Basic design may be altered to include measurement of other flowing materials.

  9. Mammography: interobserver variability in breast density assessment

    NARCIS (Netherlands)

    Ooms, E. A.; Zonderland, H. M.; Eijkemans, M. J. C.; Kriege, M.; Mahdavian Delavary, B.; Burger, C. W.; Ansink, A. C.

    2007-01-01

    Our objective was to determine the interobserver variability of breast density assessment according to the Breast Imaging Reporting and Data System (BI-RADS) and to examine potential associations between breast density and risk factors for breast cancer. Four experienced breast radiologists received

  10. Density functional theory and multiscale materials modeling*

    Indian Academy of Sciences (India)

    Unknown

    wide class of problems involving nanomaterials, interfacial science and soft condensed matter has been addressed using the density based ... Keywords. Density functional theory; soft condensed matter; materials modeling. 1. Introduction ... the basic laws of quantum mechanics, their prediction through a direct ab initio ...

  11. Cross-National Comparison of Population Density

    Science.gov (United States)

    Day, Alice Taylor; Day, Lincoln H.

    1973-01-01

    Examines the fallacies inherent in the concept of human population density, and demonstrates how viewing population density within both a demographic and cultural context can throw into question some of the standard current conceptions concerning the meaning of man-land ratios. (JR)

  12. The density limit in JET diverted plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, D.J.; Clement, S.; Gottardi, N.; Gowers, C.; Harbour, P.; Loarte, A.; Horton, L.; Lingertat, J.; Lowry, C.G.; Saibene, G.; Stamp, M.; Stork, D. [Commission of the European Communities, Abingdon (United Kingdom). JET Joint Undertaking; Monk, R. [Royal Holloway Coll., London (United Kingdom). Dept. of Physics

    1994-07-01

    In JET limiter plasmas the density limit is associated with radiated power fractions of 100% and, in plasmas with carbon limiters, it is invariably disruptive. However, in discharges with solid beryllium limiters the limit is identified with the formation of a MARFE and disruptions are less frequent. In addition, the improved conditioning of the vessel arising from the use of beryllium has significantly improved the density limit scaling, so that the maximum density rises with the square root of the input power. In diverted plasmas several confinement regimes exist, making the characterization of the density limit more complex. While the density limit in L-mode plasmas is generally disruptive, the limit in ELMy and ELM-free H-modes generally prompts a return to the L-mode and a disruption is not inevitable. The density limit does rise with the increasing power, but the L-to-H transition complicates the analysis. Nevertheless, at low plasma currents (<2 MA), densities significantly above the Greenwald limit can be achieved, while at higher currents power handling limitations have constrained the range of density which can be achieved. (authors). 7 refs., 4 figs.

  13. Non-Local Translationally Invariant Nuclear Density

    Science.gov (United States)

    Gennari, Michael; Calci, Angelo; Vorabbi, Matteo; Navratil, Petr

    2017-09-01

    Nonlocal nuclear density is derived from the no-core shell model (NCSM) one-body densities by generalizing the local density operator to a nonlocal form. The translational invariance is generated by exactly removing the spurious center of mass (COM) component of the harmonic oscillator wavefunctions. This enables the ab initio NCSM nuclear structure to be used in high energy nuclear reactions and density functional theory. The ground state local and nonlocal density of Helium-4, Helium-6, Helium-8, and Oxygen-16 are calculated to display the effects of COM removal on predicted nuclear structure. We show that amplified effects of the COM removal can be seen in related quantities like kinetic density, which is dependent on gradients of the nonlocal nuclear density. Additionally, we include nonlocal density in calculations of optical potentials - as opposed to using the local approximation - which produces more accurate theoretical predictions for the optical potentials of lighter nuclei. We present differential cross sections and analyzing powers for proton scattering on Helium-4, Helium-6, Helium-8, and Oxygen-16 at high energies using modern nucleon-nucleon and three-nucleon chiral interactions.

  14. Density Gradient Columns for Chemical Displays.

    Science.gov (United States)

    Guenther, William B.

    1986-01-01

    Procedures for preparing density gradient columns for chemical displays are presented. They include displays illustrating acid-base reactions, metal ion equilibria, and liquid density. The lifetime of these metastable displays is surprising, some lasting for months in display cabinets. (JN)

  15. A multiconfigurational hybrid density-functional theory

    DEFF Research Database (Denmark)

    Sharkas, Kamal; Savin, Andreas; Jensen, Hans Jørgen Aagaard

    2012-01-01

    We propose a multiconfigurational hybrid density-functional theory which rigorously combines a multiconfiguration self-consistent-field calculation with a density-functional approximation based on a linear decomposition of the electron-electron interaction. This gives a straightforward extension ...

  16. Analyticity of the density of electronic wavefunctions

    DEFF Research Database (Denmark)

    Sørensen, Thomas Østergaard; Fournais, S.; Hoffmann-Ostenhof, M.

    2004-01-01

    We prove that the electronic densities of atomic and molecular eigenfunctions are real analytic in R^3 away from the nuclei.......We prove that the electronic densities of atomic and molecular eigenfunctions are real analytic in R^3 away from the nuclei....

  17. Effective Density Queries of Continuously Moving Objects

    DEFF Research Database (Denmark)

    Jensen, Christian Søndergaard; Lin, D.; Ooi, B.C.

    2006-01-01

    In this paper, we study a newly emerging type of queries on moving objects - the density query. Basically, this query locates regions in the data space where the density of the objects is high. This type of queries is especially useful in Location Based Services (LBS). For example, in a traffic...

  18. Density functional theory and multiscale materials modeling

    Indian Academy of Sciences (India)

    One of the vital ingredients in the theoretical tools useful in materials modeling at all the length scales of interest is the concept of density. In the microscopic length scale, it is the electron density that has played a major role in providing a deeper understanding of chemical binding in atoms, molecules and solids.

  19. Absolute density measurements in the middle atmosphere

    Directory of Open Access Journals (Sweden)

    M. Rapp

    Full Text Available In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ( ~ 70° N to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values. Here, we present the results of both Monte Carlo simulations and wind tunnel measurements to quantify this aerodynamical effect. The comparison of the resulting ‘ram-factor’ profiles with empirically determined density ratios of ionization gauge measurements and falling sphere measurements provides excellent agreement. This demonstrates both the need, but also the possibility, to correct aerodynamical influences on measurements from sounding rockets. We have determined a total of 20 density profiles of the mesosphere-lower-thermosphere (MLT region. Grouping these profiles according to season, a listing of mean density profiles is included in the paper. A comparison with density profiles taken from the reference atmospheres CIRA86 and MSIS90 results in differences of up to 40%. This reflects that current reference atmospheres are a significant potential error source for the determination of mixing ratios of, for example, trace gas constituents in the MLT region.

    Key words. Middle atmosphere (composition and chemistry; pressure, density, and temperature; instruments and techniques

  20. Absolute density measurements in the middle atmosphere

    Directory of Open Access Journals (Sweden)

    M. Rapp

    2001-05-01

    Full Text Available In the last ten years a total of 25 sounding rockets employing ionization gauges have been launched at high latitudes ( ~ 70° N to measure total atmospheric density and its small scale fluctuations in an altitude range between 70 and 110 km. While the determination of small scale fluctuations is unambiguous, the total density analysis has been complicated in the past by aerodynamical disturbances leading to densities inside the sensor which are enhanced compared to atmospheric values. Here, we present the results of both Monte Carlo simulations and wind tunnel measurements to quantify this aerodynamical effect. The comparison of the resulting ‘ram-factor’ profiles with empirically determined density ratios of ionization gauge measurements and falling sphere measurements provides excellent agreement. This demonstrates both the need, but also the possibility, to correct aerodynamical influences on measurements from sounding rockets. We have determined a total of 20 density profiles of the mesosphere-lower-thermosphere (MLT region. Grouping these profiles according to season, a listing of mean density profiles is included in the paper. A comparison with density profiles taken from the reference atmospheres CIRA86 and MSIS90 results in differences of up to 40%. This reflects that current reference atmospheres are a significant potential error source for the determination of mixing ratios of, for example, trace gas constituents in the MLT region.Key words. Middle atmosphere (composition and chemistry; pressure, density, and temperature; instruments and techniques

  1. The Thermal Entropy Density of Spacetime

    Directory of Open Access Journals (Sweden)

    Rongjia Yang

    2013-01-01

    Full Text Available Introducing the notion of thermal entropy density via the first law of thermodynamics and assuming the Einstein equation as an equation of thermal state, we obtain the thermal entropy density of any arbitrary spacetime without assuming a temperature or a horizon. The results confirm that there is a profound connection between gravity and thermodynamics.

  2. The effect of aggregate density on pavement performance of SMA-13 asphalt mixture

    Directory of Open Access Journals (Sweden)

    Qiao Yinping

    2016-05-01

    Full Text Available This paper chooses the top layer SMA-13 asphalt mixture material as the research object. Basalt was selected as pavement material, and modified SBS asphalt was used as a cementing material. Two basalt aggregates with different densities were used to carry out standard Marshall test in the laboratory.Aimed at the volume parameters of the asphalt mixture carry on anaiysis,and obtian the effect of aggregate density on pavement performance of SMA-13 asphalt mixture, which is that the density of aggregate has a significant effect on the void ratio, saturation, and the gap rate of the aggregate, thus affecting the pavement performance of the asphalt mixture

  3. The effect of transient density profile shaping on transport in large stellarators and heliotrons

    Science.gov (United States)

    Dinklage, A.; Sakamoto, R.; Yokoyama, M.; Ida, K.; Baldzuhn, J.; Beidler, C. D.; Cats, S.; McCarthy, K. J.; Geiger, J.; Kobayashi, M.; Maaßberg, H.; Morita, S.; Motojima, G.; Nakata, M.; Nunami, M.; Pablant, N.; Ogawa, K.; Proll, J. H. E.; Satake, S.; Tanaka, K.; Warmer, F.; Wolf, R. C.; Xanthopoulos, P.; Yamada, H.; Yasuhara, R.; Yoshinuma, M.; the LHD Experiment Group

    2017-06-01

    Transport studies of pellet fuelling experiments on LHD are reported. Spatio-temporal evolutions after pellet injection into LHD discharges show cases where central density increases on the time scale of particle transport processes. Both the temperature gradient and the density gradient change during the density relaxation, the latter even in sign. The resulting thermodynamic forces influence radial electric fields—both as a driving term but also by, e.g. affecting the E r dependence of ion transport. Magnetic fluctuations have been found to be induced by pellet injection but die out with the relaxation of the pressure profile.

  4. Positive affect and psychobiological processes

    Science.gov (United States)

    Dockray, Samantha; Steptoe, Andrew

    2010-01-01

    Positive affect has been associated with favourable health outcomes, and it is likely that several biological processes mediate the effects of positive mood on physical health. There is converging evidence that positive affect activates the neuroendocrine, autonomic and immune systems in distinct and functionally meaningful ways. Cortisol, both total output and the awakening response, has consistently been shown to be lower among individuals with higher levels of positive affect. The beneficial effects of positive mood on cardiovascular function, including heart rate and blood pressure, and the immune system have also been described. The influence of positive affect on these psychobiological processes are independent of negative affect, suggesting that positive affect may have characteristic biological correlates. The duration and conceptualisation of positive affect may be important considerations in understanding how different biological systems are activated in association with positive affect. The association of positive affect and psychobiological processes has been established, and these biological correlates may be partly responsible for the protective effects of positive affect on health outcomes. PMID:20097225

  5. State based factors affecting inward FDI employment

    Directory of Open Access Journals (Sweden)

    Lucyna Kornecki

    2012-12-01

    Full Text Available This empirical research investigates state based factors affecting the inward FDI employment among fifty states of the United States, uses annual data for the period of time from 1997 to 2007 and identifies several state-specific determinants of FDI employment. The results indicate that the major factors exerting positive impact on inward US FDI employment are: real wages, infrastructure, unionization level, educational attainment, FDI stock and manufacturing density.  In addition, the results show that gross state product growth rate, real per capita taxes and share of scientists and engineers have negative impact on FDI employment. Our findings indicate the importance of selected variables in evaluating the effects of FDI flow.Keywords: FDI, Growth, Employment, State, Economy

  6. Population density and phenotypic attributes influence the level of nematode parasitism in roe deer.

    Science.gov (United States)

    Body, Guillaume; Ferté, Hubert; Gaillard, Jean-Michel; Delorme, Daniel; Klein, François; Gilot-Fromont, Emmanuelle

    2011-11-01

    The impact of parasites on population dynamics is well documented, but less is known on how host population density affects parasite spread. This relationship is difficult to assess because of confounding effects of social structure, population density, and environmental conditions that lead to biased among-population comparisons. Here, we analyzed the infestation by two groups of nematodes (gastro-intestinal (GI) strongyles and Trichuris) in the roe deer (Capreolus capreolus) population of Trois Fontaines (France) between 1997 and 2007. During this period, we experimentally manipulated population density through changes in removals. Using measures collected on 297 individuals, we quantified the impact of density on parasite spread after taking into account possible influences of date, age, sex, body mass, and weather conditions. The prevalence and abundance of eggs of both parasites in females were positively related to roe deer density, except Trichuris in adult females. We also found a negative relationship between parasitism and body mass, and strong age and sex-dependent patterns of parasitism. Prime-age adults were less often parasitized and had lower fecal egg counts than fawns or old individuals, and males were more heavily and more often infected than females. Trichuris parasites were not affected by weather, whereas GI strongyles were less present after dry and hot summers. In the range of observed densities, the observed effect of density likely involves a variation of the exposure rate, as opposed to variation in host susceptibility.

  7. Density of Spray-Formed Materials

    Energy Technology Data Exchange (ETDEWEB)

    Kevin M. McHugh; Volker Uhlenwinkel; Nils Ellendr

    2008-06-01

    Spray Forming is an advanced materials processing technology that transforms molten metal into a near-net-shape solid by depositing atomized droplets onto a substrate. Depending on the application, the spray-formed material may be used in the as-deposited condition or it may undergo post-deposition processing. Regardless, the density of the as-deposited material is an important issue. Porosity is detrimental because it can significantly reduce strength, toughness, hardness and other properties. While it is not feasible to achieve fully-dense material in the as-deposited state, density greater than 99% of theoretical density is possible if the atomization and impact conditions are optimized. Thermal conditions at the deposit surface and droplet impact angle are key processing parameters that influence the density of the material. This paper examines the factors that contribute to porosity formation during spray forming and illustrates that very high as-deposited density is achieved by optimizing processing parameters.

  8. Epidemiologic Studies of Isoflavones & Mammographic Density

    Directory of Open Access Journals (Sweden)

    Jeffrey A. Tice

    2010-01-01

    Full Text Available Isoflavones, phytoestrogens in soy beans with estrogen-like properties, have been examined for their cancer protective effects. Mammographic density is a strong predictor of breast cancer. This review summarizes studies that have examined the association between isoflavones and breast density. Observational investigations in Hawaii and Singapore suggest slightly lower breast density among women of Asian descent with regular soy intake, but two larger studies from Japan and Singapore did not observe a protective effect. The findings from seven randomized trials with primarily Caucasian women indicate that soy or isoflavones do not modify mammographic density. Soy foods and isoflavone supplements within a nutritional range do not appear to modify breast cancer risk as assessed by mammographic density.

  9. Novel metaphor comprehension: Semantic neighbourhood density interacts with concreteness.

    Science.gov (United States)

    Al-Azary, Hamad; Buchanan, Lori

    2017-02-01

    Previous research suggests that metaphor comprehension is affected both by the concreteness of the topic and vehicle and their semantic neighbours (Kintsch, 2000; Xu, 2010). However, studies have yet to manipulate these 2 variables simultaneously. To that end, we composed novel metaphors manipulated on topic concreteness and semantic neighbourhood density (SND) of topic and vehicle. In Experiment 1, participants rated the metaphors on the suitability (e.g. sensibility) of their topic-vehicle pairings. Topic concreteness interacted with SND such that participants rated metaphors from sparse semantic spaces to be more sensible than those from dense semantic spaces and preferred abstract topics over concrete topics only for metaphors from dense semantic spaces. In Experiments 2 and 3, we used presentation deadlines and found that topic concreteness and SND affect the online processing stages associated with metaphor comprehension. We discuss how the results are aligned with established psycholinguistic models of metaphor comprehension.

  10. Behavioural and physiological effects of population density on domesticated Zebra Finches (Taeniopygia guttata) held in aviaries.

    Science.gov (United States)

    Poot, Hanneke; ter Maat, Andries; Trost, Lisa; Schwabl, Ingrid; Jansen, René F; Gahr, Manfred

    2012-02-01

    Zebra Finches (Taeniopygia guttata) are highly social and monogamous birds that display relatively low levels of aggression and coordinate group life mainly by means of vocal communication. In the wild, small groups may congregate to larger flocks of up to 150-350 birds. Little is known, however, about possible effects of population density on development in captivity. Investigating density effects on physiology and behaviour might be helpful in identifying optimal group size, in order to optimise Zebra Finch wellbeing. A direct effect of population density on development and reproduction was found: birds in lower density conditions produced significantly more and larger (body mass, tarsus length) surviving offspring than birds in high density conditions. Furthermore, offspring in low density aviaries produced slightly longer song motifs and more different syllables than their tutors, whereas offspring in high density aviaries produced shorter motifs and a smaller or similar number of different syllables than their tutors. Aggression levels within the populations were low throughout the experiment, but the number of aggressive interactions was significantly higher in high density aviaries. Baseline corticosterone levels did not differ significantly between high- and low density aviaries for either adult or offspring birds. On day 15 post hatching, brood size and baseline corticosterone levels were positively correlated. On days 60 and 100 post hatching this correlation was no longer present. The results of this study prove that population density affects various aspects of Zebra Finch development, with birds living in low population density conditions having an advantage over those living under higher population density conditions. Copyright © 2011 Elsevier Inc. All rights reserved.

  11. Disentangling density-dependent dynamics using full annual cycle models and Bayesian model weight updating

    Science.gov (United States)

    Robinson, Orin J.; McGowan, Conor P.; Devers, Patrick K.

    2017-01-01

    Density dependence regulates populations of many species across all taxonomic groups. Understanding density dependence is vital for predicting the effects of climate, habitat loss and/or management actions on wild populations. Migratory species likely experience seasonal changes in the relative influence of density dependence on population processes such as survival and recruitment throughout the annual cycle. These effects must be accounted for when characterizing migratory populations via population models.To evaluate effects of density on seasonal survival and recruitment of a migratory species, we used an existing full annual cycle model framework for American black ducks Anas rubripes, and tested different density effects (including no effects) on survival and recruitment. We then used a Bayesian model weight updating routine to determine which population model best fit observed breeding population survey data between 1990 and 2014.The models that best fit the survey data suggested that survival and recruitment were affected by density dependence and that density effects were stronger on adult survival during the breeding season than during the non-breeding season.Analysis also suggests that regulation of survival and recruitment by density varied over time. Our results showed that different characterizations of density regulations changed every 8–12 years (three times in the 25-year period) for our population.Synthesis and applications. Using a full annual cycle, modelling framework and model weighting routine will be helpful in evaluating density dependence for migratory species in both the short and long term. We used this method to disentangle the seasonal effects of density on the continental American black duck population which will allow managers to better evaluate the effects of habitat loss and potential habitat management actions throughout the annual cycle. The method here may allow researchers to hone in on the proper form and/or strength of

  12. Effective spatial scales for evaluating environmental determinants of population density in Yakushima macaques.

    Science.gov (United States)

    Agetsuma, Naoki; Koda, Ryosuke; Tsujino, Riyou; Agetsuma-Yanagihara, Yoshimi

    2015-02-01

    Population densities of wildlife species tend to be correlated with resource productivity of habitats. However, wildlife density has been greatly modified by increasing human influences. For effective conservation, we must first identify the significant factors that affect wildlife density, and then determine the extent of the areas in which the factors should be managed. Here, we propose a protocol that accomplishes these two tasks. The main threats to wildlife are thought to be habitat alteration and hunting, with increases in alien carnivores being a concern that has arisen recently. Here, we examined the effect of these anthropogenic disturbances, as well as natural factors, on the local density of Yakushima macaques (Macaca fuscata yakui). We surveyed macaque densities at 30 sites across their habitat using data from 403 automatic cameras. We quantified the effect of natural vegetation (broad-leaved forest, mixed coniferous/broad-leaved forest, etc.), altered vegetation (forestry area and agricultural land), hunting pressure, and density of feral domestic dogs (Canis familiaris). The effect of each vegetation type was analyzed at numerous spatial scales (between 150 and 3,600-m radii from the camera locations) to determine the best scale for explaining macaque density (effective spatial scale). A model-selection procedure (generalized linear mixed model) was used to detect significant factors affecting macaque density. We detected that the most effective spatial scale was 400 m in radius, a scale that corresponded to group range size of the macaques. At this scale, the amount of broad-leaved forest was selected as a positive factor, whereas mixed forest and forestry area were selected as negative factors for macaque density. This study demonstrated the importance of the simultaneous evaluation of all possible factors of wildlife population density at the appropriate spatial scale. © 2014 Wiley Periodicals, Inc.

  13. Neutrals density profiles in EXTRAP-T2R based on Monte Carlo simulations

    Energy Technology Data Exchange (ETDEWEB)

    Cecconello, M

    2002-07-01

    The role of neutral particles in fusion plasmas is very important affecting several aspects of the discharge properties. In particular the neutrals affect the particle and energy balance, the plasma confinement properties, the density profile, the particle and energy fluxes at the wall and the wall erosion. In addition, highly energetic neutrals are used as a diagnostic of the plasma ion temperature. This report describes MCNC a Monte Carlo code used in EXTRAP T2R for the calculation of the neutrals density profile of hydrogen plasma.

  14. Factors Affecting Seismic Velocity in Alluvium

    Science.gov (United States)

    Huckins-Gang, H.; Mercadante, J.; Prothro, L.

    2015-12-01

    Yucca Flat at the Nevada National Security Site has been selected as the Source Physics Experiment (SPE) Dry Alluvium Geology Phase II site. The alluvium in this part of Yucca Flat is typical of desert basin fill, with discontinuous beds that are highly variable in clast size and provenance. Detailed understanding of the subsurface geology will be needed for interpretation of the SPE seismic data. A 3D seismic velocity model, created for Yucca Flat using interval seismic velocity data, shows variations in velocity within alluvium near the SPE Phase II site beyond the usual gradual increase of density with depth due to compaction. In this study we examined borehole lithologic logs, geophysical logs, downhole videos, and laboratory analyses of sidewall core samples to understand which characteristics of the alluvium are related to these variations in seismic velocity. Seismic velocity of alluvium is generally related to its density, which can be affected by sediment provenance, clast size, gravel percentage, and matrix properties, in addition to compaction. This study presents a preliminary subdivision of the alluvial strata in the SPE Phase II area into mappable units expected to be significant to seismic modeling. Further refinements of the alluvial units may be possible when seismic data are obtained from SPE Phase II tests. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy.

  15. Can Solution Supersaturation Affect Protein Crystal Quality?

    Science.gov (United States)

    Gorti, Sridhar

    2013-01-01

    The formation of large protein crystals of "high quality" is considered a characteristic manifestation of microgravity. The physical processes that predict the formation of large, high quality protein crystals in the microgravity environment of space are considered rooted in the existence of a "depletion zone" in the vicinity of crystal. Namely, it is considered reasonable that crystal quality suffers in earth-grown crystals as a result of the incorporation of large aggregates, micro-crystals and/or large molecular weight "impurities", processes which are aided by density driven convective flow or mixing at the crystal-liquid interface. Sedimentation and density driven convection produce unfavorable solution conditions in the vicinity of the crystal surface, which promotes rapid crystal growth to the detriment of crystal size and quality. In this effort, we shall further present the hypothesis that the solution supersaturatoin at the crystal surface determines the growth mechanism, or mode, by which protein crystals grow. It is further hypothesized that protein crystal quality is affected by the mechanism or mode of crystal growth. Hence the formation of a depletion zone in microgravity environment is beneficial due to inhibition of impurity incorporatoin as well as preventing a kinetic roughening transition. It should be noted that for many proteins the magnitude of neither protein crystal growth rates nor solution supersaturation are predictors of a kinetic roughening transition. That is, the kinetic roughening transition supersaturation must be dtermined for each individual protein.

  16. Microcystins affect zooplankton biodiversity in oxbow lakes.

    Science.gov (United States)

    Krztoń, Wojciech; Pudaś, Krzysztof; Pociecha, Agnieszka; Strzesak, Magdalena; Kosiba, Joanna; Walusiak, Edward; Szarek-Gwiazda, Ewa; Wilk-Woźniak, Elżbieta

    2017-01-01

    The authors tested the hypothesis that zooplankton diversity and density are affected by the presence of cyanotoxins in the water. The authors focused on 4 oxbow lakes of the Vistula River in southern Poland, which are subjected to mass cyanobacterial development. In 2 of the oxbows (Piekary and Tyniec), microcystins released into the water were found. The highest concentration of microcystins (0.246 μg/L) was observed for microcystins LR. Zooplankton diversity showed a weak response to the presence of microcystins released into the water. The Shannon index (H') of total zooplankton diversity decreased in the Piekary and Tyniec oxbows during periods when the microcystin concentrations were highest. The same trend was noted for diversity of rotifers in both oxbows and for diversity of copepods in Piekary, but not for copepods in Tyniec. No such trends were found for the diversity of cladocerans in any of the oxbows, nor was a relationship found between density of zooplankton and microcystins. Statistical analyses showed that the number of species in individual samples was negatively correlated with the levels of sulfates, phosphates, and ammonia, but the microcystin concentration was positively related to those levels. This points to the complexity of the interactions and synergies among toxins, abiotic factors, and zooplankton biodiversity. In focusing on the problem of cyanotoxins, conservation studies should pay attention to this complexity. Environ Toxicol Chem 2017;36:165-174. © 2016 SETAC. © 2016 SETAC.

  17. Multicomponent density functional theory embedding formulation.

    Science.gov (United States)

    Culpitt, Tanner; Brorsen, Kurt R; Pak, Michael V; Hammes-Schiffer, Sharon

    2016-07-28

    Multicomponent density functional theory (DFT) methods have been developed to treat two types of particles, such as electrons and nuclei, quantum mechanically at the same level. In the nuclear-electronic orbital (NEO) approach, all electrons and select nuclei, typically key protons, are treated quantum mechanically. For multicomponent DFT methods developed within the NEO framework, electron-proton correlation functionals based on explicitly correlated wavefunctions have been designed and used in conjunction with well-established electronic exchange-correlation functionals. Herein a general theory for multicomponent embedded DFT is developed to enable the accurate treatment of larger systems. In the general theory, the total electronic density is separated into two subsystem densities, denoted as regular and special, and different electron-proton correlation functionals are used for these two electronic densities. In the specific implementation, the special electron density is defined in terms of spatially localized Kohn-Sham electronic orbitals, and electron-proton correlation is included only for the special electron density. The electron-proton correlation functional depends on only the special electron density and the proton density, whereas the electronic exchange-correlation functional depends on the total electronic density. This scheme includes the essential electron-proton correlation, which is a relatively local effect, as well as the electronic exchange-correlation for the entire system. This multicomponent DFT-in-DFT embedding theory is applied to the HCN and FHF(-) molecules in conjunction with two different electron-proton correlation functionals and three different electronic exchange-correlation functionals. The results illustrate that this approach provides qualitatively accurate nuclear densities in a computationally tractable manner. The general theory is also easily extended to other types of partitioning schemes for multicomponent systems.

  18. Density vs distance for the DUNE beam from two recent geology density maps

    CERN Document Server

    Roe, Byron P

    2016-01-01

    The densities passed through for neutrinos going from Fermilab to Sanford lab are obtained using two recent density tables, crustal [1] and Shen-Ritzwoller[2], as well as the values from an older table PEMC[3].

  19. Effect of the medium's density on the hydrocyclonic separation of waste plastics with different densities.

    Science.gov (United States)

    Fu, Shuangcheng; Fang, Yong; Yuan, Huixin; Tan, Wanjiang; Dong, Yiwen

    2017-09-01

    Hydrocyclones can be applied to recycle waste plastics with different densities through separating plastics based on their differences in densities. In the process, the medium density is one of key parameters and the value of the medium's density is not just the average of the density of two kinds of plastics separated. Based on the force analysis and establishing the equation of motion of particles in the hydrocyclone, a formula to calculate the optimum separation medium density has been deduced. This value of the medium's density is a function of various parameters including the diameter, density, radial position and tangential velocity of particles, and viscosity of the medium. Tests on the separation performance of the hydrocyclone has been conducted with PET and PVC particles. The theoretical result appeared to be in good agreement with experimental results. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. The affective depth of bereavement

    DEFF Research Database (Denmark)

    Køster, Allan

    with relatively clear boundaries, suffering remains a constant affective reality. What Barthes ventures into, is the complexity of the poorly understood affective dimension of grief. Grief is usually referred to as a cluster of mixed emotions, including anger, longing, despair etc., and only rarely...... is it understood in simple terms as a specific emotion with clear-cut boundaries etc. Unfortunately, there are therefore close to no resources in contemporary literature that can help us theorise what Barthes refers to as ‘suffering’ in grief, when this designates the affective constant throughout waves...... of emotivity. In this paper, I shall pursue the idea that there is an affective dimension of grief that precedes particular emotional manifestations. Specifically, I will draw on recent phenomenological theories of affectivity which all emphasise a basic level of affectivity responsible for how the world...